What is HTCC?
HTCC (High Temperature Co-fired Ceramic)， using high-melting-point metal heating resistor paste made of tungsten, molybdenum, molybdenum, manganese, is printed on 92~96% alumina cast ceramic according to the requirements of heat circuit design. On the green body, 4 to 8% of the sintering aid is then laminated, and co-fired at 1500 to 1600 ° C at a high temperature. Therefore, it has the advantages of corrosion resistance, high temperature resistance, long life, high efficiency and energy saving, uniform temperature, good thermal conductivity and fast thermal compensation, and is free from lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls, polybrominated diphenyl ethers, etc. Substance, in line with EU RoHS and other environmental requirements. Due to the high firing temperature, HTCC cannot use low-melting metal materials such as gold, silver, copper, etc., and must use refractory metal materials such as tungsten, molybdenum, manganese, etc. These materials have low conductivity and cause signal delay and other defects, so it is not suitable for A substrate for high speed or high frequency micro-assembled circuits. However, the HTCC substrate has the advantages of high structural strength, high thermal conductivity, good chemical stability, and high wiring density. HTCC ceramic heating sheet is a new type of high-efficiency environmental protection and energy-saving ceramic heating element. The products are widely used in daily life, industrial and agricultural technology, military, science, communication, medical, environmental protection, aerospace and many other fields.
The classification of HTCC
Among the high-temperature co-fired ceramics, ceramics mainly composed of alumina and aluminum nitride are mainly used. Alumina ceramic technology is a relatively mature microelectronic packaging technology. It is made of 92～96% alumina, plus 4～8% sintering aid at 1500-1700°C. The wire material is tungsten and molybdenum. , refractory metals such as molybdenum-manganese. The disadvantages of aluminum nitride substrates are:
(1) The wiring conductor has high resistivity and large signal transmission loss;
(2) High sintering temperature and high energy consumption;
(3) The dielectric constant is higher than that of the low temperature co-fired ceramic dielectric material;
(4) After the aluminum nitride substrate is co-fired with a conductor such as tungsten or molybdenum, the thermal conductivity thereof is decreased;
(5) The outer conductor must be plated with nickel to protect it from oxidation, while increasing the electrical conductivity of the surface and providing a metallization layer capable of wire bonding and soldering component placement.