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Ground Planes and Proto Board — Parallax Forums

Ground Planes and Proto Board

idbruceidbruce Posts: 6,197
edited 2011-07-21 19:57 in Propeller 1
Hello Everyone

I may be destroying a perfectly patentable idea here, but I would like other peoples input.

Anyhow, let's say that a person is using one of those beautiful, awesome, and lovely Parallax Propeller Proto Boards, and let's say this person wants to add an IC to the Proto Board that requires a substantial ground plane under the IC, such as a stepper driver IC.

Is this feasible or does this already exist:
Copper sheeting with pins spaced 0.10" apart that can be cut to form a ground plane that can be soldered to a prototype board?
Bruce

Comments

  • ElectricAyeElectricAye Posts: 4,561
    edited 2011-07-20 13:17
    Go to Digikey and search for SurfBoard. I don't know if they have anything with ground planes, but they might.

    http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=33115CA-ND
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 13:26
    @ElectricAye

    Well that was pretty cool! I went to their home page and they have some pretty interesting stuff. Definitely worth a visit and marking as a favorite.

    http://www.capitaladvanced.com/index.html

    Bruce
  • LeonLeon Posts: 7,620
    edited 2011-07-20 13:31
    Mount the chip on a small piece of copper-clad board and ground the copper.
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 13:35
    @Leon - Yeah, but those boards are 1/32 -1/16" thick, some IC pins barely penetrate a Proto Board.

    Bruce
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 14:02
    Okay here is an idea.

    Cut copper sheeting to the desired shaped. Drill (4) 0.026 diameter holes 0.10" on center, and tack in place with 22 gauge wire and attach to ground.

    Bruce

    EDIT: Route all (4) 22 gauge wires back to ground. It is just a suggestion.
  • LeonLeon Posts: 7,620
    edited 2011-07-20 14:06
    You don't drill holes in the board, the chip is simply wired up directly on the copper "dead-bug" or "live-bug" style. The technique is often used for RF prototypes.
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 14:08
    LOL
    "dead-bug" or "live-bug" style

    What the heck does that mean? :)

    Bruce
  • LeonLeon Posts: 7,620
    edited 2011-07-20 14:11
    The chip is mounted with the pins pointing up, or down.
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 14:11
    I think I know what you mean. Extend wires out from copper clad board and attach to Proto Board, if so, you lose real estate, much larger footprint.

    Bruce
  • LeonLeon Posts: 7,620
    edited 2011-07-20 14:12
    It can be very compact if several chips are put on the same piece of PCB material.
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 14:13
    I suppose it could be, never seen it done.
  • LeonLeon Posts: 7,620
    edited 2011-07-20 14:14
    It's used a lot by radio amateurs and RF professionals.
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 14:15
    Thanks for the tip. However, I also like my idea, but I am sure it would be more time comsuming.
  • LeonLeon Posts: 7,620
    edited 2011-07-20 14:16
    Building prototypes like that is very fast, which is why it's so popular. Circuits often work better than when they are put onto a PCB, because of the short connections and excellent grounding.
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 14:17
    I meant my way would be more time consuming.
  • LeonLeon Posts: 7,620
    edited 2011-07-20 14:20
    This doc shows what it looks like:

    http://www.dartmouth.edu/~sullivan/prototyping.pdf
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 14:27
    @Leon

    Thanks for the document link. It is always nice to see the techniques of others.
  • markaericmarkaeric Posts: 282
    edited 2011-07-20 14:33
    Bruce,

    If I'm understanding you correctly, some 3M adhesive copper foil strip tape might do the trick.


    -Mark
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 14:41
    @markaeric

    That also sounds pretty good. Just entend it out from under the IC and tack it to ground. Never seen that product from 3M though. What is it normally used for?

    Bruce
  • RS_JimRS_Jim Posts: 1,768
    edited 2011-07-20 17:54
    I used to use it to seal seams in metal boxes to keep RF in/out
    Jim
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 18:43
    @Leon

    There is another thing I should have mentioned during our conversation. For stepper drivers and bridges, the ground plane is used primarily for heat disappation as compared to interference. So I believe the "dead bug" option might be excluded in this instance :)

    Bruce

    EDIT: A lot of the datasheets explain the use of a large ground plane extending from the ground pin to be used as a heat sink. However, perhaps the "dead bug" might even be better, I just don't know :)
  • ElectricAyeElectricAye Posts: 4,561
    edited 2011-07-20 19:16
    When I first saw an image of dead-bug prototyping, it was like a religious experience. It was an inspiration. I had an epiphany: if something that appears this horrible can be used by professionals and work so well, then maybe, just maybe, I can make something work, too.

    PDA_proto.jpg

    jimmy-swaggart-1988.jpgjimmy-swaggart-1988.jpgjimmy-swaggart-1988.jpgjimmy-swaggart-1988.jpg
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 20:00
    ElectricAye

    Truly inspirational

    Bruce
  • markaericmarkaeric Posts: 282
    edited 2011-07-20 20:38
    Bruce,

    I don't know what it's "normally" used for, but you can get them in various width and thickness. I've just recently started using it to easily add power traces on prototype boards - especially nice when you have a bunch pull up/down resistors in a row. And since it's an adhesive, it could be much more convenient than using jumper wires and/or solder bridges. It seems to make prototyping a lot easier. I would probably recommend getting two rolls - one narrow and one wide. I currently only have wide, so sometimes I have to do a bit more cutting than I'd like.

    -Mark
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 20:42
    markaeric

    As mentioned in an earlier post, this makeshift ground plane would be primarily used for heat disapation. Of course I would tack it in place with solder or wire, but the thought of oozing adhesive worries me a little :)

    Bruce

    EDIT: Especially 3M adhesive :)
  • idbruceidbruce Posts: 6,197
    edited 2011-07-20 20:47
    I believe K&S Engineering sells bare copper foil in varying degrees of thicknesses and widths. I think I might try my earlier idea.
    Cut copper sheeting to the desired shaped. Drill (4) 0.026 diameter holes 0.10" on center, and tack in place with 22 gauge wire and attach to ground.

    Bruce
  • LeonLeon Posts: 7,620
    edited 2011-07-21 03:42
    I've used double-sided tape for sticking things down when prototyping. I don't think it will last long with any heat, though.
  • frank freedmanfrank freedman Posts: 1,983
    edited 2011-07-21 19:34
    You could alway check out McMaster-Carr or si,ilar for copper shim metal. There are various sizes. shapes and thicknesses.

    Frank
  • markaericmarkaeric Posts: 282
    edited 2011-07-21 19:57
    idbruce wrote: »
    markaeric

    As mentioned in an earlier post, this makeshift ground plane would be primarily used for heat disapation. Of course I would tack it in place with solder or wire, but the thought of oozing adhesive worries me a little :)

    Bruce

    EDIT: Especially 3M adhesive :)

    Ah, right.. I never needed to use it for heat dissipation, but I have applied excessive heat with my iron on a few occasions and didn't notice any funny business from the adhesive.
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