Industry dynamic

Classification and application of electronic potting adhesives

2021-01-29
Potting glue has been widely used in the electronic device manufacturing industry, is an indispensable and important insulating material for the electronics industry. Potting is a liquid resin compound that is mechanically or manually filled with electronic components and circuits and cured under room temperature or heating conditions to become a thermosetting polymer insulating material with excellent performance.
Functions:
Strengthening the integrity of electronic devices and improving the resistance to external shocks and vibrations.
Improve the insulation between internal components and lines;
Facilitate the miniaturization and lightweight of devices.
Avoid direct exposure of components and lines, improve the waterproof and moisture-proof performance of the device
 Classification of potting adhesives:
According to the material type of potting adhesive, the potting adhesive is mainly divided into three categories
Epoxy resin potting adhesive: mostly hard, but also a small part soft. The biggest advantage, good adhesion to hard materials, can not be opened after potting, high hardness, good insulation performance, ordinary temperature resistance in 100, temperature curing temperature resistance in 150 degrees Celsius or so. Because of its high hardness after curing, the bonding force is strong, so basically does not have repairability
Silicone resin potting adhesive: soft after curing, poor adhesion; advantages, high and low-temperature resistance, can be used for a long time at 260 degrees Celsius, temperature curing type higher temperature resistance, insulation performance than epoxy resin is good, can withstand voltage 10000V or more, good repairability
Polyurethane potting adhesive: bonding between epoxy and silicone, temperature resistance generally does not exceed 100 degrees Celsius, bubbles, must be vacuum pouring. Advantages, good low-temperature resistance.
 Epoxy resin potting adhesive application:
Epoxy potting adhesive refers to a class of electronic potting adhesive made of epoxy resin, divided into.
One-component epoxy potting adhesive
Two-component epoxy potting adhesive
Features.
Good chemical corrosion resistance and moisture resistance
Good mechanical properties
No primer required
Working temperature up to 155°C
The low exothermic peak during curing, low curing shrinkage
Good confidentiality.
 There are many kinds of epoxy potting adhesives, different kinds of epoxy potting adhesives have great differences in temperature resistance, waterproof performance, insulation performance, optical performance, adhesion performance to different materials, and softness and hardness. Epoxy potting adhesive can be added with some functional fillers to give it the performance of electrical and thermal conductivity and magnetic conductivity.
The color of epoxy potting adhesive can be adjusted according to the need. Transparent or non-transparent or colored.
The two-component epoxy potting adhesive is the most common, and the two components A and B are blended evenly before use. Usually, the A component is the adhesive (which contains reinforcing additives and various functional fillers, etc.), and the B component is the curing agent. Two-component epoxy potting adhesive can be cured at room temperature or heated for fast curing, used for encapsulating electrical modules and diodes, etc. The use of two-component potting adhesive is basically the same, generally: ingredients - mixing - vacuum - potting - resting - inspection into the warehouse. You can use two-component potting equipment to simplify the whole operation process, and also save operation time and reduce the waste of raw materials.
Some two-component epoxy potting adhesives have high viscosity, so it is usually used to add appropriate active diluent or add A and B components separately (heating will greatly reduce the viscosity of the adhesive) and then mixed and potted.
One-component epoxy potting adhesive generally need high-temperature curing, some varieties require 80 degrees Celsius curing, some require more than 150 degrees Celsius to cure. Usually, the lower the curing temperature requirements of one-component epoxy potting adhesive room temperature storage period are shorter, and vice versa, so some epoxy potting adhesive even require low-temperature refrigerator storage.
Application of silicone resin potting adhesive:
Silicone resin potting adhesive is used for potting of electronic and electrical components, which can play the role of moisture-proof, dust-proof, corrosion-proof, shock-proof, and improve the use of performance and stability parameters
Features
It is liquid before vulcanization, easy to be filled and convenient to use
When potting, no low molecules are released, no stress shrinkage.
Can be deeply vulcanized without any corrosion.
With repairability and good thermal cycling performance
Excellent resistance to high and low temperature, the temperature range of -155℃-260℃
Transparent silica gel becomes transpa
rent elastomer after vulcanization, the components encapsulated in the rubber layer are clearly visible, and the components can be measured one by one with a needle, which is easy to detect and rework.
Classification:
Condensation type silicone grease potting adhesive
Silicone potting adhesive with molding

Like epoxy resin potting adhesives, there are many kinds of silicone grease potting adhesives. It is generally two-component, and the ratio of the two components is different according to different formulations. Curing conditions also vary depending on the potting adhesive product. When evaluating and using potting adhesives, it is important to have a clear understanding of the performance of potting adhesives. If using it for the first time, you may want to do a small trial production first.