What is LTCC?
LTCC stands for Low Temperature Co-fired Ceramics. It is a ceramic multilayer substrate. This technology permits to use low resistive material as conductor patterns due to the lower temperature needed during firing process compared to general ceramic firing process. This is achieved by adding glass to alumina.
Combining alumina and glass-based materials enables the firing at 1000 ºC or lower, and silver (Ag: melting point = 960 ℃), which is a low-resistance conductor, can be used as a wiring conductor.
This make it possible to fabricate a multilayer substrate with excellent electrical characteristics with less loss due to low conductor resistance, which is advantageous for high frequency performance.
Since the base material is ceramic, it has excellent heat and moisture resistance and no outgassing. In addition, since the thermal expansion coefficient is relatively close to that of silicon, it is an advantageous substrate for bare chip mounting. Moreover, the height can be reduced by mounting in the cavity.
Because of these features, they are widely used in high-frequency modules, substrates for semiconductor packages, and substrates for applications that require environmental resistance.