Flex PCBs & Rigid Flex PCBs

Flex PCBs, also known as flexible printed circuits or flexible electronics, provide greater options for designers and engineers when assembling electronic circuits.


They are constructed from flexible, high-performance plastic material, usually polyimide, which enables the board to bend or "flex" during use. This flexibility opens them up to use in a wide range of applications.


Here are the most common types of flex circuit construction:

  • Single-sided flex PCB
  • Double-sided flex PCBs
  • Multi-layer flex circuits
  • Rigid flex PCB
  • Sculptured flex circuit board
Flexible PCB Capabilities & Tolerances
Multi-layer Flex Circuits English Metric
Maximum Board Size 19.68” x 13.38” 500 x 340 mm
Maximum Board Thickness 1 (copper) layer 8.5 mil 0.22 mm
2 layers 12.6 mil 0.32 mm
4 layers 16.5 mil 0.42 mm
Minimum Board Thickness 1 (copper) layer 2.5 mil 0.065 mm
2 layers 4.7 mil 0.12 mm
4 layers 11.8 mil 0.30 mm
Maximum Number of Layers 16 layers
Minimum PTH (Plated Thru Hole) Diameter 0.0079” 0.2 mm
Maximum aspect ratio 10:1 (max. thickness 0.0066”,
min. PTH 0.0079”)
10:1 (max. thickness 2 mm,
min. PTH 0.2 mm)
Minimum Traces / Spaces 0.002” / 0.002” 0.05 mm / 0.05 mm
Lead Solder (HASL) OSP (Entek)
Lead Free Solder (HASL) Electrolysis Gold Plating
Immersion Gold (Electroless Nickel Gold - ENIG) Immersion Tin (White Tin)
Immersion Silver
FR-4 Teflon
FR-5 Ployimide
Aluminum BT
Other material available upon request