Here's a beginners guide to soldering. You'll need to solder many of our keyboards like the M0lly and Godspeed, as well as many other companies keyboards that aren't hotswap. All soldering is is making a permanent connection between the switches and the PCB by melting the soldering wire to bond the switches to the PCB.
To briefly summarize it, the steps are:
- Arrange switches to your liking in plate
- Put switches into PCB
- Melting soldering wire into the correct place
- Test switches in VIA Configurator
- Remove solder of any failing switches
- Redo the soldering on failed switches
- Admire your work
Before You Begin/Safety Warning
You will be using tools that get very hot and molten tin wire. It is important to make sure that you are doing everything you can to stay safe while soldering. Wearing ample protection and staying focused will make sure that building your keyboard stays more fun than painful.
Recommended Safety Measures
- Wearing eye protection like goggles (and removing your glasses if possible)
- Long sleeves
- Soldering in a well-ventilated area (most soldering wire contains lead, and you don't want to breathe that in. It is also possible to find soldering wire that doesn't contain lead)
- Getting a soldering iron stand (most soldering stations will come with the stand, but in the case you don't have one getting one is recommended)
- Keeping your space clean (removing anything that could get in the way while soldering will prevent you from bumping into things and messing up, or worse hurting yourself
- Don't leave your iron unattended while it is on
- Soldering Wire
- Soldering Iron or Soldering Station
- Desoldering Pump
Now that all of the not fun stuff is out of the way, let's get all ready to solder.
Soldering is a simple task when you get the hold of it. With bigger keyboards, soldering over 100 switches in can get repetitive and quite frankly boring, so take breaks and stay focused while soldering.
First, turn the iron on. Seems like a no-brainer, but if we had a dollar for every time we tried to solder with a cold iron we'd have more than 1 dollar. The iron will heat up and melt the soldering wire onto the PCB. The wire will then cool and solidify to make the permanent connection. That's really all there is to it.
Pictured above: what a finished soldering connection will look like on a PCB, as seen from the bottom of a PCB
The first step in soldering is aligning the switches with the PCB. Many keyboards will allow for multiple layouts, so the switches can be placed in different places in the PCB. For example, the M0lly keyboard allows for a 4x5 grid where the numpad is or a standard numpad with multiple keys that require stabilizers. If this is the case, make sure you put the switches in the right spot for the type of keyboard you want to build. Screwing in any stabilizers before soldering may help with getting the switches into the right spaces.
Using the plate of your keyboard, you can snap in the switches to get them all into the right spaces. This makes soldering easier because the switches wont fall out while soldering. If you are building a keyboard without a plate, ignore this step.
Pictured above: how the switches fit into the plate when popped in, as seen from the side
Now that the switches are all in the plate and aligned it's time to put the switches in the PCB. Flip the plate over so everything is upside-down and the pins of the switches are facing up. Make sure that all the pins are straight with a pair of tweezers. This will make sure that the solder has enough of the pin to grab on to. You can then place the PCB, face down, onto the switches. Make sure not to bend any pins in the process. when the PCB is correctly placed all the pins should be visible poking out a little through the PCB.
Pictured above: how the pins should poke out through the PCB. The pins are the little metal pieces seen in the middle of the longest metal opening and the lower opening of the two circles that are touching. Seen from the bottom of the PCB
Next, you can solder the switches to the PCB. Use the soldering iron to heat up the pin for just a second or two. This will help the wire melt evenly and clean. Keep the iron's tip touching the pin and take a length of the soldering wire, place the end of the wire onto the pin, avoiding the tip of the iron. This will cause the wire to melt and fill the PCB. Making a "u" shape around the pin, continue to add more of the wire to the PCB. You will end up adding wire until you are left with a nice mound of solder. The solder should still be semi-contained by the PCB hole while making sure to cover all around the pin. While doing this, make sure you continually move your hand that is holding the wire 1-3 inches away from the PCB so you don't burn yourself on accident.
Now that you've done one pin it is time to do the other the same way, and then you've successfully soldered a switch. People have many different ways to fill in the board. Some do the corners first. Some go top to bottom and left to right. Whatever way you find to work for you is best, but making sure that the switches are making good connections to the PCB is important. We've had good success doing the corners first so the PCB doesn't lean to any side and is balanced at all times.
Pictured above: what soldering will look like while doing it. Note: the wire should not come into contact with the iron, this would cause the wire to burn and build up
If you find that you messed up a connection you are now officially soldering. This is normal and happens to the best of us. The most simple and cost effective way to do this is with Desoldering Pump. People will call this a Solder Sucker. The process is simple, but be prepared to attempt to suck the solder more than one time to get it out. Place the solder sucker partially over the soldered connection and heat up the solder with the soldering iron. This is the tricky part. You need to place the solder sucker all the way over the solder before it cools then push the button n the solder sucker that sucks up the solder. A good seal is needed to make sure the solder is pulled up into the sucker. This will take a couple attempts more than likely, so take your time. Solder cools quickly, so the timing of removing the iron, sealing with the solder sucker, and activating the plunger to suck up the solder needs to be good.
Pictured above: melting the soldering and creating a seal with the desoldering pump, as seen from the bottom of the PCB
Test the switches' connection
Next, you should test the connections and switches using VIA. Plug your keyboard into your computer and open up VIA Configurator. You’ll be using this to test that your switches are registering keypresses.
- VIA will automatically detect that the keyboard is plugged in and compatible.
- In the Key Tester tab, you'll see a standard keyboard layout. When you press a switch on the keyboard that corresponds to a key, it will light up in the Key Tester. For example, when you press the top left key on the M0lly, the Esc key in the Key Tester will light up to show that the switch is working.
Troubleshooting: If your switch isn't registering, you will need to undo the solder and pull it out and check the pins on the bottom. It's easy to accidentally bend switch pins.
Pictured above: what a group of finished soldering connections will look like on a PCB, as seen from the bottom of a PCB
Congratulations 🎉 you've learned to solder a keyboard! Take some glamor shots and share online, we’d love to see your builds if you tag us @thekey.company on Instagram.