Rigid Flex PCBs
What Is Rigid Flex PCBs
Rigid flex PCB design integrates elements from both hardboard and flexible circuit boards and features advantages of both. Therefore, the rigid flex PCB can be folded or flexed while keeping the shape of areas where need extra support. The rigid flex board is typically multi-layered and includes flexible circuit substrates joined with rigid boards. Rigid flex PCB manufacturers bury the flexible layers internally and penetrate the rigid sections of the PCB completely.
- Resistance of high levels of shock and vibration
- Light weight
- High circuit density
Rigid flex board is more expensive than other kinds of the printed circuit board while its application has a wide range of industries. It is popular in the industry such as, aerospace, medical devices, and the military. Besides, it is ideal for certain commercial products.
Rigid flex PCBs can be implemented in several circumstances as an optimal solution. This kind of printed circuit board used in this kind of situation can be seen as the most cost-effective choice.
- High-vibration and high-shock environment.
- Industries that need high-level reliability and precision more than cost considerations.
- High-density applications.
- Applications that need multiple rigid circuit boards.
There are 4 steps for rigid flex PCB manufacturing process: the photochemical patterning of circuit, the formation of microvia, adhesion, clearing.
Step 1: Imaging pattern on rigid flex circuits is the primary process during the rigid flex PCB manufacturing process. The quality of images depends on the thickness of the light source and the resist. Rigid flex PCB manufacturers implement a highly collimated, intense lights source to create straight, clean image. The fine image is made from thinner resist.
Step 2: The formation of microvia. This operation is a crucial process during the rigid flex PCB manufacturing process. Rigid flex PCB is different from the rigid one. Though rigid manufacturers have a breakthrough in the control of size and quality of drilled holes, the difference between rigid PCB and rigid board makes this process is difficult.
Step 3: Rigid flex board uses acrylic adhesive materials with high thermal coefficient of expansion (TCE) that has low-flow and no-flow prepreg epoxies which an reduce the adhesive tensility.
Step 4: The cleaning process is made after drilling to remove some smear that might cause low-reliability of rigid-flex PCB.
Rigid flex circuit boards have various applications in a wide range of industries because of their special flexible design.
There are advantages of rigid flex PCB:
Reliability: Adding connectors on printed circuit boards might increase the risk o failure. Rigid-flex printed circuit boards can be regarded as a counterpart of the connector that will reduce the failure risk.
Saving Space: Rigid flex boards have a special design which can be folded that will reduce the using space. The rigid flex board can save the space to install the wire harnesses and high-profile connectors.
Easy to Test: Rigid flex PCB manufacturers test the rigid flex circuit board is easy because there is an interconnection for all the subcircuits during the rigid flex printed circuit board manufacturing. Regular tests for rigid flex circuit boards can protect PCBs from some defects.
Rigid flex circuit board is popular because of the features of flexibility, reliability, and lower cost. As professional rigid flex PCB manufacturers, UETPCB will provide the reasonable rigid flex PCB cost and the factors that will influence the cost of rigid flex circuit boards.
Generally speaking, the rigid flex PCB is expensive than the equivalent rigid PCB, because of its materials and lower overall yields.
Flexible copper clad laminates within the packaging is an important cost driver during rigid flex circuit board manufacturing. There are various materials that can be implemented for PCB manufacturing, such as polyester, polyimide, PEN, etc. Some of those are made from adhesive systems that can be bonded the copper towards the circuit board, while others not. In order to improve the production and quality of products, rigid flex PCB manufacturers usually use exclusively adhesiveness laminates with polyimide base materials that are expensive. In addition, the manufacturers also need thicker polyimide films for controlled impedance designs to ensure the normal function of the rigid flex circuit board.
The complex manufacturing process is another factor for rigid flex PCB cost. Rigid flex PCB manufacturers create rigid flex boards in separate components and assembled them into the final board that increased the cost of rigid flex PCB cost.