Choose Leadsintec as your flexible PCB manufacturing partner

The manufacturing of flexible printed circuit boards (FPCs) is a multidisciplinary field that integrates material science, precision machining and electronic engineering. Its technological evolution has directly promoted innovation in industries such as consumer electronics, medical equipment, and automotive electronics. Leadsintec is a professional flexible PCB manufacturing and assembly company. We have a professional design and processing team to meet all customer needs. Let’s take a look at our manufacturing capabilities.

Exceptional Flexible PCB Manufacturing Capability

Layer Configurations

LSTPCB offers a wide range of flexible circuit board configurations to meet the diverse demands of various industries for circuit complexity and mechanical flexibility:

Single-Layer Flexible PCBs: Our single-sided flexible circuits feature a conductive copper layer on a high-performance flexible dielectric substrate. They are optimized for simple designs, offering excellent bendability and cost efficiency. These lightweight structures ensure electrical reliability while enabling dynamic flexing.
Double-Layer Flexible PCBs: This configuration includes two conductive copper layers separated by a polyimide insulating layer, typically interconnected through plated through holes. It allows for increased circuit density without compromising flexibility.
Multi-Layer Flexible PCBs: We produce 4-layer flexible PCBs tailored for highly integrated systems such as wearable devices, flexible displays, medical sensing modules, and advanced automotive electronics.
Advanced Multi-Layer Designs: LSTPCB can manufacture 6-layer flexible circuits that balance precision signal routing with effective power distribution, ideal for high-performance systems with limited space. Our 8-layer flexible PCBs represent the leading edge of flex circuit technology, offering superior multifunctional integration and compact packaging.
Rigid-Flex PCBs: As a UL-certified rigid-flex PCB manufacturer, LSTPCB offers hybrid structures with up to 32 rigid layers and 12 flexible layers. These boards combine the stability of rigid substrates with the bendability of flex layers, making them ideal for complex 3D interconnect designs in aerospace, defense, and premium consumer electronics.

Technical Advantages

Our expertise in flexible PCB manufacturing encompasses the following core capabilities:

Fine-Line Processing: We achieve line/space widths as narrow as 25μm on multi-layer flexible materials, with layer-to-layer alignment accuracy within ±50μm.
Premium Material Selection: We use high-grade materials such as polyimide and specialty thermoplastics to ensure stability and durability in a wide range of applications.
Bend Reliability Design: We account for critical minimum bend radius requirements to enhance product lifespan under dynamic bending conditions.
Custom Stack-Up Solutions: From basic single-layer to complex 8-layer configurations, we provide optimized stack-ups tailored to specific application needs.
Diverse Surface Finishes: We offer a variety of surface treatments including ENIG (Electroless Nickel Immersion Gold), immersion tin, and others to protect exposed copper and enhance solderability.

Our Manufacturing Capabilities

Item	Description
Layer	Flexible board: 1-12Layers Flex-Rigid Board: 2-32Layers
Material	PI, PET, PEN, FR-4,dupont
Stiffeners	FR4, Aluminum, Polyimide, Stainless Steel
Final Thickness	Flexible board: 0.002″ – 0.1″ (0.05-2.5mm) Flexible-rigid board: 0.0024″ – 0.16″ (0.06-4.0mm)
Surface Treatment	Lead-free: ENG Gold; OSP, Immersion silver, Immersion Tin
Max / Min Board Size	Min: 0.2″x0.3″ Max: 20.5″x13″
Min Trace Width / Min Clearance	Inner: 0.5oz: 4/4mil Outer: 1/3oz-0.5oz: 4/4mil 1oz: 5/5mil 1oz: 5/5mil 2oz: 5/7mil 2oz: 5/7mil
Min Hole Ring	Inner: 0.5oz: 4mil Outer: 1/3oz-0.5oz: 4mil 1oz: 5mil 1oz: 5mil 2oz: 7mil 2oz: 7mil
Copper Thickness	1/3oz – 2oz
Max / Min Insulation Thickness	2mil/0.5mil (50um/12.7um)
Min Hole Size and Tolerance	Min hole: 8mil Tolerance: PTH±3mil, NPTH±2mil
Min Slot	24mil x 35mil (0.6×0.9mm)
Solder Mask Alignment Tolerance	±3mil
Silkscreen Alignment Tolerance	±6mil
Silkscreen Line Width	5mil
Gold Plating	Nickel: 100u” – 200u”	Gold: 1u”-4u”
Immersion Nickel / Gold	Nickel: 100u” – 200u”	Gold: 1u”-5u”
Immersion Silver	Silver: 6u” – 12u”
OSP	Film: 8u” – 20u”
Test Voltage	Testing Fixture: 50-300V
Profile Tolerance of Punch	Accurate mould: ±2mil
	Ordinary mould: ±4mil
	Knife mould: ±8mil
	Hand-Cut: ±15mil

Flexible PCB Manufacturing Process

At Leadsintec, the flexible PCB manufacturing process consists of a series of sophisticated and tightly controlled steps, forming a precise production chain from raw materials to finished products:

1. Substrate Preparation

Material Selection: Polyimide (PI) is the primary substrate material due to its excellent heat resistance (up to 400°C), chemical stability, and mechanical flexibility—suitable for most application scenarios. Liquid Crystal Polymer (LCP), with its low dielectric loss (Dk = 2.85 at 1GHz), is preferred for high-frequency 5G applications.
Surface Treatment: Plasma cleaning or chemical etching is used to increase the surface energy of the substrate, improving copper foil adhesion.

2. Copper Lamination & Pattern Transfer

Copper Deposition: A sputtering followed by electroplating process is used to create an ultra-thin seed copper layer (thickness <1μm), eliminating the thickness limitations of traditional lamination methods.
Photolithography: Dry film photoresist is applied, and high-precision pattern transfer is achieved using Laser Direct Imaging (LDI), enabling 50μm line width/spacing. After development, the resist protects desired copper areas.

3. Etching & Lamination

Chemical Etching: Acidic cupric chloride solution removes unprotected copper. Etch rate control is critical, as polyimide and FR-4 materials have up to 15% difference in etching behavior, requiring compensation to avoid undercutting.
Multilayer Lamination: Automated hot presses are used to bond layers under controlled temperature (180–220°C) and pressure (30–50 kg/cm²) gradients, effectively managing CTE (Coefficient of Thermal Expansion) mismatches.

4. Drilling & Metallization

Laser Drilling: Ultraviolet (UV) lasers (355nm wavelength) are used to create 50μm microvias without inducing mechanical stress, as seen with mechanical drilling.
Via Metallization: Electroless copper plating forms a 0.5–1μm conductive layer, ensuring reliable interlayer electrical connections.

5. Surface Finishing & Protection

ENIG (Electroless Nickel/Immersion Gold): Provides excellent solderability and corrosion resistance. Thickness is precisely controlled: Ni 3–6μm / Au 0.05–0.1μm.
Coverlay Application: Heat-laminated polyimide coverlays (25μm with adhesive) are applied, with laser window opening precision reaching ±25μm.

6. Profiling & Testing

Laser Cutting: UV laser systems ensure clean, burr-free cutting of complex board outlines.
Reliability Testing: Includes dynamic bend testing (100,000 cycles from 0° to 180°), thermal shock cycles (-40°C to 125°C, 1000 cycles), and signal integrity testing (TDR impedance control within ±10%).

Cross-Industry Applications

Leadsintec’s flexible printed circuit boards (Flex PCBs) are driving innovation across a wide range of industries:

Medical Devices: Implantable electronics, wearable health monitors, diagnostic systems
Automotive Electronics: Engine control units, dashboard displays, sensor networks
Consumer Electronics: Smartphones, digital cameras, wearable tech
Aerospace & Aviation: Satellite systems, aircraft control panels, navigation instruments
Industrial Automation: Control systems, sensor modules, interface boards
Telecommunications: Networking equipment, mobile devices, transmission systems

Advantages of Leadsintec Flex PCBs

Choosing Leadsintec for your flexible circuit needs brings a host of clear benefits:

Space and Weight Savings
By eliminating the need for traditional connectors and ribbon cables, our flexible and rigid-flex PCBs dramatically reduce overall system size and weight. This allows for more compact, efficient internal layouts—ideal for devices where slim and lightweight design is critical.
Enhanced Reliability
Flexible circuits minimize physical interconnects between components, lowering the risk of failure points. This enhances the durability and reliability of the system, while also allowing for easier modifications to adapt to evolving design requirements.
Superior Design Freedom
With advanced 3D routing capabilities, circuits can be precisely shaped to fit non-standard geometries. Shorter signal paths and better impedance control are achieved, making our solutions ideal for spatially constrained and complex structures.
Outstanding Thermal Management
Compared to traditional rigid boards, our flexible PCBs offer improved heat dissipation, helping maintain thermal stability under continuous operation.
Exceptional Vibration Resistance
The inherent flexibility of our materials reduces mechanical stress on solder joints, ensuring excellent durability and performance even in high-vibration or harsh operating environments.
Cost-Effective Performance
While initial costs may vary for highly customized or low-volume designs, our mature production processes and scalable manufacturing capabilities ensure highly competitive overall value for our clients.

Quality Assurance and Certifications

At Leadsintec, we adhere to rigorous quality control protocols throughout the entire manufacturing process:

UL-Certified Production for Both Rigid and Flexible PCBs
ISO-Compliant Quality Management System
Comprehensive Environmental and Reliability Testing
Strict Electrical Performance Validation
Customer-Centric Engineering Approach

At Leadsintec, we understand that flexibility and strong client relationships are just as critical as advanced engineering. We offer premium, customized engineering and manufacturing services tailored to specific requirements—from rapid prototyping of single units to high-volume production runs.

Conclusion

With nearly two decades of expertise in flexible PCB manufacturing, Leadsintec delivers world-class flexible circuit solutions that combine innovative design, precision engineering, and exceptional reliability. Our comprehensive capabilities—from basic single-layer circuits to advanced multilayer and rigid-flex configurations—empower clients across industries to push the boundaries of electronic product development.

Partner with Leadsintec for your flexible PCB needs and experience the perfect balance of cutting-edge technology and customer satisfaction.