In electronic packaging, it is required that the integrated circuit has high moisture resistance, low stress, low alpha radiation, resistance to immersion and reflow soldering, and good performance in the plastic packaging process after packaging. In response to these requirements, epoxy sealant must be doped with inorganic fillers in the resin matrix. The currently used inorganic fillers are mostly silicon micro powders, which have the functions of reducing the thermal expansion coefficient of the sealant, increasing thermal conductivity, reducing dielectric constant, environmental protection, flame retardancy, reducing internal stress, preventing moisture absorption, increasing the strength of the sealant, and reducing the cost of the sealant.
The advantages of using spherical silicon micro powder for EMC Epoxy Molding Compound are:
1. The surface fluidity of the ball is good and the resin is stirred evenly to form a film. The amount of resin added is small, and the filling amount of powder can reach the highest, with a mass ratio of up to 90.5%. Therefore, spheroidization means an increase in the filling rate of silicon micro powder. The higher the filling rate of silicon micro powder, the smaller its thermal expansion coefficient and the lower its thermal conductivity, which is closer to the thermal expansion coefficient of single crystal silicon. As a result, the performance of electronic components produced from this is also better.
2. The stress concentration of the plastic encapsulation material formed by spheroidization is the smallest, and the strength is the highest. When the stress concentration of the plastic encapsulation material for angular powder is 1, the stress of the spherical powder is only 0.6. Therefore, when encapsulating integrated circuit chips with spherical powder plastic encapsulation material, the yield is high, and it is not easy to cause mechanical damage during transportation, installation, and use.
3. Spherical powder has a lower friction coefficient and less wear on molds compared to angular powder. Compared to angular powder, the service life of molds can be doubled. The price of plastic packaging molds is very high, and some even need to be imported. This is also important for packaging factories to reduce costs and improve economic efficiency.