AMD 1207 Manuale Utente

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Chapter 5
Thermal Design of Custom 2U-4P Systems
35
Thermal Design Guide for Socket F (1207) Processors
32800
Rev. 3.02
August 2006
on flow simulations of an AMD reference 2U system, the flow-through of the heat sink is 
approximately 18 CFM. Figure 11 shows that this flow rate corresponds to a case-to-ambient thermal 
resistance of 0.22°C/W. This case-to-ambient thermal resistance exceeds requirements (see Table 7 
on page 30). 
 
Figure 11.
Thermal Performance Chart of Heat Sink When Used with a Dual-Core Processor 
in 90 nm Process
5.3.5
Fans
AMD has conducted simulations of the heat sink described in Section 5.3.4 on page 33 with two 60 
mm x 60 mm x 38 mm fans (Delta Part number FFB0812EHE-HS2) in series, that is, back to back. 
The fans have a maximum flow rate of 80.2 CFM and a maximum pressure drop of 0.8 inches of 
water. The heat sinks are ducted so the flow from the two fans enters the processor heat sinks with 
some bypass. The bypass is designed to cool the core VRM.
5.3.6
Thermal Interface Material
The heat sink makes contact with the top surface of the processor package utilizing the thermal 
interface material between the processor lid and the heat sink. AMD recommends using a high 
performance grease such as Shin-Etsu 7783D or Dow Corning TC-5022. AMD does not recommend 
using phase change materials between the heat sink and the processor. Phase-change materials 
develop high adhesion forces between the heat sink and processor when the material is in the solid 
phase. This strong adhesive force may cause the processor to stick to the heat sink, making heat sink 
removal difficult and damaging the socket solder balls.