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Surface mount and electro-mechanical Assembly are two circuit board assembly procedures manufacturers commonly use. But which one is better? To find out the answer to this question, you have to first find out about both assembly procedures, how they differ from each other, and their similarities.

Surface Mount Assembly

SMT, or surface mount technology, allows manufacturers to create circuit boards. The alternative to this technology is through whole technology, which caters to a different design of circuit boards. Most circuit boards in a smartphone or any other electrical appliance nowadays include small miniature chips on top of a circuit board. Surface mount assembly is usually a semi-automated process that allows manufacturers to build circuit boards for various products.

This technique involves installing the components directly onto the surface of printed circuit boards to create electrical circuits. Every component or device is mounted on the circuit board using a solder mask. Production will be extremely fast if you use surface mount assembly. But, it also has a lot of disadvantages.

With components being incredibly miniature and circuits packed densely with multiple electrical components, testing and inspection can be problematic when assembling printed circuit boards using surface mount technology. However, with advanced technology and expertise, manufacturers can optimize testing.

Several steps are involved in producing printed surface boards utilizing surface mount assembly. The application of solder paste marks the beginning of the assembly procedure. The material that the electronic parts are installed on is this. Component placement begins once the solder mask has been applied to the board. Both physical labor and mechanical assistance are acceptable for this.

This procedure then advances to the reflow soldering stage, when all the extra solder is removed. After completing these procedures, the printed circuit boards surface mount assembly process is finished, and you may start the testing process.

Electromechanical Assembly

Machines and other automatic driving systems are crucial to electro-mechanical Assembly. Electronic items are made up of several components and connections. These parts may also include resistors, conductors, and capacitors—devices that modify the direction of electrical flow.


Since it creates a path for electricity to go to all components, the circuit board assembly is the engine behind most electronic devices. Components can mount on circuit boards in two different methods. And the through-hole method is the primary focus of most electro-mechanical assembly procedures.

SMT vs. Electro-mechanical assembly

The mounting process is the electro-mechanical assembly’s main difference when you compare it to surface mount technology. The electro-mechanical assembly uses through-hole technology. You can use both of these methods in a printed circuit board.

In the through-hole method, there are pre-drilled holes in the circuit board, and you have to push the components through them and solder them to secure them in place. On large-scale productions that use through-hole components, manufacturers use wave soldering.

This is where a circuit board moves through a solder wave tank and applies a strong bond to the board—a strong bond results in component placements that can withstand severe environmental stress and high heat.

Through-hole components are easier to change and replace for testing and prototyping applications that require manual adjustments. In the surface mount method, thousands of tiny components place directly on the PCB with the help of a flux paste. This reflow soldering method does not require pre-drilled holes, and components are typically smaller.

The Verdict

Electro-mechanical assembly can be costly and time-consuming, but it is reliable and durable for applications that undergo high stress. SMT assembly is ten times faster and more economical. On the other hand, SMT components can fit inside a circuit board at a higher volume. Overall, each technology can be favorable depending on the electrical appliance.