Advancements of Temporary Bond and Debond: Creating Photonic Debonding Methods and Materials for Wafer-Level Packaging

Wafer-level packaging (WLP) has become an ever-advancing technology to assist in the advancement of integrated circuit (IC) performance by creating a faster package with shorter interconnects between multiple ICs. Advancing the technologies for WLP have become more important as the years have gone by in order to compensate for the slowing down of Moore’s Law, so that performance increase and cost reduction can be maintained at a study pace. Due to the need of newer technologies, more investments are being made by outsourced semiconductor assembly and test (OSAT) facilities, packaging houses, foundries, and integrated device manufacturers (IDMs) in advanced packaging. One important field in advanced packaging that is benefiting from the investments being made is temporary bond and debond (TB/DB) technologies, where adoption and use of these technologies are steadily increasing due to the rise of more complex problems. TB/DB has been commonly utilized to enable technologies such as fan-out wafer-level packing (FOWLP), where highly warped epoxy mold compound (EMC) wafers are used, to help reduce the overall warpage of the wafer as well as enable backside processing of the EMC wafers. Traditionally, TB/DB has utilized three main debond methods: thermal slide debond, mechanical debond, and laser debond. Each of the three debond methods have their own advantages and disadvantages compared to each other, offer different types of combinations of material systems, and offer different levels of wafer throughput. In this paper, a novel flashlamp-based photonic debonding method, and corresponding materials, will be discussed. The photonic debond method combines advantages of the other debonding systems, while reducing the disadvantages. This new debond technology drastically increases throughput by offering debond times within the seconds range for the whole wafer, will provide a lower cost of ownership, and offer a wide variety of material solutions consisting of thermoplastic, thermoset, and multifunctional materials.