Surface-mount devices must stay dry from their manufacturer’s time to the time they’re reflow soldered to printed circuit boards. Thus, the need for moisture barrier bags. These bags comprise of quite a few layers of aluminum and plastic for controlling moisture vapor leakage. These bags aren’t moisture vapor resistant, and moisture vapor leaks into them over time.
Desiccant is placed inside them to lessen humidity and hunt down moisture that enters them.
Sometimes, a HIC is also placed into them. What is the role of HICs? They show the relative humidity with their chemical spots that change color. They guarantee that the devices Surface-mount are dry at the time of delivery.
The Barrier Technologies used for moisture barrier bags.
Aluminized polyester and Aluminium foil are the barriers used when there is a need for low WVTR bags. The packaging mostly used for Surface-mount devices are metal barrier bags. Dense plastic layers are sometimes used in interim applications.
Aluminum foil is the most time-honored and efficient barrier technology. How is it made? A thin aluminum foil of a thickness of approximately 0.00035 inches is coated onto nylon.
Aluminized Polymer is a newer technology that’s more cost-effective. How is it made?
Aluminum is coated onto polyester. Several aluminized polyester layers are coated together.
As mentioned above, plastics are suitable for a limited moisture barrier. They’re used in food packaging and electronics in clean-room situations.
The thickness of moisture barrier bags
Moisture Barrier Packaging comes in various thicknesses starting from 3.2 mils to 10 mils. Significant differences in thickness have an effect on the performance and cost of bags.
The fairly standard thicknesses are 3.6 mils, 6.0 mils, and 10 mils. Tests on moisture barrier bags that have the same structure but have different thicknesses show that thicker materials are more puncture resistant.
A case in point is an aluminized polyester structure of 3.6 mils. Its puncture resistance is approximately 20 lb/in. The puncture resistance of the same aluminized polyester structure of 7.0 mils could be as much as 32 lb/in.
The right Bag Supplier
Even the premium barrier material is rendered of no use when the nag has leaky side seals or holes. A point to note is that barrier materials have got to be specially handled to thwart pinholes. Moreover, the right bag-converting equipment must be used for the heat sealing of thick barrier materials. The right supplier is the one that performs routine bag integrity checking of some form.
What are the considerations while picking a Moisture Barrier Bag?
Companies who are out to get a barrier bag from the numerous Online Cleanroom Equipment suppliers must consider several things. They are puncture, MVTR, cost, ESD properties, terms of usage, and supplier trustworthiness.
Moisture Barrier Bags are used in various applications in various industries. They are made with some specific technology and are available in some particular thicknesses.
