Precautions For Potting Glue Of Switching Power Supply

Precautions for potting glue of switching power supply

1. Waterproof, potting glue, tightly wrap the electrical part of the whole product, and completely isolate it from the outside; including water, water vapor, acid, alkali and salt, can not touch the circuit components, which can improve the waterproof, moisture-proof and corrosion-proof ability of the power supply . Therefore, when choosing a potting compound, it is necessary to choose a potting compound with good fluidity; the other is the cohesive force, otherwise it is useless to alternate between cold and heat for a long time after potting and the components come out separately, and the product service life performance index Also affected.

2. Thermal conductivity. The power supply is a power product that converts, manipulates, and outputs energy. The product needs to generate heat when working, and devices such as switching tubes, transformers, electrolytic capacitors, and inductors are all sensitive to heat. Potting adhesives need to conduct their heat quickly and effectively. Therefore, there is no doubt that the glue requires high-quality thermal conductivity. It can be said that the higher the thermal conductivity of the glue, the better the heat dissipation effect. The electrolytic capacitor in the power supply, the service life can be said to be reduced by half every time the temperature rises by ten degrees. When the temperature of the transformer and inductor is high, many basic parameters will change, and the difficulty factor of the overall design will increase.

The waterproof power supply needs to be isolated as a whole, and the thermal conductivity of air is very low, generally speaking, it depends on convection and radiation. Therefore, pouring glue with good thermal conductivity can be equivalent to placing each component outside the shell to dissipate heat, which not only improves the service life but also simplifies the design.

3. Dielectric strength. It can be said that all glues have no conductivity, but it should be noted that if the curing reaction of AB glue like epoxy is not complete, there may be some local conductivity. Others are mixed with sand in order to save money, so it is hard to say. First of all, whether your sand has been dehydrated and other finishing processes, that is, whether there are some other elements in your sand that interfere with curing; whether the dosage of AB agent is reasonable, whether the mixture is fully balanced, and whether other necessary conditions are met.

4. Environmental protection requirements are generally certified. It depends on whether the products provided are the same as the certified ones. There is still a lot of price difference between environmentally friendly and non-environmentally friendly materials.

5. For flame retardant regulations, usually it depends on the flame retardant test in UL. The normal requirement is above 94-V0.

6. There are many other basic parameters, you need to pour it yourself and try it. And your supplier must be constant, his supply must be stable, and the processing technology must be stable. Otherwise, the discreteness is too large.