Advanced precision laser marking and other microelectronics applications including wafer dicing, PCB drilling/trimming and ITO trimming using industrial nano-second lasers

Marking on semiconductor devices becomes complicated and difficult because ultra-reduction of the device size is being made to increase the memory capacity and processor speed. Wafer-level package marking requires even down to 100um × 100um character height and a couple of micron marking depth. Microelectronics industry includes semiconductor devices, flat-panel display, and printed-circuit boards (PCBs). Key applications for semiconductor industry include wafer marking, dicing, and drilling for wafer and cutting for stacked memory or multi-function-chip package. Key applications for display industry include in-glass marking, transparent electrode trimming, and metal electrode trimming. Key applications for PCB industry include PCB drilling and embedded PCB trimming. Especially for wafer dicing, key issues include achieving good die strength similar as the one in mechanical dicing for patterned silicon wafer, and cutting without abrupt expansion for oxide passivation layer, grooving for low-k materials, and good cutting with clean cutting surface and no residual particles for die-attach film (DAF). As one of new and proprietary processes to get the quality and speed above-mentioned, multi-beam cutting or grooving using polygon mirror is introduced. The types of lasers for the microelectronics industry include 1064nm, 532nm, and 355nm in the wavelengths, Nd:YAG and Nd:YVO4 lasers in laser materials, and 10.6 um for CO2 lasers. In this talk, overall industry trend and new technologies for laser’s microelectronics applications are briefly introduced focusing on nanosecond lasers which can create the industrial demand for quality, throughput or processing speed, and total cost.