ACB & IPC
Eyes on the future,
Feet on the ground
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
1 © ACB 2010 / acb@acb.be / NPI
The Theory
Printed boards are classified by one of three general Performance Classes as
defined in IPC-6011.
Class 1 General Electronic Products — Includes consumer products, some computer and
computer peripherals suitable for applications where cosmetic imperfections are not important
and the major requirement is function of the completed printed board.
Class 2 Dedicated Service Electronic Products — Includes communications equipment,
sophisticated business machines, instruments where high performance and extended life is
required and for which uninterrupted service is desired but not critical. Certain cosmetic
imperfections are allowed.
Class 3 High Reliability Electronic Products — Includes the equipment and products
where continued performance or performance on demand is critical. Equipment downtime
cannot be tolerated and must function when required such as in life support items or flight
control systems. Printed boards in this class are suitable for applications where high levels of
assurance are required and service is essential.
Space and Military Avionics performance classification deviations are defined and
listed in Appendix A of this specification. These are commonly referred to as Class
3/A.
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
2 © ACB 2010 / acb@acb.be / NPI
Some statements
Customers often do not understand the impact
of ordering pcbs meeting IPC class 2 or 3(A)
requirements and consequently underestimate
or do not allow for the costs involved.
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
3 © ACB 2010 / acb@acb.be / NPI
Some statements
Pcb suppliers rarely deliver pcbs meeting
IPC class 2 or 3 (A) , this without advance
warning or discussion prior to PO acceptance
Most suppliers justify this by saying that they
manufacture ‘in accordance to’ IPC class 2 or 3
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
4 © ACB 2010 / acb@acb.be / NPI
Some statements
By imposing an IPC Class, customers
believe that they have specified a reliability
guarantee and will receive pcbs accordingly.
This is not the case but the routine continues
due to a lack of understanding.
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
5 © ACB 2010 / acb@acb.be / NPI
ACB & IPC
IPC requirements can be divided into 3
categories
• Design related requirements
• Process related requirements
• Inspection related requirements
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
6 © ACB 2010 / acb@acb.be / NPI
Design related requirements
If you introduce IPC class 3 without adjusting your
design rules , you make manufacturing more difficult
or impossible and thus add an important cost driver
We evaluate design rule complexity by using a
classification system with integrated IPC design
rules, see our DRC table
Please use it as a guideline
Feasibility of the combination of a HDI, fine pitch
design and class 3 (A) requirements doubtful
( For example annular ring, ...)
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
7 © ACB 2010 / acb@acb.be / NPI
Design related requirements
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
8 © ACB 2010 / acb@acb.be / NPI
Process related requirements
Requirements :
Scientifically substantiated ?
Relevancy for reliability or quality not always clear or
proven
Class 3A is excessive and unrealistic
See summary table
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
9 © ACB 2010 / acb@acb.be / NPI
Process related requirements
Just as an example
Why this difference
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
10 © ACB 2010 / acb@acb.be / NPI
Process related requirements
Characteristic
Inspection
Requirements
Class 2
Class 3
Class 3/A
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
Requirement
Paragraph
11 © ACB 2010 / acb@acb.be / NPI
Process related requirements
Characteristic
Inspection
Requirements
Class 2
Class 3
Class 3/A
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
Requirement
Paragraph
12 © ACB 2010 / acb@acb.be / NPI
Process related requirements
Characteristic
Inspection
Requirements
Class 2
Class 3
Class 3/A
Requirement
Paragraph
For example : How to combine with HDI ?
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
13 © ACB 2010 / acb@acb.be / NPI
Process related requirements
Characteristic
Inspection
Requirements
Class 2
Class 3
Class 3/A
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
Requirement
Paragraph
14 © ACB 2010 / acb@acb.be / NPI
Process related requirements
Characteristic
Inspection
Requirements
Class 2
Class 3
Class 3/A
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
Requirement
Paragraph
15 © ACB 2010 / acb@acb.be / NPI
Inspection related requirements
The real cost driver.
Almost no customer realises how much inspection
is needed to comply with IPC
Almost no supplier explains customers how much
inspection is required. They don’t do it because
competition doesn’t mention it neither and the
supplier doesn’t want to push the customer towards
the competition. Consequence is that no supplier
gets paid for inspection according IPC and that the
situation on the market doesn’t change.
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
16 © ACB 2010 / acb@acb.be / NPI
Coupons
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
17 © ACB 2010 / acb@acb.be / NPI
Coupons
C: Peel strength
D: Interconnect resistance
E: moisture and insulation resistance
G: solder mask adhesion
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
H: Surface insulation
resistance
18 © ACB 2010 / acb@acb.be / NPI
Coupons
F: registration
R: registration
ACB registration coupon
N: surface mount bond strength
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
19 © ACB 2010 / acb@acb.be / NPI
Coupons
M: Surface mount solderability
S: Hole solderability
T: solder resist tenting
X: bending flexibility
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
20 © ACB 2010 / acb@acb.be / NPI
Coupons
19 coupons for a standard rigid pcb class 3
+ An extra coupon for every additional run
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
21 © ACB 2010 / acb@acb.be / NPI
Some panel samples
This panel is not IPC compliant, the customers allowed already some simplifications
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
22 © ACB 2010 / acb@acb.be / NPI
Some panel samples
This panel is not IPC compliant, the customers allowed already some simplifications
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
23 © ACB 2010 / acb@acb.be / NPI
Some panel samples
This panel is not IPC compliant, the customers allowed already some simplifications
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
24 © ACB 2010 / acb@acb.be / NPI
Coupons
Often a significant part of a production panel is
filled with coupons
Who wants to pay for that ?
What is the added value ?
...and all these coupons have to be checked also !
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
25 © ACB 2010 / acb@acb.be / NPI
Acceptance Testing
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
26 © ACB 2010 / acb@acb.be / NPI
Acceptance Testing
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
27 © ACB 2010 / acb@acb.be / NPI
Acceptance Testing
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
28 © ACB 2010 / acb@acb.be / NPI
Acceptance Testing
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
29 © ACB 2010 / acb@acb.be / NPI
Acceptance Testing
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
30 © ACB 2010 / acb@acb.be / NPI
Acceptance Testing
Huge amounts of ‘cross sections’ have to be
made and checked !
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
31 © ACB 2010 / acb@acb.be / NPI
Acceptance Testing
Example: check a batch of 30 production panels
of 4 layer pcbs on registration according to IPC
class 2
Class 3 :
make and
evaluate 2
sections /
panel = 60
cross
sections
Class 2 :
still 16
cross
sections
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
32 © ACB 2010 / acb@acb.be / NPI
Way forward
Solution consists of different aspects
• Don’t over specify your products
• Don’t expect IPC acceptance testing compliance for free
• Check what you get from your supplier
Don t expect miracles from requiring an IPC class
• Select your suppliers in a proper way
•
• Make clear agreements with your suppliers about requirements
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
33 © ACB 2010 / acb@acb.be / NPI
Way forward
Don’t over specify your products
Major defense and medical customers order life
critical pcb’s specifying IPC class 2 with exceptions
They use other approaches to insure product
reliability
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
34 © ACB 2010 / acb@acb.be / NPI
Way forward
Check what acceptance testing you get from
your suppliers
It helps to understand what you are specifying and what
interpretation your supplier is applying on your specification
Everything is better then leaving specifications and
compliance to it in the dark
Don’t expect IPC acceptance testing
compliance for free
The reality is simple: if it is offered for free, it is not done.
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
35 © ACB 2010 / acb@acb.be / NPI
Way forward
Don’t expect miracles from specifying an IPC
class 2 or 3
We have seen many pcb’s with very poor quality although
they were certified to be compliant to IPC Class 3.
Select your suppliers in a proper way
You can’t select a supplier, just using a spreadsheet
Visit / audit your suppliers. Understand and evaluate their
technical capabilities and engineering support to optimise
your pcb designs and specifications.
Check QA, process control and reliability testing
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
36 © ACB 2010 / acb@acb.be / NPI
Way forward
The process defines the quality and robustness of a pcb.
Focus on the process and the way reliability is checked when
you select a supplier
Checking the product is just a final confirmation
If you don’t have the possibility to visit / audit your suppliers,
check a number of important indicators
• What quality certificate do they have, for example ACB
production plants have EN 9100 ( aerospace ) and Nadcap
in progress, which is a process focused approval
• IPC 1710 A questionnaire gives a lot of info
• Customer reference list
• Technical roadmap
• Market sectors
• International presence
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
37 © ACB 2010 / acb@acb.be / NPI
Way forward
Select your suppliers in a proper way
Market sectors ACB group
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
38 © ACB 2010 / acb@acb.be / NPI
Way forward
Select your suppliers in a proper way
International presence
UK
9%
Italy
8%
Germany
10%
France
32%
Netherlands
8%
Scandinavia
2%
Spain
6%
USA
1%
Others
5%
Belgium
19%
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
39 © ACB 2010 / acb@acb.be / NPI
Daisy chain resistance (Ohm)
Select your suppliers in a
proper way: Reliability testing
• In house qualification of all
60.0000
50.0000
40.0000
30.0000
20.0000
– base materials
– new processes
– new build ups and material combinations
0
75
150
225
300
Time ( min ) - cycle time 36 min
Thermal cycling
15 min 125 °C
15 min -55 °C
Transition time = 30 sec
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
40 © ACB 2010 / acb@acb.be / NPI
Reliability: 12 L test pcb:
daisy chain
Vias 1: # = 58000
vias 2
Vi
as
1
Test area for
µvia in pad
vias 1
Vi
as
1
vias 2
vias 2
vias 2
vias 2
Test area for
µvia in pad
Vi
as
2
vias 2
vias 2
vias 1
vias 3
vias 3
Vias 3: # = 2400
vias 2
vias 2
vias 1
vias 3
Vi
as
1
Vias 2: # = 2400
Test area for
µvia in pad
Test area for
µvia in pad
Vi
as
1
vias 3
Test area for
µvia in pad
Vi
as
3
vias 3
vias 2
vias 1
vias 1
vias 2
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
41 © ACB 2010 / acb@acb.be / NPI
Reliability testing
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
42 © ACB 2010 / acb@acb.be / NPI
Reliability testing
• Conclusion:
– Higher Tg = Higher resistance
– µvias never failed
• Conclusion confirmed with
14 Layer pcb 3 + X + 3
– 199520 µvias / pcb
– 1440 buried - 4200 PTH / pcb
– 80 µm track & gap
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
43 © ACB 2010 / acb@acb.be / NPI
Way forward
Make clear agreements with your suppliers
about specifications
ACB has virtually no customers who define IPC “blind”
ACB standard procedure define 100 % AOI, 100 %
Visual inspection and 100 % Electrical Testing as a
starting point.
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
44 © ACB 2010 / acb@acb.be / NPI
Way forward
How can we optimise / minimise cost impact ?
• pcb manufacturing according to IPC class 2
without cross sectioning
• pcb manufacturing according to IPC class 2,
but with Cu plating thickness from class 3.
number of cross sections / batch = 2 using ACB
standard test coupons.
• pcb manufacturing according to IPC class 2,
but with Cu plating thickness and annular ring
requirements from class 3.
number of cross sections / batch according to
sampling plan level 4.0 using ACB standard test
coupons.
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
45 © ACB 2010 / acb@acb.be / NPI
Way forward
ACB standard test coupons
•
•
•
•
•
1 in every corner, 2 X and 2 Y
containing the smallest diameter of each run
annular rings according to design
is small, doesn’t consume half of a panel surface
1 cross section to evaluate all runs
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
46 © ACB 2010 / acb@acb.be / NPI
Way forward
ACB standard test coupons: cross section examples
7 layers µvia with buried run
5 layers µvia with 3 layers
Cu filled and stacked
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
18 layer HDI : 3 + 12 + 3
47 © ACB 2010 / acb@acb.be / NPI
Way forward
ACB standard test coupons: cross section examples
HDI with thermal management :
2 x 210 µm Cu
20 layer Flex Rigid
with 18 flex layers
CTE Control:
4 layers Cu Invar Cu in blind runs
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
48 © ACB 2010 / acb@acb.be / NPI
ACB & IPC
Eyes on the future,
Feet on the ground
Over 20 years experience in “ High Reliability “
Pcb Manufacturing has shown us that our approach works
Wim Perdu Sales & Technical Director wim.perdu@acb.be
Steve Carr Scandinavia Sales Manager steve.carr@acb.be
www.acb.be
ACB nv
Vosmeer 3
9200 Dendermonde Belgium
DNU - Den Norske Utleggerforening Trondheim 25th/26th August 2010
49 © ACB 2010 / acb@acb.be / NPI