DIY PRINTED CIRCUIT BOARD MANUFACTURING!


Under Construction, I'll finish this very soon!

Have you ever wanted to make a printed circuit board from your own custom electronics creations, but didn't know how or where to start? Well here's a short tutorial on how Electromagics makes its circuit boards. This process is relatively fast and cheap. With a little practice, you can make a few boards in an afternoon. This process can be extrapolated to create double-sided PCBs, but for the purposes of this tutorial, we will stick to single-sided PCB manufacturing.

Let's get started with materials! You will need the following:
- A method of cutting circuit board to size (we use a really big paper cutter and "nibblers")
- A method for drilling the boards (a drill press or Dremel is highly reccomended)
- Access to a laser printer or photocopier
- Clothes Iron
- Round dowel-like object
- Flat clean workspace
- Ruler
- Scissors
- Files (for shaping cut pcb)
- Drill bits for component lead sizes
- Blank copper-clad circuit board (double or single sided)
- Plain printer paper
- Blue Press-N-Peel sheets (do a google search)
- Ferric chloride solution (or make your own with 1:4 ratio FeCl to H2O)
- Rubber gloves
- Chemical goggles
- Protective clothing that can be stained without worry
- Acetone (nail polish remover)
- Rubbing alcohol (the higher the concentration the better)
- Paper towels
- Steel wool or similar abrasive

To create a finished PCB from these materials, steps are illustrated in detail below. But the basic process is:
- Clean & prepare the PCB Material
- Transfer trace design onto PCB
- Etch away uncovered copper
- Drill the PCB
- Sand, clean, and Tin PCB

STEP 1:
The first step of PCB Manufacturing (besides acquiring the materials) is to get the design for your PCB traces onto the Press-N-Peel blue sheets. To do this properly, the image must be "burned in" using a laser printer or a photocopy machine. As Electromagics does not have an in-house laser printer, what we usually do is print the design (or a sheet of designs) onto a piece of plain printer paper, and bring it down to the local convenience store and make a copy of it onto the Press-N-Peel. It is very important as well that the image is printed on the matte side of the Press-N-Peel, and that it is a mirror of what it should look like on the actual board (which, is a mirror of the layout looking from the component side of the board).

STEP 2:
The next step is to cut the PCB material to the size of the design. Cut the edges relatively close as shown to save valuable PCB material. Cut the design close as well. This will help with ironing as long edges hanging off of the board may tend to shrink wrinkle when applying the heat from the iron. Make sure to also file the edges of the PCB down so that they are not higher than the rest of the copper layer. This is important because a flat copper layer will conduct heat better from the iron, and transfer the design evenly.

Step 3:
Once the PCB material and the Press-N-Peel label are properly shaped, the PCB will need to be cleaned thoroughly. Rub the copper down with rubbing alcohol and steel wool, or a similar abrasive material. When the copper has been polished with the abrasive, rub it down with paper towels and rubbing alcohol until the towel remains clean.

Step 4:
Preheat the iron to a setting somewhere between cotton and wool. Here are a number of polished and cleaned boards ready for transfer!

Step 5:
To transfer the image properly to the PCB material, lay the design on your ironing surface face up, and place the PCB face down on it so that the design lines up properly.

Step 6:
Place the hot iron on the back of the PCB and wait about a minute. Heating the PCB in this way will cause the Press-N-Peel label to adhere to the copper face without shifting. Starting the ironing on the Press-N-Peel side can cause a shift of the design due to the force of the iron before the label has adhered to the copper.

Step 7:
After the label has adhered to the copper, remove the iron and carefully flip the board over, and start the real ironing. In the photo above, a drill bit is used as a rolling pin to apply even concentrated force to the board as the iron rolls the board over the pin. This is not entirely necessary for small boards, but may prove very useful in getting even transfers of larger boards.

Iron the board with slight force for between 2 and 4 minutes depending on the size of the board. Experiment with your iron, as the times may vary. The thing to watch for is a slight rising of the traces on the design implying that the ink has transferred.

Step 8:
When the design is suspected of being completely transferred, carefully move it (it will be very hot) to a water source to cool it completely. It is very important to cool the board before the label is removed, or the ink may lift off the hot copper.

Step 9:
Carefully peel off the Press-N-Peel label. Here is a board with a recently removed Press-N-Peel label. You can tell where the traces have only half-transferred by looking at the Press-N-Peel. Everywhere there is ink on the label will need to be fixed on the PCB with a sharpie or other fine tip permanent marker to ensure the trace will not be etched. In the photo above there is only ink on the border layer which will not transfer signal, so it won’t need to be fixed for full functionality.

Here are 4 completed transfers that have been fixed up with a purple sharpie.

Step 10:
Prepare the etchant. Electromagics uses Ferric Chloride solution as its copper-etchant. The etchant cannot be placed in metal! It will totally corrode anything metal it touches, including your pipes, so do not dump it down the sink when you are done! Corning ware makes a good etching tank, as does most plastic containers, however any containers that are used for toxic chemicals like those used in this tutorial should never be used for food again, and that goes for any tooling the chemicals come in contact with, including the toaster oven in the picture above. If the etchant is mixed fresh from water and Ferric Chloride (FeCl), the reaction will be exothermic, heating up the fluid and its container considerably, so be careful to use a microwave safe container. For this tutorial, the solution was mixed a week before, so the toaster oven was used to heat the solution back up. A hot solution will generally etch faster than a cold one.

Step 11:
Carefully place the board in the etchant. Use gloves, wear junk clothes, and try to clean up any spills as fast as possible, this stuff is nasty in that it will permanently stain almost anything, and seems to just get out the container on its own. Carefully agitate the solution periodically. The etching process creates sediment from the copper which needs to be removed from the surface for maximum efficiency. Vertical etching tanks with bubble agitation would be ideal, but laying the board flat is a quick fix that generally works well enough. Watch for little bubbles on the board, and try and pop them with a stick so that the board will be etched evenly.

Step 12:
Rinse the board when it is finished etching. Here are 4 etched boards ready for drilling!

Step 13:
Drill the board for through-hole components. Experiment with different bit sizes for different components, jumper wires, etc until you find a good fit. A scrap piece of PCB is a good idea for this. Try and use as fast a drill speed as possible. For this reason, a dremel is often used. However a press is a great option as it allows you to lay the board on a piece of wood and manipulate it under a stationary bit. Be careful and work out a system that fits your needs.

Step 14:
When the board is fully drilled, it must be cleaned. This process is similar to the cleaning process before the Press-N-Peel transfer, except that now the Press-N-Peel ink is the thing that needs to be removed. Acetone (nail polish remover) works wonders, but it can cause the ink to seep into the PCB board, which is only an aesthetic problem, but this can be avoided by removing the majority of the ink with steel wool and alcohol first. When the ink is removed, wipe the board clean with alcohol.

Step 15:
When the board is fully cleaned, carefully submerge it in Liquid Tin. Liquid Tin is a remarkable product from MG Chemicals that will change the copper, making it silver, easy to solder to, and resist corrosion. The board will change almost instantly, but generally will benefit from a deeper soaking, 2-3 minutes is recommended. The same rules apply to Liquid Tin as they do for the etchant, except that Liquid Tin is a lot more harmful, and carcinogenic. Use proper ventilation, and be careful not to get it on your skin.

Step 16:
After the board has been tinned, rinse it clean, and you’re ready for soldering! Remember, this is just one of many ways to make PCBs in the home, but this method is relatively cheap, fast, and easy for small-run PCB jobs. Good luck and feel free to contact me at chris@electromagics.com with any questions or comments on this tutorial!