Thursday, August 7, 2014

ETCHING A PCB (old tech)

I have started etching the pcb on the old style, with oil paint and brush using the free hand drawing small non critical pcb.
it worked out good . will soon publish the foto graphs of the process. its an 80 meter oscillator and buffer.
Etching the PCB

From my last visits to metro I bought glass epoxy pcb 1foot size, prize rs.175/- .

I needed something to etch. I was very busy. Now, when I am not working for govt, I have to put more quality hours for family ,works etc and its little odd  for me. So, I started  with a small simple thing first carved out 1.5 inch by 2.5 inch piece from big board by small hacksaw.

Then bought small FECL3. Ferric cloride. The dealer did not give me big bottle but  a small bottle for 50/- even that was half empty. Due to rainy weather this fecl3 became semi liquide from the crystal powder. Ok.

I can not find the small size drill-beat , so will place the components as  SMD style without any hole. The pcb was traced as an island pads with lots of ground plance to sooth the rf. Oil paint for covering the copper to protect it from etching. Then  let it dry for over night. It did not look like straight line but just work of the picaso ( the artist). In the morning I could not find it dry so, used a simple  fan to throw air on it .PCB dried somewhat after 4 hours.

Then put PCB into the solution for etching and after one hour it started eating up the pcb. After rinsing I will see what it looks like. i used small glass bowl for etching container. You should never use metal. Use plastic or glass. It is possible that material may stain your workbench, so i put the bowl away from childrens in verandah. within 1 hours it started eating the copper and around 1 and half hour it was done.

As of 28 april 2015 . I have downloaded and installed the student version of the deeptrace.exe. the pcb design software. Its very good one. It has everything needed for designing the professional quality pcb.

On suggestion of friends I tried the H2O2= hydroge paroxide, HCL-hydrochloric acid. Pour about 100ml of h2o2 in the plastic bucket. Then gently pour the hcl. put  the pcb and within 10 minutes your pcb is etched out . Clean it with water and its good. Etching process if very faster , even with this.

Earlier I was using the fecl3 but that took lost time and was not good.