Do I Need An EMS Supplier In China To Manufacture My Electronic Devices?

If you’re producing large amounts of electronic devices then an EMS supplier in China could be a good option for you in comparison with an OEM or Contract Manufacturer. However, working with an EMS may not always be necessary for every manufacturing project.

Here’s what you need to know about EMS suppliers and some tips to help you make the right decision on who you need to work with…


What can an EMS supplier do for you?

EMS stands for “Electronic Manufacturing Services”. An EMS supplier in China is typically able to handle the design, manufacturing (including PCBA and final assembly), testing, and packaging of electronic products.

Typically they’ll focus on these three kinds of projects:

  1. Designing and manufacturing a PCB – You are developing a new electronic product and need the assistance from a capable supplier to take your specifications and then design the electronic circuit that will provide all the features and functionality of the product. In this case, the EMS buys the bare PCB boards, populates (aka ‘assembles’) these boards on their SMT flow line, tests the assembled PCBs, and ships them to the company that will do final assembly & testing.
  2. Further assembly as well as the PCB – The EMS assembles the PCB (as above) but you also need some additional components added to make a sub-assembly. You and the EMS may both source the components required, then they complete the assembly (such as soldering connector wires to a motor or switch, assembling the PCB into a mounting cage, then adding different components to that assembly). The EMS ships the completed pieces to another factory for the remaining manufacturing steps.
  3. Manufacturing the entire electronic device – You need an EMS to manufacture your entire product. You normally source all of the non-electrical components and send them to the EMS who takes care of PCB assembly. They then assemble the battery, motor, etc around the board, all the way to the full product enclosure, and then conduct product testing, pack the products, and, finally, ship them to you.


What should you use an EMS for?

In China, there is a general rule. Once they get a customer, manufacturers try to do more and more for that customer. They often try to replace the other manufacturers as soon as they think their activities are easy to internalize. 

And the customer has to be careful. A Chinese EMS supplier will push for project 3 (manufacturing the entire electronic device). What are the pros and cons?

The obvious advantage is the lower risk of leakage of intellectual property, as fewer suppliers see the PCBA and can access the firmware. (However, note that the firmware can usually be flashed by the final assembler, out of sight from the PCBA supplier.)

There are several drawbacks to consider, though:

  • The EMS might not be experienced at managing the supply chain for non-electronic parts (plastic, silicone, metal, etc.) and that can lead to a lot of quality issues.
  • They are often weak at final assembly, which is often semi-manual or completely manual and is quite different from the SMT & reflow processes.

So, for the customer, the choice is often as follows:

Working with 1 supplier that may not be good at a portion of the work vs. working with 2 best-in-class suppliers. 


When does it make sense to give the full manufacturing project to an EMS supplier?

In most cases, it makes sense if your volumes are in the millions of pieces.


What if my volumes are too low?

Below that level, EMS suppliers in China usually don’t pay much attention to the setup of final assembly, as they tend to focus on making the PCBAs, and that’s where it makes better sense to work with a specialized contract manufacturer that does the electronic assembly, and at the same time to qualify the right fit PCBA supplier (right quality level, right pricing, correct equipment for the size & type of board, etc).


How Sofeast can help you…

We provide the final assembly of electronic products in our Dongguan manufacturing facility. In 2020, we shipped about 1.2 million products, and 90% of them had electronic parts and a battery. We work with 3 regular PCBA suppliers, depending on the size of the boards, the quality level, etc. We do functional testing of the PCBAs in our assembly center, and we can flash the firmware if you don’t want the PCBA supplier to know about it.

If sourcing EMS plants, we can help you do sourcing and conduct necessary audits.

For sourcing, we can help you source suppliers for your products and obtain quotations. All details will be provided in an Excel overview. Then after selecting 1 or 2 suppliers we can proceed with collecting samples, negotiating prices, mass production, logistics and inspection.

For factory auditing, we can help you do an on-site evaluation of their capabilities and quality management system.  With supplier cooperation, we can typically complete the on-site work in 1 day, and issue the report to you within the next day.

Our most popular audit is IFE (Initial Factory Evaluation), for just 279 USD per factory in the main manufacturing areas of China. You can also read about our other audit services on that page.


Information we need from you to get started

First, we need you to provide us the following so we can run a quick market study to evaluate the time we will have to spend:

  • What particular product you want to source with?
  • Please share the product requirement and specifications.
  • What is the projected purchase quantity?

Our standard fee for this solution would be 34 USD per hour.


Are you working with an EMS supplier in China? What are your experiences? Please share by commenting.


Are you designing, or developing a new product that will be manufactured in China?

Sofeast has created this Importer’s Guide to New Product Manufacturing in China for entrepreneurs, hardware startups, and SMEs which gives you advance warning about the 3 most common pitfalls that can catch you out, and the best practices that the ‘large companies’ follow that YOU can adopt for a successful project.

Just hit the button below to get your copy:

An Importers Guide to New Product Manufacturing in China Guide

About Renaud Anjoran

Our founder and CEO, Renaud Anjoran, is a recognised expert in quality, reliability, and supply chain issues. He is also an ASQ-Certified ‘Quality Engineer’, ‘Reliability Engineer’, and ‘Quality Manager’, and a certified ISO 9001, 13485, and 14001 Lead Auditor.

His key experiences are in electronics, textiles, plastic injection, die casting, eyewear, furniture, oil & gas, and paint.

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