MB95710M Series
MB95770M Series
Document Number: 002-09307 Rev. *D
Page 30 of 172
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Storage of Semiconductor Devices
Because plastic chip packages are formed from plastic resins, exposure to natural environmental conditions will cause
absorption of moisture. During mounting, the application of heat to a package that has absorbed moisture can cause
surfaces to peel, reducing moisture resistance and causing packages to crack. To prevent, do the following:
(1) Avoid exposure to rapid temperature changes, which cause moisture to condense inside the product. Store
products in locations where temperature changes are slight.
(2) Use dry boxes for product storage. Products should be stored below 70% relative humidity, and at temperatures
between 5°C and 30°C.
When you open Dry Package that recommends humidity 40% to 70% relative humidity.
(3) When necessary, Cypress packages semiconductor devices in highly moisture-resistant aluminum laminate bags,
with a silica gel desiccant. Devices should be sealed in their aluminum laminate bags for storage.
(4) Avoid storing packages where they are exposed to corrosive gases or high levels of dust.
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Baking
Packages that have absorbed moisture may be de-moisturized by baking (heat drying). Follow the Cypress recom-
mended conditions for baking.
Condition: 125°C/24 h
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Static Electricity
Because semiconductor devices are particularly susceptible to damage by static electricity, you must take the following
precautions:
(1) Maintain relative humidity in the working environment between 40% and 70%.
Use of an apparatus for ion generation may be needed to remove electricity.
(2) Electrically ground all conveyors, solder vessels, soldering irons and peripheral equipment.
(3) Eliminate static body electricity by the use of rings or bracelets connected to ground through high resistance (on
the level of 1 M
Ω
).
Wearing of conductive clothing and shoes, use of conductive floor mats and other measures to minimize shock
loads is recommended.
(4) Ground all fixtures and instruments, or protect with anti-static measures.
(5) Avoid the use of styrofoam or other highly static-prone materials for storage of completed board assemblies.
8.3 Precautions for Use Environment
Reliability of semiconductor devices depends on ambient temperature and other conditions as described above.
For reliable performance, do the following:
(1) Humidity
Prolonged use in high humidity can lead to leakage in devices as well as printed circuit boards. If high humidity
levels are anticipated, consider anti-humidity processing.
(2) Discharge of Static Electricity
When high-voltage charges exist close to semiconductor devices, discharges can cause abnormal operation. In
such cases, use anti-static measures or processing to prevent discharges.
(3) Corrosive Gases, Dust, or Oil
Exposure to corrosive gases or contact with dust or oil may lead to chemical reactions that will adversely affect
the device. If you use devices in such conditions, consider ways to prevent such exposure or to protect the devices.
