Flexible PCB

Flexible circuit board is a special type of printed circuit board with it’s epical property of bendable feature. The demand for flexible PCBs is growing in electronic filed with especially strong demands from medical, defense and industrial markets.

Widely Application

As flexible printed circuit board can provide a great solution to connection between rigid PCBs with a reliable and repeatable electronic product. So,they have so many and wide applications that it would be impossible to completely list them all here.

Outstanding Advantages

Flex PCB provide a third dimension to connect between rigid PCB boards or to the interface between a printed circuit board and a remote electronic device, for example a sensor or a camera as in a mobile phone. They offer a light-weight solution to make the electronic product more and more lighter in weight, nearly half the weight of a rigid or a cable harness, to interconnections;as well much thinner in thickness.

Whats more, flexible PCBs are also highly robust and can be flexed numerous times without any degradation to the electronic product. In a thorough designed dynamic situation, the flex PCB can go through millions of bendable cycles, a common existing example would be on an inkjet printer head. They also have the advantage of absorbing some unexpected shock so in a small device, such as a cell phone, they can take an impact without any damage to disconnect to the circuits.

They are also widely used to mount LEDs strips for applications such as down lighters on kitchen benches, outside deck lighting, etc. And, safety lights applied in transport systems, for example planes, trains and boats all utilise LED flex strip for guide sign of the emergency exit routes.

The Cost Alert of Printed Circuit Board

Normally, the cost of flex PCBA is more expensive than a standard rigid PCB, but it can be optimized and saved by the right design and using it in the right application. Plus it’s lighter weight and less time in assembly process, coupled with the reliability which makes flexible printed circuit board a worthwhile consideration. It’s cost variations are mainly base and overlay thickness, typically 0.001” to 0.002”, different copper thickness, single or double sided plated through hole. Flex or rigid Stiffeners are an option which can help in handling during flex PCB assembly and allows electronic components to be assembled to the product easier. Another cost factors is from it’s raw material, big gap cost between famous raw material provider such as Panasonic and DuPont and normal base material manufacturer such as Taiflex.

Flex Materials

Weller Technology only uses hi-temp resistant polyimide (PI) materials unless customer insist to use low grade of material to cost down the price. Our preferred types are Panasonic and DuPont adhesivless materials, and Shengyi adhesive-based materials and coverlays.

Why Choose Weller as your flex PCB manufacturer

Weller Technology has the capability to build types 1 through 4 flexible printed circuits. Most FPC’s are designed as single-sided or double-sided, as bendability is reduced with increasing copper layers and thickness. Weller Technology has flex PCB manufacturing capability from single flex PCB to multilayer flex PCB (up to 4 layers),as well Rigid-flex.

  • Single-Sided Flex
  • Double-Sided Flex
  • Multilayer Flex (up to 4 layers)
  • Rigid-Flex (link to Rigid-Flex page)
ItemFlex PCB Capability
PCB Layer Count1~6Layers
Flexible Circuit Materials:Dupont, Panasonic, Taiflex, Shengyi

Min. Line Width/Space
18um(finish Cu): 3.5/3.5mil
35um(finish Cu): 4.0/4.40mil
Min Space Between Coverlay Opening0.2mm
Edge of Coverlay Opening to Trace0.20mm(preferred)
Min Space between coverlay and solder pad0.15mm
Polyimide Films0.5 mil (12.5µ), 1 mil (25µ), 2 mils (50µ)
Thermabond AdhesiveThermosetting Adhesive, 3M high adhesion tape
Copper Foils (RA or ED)1/3oz, 1/2oz, 1oz
Flex Circuit StiffenersPolyimide, Rigid FR4, metal
Solder ResistCoverlay, LPI
Min. Finished Hole size0.2mm
Max. Finished Hole size6.30mm
Hole tolerance±0.05mm
Min.space between holes0.15mm
Minimum conductor edge to outline edge ≥0.1mm
Minimum space between coverlay and conductorMinimum space between coverlay and conductor
Hole to outline edge ≥ 0.10mm

Tooling tolerance
Knife(Soft) tooling ± 0.25mm
Steel(Hard) tooling ± 0.05mm
CNC drill/rout ± 0.10mm
Maximum Layer to Layer Mis-registration± 0.10mm
Copper Plated Thickness (PTH only)8~15um;20~30um;30~70um(special)
Surface FinishImmersion Gold, Plating Hard Gold, OSP


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