Wave Soldering Defects


Lifted Resist on a Printed Circuit Board

Figure 1 shows a very obvious example of resist lifting from the surface of the board after soldering. Quite simply this is due to incorrect specification of the printed board. Tin/lead should not be used under resist on professional circuit boards. As the tin/lead moves into a liquid phase it expands and may cause loss of adhesion between the solder and the resist. If the resist is brittle or thin it will separate as shown in Figure 1. It is possible to use tin/lead if the thickness of the coating is less than 3-5┬Ám as there will be very little movement during wave or reflow soldering.



Figure 1: The resist lifting here is due to incorrect specification of the PCB
Figure 1: The resist lifting here is due to incorrect specification of the PCB.

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As the oldest production Printed Circuit Board Company in North America, perhaps in the world, the 60-year plus story of Epec is connected to the development of the PCB and the electronics industry.

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  • Epec Founded in 1952
  • IPC Founded in 1957
  • Epec Builds PCB for Apollo 11