Best way to finalize circuits?

Discussion in 'General Electronics Chat' started by protomor, Dec 31, 2008.

  1. protomor

    Thread Starter Member

    Dec 23, 2008
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    Now that I have my bread board prototype done, I want to get things soldered into something permanent. From what I've read, there are two different options: Etching my own boards or using a generic multipurpose pcb

    Etching sounds like the best option but my main problem is attaining the etching solution and disposal of the used solution. If I could design my own board, I could make things as compact as possible and not have to worry about connections. I would just solder in and go.

    The multipurpose PCB seems to be the quicker solution here. My main problem is connecting the soldered in pieces together. I haven't found a good way of doing this without running into situations where leads run over top of each other and a bunch of things go to one point. Are there any good tutorials out there?

    I want to get the best quality product while not killing myself or the environment. Which should I do or what other ways could I do this?
     
  2. bertus

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  3. beenthere

    Retired Moderator

    Apr 20, 2004
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    The decision is really governed by the number and function of circuits you might be assembling in the future. General purpose boards can be had - or made by etching at home.

    Most chemicals used in etching are benign, if not so in concentration. Ferric chloride (FeCl) has a shelf life of at least 10 years - based on my current batch still in use. The end product is pretty well inert, and some stray chloride ions running around are not going to cause much damage - it's about the most common one loose already.

    As far as not killing yourself - don't use pcb stock with a resist that uses solvent chemistry. Always look for aqueous developers. Most of them will set up into a gel or even a solid is left to stand for a few days - just dispose in the trash instead of down the drain.

    Nothing comes without cost. look into the chemical processes that produce the phenolic base or the epoxy in pcb stock. Even making a bicycle causes quite a bit of pollution.
     
  4. protomor

    Thread Starter Member

    Dec 23, 2008
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    hmm etching doesnt sound so bad now. My local radioshack has the copper backed boards but no etching solution. Where can you get some?
     
  5. beenthere

    Retired Moderator

    Apr 20, 2004
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    I get my supplies - pcb stock, etchant, and developer from Circuit Specialists (www.circuitspecialists.com). The pcb stock is a positive resist type, so you can use transparencies made from a laser printer. I get consistent line reproduction down to 6 mils, althought I have got test lines as thin as 4 mils.

    Here is a link to a thread we had discussing ways to do pcb's - http://forum.allaboutcircuits.com/showthread.php?t=12474.
     
    Last edited: Dec 31, 2008
  6. protomor

    Thread Starter Member

    Dec 23, 2008
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    sweet thanks!
     
  7. Wendy

    Moderator

    Mar 24, 2008
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    The two methods of making PCBs are actually pretty close. Unless you are going to had draw a PCB (which I have) the software is the same. Doing it yourself means after you have a layout instead of sending it into a vendor you proceed to get into the home chemistry. Beenthere's methods is good, but again, there are choices. Radio Shack also sells the chemicals (it will be interesting to see if they continue to do so though). Ferric Chloride (which is what Radio Shack sells) is pesky, I have been able to control it by wrapping a single sheet of paper towel tightly around the cap and taping it into place after using it, otherwise the fumes slowly escaping the bottle will find metal to rust (usually favorite tools), as is the paper towel gets all crispy. I can't speak for Ammonium Perchlorate, the other favorite enchant, other than to observe they are more or less interchangeable. Ammonium perchlorate is clear (don't know if it stays that way) and ferric chloride is a deep brown green.

    If you have a laser printer (or good access to one) Tom Gootee's website has a good technique, which is what I use. Check this website out...

    http://www.fullnet.com/~tomg/gooteepc.htm
     
  8. beenthere

    Retired Moderator

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    Good point about storage, Bill. I have "proper" heavy plastic carboys for my FeCl. But 2 liter drink bottles, kept in a storage container against accidental kicks, etc., should do well. No metal to attack.

    By the way, ferric chloride eats stainless steel with enthusiasm. It needs to be in glass or plastic containers.
     
  9. duffy

    Active Member

    Dec 29, 2008
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    Let me recommend the other technique. Desiging PCB's and etching boards is fine and even necessary sometimes, but to get going quickly on a circuit that doesn't have a bunch of hundred pin QFP's there's noting that beats point-to-point.

    Use through-hole and perf board for the stuff you can, and those multipurpose "breakout" boards (beldynsys.com's boards, surf boards) for the rest. Stick them to the perf board with double-stick FOAM tape. Use wire-wrap wire, but just go point-to-point and solder everything. Have the circuit running before the next guy has gotten far along enough to realize he has to cut and re-route a bunch of traces and used the wrong pad layout for something else.
     
  10. bertus

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    Apr 5, 2008
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