Analysis of the laser transmission rate of silicon (Si) applied to flip-chip bonding

The present study explored a flip-chip packaging method where transmission bonding is performed using the laser beam transmission rate of Si, the main material of flip chips. Here, the transmission of Si by a laser beam using laser wavelength in the IR domain (1,064 nm) was demonstrated through experiments. Further experiments were then conducted where the results were applied to actual flip chip bonding. The mechanical properties of the flip-chip solder joints were analyzed through experiments, and the degree of thermal effect was analyzed through simulation. The results showed that, in flip chip bonding, laser transmission bonding was advantageous in mechanical, thermal, and temporal terms relative to conventional bonding (thermo-compression).