Humidity Indicator Cards:
The HIC should comply with MIL-I-8835 and, at a minimum, have three color dots with sensitivity values of 30% RH, 40% RH, and 50% RH.
PCB Dry Packaging:
Proper packaging of the lead-free compatible PCB is critical. The packaging system must be carefully developed by the PCB fabricator to protect the PCB from atmospheric moisture that may enter the packaging materials by diffusion. The packaging system should be developed to offer a shelf life of 12 months at ≤40°C and 90% RH.
Desiccant:
- Proper selection of the desiccant should include consideration of the environmental conditions during shipping as these may effect the function of specific desiccant materials.
- Check with your desiccant supplier for moisture capacity capability in ´units´.
PCB's should be vacuum packed in a width adequate desiccant and humidity indicator card.
- PCB's should be packaged immediately after final inspection. The exposure time for the PCB prior to packaging should be minimized to eliminate the potential for moisture/volatile absorbtion as defined above.
- Moisture Barrier bags must be hermetically heat sealed with an adequate seal width per manufacturers recommendations to ensure proper bag performance.
- One humidity indicator card should be placed in the bag with the PCB's.
- The HIC should be placed adjacent to the desiccant, not on top of the packet(s).
- The amount of desiccant should provide protection for a minimum of one year.
- Other packaging materials used in the bag will also have a moisture content. The moisture/volatile content of these materials must be considered in calculating the number of desiccant packets to be used.