Epoxy encapsulant has a wide range of applications, various technical requirements and a wide variety. There are two types of curing conditions: room temperature curing and heating curing. From the dosage form, it can be divided into two types: two-component and one-component. Multi-component dosage forms are rare as commercial products due to the inconvenience of use. According to the coating online, the room temperature curing epoxy potting glue is generally two-component, which can be cured without heating after potting. It does not require high equipment and is easy to use. The disadvantage is that the compound has high viscosity, poor impregnation, short pot life, it is difficult to realize automatic production, and the heat resistance and electrical properties of the cured product are not very high. It is generally used for potting of low-voltage electronic devices or occasions where heating and curing are not suitable.

Heat-curing two-component epoxy potting compound is the most widely used variety. Its characteristics are that the compound has low operating viscosity, good manufacturability, long pot life, good impregnation, and excellent comprehensive properties of the cured product. It is suitable for the use of single-component epoxy potting compound in the automatic production line of high-voltage electronic devices. It is developed abroad in recent years. New varieties need to be heated and cured. Compared with the two-component heat-curing potting adhesive, the outstanding advantages are that the required potting equipment is simple, easy to use, and the quality of the potting adhesive is less dependent on equipment and processes.

In addition to the shortcomings, the cost is high, and the material storage conditions are strict. The epoxy potting compound used should meet the following requirements:

1、Good performance, long service life, suitable for large-scale automatic production line operations.

2、Low viscosity, strong impregnation, can fill components and lines.

3、In the process of potting and curing, the powder components such as fillers have small sedimentation and no stratification.

4、The curing exothermic peak is low, and the curing shrinkage is small.

5、The cured product has excellent electrical and mechanical properties, good heat resistance, good adhesion to various materials, and low water absorption and linear expansion coefficient.

6、In some occasions, the potting compound is also required to have properties such as flame retardancy, weather resistance, thermal conductivity, and high and low temperature resistance.