Defect of the Month
Lifted Solder Mask: Don’t Blame the Resist
When separation occurs, check the oven settings.
THIS MONTH WE look at printed circuit board delamination. As FIGURE 1 shows, delamination is barely visible on the surface of the board and confined to the area around through-holes and where the solder mask is cracking.
Most examples of delamination are visible and generated by high soldering temperatures or excess time for soldering. Although during soldering there are differences in the expansion rate of materials used in PCB manufacture, the board content can have a dramatic impact.

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PCB delamination, likely caused by excessive soldering temperatures
Figure 1. PCB delamination, likely caused by excessive soldering temperatures.
Bob Willis Caricature
Bob Willis
is a process engineering consultant; bob@bobwillis.co.uk. His column appears monthly.