Laser Beam Soldering of exotic optic materials

Low-stress bonding using the laser-based soldering technique Solderjet Bumping is presented for the assembly of optical systems. Selected systems include SQ1 and INVAR 36 (baseline system), CaF2 and 1.4371 stainless steel, BBO and Dilver P1, and KTP and Super Invar, the first two proposed as lens demonstrators and the other two as laser crystal demonstrators. Solder parameters found for the SQ1 and INVAR using the DoE method using 400μm SAC305 alloy with the desirability of 0.655, for BBO and Dilver P1 and CaF2 and stainless steel 1.4371 systems, parameters must be changed due to damage observed in the optical components. KTP and Super Invar system parameters are still under investigation. In the case of BBO, the parameters were successfully found while CaF2 is still under investigation, changing the solder bump size due to the constant presence of damage in the samples. Finite elements simulations show that excessive stress occurs locally at the singularity of the soldered interface, but is still below the critical value, nevertheless, the survival of the demonstrators under environmental loads (Δ60 K, 600 g) is expected.