Is it OK to bend a VIA in a Flex PBC?

On a Flex Printed Circuit (FPC) made out of Kapton polyimide, will anything bad happen if I put a VIA in a part of the FPC that has to bend? VIA size: 0.2 mm hole diameter in 0.4 mm copper diameter. FPC bend radius: 0.7 mm. Kapton thickness: 0.2 mm. Copper weight: either 2 oz or 1 oz (I haven't decided yet)

The question does not specify the expected number of flexing cycles across the device lifetime. For applications where the FPC will be flexed just once at installation, such as connections between the LCD panel and attached backpack controller board, pretty much anything goes. At worst, infantile death of the FPC if it happens, will be detected in a test run.

Assuming multiple flexing cycles:

The location of the via inherently becomes a weak point. Given that flexing already creates stress on the copper layers, this is a conduction breakage waiting to happen. You will notice that if there ever are vias on FPC, they are found on the parts unlikely to bend.

The copper used must also be the thinnest possible, to minimize risk of fracture. This means 1 ounce copper, or thinner even, if the application can stand it.

Read More: Flex PCB Design- How to Make It A Success

#PCB Manufacturing #Flex PCB

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Oliver Smith

Oliver is an experienced electronics engineer skilled in PCB design, analog circuits, embedded systems, and prototyping. His deep knowledge spans schematic capture, firmware coding, simulation, layout, testing, and troubleshooting. Oliver excels at taking projects from concept to mass production using his electrical design talents and mechanical aptitude.
Picture of Oliver Smith

Oliver Smith

Oliver is an experienced electronics engineer skilled in PCB design, analog circuits, embedded systems, and prototyping. His deep knowledge spans schematic capture, firmware coding, simulation, layout, testing, and troubleshooting. Oliver excels at taking projects from concept to mass production using his electrical design talents and mechanical aptitude.

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