High-Mix Prototype PCB Assembly

  • Small to Medium Volume Production
  • No MOQ & Quick Turn Production Available
  • SMT assembly, PTH assembly, SMT+PTH mixed
  • Kitted Parts Assembly & Turnkey Assembly
  • ISO9001:2015, ISO 13485:2016 Certified & UL Listed
  • 100% E-test, AOI, X-RAY, ICT, FCT and Visual Inspection

Why is Prototype PCB Assembly Needed?

When a printed circuit board is designed by an engineer, no one can assure it will be functionally well 100%. So a few prototypes are always needed to avoid big losses in mass production if there are any design errors. The quantity is around 1 to 100 pcs normally. We call this prototype PCB assembly.

Besides, Prototype PCB assembly may also be needed to evaluate a new supplier, even if is it a mature product. Since there is a potential risk if moving an existing product to a new supply.

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    Why Choose Visasion's Prototype PCB Assembly?

    Prototype Printed Circuit Board Assembly Process Steps

    The application of solder paste

    First, the solder paste (a small particle of solder paste mixed with flux) is applied to the circuit board. For this application, most PCBA manufacturers use stencils ( They are available in several sizes. Shapes and specifications are in line with the specifications), which can only apply the correct amount of solder paste to certain parts of the circuit board correctly.

    Component placement

    Unlike in the past, this stage of the PCB assembly process is now fully automated. The picking and placing of components (such as surface-mounted assemblies), once done manually, is now performed by robotic pick-and-place machines. These machines place components accurately into pre-planned areas of the circuit board.

    Reflow soldering

    Now the solder paste and all surface mount assemblies are in place. What's your next step? Curing the solder paste to the correct specifications is critical to properly adhering the PCB components to it. This is the relevant part of the PCB assembly process - reflow soldering. To do this, the assembly with the solder paste and the components on it is passed through a conveyor belt, which passes through an industrial-grade reflow oven. Heaters in the oven melt the solder in the solder paste. Once the melting is complete, the assembly will again move through the conveyor and be exposed to a series of cooler heaters. The purpose of these coolers is to cool the melted solder and allow it to cure.


    After the reflow soldering process, the PCB should be inspected to check its functionality. This stage helps identify poor-quality connections, misplaced components, and shorts due to the continuous movement of the board during the reflow soldering process. PCBA manufacturers use multiple inspection steps such as manual inspection, automated optical inspection, and X-ray inspection to check the functionality of the circuit board, identify lower-quality solder and identify any potential pitfalls. Once the inspection is complete, the assembly team will make the critical decision. Circuit boards with several functional errors are usually scrapped. On the other hand, if there are smaller errors, the circuit board is resent for rework.

    Insertion of through-hole components

    Certain types of PCBs require the insertion of through-hole components along with conventional SMD components. This stage is dedicated to the insertion of such components. For this purpose, the signal is passed from one side of the circuit board to the other with the help of those PCB components to create plated through-hole. Through-hole insertion of PCB is usually done by manual soldering or wave soldering.

    Final inspection

    Now it is time for the second level of inspection. Here, the PCB assembly is tested for functionality, or the PCB assembly is thoroughly inspected to monitor its electrical characteristics, including voltage, current or signal output. Today's manufacturers utilize a variety of advanced test equipment to help determine the success or failure of the finished PCB assembly.


    Because there is a lot of flux left on the PCB during the soldering process, it is critical to thoroughly clean the PCB assembly before delivering products to the customer. For this purpose, PCB assemblies are cleaned in deionized water. After the cleaning process, PCB assemblies are thoroughly dried with compressed air. The PCB assembly can now be prepared for customer inspection.

    How to Select A Prototype PCB Assembly Manufacturer

    The following can guide how to select a prototype PCB assembly manufacturer.

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    Viasion Technology is your trusted partner & one-stop shop for PCB fabrication, components sourcing, PCB assembly and electronic manufacturing. With more than 16 years of experience, we have been supplying high-quality PCBs with competitive pricing for 1000+ customers worldwide. Our company is ISO9001:2015 Certified & UL Listed, and all our products are 100% E-tested and inspected by AOI & X-RAY to meet the highest industry standards. So please get an instant quote from our sales team now, and we will take care of the rest.

    Frequently Asked Questions

    A prototype PCB assembly acts as a small number of samples to test the quality of the products before mass production of PCBA products, to a certain extent, to avoid risks for future mass production.

    1) A prototype PCB assembly can help you identify design flaws that can be corrected before mass production runs.
    2) Testing prototype PCB assembly ensures that PCBA designs are working properly and reduces the risk of errors before mass production.

    The types of prototype PCB assembly we offer include SMT assembly, PTH assembly, SMT+PTH mixed assembly, manual assembly as well as the assembly of rigid PCB, flex PCB, and rigid-flex PCB.

    The following are prototype assembly testing are used in prototype PCB assembly.
    1) Electrical Test (E-test)
    2) AOI (Automated Optical
    3) Inspection)
    4) ICT (In-circuit Test)
    5) FCT (Functional Test)

    Viasion’s prototype PCB assembly capabilities are as follows.
    1) Assembly type: SMT assembly, PTH assembly, SMT+PTH mixed, manual assembly
    2) PCB type: rigid PCB, flex PCB, rigid-flex PCB
    3) PCB parts: turnkey, partial turnkey, consigned assembly
    4) Components type: all kinds of passive and active electronic components .
    5) SMT components type: SOP, BGA, uBGA, QFN, DFN, PLCC, POP, CGA, CSP
    6) Min. SMT component size:0201
    7) Min. PCB dimensions: min. 0.2 *0.2”
    8) Max. PCB dimensions: max. 20*28”
    9) Inspections: AOI (automatic visual inspection), X-ray
    10) Testing: ICT (in-circuit test), FCT(functional test)
    11) Cable assembly available
    12) Conformal coating
    13) IC programming
    14) Box build assembly
    15) Electro-mechanical assembly
    16) PCB Repair services
    17) Lead time: 1-5 days
    18) Quantity available: 1 to 10,000pcs

    Yes, Viasion will perform a components analysis for prototype PCB assembly if our customers require it. In addition, we also can carry out the manufacturing of prototype PCB assembly according to the BOM that is provided by customers. Which is very important for rapid prototyping PCB assembly.

    PCB prototype assembly service means PCB assembly for samples or prototypes, but PCB prototype service means production of bare printed circuit board.

    The standard turnaround time for a prototype PCB assembly takes 1-5 days.

    The following factors need to be considered to estimate the cost of prototype PCB assembly.
    1) The total number of components
    2) Quantity and the size of the batch
    3) The assembly technology used
    4) The required manufacturing process
    5) The number of layers of bare PCB and materials used
    6)The requirements of conformal coating

    1) Validate the design by facilitating testing of system operation and performance.
    2) Continuously modify the design until the highest-quality PCB assembly is obtained.

    The production of prototype PCB assembly mainly includes the following process steps.
    1) The manufacturing of the PCB
    2) Purchasing and inspection of components
    3) The SMT processing
    4) DIP plug-in processing
    5) Cleaning
    6) Testing of the PCBA

    1) It can ensure that the subsequent mass production process is smoother, and the related material management and personnel management can also be arranged and scheduled according to the process of prototype PCB assembly, so it can effectively eliminate the waste of human resources and waste of material resources.
    2) One of the purposes of the prototype PCB assembly is to reduce the occurrence of errors during the mass production of PCBA.

    1) The cost of prototype PCB assembly is high.
    2) More manpower and resources are needed to produce low-volume and high-mix assemblies.

    We offer both prototype SMT assembly and prototype PTH assembly.

    Yes, we are a PCB prototype and assembly supplier. Besides PCB Prototype Assembly, we also supply all kinds of PCB Prototype, including rigid PCB Prototype, flexible PCB Prototype, rigid flex PCB Prototype, HDI PCB Prototype, aluminum PCB Prototype, metal PCB Prototype, blind & buried vias PCB Prototype etc.