Issue link: https://iconnect007.uberflip.com/i/1481876
14 PCB007 MAGAZINE I OCTOBER 2022 going up to 2-ounce copper on the layers. ere is some wet process equipment, and unfor- tunately, our SCHMID lines are five years or older, so we don't even have the latest, greatest technologies that way. Some of the really inter- esting stuff is in China; there's not a U.S. repre- sentative for it. Johnson: With the interesting stuff in China, is there any sense that U.S. equipment manufac- turers are looking at similar technologies? Do you get a feel for that? Davidson: I hope they are. I haven't seen any- thing from Chemcut. Obviously, we have a lot of SCHMID equipment. I saw a presen- tation about two years ago regarding a nano- etch technology in China. To give you that straighter sidewall, it's a finer droplet of cupric that helps clear out the traces without creating as much of the trapezoid shape. I have not seen anyone pick that up here and create an alter- native. Obviously, there's a patent and intel- lectual property to be careful of, but TTM has facilities in China, so we use some leverage to see whether there are opportunities to bring it over. It's just difficult to do that. Johnson: Is the best play for the North American market to jump into additive and semi-additive? Davidson: ere are some advantages to it, and we have some product here where we are doing that. It's not our main area, but as you push things tighter together, registra- tion becomes a problem, especially with material shrinkage, growth, and some of the new exotic materials that are not lin- ear in their movement. We've been so used to a glass cloth inside with a grain and a cross-grain, and it's pretty predictable. e film materials are anything but predictable. If you do an addi- tive, you can look at the features, whether it's a drilled hole, see where it moved in relation to where you think it should be, and adjust accord- ingly. at's an advantage so you can build up that way. But the majority of our product is still just build-up. We go up to 67 layers right now, and it's about getting them all to line up. We do things to help registration, such as stiffer borders, more copper, some different lamina- tion techniques that we're trying out, and they seem to show some promise. But you are still at the mercy of what the material wants to do. You have the high stack up to 67, and the flip side is we have some that are four layers on essentially film material and the spacing is super tight. When they move, and they're not linear, we're chasing regis- tration back and forth. e ones I hate to see come through my areas are the super thin and the super thick. ey're never fun. Shaughnessy: What would you say is your sweet spot? Davidson: I almost never get calls for product that's between 100- and 200-mils thick. It's very rare anything is creating a problem there. I get calls for the 20-mil thick panel, and then the Regular tracking.