SI53156 Datasheet, PDF (20/22 Pages) Silicon Laboratories – PCI-EXPRESS GEN 1, GEN 2, GEN 3, AND GEN 4 FANOUT BUFFER

Si53156
Table 8. PCB Land Pattern Dimensions
Dimension
mm
S1
4.01
S
4.01
L1
3.20
W1
3.20
e
0.50
W
0.26
L
0.86
Notes:
General
1. All dimensions shown are in millimeters (mm).
2. This Land Pattern Design is based on the IPC-7351 guidelines.
Solder Mask Design
1. All metal pads are to be non-solder mask defined (NSMD). Clearance between the
solder mask and the metal pad is to be 60 m minimum, all the way around the pad.
Stencil Design
1. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls
should be used to assure good solder paste release.
2. The stencil thickness should be 0.125mm (5 mils).
3. The ratio of stencil aperture to land pad size can be 1:1 for all perimeter pads.
4. A 3x3 array of 0.85mm square openings on a 1.00mm pitch can be used for the
center ground pad..
Card Assembly
1. A No-Clean, Type-3 solder paste is recommended.
2. The recommended card reflow profile is per the JEDEC/IPC J-STD-020
specification for Small Body Components.
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Rev. 1.1