How to Make a Circuit Board

Circuit boards have made electronic products more compact.

Circuit boards have enabled electronics to leap forward in terms of complexity and consumer convenience. The simple sheet of non-conducting material with thin copper tracks etched onto one surface did away with wires and enabled complex circuits to be fitted into tiny spaces. Thin copper tracks replace wires, and the non-conducting sheet forms a strong base to mount the components on. Producing your own circuit board is a straightforward task requiring no previous electronic or engineering experience.

Difficulty:

Moderately Easy

Instructions

Things You'll Need

• Blank copper coated circuit board
• Indelible marker pen
• Nail polish
• Chemical resistant gloves
• Shallow glass dish
• Etching fluid -- ferric chloride
• Running water
• Acetone
• Cotton wool
• Model maker's drill

1. Sketch out the schematic circuit on a piece of paper. Draw all the components, the connections between them and any external connections such as links to a power supply or a jack socket. With the schematic circuit complete and checked for errors, start to rearrange the layout to create a circuit diagram based on straight lines with no overlapping wires, much as you'd see on a finished circuit board.

2. Cut a sheet of copper coated board to the desired size. Rub the copper surface with fine emery paper or a domestic scouring pad until it shines.

3. Copy the circuit diagram onto the copper side of the board using an indelible marker pen. Check the diagram for accuracy, and then when you are satisfied that it is correct, carefully go over the marker pen lines with nail polish applied with a fine brush.

4. Ensure that the area is well-ventilated. Don chemical-resistant gloves and mix a ferric chloride etching solution in a shallow glass container, using the concentration recommended by the manufacturer. Avoid skin contact at all times.

5. Lower the circuit board into the etching fluid, with the copper side facing up. Agitate the dish to ensure the fluid flows over the surface of the board. Check the progress of the etching process every few minutes until the unprotected copper areas -- those not covered in nail polish -- have all been dissolved. Remove the board from the solution and wash it thoroughly under running water.

6. Dry the board, and pour a little acetone onto a ball of cotton wool. Rub the etched circuit board with the acetone to remove the nail polish while avoiding contact with your skin.

7. Drill holes for the legs of the components using a model-maker’s drill and a bit of the appropriate size for the component legs.

Tips & Warnings

• Do a small "test piece" before attempting a complicated circuit layout. Becoming familiar with the thickness of the resistant pen and the correct way to apply transfers to the board before you lay out a complex design will save time and money.

• Every connection between components in the circuit diagram becomes a copper track on the circuit board. If wires cross over each other it doesn't matter -- they are insulated -- but if the lines on your circuit board diagram cross they will be joined together.

• The applicator brush that forms part of the bottle of nail polish is usually sufficiently fine for applying the polish to the board.

• Check the circuit board design carefully before moving to the etching stage. Once the copper has been stripped from the board it cannot be replaced.

• Acetone is the main ingredient in nail polish remover, which obviously is excellent for removing nail polish.

• Some types of etching fluid may trigger asthma attacks or breathing difficulties: Avoid inhaling the fumes.

• Etching fluid may attack other metal objects. Do not stir the solution with a metal object, and don't get it on jewelry, watches or other metal items.

References

• YouTube: How to Make Circuit Boards Fast -- Dx Way
• Make Magazine: Make Your Own Printed Circuit Boards on a Laserjet! (Video)
• Make Magazine: Circuit Skills: Circuit Board Etching (Video)