What is BS EN 62435-5 - Long-term storage of die and wafer devices about?  
BS EN 62435 is a European Standard that discusses electronic components. The IEC 62435 series is intended to ensure that adequate reliability is achieved for devices in user applications after long-term storage.
BS EN 62435-5 is the fifth part of the multi-series that applies to the long-term storage of electronic components.
BS EN 62435-5 is applicable to long-term storage of die and wafer devices and establishes specific storage regimen and conditions for singulated bare die and partial or complete wafers of die including dying with added structures such as redistribution layers and solder balls or bumps or other metallization. This part also provides guidelines for special requirements and primary packaging that contain the die or wafers for handling purposes. Typically, this part is used in conjunction with IEC 62435-1 for long-term storage of devices whose duration can be more than 12 months for products scheduled for long-duration storage.
Who is BS EN 62435-5 - Long-term storage of die and wafer devices for? 
BS EN 62435-5 on die and wafer devices is useful for: 
- Manufacturers of electronic semiconductor devices
- Manufacturers of dye and wafer devices
- Authorities involved with storage, handling, management and inspection of electronic semiconductor devices
- Manufacturers of electronic equipment and components
- Companies involved in R&D of semiconductor technology
- Aerospace and automobile industry
- Product design engineers
- Electronic engineers
Why should you use BS EN 62435-5 - Long-term storage of die and wafer devices?  
Long-term storage is defined as planned storage of components to extend the life-cycle for a duration with the intention of supporting future use.
BS EN 62435-5 is a document for long-term storage (LTS) of electronic devices drawing on the best long-term storage practices currently known.
BS EN 62435-5 is intended to give practical guide to methods of long-duration storage of electronic components where this is intentional or planned storage of product for a number of years.
BS EN 62435-5 details the exposure concerns for wafers and dies and lists recommended packaging methods, verification, suitable environment, and storage time limitations according to the particular exposure concern.
BS EN 62435-5 can assist you in storing electronic devices for long periods of time, in order to maintain as-received solderability and avoid any degrading impacts to the part over time. Degradation concerns such as moisture, electrostatic fields, ultraviolet light, large temperature changes, airborne pollutants, and outgassing can thus be avoided.
