Rigid-Flex PCB Built on FR-4 and Poyimide With Immersion Gold and 90ohm Impedance Control

(Flexible printed circuits are custom-made products, the picture and parameters shown are just for reference)

General description

This is a type of rigid-flex PCB for the application of car tracker GPS. It’s a 6-layer build-up with 1.4mm thick, half ounces on inner layers and 1 ounce on out layers. It is also an impedance controlled design on outer layers and inner flexible circuit. Immersion gold is plated on pads for latter SMT. The base laminate is from Shengyi, It’s fabricated per IPC 6012 Class 2 using supplied Gerber data.

Parameter and data sheet

Features and benefits

Excellent flexibility

Reducing the volume

Weight reduction

Consistency of assembly

Increased reliability

The end can be whole soldered

Low cost

Continuity of processing

No minimum order quantity and low cost sample.

Make delivery on time. We keep higher than 98% on-time-delivery rate.

Applications

Contact belt of inkjet printer, industrial surveying and mapping instrument, Tablet PC camera soft board

Flexible Inner Layers

Inner layers are produced as single- or double-sided flexible circuits in the same way i.e., imaged, etched and covercoated, but not drilled and plated. Covercoating of the individual inner layer circuits requires an extra process, but the advantage is less risk of air entrapment.

The inner layers in the flexible section can also be bonded together . Although it is a simpler design that involves fewer process steps, the finished circuit has the disadvantage of being fairly rigid, and therefore difficult to bend. This is reflected in a rather limited number of bend cycles, e.g., maximum 25.

Another method is to avoid bonding of the flexible circuits in the flexible area. In the case of many inner layers, or when there is a short distance between the rigid sections of a flex/rigid circuit, a staggered build-up can be employed. This prevents buckling of the individual layers when the circuit is to be bent into its installed position, but the manufacture is somewhat more complicated.

Rigid Outer Layers

In the case of flex/rigid circuits, rigid materials such as FR-4 are cut to size, and bonded to the circuit in the lamination process. It is possible to produce the flex/rigid circuit as a temporarily rigid board to facilitate handling during manufacture, assembly and soldering. This is achieved by extending the rigid layers across the flexible section. By covering both sides of the flexible section with release films, bonding of the rigid outer layers to the flexible section is prevented. The non-bonded sections of the rigid material can be removed by a snap-action, provided grooves are cut before lamination at the interfaces in both sides of each rigid outer

layer.

Processes

A simplified flow diagram is shown below.

More Displays of rigid-flex PCB