I have seen several tutorials on the Internet for making professional looking PCBs at home. In fact, I attempted making a few last year with limited success. However, I managed to perfect the technique yesterday. The procedure I used is described in this tutorial.
I made some minor changes to materials and made a few perfect PCBs. First of all, the quality of bare copper clad sheet is very important. There are two type of copper clad sheets available here (in Trivandrum):- Paper phenolic and Glass epoxy. Never use paper phenolic type for this technique. The copper layer detaches itself from the paper phenolic substrate when you apply heat.
Secondly, clean the surface of the glass epoxy board using Brasso. Brasso is available in hardware/stationary shops. Put 5ml Brasso on the copper clad sheet and rub it with cotton waste. The oxide coating on the board will be completely removed and its surface will become shiny. The paper I used is called “art paper” , as per the local store keepers nomenclature. A2 size sheet cost around Rs.5.
I printed the mirrored layout on a HP1020 printer at 600dpi. The iron was set at the maximum temperature range and heated for some 5 minutes. Then I fitted the printout on the copper clad and applied the iron for another 3 minutes ( until the paper turned slightly brownish) . The board was them socked in water and I could peel of the paper. The pattern was perfectly transferred to the board.
I have observed the following while developing the procedure.
a) Cleanliness of the board is very very important. Give extra care to it if you ever attempt making PCB at home.
b) Transfer the image as soon as possible after printing.
c) Keep the temperature of the iron maximum.
d) ( In Trivandrum, you should attempt it only after 2. AM in the morning. Your power supply voltage will be 230v around that time. Normally, I get 160 -190v during day time. So this condition applies to Trivandrum only 😀 😀 )