In the fields of aviation, aerospace, and shipbuilding, there is a high demand for the manufacturing level of electronic components, especially the reliability and stability of electrical performance. For encapsulated electronic components, the presence of bubbles in the encapsulation adhesive is an important factor affecting the reliability and stability of electrical performance. Due to the large pressure difference in environments such as space or deep sea, bubbles are prone to migrate and cause cracking of components or a decrease in insulation resistance.

Sealing technology refers to the process of mechanically or manually pouring liquid sealing materials into products or molds containing electronic components and circuits, and curing them into high-performance polymer insulation materials. It uses solid media instead of air to fill around the components, achieving reinforcement and improving electrical strength. Sealing technology refers to the process of mechanically or manually pouring liquid sealing materials into products or molds containing electronic components and circuits, and curing them into high-performance polymer insulation materials. It uses solid media instead of air to fill around the components, achieving reinforcement and improving electrical strength. There are two commonly used sealing processes, one is the traditional atmospheric pressure sealing process, and the other is the vacuum sealing process.

Vacuum sealing can not only quickly eliminate physical and chemical bubbles, but also facilitate the effective natural penetration of the adhesive solution. Products that have been vacuum sealed have high reliability, low leakage coefficient, small partial discharge, and high insulation strength. Therefore, vacuum sealing is an important means to reduce the insulation risk of electrical components and improve the reliability of electrical systems.

In high-voltage electronic products, a large number of low surface energy materials are usually used, such as polyester (PET), polyimide (PI), ethylene tetrafluoroethylene copolymer (ETFE), polytetrafluoroethylene (PTFE), polyethylene (PTFE), nylon, etc. The surface of low surface energy materials is very smooth at the nanoscale, with poor hydrophilicity and surface inertness, resulting in poor adhesion performance. They have poor wetting and adhesion performance with the potting resin, low bonding strength, and are prone to delamination and debonding under temperature cycling, thermal vacuum, and other working conditions, posing a fatal hazard to aerospace high-pressure products. Therefore, it is necessary to perform pre sealing treatment on low surface energy materials to improve their bonding performance with the sealing material.

Plasma treatment

Plasma treatment plasma is a quasi neutral ionized gas composed of free electrons, ions, neutral substances, and photons. When sufficient energy is supplied to the gas to excite at least one electron from the gas molecule, plasma is generated. Plasma can be divided into two types based on ionization degree: "hot" and "cold" Hot plasma approaches thermodynamic equilibrium, characterized by high energy density and equal temperature between heavy particles and electrons On the contrary, cold plasma is in a non-equilibrium state, where the temperature of electrons is much higher than that of ions and neutral particles For cold plasmas, electrons are the main energy carriers, and they control the chemical reactions of the plasma through collisions with other substances (mainly neutral substances) In chemical reactions, high-energy electrons in cold plasma can break the chemical bonds on the surface of polymers and activate the surface of polymer materials. Plasma treatment can improve the surface roughness and surface energy of polymer materials, enhance the interfacial bonding and wetting properties between materials and other materials, and improve the adhesion of materials. Therefore, plasma treatment can be applied to the surface of encapsulated parts to increase their surface activity, enhance their wetting ability to the adhesive solution, and thus improve the bonding strength of the encapsulated adhesive to the components.