Issue link: https://iconnect007.uberflip.com/i/1540425
32 PCB007 MAGAZINE I OCTOBER 2025 has two ways to dissipate: heat or ablation. The shorter the pulse, the more energy goes directly into ablation and the less into heat. Using a pico-green laser source, we see sig- nificantly less carbonization and a cleaner, more precise cut. Mechanical Operations Every material has a different recommended cutting speed, and this is a significant chal- lenge when drilling a mixed-material PCB. The process engineer's goal is to find the "perfect recipe" by slightly varying the set- tings and performing micro-sections to iden- tify the limits of the tools and set a proper hit count. Working with mixed materials, the need for differ- ent cutting speeds forces a compromise, making the process engineer's job even more critical. In such cases, simply following the material and tool man- ufacturers' recommendations may not be enough; dedicated time must be spent finding the ideal drill- ing parameters for that specific combination. Depth routing for rigid-flex is a critical mechanical process. After lamination, the board is entirely rigid, but at the final stages, a precise depth-routing oper- ation removes the unnecessary rigid parts to free the flex layer—a process often called "cup elimina- tion." If this depth routing is even slightly overdone, the flexible part would be damaged, and the entire PCB scrapped. To prevent this, it is critical to con- trol the depth routing with a second measuring sys- tem (like a pressure foot). Process engineers must adjust the depth and choose the proper inserts for the pressure foot, making this a highly technical and precise operation. Summary I often tell people at PCB shows that I love this indus- try because it's not simply about the machines. It's about people, processes, materials, and the envi- ronment. Many factors influence the final result, and in the end, machines are simply tools in the operator's hands. Some people can produce com- plex PCBs with simple tools, but to achieve a stable and repeatable serial production, one needs good tools. At the same time, when working with specialized PCBs like rigid-flex, the influence and expertise of the process engi- neer is even more critical. PCB007 Kurt Palmer is president of Schmoll America. To read past col- umns, click here. C o v e r l a y a f t e r c u t t i n g w i t h p i c o g r e e n l a s e r s o u r c e ( m i n i m i z e d c a r b o n i z a t i o n , n o h e a t - a f f e c t e d z o n e v i s i b l e ) . ▼ D e m o n st rat i o n of t h e l a st p ro c e s s ste p s d u r i n g r i g i d -f l ex P C B p ro d u ct i o n , i nvo l v i n g d e pt h ro u t i n g . ▼ D R I V I N G I N N OVAT I O N