Flex PCB Capability  

///Flex PCB Capability  
Flex PCB Capability
No. Item Flex PCB Technical Data
1 PCB Layer Count 1~6Layers
2 Min. Line Width/Space 18um(finish Cu): 3.5/3.5mil
35um(finish Cu): 4/4mil
3 Min Space Between Coverlay Opening 0.2mm
4 Edge of Coverlay Opening to Trace 0.20mm(preferred)
5 Min Space between coverlay and solder pad 0.15mm
6 Polyimide Films 0.5 mil (12.5µ), 1 mil (25µ), 2 mils (50µ)
7 Thermabond Adhesive Thermosetting Adhesive, 3M high adhesion tape
8 Copper Foils (RA or ED) 1/3oz, 1/2oz, 1oz
9 Stiffeners Polyimide, Rigid FR4, metal
10 Solder Resist Coverlay, LPI
11 Min. Finished Hole size 0.2mm
12 Max. Finished Hole size 6.30mm
13 Hole tolerance ±0.05mm
14 Min.space between holes 0.15mm
15 Minimum conductor edge to outline edge ≥0.1mm
16 Minimum space between coverlay and conductor ± 0.15mm
17 Hole to outline edge ≥ 0.10mm
18 Tooling tolerance Knife(Soft) tooling ± 0.25mm
Steel(Hard) tooling ± 0.05mm
CNC drill/rout ± 0.10mm
19 Maximum Layer to Layer Mis-registration ± 0.10mm
20 Copper Plated Thickness (PTH only) 8~15um;20~30um;30~70um(special)
21 Surface Finish Immersion Gold, Plating Hard Gold, OSP

Flex and Rigid-Flex boards

Please observe the following Design-Rules for your Flex- or Rigid-Flex circuit boards. Powered by China Printed Circuit Board manufacturer (offshore PCB Manufacturer),

For designers of flexible circuit boards we recommend the IPC-2223 Guideline / Design guidelines for flexible circuit boards, which is available from the IPC online store.

Calculation of the bending radius


The minimum bending radius r results from the factor 6 to 25 (depending on the number of layers or application) multiplied by h, the overall height of the flexible part.

2 layers flexible PCB; overall height of flexible part: 300µm
minimum bending radius r = 10 x 300µm = 3000µm = 3mm

Flexible PCB for dynamic installation; overall height of flexible part: 400µm
minimum bending radius r = 25 x 400µm = 10000µm = 10mm

Design of bending areas


Divide wide conductor traces into narrower conductor traces in the bending area.


Fill open regions in the bending area with blind conductors.


Ensure a perpendicular path of the conductor traces to the bending axis. Avoid pads plated-through holes in the bending area.

The bending area may be optimized depending on the application.

Dynamic bending:
spontaneous and frequent bending
Optimization for dynamic bending:

  • drill holes or slots
  • copper edges at the bending location
  • copper stiffeners as bending aids
Durable bends:
single occurrence bending, such as for a bending tool
Optimization for durable bends:

  • drill holes or slots
  • Contour narrowing
  • Stabilization through more copper


For 2 or more flex layers, please ensure an alternating arrangement of the conductor traces on the front and back sides of the flexible portion.


Use curves instead of corners in the conductor trace path.

2019-07-22T15:24:37+00:00November 13th, 2016|PCB Assembly|