Flexible PCBA

Flexible PCBA


Flex & Rigid-Flex circuits can be shaped to fit where no other design can. They are a hybrid of ordinary printed circuit boards and round wire, exhibiting benefits of each. In essence, flexible circuits give you unlimited freedom of packaging geometry while retaining the precision density and repeatability of printed circuits.

As a high reliability replacement for wire and wire harness assemblies, flex circuits provide a significant cost savings with no reduction in performance.

There are varieties of terminations for flex circuits and we can provide all of these as standard manufacturing process. Adding connectors and other minor component assembly is a common practice when producing flex and rigid flex circuits.

SAMRT  has over 20 years of experience in building Printed Circuit Boards. Let our expertise in engineering and manufacturing assist you in meeting your Flexible Circuit Board needs.



Each type of flex circuit offers different advantages. While some types of flex circuits can offer lower production costs, others have additional increased functionality.

We provide early design services for all your Flex and Rigid-Flex needs. From selecting the best functional configuration to choosing the proper connectors or components, we will help you with your product from early design stages to production.

 Single-Layer Flex Circuit


·         IPC 6013 - Type 1

·         One conductive layer, either bonded between two insulating layers or uncovered on one side.

·         Stiffeners, pins, connectors, components, are optional. 


Double-Sided Flex Circuit


·         IPC 6013, - Type 2

·         Two conductive layers with an insulating layer between; outer layers may have covers or exposed pads.

·         Plated through-holes provide connection between layers.

·         Stiffeners, pins, connectors, components are optional.


Multi-Layer Flex Circuit


·      IPC 6013 - Type 3

·      Three or more flexible conductive layers with flexible insulating layers between each one; outer layers may have covers or exposed pads.

·      Plated through-holes provide connection between layers.

·      Controlled impedance possible. 


Rigid-Flex Circuit


·      IPC 6013 - Type 4

·      Two or more conductive layers with either flexible or rigid insulation material as insulators between each one; outer layers may have covers or exposed pads.

·      Rigid-flex has conductors on the rigid layers, which differentiates it from multi-layer circuits with stiffeners. Plated through-holes extend through both rigid and flexible layers (with the exception of blind and buried vias). Rigid-flex costs more than a standard circuit with stiffeners.

 Package Size Reduction

  • Flexible circuit thinness and light weight will enable a substantial packaging size reduction.
  • Flexible circuit’s ability to be folded or creased and positioned into the smallest areas makes miniaturization of many devices possible.

 Cost Reduction

  • Thin and flexible polyimide film requires a much smaller area, reducing the packaging size and overall material costs.
  • Flex circuits used as interconnects reduce the number of connections to be soldered.

 Replacement for Wires & Wire Harness Assemblies

  • Flexible circuits used to replace wiring reduces the errors common in hand wired assemblies.  

High Temperature Applications

  • Flex circuits dissipate heat at a better rate than other dielectric materials.
  • Expansion and contraction are minimized when using polyimide material.

 Weight Reduction

  • Substantial weight reduction is a benefit over wires and wire harnesses.

 High Density Applications

  • Flexible circuits allow for narrow lines giving way to high density device population. Denser device populations and lighter conductors can be designed into a product, freeing space for additional product features.

Reliability & Durability

  • The exceptional thermal stability of polyimide allows the circuit to withstand applications with extreme heat, as the materials excellent thermal stability provides a better base for surface mounting than traditional boards. Because the compliant base film places less stress on soldered joints, thermal mismatch is less likely to occur.

Typical Properties of Dielectric Material for Flexible Printed Circuitry

Property (Typical) Units Polymide Polymide (Adhesiveless) Polyester
Representative Trade Name
Thickness Range mil 0.5 to 5 1-6 2-5
Tensile Strength (@25°C) psi 25,000 50,000 20,000 to 35,000
Break Elongation % 70 50 60 to 165
Tensile Modulus (@25°C) 100,000 psi 4.3 0.7 5
Tear Initiation Strength lb/in 1000 700-1200 1000 to 1500
Tear Propagation Strength g/mil 8 20 12 to 25
Resistance to:

Strong Acids
Good Good Good
Strong Alkalis
Poor Good Poor
Grease and Oil
Good Good Good
Organic Solvents
Good Good Good
Good Good Good
Good Good Fair
Non-nutrient Non-nutrient Non-nutrient
Water Absorption % (24 hours) 2.9 0.8 <0.8
Service Temperature (min/max) degree C -0.625 -0.625 -0.571428571
Coefficient of Thermal Expansion (@22°C) PPM/degree C 20 20 27
Change in Linear Dimensions (100°C, 30min) % <0.3 0.04-0.02 <0.5
Dielectric Constant (ASTM D150) 1MHz
3.4 3.4 3
Dissipation Factor (ASTM D150) 1MHz
0.01 0.003 0.018
Dielectric Strength (ASTM D149) V/mil 6000 6000 3400
@ 1 mil thickness ohm-cm 1.00E+16 1.00E+16 1.00E+16
Volume Resistivity (ASTM D257)

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