欢迎访问ic37.com |
会员登录 免费注册
发布采购

IBM25EMPPC750LCBE4000 参数 Datasheet PDF下载

IBM25EMPPC750LCBE4000图片预览
型号: IBM25EMPPC750LCBE4000
PDF下载: 下载PDF文件 查看货源
内容描述: [RISC Microprocessor, 32-Bit, 400MHz, CMOS, CBGA360, 25 X 25 MM, 1.27 MM PITCH, CERAMIC, BGA-360]
分类和应用: 时钟外围集成电路
文件页数/大小: 50 页 / 600 K
品牌: IBM [ IBM ]
 浏览型号IBM25EMPPC750LCBE4000的Datasheet PDF文件第41页浏览型号IBM25EMPPC750LCBE4000的Datasheet PDF文件第42页浏览型号IBM25EMPPC750LCBE4000的Datasheet PDF文件第43页浏览型号IBM25EMPPC750LCBE4000的Datasheet PDF文件第44页浏览型号IBM25EMPPC750LCBE4000的Datasheet PDF文件第46页浏览型号IBM25EMPPC750LCBE4000的Datasheet PDF文件第47页浏览型号IBM25EMPPC750LCBE4000的Datasheet PDF文件第48页浏览型号IBM25EMPPC750LCBE4000的Datasheet PDF文件第49页  
PowerPC 740 and PowerPC 750 Embedded Microprocessor  
IBM CMOS 0.20 um Copper Technology EMPPC740L and EMPPC750L  
Figure 21. C4 Package with Heat Sink Mounted to a Printed-Circuit Board  
External Resistance  
Radiation  
Convection  
Heat Sink  
Thermal Interface Material  
Die/Package  
Chip Junction  
Internal Resistance  
Package/Leads  
Printed-Circuit Board  
Radiation  
Convection  
External Resistance  
(Note the internal versus external package resistance.)  
Heat generated on the active side (ball) of the chip is conducted through the silicon, then through the heat  
sink attach material (or thermal interface material), and finally to the heat sink; where it is removed by forced-  
air convection. Since the silicon thermal resistance is quite small, for a first-order analysis, the temperature  
drop in the silicon may be neglected. Thus, the heat sink attach material and the heat sink conduction/con-  
vective thermal resistances are the dominant terms.  
Adhesives and Thermal Interface Materials  
A thermal interface material is recommended at the package lid-to-heat sink interface to minimize the thermal  
contact resistance. For those applications where the heat sink is attached by a spring clip mechanism,  
Figure 22 shows the thermal performance of three thin-sheet thermal-interface materials (silicon, graphite/oil,  
flouroether oil), a bare joint, and a joint with thermal grease, as a function of contact pressure. As shown, the  
performance of these thermal interface materials improves with increasing contact pressure. The use of ther-  
mal grease significantly reduces the interface thermal resistance. That is, the bare joint results in a thermal  
resistance approximately 7 times greater than the thermal grease joint.  
Heat sinks are attached to the package by means of a spring clip to holes in the printed-circuit board (see  
Figure 20). Therefore the synthetic grease offers the best thermal performance, considering the low interface  
pressure. Of course, the selection of any thermal interface material depends on many factors – thermal per-  
formance requirements, manufacturability, service temperature, dielectric properties, cost, etc.  
5/20/99  
Version 1.51  
PowerPC 740 and PowerPC 750 Datasheet  
Page 41  
 复制成功!