How to make a homemade PCB (shield for arduino)

Sometimes in our projects we need to connect different sensors and peripherals at the same arduino board and usually this thing involve many wires and space, don’t have a solid base for the parts so, those few inconveniences are eliminated with a PCB.

First of all this are the materials we will use:

-one side copper clad

-a laser printer

-photographic paper

-isopropilic alcohol

-acetone

-ferric chloride(corrosive and use gloves)

-kitchen sponge(with one more abrasive part)

-iron

-1 mm(0.8 mm) drill bits

-electric screwdriver

To start making the pcb we need the circuit, which we’ve made with fritzing (you can download it from here). When you finish the pcb go to File-Export for Production-Etchable(PDF). After that go in the folder where you save the pdfs and for copper layer choose “…._etch_copper_bottom”.

Next, print the pdf to a photographic paper as you can see in pictures below:

To prepare the copper layer use the kitchen sponge and with the rough part scratch the layer until it looks like in the picture:

Clean it with isopropilic alcohol and put the schematic with face down(to the copper) like below:

Next step with the iron start to push the paper from a corner to another. We use the highest temperature but with no steam. After one minute with iron on paper take a napkin and try to aplly pressure on paper with linear moves(be carefully is hot), and again with iron.

After three minutes while you alternate these processes let the board to cool down at the same temperature as water temperature, ant put it in the tank. When you see the paper mouisturing try to remove the paper like in the images:

To remove the finest paper residues use a thootbrush.

To see if it is no paper between the tonner lines let it dry and must bee no withe material between them. If it is, wet the board and rub with thootbrush again, otherwise it will remain copper around lines and problems appear.

The final board look like this:

Now we need to eliminate the cooper outside the lines so, in a dry tank put the feeric chloride and insert the board. Check after five minutes to see if the copper between lines is fully corroded, if not, insert it again and check later, if no copper is existing between the lines wash the board and let it dry.

The result is like in the image(the board is still wet):

Now with some acetone remove the tonner from the board and you shold have a bord like:

To drill the board we use a electric screwdriver(is slow than a drill but with the drill is a high risk to broke the 1mm bit) with a drill bit chuck adapter.

In the picture below is what we use(recommend a straight screw driver-easy to grip and hold above the board)

Tip!!!

Before to start drilling use a center punch or if you have a hard metal screw (like a sharp point screw) you can sharpen it more if is necessary and use.

After drilling the board look like

Now, to look like a professional board, on the other side with the “….etch_silk_top_mirror pdf” from the folder created before we will print the number and name of each component. This procedure it will be done with normal paper and without water.

After printing, on a window or a lamp match the shematic on the paper with the holes on board. When you match them on the paper’s corners(one or two because we use the iron) put some tape to keep it in position. With iron, easy not to move the paper push it on the board with circular moves. After 1 minute try to raise a corner of the paper and see how it looks. If it’s not so great let it down and apply more pressure on that spot, again easy not to move the paper.

The final result without the parts mounted on it in our case(is a little glossy because we use a Plastik70 spray to protect the toner) is: