Solderjet bumping packaging technique optimization for the miniaturization of laser devices

Abstract

Background: Low-stress soldering techniques can guarantee a minimized input of thermal energy allowing for the design and later assembly of more robust and miniaturized optical devices. However, in order to build miniaturized optical devices, these small-induced stresses produced by soldering techniques have to be investigated to guarantee that the stress-induced birefringence effects do not alter the device optical properties and requirements. Methods: An analytical method that relates the stress-induced birefringence of laser components with their corresponding lasing capabilities has been compared to the real induced-stress results created in components packaged using solderjet technology. The main goal was to optimize the optical component packaging by using this low induced-stress soldering technique. The optimization was carried out by assessing components miniaturization while still assuring high robustness of the bond strength without creating a beam depolarization ratio of more than 1%. Results: The outcome of the study showed the possibility of assembling laser optical components down to sizes of around 300 μm, creating a bond strength of 5 N and higher, and a depolarization ratio much lower than the proposed target of 1%. Conclusions: Our results in terms of induced stress agreed with the finite element method result, which would imply correct post-processing laser simulations. This suggested that the solderjet bumping technique could robustly join components down to the laser emission beam size without strongly affecting the optical properties.

Insights of the Qualified ExoMars Laser and Mechanical Considerations of Its Assembly Process

“…ij was later imported in VirtualLab Fusion software, which was used to analyze the effects on the different laser wavelength propagation's across the stressed laser materials. The VirtualLab Fusion results helped to understand if the laser beam was affected due to the stress on components because of the soldering packaging processes [28].…”

Direct Drop-on-Demand Printing of Molten Solder Bumps on ENIG Finishing at Ambient Conditions Through StarJet Technology

“…Consequently, some novel packaging technologies for directly soldering and interconnecting electronic components and printed circuit boards (PCBs) in two (2D) and three (3D) dimensions have been developed. The so-called contact-free metal deposition techniques, such as laser solder jetting [3]- [5], inkjet printing of solder droplets [6], [7], and Ag nanoparticle-based inks [8]- [10], can deposit conductive metal without directly contacting the sample and provide various advantages such as high compatibility with 3D structures and flexible PCBs, low local heating while establishing the electrical contact, avoiding direct contamination and damage, and reduced process steps and cost due to the digital fabrication concept. Amongst all these contact-free metal deposition methods, the StarJet direct printing technology provides a single-step, noncontact metallization by directly applying molten metal droplets in liquid state for metallization and soldering on various materials in 2D and 3D.…”