Issue link: https://iconnect007.uberflip.com/i/1511625
8 PCB007 MAGAZINE I NOVEMBER 2023 Nolan's Notes by Nolan Johnson, I-CONNECT007 The Registration Sweet Spot Registration is underrated and underap- preciated. You can try to argue with me about this, but aer diving into the current state of registration, I'm convinced. For example: • 30 years ago, the state-of-the-art for integrated circuit geometries was in the low-double and high-single digits of microns, single-sided, on a consistently planar and highly polished crystalline substrate. Almost without exception, the entire integrated circuit was built on top of the substrate. • Today, the bleeding edge of traditional PCB fabrication can reach into the 20-micron range, possibly multilayer, oen still on epoxy-and-fiber substrate into which holes are drilled and metal plated; and it's expected that features across multiple layers will match up across the entire stackup. at's asking a lot. I am reminded of a scene in "From the Earth to the Moon" (Kinda want to get the boxed set, but is that still a thing?), an HBO series about the NASA space program of the 1960s. One particular episode opens with an aero- space engineer giving a presentation, stand- ing next to an overhead projector. It went something like this: "How hard is it to get a spaceship to the moon? Pretty hard. e ballistics are very