Gang-bonding CoC assembly by NCF-TCB using newly developed bonding force leveling film

The performance of the newly developed film to level the die height in the process of multi dies chip on chip gang bonding was evaluated. Non-conductive film was used as pre applied underfill. The bonding was carried out with the equipment having a head of 100 mm × 100 mm and a large stage. The parallelism of them was investigated. The head was inclined to the stage, which was 10 μm at bonding temperature. Leveling performance was evaluated by the three dies gang-bonding. The height of the dies were intentionally differed one another, which was controlled by a SUS tape insertion between the head and the dies. PTFE and the newly developed films were used as the insertion films. In case of the gang-bonding with PTFE film, some lack of the electrical interconnections occurred in the daisy chain test, where the SUS tape wasn't inserted and void in NCF was detected especially at the peripheral area in the lower height die. In contrast good electrical connection and no void in NCF observed in the dies bonded with the BFL film.