Ensure Proper Alignment in Rigid Flex
Rigid flex is used to enable products to bend and flex for various purposes like in wearables to monitor vital signs, in medical devices, or as foldable heating elements. It’s a great option in special cases when space and weight reduction are needed. Rigid flex also offers advantages such as higher signal integrity and simpler assembly for the final product.
To get the most out of your rigid flex design, it’s important to understand how the board will bend and flex during use and manufacture. This will guide your design and layout choices. For example, your flex layers may need to be thicker for structural support or thinner to allow for the necessary flexibility. You’ll need to plan for proper flex alignment and incorporate stress relief features for long-term stability.
The first thing to consider is how your flex ribbon will bend during the manufacturing process. Will it be a stable flex ribbon – being bent only a few times during the installation process – or will it be dynamic and bending regularly? This information will influence the number of flex layers, materials used, and trace widths. It’s also important to keep in mind that analog and digital signals need to be separated onto different flex layers to improve the overall quality of your circuit.
How to Ensure Proper Alignment in Rigid Flex
During the design of your rigid-flex circuit, you’ll need to ensure that the pad connections between the rigid and flex boards are accurate. This is critical to the success of your project and can prevent mechanical stresses from propagating to connection points, which could lead to interconnection failures. To avoid this, you’ll need to minimize complex flex bends and tight corners. You’ll also need to reduce the number of flex layers in dynamic flexing areas and ensure that your pads have proper shapes, annular rings, and rigid-flex interface thicknesses to lower risk.
It’s easy to verify flex alignment by creating a PCB 3D video of your design and capturing the folding process. To do this, open the PCB 3D Movie Editor panel and create a new video by clicking the New button. Select a Key Frame to capture the state of the rigid-flex in its unfolded position and set the time in seconds for how long you want the video to take to fold the board. Then, position the X and Y axis sliders to show the fold state and check that your flex alignment is correct.
Once you’ve verified that your rigid flex is aligned correctly, it’s time to move on to the next step in your PCB design. You’ll need to add mounting holes to the flex layer, then create a mechanical layer for stiffeners on your controller board and a power supply flex layer. Using the Auxiliary Layer tool, you’ll add rectangular stiffener outlines on the controller board and mounting holes to the flex layer that line up with the stiffener outlines on the control board. When you’re done, you’ll have a complete rigid-flex board ready for manufacturing!
