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42 DESIGN007 MAGAZINE I SEPTEMBER 2020 Johannes has been a great help to me. I'm now retired, which allows me time to do some of these things. Artech House is going to pub- lish an updated version of our book in the first quarter of 2023. Shaughnessy: Johannes, give us a quick back- ground. You are a rocket scientist, correct? You're one of the few that I know. Johannes Adam: I'm not a rocket scientist, but I am an astrophysicist (laughs). And by the way, conduction-cooled boards in vacuum can also be simulated. I've been involved in pro- gramming since my undergraduate studies or even in high school, starting with punch cards. Doug actually contacted me in November of 2014 when I was giving an electronics cooling seminar in Hannover. At that time, I had been working in the field of trace heating and tem- perature prediction more or less since 2001. I knew Doug's work, but I was too shy to con- tact him. The interest in trace heating came from questions from users of FloTHERM at Bosch, who I was supporting as a support en- gineer at that time. They asked about the tem- perature of the trace, and I had to say, "I can calculate the ventilation of your device, but an amp is not an input value." I started looking at these IPC design rules and literature. It was not until much later that I had the idea of writing my own software that focuses on the PCB traces, layer structure, pads, and drilled holes to calculate the temperature of the traces and components if the amps or the watts are given. This began in 2009, when I started my developments. Now, we have a very good third- generation TRM software tool, and the users are happy because it is easy to use, and neutral design data can be read and parameterized, but you are still free to add additional technologi- cal ideas and play with them. We have already made a small step toward electrodynamics in which it is possible to calculate the self-induc- tance and mutual inductance of nets. Shaughnessy: I understand your tool now has an Altium interface. Adam: We have a wizard for Altium users that we created ourselves. Users can export and im- port the board with just two clicks—one for export and one for import. You can even de- fine amps or watts already in the schematic, but that's optional. There, you specify a cer- tain current to a net, and this can be taken di- rectly from Altium, or define the watts for the components if you want to store it there. But you can also supply the current and the watts after import to our tool, either from keyboard or with ASCII files prepared by other people. Then, you can calculate the voltage drop or current density distribution in a matter of sec- onds. Wizards for other vendors can be done if the interest is there. Shaughnessy: That's one of the things that was always said about the existing thermal man- agement tools was that you kind of had to have a Ph.D. to operate them. Adam: Not at all, but one should have a certain understanding of thermal issues. You should understand that thermal conductivity or a data- sheet does not tell you everything. Tempera- ture is always an interaction between general physics and local design. Where is the copper? Where is the FR-4? How wide and where are the gaps? What is the power? What is the num- Johannes Adam

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