Byron A Jeff wrote: ----------- >=20 > > possibly using just etch resist pens at first and then using some o= f > >the simpler photolithography systems. >=20 > Even as a rank novice who has never etched a board before I don't think > that's the right approach. With software such as Eagle and gEDA/PCB ava= ilable -------- as i said, possibly. learning a lot of things at the same time is difficult for some people and makes it much harder for them to get it right, they sometimes even get frustrated and give up. every pcb board program i've seen has a significant learning curve, as do schematic entry programs. you have to define your parts (or use the libraries if you like them), make sure you handle power and ground connections correctly (which is very easy to mess up on most cad programs, particularly if you use more than one parts library and or your own parts). with the board layout you also sometimes have to define new lan patterns etc., so there can be a lot to do long before breaking out the copper panels and chemicals. > > then > > try tin plating and other things like building an etching tank with a > > bubler and doing double sided boards. >=20 > I think the days of the resist pen on bare copper dipped in FeCl are > over. Nothing about an etching tank is too terribly difficult or > expensive. >=20 > BTW another dumb question: Can etchant be heated in a microwave? > I mean it does contain metal right? the dissolved metal, will be metal ions, which is very, very different than solid metal. they will tend to make the solution absorb microwaves faster and heat faster most likely (as they are polarized and hence react to electric fields). the problem is you'll be producing etchant fumes in your' microwave, which won't do anything good for the microwave. you'd also want to watch it very closely, if you walked away and it started boiling a huge volume of fumes would be released, very bad for the microwave (which you might not be able to get to) the house and you. microwaves are used in some chem labs to heat things quickly, but generally only in closed containers designed to handle the pressure or those with a vent line that's run out of the microwave through a suitable hole with some shielding, i.e. it has to go around some plates that make "shadows" in the microwave field so the microwaves don't leak too much. best not to use a microwave for these things unless you are very careful and don't mind wrecking the microwave. normally, the best way to heat etchant is to use a fish tank heater in the tank, they have a glass sleeve so are compatible with nearly anything (other than solvents because of the switch contacts and the risk of fire/explosion). these are cheap and have a thermostat, it's not calibrated so you definitely want a glass thermometer or suitable thermocouple probe to set initially, but once you know what setting is the right temperature you can mark that on the thermostat. much better than using a very high wattage, very quick heating microwave that cost money and has to be watched like a hawk watching a mouse. given your' apparent lack of chemical knowledge (and i'm trying to be helpful, not rude, everyone is ignorant of many things) if you are still in school i'd strongly suggest taking some chemistry. it's very useful in other technical fields and teaches you the basics and the basics of good lab practice which is important with hazardous chemicals to avoid injury and property lose. if not, some self study with a chemistry text and a chemistry kit are a good idea (though the chemistry kits i've seen are very weak on theory, it might be better to get a lab manual for an introductory chem class that goes with the book and try some of the experiments). of course if you are going to do chemistry, you should get a decent balance or scale, ebay is a good place to look for basic lab ware are some surplus companies. even just reading through instructions and expected results for chemical experiments can be educational and you may have trouble getting some of the chemicals unfortunately (though the companies that sell chemistry sets cary many of them in small quantity, i don't know if gilbert has a web site or not). in any case, even an expert needs to take care when handling strong oxidizers, acids, and solvents, particularly in the largish quantities needed to make a pcb board (there are few if any chem lab courses that use quarts of reagent at a time! it's usually a lot less than an once and only a few grams at a time, just in case, and the reagents are also usually diluted for safety as well). any thing you learn about chemistry will likely be of some use to you in your life. many chemical supply companies have charts of chemical compatibility, it's good to check them out. cole-parmer.com has a good one that you should be able to download. sometimes it's surprising what a given material can or can't handle without problem. --=20 Philip Stortz--"In Germany they came first for the Communists, and I didn't speak up because I wasn't a Communist.=20 Then they came for the Jews, and I didn't speak up because I wasn't a Jew.=20 Then they came for the trade unionists, and I didn't speak up because I wasn't a trade unionist.=20 Then they came for the Catholics, and I didn't speak up because I was a Protestant.=20 Then they came for me, and by that time no one was left to speak up." -- Martin Niem=F6ller, 1892-1984 (German Lutheran Pastor), on the Nazi Holocaust, Congressional Record 14th October 1968 p31636. _______________________________________________ http://www.piclist.com View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist