Issue link: https://iconnect007.uberflip.com/i/1484263
24 PCB007 MAGAZINE I NOVEMBER 2022 Where we are today approximately on BGA pitch below 350 microns, we talk about pads of 140, and then you are basically into mSAP or substrate-like PCB technologies, whatever that is. ere are quite a few technologies out there now that can be used. But we see that we are going from a subtractive into an mSAP level; this depends on where you are com- ing from and how far you are coming with the investments in your factory, because some of the factories that are producing mSAP have invested in imaging, AOI—everything needed for that resolution now. When you have a subtractive in that factor, they can go quite far down here. But if you don't have all the other investments and just go for mSAP, that doesn't help you. I'm saying this as background because you have this producibility level C in IPC-2226, where you have 50-micron track and gap. Every- thing below that is ultra HDI—substrate-like PCBs can be produced by either subtractive or SAP-related technologies. If you go below that again, down to 15 to 20 microns, you need an embedded trace substrate or similar technolo- gies. en of course you come to high-end IC substrates which are in single microns. In the U.S. today for substrate-like PCB, it's below 50 microns, not touching 20 microns, but maybe 35 or 40. When I had my Gerbers and asked for quotations, they said they couldn't do it. ey do have mSAP equipment, if you can call it that, or a process in-house, but have not yet invested in the imaging and AOI that is able to detect down to 20 microns. I think they stop somewhere around 35 today. Johnson: at coincides with some of the num- bers that I've heard from the U.S. manufactur- ers. ey're saying it's under 50. Pedersen: at's also what you see in Asia when people haven't gone to mSAP yet, but invested in imaging, etching, plating, and inspection equipment that brings them down to some- where around 30 microns. want to produce boards there, they say, "Oh, sorry. is is basically for one customer," and they don't accept us putting their competitors, which could be anybody, into the same factory. Johnson: Given that, what is driving the devel- opment of UHDI? Pedersen: For us, it's coming from telecom and 5G, and you assume we'll see 6G. But quite a few of our customers come from these indus- tries. We see that need growing in the automo- tive and medical industries, and I'm discussing it almost globally. I'm looking to see if there is any availability of production capabilities in the U.S. today. We don't find it. ere's one fac- tory in Europe that has limited capacity, and then the rest are in Asia and producing for the big names. Johnson: Where does HDI stop and UHDI begin? Pedersen: Let's use the ultra HDI definition of 50 microns down. It's subtractive down to approximately 40 microns. Jan Pedersen