rigid flex and traditional PCBs
Impedance control plays an important role in rigid flex circuit board design. It ensures that signals travel down the trace as efficiently as possible, which maximizes the power that can be dissipated and prevents reflected signals that could degrade the signal’s integrity. This is especially important in applications that require a high level of reliability, durability and flexibility like medical imaging equipment, military missile guidance systems and automotive robotics.
Impedance control involves a combination of modeling techniques and tools that help designers optimize the impedance of the signals on the rigid flex circuit board for its specific application. It takes into account the material and insulation used in the rigid flex circuit board, as well as the signal’s thickness and distance from reference plane layers. A rigid flex circuit board that is designed with this process will perform better and have a more stable impedance than one that is not designed with it.
rigid flex board are becoming more popular as a way to connect devices to each other and to the outside world. This is due to the ability of rigid flex circuit boards to accommodate more component density than their rigid counterparts while still maintaining a significant degree of flexibility and stability. Rigid flex circuit boards are also known for their lower overall weight, which makes them ideal in systems that need to be compact and durable.
What factors influence the choice between rigid flex and traditional PCBs?
To achieve this, rigid flex circuit boards often incorporate advanced construction features such as blind and buried vias, integrated ZIF contacts, and designs that mount components in both the flexible areas and the rigid sections of the board. This allows for higher level design integration and increased packaging density while reducing costs and improving reliability.
The design of a rigid flex circuit board can also be simplified by using odd layer count constructions that minimize the flex section and improve mechanical bending capabilities. This can be done by dividing the board shape into multiple Board Regions that each have their own unique layer stack. Each of these regions can be manipulated independently and can include either an odd or even layer count.
Other factors to consider when designing a rigid flex circuit board include minimizing stress by avoiding sharp corners on routes that travel over the flex area, and by orienting pads toward the direction of the flex bend. It is also important to avoid exposing any signal layers to the coverlayer when designing a flex circuit, and to stagger layer lengths to minimize buckling when the flex is bended (this is referred to as a service loop).
In addition to the advantages of using rigid flex circuit boards, there are several other ways that these unique constructions can make it easier for you to design and manufacture your product. These benefits include streamlined PCB assembly processes, reduced total cost, simplified test conditions and enhanced device performance. However, it’s important to understand that rigid flex PCBs are a specialty product that requires specialized fabrication methods and expertise. For this reason, they are typically best suited for medium to high-volume production runs.