● Clean the area
● Remove all of the extra solder
● Scrape or grind
● Prepare solder mask material
● Apply solder mask material
● Cure in an oven
● Confirm that the repair
Generally the soldermask is not easy to drop off after curing. The solder resist itself is a protective layer for printed circuit boards. If there is solder mask damage on a PCB, there are several methods to repair it.
You can use a dedicated soldermask repair pen to apply the ink to the circuit board. And then make it dry in an oven. If the PCB board is not assembled, you can bake it in the temperature of 150 degrees for 20-30 minutes. If it has already been assembled, you can bake it in the temperature of 120 degrees for about half an hour. It dries quickly in the oven. The repair pen is usually simple to use, and the ink mask is durable.
If it is just for aesthetic purpose, you can use something like oily color pen to repair the board. But this can only serve to temporarily to improve the appearance, no insulation and protection effects.
The BGA solder mask repair steps can be summarized as the following:
1. Clean the area to ensure enough adhesion, to optimize electrical properties and minimize corrosive effects.
2. Remove all of the extra solder from the BGA pads.
3. Scrape or grind.
4. Prepare the replacement solder mask material.
5. Apply the coating replacement mask material.
6. Let the epoxy cure in an oven.
7. Confirm that the repair is completed correctly by checking the electrical continuity between the vias and the BGA pads.