Applications That Benefit From Rigid-Flex PCB Fabrication
With a wide range of benefits and applications, multilayer rigid-flex circuits are poised to take electronic products to new heights of sophistication and functionality. From mobile phones that feature fingerprint, face recognition modules and multiple cameras to advanced automotive electronics that work in tight spaces and withstand high-speed vibrations, this type of flexible PCB can be used in almost any product that needs to perform under harsh conditions.
A hybrid of standard rigid PCBs and flex circuits, rigid-flex boards consist of rigid sections that connect to flexible regions using stiffeners or mechanical reinforcements. This enables the rigid sections of the board to withstand high temperatures and vibration, while the flex circuits can bend and adapt to a product’s physical dimensions. In addition to providing greater design freedom and flexibility, rigid flex pcb fabrication can reduce assembly costs by allowing for more components to be mounted within a smaller package.
Unlike traditional PCBs, which are made from a thick epoxy or polyimide substrate, multilayer flex-rigid PCBs use ultra-thin polyester and/or polyimide films, typically 12-120 microns in thickness. Conductor material traces are then etched on these thin layers to form the circuit patterns. These traces are typically shielded with an opaque layer of material called a coverlay. To protect the exposed copper from moisture and dust, the coverlay is then laminated to a rigid substrate such as prepreg fiberglass.
What Are the Typical Applications That Benefit From Rigid-Flex PCB Fabrication?
The rigid sections of the board are then stiffened and strengthened with a layer of materials such as fiberglass, and the flex circuits are mounted to these rigid areas. To accommodate different components, a number of mounting options are available, including solder lands, pins, sockets and buried vias. Rigid-flex circuits also allow for the separation of analog and digital signals on alternating layers in the rigid and flex sections.
Rigid-flex circuits are typically designed for medium- to high-volume production runs and must be compatible with a product’s case specifications. This requires a high level of technical expertise and collaboration between the manufacturer and the designer to ensure that the circuit board will meet its design requirements, especially with regard to thermal management.
A key advantage of a rigid-flex circuit is that it can reduce the number of connections in a product, helping to reduce its weight. This reduction in weight can also improve reliability by reducing the risk of premature circuit failure due to vibration or shock, especially when the device is being handled or dropped.
In addition to consumer electronics such as laptops, smartphones and smart devices, a growing number of medical devices are being made with flex-rigid PCB technology. These include hearing aids, pacemakers and imaging equipment that need to bend and flex with body movements, as well as prosthetic limbs that need to be lightweight and adaptable to movement. In these types of devices, a rigid-flex circuit can be used for the control unit module, sensors and switches. Other examples of applications that benefit from rigid-flex circuits are augmented reality headsets, wearable VR products and smartwatches.