3D Die-to-wafer Cu/Sn Microconnects Formed Simultaneously with an Adhesive Dielectric Bond Using Thermal Compression Bonding

The simultaneous formation of Cu/Sn microconnects and an adhesive bond during wafer level thermal compression bonding was evaluated using a 3D enabled single metal level test die and wafer. The wafer level bond process relied on locally dispensed adhesive to fix the dice to the wafer prior to bonding and to become a permanent bond during the bonding process. The die-to-wafer microconnect resistance was measured for micropad pitches of 59, 64, and 69 μm. The robustness of the Cu/Sn and adhesive bond was demonstrated by thinning the bonded die to 50 BC;m. Package level reliability testing of parts that were wire bonded into a thermally enhanced plastic ball grid array (PBGA) package indicates good reliability behavior and the absence of any intrinsic reliability-related issues in the microconnects.