Shear test for adhesion measurement of small structures

In this study adhesion measurements using shear testing and investigation of the failure mode were carried out. We determined the average shear force of small polyimide structures on metal or oxide surfaces and of metal bumps on sputtered metal layers. Results show clearly, that the type of polyimide has an influence on average shear force for polyimides on metal or oxide surfaces and that sputter conditions can influence the average shear force of the metal layer. The location of fracture is also influenced by the type of combination of polyimide and substrate. Temperature cycling and temperature-humidity testing show a greater influence on average shear force for the polymer specimen than for the sputtered layers. The shear test could be used for occasional monitoring or for routine production monitoring.