Wednesday, August 19, 2009

PCB! What the heck???

This post is especially for the beginners and hobbists. Its a great pain making huge circuits on bread boards and much more keeping them alive on them. Its good though in the start but when, its a matter of circuit with communication or clocks, u need noise free circuits. I remember trying UART for the first time and communicatig with the PC via RS232. It took us 3 days to figure out what went wrong. Our code was correct, written over many times, but still it didn't worked! And i guess the hardware was correct too.We finally decided to make a PCB. And it worked! But then what was wrong???

I would call it the inherit devil in each circuit. The "Noise". The more you keep your circuits open, they catch more noise. Remember each conductor is intelf an antenna. So when when it was on a PCB, following happened.

  1. No open or loose wires, which means proper connections.
  2. Atleast half of the noise due to wires was suppresses.
  3. It was easier to track down faults.
  4. Probability of working of project increased many folds.
Its not hard to make your own PCB at home. There are a lot of Free tools available to design PCBs. The idea I'm using here holds good only for single-layer PBCs.

Making a PCB is like developing a photograph. Here's what to do

1. Draw your layout using some PCB designing software (PCB EXPRESS (free of cost), EAGLE(Free for small boards), ULTRA ROUTE or anything that’s worth the money and you can lay your hands on.

2. Get its LASER print out on a cheap glossy sheet (my own method of cost effectiveness).

3. Put it upside down on to the copper plate.

4. Iron it for 3-4 minute.

5. Remove the sheet in one go.

Now you'll have a copper plate with black lines on it. Thats your circuit! Dip this in FeCl3 or H2O2

for 15 minutes. These will replace the copper, which comes in contact with the acid. The left over is your PCB. Yes one more problem though. the holes are still required. Well a small drill should do for you. Enjoy!!

1 comment:

  1. good h be....tu college walon k kaafi paise bacha rha h....apne clg jaisi jitni bhi PCB labs hoti hain....sab band karwayega tu....but yes its actually good for hobbists...keep it up!!!!