Desiccant

What is desiccant?

Desiccant absorbs moisture vapour (humidity) from the air from any given environment. Desco Europe’s desiccant are designed to be left inside a moisture barrier bag after it has been sealed to protect its contents from moisture corrosion. If moisture penetrates the bag, it will also be absorbed. Desiccant will remain dry to the touch even when it is fully saturated with moisture vapour. It can be regenerated and re-used by baking, see the recommended MIL-D-3464 method.

Why is desiccant required?

Certain kinds of electronic devices, such as Surface Mount Devices (SMDs), are mounted on a circuit card by high temperature soldering. The body of the SMD is made from plastic that absorbs moisture from the air. When the case is heated during soldering, the moisture inside turns to steam and may break the device as the steam escapes. Keeping SMDs dry before soldering means that the devices will not be damaged.

How is desiccant used?

It used together with a Moisture Barrier Bag (MBB), a Humidity Indicator Cards (HIC) and Moisture Sensitive Level (MSL) label to form a dry packaging system.

How is desiccant purchased?

Desiccant is available as a “unit” or fractional “unit”. A unit of desiccant absorbs a specific amount of moisture. One unit of desiccant weighs about 28 g. The recommended amount of desiccant depends on the interior surface area of the bag to be used. Use this desiccant calculator to determine the minimum amounts of desiccant to be used with Moisture Barrier Bags.