Intel 945GC ユーザーズマニュアル

Thermal and Mechanical Design Guidelines   

 15 

The system designer must measure temperatures to accurately determine the thermal 

performance of the system. Intel has established guidelines for proper techniques of 

measuring (G)MCH component case temperatures.  

To ensure functionality and reliability, the (G)MCH is specified for proper operation 

when T

C

 is maintained at or below the maximum temperature listed in Table 2. The 

surface temperature at the geometric center of the die corresponds to T

C

. Measuring 

T

C

 requires special care to ensure an accurate temperature reading. 

Temperature differences between the temperature of a surface and the surrounding 

local ambient air can introduce error in the measurements. The measurement errors 

could 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 heatsink 

base (if a heatsink is used). To minimize these measurement errors a thermocouple 

attach with a zero-degree methodology is recommended.

 

1.  Mill a 3.3 mm [0.13 in] diameter hole centered on bottom of the heatsink base. 

The milled hole should be approximately 1.5 mm [0.06 in] deep. 

2.  Mill a 1.3 mm [0.05 in] wide slot, 0.5 mm [0.02 in] deep, from the centered hole 

to one edge of the heatsink. The slot should be in the direction parallel to the 

heatsink fins (see Figure 3). 

3.  Attach thermal interface material (TIM) to the bottom of the heatsink base.  
4.  Cut out portions of the TIM to make room for the thermocouple wire and bead. 

The cutouts should match the slot and hole milled into the heatsink base. 

5.  Attach a 36 gauge or smaller calibrated K-type thermocouple bead or junction to 

the center of the top surface of the die using a high thermal conductivity cement. 

During this step, make sure no contact is present between the thermocouple 

cement and the heatsink base because any contact will affect the thermocouple 

reading. It is critical that the thermocouple bead makes contact with the 

die (see Figure 2). 

6.  Attach heatsink assembly to the (G)MCH and route thermocouple wires out 

through the milled slot.