As the temperature continues to rise, the gas accumulated in the vicinity of the buried hole is more and more, forming a large expansion pressure, so that the browning surface of L2 and the PP are subjected to a separation force for separating them.When the final expansion pressure (f) is less than the adsorption force (F) between the browning surface and the PP (fF), separation occurs between the browning surface of L2 and PP. A distinct blocky blistering phenomenon.

In the following, the existence of water in the PCB, the way of water vapor diffusion and the change of water vapor pressure with temperature, reveal that the existence of water vapor is the primary cause of PCB explosion.

Obviously, the sufficient and necessary conditions for the latent burst must be induced by the temperature factor. Optimizing the reflow soldering temperature profile based on a comprehensive analysis of specific product characteristics is effective in suppressing the occurrence of cracking