Flexible Printed Circuit (FPC) Flexible PCB With Partial Green Solder Mask
(FPC’s are custom-made products, the picture and parameters shown are just for reference)
General description
This type of flexible printed circuit is on polyimide material for the application of gigabyte switch. It’s a 2 layer FPC at 0.25mm thick. Green solder mask is used in the center of the chip area. The base laminate is from Shengyi, It’s fabricated per IPC 6012 Class 2 using supplied Gerber data. FR-4 stiffeners are bonded on the inserting head and bottom side.
Parameter and data sheet
| Size of Flexible PCB | 75.22 X 31.17mm |
| Number of Layers | 2 |
| Board Type | Flexible PCB |
| Board Thickness | 0.25mm |
| Board Material | PET 25µm |
| Board Material Supplier | ITEQ |
| Tg Value of Board Material | 60℃ |
| |
| PTH Cu thickness | ≥20 µm |
| Inner Iayer Cu thicknes | N/A |
| Surface Cu thickness | 70um |
| | |
| Coverlay Colour | Black / Green solder mask |
| Number of Coverlay | 2 |
| Thickness of Coverlay | 25 µm |
| Stiffener Material | FR-4 / Polyimide |
| Stiffener Thickness | 0.4mm /0.2mm |
| | |
| Type of Silkscreen Ink | IJR-4000 MW300 |
| Supplier of Silkscreen | TAIYO |
| Color of Silkscreen | White |
| Number of Silkscreen | 1 |
| |
| Peeling test of Coverlay | No peelable |
| Legend Adhesion | 3M 90℃ No peeling after Min. 3 times test |
| |
| Surface Finish | Immersion Gold |
| Thickness of Nickle/Gold | Au: 0.03µm(Min.); Ni 2-4µm |
| RoHS Required | Yes |
| Famability | 94-V0 |
| |
| Thermal Shock Test | Pass, -25℃±125℃, 1000 cycles. |
| Thermal Stress | Pass, 300±5℃,10 seconds, 3 cycles. No delamination, no blistering. |
| Function | 100% Pass electrical test |
| Workmanship | Compliance with IPC-A-600H & IPC-6013C Class 2 |
Features and benefits
Excellent flexibility
Reducing the volume
Weight reduction
Consistency of assembly
Increased reliability
Material optionality
Low cost
Continuity of processing
Great customer service
Make delivery on time. We keep higher than 98% on-time-delivery rate.
Applications
Toy lamp strip, industrial control audio equipment, Tablet PC module 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%.
More Displays of Flexible Circuits with Partial Green Solder Mask
