3D-TSV vertical interconnection method using Cu/SnAg double bumps and B-stage non-conductive adhesives (NCAs)

In this study, the chip to chip eutectic solder bonding method using NCAs for TSV stacking was investigated as an alternative 3D-TSV interconnection method. The non-conductive polymer adhesive was applied at TSV wafers as a film format before eutectic solder bonding resulting in no extra underfill process. The electrical interconnections between micro-sized bumps for TSVs of the stacked chips were investigated. The electrical interconnection through the arrays of the bumps between two chips showed no change even after the reliability tests which meant that vertical interconnection by one step metal/polymer hybrid bonding was rapid as well as stable.