Apparent Mobility of Interfaces in Integral Resistor Material

Temperature at a constant heat flux was measured on an integral resistor sample that showed apparent interfacial mobility. Initial measurements were made using infrared, optical, and scanning electron microscopies. Analysis of infrared microscopy measure- ments showed a broadening of an interfacial region, which behaved like diffusion. The feasibility of thermal scanned-probe microscopy for increased spatial resolution was examined. Electron microprobe analysis confirmed the diffusion mechanism. The polymer matrices of many materials com- monly used in electronic packaging applica- tions allow significant diffusion of metals, which may play a role in failure of devices, particularly integral and embedded passives.