A lifted pad on a printed circuit board is a pad that detached from the surface of a PCB in Flexible PCB supplier china. This results in an improper connection to the lead or component causing the PCB board that produced by Flexible PCB supplier china to malfunction or not work. This defect is usually found on single-side PCBs that use a thin copper layer with no through-hole plating. It is caused by excess heat and/or excessive force on the solder joint. The lifted pad issue can occur in both through-hole and surface mount connections.

In the wave soldering process, the surface of the PCB tends to heat up. This can reduce the adhesion of copper and therefore result in a lifted pad if the PCB in Flexible PCB supplier china is handled roughly or mishandled. So, it is important to handle the printed circuit boards carefully when taking them off the conveyor belt after soldering.
Another thing that can cause a lifted pad is using a hot soldering iron for the de-soldering or rework of components. Again, the principle is the same, heating of the board can reduce adhesion of copper. So once the repair/rework process is complete and the board not handled carefully before the connections set in, a pad can lift.
How to avoid PCB pad lifting?
The best way to avoid lifted PCB pads is to handle the board carefully after the soldering process till the solder has solidified properly.