P.C.Board design

[Bern]

There are some adds in the N&V magazine for PC board layout software, and ordering small quantities. Which one have you used, and how did it go? Did the free software download OK, and how about learning to use it? Were you satisfied with the end product? Thanks for any information or suggestions you have on this subject.

[Mike]

Those companies have lousy software plus are overpriced. go to www.cadsoftusa.com and download Eagle layout editor.<p>Then design your board and use either the toner transfer method or the photo method to make your boards.<p>If you need to know what either of those are, ask.

[hp]

Mike,<p>I have been trying to make pc boards with the toner method and I haven't had much of a success. I am using the pcboards and etchant sold by radioshack. I am setting my laser printer to darkest 1200dpi resolution to achieve max toner output. But I do not get good transfer to the board. May I ask what paper you use and what temperature you use on your iron / heat souce? Also, how long do you heat your paper + pcb?<p>Thanks,
Harrison

[Bern]

Thanks for the return, Mike. I have a very limited knowledge of these methods. I have read some, but never tried them. I have been using tape and flow pens, but now working on a project that will need several of the same board. I would appreciate if you could point me in a good starting direction. Thanks..

[haklesup]

Are you looking for a recommendation for CAD software or on an inexpensive PCB fab<p>www.pcdandm.com is a trade magazine with links from its website for vendors. Click on the current advertizers link<p>I use www.pcbnet.com because I can get 5 two layer boards delivered for $100 full spec, standatd process. Larger boards are also reasonable. Some of the outher places look like they have lower prices but then you look at the specs and see there is no soldermask or silkscreen from them.<p>Always use proto services and on line quote forms. If you go directly to a sales person you will get a quote with tooling and setup charges extra. This will kill the price for small quantities. Avoid cutouts, gold surface, tolerances less than 7mil or other non standard things as this will bump you out of the proto pricing bracket.<p>For S/W the Free or student versions usually are limited in the number of nets or layers and generally have no autorouting capability. If your designs are not large, these offer big program features at a smaller price. Try the bookstore at your local university.<p>Most programs will lay traces etc but the library editor is where you spend the time up front making new components to put in the design. If this is hard to use, it dosen't matter how slick the main GUI is. Programs with large libraries often contain lots of stuff you'll never use.<p>To be fair,Here are a few other fabs with similarly low proto prices
www.pcbnet.com
www.pcborder.com
www.pcb4less.com
www.pcb4u.com
www.pcbfabexpress.com
www.gerland.com<p>You will need software that produces Gerber Files for most places. One company offers free software but you have to use their fab since the S/W only outputs their propriatary file format.<p>If you have a high layer count or very large board, I might recommend a differnt set of vendors.<p>I've used several CAD programs and while they all produce the same result, there can be substantial differences in how the program is used. It's no fun to change CAD programs too often. Pick one you like that will suit your needs for a while. Do more than just load the example files that come with the demo. Actually try to create a simple layout from scratch to see what it really takes.

[Mike]

about the toner transfer method,<p>I use glossy thick paper from a copy store (in my case, kinkos), but go to your local copy store and ask for the glossy paper they have and use in their laser copier machines (dont use inkjet paper in a laser printer, the fuser can melt it). Then print your design at 100% size at at least 600x600dpi, 1200x1200 is better.<p>now, cut out the design to the correct size, and cut the board. Thats the only hard part. I've tried cutting boards with a hacksaw, and the edges were rough and uneven. I have also tried a dremel. The quality of the cut was excellent, but the cutting discs tend to snap easily. If anybody knows of a good way to cut pcbs, please let me know.<p>take an iron and put it to the highest heat, then get a small piece of plywood. Then, heat some water. Place the board on the plywood and heat the copper on the board with the iron for about 30 seconds, then set the paper face down on the copper. The heat should help it stick. Now, heat the board putting even pressure on it for 2-3 minutes. Then, put the board in the water for about 30 seconds, then peel off the paper carefully. Some paper will most likely stay on the board, so use very fine sandpaper to get it off. Be careful not to sand off the toner.<p>You will now most likely have to touch up a few traces with a sharpie, and use an exacto knife to remove smeared together traces of toner.<p>Hopefully this was helpful.<p>remember, the printout will be mirrored. So, when designing your board, design it from the top as if the board is transparent. so if you have an IC chip, it would look on the computer like this:<p>1 3 5 7 9
2 4 6 8<p>that way its easy to design, and you don't have to mirror anything, just print, iron and etch.<p>-Mike

[russlk]

I cut PCBs on my table saw using a metal cutting fibre disc instead of a saw blade. It makes very smooth cuts. I just bought a 4 inch table saw from Harbor Freight Tools with a diamond blade. It cut great for about 1 minute, then all the diamond was gone. I bought a 4 inch metal cutting disc but have not tried that yet.

[jwax]

Your office folks won't like it, but an old fashioned guillotine-type paper cutter works on boards- just make sure it doesn't move while shearing it, and, ah, miss your fingers! Sharp blade required! And of course, avoid the fiberglas dust.

[perfectbite]

Russ, Try a 4" carbide tooth blade and don't expect a high rate of cutting speed. Dremel used to make 4" circular saw blades but seems to not now. In a pinch the roto tool (Home Depot) has a diamond 4" blade but the centre hole may have to be enlarged or bushed out to fit the spindle on your Harbor Freight machine. There is also a miniature tool catalog called Micro Mark and they have some interesting tools. Expensive but interesting.<p>Like jwax says, mind that fiberglass dust.

[toejam]

You get a free board layout program from express pcb. I find it pretty good.

[Mike]

nooooooo, theirs is the worst. the only decent software for pcb and schematic really is eagle. i've tried it, and the boards i could make were such low quality i didn't even bother saving them.

[hp]

I use PCB123's software. It is great for my needs due to its simplicity. It even has auto route capabilities (its messy but it does work).<p>HP

[toejam]

I did'nt try using the toner method with express, i give them thier money and they sent me boards.I tried loading eagle and they seem to want money, but it looks like a good program.
I made a nice board cutting tool by clamping a dremel to the long side of a box about 12"x4"x4" with an abrasive cutting wheel that protrudesabout 3/8 inch above the the top of a long side.I than took a 4"x4" piece of thin plastic and cut a slot in it by lowering it on the cutting wheel so it had the wheel coming through it like a little table saw and tacked the plastic piece in place.Very little dust.

[wd5gnr]

If you are looking for some guidance on Eagle (or toner method or even outsourcing boards) look at http://www.nutsvolts.com/Store_Pages/Bo ... tBoard.php.<p>The free version of Eagle is very capable. They do want money if you use it commercially or you want to do larger or 3+ layer boards. But for personal use, you can do a 2 layer board up to 1/2 Eurocard size for free. That includes schematic capture and autorouting. I haven't found anything that beats it.

[Edd]

I use a variance of jwax’s …the use of a guillotine TILE cutter with an initial modification of the mounting of a sheet of 1/8 in hard masonite to the work area to heighten it that amount. Using either mentioned device , a quick slice action minumizes crazing/splintering of the edges. if you happen to be using old phenolic based stock.
No problem on fiberglass, with the exception that its he** on retention of any tools surfacing/edge.
On fiberglass, overcutting a slightest smidge and dressing to size on the flat bottom
pressure/sole plate of a belt sander @220+ grit will typically present a prettier face than the PCB’s orig factory edge.
On cutting small PCB blanks to size with a Dremel tool mounted cut off wheel , the set of 3-5 carbide impregnated fiberglass wheels is a greater time saver than the higher count #411 or 412 units due to their quick erosion and lateral fragility/breakage.
73's de Edd
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<p>[ November 22, 2004: Message edited by: Edd Whatley ]</p>