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Arbitrary Pad Shapes

e14 Contributor

Hi,

 

Last June, I posted about arbitrary pad shapes.  I was eventually able to

solve my problem and go to fab on my board.  There were 2 problems which

apply to the new issue I describe below.  One is line width and the other

is placement of the arbitrary pad shape on the final layout.

 

My new issue is I'm using a device which has through holes which are

basically rectangles with rounded corners.  I can create the hole using the

milling layer as described in the manual.  The problem (again) has to do

with the arbitrary pad shapes.

 

There are a couple of issues:

 

- In my previous post, the device was an SMT so a single pad wasn't a

problem.  But my board is 6 layers.  It seems (to me, a complete Eagle

novice) that this is a big deficiency in Eagle.  The reason is you need to

create the pad in each layer, making lots of work.  Another big problem

with this is the pad is not associated with the library part.  So if you

move the device, you need to move the pad in every layer you've built it.

Wouldn't it be better to build the pad in the library part itself and then

have Eagle place the pad in all the layers, as it does with "normal"

devices?

 

- Line width is still an issues.  It seems that since everything inside of

the lines of the pad are the pad itself, then zero width lines should be

allowed.  Then you could specify the outer limits of the pad, preventing

the pad from encroaching on other devices, without having to calculate how

far outside the line the pad goes, or whether the line width is going to

violate the design rules.

 

I expect that any responses to this will essentially be "Yeah, that's the

way it is.  Deal with it."  But any advice on how to make this easier would

be greatly appreciated.

 

Thanks!

 

Dave

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

 

Parents

  • Hi Jorge,

     

    The problem is the 124 errors.  I think the pictures are still attached.

    They show the layout I did and I suspect I did something wrong with the

    layout of the through-hole pad and the top and bottom layer SMD pads.  (See

    the post with the pictures attached.)

     

    Thanks,

     

    Dave

    --

    Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

     

  • in reply to e14 Contributor

    On 4/16/2013 12:27 PM, Dave Wills wrote:

    Hi Jorge,

     

    The problem is the 124 errors.  I think the pictures are still attached.

    They show the layout I did and I suspect I did something wrong with the

    layout of the through-hole pad and the top and bottom layer SMD pads.  (See

    the post with the pictures attached.)

     

    Thanks,

     

    Dave

     

     

    Hi Dave,

     

    I hope you're doing well. I checked the images out, and there are a

    couple of things to note.

     

    1. The component has two mounting holes in the center of the part, what

    you'll want to do here is change the Copper/Dimension value in the DRC

    which is one of the errors you're running into.

     

    2. The four corner pads need a little work. For the two front ones I

    would use an oblong pad instead of the round pad, this will fill in the

    desired slot better. From the drawing It looks like you're drawing both

    the slot and the desired annular ring on layer 46 milling.

     

    The only thing you want on layer 46 is the slot, the pad's shape should

    be chose to be a close match to the desired shape. If you switch the two

    front pads to oblongs that should take care of it. For the two back pads

    you may just want to define a larger diameter that way you'll get the

    copper you want even if the overall shape of the pad is not exactly correct.

     

    Let me know if you need any clarification.

     

    Best Regards,

    Jorge Garcia

     

  • in reply to autodeskguest

    Jorge Garcia wrote on Tue, 16 April 2013 13:30

    On 4/16/2013 12:27 PM, Dave Wills wrote:

    Hi Dave,

     

    I hope you're doing well. I checked the images out, and there are a

    couple of things to note.

     

    1. The component has two mounting holes in the center of the part, what

     

    you'll want to do here is change the Copper/Dimension value in the DRC

     

    which is one of the errors you're running into.

     

    2. The four corner pads need a little work. For the two front ones I

    would use an oblong pad instead of the round pad, this will fill in the

     

    desired slot better. From the drawing It looks like you're drawing both

     

    the slot and the desired annular ring on layer 46 milling.

     

    The only thing you want on layer 46 is the slot, the pad's shape should

     

    be chose to be a close match to the desired shape. If you switch the

    two

    front pads to oblongs that should take care of it. For the two back

    pads

    you may just want to define a larger diameter that way you'll get the

    copper you want even if the overall shape of the pad is not exactly

    correct.

     

    Let me know if you need any clarification.

     

    Best Regards,

    Jorge Garcia

     

     

    Hi Jorge,

     

    Again, thanks for the reply.

     

    1. If you're referring to the 2 round holes on either side of the outer

    signal pads, I don't know what these holes are for.  They are shown on the

    preferred layout drawing from the manufacturer.  I was assuming the

    manufacturer put in the round holes knowing the clearance to the edge of

    the pads, and I was going to ignore those 2 errors.

     

    2. Sorry, the colors don't show well in the picture.  In the library part,

    these are the components of the 4 mounting holes:

     

      Round through-hole pad: The hole in the pad is the same size as the inner

    dimension of the slot.  The width of the round through-hole pad is the same

    as the width of the pad after the slot is milled.

     

      Milled slot: The milled slot on layer 46 is the oblong ring with its

    shortest dimension the same size as the round through-hole.  There is no

    other annular rings at this location.

     

      Top SMD pad: This pad is defined by the outside oblong ring with its

    shortest dimension the same as the size of the pad on the round-through

    hole pad.  So the space between the 2 oblong rings should be pad and the

    space inside the smaller ring is milled out.

     

      Bottom SMD pad: Exactly the same as the top but on the bottom of the

    board.

     

    And yes, the only thing on layer 46 is the milled out area.

     

    I tried oblong through-hole pads.  I found is the hole / pad ratio is very

    high.  That is, the actual pad size WRT the hole size is very small in

    order to make the hole still fit inside where my slot needs to be.  I'll

    try again though.

     

    Thanks, and sorry this is taking a lot of iterations.

     

    Dave

    --

    Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

     

Reply
  • in reply to autodeskguest

    Jorge Garcia wrote on Tue, 16 April 2013 13:30

    On 4/16/2013 12:27 PM, Dave Wills wrote:

    Hi Dave,

     

    I hope you're doing well. I checked the images out, and there are a

    couple of things to note.

     

    1. The component has two mounting holes in the center of the part, what

     

    you'll want to do here is change the Copper/Dimension value in the DRC

     

    which is one of the errors you're running into.

     

    2. The four corner pads need a little work. For the two front ones I

    would use an oblong pad instead of the round pad, this will fill in the

     

    desired slot better. From the drawing It looks like you're drawing both

     

    the slot and the desired annular ring on layer 46 milling.

     

    The only thing you want on layer 46 is the slot, the pad's shape should

     

    be chose to be a close match to the desired shape. If you switch the

    two

    front pads to oblongs that should take care of it. For the two back

    pads

    you may just want to define a larger diameter that way you'll get the

    copper you want even if the overall shape of the pad is not exactly

    correct.

     

    Let me know if you need any clarification.

     

    Best Regards,

    Jorge Garcia

     

     

    Hi Jorge,

     

    Again, thanks for the reply.

     

    1. If you're referring to the 2 round holes on either side of the outer

    signal pads, I don't know what these holes are for.  They are shown on the

    preferred layout drawing from the manufacturer.  I was assuming the

    manufacturer put in the round holes knowing the clearance to the edge of

    the pads, and I was going to ignore those 2 errors.

     

    2. Sorry, the colors don't show well in the picture.  In the library part,

    these are the components of the 4 mounting holes:

     

      Round through-hole pad: The hole in the pad is the same size as the inner

    dimension of the slot.  The width of the round through-hole pad is the same

    as the width of the pad after the slot is milled.

     

      Milled slot: The milled slot on layer 46 is the oblong ring with its

    shortest dimension the same size as the round through-hole.  There is no

    other annular rings at this location.

     

      Top SMD pad: This pad is defined by the outside oblong ring with its

    shortest dimension the same as the size of the pad on the round-through

    hole pad.  So the space between the 2 oblong rings should be pad and the

    space inside the smaller ring is milled out.

     

      Bottom SMD pad: Exactly the same as the top but on the bottom of the

    board.

     

    And yes, the only thing on layer 46 is the milled out area.

     

    I tried oblong through-hole pads.  I found is the hole / pad ratio is very

    high.  That is, the actual pad size WRT the hole size is very small in

    order to make the hole still fit inside where my slot needs to be.  I'll

    try again though.

     

    Thanks, and sorry this is taking a lot of iterations.

     

    Dave

    --

    Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

     

Children
  • in reply to e14 Contributor

    On 4/16/2013 5:45 PM, Dave Wills wrote:

    Jorge Garcia wrote on Tue, 16 April 2013 13:30

    On 4/16/2013 12:27 PM, Dave Wills wrote:

    Hi Dave,

     

    I hope you're doing well. I checked the images out, and there are a

    couple of things to note.

     

    1. The component has two mounting holes in the center of the part, what

     

    you'll want to do here is change the Copper/Dimension value in the DRC

     

    which is one of the errors you're running into.

     

    2. The four corner pads need a little work. For the two front ones I

    would use an oblong pad instead of the round pad, this will fill in the

     

    desired slot better. From the drawing It looks like you're drawing both

     

    the slot and the desired annular ring on layer 46 milling.

     

    The only thing you want on layer 46 is the slot, the pad's shape should

     

    be chose to be a close match to the desired shape. If you switch the

    two

    front pads to oblongs that should take care of it. For the two back

    pads

    you may just want to define a larger diameter that way you'll get the

    copper you want even if the overall shape of the pad is not exactly

    correct.

     

    Let me know if you need any clarification.

     

    Best Regards,

    Jorge Garcia

     

    Hi Jorge,

     

    Again, thanks for the reply.

     

    1. If you're referring to the 2 round holes on either side of the outer

    signal pads, I don't know what these holes are for.  They are shown on the

    preferred layout drawing from the manufacturer.  I was assuming the

    manufacturer put in the round holes knowing the clearance to the edge of

    the pads, and I was going to ignore those 2 errors.

     

    2. Sorry, the colors don't show well in the picture.  In the library part,

    these are the components of the 4 mounting holes:

     

       Round through-hole pad: The hole in the pad is the same size as the inner

    dimension of the slot.  The width of the round through-hole pad is the same

    as the width of the pad after the slot is milled.

     

       Milled slot: The milled slot on layer 46 is the oblong ring with its

    shortest dimension the same size as the round through-hole.  There is no

    other annular rings at this location.

     

       Top SMD pad: This pad is defined by the outside oblong ring with its

    shortest dimension the same as the size of the pad on the round-through

    hole pad.  So the space between the 2 oblong rings should be pad and the

    space inside the smaller ring is milled out.

     

       Bottom SMD pad: Exactly the same as the top but on the bottom of the

    board.

     

    And yes, the only thing on layer 46 is the milled out area.

     

    I tried oblong through-hole pads.  I found is the hole / pad ratio is very

    high.  That is, the actual pad size WRT the hole size is very small in

    order to make the hole still fit inside where my slot needs to be.  I'll

    try again though.

     

    Thanks, and sorry this is taking a lot of iterations.

     

    Dave

     

    Hi Dave,

     

    I hope you're doing well. If you don't mind send me the library along

    with the component you're trying to make, I want to make sure that

    you're part is drawn correctly so that you don't have any issues on your

    finished board.

     

    Send the files to support@cadsoftusa.com.

     

    Best Regards,

    Jorge Garcia