AMD 1207 manual Spring Clip, Chemical Element of SK7 Spring Steel

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32800 Rev. 3.02 August 2006

Thermal Design Guide for Socket F (1207) Processors

5.3.2Spring Clip

The spring clip is designed to apply 75 lbs of force to the center of the heat sink. This force is necessary to help prevent the heat sink from lifting off of the package during shock or vibration- induced events. Lifting the heat sink away from the processor can result in damage to the processor contact pads, the socket contacts, or the socket solder-ball joints. Maintaining the spring force is important for the life of the processor and for repeated installations and upgrades of the processor.

The spring clip material is heat-treatable spring steel, SK7. AMD strongly recommends using SK7 or an equivalent material for the spring clip. The clip should be plated after heat treatment for cosmetic and anti-corrosive reasons. Table 9 gives the chemical composition of SK7. The heat treatment used should bring the ultimate strength of the material to a minimum of 1,300 megapascals (MPa) or 189 kilopounds per square inch (kpsi), and it should bring the yield strength to 940 MPa (or 136 kpsi).

Other materials commonly used for heat sink spring clips have been shown to yield under the high load of the initial spring-clip deflection and become deformed so that the spring clip can no longer apply the same load.

Table 9.

Chemical Element of SK7 Spring Steel

 

 

 

 

Element

Percentage of the Element

 

 

 

 

C

0.60-0.70

 

 

 

 

Si

Maximum 0.35

 

 

 

 

Mn

0.80-0.90

 

 

 

 

P

Maximum 0.030

 

 

 

 

S

Maximum 0.030

 

 

 

 

Fe

Remaining balance

 

 

 

5.3.3Retention Frame

The plastic retention frame, made of 20% glass-filled Lexan, is a two-piece implementation rather than the single-piece frame used for socket 940. This change accommodates the larger foot-print of socket F (1207) processors.

The retention frame serves multiple purposes. The retention frame aligns the heat sink and provides a stop for the heat sink in large shock-force events. The retention frame and backplate are attached to the motherboard by the motherboard vendor. Two screws securely hold the backplate and retention frame together. The two mounting tabs on the retention frame serve as attachment points for the heat sink spring clip.

5.3.4Heat Sink

Figure 10 on page 34 shows a picture of the reference design heat sink for 2U-4P systems. The footprint of the reference design heat sink is 92 mm x 58 mm. The heat sink weighs 378 g and has an aluminum fin stack soldered to the copper base. The copper base tapers from a thickness of 7 mm at

Chapter 5

Thermal Design of Custom 2U-4P Systems

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Contents Thermal Design Guide for Socket F 1207 Processors Advanced Micro Devices, Inc. All rights reserved Contents Heat Sink Fans Thermal Interface Material List of Figures List of FiguresList of Figures List of Tables List of TablesList of Tables Revision History Revision HistoryRevision History Chapter Introduction Summary of RequirementsChapter Chapter Processor Thermal Solutions Processor Specifications1207-Pin Socket Socket DescriptionMotherboard Component Height Restrictions Sample Heat Sinks and Attachment Methods Thermal Solution Design RequirementsPart Description Material Quantity Backplate Assembly Retention Frame Thermal Design of Platforms Using the AMD Processor-In-a Chapter Thermal Design of Custom 1U-2P Systems Thermal Design of Custom 1U-2P SystemsSymbol Systems Spring Screws Exploded View of Thermal Solution for Custom 1U-2P SystemsFin Parameters Heat SinkFans Thermal Interface Material Thermal Design of Custom 1U-2P Systems Chapter Thermal Design of Custom 2U-4P Systems Thermal Design of Custom 2U-4P SystemsThermal Solution Design Requirements Heat sink Aluminum Fan Plastic Spring clip Backplate Assembly Chemical Element of SK7 Spring Steel Spring ClipHigh Performance Heat Sink for Custom 2U-4P Systems Fans Thermal Design of Custom 2U-4P Systems Appendix a Solution for Socket F 1207 ProcessorsSocket F 1207 PIB Board Component Height Restrictions 64.36 76.41 49.91 59.81 787724 000 784 520 189 Socket F 1207 PIB Socket Outline and Socket WindowZone 1207 PIB Heat Sink Height2x11.44 2x51.26 2x61.08 36.59 32.13 27.591207 PIB Keep-Out318 000 885 Thermal 23310.09 33.91 49.91 Solution for Socket F 1207 Processors Socket F 1207 Processor Appendix B1207 Drawings for2P Systems Processor Height RestrictionsHoles, Contact Pads, BasedNo-Routing Zone 32.16 71.98 24.54 10.09 49.91 64.36Processor Based onWindow 1U-2P Systems 1207 Processor Height Restriction Zone42.71 82.53 32.16 71.98 2P Board No-Through-Hole Keep Keep-OutOut 598 000 166 40.59 80.41233 335 965 1207 1U35.04 22.04 10.09 33.9 49.91 61.86Socket F 1207 Processor Appendix C Socket F 1207 2U-4P Board Component Height Restrictions 47.40 87.22 35.65 4P Mounting Holes, Contact Pads, and No-Routing Zone24.54 64.36 75.47Custom 2U-4P 1207 2U-4P Socket OutlineSocket Window 17.59 2U-4P Systems 1207 Processor260 681 26640.59 80.41 Socket F 1207 2U-4P Board No-Through-Hole Keep-Out166 80.41 1207Socket F 1207 Processor Socket F 1207 Processors Appendix DStreamline Plot of AMD Reference Custom 2U-4P System
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