SI7015-A10 Datasheet, PDF (35/39 Pages) Silicon Laboratories – Excellent long term stability

Si7015-A10
Table 27. PCB Land Pattern Dimensions
Symbol
mm
C1
4.00
C2
4.00
E
0.50
P1
2.75
P2
2.75
X1
0.30
Y1
0.75
Notes:
General
1. All dimensions shown are at Maximum Material Condition (MMC). Least
Material Condition (LMC) is calculated based on a Fabrication Allowance of
0.05 mm.
2. This Land Pattern Design is based on the IPC-7351 guidelines.
Solder Mask Design
3. 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
4. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls
should be used to assure good solder paste release.
5. The stencil thickness should be 0.125 mm (5 mils).
6. The ratio of stencil aperture to land pad size should be 1:1 for all perimeter
pins.
7. A 2x2 array of 0.95 mm square openings on 1.35 mm pitch should be used
for the center ground pad.
Card Assembly
8. A No-Clean, Type-3 solder paste is recommended.
9. The recommended card reflow profile is per the JEDEC/IPC J-STD-020
specification for Small Body Components.
Rev. 1.0
35