Manufacture Rigid Flex Circuits

Rigid flex circuits are used in high-quality applications, like TVs and medical devices. Their flexibility allows them to fit into tight spaces and minimize layout flaws. Their strength means they can support more power without overheating or complete system failure. Using rigid flex can also reduce the amount of wires and connectors needed in the final product.

These benefits are why rigid flex is the perfect solution for high-speed, high-density PCBs. The design and fabrication process is more complex and requires greater care than other PCBs. However, the added advantages of rigid flex are worth it. This is especially true for high-end applications that demand reliability and durability.

There are a few different ways to make a rigid flex circuits. One way is to use an epoxy-based system that creates a flexible copper layer on top of an adhesive base. Then, the circuit pattern is etched using a chemical or mechanical process. Afterward, the copper is plated through the holes to establish layer-to-layer electrical interconnection.

How Do You Manufacture Rigid Flex Circuits?

Another method is to use a glass-epoxy material that is both flexible and durable. This material can be etched through with precision drilling systems, making it ideal for manufacturing rigid-flex circuits. A third method is to use a copper-plated substrate with an adhesive backing. The substrate can be either a FR-4-style board or an ultra-thin metal foil.

Once the copper is plated through the holes, the etch resist is removed from the surface of the circuit. This exposes the copper and allows for a smooth, even etch during the next step. The copper is then deposited and chemically plated through the holes in the same way that it is plated onto rigid PCB cores. Unlike rigid PCBs, which typically have 1 mil of copper plating thickness, rigid flex has 2 mil of copper to provide enough mechanical support for the pads and vias.

Lastly, the cover lay material is applied to protect the circuit from harsh chemicals, solvents, and weather conditions. It also protects the underlying circuit from scratches and UV radiation. For this reason, most manufacturers use a polyimide film with adhesive as the cover lay material.

To complete the manufacturing process, the flex circuit is affixed temporarily to a rigid backing board. Then it is blanked into a final assembly panel with borders for frame attachment. This will keep the flex circuit flat during assembly with the rigid sections and avoid damage to its edges.

Rigid-flex circuits require more steps to fabricate than rigid boards, so they are often a more expensive option. But the extra cost can be offset by the streamlined assembly process, lower materials use, and reduced number of wires and connectors required. In addition, the improved heat dissipation provided by rigid-flex can extend the lifespan of your electronics. This can be especially beneficial in critical applications where your products will be exposed to extreme temperatures and shocks.