How Is a PCB Flex Rigid Manufactured?

PCB Flex Rigid Manufactured

A pcb flex rigid is a circuit board that uses both flexible and rigid PCB technology to combine the best of both worlds. The flex portion allows it to bend and fold into tight spaces, while the rigid parts provide strength and stability. It is more complex and costly to produce than a conventional rigid PCB, but it can solve many design issues that plague traditional PCBs. Choosing an experienced and reputable rigid flex PCB manufacturer is essential for achieving high-quality boards.

The first step in manufacturing a pcb flex rigid is cleaning the laminate, which contains the copper layer and is bonded to a rigid substrate. The laminate must be free from contaminants, such as oil, dirt, and oxide. This is done to ensure proper adhesion of the etching process and the subsequent copper deposition. The next step is to apply the cover lay. This layer protects the flex circuit from harsh chemicals and environmental conditions. This can be an additional polyimide film with adhesive or a photo-imageable solder mask, both of which are cured with UV exposure. If required, localized stiffeners can also be added.

After the cover lay is applied, the flex circuit is laminated to the rigid section. The flex circuit can then be cut to shape. For larger production runs, this can be accomplished using a hydraulic punching method. For prototyping and small production runs, a specialized blanking knife can be used.

How Is a PCB Flex Rigid Manufactured?

Once the flex circuit is cut, it must be cleaned in preparation for assembly. Any components that are to be mounted on the flex section must be plated prior to the lamination process. This can be done manually or using a automated programmable system. The plated holes are then drilled, using either mechanical methods or laser drilling depending on the size of the hole. Laser drilling offers superior accuracy, especially for microvias, but is expensive for large production runs.

The etched flex circuit is now ready for assembly. It is important to use sharp drill bits, as these are critical for ensuring a good hole wall and avoiding the formation of a nail head. It is also important to check the feed speed and rotational speed of the drill. If the feed is too slow, the copper will heat up and cause the hole to melt. If the rotational speed is too fast, the hole will be drilled unevenly and lead to misalignment problems during assembly.

Once the flex circuit is assembled, it moves to quality assurance (QA). It undergoes extensive electrical testing to verify continuity, isolation, and circuit performance against design specifications. After QA passes, the rigid-flex PCB can be packaged for shipment and use. Printed Circuit Boards (PCBs) have undergone a significant evolution over the years, adapting to the demands of modern electronics. Among the advancements, the emergence of flexible and rigid-flex PCBs has revolutionized the industry, offering versatility and efficiency in design and manufacturing processes.