Coursen Coating Labs has been quietly working in the shadows for over 25 years to provide alternative to gold solderable coatings. Night vision optical systems, guidance systems, endoscopy, and other industries all use our 3LPT coating. Our proprietary coating excels when used to create hermetic seals for optical housings. This solderable coating is resistant to environmental changes and displays superior adhesion to most substrates, from glass to ceramics, as it is less susceptible to thermal expansion. We developed our 3LPT coating as a solution to our customers’ problems. One example featured a customer attempting to bond miniature optical components to ceramic using a high-grade epoxy. The epoxy would break down with exposure to radiation, causing the optics to come loose or move out of alignment. Our 3LPT coating was used to replace the joints (Figure 1), resulting in no broken bonds with the ceramic when soldered correctly. The soldered joint often outlasted the actual components.