Intel Intel E7500 MCH, Руководство по тепловому проектированию

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Intel
®
E7500 and Intel
®
E7501 Chipsets MCH Thermal Design Guide
Thermal Design Guide 13
5.0 Thermal Metrology
The system designer must obtain temperature measurements in order to accurately determine the
thermal performance of the system. Intel has established guidelines for proper techniques of
measuring chipset MCH die temperatures.
Section 5.1 provides guidelines on how to accurately
measure the MCH die temperatures. Section 5.2 contains information on running an application
program that will emulate anticipated maximum thermal design power. The flowchart in Figure 6
offers useful guidelines for thermal performance and evaluation.
5.1 Die Temperature Measurements
To ensure functionality and reliability, the chipset MCH is specified for proper operation when T
die
is maintained at or below its respective maximum temperature listed in Table 3 . The surface
temperature at the geometric center of the die corresponds to T
die
. Measuring T
die
requires special
care to ensure an accurate temperature measurement.
Temperature differences between the temperature of a surface and the surrounding local ambient
air may introduce error in the measurements. The measurement errors may be due to a poor thermal
contact between the thermocouple junction and the surface of the package, heat loss by radiation
and/or convection, conduction through thermocouple leads, or contact between the thermocouple
cement and the heat sink base (when a heat sink is used). To minimize these measurement errors,
the following approaches are recommended for thermocouple attach.
5.1.1 90° Angle Attach Methodology
1. Use 36-gauge or smaller diameter K-type thermocouples.
2. Ensure that the thermocouple has been properly calibrated.
3. Attach the thermocouple bead or junction to the top surface of the die in the center using a high
thermal conductivity cement. It is critical that the thermocouple bead makes contact with
the die.
4. The thermocouple should be attached at a 90° angle when no interference exists between the
thermocouple wire and retention mechanism (see Figure 3 ). This is the preferred method and
is recommended for use with both bare packages as well as packages employing a thermal
solution.
5. The hole size through the heat sink base to route the thermocouple wires out should be smaller
than 3.3 mm [0.13 in] in diameter.
6. Make sure no contact exists between the thermocouple cement and heat sink base. This contact
will affect the thermocouple reading.