Study of adhesive flip chip bonding process and failure mechanisms of ACA joints

High temperature reliability of electrically conductive adhesive attached temperature sensors on flexible polyimide substrates

“…The ACF1 with gold-coated polymer particles was found to be less reliable than the ACF2 with gold-coated nickel particles. In other studies it has been found that pliable polymer particles may adjust better to thermal stresses created in the interconnection at high temperatures [19,20]. However, a very high temperature was used in this study, and this may have affected the polymer particles more than the metal particles, thereby explaining the differences between the ACFs.…”

Flip chip attachment on flexible LCP substrate using an ACF

“…It was difficult to determine the reason for failure in test samples showing failure at high temperatures, since no indication of delamination was found. One explanation may be the relaxation of the compressive forces of the adhesive matrix at high temperatures [10]. When the temperature decreases, the adhesive matrix contracts enabling the particles to reform an electrical contact.…”

“…doi:10.1016/j.microrel.2004. 10.009 due to their excellent combination of thermal, mechanical, chemical and electrical properties [5]. Melt processable main chain thermotropic LCPs are typically used in flexible printed circuit boards.…”

Reliability aspects of electronics packaging technology using anisotropic conductive adhesives

“…Yin, et al [10] found that the contact resistance of ACA joints increased significantly after reflow process and conduction gaps formed between the conductive particles and the electrode. Seppälä and Ristolainen [11] also reported the detrimental effects of reflow on the reliability of ACA joints. The possible reason is that, due to its much higher coefficient of thermal expansion (CTE), the adhesive matrix expands in the Z direction much more than the particles during the reflow.…”