How to Protect from ElectroStatic Discharge and Moisture when Storing PCBs
To protect PCBs from both ESD and Moisture they should be stored in a vacuum sealed Moisture Barrier Bag. To complete a Dry-Packaging System, Desiccant Packs and Humidity Indicator Cards should be used in addition for best storage conditions
Steps to a Dry-Packaging System:
1. Moisture Barrier Bags (MBBs) work by enclosing a device with a metal or plastic shield that keep moisture vapour from getting inside the bag. These bags have specialised layers of film that control the Moisture Vapour Transfer Rate (MVTR). The bag also provides static shielding protection.
2. Desiccants are drying agents which are packaged inside a porous pouch so that the moisture can get through the pouch and be absorbed by the desiccant. It absorbs moisture vapour (humidity) from the air left inside the barrier bag after it has been sealed. Moisture that penetrates the bag will also be absorbed. The desiccant remains dry to the touch even when it is fully saturated with moisture vapour.
3. Humidity Indicator Cards (HICs) are printed with moisture sensitive spots which respond to various levels of humidity with a visible colour change from blue to pink or yellow to brown. The humidity inside barrier bags can be monitored by the HIC inside. Examining the card when you open the bag will indicate the humidity level the components are experiencing so the user can determine if baking the devices is required.
Don’t know how to put it all together? Not to worry – we’ve got you covered! See our range