For some time now I have been tinkering with electronics again. It has been over 8 years that I've touched my electro stuff, so I'm trying to get the hang of things again. Today I made a second attempt at etching a couple of designs a have been working on for the past months. The results of the first attempt, three weeks ago, were a little disappointing to me. The etched boards looked bad; Thin, ragged traces and shabby pads and vias. So today I decided to give it another go. And Lo and Behold! The resulting boards are absolutely gorgeous! Compare the first and second attempt and you'll see what I mean:
I am one happy camper. Lovely results. The smallest IC pads you see there are 10mil (0.3mm) wide. Not bad at all. The etchant I use, sodium persulfate, is pretty nice stuff. Besides its pretty blue color, after etching a few boards that is, it is also very consistent in the time it takes to etch a board. After 6 minutes of etching, bare spots start to appear. At 6:30 most of the copper has been eaten away and at 7:00 the board must be removed from the etching tank because it is ready. If you do not remove the board in time, the etchant will ruthlessy eat away at you board and in no time flat it will be ruined. That is what happened in my first attempt at etching when I let the boards hang in for much longer than 7 minutes. Oh well; lesson learnt.
Oh, and check out the nifty baskets I made today, in which to suspend the boards in the etching tank:
I didn't want to drill holes in the boards to assist in etching, so I fabricated a few of the above baskets. It took one piece of electrical wire and one minute of folding to make. In my first attempt at etching, I used another type of basket, but the boards kept falling out of it, which is quite a nuisance considering they don't float and are suspended in a bath of deadly etchant. So now I have new and better baskets from which my boards can no longer escape. Yay.