If you have finished your project and now are searching for a way to keep all the components in the correct place, the best way to do it is to make a Printed Circuit Board (PCB).
In this tutorial, you will learn how to design a PCB using Kicad and order the PCB you created.
This tutorial is divided into three main sections. In the first section is presented to you the circuit that we pretend to make, a Flip-Flop. In the second section, you will learn how to design the board in KiCad software. In the final section, is presented to you how to order the PCB at JLCPCB manufacturer.
In the video below you can see the creation of a PCB with the description of the steps in Portuguese. You can turn on the subtitles for better understanding.
The circuit – Flip-Flop
The circuit that will be used in this tutorial will be a Flip-Flop, which can be used for data storage. With the circuit of Figure 1, it will be possible to save a single bit of information. If you look at the schematic we have two LEDs. If LED1 is turned on, then the value is “0” (zero) 1 is LED2 is on, then the value is “1” (one).
When transistor Q1 is conducting, then the LED1 will be ON and LED2 will be OFF. When transistor Q2 is conducting, then the LED1 will be OFF and LED2 will be ON.
If button S1 is pressed, the current base of the Q1 will be zero and the transistor will be at the cut region. This way LED1 will be turned off. Since Q1 is off, the current will flow to the Q2 base, turning Q2 to the saturation region and turning on LED2.
When S2 is pressed the reverse will happen.
Design your PCB
To turn the schematic previously presented into a PCB it may be required one software. Currently, there are several good options such as Autodesk EAGLE, Altium, Fritzing, but the one that today will be presented to you is the KiCad.
KiCad is a free software and is of simple intalation. You can download it here.
Create a new project
Open KiCad. You can create a new project using shortcut Ctrl+N or accessing File→New→Project. Figure 2 shows you how to create a new project.
Open Schematic Layout Editor
Double click on the icon of Figure 3a to open Schematic Layout Editor. Here you want to draw the schematic of your circuit.
Firstly, I will add all the components that I need for the circuit, i.e., 2x LEDs, 4x resistors, 2x transistors, and 2x pushbuttons. To do this task you need to click on the third icon of the toolbar at your right (Figure 3b) and then click on the schematic background. The windows of Figure 4 will be opened, there you can search for your components symbols.
While you find and place the symbols at the schematic you may need to use the shortcuts of Copy, Move and Rotate. To use them place the mouse over the symbols and press the key C to copy, M to move and R to rotate the symbols.
To make the connections between the symbols use the fifth icon of the toolbar (Figure 3b). To place the power supply click at the fourth icon of the toolbar (Figure 3b) and then at the schematic background.
At this moment you should have your circuit schematic completed but all of your symbols don’t a unique identification. To attribute a different identifier to each symbol click at the “Annotate schematic symbols” icon on the top toolbar (Figure 5) and then at the “Annotate” button.
Now is only missing to assign the PCB footprints to each symbol. To do it you must click on the third icon of Figure 5. The windows of Figure 6 will be opened.
In the left side of the window are presented the libraries and in the right side is presented all the footprints that can be assign to each symbol. In the second icon of the top toolbar of Figure 6 is possible to have a better understanding about the footprint.
After assigning all the footprints, click on the button “Apply, Save Schematic & Continue”.
PCB Layout Editor
Your schematic is concluded, it is time to create the PCB layout. Click at the seventh icon of Figure 5 that says “Run Pcbnew to layout printed circuit board”.
With the PCB Layout Editor click on the icon of the top toolbar (Figure 7a) to add all the components from the schematic. The window of Figure 7b will be opened, click on “Update PCB” button and all the PCB footprints will be added to the layout with connections.
Display all the components in a way to have the minimum white lines interception.
It is time to add the borders of your board. In the “Layers Manager” of the right side of the window (Figure 8a), click on the “Edge cuts” layer. Click at the ninth icon of the toolbar placed at the right side of the window of the PCB Layout editor (Figure 8b), then draw the borders around the components.
Now that you have the borders defined you can define the tracks of the PCB. Click at the fifth icon of Figure 8b then draw lines over the white lines present in the layout. If you want to route tracks in the back of the board, select the “B.Cu” layer in Figure 8a.
To create a ground plane, select the seventh icon in the toolbar of Figure 8b. The window of Figure 9 will appear. Since we want to create a ground plane in the back of the board we will select B.Cu Layer and the GND Net. Press Ok and then draw the border of your ground plane.
Generate Gerber files
Now that you are happy with your PCB Layout you need to generate the Gerber files. To do this, access File→Plot (Figure 10).
The window of Figure 11 will appear. Define the Output directory and click at “Run DRC” to search for errors. If there are no errors press the “Plot” button. Then press “Generate Drill Files” and the window of Figure 12 will be presented. Click at “Generate Drill Files”.
Access to the folder that you defined as the “Output directory”. Create a zip file with all the gbr and drl generated files.
There are many PCB manufacturers from whom you can order your PCBs. The one selected to show you were the JLCPCB. Create an account.
Access to the main page (Figure 13) and click at the “Quote Now” button.
The page of Figure 14 will be opened. Drag the zip file, that was previously created, to the “Add gerber file” button. All the entries will be automatically filled and you can click on “Save to Cart” and then finish your order.
In this tutorial was presented a PCB manufacturer. In a future post, I will show you how you can make your PCB at home.