
PCB Assembly Service
The PCBA is a rigid body having various electronic components and is typically green in color. PCBs with electronic components are generally called “Printed Circuit Board Assembly” or “PCBA board”. The PCBA board comprises a fiberglass substrate, electronic components, conductive traces on the copper layer, holes in which the components are fitted, and different layers.
PCB substrate and electronic components are held together in a PCBA with epoxy resin and to avoid short-circuiting electronic components with conductive traces solder mask is used which is available in different colors like green, and blue are commonly used. These conductive traces are used to deliver message signals either digital, high-speed signal, or analog signal between different points in a PCB. These traces are customizable during the designing phase, and their width can be set according to the requirement of signals they carry.
The functionality of PCB assembly is the most important thing. To achieve the proper functional PCBA board, intended electronics components are soldered in the right place by circuit board assemblers. Even a small SMT resistor being misplaced or a tiny cut in a trace can cause the assembly to malfunction.
FS Tech, a PCB assembly company from Shenzhen, China, provides the most professional and widest range of assembly services in the market. If your project requires PCBA services, we would be happy to assist you without any hesitation. Please contact us by email to receive a timely quotation.
PCB Assembly in China
FS Technology can provide a one-stop assembly service for your project, no matter how difficult your PCBA board manufacturing needs may be or how large the demand is.
We source electronic components from world-renowned IC manufacturers, such as Qualcomm, TSMC, DigiKey, and Mouser, and we ensure that these components are original and authentic for PCB electronics assembly. In the face of the chaotic component market, we have our own management system and contingency plan. If there is a shortage of materials, our engineers will provide cost-effective alternatives for your review. Additionally, we have a large storage space for components to minimize the risk of global component shortages.
PCB Assembly Capabilities
Production line | 7 SMT assembly and DIP assembly lines |
Yield | 52 million placements per month |
Max Board Size | 680×500 mm Smallest:0.25″x0.25″ |
Min Component size | 0.2 – 54 mm. (0.084 sq. inch), long connector, CSP, BGA, QFP |
Speed | 0.15 sec/chip, 0.7 sec/QFP |
Wave-Solder | Max. PCB width:450 mm. |
Min. PCB width: no limited. | |
Component height: Top 120 mm/Bot 15 mm | |
Sweat-Solder | Metal type: part, whole, inlay, sidestep |
Metal material: Copper, Aluminum | |
Surface Finish: plating Au, plating sliver, plating Sn | |
Air bladder rate: less than20% | |
Press-fit | Press range:0-50KN |
Max. PCB size:800×600 mm. | |
Quantity | No MOQ, Prototype & Small Batch & High volume |
Type of Assembly | SMT, conventional through-hole and mixed technology PCB assembly (Component sequencers, Axial lead inserting, DIP sequence inserting (DIP) system), |
Solder Type | Water Soluble Solder Paste, Leaded and Lead-Free |
Components | Passives Down to 0201 Size BGA and VFBGA Leadless Chip Carrier/CSP Double-Sided SMT Assembly Fine Pitch to 08 Mil BGA Repair and ReballPart Removal and Replacement-Same Day Service |
File Formats | Bill of Materials, Gerber Files, Pick-N-Place File(XYRS) |
Type of Service | Turnkey PCB Assembly, Partial Turn-Key or Consignment, Mechanical Assembly |
Component Packaging | Cut Tape, TubeReels Loose, Parts |
Turn Time | Same Day Service to 15 day service |
PCB Assembly Inspection | XRAY Inspection, AOI Testing, ICT,Probe flying,burn-in,function test,temperature cycling. |
Our Machines | Japanese SONY high-speed SMT SI-F130WR Qty: 23 Japanese SONY multifunctional SMT SI-F209 Qty: 7 Japanese YAMAHA multifunctional SMT YV100XGP Qty: 7 DESEN Automatic silk printing machine DSP-1008 Qty: 10 YoungXin lift slab machines BL-250W-ST Qty: 8 American Heller 18 zones reflow oven Qty: 4 America PACEB BGA repair station Qty: 2 Japanese SONY AOT tester Qty: 4 3D-SPI checkout equipment Qty: 2 ChaoJinDa full-aotumatic ultrasonic cleaning machine Qty: 3 Japanese X-Ray detector Qty: 1 YongXing Industrial oven Qty: 3 Automatic double wave peak welding line Qty: 2 Automatic belt post-welding production line Qty: 5 Automatic belt assembly line Qty: 1 Automatic belt cleaning packaging line Qty: 2 Computer test maintenance equipment Qty: 15 Online AOI detection equipment Qty: 4 |
PCBA Board Sample
Circuit Assembly Scheme
Turnkey Assembly
Turnkey assembly refers to a comprehensive service provided by EMS providers that encompasses the entire electronic assembly process, from component procurement to final assembly and testing. In other words, customers provide the PCB design files and specifications, and the EMS company handles the rest.
At FS Technology, we offer a complete range of support and services, from circuit design to product delivery. As a manufacturer with our own manufacturing and assembly workshop, we can meet most customer needs, including prototype to batch, manufacturing to assembly, procurement to testing, and more.
The turnkey PCB assembly service is suitable for customers who wish to outsource the entire assembly process and have a single point of contact for their electronic projects. This enables customers to save time in project management and allocate resources to the final sales process.
Partial Turnkey Assembly
Partial turnkey assembly is a cost-effective solution for PCB electronics assembly that involves the customer handling some aspects of the assembly process, while the assembly company takes care of the rest. In some cases, customers can provide specific components, such as ICs and main control chips, while the service provider is responsible for purchasing conventional components, such as inductors and capacitors.
This assembly option is suitable for customers who have specialized or unique components they prefer to supply, or who wish to have greater control over the assembly process. It is also cost-effective for customers who want to save on some component procurement costs. However, it is important to note that this option requires the assembly company to have sufficient procurement and management experience, and involves more coordination, otherwise it may impact the overall quality of the project.
Consigned
The consignment PCB assembly service means that the customer provides the PCB board and all the required electronic components, and the service provider only needs to carry out the final assembly and testing. This option can be the most cost-effective for customers as they can purchase components in larger quantities and benefit from volume pricing.
However, consignment to a client comes with higher risks, reflected in procurement costs and multiple service providers. Firstly, it requires electronics manufacturers to have certain storage management capabilities, risk tolerance for component failures, and extensive component procurement channels. Additionally, most electronics manufacturers do not have PCB manufacturing capabilities, which means that they need to cooperate with PCB manufacturers and PCBA processing plants simultaneously. This can cause information gaps, making communication less convenient than point-to-point communication.
Kitted
The customer is responsible for procuring all materials, while FS Technology handles the PCB manufacturing and assembly, as well as PCB testing according to customer needs after the production process is completed. Through past service projects, we have found that some of our customers rely on foreign trade service providers in Hong Kong for procurement, although it is an undisputed fact that their services are good. However, this means that our customers have to bear unnecessary costs, because FS Technology can provide all the services that these service providers offer.
Bare Board Assembly
This solution assumes that the customer already has a stable and high-quality PCB manufacturer. The PCB manufacturer is responsible for manufacturing the bare boards and delivering them to FS Technology. We then purchase and assemble electronic components according to the requirements of the customer’s documentation.
Fully Custom PCB Assembly
This type of service can also be referred to as mixed assembly, and it is a fully customizable service option. Customers can combine the different solutions we have mentioned according to their specific needs. This form of service provides maximum flexibility to meet individual customer requirements and achieve successful electronic assembly processes.
High Quality PCB Assembly
If you require factory inspections, we will meet your needs without hesitation. You will observe uniform production lines, qualified technicians, advanced equipment, and more. Below, we have outlined our equipment and production line. If you are interested in our services, please contact us via email, and we will promptly provide you with a quote for cheap PCB assembly.
Our partner
FS Technology has been serving the PCBA industry for 20 years, providing electronic assembly services to the most discerning PCB engineers and designers who choose us as their business partner in China. Almost all of the customers we have served have given us positive reviews, and they come from various channels including our official website, Alibaba, and customer referrals.
Here are some of the top customers we are currently working with:
Assembly workshop
Our PCB manufacturing and assembly workshop is situated in Shenzhen’s largest science and technology park, covering an area of approximately 50,000 square feet. Equipped with state-of-the-art automation equipment, we can accurately and efficiently fulfill any PCBA orders in large quantities. Our standard and advanced modes can be switched to strike the perfect balance between cost and performance. Our standard and advanced modes can be switched to strike the perfect balance between cost and performance.
Our strong service capabilities are endowed by advanced assembly and manufacturing equipment. Currently, we can provide services to industries such as industrial, medical, consumer electronics, military, aerospace, and more.
Printed Circuit Assembly Process
Step 1: Applying Solder Paste
The first step in the PCB assembly process is applying solder paste to the intended areas of the PCB component where components will be soldered. This is done by applying solder paste to a stainless steel stencil. It is crucial to apply the solder paste evenly and in the correct amount to the intended areas of the PCB component. After some time, when the solder paste is removed from the PCBA, any excess solder paste is peeled off from the PCB surface, leaving only the desired areas where components will be soldered.

Step 2: Automated Component Placement
The second step in PCB assembling is the automated placement of electronic components, which is usually done by pick-and-place robots. At the design level, the designer creates a file that contains the preprogrammed X and Y coordinates of all PCB components and identifies the location of each component. Using this information, the pick-and-place robot precisely places the surface-mounted devices (SMD) on the board using a vacuum grip.
Before the invention of pick-and-place robots, this placement job was done manually by technicians who mostly used tweezers to pick and place components on the intended designator. This resulted in longer lead times, eye strain, and fatigue in technicians.
With the advancement of technology, pick-and-place robots have reduced the workload of technicians and improve the efficiency of PCB board assembly manufacturing.

Step 3: Reflow Soldering
Reflow soldering is the process of placing PCBs and electronic components in the correct position on a conveyor belt. The conveyor belt carries the PCBs and components into a large oven that heats up to 250°C, which is sufficient to melt the solder. The melted solder adheres the components to the PCB and forms joints. After being exposed to high temperatures, the circuit board is transferred to coolers where the joints are cooled and solidified, creating solid connections between the components and the PCB.
Step 4: Quality Control and Inspection

After reflow soldering, the electronic components may become misaligned due to movement in the PCB holding tray, resulting in open connections or short circuits. These flaws must be identified, and the process of identifying them is known as inspection. There are three types of inspection commonly practiced by many OEM PCB assembly factories.
- Manual Inspection: Technicians carry out this type of inspection with their naked eyes. However, manual inspection of small SMD components can be a hectic job that may cause fatigue or eye strain for technicians. This method is more suitable for Through-hole components but not feasible for small SMD electronic components.
- Optical Inspection: This method is beneficial for inspecting large batches of PCBA assembly. An automated machine equipped with high-resolution cameras installed at various angles is used to view the joints of soldered components from various angles. Depending on the quality of the solder joints, the light will be reflected at different angles. Compared with other methods, AOI Inspection is faster.
- X-ray Inspection: X-ray inspection is used to inspect the inner layers of complex and complicated PCBAs. This method is extremely complex and has the disadvantage of resulting in a rework or trashing of the PCB if not done properly, which eventually results in material cost, lead time longer, and wasting resources.

Step 5: Placement and Soldering of Through-hole Components
If a PCB assembly contains both SMT and THT components, the above-mentioned steps are valid for SMT components but not for THT components. THT components, also known as Plated Through Holes, PTH or DIP assembly, have connecting leads that pass through the holes in the PCB and are then soldered there. Conductive traces are used to connect these holes to complete the circuit. There are two methods employed in THT component soldering.
Manual Soldering: The manual soldering method takes longer than the automated SMT setup method. Typically, one technician is assigned to insert one component at a time before passing the board to another technician who inserts another component on the board and so on until all THT components are installed. As it takes longer, many PCB components assembly vendors avoid using THT components in their circuit design.
Wave Soldering: This automated method is only useful for single sided PCB assembly but not for double sided assembly. This method can be considered an automated version of manual soldering. In this method, after being fully loaded with THT components, the PCBA is placed on the conveyer belt to take it to a specialized oven where molten solder is splashed in the form of waves on the bottom side of PCBA to create solder joints on all pins of THT components at once. This method results in time-saving and increased productivity, but only when single-sided PCB assembly is being produced.

Step 6: Final Inspection before Functional Testing
The high-quality PCBA process is now complete and ready for testing and inspection. The functionality test involves applying electrical signals and power to the predefined pins of the electronic component and checking the output at the specified test points or output connectors. This test is usually performed using basic lab instruments, such as an oscilloscope, digital multimeter, and function generator. Generally, electrical parameters, such as voltage and current, are tested during functional tests. If any of the electrical parameters do not meet the standards set by the PCB assembler, the specific PCBA is discarded.

Step 7: Final Touching and Cleaning
Once the PCBA board has been thoroughly tested and deemed to be perfect in all aspects, it needs to be cleaned to remove any unwanted dirt or stains. A stainless steel high-pressure washing tool is sufficient for cleaning all types of dirt. For some special projects that require conformal coating service, we provide this additional service after cleaning. For small batch prototype PCBA manufacturing, we offer customers free conformal coating service. After the entire assembly process is completed, the PCBA board is almost perfect and can now be packed and shipped.

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Best China PCB Assembly Manufacturer
FS Technology is a China-based PCB assembly service provider that was established in Shenzhen, China in 2004. As a full service electronic manufacturing services company providing complete assembly solutions, FS Tech has expertise in fast turnkey PCBA services. Our mission is to provide cost-effective solutions by maintaining high quality for the clients.
In terms of speed: As of now, we have 7 fully automatic SMT assembly lines for fast turnaround and we are expanding our production line.
In terms of quality: FS Technology has obtained a number of qualification certifications including: ISO9001:2015, ISO14001:2015, ISO45001:2018, ISO13485:2016, IATF16949:2016, and has the ability to complete electronic PCB assembly in aerospace, medical, military and other industries
Comprehensive PCB Assembly Services
Our PCBA services include PCB Fabrication, Component Sourcing, IC Programming, Uploading Firmware, Mechanical Assembly redesigning, and Upgradation. The following is the specific content:
- A wide range of assembly services: Including SMT, THT, mixed assembly, flexible, rigid, and rigid-flex.
- 100% Quality Guarantee: FS Technology sources all of its parts from reputable suppliers and manufacturers. We thoroughly test and inspect all circuit board components to ensure that they meet the highest quality standards.
- Custom Services: We offer customized services that cater to the unique needs of our customers, providing PCBA boards with varying performance parameters to suit different environments. Our team of experts collaborates with you during the process to understand your design requirements and recommend a tailored solution.
- Fast turnaround: Our top priority is to deliver PCBAs to electronics manufacturers faster, and this can be easily achieved through our fast turnaround service. Project lead times vary from case to case but typically take a few weeks for standard projects. Assembly lead times may be improved if all components are procured quickly.

Customer reviews
PCB Assembly Blog
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