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

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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.

Example:
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

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

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Fill open regions in the bending area with blind conductors.

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

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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

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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.

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Use curves instead of corners in the conductor trace path.

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