C8051F391 View Datasheet(PDF) - Silicon Laboratories
Part Name
Description
MFG CO.
'C8051F391' PDF : 300 Pages View PDF
C8051F39x/37x
Figure 6.2. QFN-24 Recommended PCB Land Pattern
Table 6.2. QFN-24 PCB Land Pattern Dimensions
Dimension
Min
Max
Dimension
Min
Max
C1
3.90
4.00
X2
2.70
2.80
C2
3.90
4.00
Y1
0.65
0.75
E
0.50 BSC
Y2
2.70
2.80
X1
0.20
0.30
Notes:
General
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
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 µm 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 pads.
7. A 2 x 2 array of 1.10 mm x 1.10 mm openings on a 1.30 mm pitch should be used for the
center 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-020C specification for
Small Body Components.
Preliminary Rev. 0.71
31
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