3D Integration technologies using self-assembly and electrostatic temporary multichip bonding

We developed a new chip-to-wafer 3D integration technology using self-assembly and electrostatic (SAE) bonding. High-throughput multichip self-assembly with a high alignment accuracy within 1 μm was achieved by the SAE bonding technique. Self-assembled known good dies (KGDs) were temporarily bonded on SAE carriers by electrostatic bonding force. We implemented multichip transfer processes twice and then formed through-silicon vias (TSVs) for the self-assembled KGDs to fabricate 3D-stacked chips with Cu-TSVs and Cu/SnAg microbumps. By using the new multichip-to-wafer 3D integration process with SAE bonding, we obtained good electrical characteristics from the self-assembled KGDs having Cu-TSVs and Cu/SnAg microbumps.