Role of Flexible Circuit Boards

The medical industry is always looking for better ways to diagnose and treat patients. This has led to the emergence of wearable devices that keep track of your heart rate, blood pressure, and other vital metrics. In order to meet the specialized requirements of these new medical devices, it is critical that the circuitry inside be powerful, compact and lightweight. This is where flexible circuit boards come into play.

The flexible circuit board can be easily bent, wound, and folded. It can also withstand millions of dynamic bending cycles without damaging the wires. This means that the flex PCB can be incorporated into medical equipment that expands, retracts or moves during use. For example, a hearing aid device can incorporate the microphone, digital signal processing (DSP), and battery components into a tiny unit that fits discreetly behind the ear.

In addition to being flexible, a flexible circuit board is thinner and lighter than a traditional PCB. This enables the devices to be compact and thin enough for wearable applications, such as wristwatches that can monitor your heartbeat or blood pressure and send the data to your cardiologist. Another reason for the popularity of flexible circuits is their ability to increase reliability in a wide range of environments and conditions. This is because they reduce the number of points of interconnection, which are a common cause of electronic failures and malfunctions.

The Role of Flexible Circuit Boards in Medical Devices

When designing a flex PCB, engineers need to take into account the various components that will be used in the final product. For instance, the tin finishing and soft gold coverings will need to be chosen carefully so that they are compatible with the material used in the flex circuit board. They also need to consider the rigidity of the flex circuit, which can be altered by adding a stiffener, which supports different areas of the board while reducing the amount of flex.

In a typical multilayer flex PCB, the copper traces are laid out in layers that are separated by adhesives, laminates and polyimide materials. The layer thicknesses vary, but generally they are thinner than those of conventional PCBs. This allows them to withstand vibrations and a wide range of temperatures.

The rigidity of a flex PCB can be increased by adding a stiffener, which is usually made of a polyimide material similar to those used in the substrate layer. The stiffener can be added in the middle of the circuit, between the layers of copper, or at the end near the connectors.

Medical devices are becoming increasingly complex and smaller at the same time, and the use of flexible circuit boards has enabled them to do so while maintaining their functionality. Whether it’s a hearing aid that allows you to hear better or a smartwatch that can track your health, these new gadgets wouldn’t be possible without the use of flexible circuit boards.