Missing chip or flag

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Joined: 24 Jul 2013, 12:32

Missing chip or flag

Post by VTiederle » 06 Aug 2014, 13:16

Recently I made a simulation for a multi-chip module where some BGA, QFN and a lot of capacitors and resitors are mounted. This module was attached as LGA to a PCB.
I defined the package as BGA and set the chip thickness to 0 - would this lead to valid results?

For QFN without flag - is it possible to set the thickness of the flag to 0?

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Nathan Blattau
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Location: Beltsville, Maryland

Re: Missing chip or flag

Post by Nathan Blattau » 08 Aug 2014, 17:00

Hi Viktor,

A QFN device without a center solder pad needs to be treated as a SON device (small outline no-leads). The lead geometry is then set to STUB.

Setting the flag thickness to zero will likely generate an error or unrealistically short life.

Nathan Blattau, PhD
Senior Vice President
DfR Solutions, LLC
9000 Virginia Manor Rd, Ste 290
Beltsville MD 20705

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