What is the shelf life of Cypress Flash memory products that are vacuum-sealed and stored in a controlled environment?
The proper storage of Cypress Flash memory devices is important in order to maximize shelf life. By adhering to the following recommendations, a shelf life of at least one year should be expected.The devices should be stored in a room with a temperature less than 40°C and relative humidity less than 90 percent. The products should be sealed within a moisture barrier bag that is in compliance with IPC/JEDEC J-STD-033.
These bags are comprised of three laminated layers consisting of the following:
- An inner layer of nylon with a static-dissipative coating
- A second layer of aluminum foil
- A third layer of polyethylene with a static-dissipative coating.
The moisture barrier bag meets the requirements specified in MIL-PRF-81705D, Type I, Class 1 for flexibility, ESD protection,mechanical strength, and puncture resistance.
Furthermore, the bag complies with the drop test requirements defined in ASTDM 4169-94 and the water vapor transmission rate defined in ASTM F-1249.
All moisture bags are coated with antistatic material to provide ESD protection on all surfaces and to comply with the requirements set forth in EIA 625.
A humidity-sensitive card is included in each moisture barrier bag. The card can be reused if all the humidity-sensitive elements are blue. If one has turned pink, bake the card at 125°C ±5°C for 15 minutes. The humidity indicator cards used with Cypress products meet the standards specified in MIL-I-18835. Also included in the moisture barrier bag are desiccant pouches, the quantity of which depends upon the size of the bag used. The desiccant that is used with Cypress products exceeds the rigid standards of Military Specification D-3464D, Type II. It is a molecular sieve desiccant packed in Tyvek(R), spun-bonded, polyolefin type II pouches. The desiccant pouches help to maintain the environment in the bag at no greater than 10 percent RH, thus protecting the devices during shipment and storage for at least 12 months. If the moisture barrier bag has been opened, reseal the bag containing the device(s), the desiccant pouches, and the humidity card within one hour. If the bag is not resealed, the devices can be stored indefinitely in a dry storage chamber that is maintained at a 5 percent RH level or less. The dry storage chamber and its shelves should be grounded.