More and more designers are now facing the pressure to build more and more high-density electronic devices, and their headaches are to continue to reduce manufacturing costs and time. It is wise to learn how to make rigid and flexible circuit boards. In this way, we can easily find the design mistakes and prevent them from happening.

This project comes from a design company in India. We have cooperated since 2017, a flex PCB board with dimple and tear drop pads. It was very successful, then they place us another 6000pcs order for flex board. This time they design 6 layer rigid-flex PCB board. Multilayer PCB is very complex, as the designer must consider stack-up of rigid part and flex part. We make the samples first.

6 Layer Rigid-flex PCB Specification: 

Min Line Width/Space: 0.13mm(5mil).

Min Drilled Hole Size: 0.25mm(10mil).

Base material: FR4+PI

Copper Thickness: 1oz,

Board Thickness: 1.6mm for FR4,and 0.15mm for PI

Stiffener:0.3mm.

Surface Finishing: ENIG and Gold Finger

Solder mask: Red

Silk Print: White.

TG:150

This design include some blind via holes and buried via holes. It adds more difficulty to PCB production.

This PCB is double-sided assembly, with lots of delicateness components, like BGA. The board material in the IPC standard  specifically point out that PCB boards with surface mount devices allow for a maximum deformation of 0.75%. In fact, in order to meet the demand for high-precision and high-speed placement, our customer only allow for a maximum deformation of 0.6%.

During the design, our customer hope our engineer to give some suggestion or solution about the stack-up of the 1.6mm thick FR4 PCB and best possible thickness for flex board.

Then we provide him a stack up example, our customer understand very well. The stack up picture as below:

2 weeks later, the customer sent us the final gerber file, then we finished their design.

Although our customer just order 10pcs samples, we should make more, such as 15-20pcs. We will test all the boards to make sure all circuits work well. We will remove the X-PCB like the image :

We guarantee that all products delivered to our customers are good quality. This is our responsibility.

Finally, this sample was very successful.This customer give us a new order.A 4 layer rigid-flex PCB board.

The Rigid-flex PCB board is a new type of printed circuit board that combines the durability of a rigid PCB and the adaptability of a flexible PCB.

Among all PCB types, rigid-flex PCB boards are the most resistant to harsh application environments, therefore it is favored by industrial control, medical, and military equipment manufacturers. It will have wider broad prospects for development and demand in the future.