MEDICAL ELECTRONICS
Length-unlimited flexible printed circuits replace bulky wire harnesses to deliver smart interconnect solutions for advanced medical applications
Philip Johnston, CEO at Trackwise explains how its Harness Technology (IHT) builds on the space, weight and cost-saving attributes of flexible printed circuits (FPCs) to meet interconnect challenges presented by advanced medical applications, that demand extended connection length, high reliability, bio-compatibility, and support for integrated smart features
T
oday’s medical technology is becoming ever smarter, from processing-intensive imaging systems, to smart wearable monitoring devices, to cutting-edge research equipment. Increasing sensitivity and intelligence requires greater connectivity to handle the control signals and feedback data, and to provide power. Conventional wire harnesses, coupled with high-quality connectors designed specifically for medical applications, have traditionally handled this task adequately. However, as medical technology continues its mission to improve standards of care, help treat more conditions, and improve patient outcomes, connectivity must satisfy new technical demands. Miniaturisation is a constant demand, but today’s medical interconnect solutions must also feature greater flexibility to connect moving parts, and extra length to reach smart circuitry in large items such as full body scanners and surgical robots. Increasingly, medical connectivity solutions must also integrate intelligent functionality and handle more signals, more bandwidth, and more power.
New alternatives that can fulfil these emerging demands while at the same time elevating performance and reliability are needed.
36 NOVEMBER 2022 | ELECTRONICS TODAY
Next-generation interconnects Flexible printed circuits (FPCs) are commonly used in space-constrained applications such as mobiles and DSLR cameras, as they offer considerable space and weight savings over wire harnesses. FPC technology is mature and it can be produced to high quality standards in many locations worldwide. Unlike the conventional wire harness, FPCs do not necessarily need associated connectors. Whilst often connectors are used, in other applications the FPC can be integrated within the system to directly link system elements. Another benefit is that the typical FPC manufacturing processes minimises human intervention, whereas conventional wire harnesses are often very manual-labour- intensive. This can boost production quality and efficiency, eliminate human errors and result in manufacturing time and cost savings. A typical FPC stack-up comprises a polymer carrier and a conductor layer, which is usually etched copper. The most basic FPC combines one layer of each type and can have a thickness of 25µm or less. A cover layer may be added to protect the conductor. Successive copper and dielectric layers can be added to create multilayer interconnects. Plated-through holes may be used to connect conductors in different layers, if needed, and
terminations can be applied on one or both sides. FPCs can combine the functions of a PCB and interconnect in a single part, which can simplify the assembly of the final product and enhance reliability.
Therefore, FPCs deliver many of the characteristics needed to realise the next generation of advanced medical systems and devices, including mechanical flexibility, increased interconnect density and bandwidth, and the ability to include built-in intelligent functions.
However, traditional FPC production processes that use sheet materials typically restrict the maximum length to about 600mm. A small number of producers can supply lengths up to about two metres. Trackwise’s Improved Harness Technology (IHT) is a roll-to-roll manufacturing process, performed using advanced machinery and custom software, that allows interconnects of practically unlimited length to be produced (figure 1). These can address the most demanding applications in large items of equipment such as full body scanners and industrial robots.
Several medical device makers have already selected FPCs made using IHT for catheters. Other medical applications include endoscopes, and related devices such as
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44
