Here's instructions how to make a circuit board at home.
It takes about an hour and you have a self-designed pcb.
You can also watch my video on You Tube.
Step 1: Make Exposure Mask
Print a pcb picture on a transparent film. Print two identical copies of the picture.
Put them over, align well and tape together. The transparencies must be negative.
All transparent areas are final copper areas. All black areas are etching away.
You get best resul when print picture so that ink side is against to the pcb's copper (see the picture).
Sometimes you need to print a mirrored image. Usually it means that if the copper side is bottom, print normally picture and if the copper side is on top, print the mirrored picture.
Step 2: Clean Up Pcb.
If there is grease on the surface of the PCB, clean it with a solvent.
All alcohol based are good choice, example isopropanol.
Next remove all oxide using steel wool.
Now surface should be clean and polished.
Step 3: Film Over the Plate
When using a Dry Film, use only light that does not contain UV radiation..
Remove protective film. My experience shows that the dental tool is the best for this.
Sharp needle works as well.
Put the Dry Film top of pcb. Remove all air bubbles.
Heat up a moument with a hair dryer or heat gun.
Now the dry film adheres to the pcb. If the film not stick to pcb , heat is too low or time too short.
Step 4: Exposure
You can buy an exposure device or make your own. One simple option is to use a glass sheet and a lamp above it. The only condition is that the lamp emits ultraviolet light.
The exposure time is usually few seconds to few minutes, the time depends on the lamp power and distance to the pcb. My own exposure device is made from an old scanner and a face solarium.
It works well, the exposure time is only 15 seconds.
And that exposure.......
Put exposure mask against to pcb and switch light on. When the time is full switch light off. If everything went as it should, the same image as the mask appears on the surface of the plate (as in the picture).
WARNING!!!! uv light is dangerous for the eyes, use suitable goggles (block uv), do not stare at light or cover the exposure unit.
Step 5: Development
Remove second protective film from top of pcb.
Place the pcb in a container with 1.5% sodium carbonate solution.
Sodium carbonate (Na2CO2) also known as soda ash and washing soda.
In a few minutes and pcb should look the same as in the picture.
All the areas to be etching are clean from the dry film.
If something is missing on the pcb, it can be fixed with a permanent marker.
In the picture, the letter H has been fixed.
Do not forget to wear protective gloves and goggles when using chemicals.
Step 6: Etching
Place the pcb in container with 15-25% ferric chloride solution.
If you want to speed up this process, warm the liquid.
The liquid can be used multiple times, so don't throw it away.
The process takes about 15 minutes. At the end rinse well.
Remember protective gloves and goggles when using chemicals.
Step 7: Peel of the Dry Film
Also this time use protective gloves and goggles.
Place the pcb in container with 5% sodium hydroxide solution.
Sodium hydroxide, also known as caustic soda and lye.
The process takes a minute or two and the dry film is peeled off.
Rinse well and the pcb is ready for drilling and use.