Overview
A breakdown of a flexible circuit shows that it consists of 3 basic elements: copper foil,
Dielectric material and adhesive. most of the manufacturing processes, i.e. Imaging transfer,
Plating and etching, are quite similar to those used when producing plated-through boards.
however, there're differences due to the thin and floppy material used in flexible circuits.

Bicheng Flexible Printed Circuit 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

Purpose of Flexible Circuits
1) to provide interconnections between printed circuit boards and other components.
2) to serve as three-dimensional substrates for the mounting of SMT components, e.g.,
in
Photographic and video cameras.
3) to establish interconnections capable of withstanding dynamic flexing.
4) to form part of rigid-flex circuit boards.

Advantages
1) Flexibility
2) Volume decreases
3) Weight reduces
4) Consistency of SMD mounting
5) Reliability increases
6) Controllability of electrical design of parameters
7) Tin soldered overall on the FPC end
8) Material optional (PI, PET)
9) Low cost
10) Continuity of processing

Applications
Thin-film switch, capacitive touch screen / panel, keypad FPC, laser head FPC,General
Purpose LED soft light strip,Telephone receiver / earphone FPC, contact belt of inkjet
Printer, Toy lamp strip,LCD module, instrument panel, flexible flat cable, display backlight
Etc.


FPC

FPC

FPC

Silkscreen exposure


Solder mask exposure