A study on the adhesion performance of copper to polyimide for microelectronic packaging-flex substrates

The objective of this study is to investigate the adhesive strength and the failure modes of Cu to polyimide for the two and three layers of flex substrates. Peel test was applied to measure the interfacial strength of Cu to polyimide and Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and Energy Disperse Spectroscopy (EDS) were used to observe the failure modes. The durability of Cu bonding to polyimide for the two and three layers of flex substrates was also studied by aging at various temperatures from 25/spl deg/C to 400/spl deg/C.