Ceramic Submount

    Types of ceramic materials include aluminum nitride (AlN) ceramics, alumina (Al2O3) ceramics, and many other materials.
One. Advantages of ceramic heat sink substrates;
1, the melting point is lower, the brazing temperature is moderate, greatly shortening the entire brazing process. Ceramic circuit board, using gold tin solder, brazing temperature is only 20 ~ 30 ° C (that is, about 300 ~ 310) higher than its melting point, because the gold tin alloy eutectic, alloy melting faster, solidification is also fast. Component assembly with high stability requirements is generally more suitable for gold and tin alloys.
2, at a high temperature of 250 ~ 260 ° C can meet the requirements of high strength of air tightness.
3, good wettability, good wettability and corrosion of lead-free solder in the gold plating layer. Because the composition of gold-tin alloys is close to that of the gold plating layer, the degree of immersion in the very thin coatings by diffusion is very low, and there is no migration phenomenon.
4, low viscosity - can fill a relatively large void stable no flow.
5, good thermal conductivity, because its solder has high corrosion resistance, high creep resistance and good thermal and electrical conductivity, thermal conductivity of 57 W/m·K.
6, lead-free, environmentally friendly.
Two. Application of ceramic heat sinks
1, can be laser diode, photodiode packaging with ceramic heat sink prefabricated AuSn and other materials of thin film solder, in the heat sink can be scribbled, its surface metal into Ti, Pt, Au, Cr, Cu, Sn, Ag or AuSn solder, etc., thickness and composition can be customized.

2, the application of heat sinking of aluminum nitride, alumina, diamond and other materials can improve the heat dissipation capacity, reduce thermal resistance, improve the output power of the laser, and prolong the life of the laser.
Three. Usually, there are several main classifications of heat sinks
1, industrially refers to a miniature heat sink, used to cool the electronic chip device.
2, aerospace engineering refers to the use of liquid nitrogen wall plate inner surface black paint to simulate the cosmic cold black environment device.
3, refers to the current LED lighting package, because the LED emits high heat when emitting light, will use a copper column with high thermal conductivity to guide the heat outside the package body. This LED copper column is also called heat sinking. LD (laser diode) also generates more heat and also needs to be mounted on a heat sink to help dissipate heat and stabilize the operating temperature.
    In recent years, with the upgrading of demand, the development trend of laser chip miniaturization is obvious, but the small chip has low heat dissipation, the temperature difference between the working and non-working heat sink is small, the heat matching requirements are low, and the aluminum nitride material can be used as the substrate to connect with the chip. In the field of electronic packaging, heat sink mainly refers to a miniature heat sink, a device used to cool the electronic chip, is one of the core components, and there is a large room for improvement in assembly efficiency, reliability, performance and other aspects of traditional heat sink products. Ceramic heat sinks can meet the needs of high-power semiconductor laser chip bonding, and have broad application prospects in optical communications, high-power LED packaging, semiconductor lasers, fiber laser pump source manufacturing and other fields.