Explosive Board Phenomenon In PCBA Reflow Welding

Explosive board phenomenon in PCBA reflow welding

        What's the explosive-board?

        Definition: during reflow welding (especially in lead-free applications), the separation of copper foil browning surfaces occurs between the second compression of HDI laminates and the secondary layer of PCB, which we define as exploding board, as shown in the figure.

Explosive board PCBA.jpg

         From the slice analysis, the location of the explosive board occurred in the area with dense holes in the L1-L2 layer, and no debris or other anomalies were found. The explosive board of the slice display panel was very violent, and some of the second layer lines were pulled apart.

Explosive board PCBA 01.jpg