FreeLists / si-list / [SI-LIST] Decoupling capacitors for BGA

["Subramanian R" <subramanian1683@xxxxxxxxx>]

Hello All,
We are using a 0.5mm Pitch 457-Pin BGA Processor. It is running at a maximum
of 532MHz.
It has 60 Power pins (Core & I/O)

How do i place the Decoupling capacitors?

Now we have placed all decaps (0402 pack) around the BGA (like an island)
and connected it to the VCC plane. Should i need to route it to the
individual pins itself?

The BGA does not have much space between the Balls. So not more than 4-5
caps can be placed right over the BGA on the other side.

The other thing i can go for is Inter-plane capacitance. But for that
VCC-GND dielectric should be around 2-3mils, i understand. That doesn't look
possible with our PCB thickness requirements. It is a 6-layer PCB

Thanks for any suggestions.

Regards
Subbu

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