Explain keepout please

Morten Leikvoll wrote:

My manufacturer asks me to put some more spacing around 0402

components specifically, and I thougt I could do that with the

keepout layer, however I see errors in that layer that makes me

wonder what this layer REALLY looks for.

 

Manual of 5.12.0 says:

"Keepout:

Restricted areas for components drawn in layer 39, tKeepout, or 40,

bKeepout, lie one upon another. This check is executed only if layers

39 and 40 are displayed and if the keepout areas are already defined

in the Package Editor of the library."

 

>

It does not check keepout on keepout, cause that doesnt make sense.

It doesn't seem to check for keepout on pads/smd's, cause the DRC

errors I saw didn't highlight that.

So my question is, what does it really check for?

(the holes in the pad's are microvias)

 

See attached img:keepout error with blue keepout..

The attached drawing should pass DRC imho.

Hi Morten

The answer is Keepout to Keepout

Elsewhere in the manual it describes using a rectangle over the complete

part or a wire frame surrounding your part. DRC  checks that no two keepout

objects intersect.

That implies that unless all your packages define keepout areas then the

presence of one is useless. I would have thought that a keepout on one part

would flag an error if another part was inside its keepout area, like a

solitary star ship with its sheilds up. Alas no, I have just tried it and

other parts can be within the keepout area of another part.

So in your image there will be a DRC error as your blue keepout areas

overlay each other.

The small blue wedges are errors because of lack of pad clearance and not to

do with keepout

HTH

Warren

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"Warren Brayshaw" <warrenbrayshaw@paradise.net.nz> wrote:

Morten Leikvoll wrote:

>> My manufacturer asks me to put some more spacing around 0402

>> components specifically, and I thougt I could do that with the

>> keepout layer, however I see errors in that layer that makes me

>> wonder what this layer REALLY looks for.

>>

>> Manual of 5.12.0 says:

>> "Keepout:

>> Restricted areas for components drawn in layer 39, tKeepout, or 40,

>> bKeepout, lie one upon another. This check is executed only if layers

>> 39 and 40 are displayed and if the keepout areas are already defined

>> in the Package Editor of the library."

>>

>>

>> It does not check keepout on keepout, cause that doesnt make sense.

>> It doesn't seem to check for keepout on pads/smd's, cause the DRC

>> errors I saw didn't highlight that.

>> So my question is, what does it really check for?

>> (the holes in the pad's are microvias)

>>

>> See attached img:keepout error with blue keepout..

>> The attached drawing should pass DRC imho.

 

Hi Morten

 

The answer is Keepout to Keepout

 

Elsewhere in the manual it describes using a rectangle over the complete

part or a wire frame surrounding your part. DRC  checks that no two keepout

objects intersect.

 

That implies that unless all your packages define keepout areas then the

presence of one is useless. I would have thought that a keepout on one part

would flag an error if another part was inside its keepout area, like a

solitary star ship with its sheilds up. Alas no, I have just tried it and

other parts can be within the keepout area of another part.

 

So in your image there will be a DRC error as your blue keepout areas

overlay each other.

The small blue wedges are errors because of lack of pad clearance and not to

do with keepout

Not true. The highlighted stuff says "keepout" in the DRC list.

Quote:

So in your image there will be a DRC error as your blue keepout

areas

overlay each other.

The small blue wedges are errors because of lack of pad clearance

and not to

do with keepout

 

Morten replied

Not true. The highlighted stuff says "keepout" in the DRC list.

Yes, apologies to all for the incorrect statement.. I did not really feel

my statement was correct, after I pushed 'send' but it did not look right

for Keepout notification either so I have now revisited it. Attached is a

clearer view of what is being displayed and I feel it is a bug and should

be fixed if it is occurring in v6

The image on the left is the DRC keepout error highlighting and on the

right what I would expect. A clearer and more accurate depiction of the

offending area (Blue area).

Would Cadsoft please review and comment.

Thanks

Warren

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Hmm. Cadsoft usually isnt this slow to respond. I guess they DO answer Q's

for older versions even if bugs are not fixed?