Intel 845GE, Руководство по тепловому проектированию

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Product Specifications
R
Intel
®
845GE / 845PE Chipset (G)MCH Thermal Design Guide 15
2.4.2 Maximum Case Temperature
To ensure proper operation and reliability of the (G)MCH components, the temperature must be
at or below the values specified in Table 4. If the temperature of the component exceeds the
maximum temperatures listed, system or component level thermal enhancements are required to
dissipate the heat generated. Section 2.5 provides the temperature measurement metrology for
case temperature measurements.
Table 4. Intel
®
(G)MCH Maximum Case Temperature
Parameter Maximum (G)MCH Case
Temperature
T
C-MAX
92
°
C
2.5 Temperature Measurement Metrology
To accurately assess junction temperature for an application or to determine if you are not
exceeding a T
C-MAX
of 92
°
C, it is necessary to have a good thermocouple attach. Intel has
established guidelines for the proper techniques to be used when measuring the (G)MCH case
temperature. Section 2.6 contains information on running an application program that emulates
anticipated maximum TDP. The flowchart in Figure 7 offers useful guidelines for thermal
performance and evaluation.
2.5.1 Case Temperature Measurements
To ensure functionality and reliability, the 82845GE GMCH / 82845PE MCH is specified for
proper operation when Tcase is maintained at or below its respective temperatures at 50 lfm for
the (G)MCH (see Table 4). The surface temperature at the geometric center of the die
corresponds to the maximum Tcase or T
C-MAX
.
2.5.2 90 Degree Angle Attach Methodology
1. Use 36 gauge or smaller K-type thermocouples.
2. Ensure that the thermocouples have been properly calibrated.
3. Attach the thermocouple bead or junction to the top surface of the die in the center using
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-degree angle if there is no interference with the
thermocouple attach location or leads (see Figure 4). This is the preferred method and is
recommended or use with both bare packages as well as packages employing a thermal
solution.
5. The hole size through the heatsink base to route the thermocouple wires out should be
smaller than 3.3 mm (0.13 inches) in diameter.
6. Make sure there is no contact between the thermocouple cement and the heatsink base. This
contact will affect the thermocouple reading.