Two-phase immersion-type heat dissipation structure having fins with different thermal conductivities

A two-phase immersion-type heat dissipation structure having fins with different thermal conductivities is provided. The two-phase immersion-type heat dissipation structure includes a heat dissipation substrate, and a plurality of fins. The heat dissipation substrate has a fin surface and a non-fin surface that face away from each other. The non-fin surface is configured to be in contact with a heating element immersed in a two-phase coolant. The fin surface is connected with the plurality of fins. At least one of the plurality of fins is a functional fin that is made of a single metal material and has two or more thermal conductivities. A thermal conductivity of a lower portion of the functional fin that is connected with the heat dissipation substrate is lower than thermal conductivities of other portions of the functional fin.

FIELD OF THE DISCLOSURE

The present disclosure relates to a heat dissipation structure, and more particularly to a two-phase immersion-type heat dissipation structure having fins with different thermal conductivities.

BACKGROUND OF THE DISCLOSURE

An immersion cooling technology is to directly immerse heat producing elements (such as servers and disk arrays) into a coolant that is non-conductive, and heat generated from operation of the heat producing elements is removed through an endothermic gasification process of the coolant. Therefore, how to dissipate heat more effectively through the immersion cooling technology has long been an issue to be addressed in the industry.

SUMMARY OF THE DISCLOSURE

In response to the above-referenced technical inadequacy, the present disclosure provides a two-phase immersion-type heat dissipation structure having fins with different thermal conductivities.

In one aspect, the present disclosure provides a two-phase immersion-type heat dissipation structure. The two-phase immersion-type heat dissipation structure includes a heat dissipation substrate, and a plurality of fins. The heat dissipation substrate has a fin surface and a non-fin surface that face away from each other. The non-fin surface is configured to be in contact with a heating element immersed in a two-phase coolant. The fin surface is connected with the plurality of fins. At least one of the plurality of fins is a functional fin that is made of a single metal material and has two or more thermal conductivities. A thermal conductivity of a lower portion of the functional fin that is connected with the heat dissipation substrate is lower than thermal conductivities of other portions of the functional fin.

In certain embodiments, a difference between the thermal conductivity of the lower portion of the functional fin that is connected with the heat dissipation substrate and the thermal conductivities of other portions of the functional fin is less than 20%.

In certain embodiments, the lower portion of the functional fin that is connected with the heat dissipation substrate has an indentation or a crease formed thereon through localized processing using forging, extrusion, or bending, and wherein an area of a portion of the functional fin that is processed through the localized processing is from 5% to 20% of a total area of the functional fin.

In certain embodiments, the functional fin is made of one of copper, copper alloy, aluminum, and aluminum alloy.

In certain embodiments, the plurality of fins are plate-fins, wherein each of the plate-fins has a thickness of from 0.1 mm to 0.5 mm, and a height of less than or equal to 10 mm, and wherein any adjacent two of the plate-fins have a distance of from 0.1 mm to 0.5 mm therebetween.

In certain embodiments, the plurality of fins are pin-fins, wherein each of the pin-fins has a diameter of from 0.1 mm to 0.5 mm, and a height of less than or equal to 6 mm, and wherein any adjacent two of the pin-fins have a distance of from 0.1 mm to 0.5 mm therebetween.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

First Embodiment

Referring toFIG.1toFIG.4, a first embodiment of the present disclosure provides a two-phase immersion-type heat dissipation structure having fins with different thermal conductivities for contacting a heating element immersed in a two-phase coolant. As shown inFIG.1andFIG.2, the two-phase immersion-type heat dissipation structure according to the first embodiment of the present disclosure includes a heat dissipation substrate10, and a plurality of fins20.

In this embodiment, the heat dissipation substrate10has a fin surface101and a non-fin surface102that face away from each other. The non-fin surface102is configured to be in contact (e.g., in direct contact, or in indirect contact via an intermediate layer) with a heating element800immersed in a two-phase coolant. The fin surface101is connected with the plurality of fins20, and the heat dissipation substrate10and the plurality of fins20can be integrally connected with each other by metal injection molding or skiving. The heat dissipation substrate10and the plurality of fins20can also be connected by soldering. Moreover, the plurality of fins20can be plate-fins, each of the plate-fins preferably has a thickness T of from 0.1 mm to 0.5 mm, any adjacent two of the plate-fins preferably have a distance of from 0.1 mm to 0.5 mm therebetween, and a height of each of the plate-fins is preferably less than or equal to 10 mm.

In this embodiment, at least one of the plurality of fins20is a functional fin20athat is made of a single metal material (such as copper, copper alloy, aluminum, and aluminum alloy) and has two or more thermal conductivities. Furthermore, a thermal conductivity of a lower portion201of the functional fin20athat is connected with the heat dissipation substrate10is lower than thermal conductivities of other portions of the functional fin20a.

In more detail, the lower portion201of the functional fin20athat is connected with the heat dissipation substrate10can have an indentation F (as illustrated inFIG.3) formed thereon by a partial processing manner of forging or extrusion, so that the functional fin20athat is made of a single metal material can have two or more thermal conductivities. Furthermore, after the indentation F is formed on the lower portion201of the functional fin20athrough forging or extrusion, a thermal conductivity of the lower portion201of the functional fin20ais lower than the thermal conductivities of other portions of the functional fin20a, so that an amount of heat conducted to the plurality of fins20on the heat dissipation substrate10can be uniformly distributed, and most of the plurality of fins20can be properly utilized. In addition, none of the plurality of fins20is formed by soldering different metal materials, so that high interface thermal resistance does not occur in this embodiment.

Moreover, in order to avoid an excessive increase in a temperature of the heating element800, a thermal conductivity of the lower portion201of the functional fin20aneeds to be prevented from being excessively decreased. In this embodiment, a difference between the thermal conductivity of the lower portion201of the functional fin20aand the thermal conductivities of other portions of the functional fin20ais required to be less than 20%. For example, the functional fin20aof this embodiment can be made of copper, and a thermal conductivity of copper can be approximately 400 W/mK, so that a lowest thermal conductivity of the lower portion201of the functional fin20acan be approximately 320 W/mK, and preferably is 360 W/mK. That is, a difference between the thermal conductivity of the lower portion201of the functional fin20aand the thermal conductivities of other portions of the functional fin20ais approximately 10%.

The lower portion201of the functional fin20acan have the indentation F formed thereon by the localized processing manner of forging or extrusion, and a center portion202that is integrally connected to an upper portion203and the lower portion201of the functional fin20acan also have the indentation F formed thereon by the localized processing manner of forging or extrusion. Therefore, the functional fin20athat is made of a single metal material can have thermal conductivities that are increased in a stepwise manner. Moreover, a total area of a portion of the functional fin20athat is processed by the localized processing manner is from 5% to 20% of a total area of the functional fin.

In this embodiment, at least two functional fins20aof the plurality of fins20correspond in position to locations above the heating element800, so as to prevent heat absorbed by the heat dissipation substrate10to be mostly transferred only to one portion of the fins20above the heating element800through a shorter thermal conduction path. Accordingly, heat absorbed by the heat dissipation substrate10can also be transferred to another portion of the fins20that are away from the heating element800through a longer thermal conduction path (as illustrated by arrows inFIG.4), so that the another portion of the fins20that are away from the heating element800can also be properly utilized.

In this embodiment, the plurality of fins20can all be functional fins20a. In another embodiment, a leftmost one and a rightmost one of the plurality of fins20can be fins that are made of a single metal material and have only a single thermal conductivity.

Second Embodiment

Referring toFIG.5andFIG.6, a second embodiment of the present disclosure is substantially the same as the first embodiment, and the difference therebetween is described as follows.

In this embodiment, a lower portion201of a functional fin20bthat is connected with the heat dissipation substrate10can have a crease C (as illustrated inFIG.6) formed thereon by a localized processing manner of bending, so that the functional fin20bthat is made of a single metal material can have two or more thermal conductivities.

Third Embodiment

Referring toFIG.7, a third embodiment of the present disclosure is substantially the same as the first embodiment and the second embodiment, and the difference therebetween is described as follows.

In this embodiment, the plurality of fins20can be pin-fins, each of the pin-fins has a diameter that is preferably from 0.1 mm to 0.5 mm, and any adjacent two of the pin-fins preferably have a distance D of from 0.1 mm to 0.5 mm therebetween. Similar to the first embodiment, a height of each of the pin-fins is preferably less than or equal to 6 mm.

Beneficial Effects of the Embodiments

In conclusion, in the two-phase immersion-type heat dissipation structure having fins with different thermal conductivities, by technical features of “a heat dissipation substrate having a fin surface and a non-fin surface that face away from each other, the non-fin surface being configured to be in contact with a heating element immersed in a two-phase coolant, and the fin surface being connected with the plurality of fins,” “at least one of the plurality of fins being a functional fin that is made of a single metal material and has two or more thermal conductivities,” and “a thermal conductivity of a lower portion of the functional fin that is connected with the heat dissipation substrate being lower than thermal conductivities of other portions of the functional fin,” an amount of heat conducted to the plurality of fins on the heat dissipation substrate can be uniformly distributed, and most of the plurality of fins can be properly utilized, so as to improve an overall immersion-type heat dissipation effect.