Issue link: https://iconnect007.uberflip.com/i/623116
24 The PCB Magazine • January 2016 Recently, I was involved in a group discus- sion about flexible circuits and the role of this product in medical equipment development and medical research. We were having a light- hearted discussion over lunch, when I was asked about the most interesting flex application I had been involved with. The first thing that sprang to mind was an application from several years ago. In this application, flex was being used for purely aesthetic reasons. A handheld piece of surgical equipment in - cluded wires that were visible to the patient. The wires were functioning perfectly, but the nega- tive perception of patients when seeing these wires during a medical procedure prompted the equipment designer to replace the wires with a sleek, high-tech-looking flexible circuit. In terms of technology, this was probably one of the sim- plest flex designs to be manufactured: standard materials, single-sided, two big traces, and toler- ances that weren't particularly critical. Needless to say, the group was amused. Of all of the pos- sible medical applications that I have had the opportunity to be involved with, THAT was the first one I thought of? Honestly, I have always appreciated that unusual application! But after giving that question more serious consideration, I realized that there truly has been a marked increase in flexible circuit designs in medical products over the past several years. Flex is the perfect solution for solving space, weight and packaging issues. A visit to the doc - tor's office or hospital clearly reveals that medi- cal equipment has become much smaller, light- er-weight and more portable, all while increas- ing functionality. Flex and rigid-flex designs are becoming commonplace in this field. As we see an increase in the number of flexible circuit ap- plications in this field, we also see an increasing need for finer lines and spaces, microvia tech- nology and mixed material stack ups. This is not unlike the technology advancements we see with rigid printed circuit board technology. Neural Probe Technology If I had to choose one of the most interesting flex applications that I have been involved with recently, it would be applications that involve neural probe technologies. Developers work - ing on research studies designed a sensor that required trace and space in the one mil range, which is not a simple technology to manufac- ture. Compounding the complexity of this un- usual request was the need for those traces to be gold rather than copper. I did need to clarify that this was a need for gold traces, not copper traces with ENIG or gold plated traces! Wanting to learn more about the technology required to by Tara Dunn omni pcB flex talk Medical Research is Golden Feature coluMn