What is the reason for PCBA baking explosion?

First of all, we need to understand why PCBA needs to be baked. PCBA baking is to remove excess moisture and improve the reliability of the plate. Generally, the tidal sensitivity level of the PCB board is defaulted to three-level tactile sensitive components. So the baking will be in accordance with Level three. But sometimes, the opening time is too long, or the moisture is too severe. According to this situation, if baking in accordance with the three moisture sensitive components, there will be PCB board explosion, which generally occurs in the middle of the insulation layer. The reason for this is that the PCB board is subjected to high temperature and heat after being exposed to moisture. And the moisture in the board will generate a strong vapor pressure. If the expansion force caused by the vapor pressure is greater than the binding force at each interface in the material , it will burst board.