What's SMT Assembly All About?

As today’s electronic gadgets get tinier and more intricate, more engineers are turning to surface mount technology (SMT). Since the 1980s, this tech has become the go-to for assembling PCBs in electronics manufacturing and hasn’t slowed down since.

Most parts inside your phone, whether it’s the latest iPhone or an old-school flip phone, were likely put together using SMT. Even many components in your car or your Uber ride probably came from SMT assembly.

So, what exactly is SMT assembly, and why was it necessary to develop this technology?

The Basics of SMT Assembly

Surface mounting is a technique to create electronic circuits by placing components directly onto the board’s surface.

SMT assembly is a modern alternative to the older through-hole method of PCB manufacturing, which was big in the 1970s and 1980s. As electronics manufacturing kept growing, a faster, more efficient process was needed. That’s where SMT assembly comes in.

SMT assembly is used in a wide range of PCB applications. However, your design team should be aware of a few limitations.

Advantages of Surface Mount Technology (SMT)

Just like through-hole technology, SMT comes with its own set of pros and cons. Let's dive into the advantages of SMT assembly:

1. Cost-Effectiveness

One of the main reasons SMT assembly was developed is to cut down manufacturing costs.

SMT requires fewer holes to be drilled into the circuit board, which significantly reduces processing and handling expenses.

Additionally, SMT can handle higher volumes, leading to a better per-unit cost.

2. Space Efficiency

SMT assembly uses circuit board space much more efficiently. Engineers can now pack complex electronics into smaller assemblies thanks to SMT.

Besides making better use of PCB space, SMT assembly is much quicker, boosting overall production. For example, tasks that might have taken 1-2 hours with through-hole technology can be completed in just 10-15 minutes using SMT.

3. Simplicity

Unlike through-hole assembly, which uses lead wires passing through holes to connect components, SMT components are soldered directly onto the PCB. This makes the overall design much simpler.

4. Reduced Error Rate

SMT assembly relies heavily on automation, reducing the chance of human error. Since the process is mostly automated, it's less prone to mistakes.

Where Is Surface Mount Technology Used?

SMT assembly came about as a way to build better, more powerful electronic products.

Take a glance around your office or living room, and you'll spot several devices using surface mount technology. Basically, go for surface mount PCB assembly when you need a product that’s:

• Compact
• Lightweight
• Speedy
• Powerful

Though through-hole tech still has its place in certain applications or specific parts of a board, SMT assembly has mostly taken over.

Downsides of Surface Mount Technology

Like all manufacturing methods, SMT assembly has its drawbacks. The main issue is it demands more precision than through-hole assembly. Even with automation, meeting design specs is crucial for a quality end product. This responsibility mainly falls on the designer and the electronics manufacturer.

Problems can also pop up when SMT is used in environments involving:

• Mechanical stress
• Environmental stress
• Temperature fluctuations

This issue can be lessened by combining SMT with through-hole methods to harness the benefits of both. Yep, you can use both on the same board!

Upgrade Your Design

The best way to avoid potential pitfalls with SMT assembly is to work with a skilled, reliable partner. A contractor experienced in the design phase can guide you on any issues with using SMT versus through-hole.

As you can see, SMT assembly is central to nearly every modern electronics design. If you’re still using through-hole in your PCB design, think about whether SMT assembly might be the upgrade you need to take your product to the next level.