Thermal Method for Localizing High Resistance Shorts
Original Publication Date: 1987-Feb-01
Included in the Prior Art Database: 2005-Feb-01
Plated through holes (PTHs) shorted to power planes or signal lines of multilayer printed circuit (PC) structures, e.g., boards or module substrates, are detected by measuring the short resistance value while heat from an external source is applied to the individual shorted PTH or, alternatively, to a group of PTHs which includes at least one shorted PTH. A shorted PTH in the presence of the applied heat results in a changing value of the measured short resistance. Thus, in the case where the heat is applied sequentially to each of the PTHs connected to the shorted power plane or signal line, each shorted PTH is localized, i.e., is individually identifiable with respect to its position in the PC structure.