Laser Ablation Dicing Revolutionizes Ultra-thin Wafer Saws Beyond the Capability of Blade Dicing

Driven by increasing power efficiency requirements in new advanced power electronic packages, the thickness of power semiconductor dies is decreasing. Fabricating ultra-thin wafers is the most direct and economic way to achieve improved power efficiency. Consequently, semiconductor companies are exploring silicon wafer thicknesses below 50 μm, which may have already reached the capability of blade dicing. Issues such as metal peeling at the side walls of dies and large bottom side die chipping sizes are always the bottlenecks for ultra-thinned wafers when using the common blade dicing technology. This study presents a comprehensive investigation on laser ablation dicing technology to overcome these issues. The process characterizations of laser ablation dicing on 50 μm thick wafers along with validation on 30 μm thick wafers are discussed. Additionally, solutions to reduce die strength concerns caused by laser ablation dicing are presented, too. Results indicate that laser ablation dicing is effective in the range of 30 μm to 75 μm wafer thickness and down to-30 μm narrowed saw street width, where the capability intersection between laser ablation and blade dicing is at the thickness of 50 μm and the saw street’s width of 60 μm.