Hello Everyone. Ok, now that I have gotten caught up in burning my own eproms for my 8747 I got a few ideas I want to try that require making my own pc board. I have no experience with doing this, but have a lot of experience with protoboarding. I am looking for a good way to get started with making my first pc board. Any one here have experience? Which software is the best for design? And which techinique is the best for creation of pc boards?
I have been looking at MG chemicals and their system for boarding. Any comments?
I am just trying to find the least painful way to get started.....

Thanks,

Marcello

 

FWIW, I found my original DIY info years ago in old copies of a magaine called "the Audio Amateur" out of Peterborough, NH. Do a web search for them, and for 'photo etching of printed circuit boards'. Detailed up-to-date info should be around on DIY electronic sites somewhere...

Here is what I recall doing, for photo etching custom boards:

There used to be free(or nearly free) PC CAD software around for electronic component/trace layout on small boards (like 4 X 6 inch). Don't know off-hand what is currently available, but I'm sure there is still hobbyist software around...

The image created in S/W would be sent to a laser printer, to make a 1:1 Positive Transparency (on a Mylar sheet) of the copper layer as you wanted it made.

That transparency image would then be used with a UV light, and Positive photo-resist circuit-board blanks, to print the copper image WYSIWYG (as you would contact-print a photo, back in olden times) on surface of the board.

You had to immediately etch the exposed board in Ferric Chloride(?) from Radio Shack. Once the copper was etched & cleaned up, I used to plate mine with a cold tin solution (I think DigiKey still sells the boards & tin).

Then you have to drill the component mounting holes, through the copper & fiberglass of the boards. Best thing for that was a little Dremel Drill-Press, and some very fine carbide bits - you see them sold in electronics catalogs form time to time. Buy a BUNCH of bits - they are very fragile. A bench-mounted magnifer helps too, if you are drilling for IC's.

Once it's drilled, voila - a custom printed circuit board. I never tried anything with connections at less than a 0.10 inch pitch - if you are using components smaller than that, or for multi-layers of copper, you are on your own...

Have fun.

Edit: An engineer (with far too much time on his hands) informs me that photo printing PC boards is way old-school. Nowadays you can build a DIY CNC machine, and mill the copper off the blanks. This is such an obvious solution - why didn't I think of it ???

The mind boggles. DIY Drill-Robot:

http://home.comcast.net/~scottxs/pcbcnc/cncindex.htm

Have more fun!
DrJ

 

Cnc! Now that sounds like the way a DIY'er would do it today. I would love to get to that point, but first I need to get my cnc up and running. And without pcb boards I'm dead in the water. I am actually working very studiously towards controlling stepper motors from a pc. Or perhaps without a pc, using a pic controllers (stand alone). And with stepper motors, cnc is only a few more steps away.
I have a friend who wants 4 different bins quickly accesible in his car (27c256 bin based pcm). I'm working on it. I really want to give it to him for christmas. I am hoping we will be able to switch on the fly between them. The only changes we will be making will be in the fuel and timing tables, so it should work. Crossing my fingers.
Thanks DrJ for your input. I have been reading all I can find. And today found a video at MG chemicals on creating a pcb. A picture is truly worth a thousand words. The etching process seems rather simple now that I have seen the video. I just need to find the right software to get my design onto the transparency now. Almost there.

 

Good point - how do you build a CNC machine without circuit boards to start with?


The reason for photo printing was this: Audio magazines used to print full-size board
artwork in black & white. You could just xerox the board layout to Mylar & go directly
to a UV print, without the need for CAD.

Couple of thoughts on photo printing:
With an old sun lamp, my board exposures took around 4-5 minutes. Buy some extra
boards - you need to experiment to see what exposure time works with your set-up.

Also - the ink on a single Mylar transparency was often not dark enough to give a
crisp print. Solution - make two or three Mylars & stack them up. That usually gave
enough ink opacity to produce a sharp trace.

Re etching - buy a Pyrex baking dish at the grocery store, and use that for an etch tank.
Get some extra tweezers or tongs too - you don't want to put your hands in that stuff.

The Robot article mentions some CAD s/w. The program I used was called "PC-CAD" or
words to that effect. It was some ancient DOS thing, that probably doesn't exist anymore.

Good luck.

 

In my search for software I came across this pcb123 . I can hardly believe it. They give you the software and will make a pcb for as little as $10.79 . You do the design work, and then over the internet send them the design. In a couple days you have a pcb being sent to you! Wow! I really want to do this all myself, but maybe I am crazy?

 

EagleCAD is a good program, especially for DIY stuff because then its free.

www.apcircuits.com is a place to look for getting pcbs.

 

I used eagle cad for a while with good results. I used the positive photo etch process. I know it is old school but it is cheap and easy. Jamco has all the supplies you could need in one stop. I made an etch tank out of an old jug and an air pump(fish tank type). The pump moves the etching solution around and speeds etch times. It takes some practice but it's not hard to pick up. It's all about the amount of tim to leave in each solution. It beats going to Rad Shak and using dry transfers. Plus looks alot better.

 

Alright I thought about it, and bite the bullet. Went to Fry's today and bought everything to do it. I really want to have done it myself. So I just have to get the positive printed on a transparency, and I'll be in business.
I think I just have two questions left.

• With a double sided presensitized board, how much time do you have before you have to etch?
• And once you create a positive on one side, you flip over and then do positive on other side and then develop, right?

Thanks for all the replies.

 

This is the best way to go that I have found and I have been doing my own PCB's for 20 years. http://www.expresspcb.com/ If you can point and click a mouse, you can design your own circuits and lay out your own pcb'c and they come straight to your house all done. The software is real easy to use and it is free. These people do a great job.

 

1. Once the board is exposed you need to keep it out of bright sunlight. After exposure, I always finished developing & etchng within an hour or two - I don't think you want to leave the boards around like for a month in between steps.

2. Sure, just keep the exposed side out of the UV light - think of it as light-sensitive camera film ('cause that's what it is).

HTH

 

Alright I am down to the wire here. I thought I was going to be etching my first pcb tomorrow. The first program I found that I could actually understand and create a layout for a pcb was ExpressPCB. Now I went to print out the pcb layout of the top copper layer, and it came out with a light colored background and the grid points. No matter what I did with the options - changing the colors of the background, etc,.. - I come out with the same printout. I am guessing they don't allow you to print out a correct layout, so you won't use their program to etch your own boards. Oh well. They want $90 to burn 2 boards! If I made 4 boards I would have paid for all the supplies I purchased to make boards. Any ideas??? There has to be a freeware software I could use for my first run.

Thanks,

Marcello

 

Ahhh! I love the smell of panic in the morning! Here's an initial suggestion:

Can you get your software to show you a 1:1 image of the copper layer on the monitor/screen?

Is so, use a screen-capture utility (e.g. Snag-It) to save the screen image as a jpg.

Edit the jpg in a photo program, convert to black & white, and print to scale.


Can't help with the alternate software choices. I got a copy of that PCB123, and it looks
interesting - but I haven't had time to learn it yet. Over the years I've found it's better
not to start a new hobby on a tight schedule. My projects have a way of taking a lot longer
than I first expect...

Good luck

 

dont convert to JPG... you loose detail... esp with the sharp contrasting edges.
save as a bmp... a bitmap file... its larger, with no compression, but it keeps a sharp line.

 

Eagle cad for software, then get a product called "press & peel", print out a copy of your board, take that and your press & peel to a laser copier and copy it to the press & peel. Next iron the image from the press & peel onto the board, then etch it.

 

we have this thing in our electronics shop forget what it is called but it is special board you use the program express pcboard free program from http://www.expresspcb.com/ and then print it onto a transparency tape the transparency to the board and hold it directly under floresunt light peel the transparency drop it in the acid your all set much easier than using the evil black tape and copper board i know i had to use that for 2 years until we switched teachers

 

Ok, the only software I can find that I understand is the ExpressPCB software. But it very carefully doesn't allow for a correct picture to be printed, nor can you export individual layers to cad. I have been trying to use AutoTrax EDA, and so far I don't get it. I don't understand why the libraries don't have epproms, nor either of the two type of connectors I had been using in ExpressPCB. Why couldn't they sell the software for ExpressPCB? I am going to break down and let them do the board for now. I already did all the work of setting it up. I figure my time is worth more than the money I am going to spend of redoing the pcb.
I remember when electronics magazines were all over the place. Now the only one I can find is "Nuts and Volts", and I haven't been able to find it at any stores in my area.
Is anybody using anything other than ExpressPCB to create layouts for PCB boards??? There must be another way to go.

Marcello

 

Eagle cad http://www.cadsoft.de/freeware.htm

 

Ok, I've downloaded the Eagle software and am going to give it a try tonight after work. I figure if I can't get it done by sunday evening, I'll order a board made on monday. Thanks everybody for helping me out here. Mab

 

I have been using www.expresspcb.com for my needs.

Free software, easy to use, and fast turn around on small runs.

BW

 

I was using the software from expresspcb. I love that software, but I want to be able to do my own pcbs. I don't want someone else to do them. I am in the middle of trying the software from eagle. Crossing my fingers. Mab

 

I hear ya.. I've etched a few myself. For simple circuits, like a crossover, I can make a decent board. For something like my ECM test bench board, there is no way I could match the quality of a custom board. BW

 

I finally have a transparency!!! I did it! After many attempts I am finally there. I used Autotrax to create the layout. I just about blew a gasket when I did my trail run of printing and the image came out to small. There was what I think a strange option in the printing, "autofit." This is one time when you want "print to exact size." I am taking my transparency to work tomorrow, and attempt my first etching. Thanks everyone for the help. Mab

 

I have done it!!! It actually works! I did a single sided board for my first attempt. It turned out very good. It is not perfect, but will more than suffice for the job. I have learn so much doing this I think all the headache was well worth it. I think the one thing that I should have done was heat the copper etchant. It was probably no warmer than 50F in the shop when a fianlly got to making the pcb. I bet if I had heated the solution to the specified 120F It would have come out absolutely perfect. I had to etch it for I think at least 1/2 hour, instead of the suggested 4 minutes. I did have a bubble aggitator though. I would hate to think If I hadn't at least done that. It might have taken all night. As it was my wife was already pissed off at how late I was getting home. But it worked and that is all that matters. I think I will be making a lot more pcbs. It isn't all that bad once you are set up. My boss was really worried about the smell of the chemicals, but you'd never known I was even using any. There is no smell.
In trying to use many different pieces of software to do this job, the one thing that surprised me was the lack of perfect device matches. I was using some eproms, and the only program that had them listed was expresspcb's software. It made the job very easy. When you have to design the parts for the library yourself before you can even start putting the circuit together you waste a lot of time. Just learning the software is time consuming enough. I really wish I could have just used the software from expresspcb, it was the most intuitive. I think I will spend some more time trying to learn the eagle software, but in the end the one that got it done was Autotrax.
Well I am off to sleep, finally. Thanks again everyone for the input. It kept me going.

Marcello