Manufacturing Process
CFS is an OEM/ODM solutions provider specializing in alarm systems, backed by over 20 years of industry experience. Our company has a modern factory of
over 10,000m² and more than 200 staff members. We have 4 SMT placement lines and 4 post-soldering lines, with an annual production
capacity of 5 million units, covering multiple alarm products like smoke detectors, CO detectors, gas detectors, and temperature detectors.
Four Core Manufacturing Processes
Our comprehensive manufacturing system covers every stage from raw
material molding to final assembly and factory release.
Injection Molding
180-ton and 250-ton injection molding machines for device housings and accessories
SMT Assembly
High-precision SMT lines for automated component placement, soldering, and inspection
Product Assembly
Human-machine collaborative approach for final unit assembly and firmware packaging
Full-Function Testing
Real-time testing of electrical parameters, audio-visual responses, and button reliability
Our company enforces stringent verification protocols at every stage — from raw material molding and
PCB processing to final assembly and factory release — to prevent defective products from advancing to
subsequent stages or entering the market.
Annual Capacity
Production Lines
QC Coverage
Key & Special Process Control
The company maintains strict control over all key
processes and special processes to ensure product quality and reliability.
Key Process
Special Process
Assessment Criteria of key process and critical process
| Evaluation item | Content | Evaluation Standard | ||
| 1 | 2 | 3 | ||
| Quality | Mistake frequency | <100PPM | 100PPM~1000PPM | 1000PPM~10000PPM |
| Severity | Minor defect | Major defect | Critical defect | |
| Technique | Training time | <4H | 4H~8H | 8H~3days |
| Proficiency | 1 day to meet efficiency | 3 days to meet efficiency | 7 days to meet efficiency | |
Note: Key process and special process should be reviewed and approved before launch and marked on production flow chart. Operators of key process and special processes should be trained with certification to work after passing the examination. After certificate expires, there should be re-evaluation and recertification.
CO Sensor Manufacturing Process
The process control of CO sensor manufacturing directly determines the product’s
stability and lifespan. A stable mass production system compliant with
UL2034 and EN50291 requirements.
01. Raw material cleaning
Ultrasonic automatic cleaning and drying machine cleans oil and dust from material surfaces, ensuring that materials do not contaminate electrode films and electrolytes. Its main functions include:
1. Extending product lifespan;
2. Effectively preventing zero-point and baseline drift;
3. Improving product consistency, especially at high and low temperatures.
Hardware material cleaning process: Acid pickling ➡️ Deionized water cleaning ➡️ Drying
Other material cleaning process: Deionized water cleaning ➡️ Drying
02. Place canister onto pallets
The iron cans are packed into trays and arranged in an orderly manner to automatically fill with electrolyte in the next process.
03. Electrolyte Injection
The automatic and precise control of electrolyte injection volume serves the following purposes:
1. Wetting the membrane electrode to ensure unimpeded proton conduction
2. Preventing electrolyte contamination
3. Ensuring a 10-year product lifespan and stability
04. Component Assembly
Fully automated assembly machines assemble high-quality, high-efficiency components. Their functions include:
1. Loading core components into the container and completing the assembly sequentially.
2. Ensuring the concentricity of electrode films and diffusion films guarantees performance stability and consistency.
3. Avoiding deviations and omissions associated with manual assembly.
05. Seal Ring Installation
100% re-inspection of components assembled at the previous workstation is performed to confirm there are no misalignments or omissions. Then, sealing rings and activated carbon are installed. Their functions are:
1. Sealing rings prevent external interfering gases from entering the cavity and prevent electrolyte leakage.
2. Activated carbon filters interfere with gases.
06. Crimping & Sealing
The automatic edge-sealing machine assembles the filter carbon and electrode onto the front end of the electrode membrane and then edge-seals it, achieving:
1. Preventing electrolyte leakage
2. Preventing the entry of external interfering gases
07. Vacuum Test
Tests whether the sensor is completely sealed, quickly determining if there is electrolyte leakage.
08. Impedance and capacitive reactance testing
Product quality is assessed by testing the internal impedance and capacitive reactance after edge crimping.
1. Impedance testing reflects electrode conductivity and the contact between the electrode and the electrolyte.
2. Capacitive reactance testing reflects the capacitance characteristics of the electrolyte/diaphragm, indicating whether ion transport and interfacial wetting are normal.
3. It also reflects the internal space of the tank after edge crimping and the contact condition of internal components.
09. aging test
Placing the sensor with its edges rolled short-circuited between the positive and negative electrodes for at least 14 days can achieve the following:
1. Stabilized electrochemical performance
2. Release mechanical stress from the processing
3. Achieve electrode equilibrium
Prevent polarization
10. CO gas sensitivity & insulation resistance testing
Sensors that have completed aging are 100% tested with 0PPM, 150PPM, and 400PPM gases before shipment, achieving the following:
1. Passive sensitivity and linearity
2. Stable zero point without drift
3. Product response time within specifications
4. High insulation resistance value to avoid impact on circuitry
11.Lead welding & laser logo
We use automatic welding machines and laser engraving machines to weld leads and laser logos and date codes according to customer requirements.
12.Packaging
Pack according to customer specifications and send to the designated location.
PCBA Manufacturing Process
CFS is equipped with two fully automated high-end SMT placement production lines, featuring imported high-precision Yamaha and Panasonic
placement machines, fully automated solder pastes printers, online SPI solder pastes inspection equipment, reflow ovens, and AOI optical
inspection instruments. This enables fully automated operation from solder paste printing, precision placement, soldering, and curing to visual
inspection. The equipment supports precision placement of micro-components in 0201, 0402, and 0603 packages with a placement accuracy of
±0.02mm. It can stably complete the placement of precision chips such as BGA and QFN, eliminating defects such as cold solder joints, misalignment,
and missing placement. With the 4 production lines operating in tandem, the annual PCBA production capacity can reach 5,000,000 units.
All PCB components are automatically placed and then subjected to visual inspection and automatic X-ray inspection after soldering,
resulting in a first-pass yield of over 99.5%. Strict quality control is implemented throughout the process, making it suitable for mass production of
PCBAs for fire protection electronics, industrial control modules, communication boards, and power supplies.
Stencil Printing
01
Apply solder paste evenly to the PCB pads.
Key control points:
👉 Incorrect printing = all subsequent attempts fail
SPI
02
Inspecting solder paste thickness and printing area
Pick & Place
03
Precise placement of electronic components on the PCB
Key metrics:
AOI
04
Check if components are correct.
Check items:
Reflow
05
Soldering is achieved by melting solder paste using a temperature profile.
Key controls:
AOI
06
Inspect solder joint quality
Inspection items:
DIP
07
Manual and automatic insertion
Applicable to:
Wave Soldering
08
Soldering is achieved by melting solder wires using a temperature profile.
Key controls:
Programing
09
Load the Firmware to the MCU.
PCBA Functional test
10
Verify product electrical functions
±0.02mm
Placement Accuracy
0201/0402/0603
Micro-Component Support
BGA/QFN
Precision Chips
5M+
Annual Capacity
Assembly Manufacturing Process
CFS is equipped with four fully automated, standardized finished product assembly lines, each equipped with fully automated PCB
de-paneling machines, automatic glue spraying and dispensing equipment, automatic welding stations, and automatic
screw-driving machines. This enables integrated operation of the entire process, from component welding and screw assembly to
precision PCB de-paneling and molding. The production lines feature an intelligent data acquisition system that records
test data in real time, preventing defective products from leaving the factory. Our factory has an annual production capacity of
over 5 million alarms on 4 production lines, capable of handling orders for various standard and customized alarms,
including smoke detectors, carbon monoxide detectors, and combination detectors. Before the production line starts, the line leader and PE
engineer conduct spot checks on the production equipment. Inspection points are set up for each key process. All components are
assembled 100% according to the work instructions to ensure the consistency of the final assembly.
STEP 1
Coating
STEP 2
De-panel
Separate it into an independent circuit board without damaging the components and solder joints.
STEP 3
Sensor module installation
Key Technologies:
STEP 4
Battery installation
10-year battery life (sealed)
Key control points:
STEP 5
Installation of audible and visual alarm module
Key control points:
STEP 6
Assembly of the outer shell and structure
Key control points:
4
Assembly Lines
5M+
Annual Capacity
100%
Data Recording
10 Years
Battery Life
Functional test process
CFS is equipped with 4 self-developed finished product testing lines, covering all quality inspection processes for alarm devices.
These lines integrate core workstations such as precise carbon monoxide calibration testing, smoke sensitivity calibration testing,
sound and light intensity testing, overall power consumption testing, and button function reliability verification.
CO calibration and test
01
Complete the calibration of the CO sensor to avoid false alarms and missed alarms in the product.
Smoke calibration and test
02
Sensitivity testing using simulated smoke
Power Consumption Test
03
Sound Test
04
Standard: ≥85dB @3 meters (Common Standard)
Button and Function Testing
05
Automated Quality Control
The entire process is automated, with data retention and automatic defective product identification to prevent defective products from escaping. Each assembled alarm must pass triple tests, including smoke, CO gas, and accelerated aging. The testing equipment meets the standards of UL/EN certified laboratories, and the stability meets the standards after aging 24 hours, ensuring a factory pass rate of over 99%. The four testing lines operate efficiently and collaboratively, rigorously controlling every performance indicator. We can complete the testing of over 5 million alarm devices annually, ensuring that each product has accurate sensitivity, stable performance, and fully complies with customer and regulatory requirements.
5M+
Tests/Year
100%
Data Retention
Packing & Shipping
The entire machine undergoes comprehensive inspection, cleaning, labeling, and quality verification
before shipment to ensure every product meets the highest standards.
01. Inspection
The exterior was inspected for dirt and missing parts.
02. Cleaning
Clean with lint-free cloth to ensure a neat and aesthetically pleasing appearance.
03. Labeling
Apply product labels or lasers according to their placement.
04. Packing
In accordance with customer requirements, we guarantee product reliability, compliance, and logistics safety.
05. OQA Inspection
Outgoing Quality Assurance inspection before shipment.
06. Shipping
Deliver to the customer’s designated location and warehouse on time, in accordance with quality and quantity requirements.
Ready to Ship Worldwide
Every product is traceable, certified, and delivered with complete documentation to meet international shipping requirements.
UL
Certified
CE
Certified
UKCA
Marked
6σ
Management