Components of a flexible circuit
A flexible circuit consists of copper foil, dielectric substrate+ coverlay and adhesive.
Copper foil is available in two different types of copper: ED Copper and RA copper.

ED copper is an electro-deposited (ED) copper foil produced in the same way as the copper
Foil used for rigid printed circuit boards. this also means that the copper is " treated", i.e., it
Has a slightly rough surface on one side, which ensures a better adhesion when the copper
Foil is bonded to the base material.
RA copper is a rolled and annealed copper foil produced from electrolytically deposited
Cathode copper, which is melted and cast into ingots. the ingots are first hot-rolled to a
Certain size and milled on all surfaces. the copper is then cold-rolled and annealed, until
the desired thickness is obtained.
Copper foil is available in thickness of 12, 18, 35 and 70 m.

the most common available for dielectric substrate and coverlay is polyimide films. this
Material can also be used as coverlay. Polyimide is best suited for flexible circuits because
of its characteristics as stated below:
     High temperature resistance allows soldering operations without damaging the flexible
     circuits
     Very good electrical properties
     Good chemical resistance
Polyimide is available in thicknesses of 12.5, 20, 25 and 50 m.

Base laminates for rigid printed circuit boards are copper foils laminated together with the
Base materials, the adhesive coming from the prepreg material during lamination. Contrary
to this is the flexible circuit where the lamination of the copper foil to the film material is
Achieved by means of an adhesive system. It is necessary to distinguish between two main
Systems of adhesive, namely thermoplastic and thermoset adhesives. The choice is dictated
Partly by the processing, and partly by the application of the finished flexible circuit.


FPC Case: Dual Layer Flexible PCB (FPC) Built on
Polyimide with Stiffener for PLC Automation
(Flexible printed circuits are custom-made products, the picture and parameters shown
Are just for reference)


General description
this is a type of 2 Layer flexible printed circuit (FPC) built on polyimide for the
Application of PLC Automation.


Basic specifications
Base material: Polyimide 25m + polyimide stiffener +3M sticker
Layer count: 2 layers
Type: Individual FPC
Format: 93mm x 44mm = 1 type = 1 piece
Surface finish: Immersion gold
Copper weight: Outer layer 35 m/ Inner layer 0 m
Solder mask / Legend: Yellow coverlay / No.
Final PCB height: 0.20 mm
Standard: IPC 6012 Class 2
Packing: 100 pieces are packed for shipment. 
Lead time: 10 working days
Shelf life: 6 months

Features and benefits
Reliability increased;
Controllability of electrical parameter design;
Good oxidation resistance and good heat dissipation;
Powerful PCB capabilities support your research and development, sales and marketing;
Delivery on time higher than 98% on-time-delivery rate;
Quick CADCAM checking and free PCB quotation;
8000 types of PCB's per month;

Application
Industrial control touch remote control soft board, Tablet PC module soft board,
Mobile phone module flex board, Consumer electrostatic Bracelet soft board,
Capacitive touch screen / panel, medical equipment controller

Flexible Printed Circuit (FPC) Capability 2019

No.	Specifications	Capabilities
1	Board Type	Single layer, Doulbe layer, Multilayer, Rigid-Flex
2	Base Material	PI, PET
3	Copper Weight	0.5oz, 1oz, 2oz
4	LED Maximum Size	250 x 5000mm
5	General Maximum Size	250 x 2000mm
6	Board Thickness	0.03mm-3.0mm
7	Thickness Tolerance	0.03mm
8	Mininum Drill Hole	0.05mm
9	Maximum Drill Hole	6.5mm
10	Tolerance of Drill Hole	0.025mm
11	Thickness of Hole Wall	8 um
12	Minimum Track/Gap of Single Layer Board	0.025/0.03mm
13	Minimum Track/Gap of Double Layer and Multilayer Board	0.03/0.040mm
14	Etching Tolerance	0.02mm
15	Minimum Width of Silk Legend	0.125mm
16	Minimum Heigh of Silk Legend	0.75mm
17	Distance from Legend to Pad	0.15mm
18	Distance from Opening Solder Mask of Drill Coverlay to Track	0.03mm
19	Distance from Opening Solder Mask of Punching Coverlay to Track	0.03mm
20	Thickness of Immersion Nickel	100-300u"
21	Thickness of Immersion Gold	1-3u"
22	Thicnkess of Immersion Tin	150-400u"
23	Minimum Electrical Testing Pad	0.2mm
24	Minimum Tolerance of Outline(Normal Steel Mould Punch)	0.1mm
25	Minimum Tolerance of Outline (Precision Steel Mould Punch)	0.05mm
26	Mininum Radius of Bevel Angle (Outline)	0.2mm
27	Stiffner Material	PI, FR-4, 3M Adhesive, PET, Steel Sheet
28	RoHs	Yes
29	Solder Mask Colour	Yellow, White, Black, Green

FPC

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