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.
Preview the slides below to discover how we do it.
This image shows typical damage to surface mount pads. During rework they can become damage or lifted. If you attempt to re-bond the damaged pad using liquid epoxy, you are likely to have a poor result.
We evaluate the extent of the damage and determine the labor time and materials costs. We confirm to you the full cost before we proceed. Once you give us the approval, we schedule the work.
Step 1: We remove the defective pad and any contamination from the circuit board surface. We also remove solder mask or coating from the connecting circuit and tin the connecting circuit with solder.
Step 2: We select a replacement surface mount pad that matches the size and shape of surface mount pad to be replaced. The replacement surface mount pad has a dry-film adhesive bonding film applied to the bottom side.
Step 3: Before trimming out the new 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.
Step 4: We cut out and trim the new pad. We include a length of connecting circuit that will overlap the circuit remaining on the circuit board surfaces to allow for a lap solder connection.
Step 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.
Step 6: We use a special bonding system and heated bonding tips to apply heat and pressure to cure the dry-film adhesive backing on the replacement pad.
Step 6: The heated tips are matched to the size and shape of the replacement surface mount pad.
Step 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.
This photo shows many repaired surface mount pads. This high conformance level repair follows documented IPC guidelines to ensure the repair is reliable and robust.