Pouring printed circuit boards with epoxy resin, viksint, varnishing

Resin, compounding, varnishing

In order for the finished modules to be durable and work in extreme conditions, they must be covered with special means (sealing of printed circuit boards, modules, products) that protect the board from external factors:

• moisture – changes the dielectric properties of components, and also affects electronic components, increasing their resistance
• dust – creates overheating of components
• mechanical protection – uncoated boards are not mechanically protected

The board sealing process

The filling process can be divided into the following stages:

• cleaning boards from flux residues and “fat spots”, which can appear even if the board is simply held in hands;
• applying the mixture to the PCB and components so that there are no exposed pads left;
• drying (polymerization) occurs at the last stage

Selecting a protective coating

Varnishing

Varnishes are considered a good alternative to compound. They also protect the board well from dust and moisture. It should be noted that the cost of coating with varnish is several times lower than with a compound. But if your device will succumb to vibrations during operation or will not be operated in dry rooms, it is worth using another coating – a compound.

Compound (wixint)

The compound has a number of advantages that more effectively protect the working module. It has a higher resistance to mechanical stress, protects against vibrations and has a high heat transfer, which prevents the product from overheating during operation. The compound is suitable for all types of boards and elements. A module coated with a compound will work correctly in any environment, even aggressive, as it perfectly protects the product from corrosion. The only disadvantage of using the compound is the inability to repair the product.