Study on thin die pick-up process based on Taguchi method

Thinner and lighter chips raise great challenge to the existing electronic package technology, including the IC chip pick-up process. A DOE (Design of Experiment) methodology based on dynamic numerical simulation is conducted to investigate the effects of the major parameters of the chip pick-up process, including the ejector speed, picking force, vacuum pressure, and needle radius. A L9(3⁴) orthogonal array is built based on Taguchi method to figure out the optimized factor combination design. Blatz-Ko rubber elastic model is used for describing the hyperelastic deformation behavior of the rubber tip in the numerical simulation. A bonding contact with a failure criteria is employed to simulate the die peeling process from tape. Dynamic mechanical behavior is studied by a 3D Quarter finite element model in the die pick-up process. Results indicate the picking force and the ejector speed have critical influence on die damage. The maximum 1st principal stress of the die with original process parameters is 127.37 MPa, which can be substantially reduced by 43% after the optimized factor combination design during the pick-up process.