Power supply and protection materials
In modern society, the power supply is everywhere. Its main function is to transfer and control the power into the circuit to drive the whole circuit. Commonly used are A-D, D-A, A-A, D-D conversion and transformation devices. Because of its high precision or high power characteristics, it usually needs adhesives, coating adhesives, heat conducting materials, etc. to ensure the stability and reliability of the power supply. Among them, in AC-DC power supply, due to the rapid development, various types and complex structure, there are also high requirements for protective materials.
Generally, the protective materials shall have the characteristics of insulation, moisture-proof, anti pollution, anti-corrosion, low stress and high stability. At present, the protective materials used in power supply products mainly include yellow glue, white glue, hot melt glue, epoxy resin, acrylic resin and organic silica gel. Among so many materials, silicone material is the most special one, which is the best choice for AC / DC power supply.
Properties of organic silica gel materials
Organic silica gel material is a kind of material with both excellent properties of inorganic material and organic material. In structure, Si-O is the main chain of polymer material. Because the bond energy of Si-O bond is much larger than that of C-C bond, compared with other organic compounds, organosilicon polymer has higher heat and temperature resistance. Organosilicon materials exhibit excellent physical and mechanical properties at high and low temperatures, and their properties are not affected by repeated alternation at - 60 ℃ - 200 ℃. Because of the dipole effect inside the silicone material, it can effectively buffer and weaken the influence of the external electric field, so as to protect the hydroxyl connected to the silicon atom from the influence of physical factors and chemical reagents. The adhesive made of organosiloxane has the characteristics of corrosion resistance, radiation resistance, low moisture absorption, high insulation resistance, low dielectric constant, low stress and low toxicity. Therefore, various silicone products are widely used in various electronic and electrical equipment.
Application of organosilicon material in AC / DC power supply
Silicone materials can be used as adhesive glue, encapsulating glue, coating adhesive, gel, thermal conductive silicone grease, thermal conductive silica gel and thermal conductive film in AC/DC power supply.
In AC / DC power supply, adhesive is mainly used for the bonding and fixation of components, or for the auxiliary fixation of large components, such as capacitance, inductance and coil, to prevent the components from falling off due to vibration, and also has the functions of shock absorption and noise reduction. If thermal conductive silica gel is used, it can be used to fix power devices. The adhesive series of Anpin mainly include ap-688 and ap-607.
Potting glue is the main protective material in the power supply, which is used for local or all potting protection of components and parts, and has achieved the effect of moisture-proof, pollution-proof and corrosion-proof. Using potting glue can reduce stress and resist high and low temperature impact. For high-power power supply, heat conduction potting glue is used, which can also play a role in heat dissipation. Anpin potting glue series mainly include ap-905 and ap-9210.
Compared with potting adhesive, gels can further reduce stress, for fine lines, multi-layer lines, or for modules requiring shock and low temperature conditions. The very low stress of silicone gel and the excellent properties of silicone have become a special protective material, and some of them also have heat dissipation function. There are mainly AP-587, AP-599 in Annex silicon gel series.
Organosilicon coating material is mainly used for PCB protection, which has achieved the goal of moisture-proof, antifouling and anticorrosion. It can also be used on high current electrodes to prevent short circuit and fire. In addition, it can also be used on medium and high voltage coils to prevent fire jump. Through PCB coating, an insulating and moisture-proof layer can be formed, which can reduce the short circuit and the contact between components and atmospheric environment, and finally achieve the purpose of reducing corrosion. Thus, the environmental reliability of the product has a qualitative leap. Ap-577 is the main series of coating adhesive for safety products.
The power module in the AC / DC power supply will produce a lot of heat in the use process, which will make the power supply temperature in the use process. In order to avoid damage to components and circuits due to excessive temperature, it is necessary to establish proper heat dissipation channels to ensure that the equipment is within the normal operating temperature range. No matter which way of heat dissipation is used, the heat conduction material must be used as the heat dissipation medium to reduce the interface contact thermal resistance and enhance the heat dissipation efficiency. Among all organosilicon materials, heat-conducting silica gel and heat-conducting silicone grease are used for heat conduction between power components and heat sinks; heat-conducting potting adhesive is mainly used for power module potting; the type number of heat-conducting silicone grease system of Anpin is ap-505.
Application and development of organosilicon materials
Compared with other materials, the development of organic silica materials is relatively late, and its properties are not known by most people. At present, in AC / DC power supply, silicone materials have been widely used, such as the encapsulation of high-power LED waterproof power supply. It is believed that in the future, there will be more and more updated organic silica gel materials used in various power supplies.