How Can You Repair the Solder Mask on a PCB?

Solder mask or solder resist is a protective coating applied on a Printed Circuit Board (PCB) to protect the copper traces on the board and to stop electrical shorts. Over time, this layer starts to decay and is no longer able to protect the traces on the board. However this can be fixed or repaired by applying (Spraying or Brushing) the solder mask over the traces. Once the solder mask has been applied, it can be placed in an oven to dry.

PCB Solder Mask Repair Process:

• Remove excess solder from the pads to ensure enough adhesion and to have good electrical properties.
• Prepare and apply the coating replacement mask material in the designated areas. Sometimes, colour agents are also used to match the coating with the existing colour of the board.
• Let the mask dry in an oven.
• Check for the electrical continuity between the vias and pads.