Flexible Printed Circuit Board Assembly for Human Applications

There are very few flat surfaces on a human body at any age, even though some fitness enthusiasts exercise and diet hard to achieve them. So any electronic monitoring device to be worn for medical or sporting reasons has to be able to move with the body’s shape in order to function correctly. The problem here is that the process for printed circuit board assembly traditionally consists of a hard flat board with components soldered or printed on to it. This is where flexible printed circuit board assembly comes to the rescue, but only up to a point. Flexible circuits can be made to conform to the changing shape of a human body, but they still have their limits. They also have to be able to withstand forces from unexpected movements. Comfort is important for cardiac monitors and other medical monitors that can be worn for days or even weeks at a time. Circuit manufacturers have to review their designs to locate the principle points where stresses can concentrate and adapt them to accommodate dynamic forces. Stresses should not concentrate in those areas that will be flexed or bent. Such concentrations can be caused by changes in the thicknesses of substrates, coatings, covering materials and platings. Wrist-worn electronic devices are some of the most popular forms of wearable circuitry. These behave rather like an enhanced wrist watch. But every individual has his or her own method of removing a watch that can pull or twist it. This is a challenge for the designer, as the electronic circuitry has to be able to withstand such torsional forces. Foot-worn devices that count numbers of steps or irregularities in anyone’s way of walking are subject to many complex forces. This is a problem if the device is to be worn around an ankle that can twist and turn on a large number of axes. And just as shoes wear out, so a foot-worn device wears out faster than one worn on another part of the body. Ankle monitors that are used to track released prisoners on bail or other forms of restricted movement are also easily tampered with if single wires are used to create a circuit around a stiff surface. A flexible circuit is virtually impossible to tamper with. Please feel free to contact us if you have any questions or would like to know more about printed circuit board assembly.