Reliable wafer-level-bonding method for MEMS packaging using LTCC interposers

The anodic bonding of low temperature co-fired ceramics (LTCC) for the wafer-level-packaging of MEMS represents a cost efficient and highly reliable packaging method. To enable for a reliable bonding between the LTCC and the Si wafer the ceramic should have a surface roughness below 50-100 nm. With the aim of avoiding the polishing step for realizing a low ceramic surface roughness a newly developed manufacturing process was deployed, which is based on the optimization of the necessary lamination and sintering steps. The positional accuracy of the electrical feedthroughs within the LTCC ceramic should also become considerably optimized compared to the standard manufacturing process. First promising results will be presented, illustrating the anodic bonding experiments of the wafer level processed Si and ceramic LTCC wafer. Additional a MEMS concept will be introduced to demonstrate the high reliability of ceramic-Si bonding and packaging at operation temperature of up to 300 degrees C.