That shiny brown stuff is flux right? Is that bad? Should I remove it? : r/AskElectronics
Flux residues can cause corrosion on PCB assemblies - EDN
How to Clean Flux from PCB | PCBA Store
How To Remove Solder Flux / Great PCB Cleaning Methods HD - YouTube
Chemtronics ES835B FLUX REMOVER 5 OZ. CAN FLUX OFF BRUSH CLEAN SYSTEM L3 Price: Buy Chemtronics ES835B FLUX REMOVER 5 OZ. CAN FLUX OFF BRUSH CLEAN SYSTEM L3 Online in India -Amazon.in