Development of Evaluation Method for Delamination Strength Between Micro-Sized Materials in MEMS Devices

摘要

Our group developed a method for evaluating the delamination strength between micro-sized components and substrate using combining a micro-sized delamination test and FEM (Finite Element Method) analysis. We adopted a cylindrical shape for the micro-sized adhesive specimens on the substrate. A simple shape can be easily analyzed the stress field near the interface between the cylinder and substrate under shear loading with FEM. Micro-sized cylinders with four different diameters were fabricated on Si substrate by a photolithographic technique using epoxy type photoresist SU-8. According to our analysis of the test results by FEM, the delamination strength between the micro-sized SU-8 cylinder and Si substrate increased as the diameter of the cylinder increased. This suggests that the delamination loads determined by the delamination testing were influenced by natural cracks or defects in the material or at the interface.