PET Flexible PCB Material Guide

Overview

PET Flexible PCB, also known as PET Flex PCB, Polyester Flexible Circuit, or PET FPC, is a flexible printed circuit board manufactured using Polyethylene Terephthalate (PET) film as the base substrate instead of Polyimide (PI).

Compared with Polyimide-based flexible circuits, PET Flexible PCBs offer lower cost, excellent flexibility, lightweight construction, high-volume manufacturability, and good electrical performance, making them ideal for consumer electronics and cost-sensitive applications.

PET Flexible PCBs are widely used in:

  • Membrane Switches
  • Consumer Electronics
  • LED Lighting Systems
  • Keypads & Control Panels
  • Wearable Electronics
  • Medical Disposables
  • Smart Labels
  • Flexible Sensors

Due to their excellent cost-performance ratio, PET Flexible PCBs are commonly selected for medium-temperature flexible electronic applications where extreme thermal resistance is not required.


Material Specification

PropertyValue
Material DesignationPET Flexible PCB
Full NamePolyethylene Terephthalate Flexible Printed Circuit Board
Material FamilyFlexible Circuit Technology
Base MaterialPET (Polyester Film)
Conductor MaterialCopper Foil, Silver Ink
Cover LayerPET Film
Typical Thickness0.05–0.25 mm
Standard FormsSingle-Sided, Double-Sided Flexible Circuits

Structure Composition

A typical PET Flexible PCB consists of the following layers.

LayerFunction
Conductive LayerElectrical Circuit
PET Base FilmMechanical Support
Adhesive LayerBonding
Cover FilmProtection
Surface FinishSolderability & Reliability

The PET substrate provides flexibility while maintaining dimensional stability.


Common PET Flexible PCB Types

TypeCharacteristics
Single-Sided PET FPCMost Common
Double-Sided PET FPCHigher Circuit Density
Printed Silver Circuit PET PCBLow-Cost Electronics
Membrane Switch CircuitHuman Interface Applications
LED PET PCBFlexible Lighting Solutions

Mechanical Properties

Typical Values

PropertyValue
Tensile Strength150–220 MPa
Elongation at Break50–150%
Flexural ResistanceExcellent
Bend Radius1–3 mm
Fatigue ResistanceGood

Mechanical Performance

PropertyPerformance
FlexibilityExcellent
FoldabilityGood
Vibration ResistanceExcellent
Lightweight DesignOutstanding

PET Flexible PCBs are suitable for static and moderate dynamic flex applications.


Physical Properties

PropertyValue
Density1.38–1.40 g/cm³
Moisture AbsorptionVery Low
TransparencyAvailable
Surface SmoothnessExcellent
Dimensional StabilityGood

PET films offer excellent surface quality for printed electronic circuits.


Thermal Properties

PropertyValue
Continuous Operating Temperature-40°C to 105°C
Short-Term Temperature ResistanceUp to 125°C
Glass Transition Temperature (Tg)70–80°C
Melting Temperature250–260°C
Thermal StabilityModerate

PET provides lower temperature resistance than Polyimide but remains suitable for many consumer electronic applications.


Strength-to-Weight Ratio

MaterialDensity (g/cm³)Flexibility
PET Flexible PCB1.39Excellent
PI Flexible PCB1.43Outstanding
FR4 PCB1.90None
Aluminum PCB2.70None

PET offers excellent flexibility while maintaining lightweight construction.


Electrical Properties

Typical Values

PropertyValue
Volume Resistivity>10¹⁵ Ω·cm
Surface Resistivity>10¹⁴ Ω
Dielectric Strength150–250 kV/mm
Dielectric Constant3.0–3.4
Dissipation FactorLow

Electrical Performance

PropertyPerformance
Electrical InsulationExcellent
Signal TransmissionExcellent
Low Voltage ApplicationsOutstanding
Printed Electronics CompatibilityOutstanding

PET is widely used in flexible printed electronics and membrane switch technologies.


Flexibility Performance

PropertyPerformance
Static FlexingOutstanding
Dynamic FlexingGood
Folding ResistanceGood
Shape ConformabilityExcellent

PET Flexible PCBs perform particularly well in static flex applications.


Moisture Resistance

PropertyPerformance
Water ResistanceExcellent
Humidity ResistanceExcellent
Environmental StabilityGood
Outdoor ApplicationsModerate

PET exhibits very low moisture absorption and good environmental durability.


Chemical Resistance

Chemical EnvironmentPerformance
WaterExcellent
AlcoholsExcellent
Cleaning AgentsGood
Oils & GreasesGood
Mild AcidsGood

PET offers reliable chemical resistance for consumer and industrial applications.


Manufacturing Characteristics

Manufacturing ProcessRating
Printed ElectronicsOutstanding
Screen PrintingOutstanding
Flexible Circuit FabricationExcellent
Roll-to-Roll ProductionOutstanding
Membrane Switch ManufacturingOutstanding

PET is highly suitable for high-volume automated manufacturing.


International Standards

StandardCompliance
IPC-4204Applicable
RoHSCompliant
REACHCompliant
UL CertificationAvailable
GB/T (China)聚酯柔性线路板

Available Forms

Product TypeAvailability
Single-Sided PET FPCYes
Double-Sided PET FPCYes
Printed PET CircuitsYes
Membrane Switch CircuitsYes
Flexible Sensor CircuitsYes

Typical Applications

Consumer Electronics

  • Remote Controls
  • Portable Devices
  • Home Appliances
  • Electronic Toys

Membrane Switches

  • Control Panels
  • Industrial Keypads
  • Medical Interfaces
  • HMI Systems

LED Industry

  • Flexible LED Strips
  • Decorative Lighting
  • Backlighting Systems

Wearable Electronics

  • Smart Labels
  • Disposable Sensors
  • Fitness Devices

Medical Devices

  • Diagnostic Sensors
  • Disposable Electronics
  • Medical Monitoring Products

Industrial Electronics

  • Flexible Interfaces
  • Printed Sensors
  • Control Systems

Advantages

Cost-Effective

Significantly less expensive than Polyimide-based flexible circuits.

Excellent Flexibility

Suitable for a wide range of flexible electronic products.

Lightweight

Ideal for compact and portable devices.

High-Volume Manufacturing

Supports roll-to-roll production and printed electronics.

Excellent Surface Quality

Suitable for precision printed circuitry.

Good Moisture Resistance

Provides reliable performance in consumer environments.


Limitations

Lower Heat Resistance

Cannot match the thermal performance of Polyimide (PI).

Reduced Dynamic Flex Life

Not ideal for continuous bending applications.

Limited High-Temperature Assembly

Less suitable for extreme soldering environments.

Lower Mechanical Stability at Elevated Temperatures

Performance decreases under prolonged heat exposure.


Comparison with Flexible PCB Materials

PropertyPET Flexible PCBPI Flexible PCBFR4 PCB
FlexibilityExcellentOutstandingNone
Heat ResistanceModerateOutstandingGood
CostLowHighLow
WeightVery LowVery LowHigher
Dynamic FlexingGoodOutstandingNone

Comparison with PI Flexible PCB

PropertyPET FPCPI FPC
CostLower
Heat ResistanceLower
Dynamic Flex LifeLower
Consumer Electronics SuitabilityExcellent
High Temperature ApplicationsLimited

PET Flexible PCBs are preferred for cost-sensitive applications, while PI Flexible PCBs are selected for demanding thermal and mechanical environments.


Available Surface Finishes

Standard Finishes

  • Silver Ink Finish
  • Copper Circuit Finish
  • Carbon Ink Finish

Functional Finishes

  • Membrane Switch Surface
  • Printed Electronics Surface
  • Flexible Sensor Surface

Specialty Configurations

  • Single-Sided PET FPC
  • Double-Sided PET FPC
  • Printed PET Circuit
  • Membrane Switch Circuit
  • Flexible Sensor Circuit

Frequently Asked Questions (FAQ)

What is a PET Flexible PCB?

A PET Flexible PCB is a flexible circuit board manufactured using polyester (PET) film as the substrate material.

What is PET Flexible PCB used for?

Typical applications include:

  • Membrane Switches
  • LED Lighting
  • Consumer Electronics
  • Wearable Devices
  • Flexible Sensors

Why use PET instead of PI?

PET offers lower cost and excellent flexibility for applications that do not require extreme temperature resistance.

Is PET Flexible PCB suitable for high-temperature applications?

PET is generally limited to operating temperatures around 105°C and is not suitable for extreme thermal environments.

Is PET Flexible PCB flexible?

Yes. PET Flexible PCBs provide excellent flexibility and lightweight construction.

Why choose PET Flexible PCB?

Because it combines:

  • Low Cost
  • Excellent Flexibility
  • Lightweight Design
  • High-Volume Manufacturing Capability
  • Good Electrical Performance

What is the difference between PET FPC and PI FPC?

PET FPC offers lower cost, while PI FPC provides significantly higher temperature resistance and longer flex life.

Does GCNOV provide PET Flexible PCB manufacturing services?

Yes. GCNOV provides:

  • PET Flexible PCB Manufacturing
  • Membrane Switch Circuit Production
  • Flexible Sensor Circuit Fabrication
  • Printed Electronics Solutions
  • Prototype Development
  • Low-Volume Production
  • Mass Production