Issue link: https://iconnect007.uberflip.com/i/1285883
40 DESIGN007 MAGAZINE I SEPTEMBER 2020 Feature Interview by the I-Connect007 Editorial Team Johannes Adam is the creator of a simulation tool called Thermal Risk Management (TRM), used to help PCB designers and design engi- neers predict hot spots on the board before and during layout. He and Douglas Brooks, found- er of UltraCAD Design, have used the tool to produce several technical articles and a book on the subject. In this interview, they tackle the biggest misconceptions they see from de- signers and engineers who deal with thermal management issues. Andy Shaughnessy: Doug, tell us about your work with thermal and how you got involved with Johannes. Douglas Brooks: I became involved in thermal issues on PCB design when I wrote an article for a magazine in '96 and compared some re- sults from the then-IPC traces, which went back to the MBS traces. I saw data in another arti- cle that was different by about 40%. Then, IPC- 2152 was published, and that was about 25% lower temperature than previous NBS data that went back to the 1950s, primarily because they were using more current boards and also be- cause they were doing a more careful study. But it still raises a question of how come there was such a big difference between the article data and the IPC data. I began to theorize that the difference had to do with the difference in mea- surement technique. IPC used a technique that, in effect, measured the average temperature of a trace, and the article data measured the peak temperature in the center of the trace. I was looking around for a way to verify that, and I saw a thermal image of a trace that I traced back to Johannes in about 2016. I contacted Jo- hannes, and we started a conversation. He sent me a copy of his software. He was very patient while I started coming down the learning curve of that software, and we entered into a collabo- ration that went from trying to look at the dif- ferences in data to things like, "How hot is this via? Can you measure the resistivity of a trace? What happens when you bring up a parallel trace? Can you get into the fusing questions?" This ballooned over the years into what became the book that we published back in 2018. Then, there were some other ancillary articles that re- flected various chapters in that book.