Theoretical and experimental studies of spring-buffer chip peeling technology for electronics packaging

The reliable peeling-off and picking-up of thin chips from adhesive tape is still one of the crucial techniques in electronics packaging. The fracture of thin chip induced by high cracking stress, and the chip deviation after needle ejection in chip peeling-off stage have greatly affected the success ratio of chip pick-up processes. In this paper, a spring-buffer chip peeling technology is proposed, where the pick-up head is assigned to come in contact with the chip to avoid the chip deviation, and a spring is designed in pick-up heads which can prevent the chip cracking due to the buffer effect. Here, an effective theoretical chip–adhesive–substrate model considering the spring effect is presented to address the chip peeling analysis and competing fracture behavior between interfacial delamination and chip crack. The analytical results show that the spring-buffer chip peeling technology using the pick-up head with a spring can ensure chip peeling and restrain chip cracking under a large ejecting needle force as it can reduce the stress concentration by the needle tip. Additionally, the three-dimensional finite-element model and experiments are completed to verify the analytical results, and the paper introduces a process window for reliable chip peeling.