Reference Thermal Solution
24 Thermal and Mechanical Design Guidelines
4.4 Environmental Reliability Requirements The environmental reliability requirements for the reference thermal solution are
shown in Table 4. These should be considered as general guidelines. Validation test
plans should be defined by the user based on anticipated use conditions and resulting
reliability requirements.
Table 4. Reference Thermal Solution Environmental Reliability Requirements
Test1 Requirement Pass/Fail
Criteria2
Mechanical
Shock
• 3 drops for + and - directions in each of 3
perpendicular axes (i.e., total 18 drops).
• Profile: 50 G trapezoidal waveform, 11 ms duration,
4.3 m/s [170 in/s] minimum velocity change.
• Setup: Mount sample board on test fixture. Include
550 g processor heatsink.
Visual\Electrical
Check
Random
Vibration
• Duration: 10 min/axis, 3 axes
• Frequency Range: 5 Hz to 500 Hz
• Power Spectral Density (PSD) Profile: 3.13 g RMS
Visual/Electrical
Check
Thermal
Cycling
• -40 °C to +85 °C, 900 cycles Thermal
Performance
Unbiased
Humidity
• 85 % relative humidity / 55 °C, 500 hours Visual Check
NOTES:
1. The above tests should be performed on a sample size of at least 12 assemblies from 3
different lots of material.
2. Additional Pass/Fail Criteria may be added at the discretion of the user.