If you are really into electronics and robotics, then you must MUST make your own PCB's.
Introduction to PCB etching using toner transfer method
In the following technique, I use a solution of hydrochloric acid (Muriatic acid) and Hydrogen peroxide and drop my copper board into it. Within a blink of an eye, you find that the board has etched and your circuit is ready to conquer the world.
If you feel that the instructable is summerized, feel free to check out the complete documentation and a video tutorial in my site:
Fine sand paper or Kitchen Scrubber
Muriatic Acid / Hydrochloric Acid (HCL)
Hydrogen Peroxide (H2O2)
Thinner / Acetone
Electronic or Hand Driller
Fine Drill Bits (0.5mm and 1mm)
Step 1: Paper and Printer Selection
Selecting an appropriate paper is your first step in making a right selection. Glossy photo quality paper or even a glossy thick magazine sheet would do wonders
I have used a printer to transfer the circuit diagram onto the copper board. If you are using a sharpie or a marker, go ahead with it. I haven't tested it, but I guess it should be OK.
Set your printer to output maximum toner and printer your circuit on the glossy paper
Step 2: Preparing the Board and Transferring Toner
Normal Copper board availabe at your radio shop would be good enough. Use a kitchen scrub or a fine sand paper and rub surface until you feel it is clean. DO NOT over do it. Once done, clean it with water and a clean cloth and avoid touching the surface
Transferring toner to board
This step is not as complicated as the title says. Switch on your cloths iron and turn it to its highest setting. Place the printed paper over the board and start moving the iron over it for 2-3 minutes. Now drop the board into a mug of water and peel off the glossy paper.
Step 3: Etching and Removing Toner From Copper Board
Mix Hydrochloric acid to Hydrogen peroxide in a ratio of 2:3 and drop your copper board into it. Within 5-10 seconds, you can see the copper removed from the board and tracks clearly visible.
Wash the etched board thoroughly in water and then use acetone or a nail polish remover and clean the surface so that the toner is removed and copper tracks are clearly visible.
Step 4: Drilling the Circuit Board and Soldering Components
Once the toner is completely removed, use a hand driller or an electronic drill and drill holes into the board to mount the components. Place the components and solder them across.
You are ready with a complete professionally (almost) looking circuit board. If you have all the tools and parts in hand, the entire process takes less than an hour.
Muriatic Acid is dangerous. Hydrogen peroxide, although not dangerous, still gives your skin a burnt effect. Be careful with these solutions
If you succeed or in case of any doubts, share your comments.