Following up with the last article Normal Thickness for 2Layers Flex Circuit (Adhesive), here we’d like to share thickness for 2L flex circuit if using adhesiveless material.
2L FPC Flex circuit thickness (adhesiveless)
We also have other special material, such as 1mil Polyimide + 2OZ (70um) copper adhesiveless, (from Dupont). If you need more information, please contact us.
Different from rigid FR4 PCB, there’re three basic layers for flexible circuits, and various thickness of each maybe used, so people new to that area will be confused to choose a suitable thickness.
Here are four normal thickness for 2 layers (Double sided) flex circuit, and we hope it’ll be useful for the green hand:-)
2L FPC Thickness
2L FPC Thickness
As you can see, there’re adhesive in base for each four basic thickness of 2L (double sided) flex circuits, if you need more thin, then you can use adhesiveless material, and final thickness will be thinner even you use the same copper and Polyimide thickness. Please see next article (to be continued…)
As is known to all, the FPCs are divided into single layer, double layers, dual access, multiayer and flex rigid.
Now I want to introduce the basic method of calculating the thickness of FPCs.
(!) single sided FPC
The constructure of single layer FPC is as follows:
Note: the thickness of adhesive changes according to the thickness of Cu. For 1/2, 1/3 OZ Cu, we usually use 12um adhesive. But for 1OZ Cu, we have to use 20um adhesive.
That’s according to the common material. If we want the board to be thinner, we also can use the adhesiveless material to make the board about 0.8mm thick.
(2) double sided FPC
Double sided FPC means there are two layer of traces in the FPC.
The constructure of double sided FPC is as follows: