For the fabrication of Rigid-Flex PCBs, there are various materials required. There are different materials for different purposes. The person ordering the Rigid-Flex PCBs must understand different materials used for the purpose.

1) Conductor

A PCB is made for the reliable conduction of signals between the components. Thus, the main purpose is conduction; therefore, the conductor used in the PCB plays a very important role. There are many conductors of electricity, but for PCBs, the most preferred one is copper. Rolled Annealed Copper and Electro Deposited Copper are used. Silver, aluminum, gold, and iron can also be used, but copper is preferred.

Copper has excellent conductivity, long-life, and optimum reliability. There are issues of corrosion; however, they can be easily dealt with using an excellent surface finish. There is no need to use costly material like gold if there is no exceptional case. The cost of copper is also reasonable, and it offers everything that you are looking for.

If we use Aluminum, the PCB will be of less cost, but it won’t offer the desired performance as copper.

2) Base/Insulator

The base/insulator of the rigid and flexible PCBs are different. The flexible part is commonly made of Polyimide (PI) or, sometimes, PET. These are also available from different companies, such as Dupont and Shengyi. For the rigid part, there are many materials; however, FR-4 is commonly used. There can be PTFE (Teflon) or metal. Rigid PCBs can also be made on metallic bases, such as Aluminum and Iron. 

3) Surface Finish

Surface Finish is quite important to protect the conductor. It ensures long life and prevents corrosion and blistering. There are different types of surface finishes that are used for different purposes. We offer all kinds of surface finish. The most common surface finishes for Rigid-Flex PCBs are,

• OSP
• HASL
• HASL (Lead-free)
• Immersion Tin
• Immersion Silver
• ENIG
• Flash Gold

You can order any type of surface finish according to your requirements.

4) Adhesives

Adhesives are also available in a wide range, and they are used according to the customer’s needs. The common adhesives used in Rigid-Flex PCBs are,

• Epoxy
• Pre-preg
• Acrylic
• Pressure Sensitive Adhesive (PSA)