Corrosion study of anisotropic conductive joints on polyimide flexible circuits

In application, ACF joints often undergo thermal foray and since under most circumstances moisture absorption exists at the same time, the combined effects are, therefore, important. Autoclave test was used in this study as a stimulator for stress-corrosion cracking in the strong presence of hygroscopic swelling-induced stress. SEM/EDX analysis showed evidences of metal oxidation and stress-corrosion cracking at ACF joints. Apart from the physical damages, results of FTIR spectroscopy showed chemical modification to aged ACF joints under the effect of autoclave test condition. ACF joints lost their epoxy functionality after 288 h and hydrolysis was becoming obvious after 384 h of the autoclave test.