Small Holes

[Seth Renigar]

I remember, not too long ago, there was a post from someone that designed
parts with lots of small holes. If I remember correctly, it was something
like a plate with 8000, Ø.008 holes. I think the topic was related to SW
performance with such features, but I'm not sure.

Does anyone remember who this was, or know of someone that designs parts
with small holes regularly? I have got a few questions that I would like to
ask off-group. I tried to do a Google search but came up short....

Thanks,
--
Seth Renigar
Emerald Tool and Mold Inc.
(Remove ".no.spam" from my address)
__

[sjm1...@gmail.com]

it was titled 'thousands of holes' from a few months ago.

a poster named iQ had a way to model the holes.

sjm

[iQ]

iQ here. yes this was my group.

we do alot of parts files with round features. we have tried doing
this in a single body part and kills the computer. we tried in a
multi-body part and got the same results, extreamly slow to work upon.
here is my latest stab at making this function.

let me describe one situation @ a part level. it is a Ø8.0 disk that
has about 10000 holes in it. there are 12 groups of patterns arrayed
around the part. for this item they were symetrical and identical.
now what we did was make one piece of the pie, 1/12 of the disk. we
populated the the single location with the pattern. we then arrayed
the the body to complete the part and combined them. it did make it
workable, not great yet. on a part that had multiple pattern we
figured that one could assemble different bodies and then again array
the body. kind of like making a pizza with different slices put
together. remember to array the body not the features.

the new situation is a Semiconductor Probe Card. it is a Ø12.0 disk
that has 20000 small diameter pads. in a single part we could not
array the patterns around the part, it was impossible. so we drew a
single part that was one pad. we put that in an assembly and made the
primary pattern, again as an assembly. then we put that assembly into
another assembly and arrayed it to complete the total pattern on the
card. we then put this assembly into another assembly that had the
disk of the PC Board. and we were able to work and detail this item.
we tried this in a single part/multi body and the same concept failed
so it has to be done assembly to assembly.

the real problem is with how SWx deals with round items. if you look
down into a hole it looks round but it is made up of triangles, you can
see this in some exports. one triangle and another inverted triangle,
also noticable by the faceting of the edges as set in the image quality
in tools/options. a simple hole can have 10-20 facets in it, same with
round pads or any round features. so when you model 1000 holes you can
actually have 20000 facets. i do not have a number where this becomes
unmanageable but you will see that, depending on the computer, you will
hit a point where you cripple your computer and make the model
un-workable.

so another work-around is to not make round objects. if you make them
square sided, triangles squares hex, you can make 100k or more holes or
round features. now on our probe cards we model the pads as squares to
validate design intent and detail the probe card with these small
squares. we do one detail that actuall shows the real pad detail. now
we can actually do work instead of sitting around wondering if your
selection actually does something after a minute or two after we do the
selection.

hope this can help. iQ

[Seth Renigar]

I'll email you Monday.

--
Seth Renigar
Emerald Tool and Mold Inc.
(Remove ".no.spam" from my address)
__

"iQ" <mwal...@xandex.com> wrote in message
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