‘Collet Auto Clean System’, A Smart Automatic Solution for Die Bonding Pick Up Tool Lifespan & Throughput Enhancement

The common problem vespel collet; the eutectic die bonding process pick up tool; is a short lifespan. The collet tip dimension is similar to shrink chip (size<;0.05mm
²
), which causes an aggressive rubbing effect during die pick and bond cycle. Debris is generated and then accumulated the surrounding of the collet tip surface gradually. Clogged vespel collet tip will result in die pickup issue and accummulated debris will also damage the protruded guard ring design on the chip surface. As such, the vespel collet is then controlled at few ten thousand touchdown. Extending vespel collet lifespan by optimizing die bonding process parameter, changing collet tip dimension and material are not feasible in this situation. The current vespel collet is the hardest material and the smallest tip dimension that can be used in the application. Removing the damaged vespel collet tip by the cleaning process would then be a solution from other perspective. Conventional method is to have manual collet cleaning process offline by human, which lead to high machine idling time and inconsistent collet cleaning quality. An innovative smart manufacturing concept known as “collet auto clean system” is established. It is a programmable fixture that mounted on the die bonding machine to clean vespel collet tip automatically at every predefine touchdown before reaching of the total vespel collet touch down setting. The challenges face are (1) vespel collet tip shape & dimension design to maintain the same tip shape and to withstand the turning force without any broken tip after cleaning, (2) polishing paper grading selection; cleaning parameters definition and cleaned collet tip in-line buyoff for an effective cleaning process. With the implementation of “collet auto clean system”, the vespel collet lifespan is then improved from few ten thousand to few hundred thousand touchdown. Few hundred million parts are delivered without comprising process stability and quality deviation. Vespel collet material consumption has improved from few hundreds pcs to few ten pcs yearly. Also, 3 % collet changing schedule downtime is gained from collet changing interval before every 3 hours to after every 1.2 days.