1. This 100PCS copper shim set is specifically designed for repairing Android smartphone CPUs, providing targeted heat dissipation after chip reballing or motherboard maintenance. 2. Precision-customized 12.4x14mm short-circuit prevention dimensions ensure full coverage of the chip surface without edge overhang, avoiding contact and short circuits with surrounding components. 3. Made of oxygen-free pure copper, significantly reducing chip temperature when used with thermal paste. 4. Three thickness options (0.1/0.3/0.5mm) available to fit different device models. 5. Replaces damaged OEM thermal materials after CPU rework, reducing the risk of device failure caused by inadequate factory-restored cooling.