The following recommendations are for a standard module surface mount assembly:
- Land Pattern – Follow the PCB land pattern with either soldermask defined or non-soldermask defined pads.
- Stencil Aperture
- For the exposed die attach pad (DAP), adjust the stencil for approximately 80% coverage of the PCB land pattern.
- For all other I/O pads, use a 1:1 ratio between the aperture and the land pattern recommendation.
- Solder Paste – Use a standard SAC Alloy such as SAC 305, type 3 or higher.
- Stencil Thickness – 0.125 mm to 0.15 mm
- Reflow - Refer to solder paste supplier recommendation and optimized per board size and density.
- Refer to AN Design Summary LMZ1xxx and LMZ2xxx Power Modules Family for reflow information.
- Maximum number of reflows allowed is one.
Table 10-1 Sample Reflow Profile TablePROBE | MAX TEMP (°C) | REACHED MAX TEMP | TIME ABOVE 235°C | REACHED 235°C | TIME ABOVE 245°C | REACHED 245°C | TIME ABOVE 260°C | REACHED 260°C |
---|
1 | 242.5 | 6.58 | 0.49 | 6.39 | 0 | – | 0 | – |
2 | 242.5 | 7.1 | 0.55 | 6.31 | 0 | 7.1 | 0 | – |
3 | 241 | 7.09 | 0.42 | 6.44 | 0 | – | 0 | – |