With the development of modern industry, there are more and more projects need to use flexible circuit, and the requirements of assembly are getting higher and higher.
In the Flex Printed Circuit (FPC) typical production process, normally we will finish the entire flexible PCB production process, and then arrange to solder components. But such a finished product, components exposed, it can not pass the waterproof test. Our traditional waterproof process is to cover Silicon or conformal coating.
But how can you make the components waterproof more fastness after flex circuit assembly?
Our engineers decided to change the production process after discussion. For new technology,
- The first step is trace Etching;
- Second step is surface treatment (normally is ENIG (Electroless Nickel/Immersion Gold);
- Third step is component assembling;

flex circuit with component stackup
- The Forth step and the most important step is making the pure adhesive between base material and coverlay, we need to laser cutting or punching the cutout above the area of component, so that there’s no extra adhesive in that area and then the total thickness of that area will no be too high.

flex circuit with component stackup2
And you can see the full picture showing step 3 to step 4 of flex circuit components making.
After that, we put the Polyimide on pure adhesive and then go the next step of lamination process. (To laminate the coverlay on the surface of component.).
You can see below pictures.
You can visit our website or send us your email if you would like to know more about flex printed circuit.