RE: [SI-LIST] : BGA pin location

Ingraham, Andrew (Andrew.Ingraham@compaq.com)
Mon, 19 Jul 1999 15:57:49 -0400

>Does anyone help
> how to locate the power,GND pin on BGA Package?
>
>Espetially it should be located on outer lead or inner .

Power and ground pins should be located throughout the pinfield. If they
are far from signal pins, the loop between the signal pin and ground (or
signal pin and power) becomes larger so the inductance of the loop is more.
Usually you want to minimize the inductance.

When power and ground pins are all put in the corners, or just the inner
rows or outer rows (of a big pinfield), or all grouped together and away
from big groups of signal pins, it can make the SI characteristics worse.

Regards,
Andy

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