Intel
®
Pentium
®
III Processor in the FC-PGA2 Package Thermal Design Guidelines
R
249660-001
27
7.4.1.
Processor Case Temperature Measurements
To ensure functionality and reliability, the FC-PGA2 packaged processors are specified for proper
operation when T
CASE
is maintained at or below the value listed in their respective processor datasheets.
The measurement location for T
CASE
is the geometric center of the IHS. Figure 7-4 shows the location for
T
CASE
measurement.
Special care is required when measuring the T
CASE
to ensure an accurate temperature measurement.
Thermocouples are often used to measure T
CASE
and should be calibrated before any temperature
measurements are made. When measuring the temperature of a surface, which is at a different
temperature from the surrounding local-ambient air, errors could be introduced in the measurements. The
measurement errors could be due to having a poor thermal contact between the thermocouple junction
and the surface of the integrated heat spreader, heat loss by radiation, convection, by conduction through
thermocouple leads, or by contact between the thermocouple cement and the heatsink base. To minimize
these measurement errors, the following approach is recommended:
1. Obtain the necessary items needed for the quantity of thermocouple attachments and samples
desired. A list of necessary items is shown in Table 7-1.
Table 7-1. List of Items for Thermocouple Attach
FC-PGA2 Packaged Processor
Modified heatsink (see section 7.4.1.1)
Fine point tweezers
Thermocouples (Type K, 36 gauge, 36 inch, Teflon* insulation)
Ex-acto* knife (#11 blade)
3M* Kapton* tape cut into strips (1/8” X ½”)
Epoxy cement
2. Use a scribe to mark the geometric center on the topside of the IHS package. This represents the
location where the bead of the thermocouple will be placed. The center of the package can be
obtained by measurement, or by drawing two diagonal lines across the length of the package. The
cross-point will be the geometric center of the package (see Figure 7-4).
