We report on a novel technique for achieving threedimensional optical component placement and attachment with sub-micron tolerance using low cost electrical resistance spot welding. We developed this technique to realize optical chip-to-chip two-lens single mode waveguide interconnects in an integrated module incorporating a distributed-feedback (DFB) laser diode chip coupled to a lithium-niobate modulator chip. Our technique is high-yield, and requires no post-weld adjustment. The novel weld clips are low-cost etched parts, and incorporate an articulated foot structure that permits ultra-precise motion while simultaneously attenuating post-weld-shift. The tooling and welding heads form a very small overall footprint, allowing unprecedented overhead access for easy incorporation of parts loading and vision systems. We present characterization data including post-weld-shift measurements, temperature-stability data, and 3D image-correlation maps of temperature stability. | 
