Last Updated on October 22, 2023 by Kevin Chen
Image source PI my Life up
SMD is an acronym that stands for the Surface Mount Device. These are types of electronic components that are designed to be mounted on the surface of a printed circuit board.
SMD is a complete opposite to the through-hole electronic components which have pins and are designed to be inserted into holes.
SMD electronic components tend to be compact such that they can perfectly fit into small spaces.
Some of the electronic components that belong to the SMD class include capacitors, diodes, integrated circuits, inductors, transistors among others
There are many other advantages that come with SMD and we will look into them later. Of course they also have some disadvantages.
Keep reading as we break down the details of the SMD in the field of electronics.
A brief history of SMD
Where did surface mount devices come from and what is the story behind their growth?
Well, SMDs aren’t that old in the field of electronics. They started becoming popular in the 1960 when the size and weight of electronics started becoming a big issue in the different application areas.
Different industry players focused on manufacturing electronic components that will take less space and at the same time have minimum weight.
Aerospace, military and even automotive were among the first industries to utilize the effectiveness of the SMD components.
With time, SMD components such as capacitors and resistors started appearing in the consumer electronics, especially the small ones such as watches.
By early 1980s there was widespread use of the SMD technology across every other industry.
The growth of Surface Mount Technology (SMT) had a direct impact on the development of the SMD components. It contributed to the mass production of the SMDs.
SMT also enhanced the reliability of the SMD components such that we started witnessing the production of high-quality and more reliable electronic components.
The key highlight of the SMT is it promoted the use of robotics in the design and manufacturing of the SMD components. Perhaps this explains the mass production wave of SMD components that we witnessed since the 1980s.
Automation replaced the manual production of the electronic components.
Today, SMD is literally in all electronic components and devices. From the tiniest device to the largest.
More research and development is done on the SMT. After all, it is at the heart of miniaturized devices whereby designers and manufacturers are coming up with smaller products.
Implementation of SMD
How do the electronic components manufacturers manage to come up with SMD?
Well a number of techniques, tools and technologies are incorporated to achieve quality and functional surface mount devices.
Surface Mount Technology is at the core of the SMD implementation. Here, the SMT-designed robots and and machines are involved in all the productions steps of the SMD.
To give you a better perspective, here are the general steps and procedures followed when implementing SMD.
In this case, our attention will be on the PCB, how SMDs eventually end up on the printed circuit boards.
It all starts with designing a PCB that will be used to accommodate the the electronic components. This is done using advanced software tools such as CAD.
The next step is to place the electronic components on the PCB. Since we are dealing with the SMD components, the process is pretty simple, an automated robot is programmed to place each component on the PCB. The positioning of the component is already predetermined during the design process by the PCB.
Once the SMD components are on their respective positions on the PCB, the next step is soldering. Some heat is applied on the PCB to ensure that the SMD component remains strong and stable on the PCB.
After soldering, the nexts step is inspection. Electronic components manufacturers manufacturers have an inspection unit that is responsible for inspecting the components. This is done to ensure that the individual SMD components are well soldered onto their respective positions. Necessary corrections are done at this stage. Modern technology has made it possible to automate the SMD inspection process.
The final step of the SMD implementation is testing. Testing is done to ensure that everything on the PCB works perfectly as desired. Once everything is verified, SMD will be ready for shipping.
Advantages of SMD
Image source Surface mount process
What is the reason behind the popularity of SMD in electronics?
Well, there are numerous advantages and benefits associated with Surface Mount device.
These benefits include the following:
- Small size: SMD electronic components are quite small. In fact they are smaller than the through-hole electronic components. Size is a major advantage as it allows manufacturers to build devices without worrying about the space required for the electronic components. Despite their small size, SMDs tend to have quite significant density.
- Increased productivity: Ever since the revolution of surface mount technology, the field of electronic components has witnessed fast production rates. This has been achieved because assembling SMT components is easier and more efficient than assembling through hole components. Simply stated, more electronic products can be produced within a short period.
- Reduced production cost: This is another benefit that came with the surface mount technology. The fact that they are small means it is easy to handle them. Also having fewer holes means that you will spend less resources to drill them.
- Lesser weight: Other than being small-size, SMD electronic components carry lesser weight than their through-hole counterparts. This feature also makes them ideal for the weight-sensitive applications.
- Highly reliable: The fact hat these components are mounted on the surface of the PCB increases their reliability. The mechanic dynamics of the SMT shields the components from the impact of stress and wear. This will eventually improve both the performance and lifespan of these components.
- Excellent performance: SMDs tend to improve the overall performance of their devices. Intricate features such as high frequency capacity and minimizes signal paths improve the overall performance of the SMDs. The performance is further enhanced by the possibility to achieve a multilayer assembly on SMD hence improving their capabilities.
Disadvantages of SMD
Despite the pros, there are cons associated with the SMD electronic components
One major problem is not all the electronic components are designed for the surface mount technology. This means that they are not ideal for the surface-mount package. Some components are for the through-hole package. This is a problem especially when it comes to replacing some components.
There is also an issue of accessing the SMD components. As we have discussed about the implementation of SMD,the result product is a fine piece of work. It will be almost impossible to handle the electronic components manually.
Also, the small size of SMD electronic components makes the susceptible to counterfeits. The electronic components market is dominated by duplicates of the original SMD. This us why we always encourage that you should buy from reputable electronic components suppliers and distributors.
Differences between SMD and Through Hole Technology
Through-hole technology is the opposite of the SMT. In THT, electronic components are drilled into the PCB. This is unlike SMT where components are mounted on the surface of the PCB.
Just like in the case of SMT, the placement of electronic components through THT can either be done manually or automated.
FAQs about SMD
Here are the frequently asked questions about surface mount device
What are the main types of SMDs?
SMDs are divided into two major types. These are passive and active. Passive SMDs are designed to receive electric energy and signals. They can either store the energy or dissipate it. They include resistors capacitors, inductors and even transformers.
Active SMDs supply electric energy to the circuit. They include any voltage and current sources such as MOSFETs and JFET.
How do can I identify SMD components?
You will need a keen eye to identify the exact SMD component that you have. The fact that these components are very small means that you can easily confuse SMD with THT components.
The easiest way to identify these components is to check on their markings and labels. Electronic component manufacturers usually specify the technology used to make the component.
Alternatively, you can measure and define the physical specifications of the SMD components.
Buy SMD components in China
At this point you know what SMD stands for in electronics. So, you should be ready to buy the right surface mount device that will be suitable for your application.
If you are buying SMD components wholesale in China, ensure you buy from reputable distributors.
Start by knowing the exact specifications of the component that you want to buy. For instane, you should know the exact voltage and current ratings of the SMD that you want to buy.
From there, you can contact a sourcing agent to help you with the purchase.
The good thing about taking this route is you are sure of getting high quality SMD components for sale in China.
Contact us at ICRFQ and we will help you buy surface mount devices and even PCBs.
Watch the video below for summarized information about SMD.
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