Electronic Manufacturing Service Company

What Does an Electronic Manufacturing Services Company Do?

If your company is an Original Equipment Manufacturer, you must have dealt with companies that provide Electronic Manufacturing Services.

Electronic manufacturing services or EMS is a term used to define companies that design, manufacture, distribute, test, and provide return and repair services for electronic components and assemblies for OEMs, Original Equipment Manufacturers.

Different companies provide different Electronics manufacturing services. Although the general set of services would include anything from the list below:

  • Cable Assembly
  • PCB Assembly
  • Electromechanical Assembly
  • Contract Design
  • Testing
  • Prototyping
  • After Production Services
  • Specific Production

Some companies work on a single niche while some provide a variety of services. In the following paragraphs, we learn about the general set of services that these companies bring to the table.

PCB Assembly

PCB, short for Printed Circuit Boards, is the most significant part of a circuit. These are flat boards that hold different electronic components altogether. EMS companies provide these boards with all the required components. They have the capability of working with different types of boards. PCBs are generally perceived as a hard and rigid type of board that is inflexible, however, some companies provide flexible boards that can bend. These kinds are used in the automotive and medical industries.

A typical EMS company would specialize in one of the two mounting methods used in the production of PCB.

  • Through-Hole Technology

As the name suggests, THT is the method of mounting components by inserting their leads into the holes of the board and soldering them on the other side of the board to keep them intact. The soldering is generally done by hand.

  • Surface Mount Technology

SMT uses the method of soldering the components to the top of the board. The components used in this method are cheaper and smaller than THT components. The production is also easy since the pick-and-place equipment can mount the pieces together easily and accurately.

Cable Assembly

Cable Assembly is not like arranging cables in equipment. It is a lot more than that. Generally, EMS providers may provide different services with Cable Assembly, that can include:

  • Harnesses
  • Control Panels
  • Mechanical Sub-Assemblies
  • Panel Wiring and Assembly
  • Harsh-Environment Cable Assemblies

Most EMS companies perform cable assemblies with hand soldering. Some companies are also capable of injection over-molding. It is a process in which one part is manufactured by using multiple materials.

Cable testing includes two tests, a functional test of the cable and a pull test. Often, several other forms of testing are also performed including automated cable testing, continuity testing, and hipot testing. Continuity test tells us whether the cable has conductivity throughout and whether the current will flow or not. Hipot testing is the opposite of it. Hipot is short for high potential. If a cable has Hipot, it will indicate that no current will flow through the cable and it has no continuity.

Electromechanical Assembly

Electromechanical assembly is another name for box builds. A company may provide different options for the selection of a material for the box build. Sometimes a company also offers a variety of other services with its box build. Services like configuration management, 3D modeling, potting, and heat shrink.

Configuration management establishes consistency in the product’s performance and look. 3D modeling of the design will help in understanding the design better and will also help in making replicas of it later when needed. Potting is the process of adding gelatinous material to the box to avoid moisture and corrosion inside the box. It also prevents shock and vibration. Heat shrink is used on the cables to keep them safe from abrasion.

Contract Design

Most of the OEM industries don’t have expert designers with them & they generally outsource their designing needs from EMS companies.

EMS companies offer to design the product from scratch to its final stage. It includes software and firmware designing, validations tests, DFX analysis, and environmental tests for compliance.


Testing is performed in order to ensure that the product is completely safe to run in the specific conditions it is built for. EMS companies run some extensive testing on the product before delivering it to their OEM contractors.

Several tests are performed for quality assurance. Agency compliance testing is done to ensure that the product is according to the standards of a certain agency. Analytical laboratory testing assures quality control & failure inspection. Automated optical inspection is done on the PCB to locate soldering defects, broken traces, and improper etching. Environmental testing is done on different conditions to test the product’s resilience to failure. Functional testing depicts the functional capabilities of the product. In-circuit testing involves probing to test each component. X-ray testing provides a thorough analysis of the assembly.


Before running the mass production of the product, companies generally make a prototype with cheaper products and run tests on it to check its durability and reliability. The prototype is made, taking into consideration the features of the actual product & it should depict most of the characteristics of it. Prototyping also helps you in making the product cost-effective. Prototyping allows you to check all the design faults without compromising your budget. The company may have to perform prototyping on several stages of the project but it’s worth it in the long run.

After production Services

Some EMS companies also include aftermarket aspects of the product in their deals with OEMs. It includes repairing, refurbishing, calibration, and upgrading of the product. This can help you with products that require future modifications to perform better. It will also help you save costs on the failure analysis.

Obsolescence is also an issue when you are manufacturing an electronic product. EMS companies also provide in-depth research on the product’s sustaining capabilities. They can recommend three things based on their analysis.

  • The part is near its end and will no longer be supported.
  • A final bulk purchase should be made before the part gets discontinued by the production company.
  • The part should be removed from the new design as its future is uncertain.

To avoid obsolescence, the vendor should provide a life-cycle analysis, so you remain informed about the failures of the product in the future.

Specific Production

EMS companies often provide information on their production capacity. We can divide them into three types according to their production volume. Low-volume companies have a small production capacity of 1 to 100 pieces. They are generally the companies that specialize in prototyping. Medium-volume companies can produce 100 to 10,000 pieces annually. High-volume vendors can produce more than 10,000 products annually.

Some companies also offer specialty production where they provide specific services according to your needs. For example, quick turn manufacturers can assemble PCB boards within 48 hours after receiving all the components.

Electronic Manufacturing Services companies have a lot to offer & they are integral for OEMs that do not have their own manufacturing plant. Many OEMs outsource their products from EMS companies. Some of the EMS companies just print boards in huge volume while others offer more complex work.

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