Introduction: Circuit Board Manufacturing Without a Computer Part 1: the Design
If you want to design and build a circuit board, but do not have the time nor resources to design it on the computer or a laser printer to print it, then this instructable series is for you. This instructable will show you how to go from the idea of what you want to build to the copper clad board with the traces marked on it with permanent marker. The next instructable will go through the process of etching it with ferric chloride. The video below will compliment this instructable and give an audio/visual explanation of it.
Step 1: The Idea
When you are designing and building a circuit board, you first want to have an idea of what the final product needs to do. In the case of the project in this instructable, I wanted to run an LED(Light Emitting Diode) using only the power from a dead AA battery, which only supplies about 1.2 volts. This is not enough to power an LED, so a voltage booster circuit or a joule thief must be used.
Step 2: Making/finding a Circuit Diagram
After you know what you want your project to do, you need to find or design and electrical schematic for it. To do this, you can either design a circuit yourself, find a schematic on the internet, or modify an already existing schematic from the internet. Once you have your schematic, you should test it on a breadboard to make sure your modifications work and that all your components are working.
Step 3: Designing the Layout
On a PCB(Printed circuit board), each component is connected by copper lines called traces. When designing the trace layout of your board, you need to first draw a scale board on your paper. You then draw the components as they actually are (not the schematic symbol) to scale on the drawn board on the paper. Make sure to put components that are close to each other in the schematic close to each other on the board. Also, make sure to include the pins of the component in your drawing. When all the components are drawn, connect the leads by drawing lines in between the pins. This part takes a lot of brain power because you have to consider all the other connections. This step may take many different tries to get the right trace layout.
Step 4: Preparing the Copper Clad Board
To prepare the copper clad board, you need to cut it to size, clean it with acetone, and sand it with fine grit sandpaper. This will allow for the best results on the final product.
Step 5: Drawing the Traces
To draw the traces on the board, you will need 2 permanent markers, one of them fine point, and one of them regular tip. I used a sharpie marker. You can the then draw the traces on the copper clad board using the design you created from step 3 as a guide. Use the two different types of permanent markers as you see fit; using the fine tip to draw low current traces and normal tip for mounting pads and high current traces. After drawing all the traces, go over them again with the marker for a second coat.
Before actually drawing the traces, draw thick rectangles as copper pads where the component pins will be soldered.
After your circuit board is prepared, move on to my next instructable on how to use ferric chloride to etch the circuit board and remove all the unwanted copper.