The manufacture of flexible PCBs involves several complex steps that must be handled with extreme care. Tiny design or manufacturing flaws can cause an entire board to fail.

Do's and Don'ts

It's always best to prevent any design and manufacturing failures early on before escalating into major defects. The number of defects in the manufacturing process of a 6-layer rigid-flex PCB can be minimized by considering some standard rules.

During the FPCB manufacturing process, please follow the precautions listed below.

Use the correct type and amount of material to keep the flexibility "flexible". For example, if an application requires a six-layer rigid flex printed circuit boards that bends when assembled and then should remain in place, the correct kind of copper and adhesive must be used.

It is recommended to keep the circuit small. It is better to use a group of smaller circuits rather than a single larger circuit.

Bending flex circuits around corners is not a good practice. However, some design situations require bends in the corners. In this case you can do a soft bend, or use a conical radius bend.

The copper used in the 6-layer rigid flex boards tends to fall off the substrate. Therefore, it is essential to provide support for the copper to prevent it from separating. Even if you are using surface mount pads and non-plated pads, you should consider using this in conjunction with some other measures, such as attaching a cover mask to the pads.

The recommended tolerances must be adhered to as closely as possible.

It is best to avoid routing traces on each copper layer in the same direction. It is recommended to stagger the traces so that the tension between the copper layers is evenly distributed.

It is recommended to carry a power or ground plane on the flex circuit to enhance/maintain the flexibility of the board. You might consider solid copper pours or shaded polygons.

Attention to detail

In order to produce a reliable rigid-flex based product, you have to be careful enough to pay attention to detail. Otherwise, the final component may not provide the expected functionality and durability. These troublesome situations can be avoided by following the advice above.