Explore our high-precision electronic manufacturing capabilities across automotive, industrial, and consumer sectors.
In the modern electronics landscape, the demand for miniaturization, lightweight components, and dynamic mechanical flexibility has propelled Flexible Printed Circuits (FPCs) to the forefront of hardware engineering. Unlike traditional rigid boards, the Flex PCB manufacturing process requires highly specialized materials, precise thermal management, and strict environmental controls to ensure reliability under continuous mechanical stress.
As a leading China Flex PCB manufacturer, STHL integrates advanced material science with state-of-the-art fabrication techniques. From single-sided polyimide circuits to complex multi-layer rigid-flex structures, our manufacturing processes are optimized to deliver high-density interconnect (HDI) solutions that meet the rigorous demands of aerospace, automotive, medical, and consumer electronics industries globally.
Years Experience
Production Facility
Skilled Specialists
Global Regions Served
A comprehensive breakdown of the engineering steps required to fabricate high-reliability flexible printed circuits.
Polyimide (PI) or Polyester base films are selected and pre-baked to eliminate moisture, ensuring dimensional stability during subsequent thermal cycles.
Photoresist is applied, exposed to UV light through a phototool, and developed. Unwanted copper is etched away to reveal the precise circuit traces.
A polyimide coverlay coated with acrylic or epoxy adhesive is aligned and laminated under high pressure and temperature to protect the copper traces.
ENIG, ENEPIG, or Immersion Tin is applied to exposed pads. The boards undergo rigorous flying probe and optical inspection (AOI) to guarantee electrical integrity.
Shenzhen STHL is a high-quality provider of electronics manufacturing services (EMS) in China, we serve customers worldwide along the whole industry chain including PCB layout, components sourcing, PCB fabrication, PCBA assembly, cable assembly, box build assembly and comprehensive testing services.
It was established in 2006, with 20 years of experience in electronics contract assembly manufacturing. Currently, STHL has 220+ staff members. Our 10,000 sqm facilities include 7 SMT assembly lines, 2 DIP/THT lines, 2 function testing lines and 2 finished device assembly lines.
At STHL, we provide electronics assembly services for energy power, communications, automotive, medical, consumer electronics, computers & storage, safety & security, commercial and industrial products. Our customers mainly from USA, Germany, Italy, UK, Poland, New Zealand, Argentina, Brazil, Turkey, Korea, Thailand, and the other 90 regions of the world.
As an IATF16949, ISO9001, ISO14001, and ISO13485 certificated electronics assembly manufacturer, we produce products exactly comply with RoHS standard and quality guarantee. Based on our excellent engineering and production capacities in technical areas such as materials analysis & storage, advanced equipment, reliability testing (AOI, X-RAY, ICT test and function test), high effective SMT and THT assembly, we are recognized as a long-term reliable PCBA vendor by more and more customers worldwide.
Our production floor is equipped to handle the most complex component packaging and assembly requirements with absolute precision.
We can handle a wide range of advanced components, including:
But our commitment to quality goes beyond component expertise. We utilize advanced inspection techniques, including AOI and X-Ray inspection, to guarantee flawless assembly.
STHL PCBA also excels in Through-Hole Technology (THT) assembly. Our services encompass:
From prototype fabrication to full box-build assembly, we provide turnkey EMS solutions under one roof.
STHL operates 7 automated PCB assembly lines for both prototype and mass production. Advanced SMT ensures precise component placement and quality. Skilled technicians provide efficient THT assembly and RoHS-compliant lead-free soldering.
STHL PCB fabrication service produces high-quality, reliable printed circuit boards from simple singles to complex multi-layers, from flex PCB to rigid-flex PCB, we use premium materials and controlled processes to meet precise specifications.
STHL offer global electronic component sourcing and supply chain solutions. Our vast supplier network and expertise ensure access to genuine, certified parts, mitigating risks of counterfeits, allocation, and long lead times to secure your production schedule.
With the precision manufacturing of cable assembly components including handles, retention systems, connectors, and shielding in a wide range of materials and finishes, we have performed many successful cable assembly for many customers from various industrial applications.
Making your projects at STHL from SMT assembly to box build assembly is very cost-effective and fast to market. Covering everything from putting a PCBA into the enclosure with all functions testing to a complete product assembly packaged and ready for delivery to your customers, we can supply the full support.
STHL conducts functional testing (FCT) to verify product performance, preventing defects such as circuit issues, missing or incorrect components. This ensures delivered products are stable and fully qualified.
How we address the critical pain points of international procurement managers and hardware engineers.
In the highly competitive electronics industry, global procurement teams face significant challenges: component obsolescence, volatile lead times, tariff fluctuations, and strict quality compliance. A reliable China Flex PCB manufacturer must act as more than just a vendor; they must be a strategic partner capable of mitigating supply chain risks.
At STHL, we address these challenges through a multi-layered procurement strategy:
Before selecting a China factory, verify the following capabilities:
Tailored engineering and assembly services designed for high-reliability sectors.
With IATF16949 certification, we manufacture high-reliability Flex PCBs for ADAS, battery management systems (BMS) in electric vehicles, infotainment units, and heads-up displays. Our processes ensure thermal stability and vibration resistance.
Compliant with ISO13485, we support medical hardware designers with ultra-thin, biocompatible flexible circuits for patient monitoring systems, diagnostic equipment, and wearable health trackers requiring high signal integrity.
Heavy-duty flexible circuits designed for robotic arms, sensors, and control units. Our manufacturing process focuses on dynamic bending life, allowing millions of flex cycles without trace degradation.
As electronic devices become smarter and more compact, the technology driving flexible circuits must evolve. STHL is actively investing in R&D to align with the next generation of hardware design:
By partnering with a manufacturer that possesses a clear technical roadmap, you ensure that your product designs remain competitive, manufacturable, and scalable for years to come. STHL's engineering team works closely with clients during the prototyping stage to transition designs seamlessly into high-yield mass production.
Bridging the gap between Western engineering standards and Eastern manufacturing efficiency.
All materials used in our fabrication processes are fully traceable and compliant with RoHS, REACH, and UL94V-0 standards. We provide full documentation packages upon request to simplify your market entry audits.
Our bilingual engineering team provides round-the-clock Design for Manufacturability (DFM) reviews, helping you identify potential layout issues before tooling begins, saving time and costs.
We treat intellectual property with the utmost seriousness. Strict internal data controls, secure servers, and robust non-disclosure agreements (NDAs) protect your proprietary designs throughout the manufacturing cycle.
Expert answers to common queries regarding the Flex PCB manufacturing process and factory sourcing.
Browse our full range of custom PCB fabrication and assembly services for global markets.
STHL PCBA
