Repairing PCB Laminate
This how to will show you how to repair damaged laminate when you slipped and accidentally damaged the board during rework, an area of the board has been overheated or the board has been dropped. You can either find a service provider to perform this work or buy a complete kit and "do it yourself".
Repairing Damaged PCB Laminate
PCBs can have the laminate damaged by several things. You might have accidentally scraped the surface by using some rework tool on the surface and your hand slipped or you may accidentally dropped the board in its edge or corner or a device location may have been overheated. This little tutorial will show you how to professionally repair a damaged laminate.
Clean and Inspect the Damaged Area. Gather Materials Required for This Operation.
This procedure is used to repair damage to circuit base board material in IPC 7721 3.5.1 the Epoxy Method. You will need the following materials:
Cleaner
Foam Swabs
Kapton™ Tape
Knife
Microscope
Mill Cutter
Oven
Scraper
Wipes
In some case most of the necessary tools are found in a PCB laminate repair kit.
Damaged Bulk Laminate Area
Remove the burned PCB areas by using a Dremel or Micro drill rework system. Use a ball mill to remove down to the same level all of the damaged or burned laminate material.
Smooth Out the Sidewalls Using the Dremel Tool and Smaller Ball Mill
Use a smaller ball mill to “smooth out" the side walls.
Flatten Out the Bottom Surface of the Well Created in the Previous Step
Use a specialty medical scraper to "flatten out" bottom surface of the well created by the tool.
Undercut Around the Edges of the Site
Use a small thin ball mill to provide an undercut around the periphery of the excavated site
Fill in the Excavated Site
Use a 2-part epoxy to fill in the prepared area. Cure the epoxy per the manufacturers' suggested cure cycle. Wet sand. “Butter coat” mixing the epoxy with alcohol on top to give it acceptable surface finish. You my want to add colorant to color match to the board solder mask color. You may also want certification in PCB repair or hands on training.