Issue link: https://iconnect007.uberflip.com/i/1498723
10 DESIGN007 MAGAZINE I MAY 2023 In a recent I-Connect007 sur vey to PCB designers, about one-third of respondents said they consult IPC's so-called slash sheets, such as IPC-4101/126, that contain a variety of information about PCB materials. But many designers say these specs don't contain enough information. Some ask their fabricator to pick a material, and still others say, "It's an RF board, and I always use supplier X for RF." What's the best process for selecting your PCB materials? Doug Sober helped pioneer the develop- ment of IPC's first slash sheets in 1996 for IPC-4101 Specification for Base Materials for Rigid and Multilayer Printed Boards and we asked him to discuss slash sheets—what they are, what they are not, and why PCB design- ers might benefit from an IPC materials guide developed specifically for designers. Slash Sheets and Material Selection Andy Shaughnessy: Doug, let's start with your work with IPC and slash sheet development. I started in the laminate and prepreg business in 1978 for General Electric and was sent to my first IPC meeting in 1980. I got heavily involved right away with the task groups regarding spec- ifications for laminates, prepregs, copper foils, glass fabric, resin coated foil, etc. e first stan- dard we did was IPC-4101, but it did not just come out of thin air. We had a document from the military called MIL-S-13949H that had requirements for base materials. e require- ments were physical such as flex strength and peel strength, electrical such as Dk and Df, thermal such as Tg and solder float, and envi- ronmental such as moisture absorption and fungus resistance. Aer IPC-4101 was all fin- Feature Interview by the I-Connect007 Editorial Team