One of these days I will try out the photoresist approach. What copper thickness did you use for that? I think my etching time was for 1 ounce copper, although the board is from scrap and I am not sure how thick the copper is. I've been using toner transfer for my boards, usually with the DynaArt transfer paper. However, this last etch I was out of transfer paper so I used a photocopier with plain paper, which didn't work very well at all. I had to touch up the design with a sharpie to fill in all the dropouts. Later, Eric >I use photoresist and thin ccopper and it is very resistant to over-etching. >The board can be finished in 5 minutes, and if I take it out after 10 >minutes, no damage has been done. > > KreAture > >----- Original Message ----- >From: "jim barchuk" >To: >Sent: Friday, March 28, 2003 6:48 AM >Subject: Re: [EE]: Etchant tank > > > > >>Hi Eric and All! >> >>On Thu, 27 Mar 2003, Eric Schlaepfer wrote: >> >> >> >>>Well, this makes me feel good--I just etched a board today which took >>>over an hour to etch. (Fresh ferric chloride too!) >>> >>>Maybe I should get some kind of heater for the solution... >>> >>>Later, >>> >>>Eric >>> >>> >>> >>>>Just wondering... How fast do you get a board etched with this >>>>gravety-method ? >>>>With my self-modded bubble-tank I can etch a 70x120mm 1-sided board in >>>> >>>> >about > > >>>>5 minutes with fresh acid. Is it comparable to your speeds? >>>> >>>> >>I did about a year of 'small shop' PCB work many years ago. Did everything >>from film processing, resist laminating and exposing, silk screen resist, >>electroless PTH, etching, copper and solder plating, gold finger plating, >>shearing, routing. The only thing I didn't do much was drilling because I >>frigging hated it. :) >> >>There were no heaters or bubblers anywhere. In fact it was pretty cold in >>winter. The only agitation anywhere was the electroless. >> >>That '5 minute etch' sure makes me nervous. 'Enough' etch is enough. >>Anything more and it starts to undercut the resist. IIRC that was in the >>20-30 min range or thereabouts. Maybe it was the concentration, because >>now that I think about it the whole time I was there we never changed that >>solution. >> >>In any case my point is 'enough' vs 'too much.' For the solution we had, >>if 20 mins was enough and I missed it by a few % it was no big deal. The >>same % of 5 mins is *much* shorter and easier to miss, and possibly cut a >>track. >> >>I guess it's a matter of 'what's it worth?' If I spent a bunch of time >>drawing or dry transfering or photo shooting a board I don't think I'd >>mind much if it took a bunch longer to etch *and* I didn't have to worry >>about undercutting. The first two methods cost time, the last costs $. In >>either case I'd rather not risk needing to throw something away and >>starting over again. Besides, the extra time isn't exactly wasted because >>I'd be off doing something else anyway. >> >>Too eatch their own. :) >> >>Have a :) day! >> >>jb >> >>-- >>jim barchuk >>jb@jbarchuk.com >> >>-- >>http://www.piclist.com hint: PICList Posts must start with ONE topic: >>[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads >> >> >> > >-- >http://www.piclist.com hint: PICList Posts must start with ONE topic: >[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads