1.27MM Hole Spacing

Nick wrote:

Hi,

 

I'm trying to create a new device (with a new package) that is a simple 25

pin header. The pin spacing, however, is 1.27MM with a 0.75MM diameter pin.

 

When creating holes of 0.75MM in diameter spaced 1.27MM apart, I'm able to

size the pads the way I want to, without them touching each other (more that

0.005" of spacing, 0.127MM) . However, when I go to the device view with an

image of the package, it shows the pads are now touching each other, which

means all the pins are shorted together.

 

Is there something I'm missing, maybe a setting for a min diameter for a

pad?

 

Thanks for any help,

Nick.

 

 

It is the wonders of eagle's screwed up DRC

You design a package which is marginal with respect to annular ring, but you

are prepared to make an exception for this part,say. BUT eagle applies its

the global DRC setting - thinks it knows better than you and makes all the

pads bigger as the one you set explicitly violates its own idea of what your

annular ring (restring) parameters should be.

Strangely enough this then violates the min pad to pad clearance, but that

would apparently be applied after the restring parameter - Its a genuine

check rather than the resting parameter which is a ch

Once more eagle should NEVER change anything the designer does without first

asking if this is acceptable.

The solution is to reduce your global restring parameters- NOTE that this

parameters is not something that is simply checked but a global design rule

change.    In you case you will need to reduce the min restring for pads

to less than 0.1mm - this is not good for production but you could also use

elongated pads to improve things.

I really like Eagle, but I absolutely loathe this aspect of the DRC.  Please

get this sorted- check my design DO NOT CHANGE IT without asking me.

cheers

David

Nick wrote:

Hi,

 

I'm trying to create a new device (with a new package) that is a simple 25

pin header. The pin spacing, however, is 1.27MM with a 0.75MM diameter pin.

 

When creating holes of 0.75MM in diameter spaced 1.27MM apart, I'm able to

size the pads the way I want to, without them touching each other (more that

0.005" of spacing, 0.127MM) . However, when I go to the device view with an

image of the package, it shows the pads are now touching each other, which

means all the pins are shorted together.

 

Is there something I'm missing, maybe a setting for a min diameter for a

pad?

 

Thanks for any help,

Nick.

 

 

It is the wonders of eagle's screwed up DRC

You design a package which is marginal with respect to annular ring, but you

are prepared to make an exception for this part,say. BUT eagle applies its

the global DRC setting - thinks it knows better than you and makes all the

pads bigger as the one you set explicitly violates its own idea of what your

annular ring (restring) parameters should be.

Strangely enough this then violates the min pad to pad clearance, but that

would apparently be applied after the restring parameter - Its a genuine

check rather than the resting parameter which is a ch

Once more eagle should NEVER change anything the designer does without first

asking if this is acceptable.

The solution is to reduce your global restring parameters- NOTE that this

parameters is not something that is simply checked but a global design rule

change.    In you case you will need to reduce the min restring for pads

to less than 0.1mm - this is not good for production but you could also use

elongated pads to improve things.

I really like Eagle, but I absolutely loathe this aspect of the DRC.  Please

get this sorted- check my design DO NOT CHANGE IT without asking me.

cheers

David