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Nondestructively and efficiently peeling thin chip from the adhesive tape is still one of the crucial techniques in IC packaging technology. In order to improve the process efficiency, a novel approach with the inverted ejecting mechanism and spring buffer head is proposed, where, however, the ejecting and spring forces applied at the chip for generating the interfacial crack are also more likely to resulting in the damage of chip. In view of this, an effective theoretical and finite element models are established considering the tape–adhesive–chip structure with ejecting and spring forces, and in the frame of fracture mechanics, the energy release rate is calculated and introduced to reveal effects of the spring buffer on the interfacial crack growth and chip breaking stresses. It is showed that the spring buffer is able to reduce the stress concentration on chip. Furthermore, according to the competing fracture behavior between the interfacial delamination and the chip cracking, the process window of thin chip peeling is suggested for selecting an appropriate spring coefficient and ejecting needle force. [ABSTRACT FROM AUTHOR]

Chip picking-up with vacuum sorption is a critical technology in flip-chip packaging for separating chip intactly from donor adhesive tape. With increasing length/thickness ratio of chips, the incomplete separation affects the success rate of this process, even leads to the failure of chips. Here, we present a theoretical model with a bisection algorithm to calculate the effective size of tape that contributes to the crack growth, and introduce an energy release rate and pick-up force to evaluate the ability of thin chip picking-up. The finite-element method with a virtual crack-closure technique is constructed to validate the established process model. The effects of the type of pick-up head, length of chip, thickness, and material of tape on chip picking-up process are also revealed to improve the ability to propagate a crack in the adhesive layer. Furthermore, the crack propagation in the adhesive layer with increasing pick-up displacement is predicted to determine the critical value of the thin chip complete separation from compliant tape. These results suggest that the thinner and more compliant tape should be adopted in the chip picking-up process. [ABSTRACT FROM PUBLISHER]