Surface mount and BGA pad repair are routine operations performed daily at Circuit Technology Center. Damaged pads are replaced with specially fabricated, adhesive backed pads that are thermally bonded to the board surface.
This reliable IPC Recommended Procedure eliminates the need for using messy liquid epoxies to bond replacement pads in place. We stock thousands of different sizes and shapes of replacement pads.
1. We remove the defective pads and any contamination from the circuit board surface. We also remove the solder mask or coating from the connecting circuit and tin the connecting circuit with solder.
2. We select a replacement surface mount pad that matches the size and shape of the surface mount pad to be replaced. These replacement surface mount pads have a dry-film adhesive applied to the bottom side.
3. Before trimming out the new surface mount pad, we carefully scrape off the adhesive bonding film from the solder joint connection area on the back of the new pad to ensure we obtain a reliable solder connection.
4. We cut out and trim the new pad. We include a length of a connecting circuit that will overlap the circuit remaining on the circuit board surface to allow for a lap solder joint connection.
5. We place a piece of high-temperature tape over the top surface of the new pad and place the new pad into position on the circuit board surface using the tape to maintain alignment.
6. We use a special bonding iron and heated bonding tips to apply heat and pressure to cure the dry-film adhesive backing on the replacement pad. The heated bonding tip is matched to the size and shape of the replacement surface mount pad.
7. If the new pad has a connecting circuit, we lap solder the joint. We then coat the lap solder joint connection area with high-strength, high-temperature epoxy to complete the repair.