no agitation etching

[mikey]

I came across this method for etching a few weeks ago.  I dont know if anyone here uses it but it works pretty well for me.

http://www.cam.org/~burt/circuits/no-agit.html

Basically you put a piece of tape on the backside of your pcb to make a little handle and then use surface tension to float the board copper-side down on top of the etchant.  Gravity pulls the removed copper to the bottom of the tray so you dont need to agitate the junk away.

[rockgardenlove]

Wow, nice!

[Mark Hammer]

1) Buy a container of toothpicks.
2) Prior to etching, drill a small hole, the diameter of a toothpick, in each corner of the board.
3) Insert toothpicks and snap them off so that the board rests on "legs" that keep it as far from the bottom as possible, while still not above the surface of the etchant.

Point a goose-neck "study" lamp at the back of the board, from about 4-6 inches away.

Works like a charm,  I wish I used it more often, but sometimes I'd rather just sneak off into the garage and etch than tell my wife why I'm poking around the pantry looking for toothpicks.    The nice part is that while surface tension CAN keep the copper board afloat for the full etch, it is not 100% reliable.  With the toothpick legs you know the board will NEVER sink, even if it does manage to get some etchant on the component side.

[soggybag]

I always put my boards in face down. Sometimes I'll rest them on a pencil or something small to hold them up.

[Peter Snowberg]

Welcome to the forum!

Great link!

[R.G.]

I used to use the plastic clips from men's slacks that litter the fitting rooms at department stores. Clip these across the corners and it supports the board a bit off the bottom.

However - I've used the floating methods, and the suspension methods. These always etch the edges first, and later the middle, indicating to me that the stuff falling from the center is pulling in fresh etchant from the sides in a laminar flow. That would etch the edges first because the flow is always inwards, and in the center the etchant is most polluted with byproducts.

Bubble etchers and spray etchers are the way to go for fast, even etching. Trays with some suspension and rocking are for fast(er) and simple/cheap. You can get away with no agitation if your resist is good and the lines aren't fine enough to suffer from edge undercutting.

[The Tone God]

Lately I have almost completely done away with immersion style etching methodologies. Now I just soak a dish washing sponge with etchant and scrub the boards directly occasionally squeezing out the sponge of used etchant for fresh. Works great. The abrasion helps break through the initial layer of oxidation/dirt and it makes sure the etchant is moving around making contact. You can also pick a spot that is tough to etch and focus on that area not worrying about over etching other areas.

I can do a whole large-ish board in 5-10 minutes easy. You have to use a resist method that can stand up to the rubbing. I find the toner transfer methods like photo paper and transparencies work well and I suspect that P'N'P' will work too. I would not use this with etch resist markers or photo exposure. Of course I do this in a sink filled with hot water with the board and etchant in a tub while wearing latex gloves.

Andrew

[Paul Marossy]

As of late, I have been using the swirl method - a glass jar with a plastic lid. It's an old Jiffy jar or something like that. Anyhow, what I like about it is that I can put the lid on, stick the jar in hot water in one half of the kitchen sink and agitate the heck out of it. With fresh etchant, I can etch a PCB in about five minutes. And the etchant can't get into the kitchen sink because it's closed.  Works pretty good for smallish PCBs.

[mikey]

Welcome to the forum!

Great link!

Thanks.  Good to be here.  I've been a regular visitor for months but just recently registered.  This site has been immensely helpful and informative.  Everyone involved here has done a great job spreading knowledge.