A printed circuit board (pcb) mechanically supports and electrically connects electronic components using conductive tracks, pads and other features etched from copper sheets laminated onto a non-conductive substrate. pcb’s can be single sided (one copper layer), double sided (two copper layers) or multi-layer. Conductor on different layers are connected with plated-through holes called vias. Advanced PCB’s may contain components - capacitors, resistors or active devices - embedded in the substrate.
Have you ever wanted to make a circuit board at home? Now you can, for use in all types of homemade electronic components.
Method 1 of 5: Design
1. Have a procedure in mind before attempting the task. Remember, a good design comes first.
2. Draw the circuit schematic on either graph paper or a simulation programs such as MultiSim or Eagle CAD. The schematic should contain a detailed description of all parts, as well as easy to follow connections. Keep in mind that a basic form of the schematic will be drawn on the circuit board. For help drawing schematics.
3. If a simulation program is being used, test the circuit thoroughly in the simulated environment. If no simulation program is used, assemble and test one or more prototypes of the circuit on a breadboard. Breadboards are very easy to use, and allow one to view the results of a circuit in real time without the need for solder or permanent etches.
4. Make sure the circuit functions on the breadboard, or in the simulation software.
Method 2 of 5: Drawing
1. Acquire a circuit board. Circuit boards are about a dollar apiece, and are simply a layer of copper over an insulator. The typical size is usually 3.5 inches by 5 inches. Drawing is simple; all that is required is an indelible marker, such as a Sharpie. A ruler is also helpful.
2. Draw out your circuit on your board with the Sharpie. Keep in mind that copper cannot be between components, for example, if connecting an LED, there must be a gap in the copper between the positive and negative points of connectivity. Without a gap, the electricity would flow around the LED, as opposed to through it. Remember laws of electricity, all circuits must end at either a negative or ground, or no current will flow.
3. Use thin lines, but lay the ink on thick, it is important that the copper is dissolved before the ink, and that there are no thin patches in the ink exposing copper.
Method 3 of 5: Etching
• A non-metallic basin that is deep enough to submerge the circuit board
• Goggles
• Vinyl or Latex gloves
• A non-metallic device used to agitate the circuit board (a stick)
• Hydrochloric Acid ca. 30% (Muriatic Acid)
• Hydrogen Peroxide 3% (rest is distilled water)
• Rubbing alcohol
• Acetone or mineral spirits
1. Put on the goggles and gloves (non-optional!). Always remember safety first. You can easily blind yourself!
2. Make sure the area is well ventilated before mixing. The chemicals will produce hazardous fumes. You can loose your sense of smell!
3. Use a non-metallic basin. Check if it can withstand the acid using a few drops.
4. Gently pour one part hydrochloric acid into every two parts hydrogen peroxide (add acid to water). When mixed, they form a substance that is a severe skin irritant, and will produce toxic chlorine gas.
5. Make enough of the solution to completely submerge the circuit board.
6. Gently put in the circuit board and agitate it for about ten to fifteen minutes. The solution will get wamer and fume more. Don’t put your face over it!
7. Continue stirring until all copper has dissolved, and the solution has taken on a slight green tinge.
8. For cleanup, make sure you are wearing gloves. Wash the board off in cold water to remove any etching solution. Then use a paper towel or rag to dry it off completely. Set it aside. Assure that there is no solution in the workspace or containers then remove the gloves and goggles.
9. Mix a one to one ratio of acetone and rubbing alcohol. Take a paper towel, dip it into the solution, and gently rub it over the surface of the board. The permanent marker will begin to come off. Continue rubbing until all marker is gone. You should see that your circuit is now inscribed in the copper.
Method 4 of 5: Assembly
• Hand-held Drill or Drill Press
• Various drill bits
• Soldering iron
• Solder
1. Before drilling locate all the positions of the through-hole components. Copper dust is toxic, wear a dust mask.
2. Drill through the board with a bit wide enough to accommodate whatever part must be placed at that location. Remember not to make the hole to wide, or soldering will be very difficult.
3. Place the components on to the circuit board at their designated locations. Gently bend the legs of the component against the underside of the board, to hold the part in place. Make sure parts with polarity are lined up correctly with the corresponding positive and negative. Check and double-check the location of all parts before soldering.
4. Soldering is a skill that requires practice, although it is not inherently difficult.
5. Test your circuit board before installing it into its permanent location. Use a multimeter, if possible, to diagnose connection problems. A De-soldering gun can be used to make minor switches and repairs.
Method 5 of 5: Disposal
The etching solution is toxic to fish and other water organisms. Don’t pour it in the sink when you are done. It is illegal to do so and might damage your pipes. You can reuse the solution by adding a bit of Hydrogen Peroxide right beofre the next etch and a bit of acid when the solutions stops working (every 4 or 5 etches). If you have to dispose of it label it and give it to chemical waste facility. You can also fell out the copper (video) and then safely pour the remaining liquid in the sink.
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