Theoretical and Experimental Studies of Competing Fracture for Flexible Chip-Adhesive-Substrate Composite Structure

Competing fracture of chip peeling and chip cracking dominates the fast, nondestructive, and reliable peeling of ultrathin silicon-based chip from polymeric substrate. Here, a competing fracture model of chip-adhesive-substrate composite structure is developed to achieve the successful chip peeling in needle ejecting process. Influences of the thickness and length of chip and layout of ejector needle on the peeling-off behavior are investigated. The theoretical prediction is found agreed well with both numerical simulation and experimental test. The process window is preliminarily determined by combining the designed experimental platform. The traditional needle ejecting process is found helpless to achieve the purpose of nondestructive peeling off for an ultrathin chip. A modified multineedle ejecting process with independently controlled ejector needles is finally proposed to improve the chip peelability.