When potting electronic components with silicone electronic potting glue, there are two types: condensation type and addition type. What is the difference between the two?

Performance
Generally speaking, the condensation type potting glue will have better adhesion, up to IP68, so it is mostly used for electronic components that require high waterproof performance; the addition type potting glue has better thermal conductivity and electrical insulation performance, and good strength , No corrosion, small shrinkage, more environmentally friendly.

However, the addition-type potting compound has always been a problem in terms of waterproof performance. At the same time, it is relatively easy to be poisoned and not cured. It is very easy to react with compounds such as nitrogen, sulfur, phosphorus, arsenic, organic tin curing agents, stabilizers, and epoxy resin curing agents. , At present, it can only be solved by spraying primer three-proof paint.

Curing
Condensation-type silicone potting glue is made of silica gel and curing agent in the presence of moisture in the air, and the active groups are condensed to extract small molecules for glue curing. During the curing process, it will shrink and by-products will be released.
The addition type silicone potting compound is glued by the addition reaction of silicon hydrogen bond and ethylene double bond. After AB is mixed, it will be cured by itself. Even in a closed container, it does not need to be opened to the atmosphere. , no small molecules are produced during the reaction, and this is what determines the difference in their performance.
The addition type silicone potting compound can be deeply vulcanized quickly, which is especially evident in the transparent color. The condensation type transparent type with a thickness of more than 3mm will be difficult to cure, and the addition type transparent type is not affected by the thickness.