Process optimization of Flatness of LTCC Substrate for TR Module

Flatness is one of the important indicators for evaluating LTCC (low temperature co-fired ceramic) substrates. Unqualified flatness will cause the substrate to crack during the welding process, which will seriously affect the reliability of the subsequent assembly. In this paper, studying of the co-fired process and analysing the method of optimising the flatness of LTCC substrates, a TR component substrate of LTCC was used as the technology carrier, and a pressure co-firing process was developed innovatively to optimise the flatness and distortion of the substrate by studying the material of pressed burnt matter, the weight ratio of pressed burnt matter to the blank which to be pressed and fired and the effect on shrinkage rates, and the reliability of the surface layer of the substrate after co-firing was verified. The results provide a feasible solution to the flatness problem of LTCC substrate and can be extended and applied to the process route of all subsequent LTCC products with warpage risk, solving the bottleneck process problems of common LTCC substrates in the co-fire process, improving the reliability of subsequent assembly.