Surface Mount Technology & Surface Mount Devices, What Are They & How Do They Differentiate?

by | Nov 2, 2022

SMT versus SMD, What Are They & How Do They Differentiate?

As the market’s demand for consuming electronic and digital products grows, so does the demand for surface mount technology and surface mount devices. SMT, known as surface mount technology, is an innovative approach to unit placement on printed circuit boards (PCBs). This method is known for its portability, effectiveness, and rapid operation. SMD, surface mount devices, are components that are installed upon blank PCB in accordance with design specifications.

Understandably mixed up or used interchangeably, SMD and SMT have not only associated components but also processes. Given the fact that they’re both necessary for creating quicker, more dependable, as well as higher-quality PCB, Z-Tronix has developed the following blog to demonstrate how surface mount technology and surface mount devices vary from one another.

What exactly is Surface Mount Technology (SMT)?

As explained previously, SMT is a contemporary way of placing components on a blank PCB. Before, leads, which are the metallic ends of the SMDs, were utilized by designers to manually attach printed circuit board elements through PCB holes. To guarantee that each lead molded and sat onto the printed circuit board properly, adequate preparation must have been performed.

Surface mount technology assembly is a cutting edge and efficient way to solder components onto printed circuit boards. The process has developed much more rapidly, effectively, and economically by eliminating the requirements to transmit leads through printed circuit boards. Additionally it takes up considerable amount of room, allowing many devices to accommodate on smaller printed circuit boards. This makes it possible to produce smaller PCBs, which are common in consumer electronics through smart watches or cell phones.

Each device is methodically placed on a blank printed circuit board for surface mount technology, a challenging approach that ensures maximum efficiency. The misconceptions among surface mount technology and surface mount devices stems from this. You must pick the proper parts and attach them properly to get a greater quality printed circuit board.

Prior to fastening the boards with dedicated equipment in the course of the SMT procedure, you must apply solder paste onto the board. For this reason, mounting devices on the PCB’s surface is much more efficient than running leads via the ports. Additionally, directly mounting enables the PCB to function at its best even with smaller components.

Producers of PCBs are capable of automating the mounting procedure thanks to surface mount technology. Our machinery can be programmed to instantly assemble components on printed circuit boards. This not only suggests that production process is swift but also that the quality standard is ensured and unforeseen problems are significantly reduced.

The Benefits and Drawbacks of Surface Mount Technology

Surface mount technology, in essence, is more cost-effective than thru-hole mounting because surface mount technology components are compact, simple to place, and can be positioned on either end of the printed circuit board.

Surface mount technology devices are perfect for those who need lighter and more compact printed circuit boards with cost-efficient pricing, when compared to the thru-hole parts and process. Because the majority of electronic and digital devices prioritize scale, this advantage is significant. Compact devices allow for closer arrangement on printed circuit boards. Surface mount technology mechanically enables quicker placement of components throughout the printed circuit board assembly, enabling cost-efficient and massed production.

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Image to display PCB Assembly Equipment

In addition to the aforementioned advantages, surface mount technology also has its own disadvantages. For instance, while surface mounting components is quicker, the machinery can be a large investment. Due to this, surface mount technology devices’ cost may increase, particularly in lower produced quantities. Due to the fact that routing vias is much more difficult for SMD than for thru-hole mounting, SMDs require greater precision.

Surface Mount Devices (SMD), What Are They Exactly?

Throughout the Printed Circuit Board Assembly, SMDs are the components that are placed and attached onto a blank printed circuit board. In today’s technologically advanced world, consumers expect high performance, adaptable, cost efficient and miniature electronic devices. A surface mount device is ideal for these uses because it has pins that could be soldered straight onto printed circuit boards rather than depending on a lead or wire to attach them to the printed circuit board.

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Image to display Miniature 0201 SMD Components

There are several advantages to employing pins rather than leads. For example, one may use miniature components to achieve an identical result. This suggests devices can be installed on a compact printed circuit board without sacrificing performance. Due to the fact that mounting procedures are much quicker and cost efficient, drilling holes onto printed circuit boards has become unnecessary.

Nonetheless, to manufacture a top quality printed circuit board, one is required to pick the appropriate surface mount devices. It’s not only recommended to pick components that will fit your printed circuit board properly, but also opt for a method of mounting that will work with the setup. From soldering by hand to automated placement of components on boards, surface mount devices have truly come a long way. Surface mount devices work best when mounted properly for the duration of their useful lifetime.

Different Kinds of SMDs

Chip Resistor: Value of resistance is denoted by three numbers on the chip resistor itself.

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 Network Resistor: Exclusively usable in digital systems, these are modules with several resistors having matching and comparable properties.

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Capacitor: The common types of multilayer ceramic capacitors are those composed of not only aluminum but also tantalum.

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Diodes: Diodes are SMT components that are frequently used and have a colored ring solely on a single side.

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LED: LEDs come in both ordinary as well as ultra-bright varieties, such as yellow white and blue.

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Transistor: Transformers, Crystal oscillators, inductors and fuses are all parts of a surface mount device transistor.

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Integrated Circuit: Are crucial to the efficient operation of electronics.

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Surface Mount Technology Increases the Efficiency of Surface Mount Devices

Several scenarios exist where surface mount technology and surface mount devices coincide, despite the fact that the primary distinction among both is that SMT relates to the technique while SMD relates to the components mounted. To demonstrate, the primary procedure underpinning surface mount technology is essentially the proper choice and placement of surface mount devices. 

Utilizing a proper mounting technique can lead to significant gains for concept, pre-production products. To demonstrate, surface mount devices can be quickly mounted upon printed circuit board surfaces using automatic surface mount technology equipment. Moreover, production equipment chosen determines how effectively the entire surface mount technology procedure runs.

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Within the printed circuit board market, thru-hole tech is still frequently used. When shopping, one must think about availability and pricing concerns given the aforementioned applications. With the exception of thru hole devices, which by the way are not widely supplied, surface mount devices on the other hand are widely obtainable because of the technological advancements.

Through Hole Mounting, what exactly is it and what does it consist of?

SMT is the procedure for attaching parts on printed circuit boards with drilled holes. Prior to the introduction of surface mount technology, thru-hole was the preferred method to mounting parts on printed circuit boards. Due to the distinct advantages, mainly durability, this method of component placement is being used today regardless of declining prominence over time.

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For electronics that are heavily depended on a solid signal connection, making through-hole devices are perfect for these electronic applications. Leads in through-hole allow devices to withstand exposure to the elements whereas surface mount devices are connected to the PCB through solder. Due to their frequent exposure to extreme velocities, heat and impacts, industries such as the aerospace and military frequently utilized and preferred the thru-hole approach.

Additionally, this through hole technique is widely used in prototyping, which frequently requires for a user to adjust and repair. Normally, through-hole tech is still utilized to some capacity by printed circuit board assemblers.

The Pros & Cons to Through-Hole Components

When opening up a modern electronic device and comparing it to one of 20 or more years ago, the thing that will stand out the most is how few through hole devices you will see. Yet, this doesn’t indicate that they’re obsolete; rather, the majority of printed circuit boards utilized now don’t require their special advantages. For prototypes and other products utilized where elevated temperatures and power is present, through hole parts are perfect. However,

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through hole components are infrequently utilized in smaller printed circuit boards, because they must be produced in mass quantities to attain reasonable costs. Some of the advantages that through-hole delivers when in the solder stage is proficiency in requirements for high heat and impact. Devices with through hole components have leads that can be soldered to copper pads after inserting the leads through the punched apertures. As mentioned previously, through hole technology is preferred for products that experience greater temperature and stress over surface mount technology because of its reliability and durability.

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Because thru-hole components are larger than surface mount devices, these components are suitable for applications that require large amounts of power. Additionally, through hole devices are simple to remove and substitute during the prototype stage, particularly if one wishes to examine a different component type.

Nevertheless, there are drawbacks to through hole technology as well. These drawbacks can be seen in terms of printed circuit board measurements, manufacturing cost, and turnaround time. Surface mount devices are

easier to mount than those of a thru hole device. If one is looking to the through hole mounting method, aperture creation will be necessary, consequently increasing the manufacturing cost. Additionally, larger than components of surface mount technology, through hole components are limited to being soldered solely on a single section of the printed circuit board. Therefore, through hole devices may not be ideal for an application that needs a compact PCB that is cost efficient.

What exactly are radial and axial components?

Thru-Hole devices usually fall into either being an axial lead component or a radial lead component. In regards to axial lead components, the axial leads go directly past the device and leave the device at either end. The lead end(s) are subsequently mounted by the assembler utilizing two different printed circuit board apertures, enabling tight component assembly. To the contrary, radial lead components protrude outside the printed circuit board because the devices’ only end has leads.

Image to display Axial vs Radial Components

Not only one, but both radial and axial lead components have particular advantages. To demonstrate, radial leads are recognized for their compact nature, taking up less space, whereas lead devices are common due to the close and precise fitting to the printed circuit board.

Final Thoughts

Despite the fact that surface mount technology is a preferred and current mounting method for enabling smaller mounting of parts, through hole is superior for bigger printed circuit boards due to its greater reliability for the many reasons we’ve discussed. When an application will be put through severe external and extreme settings such as military or high temperature applications, through-hole technology is advised. On the other hand, if your application will be for the electronic industry, for products such as modern cell phones or electronic wristband gadgets, surface mount technology will be the best choice. These two approaches will not become obsolete anytime in the foreseeable future due to their distinctive advantages.

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