PCB designers are proud of their independent streak; this is one of the few careers in which being labeled “off-grid” is considered a resumé enhancement. Designers all have their own little tips and tricks for designing boards, and this trait carries all the way to the material selection process.
As we learned in a recent Design007 Magazine survey, when it comes to choosing the right material for their board, our readers are about evenly split. Almost 30% of respondents said they always consult IPC’s slash sheets during the material selection process. One-third said they sometimes use slash sheets in their decision-making progress, but 39% said they never utilize slash sheets.
Once again, it all comes down to data. There just isn’t one document that contains all the information that a designer needs to consider when selecting a PCB material. This is why so many designers say, “I like vendor X for my aerospace boards and vendor Y for medical.”
As you’ll see in this month’s issue of Design007 Magazine, slash sheets such as IPC-4101/126 were never meant to be used by designers when comparing PCB laminates. These documents were created to facilitate communication between purchasing and customer service departments. I guess you could say that slash sheets are made for administrative purposes, not engineering.
As the captain said in “Cool Hand Luke,” “What we’ve got here is a failure to communicate.” IPC does offer several design guidelines, created specifically for PCB designers, including one just for flexible circuits. But there isn’t such a guideline for high-speed designs.
Perhaps it’s time for a new set of design guidelines—a new materials paradigm. The ideal design guidelines would contain all the information designers would need to consider when choosing a laminate. These guidelines could also rank the materials by sector, such as aerospace, medical, or industrial. This month, we include a conversation with Doug Sober, IPC’s director of materials and IEC engagement. Doug was instrumental in the development of the first slash sheets over 40 years ago, and he details IPC’s original intent for these documents, which were not targeted at designers.
We have more features from Barry Olney, Kelly Dack, Geoffrey Hazelett, Tim Haag, and our newest contributor Michael Morando of PFC Flexible Circuits. We also have columns by Istvan Novak and Martyn Gaudion, as well as articles by Anaya Vardya and Mark Gallant.
What’s your material selection process?
This column originally appears in the May 2023 issue of Design007 Magazine