Project: How to make PCBs

jpanhalt

Joined Jan 18, 2008
10,110
A lot of the really good deals on eBay seem to have disappeared. A few years ago, I got 20 boxes of 50 each resharpened #66 (0.033") for about $20 ($0.02 each). It just breaks my heart when one breaks. :D I save the shank, just in case some day I find a use for them. EBay's new rules allowing dealers to cancel auctions more easily seem to prevent such deals from recurring.

Anyway, the smaller bits will break, even when using a drill press. So, get a lot of them. I don't think you need anything much smaller for PCB work. You may need some larger ones.

I often use just a HSS drill for the few larger holes I need to do. One caution with carbide, particularly resharpened ones, is the tip angles may be way off. Some are almost like milling cutters and don't center very well. If you snap a carbide lip off in the board, it will usually bury itself in the PCB material. Another drill will just snap off, if you try that. The best solution I have found is to dig the chip out out with a scribe or sharpened shank from one of the broken drill bits, before trying to finish drill the hole.

John
 

spinnaker

Joined Oct 29, 2009
7,835
I wanted to post tips on the bits as well. Make sure you put the bits away right after you are done using them. I have broken more bits by forgetting they are there and bumping them.

If you are drilling a small board, it helps if you tape the board to a larger wooden board. It helps you to get a better grip on the board. If it should jump you can break a bit.

Move the chuck WELL away from the board before moving it. If you over pronounce the chuck movement you will be sure to make sure the bit is clear before moving the board.
 

Thread Starter

Wendy

Joined Mar 24, 2008
22,156
With a good drill press designed for such (such as the dremel) I have heard of people who have never broke them. My set is over 5 years old, with no problems yet. I've only used it on 10 or so boards, so it may not mean much.
 

nerdegutta

Joined Dec 15, 2009
2,676
I use a somewhat simple drill press, and a Dremel-like Proxxon. The only drill bit I broke, was when I didn't put the drill bit in storage right away, and when putting the press aside, the powercord got stuck, and broke it off.

I use the Proxxon for holes 0.7mm - 3.2mm. Anything above, the Makita comes along.
 

spinnaker

Joined Oct 29, 2009
7,835
I tried the print to wax paper thing tonight. First I had a heck of a time getting it to feed through the printer. I had to tape it to a piece of paper like Bill.

But the worst part is I got a lot of voids on the paper. I think the problem might be is that the paper is not feeding smoothly. The paper makes a lot of noise going trough the printer. It sounds like the paper is being crinkled.
 

nerdegutta

Joined Dec 15, 2009
2,676
I tried the print to wax paper thing tonight. First I had a heck of a time getting it to feed through the printer. I had to tape it to a piece of paper like Bill.

But the worst part is I got a lot of voids on the paper. I think the problem might be is that the paper is not feeding smoothly. The paper makes a lot of noise going trough the printer. It sounds like the paper is being crinkled.
I tried that last year. Had to disassemble the printer to get the wax paper out. Didn't think of tapeing it to a paper sheet. :(

Started with UV-LED after that. :D
 

Thread Starter

Wendy

Joined Mar 24, 2008
22,156
Wax paper is way to limp to treat it like paper. I fold the edge over a regular sheet of paper, then either fold or cut the edges to match the sheet. Use scotch tape to hold the folded part in place, as well as the edges near the top and middle. You will trim away a lot of the wax paper with your finished, but be sure to leave yourself with enough edge material on the wax paper to work with.

I think I showed that in my pictures, right?

If you get the wax paper truly flat with the regular paper the crinkle sounds will fade to nothing. It is when the rollers are flattening all the wax paper you hear a lot of sound.

I also used scotch tape to hold the wax paper in place when feeding it through my laminator. I had to provide a lot of assistance to get the paper/PCB stock to roll through my laminator. Be sure the scotch tape is not in line with any of the wax paper transfers when rolling through, else it will spread the laminator rollers just enough to mess up the process.
 

Thread Starter

Wendy

Joined Mar 24, 2008
22,156
On mine the scotch tape definately melted. The stuff that had cooled a little, or the tape that hadn't yet gone though, took up the slack. I made the mistake of framing the PCB, which is why I mention not to do that. On the tape on either side of the PCB to not overlap the tape with the PCB.

In some ways I think a home made laminator would be easier. It is a theory at least, and the cost would be astronomical. I took mine apart, there was no obvious way to spread the rollers apart. The wasn't any way to get all the way to them without every nut and screw being removed.

So I leave enough paper for me to grab and help the motor pull it through. I suspect this unit is going to die early. Since I bought it strictly for PCBs I'll use and abuse it until it does.

Scotch tape doesn't affect the laser printer at all.
 

wayneh

Joined Sep 9, 2010
16,399
A thousand thanks to Bill for posting this procedure. Having never done my own PCB, I had asked back around Halloween how folks here get their's done.
There were many excellent replies, and many tips that aren't already in this thread. So I recommend folks interested in the topic to scan thru that thread as well. See http://forum.allaboutcircuits.com/showthread.php?t=44877.

But Bill's is the first (and only?) end-to-end write-up I've seen with all the good detail that a newbie might need to start out on their own. Kudos.

One small addition regarding PCB software: I've just investigated 3 free options mentioned here; Eagle, DIPTrace and ExpressPCB. Being a Mac user, I was pleasantly surprised that the first two are available for Mac users. I've loaded both and will start playing with them soon, possibly coming back with reviews.

My previous circuit drawing work was all done using a great drawing program (Freehand), but it wasn't specialized to the task. I'm looking forward to the autorouting and such - should save a ton of time.
 

Thread Starter

Wendy

Joined Mar 24, 2008
22,156
Wax paper is right next to the aluminum foil, in the baking goods section.

I paid $10 and $40 for my two, the toner is much more expensive. Keep an eye out for estate sales, yard sales, and what not. How much are you willing to spend? I'll keep my eye out for one, the shipping would be much more expensive that the printer though.
 

shortbus

Joined Sep 30, 2009
7,857
If you don't have a laser printer, a copy machine uses the same basic process/toner. Just don't use the 'Brother' brand, either printer or copier. Their toner works at a much higher temperature.
 

R!f@@

Joined Apr 2, 2009
9,734
I can print with lasers no problem.
I got single sided clad boards.
I can get etching chemical.

It's the wax paper that I cannot find.
 

jpanhalt

Joined Jan 18, 2008
10,110
Here is what you are looking for:



Although waxes are available with melting points up to several hundred degrees C, I believe the wax used here has a relatively low melting point. Couldn't find that specific information for Reynolds, but ordinary paraffin starts to melt between 37° and 39° . Maybe it is just not sold in the Maldives for that reason. Or, maybe it is sold in two parts. You buy the paper and get a bottle of liquid wax separately. :)

I seems one key to Bill's method is the vapor pressure of the particular wax that is used. From his description, it appears that wax in the non-trace areas is vaporized in the printer. Thus, it does not transfer to the PCB copper and interfere with etching. So, if you must improvise and use an oil-treated paper, I would suggest a relatively low boiling oil, such as kerosene. Of course, since I have never done it, that is blind leading the blind. I do not think that motor oils designed for high temperatures would work. The alternative, of course, is glossy print paper as is used in other variations of the toner-transfer method.

John
 
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strantor

Joined Oct 3, 2010
5,324
If you don't have a laser printer, a copy machine uses the same basic process/toner. Just don't use the 'Brother' brand, either printer or copier. Their toner works at a much higher temperature.
So THATS what the friggin problem is! Sheesh, I've read the writeups where they say "...and then set your Iron to about the middle setting, not too low, not to high..." and my toner didn't even begin to melt at that temperature. I had to set it all the way at the end, past all the settings and then leave it strapped to my board with bungees for about 15 min. I was thinking "man, I don't know what kind of Irons these guys are using, but mine sucks!"

I bought a Brother 2230 specifically for making PCBs. I guess I should have done a little more research. Other than the heat issue, it makes really nice prints.
 
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