• 86-0411-8853-2005
  • marketing@gespcb.com

What is the Flex PCB Thickness?

Introduction:

Understanding the flex PCB thickness is essential in the design and manufacturing of FPCs. It affects the board’s flexibility, mechanical strength, electrical performance, and space needs. A well-designed flexible PCB requires precise thickness. to deliver remarkable performance in real-world applications. From flexibility to mechanical stability. Join us as we look at the various features of flexible circuit board thickness. Join us on this journey through the complexities of flexible circuit board fabrication!

What is the Flex PCB Thickness

To understand flex PCB thickness, analyze its structure. Precisely calculate the total thickness by adding individual layer thicknesses. This method, emphasizing each component’s role, provides a precise evaluation. Essential for a comprehensive grasp of flexible circuit board construction and design applications.

SIGNEL LAYER FLEX PCB stackup
2 LAYER FLEX PCB stackup

Calculate Flex PCB Thickness

Based on the flexible circuit board’s construction diagram, we can calculate as follows:

A single-layer flex PCB thickness=12.5um(polymide)+25um(adhesive)+35um(Copper)+20um(adhesive)+25um(polymide)+25um(adhesive)+85 um(PI stifferen)

Multi-layer flexible PCBs, and so on, based on the number of layers. Note that flexible PCBs strengthened with FR4, PI, adhesive paper. PET, electromagnetic film, steel, and aluminum sheet reinforcement. when determining thickness, include the reinforcement.

a singal layer flex pcb thickness
Reinforcement TypeTolerance ControlFeaturesReinforcement Thickness
PI Polyimide±0.03mmHigh precision, High-temperature resistance (130-280℃)0.075mm, 0.1mm, 0.125mm, 0.15mm, 0.175mm, 0.2mm, 0.225mm, 0.25mm
Steel SheetManual assembly, Complex process, Higher costRequires manual assembly, Complex process, Higher cost0.1mm, 0.2mm
FR4<0.1mm: ±0.05mm; >1.0mm: ±0.1mmThickness affects tolerance, Suitable for various thickness requirements0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm,1.6mm
gesp logo

Flexible Circuit , Rigid-flex PCB, FPC Flexible PCB Assembly For One-Stop Request a Quote for Flexible PCB Fabrication

Crucial Characteristics of Flex PCB Thickness

Flexibility and Bending Capability:

The thickness directly impacts the board’s flexibility and bending ability. Thinner boards excel in bending and adapting to three-dimensional structures.

Space Efficiency and Lightweight Design:

Thickness is pivotal for devices with limited space. Thinner FPCs better accommodate confined spaces and contribute to lightweight designs. crucial for portable and highly integrated electronic products.

Electrical Performance and Signal Transmission:

The thickness of the conductive layer influences electrical performance and signal transmission quality. Striking a balance is essential to ensure both flexibility and stable signal transfer.

Bending Radius and Reliability:

Thinner boards often accompany a smaller bending radius. Choosing an appropriate thickness is a delicate balance. to maintain mechanical strength without compromising reliability and lifespan.

gesp logo

Flexible Circuit , Rigid-flex PCB, FPC Flexible PCB Assembly For One-Stop Request a Quote for Flexible PCB Fabrication

Flex PCB Thickness in FPC Design

When considering flex PCB thickness in design, several key factors come into play:

Flexibility Requirements:

The application’s flexibility demands influence the choice of thickness. Thinner flex PCBs are more flexible but might have limitations on mechanical strength.

Bend Radius:

The bend radius, or the minimum radius a flex PCB can bend without damage, is crucial. Thickness affects the board’s ability to bend tightly without compromising performance. 

If you want to know more about  bend radius or how to calculate it, please click the post about it

Understanding and Calculating Bend Radius in Flexible PCB Design

Mechanical Strength:

The thickness of the conductive layer influences electrical performance and signal transmission quality. Striking a balance is essential to ensure both flexibility and stable signal transfer.

Space Constraints:

The available space in the device or system dictates the acceptable thickness. Thinner flex PCBs are advantageous in space-constrained designs.

Copper Foil Thickness:

The thickness of the copper foil used in the flex PCB impacts electrical performance. Balancing copper thickness with overall board thickness is crucial.

Environmental Conditions:

Consider the operating environment, especially temperature variations. Thicker flex PCBs preferred for applications with extreme temperature conditions.

Cost Considerations:

Thicker flex PCBs often incur higher manufacturing costs. Balancing thickness requirements with budget constraints. That is a crucial aspect of the design process.

gesp logo

Flexible Circuit , Rigid-flex PCB, FPC Flexible PCB Assembly For One-Stop Request a Quote for Flexible PCB Fabrication

What is the Thickness of FPC Soft Board Substrate?

The thickness of an FPC substrate decided by the type of copper and layer design. The two main copper types, rolled copper and electrolytic copper, have distinct properties. Rolled copper is more flexible. but has a lesser current-carrying capability than electrolytic copper. which is tougher maintains higher currents, and is frequently used in power applications.

There are two types of substrate layers: single-sided and double-sided. Polyimide resin and copper foil combined to make single-sided substrates. Copper foil thicknesses include:1oz (35um), 0.5oz (18um), 1/3oz (12.5um). whilst insulation PI thicknesses are usually 12.5um or 25um. The substrate thickness options include 35/25, 18/12.5, and 12.5/12.5. enabling flexibility to suit a variety of design needs.

gesp logo

Flexible Circuit , Rigid-flex PCB, FPC Flexible PCB Assembly For One-Stop Request a Quote for Flexible PCB Fabrication

Ensure Precision FPC Thickness in Fabrication

Strict Adherence to Design Specifications:

Before commencing production, ensure that the entire manufacturing team is well-versed in. and adheres to the client’s design specifications and requirements. This includes confirming specific thickness values and tolerance ranges.

Utilization of High-Quality Substrates:

Opt for high-quality, certified substrate suppliers. to ensure that the chosen substrates align with design specifications. providing consistent thickness performance throughout production.

Implementation of Rigorous Process Controls:

Enforce stringent process controls across the entire production workflow. ensuring each step adheres to standardized operating procedures (SOPs). Pay particular attention to processes involving substrate lamination and pressing.

Deployment of Precision Equipment and Tools:

Employ high-precision equipment and tools, such as precision laminators and pressing machines. to guarantee consistent board thickness throughout the manufacturing process.

Regular Thickness Testing:

Establish a routine thickness testing protocol. utilizing thickness measurement instruments to inspect samples regularly. This practice ensures that each batch of circuit boards conforms to the specified design requirements.

If you have any questions about Flexible PCBs, GESFLEX welcomes your contact!

Leave a Reply

Your email address will not be published. Required fields are marked *