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SMD – The Best Guide to SMDs and the SMT Technology

With the leaps and bounds experienced in this industry, various technologies come in place to manufacture these devices, and the Surface Mount Technology is one of them.  As time goes by, electronics components size and designs aim for smaller sized devices and boards. These reduced-size components are not only low in structure but also cheap and fast. This convenience explains the major boom of the SMD.

With the leaps and bounds experienced in this industry, various technologies come in place to manufacture these devices, and the Surface Mount Technology is one of them.  As time goes by, electronics components size and designs aim for smaller sized devices and boards. These reduced-size components are not only low in structure but also cheap and fast. This convenience explains the major boom of the SMD.

What are SMDs?

As we have stated above, Surface Mount devices are devices that are manufactured through the Surface Mount Technology. Widely known as the SMT, the surface mount technology is used to mount electronic components on the SMD’s PCB’s surface. With this technology, the leads and axils lay on the PCB’s conductive tracks, wherewith the use of soldering iron, they are mounted on the board, and no form of drilling is done to reinforce the components.

Once employed, the SMT speeds up the production process. An SMT component is mostly smaller than its through-hole counterpart because usually, it has shorter leads or no leads whatsoever. The existence of the elements is so tiny in size. Hence, they give space as holes are not bored, and both sides are available for use.


Repair and Maintenance of SMD Components

To grow and stay put, we all have to maintain our bodies, and so does the SMDs. The surface-mount devices use conductive tips or hot air blowers for removal and replacements of electronics components.

Soldering iron tip attachment is a conductive tool that comes at a pocket-friendly price. The tips are in different shapes, sizes, and configurations for various SMT components and through-hole components. Composite tips are slightly at a higher cost than the soldering iron tips attachments that have the heating elements.

The Hot Air SMD rework stations are more expensive than the latter two. They use nozzles of different types and sizes. The hot air repair tooling is a standard tool mainly because it is ideal for damage-free repair. An example of a perfect solution for surface mount technology components is the GOOT GSR-302.

Choosing Repair Equipment for SMDs

Repair systems are readily available in the market, but electronic companies need to keep in mind that repair tools don’t need to be expensive when it comes to choosing the right repair equipment.

If you need to repair many boards, you should avoid the automated repair equipment and opt for the SMT inspection equipment. Though while the inspection tools are still in the developing stages, the x-ray and laser inspection are the only available automated inspection equipment in the market.

Most electronic companies worldwide depend on visual inspection at 2 to 10X using either a microscope or magnifying lamp.


Identification of SMDs


These are simply metal conductors looped through a ferrite bead and just as similar to the through-hole designs, but instead, they have axials and caps instead of leads. They have a dark grey color and also have magnetic features.


They often have two or three symbol codes such as diodes and transistors because their size does not facilitate them to be marked by average numbers as other more prominent components.


They are generally large enough to be imprinted with the complete part number, including the manufacturers’ specific prefix.


Advantages of Surface Mount Technology

Surface Mount Technology allows the creation of smaller SMD PCB designs by enabling components to be placed together on the board leading to more lightweight devices designation.

1.The SMT parts are often less costly than the comparable through-hole parts. The components are replaceable on both sides of the circuit board in higher density.

2.The SMT process is faster than through-hole technology because it does not necessarily require the circuit board for assembly, making its initial costs cheaper.

3.It reduces the unwanted effects of RF, which is the Radio Frequency, by lowering resistance and induction at the connection.

4.It has a smaller radiation loop area due to its compact package, and lower lead induction has better Electromagnetic Compatibility.

5.Allows multitasking by combining high-end components.

6.PCBs created with the SMT process provides higher circuit speeds because they are more compact, leading to many manufacturers opting for this method.

7.Surface Mount Technology provides stability and better mechanical performance under conditions like shaking and vibration.

5.1.Limitations to Surface Mount Technology

As much as the Surface Mount technology is excellent for SMD devices, we can clearly tell that it has its drawbacks. To get a clear glimpse of what we are talking about, let’s explore some of the demerits.

1.The surface mount technology components are quite small in size, making it challenging to repair them once any damage occurs.

2.There is no assurance that the solder connections can withstand the compounds used during potting application. The links may undergo damage when going through thermal cycling.

3.The solders can also be destroyed and weakened by mechanical stress.

4.With components that generate too much heat on their PCBs, the mounting soldering iron can melt off, rendering the whole device faulty.

Alternatives to SMD Technology

Although Surface mount technology is widely used and highly preferred, there are other alternatives such as the through-hole printed circuit board and the solderless breadboard technology that has been used for a variety of electronic devices.

6.1.Through-Hole PCB Design

Through-hole technology is a technique that uses the ideology of mounting the leads of electronic components onto the PCB by drilling through the circuit board.  These components are inserted into holes drilled on the printed circuit boards and soldered to pads on opposite sides. They provide a stronger mechanical bond and are suitable for test and prototyping.

6.2.Pin Grid Array

Often abbreviated as PGA, the pin grid technology works the same as through-hole technology. Pins form a rectangular or square array then mounted to the PCB via the surface mount technology.  These pins are later inserted into a socket and do not need to be soldered on to.

6.3.Solderless  Breadboard

A Breadboard facilitates the building and testing of circuits before finalizing any circuit design. They are easy to change, as they are easily removable and adjustable. Most electronic manufacturers do not prefer this method because they do not have enough proper tools to design circuits with high voltage. It also jeopardizes your signal integrity when dealing with frequencies in the higher.


Surface Mount Technology is instrumental and useful in the fabrication of electronic circuits on the Printed Circuit Board [PCB]. With this design, it facilitates the production of better and easy to manufacture devices. SMDs are among the world’s most commonly used devices ranging from new generations of computers to phones and air conditioning devices, to name a few.

So whenever you need one SMD PCB for your electronic devices, reach out to our sales team and be assured of world-class services from us!

Hi, I am Hommer, the founder of WellPCB. So far we have more than 4,000 customers worldwide. Any questions you can feel free to contact me. Thanks in advance.