GB/T 8446.2-2022 in English
VALIDHeat sinks for power semiconductor devices—Part 2: Measurement methods of thermal resistance and inlet-outlet fluid pressure drop
- Issued on:2022-03-09
- Implemented on:2022-10-01
- File Format:PDF
- Delivery:Via email within 1~3 business days
$243.00
《GB/T 8446.2-2022电力半导体器件用散热器 第2部分：热阻和流阻测量方法》由TC60（全国电力电子系统和设备标准化技术委员会）归口，TC60SC6（全国电力电子系统和设备标准化技术委员会电力电子器件分会）执行，主管部门为中国电器工业协会。
Introduction
Analysis of the core content of the standard
GB/T8446.2-2022 is an important standard in the field of power electronic heat dissipation. It systematically specifies the thermal resistance and flow resistance measurement methods of products such as profile heat sinks and heat pipe heat sinks. Compared with the 2004 version, the new version of the standard has been comprehensively optimized in terms of measurement system structure, terminology definition, and test process.
Comparison of key technical indicators
| Measurement parameters | 2004 version requirements | 2022 version improvements |
|---|---|---|
| Thermal resistance measurement accuracy | Unspecified system-level error | Requires the temperature meter accuracy ≥0.5 |
| Flow resistance measurement point location | Only specifies the approximate area | Accurate to ±5mm |
| Dual-side heat dissipation measurement | No detailed calculation model | New parallel thermal resistance formula (4) |
Key points for thermal resistance measurement
Specifications for setting up the measurement system
The standard requires the use of the DC current method as the benchmark measurement method. The system consists of the following:
- Heating unit: It is recommended to use a rectifier diode as the heat source
- Temperature acquisition system: Thermocouple diameter ≤0.25mm
- Environmental control system: Wind speed (6±0.2) m/s or water flow (4±0.1) L/min
Key operating steps
For water-cooled heat sink, special attention should be paid to the following:
- The temperature measurement point is located at a height of 1/3 of the inner diameter d of the pipe
- The cooling water inlet temperature is controlled at 35+3-0℃
- Thermocouple installation requires metal cold forging fixing process
Engineering application suggestions
Error control strategy
According to the thermal balance error calculation formula provided in Appendix B:
η=(PQc)/Qc×100%
It is recommended to control η≤5% through the following measures:
- Regularly calibrate the flow meter to ensure ±3% accuracy
- Use a three-wire PT100 temperature sensor
- Thermal balance waiting time ≥30 minutes
Special working condition processing
For measuring the heat pipe heat sink:
- The temperature difference between the evaporation section and the condensation section needs to be additionally monitored
- The power loading gradient is recommended to be ≤5%/min
- Repeated tests in the positive and negative directions are required
Analysis of Standard Evolution
This revision focuses on solving three problems existing in the 2004 version:
- Increased the normative reference document system (such as GB/T3859.1)
- Reconstructed the logical structure of the measurement chapter
- Supplemented the heat flux distribution calculation model (Appendix A)
These improvements make the standard more adaptable to the testing needs of modern high-power IGBT modules and other new devices.
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