1.4. Dry Packing J-Lead, QFP, BGA, FBGA, and Lidless BGA Devices
Dry packing is a method of packing moisture-sensitive devices for shipment. Risk to moisture-sensitive devices can occur when the high-soldering temperatures of the reflow process suddenly heat any moisture absorbed by a plastic package. Although many of Intel® devices are not sensitive to moisture, Intel® adopted dry packing as a standard practice for moisture-sensitive devices to eliminate all risk of moisture. Additionally, Intel® can dry-pack other devices upon request. During dry packing, devices are first baked to remove any existing moisture and then packed and vacuum-sealed in moisture-barrier bags.
The following table lists the contents of a typical package.
|MIL-B-81705C, Type I or equivalent
|MIL-D-3464, Type II or equivalent
|Compliant with MIL-I-8835A
|ID label and caution label
To maintain a moisture-free environment, follow these guidelines after receiving dry-packed devices from Intel® :
- Open bags as close to the seal as possible to leave enough of the bag for resealing.
- Reseal bags after opening to minimize exposure to moisture.
- Inspect all dry packs for potential leaks in the seals or bags. If a leak exists and the humidity-indicator card shows an unacceptable humidity level (for example, the 20% dot has started to turn pink), rebake the devices. If a leak exists but the humidity-indicator shows an acceptable humidity level (for example, the 20% dot is blue with no pink), reseal the devices in an undamaged bag.
- Check that the humidity-indicator card shows acceptable humidity after opening dry packs. If the card shows an unacceptable humidity level, rebake the devices.
- Store dry packs in condition less than 40°C and less than 90% relative humidity.
In addition, Intel® lists the floor life on every dry-pack label. The floor life is the length of time you can expose a device to a factory environment (less than 30°C and less than 60% relative humidity) after you removed the device from the bag and before it is mounted. Parts that are not dry packed have an unlimited floor life but you must store at a proper environment (less than 30°C and less than 85% relative humidity). If the interval between opening a dry pack and mounting the devices onto a board exceeds the floor life of the device, rebake devices prior to mounting.
Distributors have an additional allotment of time beyond the labeled floor life. Six hours are available for products with a 24-hour floor life, and 24 hours are available for products with a 168-hour or one-year floor life. These time allotments allow for programming and repacking as required.
When dry-packing devices, follow these guidelines:
- When transferring parts to new dry pack bags, operators must remember to copy the floor life and expiration date accurately to the new dry-pack labels.
- Bake QFP or BGA devices in strapped heat-resistant trays at 125°C for at least 12 hours.
- Bake J-Lead devices in heat-resistant tubes at 125°C for at least 12 hours. If you lack heat-resistant tubes, bake J-Lead devices on a cookie sheet in a dead-bug orientation.
- Use heat-sealed bags that are resistant to punctures and abrasion.
- Use foam covers or bubble wrap around a stack of trays inside the moisture-barrier bag to avoid punctures.
- Seal bags with a vacuum-operated bag-sealing machine. Relax the vacuum enough to prevent the tube or tray from puncturing the bag.
- If the dry pack is open for longer than one hour, replace the desiccant and humidity indicator card.
- Use at least one unit of desiccant per dry pack.
- You must not use zip-lock and dry-pack bags for longer than one week.