question about PCBs and etching

[Blatant]

hey guys I tried etching for the first time today and it was a complete failure.  I used the toner transfer method but I think I accidentally moved the paper when ironing it so the resist was sort of blurred.  As a result the etchant didn't desolve enough of the copper areas and the whole circuit is joined as one.  I will try uploading a pic later if you want

So, what can I do to stop this happening? Obviously don't move the paper, but how? do you tape it etc?

also, what do you use to cut coper clad PCB to size?

[Taylor]

I lay the transfer onto the copper clad (steel wool/scotch brite the surface first), hold down the transfer and place the iron down on the transfer and hold it still until it's tacked down. Tack down the rest of the transfer, and only then should you start moving the iron around like you're ironing clothes.

[Blatant]

cool, i think part of the issue is that i pre-heated the pcb maybe i wont do that next time.

[Blatant]

Uploaded with ImageShack.us

here's the pcb

[smallbearelec]

Here's my tutorial on doing boards using the Press N' Peel film:

http://www.smallbearelec.com/HowTos/DirectPCBoards/DirectPCBoards.htm

I did it this way for years with consistently good results before switching to the photo-positive method. Either is very consistent if you follow directions patiently and carefully and use good materials. They don't have to be the ones I sell. However, the right stuff will cost a few dollars.

The best method/tool I have found for cutting FR-4 is an abrasive cutoff wheel in a Dremel tool or similar handpiece. WEAR GOGGLES AND A FACEMASK!

Regards
SD

[tasos]

i cut pcb's using hacksaw...works great!
now...i use transparency for toner transfer method...it slides much more!the secret is getting the right temperature...[hot enough to take off toner but not too hot to melt the paper...]
when ironing you should begin with a low setting and then gradually increase temperature...

[davent]

More good info on toner transfer from John Lyons. http://www.mrdwab.com/john/How-to-make-PCBs.html

dave

PS. For rough cutting boards to size, a hacksaw, for final trimming after etching, a Dremel with a diamond cutoff wheel, like a hot knife through butter.

[bean]

I use Sterling Ultra Digital paper. 500 sheets will last you a decade and it's about $.05 per letter-sized sheet. The only caveat is that it works best with high resolution images. I also use an iron then a laminator for transferring. Soak the paper in water for 10 minutes and it will peel off easily. For cutting, I use a bandsaw.

[chi_boy]

I use Sterling Ultra Digital paper. 500 sheets will last you a decade and it's about $.05 per letter-sized sheet. The only caveat is that it works best with high resolution images. I also use an iron then a laminator for transferring. Soak the paper in water for 10 minutes and it will peel off easily. For cutting, I use a bandsaw.

Brian,

What kind of laminator are you using?  I just bought one for using with the DecalProFx system for graphics.  I know they have a PCB system too, but they use .032 PCB stock to work with the laminator.  They also talk about using 1/2oz copper.  I thought 1oz was the standard for DIY.

Just curious what you use since you make so many.

-G

[trjones1]

I never had any luck with the toner transfer method, but I love using photosensitive boards.  The only hard part about it is getting the materials if you don't yet know where to find them.  Everything after that is simple, and the results are great, though I know many people on the board get great results with toner transfer too.  It's just not my thing.

[bean]

Brian,

What kind of laminator are you using?  I just bought one for using with the DecalProFx system for graphics.  I know they have a PCB system too, but they use .032 PCB stock to work with the laminator.  They also talk about using 1/2oz copper.  I thought 1oz was the standard for DIY.

Just curious what you use since you make so many.

-G

http://cgi.ebay.com/GBC-HeatSeal-9-Creative-Pouch-Laminator-SAVE-58-/230568145406?pt=LH_DefaultDomain_0&hash=item35aeeeb1fe

It'll take up to .062", although it gets a bit cranky. Works well!

[Blatant]

I thought about using transparencies but didn't want to melt the sheets!

Resolution isnt the issue, it's perfectly fine before I transfer haha.  Oh and I tried the photoresist method too but I either didn't expose it for long enough, or had a cheap board so it was a failure. I'll keep trying, I guess practise makes perfect! It definately does look better than a breadboard though.

[chi_boy]

Brian,

What kind of laminator are you using?  I just bought one for using with the DecalProFx system for graphics.  I know they have a PCB system too, but they use .032 PCB stock to work with the laminator.  They also talk about using 1/2oz copper.  I thought 1oz was the standard for DIY.

Just curious what you use since you make so many.

-G

http://cgi.ebay.com/GBC-HeatSeal-9-Creative-Pouch-Laminator-SAVE-58-/230568145406?pt=LH_DefaultDomain_0&hash=item35aeeeb1fe

It'll take up to .062", although it gets a bit cranky. Works well!

I didn't realize that one was out there when I bought mine.  I have the H-220, which apparently is the "next generation."   The specs for maximum pouch thickness is the same though, but the H-220 has a specific maximum thickness of 1mm.  Didn't see that for the Creative, but you may want to be cautious.

I'm getting some .031, 1oz copper clad to give this a try.

[kirs]

No luck with the toner method here.  Only one in every five transferred well and still needed some hand fixing up.  Most cases the board is 90% good but some spots, mainly corners, don't transfer at all.  Kept the iron on for a while and got consistent coverage.

[chi_boy]

hey guys I tried etching for the first time today and it was a complete failure.  I used the toner transfer method but I think I accidentally moved the paper when ironing it so the resist was sort of blurred.  As a result the etchant didn't desolve enough of the copper areas and the whole circuit is joined as one.  I will try uploading a pic later if you want

So, what can I do to stop this happening? Obviously don't move the paper, but how? do you tape it etc?

also, what do you use to cut coper clad PCB to size?

Looking at your picture, it seems like there is still a lot of paper on the board, like you didn't get enough off before etching.  There really isn't much that looks like circuit traces.  Maybe a couple of more pics will help.  Include an overall shot, if you do.

[davepedals]

i'm using the photosensitive board method - simple once you work out the exposure/developing settings.

on my first try i placed a small pcb under 30 watt CFL with reflector about 2" above pcb - exposed for 6 minutes... NO GOOD!
2nd try 5" above pcb for 12 minutes.....excellent!  my only mistake with 2nd try was adding some developer to the water while the board was in there - some crystals fell on the board and quickly ate through all the photo-resist that it came to rest on!

i added the extra dev because my first mixture was too slow/weak!  it's fine to add extra dev but add only tiny amounts at a time and be CAREFUL NOT to let any fall on the PCB!  it will eat whatever it contacts within seconds!  add it to the side of the board and gently agitate to mix it. and always use very warm water, never cold water! not hot enough to burn you, but pretty darn hot!

agitation is another IMPORTANT factor. if you just drop the board into the solution it appears to do nothing (trust me, it IS doing something) and it can be too late for any good outcome if you let it sit!  gently agitate back & forth, i actually use a circular motion, rather violently but not enough to splash the solution out of the tray!  in my best experience, all the parts you want removed should be gone in
30 - 50 sec. if dev is mixed correctly.

my conclusion is:
30 watt CFL 5" above transparency. - 11-13 minutes. use a reflector hood!
go with known ratios of dev + water mixtures, add more carefully if it's not doing the job - you should see blue ink swirls within a few seconds of agitating if mixed correctly!
when happy with the removal process, wash board under a faucet and dry. now put that sucker back under the light for another 10 minutes to further harden the resist before etching.

do like i did, run a couple of small pcbs to test exposure and development times before doing a major run!  IMHO, this method blows away ironing a pcb! and it's not expensive.

etching is the easier part - there are 100's of tutorials thus i end here! enjoy your new great looking boards!

[smallbearelec]

...I tried the photoresist method too but I either didn't expose it for long enough, or had a cheap board so it was a failure.

The photoresist method is excellent:

http://www.smallbearelec.com/HowTos/PhotoPCBoards/PhotoPCBoards.htm

You Don't need a laser printer or an iron. You Do need to pay attention to what materials you use and the exposure conditions. I have always been able to get it to work. However, I found that the window decal stock that I describe in the tutorial eliiminates the need for a contact printer, (or even the sheet of glass that some tutorials recommend,) and makes the exposure time much less critical.

Resign yourself to spending a little money for the right stuff, (not necessarily from my store,) follow directions carefully, and you will find that the process works well.

Regards

SD

[deadastronaut]

as long as you keep everything clean, you should be ok..no fingers on the copper etc...

i use crappy pound shop gloss paper, laser toner...iron on full heat..let cool, just peel off...no residue , no faffing around peeling little bits off and scrubbing..

very clean, and cheap too!..persevere, it'll work, its been tried and tested and verified a million times ok....

[StereoKills]

For those looking for a super cheap paper, I started using the pages from a DigiKey Tech Zone magazine they sent me. They're super thick glossy pages, and they have been working out fantastic for the toner transfer method. One free catalog should last me forever.

[Govmnt_Lacky]

i use crappy pound shop gloss paper

Exactly where can I find "crappy pound shop gloss paper?" Who makes it?