signals routed in PCB flex rigid
PCB flex rigid can be used in many types of electronic devices, from handheld ultrasound machines to laptops. Rigid flex PCBs have high reliability to survive drops because they reduce points of interconnect and are lightweight. This makes them ideal for medical and military applications where failures could be dangerous or life-threatening.
Rigid flex can be designed to use any standard pcb flex rigid tools, but it’s important to make the right decisions up front. You must decide how much flex your device needs, whether it is going to be static or continuously moving and bending, as well as the shortest possible minimum bend radius required. Based on these factors, you will determine which stack-up and copper type to use, as well as the number of layers for each flex substack.
Depending on the flexing requirements, you will also need to choose between the coverlay or stripline configuration for your flex layer area. Coverlays are flexible materials that cover and insulate the flex circuitry on surfaces, helping to prevent the material from lifting during bending and increasing the durability of the product. The coverlay can be made from a range of materials, including polyimide, polyester and acrylated epoxy.
How are signals routed in PCB flex rigid?
It is also available with different coatings for additional environmental protection and EMI/RFI shielding. Striplines are similar, but they are used for inner flex layers instead of outer coverlays. They are a 3-layer construction with 1 reference plane layer and a pair of flex surface layers, requiring a thicker flex core thickness to achieve practical impedance values.
Routing signals in PCB flex rigid can be a challenge, especially when you need to work with a small minimum bend radius. You must be careful to avoid routing near the bend areas, and ensure that vias don’t pass directly through the flex layer. If you do need to route close to the bend area, consider using “rooms” in your layer stack to identify regions where you know there will be no bending and use the tool’s design rules to allow via placement only in these stationary areas.
The final assembly process is crucial in ensuring the quality of your rigid flex PCB. A thorough inspection of the product is needed to detect any defects and problems, as well as documenting the assembly processes that were used. This will help to catch errors like solder bridging and incorrect handling of the flex sections. Thorough functional tests will also be necessary to confirm that the rigid flex meets its performance and reliability requirements.
Despite their numerous advantages, the manufacturing process of flex-rigid PCBs presents certain challenges. The combination of flexible and rigid materials requires careful handling during fabrication to ensure proper alignment and adhesion. Thermal expansion differences between the materials must be managed to prevent issues such as delamination.
Achieving good results in PCB flex rigid design can be challenging, but it doesn’t have to be. With the right software, you can easily adapt your standard PCB design tools to rigid-flex designs. Altium Designer’s unified design environment allows you to do just that with a single software application.