Anyone else come across this PbF situation? With pbf solder joints on green finish pcb and viewing pins for solder problems under x30 microscope. Perhaps an optical effect from the curvature of the solder blobs being concave rather than convex. Makes it appear as though there are green rings around the pins as though failed solder and you can see the underlying board through a solder ring-crack. As viewing pin end on it is all a bit iffy. To convince yourself it is an optical effect , surround the pin ,covering the green board with sticky paper labels of another colour and this green ring turns to the colour of the paper
- posted
13 years ago