what is Neck mode ..please explain anybody??

[kabaleevisu]

Hi

Any body please explain about Neck width with example




if i set the minimum and maximum value for Neck what will happen

 

[ckshivaram]

Neck length/width is the same as truncation. What this means is trace that has x width for some distance but has to be smaller to route inside something like a bga. While routing within bga, trace has to neck down or truncate to a smaller width to allow routing without violating rules or causing a short. The neck length would be the distance a trace is necked down or truncated.
neck parameters should be taken into account. Especially if you are trying to control timing. (you will want to know the entire trace length neck included)
the neck length is usually some minimum distance required to complete the circuit. (the necked down portion of net will no longer have the same impedance value as Line Width)

 

[kabaleevisu]

hi sir

thanks for reply but i want some snopshot is it possible

 

[marce]

Transition from Un-necked to necked

 

[kabaleevisu]

hi marce

thanks for your reply
if neck width is more than trace width what happen in this trace ??
or error will occur ???

 

[marce]

Necked is always the narrower width, most packages will not let you have a necked width wider than an un-necked width.

 

[kabaleevisu]

is it possible to use the neck in BGA package ??

---------- Post added at 12:56 ---------- Previous post was at 12:54 ----------

please answer for this post also how to create customize outline???

 

[marce]

yes you can with the caveat metioned above, for high speed signals necking a track will cause an impedance mismatch.