Datasheet
DD2.X
Preliminary
PowerPC 750CL Microprocessor
The board designer can choose between several types of thermal interfaces. Heat-sink adhesive materials
should be selected based upon high conductivity, yet adequate mechanical strength to meet equipment
shock/vibration requirements. There are several commercially available thermal interfaces and adhesive
materials provided by the vendors shown in Table 5-6.
Table 5-6. 750CL Thermal Interface and Adhesive Materials Vendors
Company Names and Addresses for Thermal Interfaces and Adhesive Materials Vendors
Dow-Corning Corporation
Dow-Corning Electronic Materials
P.O. Box 0997
Midland, MI 48686-0997
(989) 496-4000
http://www.dowcorning.com/content/etronics
Chomerics, Inc.
77 Dragon Court
Woburn, MA 01888-4850
(781) 935-4850
http://www.chomerics.com
Laird Technologies (formerly Thermagon, Inc.)
4707 Detroit Avenue
Cleveland, OH 44102-2216
(888) 246-9050
http://www.lairdtech.com
Loctite Corporation
1001 Trout Brook Crossing
Rocky Hill, CT 06067
(860) 571-5100 / (800) 562-8483
http://www.loctite.com
AI Technology
70 Washington Road
Princeton, NJ 08550-1097
(609) 799-9388
http://www.aitechnology.com
Section 5.9 provides a heat-sink selection example using one of the commercially available heat sinks.
5.9 Heat-Sink Selection Example
In most cases, the thermal path through the package balls is not significant, and is not included in the heat
sink calculations. Considering only the thermal path through the heat sink, the thermal equation is
T = Ta + Pd × (ꢀjc + ꢀcs + ꢀsa)
J
where:
T is the junction temperature.
J
Ta is the ambient temperature (that is, the temperature of the air at the heatsink).
Pd is the maximum power dissipated by the 750CL.
ꢀjc is the thermal resistance from the junction to the case (the top surface of the package).
ꢀcs is the thermal resistance from the case to the heatsink.
ꢀsa is the thermal resistance from the heatsink to ambient.
Version 2.5
December 2, 2008
System Design Information
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