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Altera_Forum's avatar
Altera_Forum
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8 years ago

Power decoupling capacitors placement

Hi all! I'm going to develope a board with Cyclone V SoC in UBGA484 or UBGA672 (in both packages distance between balls is 0.8 mm). I have several Terasic development kits with Cyclone V and Cyclo...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
8 years ago

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Use via-in-pad. The capacitor pad can sit on top of the via to the FPGA pin. This increases board (raw fab) cost, maybe 20-25%. I do recall, in the distant past, using 0201 caps without via-in-pad on a 0.8mm BGA, but I couldn't give you any details.

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In the past I have used VIA-in-pad on 1mm BGA parts, and placed 0402 parts at 45degrees over a pair of pads.The trick is rotating the parts 45degrees, using VIP, and finding PWR/GND pairs to use.