Black Pad: When it can be happen on PCBs
Black pad can happen on PCBs that have an Immersion Gold Finish (ENIG). It is a condition where a surface mount component soldered to a PCB loses connection. The nickel under the gold becomes corroded and creates a break in the connection. Black Pad: When it can be happen on PCBs, Black Pad: When it can be happen on PCBs see with complete details here in this article step by step