Issue link: https://iconnect007.uberflip.com/i/1526666
58 PCB007 MAGAZINE I SEPTEMBER 2024 Matties: Regarding the lamination cycles, we're seeing induction presses being widely adopted here in the U.S. Is Wus using induc- tion lamination, and is there an advantage to induction? For surface induction lamination, we've used induction presses for 25 years. On our automo- tive side, we have very thick four-layer boards. It works great for those where there are no flat- ness issues. ey tend to football a little bit on the surface due to the physical lack of very thick lamination plates (image transfer), but they're very inexpensive to run. We even have the ones that can rotate the foil and stack loads on top of each other and have stainless steel plates between them. It's a good process but for a limited application. Our lami- nation presses are greater than 10 openings so we can get the advantages of hot oil and very thick platens, but also have high throughput. It's not something that volume manufactur- ers will look at for volume production, but yes, it's great for small-scale, advanced, single-lam- ination layering. If you want to build a 60-layer hybrid board for advanced LiDAR that can be used in robotics, you need oil and thick plat- ens, you need high-capacity press lamination. LaRont: Joe, what are the realities or hard stops around subtractive etching? Low-profile additive copper is coming fast— not foil, but electrolytic, fully additive, never etched low-profile copper. Having low-profile copper foil and doing 50-µm lines and spaces with conventional subtractive etching on a large scale is very difficult, but not because of the etching capability. We have the gas/vac- uum etch capability, and it's very effective in etching the copper on top and bottom. e problem is that the extremely smooth low-profile foil does not bond to the dielec- tric well, especially if you create sheets like 36x48. e current technologies for bond- ing cores and building up have this challenge. Plus, everywhere there's a glass bundle under- neath a trace, you potentially have a poor bond Figure 4: Advanced HDI and mechanical PCB interconnect solutions for 0.45 to 1.0 mm pitch. (Source: Wus International)