Folded fin heat sink assembly

Abstract

A folded fin heat sink assembly and a method of fabricating a folded fin heat sink assembly for use as a cooling solution in micro-electronics and / or telecommunication applications. The heat sink assembly is formed by placing a sheet or paste of Sn—Zn solder upon a copper base plate, placing one or more aluminum folded fin assemblies on the solder sheet or paste, heating the base plate, the folded fin assembly and the solder to a temperature exceeding the liquidus temperature of the solder and allowing the solder to flow, and cooling the solder to form a soldered joint between the base plate and the folded fin assembly.

Description

REFERENCE TO RELATED APPLICATION [0001] This is a continuation of application Ser. No. 10 / 073,991, filed Feb. 14, 2002, which was a formal application based on provisional application No. 60 / 268,414, filed Feb. 14, 2001.FIELD OF THE INVENTION [0002] The invention relates to a folded fin heat sink assembly and to a method of fabricating a folded fin heat sink assembly for use as a cooling solution in micro-electronics and / or telecommunication applications. In particular, the invention relates to a method of mounting and soldering an aluminum folded-fin assembly to a copper base plate to form a folded fin heat sink assembly. BACKGROUND OF THE INVENTION [0003] Integrated circuit devices are increasingly being used in modern electronic applications such as computers. During normal operation, integrated circuit devices generate significant amounts of heat. If this heat is not continuously removed, the device may overheat resulting in damage to the device and / or a reduction in operating p...

AI Technical Summary

Benefits of technology

[0015] It is an object of the invention to provide a method of bonding an aluminum folded-fin assembly to an unplated or a nickel plated copper base plate, to form a folded-fin heat-sink assembly, which obviates or mitigates the disadvantages of known methods and processes as discussed above.

Problems solved by technology

During normal operation, integrated circuit devices generate significant amounts of heat.

If this heat is not continuously removed, the device may overheat resulting in damage to the device and / or a reduction in operating performance.

Consequently, the heat generated by these devices has also increased.

The efficiency of the heat sink in spreading the heat from the heat source to the fins can become a limitation of the heat sink design.

In today's marketplace, with microprocessor solutions being offered in the 2.2 GHz clock frequency range, cooling requirements often cannot be met by the technical capabilities offered by aluminum extrusion technology.

Assembled heat sinks offer the ability to use higher conductive materials such as copper in the design of the base plate along with aluminum fins, when spreading the heat from the heat source becomes a limitation.

This however reduces the performance of the heat sink, as thermal epoxies in general have conductivity levels of only about 1 W / mK.

However, nickel plating densely packed aluminum fins typically requires an electro-less nickel-plating process, which adds significant cost in manufacturing.

However, this process step requires an intermediary material such as nickel or iron between the aluminum fins and copper base plate to ensure that low temperature inter-metallics of Cu and Al do not form, resulting in an uncontrollable joining process.

Once again, this process requires the additional manufacturing cost associated with providing an intermediary material.

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