scope:

This part of IEC 62047 specifies a four-point bending test method for measuring interfacial adhesion energy of the weakest interface in the layered micro-electromechanical systems (MEMS) based on the concept of fracture mechanics. In a variety of MEMS devices, there are many layered material interfaces, and their adhesion energies are critical to the reliability of the MEMS devices. The four-point bending test utilizes a pure bending moment applied to a test piece of layered MEMS device, and the interfacial adhesion energy is measured from the critical bending moment for the steady state cracking in the weakest interface. This test method applies to MEMS devices with thin film layers deposited on semiconductor substrates. The total thickness of the thin film layers should be 100 times less than the thickness of a supporting substrate (typically a silicon wafer piece).