Another day, another lesson (homemade PCB)

Discussion in 'General Electronics Chat' started by Georacer, Oct 13, 2012.

  1. Georacer

    Thread Starter Moderator

    Nov 25, 2009
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    So I've been building a PCB these days. Eagle, dual layer, through-hole parts, the works.

    So after I designed, printed, masked, etched and soldered the PCB I realized this:

    There was no electrical connection between the IC pins and the top layer pads, nor was space for solder to create one.
    Cursing ensued.

    Let's just say that v0.2.1 of that board will work around that problem.
     
  2. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    Why can´t you solder the top traces to the pins? I managed that even with sockets, so it should be possible. The half melted socket looks horrible, but it works.
     
  3. t06afre

    AAC Fanatic!

    May 11, 2009
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    Do not use the el cheapo sockets. Use the type that cost somewhat more. And yes in a non plated hobbyist board. Both sides must be soldered since the board will not have through-plated holes.
    Here is a picture The socket to the right is the el cheapo type. That I never use. The one to left is solderable from both sides on a hobbyist board and much better overall quality
    Edit: And as Kubeek says. This type of socket may be some scorched then soldering on the top layer. But it will still work.
     
    Last edited: Oct 13, 2012
  4. Georacer

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    The most expensive one costs at about 50c more that the cheap one, IIRC. It could be worth it since it saves me from soldering a via for each pad I solder on top.

    But I still can't get around pin connectors and headers that go as low as the board surface.
     
  5. Ron H

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  6. Wendy

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    Mar 24, 2008
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    Use a really thin wire to connect the top and bottom pads. Solder away from the pads. As long as you are not carrying current through it it should work.
     
  7. Georacer

    Thread Starter Moderator

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    I believe you are referring to chemical methods, right?

    I must admit that I 'm not familiar with any, and I don't think that they are worth it for the prototyping phase. What do you think?

    @Bill,

    I don't want to plan beforehand where the power needs to go. I 'll stick to making a via next to the pin, for now.

    If I get more comfortable with recognizing all of the power paths on a board, I 'll use your method. Soldering a very thin wire on a trace under tension sounds like work, though.
     
  8. bountyhunter

    Well-Known Member

    Sep 7, 2009
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    Far from the dumbest mistake I have seen on PC boards.... I should write a book.

    What was really funny was a board we had made where all the pads and vias were done right, but the knothead who made the fabrication drawing was too lazy to spec the right size holes for the larger resistors and caps and diodes.... so the assembly tech just took a drill and drilled the holes out so she could assemble the boards.

    Funny trying to troubleshoot a board where the top layer traces don't make contact to half the components on the board.....:p
     
  9. Georacer

    Thread Starter Moderator

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    Not funny, man, not funny.

    I virtually copied the top layer under the bottom one using wires.
    I just hope I roll out the next version soon enough so that I don't have to look at this atrocity. And it was so pretty off the bath...
     
  10. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Reminds me of way back when [before plated thru holes ], " we " speced PCBs with fluted eyelets from TI-- they realy did make custom boards.
     
  11. Georacer

    Thread Starter Moderator

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    You speced (?) them with what? What's a fluted eyelet?
     
  12. nerdegutta

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    Dec 15, 2009
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    December last year. I made this:
    [​IMG]

    I just forgot to scale it properly. I had earlier experimented with the scale, and forgot to set it to 1:1. This board is made in 1:1.3.

    The 555 IC didn't make the split...:)
     
  13. t06afre

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    Not very high standard either I would say:p
     
  14. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    That is the neatest, most beautiful failure I have seen in a long time. :)

    I too made a beautiful failure PCB using toner transfer. After getting the toner density perfect and transfer perfect and every trace checked as being perfect, (guess?) I realised I had forgotten to flip the artwork and the PCB was backwards. :eek:
     
  15. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    The name has changed from fluted to funnel. " What is the purpose of funnel flange eyelets ?" Specifically developed for electronic use, funnel flange eyelets allow solder to flow around the barrel. Lead wires are easier to insert and solder fillet is quickly inspected." Internatoonal Eyelets Inc.
     
    SgtWookie and Georacer like this.
  16. Georacer

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    Nov 25, 2009
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    That happened the first time I went out to a photo shop to print my mask. Luckily I checked it before taping it. I went back to the shop to complain. The owner said "that's what the printer gives, I can't do anything else."

    The next shop printed it just fine.

    I 'm feeling competitive, so here's my beautiful failure. Drilled too!
    Hill Cruiser Board v0_2_1_c 015 [Ανάλυση οθό&#.JPG

    I still can't manage the camera flash settings correctly.
     
  17. Georacer

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    So it's a copper sleeve inserted in the whole and soldered on both sides. Clever, but a lot of work.
     
  18. t06afre

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    A trick I use. Is to print out on paper then place some components on the paper. Like big ICs. This will give some clues on how your scaling is.
     
  19. t06afre

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    If you work with through holes ICs. The decoupling caps makes a very good via. Must still be soldered on both sides although
     
  20. Georacer

    Thread Starter Moderator

    Nov 25, 2009
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    Yes, I, or better, the Eagle software uses the pads to switch between layers.

    From now on I just have to restrict routing from the top side pads that can't be soldered upon. The change has been done in the version 0.2.1 of the board.
    It pulls the track a bit off the bottom pad and creates a via next to it, where I can solder through it.

    I 'm quite happy with the options I 'm given by this software.
     
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