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Electronic Manufacturing Services (EMS) Ultimate Guide

pcbonline PCBONLINE Team Thur, Sept 28, 2023
electronic manufacturing services

For many companies and research institutes that focus on R&D and brand marketing, electronic manufacturing on their own is difficult and inefficient.

In such a case, these companies or institutes typically outsource electronics manufacturing to other companies.

The companies that deal with electronics manufacturing are electronic contract manufacturers. One-stop electronic contract manufacturing covering everything is electronic manufacturer services (EMS).

In this article, you will see a comprehensive guide to electronic manufacturing services, including what the EMS business mode is, what electronic manufacturing services cover, choosing appropriate EMS manufacturers, and the benefits of electronic manufacturing services.

Part 1: What is Electronic Manufacturing Service (EMS)

Electronic manufacturing services (EMS) is an electronic production business mode, in which a contract manufacturer provides R&D, contract manufacturing, materials, quality management, and product shipping for its client.

electronic manufacturing services

Electronic manufacturing services are an output of the production labor division in the electronics industry. It belongs to electronic contract manufacturing.

The companies working on electronic manufacturing for other companies are known as contract manufacturers. They bring out electronic manufacturing services, and the products they manufacture are under the name of their client. So does an EMS supplier.

An EMS manufacturer is developed from an ODM (original design manufacturer), and an ODM is developed from a contract manufacturer working for OEMs (original equipment manufacturers).

Electronic manufacturing requires production lines, component supply chains, and management of production employees.

An OEM pays attention to the R&D of products under their brand. For an OEM, electronic manufacturing can be a heavy burden, and they hand it up to another company that works on the production lines.

OEM contract manufacturing

The contract manufacturer working for the OEM doesn't design the product but only fabricates it according to the specifications and requirements using the credential materials provided by its clients.

Later, the contract manufacturer developed to be an ODM. It now has R&D and software-building capabilities.

In the next developing stage, the contract manufacturer has more engagements in the product creation process, including R&D, specifications, materials, hardware, software, electronic manufacturing, quality management, and shipping.

In the electronic manufacturing services business mode, the R&D engineers from the EMS supplier have close exchanges and cooperation with the R&D team of the client.

In the fabrication stage, nearly all the job is done by the EMS manufacturer. Only the supplier quality engineers (SQE) from the client have engagement with the EMS manufacturer.

The fabrication stage includes design for manufacturing (DFM), prototyping, and volume production in batches.

Part 2: What do Electronic Manufacturing Services Cover

Electronic manufacturing services cover a wide range from the R&D stage to electronics fabrication and after-sales support.


An EMS manufacturer, such as PCBONLINE, provides design to turn your initial idea into complete product designs, including hardware and software.

electronic manufacturing services PCB design

The hardware design includes schematics drawing, PCB design, BOM (bill of materials), and enclosure design.

The software design is the designing program in the IC mounted on the printed circuit board (PCB) that controls the product's critical functions.

In an EMS business mode, R&D is flexible.

You and the EMS manufacturer can cooperate in the product R&D stage.

If you only have a product concept and do not have the R&D and design capabilities, it is also okay. The EMS manufacturer PCBONLINE can complete the whole product design task meeting your expectations.

Typically, the EMS manufacturers charge for its R&D, but from PCBONLINE, you can have the product R&D for free if you order high-volume PCBA production.

Design for Manufacturing, Testing, Assembly, and Excellence (DFM, DFT, DFA, and DFX)

After the R&D stage, the engineers from the EMS manufacturer have to make sure the minimum risks happen in the electronic product fabrication stage.

The EMS manufacturer has DFM, DFT, and DFA to avoid risks in circuit design, PCB layout, PCB fabrication, and PCB assembly processes.

Besides the necessary DFM, DFT, and DFA, EMS manufacturers such as PCBONLINE provide DFX to ensure the enclosure PCBA alignment, and end product performances.

EMS design


The aim of DFM is to ensure the compatibility of the circuit design and fabrication methods. Besides, it ensures the components' functionality and EMC (electromagnetic compatibility).

With proper DFM, the PCB fabrication process can get smooth, and the fabrication cost and time are reduced.

During the DFM, the CAM (computer assistance manufacturing) engineers review the circuit board size, shape, and component positions, check the minimum line width/space and hole clearance, and make sure the EMC PCB design.

Besides, the CAM engineer at PCBONLINE can reduce the components to reduce the fabrication cost and simplify the fabrication process without function/quality sacrifice.


DFT is adding testing points to the PCB. These testing points are around the critical components for multimeter testing.

electronic manufacturing service DFT

After the PCB prototyping, the engineer from the EMS supplier uses two probes of the multimeter to touch the testing points to check conductivity.

After PCBA prototyping, the engineer from the EMS supplier still uses the multimeter to check the conductivity of the assembly.

Besides the multimeter test, there is the flying probe test, ICT (in-circuit test), x-ray inspection, automatic optical tests, functional tests, etc.

During the DFT, the engineers prepare all the test files and set up specifications of testing references.


The aim of DFA is to ensure the PCBA manufacturing process is smooth and efficient with the minimum risk of errors.

During the DFA, the CAM engineer from the EMS supplier validates the component sources, checks the corresponding component number and the component package, ensures the PCBA specifications are within the manufacturer's capabilities, and optimizes the PCB panelization.


electronic manufacturing services DFX

DFX involves many things, including product performance, quality, reliability, user experience, and cost-effectiveness.

The EMS manufacturer comprehensively considers the product design and optimizes it to improve the whole project and ensure the optimum product in its every product life cycle.


With all the designs settled down, the EMS manufacturer first fabricates a few products as samples to validate the designs and fabrication processes.

The EMS manufacturer typically fabricates 5 pieces of PCBs, buys the components needed, and cooperates with its partner factories for manufacturing of the jigs, enclosures, cables, and models.

At PCBONLINE, PCB prototypes are manufactured on the same production lines with bulk production orders, so the quality and product effect are the same as batch production.

After PCB prototyping, the EMS manufacturer mounts components on bare PCBs to make them PCB assemblies.

electronic manufacturing services prototyping

At PCBONLINE, low-volume PCB assembly happens in the same conditions as batch production to ensure the sample quality same as batch production.

After prototype PCB assembly, the EMS manufacturer PCBONLINE randomly picks up one piece of PCBA for the FAI (first article inspection), which inspects the values of components mounted on the PCBA. The EMS manufacturer will send an FAI report for the client to review.

After PCB assembly, the EMS manufacturer PCBONLINE can have value-added services to the assemblies, including functional testing, IC programming, thermal aging, and conformal coating.

Then the EMS manufacturer installs the enclosure to the PCBA to make it a finished product.

In every stage of the sampling process, the SQEs can check the electronics manufacturing quality.

PCB Fabrication

PCB, or printed circuit boards, are the motherboard connecting circuits and supporting components.

PCB fabrication is an important cycle in electronic manufacturing services.

To have the PCB manufactured, the EMS manufacturer must have the Gerber, which is a compressed file containing the graphic files and drill files. Each layer of the PCB corresponds to a graphic file.

The PCB fabrication process is custom. Generally, the fabrication steps are:

Cut laminate > inner layer circuit generation > lamination > drilling > VCP (vertical continuous plating) > outer layer circuit generation > copper plating to increase copper thickness > etching > solder mask > silkscreen printing > surface finish > profiling > ICT and flying probe test > final quality inspection.

From PCBONLINE, the PCBs include FR4 PCB, flexible PCB, ceramic PCB, high-frequency PCB, rigid-flex PCB, HDI PCB, aluminum PCB, and copper-core PCB. The PCB layers are up to 64.

You can check out the flexible PCB manufacturing process from PCBONLINE.

PCB Assembly

PCB assembly is the most important step in electronic assembly.

SMT (surface-mount technology) and PTH (through-hole assembly) are two assembly technologies for PCB assembly.

SMT assembly is suitable for high-density circuits and fine-pitch components. And it's automatic and efficient.

The SMT assembly process steps include:

Solder paste printing > SPI (solder paste inspection) > placing components > X-ray inspection > reflow soldering > AOI (automatic optical inspection).

PTH assembly is inserting through-hole components' leads through the PCB holes and soldering the leads to the hole copper. It is suitable for half-automatic.

The PTH assembly process steps include:

Inserting PTH components' leads through PCB holes > wave soldering > trimming leads > cleaning.

After the PCB assembly process, the EMS manufacturer PCBONLINE can have value-added services to the PCBA according to the application requirements.

Box-Build Assembly

Box-build assembly is installing enclosures to the PCBA to create end products.

The EMS manufacturer installs the enclosures to make the PCBAs box-builds and labels them according to the client's requirements.

After that, the EMS manufacturer has the environmental test by simulating the product's working environments to ensure the product's performance and reliability.

Components and Materials

The EMS manufacturers have cooperative factories and suppliers to provide components, PCB laminates, solder paste, jigs, and any other materials needed for electronic manufacturing services.

The EMS manufacturer PCBONLINE allows its clients to provide components and materials for electronic manufacturing, such as confidential components and military-grade Rogers laminates.

Regarding electronic components, PCBONLINE can integrate BOMs and join procurement with other large EMS factories to gain original components at a lower price. Besides, it has a worldwide supply network to source components cost-effectively with regional price differences.

Quality Management

Quality management is implemented throughout the entire electronic manufacturing service.

Quality control is a systematic work. It includes the traceability of components and materials, standard operation procedures, IC counterfeits, PCB tests, PCBA tests, end-product environmental tests, etc.

At the PCB manufacturing bases and PCB assembly factory of the EMS manufacturer PCBONLINE, the ISO 9001 quality management system has already been built and implemented.

The above is what the electronic manufacturing services cover. Besides, the EMS manufacturer is responsible for product maintenance once there are quality-related issues.

Part 3: Choose Appropriate EMS Manufacturers

Reliable electronic manufacturing services are critical to electronic product creation. Choosing appropriate EMS manufacturers is vital to your business success.

Here are some advice for you to choose appropriate EMS manufacturers:

Choose an EMS manufacturer with R&D capabilities who can involve design and provide engineering assistance,

It should provide value-added services in the post-assembly stage,

It should provide high-quality components, materials, and electronic manufacturing,

Make sure the EMS manufacturer has the quality certificates needed for your application shipping and selling,

Make sure the EMS manufacturer quotes without hidden paid items,

It would be better to choose electronic manufacturing services with cost-effectiveness.

If you have a plan for having electronic manufacturing services to make electronic products, you can work with a reliable EMS manufacturer PCBONLINE.

electronic manufacturing services provider

PCBONLINE, founded in 1999, has two large advanced PCB manufacturing bases and one EMS PCB assembly factory. It has strong R&D and fabrication capabilities to provide electronic manufacturing services for all electronic industries.

PCBONLINE has developed on-the-shelf ODM solutions, you can choose one and ask PCBONLINE to make changes to customize your products.

If you have an initial idea, PCBONLINE can design it from scratch according to your idea to make it end product.

If you have an R&D team, PCBONLINE can also be involved in your project from the early developing stage to provide one-on-one technical assistance all the way.

Here are some advantages of PCBONLINE

Whether you have an R&D department or not, PCBONLINE can provide you with electronic manufacturing services.

Regarding circuit and product design, PCBONLINE is extremely experienced in thermal dissipation design (hot runner design, the most important step in structural design).

You can have electronic manufacturing services at PCBONLINE from design to end product shipping and after-sales under one roof.

The electronic manufacturing services at PCBONLINE, from materials to end products, are certified with ISO 9001:2015, IATF 16946:2016, REACH, RoHS, UL, and IPC.

If you order low-volume EMS production, PCBONLINE can charge free for the R&D on your project.

In the past years, PCBONLINE has successfully provided electronic manufacturing services for many applications, including projectors, 4000-lumen ship lights, false eyelashes UV disinfection boxes, Bitcoin mining machines, flexible LED strips, CCS modules for electric vehicles, controllers on tanks, radar devices, automotive communication modules, etc.

If you need electronic manufacturing services for automotive, consumer, computer, communication, industrial, medical, military, and agricultural electronics, you can contact PCBONLINE by email at info@pcbonline.com to get a quote.

Part 4: Benefits of Electronic Manufacturing Services

The benefits of electronic manufacturing services are obvious—

  • Hassle-free: Electronic manufacturing services are turnkey contract manufacturing services. As a client, you only need to provide the EMS manufacturer with the initial idea or product concept and some necessary specifications, the EMS manufacturer can bring your idea into reality.
  • Focus on R&D and/or marketing: With electronic manufacturing services, you can focus on R&D and/or brand marketing. If you maintain the most technical R&D capabilities, you can create more innovations and take up the most interest. If you are good at brand marketing, you can focus on promotion with robust electronic product supplies.
  • Security of intellectual property: It is safe to work with EMS manufacturers. The EMS manufacturers will sign an NDA. Most importantly, there is a tacit industry rule that EMS manufacturers do not compete with their customers for business.
  • Flexibility: Electronic manufacturing services belong to electronic contract manufacturing and are flexible production. The EMS manufacturer produces on-demand products according to your project's needs at different stages. You can freely control all aspects of production according to your products' market demand.
  • Efficiency: Electronic manufacturing services offer great time and cost-effectiveness. The EMS manufacturers complete the electronic manufacturing on time, quality, and quantity within the delivery time. You don't need to spend time and energy on factory and supply chain management, as long as your SQE checks their completion status.
  • Conclusion

    Electronic manufacturing services are one-stop electronic contract manufacturing covering everything. EMS includes R&D, materials, PCB fabrication, PCB assembly, value-added services, box-build assembly, shipping, and after-sales maintenance. Whether you have a product design or not, as long as you have an idea and want to bring it into reality, you can have electronic manufacturing services from PCBONLINE.

    © This article is an original work of the PCBONLINE team. Please indicate the author PCBONLINE if you reprint. If the article is reproduced without permission or indicating the author's source, PCBONLINE reserves the right to investigate the infringement.
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