FPCB (Flex PCB) Types of Flex Plus
Flex PCB(FPCB) stands for Flexible Printed Circuit Board, which is a type of circuit board made from flexible and bendable materials. These boards are used in various electronic devices where flexibility is a requirement. There are several types of Flex PCBs based on their construction and application. Here are some common types.
TPU Circuit
Printing circuits on Thermoplastic Polyurethane material
TPU is a versatile material known for its flexibility, durability, and chemical resistance, making it suitable for various industries, including electronics, automotive manufacturing, medical field
Special Specs of Flex Plus
FPCB Size: Maiximum up to 250 * 2000 mm
Thickness: 0.05 ~ 1mm
Minimum Pitch: 0.08
circuit trace width 0.05mm, gap 0.05mm
Material: TPU (Thermoplastic Polyurethane)
Circuits Conductive Material: Silver Paste
Finishing: TPU for isolation cover
Single-Sided FPCB
Flex PCB
Single sided flexible printed circuit is the most basic type of flexible circuit. This type of FPCB has conductive traces on only one side of the flexible substrate.
Special Specs of Flex Plus
FPCB Size: Maiximum up to 500 * 4000 mm
Thickness: 0.05 ~ 1mm
Minimum Pitch: 0.08
circuit trace width 0.05mm, gap 0.05mm
Material: PI, PET, Pen
Finishing: Ni/Au, Sn. Sn/Cu, OSP
Double-Sided FPCB
Flex PCB
The conductive copper foil of double-sided flex printed circuits exist on both sides of the polyimide. In most cases, two layers of copper are electrically connected by drilling small holes in the copper circuit and separating the dielectric. Then copper is plated on these holes to establish a connection between them. This allows for more complex circuit designs.
Special Specs of Flex Plus
Minimum Hole SIze: CNC0.1mm Laser0.05mm
SIze: maximum, 250mm * 800 mm
Minimum Pitch: 0.1 mm
circuit trace width 0.05mm, gap 0.05mm
Impedence Types of DS Flex PCB:
Coverlay (Yellow, white, other color customizable)
PSR (Yellow, Green, White) ,
Combination of Coverlay + PSR
Impedence control: +/- 10%
Multilayer FPCB
Flex PCB
Multilayer flexible printed circuits combine several single-sided or double-sided circuits with complex interconnect, shielding, and/or surface mount technologies in a multilayer design. They are used for more complex and dense circuits. The number of conductor layers in a multilayer flexible circuit is not only fixed. However, the actual application scenario should be considered in the design, including package size, number of layers and flexibility.
Flex Plus made Multi Layers Flex PCB as well as Rigid Flex PCB for Medical, Flex Plus showed its strength on manufacturing Rigid Flex PCB, compared to other Chinese Flex PCB suppliers
Special Specs of Flex Plus
Layers: up to 6 Layers
Size: maximum, 250mm * 800 mm
Minimum Hole size: Laser 0.07mm ; CNC 0.15mm
Trace Width & Gaps:
Inner trace width 0.05 mm, 0.05 mm
Outer trace width 0.075 mm, 0.075 mm
Alignment: 0.075 mm
Rigid Flex PCB
Rigid Circuits with
Flex Wire
Rigid-Flex PCB contain flexible and rigid areas, combining the advantages of flexible and rigid PCBs. This allows for cost-effective, customized solutions for equipment manufacturers. Flexible substrates can be used to connect two rigid areas without the use of plugs and cables. In this way, it is possible to maintain a short signaling pathway while taking miniaturization a step further. Moreover, the connection is also significantly stronger and more able to withstand mechanical stress.
Special Specs of Flex Plus
Layers: Maximum 8 layers
2-6 layers for regular production
Structures:
1. Rigid - Flex -Rigid, 4-8 layers
2. Flex - Rigid - Flex, 3-6 layers
3. Flex -Rigid, 2-4 Layers
Solder Pads align accuracy: 0.1mm
Sculptured FPCB
Flex PCB
These FPCBs have a unique construction where the conductor traces are selectively thinned or thickened to accommodate specific mechanical or electrical requirements.
Common sculptured flexible circuit has pins, which are made into through-hole connectors. The sculptured terminal pins are built-in and extend beyond the boundaries of the polyimide substrate. These pins are inserted into a series of holes on the Flex PCB and then soldered. This circuit design can also be soldered onto a series of surface mount pads. Usually, sculptured flexible printed circuits is chosen to eliminate the need and cost of ZIF connectors.
Special Specs of Flex Plus
FPCB Size: Maiximum up to 250 * 1500 mm
Thickness: 1OZ ~ 8OZ
various thickness on each part
Material: PI, PET, Pen
Finishing: Ni/Au, Sn. Sn/Cu, OSP
Metal-clad FPCB
In this type, a layer of metal, such as copper, is applied to the flexible substrate to enhance its conductivity.
Adhesiveless FPCB
These FPCBs do not use adhesive materials between the layers, making them more suitable for high-temperature applications.
Coverlay Flex PCB
Coverlay is a protective layer added to an FPCB to insulate and protect the conductive traces from environmental factors.
Terminology of FPCB, Flex PCBs
Staggered Etchback / Step Etchback
In the context of Rigid Flex PCB manufacturing, "staggered etchback" or "step etchback" refers to a process used to create controlled depth variations in the copper traces or conductive layers of a Rigid-Flex circuit board.
This process involves selectively etching away portions of the conductive layers to achieve different copper thicknesses at different locations on the board.
The purpose of staggered etchback is to optimize the flexibility and bending characteristics of the Rigid-Flex PCB. By varying the copper thickness, the board can have different degrees of flexibility in different regions, allowing it to bend and conform to the desired shape without compromising the electrical performance or mechanical integrity.
Staggered etchback is an essential technique in the fabrication of Rigid-flex PCB, as it enables the board to accommodate the varying mechanical requirements and fit into complex geometries, common in applications such as aerospace, medical devices, and other electronics where space and weight constraints are critical.