Paumanok Publications, Inc.
Electronic Industries Alliance
May/June 2003
An affiliate publication of the
A sector of the Electronic Industries Alliance
The Only Magazine Dedicated Exclusively To The Worldwide Passive Electronic Components Industry
Top Tantalum
Capacitor Suppliers
Tantalum: Cash Cow
or Ground Beef?
The Business of Mining Tantalum
TABLE OF CONTENTS
Volume 5, No. 3
May/June 2003
The Only Magazine Dedicated Exclusively To The Worldwide Passive Electronic Components Industry
FEATURE STORIES
6
Top Tantalum Capacitor Suppliers
The global tantalum capacitor industry has been under siege since late 2000, when shortages led to
allocations and a substantial increase in average unit pricing for all tantalum capacitor case sizes.
9
Tantalum: Cash Cow or Ground Beef?
The market for passive components is starting to show some signs of life.
10
Lead, Follow, or Get Out of the Way!
The constant need to become smaller, faster and cheaper drives
a never-ending search for technologies that promote miniaturization.
14
Lowest ESR Tantalum Capacitors with High CV Values
Standard tantalum capacitor technology offers high capacitance
per volume in combination with high rated voltages.
16
The Business of Mining Tantalum
It is a better than even money bet that the tantalum used to make the
powder currently going into tantalum capacitors in 2003 comes from one
of two mines operated by Sons of Gwalia Ltd (SGW) in Western Australia.
DEPARTMENTS
4
Letter from the Publisher
The Paumanok passive component revenue index.
5
Letter from ECA
The supply chain is a “disaster,” there’s a commerce lesson in SARS, and maybe, just maybe,
this is will be the year when the second-half rebound actually occurs.
22
Featured Technical Paper
Surface mount technology tantalum capacitors are increasingly being used in new circuit designs
because of their volumetric efficiency, basic reliability and process compatibility.
34
Newsmakers
New product offerings and important developments in the passive components industry.
Cover Photo: Courtesy of Sons of Gwalia Ltd.
PASSIVE COMPONENT INDUSTRY
MAY/JUNE 2003
3
LETTER FROM THE PUBLISHER
T
he Paumanok passive compo- differed about Vishay’s reporting
nent revenue index for the was that their operating profit marfirst quarter of 2003 grew by gins in their passive components
3.2% in value, but this was primarily sector increased by almost 100%
due to the inclusion of BCcom- from the first quarter of 2002,
ponents in Vishay’s quarterly earn- catching many analysts by surings statement. Without the added prise. Equally important, Vishay
value from the BCcomponents acqui- stated they had seen an increase in
sition, the passive component rev- sales in Asia, while all other passive
enue index (which is included in component vendors cited a substanPaumanok’s monthly report series) tial slowdown in Asia (they generally
would have been down by 1.8% on a blamed SARS in China but were not
quarter-to-quarter basis in the first sure that would have affected first
quarter revenues).
quarter of 2003.
The industry consensus is that
Of equal importance are industhe Vishay model, of
try statements that April
manufacturing one of
was not a good month,
the broadest product
leading many to believe
lines in passives, is exthat the second quarter
tremely attractive to the
of 2003 will be either
large contract electronic
flat, or down slightly on a
m a n u f ac tur ers ( w ho
quarter-to-quarter basis.
have an increasingly
Continued price erosion
larger number of assets
on a quarter-to-quarter
in Asia). The compartbasis has been discussed
mentalized passive comas the primary reason.
ponent solution (oneEPCOS, for example, Dennis M. Zogbi
s t o p sh o p p i n g ) i s
reported in December
that new orders were up by 16% extremely beneficial to a large-scale
heading into the first quarter, but customer, especially when they do
subsequently that did not turn into not have to pay distributor markadded revenues due to severe price ups. Traditionally, distributors
erosion in the first quarter (thus solved many of the large CEM probunits are up for all passive products lems by offering a broad product
around the globe, but price erosion line from multiple vendors. But no
is keeping revenues in check). matter how much the customer
EPCOS’ revenues dropped by 2.1% squeezed the distributor on price,
there would always be costs associon a quarter-to-quarter basis.
AVX also reported a downturn ated with the overhead of distribuin the first quarter of 2003, with tion. Thus, the Vishay model does
revenues dropping by 7.8% on a away with the middleman, so
quarter-to-quarter basis. KEMET’s Vishay can charge a bit more for
revenues grew slightly, by 2.9% on offering such a broad product catea quarter-to-quarter basis, but no gory. In effect, Vishay becomes both
one in Greenville was happy with the manufacturer and the distriburevenue growth because their tor in their high end-customer base.
Paumanok estimates that there
quarterly operating margins were
are 55 companies in the world that
too high to make a profit.
Vishay, on the other hand, was buy $100 million worth of passive
the most upbeat, with quarterly components per year, and it is this
revenue growth of 13.9%, due largely market in which Vishay is having
to the addition of BCcomponents on the greatest success. Let’s see what
their financial statements. What the future holds.
4
PASSIVECOMPONENT INDUSTRY
MAY/JUNE 2003
PUBLISHER
DENNIS M. Z OGBI
DIRECTOR
OF
ADVERTISING
SAM COREY
EDITOR
JOHN D. AVANT
ART DIRECTOR
AMY DEMSKO
MARKETING
CAROLYN HEROLD
RESEARCH EDITOR
NAUREEN SYED
ADVISORY BOARD
Glyndwr Smith
Vishay Intertechnology, Inc.
Ian Clelland
ITW Paktron
Pat Wastal
Avnet
Jim Wilson
MRA Laboratories
Michael O’Neill
Heraeus Inc.
Bob Gourdeau
Vishay BCcomponents
Dan Persico
Passives Strategist
Editorial and Advertising Office
130 Preston Executive Drive, Suite 101
Cary, North Carolina 27513
(919) 468-0384 (919) 468-0386 Fax
www.paumanokgroup.com
The Electronic Components – Assemblies – Materials –
Association (ECA) represents the electronics industry
sector comprised of manufacturers and suppliers of passive and active electronic components, component arrays
and assemblies, and commercial and industrial electronic component materials and supplies. ECA, a sector of the
Electronic Industries Alliance, provides companies with a
dynamic link into a network of programs and activities
offering business and technical information; market
research, trends and analysis; access to industry and government leaders; standards development; technical and
educational training; and more.
The Electronic Industries Alliance (EIA) is a federation of
associations and sectors operating in the most competitive and innovative industry in existence. Comprised of
over 2,100 members, EIArepresents 80% of the $550 billion U.S. electronics industry. EIA member and sector
associations represent telecommunications, consumer
electronics, components, government electronics, semiconductor standards, as well as other vital areas of the
U.S. electronics industry. EIA connects the industries
that define the digital age.
ECA members receive a 15% advertising discount for
Passive Component Industry. For membership information, contact ECA at (703) 907-7070 or www.ec-central.org;
contact EIAat (703) 907-7500 or www.eia.org.
LETTER FROM ECA
Supply Chain “Disaster,’’ Lesson of SARS, Part
of Information Exchange of ECA Spring
T
he supply chain is a “disaster,” there’s a commerce lesson in SARS, and maybe, just maybe,
this is will be the year when the second-half
rebound actually occurs. These were just a few of the
thoughts, projections and information points exchanged
during ECA’s Spring Meeting in Washington, D.C.
The meeting, part of the Electronic Industries
A lliance’s annual Spring Gala, brought together representatives from electronic components manufacturers,
distributors and EMS providers. They used the opportunity to exchange information, network socially, find
out about trends that will define the future, and try to
gain a competitive advantage in navigating choppy
business waters.
EMS Grows and Shifts
Jeff Bloch, a vice president of iSuppli, provided an
overview of the state of the EMS industry, including the
following information:
• The trend toward outsourcing continues to grow.
A likely outsourcing scenario of the future has ultra
high-volume manufacturing being done in China
by EMS and ODM (original design manufacturers);
high-volume products made by EMS and ODM in
Mexico, China and Southeast Asia, and Eastern
Europe; and medium- to low-volume manufac
turing in North America and Western Europe by
EMS.
• SARS has provided a painful reminder that companies cannot produce everything in one region,
no matter how enticing the economics.
• Manufacturing continues to shift rapidly to lowcostregions, increasing to an estimated 70 percent from 30 percent in FY 2000.
• The Americas are losing steam as electronic consumers while Asia gains momentum; by 2005,
the Americas and Asia will generate equal revenues.
• Second- and third-tier manufacturing in the
Americas is still strong, accounting for $18 billion
in goods today and expected to grow to $30 billion
in 2006.
•Just as it did in the past in Japan, lowest-price
manufacturing could give way in some sectors to
flexibility and “total landed cost” – the complete
cost of manufacturing and shipping a product.
Bloch presented results of a recent supply chain
survey, which included the following findings:
• OEMs plan to retain control of high-volume components, but give EMS more control of multisourced components and lower-technology PCB
andmechanical parts.
• There remains a perception gap between OEMs
and EMS in the supply chain, and there are no
clear rules of engagement.
• OEMs are not convinced of EMS’ skill sets, systems and processes.
Real Growth or False Read?
The roundtable discussion centered primarily on the
state of the market and relationships among different
elements in what ECA calls the “electronics flow
wheel.”
Most participants reported revenue growth tempered
by price erosion. The pricing of commodity parts was
characterized by one participant as “devastating.”
There is also some concern that the perceived growth
could be a “false read” due to replacement of inventory
instead of inventory turnover. One manufacturer expressed hope that after three years of soothsayers
predicting a second-half rebound, this will be the year
it actually happens.
Surviving the Disaster
The roles of manufacturers, OEMs, EMS, reps and
distributors continue to be muddled, so much so that
one manufacturer called the supply chain a “disaster.”
With products passing through so many hands, it
becomes increasingly difficult to track rep sales. This is
a byproduct of general problems with global business
tracking. One manufacturer said his U.S. division is
doing an “incredible amount of design work” that is not
being captured. This creates a tainted picture of the ROI
the U.S. division delivers for its Asian parent company.
One OEM said a fight continues among EMS and
large OEMs for demand and supply chain management
rights. A major trend, he said, is second-tier OEMs
turning the AVL (approved vendor list) process to EMS.
Most of the large OEMs, however, want as much control
Continued on page 21
PASSIVE COMPONENT INDUSTRY
MAY/JUNE 2003
5
FEATURE
Top Tantalum Capacitor
Suppliers: 2002
T
he global tantalum capacitor industry has been
under siege since late 2000, when shortages led to
allocations and a substantial increase in average
unit pricing for all tantalum capacitor case sizes. These
shortages in 2000 led to extreme problems in some of
the prime end-use market segments, resulting in factory
production delays and bitter resentment on the part of
many capacitor buyers and design engineers.
Subsequently, in many end-use market segments where
the performance of tantalum was not mission critical,
design engineers were instructed to design tantalum
capacitors out in favor of high capacitance ceramic
capacitors, aluminum V-chip designs, solid polymer
aluminum alternatives and, in some instances, the new
niobium capacitors.
There was also a general perception among capacitor
buyers and design engineers at the customer level that
the supply chain related to raw materials consumed in
the tantalum capacitor industry was too narrow, with
only a limited number of suppliers of quality tantalum
ore and capacitor-grade tantalum metal powder and
wire. Ironically, it was the shortages, allocations and
higher tantalum capacitor prices in 2000 that led many
major global OEM and CEM customers to take a
d etailed look at the viability of the tantalum supply
chain. The results were not encouraging, and this
added to the skepticism about the continued use of tantalum capacitors in specific market segments, especially
in the computer market and its various subassembly
segments (i.e. hard disc drives, power supplies) and the
wireless communications segment.
The subsequent negative effects on tantalum capacitor producers worldwide in calendar year 2001 and
2002 were significant. The downturn in the tantalum
market was more pronounced than any other capacitor
segment; and this was reflected in the public financial
statements issued by the major tantalum capacitor
producers– KEMET, AVX and Vishay Intertechnology.
However, in 2003 it has become apparent that tantalum capacitors cannot be readily dismissed as a dielectric for the future of the high-tech economy. Ceramic
capacitors, with their high individual ceramic layer
count, represent the greatest threat to tantalum, but
6
PASSIVE COMPONENT INDUSTRY
MAY/JUNE 2003
have caused some concerns among design engineers as
they move from 100µF to the higher 220µF range. The
high layer counts suggest to design engineers that these
multilayered high capacitance devices may face mechanical stability issues. Such concerns have also been voiced
regarding niobium capacitors; and while aluminum
capacitors offer a viable field-tested alternative, they are
not as volumetrically efficient, nor do they offer the same
performance longevity as tantalum. Thus, it is highly
likely that end-use segments such as automotive, telecom infrastructure, medical and defense are less likely to
move to alternative dielectrics. Also, in Japan, there has
been a noted movement toward the new extremely small
case size tantalum capacitors in the P and J case sizes for
applications in digital video circuits (i.e. streaming video
in wireless phones and digital video cameras at Sony and
Cannon). Thus, the future of tantalum is not in as dire
straits as many believe. The most probable scenario is
that tantalum capacitors will be a smaller unit market in
the future, but with higher overall average unit pricing
because customers will consolidate their demand in
areas where high cap ceramics are not a threat, or where
the performance of tantalum is required in a missioncritical application.
In the second quarter of 2003 many of our tantalum
capacitor vendors have embarked on a strategy of
continued severe price erosion to combat encroachment
of ceramics and other electrochemical dielectrics into
their market spectrum. This aggressive price cutting is
also designed to get more engineers to design in tantalum instead of an alternative product.
Changes in Market Share In 2002
According to a detailed industry analysis on behalf of
Paumanok Publications, Inc. it is apparent that KEMET
Electronics lost market share in 2002. All companies involved in the tantalum spectrum lost substantial
amounts of revenues and unit sales between 2000 and
2002, but some suppliers realized slightly greater declines
than others. Companies like Vishay counteracted their
decline in unit shipments by securing additional tantalum capacitor manufacturers in the specialty component
Continued on page 8
Top Tantalum Capacitor Suppliers
Continued from page 6
erosion will slow to a point where unit shipments will
exceed the drop in prices on a percentage basis, thus
sector (i.e. tantalum wets from Tansitor and Mallory),
resulting in increased revenues for the industry. Howthus cushioning their overall decline. It is also apparent
ever, Paumanok expects no great instances of recovery
that the gap between KEMET and AVX narrowed in
for the year as a whole.
2002, although Paumanok still believes KEMET to be
the largest supplier of tantalum capacitors in the
world. The difference between KEMET and AVX
can be measured in less than 1 percentage point
(revenues for tantalum capacitors at both these
2002 Global Market Share Estimates
companies is very close).
(Based on Revenue)
In Japan, innovation came from two of the
Tantalum Capacitors
Capacitors
2002
Rank
Tantalum
2002
Rank
smaller tantalum capacitor sources, Matsuo and
Nichicon, who invested in the development of
KEMET Electronics
20.9%
1
extremely small case size tantalum capacitors in
AVX Corporation
20.5%
2
the P case, J case and the 1005 case (EIA case
sizes 0805, 0603 and 0402). Other companies
Vishay Intertechnology
19.0%
3
have small case tantalum capacitors, but Matsuo
NEC/Tokin
15.4%
4
and Nichicon are offering the broadest product
portfolios now when it comes to extremely small
EPCOS
4.8%
5
case sizes.
Tantalum Capacitor Suppliers
Tantalum Forecasts
Paumanok believes that in 2003 there will be
some minor recovery in the tantalum capacitor
segment. This is, of course, dependent upon how
much additional price erosion occurs in 2003 for
tantalum capacitors. Unit shipments should continue to increase on a quarter-to-quarter basis,
but price erosion will be the variable. It is
b elieved that in the second half of 2003 price
Matsuo
4.8%
6
Hitachi AIC
4.4%
7
Nichicon
4.4%
8
Matsushita
3.7%
9
Other
2.1%
10
Total
100.0%
Source: Paumanok Publictions, Inc. Monthly Tantalum Capacitor Report, April 2003
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8
PASSIVE COMPONENT INDUSTRY MAY/JUNE 2003
FEATURE
Tantalum: Cash Cow
or Ground Beef?
Daniel F. Persico, Ph.D.
Abstract: Significant overcapacity and considerable not-in-kind competition exists in the traditional solid tantalum capacitor world (MnO2
as a counter-electrode).As the industry hopefully moves into a sustained
period of economic prosperity, will the demand for tantalums rebound
to the point where they can once again carry their own weight as well
as that of other products in the portfolio?
T
he market for passive components is starting to show some signs
of life. Inventories seem to be burned down to the point where
true demand is starting to show up on the trend charts and the
abatement of military activities in the mid-east appears to have eased
the minds of the consumer, if at least for a while. However, even with
these positive indicators, the specter of significant industry overcapacity remains. With it comes the realization that the highs seen at the
peak of the bubble are not likely to be enjoyed again in many participants’ lifetimes. So the question is; “what does one do with all that
shiny new stainless that was put on the floor during the bubble?”
The economic boom of the 1990’s was a product of the confluence of
many independent factors, a situation not likely to be duplicated. Just
as the run-up of the 1990’s stock market and subsequent crash is most
likely to be followed by many years of relatively unambitious but stable market growth (so say some), the electronics market is most likely
looking forward to more stable and ultimately more predictable and
manageable growth. After all, the two phenomena were inextricably
tied, so why shouldn’t their future also be juxtaposed? While this does
not answer the ultimate questions concerning the future for tantalum,
it does form the backdrop, and certainly influences significantly the demand for tantalum capacitors and all passives in general.
The electronics industry will continue to see pockets of high growth,
innovation will take care of this; however, the most recent shakeout,
largely fueled by speculation in what I will broadly call information
technology, was just what was needed and in fact not unprecedented.
W. Brian Arthur of the Sante Fe Institute has the following general
comments regarding technology and this type of shakeout:
“In the first stage of a technology revolution, a period of speculation
is followed by a crash. Then comes a build out period – the golden
age of the technology…after a crash much of the glamour of the new
technology is lost. The mood is different. Investment profits begin to
reflect real returns.” [1]
In his article, Arthur discusses the UK canal mania of the 1790’s
and the railway enthusiasm of the 1840’s, and how they showed similar patterns of over-enthusiasm, crash, and manageable long-term
growth. There are significant similarities among all three situations,
Continued on page 12
PASSIVE COMPONENT INDUSTRY
MAY/JUNE 2003
9
FEATURE
Lead, Follow, or Get Out of
the Way!
Al Arcidy
RCD Components Inc.
Y
ou may have seen the bumper sticker that reads,
“Lead, follow, or get out of the way!” The constant
need to become smaller, faster and cheaper drives
a never-ending search for technologies that promote
miniaturization.
Surface mount resistors and capacitors are being used
in a wide range of applications including current sensing,
de-coupling, filtering and energy storage. As the number
of passives used per system is on the rise, the relentless
march to unparalleled processing speeds mandates
shrinkage of the distance between components to eliminate inductance and processing delay times.
The need for smaller, faster, and cheaper passives
has always been a driving force behind the boundless
requirement for increased passive miniaturization.
Most cell phone manufacturers implement 0201 into
their latest designs and, in the near future, other
industry areas will adopt the same
technology. Wireless communication
products in the automotive industry
use 0201 technology in global positioning systems (GPS), sensors and communication devices. Additionally, companies use 0201 technology in
multichip modules (MCM) to reduce
overall package size. Today, the focus is
on higher density requirements and
embedded resistors and capacitors
technology. One result is the 01005
size, which is about 2/3 smaller than
0201, currently the industry’s smallest
known passive.
Modules like the one shown in Figure 1
are an example of how passive devices can
actually be co-designed with ICs to
make an optimized module. Multichip
modules like this are often required for
Figure 2
RF applications, to include both gallium
arsenide and silicon ICs, and passive devices are critical
in RF applications. Co-designing all components and
making the passives part of the substrate is a natural
10
PASSIVE COMPONENT INDUSTRY MAY/JUNE 2003
design synergy.
All electronic systems continue to be subject to the
trend of added functionality in an ever-shrinking envelope. Consumers have become accustomed to the
benefits of increased functionality that are
enabled by the evolution of silicon integrated circuits.
Unfortunately, passive components have not kept up with ICs in
this regard. Peripheral passive
Figure 1
components are not as functionally
space-efficient as ICs and are
seen as one of the major roadblocks in increasing the functional density of electronic systems.
Clearly, the need for functional density will force
designers to look at creative packaging alternatives. If
the historical rate of passive component density continues,
by 2010 it is reasonable to expect passive component
density of 20 to 30 passives/cm2. To put this into per-
spective, Figure 2 charts the passive component density
over time for cellular phones, the most complex, high
volume passive systems to date.
Miniaturization
There is a wide range of solutions available to the
design engineer to meet functional density challenges
with respect to passives. Historically, the industry has
kept up with these demands by reducing the size of
discrete surface mount components. While the move to
0201 (and soon 01005) size passives can bring about
many manufacturing process challenges, several OEMs
have had success in implementing these components
into embedded modules.
Embedded passives and co-designed chip modules
are considered to be the Holy Grail of passive integration. Integrated passive devices, where arrays of resistors
or capacitors are swept into a component, have also
gained in popularity. These devices have been used by the
computer industry for quite some time as an effective
way to implement resistors at a high I/O port interface.
However, these devices are only available for arrays of
standard values or commonly used functional blocks,
and customized designs are expensive and offer a limited
supply base. Still, the resistor, capacitor and inductor
value of a discrete is very much the function of physical
size. The inability to create high value embedded
devices in a space-efficient manner puts limitations on
the amount of integration possible.
Most embedded advances will continue to suffer
primarily from component density and tolerance limitations when compared to discretes. Because the tolerance
of most discrete chip resistors is in the range of 1%, a
design with 15% or more variation is not an attractive
proposition.
If we gaze at the transition of various surface mount
sizes, we find that smaller (nominal) packages become
mainstream about every five years. Currently, 0603 is
the highest usage component. A close second is 0402,
which should become the most widespread size within
the year. Usage of 0201 discretes has accelerated and is
becoming most popular in higher density systems. The
initial hesitation among OEMs in moving to the 0201
package is subsiding and the manufacturing challenges
have been overcome. RCD predicts the same historical
trend to continue in discrete passives. If we were to
develop this trend line past 01005s, we can forecast that
embedded passives are still about 7 to 10 years away. Of
course, this prediction assumes that the technology
Not just the car.
EPCOS components inside.
HigPherformance
Documented
Performance:
•QS-9000
•FMEA
•PPAP
• APQP
• AEC-Q200
•Bluebook
Qualification
• ISO/TS-16949
EPCOS components perform reliably,
even under extreme conditions.
For a proven automotive track record
with documented performance,
count on EPCOS electronic
components:
Capacitors
Varistors
Thermistors/Sensors
Gas Discharge Tubes
Inductors
SAW Filters
•
•
•
•
•
•
For immediate assistance,
log on to www.usa.epcos.com
EPCOS, Inc., Iselin, NJ 08830 U.S.A.
800-888-7729
EPCOS – just everywhere…
PASSIVE COMPONENT INDUSTRY
MAY/JUNE 2003
11
Tantalum Future
Continued from page 9
the canals, the railways and the electronics industry.
Therefore, by overlaying this model on the electronics
industry one can reasonably expect a similar long-term
response in all that encompasses this broad and important market segment.
So, if there are no other perturbations to the system,
can we expect tantalum volumes to rebound to precrash equivalents? Picking an individual reference
point may be the hard part; however, the reference
point really is not important as it is much more complicated than that. There are a number of pertinent factors that complicate the picture, among them: 1) the impact and hangover associated with “aggressive
marketing” by both tantalum capacitor manufacturers
and powder suppliers, 2) bold and assertive product innovation focused on taking advantage of market trends
and this “aggressive marketing,” and 3) the advances in
electronic circuitry which have increased the need for
low ESR and ESL solutions and introduced the models
such as distributed capacitance. Let’s look at each of
these factors on an individual basis.
Aggressive Marketing
When determining what the market will bear in a
tight supply or shortage situation, a product’s place in
its life cycle should be considered. This is Marketing
101. Mature technologies, with significant in-kind and
not-in-kind competition, are very susceptible to the realities of price-volume elasticity. The consequences do
not manifest themselves when the products are all in
short supply (real or otherwise), as the customer has no
choice under these conditions. Only when the situation
evolves to equilibrium or an over-supply situation are
the consequences observed. It is easy to say, or at least
hope, that customers have short memories; however,
this is not always the case. Independent of the reasons
for the tantalum capacitor shortage (perception vs. reality) the compounding factor of large price increases
pushed many customers to a point not achieved in prior
cycles. The result, in many cases, was the elimination of
tantalums wherever possible or across the board. What
made this possible and sustainable was the proliferation of in-kind and not-in-kind technologies.
Aggressive Product Innovation
Tantalum polymer capacitors, aluminum polymer
capacitors, niobium capacitors, and high capacitance
ceramics are all coming into their own and challenging
the domain of the traditional tantalum capacitor. The
bubble, coupled with higher operating frequencies,
allowed tantalum polymer capacitors to gain a foothold
that would have otherwise taken more time and had
less impact on tantalums. In addition, aluminum polymer capacitors, wound and stacked, are also aggressively
12
PASSIVE COMPONENT INDUSTRY MAY/JUNE 2003
attacking tantalums. One can only imagine the impact
these products would have had on tantalums if they
were available from multiple sources and on a mass
scale during the period of high demand. In addition,
many pundits see high capacitance ceramics as the
capacitor product of the future. These devices are
already aggressively attacking the 1-10mF range, on an
economic basis, and will soon achieve economic parity
at 22mF.
The fact that continual product innovation is the
lifeblood of any business and part of the natural evolutionary process is not news. What is of additional concern for tantalum is the potentially destabilizing effects
of niobium. The point is that it is potentially foolhardy
to ignore niobium in an attempt to maintain “business
as is.” There are many opinions concerning the economics
of niobium vs. tantalum; however, independent of
opinion, there does appear to be room for niobium,
should customers be willing to compromise on certain
electrical performance criteria.
Other than cost, it is not obvious that niobium offers
anything over tantalum. That said, price might be
enough. Market share being king in a down market, the
perception is that the purer tantalum players are willing to meet price to protect their share position until
something closer to market equilibrium is achieved.
The strategic side of niobium is an opportunity to take
power away from the traditional tantalum powder suppliers. As a tactic, this is reasonable and justifiable if it
ultimately settles down the tremendous swings in tantalum powder pricing over the long term. There is nothing like introducing alternate materials of construction
as well as alternate suppliers to settle down an oligopoly.
And who is to say that niobium is the final word in volumetrically efficient materials? Volumetric efficiency is
the domain of, and the single most important virtue of
tantalum. If another material seizes this moniker from
tantalum, its future potential dims significantly.
Advances in Circuit Design
As operating frequencies increase, so do the needs for
products with low ESR and ESL. Parasitics become
more problematic with increased circuit speeds, requiring changes in the physical structure and placement of
components. Necessity being the mother of invention,
there has been a proliferation of low ESR solutions
available to designers. These low ESR solutions diminish the need for tantalum as a whole. Requirements for
bulk capacitance will continue to decline as operating
frequencies increase, further opening up opportunities
for not-in-kind solutions. Additionally, models for distributed capacitance, which are being articulated and
promulgated, will serve to only further diminish the
need for bulk capacitance solutions.
Continued on page 32
FEATURE
Lowest ESR Tantalum
Capacitors with High CV Values
V. Döge and W. Braunwarth,
EPCOS AG, Capacitor Division
Background
Standard tantalum capacitor technology offers high
capacitance per volume in combination with high rated
voltages. The demand for low ESR values in short-term
switching and filtering applications increases year by
year. Every new generation of processors requires higher
electrical characteristics on the DC/DC converter. The
working voltages of modern CPUs are getting lower,
while voltage stability and power requirements are rising. Therefore, the corresponding in-series connected
capacitor arrays have to lower their overall ESR and
ESL values, and the sum capacitance has to increase.
One promising approach to these challenges is to combine polymer technology with multiple anode technology.
Multiple anode developments at EPCOS are not only
focused on lower ESR, but also on the implementation
of higher CV powders to get higher capacitance values.
New powders will offer the opportunity to extend the
capacitance range significantly above 1000mF. Thanks
to the variety of capacitor technologies, it is possible to
combine all these new technologies with amazing results. For example, a 1000µF with 10mΩ ESR multiple
anode polymer capacitor is already in mass production.
Introduction
A popular trend in capacitor design is to reach lower
ESR values while raising the capacitance values.
Worldwide, there has been much research activity to
meet the actual low ESR demand. One result is the development of molded SMD tantalum capacitors offering
new low ESR values. All of these new products represent new technical solutions that differ more or less
from classical ones. Standard tantalum anodes are
made out of porous cylindrical or cuboid-like pellets. An
electrochemical process forms the amorphous Ta2O5
dielectric layer. The negative side of the dielectric is
commonly coated by manganese dioxide or a conducting
polymer. The outer part of the resulting anodized body
is contacted with graphitic and silver paint layers.
In a common mechanical construction an in-sintered
tantalum wire builds the electrical positive contact to
14
PASSIVE COMPONENT INDUSTRY MAY/JUNE 2003
Figure 1: Schematic structures of a tantalum
capacitor body.
the sintered pellet. This wire is welded to the outer
metallic terminal. The negative side of the capacitor
element is represented by the outer paint layer. The
electrical contact of this layer to the negative terminal
is formed by conductive glue. Figure 1 shows the cross
section of a tantalum chip capacitor that represents
standard tantalum or niobium mounting technology.
Origin of ESR and Capacitance
The ESR of a capacitor is determined by the sum of
effective ohmic series resistances in the overall capacitor arrangement. It is represented by the real part of
the complex impedance Z.
Z = ESR + iωLeff - i/(ωCeff)
ω
angular frequency
Leff effective inductance of the capacitor
Ceff effective capacitance of the capacitor
The impedance of an electrolytic capacitor is determined by its microstructure. A realistic electrical equivalent circuit has to be built with three dimensional
interconnected transmission line elements representing the pore structure of the capacitor pellet. Simplified, one can discuss the impedance response in terms
of a linear RC-transmission line. Therefore, the ESR of
a tantalum or niobium capacitor is frequency dependent.
Low ESR
It is a result of geometric effects in electromagnetic wave propagation
and the frequency dependency of loss mechanisms. The ESR value
commonly mentioned in tantalum data books is specified for the frequency of 100kHz.
Every electric path from the negative to the positive capacitor terminal has a certain contribution to the ESR. Main ESR contributions
result from:
• the MnO 2 or conducting polymer layer
• the graphite and silver paint layer
• the conductive adhesive
• contact resistances between adjacent layers
• the dielectric layer
• the metallic terminals
Replacing MnO 2 by conducting polymers with metallic-like electric
conductivity was a very important step on the way to lowest ESR
capacitors. The commonly used conductive polymers reveal a specific
electric conductivity that is two to five orders higher than that of
MnO2. The usage of a conducting polymer will reduce the ESR level at
100kHz of a certain capacitor type by approximately 30% to 60 %. A
loss mechanism in tantalum and niobium electrolytic capacitors is
typically found in addition to the electronic bulk and contact resistances polarization in the dielectric.
The electrical capacitance C of a certain tantalum capacitor element is mainly determined by its microscopic surface, the thickness of
the dielectric layer and, more generally, the dielectric constant of the
effective dielectric.
C = e 0 e rA/d
dielectric constants
e0 , e r
A
effective surface of the dielectric
d
thickness of the dielectric
Because of stability aspects, one needs a minimum thickness in the
dielectric layer. Therefore the capacitance of certain pellet geometry can
only be raised by using powder of higher specific charge. Currently, powder suppliers offer powders up to 150mC/g. The higher specific charge
results from using powder particles with smaller grain sizes. Smaller
grain sizes lead to smaller average pore sizes. The result is that high
capacitance powder is limited to rated voltages up to 10-16 volts.
Lowest ESR – Highest Capacitance
ESR optimization of the standard tantalum capacitor design has
been done for decades. It involves the variation of the pellet design
and the adjustment of coating processes. However, essential progress
in decreasing the ESR-level is only possible when processes or designs
undergo major changes. New technologies now provide the lowest ESR
and highest capacitance, or “Multiple Anode Polymer.”
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Multiple Anode Design
Typical 2- to 6-polymer low profile anodes with close contact to each
neighbor are put between the inner metallic terminals (Figure 2). The
result is an inner parallel connection of individual capacitor elements.
When three elements are combined, the ESR value of the complete
component is reduced to one third of the single element. The larger
surface of the conductive paint contributes to the good ESR behavior
Continued on page 30
PASSIVECOMPONENT INDUSTRY
MAY/JUNE 2003
15
®
800-411-6596 > www.anaren.com
In Europe, call 44-2392-232392
ISO 9001 certified
Visa/MasterCard accepted
(except in Europe)
FEATURE
The Business of Mining Tantalum
David Paull, Sons of Gwalia Ltd.
I
t is a better than even money bet that the tantalum
used to make the powder currently going into tantalum capacitors in 2003 comes from one of two
mines operated by Sons of Gwalia Ltd (SGW) in
Western Australia.
Given the significant supply position and the importance of SGW’s mining operations in terms of reserves
and production capabilities to support the global tantalum industry, it is important that consumers have an
understanding of where this tantalum comes from, how
it is produced and what the future holds for these tantalum assets.
Sons of Gwalia
• Market capitalization of US$225M
• Reserves of nearly 100Mlb Ta2O5
managed for a specific volume of production, whereas
byproduct-mining production is dependent on the markets for the principal product.
The Benefits of Hard Rock Mining
One of the principal benefits of hard rock mining is
that the contained resources, which are the building
blocks of any mining operation, are more readily quantifiable. This means that there is a high degree of confidence that the tantalum is in the rocks and, with
economic analysis, that it can be recovered in a commercially viable manner. The size of the resources can
either be limited by the geological structure concerned
or, as is the case in both Greenbushes and Wodgina, by
the data. There is continuing scope with additional
drilling at the Greenbushes and Wodgina mines to
continue to increase reserves and resources with additional data.
With the high level of confidence regarding the size of
the resources, engineering can then be undertaken to
design a mining operation and a processing combination
that meet the business objectives of the mine’s owner.
• Production capacity of 3.0Mlb Ta2O5 per
annum
• Mine lives of +20 years
• Quality and Environmental management
processes ISO accredited
• Consistent, dependable producer of high
quality tantalum concentrates
“Sons of Gwalia’s strategy is to provide the
global tantalum industry a base load of
tantalum minerals at consistent and reasonable pricing in order for the entire
industry to maintain its attractive rate of
growth.”
Figure 1: Hard rock mining
SGW owns the Greenbushes and Wodgina tantalum
mines. These are hard rock mines developed solely for
their tantalum content. Many other mining sources of
tantalum are a result of chasing other minerals, such as
tin, where the tantalum is a valuable byproduct. This
differentiation is important, as SGW’s mines are
16
PASSIVE COMPONENTINDUSTRY MAY/JUNE 2003
Readers should understand that we are talking about
relatively low concentrations of tantalum in ore. Grades
at the high-grade Wodgina mine, for instance, average
around 350 parts per million. In addition, to achieve
economic concentrations of tantalum, approximately 3
tons of rock need to be removed for every ton of the ore.
A hard rock mine requires drilling and blasting of the
Continued on page 18
Sons of Gwalia
Continued from page 16
rock, then digging and hauling to the treatment facility.
Then, the ore is crushed and ground to assist with liberation of the tantalum minerals from the host rock.
Other sources of tantalum are principally alluvial in
nature, whereby panning and other forms of surface
extraction can gather pure tantalite crystals. These
normally require a measure of beneficiation before
packaging and shipment to tantalum processors. Due to
the often random distribution of tantalite across quite
large surface areas, it is often difficult to quantify
grades and tons available to alluvial miners and hence
mine life.
SGW’S Tantalum Mines
SGW’s mines support significant processing facilities, with a 3 million tons per annum treatment capability at the Wodgina mine in the northwest of Western
Australia, and a 4 million tons per annum treatment
capability at the Greenbushes mine in the southwest of
Western Australia.
Gre enbushes
The Greenbushes mine is based on the geologically
famous Greenbushes pegmatite, which is the largest
zoned mineralized pegmatite in the world and is some
3.5km long by 0.5km wide. Reserves at Greenbushes
total around 44Mlb Ta2O5 with an additional 64Mlb in
resources. The ore body also contains tin and lithium,
which are economically recovered as a byproduct or
co-product.
gravity and magnetic separation techniques. The mineral assemblage is a key, as processing requires the
ability to remove impurity elements based on relative
specific gravity. As the specific gravity of tantalum and
niobium is quite similar, the tantalum and niobium are
concentrated to a similar extent. Hence, to produce a
tantalum concentrate the ratio of niobium to tantalum
in the original mineral assemblage usually needs to be
around 1:1 or less. Only certain pegmatites, such as the
Greenbushes and Wodgina ore bodies, have the mineral
species that can achieve a high percentage tantalum
concentrate.
The Greenbushes mine is certified ISO14002 for
environmental management and ISO9001 for quality,
and was one of the first mines in Australia to achieve
such status.
The Importance of Concentrated Tantalum
There are numerous deposits around the World that
contain high quantities of tantalum and niobium. Many
of these deposits, however, have niobium to tantalum
ratios of 10:1 or more.
Low cost separation techniques like those used at
Greenbushes and Wodgina are not effective in achieving a high tantalum concentrate in these circumstances.
Therefore, more costly and complex hydro-metallurgical
flowsheets are required in order to achieve a tantalum
product attractive to the secondary processes.
In 1992, the mine was developed as a hard rock operation, which required more sophisticated and substantial
crushing and grinding capabilities to extract the contained tantalum minerals. Over time and through
continual investment, the Greenbushes operation has
Figure 2: Greenbushes production
The Greenbushes mine has a long history, with mining
activities commencing in 1888. Mining of Greenbushes
was initially for the near-surface tin deposits, which
covered the top of the pegmatite. It was only in the 1960s
and early 1970s that mining specifically for tantalum
overtook the importance of tin in terms of revenues.
Processing of Greenbushes ore is achieved through
18 PASSIVECOMPONENT INDUSTRY MAY/JUNE 2003
Figure 3: Greenbushes aerial photo
Continued on page 20
Sons of Gwalia
Continued from page 18
increased its production capabilities from 400,000lb/pa
to more than 1.2Mlb/pa.
The Greenbushes mineralized pegmatite is massive,
and the current operation is at a relatively low extraction rate given the size of the deposit. If the deposit was
copper or nickel and the market demand did not limit
the economic development of this deposit, the Greenbushes pegmatite is capable of supporting a mining
operation some three times the size producing more
than 3.5Mlb/pa, for more than 20 years.
Due to depressed market conditions, the Greenbushes
underground mining operation, which was near completion in terms of development, was deferred in 2002. All
ore is now being treated from the relatively lower grade
open pit. Should the market require, the higher-grade
Greenbushes underground mine can be restarted on
relatively short notice, and production from the operation increased from 0.9Mlb to 1.3Mlb.
Figure 5: Wodgina aerial photo
Wo dgina
The Wodgina mine first operated as a tin mine around
World War I. During World War II, it was opened by the
British Metal Company, which mined the area for surface deposits of tantalum. The tantalum was used in the
construction of the early radar systems that helped
protect England during the Battle of Britain.
The Wodgina mine is actually the first mine developed
solely for its tantalum. It was reopened in the mid 1980s
and SGW purchased this property in June, 1996. SGW
Figure 6: Mining at Wodgina
SGW’S Marketing Strategy
Figure 4: Wodgina production
subsequently conducted a significant drilling program
and increased reserves/resources tenfold, which has
enabled three progressive expansions to be completed.
Given the reduced production at Greenbushes, the
Wodgina mine at 1.2Mlb per annum is now the largest
producing tantalum mine in the world. It can maintain
this level of production for at least 20 years, and the
size of the resource is limited by the amount of drilling
data required.
20
PASSIVE COMPONENT INDUSTRY
MAY/JUNE 2003
Since 1996, SGW’s two tantalum mines have increased production by 200%. This remarkable growth
was achieved by having very large and high-quality
resources, and by the market support provided by
SGW’s two customers, Cabot Corporation and HC Starck.
Since 1992, SGW has entered into long-term fixed price
and quantity contracts with these two customers, which
has allowed SGW to continue to invest with confidence
in its mining resources. This investment was important
to support the industry’s transition from dependence on
tin slag retreatment and byproduct production to the
sustainable and predictable long-term ore sources
provided by hard rock mining.
Given the small nature of the tantalum market and
the level of consolidation that has occurred over time,
such investments by SGW would not be justifiable without these customer commitments. Because of these
commitments and the company’s successful investment
Sons of Gwalia
Letter From ECA
Continued from page 5
over the demand and supply as possible.
Another Opportunity
Figure 7: Tantalum product shipments
of over A$300M in these high-quality tantalum assets,
during the last 4-5 years SGW has been able to support
the growth aspirations of the tantalum industry.
Since the mid 1990s, the use of tantalum in electronics
has grown considerably to the point where more than
60% of tantalum is consumed in the
electronics sector. This steady increase in tantalum usage in electronics is driven by the increase in
the volume of tantalum capacitors
consumed in the electronics industry. These increases owe as much to
the increasing availability of raw
materials at consistent pricing
from miners such as SGW, as they
do to the technology road maps followed by designers during this
time.
SGW’s strategy is to provide a
base load feed for the tantalum
industry at a stable and consistent
cost, so the tantalum industry can
predict, with confidence, the cost
and supply of tantalum raw materials used in various end products.
As the tantalum industry, and
the tantalum capacitor industry in
particular, start to recover, SGW intends to remain a responsible longterm provider of tantalum raw materials. The company plans to
continually reinvest in its production capability and its resources, to
allow the tantalum industry to grow
in confidence. It is through this continued growth that all participants
in the industry will prosper.
ECA meetings such as the one in the spring provide
access to information from leaders within all sectors of
the electronic flow wheel. Participants have the opportunity to exchange information and viewpoints, and to
network with competitors, business associates, and
potential partners. The next opportunity will be the
ECA Summer Meeting the week of June 16 in Hilton
Head Island, S.C. For more information, visit www.
ec-central.org.
—Bob Willis is president of ECA, the electronic components sector of the Electronic Industries Alliance (EIA).
He can be reached at rwillis@ecaus.org.
PASSIVE COMPONENT INDUSTRY
MAY/JUNE 2003
21
FEATURED TECHNICAL PAPER
Basic Tantalum Capacitor
Technology
John Gill
AVX Ltd., Tantalum Division
Introduction
Surface mount technology tantalum capacitors are
increasingly being used in new circuit designs because
of their volumetric efficiency, basic reliability and
process compatibility. Additionally, they are replacing
aluminum electrolytics, which use a wet electrolyte.
This electrolyte tends to have problems with drying out
during the manufacturing reflow of components to a
circuit board.
The steady state and dynamic reliability of a tantalum
capacitor are influenced by several factors under the control of the circuit design engineer. These factors are maximum operating temperature and circuit impedance.
It is also of interest that because of the solid nature
of the tantalum capacitor’s construction, there is no
known wear out mechanism in tantalum capacitors.
This paper has been written to provide the user of
tantalum capacitors with an idea of the effect of design
criteria on the capacitor, and the methods used in their
production.
high voltage capacitors. This is because when the
dielectric is produced, it grows out of the surface of the
tantalum powder by about one third of the thickness
and into the powder by around two thirds, thus if small
particle size powders were used, each particle would
quickly become consumed and isolated.
The production of the dielectric will be discussed in
more detail later.
Since capacitance is proportional to surface area, the
larger the surface area the more final capacitance. Over
the past ten years the powder CV (capacitance/voltage
product), which is a measure of the volumetric efficiency,
has increased steadily through joint development programs between AVX and the powder suppliers. This
increase has been brought about by changing the particle
shape from spheres to flakes, and in recent years to a
coral type structure, as shown in the stylized drawings
in Figure 1. Figure 2 shows scanning electron microscope (SEM) photographs of a low CV, a medium CV
and a high CV powder. The change in particle size is
easily apparent.
Low CV
Medium CV
High CV
Tantalum Powder
Tantalum capacitors are manufactured from a powder of pure tantalum metal. A typical particle size for a
high voltage powder would be 10µm. By carefully choosing which powder is used to produce each capacitance/voltage code the surface area can be controlled.
Powders with large particle size are used to produce
(8000 CV/g)
(18000 CV/g)
Magnification x 4k
(27000 CV/g)
Figure 2: Particle size variation in CV powder.
Manufacture
(a) Pre ssing
Figure 1: Development of high gain tantalum
powders.
22
PASSIVE COMPONENT INDUSTRY MAY/JUNE 2003
The powder is mixed with a suitable binder/lubricant
to ensure that the particles will adhere to each other
when pressed to form the anode, and flow easily into
the press tool. The powder is then compressed under
high pressure around a tantalum wire to make a tantalum
Continued on page 24
ECA’s Distribution WhereHouse
is a comprehensive online
catalogue of products available through
authorized distribution. The WhereHouse
complements ECA’s programs that promote
the distribution channel as a major sales
and marketing vehicle for manufacturers.
Users can search by product or manufacturer.
ECA Resource Central is the one place where you can find any information you need about electronic
components in real time. The Distribution WhereHouse makes the product distribution channel visible to
customers. It also provides an opportunity for ECA members to market their products.
To find out more, visit the ECA Resource Central Distribution WhereHouse.
www.ec-central.org
2500 Wilson Blvd.
Arlington, VA 22201
Tel: 703-907-7500 • Fax: 703-875-8908
Technical Paper
Continued from page 22
“slug”. The term “slug” is used in the tantalum capacitor manufacturing industry to refer to the tantalum.
The riser wire will eventually become the anode
connection to the capacitor. Figure 3 shows an
SEM picture showing how
the particles have been
bound together.
The binder/lubricant is
driven off by heating the
slugs under vacuum at
temperatures
around
150°C for several minutes.
Figure 3: SEM of pressed
Pressing is followed by powder particles.
sintering at high temperature (typically 1500°C-2000°C) under vacuum. This
causes the individual particles to join together to form
a sponge-like structure. This structure is of high
mechanical strength and density, but is also highly
porous, giving a large internal surface area.
If the anodes are sintered too long or at too high a
temperature, the particles fuse together too much, and
thus the final capacitance of the anode will be too low.
Similarly if the anodes are sintered for too short a time,
or the furnace temperature is too low, the capacitance
will be too high.
A verification is made on each sinter lot by anodizing
several quality control anodes and performing a wet
capacitance check.
To illustrate how much surface area is inside a common value tantalum capacitor, let us take the example
of a typical 22mF 25 volt rated part:
Capacitance, C = E Eo A / d
where E is the dielectric constant for tantalum
pentoxide (about 27 )
Eo is the dielectric constant for free space ( 8.855
x 10-12 Farads / m)
A is the surface area in m2 and
d is the dielectric thickness in m
(b) Sintering
The dielectric thickness is given by the equation:
d = Typical formation ratio x Rated voltage
x Dielectric growth rate in meters / V
= 4 x 25 x 1.7 x 1O-9
= O.17µm
Substituting this value into equation 1 and rea rranging gives:
Surface area, A = (Cd) / Eo
= (22 x 10 -6 x O.17 x 10 -6) /
(27 x 8.855 x 10-12)
= 0.0156 m 2 or 156 cm 2
24
PASSIVE COMPONENT INDUSTRY
MAY/JUNE 2003
which is the same size as a standard 6″x 4″ photograph
or birthday card.
The sintering process also helps to drive off the
majority of the impurities within the powder by migration to the surface. Figure 4 shows the same powder
type anode as previously seen in Figure 3, after it has
been sintered. The joints between particles are clearly
visible.
The tantalum slugs are now welded onto a metal
carrier strip to enable subsequent processes of manufacture, and a Teflon washer
is added to the riser wire.
This prevents the manganese dioxide counter electrode from passing up the
wire and causing short circuits during manufacture.
When the slugs have been
welded to the carrier strip Figure 4: SEM showthey are then referred to as a ing how particles
“stringer” of anodes.
have merged during
sintering.
(c) Die le ctric Formation
The next stage is the production of the dielectric layer of tantalum pentoxide. This is produced by the electrochemical process of anodization. The slugs are
dipped into a very weak solution of acid, for example
phosphoric acid, at an elevated temperature, for example 85°C, and the voltage and current are controlled to
form the pentoxide layer. Tantalum is valve metal, and
the amorphous pentoxide grown is able to form a uniform, closely coupled layer over the tantalum surface.
Figure 5 shows an SEM picture of a slug that has been
cracked into two pieces to show the dielectric layer.
The dielectric thickness is controlled by the voltage
Tantalum Metal applied during the formation
process. Initially the power
supply is kept at a constant
current until the required formation voltage has been
reached. The power supply is
then kept at a constant voltage
to ensure the correct dielectric
thickness is formed all over the
Tantalum Pentoxide (Dielectric)
Tantalum slug’s surface, and
Figure 5: SEM show- therefore the forming current
decays. Figure 6 shows the
ing dielectric layer.
typical voltage and current
profiles measured during the formation process.
The chemical equations describing the anodization
process are as follows:
Anode: 2 Ta
2 Ta5+ + 10 e
5
2 Ta + + 10 OH
Ta2O5 + 5 H 2O
5H2 +10 OHCathode: 10 H 2O + 10 e
Continued on page 26
Technical Paper
Continued from page 24
As was stated earlier, the oxide forms on the surface
Figure 6: A typical anode formation profile.
of the tantalum, but it also grows into the metal. For
each unit of oxide one-third grows out and two-thirds
grow in. Intrinsic to the dielectric are a low ppm level of
impurity sites that are evenly distributed over the
anode. The impurity sites give a characteristic leakage
signature for the capacitor. For a given dielectric thick ness their statistical distribution will give a characteristic per square, so a capacitor having twice the capacitance value of another of the same voltage rating will
typically have twice the leakage current. Because the
pentoxide grows into the anode as well as upon its
surface, these impurities can be partially isolated as
shown in Figure 7, if the formation voltage is increased.
There is a limit of how far the formation voltage can be
increased, since the capacitance of the part falls as the
dielectric thickens.
The formation voltage can be checked visually by
examining the color of the slug. This is because different
The capacitor’s formation voltage is typically 3 to 4
times the capacitor’s rated voltage. This is to ensure
good reliability. It is also because when forming the
dielectric, one actually produces a semiconducting tantalum oxide region between the wanted pentoxide and
the tantalum metal. This region is kept to a minimum
by removing the stringers from the formation bath
when approximately 90% of the final formation voltage
is reached, and placing the stringers in an oven at
approximately 350°C to 400°C.
This semiconducting region is why tantalum capacitors are polar devices. Figure 8 shows the reverse leakage characteristics of several different voltage rated
parts. Note the similarity to the behavior of a diode.
The dielectric will be subjected to very large electric
field strengths in the finished capacitor. It is for this
reason that tantalum capacitor manufacturers recommend derating of at least 50% to further improve the reliability of the product. Consider again a 22mF 25V part:
Formation voltage = Typical formation Ratio x Rated
Voltage
= 4 x 25
= 100 Volts
Figure 8: Reverse voltage leakage current.
The pentoxide (Ta2O5) dielectric grows at a rate of
1.7 x 10 -9 m / V:
Dielectric thickness (d) = 100 x 1.7 x 10-9
= O.17µm
Electric Field strength = Working Voltage / d
= 25 / 0.17 x 10-6
= 147 kV/mm
Figure 7: Isolation of impurities during dielectric
growth.
thicknesses of dielectric create different interference patterns when light is shown onto them, similar to an oil film
on water. For example, a light green color could mean a
formation voltage in the range 100 to 104 volts and a light
purple color could mean a range of 72 to 76 volts.
26
PASSIVE COMPONENT INDUSTRY
MAY/JUNE 2003
(d) Manganizing
The next stage of manufacture is the production of
the cathode electrode plate. This is achieved by pyrolysis
of manganese nitrate into manganese dioxide. The
“slug” is dipped into an aqueous solution of manganese
nitrate and then baked in an oven at approximately
250°C to produce a dioxide coat.
Continued on page 28
Technical Paper
Continued from page 26
The chemical equation, simplified, is:
Mn (NO 3)2
Mn O 2 + 2 NO 2
This process is repeated several times through varying concentrations of nitrate soManganese
lution to ensure good penetraDioxide
tion of the anode, and to build
up a thick outer coat on the surTantalum Metal
face of the capacitor. Figure 9
Tantalum
shows a manganized anode. The
Pentoxide
flake-like outer layer is the
manganese dioxide. This has a Figure 9: SEM of
resistivity of about 1 to 10 V/cm. manganized anode.
frame tab. The stringer is then cut away leaving the
element attached to the lead frame. The silver glue is
cured and the element is then molded into an epoxy
resin case. This ensures excellent pick-and-placeability,
and tight control over the component’s dimensions. The
molded body is finally coded with its capacitance and
rated voltage values, and then tested for all its electrical
parameters; capacitance, leakage current, impedance
and ESR. Figure 11 shows a sectioned capacitor, with
all the areas of interest highlighted.
Anode
Teflon Washer
(e ) Ref o rm
Anode Wire
The stringers are now dipped into an acid bath, generally of acetic acid, and a voltage applied of approximately half the original forming voltage. This removes
manganese from high leakage current areas within the
slug and grows a dielectric layer to plug the site.
Weld
Leadframe
(f ) Ex ternal co ntact laye rs
The stringer is then dipped into a graphite dispersion
and transferred to an oven where it is heated to ensure
good adherence to the slug. The process is then repeated
with a silver dispersion to proLeadframe
vide the final connection layer
to the cathode terminal. Figure
Silver
10 shows a section through the
Loaded
Epoxy
capacitor with all the external
Silver
contact layers labeled.
Outer
Coat
The graphite layer is used to
Anode Manganese Dioxide Graphite
prevent the silver layer from
coming into direct contact with Figure 10: External
the manganese dioxide. If this contact layers.
were to occur a chemical reaction would take place, and
the silver would be oxidized to high-resistivity silver
oxide, and the manganese dioxide reduced to manganese (III) oxide, which again has a high resistivity.
The part would therefore become high resistance, and
the capacitor would cease to function adequately.
Ag + 2 Mn O2
Ag O + Mn 2O3
The stringer now contains up to 70 finished
processed anodes, also known as elements, which can
be assembled into the appropriate package. The available packages are many and varied. The two most common are covered here.
Packaging
a) Surf ace m o unt package
The element’s cathode terminals are joined to the
cathode lead frame tab using silver loaded epoxy resin,
and the anode riser wire is welded to the anode lead
28
PASSIVE COMPONENT INDUSTRY
MAY/JUNE 2003
Silver Loaded Epoxy
Figure 11: Section of SMD tantalum chip.
b) Re sin dippe d package
The anode riser wire is welded onto the anode lead
wire, and cut away from the stringer. The cathode lead
termination is soldered to the silvered anode by dipping
the silvered anode and cathode lead wire into a solder
bath. The unit is then dipped into an epoxy-based encapsulant, and transferred to
an oven for curing.
Negative
Wire
The encapsulation is coded
with the capacitor ’s capaciPositive Wire
tance and rated voltage values.
Finally the capacitor is tested
for all its electrical parameters:
Anode
Weld
capacitance, leakage current,
impedance and ESR.
Figure 12: Section
Figure 12 shows a sectioned of resin dipped
finished unit. Areas of interest s o l i d t a n t a l u m
are highlighted.
c a pacitor.
Electrical Characteristics
The electrical characteristics of a tantalum capacitor
are determined by its structure, for example, the ESR of
a tantalum capacitor is very dependent on the tantalum
pentoxide dielectric at low frequencies and on the internal
manganese dioxide at higher frequencies. There are
several papers published by AVX that explain in detail
the factors affecting capacitor behavior.
Continued on page 40
Low ESR
EPCOS series in the same case size and with the same
CV value. The ESR value at 100kHz is essentially lower
when three capacitor elements are used in the multiple
anode design, and lowest when polymer-coated elements
are used.
At the low frequency end of the spectra shown in
Figure 4, the ESR of the multiple polymer anode reaches
the values of the standard multiple anode type. This
behavior is typical for conductive polymer tantalum
Continued from page 15
ESR Dispersion of Tantalum Capacitors 470µF / 6.3V
Figure 2: Multiple anode polymer capacitor.
of this design, as compared to a standard single anode
capacitor. This produces a lower resistive contact of the
dielectric.
Electrical characterization
Impedance spectra show the electrical effects of different capacitor designs. Each measurement represents
the linear response of the capacitor related to a sinoidal
voltage excitation. At the upper and lower end of the
shown frequency range in Figure 3, the modulus of the
impedance Z is dominated by the capacitive or the inductive contributions. At frequencies around 100kHz up
to 1Mhz, the ESR dominates the impedance. Figure 3
shows the ESR and Z curves of the 1000mF 4V type for
the high capacitance series and for the two EPCOS
multiple anode series. Compared to the single anode
capacitor, the MnO2 type multiple anode shows approximately 50% of the ESR value at 100kHz; the polymer
type less than 20%.
Figure 4 shows the ESR dispersion of three different
Figure 3: Impedance spectra comparison of single
anode and threefold multiple anode designs.
30
PASSIVECOMPONENT INDUSTRY
MAY/JUNE 2003
Figure 4: ESR dispersion of tantalum capacitors.
Capacitance Dispersion of Tantalum Capacitors 470µF / 6.3V
Figure 5: Capacitance dispersion of tantalum
capacitors.
Continued on page 32
Low ESR
Continued from page 30
capacitors. When coated with polymer, a different selfhealing process appears compared to that at the MnO2
/ Ta2O5 interface. The polymer self-healing mechanism
results in a slightly higher leakage current level unlike
that of the MnO 2, and the corresponding low frequency
ESR value rises.
In general, a lower specified ESR value of a tantalum
capacitor shifts the so-called capacitance roll-off to
higher frequencies. A corresponding effect is the decrease of the resonant frequency w0. The resonant frequency w= is defined by the identity of wLeff and 1/(wCeff).
The effective capacitance Ceff at w0 is generally different
from the specified value. Data book values are related
to the frequency of 120Hz.
Conclusion
Multiple-element, low-ESR design is essential when
very low ESR values have to be obtained. Multiple anode
technology offers the opportunity to combine lowest ESR
values with highest capacitance values. A principle decision is to use either MnO2 or polymer-coated types. Lowest ESR values can only be obtained by using polymercoated capacitor elements. A 1000µF/4V in 10mΩ is
already available at EPCOS. A 1500µF/4V with 6mΩ will
be available soon.
Tantalum Future
Dead,” Business 2.0, March 2002, pp.65-72.
Continued from page 12
The seeming plethora of solutions, while problematic
to some, is to be expected. Independent of the market,
solution proliferation is the norm. Product segmentation and sub-segmentation, as with market segmentation, represents an opportunity to add and retain value
for the truly innovative company.
Conclusion
Where does all this discussion leave us relative to the
ultimate demand for tantalum capacitors and its corresponding position as a cash cow? It is rather simple: tantalum is on a decline as a percentage of the total pie, but
managed correctly, life as a cash cow is still possible.
There are a considerable number of competitors in the
marketplace, each with their own corporate and product
strategy. The rate of new and innovative solutions will
continue to increase, with a corresponding impact on this
share position. In addition, the synergistic impact of high
prices and lack of availability during the bubble have left
a negative and lasting impression on customers. The bottom line is the continued erosion of the tantalum market
at a rate greater than that consistent with a product at
this point in its life cycle.
There will always be a place for tantalum as it matures, given the particular benefits it brings to customers.
That said, it will not be the cash cow it was in past years.
The strategic competitors must look closely at their product portfolio, making certain they have the right mix of
mature, growing, and emerging technologies to optimize
profit and cash flow, and to guarantee the future.
References
[1] W. Brian Arthur, “Is the Information Revolution
32
PASSIVECOMPONENT INDUSTRY
MAY/JUNE 2003
Dr. Daniel Pe rsico is a strategist for the passive component industry. Dan has 20 years of industrial experience
primarily in sales, marke ting, business development and
te chnology, most recently with KEMET Electronics.Dan
is a contributing editor to Passive Components Industry
magazine.
Leading
Manufacturers of
Tantalum Capacitors
If interested in submitting
an article, contact
Eric Gregg by
July 11, 2003 at
sales@paumanokgroup.com
or call (919) 468-0384
NEWSMAKERS
RCD Expands Surface Mount Power Resistor Line
RCD Components has expanded its MWM resistor
family with six new models of molded wirewound resis tors. RCD Series MWM features inherent wirewound
performance (per MIL-R-26) designed for applications
that are too demanding for film resistors.
The MWM product line includes eleven sizes ranging
from 0.5-watt to 5-watts including three new low-profile
models. RCD’s new mini low-profile package sizes
include a 0.5-watt (MWM1/2L), 1-watt (MWM1L) and
2-watt (MWM2L) specifically designed for ultra-low
ohmic applications and available in a limited resistance
range from 0.002W to 0.2W, with tolerances from 0.01% to
10%. Dimensions are .200″ long x .100″ x wide x .053″ high
for the MWM1/2 (0.5W), .250″ long x .126″ wide x .057″
high for the MWM1L (1W) and .330″ x .157″ x .057″ for
MWM2L (2W).
Additionally, RCD released 3 new intermediate sizes,
including a 2-watt (MWM2S), 2.7-watt (MWM27) and a
3-watt (MWM3S) that offer package savings of nearly
40% when compared to their traditional counterparts.
RCD’s MWM2S, MWM27 and MWM3S models are
available in a wide resistance range from 0.005W to
25KW, and tolerances from 0.01% to 10%.
Typical pricing is less than $.39 each at 1000 piece
level for the 0.5-watt and about $.90 for the 5-watt
version. Available through RCD’s SWIFT™ delivery
program (Ship WIthin Fifty Two hours) for faster delivery
requirements with a modest price premium, or standard production lead-times of six to eight weeks.
Vishay Develops Thin-Film Back Contact Resistors
for Film Stability
Vishay Intertechnology announced a series of thinfilm resistors designed to help makers of commercial-
and military-grade hybrid assemblies create more compact
designs while significantly reducing assembly costs.
34
PASSIVECOMPONENT INDUSTRY
MAY/JUNE 2003
The Vishay Electro-Films Back Contact Resistor
(BCR) series combines film stability over time and temperature with a single-bond design that reduces the
number of steps required to manufacture hybrid circuits
and minimizes the resistor footprint, ultimately reducing board space.
With dimensions of just 0.020″ by 0.020″ (0.50mm by
0.50mm) the BCR devices are among the smallest
resistor chips available on the market. The resistor
chips require just one wire bond because a second electrical connection is made through the back of the chip,
which may be attached to the substrate either eutectically or with conductive epoxy.
Available in a resistance range from 10W to 1MW,
with tight tolerance values down to 0.1% and TCR
values ranging from ±250ppm/°C down to ±25ppm/°C,
the new BCR resistor chips feature a maximum operating voltage of 75V, a breakdown voltage of 200V, and a
DC power rating of 250mW at +70°C.
Samples and production quantities of the BCR series
are available now, with lead times of two weeks for
stock orders and 12 weeks for custom orders. Pricing for
U.S. delivery in 1,000-piece quantities with a tolerance
of 1% and TCR of ±250ppm/˚C is $0.60. For more information, visit www.vishay.com.
AVX Introduces Microwave SLC with Tighter
Temperature Characteristics
AVX Corporation introduced a microwave single
layer X7S dielectric capacitor (SLC) family. The new
dielectric, designated “Z”, was developed as a replacement for Z5U and Y5V dielectrics currently used in SLC
capacitors, to improve on the inherent weaknesses of
these systems – namely limited operating temperature
range and widely variable temperature characteristics.
The new SLC family can operate over an expanded
temperature range of -55˚C to +125˚C, and offers much
tighter temperature characteristics of ±22%.
“This new series provides a range of dielectric constants from 2,500 to 15,000 and features dissipation
factors less than 2.5% at 1KHz, thereby offering another
advantage over both Z5U and Y5V dielectrics,” said
Larry Eisenberger, AVX Senior Applications Engineer.
“This capacitor can be used in high frequency broadband applications where other SLCs would be less than
ideal. The broadband characteristics and high dielectric
constants make the “Z” dielectric ideal for use in wireless and optical communications products.”
Applications for the “Z” dielectric include decoupling,
wireless LANs, and use in the telecommunications
Newsmakers
market. Made from fine grained, high-density ceramic
dielectric, the surface finish is especially well suited for
thermo compression wire bonding. In addition, sputtered electrodes provide exceptional termination
strength.
Typical pricing for the “Z” dielectric capacitors
ranges from $0.25 to $1.00 with lead times from stock
to four weeks. The cost and lead time of the units varies
depending on the quantity and specifications desired.
For more information on the AVX single layer capacitor series, see www.avxcorp.com.
the company’s four major categories of inductors,
including surface mount RF inductors, surface mount
power inductors, leaded RF inductors and leaded power
inductors. A glossary of terms, views of applicationspecific base designs, and information about technical
data available at the company’s website are also provided
in the 80-page catalog.
Included in the catalog are more than a dozen new
products introduced since the last printing. They include
five SMP Molded Power Surface Mount Inductors for
power applications (including vertical mount and
shielded designs), four SMT Toroidal Surface Mount
Inductors for power applications (including low profile
and high current designs), two SMRF Surface Mount
Inductors for RF applications (unshielded and shielded
designs) and two CC Ceramic Chip Inductors for RF
applications.
For additional information, visit www.gowanda.com.
Littlefuse Offers High-Power Transient Suppressor
Littelfuse is now offering the AK series high-current
silicon transient suppressor, for more efficient electrical
and electronic device protection against destructive
Gowanda Publishes Inductor Catalog
Gowanda Electronics published a comprehensive
product catalog that addresses technical specifications,
design details, custom products and designer kits for
higher power transient voltages. The AK series replaces
the ganging of between 40 and 150 5000-watt silicon
avalanche diodes (SAD), virtually eliminating manufacturing errors caused by incorrect board placement and
connection of individual components.
The series also simplifies design configuration and
testing, while increasing operating efficiency with less
capacitance, leakage and resistance. The AK series
offers current handling up to 10,000 amps (using
8/20µS wave shape pulse as defined in IEC 61000.4.5)
in a compact 16.5mm leaded package. The configuration allows module manufacturers to fit high levels of
surge capacity into smaller envelopes, for example, a
10KA product into a slim DIN rail package. The device
PASSIVE COMPONENT INDUSTRY
MAY/JUNE 2003
35
Newsmakers
utilizes Littelfuse’s exclusive FoldbakTM technology,
that further lowers clamping voltage levels below the
diode’s inherent “avalanche” state, providing increased
protection levels.
Offered in both an AK6 (6 kiloamp) and AK10 (10
kiloamp) series, the devices can be used for AC line
protection in susceptible applications such as TVSS
panels, motor controls, UPS, and power conversion,
where both space and performance can be an issue.
Littlefuse reports the AK series has been shown to
increase manufacturing yields by up to 10 times by eliminating placement errors and rework during the board
assembly process. For more information, see
www.Littelfuse.com.
J. W. Miller Introduces Multi Six Pack SMT
I nductor/ Transformer Series
J.W. Miller introduced the Multi Six Pack surface
mount Inductor/Transformer Series. The series features
dual functionality by acting as either an inductor or a
transformer, and includes three sizes to provide a multitude of connection options for optimum connection
versatility.
The devices’ six-winding design allows engineers to
wire each coil differently to create a wide range of
values for individual application requirements. Functions can be changed without the need to add additional
components to the board, saving space and providing
more versatility for designing and modifying the board.
This new series is offered in three sizes with the
smallest measuring just 12.2 x 12.7 x 6.2mm (W x D x H),
and is available in 32 part numbers. The six winding
design allows over 20 different connection combinations
per part number, providing over 600 inductor or transformer configurations.
As an inductor, the series is suited for a wide range
of applications including buck, boost, coupled, input,
36
PASSIVE COMPONENT INDUSTRY
MAY/JUNE 2003
output, choke, filter, resonant, high-Q, EMI/RFI filtering,
differential, forward, and common mode chokes. When
used as a transformer, typical applications include fly
back, forward, push-pull, bridge, multiple outputs, inverter, step-up, step-down, gate drive, base drive, signal,
wide band, pulse, impedance, isolation and converter.
Performance characteristics include a frequency
range to over 1MHz, operating temperature range of
-40°C to +105°C, and dielectric strength of 500Vrms
between each winding. Other features include: low
profile, low core loss at high frequency applications and
low noise radiation.
Multi Six Pack surface mount devices are shipped in
tape and reel or tray packages priced from $0.95 in
production quantities.
For more information, see www.jwmiller.com.
NESSCAP Announces Electric Double-Layer
Capacitors
NESSCAP announced new 4.6V Electric DoubleLayer Capacitors (EDLCs) in capacities of 1.5 farad and
3.5 farad, to act as a power bridge between conventional
capacitors and batteries. The EDLCs are designed to
supply peak power for portable and handheld devices
that transmit data for 10 seconds of more. The NESS
EDLC bridges the gap between the battery and capacitor by providing energy bursts that neither batteries
nor traditional capacitors can provide efficiently. The
EDLC relieves the battery of peak power functions to
extend battery life and reduce battery size and cost.
Delivering energy bursts that are 300 times that of
conventional capacitors, NESSCAP says the new
EDLCs offer significant advantages in applications
such as mobile electronics where power,
size and cost are at a
premium. The 4.6V
EDLC provides a seamless solution for retrofitting portable designs
that commonly operate
in the 4.5V-5V range.
The EDLC is characterized by its high energy
density (twice that of
comparable products)
made possible by a proprietary electrode and
sp e c ia ll y d eve l op ed
electrode manufacturing process. The 3.5F 4.6V EDLC
exhibits capacitance of 3.5F and an ESR value of only
150mΩ (DC) at currents over 1 amp.
Prices begin at $2 in OEM quantities of 2,000. For
more information, see www.nesscap.com
Newsmakers
Frontier Releases SMD Low Profile Inductor
Frontier Electronics introduced a series of low profile
CSC042A-XXX SMD power inductors. The inductors
are designed for SMD IR re-flow soldering and measure
6.5mm (length) x 5.3mm (width) x 2.0mm (height).
Key specifications include:
• Inductance from 1µH to 22µH
• Low DCR from 0.11Ω to 0.8Ω
• Operating current from 0.8A to 2.0A
• Saturation current from 1.0A to 3.0A
• Operating temperature from -40ºC to +85ºC
• Self-shield
• Inductance drops 30% max. of the initial value
at Isat current
• Temperature rise 40ºC max.
Typical application is power supply filters, packaging
is tape and reel, and delivery is 8-10 weeks ARO. For
more information, see www.frontierusa.com.
SEI Develops SM Series Wirewound Resistors
Designed to provide power supply, automotive design
and component engineers with true surface mount
(SMD) precision high-power resistors rated at 1W to
3W, SEI Electronics introduced its SM Series of wirewound resistors. The series delivers resistance values
from 0.01Ω to 3KΩ in tolerances from .1% to 5%
and a standard temperature coefficient of resistance (TCR) of ±100
ppm/˚C to ± 20 ppm/˚C.
The devices feature
high-temperature molded
encapsulation and all
welded construction with
tinned copper terminals
to provide flex termination for absorbing thermal expansion. The SM
Series is available in inductive and non-inductive styles and come in four types:
• SM1 with a power rating of 1.0W @ 70˚C, max
imum working voltage of 25V, TCR of ±100
ppm/˚C to ± 20 ppm/˚C, resistance range and
tolerance of 0.01Ω to 1KΩ and to 0.1% with 10
to 1K R-values.
• SM2 with a power rating of 2.0W @ 70˚C, max
imum working voltages of 50V, TCR of ±100
ppm/˚C to ± 20 ppm/˚C, resistance range and
tolerance of 0.01Ω to 2KΩ at 1% and 10Ω to
1KΩ at 0.1%.
• SM2A with a power rating of 2.0W @ 70˚C,
maximum working voltage of 60V, TCR of ±100
ppm/˚C, resistance range and tolerance of
0.01Ω to 0.1Ω at 1%.
• SM3 with a power rating of 3.0W @ 70˚C, max
imum working voltage of 100V, TCR of ±100
ppm/˚C to ± 20 ppm/˚C, resistance range and
tolerance of 0.01Ω to 3KΩ at 1% and 5%.
Special TCRs and 0Ω (jumpers) are available in all
four types.
Typical volume pricing for the SM Series wirewound
resistors is in the mid $.20 to $.30 range, with a
lead-time from 4 to 6 weeks. For more information
about the SM Series wirewound resistors visit
www.marketing@seielect.com.
EPCOS Extends 3-Line EMC Filters to 150A
EPCOS extended its 8A to 50A types of 3-line EMC
filters by adding four new ratings: 66A, 90A, 120A and
150A.
Designed to suppress interference in frequency converters and power electronics components, B84143-A**R105 standard series 3-line filters offer volume reduction and an approximate 30% price reduction compared
to other line filters.
Because of their low weight and compact design, the
company said the filters are especially suited for applications where space is at a premium, such as switching
cabinets.
The entire series is currently available from stock.
For more information, see www.epcos.com.
Selco Introduces Custom Thermistors and Probes
Selco Products Company introduced customizable CS
Series Thermistors and CP Series Probes. These negative (NTC) temperature coefficent thermistors and
probes can be modified from Selco’s standard thermistor
product line to completely custom designs. The company
said it has virtually unlimited options in materials,
configurations, connections, lead types and lengths, and
can provide versatile packaging options to provide labor
saving cost economies and value-added convenience for
OEM manufacturers.
“Working from the OEM’s drawing and specifications, Selco can produce the most specialized product
that allows easy incorporation into the end-product,”
said James Reed, Director of Operations for Selco Products. “OEMs looking for special thermistor/probe packaging requirements can request virtually any configuration and obtain a turn-key product that saves labor
costs and speeds product time to market.”
The new CS Series Thermistors are available in
point matched or interchangeable tolerances of ±0.10ºC,
±0.20ºC, ±0.25ºC, ±0.50ºC, ±1.00ºC, ±1º%, ±2º%, ±3º%,
±5º%, and ±10º%. Resistance values at 25ºC can be
PASSIVECOMPONENT INDUSTRY
MAY/JUNE 2003
37
Newsmakers
specified from 300Ω to 1 MΩ. Lead customization allows
for selection of lengths, AWG, and lead diameter in
materials of tinned copper, nickel, tinned alloy 180, red
Teflon alloy 180, and Ag/Cu twisted kynar, including
any other wire insulation options available on the
market. Chip coatings can be manufactured uncoated or
with epoxy or phenolic.
The Custom CP Series Thermistors Probes features
standard tolerances of ±0.5ºC, ±0.10ºC, ±0.20ºC,
±0.25ºC, ±1.00ºC, ±1º%, ±2 º%, ±3º%, ±5º%, ±10º% and
are available in all resistance-temperature curve materials. The probes may be intermittently cycled at temperatures from -50ºC to 150ºC. Optimum stability is
achieved when stored at temperatures below 50ºC and
operated continuously in temperatures below 100ºC.
Pricing ranges from $0.50 to $10.00 each, with lead
times from 4-5 weeks for initial deliveries. For more
information visit www.selcoproducts.com.
Cooper Releases Dual Winding Inductor/
Transformers
Cooper Electronic Technologies, a business unit of
Cooper Bussmann, introduced the Coiltronics® brand of
DRQ Series dual winding inductor/transformers. The
devices can be used as single inductors or in coupled
inductor/transformer applications.
Inductor uses include buck, boost or coupled inductor.
Transformer uses include SEPIC or flyback. Additional
applications include DC/DC converters, VRM inductors
for CPU or DDR memory power supplies, and input and
output filter chokes.
Windings can be connected in series or parallel to
offer a broad range of inductance ratings (0.33mH to
4.02mH), peak current ratings (0.13Amps to 56.0Amps)
and RMS current ratings (0.128Amps to 17.9Amps).
The DRQ Series of shielded drum core inductors is
available in four surface mount sizes with 200 VAC
38
PASSIVECOMPONENT INDUSTRY
MAY/JUNE 2003
isolation between windings. The DRQ is available in
tape and reel packaging on a 13″ diameter reel; DRQ731,350, DRQ74 1,100, DRQ125 600 and DRQ127 350
parts per reel.
For more information about Cooper Electronic
Technologies and its products, see www.cooperET.com.
Murata Wins Intel’s Preferred Quality Supplier
Award
Murata Manufacturing Co., LTD. was named a
recipient of Intel Corporation’s Preferred Quality
Supplier (PQS) award for outstanding performance in
providing products and services deemed essential to
Intel’s success. The company was cited for its efforts in
supplying Intel with ceramic capacitors, ferrite beads,
inductors, and other passive components.
"Murata has been an integral part of Intel's success.
Murata has consistently provided Intel with leading
edge capacitor technology, outstanding quality, and
strong technical support. Murata has also demonstrated
a strong commitment to Intel’s business by focusing
continuous improvement on customer support and cost
reduction initiatives," said Mostafa Aghazadeh, Intel
Platform, Material and Enabling Technology Development director. "We are pleased to present the 2002 PQS
award to Murata in testimony of their leadership in
both technology and quality."
The PQS awards are part of Intel’s Supplier Continuous Quality Improvement (SCQI) process that encourages suppliers to strive for excellence and continuous
improvement. To qualify for PQS status, suppliers must
score 80 percent on a report card that assesses performance and ability to meet cost, quality, availability,
delivery, technology and responsiveness goals. Suppliers
must also manage and deliver on a challenging improvement plan and a quality systems assessment.
Taiyo Yuden Introduces Ceramic Chip Antenna
for Ultra Wideband (UWB) Technology
TRDA Inc., the US-based R&D arm of Taiyo Yuden
Co, Ltd, announced the development of the world's first
ceramic chip antenna for Ultra Wideband (UWB)
applications.
UWB is widely recognized as the next-generation
short-range wireless communications technology that
will provide simultaneous high data rate and low power
consumption. Taiyo Yuden said the successful antenna
miniaturization opens the floodgate to new commercial
implementations, including greater downsizing of
portable devices and the availability of streaming video
for the 3.1GHz to 10.6GHz frequency band.
The chip antenna measures 10mm x 8mm x 1mm.
Engineering samples are being released to standardiza-
Newsmakers
10 Plus, as well as DC Hipot testing to 6000VDC
and a current detection range from 0.1µA to 5mA.
• Sentry 30 Plus includes all features of the Sentry
20 Plus, as well as Insulation Resistance (IR) measurement capability over the range of 100k to 50G,
at test voltages from 50VDC to 1000VDC
The units meet UL Hipot tester requirements by
employing both visual and audible fail indicators as
well as the necessity to reset the unit after a failure,
prior to making another measurement. Besides fast
device discharge and rapid shutdown on fail, the Sentry
Plus includes the Ground Fault Interruption (GFI)
circuit, a safety feature designed to shut down the unit
should an operator inadvertently come in contact with
the output.
Other features include:
• Ground continuity test with displayed results
• 60 memory locations & entry of a device name
• Front and rear panel connections
• Selectable 3mA
current limiting per
EN 50191
• Pause mode with
operator prompts
tion working groups in various locations, including Japan.
Taiyo Yuden said the UWB antenna completes its
total 1mm antenna solution for the full range of
a p p l i c ations from current products to the next generation of high-frequency ceramic antenna-based solutions.
The company has previously released products for
2.4GHz (Bluetooth and wireless LAN), 5.2GHz (wireless LAN), dual band (2.4/5.2GHz) and others.
About UWB (Ultra Wideband) Technology
Assumed by many to be the next-generation shortrange wireless communication standard, UWB utilizes
a data transmission frequency band of 3.1GHz to
10.6GHz. UWB is different from traditional carrierwave technology in sending very low power pulses below
the transmission noise threshold. Traditionally used in
military applications, UWB technology was released for
commercial use by the FCC in February 2002. UWB
guidelines are currently being formulated under the
auspices of the IEEE standardization process as well as
undergoing development in a number of countries.
The Sentry Plus
can run one or more
stand-alone continuity tests, with programmable pass/fail limits and display of measured results over the range of 0.1Ω to 5Ω. The instrument is
capable of performing 10 individual tests in sequence
with the push of one button, and pause if necessary
(with prompt messages) allowing an operator to change
lead connections to the devices under test. With its remote start input and pass/fail outputs the Sentry Plus
adapts to most manufacturers’ production test environments.
The price for the Sentry Plus Series starts at $1,195,
which includes a NIST traceable calibration certificate
and a set of test leads for connecting to a variety of
devices. For more information visit www.quadtech.com.
QuadTech Adds Three Hipot Testers
QuadTech announced it has added three Hipot testers
to its family of Sentry Hipot Testers, for electrical safety
testing of appliances, motors, cables, medical devices,
and a multitude of electronic products and components.
The Sentry Plus Series includes three models:
• Sentry 10 Plus performs AC Hipot tests over a programmable voltage range from 50VAC to 5000VAC
with a pass/fail leakage current detection range
from 1µA to 20mA.
• Sentry 20 Plus includes all features of the Sentry
Raychem Announces Resettable Devices for Line
Voltage Applications at 240VAC
Raychem Circuit Protection, a unit of Tyco Electronics,
announced the LVR series of PolySwitch® resettable
devices. Designed for use in line voltage applications,
the polymeric positive temperature coefficient (PPTC)
devices are rated at 240VAC, permitting maximum
voltages of up to 265VAC, and are available in hold
currents from 50mA to 400mA. The thermally active
devices can help protect against both overcurrent and
overtemperature faults on the primary side of power
PASSIVECOMPONENT INDUSTRY
MAY/JUNE 2003
39
Newsmakers
supplies and transformers.
The LVR device was developed to help prevent damage to control boards and components by limiting
current in the event of a load-side short-circuit or overdraw, or improper incoming voltage. Unlike a singleshot current fuse, the resettable LVR device can help
protect against conditions where faults may cause a rise
in temperature with only a slight increase in current
draw. When installed on the primary side of the circuit,
in proximity to potential heat-generating components
such as magnetics, FETs, or power resistors, the LVR
device can help provide both overcurrent and overtemperature protection with a single installed component.
“For many years, circuit designers have relied on
PPTC devices for secondary-side protection. This devel-
opment makes possible, for the first time, resettable
PPTC circuit protection on the primary side of power
circuitry,” said Karin Kinsman, product manager for
radial-leaded PPTC devices for Tyco Electronics Power
Components. “Higher voltage ratings and the thermal
characteristics of the LVR series PolySwitch device
make it a logical and innovative solution for power
supply and charger designs,” she added.
The LVR devices are available in straight-lead or
kinked-lead configurations, and can be supplied in
tape-and-reel packaging for compatibility with highvolume assembly. The LVR parts have UL and TUV
certifications, and CSA certification is currently pending.
Starting price is $0.15 – 0.25 each in 250K/yr volumes, delivery lead-time is 8 weeks ARO. For more
information see www.circuitprotection.com/lvr.
Littelfuse Introduces Nickel Barrier Termination
Option for Varistors
Littelfuse introduced a nickel barrier termination option for its complete line of 0402 (EIA 1005) size multilayer varistor (MLV) products. This feature enhances
40
PASSIVECOMPONENT INDUSTRY
MAY/JUNE 2003
the solderability of the MLV’s by improving the wetting
characteristics of the termination and thus resisting
sliding and tombstoning during the board assembly
process. The company said the option helps answer
growing concerns about manufacturing yields for printed circuit boards populated with increasingly smaller
components.
The improved solderability feature is especially important in the manufacture of digital consumer technology products (handheld devices, computers, game
consoles, etc.) where board space is at a premium. The
Littelfuse nickel barrier treatment (enabled by a soonto-be patented process) provides a component with
greater flexibility in board layout and processing. It
maintains high quality solder coverage, superior fillet
heights and resistance to tombstoning. In addition to its
0402 sizes, Littelfuse is now offering the nickel barrier
option for all of its MLV products.
For samples and additional information, visit
www.Littelfuse.com.
Featured Technical Paper
Continued from page 28
These include:
1. “Equivalent series resistance of tantalum capacitors”
by R. W. Franklin
2. “Thermal management of surface mounted tantalum
capacitors” by I. Salisbury
3. “Surge in solid tantalum capacitors” by J. A. Gill
4. “An exploration of leakage current” by R. W. Franklin
5. “Capacitance tolerances for solid tantalum capacitors” by R. W. Franklin
These papers are available through the AVX worldwide sales offices.