11.1.3 Aperture Design for Thermal Pad
- Small multiple openings are used
instead of one big opening, as shown in the following figure
Figure 11-1. IS20xxS SoC Reflow Profile Aperture Design 
- 60 to 80% solder paste coverage
- Rounded corners to minimize clogging
- Positive taper walls (5°
tapering) with the bottom opening is larger than the top opening, as shown in the
following figure
Figure 11-2. IS20xxS SoC Stencil Type 