How to Solder Surface-Mount (SMD) Components

0Shares

Introduction

Hello! In this post we will go over how to prepare for and perform SMD soldering work. Okay, what does SMD mean? It's an acronym that means surface mount device. What does this have to do with soldering? Most pocketed devices use SMD work for their circuit boards so that the device can fit in small areas. Phones, handheld game stations, music devices, etc. So, why is this important to learn? Well believe it or not there is more than one way to go about SMD work. 

Let's take a look shall we?

The Well Known Way...

Most solder users know the common way of soldering SMD work. It includes paste, a heat gun, maybe a set of tweezers, and components. That's it. Just the three (possibly four) things. So, why do we need to tell you how to do this? Breaking down the steps comes in handy when you haven't seen them before. Also, do you know what you need to do this? I know I gave you a short list before but what are those things?

First, paste. There are many different types of paste available and we go over it here. For this example I am going to use Type 3 paste. Secondly, there is the heat (or hot air) gun. Now this is different than a soldering iron. Although it is self explanatory, it is an apparatus that uses heat. Most of the time it is shaped like a gun and is attached to a vacuum pump or fan. The reason for this is to keep it from over heating the components. There are units out there that are just a gun and there are ones that are a combination. The choice is up to you dependent on the work you will be doing. Also be aware there are some guns out there that have attachments for different work. They can focus the heat from the gun but be careful. This can cause damage to more frail components. 

Speaking of, let's move on to the all too tricky components. These will depend on what you are trying to make in the long run. If you know what thru-hole components are then you know these as well. The main difference is that SMD components do not have "legs" on them. If not, take a look into what you need.

Simple Steps

Let's get to it:

  1. Warm the hot air gun to about 300°C. This can vary dependent on if you chose to use the attachment pieces and what you are warming up.
  2. Place the paste down on one part of available space for the component on the circuit board. 
  3. Place the corresponding component on the board with a set of tweezers. 
  4. Using the hot air gun begin to warm the paste on the board until it joins the component to it. 
  5. Place more paste on the opposite side of the component.
  6. Heat up the new paste, using the tweezers to keep the component in place.
  7. That's it!

Lesser Known Way

A newer way of SMD soldering includes the same things as above but with one added object. A stencil. Do you remember when you were younger and wanted to draw? If it was something you never did before you would look for a stencil. Tracing the stencil you found a hidden drawing talent to be able to draw the same thing. Over and over again. Well this is kind of the same situation. For SMD work that requires making the same board numerous times, a stencil comes in handy. There are somethings to keep in mind for this way of SMD soldering.

First, the paste for this type of work will vary. Although it depends on what kind of work you're doing. Most solder users find it easier to use Type 5 paste for stencil based work. This is because Type 5 paste has a larger surface area coverage and smaller sized balls. This allows for quick melting points over larger work areas. Meaning using it in stencil work will allow for smooth application and smoother joining. Shall we get going on the steps then?

Stencil Steps

Let's start:

  1. Turn on your hot air gun station and set it to 260°C. This way you start low and can increase the temperature as necessary. 
  2. Create a "station" for the board you will be using. What this means is to either use a pre-cut holder for your circuit board or create one. If you don't have a pre-made one you can use multiple boards and tape to make one. This holder should fit around your working circuit board perfectly. 
  3. Place the stencil above the work area created for the circuit board. It's really important that the stencil doesn't move while in use so make sure to tape one side down. It should align perfectly with the circuit board for soldering. 
  4. Once the stencil is in place the fun begins! Place a glob of paste on the stencil above the cut out. It needs to be enough to fill the stencil over the circuit board. Using a squeegee of some sort start to move the glob down over the stencil.
  5. If you're not sure if the first squeegee was enough do it again in the opposite direction. 
  6. Remove the excess paste and lift the stencil.
  7. You should have a circuit board perfectly prepared and ready for the components now.  
  8. Being very careful place the components on the board one by one.
  9. Once they are all on you can use the hot air gun to heat up the board. This can take a while depending on if you will need to raise the temperature or not.
  10. That's it! Check your work and make sure the joints look solid and you are done!

See, now wasn't that easy? Hope this helped!

0Shares

Was this post helpful?

Providing soldering and brazing solutions 
for more than 50 years.
cross-circle
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram
Share via
Copy link
Powered by Social Snap