Last Updated on October 22, 2023 by Kevin Chen
Image source Freepik
When it comes to the printed circuit board assembly process (PCBA), one of the activities that make up the process entails component placement. It entails putting electronic components on the board. These are the components that will perform various functions on the PCB.
There are two main technologies or methodologies used for placing components on printed circuit boards. These are surface mount technology (SMT) and through-hole (TH). Each of these methods comes with advantages and disadvantages. The focus of this article will be on the surface mount technology. We are going to discuss the main advantages that come with this method when used in the PCBA manufacturing process.
Overview of surface mount technology
As the name suggests, surface mount technology is characterized by mounting electronic components on the surface of a printed circuit board (PCB). This is unlike through-hole technology where components are inserted through holes that are drilled on the printed board. Once the components are mounted on the board, they are soldered through the sides of the printed board so that they can attain much-needed stability.
The idea of using SMT technology on PCBA starts at the stage of manufacturing the electronic components. They must be designed to be suitable for this type of component placement. For example, the terminals of the components should be made of metals and also be flat, making it easier to be connected through the sides.
Beyond the components, the physical design and features of the printed circuit board should also allow this method of component mounting. For example, the top surface of the printed board should have land pads on which the components will be placed. Usually, these pads exist in a defined pattern that will determine the flow of electrons on the circuit board.
How are electronic components placed on the PCB? In the past, component placement in the surface mount technology was done manually. But thanks to the technological advancement, the whole process can be done automatically. Some specialized machines and systems are fully capable of doing this job. The placement should be done with the highest levels of precision to ensure that the PCB will perform in the desired way.
After the component, the next process is soldering. Electronic components must be well-soldered on the printed circuit board so that they can remain stable and operational for long periods.
Due to the sensitivity of the PCB and the small size of the components, advanced soldering procedures are used. One such method is the reflow soldering process. It minimizes the impact of heat and physical abrasions on the surface of the printed circuit board.
After everything is done, the results of the surface mount technology have to undergo vigorous tests and quality assurance procedures. PCBA manufacturers are required to ensure that the mounting is properly done and the printed circuit board will be able to function perfectly when embedded in electronic devices and appliances.
Benefits of surface mount technology in PCBA
Now let’s look at some of the key advantages of using surface mount technology in the printed circuit board assembly process.
Miniaturization has been a major topic in the world of electronic components. It emphasizes the building of tiny electronic devices and appliances. Miniaturization starts with the size of the printed circuit boards. Surface mount technology makes it possible to design and build small or miniaturized printed circuit boards.
The most basic way in which SMT permits miniaturization is it allows components to be placed close to each other. The overall impact is the board will cover a very small surface area. This will be of great benefit when the PCB design is finally implemented on the final electric device. Keep in mind that miniaturization is among the main drivers of modern electronic devices and appliances. They are small, lighter, and portable.
Time is a vital component in any production environment. The same applies to the PCBA process. Surface mount technology has proven to be a way faster technique for assembling PCB components than the through-hole method of assembling printed circuit boards.
Various operational parameters make SMT faster. First, you don’t have to drill the board, a practice that should be done in the through-hole method of PCBA. All you need is to identify the perfect positions on the board and from there you can proceed to place your electronic components. The importance of SMT comes in handy when you want to do mass production of printed circuit boards within tight deadlines.
Easy to customize
Surface mount technology makes it easy to customize or modify component placement on the printed circuit board. This is possible mainly because of the selective solder process that is used in the component placement. In this method, the application of solder on each component is customized to meet specific needs.
One advantage of the selective solder process is it minimizes the thermal stress on the PCB. Also, the fact that selective solder doubles as a glue means you can solder a component while at the same time etching it permanently onto the printed circuit board.
As a method of PCBA manufacturing, surface mount technology guarantees the stability of the components on the printed circuit board. Stability in this context refers to the ability of the electronic components to remain intact in their original positions. Reflow solder and as well as selective solders are some of the factors that
With high stability, it means that the PCBA modules will easily suppress vibrations and other mechanical factors such as movements. It also makes the printed circuit boards applicable in harsh conditions that involve constant mechanical forces. One of them is in automotive applications.
High component density
Component density in PCBA refers to the volume of the electronic components that can be accommodated on the printed circuit board. Surface mount technology makes it possible to achieve a high component density on the printed circuit board. Despite a high component density, the printed circuit boards are still able to preserve the miniaturization while at the same time being lightweight.
Easy to assemble
Surface mount technology is pretty easy to assemble. Once you mark the positions of component placement, the only step that you will need to take is component placement. If you are doing it manually, component placement through SMT can be executed without any technical difficulties. The ease of component placement also makes it possible to deploy automation on the surface mount technology. You can use machines to place components on the oriented circuit boards.
Minimum damage on the printed circuit board
Surface mount technology does minimal physical and structural damage to the circuit board during the PCBA process. First, there is no drilling on the board, which means that there will be no holes in the board. Secondly, there will be minimal routing traces on the board. In overall, the surface mount technology preserves the physical and structural integrity of the printed circuit board.
Better thermal management
Thermal management is among the key parameters that you should look at when doing PCBA. The good news is SMT performs better when it comes to thermal management on the printed circuit board, especially when we compare it to the through-hole technology.
With SMT, it is easy to position components on the board in a particular pattern that will facilitate a smooth and efficient flow of heat from the board. You can easily integrate heat management solutions such as sinks in between the electronic components. Better thermal management makes SMT technology ideal for heat-sensitive electronic modules such as motherboards, processing units, and power modules.
Better electrical performance
Using SMT in the PCBA helps to elevate the electrical performance of the circuit board. There are several ways in which this form of component mounting and assembling improves the overall performance of the component.
One of the tenets of SMT is ensuring that components are close to each other. The minimal distance between electronic components ensures that electric signals can be relayed quickly and efficiently between the components. Additionally, it protects against any form of electric signal interference.
Are there any disadvantages of SMT in PCBA
Despite the many benefits that come with using surface mount technology, there are also some demerits. Compact design can make it hard to work on the components. The fact that they are too close to each other makes it hard to repair. Also, being too close to each other can make components generate heat.
Are you in the PCB assembly business? Chances are surface mount technology could be your go-to technique for assembling the components. As we have seen, this method of PCBA manufacturing has proven to be highly effective, especially when we consider the many benefits that come with using it.
Even if you are planning to use SMT, you should also consider the quality of electronic components to use. While the PCBA technique may be good, it could be let down by the use of low-quality components. The surest way of ensuring that you use quality PCB components for your SMT is by choosing reputable PCB components suppliers and distributors in China.
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