How do I handle & store bare die ?

In all cases, the customer must determine the applicability of extended storage durations and conditions with respect to their assembly process and end product criteria.

Handling

• Product must be handled only at ESD safe workstations. Standard ESD precautions and safe work environments are as defined in MIL-HDBK-263.
• Product must be handled only in a class 10,000 or better-designated clean room environment.
• Singulated die are not to be handled with tweezers. A vacuum wand with a non-metallic ESD protected tip should be used.
• Ultraviolet (UV) sensitive products need to be handled in a manner that minimizes the exposure of the product to UV light. (Note: Products with UV light sensitivity will be identified on the applicable datasheet.)
• EPROM-based microcontrollers that have been programmed will be erased if exposed to an energy level of 15 Watt-Seconds/cm2 based upon a UV-C wavelength of 253.7 nanometers. In general, UV-C (200-280 nm) and UV-B (280-315 nm) will also result in erasure if the product is exposed to a 15 W-S/cm2 energy level.
• It is recommended that any manufacturing/handling environment where UV sensitive products are exposed to light be monitored for UV-C and UV-B levels to ensure that the 15 W-S/cm2 is not violated. To determine the energy exposure level multiply the irradiance (Watts/cm2) by the time of exposure (Seconds) at a given location. The summation of the calculated energy levels for each location will be the total energy level the product has been exposed to. This energy level should not exceed the 15 W-S/cm2.
• A typical irradiance value (Combined UV-C and UV-B spectrum) for an office area lit by overhead fluorescent lighting is ~ 0.02 microWatts/cm2. Irradiance on assembly type equipment can be on the order of ~ 1.00 microWatts/cm2. These values should not be used to determine the energy level of the manufacturing/handling area in question but as a guideline in regards to the order of magnitude for irradiance.

Wafer/Die Storage

• Proper storage conditions are necessary to prevent product contamination and/or degradation after shipment.
• Unsawn wafers and singulated die can be stored for up to 12 months when in the original sealed packaging at room temperature (45% +/- 15% RH controlled environment).
• Unsawn wafers and singulated die that have been opened can be stored when returned to their containers and placed in a Nitrogen purged cabinet, at room temperature (45% +/- 15% RH controlled environment).
• Note: To reduce the risk of contamination or degradation, it is recommended that product not being used in the assembly process be returned to their original containers and resealed with a vacuum seal process.
• Sawn wafers on a film frame are intended for immediate use and have a limited shelf life. However Mintech Semiconductors have developed a foil that allows die to be stored in a nitrogen-purged cabinet at room temperature (45% +/- 15% RH controlled environment) for up to ten years.
• Die in Surf Tape type carrier tape are intended for immediate use and have a limited shelf life. This is primarily due to the nature of the adhesive tape used to hold the product in the carrier tape cavity. This product can be stored for up to 30 days. This applies whether or not the material has remained in its original sealed container.