Cypress’s standard shelf life for MSL 3 products is 12 months from the bag seal date, at conditions of <40°C and <90% Relative Humidity (R.H.)
For customer use conditions that require storage beyond this duration, Cypress advises that the packing, storage, excursion control and sample evaluation (HIC verification and other testing) recommendations outlined in JEDEC standard JEP160 be strictly followed to minimize storage/age related degradation.
Cypress’s MSL 1 products do not require special storage conditions provided they are maintained at conditions equal to or less than 30°C / 85% RH.
As a best practice, Cypress also recommends that reflow profiles for board mount be developed based on specific process needs and board designs. Cypress also recommends that for optimal profiles, the customer not only review conditions provided by the solder paste manufacturer, but also adhere to the conditions specified in industry standard IPC/JEDEC J-STD-020.
You can also download Cypress’ official statement regarding Shelf Life Condition on the link: http://www.cypress.com/?rID=62134. A current copy of JEP160 is attached on this letter for your reference.