Smart adhesive gap design to minimize volumetric shrinkage misalignment effects in the automated assembly of FAC to Bottom Tab subassemblies (Conference Presentation)

Fast axis collimator (FAC) to Chip in the assembly of High Power Diode Lasers (HPDL) systems is state of the art done in active alignment. Micro manipulators and (semi-) automated machines are available for purchase on the market. Neither the precision of the manipulation tools (step resolution < 10 nm) nor the measurement systems utilized in active alignment algorithms (alignment precision of ~50 nm) are the quality limiting factors but the bonding process is. This is due to the volumetric shrinkage of fast curing UV-adhesives in the curing process. The objective of this work is to reduce the absolute volume of adhesives in optical systems by smart design of the glue glap so no significant misalignment while curing is expected. The assertion is that the overall system quality is improved with the implementation of additional adhesive gaps if the amount of adhesive is reduced in this way. In high quality systems as HPDL this approach is state of the art with the implementation of FAC lens on Bottom tab. In other industries as automotive sensors that are drastically reducing component tolerances and improving system quality this approach is rather unknown. Results of glue gap reduction for HPDL assembly is described in this work by combining active alignment of FAC to edge emitter with a tolerance compensated individualized FAC on bottom tab subassembly in a fully automated production process. The approach was described in the papers [SPIE 10086-28] and [SPIE 10514-38]. Furthermore the approach of systemizing the smart glue gap design is done.