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What's Going on in the Electronic Assembly? Answer's Here


Thur, Oct 22, 2020

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In general, an electronic assembly showcases a number of electronic components (integrated circuits or elements) that are connected together in order to perform one or several specific functions. Components on the board are connected and they can be replaced or disassembled. It is capable of being disassembled and replaced as an entity. 

Electronic assembly or also called the printed circuit board (PCB) assembly finds application in almost every piece of technology that surrounds us in our daily lives. For instance, an end design of an electronic assembly is used in your smartphone, in your pocket, or on any desktop computer. Most people can easily recognize a printed circuit board when they see it. In this article, we will review the whole assembly process, so make sure to stick around.

Part 1: The Process of the Electronic Assembly

Electronic assembly is the process of mounting electronic devices on a printed circuit board. Even the most advanced board will not be able to deliver functionality unless it has electronic components mounted on it. The mounted circuit boards are called assembled PCBs.

There are several main stages in the electronic or PCB assembly. The process includes inserting solder paste onto the board, component placement, test, and inspection. These four stages of electronic assembly are the main stages required for the production of a high-quality entity. They have to be executed one after another in a specific order and the leaders in that field of work are using the latest surface mount technology that we will review on its own later in this article. First, we will review the four main steps in electronic assembly to a printed circuit board.

PCB Fabrication

When the EMS manufacturer PCBONLINE receives your Gerber (a PCB design file), their CAM engineer will check it and contact you to discuss the details of your requirements.

PCB boards

When you figure out everything, the PCB fabrication starts. No one can guarantee that an advanced PCB design is okay for bulky production, so we will manufacture the prototypes and test them. When the prototypes work, then we start bulky fabrication.

Component Sourcing

While PCB fabrication, the EMS manufacturer PCBONLINE also sources the electronic components for assembly.

Generally, our clients will send the confidential components and active components to us. Because they want to control the key components' source.

We usually provide the basic components. If there are custom components, we can also contact our local factory to fabricate them.

PCB Assembly (SMT + THT)

PCB assembly

Now, when the components are added to the board, the next step of the electronic assembly is the production process on the soldering machine. As we already mentioned, the wave assembly processes do not pass through the soldering machine, this process is not preferred for surface mount components. However, in these cases, the solder is provided by the wave soldering machine, but reflow soldering is the method that most assemblers go with these days.

solder paste


This is one of the most important objectives in the process. It is extremely important for PCB manufacturers to test their entities after the electronic assembly process.

The PCB assembly includes solder paste inspection, X-ray, AOI, and thermal aging testing. After the assembly, we just need to put the PCBAs on a jig for a power-on self-test. If the PCBA functions, it works.


During and after the process of electronic assembly, the input and output of the printed circuit board are monitored in order to ensure the rightful execution of its duties. Many failures and malfunctions are detected via this method, and the issues are resolved in the early stages, preventing further complications. The perfect place for a feedback test is right after the soldering process because this is the part in which most of the issues are occurring. This way the defect is detected quickly and resolved before the next step of the assembly process.

Have in mind that the process of the electronic assembly is simplified as an overview in this article and there are a lot more details that are taken under consideration by manufacturers when assembling printed circuit boards. High-end developers are using optimized methods in which the cases of failure are minimal and the quality is a top priority.

Part 2: Techniques We Use in Electronic Assembly

The process of electronic or PCB assembly includes several different approaches, including SMT, THT, and DIP. We will take a look at each of them with a basic overview.

SMT - Surface-Mount Technology

As we discussed, SMT, surface-mount technology is a method in which the electrical components are mounted onto the surface of the printed circuit board (PCB). The component itself is mounted in an action referred to as a surface-mount device (SMD) with an SMT stencil. SMT is the latest and widely used electronic assembly approach because complete automatization with this process is possible. This remarkable technology reduces the cost and increases the quality of the assembly, which makes it the preferred method over Through-Hole Technology (THT). The electronic components of SMT are often smaller than its through-hole competitors because in most cases they don’t have leads and even if they have, they are smaller.


THT - Through-Hole Technology

THT or DIP is another mounting scheme, used mainly for electronic components. This method is using leads on the components that are inserted through the holes, and pre-drilled on the printed circuit board. The pads on the opposite side are soldered either by insertion mount machines or by hand. The innovation of the through-hole technology replaces many earlier electronic assembly approaches. Invented in the 1950s, slowly grew until the 1980s when it became the main process that high-profile manufacturers are using. Unfortunately, this method was later replaced with the innovation of surface mount technology. However, many manufacturers still use this technology for projects demanding through-hole methods.

Part 3: Best Electronic Assembly Services Are Here

If you are looking for reliable PCB manufacturing with high standards and quality of work, PCBONLINE is a global electronic group with 20+ years of experience in PCB fabrication, assembly, and EMS solutions. They have a world-leading quality management system, focusing on advanced PCB manufacturing and assembly. This is the best physical and online retailer with the lowest prices on the market.

Electronics manufacturer PCBONLINE

With their years of experience, PCBONLINE has become a large technology-oriented team with 60+ software developers, 45+ member hardware department, and 500+ senior technical engineers. They have fully automatic intelligent equipment and an independent developing team, constantly investing in R&D and technical training.

Their innovative workflow includes IMS intelligent manufacturing system, SCM in-time delivery, and traceability to ensure product quality and lean manufacturing. If you are interested, they provide an online quote option for free, so if you have any concerns or inquiries, make sure to get a quote on their website.


High-end PCB assembly manufacturer delivering customizable solutions and good quality. Here are some of the efficient options when working with PCBONLINE.

  • Low Volume PCB Assembly - One of the most advanced solutions provided by PCBONLINE. It refers to 5 to 2,000 pieces that require soldering parts. It is one quick and reliable way with electronic sample production and testing. This is an optimal solution with a quick turnaround and a small volume.
  • High Volume PCB Assembly - You can have both, consigned high-volume PCB assembly and turnkey service. If the demand is more than 10,000 pieces of PCB to be assembled then this is the workaround for you. It includes soldering components, SMT stencils, AOI inspection, DFT checking, and more.
  • Turnkey PCB Assembly - This is a process that enables you to complete assembly and manufacturing in one place. If time is a valuable resource to you, the turnkey PCB assembly is the optimal solution, as you don’t need to worry about anything. One-stop PCB service is designed to provide reliable components, full assembly, and delivery packaging. The turnkey PCB assembly involves all possible steps that certain projects might require. Starting from the fabrication to the assembly process passing through all necessary details covering every aspect and delivering high standards.

Part 4: What Does an Electronic Assembler Do?

The electronic assembler has a wide range of meanings depending on your duties. You could be assembling electronic parts such as circuit boards, and mounting them into larger assemblies or casings. Electronic assemblers also ensure that the installation and soldering are properly performed as well as electric wiring. As an electronic assembler, you might be even troubleshooting equipment in case it is returned to service or failed.

With the innovation of electronic components, they have become smaller and smaller. Most of the processes are ones with automatization equipment that require a human touch to perform as per the requirements. As an electronic assembler, you will need to have excellent knowledge of the equipment responsible for the major electronic assembly. The assembler’s duties are depending on the field of work and focus area. One thing is for certain, electronic assemblers have extreme dedication and precision towards outstanding quality in production.

Bottom Line

In general, when most people hear of electronic assembly putten this way, they are referring to a collection of electronic parts assembled together into a larger unit. As we already discussed in this article electronic assembly would be printed circuit board and the implementation of electronic components via technical processes with substages. Electronic Manufacturing Services - (EMS) is another way that we could describe electronic assembly including design, development, test, distribution, and repair services.

Keep in mind that the process is far more complicated than in this overview. There are many details and complex issues that are occurring during the process of electronic assembly, which suppliers are optimizing every day towards a lower volume of failure. If this article was interesting to you and you want to find out more about electronic assembly, make sure to check the "What Do You Need to Know About Turnkey PCB Assembly and EMS?"