Flexible Printed Circuit (FPC) Flexible PCB With Partial Green Solder Mask

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

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