I met with James Hofer, General Manager of Accurate Circuit Engineering, during DesignCon 2021 in San Jose. He discussed some of the new technology they’ve been working on, including copper coins. James explains the benefits of making copper coins—a technology that’s been around for years—in 3D and even laminating them into the board to control heat in one area.
Andy Shaughnessy: How’s it going, James?
James Hofer: It’s going well. It’s been a while, Andy.
Shaughnessy: It has been a while. I understand that you’ve been working on some pretty cool things at ACE. Why don’t you give us an update?
Hofer: We’ve always got cool things going on at ACE. That’s exactly what ACE is all about—manufacturing cool things. Right now, I would say one of our standout technologies that we’re working with is copper coins. Copper coin is not a new term; copper coins are selective heat sinks. They’ve always been in a two-dimensional use. What’s new and exciting about what we’re doing now is looking at them not as a flat chunks of copper that are made into a circle or a square that you embed into a PCB. That technology is not necessarily new, and heat sinks aren’t new.
Let me digress a little. The benefit of a selective heat sink or a copper coin is less weight. You can put the heat sink in the area where it’s needed and not across the entire board. Up until today, that technology has been very linear and two-dimensional. You make it flat. You make it in different thicknesses, and you make it in whatever size you need. It provides a smaller more intimate heatsink with less weight and space than a standard heat sink.
What we’re doing now is milling and forming these selective heat sinks into different shapes and heights. Rather than put a flat, round, 30-mil thick copper coin into a board, we’ll instead make it with some podiums so that the heat sink gets mounted to the board and is below level, except in particular areas where you bring it flush to the surface of the board, or even higher.
We are also developing ways to laminate them into the boards so that the heat sink isn’t a square or a circle, but instead a small post, which, like a plated-through hole, will conduct heat and current. A copper coin that’s a post can be laminated into the board, not a hole, so now a component can sit on it and heat can be pulled directly down that post. What’s nice is that you don’t have a lot of weight because there’s no extra copper that is not directly being used.
We’ve been working on several different ideas and implementing some of them. Some of those are going on vehicles that can’t carry a lot of weight like drones or on wearable tech. We’ve been using some very interesting styles of heat sinks in those. We are also putting them into other packages that have very small form factors. It’s hard to put a 30-mil copper coin on a board that’s 20 mils thick and one inch by three quarters of an inch. But I can machine those coins down to very small, selective areas, and again, when I use the term coin, it actually refers to a selective heat sink. When I can make those into three-dimensional structures and laminate them into the circuit board, the possibilities become quite creative. That is what we do best “bring ideas to reality.”
To read the entire interview published by I-Connect007, click here