Why no EMIB?

By: Maynard Handley (name99.delete@this.name99.org), November 10, 2018 9:27 am
Room: Moderated Discussions
dmcq (dmcq.delete@this.fano.co.uk) on November 10, 2018 6:35 am wrote:
> David Hess (davidwhess.delete@this.gmail.com) on November 9, 2018 8:43 pm wrote:
> > anon.1 (abc.delete@this.def.com) on November 6, 2018 7:15 am wrote:
> > >
> > > Is it possible to put 2x 200W dies maybe a mm apart and not run into mechanical stresses
> > > or thermal issues?
> >
> > Having so much power dissipated over a limited surface area by two devices is merely inconvenient. A 3x3
> > array with the same close spacing would be a major problem because of access to the die in the center.
> >
> > Mechanical stress depends on matching the temperature coefficient
> > of expansion between the silicon and anything
> > attached to it like the lead frame, substrate, die attachment,
> > and heat spreader. If a socket is used, then
> > this only has to be handled by the packaging but it becomes
> > a major issue with BGA packages soldered to standard
> > printed circuit boards as nVidia has demonstrated for more
> > than 10 years. Lead free solder made this considerably
> > worse because the more ductile leaded solders have greater mechanical compliance.
>
> As a matter of interest why are substrates hard rather than
> soft and leaving the connections within them to flex?

Presumably you want the substrate to have low capacitance (for higher switching speed and lower wasted power), and all the normal low capacitance materials (Si because it's already easy to handle given fabs, or ceramics if you're IBM) just happen to be hard. Or, alternatively, soft usually means organics, which usually means floppy electrons and high capacitance.

< Previous Post in ThreadNext Post in Thread >
TopicPosted ByDate
Why no EMIB?dmcq2018/11/06 03:45 AM
  Why no EMIB?anon2018/11/06 04:31 AM
    Why no EMIB?anon.12018/11/06 08:15 AM
      Why no EMIB?Kevin G2018/11/06 09:06 AM
        Why no EMIB?useruser2018/11/06 10:41 AM
        Why no EMIB?anon.12018/11/07 08:00 AM
          Why no EMIB?Jeff S.2018/11/07 09:45 AM
      Why no EMIB?David Hess2018/11/09 09:43 PM
        Why no EMIB?dmcq2018/11/10 07:35 AM
          Why no EMIB?Maynard Handley2018/11/10 09:27 AM
          Why no EMIB?David Hess2018/11/10 09:37 AM
  TTMDaniel B2018/11/06 02:21 PM
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