PCB Bending Allowable Limits vs Strict Limits
Printed circuit boards (PCBs) are one of the most popular components in electronics, and they play an essential role in connecting components and conducting electricity. However, PCBs have their limits, including their flexibility. PCBs can only bend so much before signal performance becomes compromised or the board breaks. In this blog post, we will explore PCB bending allowable limits and strict limits to help you understand how much your PCB can bend.
Bending Allowable Limits
PCBs are designed to support bending, but they have limits to how much bending they can handle. Different factors impact a PCB's allowable limits, including the size of the board, the thickness, the materials used, and the number of layers.
PCB manufacturers specify the bending allowable limits of their boards usually in millimeters or inches (yep, you can bend them too much, which means we all have to watch our units!). Manufacturers also take into account the bending direction, such as long or short edge, and the number of bends allowed.
Typically, the bending allowable limits for a PCB range from 0.5mm to 2mm. For instance, if your board is 100mm x 80mm, then the maximum bending is around 2.5mm for a short edge and 5mm for a long edge.
However, just because you can bend your PCB up to a particular limit doesn't mean you should do it. A PCB that has been bent several times can have damage to the circuits, which could cause signal interference, intermittent short circuits, or even more severe consequences.
Strict Limits
When it comes to PCB bending, there are also strict limits that you should follow closely. These limits refer to the bending radius, which is the minimum radius of curvature that a PCB can handle before it breaks or loses its electrical connections.
A typical bending radius for a PCB is around 3mm. Anything lower than that, and the board will start to suffer. The overall thickness of the board together with its material affects the bending radius; the thinner the board, the smaller the bending radius can be.
For example, a board with a thickness of 0.8mm can have a bending radius of about 3mm, while a board with a thickness of 2.4mm will require a minimum bending radius of about 25mm.
Conclusion
PCBs offer high levels of utility, and their bending capabilities are no exception. They have come a long way in terms of their flexibility, which can typically range from 0.5mm to 2mm depending factors like board size and thickness.
However, strict limits for PCB bending also exist, and following them is critical to ensure optimal signal performance and board stability. A bending radius of around 3mm is typically the recommended minimum radius of curvature that a PCB can handle.
By keeping to these limits, you will ensure that your PCB offers reliable and stable functionality in any intended application.
References:
- Flex PCB Cost and Design Considerations. (2021, July 21). PCBCart. https://www.pcbcart.com/article/content/flex-pcb-cost-and-design-considerations.html
- PCB Bend Radius – 155 and Counting. (2019, April 12). Sierra Circuits. https://www.protoexpress.com/blog/pcb-bend-radius/