Anyone who knows me well will tell you that I am a true do-it-yourselfer. My father instilled in me at a young age a "you can do anything you set your mind to" attitude. So when I heard that it is possible to make your own PCBs at home using a laser printer, photo paper, and a regular household iron, I knew I had to find out just how to do it.
As an aside, this idea reminds me of the 25-year-old law student at the University of Texas who earlier this year thought that everyone in the world should be able to manufacture their own guns at home and distributed blueprints via the internet to do just that using a 3D printer. The US Government quickly shut that operation down. But the idea of being able to 3D print practically anything at home (with components less than 3 feet in length) is mind-boggling. Imagine the possibilities!
Let's face it, homemade PCBs are far less controversial and can be done with a simple laser printer. As I looked further into the process of making a PCB at home, I realized that I might have oversimplified the list of materials needed. In addition to the laser printer, photo paper, and iron, you are also going to need stripping pads, a copper board, isopropyl alcohol, masking tape, a soft toothbrush, ferric chloride, safety glasses, rubber gloves, acetone, liquid tin, and some sort of PCB layout program. Don't let this list intimidate you. All of these materials are a few mouse clicks away and can be at your doorstep within a couple of days.
The first step is to layout the circuit you wish to create, including all required parts and copper traces, in your PCB design software program of choice. There are many very good, and easy-to-use, PCB design software packages available. However, for making a PCB at home, a free program such as DesignSpark PCB from RS Components is ideal. Once the layout is complete, use a laser printer to print it onto a piece of laser photo paper.
As we learned early on in school, it is always good practice to put on safety glasses before starting any science experiment. So with safety glasses on, use a stripping pad to remove the oxidation layer from a copper board, appropriately sized for the circuit you plan to make. Clean the surface with isopropyl alcohol and then carefully lay the photo paper with the printed circuit face side down onto the copper board.
Next, use an ordinary household iron at high heat to press firmly on the backside of the photo paper to transfer the printed circuit onto the copper board. Place the board with the paper stuck onto it in a warm water bath to remove the paper from it. Using a soft toothbrush and water, remove any residual paper from the copper board to reveal a toner trace of your circuit on it.
Submerge the printed circuit board into a warm bath of ferric chloride. Using a sponge and rubber gloves, gently rub the ferric chloride onto the surface of the board to etch the copper traces and then rinse the board with water. Next, clean the board with acetone to reveal the copper traces and immerse it in a bath of liquid tin to protect it against oxidation and make it easier to solder components onto it. Give it a final rinse with water, and voila, your printed circuit board is ready to be drilled for any leaded components and mounting holes.
The entire process can be done in a few hours. Maybe I'm easily impressed, but I think that this is a really cool project for any hobbyist or do-it-yourselfer like me. What do you think? Last year I gave my 13-year-old son a robotic kit for his birthday. Guess what he is getting this year? A beautifully wrapped box containing all of the materials listed above and a copy of this blog. (See figure below of my shopping results...)
How about you? What PCBs have you made at home?
This article was originally published on EDN.