Thermal solutions to Pentium processors in TCP in notebooks and sub-notebooks

Abstract

In this paper, we will review the various thermal enhancements from the component, board, and system level for the use of the Pentium processor in tape carrier package (TCP) in notebooks and sub-notebooks. The thermal tests were conducted in one reference notebook and sub-notebook using test boards and thermal test dies. With the assumption of a maximum junction temperature of 100/spl deg/C and an outside ambient temperature of 35/spl deg/C, thermal characterizations of TCP found that with 4 W of board power, TCP can dissipate up to 3.55 W of CPU power in the reference notebook and 2.72 W in the reference sub-notebook. Various thermal enhancements such as venting holes, metal plates, and heat sinks were evaluated in the reference notebook. For the design target of 6.5 W of CPU power with 4 W of board power, four thermal solutions were proposed for the reference notebook: The heat sink and aluminum plate solution, heat pipe connected to the keyboard solution, heat pipe connected to outside aluminum plate solution, and fan/heat sink solution. Two solutions were proposed for the reference sub-notebook: The heat pipe connected to keyboard solution and heat pipe on the bottom chassis solution. Although the study was conducted in the reference notebook and sub-notebook, the thermal design trade offs and relative cooling capabilities are applicable to the general notebook and sub-notebook thermal designs.