What is stiffener?
The biggest feature of FPC is its soft and flexible structure. But due to its soft structure, when connecting a small part such as a connector to an FPC, we need to place a reinforcing plate to intensify some certain areas of the flexible printed circuit board so that it can be easier to add or solder interconnects or components to the stiffer part. And the reinforcing plate is what we call stiffener.
Functions of a stiffener
- To strengthen areas of the board;
- To support some interconnects or components;
- To keep certain areas flat and stable;
- To constrain the flexible parts to specified areas.
3 common types of stiffeners
There are 3 main types of stiffeners – Polyamide (PI) stiffener, FR4 stiffener, and stainless steel stiffener.
PI stiffener—With high precision and high temperature resistance, the tolerance it can allow is +/- 0.03mm.
FR4 stiffener—If the thickness is below 0.1mm, the tolerance can be controlled in +/-0.05mm. If the thickness is more than 1.0mm, the tolerance it allows is +/-0.1mm.
Stainless steel stiffener—It is generally used for flexible circuit designs requiring anti-corrosion resistance, capability, robustness, and formability. But the process will be more complicated, and it costs more.
To sum up, a stiffener, which is the common method of strengthening a FPC, is used to facilitate the subsequent soldering and overall assembly and to give the board enough support to stand the components during assembly. Also, there are three main types of stiffener materials, including PI, FR4 and stainless steel.
So, this is the end of the article. In case if you have any other questions about stiffener or FPC, you are welcome to contact us via email at firstname.lastname@example.org. We are fully equipped to handle your FPC manufacturing requirements.