SMT PCB Assembly

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Surface Mount Assembly (SMT) is used across the world and the SMT market is currently valued at more than 3 billion USD. Several different smaller markets have emerged within this niche, including repair, rework, printing and placement. It’s anticipated that the SMT market will keep on growing across the world, offering improvements in product technology.

Introduction To SMT

Surface Mount Assembly (SMT) is a method of building circuit boards, in which the electrical components are mounted right onto the surface. You place the components on the board and solder them to it, instead of taking leads through the board. Printed circuit boards (PCBS) that are built in this manner use less space and are smaller than PCBs made using previous technology.

Each component that is mounted onto the surface of a PCB in this way is referred to as a surface-mount device (SMD). In addition to being more compact, these PCBs are also more lightweight than those constructed using other technology. In industry, SMT has almost completely replaced traditional through-hole technology.

Benefits of SMT Assembly

SMT Assembly is used in a wide range of consumer electronics and this is what is driving the growth of the global market for SMT technology. PCBs made via SMT are lightweight and they are compact. This in turn affects the type of designs that can be used in everything from your phone to a handheld hair dryer. Every type of consumer electronic device that uses SMT technology can be smaller than one that doesn’t, resulting in devices that are more elegant and easier to hold.

SMT boards offer great benefits to small designers and large manufacturers. Devices made with SMT can be more portable because they are lightweight. SMT Assembly almost completely eliminates the extra weight that came from leads because it uses smaller leads and where possible, no leads at all. Instead, SMT Assembly relies on leads in a wide range of sizes and short pins, which make more efficient use of space and materials on the printed circuit board.

Visually, components built through SMT Assembly are thinner and lighter than those that are built via through-hole technology. Not only do they require less space but they also consume less power than their predecessors. This drives increasing innovation on everything from telecom applications to automotive. If you’re working on boards that have already been built, you should exercise great care to avoid damaging these boards..

Three Different SMT Package Styles Explained

There are three different SMT package styles for each type of component and these should be kept in mind you want to have a PCB built for your own applications. These are:

  1. Transistors and diodes
  2. Integrated circuits
  3. Passive SMDs

Transistors and diodes are usually found in small plastic packages. You’ll find leads on them which emanate from the package and this makes it easy to connect them to the board. The leads are usually bent for your convenience, so that they can touch the board. You’ll usually find three leads on each package and that makes it easy for you to determine which way you should turn the package when placing the resistor or diode on the board.

The packages for integrated circuits vary according to the type of connectivity that you need, so you’ll find a variety of packages available. If you’re examining a simple logic chip, you’ll find that it usually has between 14 and 16 pins. On the other hand, a VLSI processor could have as many as 200 pins. These should always be handled with care because the pins can easily be bent.

A passive SMD package will consist of either SMT resistors or capacitors. You will find that the SMT capacitors and resistors in these packages stick to a standard in terms of size and other criteria. You can select a package with components in the size that fits your needs. For example, you may see a package with a designation such as 0402 and this gives you an idea of the dimension, in hundreds of an inch.

The size designation generally tells you what power levels may be required. For example, a package with a size designation of 1812 can be used in applications where large power levels are needed. You won’t find coils, crystals and other components in these packages, because these components tend to come with requirements that are more individual.

Automated PCB Assembly Cost

Several factors will affect the cost of assembling your PCBs, you can learn how to calculate it on PCBA Store. If you have a number of layers in the design, this is one of the factors that will cause your cost to rise. The board size will also affect the price, so to make the most of all of your resources, try to use the entire space, so you don’t have any unused board material wasted.

Your Bill Of Material (BOM) lines are always important, as are the number and types of components that you use. While improving your designs, looking for ways to achieve a solution with fewer components will benefit your pocket. It will also help to make your board more lightweight, easier to repair and potentially more attractive to customers as the final product will be cheaper.

The lead time given to your PCB manufacturer is also an essential consideration. If you only give them a few weeks or days for an order, they will charge you more. The volume of your order is also essential, since if your volume s high enough, you will usually be charged less.


SMT assembly makes it easier to bring your designs and ideas to life, than through-hole technology. While some PCBs of this type can be assembled at home, it is often better to solder SMT components with 50 or more pins at facilities that have special gear for that purpose. If you’re bringing a design to market, automated assembly can help you to do so at an affordable cost. A turnkey PCB manufacturer with experience in your sector can help you to get to market quickly and achieve your goals with less hassle.