Issue link: https://iconnect007.uberflip.com/i/1007258
26 FLEX007 MAGAZINE I JULY 2018 engineering department, in the early 2000s, I believe. They weren't having great luck with a lot of them at that time and so, until recently, we had been doing rigid, 90-degree intercon- nects between our patient connector boards and the amplifier or stimulator boards we were building. As of late, we've been trying to design to a high level of ruggedization. We drop test every- thing far beyond the requirements, and we were breaking those rigid 90-degree connec- tors off pretty easily. Shawn and I brought up flex as a possible solution. Since they flex, you get the robustness of the connection, but it's a dynamic thing; the boards can move indepen- dently of one another when you drop it. We went that route and it's been working well for us. We've done three flex designs this year. All of them are some sort of interface from two perpendicular boards and we've reused a cou- ple in new projects. Shaughnessy: So it's similar to rigid-flex, but not quite. Schulte: Yes, we just design the flex and rigid portions independently. We've been doing rigid boards for most designs and if we're concerned about durability then we'll do a flex intercon- nect cable, if you will, where each end has a snap fit connector on it. It's a lot cheaper than doing a rigid-flex design and it adds a bit of modularity to the designs; if a flex portion of the circuit fails you can just replace that bit instead of an entire expensive rigid-flex design. Shaughnessy: You're just using flex as a cable, basically. Schulte: Yes. We're just cabling over from some sort of patient input or output connector board into the amplifier or a recorder or whatever device it is. The rigid-flex stuff is complicated and expensive to build, so we tend to stay away from that. If we can get away with doing designs without blind or buried vias or other things that add a level of complexity to the manufacturing, then we will. We try to keep it simple, and we only go to those complicated measures if the product size or something else of that nature is a driving factor. If it's really got to be small, we can do that. We also service all our products here in the same building, and so we try to design in a way that you can repair or replace just the board that's misbehaving instead of having to throw out a big, electro- mechanical assembly. You can just replace the particular board as needed, which keeps repair costs lower for the customer. Shaughnessy: What are some typical devices that you are building that use flex circuits? Schulte: We're in the neuro diagnostics field. We design tools for electromyography (EMG) and nerve conduction velocity (NCV) studies. We design electroencephalogram (EEG) ampli- fiers with channel counts starting at 32, we're actually working on a new product right now that's going to have 512 channels available. We've got some new sleep study or polysom- nography (PSG) products coming down the pipe. Figure 1: Jarrod (right) and his brother Brandon Schulte relax after completing a 10-mile Tough Mudder endurance competition. He and his brother both played football at the University of Idaho.