Mechanical Keyboard PCB Introduction:
A mechanical keyboard is a type of keyboard with special tactile feedback so accurate that it allows you to execute every click with superfast accuracy and it is made in such a way that it lasts longer than every other keyboard. Because of its uniqueness in architecture, awesome durability, and superfast responsiveness, Its demand is increasing day by day
Computer keyboards are usually of two types depending on the switch. The first one is the membrane keyboard which is easily available on the market so it is used in all cases. Another one is the mechanical keyboard. There is currently no substitute for a gaming mouse and a mechanical keyboard for gamers. Many people are interested in using the mechanical keyboard for all the reasons like response time, build quality, look, RGB. Since it is not like a conventional keyboard, it costs more than a normal keyboard. Mechanical keyboards are now widely used by gamers, but now many content creators are using mechanical Keyboard. In Gaming or typing mechanical keyboard brings a new dimension of typing experience. However, according to the price, brand, switch type, the fun of using a mechanical keyboard is different. And if there are RGB LEDs on the keyboard, then you can change the key color as you want. Mechanical keyboards are usually made of printed circuit boards and switches. A metal object and a spring are used inside the switch. The key is registered when two metallic objects touch the key. Since the mechanical keys are placed on the printed circuit board, it is possible to change the switch if the switch is not working. One of the key differences between mechanical keyboards and membrane keyboards is that, unlike mechanical keyboards, they do not have a separate key switch. A rubber dome is placed on top of a membrane sheet so that the key is registered on the keyboard when pressed. Since the keys or rubber domes are placed on top of a membrane sheet, it is not possible to change the switch if it is not working.
In the case of mechanical keyboards, there are 3 types of keyboard switches.
These 3 types of switches have some distinctive features known as the color of the switch.
- Linear: Cherry MX Black, MX Red, MX Gray Linear, Logitech Roma G
- Tactile: Cherry MX Brown, MX Clear, MX Tactile, Razor Orange GT
- Click-through switch: Cherry MX Blue, MX Green, MX White, and Razor’s Chroma Green GT.
Here Cherry, Logitech, Razor are the switch maker brands. The most popular of these is the Cherry MX Switch. Cherry is a German-based company. Many Chinese switch makers also make mechanical switches in the form of Cherry MX switches. For example, Otemu, Gritech, GETRON, etc. Above all, there are now optical-mechanical switches that feel similar to mechanical keyboards and the keyboards claim to have a faster response time. However, depending on the name of the switch, the switch will be clicky, silent, or tactile. Most of the time we say click switch, we mean a blue switch. Clicky sound gives a comfortable feeling while typing on the keyboard. Tactile switches usually do not have clicky sound but do have tactile feedback. Such as Cherry MX Brown or Razor Orange Switch. Linear switches, on the other hand, are silent and do not have much clickiness or feedback like linear switches. Such as Cherry MX Black, MX Red. In the early 1970 IBM keyboards were one of the earliest keyboards which were famous for their capacitive sensing Beam spring switches. Earlier in the keyboard capacitive sensing technology was similar to touchscreen technology it works exactly like a touchscreen but instead of your finger touching a screen directly with your finger there was a small pad under the switch that simulates your finger which helps to increase the capacitance of the electrodes. Eventually, this technology gave away. Beam springs are unique because of the way they behave. When you pressing them some internal parts inverts and goes up. The feeling of the keyboard was nearly using a typewriting machine. The actual goal to develop something which would able to give the feel of an actual typewriting machine. Because at that time most of the people were familiar with the typewriters clicky sound and nose. The keyboard was beautiful because of its double-shot keycaps, a split space bar, and its massive 10-pound weight. It was louder than IBM model Ms. It also uses some solenoid that fires with every click and makes more noise and gives a more type writing feeling. But this keyboard was huge in size and weight and impractical. Also, it was expensive, in 1970 it costs $1500 which is $8000 in today’s market price. IBM has been producing some of the most amazing keyboards for decades and the Model F switches were one of the best switches. The main goal was to give the same typewriter feeling in a more compact size box with lower cost and it was successful. Nowadays professional typer prefer mechanical keyboard because in membrane keyboards there is a high chance of falls pressing means you thought that you have pressed but it did not work due to membrane somehow not able to touch the key but in the mechanical keyboard there is a high chance that if you click a switch it will definitely response because of its unique mechanism. Now we will discuss the mechanical keyboard PCB. How can we able to design a mechanical keyboard PCB. How to build a custom mechanical keyboard and how to make a Bluetooth mechanical keyboard. At the end of the article, we will discuss how to choose the best mechanical keyboard PCB manufacturer.
How to Design A Mechanical Keyboard PCB:
We have to follow a few steps before designing the PCB for the mechanical keyboard.
We are going to use KiCad for designing the keyboard PCB. So at first download, it and install it so that you can follow every technique and tip shared by us. KiCad is now one of the most widely used software for designing purposes. So you can get many tutorials about how to design in Kicad software. If you are already installed it then we are ready to go. One of the things you have to make sure that you have all the official libraries of KiCad.
First start KiCad and then then you can see a screen with so many options. Now click on the new project. Then give a proper name for your project such as Keyboard PCB or whatever you want. Now we are going to design our schematic. So be careful.
First, double click on the “.sch” file and you can see a completely empty sheet like this.
Now we have to add a component library. If you look at the top of the window click on preferences > Component Libraries. Now click on ‘Add’ and then try to find the ‘keyboard_parts.lib’ file from House’s Libraries. Then you can go with directions and suggestions by the software. There are so many tutorials on the internet you can watch them and easily able install libraries.
Now to start we will suggest you a list of basic commands:
- “m: pick the component up and move it
- g: drag the component up and move it while keeping wires attached to it
- c: copy the component
- e: edit the component
- r: rotate the component
- y: mirror the component
- del: delete the component
- ESC: abort!”
Then click on Place > Component. Now can see that your courser looks like a pencil. Just click any part of the sheet and search for ATMEGAGA32U4 in the library use install.
Click OK and click on the schematic sheet to place the component. We have to edit the component and change the reference from U to U1.
We will place the crystal. Crystal is a very vital part of all the components available on the keyboard PCB. Because it determines the speed of the keyboard performance. Now we will place the ‘XTAL_GND’ component next to the controller. Just change the reference to X1.
One thing we have to remember that there is a high chance of too much noise disturbing the signal to the controller. So we should use two decoupling capacitors to prevent it. Now we will use a crystal with 18pF load capacitance so that our desired decoupling capacitors C1&C2 will be 22pF. At last, we will add a GND symbol and then connect everything.
Next, we will add 4 decoupling capacitors C1, C2, C3, C4 each of 0.1uF and one 4.7uF capacitor named C7. You can see all these capacitors in the image given below Fig 4.
Look at pin no 13. It is the reset pin. We want to add a push switch with this pin so that we can reset it easily when we need it. For that, we will add a ‘SW_PUSH’ switch and named it SW1. Now we have to add a 10k pulp register with this switch named R1. Then it will look like this Fig.5:
Now we have to add a USB port. So go to the library and select ‘ usb_mini_micro_B’ and add to the sheet and named it as J1. Now if you look at the USB there are several pins like VUSB, D-,D+, ID, GND, SHIELD. Now connect VUSB to VCC and then to UVcc of the controller. D- &D+ of both the controller and USB will be connected with two 22 ohm resistance named R1 and R2. GND and shield will be shorted and then it will be connected with the controller’s UGND and with UCap with a 1uF capacitor. The whole thing will look like this Fig 6.:
After that check all the VCC connections and GND connections if they are connected properly then it’s ok to go with the next step. But if they are not connected then connect them properly. Remember that you may have to place a capacitor between AVCC and VCC if you are using built-in-ADC. Here we will go without it.
Now we will arrange the switch matrix. For the tutorial purpose, we will show you a 2X2 matrix. So first go to the library select ‘KEYSW’ for the switch and ‘D’ for diode components. Now connect them respectively K1 with D1 and K2 with D2 and as we say earlier that it is a two 2×2 matrix then we have to do the same thing with K3, K4, D3, D4. Now the matrix will look like this Fig 8:
As you can see that there are so many unused components labeled then as unused pins. Click on the blue X button on the right side and select all the unconnected pins on the controller and USB port. Now our desired schematic will look like the image given below Fig 9.:
After that was done finally the schematic of the Mechanical keyboard PCB is successfully finished.
Let us consider that all the capacitors and resistors we use are 0805 imperial sizes. For atmega32u4 we consider it is going to be in a TQFN package. From Hasu’s library, we will get a hybrid through-hole and surface mount footprint for diodes.
The crystal will be an FA-238 series crystal.
The reset button will be the TL3422 series button.
The USB mini B port will be a Hirose 5S8 connector. Etc.
Here this the list you can check out Fig 10.:
Save the above all the associations and close the window.
Now we have to generate the netlist. This is essentially a list of connections to our schematic. Next Click on the netlist button.
Then click on the generate button. Next, use the default netlist in name in the save dialog.
PCB: Now we have to create our PCB. So save and close the previous Schematic editor. Open the ‘kicad pcb’ file. Then you will see a blank PCB editor like this Fig 11.
First check whether all the footprint is there or not. Double-check it and confirm it. Click on preferences then click on footprints libraries manager and check that all the imported footprints are there. If you are not able to find them then import them again.
Next, we have to set up our grid. Go to the ‘Dimension’ click on it and then go to ‘Grid’ and set size X and size Y both to 0.09375 and units to inches.
Now change the ‘Grid option’ to ‘User Grid’. And try to get the footprints onto the board. So click on ‘Read current Netlist’ and you will see so many messages. Close it then you will see a bunch of footprints like this Fig 12.
Now go to the render tab and uncheck rat nest then you will see all the wired connections vanish. Now earlier we share some useful commands that are very useful for PCB designing:
- m: move the footprint
- g: drag the footprint while keeping connectivity
- e: edit the footprint
- r: rotate the footprint
- f: flip the footprint
- del: delete the footprint
- ESC: abort!
Separate all the footprints and place them on the correct side of the PCB so that we can easily work with them. The switch footprint will be the only footprint that will be on the front side of the PCB and except switch footprint, other footprints will be on the backside of the PCB. Now it will look like this Fig 13.:
Then we will start arranging the footprints as per our desired combination. Then edit switch footprints from the ‘Move and Place’ option to the “Lock footprint’.
Now put all the diodes under switches and make sure that each switch placed exactly corresponds to its switch.
Since we have placed our microcontrollers near the switch we will keep some room for that Fig 15.
Now crystal is one of the most important parts of our PCB. We discussed it earlier. Because it decides the speed and performance of the keyboard. Be careful that all traces to the crystal must be short and the same in length. You can use the highlight net tool to decide what pads are connected to what pad. Then we place all the components one by one.
First, put the crystal above the microcontroller and give it a 45-degree rotation. Then put 2 decoupling capacitors just next to responsive pads. Then for VCC place 4, 0.1uF capacitors next to each VCC and AVCC. At last, place the last capacitor. As we know the USB connector is not even placed so place a USB connector and reset switch. Put all the resistors in such a way that routing traces can be easier for us.
Now we have to draw the outline for our board. For that go to the Layer and click ‘Edge. Cuts’ to move the blue arrow and select it as the layer. You can use the drawing tools to draw an outline for the PCB. It will look like this Fig 17.:
Earlier we say that you don’t have to think about ground because we will create a separate ground plane in the PCB where we can add all the GND points in a star topology. Mainly it is a big copper plate that will be connected to all other GROUND points. When there are a lot of components in the PCB that are connected to different GND points like our PCB then the PCB plane is very useful. Now to create a ground plane you can use a zoning tool. First, select the ‘F.cu’ option then select GND from the ‘Net’ option and then click “OK”,see Fig 18.
Draw a border around which you want the edge cuts. There are several tutorials for it. You can check them. After those process your PCB will look like this Fig 19.:
Routing is a very important step. For this, we want to use the “Add tracks and Vias tool”. Before routing it is important to set your grid size. It is recommended to set it to 0.25mm for routing purposes. Now you can question what a trace is or what is vias. We will discuss it a little bit. Trace is just like a physical wire made up of copper. Via is a hole that goes through both sides of the PCB. At the time of routing, you can press ‘V to switch layers and create vias.
There are few rules we have to maintain when we create traces and vias. Such as no vias between the crystal and controller are not allowed. Because vias can capture a small amount of capacitance that can make an impact on crystals operation.
First route the crystal and the decoupling capacitor. And it is very simple in this case. Confirm that the B.Cu layer is selected because that is the place where most of the components are placed. And it will look like this Fig 20:
We start of by routing all the VCC connections. Confirm that all the decoupling capacitors routed to appropriate VCC pins on the microcontrollers. Next route USB port as per the circuit diagram. The circuit will look like this Fig 21:
Route the UCap and the rest of the resistor accordingly. Try to make your design as clean and look good as possible. You can turn the rat nest in the render tab to check whether any connection is missed or broken. After fixing all the missing connection your circuit will be look like this Fig 22:
Then we route all the route diodes and switches. Route diodes and switches in such a way that it cannot touch the controller. At last, we will route the controller to the rows and columns.
Double-check all the connections have been made using the Design Rule Check tool or DRS tool.
After that was done press Start DRC and make sure there are no problems in design. Now go to the “List Unconnected Tab and check whether there are any unconnected nets or not. If you are not able to find any unconnected nets then it is fine. Now your desired PCB design is completed.
Finally generate Gerber files and send them to a manufacturer who can manufacture them as per our design and then assemble them with necessary components so that they will be ready to use.
How to Make a Custom Mechanical Keyboard:
As we show you all the process of how to design a custom mechanical keyboard in detail so it is now easy for you to design a mechanical PCB keyboard. Now if you want to add some custom feature to it then at first write down all those features and think about what changes you need to make in the design. Most of the time there is no need to change the design but you can change the code at the time of the controller as per your requirement. Whenever you want to design a custom PCB board for a mechanical keyboard just try to follow all the design guidelines we discuss earlier.
There are many tutorials on the internet. You can watch them and implement them. First set your goal for the project. Then think about what changes you have to make in the design. Which type of controller you want to use and then start design. Install required libraries so that later you don’t have to face any troubles. Then focus on the schematic. Because it is a very vital part of PCB designing. Then place all the components correctly and do routing properly. After completing the PCB design you can manufacture your desired PCB from a manufacturer.
What is Bluetooth Mechanical Keyboard?
Bluetooth Mechanical keyboard is a type of wireless keyboard that can control your PC or Laptop without wire just by using a Bluetooth module. Basically in this case the main Bluetooth module or master device will be connected with the main keyboard PCB output and the slave part will be connected with the other device which you want to control with your keyboard. If you don’t know what Bluetooth technology is and how it works then we will discuss it a little bit. If we want to use a mechanical keyboard wirelessly then we have to add a Bluetooth module to the Keyboard so that we can use it wirelessly. One of the main advantages of wireless keyboards is that you don’t care about the wire. You may know that most of the keyboard works on 2.4 GHz radiofrequency but Bluetooth is another technology that is being widely used by wireless keyboards. Here the communications happen between two types of devices. The first one is Master Device and the Second one is the slave device. This is a short-range communication technology that works maximum within the range of 10 meters. It can connect up to a maximum of 7 or 8 devices. Bluetooth network mainly consists of Personal Area Network or we can call it a piconet. Bluetooth devices always work with exchanging some codes so to use Bluetooth we need the approval of other devices which means both master and slave devices. There are few advantages to working with a Bluetooth module such as it contains sound facilities and RGB led facilities to indicate the connection status. Then it enables multiple devices to transfer data seamlessly and use wireless connectivity. Also, it is designed in a simple way and programmed so smartly that users can use it without knowing much about it. You can easily connect it with your keyboard PCB. Lastly, the Bluetooth antenna PCB is designed in such a way that it is able to connect the last paired device or the closed device within the preferred range. In a Bluetooth Mechanical keyboard, a Bluetooth device will be connected with the main PCB output and another part of the slave part will be connected to the device you want to control with your keyboard. There are other mechanisms like you can directly connect the keyboard to your device without the slave part but at that point sometimes pair confirmation may be necessary from both the devices.
Bluetooth Mechanical Keyboard
How to Find the Best Mechanical Keyboard PCB Manufacturer:
High-end equipment and expertise:
Before choosing your manufacturer be careful about the technology and expertise option of the manufacturer. Because manufacturing accurate keyboard PCB as per given design is not easy. So many newbies become frustrated with their PCB performance because the manufacturer they choose either not have high-quality expert or don’t have sufficient expertise to check a PCB board.
Modeling your requirements:
Always try to choose a manufacturer who can help you, in the beginning, to model the requirements of your board and help you model your requirements with their high-end software. It is also mandatory to choose those manufacturers who can test your board once it is completed and can crosscheck all the impedance values you want.
Quality to cost ratio:
Always confirm from the manufacturer how much quality they are able to provide to you within your budget range. Because Mechanical Keyboard is used for high-end works like gaming and rapid typing. So the quality of the PCB should be premium standard. Always try to find a manufacturer who is able to provide you a higher quality to cost ratio.
Higher customer rating:
Of course, customer rating is a big sign of a good manufacturer. After checking all the above factors you have to check the customer rating of a manufacturer and choose accordingly.
Mechanical keyboard PCB
So we can see that there are so many advantages of using mechanical keyboard PCB,what’s more,PCBMay could help you to produce mechanical keyboard PCBs. Demand for Mechanical keyboard PCB is increasing abruptly. Especially gaming communities are demanding more accurate and super-fast mechanical keyboards from manufacturers. There is a huge demand for Custom Mechanical Keyboards PCB from so many users. So we think this is the best time to learn how to design a mechanical keyboard and manufacture it as per customer requirement or for your own hobby. You can follow the above article carefully and see some tutorials out there on the internet. I am sure you are able to design a PCB within a month. Of course, learning new skills takes time but read the above article carefully and Build your concept accordingly. Thank you for being with us so patiently.