PCB Assembly Service

FS Tech is Printed Circuit Board Assembly Company from China, providing most professional assembly services available in the market.

Circuit Board Assembly overview

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 PCB 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 PCB Assembly 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 PCB assembly, intended electronics components are soldered in the right place by circuit board assemblers. Even if a single small SMT resistor is misplaced or a minute cut in a trace can result in a faulty PCB Assembly.

Quick Turn PCB Assembly Project Samples

Why Choose FS Technology's PCB Assembly Service

Electronic PCB Assembly Certificate

Rich Rapid PCB Assembly Experience

FS Technology is a china based PCB Assembly Service provider, established in 2004 in Shenzhen, China. 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: FS Technology continues to expand its production lines. Up to now, it has 7 fully automatic SMT assembly lines, which can realize rapid turnaround of PCB assembly projects.

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 Fast Turnaround PCB Fabrication, Component Sourcing, Uploading Firmware, Mechanical Assembly redesigning, and Upgradation. The following is the specific content:

  • A wide range of PCBA Services: Such as SMT, THT, mixed assembly, flexible, rigid, and rigid-flex.
  • 100% Quality Guarantee: FS Technology sources all of its parts from reputable suppliers and manufacturers. All PCB assemblies are thoroughly tested and inspected which allows us to ensure that all PCB assemblies are of the highest quality.
  • Custom PCB Assembly Services: FS Technology provides services according to customer requirements as different performance parameters are required for different PCBs that are employed in different kinds of environments. Our experts will collaborate with you to discuss your design needs and then recommend solutions.
  • Fast Turnaround: Our main priority is to provide the fastest turnaround for PCBA manufacturing in the industry. Our lead time varies from project to project but it’s only a matter of a couple of weeks on standard projects. This assembling lead time sometimes improves if all components are sourced quickly.
Full PCB Assembly Services​

Quick Turn PCB Assembly Capability

SMT PCB Assembly Line7 Lines
Capacity52 million placements per month
Max Board Size680×500mm  Smallest:0.25″x0.25″
Min Component size0201 – 54 sq. mm. (0.084 sq. inch), long connector, CSP, BGA, QFP
Speed0.15 sec/chip, 0.7 sec/QFP


Max. PCB width:450mm
Min. PCB width: no limited
Component height:Top 120mm/Bot 15mm


Metal type :part, whole, inlay, sidestep
Metal material:Copper , Aluminum
Surface Finish:plating Au, plating sliver , plating Sn
Air bladder rate:less than20%
 Press-fitPress range:0-50KN
Max. PCB size:800X600mm
QuantityNo MOQ, Prototype PCB Assembly & Small Batch PCB Assembly & Wholesale PCBAs
Type of AssemblySMT, conventional through-hole and mixed technology PCB assembly (Component sequencers, Axial lead inserting, DIP sequence inserting (DIP) system)
Solder TypeWater Soluble Solder Paste,Leaded and Lead-Free


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 FormatsBill of Materials, Gerber Files, Pick-N-Place File(XYRS)
Type of ServiceTurnkey PCB Assembly, Partial Turn-Key or Consignment, Mechanical Assembly
Component PackagingCut Tape, TubeReels Loose, Parts
Turn TimeSame Day Service to 15 day service
PCB Assembly InspectionXRAY 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 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

Fast Turnaround PCB Assembly Processes

Step 1: Applying Solder Paste

In the first step, solder paste is applied to the intended areas of PCB assemblies where components are meant to be soldered. To do so, solder paste is applied on a stencil-stainless steel. The only important thing is to apply the solder paste evenly and in the right amount on the intended areas of PCB assemblies. After some time, when the solder paste is removed from the PCBA, all of the extra solder paste peeled off from the PCB surface but on desired areas of PCBA where soldering of components is required.

Quick PCB Assembly Step 1: Applying Solder Paste

Step 2: Automated Component Placement

The second step PCB assemblers do while providing rapid electronics PCB assembly services is the placement of electronic components, and this placement is fully automated usually done by pick-and-place robots. The designer creates a file that will be fed to the automated robot at the design level. This file contains the preprogrammed X, and Y coordinates of all PCB components and identifies the location of all components. Using this information, the robot will precisely place the SMD devices on board. Pick and place robots use their vacuum grip to pick and hold electronic components and place them precisely on top of solder paste.

Before the invention of pick-and-place robots, this placement job was done manually by technicians. They mostly used tweezers to take components and place the precisely on the intended designator. This results in a lack of a fast turnaround period and also eyesight-related problems and fatigue in technicians.

With the advancement in technology, pick-and-place robots help technicians reduce their workload and also aid in improving the fast turnaround period for PCB assemblies to be manufactured.

Fast and automatic PCB component assembly

Step 3: Reflow Soldering

Reflow soldering is the process of placing PCBs and right-positioned electronic components on a conveyer belt. This conveyer belt then takes the PCBs and components into a large oven, which heats up to 250o C. This temperature is sufficient to melt the solder. The melted solder will then adhere the components to the PCB and form joints. After being exposed to high temperatures, the circuit board is placed in coolers. Where these joints cooled and create solid joints.

10 temperature zone PCBA assembly reflow soldering

Step 4: Quality Control and Inspection

After reflow soldering, the electronic components may be misaligned as a result of high movement in the PCB holding tray, resulting in an open connection or short circuit. These flaws must be identified, and the process of identifying these flaws is known as inspection. The following are three types of inspection which are commonly practiced by many fast turnaround OEM PCB assembly service providers.

  • Manual Inspection: This type of inspection is carried out by technicians with their naked eyes. Manual inspection of very small SMT components may result in a hectic job responsible for fatigue or eye stains of technicians in many cases. This method is better suitable for Through-hole components but not feasible for small SMT electronic components.
  • Optical Inspection: This method proved beneficial for large batches of PCB. This method utilizes an automated machine fully equipped with high-resolution cameras installed at various angles to view soldered components’ joints from various angles. Depending on the quality of the solder joints, the light will be reflected at different angles. This automated Optical Inspection (AOI) machine is extremely fast and can process large batches of PCBs in a very short period.
  • X-ray Inspection: To inspect the inner layers of PCB Assembly, X-Ray inspection comes to play a role. This method is extremely complex and used for very complicated and complex PCBAs. The main disadvantage of this kind of inspection is that if this is not done properly then it may result in a rework or trashing of the PCB for good eventually resulting in material cost, degrading fast turnaround period, and waste of resources.

PCBA Assembly Quality Inspection

Step 5: Placement and Soldering of Through-hole Components

If PCB assembly have SMT and THT components then for SMT component, the above- mentioned steps are valid but not for THT components. THT components are also known as Plated Through Holes (PTH). These components have connecting leads that pass through the holes in the PCB and then soldered there. Conductive traces are used to connect these holes to complete the circuit. There are two methods employed in THT components 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 till all THT components are stuffed onto it. As it takes longer time, many PCB components assembly service providers and PCB assemblers avoid using THT components in their circuit design.

Wave Soldering: This automated method is only useful for single-sided PCB assemblies but not for double-sided PCBAs. This method can be considered an automated version of manual soldering. As in this method, fast electronics PCB Assembly after fully stuffed with THT components, is placed on the conveyer belt to take it to the specialized oven where molten solder splashed in 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 more productivity but only when single-sided PCB assembly is in production.

DIP PCBA assembly

Step 6: Final Inspection before Functional Testing

The high-quality PCB assembly process is now complete and ready for testing and inspection. This is a functionality test in which electrical signals and power are applied at the predefined pins of the PCB assembly and the output is checked at the specified test points or output connectors. This functionality test is usually carried out using basic lab instruments for example oscilloscope, Digital Multimeter, and Function Generator. Generally, electrical parameters like voltage and current are being tested in functional tests and if any of the electrical parameters is not up to the mark then the specific PCBA is discarded as per PCB assembler standards.

function test

Step 7: Final Touching and Cleaning

Now that the PCBA board has been thoroughly tested and declared perfect in all aspects, there is a need to remove unwanted dirt and stains. To clean all types of dirt, a stainless steel high-pressure washing tool is sufficient. After washing, the PCBA electronic circuit board is dried and now is ready for packaging and shipping.

Clean the assembled PCBA

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