What is OEM PCB Assembly - Process and Benefits

OEM means original equipment manufacturer. If a company designs and manufactures electronic products and owns the brand of the manufactured products, it is an OEM.

Shenzhen Thriver Digital Tech Co., Ltd. supply professional and honest service.

OEMs have the product brand and design and produce their electronic products. However, they typically outsource the manufacturing and assembly of printed circuit boards (PCB) and enclosures to an ECM (electronic contract manufacturer), usually, an EMS (electronic manufacturing services) provider.

OEM PCB assembly refers to PCB manufacturing and assembly for an OEM who designs and sells electronic products.

In this article, you'll understand the working mode and process of OEM PCB assembly, and what benefits it can bring out to OEM companies.

Part 1: What is OEM PCB Assembly

OEM PCB assembly involves outsourcing the manufacturing and assembly of the PCBs to a specialized EMS provider.

In OEM PCB assembly, the OEM company typically draws the schematics, selects the components, designs the PCB, and specifies the requirements for the PCB assembly.

And then the OEM entrusts the PCB manufacturing and assembly process, including component sourcing, to an electronic contract manufacturer, typically an EMS provider.

In the OEM PCB assembly working mode, the OEM company and EMS manufacturer collaborate tightly to bring electronic products to market.

The OEM creates products that are branded and sold under their brand, but they rely on external manufacturing partners, such as EMS providers to handle the actual PCB fabrication and assembly.

The EMS manufacturer provides a wide range of services, including PCB fabrication, PCB assembly, component sourcing, value-added services, testing in the post-assembly stage, box-build assembly, and logistics.

If you choose an EMS provider with R&D capability, such as PCBONLINE, you can receive co-R&D in early development. PCBONLINE can help reduce the fabrication price of the PCB assembly project with an optimized PCB design and substitute components at lower prices.

Overall, in the context of OEM PCB assembly, the OEM company focuses on design and marketing, while the EMS provider handles the electronic manufacturing process, especially PCB fabrication and assembly.

Part 2: OEM PCB Assembly Process

According to the requirements of an OEM, the OEM PCB assembly process involves PCB manufacturing, PCB assembly, and a series of post-assembly services and testing.

Here's the OEM PCB assembly process:

• Design and Documentation

The OEM provides the necessary Gerber, drill file, BOM (bill of materials), and pick-and-place file. If the PCBA project needs IC programming, the OEM also needs to provide an IC programming file.

The EMS provider checks the design files and documentation to understand the PCB specifications, component placement, and other fabrication requirements.

And the CAM and PCBA engineers from the EMS company can complete the engineering, such as the design for manufacturing (DFM), testing (DFT), assembly (DFA), and excellence (DFX).

• PCB Fabrication

The PCB fabrication process varies according to different PCB materials, layers, holes, circuitry complexity, line width/space, and components. The general process of multilayer PCBs is below.

The EMS provider cleans and cuts the laminate materials to be the required size of the PCB panel. The following PCB fabrication steps include inner layer circuit generation (circuit imaging and etching) > lamination > drilling > PCB hole copper plating > outer layer circuit generation > circuit image plating and outer layer etching > automatic optical inspection (AOI) > solder mask and silkscreen > surface finish > profiling > electrical test and final quality control > packaging and delivery.

During PCB fabrication, the SMT stencils for PCB assembly are also manufactured. And the component procurement also starts when the PCB design is put in fabrication.

• Component Procurement

Component procurement is called component sourcing. The EMS provider purchases all the active and passive components specified in the BOM and ensures the quality.

The component price takes the largest portion of the cost and turn-around time of the OEM PCB assembly.

From the EMS provider PCBONLINE, you can have cheaper options with substitute components made in China for some parts. Relying on rich experience and expertise, PCBONLINE ensures the substitute components they suggest have the same functions and quality.

Besides, relying on the EMS PCBA factory that has run for a dozen years, PCBONLINE can take part in co-procurement from the original component factory with other large EMS to reduce the component cost.

• SMT Assembly

Surface Mount Technology (SMT) refers to placing components onto the PCB pads. The SMT components have short pins and are called surface-mount devices (SMD).

SMT assembly is automatic from PCBONLINE.

On an SMT line, a feeder sends the PCBs one by one into a solder paste printing machine, where a scraper presses the solder paste through the holes of an SMT stencil to "print" on the PCB pads.

Then the PCB goes through a solder paste inspection (SPI) machine to ensure the solder paste on the PCB pads is qualified for soldering.

Next, the PCB goes into two automatic surface-mount machines - high-speed and functional SMT machines, where the smaller and larger SMDs are placed on the PCB pads according to the pick-and-place file from the OEM.

If there's any BGA in the SMDs, the PCBA goes through an x-ray inspection to ensure the solder balls are qualified for soldering.

Then, the PCBA goes into a reflow soldering oven to preheat and bake so that the solder and PCB pads form intermetallic compounds (IMC). From PCBONLINE, the reflow ovens have 10 temperature zones and can adjust temperatures for all types of complex PCB assembly.

Last, the PCBA goes past an AOI machine to ensure no surface defects happen, including bridges, tombstones, solder voids, missing components, etc.

• THT Assembly

If the PCB design has through holes, after SMT assembly, the EMS provider has THT assembly to the assemblies.

THT refers to through-hole technology. The THT components have long leads, and the EMS provider inserts the leads through the PCB holes to the opposite side.

Depending on the volume of PCB assembly, THT assembly can be manual or automatic.

If it is a high-volume PCB assembly, the EMS provider such as PCBONLINE can design and make jigs to insert the leads of THT components. If it is a low-volume PCB assembly, the EMS provider manually inserts the leads.

Then the EMS provider puts the PCBA into a jig for wave soldering. The jig covers the PCBA and leaves only the THT leads and through holes exposed for tin soldering.

The assemblies are one-by-one sent into the wave soldering oven. They are preheated and sprayed with flux first.

In the wave soldering oven, there's the liquid tin that flows in waves. The areas that need soldering contact the tin waves at a specific angle for a specific time duration.

And then the EMS provider trims the leads to be 1mm to 2mm long and visually inspects the PCBA.

• Testing in the Post-Assembly Stage

At the EMS provider PCBONLINE, the OEM PCB assembly services don't come to an end once the PCB assembly is complete.

All PCBA testing and inspections are available from PCBONLINE, such as functional PCBA testing, thermal aging, tension test, metallographic inspection, hand sweat test, environment test, and salt spray test.

• PCBA Value-Added Services

In the post-assembly stage, IC programming, conformal coating, and PCBA box-build assembly services are available from PCBONLINE.

Box-build assembly means installing cables, enclosures, and other components required by the OEM onto the PCBA to make it a finished product.

The EMS provider then packages and ships the final products to the OEM.

Part 3: Benefits of OEM PCB Assembly

OEM PCB assembly offers several benefits for the OEM, including flexibility of production, cost saving, quality control, professionalism, and enabling the OEM to focus on core competencies.

Part 4: Reliable OEM PCB Assembly Manufacturer

PCBONLINE is a one-stop OEM PCB assembly manufacturer for middle and high-end applications, including industrial, automotive, communication, computing, aerospace, defense, and consumer electronics.

PCBONLINE is an EMS source factory manufacturer. It is a private-owned company founded in . So far, it has two large advanced PCB manufacturing bases in Jiangsu and Jiangxi and one EMS PCB assembly factory in Shenzhen.

Below are some reasons for you to choose PCBONLINE for OEM PCB assembly:

Up till now, PCBONLINE has had many successful OEM PCB assembly cases for clients around the world, such as automotive lights, servers, COB LEDs, industrial controllers, false eyelash UV disinfection boxes, communication interfaces, etc. If you have any OEM PCB assembly needs, feel free to send your inquiry to .

Conclusion

OEM PCB assembly is a working mode where an OEM entrusts the PCB manufacturing and assembly to an EMS manufacturer. It releases the OEM from the burden of electronics manufacturing. If you need OEM PCB assembly for the production of electronic products, choose a source factory manufacturer such as PCBONLINE, which is the most affordable and reliable.

What is PCBA? PCBA stands for Printed Circuit Board Assembly. It refers to the process of assembling electronic components onto a printed circuit board (PCB) to create a functional circuit. The main components involved in PCBA are:

· PCB: The base substrate, typically made of materials like FR4 or flexible PCB, serves as the foundation for mounting electronic components.

· Electronic Components: These include resistors, capacitors, integrated circuits (ICs), transistors, and connectors.

· Soldering: A process that ensures electrical connections between components and the PCB, using techniques such as wave soldering, reflow soldering, and hand soldering.

PCBA plays a crucial role in modern electronics, enabling everything from simple consumer electronics like mobile phones and laptops, to advanced industrial equipment, automotive systems, and HDI (High-Density Interconnect) PCBs.

What is OEM?

OEM stands for Original Equipment Manufacturer. In the context of PCBA, OEM refers to companies that manufacture products based on the designs and specifications provided by another company. In this case, the OEM typically manufactures the PCB boards and assembles them with electronic components to produce a finished product. OEMs in the electronics sector offer custom solutions that cater to specific client needs.

The role of OEM in the electronics manufacturing supply chain is pivotal, as OEMs handle the design, sourcing, assembly, and quality control of PCBs, offering cost-effective solutions and quick turnaround times.

What is PCBA OEM?

PCBA OEM services provide a complete solution for companies looking to outsource their PCB assembly. This includes everything from designing the PCB layout, sourcing the components, manufacturing the multi-layer PCB boards, and finally assembling the components into a fully functional circuit board. Shenzhen PCBA OEM companies, renowned for their manufacturing expertise, are leading the way in offering OEM customized PCBA boards that meet international standards.

PCBA OEM Process

Step 1: Design and Specification In the first step, customers provide the design files (such as Gerber files, BOM (Bill of Materials), and specifications for components, layout, and manufacturing standards). The OEM then validates the design for manufacturability and may recommend modifications to optimize the process. The PCB layout and component placement must be carefully planned to ensure the board is functional and meets design requirements.

For complex designs, such as HDI PCBA or flexible PCBs, the design process becomes more intricate, requiring specialized knowledge in PCB routing and layer stacking.

Step 2: Material Sourcing Once the design is validated, the next step is sourcing the required materials. This involves procuring:

· FR4 (common for standard PCBs)

· Multilayer PCB boards (for complex and high-density designs)

· Flexible PCB materials (for applications requiring flexibility, such as wearables or mobile devices)

· Electronic components such as resistors, capacitors, and ICs.

Choosing reliable suppliers is crucial to ensure quality and reduce the risk of component failures. Shenzhen PCBA OEM manufacturers are well-known for their strong relationships with global suppliers and high standards of quality assurance.

Step 3: PCB Manufacturing The PCB manufacturing process includes etching, layering, and surface finish to create the base board. The process varies depending on the type of PCB:

· Single-sided: Components are mounted only on one side.

· Double-sided: Components can be mounted on both sides of the board.

· Multilayer: More than two layers are used, with internal layers that allow for more complex circuit designs.

For high-density designs, HDI PCBs are manufactured using fine lines and micro vias, ideal for high-performance applications like smartphones and computing devices.

Step 4: Component Sourcing & Mounting Components are sourced, and the pick-and-place machine is used to position the components accurately on the PCB. Surface Mount Technology (SMT) and Through-Hole Technology (THT) are used for mounting components. Automated soldering methods like reflow soldering are commonly used for surface-mount components, while wave soldering is typically used for through-hole components.

Shenzhen-based PCBA manufacturers often specialize in flexible PCBs, which require specialized assembly techniques to ensure reliability in compact designs.

Step 5: Testing and Quality Control After assembly, testing is critical to ensure that the PCBA functions as intended. Different types of tests include:

· In-circuit testing (ICT): Ensures all components are correctly placed and soldered.

· Automated Optical Inspection (AOI): Identifies visual defects such as soldering issues or component misplacement.

· Functional testing: Verifies the functionality of the assembled board.

PCBA OEM companies ensure that all boards meet the necessary quality standards such as RoHS, CE, and UL certifications, guaranteeing compliance with global regulations.

If you are looking for more details, kindly visit OEM PCBA Service.

Step 6: Final Assembly and Packaging Once testing is complete, the boards are assembled into their final product (encapsulation, connectors, enclosures). Packaging is done carefully to protect the boards from ESD (electrostatic discharge) and physical damage during transportation. Proper packaging is especially important for flexible PCBs and multi-layer PCB boards, which are more sensitive than standard boards.

Types of PCBA OEM Services

Full Turnkey PCBA:

A full turnkey PCBA service means the OEM handles the entire process, from designing the OEM PCBA to sourcing materials and components, assembling, testing, and delivering the final product. This is ideal for clients looking for a one-stop solution to streamline their production.

Partial Turnkey PCBA:

In a partial turnkey PCBA service, the customer supplies some components (e.g., specific ICs or connectors), while the OEM handles the rest. This option provides flexibility and can be more cost-effective for customers who have specific component requirements.

Prototype and Low-Volume Production:

OEMs also offer services for prototyping and low-volume production runs, allowing companies to test their designs before scaling up to mass production. This is especially important for companies developing new products or seeking validation for their OEM customized PCBA boards.

High-Volume Production:

For clients needing large quantities, high-volume production ensures that the PCBA OEM has the capacity and equipment to efficiently manufacture and assemble thousands of boards. With automated assembly lines and advanced SMT technology, these services cater to industries like consumer electronics, automotive, and telecommunications.

Testing and Post-Production Support:

Even after the assembly is completed, PCBA OEM providers offer post-production support like design validation, rework services, and after-sales testing to ensure the reliability and longevity of the product.

Key Components in PCBA OEM

Printed Circuit Boards (PCBs)

Single-sided PCBs: These are the simplest type of PCBs, with components mounted on only one side of the board. They are used in low-complexity applications where space is not a primary concern.

Double-sided PCBs: These PCBs have components mounted on both sides, allowing for a more compact design and increased functionality. They are commonly used in consumer electronics and industrial applications.

Multilayer PCBs: These PCBs consist of multiple layers of conductive material, enabling higher component density and smaller form factors. Multilayer PCB boards are commonly used in high-performance devices like smartphones, laptops, and networking equipment.

Electronic Components

Passive Components:

Resistors: These are components that limit the flow of electrical current. They are essential in controlling voltage levels in circuits.

Capacitors: Used for storing electrical energy, capacitors are crucial for smoothing out voltage fluctuations in circuits and in filtering applications.

Inductors: These are used in power supplies and signal filtering, where they store energy in a magnetic field when electrical current passes through them.

Active Components:

Integrated Circuits (ICs): These are the "brains" of many electronic devices. ICs contain multiple transistors and other components in a small, integrated form.

Transistors: Acting as switches or amplifiers, transistors are fundamental to modern electronics and are used in signal processing, power regulation, and logic circuits.

Sensors: These detect physical quantities like temperature, pressure, or motion and convert them into electrical signals that can be processed by other parts of the circuit.

Assembly Methods

Surface-Mount Technology (SMT):

SMT is the most commonly used method for assembling components on PCBs, especially for OEM PCBA services. It involves mounting components directly onto the surface of the PCB using automated machines. SMT allows for higher component density and more compact designs, which is crucial in consumer electronics and mobile devices.

Through-Hole Technology (THT):

THT involves inserting components with leads through holes in the PCB and soldering them on the other side. It is mainly used for larger components that require more robust mechanical connections, such as connectors, switches, and heavy-duty resistors.

Mixed Technology:

In some cases, a combination of SMT and THT is used. This is known as mixed technology and is often required when a design involves components that are best suited for each technology.

Soldering Techniques

Wave Soldering:

Wave soldering is typically used for THT components. The PCB is passed over a wave of molten solder that coats the exposed leads of the components. This method is efficient for mass production and ensures a reliable bond for components.

Reflow Soldering:

Reflow soldering is used in SMT assembly. The PCB with surface-mounted components is passed through a reflow oven, where the solder paste melts and forms solid solder joints between the components and the PCB. This method is ideal for high-density boards with small components.

Hand Soldering:

While not as automated as wave or reflow soldering, hand soldering is still used for small-volume runs, repairs, and rework. It requires skilled technicians to manually apply solder to specific points on the PCB.

Testing Equipment

Automated Optical Inspection (AOI):

AOI systems are used to detect defects in PCB assembly by capturing high-resolution images of the board. The system compares the images with the design files to identify missing or misplaced components, poor solder joints, and other assembly errors.

X-ray Inspection:

X-ray inspection is used for inspecting Ball Grid Array (BGA) and other complex assemblies. It enables manufacturers to see through the PCB and examine solder joints beneath the components, which are not visible with AOI alone.

In-Circuit Testing (ICT):

ICT is used to test each individual component on the PCB to ensure it is correctly placed and functioning. It checks for issues such as open circuits, shorts, and incorrect component values.

Functional Testing and Validation:

This testing method involves powering up the assembled board and testing its overall functionality. The board is subjected to real-world conditions to ensure it performs as expected under normal operating conditions.

Benefits of PCBA OEM Services

Cost Efficiency

Reduced Manufacturing Overhead: By outsourcing the PCB assembly process, companies can significantly reduce overhead costs associated with in-house production, including equipment, labor, and facility maintenance.

Economies of Scale: PCBA OEM services benefit from economies of scale, which lower the unit cost for high-volume production. China OEM manufacturers, for example, are known for their ability to produce large quantities at competitive prices.

Access to Lower-Cost Component Sourcing: OEMs typically have strong supplier relationships that allow them to procure components at lower costs, passing those savings on to customers.

Time-to-Market Reduction

Faster Prototyping and Testing: Shenzhen PCBA OEM providers(like PCBasic) specialize in rapid prototyping and testing services, helping clients bring their products to market faster.

Streamlined Production Process: By handling all aspects of the PCBA process—from OEM PCBA designing to assembly and testing—OEM partners ensure a more efficient and seamless production timeline.

Quicker Iterations and Revisions: When revisions are needed, the flexibility of OEMs to adapt quickly allows for faster iteration cycles and faster time-to-market for new products.

Expertise and Quality Assurance

Access to Specialized Manufacturing Expertise: PCBA OEM providers bring years of specialized experience in designing, sourcing, assembling, and testing PCBs, ensuring a high level of expertise is applied to your project.

High-Quality Control Standards: PCBA manufacturers are often certified under international standards such as ISO , ensuring that quality control processes meet rigorous global standards.

Compliance with International Standards: Many PCBA OEM partners adhere to RoHS, CE, and UL compliance, ensuring that products meet the necessary environmental and safety regulations.

Flexibility and Customization

Tailored Solutions: OEM customized PCBA boards are designed to meet specific requirements, whether for flexible PCBs, multilayer PCBs, or HDI PCBA.

Ability to Handle Small to Large Volume Production Runs: From prototyping small batches to handling large-scale production, OEMs provide flexibility for businesses of all sizes.

Focus on Core Competencies

R&D, Marketing, and Branding: By outsourcing manufacturing to PCBA OEM, customers can focus on their core competencies such as research and development, marketing, and product branding.

Offloading Manufacturing Responsibilities: Businesses can delegate complex manufacturing tasks to experienced OEM partners, reducing internal workload and improving efficiency.

Choosing the Right PCBA OEM Partner

Selecting the right PCBA OEM partner is a critical decision that can directly impact the success of your product development and manufacturing. Here are key factors to consider when evaluating a potential partner for your OEM PCBA needs:

Manufacturing Capacity, Equipment, and Technology

A reputable PCBA OEM partner should have a robust manufacturing capacity that aligns with your production requirements, whether you're looking for prototype assembly, low-volume production, or high-volume manufacturing.

Assess the equipment and technology they employ. Do they have the necessary SMT (Surface Mount Technology) lines, THT (Through-Hole Technology) machines, and pick-and-place machines for precise component placement? For complex designs such as HDI PCBA or flexible PCBs, it's essential that the OEM has experience and advanced capabilities in handling these technologies.

Advanced technology like automated optical inspection (AOI), in-circuit testing (ICT), and automated soldering systems is crucial for ensuring high-quality PCBs with minimal defects.

Experience in Handling Specific Types of PCBs and Components

Not all PCBA OEMs are equipped to handle all types of PCBs. If you're working with multi-layer PCB boards, flexible PCBs, or complex HDI PCBs, ensure that your potential partner has experience with these specific types.

Evaluate their track record with specific electronic components—whether they are capable of sourcing high-quality components and assembling advanced components like microchips, power management ICs, or connectors that may be part of your design.

Quality Certifications and Standards

ISO  is a standard for quality management systems that indicates an OEM’s commitment to delivering products that meet customer requirements consistently. Look for ISO  certification to ensure your OEM partner follows structured quality control procedures.

ISO  certification shows that the OEM has implemented environmentally responsible practices, which is increasingly important as businesses and consumers demand sustainability in manufacturing.

RoHS (Restriction of Hazardous Substances) certification ensures that the PCBA complies with environmental standards by limiting the use of certain hazardous materials in the manufacturing process. If your product will be sold in the European market or used in industries with strict regulatory requirements, RoHS compliance is essential.

CE Marking indicates that the PCBA complies with European Union health, safety, and environmental protection standards.

UL Certification is necessary for ensuring the safety and reliability of your OEM PCBA in critical applications, particularly in industries like automotive, medical devices, and telecommunications.

Customer Support and Communication

Clear communication is key to a successful partnership with your PCBA OEM. Ensure they offer project management support throughout the process, from the initial PCBA designing phase to final production.

A good partner should be responsive, proactive, and able to provide updates on the status of the project, lead times, and any potential issues that may arise.

After the production process, the right PCBA OEM partner should be able to provide comprehensive after-sales services. This includes technical assistance, troubleshooting, and the ability to manage repairs and rework if necessary.

Evaluate the OEM's ability to provide long-term support, as your product may require modifications, updates, or maintenance over its lifecycle.

Cost vs. Quality Balance

One of the main considerations when choosing a PCBA OEM is balancing cost and quality. While it's tempting to go for the lowest cost option, it’s important to remember that quality issues such as faulty assembly or poor component sourcing can lead to delays, higher repair costs, and even reputational damage.

Assess the long-term value: A reliable OEM PCBA partner may offer a slightly higher upfront cost but can reduce costs in the long run through improved reliability, fewer defects, and faster time to market.

Conclusion

Choosing the right PCBA OEM partner is one of the most important steps in the successful development of your electronic products. The key factors in making this decision include:

· Evaluating the OEM's manufacturing capabilities and technology to ensure they can handle your specific PCB requirements.

· Verifying quality certifications like ISO , RoHS, and UL, to ensure the PCB meets industry standards.

· Assessing customer support and communication efficiency to ensure smooth project management and after-sales service.

· Balancing cost and quality to get the best value for your investment.

A reliable PCBA OEM partner can be a game-changer for your business, enabling faster time-to-market, better product quality, and lower overall costs. They can provide the OEM customized PCBA boards you need while offering the necessary expertise in multi-layer PCB boards, flexible PCBs, and other advanced technologies like HDI PCBA.

In conclusion, the future of PCBA OEM services is bright, offering immense potential for companies that partner with the right OEM to bring innovative products to life. Whether you're looking for high-quality Shenzhen PCBA OEM solutions or need specific HDI PCBA expertise, choosing the right partner can make all the difference in delivering successful, market-leading electronic products.

The company is the world’s best PCB Electronic Board Assembly supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.