New heterogeneous multi-chip module integration technology using self-assembly method

We have newly proposed heterogeneous multi-chip module integration technologies in which MEMS and LSI chips are mounted on Si or flexible substrates using a self-assembly method. A large numbers of chips were precisely and simultaneously self-assembled and bonded onto the substrates with high alignment accuracy of approximately 400 nm. Thick MEMS and LSI chips with a thickness of more than 100 mum were electrically connected by unique lateral interconnections formed crossing over chip edges with large step height. We evaluated fundamental electrical characteristics using daisy chains formed crossing over test chips which were face-up bonded onto the substrates by the self-assembly. We obtained excellent characteristics in these daisy chains. In addition, RF test chips with amplitude shift keying (ASK) demodulator and signal processing circuits were self-assembled onto the substrates and electrically connected by the lateral interconnections. We confirmed that these test chips work well.