SMD components are now so cheap, its like they are free. They allow one to make a super small PCB for their inventions and projects. This blog covers my tips for making the transition to SMD components and the reasons why to do so.
-Sean J. Miller 11/13/2022
I had applied SMD components a few times before, but never designed fully for it. I was a bit clumsy on my first attempt and it didn't seem to be an advantage to the Maker who likes to chug out quick projects. With our Drone project, I elected to go 100% SMD for the resistors. In doing, I got the knack for landing them well, even without a reflow oven. This opens up for some fast home manufacturing in that my chemically etched boards can now be made much faster with my 3D laser etcher and no need to drill holes with the exception of wire to board connectors.
Just about the only thing you need to learn for SMD versus through-hole components is sizing. Otherwise, they are actually easier overall - particularly for resistors, in that they have numbers on them instead of color bands to reference. Note: for handling them, you definitely need some sharp tweezers.
When you design for SMD, be sure to look for the code as shown in the table below. This is very important to match to your supply or your order of SMD components. The smaller the better.
You can make a slightly bigger SMD resistor work if you align it just right, but it is a major pain to keep things aligned. Getting the pad layout exactly matched to the size (code), you will be able to install SMDs easily even without a reflow oven. My size preference is 0805. They are small, but not so small I can't handle them.
To install an SMD component without a reflow oven, you can simply use a normal soldering iron. I found that a combination of an iron along with a hot air station is the best approach. These are the components I use (If the links do not work, the descriptions will do the trick for a search):
Here is my soldering iron approach:
Here is my Hot Air Station Approach:
If you like to make professional grade projects, a good Birthday present is a reflow oven:
With those designs, you use a stencil that helps you accurately paint on the solder paste to the pads. If you have your boards made by PCBWay.com, they can also make you a stencil. If you make your own, I suggest using a 3D laser etcher and chemically etch the board and laser out a stencil as well which just can be paper. These are the blank copper boards I use:
PCBWay.com can now get fabricated boards to the middle of the United States in 5 days for less than $30 for ten boards. This option is becoming almost impossible to beat.
Now that I've got the knack for landing SMD components, my bins of through-hole are now just collecting dust. The ability to make my boards as small as Panasonic would do it, makes it such that I never want to go back. If you haven't tried them, yet, it'll be worth it.