Quality and Reliability of Laser Depaneling for Electronics in Harsh Environments

ABSTRACT Laser depaneling offers several technological advantages, including stress-free singulation, high design flexibility, and improved material utilization through optimized panel layouts. These benefits are particularly relevant for electronics used in harsh environments, where the integrity of printed circuit boards (PCBs) and long-term reliability are critical. The gentle, non-mechanical nature of laser processing has the potential to significantly enhance product robustness. To evaluate the suitability of laser depaneling for such applications, systematic investigations were conducted focusing on cutting edge quality, technical cleanliness, and thermal effects in the vicinity of the cutting channel. Edge quality was assessed for two cutting approaches - one with a focus on maximum throughput and the other one on maximum quality and cleanliness using breakdown voltage and surface insulation resistance (SIR) tests to identify any influence on electrical performance. Technical cleanliness was evaluated in accordance with ZVEI guidelines, VDA 19.1 / ISO 16232, and IEC TR 611917 standards. The influence of key parameters such as laser type, cutting strategy, and PCB design (including thickness and tab versus full cutting layout) was analyzed to determine achievable cleanliness levels. In addition, thermocouple elements integrated into the PCB substrate were used to measure peak temperatures at varying distances from the cutting channel. This enabled characterization of the thermal behavior for different laser power levels and comparison with the liquidus temperatures of standard SAC solder alloys as well as low-melting alternatives. The objective of this study is to provide a comprehensive understanding of the capabilities and limitations of laser depaneling technology, thereby supporting informed decisions on its applicability and benefits for specific use cases in harsh-environment electronics.