High-precision integration approach based on alignment maintaining flip-chip bonding using cone shaped bump and truncated pyramid pad

In this paper, a high-precision heterogeneous integration approach based on a high alignment accuracy flip-chip bonding using nanoparticle deposition (NpD) cone shaped (CS) bumps and anisotropic wet-etching truncated pyramid (TIP) bonding pads is introduced to precisely control the post-bond position of the bonding chip. Experimental results show that the bonding chip could be confined within sub-micro ranges in all the X-, y- and z-axis. Moreover, reliable bonds with ohmic contacts were realized at 150°C, capable for edge emitting laser (EEL) chip staking applications.