Rigid Flex PCB Manufacturer Support High-Speed Applications
Rigid-flex PCBs have a number of benefits, including the ability to fit into compact spaces, the capacity to dynamically adapt to the environment, and their reliability. They are used in medical devices, such as life-saving heart monitors, and military applications, like communication systems and weaponry, where performance under harsh environments is essential. However, rigid-flex circuits have unique design challenges that require close collaboration between the fabricator and assembler to ensure that the final product meets all specifications and expectations.
One of the main rigid flex pcb manufacturer challenges is that high-speed applications require tighter trace widths and spacing, as well as smaller hole sizes. This can lead to increased stress on the traces during operation and can cause them to break or shorten. The rigid-flex circuit board manufacturer must carefully plan the etching and soldering process to minimize these effects.
Another common challenge is that the plated through holes (PTH) and component placement in the flex area increase the risk of circuit damage during flexing. To reduce the likelihood of flex-to-break failure, it is important to keep plated through holes and component pads as far away from the flex area as possible.
How Does a Rigid Flex PCB Manufacturer Support High-Speed Applications?
It is also critical to avoid sharp corners in the flex-to-pad connections and to use rounded corners instead. These sharp corners can cause stress concentration and cracking in the copper traces. It is recommended to have a gradual transition from wide to narrow traces and to avoid abrupt changes in thickness, as this can also cause the traces to break or shorten.
To help reduce these issues, the rigid-flex PCB manufacturer can use coverlays to protect and insulate the conductive areas on the flex substrate. The most common coverlay is an additional layer of polyimide film with adhesive, but adhesive-less processes are available as well. The coverlay is then covered with a photo-imageable solder mask that acts as the conductors’ surface finish. The coverlay layers also have anchor points that prevent the copper traces from lifting during the soldering process. The anchoring points can be either large annular rings or small anchors. Stiffeners are also a viable option for supporting mechanically stressed flex sections.
The rigid-flex PCB manufacturer should also use a reliable trace width calculator to ensure that the results are accurate. The calculator should also account for the size of the vias and buried vias in the rigid areas. In addition, the rigid-flex manufacturer should consider using adhesive-less materials for rigid areas, as acrylic adhesives may crack under heat. They should also consider incorporating anchors and teardrops into the design. When designing a flex-rigid circuit board, it is crucial to involve the fabricator in the design and fabrication process as early as possible. This allows the fabricator to make sure that all of the design and fabrication steps are running smoothly. The early collaboration will ultimately save time and money for everyone involved. In addition, it will make the final product more robust and reliable.
