EMIF08-1005M16
Recommendation on PCB assembly
4
Recommendation on PCB assembly
4.1
Stencil opening design
1. General recommendation on stencil opening design
a) Stencil opening dimensions: L (Length), W (Width), T (Thickness).
Figure 12. Stencil opening dimensions
L
TW
b) General design rule
Stencil thickness (T) = 75 ~ 125 µm
Aspect Ratio
=
W-----
T
≥
1.5
Aspect Area
=
-------L-----×-----W----------
2T(L + W)
≥
0.66
2. Reference design
a) Stencil opening thickness: 100 µm
b) Stencil opening for central exposed pad: Opening to footprint ratio is 50%.
c) Stencil opening for leads: Opening to footprint ratio is 90%.
Figure 13. Recommended stencil window position
5 µm
5 µm
15 µm
350 µm
390 µm
190 µm
200 µm
2600 µm
15 µm
0.40
0.20
0.60
0.35
50 µm
2.60
1820 µm
50 µm
390 µm
Footprint
Stencil window
Footprint
0.275
7/10