[Amps] Using surface-mount devices

[peter.chadwick at Zarlink.Com]

Chris said:

>The only thing I wouldn't attempt is to mount a BGA package:

They're nothing - just wait until you get WSP (Wafer Scale Packaging). In
that, you take the IC chip and put a layer of insulation over the top, with
via holes to the pads. Then you metalise through the vias, and put tracks
on the insulation to connect to set of solder balls, spaced 10 thou (10mil
in US terms, 25micron apart)and about 3 thou in diameter. That you solder
down like a BGA, and a 40 ball device is about .05 inches square. I don't
think you'll do that with a normal hot air gun, and it's even closer to be
totally unrepairable. It's not a bad package from the viewpoint of RF
parasitics, though.

73

Peter G3RZP (Back in Stockholm for the week)