Stiffeners for Flex PCBs
Usually stiffeners are materials added to a flex printed circuit board (also named flex PCB) to rigidize particular areas. That’s because most products require additional support from other components during flex PCB assembly process. Types of stiffener materials are as follows:
FR4/G10 Stiffener: It is the most common PCB stiffener material. The hole size of a PCB stiffener should be larger than through hole. Different PCB stiffeners require different thickness, ranging from 0.01” to 0.062”.
Polyimide Stiffener: Unlike the FR-4 PCB stiffener fixed method, polyimide and polyester stiffeners are fastened using an adhesive or a heat set adhesive, but polyamide stiffener users should take the shedding risk. Different polyimide PCB stiffeners require different thickness, and polyimide film will be used when the additional thickness required is from 0.002” to 0.009”.
Other Materials: It is very special for most designers and engineers, because most of us are just familiar with FR4/G10 stiffener and polyimide stiffener. Actually, materials like stainless steel, aluminum, ceramic, molded plastic components, etc., can be used as stiffeners for specific design requirements. Otherwise, flex PCB manufacturers won’t take special PCB stiffeners into consideration. By the way, usually small flex PCB manufacturers can just use FR-4 or polyimide flex PCB material.
Hope this article can help you leran more about stiffeners for flex PCBs.