Come up and see my etchings December 9, 2007
I finally got around to doing some PCB etching. For my first experimental attempt, I made some little carrier boards for an SMD IC: a M62364FP digital/analog converter, intended for the analog meter project.
It’s been more than a month since I did the toner-transfer with a clothes iron to the copper-clad board (some incredibly thin stuff I bought at the MIT Swapfest a while back), but I’ve been reluctant to break out the ferric chloride and do the actual etching. The transfer was only moderately successful; there was a small degree of smudging. I don’t think the paper moved; I may have used too much pressure and/or heat. The smudging would have been acceptable for a board with larger traces, but it was enough to short some of the board’s traces. I had tried to scrape away some toner with an X-Acto knife before the etching, but that was only moderately (if at all) successful. I may try scraping away the tiny shorts with a diamond-tipped stylus; I think I have one around, somewhere.
The etching took a remarkably long time. I’d pre-heated the ferric chloride by placing the bottle in a tub of warm water, and the ambient temperature was probably 65°F, but it took nearly 30 minutes to complete etching. I etched two, one after the other, and each took about the same length of time. I should have probably left it in even longer; it could have removed the shorts.
While this wasn’t the most successful attempt, it was my first try. I’m optimistic. Once I get some heavier copper-clad board, I’m going to try making the motor controller board. More board, along with some 3A diodes, is in the mail.