Is this PCB correct ?

Discussion in 'The Projects Forum' started by André Ferrato, Apr 13, 2015.

  1. André Ferrato

    Thread Starter Member

    Apr 5, 2015
    206
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    Can anyone validate it for me ?

    Diagram

    [​IMG]

    PCB

    [​IMG]

    I'm concerned about the switch ground pins, i got some errors in eagle and the airwires just disappeared, so how bad it is ?
     
  2. paulktreg

    Distinguished Member

    Jun 2, 2008
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    Is it single sided?
     
  3. André Ferrato

    Thread Starter Member

    Apr 5, 2015
    206
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    Yes, the circuit is just on one side
     
  4. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    With nothing labeled on the PCB, it is hard to be sure, but at first glance, it appears that you may not have done proper mirroring -- assuming your PCB rendition is what the copper layer will look like. Remember, through-hole devices are set on the non-copper side of the PCB in most cases.

    Please mark the #1 IC pin or something else to give a reference point.

    John
     
  5. André Ferrato

    Thread Starter Member

    Apr 5, 2015
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    Oh, of course, i'm new to this, but yes i know that devices are mounted on the non cooper side. The IC first pin is the left top one, A0. You said i may have not done proper mirroring? How so

    EDIT: Oh you mean flipping the image for transfer?
     
  6. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    You mentioned Eagle. It usually shows the bottom layer in Blue and the top layer in Red. What you appear to have is the bottom layer, but being in black, I can't tell. The bottom layer is assumed to be viewed through the board. That is, if you turn the board over and actually look at the bottom, it would be a mirror image.

    You did not mention how you were going to make the PCB or even whether you were making it or sending it out. Some of the details in making a board can affect whether you need to flip the image or not. If you had shown the colors or even stated the colors, it would have been clearer.

    Some of the errors you mention in Eagle may be because it is sensitive to layer violations. For example, if you are working on a two-layer board, you may think you have a device on the bottom layer, but Eagle may think it is on the top. Your routing will give errors in that case.

    Your follow-up comment shows you are aware of that mirroring problem, so I would put my trust in Eagle. Can you be more specific about the errors Eagle gave? If you zip your board and schematic files, you can post them here. That would make review a lot easier.

    John
     
  7. André Ferrato

    Thread Starter Member

    Apr 5, 2015
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    I really don't have any eagle skills and this is just a primitive thing, but i think it may be right, with your support i could correct some of my mistakes! The link to the file, i hasnt able to upload the board on the forum so i uploaded to 4shared.

    EDIT: The image white and black image i uploaded first, was the pcb i intended to toner transfer on a one sided copper pcb. Note: first time doing this, 99% chance of doing it wrong!

    http://www.4shared.com/rar/XmYYO1Ihce/transmitter.html?
     
  8. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    90-degree angles on PCBs are often considered bad practice. Try to limit your traces to 45-degree angles.
     
  9. André Ferrato

    Thread Starter Member

    Apr 5, 2015
    206
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    Why..? 90 degrees are so cool
     
  10. MrChips

    Moderator

    Oct 2, 2009
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    If you are planning a DIY PCB, here are some additional tips.

    1) Make your traces twice the width of what you have showing. I am guessing those are 20mil. Make it 40-50mil since you have room.

    2) Use Eagle to flood a ground plane. It will be easier to etch.

    btw - where are your GND connections?
     
  11. ebeowulf17

    Active Member

    Aug 12, 2014
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    I was wondering about those ground connections too!
     
  12. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    I am reluctant to download anything from 3rd party sides. Can you use ZIP and upload it here? If there is a limit for posts, I think you are probably over it.

    Copper fills are neat to work with, particularly for ground connections, but for other things as well. The 90° vs. 45° for trace bends is a mechanical thing more than electrical. With a 90° bend, it is easier to snag a corner and lift a trace. Also, 45° may be shorter. I agree on trace width. There is no reason to use a narrow trace when a wider trace will fit. If you look at some of the recommended layouts for power supplies by the major manufacturers, you will see lots of copper pours with square edges. I am just a hobbyist, but here is an example of using pours for a little linear supply that I sent off recently (NB: bottom layer is not shown for clarity):

    upload_2015-4-14_6-13-19.png


    John
     
    DerStrom8 likes this.
  13. André Ferrato

    Thread Starter Member

    Apr 5, 2015
    206
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    Okay, this is the two files i have, the schematic and the board. I will correct the width of the paths, and about the ground connections, i thought when we left like that, it would be ground? Or i'm a wrong ? Also i uploaded the zip file now, if you could have a look and see the errors i'm getting and help me fix it, it would be nice. Thanks in advance.

    [​IMG]
     
  14. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    In the image above, why do you have that blue trace looping down between the leads of S4 when you can simply connect it to the top left pad?

    PLEASE fix the 90-degree corners. It's poor practice.
     
  15. André Ferrato

    Thread Starter Member

    Apr 5, 2015
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    I'll fix it, but please, first help me fix the other things

    EDIT: Because i'm new to eagle, still on tutorials and stuff.. :(
     
    Last edited: Apr 14, 2015
  16. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    You need to name your polygon "GND" in order for it to connect as a ground pour.
     
  17. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    There seems to be a linking error between your schematic and your PCB. The PCB is not finding all the required nets. I suggest deleting the PCB file altogether and trying again.
     
  18. André Ferrato

    Thread Starter Member

    Apr 5, 2015
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    Understood, i'll make a new board and put it here. I thought by just connecting to the gnd in the schematic this would be done in the board.
     
  19. MrChips

    Moderator

    Oct 2, 2009
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    [​IMG]

    1) Straighten your lines
    2) Connect to the nearest pad
    3) Make those pads as large as the allowable space. 60 thou is ok for 0.1" pitch. Why not use a 18-pin DIP package with elongated pads?
    4) You have to route your GND pins or use a polygon fill labeled as GND.
     
  20. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    Nope, you still have to design the board. Connecting to ground in the schematic will only show you airwires (the thin yellow lines) in the PCB. You still have to do all the routing yourself.
     
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