May. 16, 2023
With the birth and development of FPC and PCB, a new product of soft and rigid combined board was born. Therefore, the combination of soft and rigid board, is the flexible circuit board and rigid circuit board, after pressing and other processes, according to the relevant process requirements combined together, the formation of a circuit board with FPC characteristics and PCB characteristics.
Initially, the basic design concept and manufacturing process of multilayer rigid board was developed from space equipment, because of the need for reliable wiring in the limited space. In some complex products, more than 30 conductor layers of soft - rigid - bonded pcbs are used. On the other hand, in consumer electronics, such as mobile phones and digital cameras, high-density, low-cost wiring technology has always been needed, so new design concepts and manufacturing processes have emerged.
Multilayer soft and rigid combined pcb is basically a combination of rigid pcb and flexible pcb. However, for circuit board manufacturers to successfully combine the two, they need to have good skills in both rigid and flexible board manufacturing processes. Therefore, it is important to understand the capabilities and limitations of the PCB manufacturer before designing such a PCB.
There are many different types of structure in the design of soft - rigid board. Picture shows the basic structure of a multilayer flexible and rigid composite pcb, including a flat view and a cross section (laminated structure).
Stack up information
The non-adhesive layered structure is used between the multiple flexible layers, which can provide better bending performance. In the extreme, more than 30 layers of PCBS can be made with this structure for use in aerospace products. Because of the need for high reliability, fine line graphics and microporous technology cannot be used. Furthermore, lead components are used instead of SMT components, which usually require a large line width/line spacing. And large diameter through holes with thick copper walls.