Rigid-flex PCB is a new printed circuit board combines with both the durability of the rigid PCB and the flexibility of the FPC. In all types of PCB, rigid-flex PCB can be used in the harshest environment, so the medical and military equipment manufacturers are tending to use rigid-flex circuit boards normally.
There are differences in the raw materials, produce equipment and technical process between the rigid flex PCB and rigid PCB of flex PCB. We use FR4 or similar substrate for rigid PCB and use the PI or PET material for flex PCB. Relatively speaking the key point is about the stability of the rigid flex PCB, because there are the connecting problems between two different PCB, also there is the different hot pressing shrinkage issues. There is the special three-dimensional space configuration of the rigid flex PCB, we have to consider the stress of the X-axis and Y-axis direction, also the stress on the Z-axis direction is important consideration, we have the raw materials suppliers provide us the improved materials such as epoxy (Epoxy) or modified resin (Resin) for rigid flex PCB to fix the bonding problems between rigid PCB and flex PCB.
Regarding to the production equipment, we have to modify/reset some of them in laminate and plating process because of the special raw material and specification of the rigid flex PCB. The equipment will affect the product yield and stability, so we must pay attention to the production equipment first.
The global area for rigid flex PCB manufacturing concentrated in Europe and the United States and Japan, and only small number of the producers have the better yield. It is mainly the military and medical products application in EU and US; while in Japan recently, it is DSC, DV or mobile phone product applications; in Asia, the rigid flex PCB has instead the rigid board – flex PCB board – cables combination design, and are mainly used for mobile application.
Our professional production of rigid flex boards has more than 10 years, the product application involved the following:
1. Industrial – including the Industrial, military and medical application. Most of the industrial parts are required to be more accurate, safe and not easy to damage, so the rigid flex PCB should be: high reliability, high precision, low impedance loss, complete signal transmission quality and high durability.
But because of the high complexity of the process, it is small amount output but high price.
2. Mobile phone – the normal application in the mobile phone are the Hinge, Camera Module, Keypad and RF module.
The advantage of using rigid flex circuit in Mobile phone: one is the integration of all parts in the mobile phones, the second is the amount of signal transmission considerations.
We use the rigid flex PCB instead of the combined two FPC plus connectors in the current mobile phones, this most meaningful for the product is increasing the reliability and long-term durability at the mobile Hinge. On the other hand, due to the popularity of the camera phones, coupled with the integrated multimedia and IT functions in the mobile phone, making the mobile phone internal signal transmission becomes larger, modular demanding is coming.
3. Consumer electronics – the representative products are DSC and DV, can be divided into “performance” and “structure” two major spindle. In terms of performance, the rigid flex PCB can be connected to different PCB rigid board and components, which can increase the total area of the PCB under the same circuit density, relatively can increase its circuit load, and reduce the contact signal transmission and PCB assembly error rate. On the other hand, since the rigid flex circuit board is light and thin, it can be flexed for wiring, so it is helpful to reduce the volume and reduce the weight.
4. Car – commonly the rigid flex PCB used for connecting the motherboard to the motherboard keys, connecting the car video system screen with the controlled panel, used for the audio on the side door, or for function keys, reversing radar imaging system (Sensor, air quality, temperature and humidity, special gas regulation, etc.), vehicle communication system, satellite navigation, rear control panel and front controller connection board, vehicle detection system and so on.