In Plane Collective CoS Assembly by NCF-TCB Enabled Using the Newly Developed Bonding Force Leveling Film

In plane collective bonding by NCF-TCB with the film inserted between the die and the substrate, which had a significant potential to enhance the productivity, was studied. PTFE and the newly developed film which consisted of thermosetting resin layer were evaluated as the insertion films. The performance of the bonding force leveling was evaluated. Bonding was carried out by the intentionally inclined head with the test vehicle equipped with Au plated bump at the peripheral area. The result showed that the newly developed film could make the deviation of the height of the smashed bump smaller than PTFE film. Boding test without insertion film showed the largest deviation. The larger elastic modulus of the thermosetting layer was found to exhibit the smaller deviation. In plane collective bonding was performed. 5 dies were pre-bonded on the 5 substrates and 15 dies were pre-bonded on a single substrate. Both of them were bonded by a large single head as a main bonding. The evaluation of them revealed that all of the dies were electrically connected to the substrates and void wasn't detected in the NCF when the main bonding was performed with the newly developed film insertion. Electrical connection error and void formation were detected in the samples prepared with PTFE and without the film. The die shift was suppressed by the newly developed film insertion most at in plane collective bonding. The film showed the performance of leveling the difference in thickness of 10 μm between dies at the bonding. The simultaneous bonding of 15 dies at this experiment corresponds to the bonding of 2700 unit/ h.