FBGA Stencil Apertures

I need some guidance here. I've got a new board w/ a FBGA-48 package, Samsung CMOS SRAM. It's a full matrix BGA w/ 0.30mm-0.40mm ball diameter @ 0.75mm pitch. Balls are eutectic. PCB land diameter is 0.4mm. There are TSOP I 0.5mm lead pitch components as well on the board w/ the usual 1608 Chip R's & C's. PCB is 1mm thick. We use Multicore MP100 solder paste, J-STD-005 Type 3, (particle size is 45-20um).

What should be the recommended aperture size for this FBGA, square, aye? What should the Stencil Thickness be?

I looked at IPC-7525 and a paper from Speedline. Still not sure.

Thanks in advance for your help.

PeteC

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