IPC International Community magazine an association member publication
Issue link: https://iconnect007.uberflip.com/i/1543307
114 I-CONNECT007 MAGAZINE I FEBRUARY 2026 Designing for the Future of Manufacturing Reality Strip-Etch-Strip The demand for ultra-high density intercon- nect (UHDI) PCBs is growing as electronic devices become increasingly advanced. That means we will be creating more designs that need to align with the reality of manufacturing UHDI boards. My last column on this subject focused on plat- ing, and we are ready to discuss the strip-etch- strip (SES) process. With UHDI boards, footprints are smaller and tolerances are tighter. Your big design challenge associated with the SES process involves trace width and spacing control. The etch- ing process can undercut traces and alter their final size. Before I get to design best practices, this is how C O N N ECT T H E D OT S BY M AT T ST E V E N S O N , AS C S U N STO N E C I R C U I T S the SES process works. Having just completed pattern plating, we have: 1. Laminated all the internal layers together. 2. Drilled the through-holes. 3. Made the through-holes conductive in the electroless copper process. 4. Applied the image to the external layers through photoresist. 5. Plated the copper in those channels to beef up the copper thickness for traces, pads, and through-holes. 6. Added a layer of electrolytic tin over the top of that copper to protect it during subse- quent stages of production.