its PCB time

[zachtheterrible]

I'm getting sick of making my circuits on perfboard. i thought that pcb was rather expensive, but have recently come to find out that it's not as expensive as i thought.

So what I need to know is what's the best way to go? press n peel sounds pretty good (of course i don't have a laser printer, but ill go to kinkos). I looked @ allelectronics.com, and their sheets were 5 for 11 bucks or something like that which does seem a little expensive.

So what's the best way to go?(remember i'm looking for cheapest) Thanx very much :lol:

 

[jrz126]

I've been looking into this for quite a while now. electronics goldmine has the copper board for a great price, a little thin though. (i cant remember the address, I just googled it). Digikey has decent prices on it too, but not nearly as good as electronics goldmine.

I'm going to use the photo quality paper as my transfer method instead of the Press n peel. Then I'm going to use ammonium persulfate? (or sodium persulfate, one of the 2 is better, but I cant remember right now) as my etchant. this etchant is more expensive than the ferric chloride, but it's a lot easier to use (so I've heard).

Harbor frieght tools sells a 20 pack of various small sized carbide drill bits that you need (you can use a different kind, but they dull quicker). (only 5 bucks too ) These break very easily so you will need a drill press of some sort. (again so I've heard).

I'm hoping to get to make a pcb sometime next week, but yet again all of my professors decide to have a test in the same week, so I'm probably going to be studying :cry:

 

[Johnson777717]

I think the cheapest way is to use sharpie ink as the etch resist, although the process is labor intensive. There are several sites on the web which detail this method. Search for "Making PCB's" or something along the lines, you're bound to come up with several sites. Simply stated, it involves using a sharpie marker and you hand draw the traces and pads. I wouldn't suggest this method for densely arranged boards where tracks and pads are in very close proximity. I do find this technique very easy if you have a small prototype board, or if you're just messing around with getting to know how the etchant works.

There are several other ways of making PCB's, which are listed on the web as well. To me, the easiest, and moderately cheap way of making PCB's is to use the photoresist method.

There's a video clip that you can download at MG Chemicals which summarizes this process. It's also gives tips on the other types of etchants, their pro's and con's etc.

The video is located under the "Tech Support" button, which also includes some helpful FAQ and MSDS information etc. Good stuff.
https://www.mgchemicals.com/

The drill press is a very handy tool because the small drill bits tend to "walk" when you're just beginning to start to drill a hole (Drill bit rotates out of center, drilling outside of where you actually want to place the hole). Because the copper doesn't indent very easily (unlike wood) it's sometimes difficult to get a hole started without the bit walking on you. A drill press will help keep the walking to a minimum.

 

[zachtheterrible]

thanx johnson and jrz. i looked into the photoresist method, and it looked rather complicated. Press n peel seems pretty simple . . . print it out, iron it on, and stick it in the solution, right? And with the photoresist method, do you print it out?

Yeah, im going to have to get a drill press. I know all about walking. I've been using a handheld non-variable speed drill to drill holes in brass tubing (and ive gotten pretty adept at it i might add). I've been building a cross between a paintball gun and an airsoft gun :lol: . i know id be breaking bits left and right.

 

[jrz126]

thanx johnson and jrz. i looked into the photoresist method, and it looked rather complicated. Press n peel seems pretty simple . . . print it out, iron it on, and stick it in the solution, right? And with the photoresist method, do you print it out?

Yeah, you print it out and attach it to the board, then you need an ultraviolet source to "expose" the board, then etch like normal.

Here's a link that I was reffering to for track width and grid spacing, but it uses this process: http://hompage.ntlworld.com/electricstuff/pcbs.html but it looks like the link is down. just google for photoresist and you should come up with something.

I've been building a cross between a paintball gun and an airsoft gun :lol: . i know id be breaking bits left and right.

:shock: I need more info on this...does it shoot both airsoft and paintballs or what? it would be like 2 of my favorite "sports" combined! do you have any pictures?

 

[zachtheterrible]

Well, it basically is a c02 powered airsoft gun :twisted: . What i did was elongate the (wuddya call that thing, it moves back and forth in the paintball gun wen u shoot, u pull it back and cock it . . .) by attatching a piece of brass tubing to it. This sticks out of the gun. I took off the paintball barrel and plugged a 1/2" pvc pipe in it. Inside of the pvc pipe is the actual barrel. The actual barrel is connected to sort a drip line T connector. If you're looking @ the T connector, the airsoft BBs feed into the bottom of it, on the left side of the T, is the barrel, and on the right side of the T is elongated cocking thing from inside the gun slides in and out of the T connector. (did that sentence sound a little bit wrong??) . The BB feed is spring loaded.
So it pretty much loads and shoots the exact same way that a paintball gun does, accept for it has a spring loaded feed.

I've spent about a year developing the thing. Half the reason it took so long is that i was always needing parts n stuff, and of course i don't have a license YET, so i always had to wait on my mom. I had it shooting flawlessly the other night, but a little piece in there broke and ive gotta fix it. The trick to getting it to not jam, spit out too many BBs, etc. is a little piece of fishing wire that you put right where the BBs load into the barrel, so they don't roll out and stuff. I need to find something more durable, but just as small. Can you think of anything?

It is SOOOOOOOOOOOOO cool. My barrel is just a piece of aluminum tubing from hank's hardware, so its not rifled. If i can get my hands on an actual airsoft barrel, I'd expect to be able to shoot like 300 ft. pretty accurately. When I had it working, it was the awesomest thing ever :lol: . It is totally homebrew, I have no machining skills or anything like that, so I've just bought stuff from lowe's, ace's, home depot, and modified them to suit my purpose :lol:

Itll screw off the gun of course, so if i take out the elongated thingy, and put the paintball barrel back on, i got my paintball gun back :lol: .Yeah, you print it out and attach it to the board, then you need an ultraviolet source to "expose" the board, then etch like normal.

I'd say the press n peel sounds a bit easire because you don't have to deal with lights and stuff.

 

[jrz126]

Well, it basically is a c02 powered airsoft gun :twisted: . What i did was elongate the (wuddya call that thing, it moves back and forth in the paintball gun wen u shoot, u pull it back and [bleep] it . . .) by attatching a piece of brass tubing to it. This sticks out of the gun. I took off the paintball barrel and plugged a 1/2" pvc pipe in it. Inside of the pvc pipe is the actual barrel. The actual barrel is connected to sort a drip line T connector. If you're looking @ the T connector, the airsoft BBs feed into the bottom of it, on the left side of the T, is the barrel, and on the right side of the T is elongated cocking thing from inside the gun slides in and out of the T connector. (did that sentence sound a little bit wrong??) . The BB feed is spring loaded.
So it pretty much loads and shoots the exact same way that a paintball gun does, accept for it has a spring loaded feed.

I've spent about a year developing the thing. Half the reason it took so long is that i was always needing parts n stuff, and of course i don't have a license YET, so i always had to wait on my mom. I had it shooting flawlessly the other night, but a little piece in there broke and ive gotta fix it. The trick to getting it to not jam, spit out too many BBs, etc. is a little piece of fishing wire that you put right where the BBs load into the barrel, so they don't roll out and stuff. I need to find something more durable, but just as small. Can you think of anything?

It's the bolt that moves back and forth. Can you try to rig up a piece of metal, kinda like a paper clip that will hold the ball in place, but still be able to move out of the way? Thats what I did on this little project here: https://www.cardomain.com/memberpage/435572/3 only I used a coathanger. hmm, guess I didnt take a pic. of it.

It is SOOOOOOOOOOOOO cool. My barrel is just a piece of aluminum tubing from hank's hardware, so its not rifled. If i can get my hands on an actual airsoft barrel, I'd expect to be able to shoot like 300 ft. pretty accurately. When I had it working, it was the awesomest thing ever :lol: . It is totally homebrew, I have no machining skills or anything like that, so I've just bought stuff from lowe's, ace's, home depot, and modified them to suit my purpose :lol:

How long of a barrel do you need? if it's ~10" maybe you could just buy one of those mini airsoft guns and steal the barrel from it. It should already have the "hop up" thingy thats supposed to give you more range. and the hop up functions as your ball holder.

sounds like a very cool project. about how fast do they shoot?

 

[zachtheterrible]

Paperclip would be much too large and jam things up. Maybe I can find a small gauge wire and use that. ill try that one of these days. Remember, i only used one piece of fishing wire, so its tiny.

I have to look into getting an airsoft barrel. Thats true, i wouldnt have to bother with fishing wire n junk.

They shoot about as fast as a paintball (of coruse thats just a guess). When ive got a full tank of c02, the bb will go through a cardbooard box, both sides. and thats with the velocity adjustment somewhere in the middle. there would definately have to be some kind of surrender rule if u play. from inside my garage, i could probably pretty easily knock a soda can off my neighbor's roof whose across teh street. And i'd say that i could probably hit someone from 200 feet away. of course thats with a piece of crap barrel

I'm supposed to play airsoft with a friend today, maybe ill try and get my gun working :lol:

 

[zachtheterrible]

oh yeah, back 2 my original subject :lol: . i think im probly gonna go w/ press n peel. it seems to be the simplest, other than doin it w/ a sharpie, but i dont wanna do that. I think that this is the way to do it, but i just want to make sure.

1. Print out the artwork on a laser printer or photocopier.
2. iron it on to the copper clad board.
3. Peel it off, and im not too sure about this step. i take it that when it is peeled off, there are pieces of the PnP left over.
4. Put it in the etchant solution.
5. Take it out when it is done and wash it off with water.
6. Peel off the rest of the PnP.

am i right??

 

[jrz126]

oh yeah, back 2 my original subject :lol: . i think im probly gonna go w/ press n peel. it seems to be the simplest, other than doin it w/ a sharpie, but i dont wanna do that. I think that this is the way to do it, but i just want to make sure.

1. Print out the artwork on a laser printer or photocopier.
2. iron it on to the copper clad board.
3. Peel it off, and im not too sure about this step. i take it that when it is peeled off, there are pieces of the PnP left over.
4. Put it in the etchant solution.
5. Take it out when it is done and wash it off with water.
6. Peel off the rest of the PnP.

am i right??

For step 3, the PnP that will be left is where you'll want copper traces to be after etching. The PnP covers the copper, protecting it from the etchant.
I believe they sell "PnP wet" that is supposed to come off with water?
I have some photo-paper that I'm going to use as my PnP, came free with the printer, so I'll give that a shot. I've heard that it's supposed to work just as good, if not better than the PnP.

 

[zachtheterrible]

For step 3, the PnP that will be left is where you'll want copper traces to be after etching. The PnP covers the copper, protecting it from the etchant.

I think thats what i sed. or am i missing something?

When the PnP is printed in a laser printer, does the laser cut the paper or something? And photo paper is the glossy kind u print photos out on right? Let me know how that goes, cuz im sure photo paper is much cheaper than PnP.

 

[Optikon]

Well, it basically is a c02 powered airsoft gun :twisted: . What i did was elongate the (wuddya call that thing, it moves back and forth in the paintball gun wen u shoot, u pull it back and [bleep] it . . .) by attatching a piece of brass tubing to it. This sticks out of the gun. I took off the paintball barrel and plugged a 1/2" pvc pipe in it. Inside of the pvc pipe is the actual barrel. The actual barrel is connected to sort a drip line T connector. If you're looking @ the T connector, the airsoft BBs feed into the bottom of it, on the left side of the T, is the barrel, and on the right side of the T is elongated cocking thing from inside the gun slides in and out of the T connector. (did that sentence sound a little bit wrong??) . The BB feed is spring loaded.
So it pretty much loads and shoots the exact same way that a paintball gun does, accept for it has a spring loaded feed.

I've spent about a year developing the thing. Half the reason it took so long is that i was always needing parts n stuff, and of course i don't have a license YET, so i always had to wait on my mom. I had it shooting flawlessly the other night, but a little piece in there broke and ive gotta fix it. The trick to getting it to not jam, spit out too many BBs, etc. is a little piece of fishing wire that you put right where the BBs load into the barrel, so they don't roll out and stuff. I need to find something more durable, but just as small. Can you think of anything?

It is SOOOOOOOOOOOOO cool. My barrel is just a piece of aluminum tubing from hank's hardware, so its not rifled. If i can get my hands on an actual airsoft barrel, I'd expect to be able to shoot like 300 ft. pretty accurately. When I had it working, it was the awesomest thing ever :lol: . It is totally homebrew, I have no machining skills or anything like that, so I've just bought stuff from lowe's, ace's, home depot, and modified them to suit my purpose :lol:

Itll screw off the gun of course, so if i take out the elongated thingy, and put the paintball barrel back on, i got my paintball gun back :lol: .Yeah, you print it out and attach it to the board, then you need an ultraviolet source to "expose" the board, then etch like normal.

I'd say the press n peel sounds a bit easire because you don't have to deal with lights and stuff.

you'll shoot yer eye out kid..

 

[zachtheterrible]

i NEVER EVER NEVER NADA play without safety glasses my friend :lol: . that would be plain stupid. i even wear a beanie cap to cover my ears cuz ive heard of bb's getting stuck inside people's ears. im very safety conscious.

 

[zachtheterrible]

i am making my order, and i was wondering if i should buy dry etchant or the regular liquid kind. suggestions? Thx :lol:

I am using press n peel if that makes any difference.

 

[spuffock]

I've tried press'n'peel and I'm not impressed at all. If the iron is a little too cool, the trace fails to stick in places, and you end up having to do a lot of patching with the resist pen. If the iron is too hot the plastic film will warp and stick down the tracks in the wrong place. The states of too hot and too cold overlap somewhat, so it is likely that both faults will occur.
While I'm having a go, their persulphate etchant, at least the stuff you can buy in england, consists mostly of sulphate and bisulphate, and the small proportion of persulphate is only sufficient to etch one board with the solution, then you throw it away. If you need the etch to be done in less than a few hours, you have to heat it to boiling, which erodes the etch resist.
Best method of making boards that I've found so far, use a laser printer to print onto tracing paper, use pre-coated photo-etch board, and use ammonium persulphate etchant. Good luck.

 

[jrz126]

I just ordered the sodium persulfate crystal junk from webtronics. It'll be here tomorrow along with my new soldering iron, 4000 resistors, heatshrink tubing, and some other things. I cant wait.

I dont know if the dry stuff works any better than the liquid. Also, I think the shipping might be different if it were a liquid chemical. but I dont really know.

I'd recommend the sodium persulfate because that's what everyone recommended to me, and it's clear so you can acutally see the etching taking place.

 

[evandude]

the sodium persulphate is just great because for 17 bucks you get 1 Kg, or 2.2 pounds. that's a lot... and you mix it with water so all told you get 4 liters of solution... and the being clear thing is great. plus it turns blue like windex as you etch so you can tell when it's time to mix some fresh solution.

if you really want to spend the money on press-n-peel go for it... but the staples picture paper works wonderfully and i paid 10 bucks for 30 sheets i believe...

also you may have trouble getting things done at kinkos. a lot of photo papers won't run through copiers. I know this because they tried it at my local copy place and totally jammed both their machines, had to call in an outside tech to come fix them. not good. I imagine the press-n-peel might not feed great either... at least with a laser printer you can easily fix jams and keep trying till it feeds right... at a store they'll probably get fed up and tell you they can't do it.

 

[DirtyLude]

I just bought the Staples picture paper, and that stuff is great. Better than any of the other stuff I've tried.

One thing I can recommend is learn how to pour copper, or create ground planes in whatever designer you are using. I go threw ALOT less etchant now that I don't have to remove so much copper with each board.

 

[evandude]

I agree. and it also helps the toner transfer because around large open areas with no traces, you tend to peel up sections of traces around the edge when you remove the paper, whereas if you have a copper pour there you don't have that problem. it's very easy to add a pour if you use eagle.

 

[zachtheterrible]

so go w/ the liquid eh?

what kind of paper is everyone talking about gettin @ office depot n places like that??

I guess i still don't totally understand this process. How does applying toner to the paper make it "peelable"?