Data Sheet
PowerPC 970FX
Preliminary
4.2.2 Reduced-Lead Package Version
This section describes the reduced-lead package, as indicated by the ‘R’ in the Package code field of the part
number. For the reduced lead package, lead-free solder is used for the substrate capacitors and the BGA
balls on the bottom of the package. Standard high melting point 97Pb3Sn solder (exempted by EU RoHS
legislation) is used for the C4 balls that connect the die to the substrate. The resulting module is RoHS
compatible.
All Datasheet electrical specifications apply equally to standard and reduced-lead parts.
4.2.2.1 Mechanical Specifications
The solder balls on the bottom of the reduced-lead package are slightly smaller, which will decrease the
overall module height when assembled onto a board. Heatsink solutions should be modified accordingly
.
Table 4-1. Leaded and Reduced-Lead Package, Layout, and Assembly Differences
CBGA
SubstrateI/O
Pad
Card Solder
Mask Open-
Card Solder
Screen
Diameter
Solder Ball
Composition
Solder Ball
Diameter
Card Pad
Diameter
Package
JEDEC MSL
Diameter
ing Diameter
26.5mil
open-ing in
7.5mil thick
stencil, 2500-
4600 cubic
mils
Sn 10% Pb
90%
Leaded
1
31.5 (0.80)
25 (0.635)
31.5 (0.80)
31.5 (0.80)
31.5 (0.80)
27.5 (0.70)
24 (0.61)
23mil
opening in
4mil thick
stencil, 1400-
2000 cubic
mils
Sn 95.5% Ag
3.8% Cu
0.7%
Reduced
Lead
3
28 (0.72)
Note: All dimensions in mils unless noted. Dimensions in parenthesis are in mm.
4.2.2.2 Assembly Considerations
The reduced-lead package is compatible with a 260C lead-free card assembly reflow profile. Refer to the
INEMI Consortium, www.inemi.org, for industry-standard assembly and rework information. The coplanarity
specification for the reduced-lead CBGA, like other single melt BGA packages, is 0.20 mm (8mil). The
qualification testing included a lead-free water soluble solder paste with type 3 mesh size (-325/+500). The
solder alloy is 95.5% Sn, 4.0% Ag, and 0.5% Cu, with a 90% metal loading. The paste viscosity range is 600
to 800 Kcps. The thickness of the stencil is 4 mils and the aperture size is 23 mil diameter. The target solder
paste volume range is between 1400 to 2000 cubic mils. Achieving the correct paste volume is necessary for
eliminating solder shorts and producing high reliability solder joints. The actual solder paste volume from the
qualification build ranged from 1750 to 2000 cubic mils.
Another change is the JEDEC Moisture Sensitivity Level, which is MSL 3 for the reduced-lead package.
Storage and assembly protocols should be modified accordingly.
PowerPC 970FX Microprocessor Dimension and Physical
Signal Assignments
Page 44 of 74
October 14, 2005
IBM [ IBM ]
