Laser-induced forward transfer of solder materials and laser soldering for photonic integrated circuits bonding

Among different additive manufacturing (AM) technologies, laser-induced forward transfer (LIFT) has been widely investigated, owing to the eco-friendly rapid processing and the compatibility with a broad range of materials. In this work, the combination of the LIFT of solder materials (Gold-tin (AuSn) thin film and solder paste) and of a laser-based bonding station comprising a vacuum-assisted pick-and-place tool, and a laser soldering setup is reported for the bonding of small dimension optoelectronic components onto test silicon substrates. The findings of this study determined the optimal laser soldering parameters for integrating resistors and LEDs onto test substrates comprising LIFT printed solder patterns of solder paste with particles’ size of 2–11 μm and AuSn thin film materials. Optimal conditions for solder paste and AuSn thin film bonding were determined, ensuring reliable attachment of components and consistent process performance. The proposed methodology enables thermally localized, non-contact bonding with high positional accuracy and reproducibility. Initial experimental results validate the robustness and repeatability of the process, demonstrating its potential as a scalable solution for heterogeneous integration in advanced photonic and microelectronic packaging architectures.