Recommend good PCB layout software?

[Steelwolf]

Hi all,

Just planning to take my circuit layouts one step further by having a nicely laid out PCB that I can etch. I've been hand-drawing and hand-milling the layouts so far.

A quick search on Yahoo revealed quite a few companies willing to give you free software to layout your PCB, but which is the best, most user-friendly with capability for odd shapes and angles? This is to run on a WinXP.

BTW, how do you create those nice, neat, professional looking PCBs? I know you can have them professionally milled (like what many of these companies are offering) or you can do the UV-imprint, photo-sensitive etch-resist and ferric chloride etch. Are there any other ways? Especially those that don't involve expensive photo developers and such stuff?

TIA

 

[raggie33]

i dont know if this helps googled this pcb software

 

[Doug S]

This subject comes up regularly. Do a search in the electronics forum and you will find some good stuff. For really low budget image transfer, there is a technique involving using laser printer toner as the resist.

 

[Steelwolf]

Raggie33: Thanks. That was one of the first I found and downloaded. There are a couple of others and I intend to try them out over the next few projects.

Doug: I hazily remembered that one about the toner transfer technique. Did a search on that. Thanks. It seems that the best way for that technique is to use their special paper, though someone else posted that it is possible to use normal paper in a pinch.

I saw a paper like that in the store recently. But it uses UV to develop, rather than relying on the toner to be the etch resist. So I'm not sure, but I think this one works with inkjet. Expensive though, AU$34 for a sheet, or maybe that was 5 sheets. Got to check again.

But for most of you, what is the easiest method you have found? What method do you routinely use? Are there any other cheap or simple methods for the hobbyist? I was thinking of maybe some way to apply lacquer as the etch resist?

 

[robk]

Try "Eagle Layout Editor" from www.cadsoft.de for PCB layout. Regarding toner transfer material, the best I've found is "Press'N'Peel" blue (do a google search) it takes a little practice, but works well. One other thing- use Ammonium Persulfate for etching, much nicer than that nasty Ferric Chloride. You can get it (and "Tinnit" also) at Circuit Specialists.
Rob

 

[dat2zip]

For toner transfer process the best is the company that was called Dyna Art now Pulsar. The guy doesn't get picked up by the crawlers and he doesn't show in any web searches. I've been using his stuff for over 10 years now.

http://www.dynaart.com

He has perfected it to a T. I can fully recommend his process now. It works every time.

No more fussing, cracking, peeling, partial images. Get the new TIA laminator. It's awesome. I've got the older one and the intermim vacumn press and they don't work that well. Also, get the green TRF while you are at it and you can do the etch in 1 minute process found on his site. It really does work.

(You need a laser printer for best results)

Wayne

 

[robk]

Wayne,
Have you tried the Press'N'Peel blue stuff?
Rob

 

[Doug Owen]

For several years I've used Express PCB (as suggested by Raggie33 above), a bit pricey but first rate boards and very easy to use free software.

For those 'down under' it's probably not practical? You might want to ask.....

Anyway, I recommend the software. Then print the pattern out as accurately as you can, tape a piece of PCB material to the back and with a sharp scribe, transfer all the holes (punch down through the paper and leave a mark on the copper. You can do the other side in the traditional manner (align the printed sheets first with a spacer in place between them).

Remove the paper and put 'doughnuts' on each pad location on the PCB, press them down tight (be sure the copper is very clean and fingerprint free, you don't want enchant getting in under it). Then, using your printout as a road map, lay in the traces in over the doughnuts. You can use tape (comes in several sizes), paints (fingernail polish works well) or special tar based felt tip pens sold for the purpose.

FWIW, I'm basically very much against home PCB making. What are you going to do with the copper laden enchant? Even a small batch (or traditionally the tank from radiator shops) has enough copper to 'kill' the average digester at the sewage treatment plant. Not pretty. It turns out it kills one of the thirty odd bacteria necessary to the process, if they catch it in time they can add ammonia gas to the mix and sometimes save it. Responsible citizenry (and the law) calls for treating it as toxic waste, something few of us are able to do.

At the college (where I made the students do this for money......), we paid to have a fellow come get it, evaporate it down and dispose of it properly. I suspect most hobbyists would just dump it down the drain. Don't you?

Doug Owen

 

[Steelwolf]

Hmmm... thanks Doug O. I never realised that it could be so bad. After all, they sell this stuff over the counter (Ferric and Ammonium) with no labels about proper disposal. Heck, practically everything around here seems to come with instructions for proper disposal. I don't suppose diluting it before pouring down the drain would make much difference?

If etching is so bad, what is left? Milling? I've been free-handing using a Dremel and the results are not so good. Some of the prototyping shops online show that they use something that looks like a plotter with a milling head. And there is a hobbyist micro milling machine with the footprint the size of the average keyboard which, I think, could be modified to run like a CNC machine.

What about some method that you lay printed tracks on to a fibre board and then flow solder or tin it to make the conductive tracks? Sort of like etching, but in reverse, putting in material rather than taking it out?

 

[robk]

I live in a rural area and dump my used Ammonium Persulfate on my property. The worst thing I see is a lot of earthworms coming up screaming! I only use an ounce or two at a time, I hope this isn't poisining my well. I've got a real good carbon filter on the well, so I will probably never suffer from the copper in solution.
Rob

 

[dat2zip]

robk,

I have many sheets of the blue press n peel and while it works it doesn't hold fine detail very well.

On some of my protos I had a 1mil trace that made a circle that I used for reference where a hole should be. On the ones I made a few months back all 4 that I made had enough of the 1 mil line present to allow me to dremel out to the line making the hole pretty precise. I was rather shocked the line was there after etching. Not that 100% of the line was there, but there was enough there to produce the circle. So, if it can almost hold 1 mil then 8 mil is duck soup.

In all 4 protos were two sided. So, the transfer must work first time or I'm screwed.

Here's how I did it. Per Dynaarts recommendation I xfered the first side. I then used packing tape to tape off the backside. I then sponged etched the first side. After that I cleaned and removed all tape and prepped side two with the recommended cleaning and scrubbing process. I then drilled from the front side my reference holes on the four corners. After printing side two, I drill the paper the same 4 alignment holes. I then put the image down on the board and pressing 4 seweing pins through the paper and board reference holes. I then apply a piece of post it note pad sticky portion to tape down the paper on the leading edge. Removing the pins the board is now fed back into the laminator. After that water to remove the paper and drying it run it through the laminator to apply the TRF foil. Again, taping off the front side and any excess copper on the backside before sponge etching.

The whole process is rather fast even tho there are quite a few steps. But, it is reliable and works as I made 4 double sided boards which I would have never NEVER attempted before. Before, I would do 4 up images and hope like heck I would get one good image.

For tight SMT work, the paper toner transfer is much better and if you add the TRF foil as a second step it is really robust. You can't use amonium persulfate with the 1 minute etch process. I just read that on the Dynaart web site.

I too only use less than an ounce to etch one board. Just enough to saturate a small piece of sponge which is literally nothing. So, little I neutralize with baking powder and water in the sink. Not enough to worry about taking to the chemical recycling program.

IF and this is the big IF... Many documented web sites describing toner transfer are basic through hole designs that are not fine pitch SMT and have larger traces. If you have a 10 mil gap design, the press n peel is fine. Fine pitch using 8 mil design rules can be rather touchy with the press n peel. I found not all the blue stuff comes off and there are blue bridges between traces or between traces and the ground plane. In these cases I had to use a short bristle brush to scrub off the blue in between these gaps. Eventually I would get it clear, but, the short hair brush also broke away some good areas compromising the process.

The paper process with the new laminator can produce boards in less than 1/2 hour from start to finish. I give the new process which was just introduced earlier this year a 5 star rating.

The laminator cost of $160 or so is worth every penny and will save you countless four letter words that you would emit otherwise... Believe me. Been there. Done that. I've been making PCBs since the mid 70's.

I would not recommend Dynaart 1/4 oz or 1/2 oz copper clad board. I disagree with him totally on this point. I found the 1/4 oz copper tore super easy and soldering required a delicate hand and rework was a total ***** ending up with more broken traces than it was worth. Flexing a through hole would always break the trace in single side boards.

That was 4-5 years ago when the process wasn't that good and I probably etched 50% of the copper away. The new process leaves 100% of the copper behind in all areas that are covered so maybe the 1/4 oz or 1/2 oz process would work now.


At my previous division I used to go home during lunch, make one or two PCBs, drill them and return the same day for small proto boards for myself or other co-workers. Must have saved the company several $K in small PCB proto costs.

 

[robk]

Wayne,
I'll have to give DynaArt a try, even though I find his website instructions a bit sketchy. Also, I hate Ferric Chloride, it even stains stainless steel! You're right about Press'N'Peel, it won't hold a real tight design, but this is highly dependent on the printer used. Standard HP LJ4 or 5 toner gives good results, while when I use 3rd party refilled or do-it-yourself toner, the results are very erratic. I guess it has to do with the temperature it melts at. I use an iron with a rectangular steel plate welded to the bottom and have found through much trial and error the correct temp setting and times for HP toner on 1/16" and 1/32" 1oz copper clad. I've made hundreds of boards of all sizes, but not too many for SMD. I'm guessing that your method is far better for small traces.
Thanks for the info, I'll try it out in the next month or so.
Rob

 

[Steelwolf]

Lots of good info here. Thanks guys.

Wayne: So it is possible to neutralise small quantities of Ammonium Persulfate with baking soda. How much baking soda does it require? But this doesn't really help with the copper in the solution, does it?

Looks like toner transfer is still the preferred system here. I guess I'll have to go get a good laser printer or find a reliable printer.

 

[robk]

Steelwolf,
I've got an extra HP Laserjet5 (not the little 5P) in excellent condition for $150. The plastic cases on these are notorious for turning yellow, and this one is slightly discolored, but was in an office with no smoking allowed. The insides are fine, needs a toner cartridge soon. Oh, I just noticed you're in Australia.... shipping may be a major problem.
Rob

 

[Doug Owen]

[ QUOTE ]
Steelwolf said:
So it is possible to neutralise small quantities of Ammonium Persulfate with baking soda. How much baking soda does it require? But this doesn't really help with the copper in the solution, does it?



[/ QUOTE ]

No, it's not.

I looked it up at work. Ammonium persulfate is mixed with flammable liquids and burned in a high temp incinerator with scrubber. Copper Sulfate (which as you point out is the key issue) is in fact buffered with baking soda or similar to a pH of 7 then the copper precipitated out as a sulfide (non soluble in water), filtered out and disposed of as solid waste. The remainder eventually goes 'down the drain' but not before processing I'm sure no hobbyist messes with. And for sure mixed waste would call for the copper separation followed by incineration.

A personal call, for sure, but I think at least some consideration to this should be taken.....

Doug Owen

 

[robk]

I gotta say pouring an ounce or two of Ammonium Persulfate in the dirt gets every earthworm so mad they come up to complain! When I dispose of the stuff, I dilute it with gallons of running water, as I have a well on the property and don't want to drink it tomorrow! I do have a chlorination system with carbon filtration and a softener so I think all the bad stuff is filtered from my drinking water.
Rob

 

[Doug Owen]

I wouldn't worry as much about the ammonium persulfate, it's 'toxic to half the rats' number is over ten times the copper sulfate number. And, as I said, it's my understanding that while most life tolerates (and even needs in trace amounts) the copper ions, there's a specific bacteria key to the digester process that breaks down our domestic sewage that it extremely sensitive to it. That's the way these things work sometimes.

I even recall from somewhere that ammonium persulfate was used as a component in fertilizer???

The information is out there, if folks care to look. My point was a general one. 'I'm not sure I'm comfortable with home PCB making', each citizen gets to decide how that concerns him and what he does to the world we share. For myself, at the level I deal with PCBs I choose to have the professionals at ExpressPCB deliver me 3 superb quality 'standard' 2.5 by 3.75 inch boards in 3 days. $66, second day shipping included (boards made and shipped next day) and they deal with the investment, chemicals, rejects and the like. Yes, you have to cut them out, and you only get one thickness of board, but they're plated through holes (half oz) and 1.5 oz copper with .007 minimum trace and space width. And free software to support, complete with on line ordering.

Since I also value my time, it fits my needs better than going down to the college where I sometimes teach this good stuff and using the Kaypro (photo resist) setup, light frame, developer and so on. The chemicals are dealt with in a responsible manner (by law), and the materials are free. The tape and doughnuts are there as well. And the photographer we send the students to for the $12 copy camera negatives is on the way to the school.. And the best PCB ever made there doesn't even come close to the Web ones in quality or precision. And *no* rejects (unless you screw up the layout....).

I think you should at least check it out. Just my opinions on the subject, in case ya wanted to know.....

Doug Owen

 

[Steelwolf]

RobK: Thanks for the thought. If I do go this way, I'll probably be able to get a good, cheap laser printer locally. And the point about using gallons of water to dilute the ammonia... won't that increase the chance of the liquid finding its way to your well? More water flowing and bringing the waste closer and closer?

Doug O: Yeah, I can see your point about using a professional service. As I mentioned at the start, I've been using hand drawn and hand milled boards so far. They work but they ain't pretty. And sometimes my hand slips. So far it has been alright since I'm using discrete transistors and the like, so I can bend a few pins to make them fit. But I'm looking at a couple of IC based projects and need better tolerances. I never even knew that you could get relatively cheap prototyping services like that until I started looking for the layout program. I'm investigating local companies first. Hopefully, prices will be within reason, or I'll go with the home etch kit.

Thanks for all the info. Still wondering if there is anyway to print out the circuit rather than remove excess metal. There is, after all, that horribly expensive silver contact pen. Maybe there is a way to print the layout and flow solder on to it to make it conductive?

 

[Ralph_Hilton]

If you use Eagle layout software then you can get good boards from http://www.olimex.com/pcb/ in Bulgaria.
A 6.3" * 3.9" double sided board costs $26 (USD) / $21 single sided and they cut that into smaller boards. They ship to Australia for $8. (or faster for more $).
http://www.cmeter.org/construction.html has some photos of a board they make up for me. 15 boards for $83.20.

 

[Doug Owen]

[ QUOTE ]
Ralph_Hilton said:
If you use Eagle layout software then you can get good boards from http://www.olimex.com/pcb/ in Bulgaria.
A 6.3" * 3.9" double sided board costs $26 (USD) / $21 single sided and they cut that into smaller boards. They ship to Australia for $8. (or faster for more $).
http://www.cmeter.org/construction.html has some photos of a board they make up for me. 15 boards for $83.20.

[/ QUOTE ]

Very interesting. Not a lot more than ExpressPCB for a larger board (although delivery is much longer), then again it comes with silkscreen and solder mask.

Eagle Software looks to cost an additional $50, if I read this right the free version won't do boards this big? ExpressPCB software is free (but you need to have boards made there).

May just give it a try sometime, thanks for sharing.

Doug Owen