Circuit board layout software & etching

Discussion in 'General Electronics Chat' started by DAK, Aug 9, 2010.

  1. DAK

    Thread Starter New Member

    Nov 25, 2009
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    When I build a circuit I start on a breadboard and then transfer the circuit to a solderable perf board. Building the circuit on the per board is very involved and lends itself to many mistakes, at least for me :)
    I know there are software programs that can take your circuit and transfer it to a circuit board layout for making your own circuit board. Do you have any information on the most simplest and cost effective software and or components for making your own circuit board (copper etched?)?

    Thank You for Your Time,
    DAK
     
  2. Wendy

    Moderator

    Mar 24, 2008
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  3. DAK

    Thread Starter New Member

    Nov 25, 2009
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    Thank you so much for the quick response. I will look into it :)
     
  4. DAK

    Thread Starter New Member

    Nov 25, 2009
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    Wow! What a great resource everything you need to know on creating your own circuit board.

    Do you happen to have any information on a real basic software program that will produce a pc layout so I can make my own boards using the information you have already given me?
     
  5. BMorse

    Senior Member

    Sep 26, 2009
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  6. PRS

    Well-Known Member

    Aug 24, 2008
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    Hi DAK. I used to build on copper clad boards by drawing the nodes I needed on them and then scraping away the copper with a knife in order to isolate them. Then I ordered a bottle of ferric chloride from Jameco put some of it in an old cat litter box. By painting what I wanted to keep black, using regular enamel paint, then tossing the board in the kitty box for half an hour or so, they came out great. This reduced the work of scraping the copper.

    On the other hand, I like Bill Marsen's post, too. If you happen to read this, Bill, here's a big thanks from me, too! ;)
     
  7. DangerousBill

    Active Member

    Jul 21, 2010
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    I tried the toner transfer method a couple of times in years past, with poor results. At least the problems can be reduced to mere cosmetic ones by hand working the board after etching. Strips of glass fiber paper (from the chem lab) soaked with etch can be placed carefully on the board with plastic forceps to get rid of copper that remains where it shouldn't.

    The biggest PITA is drilling the holes afterward. There are always so many of them! I used a center punch followed by a Dremel drill press, but I'd still break a couple of $8 carbide drills per board. Actually the drills worked best if they broke leaving about 1/4" of drill on the shank. This reduced bending and subsequent fracture.

    Ammonium persulfate turned out to be superior etchant to ferrous chloride and didn't stink up the place with chlorine gas. It's clear, so you can inspect the etch process as it proceeds. It also seemed to discriminate better between toner-covered and uncovered areas.

    The soldering goes much easier if you tin-plate the board afterward, but the solution is not stable and has to be reused several times in a short period of time to make it worth the cost.

    These days, even for draft boards, I mostly use ExpressPCB's free software and excellent service to get my pc boards done, even the drafts, and darn the extra cost. My time is worth more than the cost.

    Dangerous Bill
     
    Last edited by a moderator: Aug 9, 2010
  8. Wendy

    Moderator

    Mar 24, 2008
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    For the most part I use protoboards and perfboards. A good example of how I use perfboards is shown in this thread...

    Project: High Power LED Flasher

    You will see examples of my projects were scattered throughout this site using this technique.

    On the occasional times I make circuit boards I use the toner transfer technique. It has worked well for me, with an occasional misfire. You will find other projects that people have done that get even better consistent results.

    Project: Converting a hot roller laminator for toner transfer.

    Drilling holes is a hassle, but it is part of the process, unless you go surface mount technology. A lot of folks use home made CNC machines. You can buy them off the shelf, but they are expensive. They can be made much cheaper from what I've heard. A CNC machine (AKA engraver) can drill all the holes in one session. They can also cut a PCB out by removing the copper via machining techniques. There are several ongoing threads on this site where people are in the middle of making homemade CNC machines.

    Interestingly, Mr. Gootee also has info on CNC at his web site, and there are much wider resources throughout the web.

    Another popular medium for toner transfer is gloss paper, the kind used in magazines. Don't worry about the color graphics, the color printing actually helps the process from what I've heard. I've never done it, which is why it is on my list of things to try.

    Generally for a one off project I'll go breadboard as I showed earlier, but if you want consistent repeatable results nothing beats a printed circuit board.
     
    Last edited: Aug 9, 2010
  9. Markd77

    Senior Member

    Sep 7, 2009
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    If I'm using components with leads I tend to use stripboad, and for surface mount I use Edding 400 and 404 permanent markers and persulfate etchant. You can see one in my blog. The 404 pen is fine enough to draw a trace under a 0603 or SOT23 component and the LEDs are 0402 package (1mmX0.5mm).
     
  10. marshallf3

    Well-Known Member

    Jul 26, 2010
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    As to software, for the basic to medium complexity projects I use http://www.diptrace.com but there's a fair amount of learning curve to it. You can download a fully functional version that's free but it's limited to the number of pins and layers. I've got the full license version as well as ORCAD at work.

    Due to all the component patterns and not being able to have everything in the libraries I usually design the schematic, hand arrange the components on the board then have it autoroute the traces. Some boards I send off but for simple "one timers" I use the toner transfer method which, after a lot of experimentation, can work rather well.
     
  11. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    I second Diptrace... I find it far better/easier than eagle.
     
  12. marshallf3

    Well-Known Member

    Jul 26, 2010
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    DipTrace also has a new forum set up where you can pick other people's brains on any questions you have about using the program. It doesn't take too long to learn for what most of us would use it for, however it has the capability to be a very powerful tool as you get to know it better.

    Best of all the basic version is free but limited to 500 pins and two layers.

    Just don't expect to autoroute anything in a few minutes, even with a fast processor it takes time as it chooses the best layout. You can then manually tweak the results from there. I tend to design, place, autoroute then export to Gerber. I then run the Gerber files through http://www.freedfm.com and it will point out errors that may cause problems during etching. A little bit of learning on the output of that too but in no time you'll be creating nice PC board designs.
     
  13. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Diptrace now has 2 different autorouter (a shape and grid router) that is MUCH faster... Mine autoroute in under 20 seconds (typically around 30 components/150 or so pins)
     
  14. marshallf3

    Well-Known Member

    Jul 26, 2010
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    Yes, however it becomes a different matter when you've got almost 4,000 pins. I usually just leave it to run overnight. I'm using version 2.something
     
  15. Darren Holdstock

    Active Member

    Feb 10, 2009
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    Inkjet photopositive onto acetate. Use decent quality pre-coated boards. Exposure time isn't too critical, but the developing time is - here proper developer solution is much more forgiving than sodium hydroxide. You should be able to get 0.3 mm tracks and clearance with a home brew, maybe 0.2 mm with practice.

    Top tip to avoid snapping drill bits: Make all your artwork holes 0.7 mm, and this will provide the perfect locating pip for drill sizes from 0.8 mm to about 5 mm. It helps if the PCB can move around on the drill bed easily, that way if the drill is a little off centre a slow final approach will nudge the board into the perfect position for that hole. I can't remember the last time I snapped a 0.8 mm tungsten carbide drill - it's a technique that works well for me.
     
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