Abstract: With the large application of patch resistance on the PCB board of home appliances, the adverse occurrence of patch resistance also increase. In the age of metal film pin resistance, the poor resistance is mainly manifested as burning, rust, larger resistance value, and one of the bad resistance phenomena of the patch is the smaller resistance value. Through the environmental reliability test of PCB board, induce the PCB failure, lock the patch resistance through electrical performance analysis, and then observe the resistance structure, analyze the patch resistance internal silver element migration in the electric temperature and humidity environment, resulting in the decrease of resistance value.

Key words: Resistance value change, Structural analysis, Element migration