Ram S. Viswanath

Thermal modelling of the Pentium processor package

Large mono-chip packages show a trend of increasing power dissipation and power density: for example the maximum dissipation of the Pentium processor is 16 Watts compared to the 6 Watts of its 80486 predecessor. This poses challenges for equipment designers to provide satisfactory thermal environments for reliable package operation. This paper provides an example of a component manufacturer and a thermal-analysis software vendor working together to construct and validate a thermal model of first-level packaging of a die (the Pentium processor) that can be used by equipment designers concerned with second- and third-level packaging. It is proposed that this example might set a pattern for the future.<<ETX>>

Thermal modeling of high performance packages in portable computers

A numerical study was conducted to determine the thermal performance of the Pentium Processor in a Tape Carrier Package (TCP) operating inside a typical portable computer. The objective of this study is to develop a validated system level model of the portable environment and demonstrate that equipment designers can carry out design iterations of possible heat transfer configurations to analyze cost, performance and manufacturability tradeoffs. A detailed 3D numerical model of the package was constructed using a computational fluid dynamic software. In the interest of keeping the computational model tractable, some simplifying assumptions were employed to obtain equivalent compact models of the various components in the computer. The fluid motion is essentially a buoyancy driven convection inside an enclosure with multiple discrete heat sources. The results obtained indicate that the model is in good agreement with the experimental data, both qualitatively and quantitatively. Thermal performance limits were established for various package families. The validated model was used to investigate the improvement in thermal performance due to increased PCB thermal conductivity and the inclusion of heat spreaders, heat pipes and vents.