First PCB!

[graylensman]

I finally took the plunge, and etched my first PCB. Then discovered that local hardware stores don't sell drill bits small enough...  Got some en route now. Looking forward to the next stage of this project.

[bloxstompboxes]

Better than my first except for the pad holes. You may have issues drilling some of them. What method did you use? I am going to guess a clothes iron and magazine paper. Keep up the good work!

[davent]

Fun pedal!

Check the lower left corner for solder bridges, 10x jewelers loupe is indispensable for that and also for reading the tiny print on parts.

[karbomusic]

Nice! What transfer method did you use? If an iron/heat and laser printer toner, it looks like it was a little too hot causing the toner to melt instead of only fusing over. There is a sweet spot between hot enough to fuse and cool enough not to melt, again assuming that is the method you used.

[graylensman]

Thanks for the comments, everyone!

I used the toner transfer method: I had the circuit printed on a transparency sheet at Kinkos/Fed Ed Office/Whatever and then hit it with an iron. This transfer is actually my third attempt; the heat was dialed in the best I could achieve. I think next time I'll try backing off the heat just a hair. To that point - I applied heat for about five minutes or so. Would you advise lower heat and longer time?

davent, I used the magnifying glass on my "third hand" to check the traces. That particular corner needed some scraping with an X-Acto blade. Otherwise, I think I'm okay. I'll know more once I get it populated...

[karbomusic]

I used the toner transfer method: I had the circuit printed on a transparency sheet at Kinkos/Fed Ed Office/Whatever and then hit it with an iron. This transfer is actually my third attempt; the heat was dialed in the best I could achieve. I think next time I'll try backing off the heat just a hair. To that point - I applied heat for about five minutes or so. Would you advise lower heat and longer time?

You can usually tell too hot by the smudging (that's what I thought I noticed in yours) but you have to just keep trying different settings until you find the one that works for you because it is so dependent on things such as what the toner is being transferred from... PnP, regular transparency, water release paper, photo paper etc. as well as the toner brand because all of them insulate the toner by various amounts and toner fuse points vary... and the amount of pressure comes into play as well. I've been using a t-shirt press as of late and it looks like with press and peel the ideal temp is going to fall somewhere around 260-266F but I'm still experimenting.

Good job though, I'm sure you are excited because I have found making PCBs much less of a headache (for me personally) than Vero/Perf etc. Less prone to error as well as faster, YMMV of course but I'm now somewhat addicted to making my own PCBs.

[mattoverse]

I find the glossy laser jet HP presentation paper (recommended in another thread on this forum) works better than a transparency as the toner tends to smudge with the transparency and it is more prone to moving around while the presentation paper stays in place.

[bloxstompboxes]

I find the glossy laser jet HP presentation paper (recommended in another thread on this forum) works better than a transparency as the toner tends to smudge with the transparency and it is more prone to moving around while the presentation paper stays in place.

Agreed, while I have never used transparancies, I have used photo paper and magazine paper. Magazine paper worked better for me out of those two. However, the hp presentation paper is what I use now, along with my cheap but modded laminator.

[Mark Hammer]

1) Nice work for a first stab!  Good feeling, eh?

2) As others have noted, there are a couple of places where you might have some existing shorts, or be asking for them when solder gets applied.  MIght be useful to get out your X-Acto blade and scrape between the pads that are too close.

3)  YMMV, but while you're waiting for the bits, you may want to tin the board.  Personally, I dab some liquid flux on a Q-tip or other budget cotton-tipped applicator, and apply a light coat to the whole board.  If you have some solder wick - the slightly wider type - put some solder on it, and use your hot iron to slide it around the pads, leaving a thin film of solder everywhere.  Then, use either flux remover, or methyl hydrate to take the excess flux off, and give a light buff with superfine steel wool or a finer 3M pad of some kind.

The tinned board will be in good shape for a while.  A bare copper board, if ignored for a couple of weeks, can easily tarnish and be hard to solder to.

[brianq]

Right on! I'm all for pcb's, great work!!!

[karbomusic]

if ignored for a couple of weeks, can easily tarnish and be hard to solder to.

With my hands I think it starts tarnishing within a couple hours LOL.   Lately, as soon as I remove the toner and expose the fresh copper I hit it with a very thin coat of spray lacquer which burns through very easily when soldering and acts as a thin solder mask preventing those shorts that seem to want to occur. I have some liquid tin coming but I'll still use the lacquer as a solder mask because it has worked out so well.



 

[davent]

if ignored for a couple of weeks, can easily tarnish and be hard to solder to.

With my hands I think it starts tarnishing within a couple hours LOL.   Lately, as soon as I remove the toner and expose the fresh copper I hit it with a very thin coat of spray lacquer which burns through very easily when soldering and acts as a thin solder mask preventing those shorts that seem to want to occur. I have some liquid tin coming but I'll still use the lacquer as a solder mask because it has worked out so well.

Your lacquer method is far superior to Liquid Tin. Your window of opportunity from liquid tinning to needing to redo is far to short in my world where as the lacquer's effect has never been diminished even on boards that have been collecting dust for years. Solder with no problems.
dave

[graylensman]

I've got some spray polyurethane. Will that work as well as the lacquer?

Yeah, it is a good feeling. I feel like I've taken another step forward in my DIY skills. I'm really excited that it turned out so well (so far!) and looking forward to getting that sucker drilled. Hey, if I'm successful with etching boards, who knows - maybe I'll start etching enclosures!

[PRR]

> some spray polyurethane.

Ugh. I wouldn't put a hot iron on that with a 10 foot pole. Urethane is not nice when it breaks-down. And it usually goes on thick.

Lacquers (there are many sorts) are usually "thin" so less smoke-bomb.

It may be hard to find, but spray *shellac* will burn-off E-Z with mild fumes (generally accepted as safe).

[greaser_au]

Ugh. I wouldn't put a hot iron on that with a 10 foot pole. Urethane is not nice when it breaks-down. And it usually goes on thick.

Many polyurethanes give off toluene diisocyanate when heated.  I was banished to a fume cupboard to wind coils when we were using PU enamelled wire.

david

[graylensman]

Ugh. I wouldn't put a hot iron on that with a 10 foot pole.

This is why I asked rather than proceeded. Thanks as always, People Smarter Than Me!   

[davent]

> some spray polyurethane.

Ugh. I wouldn't put a hot iron on that with a 10 foot pole. Urethane is not nice when it breaks-down. And it usually goes on thick.

Lacquers (there are many sorts) are usually "thin" so less smoke-bomb.

It may be hard to find, but spray *shellac* will burn-off E-Z with mild fumes (generally accepted as safe).

Zinsser, Bullseye has shellac in a spray can, should be easy to track down.

[PRR]

> Zinsser, Bullseye

You are right. "Stain Blocker" to cover sap-pockets in pine before you paint is usually shellac base. It may be dyed white to help hide wood stain under light paint, but I think it is fine.

EDIT-- much of Zinsser's current line is "water-base", I guess to avoid VOC limits.

Zinsser's "B-I-N Shellac Base Primer" says what it says, but the MDS shows a lot of acetone as well as the expected ethanol (shellac solvent), 10% Titanium Dioxide (white dust), 5% Mica! That will break-up or cover sap-stains one way or another, but seems like a lot of crap for our purposes.

Simple shellac spray used to be available in Art Supply stores. I could probably find it over on arty-island. Problem is that it goes bad faster than most other sprays, and does not sell well, so either the store stops stocking it or you get a can of shellac-gum.

Straight shellac is still common in paint aisles. A pint diluted 50:50 and put on with a brush would do hundreds of PCBs, but it goes bad in the can in a year.

Specialty wood-work stores might still carry shellac flakes, which keep well until dissolved. Rockler has it, also some specialist websites. A "1 pound cut" would be ample and that's an ounce of flakes in a cup of hi-test moonshine (190 proof; strong denatured avoids paying the whiskey tax). So Rockler's small bag would make nine 1-cup batches and last you for years.

[davent]

I use the Bullseye Primer/Sealer after etching primer on enclosures but they do have unpigmented shellac in a spray can as well.

http://www.amazon.com/Rust-Oleum-Zinsser-408-Bulls-Shellac/dp/B0009X8HWG

[CodeMonk]

I used the toner transfer method: I had the circuit printed on a transparency sheet at Kinkos/Fed Ed Office/Whatever and then hit it with an iron. This transfer is actually my third attempt; the heat was dialed in the best I could achieve. I think next time I'll try backing off the heat just a hair. To that point - I applied heat for about five minutes or so. Would you advise lower heat and longer time?

You can usually tell too hot by the smudging (that's what I thought I noticed in yours) but you have to just keep trying different settings until you find the one that works for you because it is so dependent on things such as what the toner is being transferred from... PnP, regular transparency, water release paper, photo paper etc. as well as the toner brand because all of them insulate the toner by various amounts and toner fuse points vary... and the amount of pressure comes into play as well. I've been using a t-shirt press as of late and it looks like with press and peel the ideal temp is going to fall somewhere around 260-266F but I'm still experimenting.

Good job though, I'm sure you are excited because I have found making PCBs much less of a headache (for me personally) than Vero/Perf etc. Less prone to error as well as faster, YMMV of course but I'm now somewhat addicted to making my own PCBs.

I keep my iron on maximum heat.
Pressure and timing are far more critical factors IMO when doing thermal transfer.
Higher temperatures are better than lower temperatures, again IMO.
I read numerous tutorials on doing thermal transfer and pretty much all of them had flaws (IMO) before tackling it myself.

Regardless, OP, thats a pretty good job for a first try.
Next time, try increasing the heat, and using less pressure.
from the looks of it, you used more pressure than was necessary.
You just have to keep a close eye on things.
And practice, practice, practice.

I did these last week...
(For some reason, the full size pictures aren't showing up. think Photobucket is being flaky again)
Can ANYONE see either of these or maybe its just my connection is shit today?




Now they are showing up.
I guess for so reason those other pictures didn't want to show up all the way.
They still don't even though I reset the router and the modem.