PCBs

[Hero999]

Clearly it all comes down to personal preference, personally I am more than willing to spring for the extra 10-20 cents a board because it makes my life easier and I get faster, better, and more consistent results.

Of course it does, anyway I've found usiing pre-sensitised photo-resist board is by far the best solution but it's more expensive. I don't know how it compares to Press n Peel, it it works out about the sem then I'd recommend using it instead. Exposing it isn't hard, you could try daylight or a compact blacklight fluroescent lamp, but it isn't hard to build your own exposure from a wooden box and insect killer tubes.

I use different methods for different boards, photo-resist seems to be more accurate so I use it purely for board containing smt ICs and for everything else there's the magazine paper method.

ammonium persulfate is one that I have used, it's water clear when fresh and turns translucent blue (looks like windex) as it is used.

Your description sounds like the stuff I use. The label says sodium persulphate/sodium bisulphate. Heating it is a good idea but temperatures higher than 50C should be avoided because it will cause the solution to decompose. When mixed it smells of chlorine which is wierd since I don't think it contains chlorine but I suppose there might be similar smelling chemicals around.

 

[nye]

in my country i think itmight be very hard to get those special sorta papers..i suppose i'll jus ask for toner paper or magazine paper....btw i donwloaded a prof version of eagle 4.13..or is it better to get the unregistered eagle 4.16??or is there hardly a difference??

 

[nye]

oh..the download is corrupted
so looke like i'll hav to go with the trial version!!!

 

[evandude]

Of course it does, anyway I've found usiing pre-sensitised photo-resist board is by far the best solution but it's more expensive. I don't know how it compares to Press n Peel, it it works out about the sem then I'd recommend using it instead. Exposing it isn't hard, you could try daylight or a compact blacklight fluroescent lamp, but it isn't hard to build your own exposure from a wooden box and insect killer tubes.

I use different methods for different boards, photo-resist seems to be more accurate so I use it purely for board containing smt ICs and for everything else there's the magazine paper method.

Yeah, I would definitely like to use the photoresist method if it was more practical for me, I know it is more accurate and reliable. But, working out of a college dorm room, having the extra chemicals, exposure frame, light, etc around isn't really great for me. With toner transfer, I really just need to keep the transfer sheets around, as I need the iron and laser printer anyway (not counting etching/cutting/drilling stuff that would be necessary anyway). With PnP blue I can do traces down to 10 mils reliably, and probably smaller, except eagle doesn't go lower than that anyway, so it's good enough for me until I move somewhere with a spacious workshop and can have a dedicated PCB fab area with photoresist stuff

Your description sounds like the stuff I use. The label says sodium persulphate/sodium bisulphate. Heating it is a good idea but temperatures higher than 50C should be avoided because it will cause the solution to decompose. When mixed it smells of chlorine which is wierd since I don't think it contains chlorine but I suppose there might be similar smelling chemicals around.

I believe the sodium persulphate is nearly the same thing, except it is more compatible with etch resist pens, whereas the ammonium persulphate isn't.

in my country i think itmight be very hard to get those special sorta papers..i suppose i'll jus ask for toner paper or magazine paper....btw i donwloaded a prof version of eagle 4.13..or is it better to get the unregistered eagle 4.16??or is there hardly a difference??

I don't think it's a great idea to discuss a pirated copy of eagle 4.13 on these forums. Eagle does seem to have good copy protection, and in every case I have seen, a pirated copy of eagle will randomly corrupt any files you edit with it after a few days or weeks, and even before that happens, any files you edit with it will be unusable by other people with legitimate versions; if they try to open them it will display a message saying that the file was edited with an illegal copy of Eagle. So, using an illegal copy of eagle is not only immoral and illegal, it's also really shooting yourself in the foot, which you'll surely realize the first time you spend countless hours designing a complicated schematic and PCB layout, and then find one day that it has been corrupted and you have to start all over.

 

[philba]

I don't think it's a great idea to discuss a pirated copy of eagle 4.13 on these forums. Eagle does seem to have good copy protection, and in every case I have seen, a pirated copy of eagle will randomly corrupt any files you edit with it after a few days or weeks, and even before that happens, any files you edit with it will be unusable by other people with legitimate versions; if they try to open them it will display a message saying that the file was edited with an illegal copy of Eagle. So, using an illegal copy of eagle is not only immoral and illegal, it's also really shooting yourself in the foot, which you'll surely realize the first time you spend countless hours designing a complicated schematic and PCB layout, and then find one day that it has been corrupted and you have to start all over.

I totally agree. I will also add that eagle is far more generous with their free version than others, we should be rewarding them, not stealing from them.

 

[trherrmann]

I've tried the toner transfer method and would not recommend it. If the toner cartridge is not almost new, it does not put down enough toner and you end up with pits in your traces. (They tell you that in the small print after you buy the kit.) And I found getting the heat just right is tricky. I spent hours touching up the boards before etching. Use a photoresist method if you have access.

 

[evandude]

I've tried the toner transfer method and would not recommend it. If the toner cartridge is not almost new, it does not put down enough toner and you end up with pits in your traces. (They tell you that in the small print after you buy the kit.) And I found getting the heat just right is tricky.

With press-n-peel, I never end up with pits in the traces, because even where the toner is not very thick, the backing still sticks, and acts as an additional layer of resist. Even when I was using photo paper as a transfer media, I didn't have that much trouble getting the toner heavy enough to produce working traces, even if they sometimes had some superficial pitting.

And regarding your issue with your laser printer, I have not had that trouble with the three laser printers I have used, and most printers give you the ability (either through software, or by adjusting a dial in the printer) to set how dark your printout is, ie - how much toner it puts down.

Finding the optimum ironing heat can take a couple of tries, but it's not something you should have to do more than once, unless you change irons.

 

[philba]

sorry, tr, but there are lots of people that have had good to great success with toner transfer. I suggest that your results are more likely due to your skill level with the process rather than any flaws inherent the process itself.

 

[nye]

i've heard of some method where u use a transparency and then expose the PCB to light and then it gets etched or the layout appears on the board..can sombody explain tht method to me, or giv me a link which explains it in detail...this is since im findin it difficult to find toner paper as i cant describe it properly and i dont know the name its called over here in my country

 

[evandude]

i believe you could call it the photoresist or UV exposure method, if you search google for these you can find a bunch of links, but here's one for starters:

https://www.turbokeu.com/myprojects/pcb.htm

 

[Hero999]

If I get any breaks pitting in the toner then I just cover them using a think pernament marker pen.

 

[mramos1]

I do the same as Hero999. Sharpie marker. But I have the paper process pretty good, so only if I am in a big rush do I have to touch up.

Now I do color in open areas with a shapie as well to extend the life on my ecthant. Write in verion numbers, etc as well.

 

[philba]

I have mediocre results with sharpies - I've heard that Staedtler Red is quite good but haven't found anyplace in Seattle that sells them.

On the open areas - I use eagle and the first thing i do is put a polygon named gnd on both the top and bottom layers. so any open area that can connect to ground gets a copper pour. really cuts down on etchant usage.

 

[mramos1]

I have never had a problem with Sharpies to fill the blank areas. Again, I do not use them to fix mistakes. Just to save etchant.

I will look for Staedtler Red though and try it.

 

[Hero999]

Now I do color in open areas with a shapie as well to extend the life on my ecthant.

I do that to but I normally use insulation tape or even sellotape because it saves both toner and ink.

Write in verion numbers, etc as well.

If I've got more than one version I save it as different files and I have the version number on the artwork.

 

[davecd]

You could make your own UV light box, I made one using 4 small UV tubes from maplins, all components cost around £40 GBP. Then use laser printed transparancies, or inkjet (dried first). Then use presensitized or copper clad pcb with Photoresist spray ( around £12 a can). Exposed boards can then be developed with ordinary Ammonia ( weak solution at room temp).Exposure time for my box is around 2 mins. Last of all etch board with acid.

 

[mramos1]

If you have a laser printer...

I have used toner carts that were done and bad drums that made grey dots on the paper and still made great boards. I have even done inkjet on paper and ran to the local copy center with picture paper.

There is no need to spend all that money.

If you can do 300dpi or more, have a good iron, scuff and clean your copper well, iron well. You will get a good board to drop in the ecth.

Removing the paper has been a problem only because I am in a hurry. Let them soak well and it will come off easy.

IRON good (edges too) on CLEAN copper. I was doing boards with eagle cads defaults before someone said you can make the traces wider you know.

 

[evandude]

Then use presensitized or copper clad pcb with Photoresist spray ( around £12 a can)

anyone had good luck with spray-on photoresist? Is it reliable, and does a can cover enough board to make it any more economical than buying presensitized boards?

 

[nye]

thanks guys..tho im still findin difficulty findin the right materials and tools!!!!i think i'll put out a post to my fellow countrymen!!!!!lol

 

[gramo]

could someone set up a pole with the top 5 and let the clicking begin?