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CHAPTER 3: ELECTRICAL SPECIFICATIONS
large mass of the heat sink, attachment through the printed circuit board is suggested. If a
spring clip is used, the spring force should not exceed 5.5 pounds.
Figure 10 Package Cross Section View with Serveral Heat Sink Options
Heat Sink
Heat Sink Clip
Thermal Interface Material
CBGA Package
Printed Circuit Board
Internal Package Conduction Resistance
For the exposed-die packaging technology the intrinsic conduction thermal resistance
paths are as follows:
• The die junction-to-case (or top-of-die for exposed silicon) thermal resistance
• The die junction-to-ball thermal resistance
Figure 11 depicts the primary heat transfer path for a package with an attached heat sink
mounted to a printed-circuit board.
C3EN
FREESCALE [ Freescale ]
