6 Precautions on Use of Semiconductor Devices
Contents
6.1
Precautions on Selection of Devices
6- 1
6.1.1
Scope of application
6- 1
6.1.2
Concept of maximum ratings and operation
assurance
6- 1
Concept of derating
6- 4
6.1.4
Package selection
6- 5
6.2
Precautions on Set or System Design
6- 6
6.2.1
Precautions on circuit design
6- 6
6.2.2
Precautions on use environment
6- 9
6.3
Precautions on Packing, Storage and
6.1.3
Transportation
6-11
Precautions on packing
6-11
6.3.2
Precautions on storage
6-12
6.3.3
Precautions on transportation
6-14
6.4
Precautions on Handling of Devices
6-15
6.4.1
Precautions on electrostatic breakdown
6-15
6.4.2
Precautions on incoming inspection
(or measurement)
6-18
6.5
Precautions on Mounting
6-19
6.5.1
Selection of mounting materials
6-19
6.5.2
Processes prior to mounting
6-24
6.5.3
Mounting process
6-26
6.5.4
Precautions with special packages
6-29
6.3.1
i
6
6.
Precautions on Use of Semiconductor Devices
Precautions on Use of Semiconductor Devices
Precautions on Selection of Devices
6.1
What matters most on use of semiconductor device is the selection of a device most suited to your purpose,
that is, to quality and reliability of the electronic equipment for which a device is used.
Although our company is always committed to enhancement of quality and reliability of semiconductor
devices, it is generally true that these devices sometimes make operation error or failure. In this respect, on
use of these semiconductor devices, a safe design of the end equipment must be made on the customer side so
that human life or body and property would not be damaged or threatened due to the operation error or failure
of semiconductor devices. In particular, on design of the equipment, you are required kindly to use our
devices within the range of our guarantee, especially in terms of maximum ratings, operating supply voltage
range, heat dissipation characteristics. In case of using our devices beyond range of guarantee, it is recommended
to design a redundant circuit so that the failure of equipment caused by our devices will not be contrary to the
associated laws and regulations.
6.1.1
Scope of application
Our semiconductor devices are intended to be used mainly for general applications (office equipment,
communication equipment, measuring equipment, home appliances, etc.) or for the individual applications
described in this document.
When you want to use our devices for special applications (such as aerospace use, transportation equipment, traffic signal equipment, combustion equipment, life-support systems, safety equipment, etc.) which
require specific levels of quality and reliability and for which operation error or equipment failure would lead
to the risk of bodily injury to or the death of a human being, please consult our local sales office prior to such
use. In the event of use in such applications without prior consultation, we accept absolutely no responsibility
for any damages or injuries that may occur.
6.1.2
Concept of maximum ratings and operation assurance
Generally, maximum ratings are defined as absolutely maximum ratings or limit values which to observe under
any conditions. Once exceeded these ratings, the semiconductor characteristics are likely degraded or
semiconductor element is sometimes broken even to an extent where the characteristics are never restored to
a basic state.
The absolutely maximum ratings are the limit value which should not be exceeded even in an instant and, in
the case that the ratings are specified for more than two items, any two items cannot reach the limit value at
the same time. These limit ratings are defined in JIS C7032, too. In this sense, it is imperative to satisfy these
absolute maximum ratings even under any unfavorable conditions.
In the meanwhile, absolute maximum ratings are defined not only by the characteristics of semiconductor
but by consideration of other factors than semiconductor as well. In case of epoxy resin device, for instance,
its maximum temperature rating is determined by thermal resistance of resin. In the process of circuit design
and thermal design of electronic equipment, it must be strictly observed that semiconductor devices should
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6
Precautions on Use of Semiconductor Devices
not be used beyond the range of their absolutely maximum ratings. This is a primary condition on how to use
semiconductor devices effectively.
The items defined as absolute maximum ratings include storage temperature, operating ambient temperature,
junction temperature, applied voltage, applied current, reverse voltage, allowable power dissipation, etc.
which are defined individually. Shown below on the Tables 6.1 and 6.2 are the models of discrete device and
IC device, respectively.
Table 6.1
Category
Common
Transistor
Diode
Absolute Maximum Ratings of Discrete Device
Parameters
Definition
Storage temperature (Tstg)
Allowable range of ambient temperature at storage.
Junction temperature (Tj)
Maximum allowable value of collector junction temperature enabling
successive operation.
Operating ambient temperature (Topr)
Allowable range of ambient temperature at operation.
Collector-base voltage (VCBO)
Maximum allowable voltage applicable successively in reverse direction
against collector junction with emitter opened.
Collector-emitter voltage (VCEO)
Maximum allowable voltage applicable successively between collector and
emitter in reverse direction against collector junction with base opened.
Emitter-base voltage (VEBO)
Maximum allowable voltage applicable successively in reverse direction
against emitter junction with collector opened.
Collector current (IC)
Maximum allowable current enabling to flow reversal against collector
junction by applying forward voltage between emitter and base.
Emitter current (IE)
Maximum allowable current enabling to flow forward to emitter junction,
short-circuiting between collector and base.
Base current (IB)
Maximum allowable current to flow successively to base after applying
forward voltage between emitter and base and short-circuit between collector
and emitter.
Collector power dissipation (PC)
Maximum allowable power to be consumed successively at collector junction
in operation.
DC forward current (IF)
Maximum allowable DC value of applicable forward current.
Peak forward current (IFM)
Maximum allowable peak value of applicable forward current.
DC reverse voltage (VR)
Maximum allowable DC value of applicable reverse voltage.
Maximum allowable power
dissipation (PD_max)
Maximum allowable power to be consumed successively.
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Table 6.2
Parameters
Precautions on Use of Semiconductor Devices
Maximum Ratings of Integrated Circuit Device
Definition and descriptions
Storage temperature (Tstg)
Temperature range to store the IC, not operating it.
This temperature depends on package material and intrinsic nature of semiconductor.
Operating ambient
temperature (Topr)
IC circuit function can be guaranteed within this temperature range, but electrical
characteristics shown at Ta = 25°C are not always guaranteed.
Supply voltage (VCC)
Maximum voltage applicable between Vcc pin and GND pin.
This supply voltage rating has to do with the withstand voltage of the transistor used in the
inner circuit. If Vcc exceeds the ratings, therefore, the transistor is likely to be broken.
Input voltage (VI)
Maximum voltage applicable to input pin.
This voltage is determined by emitter withstand voltage of input transistor or input diode
withstand voltage. If exceeds this value, it is likely to be broken.
Output voltage (VO)
Maximum voltage applicable to output pin.
This voltage is determined by the transistor on the output side and cannot be set for more than
supply voltage.
Output current (IO)
Maximum current to be flew in or out to output pin.
It is determined by output transistor ratings.
Power dissipation (PD)
Maximum power dissipation allowable inside IC.
If exceeds this value, electrical and thermal breakdown are likely to be caused.
This value usually differs according to IC integrated density and kinds of package.
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Precautions on Use of Semiconductor Devices
6.1.3
Concept of derating
What level of derating is done to maximum ratings has a big effect on reliability. As is defined by JIS Z 8115
(Reliability terms), the derating means “to reduce the load from ratings systematically in order to improve
reliability”. In this respect, it is necessary to carry out deratings commensurate with necessity level for reliability
in the process of system design. Derating characteristics differ from device to device, but the factors for
derating are categorized as follows:
1. Thermal stress
2. Electrical stress (voltage, current, power, pulse, etc.)
3. Environmental stress (humidity, vibration, shock, etc.)
Shown on Table 6.3 are the derating reference examples to be considered in the reliability-centric design.
Please note, however, that these reference examples are standard ones, excluding the ones under special
conditions.
It is necessary to satisfy these derating factors as simultaneously as possible.
If you want to pursue even higher reliability design, you have to perform derating corresponding to that
high level need.
Table 6.3
Derating Reference Examples
Thermal stress
Derating factors
Junction temperature
Temperature Operating ambient
temperature
Others
Electrical stress
Keep less than 70% of maximum operating ambient temperature.
Considering the equation of (Tj) = (Topr) + (PD × Rth), derating across each
parameter is necessary.
Withstand voltage
Keep less than 80% of maximum rating.
Over-voltage
Voltage in worst cases of surge, static charge must be kept below 80% of maximum rating.
Others
Use within recommended operating ambience for integrated circuit.
Mean current
Keep less than 50% of maximum rating.
Peak current
Voltage in worst cases of surge, static charge must be kept below 80% of maximum rating.
Power
Mean power
Power in worst cases of surge must be kept less than 50% of maximum rating.
Especially, care should be taken to power transistors and power ICs. Also restriction
from operating ambient temperature and heat dissipation conditions exists.
Pulse
Area of Safe
Operation (ASO)
Keep it from exceeding maximum rating of each specification.
Surge
Keep it from exceeding maximum rating of peak voltage and current.
Temperature
Operating ambient
temperature
Keep it less than 70% of maximum operating ambient temperature.
Humidity
Relative humidity
Keep between 40% to 80%.
Voltage
Environmental stress
References
Operating maximum junction temperature measured after consideration of surge
current concentration must be kept less than 70% to 80% of maximum rating of
junction temperature.
Current
Vibration
Mechanical
Shock
Stress
T04007EE-6 2011.3 6-4
None of them be applied.
If occurs, refer to the derating coefficient of reliability forecast described later.
6
6.1.4
Precautions on Use of Semiconductor Devices
Package selection
Semiconductor device package can be classified into hermetic (air tight) sealing type such as metal, glass,
ceramic, low melting point glass (cerdip) sealing and resin (plastic) sealing. Package selection is made from
comprehensive judgment criteria including end system, its usage, use environment, reliability target and cost
target.
While hermetic seals have been mostly used for its high reliability and adaptability for special environment,
the recent resin sealing is enjoying more and more popularity because of its enhancement of reliability
resulted from technological innovation of chip protection film, improvement of resin material characteristics
and advanced sealing technique, thus securing the same level of reliability as hermetic sealing in the general
environmental conditions. In this respect, nowadays the resin sealing package is widely used for such areas
as vehicles, industrial equipment, FA, OA, computers, etc.
It can be said that resin sealing package is superior to hermetic package in terms of anti-mechanical
environment. On the other hand, due to its intrinsic characteristics of moisture absorption, moisture permeation
and thermal resistance limit, resin sealing package is said to be inferior to hermetic sealed package in terms of
anti-humidity and anti-heat characteristics. However, the technological advancement of resin sealing is highly
expected through our further improvement of chip fabrication, resin material and sealing process, thereby
presenting the users with more reliability of resin sealing package.
In the recent years, in sync with the trend of high function and low cost of the end system where
semiconductor devices are used, the semiconductor element is getting more and more densely integrated and
highly functioned, while its package is heading for more multi-pinned and thinner type, thus resulting in
diversified package structure and sealing method.
The customers have such a wide range of selection from our multiple and diversified packages that they can
make an optimal choice of packages (sealing type, shape, lead-frames, etc.) judging from usage, size, shape,
use environment, reliability target of their set or system.
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Precautions on Use of Semiconductor Devices
6.2
Precautions on Set or System Design
6.2.1
Precautions on circuit design
a) Supply voltage
Connect VDD and VSS pins directly to supply power and GND externally. Check pin locations of each device,
place it on the printed wiring board and apply power. If connected wrong way, a large current flows with
likelihood of device breakdown like inner wiring melting
Check operating voltage conditions before use. Operating voltage condition differs according to the device.
If used at a higher voltage than guaranteed one, we are not in a position to give reliability assurance including
device life against degradation by ageing.
If used at a lower voltage than guaranteed, it is likely to cause operation error due to no operation margin.
Keep voltage from exceeding absolute maximum rating even within a transition time at power rise-up.
Keep deviation of supply voltage as small as possible. It is advisable for you to add a high frequency
characteristic capacitor (ex. ceramic layer capacitor) near power source/GND and a large capacitance
capacitor (ex. tantalum electrolytic capacitor) for entire block in order to control power fluctuation.
Determine capacitor value based on adequate evaluation on actual PC board.
As for the device that requires more than two supply voltages, its rise-up order and time sometimes cause
problems. Never fail to see the product specifications.
b) Treatment of pins
Perform appropriate treatment for non-use functions and pins not to cause adverse effect on the system.
In particular, don’t connect the NC pins when they are wired in the inner circuit, even if they are open-wired.
If connected with high resistant long wires, it is likely to cause operation error due to the noise coming from
C or L coupling.
Open the non-use output exclusive pin.
Pull up or down non-use input exclusive pins by inserting several ten k Ohm resister. If input becomes
unstable, a through-current flows in the input circuit, likely causing increase of power consumption and a
noise source against power source inside the tube.
Treat the non-use I/O pins after checking carefully the pin status at reset. In case that output is in high
impedance state at reset time, pull up and down input by inserting several ten k Ohm resistor not to keep
input from being unstable. In case of ON state of output at reset, open it.
As to non-use XI/XO pins (sub-lock pins), connect XI pin to GND and keep XO pin open.
As the specifications differ according to the device type, refer to the production specifications.
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Precautions on Use of Semiconductor Devices
c) Power ON
See to it that input pin voltage will be supplied after device power source rises up. If this order is reversed,
latch-up is likely to occur and breakdown due to a large current.
After device power source rises up or after waiting time for stabilizing inner voltage, rise up so that a reset
pin voltage can be recognized adequately. In this time, keep input in a standby mode. When input is in an
operation mode, a large inrush current is likely to flow. Refer to the product specifications for details of
wait time.
d) Printed wiring board patterns
Keep VDD and VSS supply lines as near to regulators as possible. Also, keep power source wiring pattern
thick and short because load sometimes cause power voltage sudden drop and operation error.
When connecting an oscillator, consider the pattern design so as to connect it nearest to VSS of a device by
making power source wiring thick. A longer wiring makes it easy to have an effect of noise and unstable
oscillation. It is recommended to enclose oscillators and oscillation pins with VSS pattern in order to prevent
oscillation pins from noise.
For both mounted side printed wiring board, it is recommended to adopt VSS patterns on the rear side of
oscillators, too.
e) Noise
Keep signal lines as far from noise sources (ex. transformer) as possible including power source system.
High-speed changing or large current flowing signal lines should be kept far from signal lines susceptible to
noise or oscillator.
It is also important to keep a total wiring length short as it would otherwise act as the antenna to the noise.
It is advisable for you to adopt a small package to shorten a total line length.
Insert a bypass capacitor to cope with a power source noise.
When a fairly big signal (ex. sine wave) is inputted to the input pin, even small noise (ripple) would lead to
frequent reception of input near switching voltage. For the input pin that would better be kept from these
unfavorable conditions, we have its switching power source applied hysteresis. See the production
specifications for further details.
f) Surge
In sync with its ever-increasing fine patterning of process, the semiconductor device is subject to strict
demand for protection from surge voltage withstand. In particular, special care should be taken to the
following pins and devices that are designed for the characteristics vulnerable to surge voltage. The caution
items on handling of devices in terms of static electricity will be described later.
Generally, the pins (ex. LED driver pin, FL driver pin) that can be operated at higher (or lower) voltage than
operating supply voltage is protected against surge voltage with a diode on one side only, which means so
vulnerable to surge voltage. Your special care should be taken by use of peripheral systems.
The caution items on handling a device for static electricity will be described later in this chapter.
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Precautions on Use of Semiconductor Devices
g) Latch-up
The parasitic or extra transistors outside the design circuit formulated inside the device are generated due
to the device structure and turn on by external noise or surge voltage, resulting in a flow of over-current. This
phenomenon is called latch-up. To counter this phenomenon, it is necessary not to apply to un-rated supply
voltage or input voltage (signal) to the device. Thus, a full care or measure should be taken to noise and surge.
Likewise, latch-up is likely to occur due to the order of applying supply voltage and input voltage, to which
your special attention should be paid.
Be careful of the rise-up way for the device that uses more than two supply voltages. Refer to an individual
product specification for details.
When you use the plural supply voltages of the same value, be careful not to cause a flow of current made
by its potential difference.
Keep an input signal from coming in before a rise-up of device supply voltage.
Keep supply voltage or GND voltage from fluctuating. Especially, don’t apply device supply voltage after
supplying it to the load.
h) Programming
Keep a loop creation from becoming an infinite loop.
For solution to a noise problem on the input pin, it is recommended to make decision by majority after
trying inputs more then two times.
For A/D input, it is recommended to take a mean value after trying several times or eliminate abnormal
values.
When you use a heat-sourced system such as an electric heater, it is recommended to monitor operating
voltage and detect software runaway at the plural points of the system so that you can take a softwarebased countermeasure against operation error, for example, by shutting down a heat source, once even a
single condition for normal operation is found a failure.
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6.2.2
Precautions on Use of Semiconductor Devices
Precautions on use environment
a) Temperature
Operating ambient temperature is defined as one of absolute maximum ratings. It is imperative to use
within the range of ratings. Otherwise, we are unable to guarantee electrical characteristics and, further
worse, it will cause degradation of reliability, operation error or even device breaking. Furthermore, even if
you use within the range of ratings, an electrical characteristic is not always guaranteed for the item
specified at Ta = 25°C.
Allowable power dissipation (PD) is defined as one of absolute maximum ratings, but it varies depending on
ambient temperature and radiating characteristic of a device. Refer to the conditions described on the
individual product specifications. Use beyond allowable power dissipation would lead to electrical and
thermal breakdown.
Since operating ambient temperature of a semiconductor device depends largely on design of the set and the
use environment of the set on the end user’s side, special care should be taken to caution items on use of the
set.
b) Humidity
Although there is no description in maximum ratings about humidity as use environment of a semiconductor
device, it is recommended to set a yardstick of humidity to 45%RH to 75%RH on both use and storage of
the set. Likewise, a sudden change of humidity and temperature is likely to cause dew, a full care should be
taken to the environment. Dew forming between lead-frames of a semiconductor device likely leads to leak
currency and operation error. This is also true to dew forming or wetting in OFF mode.
Precaution items on moisture absorption of package resin are described in details on the pages of
“6.5.2 Processes prior to mounting”.
c) High electric field
In the place where a high electric field is applied, especially just below the CRT, there is a high likelihood
of operation error of a semiconductor device due to electric field generated from there. It is advisable for
you to shield the package surface to assure normal operation.
d) Electromagnetic wave
Electromagnetic wave is transferred as radiation noise or conduction noise in power lines from the power
source and high current circuit or equipment outside the set that generates a strong electromagnetic field,
thereby causing operation error of a semiconductor device or a set circuit. To solve these problems, it is
necessary to fit an electromagnetic shield at a semiconductor device or a set circuit or review optimization
of circuit layout pattern and take a noise preventive action for power source and GND lines.
e) Radiant ray
Our semiconductor device is not designed assuming that it is used in the environment where a radiant ray
level is higher than usual. Its use in aerospace or under X-ray in medical treatment is likely to cause an
operation error of a device.
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Precautions on Use of Semiconductor Devices
In case that a great deal of radiant ray is applied inside the device by X-ray fluoroscopy, fine leak current
is generated inside the device, thus causing abnormal operation due to characteristic degradation.
f) Gas
Use and storage of a device in the corrosive gas atmosphere and base is likely to cause lead-frame corrosion
and rusting, resulting in leak current between leads.
g) Vibration and other mechanical stress
In the use of a device in the set where strong vibration and shock are applied, stress is imposed on the leadframes of a device, resulting in disconnection. Likewise, if used in the set where a source of oscillation like
a speaker exists, care should be taken to the resonance of a circuit board.
Since handling stressful to a semiconductor device or using in such an environment would possible cause
cracks on the package or the chip inside, care should be taken.
h) Effect by light
When light is applied to a semiconductor device from outside, electromotive voltage is generated due to
photoelectric effect and likely triggers operation error. This is most likely to occur in the device whose
parts (upper side, rear side, side) are exposed.
In the process of designing, you are requested to design not to invite light.
Same consideration is needed for inspection process and actual use as well.
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6.3
Precautions on Use of Semiconductor Devices
Precautions on Packing, Storage and Transportation
In general, a semiconductor device is of high quality and high reliability. However, its wrong handling would
likely cause a device to be damaged or deteriorated. You are therefore, required to take a full care of handling.
Described hereinafter are the precaution items for carrier, packing, storage and transportation.
6.3.1
Precautions on packing
For carriers and packing of our semiconductor devices, we use the material and structure ensuring initial quality
and reliability are maintained so that they can endure even the worst environmental stress during storage and
transportation. In the case that you move these devices from our specified carriers to other ones, a full care
should be taken to handling. Take care of following points when handling the carriers (See Figure 6.1).
Tape
Tray
Case
Magazine
Figure 6.1
Example of Carrier
a) Tray
When you divide semiconductor devices into small quantity of groups, carefully take out the devices from
the tray and carefully return the devices to the tray. If a lead hits the tray, or if a pressure is applied to a lead,
the lead may be distorted. By the way, before starting baking, you should transfer devices from a magazine or
a tray to a case that is specially designed for baking. In this case, carefully transfer devices so that no
mechanical damage can be applied to the packages and so that the semiconductor devices cannot fall off. When
you have to bake the tray-packed devices, it is necessary to ascertain the tray is thermal resistant before
baking. (If it is not heat-resistant, it is impossible to bake.) A heat resistant tray has a mark like HEATPROOF
130°C MAX (thermal resistant threshold temperature). For waterproof and laminated-packed device, its use
time limit after unpacking differs according to device type. You are therefore required to check its specification
and use it within the time limit and without applying higher temperatures than specified.
b) Tape
A peeling strength of a tape depends on temperature and humidity in the storage environment. A full attention
should be paid to peel strength when mounting them with device placement machine. Likewise, when you
suspend mounting the devices by use of adhesive tapes and store the rest of the devices, don’t wind the tapes
strongly. Otherwise, the devices are likely to drop from the tapes.
The packaging material of tapes is not heat resistant. So, tapes should not be subject to high-temperature
baking without peeling off the tape. When you have to bake tapes without peeling off the tape, consult our
company’s sales division.
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Precautions on Use of Semiconductor Devices
c) Magazine
The surface of a magazine is coated with anti-static solvent. However, if you slip or wash it so often, the
coated film will be taken off and anti-static effectiveness will be decrease, thus causing a semiconductor
device to be damaged.
6.3.2
Precautions on storage
You have to pay special attention not only to storage environment/status but also to maintenance of quality,
in case of storing semiconductor devices for a long period.
a) Storage environment
In storage of semiconductor devices, it is desirable to store them in normal temperature (5°C to
35°C) and humidity (45%RH to 75%RH) to maintain device quality. It is recommended, therefore, to store
them in a clean environment with little variation in temperature or humidity and where dust and corrosive gas
are not present.
In the district where is very dry in the winter season, if you use supply water for a humidifier, chlorine contained
is likely to cause the lead frames of a device to be rusted and therefore you are requested to use boiled water.
Also avoid direct sun light. In case of large temperature deviation, it is likely to cause dew of water.
The following additional care should also be taken to storage environment. Although the devices are preferably
stored in the state of packing, but when you have to store some out of packing, it is recommended to store
them in the airtight sack made of conductive sheet.
The laminate-packed devices should be stored and used in accordance with the specifications.
b) Storage status
Following cares should be taken to storage style to maintain normal and sale storage.
1) Care should be taken not to stack up too many packing boxes, preventing the lead frames of a device
from being pressured by the load (See Figure 6.2).
2) Don’t apply vibration and shock that would deform the packing box.
3) Store the semiconductor devices with their lead frames unprocessed. If half-in-process whose leads are plated
is stored for a long period, the folded part is likely to cause rusting, thus causing soldering to be failure.
Top heavy stacking
Unstable stacking of
heavy stacking
Too many stacking
Semiconductor
devices
Semiconductor
devices
Figure 6.2
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Precautions on Storing Status
6
Precautions on Use of Semiconductor Devices
c) Precautions on long-period storage
In the case that the semiconductor devices are stored for a long period, for instance, more than one year, a
special care mentioned below should be taken except for the above-stated storage environment and status.
1) When a long period storage is anticipated, store the devices either in the waterproof packing or by
putting silica gel into the airtight container.
2) In the case that the devices are stored for a long time (1 year or longer) even in the normal storage
environment, it is necessary to check solderability and lead rusting before using them. Before mounting
devices, be sure to check solderability of the devices. In addition, check the electrical characteristics of
the devices, as required.
3) Store them where they are not subjected to mechanical stress like vibration or shock.
4) Store them where they are not exposed to radiant ray, static electricity and strong magnetic field.
d) Precautions on storage of chips and wafers
Semiconductor chips and wafers should be controlled more carefully than for packaged devices. When leaving
or storing chips or wafers at a place, you should carefully handle the chips or wafers so that they are not
directly exposed to the air.
1) Chips or wafers are stored in the specified containers. After storage in a container, the container should
not be opened unless absolutely necessary. A sealed structure is normally adopted for containers
specified for storage of chips so that chips or wafers can be protected from extremely high or low
temperature, humidity, and corrosive gas during storage, and also protected from vibration or shock
during transportation.
2) After you unseal a container, do not leave the chips or wafers as they are. This is because the chips or
wafers in the unsealed container may be oxidized or corroded due to change in the temperature or
humidity, corrosive gas, dust, chemicals or the like.
3) Store the chips or wafers under atmospheric conditions of 5°C to 30°C and relative humidity of 45%RH
to 75%RH. In addition, store the chips or wafers at a place where they cannot be affected by volatile
substances such as chemicals.
4) When you put chips into a container or take them out from the container, carefully handle the chips
using an appropriate method so that the chip surfaces do not receive a flaw.
5) For your reference, if you unseal a container, assemble the chips or wafers within 5 days.
During suspension of the chip/wafer assembly work, it is necessary to store the chips or wafers in dry
nitrogen. Note that chips or wafers can be stored 20 days in dry nitrogen, and 3 months in a sealed
container (only if the container remains continuously sealed).
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Precautions on Use of Semiconductor Devices
6.3.3
Precautions on transportation
In the transportation of the semiconductor devices, the packing should be made rightly and the packing boxes
are placed in the right direction and then handled according to the “Handle With Care” marks including “This
Side Up”, “Fragile” and “No wetting”, etc (See Figure 6.3).
Figure 6.3
Example of Outer Packing
Especially special care should be taken to reduce mechanical vibration or shock.
In the case that you want to transport the semiconductor devices in the form of unit or subsystem where
devices are built in, take care of the following points:
1) Use the container or the tool that are free from producing electrostatic charge during transportation.
2) Pay attention to lower mechanical vibration or shock as much as possible during transportation.
3) Be careful to avoid direct sunlight.
4) Be careful of temperature rise during transportation.
5) When moving from low temperature to high temperature environments, the semiconductor devices are
likely to cause dew on the surface. Avoid a sudden temperature change.
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6.4
Precautions on Use of Semiconductor Devices
Precautions on Handling of Devices
6.4.1
Precautions on electrostatic breakdown
The ever-advancing MOS technology and fine patterning semiconductor process technology have allowed
us to achieve a quantum leap improvement of a semiconductor device including integrated circuit. On the
other hand, however, these devices are so vulnerable to over-voltage like static electricity that their functions
can be easily damaged. To secure reliability, therefore, it is deadly needed to establish a standard handling and
assessment method through an analysis of static-driven degradation and breakdown along with its mechanism.
The semiconductor manufacturers are quite active to establish a protective measure, for example, by
building a lower withstand voltage junction diode or a diode of forward operation to an external static
potential in parallel or adding a resistor by diffusion layer. These protective circuits are characteristics of
absorbing external static electric energy so that they can function to protect a weak gate oxide film. On the
other hand, however, these parallel-set elements have an effect on operating characteristics and results in
sacrifice of high density that is an advantage of MOS IC.
Anti-static measure concerning the device application is left to the customer side in a full consideration of
the above-mentioned restrictions. If you leave untouched these static stresses devices are subjected to during
system or set production processes ranging from device shipment, transportation, set assembly line to a
device mounting on the end product, the problem will be escalated to a level that goes far beyond a
countermeasure conceivable for a semiconductor device.
Meanwhile, electrostatic stress can be kept at a lower level in a relatively simple method. In fact,
semiconductor manufacturers normally specify the precaution items for the devices that likely cause
electrostatic breakdown, so that they can distribute the manual to the customers.
a) Anti-static measures
Most important is to be cautious not to cause any electrostatic discharge or ESD. As a matter of fact, however,
there are so many changes of producing ESD in our daily life depending on conditions or environments such
as set materials, packing materials, humidity, working jacket, etc. Shown on Table 6.4 are the precaution
items on handling recommended by MOS device manufacturers. If you observe these rules, you can keep the
ESD stress lower in a relatively easy way.
T04007EE-6 2011.3 6-15
6
Precautions on Use of Semiconductor Devices
Table 6.4
Table of Precautions on Handling
1. Keep the device at the same potential during storage and
transportation.
14. Pack the semiconductor devices into a conductive
container. Use a metal carrying box.
2. Use cotton clothes. Choose the cotton gloves and refrain
from using the nylon or wool ones.
15. Don’t plug in or out an IC with supply voltage applied.
3. Keep a plastic surface from being exposed to the air flow.
4. Use the earthed and conductive material for the top panel
of a chair.
16. Don’t apply signal to the input with power OFF.
17. Don’t input higher voltage than supplied one.
18. Keep potential as same as earth if you have not earth at repairing.
5. Monitor induced voltage when switching on measuring
equipment or relay.
19. Earth an input pin if it is not used.
6. Use a earth-band through a resistor.
21. Don’t plug pins wrongly.
7. Pack MOS devices one by one.
22. Check that a metal case is earthed.
8. Short-circuit the pins of MOS device.
23. Don’t touch directly the lead frames of IC.
9. Earth measuring instruments, soldering irons, jigs and tools.
20. Don’t exceed the absolute maximum ratings.
24. Don’t use a tester.
10. Keep humidity more than 50%.
25. Solder fast.
11. Short-circuit the pins of printed wiring board.
26. Check no short-circuits between pins occur.
12. Blow an ionized air when it is impossible to earth.
27. Be careful of discharging of capacitors.
13. Avoid flooring that would likely cause ESD.
28. Keep all unused pins’ potential to be VSS and VDD.
b) Precautions on transportation
Refrain from using vinyl sacks and polystyrene for product packing, but instead use a conductive sponge
or anti-static magazine. Likewise, keep devices neatly arranged in the magazine so that any gap between
devices would not cause them to move and rub each other inside the magazine. Antistatic agent-contained or
-coated magazine or conductive sponge does not always promise ever-lasting anti-static effectiveness.
Therefore, reuse of it is not recommended. It is also necessary to handle the printed wiring board so as to keep
its electrodes same potential. So, keep short bar or aluminum foil to be same potential. It is also recommended
to use the conductive carrying box because abrasion between devices and box during transportation would
make the box charged with static electricity.
c) Workshop environment
The higher humidity leads to the less static and vice versa, that is, the lower humidity leads to the more static.
This results from the phenomenon that humidity rise activates conductivity on the object surface and electric
charge leaks from the surface without being accumulated on the object. Figure 6.4 shows a model of
relationship between humidity and electrostatic voltage. As shown in the figure, the downward humidity
from a point of 45% to 50%, a charged voltage is going upward sharply.
In the Figure 6.5, the transition of IC failure ratio is shown by month. You might see that the failure caused
by ESD occurs most frequently in the dry season (winter season). In this respect, it is desirable to perform
humidity control by, for example, installing a humidifier, or if necessary installing an ionizer at the gasflowing places of high-pressure gas or blower as a concrete countermeasure in the workshop.
T04007EE-6 2011.3 6-16
6
Precautions on Use of Semiconductor Devices
Charged voltage (kV)
10
Silicone rubber matt
8
6
4
Dacron working
jacket
2
Threshold where human
body can feel shock
0
20
40
60
80
100
Relative humidity (%)
Figure 6.4
Relationship between Relative Humidity and Charged Voltage
Failure ratio facto
500
Pre-amplifier IC
Measure: Only applying a diode
Pre-amplifier IC
Measure: Diode and improved IC
Pre-amplifier IC
400
Other ICs
300
First phase
Second
phase
Measure
Third
phase
200
Omitted
hereinafter
100
0
5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6
Calendar month
Figure 6.5
Roadmap of IC Failure Ratio
d) Other general anti-static measures
1) Ground the workbench by attaching a semi-conductive sheet.
2) During component mounting process, ensure that the semiconductor devices are the last of the components
to be mounted. (Especially for MOS ICs).
3) Select the less electrostatic materials for jigs and tools.
4) Ground operators using earth bands. (Insert a protective resistor to prevent electric shock.)
5) Hold without touching the leads.
6) Workers need to touch the anti-static workbench with their hands before working.
(The example of electrostatic measurements in the production workshop is shown on Table 6.5.)
T04007EE-6 2011.3 6-17
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Precautions on Use of Semiconductor Devices
Table 6.5
Electrostatic Measurement Example in the Production Workshop
General value
Highest value
12,000 V
39,000 V
4,000 V
13,000 V
Person who works at the bench
500 V
3,000 V
16-pin DIP inside a plastic box
3,500 V
12,000 V
500 V
3,000 V
Person who walks on the carpet
Person who walks on vinyl or tile floor
16-pin DIP inside the plastic carrying tube
e) Human body protection
Human body grounding method of using an earth band is an effective means against a static breakdown.
However, if a worker gets an electric shock, his or her body is exposed to danger. Therefore, a full care should
be taken for selection of a resistor which to be inserted in series between body and ground. If a resistance
value is too high, the body will lose grounding effect and if too small, the body is subjected to a large current
when getting electric shock. In this respect, JEITA specifies the resistance as 250 k Ohm to 1 M Ohm.
6.4.2
Precautions on incoming inspection (or measurement)
When removing the semiconductor devices from a carrying container for measurement or inspection including
incoming inspection, reliability test, adjustment inspection, etc., a special care need to be taken for the
following items:
1) On measurement: Arrange surge voltage prevention from a measuring instrument and no short-circuit
between erroneously connected pins.
Don’t forget to ground equipment, conveyors, work-bench, floor mat, tools, soldering iron or stick, etc.
Care should be taken regarding possible circuit operation error or device breakdown due to noise
oscillation coming from added capacitance of probes or measuring instruments connected.
When inserting a capacitor onto a measuring board to prevent noises, the accumulated electric charge of
a capacitor is likely to cause a device to be broken. It is necessary, therefore, to proactively discharge the
capacitor thoroughly.
2) Human body: It is preferable to avoid the use of chemical textile like nylon for working jackets, but
choose the anti-static materials. An earth band should be attached to the human body so that static
electricity can go out. At this time, attention should be paid to both anti-static measure and human body
protection at the same time. In this respect, insert a resistor of 250 k Ohm to 1 M Ohm between the earth
band attached to the body and the earth.
3) Storage and transportation: Use the container, jig and tool that are free from electric charge.
4) Handling method: Keep the frequency of handling the same device as few as possible.
T04007EE-6 2011.3 6-18
6
6.5
Precautions on Use of Semiconductor Devices
Precautions on Mounting
Package mounting methods can be broadly classified into two methods. One is the flow solder mounting
method, and the other is the reflow solder mounting method. In this section, the reflow soldering mounting
method for mounting surface mount type packages will be explained.
6.5.1
6.5.1.1
Selection of mounting materials
Printed wiring board design
1) Desirable conditions for printed wiring boards
Since surface mounting is high density and the semiconductor device bodies as well as the printed wiring board
will be directly subjected to high stress during the processes, printed wiring boards which will minimize the
load transferred from the printed wiring board to the semiconductor device bodies as much as possible should
be selected.
Printed wiring boards with higher performance than in the past for characteristics such as heat resistance,
moisture resistance, dimensional change ratio, warpage, dimensional accuracy, etc. are desired.
2) Warpage and heat for surface mounting
Among the various conditions mentioned in the previous paragraph, let’s consider the problems of warpage
and heat. In conventional mounting, the heat of soldering is blocked by the printed wiring board, so that the
semiconductor device body on the opposite side is not greatly affected. But in surface mounting, the semiconductor
device body is subjected to high temperatures, and directly receives heat stress. In addition, since the semiconductor
device body is adhered directly to the printed wiring board, warpage or shrinkage due to the soldering becomes
stress applied directly to the semiconductor device body or poles (See Figure 6.6).
[ Lead-through mounting ]
Printed wiring board
Solder
[ Surface mounting ]
Solder
Printed wiring board
Solder
Before soldering
Figure 6.6
Heat tempering
Cooling
Warpage and Heat During Surface Mounting
T04007EE-6 2011.3 6-19
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Precautions on Use of Semiconductor Devices
3) Printed wiring board selection
The important point for surface mounting is to greatly minimize the stress due to this heat and warpage.
In order to do so, printed wiring board material which has the minimum possible dimension change ratio or
warpage due to external stress is desirable. Figure 6.7 shows comparison data for glass epoxy material and
paper phenol material commonly used in consumer products.
Although it would be ideal to use 1.6 mm-thick glass epoxy material, its high cost cannot be avoided, and
actually paper phenol material is widely used. In this case, consideration must be given to greatly minimizing
the heat stress and reducing printed wiring board warpage during the mounting processes.
Dimensional change ratio (%)
Relationship between heating temperature and dimensional change
Paper phenol
3.0
2.0
Glass epoxy
1.0
30
50
70
90
110 130 150 170
Heating temperature (°C)
Relationship between external stress and warpage
Paper
material/phenol
resin; t=1.0mm
Force Warpage
Warpage (mm)
7
6
Glass
material/epoxy
resin; t=1.15mm
90 mm
5
Paper
material/phenol
resin; t=1.6mm
4
3
Glass
material/epoxy
resin; t=1.6mm
2
1
0
10
20
30
40
50
External stress (N)
Figure 6.7
Dimensional Change Ratio and Warpage for Printed Wiring Board Materials
T04007EE-6 2011.3 6-20
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Precautions on Use of Semiconductor Devices
4) Mounting density and package spacing
Since the main purpose for surface mounting is to achieve high-density mounting, fine patterns are also desired
in designing the printed wiring board. However, if the package spacing is too tight, incidences of solder
bridging will of course increase. Considering the three factors of the positioning accuracy of the mounting
equipment, dimensional variations in the printed wiring boards, and the external dimensions of the packages,
using a minimum spacing dimension of at least 0.3 mm is safer (See Figure 6.8).
0.3 mm
0.3 mm
0.3mm (Note)
0.3 mm
Note: Land dimension spacing is greater than 0.3 mm
Figure 6.8
Minimum Spacing Dimensions between Packages
5) Solder resist region
One point in soldering semiconductor devices is that the amount of solder on both sides be uniform. If there
is excessive solder on one side, there will be differences in the hardening time, resulting in stress toward the
side with more solder. It is necessary to use solder resist to separate the solder and keep the solder amounts
on uniform when attaching semiconductor devices or when semiconductor devices and lead-equipped
components use the same land.
6) Layout of semiconductor devices
Faults may occur due to how the semiconductor devices are laid out. In SOP type flow soldering, in order
to avoid insufficient solder wetting, it is better to arrange the leads so that they are parallel to the solder flow
(See Figure 6.9). When laying out semiconductor devices near easily bent sections of the printed wiring boards
or separation grooves, the devices should be laid out so that the received stress is uniform for both poles; in
other words, the effects of stress are reduced when the component poles are arranged perpendicular to the
separation grooves or bending line.
Component layout A
Direction of printed wiring board flow
Soldering faults are likely to occur.
Good example
Figure 6.9
Bad example
Semiconductor Device Layout
T04007EE-6 2011.3 6-21
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Precautions on Use of Semiconductor Devices
6.5.1.2
Selection of solder material
During selection, the following points should be considered.
1) Desired performance before reflow
(a) Has suitable viscosity for application
(b) Maintains the applied shape
(c) Good adhesive power to semiconductor devices or their leads
(d) Minimal change in adhesive characteristics over time
2) Desired performance during/after reflow
(a) Good soldering characteristics
(b) Low incidence of solder balls
(c) Composition which inhibits increases in temperature
3) Cleaning characteristics
The flux in the solder should be a non-halogen flux which will enable cleaning of remaining flux without leaving
remnants and which will also not adversely affect reliability if some remnants do remain.
4) Environmental factors
Previously, virtually all solder was Sn-Pb solder, but since Pb is a hazardous hazardous substance, its use is
restricted. (2006, RoHS restrictions)
For lead-free solder (solder which contains no Pb), currently the following compositions are used.
Examples of lead-free solder:
Reflow system: Sn-Ag-Cu type, Sn-Ag-Bi-In type, Sn-Zn type, etc.
Flow system: Sn-Cu type, Sn-Ag-Cu type, etc.
(For reference) Semiconductor terminals: Pd plating, Sn-Bi plating, Sn-Ag-Bi dipping, etc.
When selecting lead-free solder, care should be taken to prevent the peak reflow temperature from becoming
high. Care must be taken since the ratio of crack occurrence in the semiconductor device packages will increase
if the peak temperature increases.
T04007EE-6 2011.3 6-22
6
6.5.1.3
Precautions on Use of Semiconductor Devices
Selection of adhesive
Adhesives can be broadly classified as UV-hardening acryl polyester materials and heat-hardening epoxy
materials, and there are various combined UV-/heat-hardening types. It is necessary to select the adhesive
according to production performance, such as the application method, viscosity, hardening temperature/time,
pot life, etc., but generally, the following points should be considered:
1) Quick hardening at as low a temperature as possible
2) No adverse effects on electronic components already mounted on the reverse side
3) High viscosity with superior heat resistance after hardening for the soldering process
4) Long pot life and easily stored
5) No stringiness during printing and little sagging after printing
6) Since some will remain even after soldering, no corrosiveness
6.5.1.4
Selection of cleaning agents
After soldering, washing off of flux is recommended. If flux remains, halogen ions in the flux may cause
corrosion of metal.
Due to environmental problems such as global warming due to the destruction of the ozone layer, the use
of flon 113, 1-1-1 trichloroethane, etc. is restricted, and there are shifts to the following cleaning agents:
1) Alcohol-based cleaning agents
Ethanol, methanol, isopropyl alcohol (IPA), high-grade alcohol-based cleaning agents
2) HCFC substitute flon-based agents
AK-225AES (Asahi Glass) etc. Since the use of HCFC substitutes will become prohibited in the future,
sufficient consideration must be given.
3) No cleaning through the use of non-halogen flux
When using no-wash flux, since it contains virtually no halogens which may cause corrosion, there is virtually
no risk of residue causing fatal flaws in devices. However, residue may cause leakage between pins, resulting
in device operation malfunction or damage.
In addition, since there are also products which contain much non-ionic halogenated materials, caution is
necessary. Be sure to perform evaluation of the reliability characteristics of each mounting method, and verify
whether or not washing can be performed.
T04007EE-6 2011.3 6-23
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Precautions on Use of Semiconductor Devices
6.5.2
Processes prior to mounting
6.5.2.1
Lead shaping/cutting process
Before mounting semiconductor devices on the printed wiring board, the external leads must be bent, shaped,
and/or cut. During this process, if stress is applied to the device body, damage such as leads breaking off or
disconnection of internal wiring may occur, which reduces reliability. In particular, there may be large effects
on the seal characteristics of the border between the external leads and the package for hermetically sealed
types or on the moisture resistance for plastic sealed types. Although no problems may occur at that point,
the service life may be reduced. Therefore, care should be given to the following points during lead processing:
1) When bending external leads, fix the base of the lead in place before bending the lead so that no stress is
applied to the device body (See Figure 6.10).
2) Bend the leads at a distance of at least 2.5 mm from the base of the lead. Also, keep the bend angle to
within 90 degree and make the bend radius at least 0.75 mm. In addition, do not bend the leads toward
their thicker side (See Figure 6.11).
3) The pulling stress along the axis of the lead wires and the bending strength are specified according to the
lead diameter or cross-sectional area. Do not apply loads which exceed these specified values.
4) Depending on the shape of the forming jig, the jig may cause damage to the plating surface on lead wires,
reducing reliability. Be careful when using such jigs.
2.5 mm
Plastic
resin
section
Figure 6.10
Bending External Leads
T04007EE-6 2011.3 6-24
2.5 mm
Figure 6.11
External Lead Bending Positions
6
6.5.2.2
Precautions on Use of Semiconductor Devices
Precautions with moistureproof packaged products
1) Do not open moistureproof packages until just before mounting. After opening, use the enclosed
products as soon as possible.
2) Keep the temperature and humidity of the storage location before the package is opened to within the
range of Ta = 5°C to 30°C and 30%RH to 70%RH (For image sensors, Ta = 0°C to 30°C). The storage
period in the moistureproof package is 1 year from the date of shipment from our company.
3) After opening the moistureproof package, in order to prevent condensation, moisture absorption by
package, and oxidation of leads, store the products at Ta = 5°C to 30°C and 30%RH to 70%RH (For image
sensors, Ta = 0°C to 30°C. For Hologram Units, Ta = 5°C to 35°C and 45%RH to 75%RH).
4) Some packages have a limited storage period after opening the moistureproof package. For information
on the storage period, refer to the product specifications.
5) After opening the moistureproof package, if the specified storage has been exceeded or if the indicator of
the dehumidifying agent at the time of opening the package has changed to pink, perform baking before
mounting. Baking conditions depend on the type of package and the packaging form.
The packaging material of taped products, however, is not heat resistant. For this reason, taped products
should not be subject to high-temperature baking without peeling off the tape. For details, refer to Sec.
“6.3.2 Precautions on storage”, or consult our company’s sales division.
6) Taping materials and stick materials are not heat-resistant. Therefore, perform mounting within the
specified time, or, if it is forecast in advance that the specified time will be exceeded, store the products
in a dry box or in a packaging environment equivalent to the moistureproof package (Temperature: Room
temperature; Relative humidity: 30% or less) or lower.
7) To prevent oxidation of the leads, perform baking only once.
6.5.2.3
Precautions when using semiconductor products
Please avoid impacts such as drops to the floor when the product is handled.
The radical material might crack and be lacked.
Further, be careful that strong mechanical stress is not applied to the package. For thin packages, since the
mold is thin, if strong stress is applied the package or elements may be damaged.
In addition, since electrostatic discharge damage, deterioration of solderability, corrosion between electrode
wiring, etc. may occur if products are touched with bare hands, be sure to be sufficiently careful when
handling products.
Read the following items and handle the products with caution.
◆ Static electricity may cause incidence of break down, dysfunction, or malfunction to the product.
◆ Rough handling such as scratching, cracking, or breaking the product may lead to dysfunction and malfunction.
◆ Handling the product with your bare hands or saliva or perspiration from human body may result malfunction
of the outer electrodes and wires.
◆ Environments containing high humidity, dust, or harmful gases (hydrogen chloride, sulfurous acid gas, or
hydrogen sulfide) may cause deterioration of the soldering characteristics of the external electrodes.
T04007EE-6 2011.3 6-25
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Precautions on Use of Semiconductor Devices
6.5.3
Mounting process
6.5.3.1
Mount
Since the thickness of surface mount packages is thin and they are very susceptible to force from above or
below, do not press against them excessively with the suction nozzle (chuck). If the lower dead point for the
suction nozzle is set incorrectly, it may result in problems such as deformation of the leads or cracking of the
chip. Even for packages of similar thickness and height, they may be slightly different depending on the
semiconductor manufacturer, etc. Perform settings while checking the product specifications.
6.5.3.2
Applying solder to printed wiring board (for reflow soldering)
1) Cream solder and application method
Methods for applying cream solder include screen printing, using dispensers, or using a metal mask. However,
along with the increasing complexity of solder application, the use of a metal mask has become more and more
common. Also, when selecting cream solder, select the appropriate one according to the application method
and circuit wiring density.
2) Precautions with using cream solder
(a) Perform suitable preheating depending on the substrate size, flux type, etc.
(b) Manage the land dimensions and solder resist printing accuracy. (To prevent defects, such as deviation
from the right position, check whether solder is uniformly applied to the electrode, etc.)
(c) Maintain the proper printing thickness for any lead pitch, lead width, pattern, etc. For details, refer to
Sec. “6.5.4.2 Precautions with LGA (C-CSP/L-CSP) and BGA packages”.
(d) Do not apply vibrations to the printed wiring board after mounting the semiconductor devices.
(e) Complete the reflow process within 5 to 7 hours (to prevent deterioration of the cream solder) after
applying solder
6.5.3.3
Soldering
1) Soldering method
Soldering of semiconductor devices can be broadly classified as flow soldering and reflow soldering. In
addition, reflow soldering can be further classified into full-body heating or partial heating.
◆ Flow soldering solders together with lead-equipped components in a single process, and is suitable for
mass production.
◆ Reflow soldering enables high-accuracy soldering through the use of cream solder, but care must be taken
with the infrared radiation system for temperature control. In addition, to overcome the faults of the infrared
radiation system, recently the system combining the infrared radiation system and hot air flow and the hot
air flow system only have been mainstream. We recommend these systems.
◆ Using a laser beam or light beam causes little thermal stress and enables precise soldering, making it suitable
for multi-pin LSI mounting (See Table 6.6).
T04007EE-6 2011.3 6-26
6
Table 6.6
Precautions on Use of Semiconductor Devices
Soldering Methods for Semiconductor Devices
Evaluation
Method
Heat source
Features
Productivity
Flow
Full-body
heating
reflow
Wave solder
Enables soldering with lead-equipped
components in a single process
Infrared
radiation
Heating of entire body with
beam radiation
Soldering
accuracy
Temperature
accuracy
Thermal
stress
Infrared radiation Temperature control is
and hot air flow relatively easier.
VPS
Uniform steam heating to 215°C
Hotplate
Heat conductance reduces stress.
Partial heating Laser/
reflow
light beam
High-accuracy spot heating
2) Soldering temperature profile
Since surface mounting applies drastic temperature variations directly to the bodies of semiconductor
devices, sufficient care must be taken with temperature control, especially for solder.
In flow soldering, a maximum temperature of 260°C for 3 to 5 seconds is common. The soldering time for
the doublewave method is the sum of the two waves.
In reflow soldering, the optimum temperature should be set considering the mounting condition. If there are
large and small components are mixed, the mounting temperature should be set particularly carefully. For
example, considering a lead pin with a large heat capacity, the optimum temperature should be set for each
component so that all the components can be soldered properly. While checking whether there is an SMD
with a small heat capacity on the same board, carefully set the temperature so that the package surface
temperature cannot exceed the recommended range. Note that even if the temperature of the solder joint area
rises to the soldering possible point, the temperature of a large package main body may still be low because
of its large heat capacity.
Examples of soldering temperature profiles are shown in Figure 6.12. Also, please check with the sales
division of our company as to whether or not the semiconductor device you are investigating is compatible
260°C max.
255°C
170°C
60s to 120s
Time
(a) Hot air flow or infrared radiation reflow soldering
(Products with Pb-free solder)
10s max.
2°C/s to 5°C/s
240°C max.
235°C
150°C
60s to 120s
Time
(b) Hot air flow or infrared radiation reflow soldering
(Products with Pb solder)
Figure 6.12
Package surface temperature
10s max.
Package surface temperature
Package surface temperature
with Pb-free solder.
20s max.
215°C max.
150°C
60s to 120s
Time
(c) Vapor phase reflow
Examples of Soldering Conditions
T04007EE-6 2011.3 6-27
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Precautions on Use of Semiconductor Devices
3) Common recommended conditions for soldering
Recommended conditions for soldering semiconductor devices vary according to each semiconductor device.
In our company, we carry out soldering heat resistance tests in accordance with the JEITA standard so that
we can ensure the soldering heat resistance of semiconductor devices. Regarding the large packages with a large
heat capacity, JEITA specifies the soldering temperature for each package volume and thickness. This is
because as a package is enlarged, the package has a larger heat capacity and the package main body cannot be
easily heated.
For details of the test method, refer to Table 2.8 shown in Sec. “2.2.3 Reliability test method”.
The heat resistance of devices depends on the product. For details, refer to the delivery specifications.
Table 6.7, however, shows the recommended soldering conditions for mounting standard devices. Note that
Table 6.7 does not show the solderability guarantee temperatures, but only shows the heat resistant
temperatures of devices.
Table 6.7
Standard Recommended Soldering Conditions for Mounting
Soldering method
6.5.3.4
Flow soldering
Soldering iron
260°C max.
260°C max.
350°C max.
255°C or more,
within 10 sec
Single: Within 5 sec
Double: Within 10 sec
Within 3 sec
Temperature
150°C to 180°C
⎯
⎯
Time
60s to 120s
⎯
⎯
Recommended Temperature
soldering
Time
conditions
Preheating
before
soldering
Reflow soldering
(for Pb-free
compatible products)
Multiple cycle reflow
There are some products for which multiple cycle reflow cannot be recommended. Since it is different for
each product, when using the product, check the receiving specifications or consult our company’s sales
division.
6.5.3.5
Cleaning
1) Since flux remaining on printed wiring boards on which semiconductor devices have been installed is not
desirable in terms of moisture resistance and corrosion resistance, it is recommended that cleaning be
performed.
2) When performing cleaning using ultrasound, if the output is set too high, the strength of external
electrodes may be reduced or problems due to resonance may occur. Be careful so that these do not occur
(See Table 6.8).
3) Worrying about cleaning is not necessary for rosin flux in which the amount of chlorine is low.
4) Flon-based agents or chlorine-based agents cannot be recommended from an environmental aspect.
T04007EE-6 2011.3 6-28
6
Table 6.8
Precautions on Use of Semiconductor Devices
Example of Ultrasound Cleaning Conditions
Frequency: 28 kHz to 29 kHz (no resonance with devices)
Ultrasound output: 15 W/
Vibration source shall not directly touch the devices or the printed wiring board.
Time: 30s or less
5) The petroleum solvent may cause degradation of adhesive between hologram lens and package. Therefore,
the use of these solvents should be avoided.
In addition, ultrasonic cleaning should be avoided because this hologram is a hollow device, and also
please pay attention to brushing the surface of hologram lens not to damage the surface.
6.5.4
6.5.4.1
Precautions with special packages
Precautions with power device packages
Power loss at the connections during operation of the device is always accompanied by an increase in
temperature. Since it is necessary that the connection temperature be below the rated maximum temperature
during use, how much of a margin to provide for use is an important point in designing system reliability.
Particularly for power devices, since the cases in which they are used at temperatures close to the rated
temperatures due to large power losses, suitable heat sink designs are important. In order to reduce the
increase in heat, heat sinks are attached. At this time, since the dimensional accuracy of the attached parts and
the attachment method have a great influence on thermal characteristics and mechanical stress, which can
cause malfunctions or reduced service life, sufficient care must be taken regarding the following points:
1) Thermal grease
Since the use of thermal greases when attaching the heat sink to the power transistor can reduce the contact
thermal resistance to the levels of Rth (j-c) shown in Table 6.9, it is often used. For metal-sealed devices, this
was not a problem but for plastic-sealed power transistors, it is necessary to use care when selecting the
thermal grease to use.
Table 6.9
Examples of Contact Thermal Resistance and Insulation Plate Thermal Resistance
Shape
Presence/absence
of insulation plate
Rth(c-f) (°C/W)
Grease applied Grease not applied
0.5

Mica (100 µm)

No insulation plate
0.4
Mica (100 µm)
TO-220
Full pack
TOP-3
Full pack
TO-126
TO-220
(SC-46)
1.0

3.0

6.0

1.7


2.3

5.0
No insulation plate

2.3

4.5
No insulation plate

0.6

1.5
No insulation plate
T04007EE-6 2011.3 6-29
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Precautions on Use of Semiconductor Devices
If a highly oil-separated grease is used, the stress of the power cycle, etc. may result in faults such as partially
disconnected wires after a relatively short time. The reason for this is that the silicon oil which forms the base
oil of thermal grease separates out and penetrates into the inside of the transistor through gaps between the
plastic resin and the fins or lead frame, and swells the junction coating resin (JCR), increasing the stress on the
connection base of the Al or Au electrode lead wires and causing them to be disconnected.
Because of this, it is necessary to select a thermal grease which has low oil separation and which is based
on silicon oil which does not swell JCR easily. For example, G-746 (Shin-Etsu Chemical Co., Ltd.) and
YG-6260 (Toshiba Silicone Co., Ltd.) are recommended.
2) Mounting heat sink of package
When attaching the heat sink of power packages to the chassis, etc., attention should be paid to the tightening
torque of the attaching bolts and to the flatness of the attachment surface.
Do not bend, cut deform, or bend the mounting pins of the heat sink. Also, avoid applying solder directly
to the heat sink.
When attaching the heat sink, since if the mounting brackets or positioning tabs (projections) are in contact
with the plastic areas of the product, cracks may occur and mechanical stress may be applied internally,
resulting in element breakage or disconnection faults, care must be taken with the attachment methods.
Regarding the hole diameter of the attachment surface, it should be determined taking into consideration the
screw head diameter and the overlapping of insulation tubes, insulation plates, etc.
[ Tightening torque ]
If the tightening torque is too low, the heat resistance will be high, and the heat emission effectiveness will
be poor. On the other hand, if the torque is too high, it may cause warpage of elements or apply stress to the
semiconductor chips inside the package, causing element breakage or disconnection.
Since the recommended tightening torque, mounting hardware etc. are different for each package, refer to
the product specifications or contact our company’s sales division.
Further, when tightening at two or more points, be careful to tighten all points equally so that no warpage
is applied to the elements.
[ Flatness ]
The purpose of attaching power transistors to the chassis, etc. is to enable the efficient transfer of the heat
generated by the elements to the heat sink. In order to achieve this, the attachment surface of the transistor
must be sufficiently smooth. If the surface roughness is high, or if there are burrs or metal chips, dirt, or other
foreign materials stuck to the surface, not only will the heat sink be damaged, but the elements may also be
damaged. Therefore, be sure to keep the surface flatness to 0.05 mm or less and the surface twist to 20 μm or
less.
When the mounting plate such as a chassis is a pressed plate, be sure that there is no press burrs or bending,
and be sure to smooth the surface of the screw holes. In addition, since if gaps occur between the product and
the attachment surface, heat emission efficiency may be poor, when attaching the heat sink, be sure to check
that the mounting plate or the product are not deformed.
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Precautions on Use of Semiconductor Devices
3) Attaching to the printed wiring board
Do not attach heat sinks to the elements after soldering lead wires to the printed wiring board. Attaching
heat sinks to the elements after soldering the leads to the printed wiring board will cause excessive stress due
to variations in the lead wire length, heat sink, printed wiring board, etc. to be concentrated in the lead wires,
causing damage to the lead wires such as pulling them out, disconnecting them, etc.
Processes should be carried out in the following order:
Attachment of heat sink to power transistor → Attachment of heat sink to printed wiring board → Soldering
of power transistor to printed wiring board
6.5.4.2
Precautions with LGA (C-CSP/L-CSP) and BGA packages
1) Rules for printed wiring board design
Recommended rules for printed wiring board design applicable to LGA (Land Grid Array) (C-CSP: Ceramic
Chip Size Package; L-CSP: Leadframe CSP) and BGA (Ball Grid Array) are shown in Figure 6.13.
For land pitch of 1.0 mm
(Land diameter: φ0.6 mm)
Land
φ0.5 mm
For land pitch of 0.8 mm
(Land diameter: φ0.5 mm)
Land
φ0.4 mm
Resist hole diameter
φ0.6 mm
P = 1.0 mm
Resist hole diameter
φ0.5 mm
P = 0.8 mm
Figure 6.13
Printed Wiring Board Design Rules
2) Metal masks
The following specifications are recommended for metal masks (See Figure 6.14)
(a) Manufacturing method: Full additive
(b) Metal thickness A: 0.12 mm to 0.15 mm
(c) Opening diameter B: φ0.6 mm to 1.0 mm pitch (CSP land diameter: φ0.6 mm)
φ0.5 mm to 0.8 mm pitch (CSP land diameter: φ0.5 mm)
B
A
Figure 6.14
Metal Mask Specifications
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Precautions on Use of Semiconductor Devices
3) Cream solder
The following points should be considered when selecting the solder paste:
(a) Composition
Select a lead-free solder.
(b) Grain size
Printing characteristics are good for grain sizes of 20 μm to 50 μm
(c) Viscosity
There are no particular specifications, but focus should be placed on characteristics such as sagging
after printing, the capability to print repeatedly, etc.
(d) Other
Be careful of the creation of solder balls after reflow.
4) Reflow
For reflow soldering, it is necessary to set the individual optimum temperature conditions according to the
mounting conditions. At our company, we recommend mounting by hot air flow reflow, but infrared radiation
systems can also be used without problems.
However, as described before, if there are large and small components that should be mounted on the same
board, the temperature should be set particularly carefully. For example, considering an SMD with a small
heat capacity, carefully set the temperature so that the package surface temperature cannot exceed the
recommended conditions. For details, refer to Sec. “6.5.3.3 Soldering”. The recommended temperature
profile is shown in Figure 6.15. For details, refer to the product specifications.
10s max.
Temperature (°C)
260
150°C to 180°C
60s to 120s
Time (s)
Figure 6.15
Reflow Temperature Profile
5) Storage
Environments containing high humidity, dust, or harmful gases (hydrochlorides, sulfuric acid gases,
hydrosulfides) may cause deterioration of the soldering characteristics of the external electrodes. Avoid
storage in areas subject to high temperatures and humidity.
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Precautions on Use of Semiconductor Devices
6) Repairs
After mounting, if repairs are necessary, remove the package using hot air, etc. and mount the replacement
device. However, if it is necessary to analyze the removed device, be careful not to heat the device extremely.
This is because it is difficult to analyze the device if it is extremely heated. It is recommended that the device
should be locally heated after baking. Please consult our company’s sales division regarding repair methods
(See Figure 6.16).
Repair procedure
Hot air
Device removal
Printed wiring board with device already mounted.
Printed wiring board
Solder removal
Printed wiring board
Mounting of repair device
Repair device
Printed wiring board
Reflow
Hot air
Printed wiring board
Figure 6.16
6.5.4.3
Repair Method
Precautions with TCP (Tape Carrier Packages)
1) TCP storage
The following storage specifications are recommended for TCPs. However, they may vary somewhat
according to the product. For details, refer to the receiving specifications for each product (See Table 6.10).
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Precautions on Use of Semiconductor Devices
Table 6.10
6.5.4.4
TCP Storage Specifications
Packing condition
Storage environment
Storage period
Before opening seal
Avoid high temperatures and
high humidity.
Store in a cool, dark place.
6 months
After opening seal
Avoid high temperatures and
high humidity.
Store in a cool, dark place.
Store in a nitrous environment.
1 month
Precautions with image sensors packages
1) Precautions with soldering
◆ Unlike general SMD-type semiconductors, reflow mounting of image sensors cannot be guaranteed.
◆ Do not dip solder or reflow solder.
◆ Solder devices with a solder iron.
Table 6.11
Recommended Conditions for Manual Soldering
1/6 package
350°C, 2 sec.
Other packages
370°C, 2 sec.
◆ The temperature applied to the seal between the cover glass and package should be kept to 80°C or lower.
In addition, be sure that the tip of the soldering iron does not touch the package. To reduce the temperature
of the glass seal area, please solder the GND terminal first. Thereafter, as long as the glass seal area does not
exceed 80°C, soldering can be performed in any order.
◆ Limit temperatures for each image sensors section
The limit temperatures for each section are as follows from reference to the physical limitations of the
composite materials.
Table 6.12
Limit Temperatures for Each Image Sensors Section
Limit
temperature
Damage when limit
temperature is exceeded
Image sensors
element area
170°C
Deterioration of on-chip filter/lens material
Glass seal area
80°C
Deterioration of glass seal material
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Precautions on Use of Semiconductor Devices
2) Precautions with resoldering
◆ When resoldering a image sensor which has been removed once, there is a risk of package breakage, so extra
care should be used.
◆ When manually fixing the image sensor mounting area or removing the image sensor, be sure to leave
sufficient cooling time when performing work to keep each section below the temperatures listed in Table
6.12.
When using automatic soldering equipment, be sure to use temperature control and electrostatic discharge
countermeasures. In addition, to prevent surges from the vacuum pump motor, etc., be sure to connect the
equipment to ground.
3) Precautions with package breakage
In order to avoid package breakage, be careful of the following:
◆ Since the image sensor package has a hollow construction and plastic and ceramic materials are used, be sure
not to drop it or subject it to impact.
In particular, when the outer leads are fixed in place in a socket or on a wiring board, even smaller shocks
than for the package alone may cause breakage.
◆ When mounting, be sure not to apply stress to the roots of the image sensor outer lead areas. If stress is
applied to the outer lead areas, cracks may occur in the connected root of the leads.
◆ When attaching the image sensor to a wiring board, use a mounting method which avoids warping the
package. If the package is slightly warped and is sandwiched between hard wiring boards, etc., the package
may be broken.
4) Precautions with attaching position control plates to the bottom surface of the package
◆ Mold-release agents, organic solvents, etc. may be adhered to the bottom surface of the package. When
gluing the position control plate to the bottom surface of the package, the adhesion strength may be
reduced, depending on the components and hardening conditions of the adhesive used. The adhesive
strength should be evaluated as part of your purchasing investigations.
◆ If the materials used in the adhesive, position control plate, etc. are changed, the adhesive strength should
be evaluated. Please carry out careful investigations when selecting adhesives, etc.
6.5.4.5
Precautions with QFN packages
◆ When forming the pattern on the package mounting area of the printed wiring board, since the lead frame
which is electrically connected to the chip GND is exposed at the package corner, be very careful of leak
shorts with the wiring pattern.
◆ Since structurally the soldering connection area of QFN packages on the terminal side is small and the flat
section of the bottom surface of the solder terminal becomes the main connection point, be careful of
scratches or dirt on the terminals.
T04007EE-6 2011.3 6-35
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Precautions on Use of Semiconductor Devices
6.5.4.6
Precautions with hologram unit packages
1) Heat sink design of LDHU
The higher temperature rises, the shorter the life of semiconductor laser becomes, therefore, proper heat sink
designing is necessary. It is recommended to use thermal interface sheet or Si rubber as a heat sink material if
there is the heat sink part on the back of LDHU/LDU package.
Our verification of sealing performance is that there is no penetrating by red-ink check in 10 minutes, but
the heat sink part of LDHU/LDU is not completely sealed. When Si grease is used as a heat sink material,
there is the possibility of the characteristic degradation by penetrating of Si grease from heat sink part,
because heat isolates oil component of Si grease, and which can make Si grease penetrate the inside of package.
When Si grease adheres to hologram lens part, which may also cause solvent cracks.
Please consult our company's sales division as to the evaluation method for heat sink effect (heat resistance)
etc..
2) Precautions with soldering
Since a particular plastic is used for package and hologram lens of LDHU/LDU, please give attention to rising
temperature by heating in soldering. Adhesive temperature should be less than the recommended mounting
temperature profile specified in the product specifications, because when the temperature becomes higher,
the joint strength between hologram lens/glass and package weakens rapidly.
It is recommended to solder only one side of lead part (terminal) at short times (after heating one side with
solder iron or laser beam etc. and cooling down, please heat another side). Heating the both sides of lead part
at once or full heating method like re-flow should be avoided. In addition, it is recommended to radiate heat by
putting heat sink on the package, because the package temperature becomes higher due to heat conduction and
heat radiation, even when the lead part is heated.
Please note that when LDHU/LDU is exposed to mechanical stress like vibration etc. at high temperature
in or just after soldering, the stress can affect hologram lens/glass, and LDHU/LDU characteristic may change.
Figure 6.17 shows the mounting temperature profile. Figure 6.18 shows an adhesive temperature
Adhesive temperature
measurement points.
Maximum
temperature
(Thermocouple: Type K, 0.1 mm in diameter)
Heating
temperature/
time
(These are
specified for
each product.)
Lens
Soldering
iron
Outline Drawing of
Temperature Measurement Method
Time
Figure 6.17
Mounting Temperature Profile
Figure 6.18
Adhesive Temperature
Measurement Points
T04007EE-6 2011.3 6-36
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Precautions on Use of Semiconductor Devices
3) Mechanical stress
Panasonic LDHU/LDU is designed thinner and smaller, therefore, the characteristic may be degraded by the
mechanical stress in mounting. Please pressurize on a lead part, but on the back of a package in soldering (at
high temperature).
When it is imperative to pressurize on the back of a package in soldering, point pressurizing should be
avoided. Please pressurize on a wider plane than a package and solder with a condition, less than 2.9N
(300gf).
For pressurizing on the back of a package at normal temperature, it is also required to pressurize on a wider
plane than a package instead of point pressurizing and less than 4.9N (500gf).
6.5.4.7
Precautions with built-in heat radiation board LQFP packages
(Package Code: LQFP256-P-2828, LQFP216-P-2424, LQFP208-P-2828)
1) Influence of mounting board warpage behavior when reflowing
Mounting board might warp widely because mounting board become low-profile and high density and reflow
temperature become high with the introduction of lead-free policy.
Warpage behavior of board when reflowing will be influenced by material and thickness of board and wiring
pattern. And this will lead not only simple warpage at whole board but also local warpage and swell at parts
mounting area.
Therefore, please examine the warpage evaluation of mounting board (especially at LQFP mounting area)
at high temperature atmosphere and its countermeasures for warpage when you use this product.
For the above-described packages, a heat radiation board is incorporated in the package structure so that
the thermal characteristic can be improved. So, the package flatness and the stand-off value may fluctuate
depending on the reflow mounting temperature profile, heat capacity of the component to be mounted, board
type, etc.
When you determine the mounting conditions, carefully check the temperature profile (mounting condition
of your company) obtained by the initial mounting evaluation and the package connection condition (wettability
of solder).
After reflow mounting, if there is great difference in the solder paste solidifying speed (if the solder paste
is already solidified enough in one area, but is still melted in another area), the leads of the non-solidified area
(still-melted area) may be lifted as shown in Figure 6.19. To prevent such a problem, reduce the solder cooling
speed (slowly cool the solder). Before starting mounting, carefully adjust the mounting conditions.
T04007EE-6 2011.3 6-37
6
Precautions on Use of Semiconductor Devices
Solder paste still in melted state
Solder paste already solidified
(a) Solder paste status during cooling (solidification)
Figure 6.19
(b) Result of experiment that simulated status (a)
Lifted leads due to great difference in solder paste solidifying speed
(solder paste already solidified in one area but still melted in another area)
6.5.4.8
Handling precautions
a) Precautions for LGA (C-CSP/L-CSP) and BGA (P-BGA)
1) Precautions regarding use conditions
Influence of light
The CSP type is highly affected by light because this semiconductor chip is an exposed type (front surface,
rear surface, side surface).
If a chip receives light from the outside, the chip may generate electromotive force due to the photoelectric
effect, and this may cause abnormal operation. When designing, be sure to check that external light cannot
reach any chips. At the inspection process and in practical use, also check that chips can be kept away
from light.
Influence of temperature and humidity
There are some devices whose electrode terminal is exposed to the outside. If such a type of device is stored
in extremely humid air or extremely dry air, or if such a type of device is stored for a long time, the electrode
surface may be oxidized, and the solderability may be deteriorated. Handle this type of device carefully.
Influence of vibration and other mechanical stresses
The CSP type semiconductor chip is an exposed type (front surface, rear surface, side surface). So, if
metallic tweezers are used carelessly, or if a chip falls to the floor or a shock is applied to a chip, the chip
may be chipped or broken.
There are some devices whose electrode terminal is exposed to the outside. If you directly touch such a
type of device with your bare hand, electrostatic damage may occur, solderability may be deteriorated,
or corrosion may occur between the electrode and the wire. In addition, if contaminant is transferred
from a contaminated jig or tool to a device, or if saliva or sweat of a human being touches a device, the
external electrode or the external wiring may be damaged.
The BGA type semiconductor device has solder balls on the rear terminal. If this type of device is
handled carelessly, balls may be removed, ball surfaces may be flawed or distorted, or the base material
may be broken or chipped. Even if devices are in a magazine or a tray, carefully handle the devices so that
devices cannot fall to the floor, and shocks or vibration cannot be applied to the devices.
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Precautions on Use of Semiconductor Devices
2) Precautions regarding mounting
Influence of vibration and other mechanical stresses
After mounting BGA or CSP on a board, carefully handle the board. For example, during the in-circuit
test, be careful not to apply a shock to the board. The board may warp greatly, and the product or the
soldered area may be broken.
The CSP type semiconductor chip is an exposed type (front surface, rear surface, side surface). If the
under-fill is used after mounting this type of chip, a stress may be generated due to difference in the
shapes or the wire expansion factors between the under-fill and the fillet. This stress may delaminate the
semiconductor chip from the re-wired layer, or break the semiconductor chip.
Influence of temperature and humidity
If heat stress is applied such as when removing products for repairs, etc., be careful not to overheat the
product. Do not reuse our product if it is once removed. We cannot guarantee the quality of such a product.
After mounting BGA or CSP, if you carry out double-surface mounting using the flow soldering method,
carefully check the temperature of the flow solder in the soldering bath. If the flow temperature is too
high, the printed wiring board may warp due to the heat applied from one side of the board, and the ball
electrodes of the mounted device may be delaminated from the warped board. In addition, if the balls are
melted again by the heat, more ball electrodes may be delaminated from the board. Figure 6.20 shows
the mechanism of delamination. Figure 6.21 shows an example (analysis photo of cross section) of
delamination caused by re-melting.
Ball electrode
Warp
BGA
Delamination caused by re-melting
Heat transmission
Warp
Printed wiring board
Flow soldering
Figure 6.20
Mechanism of Delamination
Delamination caused by re-melting
BGA
Ball electrode
Printed wiring board
Figure 6.21
Example of Delamination Caused By Re-melting (Cross Section Analysis Photo)
T04007EE-6 2011.3 6-39
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Precautions on Use of Semiconductor Devices
Inspection method after mounting
After mounting BGA or CSP, you cannot visually check a soldering error. It is, therefore, recommended
that the X-ray examination should be performed to check soldering errors.
While observing the above precautions, carefully handle our products.
For detailed precautions of product handling, refer to Sec. “6.2.2 Precautions on use environment” and
Sec. “6.5.2.3 Precautions when using semiconductor products”.
b) Precautions for TCP
◆ Since the substrates of TCP use polyimide film, this structure easily generates static electricity. When
handling products, be careful to use an ion blower and attach an earth strap so that charge does not build up
in the film.
c) Precautions for CCD image sensors
1) Cautions regarding the cover glass surface
Since the glass surface is cleaned thoroughly at the time of shipment of the image sensors, be extremely
careful of the following points so that the glass surface does not become scratched or dirty:
◆ Perform work in a clean environment such as a clean booth (Clean class: Around 1,000).
◆ Be careful not to touch the product directly, since touching the glass surface with your hands may
cause dirt, etc. to adhere. If dirt or stains are on the glass surface, use an air blower in a charge-free
environment to blow off the dirt or stains. For dirt adhering to the product due to static electricity, use
of an ionized air blower is recommended. However, when using an air blower on the image sensors, be
sure to connect all terminals to ground as a countermeasure against static electricity.
◆ For stains such as oily dirt, etc. which still cannot be removed, use a cleaning swab or lens-cleaning
paper soaked with isopropyl alcohol to wipe off the stain gently, being careful not to scratch the glass
surface. Further, even when using a soft cloth or swab, if the cloth or swab is dry, the cloth or swab
itself may generate dust, and that dust may scratch the glass.
◆ Do not subject the glass surface to strong impact or strong scratching. Doing so may cause impact
gouges, cracks, etc., and such damage or scratching may result in inferior characteristics.
◆ As a countermeasure against dirt or stains, it is necessary to store the products in the packing case.
◆ To prevent condensation, when transferring products between rooms with a drastic temperature
change, be careful in eliminating the temperature differences.
2) Cautions regarding storage environment
◆ Do not store products in areas where they will be subject to strong light or infrared radiation, such as
in direct sunlight. If strong light is incident on the image sensor for a long time, the transparency of the
filter or lens material will be reduced.
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Precautions on Use of Semiconductor Devices
3) Cautions regarding image sensors as optical elements
◆ Microlenses to focus the light on the photodiodes and color filters to discriminate color information
are integrated on-chip in the photoelectric converter section of the image sensor. Since the integrated
on-chip structure is formed of plastic, the transparency of the filter or lens material will decrease
depending on the intensity and wavelength of the light incident on the image sensor and the amount of
time the light is incident.
Because of this, be careful not to expose the image sensor to infrared radiation or sunlight even when
it is not being used (during storage, transportation, and manufacturing).
◆ When the same pattern is imaged for a long time, depending on the intensity of the incident light and
the exposed time, abnormalities such as burning in of the pattern on the image sensor pixels or harshness
may occur, regardless of whether or not power is being supplied to the image sensor.
When not using the image sensor, be sure to shade it from light and switch off the power.
◆ For image sensors, as time passes white marks may appear due to cosmic radiation. Please use whitemark compensation circuits to compensate for these white marks.
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