Hello to you, presently I have a concern regarding the rework of the BGA carrying assemblies. So, we remove the bad BGA, then we clean the pads of the PCB. The problem is this cleaning. The non-fluxed solder wick (pure copper) on which we apply the rework flux used subsequently on the pads when placing the new BGA doesn't work very well, we have to heat a lot before the solder starts to go. The normal, rosin solder wick, works fine, but leaves the burned rosin on the board. All the stuff mentioned is no-clean. My question is: Is it reliable to use the rosin solder wick? We clean the remains with IPA, but still, when the rework flux is applied, won't we get some funny reaction between the two chemicals, creating voids or keeping the joint from being reliable? Are there any IPC speciffications regarding this? Thanks, Ioan