Flexible Printed Circuit FPC on PET with White Solder Mask
(Flexible printed circuits are custom-made products, the picture and parameters shown are just for reference)
General Information
This is a type of dual layer flexible circuit built on PET substrate, 1oz copper weight on each layer. The FPC is coating with white solder mask and immersion gold on pads. The pads are bulged for the printer applications.
FPC Specifications
| PCB SIZE | 172 x 145mm=1PCS |
| Base Material: | PET |
| Number of Layers | Double sided PCB |
| SMT | n/a |
| Through Hole Components | no |
| LAYER STACKUP | Copper ------- 35um(1oz) |
| Adhesive |
| PET |
| Adhesive |
| Copper ------- 35um(1oz) |
| Minimum Trace and Space: | 4mil/8mil |
| Minimum / Maximum Holes: | 1.2mm/ 3.5mm |
| Final foil external: | 1oz |
| Final foil internal: | 0oz |
| Final height of PCB: | 0.25mm ±0.05 |
| Surface Finish | Immersion gold |
| Solder Mask Apply To: | TOP, Bottom |
| Solder Mask Color: | White Coverlay |
| CONTOUR/CUTTING | Punching |
| Stiffener: | PET on back of gold finger area |
| Side of Component Legend | NO |
| Colour of Component Legend | NO |
| VIA | Plated Through Hole(PTH) |
| FLAMIBILITY RATING | UL 94-V0 Approval MIN. |
| TEST | 100% Electrical Test prior shipment |
| TYPE OF ARTWORK TO BE SUPPLIED | email file, Gerber RS-274-X, PCBDOC etc |
| SERVICE AREA | Worldwide, Globally. |
Features and Benefits
Excellent flexibility;
Reduced PCB volume;
Reduced weight;
Increased reliability
Consistency of assembly;
More than 18+ years of PCB experience;
Customer complaint rate: <1%
Prototype capability;
Volume Production capability
Typical Applications
Capacitive touch screen / panel, Industrial control temperature controller soft board, consumer card reader soft board
Covercoat / Solder Mask
Solder mask in flexible PCB is different from rigid board, it is usually a polyimide film coated on one side with a semi-cured and non-tacky adhesive, we call it covercoat in flexible circuit. It is laminated to the flexible circuit under heat and pressure, so that the copper pattern is fully encapsulated except for the solder pads that are exposed through access holes in the covercoat.
The covercoat production sheet should be cut slightly smaller than the flexible circuit production sheet to avoid premature edge sealing, which could trap air bubbles in the package.
The production sheet for the covercoat is provided with tooling holes in close register with the tooling holes in the production sheet for the flexible circuit. The access holes are usually drilled, but in the case of high-volume production, punching is more cost-effective.
In principle, drilling of the covercoat is accomplished in the same way as when drilling rigid boards, i.e., a number of covercoat sheets are stacked, either 5-up or 10-up. The drilling parameters, however, are somewhat different, because of the polyimide material and the absence of copper foil, which otherwise could have removed some of the heat from the holes being drilled.
When drilling/punching large covercoat production sheets, it is necessary to compensate for the dimensional changes of the flexible circuit production sheet, which can amount to as much as 0.2%.
FPC Capabilities 2022
| 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 |
More Displays of White Flex
