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Restring setting overrides pad size in library

autodeskguest

Hi all,

 

As far as I understand, the resulting restring size on the PCB will be the

largest of what's specified in the design rules and what's specified in the

library.

 

I use 35 % restring setting in my design rules. I have always done that, it

works fine and I would like to continue doing that. Now I'm faced with a

component that has two pins so close together that the pads will overlap

with a 35 % restring.

 

I have seen other PCB designs using this component. They have used elongated

pads with considerably smaller restring (in the narrower direction) to

prevent the pads from overlapping while still providing enough solder. When

I try changing the pad size in the library from auto to the necessary size

it is overridden by the 35 % setting in design rules.

 

Is there a way around this? Or is my only option to change the design rules

to, say, 15 % restring and then go into every single one of the other

through-hole mounted components I use in the library and set their pad sizes

to whatever they would have been with the 35 % setting? In that case, ouch.

 

//Christian

 

 

 

Parents

  • You might be able to just make the pads in the library for that one part very small. When you insert it on the board the pads will be smaller than you want but will give you the electrical connection point. Then just connect with a wide wire or overlay the pads with polygons of copper, then place a circle (or whatever) in the soldermask layer to expose that part of the copper you want to be solderable. You might have to do the same in the solderpaste layer if you are going to make a stencil for soldering.

Reply

  • You might be able to just make the pads in the library for that one part very small. When you insert it on the board the pads will be smaller than you want but will give you the electrical connection point. Then just connect with a wide wire or overlay the pads with polygons of copper, then place a circle (or whatever) in the soldermask layer to expose that part of the copper you want to be solderable. You might have to do the same in the solderpaste layer if you are going to make a stencil for soldering.

Children
  • in reply to DonQ

    You might be able to just make the pads in the library for that one part

    very small. When you insert it on the board the pads will be smaller

    than you want but will give you the electrical connection point.

     

    No, that won't work. These are through-hole pads. I have to specify the

    correct drill diameter, otherwise I will have to manually edit the drill

    files after generating them. And with a given drill diameter, specifying a

    small pad size in the library doesn't help, since it will be overridden by

    the design rules' restring setting if that results in a larger pad.

     

    //Christian