CMK Corporation

Rigid-Flex Series

Product & Technology Product & Technology

Rigid-Flex Series

Multi-layer PCB which unifies rigid boards and flexible substrates.

Meets the needs for more compactness by using foldable substrate.

It is a printed circuit board which connects 2 or more rigid boards by an integrated flexible substrate. The rigid portions offer convenient component placing and external connectors will no longer be needed.

Various line up

Rigid-Flex series lineup chart

1st generation of Rigid-Flex PCB's

1st-Gen Rigid-Flex with wide range of variation possibilities.


  • Connector-less and wireless structure reducing wiring board area, contact resistance, wiring length and therefore suitable for high-speed signal.
  • 3D design is possible and contributes to the miniaturization of a product.
  • "One set and One board" makes it possible to cut overall cost containing components, assembly cost, inspection cost and so on.
  • Impedance control of flex part and simulation is also available.


Through-hole structure (Thickness:0.55 - 1.00 mm), 6 layer RF-1

Line up 1st generation RF

outer layer inner layer
RF-1 - - - - 4 - 8 L
RF-3-S 1 - - 6, 8 L
RF-3-D 2 - 8 L
RF-3-SB 1 - 6, 8 L
RF-3-DB 2 8 L

○: Supported

Single build-up structure (Thickness:0.6〜1.0 mm), 6layer RF-3-SB. Double build-up structure (Thickness:〜0.95 mm), 8layer RF-3-DB/BVH stacked

2nd generation of Rigid-Flex PCB's

“2nd-Gen Rigid-Flex” for pursuing thinness with new material

Pursuing thinness with new material

High density and thin type by applying new material.

Features / Structure

  • All Layer corresponded to halogen-free.
  • Thin type:
    4Layer 0.25mm (R&D Thinnest 0.18mm)
    6Layer 0.39mm (R&D Thinnest 0.32mm)
  • By 4Layer, it can correspond to skip via structure.
4 layer RF 1-2-1 staggered: 0.18 - 0.25 mm, [R&D] 4 layer RF with skip-via: 0.23 mm, 6 layer RF 2-2-2 staggered: 0.32 - 0.39 mm