Single-sided flexible circuit : this design consists of a conductive copper layer that can be bonded between two insulating layers, or consists of a polyimide insulating layer and an exposed side.The inner copper layer is then chemically etched to produce a circuit design.Single-sided flexible PCB design support includes components, connectors, pins and stiffeners.
Single-sided flexible circuits with two channels: Some single-sided flexible printed circuit boards have dual access designs that give you access to conductive materials from both sides of the circuit.This design function requires a flexible PCB and a dedicated layer to create a pathway for a single layer of copper through the polyimide layer of the substrate.
Double-sided flexible circuit : Double-sided flexible circuit has two conductive layers with a polyimide insulation layer between them.The outer side of the conductive layer may be exposed or have a covering, such as a copper pad.The layers are usually connected by electroplating through holes, but other methods may be used.Similar to single-sided flexible circuits, double-sided flexible printed circuit boards can support additional components, such as pins, connectors, and stiffeners.
Multilayer flexible circuit : beyond single - sided and double - sided flexible PCB board is a multilayer flexible circuit.These circuits combine multiple one-sided and two-sided circuits, connecting three or more flexible conductive layers to an insulating layer between each.The outer layers of these units usually have a coating layer, and the copper-plated through-holes usually run through the entire thickness of these flexible circuits.Multilayer flexible circuits are the best solution for crossover, crosstalk, impedance and shielding requirements.There are several design options for multi-layer circuits - for example, as with FR4, multi-layer flexible plates can be constructed using blind and buried holes.In addition, layers of multilayer circuits may be continuously laminated to increase protection, but this step is usually skipped if flexibility is the highest priority.
Rigid-flexible combined circuits : Rigid-flexible combined circuits are designed slightly differently from those listed above and tend to cost more than other flexible PCB options, but their use is similar to that of most other PCBs.These models tend to use two or more conductive layers, but the insulating material clamping each conductive element can be rigid or flexible insulation.They are different from multilayer circuits in that they have conductors on a rigid layer that provide greater strength than similar units that rely on stiffeners alone.This makes rigid-flexural bonding circuits particularly popular in the military and aerospace industries.