Integrated thin film evaporation thermal spreader and planar heat pipe heat sink

Abstract

A heat dissipation device and method provides thermal spreading and cooling for a heat-producing body. A thin film evaporator in thermal communication with the heat-producing body removes heat from the heat-producing body using a working fluid. A heat pipe integrated with the thin film evaporator, and extending from the thin film evaporator, dissipates heat removed by the thin film evaporator to the external environment of the heat dissipation device. A pumping element at least one of: 1) pumps working fluid to the thin film evaporator; and 2) augments transfer of working fluid to the thin film evaporator.

Description

BACKGROUND[0001]The present application relates generally to thermal management. It finds particular application in conjunction with cooling heat-producing bodies, such as integrated circuits, and will be described with particular reference thereto. However, it is to be appreciated that the present application is also amenable to other like applications.[0002]Thermal management for electronics packaging is an active area of research given the increasing demands for high power density and three-dimensional (3D) integrated circuit (IC) architectures. With reference to FIG. 1, a typical electronics package for a 3D IC is shown. As can be seen, the electronics package relies upon a passive heat sink for thermal management.[0003]Most approaches for electronics gaseous working fluid thermal management are focused on back-side thermal management. An example of such an approach is described in U.S. Patent Application Publication No. 2005 / 0280162 to Mok et al. which describes an integrated v...

AI Technical Summary

Benefits of technology

This patent describes a device that helps spread heat and cool down a heat-producing object. It includes a sealed housing with a liquid phase fluid reservoir and a vapor chamber where the heat-producing object is located. A thin film evaporator inside the housing takes the liquid phase fluid and converts it to gas using heat from the object. A heat pipe then removes the gas from the evaporator and sends it back to the reservoir. A pumping element helps to move the fluid to the evaporator. Overall, this device helps control the temperature of the heat-producing object by using a closed system and efficient heat transfer.

Problems solved by technology

However, increasingly, 3D architectures (e.g., with heat fluxes approaching 100 watts per square centimeter (W / cm2)) have made this approach insufficient.

3D die stacks have severe problems with hotspots on each of the layers.

Spreading this heat is a major challenge since the typical combination of solder balls, (relatively) low thermal conductivity filler and copper-filled through silicon vias (TSVs) does not provide a sufficiently conductive thermal path.

Further, spreading the heat only partially solves the problem as the heat still needs to be dissipated to the environment.

This former realization demonstrates fairly modest thermal improvement, while the latter entails considerable complexity in terms of fluidic sealing and pumping.

However, thermoelectric thermal bumps suffer from the typical shortcomings of thermoelectric materials: poor efficiency and high cost.

A challenge in thin film evaporator design is feeding the thin film with enough material to match the evaporation rate for high heat fluxes.

However, this solution suffers from orientation dependence and the resulting film is not especially thin.

However, this realization requires external infrastructure for pumping and a relatively large thin film.

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