Handling and Operating
Epson's CMOS LSI devices are designed and manufactured to assure trouble-free operation when used under normal operating conditions. All products are subjected to stringent electrical and mechanical testing to ensure reliability, but users are strongly recommended to observe the following precautions when designing systems, handling or storing devices to minimize the chance of failure.
Handling and operating precautions
Use within the operating range
For circuits that use semiconductor products, design the circuit so that it operates within the recommended operating conditions. If the recommended operating conditions are exceeded, the specifications of the electrical characteristics of the semiconductor product cannot be guaranteed and reliability may be reduced. The absolute maximum rating is a standard that must not exceed even one item or even temporarily. Exceeding the absolute maximum rating even temporarily may result in product deterioration or physical damage. Therefore, design the circuit so that the absolute maximum rating is not exceeded even temporarily. For products that generate a large amount of heat even within the operating range (if stated in the product specifications), design a circuit that takes derating into consideration for voltage, current, power, and temperature.
Handling of input/output control pins
When a noise such as spark and electrostatic is given from an input or output terminals, IC may malfunction. Pay sufficient attention in product designing. Electromagnetic interference can cause ICs to operate erratically. Shield all interference sources in equipment that uses ICs.
Latch up phenomenon
Excessive electrical noise occurred to a power or input/output pin can cause ICs to latch up, resulting in device malfunction or damage. If this occurs, turn off the power, isolate the problem, then supply power again.
Protection against electrostatic discharge (ESD)
Although all pins are equipped with an anti-electro static circuit, electro static beyond the capacity may lead to breakage. Take appropriate countermeasures when handling ICs.
- Avoid using packing and transporting containers made of plastic. Use electrically conductive containers. Also, special care must be taken when handling ICs, by wearing a antistatic wrist strap or taking other possible measures.
- Use a soldering iron and test circuits without high voltage leakage with grounding.
Notes on storage
Storage condition
- Take care so that packages are not subjected to impact, vibration or water leakage.
- Do not store and use the product under conditions where moisture condensation may be formed due to rapid changes in temperature. Also, do not put load on products.
- When storing, avoid dusty locations or locations with corrosive gases.
- After a long period of storage, check to see that the pins are not discolored, solderability is not degraded, etc., before use.
- Check moisture-proof bags for tear or wear before use. Also check the silica gel in the bag has not absorbed moisture when the bag is opened.
- Storage conditions after opening a moisture proof-bag, soldering method and soldering temperature must meet the requirements specified by Epson for respective products.
Conditions of use environment
Precautions for use environment
Use the IC in the proper temperature and humidity. The humidity must be 85% or lower (to prevent dew condensation). In the environment where the IC is directly exposed to dust, salt, or acid gas such as SO2, it may cause electrical leakage between leads or corrosion. In order to prevent such problems, apply corrosion-proof coatings to printed circuit boards and ICs.
Protection against excessive physical stresses and rapid temperature change
Do not expose ICs to excessive mechanical vibration, repetitive shock stress, or rapid temperature changes. These can cause the plastic package resin to crack and/or the bonding wires to break.
Precautions Against the Light Irradiation
Exposing semiconductor products to the light may cause malfunction, as the light affects the device characteristics. To prevent products from malfunction, please take into account the following points regarding semiconductor mounted substrates and products.
- During product design and assembly, please consider the product structure so that the bare die is shielded from light in actual use.
- In the testing process, please provide the light-shielded environment for the bare die under test.
- Please consider shielding light from the surface, back, and sides of the bare die, as bare die should be shielded from light entirely.
Package products
Cautions on surface mount
Mechanical stress
Minimize mechanical stress to a printed circuit board during or after soldering.
Package leads
As for a surface mount device, the pattern on a board and the lead of a package are soldered surface to surface. Although we are shipping products securing sufficient lead flatness for soldering, when handling, take care not to apply force otherwise it may result in deformation of the lead.
Signal leads on the package surface
Some packages are structured to expose a portion of the signal leads on the surface. When using these products, pay sufficient attention not to let the package be soiled. Also, handling with bare hands must be avoided.
Soldering precautions
Use infrared or air reflow or the combination of these methods for soldering. Nitrogen reflow is recommended to inhibit the effects of oxidation and improve wettability.
Thermal stress to packages
Soldering process is recommended to be carried out in the shortest time at the lowest temperature to minimize thermal stress to packages. Settings of the soldering profile should be performed upon through confirmation that the state of soldering and reliability after soldering are optimized.
Solder reflow processing multiple times
If solder reflow is to be carried out multiple times, it should be performed within the allowable storage period specified as storage rank for each product. (Reflow is allowed twice.)
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Hand soldering
Maximum temperature of the soldering iron Time Times 350°C Within 5 sec per pin Twice of less Pay sufficient attention not to let a soldering iron contact any parts other than leads, such as a package body.
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Flow soldering
Flow soldering is not recommended.
Notes on storage
Moisture absorption and reliability
The resin used in surface-mount packages absorbs moisture over time even stored in room conditions. When IC packages are put into reflow ovens with much moisture absorption, the resin may have a crack or a delamination between the resin and lead frame may occur. Therefore, surface mount ICs must be kept under typical storage conditions shown below before reflow soldering.
Typical storage conditions and storage periods for (Surface-Mount) IC packages
Before opening the moisture-proof packaging
| Storage condition | Storage environments before opeing the bag | |
|---|---|---|
| Before opening sealed moisture proof bag | 30°C, 85％ RH or less | Within 12 months (1 year) |
After opening the moisture-proof packaging
Storage ranks and storage conditions
| Storage rank | Storage environments after opening the bag | |
|---|---|---|
| MSL2 | 30°C, 70% RH or less | Within 12 months (1 year) |
| MSL2a | 30°C, 70% RH or less | Within a month |
| MSL3 | 30°C, 70% RH or less | Within 168 hours (1 week) |
| MSL4 | 30°C, 70% RH or less | Within 72 hours (3 days) |
- Regarding the storage ranks of respective products (IC packages) after opening the moisture-proof bags, refer to the tables of storage ranks shown in 5-2 Package Lineup.
Surface-mount package baking conditions
When surface-mount IC packages before opening the moisture-proof package exceed the recommended storage periods, or their storage periods or storage conditions are unknown and therefore moisture absorption is a concern, it is recommended to dry-bake them before reflow soldering. This baking process will prevent the resin from cracking during soldering.When dry-baking, see below.
Standard baking conditions for IC packages
| Baking temperature | Baking hours | Max.Baking times |
|---|---|---|
| 125±5°C | From 20 to 36 hours | Twice |
When surface-mount IC packages after opening the moisture-proof package exceed the recommended storage
periods, or their storage periods or storage conditions are unknown and therefore moisture absorption is a concern,
it is recommended to dry-bake them before reflow soldering.
Storage conditions from the baking to the reflow soldering are the same as the above-mentioned storage conditions.
Note: If products are shipped in Tape & Reel, transfer the products into heatproof trays before baking.
Bare chips
General precautions
- Bare Die products have a higher risk of quality and reliability degrading depending on the handling method than general products.
- The passivation film applied on bare die products surface is not design to protect the die from external impact, but it is design to protect the internal metallization.
- Moisture and dust in the air and careless handling during assembly can cause defective products, so please take care adequately.
- Please perform sufficient evaluations for quality and reliability by the customer: such as testing and screening to detect failures.
Packing
When bare dies are shipped, they are put in dedicated trays, and the trays are taped together so that dies are properly held in the trays during transportation. Then the trays are packed in antistatic bags. Do not open the bags more frequent than necessary to prevent foreign contamination to the dies. Also, do not leave trays open for prolonged time.
Bare chip storage precautions
- Allowable storage periods before and after opening the pack are maximum 12 months under the conditions mentioned below.
- If the bags are opened, assemble the products without much delay in order to prevent the bonding degradation caused by the quality change in the bonding pad surfaces.
Bare chip storage conditions and storage periods
| State | Storage conditions | Allowable storage period |
|---|---|---|
| Before opening | Lower than 35°C, 80% RH point | 6 months |
| After opening | Lower than 30°C, 80% RH point | 30 days |
| In dry N2 gas with dew point lower than -30°C | 6 months |
Precautions for Mounting Bare Die
- When mounting bare die, perform in a clean environment where it is not exposed to contaminated atmospheres or substances.
- Please use the bare die collet for pickup and die bonding. If foreign material adheres to the collet, process defects such as scratches on the bare die surface may occur. When using a collet with a surface that comes into contact with the bare die surface, periodic cleaning should be carried out.
- Do not clean bare dies. If bare dies have to be cleaned, extreme precaution must be carried out to ensure no residue remain on die surface.
- When mounting bare die, take sufficient countermeasures against static electricity.
- Insulate the back side of the bare dies before use (if it is stated in the product specifications, follow the description).
Material
For sealing resins, use "semiconductor grade" products. This is recommended to prevent corrosion in bonding pads due to moisture absorption, and reduce internal stress due to temperature changes. Similar precautions must be taken for other materials to be used.
