Issue link: https://iconnect007.uberflip.com/i/1243344
8 SMT007 MAGAZINE I MAY 2020 Advancements in Soldering Technology Nolan's Notes by Nolan Johnson, I-CONNECT007 Earlier in the year, SMT007 Magazine pub- lished an issue on "Fine Pitch." In that issue, we learned that the critical point for the manufacturing of electronics using smaller and smaller components was the soldering process— sticking the components to the board, simply put. There was so much information in this space that we decided to c o m e b a c k with a focus solely on the topic of solder technology. "What?"you s a y . " I s n ' t solder rather boring?" Well, m a y b e . E v e n some of the solder experts expressed the endearingly self- deprecating opinion that solder is "kind of mun- dane." I would have thought the same thing until we started digging into the subject. The solder market has fractured. Tin-lead still persists, but lead-free solders abound. ROHS lead-free solders require a higher tem- perature; this puts traditional components and packages at risk. ROHS solder temperatures change the dynamic for reflow operations. The higher temps also put some of the more specialized substrate mate- rials at risk of damage. Work continues to create low- temperature ROHS sol- ders—presumably to return to the temperatures and thresholds that are more tra- ditional to our m a n u f a c t u r - ing processes. F u r t h e r - more, smaller c o m p o n e n t s and new pack- ages changethe r e q u i r e m e n t s put on the solder paste—especially the flux—not to men- tion the challenges on the machinery, stencils, jet printer heads, inspection machinery, and operator skillsets. It turns out that all of these aspects of solder are being pushed to improve. A highlight for this issue was when Dartmouth's Ron Lasky, NovaCentrix's Stan