SI53320-28 Datasheet, PDF (40/51 Pages) Silicon Laboratories – Output Enable option

7. Land Patterns
7.1 16-Pin QFN Land Pattern
Si53320-28 Data Sheet
Land Patterns
Figure 7.1. 16-Pin QFN Land Pattern
Table 7.1. 16-QFN Land Pattern Dimensions
Dimension
mm
C1
3.00
C2
3.00
E
0.50
X1
0.30
Y1
0.80
X2
1.75
Y2
1.75
Notes:
General
1. All dimensions shown are in millimeters (mm).
2. This Land Pattern Design is based on the IPC-7351 guidelines.
3. All dimensions shown are at Maximum Material Condition (MMC). Least Material Condition (LMC) is calculated based on a Fabri-
cation Allowance of 0.05 mm.
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 µm
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 0.125 mm (5 mils).
3. The ratio of stencil aperture to land pad size should be 1:1 for all perimeter pads.
4. A 2 x 2 array of 0.65 mm square openings on a 0.90 mm pitch should 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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