[Voodoochile]

Help yourself to the pics. Please do add a photo credit, simply because I took them.

As for the etching itself, I also first bought the little ratshack kit, just to test the method. Works pretty well once you get the hang of how long to iron. Took me two tries with the sample material in the kit. After that, I just bought board from Digikey, and etch from ratshack.

Here is a board I made for a Klaus Noll amp that included DIP-8 pads:

A different version of the earlier PSU:

Another PSU board, showing the cornermarks:

...and built up below

And two other single-rail PSUs on home-made boards:

And a version of the right-hand PSU above,
with a board-mounted toroidal transformer:

 

[jerb]

The hardest part of the whole process always seemed to be tinning, yet I look at your board and see shiney copper (should oxidize). Does the laquer replace this step?

EDIT: those white Boards look bvery sleek, where are they available?

 

[joostoo]

Ok great. Thanks. Ill put the pictures up. But for now I'll just post the links to the pics, just until I have time to set up a photobucket account or something to post them.

And of course I'll give you credit

 

[joostoo]

Quote:

Originally Posted by jerb The hardest part of the whole process always seemed to be tinning, yet I look at your board and see shiney copper (should oxidize). Does the laquer replace this step?

Yes I believe it does. Spraying would cover the whole board however, and tinning would just cover the traces.

 

[Voodoochile]

Quote:

Originally Posted by jerb The hardest part of the whole process always seemed to be tinning, yet I look at your board and see shiney copper (should oxidize). Does the laquer replace this step? EDIT: those white Boards look bvery sleek, where are they available?

I have "tinned" some boards using a large amount of solder before, if there are not many traces. It does work, but cleaning up the flux is not a lot of fun. I tended to just buff the board well with 600 grit wet-or-dry paper immediately before populating. After soldering it all up and testing, I clean up the flux, then spray the foil side with three or four coats of clear laquer to avoid oxidation. Conformal coating would be better, but considering in most apps I was building PSUs, the laquer works fine.

The white-ish board came from Digikey also. Same brand as the green board, but a different size. If you have access to some means to cut the board simply, it is cheaper to buy larger pieces and cut them into smaller sizes. Less waste as well.

I wanted to make a couple comments on the drilling. I started with a 1/16" and tried a 1/32" bit as well, and they seemed too big, except for large caps. I ended up using "wire guage" bits in size #58. These I found at the local Ace hHardware for $1.50 apiece. You do need an auxilliary chuck if your press or other drilling implement does not go to zero. The chuck on my old press is a 1/2" Jacobs, and it only goes down as small as 1/16".

Another note about the drilling- a HSS bit does work fine, it lasts for 50-75 holes, and is cheap. However, I found it to work better run slowly. Now if you use a carbit bit, it works better running fast. SOme of the PCB suppliers sell nice carbide bits for this, and not only are they carbide, but they also have an undercut. The shank is 1/8", then it's undercut to the final size only at the tip. So it's very strong and not wobbly. With the HSS bits, I found that going very slow helps avoid bit flexing.

Last thing about drilling- it helps to make a tiny dimple on each location with a prick punch. You don't need to tap it with a hammer, of course. Just grip the puch firmly, and give a little press on each spot. The copper is soft, and it makes a nice tiny crater that the bit will center on immediately. This does not matter much with large pads, like electrolytic spots. But with smaller items like small box caps or ICs, you have to keep the bit from walking.

 

[Pars]

Quote:

Originally Posted by Voodoochile Another note about the drilling- a HSS bit does work fine, it lasts for 50-75 holes, and is cheap. However, I found it to work better run slowly. Now if you use a carbit bit, it works better running fast. SOme of the PCB suppliers sell nice carbide bits for this, and not only are they carbide, but they also have an undercut. The shank is 1/8", then it's undercut to the final size only at the tip. So it's very strong and not wobbly. With the HSS bits, I found that going very slow helps avoid bit flexing.

A place that I ran across recently has the 1/8" shank PCB type carbide bits for good pricing and are convenient. I would not try these without a drill press however. Shipping is reasonable also and they sometimes run specials such as 4 #59s and 4 #61s for $2.00 (with purchase of another set @ ~$8.95 or so.)

 

[Garbz]

I personally wouldn't bother tinning boards. PCB lacquer is cheap in comparison to the time taken to tin a board without a tinning machine. A justifiable expense really.

Voodoochile do you drill before or after etching? I drill after as the copper itself gives a bit of a guide to the drill. Mind you ever so often on really small holes I end up ripping the hole off, but so far there's always been enough of a trace left to simply solder normally.

 

[Voodoochile]

Yeah, I also drill after etching, and found the same to be true if the project has "printed" holes. On some things, I fill in these holes with a sharpie after ironing the toner. It allows you a bit of flexibility for some components.

By the way, you don't have to have a drill press to do this. A Dremel is a bit tricker to control, but does work. You can also use a hand drill, but it would take a while. There are nice stands that accept a portable power drill that you can buy for under $50. If you think you will make more than one or two boards, it is a great convenience. And also good for casework. I use my drill press more than any other stationary tool in my shop.

 

[Pars]

Quote:

Originally Posted by Voodoochile Yeah, I also drill after etching, and found the same to be true if the project has "printed" holes. On some things, I fill in these holes with a sharpie after ironing the toner. It allows you a bit of flexibility for some components. By the way, you don't have to have a drill press to do this. A Dremel is a bit tricker to control, but does work. You can also use a hand drill, but it would take a while. There are nice stands that accept a poertable power drill that you can buy for under $50. If you think you will make more than one or two boards, it is a great convenience. And also good for casework. I use my drill press more than any other stationary tool in my shop.

Same here. I drilled an A47 board with a cordless drill and #61 HSS bit... not fun. I looked at some of the stands but wound up buying a Delta drill press for ~$100, and would agree that it has quickly become the most used tool in the shop (other than soldering iron / DMM

).

 

[Garbz]

The stands are a pain because they aren't as sturdy as a drill press. I have one somewhere but for most small PCBs I do I pull out the dremel. If there's more then 40 holes or so I will grab the power drill and the stand though, my fingers get sore after holding a dremel for so long

 

[Voodoochile]

And you definitely don't want to be hogging out any big holes with a drill stand.

An added benefit of a heavy drill press.

 

[ozshadow]

I think this should be a sticky.

 

[a1rocketpilot]

I just went and got a PCB kit from Radio Shack today (the store near me is closing down, so everything is heavily discounted, the kit+extra ferric chloride usually would be around $20, got it for $6!). I can't wait to start making some of these boards!

Where do I find more blank copper boards for etching?

Aditya

 

[AtomBoy]

I am cheap cheap cheap, so I am willing to do a little extra cleanup on the slightly dingy copper clad board I get from Goldmine.

http://www.goldmine-elec-products.co....asp?dept=1034

 

[mono]

Quote:

Originally Posted by AtomBoy I am cheap cheap cheap, so I am willing to do a little extra cleanup on the slightly dingy copper clad board I get from Goldmine. http://www.goldmine-elec-products.co....asp?dept=1034

I sand down the edges of my boards and scrub the copper with steel wool then a green scrubber pad anyway so it doesn't really matter if they were pristine or not before I prep them. IMO, more important is FR4 or fiberglass and that you get the # of sides you need so you don't waste etchant, though if you need single side you can turn the other into a ground sometimes.

Sometimes you can get insanely good deals on ebay. I bought some previously somewhat like this and it's hard to even find 0.093", let alone reasonable prices for it, but make sure your component leads are all long enough. That seller has also had some 0.063" in the past and 2oz, 3oz copper too, he continually relists items so check back if he doesn't have what you need at the moment. It takes a bit of elbow grease to sand smooth fiberglass edges on something that thick unless you use a belt sander but it comes out very smooth and dark translucent, polished looking on the sides if you put the effort into it, IF that look is ok by your tastes, it does look a bit different than the light white color of rough cut edges.

Thicker fiberglass wears out drill bits faster too though, I wouldn't use the thicker stuff if you use HSS instead of carbide bits.