Significant Advancement in Laser Ablative Release Layer Material Design Enabling Low-Energy and Low-Residue Debond

Laser release materials have become an important topic in the semiconductor industry for wafer-level packaging (WLP) due to its many advantages over other temporary bond and debond (TB/DB) methods, including mechanical and thermal slide. These methods enable higher wafer throughput, subject the device to less physical stress, and allow access to new applications where strong adhesion between material interfaces are necessary, such as fan-out wafer level packaging (FOWLP) to prevent delamination and spontaneous debond due to high stress during the process. However, with the significant benefits laser release materials offer, there are still challenges that affect the current generation of materials. The majority of these challenges are caused by low energy absorbance of current materials, which can result in increased carbon residue, potential device damage from extended laser penetration, high laser energy for debond, long cleaning times (due to thicker coatings and high carbon residue), and the possibility that materials may not effectively debond using commercially available tools such as 308-nm, 343-nm and 355-nm laser wavelengths.The research within this study addresses all of the aforementioned challenges and includes the developmental results of a next generation of laser release materials showing significant advancements to overcome challenges. Next-generation materials have greatly improved performance with increased absorbance of laser energy at 308-nm, 343-nm, and 355-nm wavelengths. This allows materials to debond with lower energy, protect the device from laser energy, produce almost no carbon residue upon ablation, and greatly reduce cleaning time because these materials offer all of this utilizing a thinner coat. This next generation of laser release materials brings an additional benefit of strong open-face solvent resistance without requiring long, high-temperature bakes or compromising the decomposition temperature of the material.