What is rigid-flex PCB?

As you can see from the name, this PCB is a PCB with a combination of flex PCB and rigid PCB. The birth and development of FPC and PCB have given birth to a new product called rigid-flex PCB.
Therefore, the rigid-flex PCB is a flexible circuit board and a rigid circuit board, combine according to relevant process requirements after pressing and other processes to form a circuit board with FPC characteristics and rigid PCB characteristics. Usually, the rigid PCB connect the flex PCB, or the places where the rigid PCBs need to be connected are the flex PCB, and the other ends of the flex PCB are gold fingers, as shown below.

rigid flex pcb board

The structure of Rigid-flex PCB

The Rigid-flex PCB are connected together through plated through holes. The Rigid-flex PCB can ensure that the functions of the supporting area (Rigid part) are satisfied, and it can also be folded or continuously flexed (Flex part).

According to product needs, the number of folding times is also divided into: Flex to install and dynamic flex.

Flex to install: This product can only be folded once and is used under fixed conditions.

Dynamic flex: is generally used in products that need to be folded repeatedly, such as previous flip phones.

Rigid-flexible plates are usually made of a combination of PI flexible materials sandwiched between FR4 epoxy and polyamide layers. The following figure shows the laminated structure of an 8-layer flexible and rigid bonded plate produced by our company. See the structure of each layer.

rigid flex stack-up layer specifications

The complete gerber is shown below

gerber files

Why rigid flex PCB?

It requires fewer parts and interconnections than rigid circuit boards. Rigid-flex PCB can meet highly complex configurations while using rigid substrates. Because rigid-flex circuit boards are dynamic and mechanical stability, resulting in 3D design freedom, simplified installation and maintenance of uniform electrical characteristics.

Here are some other advantages of flexible PCBs

1) Unlike rigid PCB, it is lighter and has no space restrictions.

2) The connection of this board is more reliable because there are fewer solder joints. Replacement connector-reduce weight, eliminate connector connection problems, provide the ability to transmit signals without loss of circuit, free up more space than connectors, reduce necessary assembly

3) Compared with only rigid boards, Regid-flex PCB are easier to handle during assembly.

4) No cables or connectors are required at all.

5) Logistics costs are greatly reduced.

6) Relatively speaking, it is an excellent portable device.

7) Ensure multiple materials and design layout options to meet the unique requirements of the application. Can build three-dimensional design, realize three-dimensional assembly, save assembly space, and make electronic products more compact and lightweight

8) The circuit density has increased significantly.

9) The system greatly reduces costs. The cost of flexibility is less than the cost of rigid plates.

10) Eliminate parasitic inductance and capacitance. It also helps preserve the signal, improving power and clarity. All of these help reduce errors.

11) Flexible part provides engineers with great versatility when developing low-cost, high-quality and lightweight miniature products. They are also preferred in thermal electronics because they are more resistant to thermal stress than rigid PCBs.

Disadvantages:

1.There are many production procedures for rigid-flex PCB boards, difficult production, low yield, and more input materials and manpower. Therefore, the price is more expensive and the production cycle is longer.

2.Rigid-flex PCB development involves more complex and time-consuming manufacturing processes. There are many considerations in design, and the flexibility of the printed circuit board must achieve the required degree of freedom.

Rigid-flex PCB Application

The characteristics of the rigid-flex PCB determine its application areas covering all application areas of FPC to PCB, such as:

Mobile phone, Keypad and side buttons, Computer and LCD screen, Motherboard and display, etc, CD Walkman, Drive, NOTEBOOK. In addition, for Aadvanced medical equipment, digital cameras, portable cameras, high-quality MP3 players and aerospace, etc.

Successful Rigid-flex PCB Products

As a professional PCB&PCBA manufacturer, we have many successful rigid-flex PCB projects, below we show several for you reference.

A445 update the program equipment.

rigid flex PCB A445

This product has a programmable chip on the rigid PCB part. There are gold fingers on the Flex PCB that can be inserted and removed repeatedly. First, use the gold finger end of the FCB to insert it into a converter connected to the computer. The product can then be easily updated by plugging this product into all large fixed devices. Avoid the complicated process of engineers having to wear computers to update all equipment.

A189 acts as a connector

flex pcb a189

The customer of this product did not tell the end use, but we can easily see that the two ends of the product are rigid PCBs, and two particularly precise connectors are soldered. The lead pitch is 0.12mm. Solved the connection problem between two Rigid PCBs.

AFD637 is also equivalent.

AFD637

This circuit board is temporarily copied to the product before assembly. There are two precision connectors at both ends, connect to the connector on the product, or can connect 2-3 products can be connected if the distance is insufficient Get longer together. The part that solders the connector at both ends is the Rigid PCB used to protect the soldering state of the connector and provide support.

AFD714 products

flex pcb afd714

This Rigid-flex PCB product is used in precision medical equipment, for blood analysis. In the current state of development, certain specific diseases can be detected through blood analysis. Because there are too many functions and programs, there is no way to focus on the same PCB, so this product needs to connect 4 of 10 PCBA products. As shown in the following figure, the connector part is Rigid PCBA. This ensures that the black connector has a force point, and the entire product can be flexibly assembled into the instrument and equipment without restrictions, making the instrument smaller and more convenient to move. This kind of product belong to “dynamic flex” because it will bend many times during it life time.

A686 Logistics Tracking

rigid flex pcb A686

German logistics company use it to track cargo. The PCB photos before mounting are shown in Figure 2. The two Rigid PCBs can be connected by a flexible board to meet the 3D effect required by the product. The small Rigid PCB has a lens that needs to be 90 degrees perpendicular to the big board such as the nose position of the big board to scan the cargo information and transmit it to the main board In this way, Rigid-flex PCB can meet the needs of this product. It belong to “Flex to install”, because the final products will potting with the silicon and never bend any more.

As a professional PCBA Manufacturer, we could supply one-stop service, including PCB board making, PCB Reverse Engineering, components sourcing, SMT assembly work, Program+Test, housing making, housing assembly…

We aslo have ERP system to manage every project from production file, quotation, purchase, production, delivery until service after it. Date will be found quickly and precise no matter when client wants to begin project.

If you have related projects, welcome to inquiry us to get free quotation.

Cecilia Wang
Cecilia WangSales Engineer
If everything seems under control, you are not going fast enough.