Nightmare on BGA Street

I seem to be in a bit of a BGA mood lately. I do that sometimes – pick a subject and talk it to death before moving on. Well, maybe not quite talk it to death, but at least talk it to the pain.

9x13 via in pad BGA land Take a look at this land pattern for a bluetooth module. Anyone see anything odd? Yeah. All of those really big open vias. I know what the designer was trying to do. A good number of the vias are ground connections of one sort or another that need to be connected to an internal ground plane layer.

Given that is is a 1 mm pitch BGA, there is plenty of room to put the vias between the pads and not cause any trouble. That would be one recommended approach. The other would be to have the vias filled and plated over at the board house. No matter what you do, though, the vias can’t be left wide open like this. It’s a real bummer.

Duane Benson
B.V.O.U.S.’s? BGA Vias Of Unusual Size. I don’t think they exist.

http://blog.screamingcircuits.com/

About Duane

Duane is the Web Marketing Manager for Screaming Circuits, an EMS company based in Canby, Oregon. He blogs regularly on matters ranging from circuit board design and assembly to general industry observations.
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One Response to Nightmare on BGA Street

  1. Mitch says:

    Yes, big bummer. Hope this HUGE via-in-pads are ‘no connect’ pins. :) NOT! Was this an off-shore design BTW?

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