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26 DESIGN007 MAGAZINE I MARCH 2019 Johnson: At the table in front of us, there are four different boards. Can you tell us about them? Burt: I have another one at home, but I have designed two of these, and I fabricated three of them. Johnson: You haven't graduated yet, but you're working in the industry. Burt: Correct. I'm an intern at Summit Wireless where some of my coworkers have to design PCBs for electrical engineering. I have to under- stand how those PCBs work, such as sizes and temperature limits, and how their circuits are laid out to interact with them via software. So, we all have to understand how it works, including all of the limitations with PCB manufacturing as well. Johnson: Right. One thing that is interesting in our industry is that many of veterans comment that young designers don't really know what the limitations are, but you're getting that ex - perience. You had to start basically from scratch by learning a CAD tool and how to create a schematic. Burt: Exactly. Building a schematic and the ac- tual circuit. Johnson: And then translate that into a physi- cal layout. Burt: Yes, and in one class, we had to design it on a breadboard after the theoretical design. So, we wrote out the schematic in a simulation pro- gram such as Multisim or PSpice, and when we saw the simulation work, then we would bread- board it. After the breadboard would work, then we would design another circuit in Altium and have the components designed—the footprint— to be placed on a PCB and lay it out. It's a long process, but it's worth it. I still use the stereo speaker I built in that class to this day when I exercise. Johnson: Awesome. How did the knowledge you gained on PCBs follow you into your work as an intern? Burt: Understanding how printed circuits are de- signed and built, how they start with a basic schematic, and how they're laid out together on a PCB is important to bring together different chips. Also, how they interact with each other on a hardware level is essential. And the need to understand the circuits and size limitations with PCBs. Johnson: For a moment, imagine that you didn't have the PCB education available to in your in- ternship at Summit. Would your work be harder? Burt: It would definitely be more difficult. I would look at the board and not under- stand what all the holes do. I wouldn't un- derstand that there would be multiple layers on the board because you can have a board with many, many layers, and I wouldn't un- derstand what a polygon pour is. And you see these different colors on the PCB—the darker and lighter—and I would have never even re- alized that one of the shades means that it's all one layer; it's all one wire in breadboard terms, at least. Being able to see that you can jump from one trace to another layer, and then to another trace, or even to another plane and seeing all sides of the board is helpful. Without that knowledge, it would be unfortunate. PCBs are much more complicated than you would initially see be - cause it's not just a flat, 2D board; it's 3D and could have multiple layers or buried vias. You could have so many different things inside of a PCB. If this was put in a breadboard scenario, it would be 20 times bigger physically. I have to understand how those PCBs work, such as sizes and temperature limits, and how their circuits are laid out to interact with them via software.

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