Rework Steps of Underfilled CSP
Rework System
Taking CSP off and cleaning UF residue
1.Spot reflow
2.Cleaning residue
3.Removing underfill residue
Using tweezers or plastic scraper, let the UF residue flake off from the PCB surface.
If this is difficult for remaining adhesion strength of the resin, spot reflow the
residue at 60~80 degrees and then break the resin.
4.Cleaning the PCB surface with IPA
Consideration
The whole process takes about 10 minutes. The UF fillet around CSP and UF over passive components could be removed before starting spot reflow the CSP. This is to prevent the surrounding components from being lifted up
