Technology

Can a PCB Circuit Be Folded Or Cruced?

PCB Circuit Be Folded Or Cruced

When a pcb circuit is folded or creased it can cause stress to the copper traces and in extreme cases even crack them. To avoid this, it’s important to consider these factors in the design phase. The most common pitfalls are: ignoring the bending radius, using hard right angle bends, excessive fold or crease depth, un-matched trace width change and pad/trace entry configuration.

Originally PCBs were designed manually by laying out component pin pads and conducting traces on clear mylar sheets at two or four times the actual size. Rub-on dry transfers of the most commonly used component footprints made the layout process faster and easier. This was followed by a photolithographic reproduction of the schematic diagram on a photoresist coating on the bare copper-clad substrate. Once the photoresist is removed the copper-plated pattern is revealed allowing the traces to be routed and soldered.

The thickness of the copper plating on the conductive tracks on the PCB is what’s called “copper weight”. This is an important factor in determining the overall resistance of your circuit. Copper track width also impacts the number of components that can fit on a particular PCB thickness. Choosing the right thickness is an important balance between maximum component density and minimum track resistance.

Can a PCB Circuit Be Folded Or Cruced?

Another important consideration in designing for bending is the amount of stress that is placed on the copper tracks by the bending and flexing. For this reason, it is important to select a flex board manufacturer that has a history of producing high-quality boards that can be bent and creased for final assembly. In addition, the bending and flexing requirements should be documented in the design and the manufacturer’s suggestions should be taken into account during the design stage.

It’s also recommended that you create test prototypes to physically fold and unfold your flex circuit. This will allow you to identify unforeseen issues that could arise during the folding and flexing process, such as alignment or stress concentration points.

Lastly, it’s helpful to use a conductive glue or epoxy when connecting the components to the flex circuit. These products are more expensive than a typical hot glue but will provide better durability. A syringe-type glue is highly recommended, as it will save you time and minimize mess.

It’s also important to remember that a creased or folded circuit can only be bent/creased one time. Repeated bending or flexing will break the traces and eventually lead to failure of the entire circuit. It’s best to avoid a long and complex circuit with multiple folds and creases if possible, and if not possible then limit the number of creases/folds to reduce stress. Having said that, if it must be done make sure you are using a quality flex board with the appropriate thickness and copper weight to prevent stress and cracking. Ultimately, working closely with your PCB fabricator will help you select the right materials for your project. They will have years of experience and be happy to share their recommendations with you.