What is the FPC Connector
FPC connector, full name Flexible Printed Circuit Connector, is a kind of flexible zigzag printed circuit connector.
The composition of FPC connector
FPC connector (Flexible Printed Circuit Connector) is a precision electronic component. Its structure is designed to achieve a reliable electrical connection and mechanical fixing.
1.Composition of core components
- Flexible contactor
As the core component of the connector, the elastic contactor is usually made of highly elastic material such as a steel plate or phosphor bronze, to ensure stable electrical contact and long-lasting mechanical properties.
- Snap mechanism
The precise snap mechanism is designed to accurately locate and firmly fix the relative position between the FPC connector and the circuit board to prevent displacement or loosening during use.
- Protective Shell
The shell structure not only provides mechanical protection but also has the important function of fixing the internal components to ensure the overall structural integrity and reliability of the connector.
1.High-performance FPC connector enhancement components
- Rubber core assembly
Function: Provide terminal protection, electrical insulation, connectivity and enhance mechanical strength.
Manufacturing process: precision injection molding
Material: PA9T and other high-performance engineering plastics
- Guide Tongue
Function: Cable crimping, electrical insulation, connection positioning, and structural strengthening.
Manufacturing process: high-precision injection molding
Material: PA10T, PP,S and other high temperature resistant engineering plastics.
- Conductive Terminal
Function: Ensure efficient transmission of electronic signals
Manufacturing Process: Precision stamping combined with electroplating (gold/tin plating).
Material: Phosphor bronze and other highly conductive alloys
- Soldering fixing piece
Function: Precise positioning, mechanical fixing, and structural strength enhancement.
Manufacturing process: stamping with electroplating treatment
Material: bronze and other high-performance alloys
This modular design allows FPC connectors to meet the stringent requirements of modern electronic products on high-density, high-reliability connections, while adapting to the needs of automated production. The careful selection of materials for each component and the precision manufacturing process ensure that the connector has excellent performance in terms of electrical performance, mechanical strength and long-term reliability.
FPC Connector Classification
FPC connectors can be categorized according to pitch, structure and usage to meet the needs of different application scenarios.
1.Classification according to pitch
The pitch of the FPC connector determines its integration degree and applicable scenarios. Mainstream specifications include:
0.3mm: ultra-high density connection for miniaturized devices (e.g. wearable devices, miniature sensors).
0.5mm: mainstream compact design, widely used in consumer electronics (e.g. smartphones, tablets).
0.8mm & 1.0mm: general-purpose pitch, suitable for devices with lower space requirements (e.g. industrial control, automotive electronics).
The smaller the pitch, the higher the integration, but also higher requirements for manufacturing precision and the assembly process.
2.Categorized by structure
Different structural designs to adapt to different connection needs, the main types include:
Top Contact:
The terminals are located above the socket, taking up little space, and are suitable for compact designs with height restrictions.
Bottom Contact:
Terminals are located below the receptacle for a more secure connection, suitable for vibration-resistant, high-reliability scenarios.
Flip-Lock:
Flip-locked FPCs can be easily inserted and removed by flipping the cover plate, and are often used in applications where FPCs need to be replaced frequently (e.g., test equipment).
Slider:
Adopting a slide locking mechanism, the connection is more solid, suitable for high vibration, high reliability requirements (such as automotive electronics, industrial equipment).
3.Classification by use
FPC connectors can be divided into different types according to the connection:
Board-to-Board (Board-to-Board):
Connection of two PCBs, suitable for multi-layer stacking design (such as modular electronic equipment).
Wire to board (Wire-to-Board):
Connecting cable and PCB, commonly used in power, signal transmission (such as display, camera module).
FPC to FPC:
Directly connecting two flexible circuits, suitable for foldable devices, flexible electronics (e.g., folding screen phones, flexible sensors).
This categorization helps engineers to choose the right type of FPC connector according to space constraints, connection stability, application scenarios, and other needs.
FPC connector product advantages
With its unique structural design and material properties, FPC connectors show excellent performance advantages in modern electronic equipment, mainly including the following aspects:
1.High flexibility
Adopting flexible circuit design, it can adapt to complex spatial layout and dynamic bending requirements, and is widely used in folding devices, wearable electronics, and other scenarios that require high shape adaptability.
2.Excellent electrical performance
Low impedance and low signal loss design ensures stable transmission of high-speed signals, suitable for high-frequency and high-precision electronic systems (e.g., 5G communication, high-definition display, etc.).
3.Ultra-thin and lightweight
Compact structure design, thickness can be as low as 0.3mm or less, significant space saving, especially suitable for portable electronic devices (such as smart phones, tablet PCs, drones, etc.).
4.Excellent environmental adaptability
With bending resistance (more than 100,000 times), high temperature resistance (up to 125 ° C), moisture and corrosion resistance, etc., to meet the needs of automotive electronics, industrial equipment and other harsh environments for long-term stable operation.
These advantages make FPC connectors an indispensable key component in modern electronic equipment, especially in the field of high-density integration, flexible electronics and miniaturized equipment has an irreplaceable role.
The role of FPC connectors
FPC connector as a key interconnect component in modern electronic systems, in equipment integration and performance optimization plays an irreplaceable role, its main functional value is reflected in the following aspects:
1.Efficient interconnection function
As a bridge between flexible circuit board (FPC) and PCB or other electronic modules, it simultaneously realizes the dual functions of mechanical fixation and electrical conduction, and supports a variety of connection modes (board-to-board, wire-to-board, FPC-to-FPC) to meet the interconnection needs of different application scenarios.
2.System reliability guarantee
The use of precision contact structure and high-quality conductive materials ensures long-term stability of the electrical connection performance, effectively avoids signal interruption or equipment failure due to poor contact,and significantly improves the service life of electronic products.
3.High-quality signal transmission
Support high-speed digital signals (such as HDMI, USB), high-frequency RF signals, and stable transmission of analog signals, low impedance, and low crosstalk design to ensure signal integrity, to meet the high-definition video, high-fidelity audio, and other demanding applications.
4.Space-optimized solutions
Ultra-thin design (minimum pitch up to 0.3mm) significantly improves space utilization, especially for smartphones, wearable devices ,and other extremely space-sensitive miniaturized electronic products.
5.Convenient maintenance characteristics
Modular design supports rapid insertion and removal, greatly simplifying the equipment assembly and maintenance process, with repeatable insertion and removal characteristics (usually supporting 5000-10000 times insertion and removal) to reduce maintenance costs and improve product repairability.
These core features make FPC connectors indispensable key components in modern electronic product design, especially in the pursuit of thin and light, high reliability, and easy maintenance, application scenarios show unique advantages. With the development of electronic equipment to a higher degree of integration, the importance of FPC connectors will be further highlighted.
FPC Connector Selection Key Parameters
To ensure the best performance of FPC connectors in the target application, engineers need to focus on the following key parameters:
1.Electrical performance parameters
Rated current: 0.5A ~ 3A (selected according to power requirements)
Voltage rating: 50V~300V (considering the system voltage margin)
Contact resistance: ≤30mΩ (low impedance design ensures signal integrity)
Insulation resistance: ≥100MΩ (typical value)
2.Mechanical Performance Parameters
Insertion and extraction force characteristics:
Insertion force: 5N~20N (balancing operational convenience and connection reliability)
Pull-out force: ≥2N (to ensure connection stability)
Terminal plating:
Gold plating thickness: 0.05~0.2μm (affects wear resistance and contact resistance)
Optional plating: tin plating, silver plating, etc.
3.Structure compatibility parameters
FPC compatibility range:
Thickness compatibility: 0.1 mm~0.3 mm (need to match the actual FPC specifications)
Insertion depth: such as 4.5mm ± 0.3 (affects the reliability of the connection)
Terminal spacing: 0.3mm/0.5mm/1.0mm, etc. (determines the connection density)
4.Environmental tolerance parameters
Mechanical environment:
Vibration resistance: 10Hz~500Hz/50m/s² (higher requirements for automotive applications)
Impact resistance: ≥50G (industrial grade standard)
Climatic environment:
Operating temperature: -40℃~+85℃ (Extended type can reach 125℃)
Protection grade: IP54 and above (dustproof and waterproof requirements)
Humidity and heat resistance: 85℃/85%RH (1000 hours test)
5.Life parameters
Mechanical life: ≥ 5000 times plugging and unplugging (high-quality products up to 10000 times)
Environmental aging life: ≥5 years (assessed according to application scenarios)
It is recommended to adopt the “parameter margin method” when selecting, i.e., to reserve 20%-30% of the design margin based on the measured parameters to cope with the variable factors in the actual application. For critical applications (e.g., automotive electronics, medical equipment), it is recommended to conduct a complete reliability verification test.
Application Scenarios
Mobile smart terminal field
Core applications: smartphones (folding screen models), tablets, TWS headphones, smartwatches
Typical connections: OLED/LCD module, multi-camera system, 3D sensing module, side button wiring
Technical Advantage: 0.3mm ultra-narrow pitch design adapts to the trend of full-screen, supports more than 200,000 times of bending life.
Automotive Electronic System
Key parts: intelligent cockpit display, ADAS sensor array, electronic gearshift mechanism, HUD projection module
Performance requirements: AEC-Q200 automotive certification, high temperature resistance of 125 ℃, anti-vibration 50Hz/30G
Development trend: applied to the domain controller high-speed interconnect, transmission rate up to 10Gbps +.
High-end medical equipment
Precision connections: endoscopic imaging modules, wearable monitoring patches, digital PCR detectors, surgical robot joints
Special requirements: biocompatible materials, support for autoclave sterilization, IP68 anti-liquid permeability
Industrial Automation Scenarios
Typical configuration: industrial robot joint harness, PLC control unit, intelligent sensor network, AGV navigation system
Environmental adaptation: anti-chemical corrosion plating, -40℃~85℃ wide temperature range, anti-electromagnetic interference design
Emerging Application Areas
Consumer electronics: AR/VR headset devices, flexible e-books, foldable smart terminals
Internet of Things: smart home control module, LoRa sensing node, 5G micro base station
Special fields: satellite communication equipment, UAV flight control system
Development trend
With the development of electronic equipment to higher performance, smaller volume, FPC connector technology is experiencing a revolutionary breakthrough, mainly showing the following four major trends:
1.Extreme miniaturization technology breakthroughs
Industry benchmark: Hirose FH28 series to achieve 0.2mm pitch mass production
Technical highlights:
Adoption of micron-level precision stamping process
Innovative suspended contact structure design
Support 15μm ultra-thin FPC connection
Application scenarios: foldable device pivot area, medical micro-implantable device
2.High-speed transmission technology evolution
Latest standard: supports 56 Gbps PAM4 signal transmission
Key Technology:
Precise control of differential pair impedance (100Ω±10%)
Low dielectric loss material application (Dk<3.0@10GHz)
Optimized crosstalk rejection design (<-40dB)
Typical applications: 400G optical modules, AI server backplane interconnects
3.Extreme environment reliability enhancement
Vehicle-grade standards:
Compliant with USCAR-2 vibration standards
1000 hours salt spray test (5% NaCl solution)
125°C continuous operating temperature
Innovative process:
Nano-coating technology (Au+Ni composite coating)
Laser welding encapsulation process
Silicone secondary injection molding sealing
4.Intelligent interconnection function integration
A new generation of smart connectors:
TE Connectivity M.2 connectors with integrated plug detection
Molex Develops FPC Connectors with Temperature Sensing
JAE Introduces Industrial Connectors with RFID Identification Features
Technology Integration:
Embedded Microcontrollers
Hybrid Fiber-Copper Transmission
Self-diagnostic fault warning system
Industry trends show that the next generation of FPC connectors will be developed in the direction of the “four super”: ultra-miniature (0.1mm pitch), ultra-high speed (112Gbps), ultra-reliable (2 million times plugged), ultra-intelligent (edge computing integration), these breakthroughs will promote the development of cutting-edge technology, such as 5G communications, automated driving, AI computing and so on.