THREE-DIMENSIONAL FLOW BALANCE FOR POWER MODULE COOLING

Abstract

A low profile semiconductor heat dissipation apparatus utilizing innovative three dimensional flow balancing to achieve both greater thermal efficiency and greater heat dissipation uniformity.

Claims

1. An apparatus for of dissipating heat from power semiconductor devices, the apparatus comprising: A device as disclosed in accompanying specification

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

[0028] The accompanying drawings illustrate various exemplary implementations and are part of the specification. The illustrated implementations are proffered for purposes of example not for purposes of limitation. Illustrated elements will be designated by numbers. Once designated, an element will be identified by the identical number throughout. Illustrated in the accompanying drawing(s) is at least one of the best mode embodiments of the present disclosure. In such drawing(s):

[0029] FIG. 1 is a perspective view of the presently disclosed heat dissipation apparatus capable of three dimensional flow balancing for increased heat dissipation uniformity.

[0030] FIG. 2 is a cutaway perspective view of the presently disclosed heat dissipation apparatus illustrating the orientation of the power semiconductor device to the heat sink and the flow balanced manifold.

[0031] FIG. 3 is a perspective view of the manifold of the presently disclosed heat dissipation apparatus illustrating the various features that enable the apparatus to balance coolant fluid flow in three dimensions.

[0032] FIG. 4 is a cross-sectional plan view of the presently disclosed heat dissipation apparatus illustrating the features designed to balance coolant fluid flow in the third dimension.

[0033] FIG. 5 is a perspective view of a different embodiment of the manifold of the presently disclosed heat dissipation apparatus than the manifold embodiment shown in FIG. 3 to illustrate an alternative possible design.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT

[0034] The above-described drawing figures illustrate an exemplary embodiment of presently disclosed apparatus and its many features in at least one of its preferred, best mode embodiments, which is further defined in detail in the following description. Those having ordinary skill in the art may be able to make alterations and modifications to what is described herein without departing from its spirit and scope of the disclosure. Therefore, it must be understood that what is illustrated is set forth only for the purposes of example and that it should not be taken as a limitation in the scope of the present apparatus or its many features.

[0035] Described now in detail are a series of drawings depicting various features and details for the purpose of further clarifying the presently disclosed apparatus and method.

[0036] FIG. 1 is a perspective view of an exemplar embodiment of the presently disclosed innovative heat dissipation apparatus 100 illustrated including an exemplar encapsulated semiconductor device 101, shown with eight power and/or signal leads extending out from the apparatus 100. The semiconductor device 101 is also shown affixed to a heat sink 102, which is coupled with a manifold 103 capable of three-dimensionally regulating coolant fluid flow across the heat sink 102 for more uniform, thermally efficient heat transfer.

[0037] FIG. 2 is a perspective cutaway view of the presently disclosed apparatus 100 illustrating some internal features to the presently disclosed apparatus 100 such as the exemplar round pin fin features 113 of the heat sink 102. As previously stated, the heat sink 102 can feature fins of a variety of shapes and sizes so long as they increase surface area and encourage greater heat transfer. From the perspective view of FIG. 2, two apertures in the manifold 103 are visible; one aperture serves as an influent 105 for cooling fluid entry, and the other serves as an effluent 109 for cooling fluid exit.

[0038] FIG. 3 illustrates a perspective view of the manifold 103 shown separately from the other major components to illustrate the internal features that serve to regulate the flow of coolant fluid. The coolant fluid first enters the manifold 103 through the influent aperture 105 which leads immediately to the first plenum 107. The hydrostatic pressure of the coolant fluid flowing through the first plenum 107 is balances in the z-axis direction by the flow-balancing wall gradient feature 106 which narrows the first plenum 107 in the Z-axis direction.

[0039] The pressure balanced coolant fluid then enters a plurality of channels 114 that connect the first plenum 107 to the second plenum 110. The number of channels 114 is not critical to the presently disclosed apparatus but there but there should be a more than one such that flow is generally restricted to flow in the direction of the y-axis after the coolant fluid enters the channel 114. The flow balancing feature 106 should ensure that coolant fluid entering each channel 114 is experiencing roughly equal hydrodynamic pressure; however, balancing can be fine-tuned with gate restriction features 115 at the entrance of each channel 114.

[0040] When the coolant fluid has reached the end of the channel 114 it will enter the second plenum 110 and exit the apparatus through the effluent 109. The hydrostatic pressure of the coolant fluid in the second plenum 110 is balanced with a wall gradient feature 106 similar to the one illustrated in the first plenum 107. The manifold illustrated in FIG. 3 is an exemplar embodiment, other embodiment may not include a wall gradient feature 106 in both the first plenum 107 and the second plenum 110. Other embodiments may include a wall gradient feature in only the first plenum 107 or the second plenum 110, or possibly neither the first nor the second plenum 107, 110.

[0041] FIG. 4 illustrates a cross-sectional plan view of the presently disclose device showing an gradient in the x-axis direction 108 along the channel 114. This gradient feature 108 of the channel 114 is responsible for the flow balancing in the third dimension. By narrowing the channel 114 in the x-axis direction as the cooling fluid flows in the y-axis direction, the channel 114 increases the flow velocity of the coolant fluid as it passes along the heat transfer surface causing the fluid to transition from laminar flow to turbulent flow which, in turn, changing the coolant fluids heat transfer coefficient.

[0042] If the flow rate of the coolant fluid and the gradient of the channel 114 are appropriately balanced, the coefficient of heat transfer of the coolant fluid will begin to increase due to its transition toward turbulent flow, thereby compensating for the otherwise reduction of thermal efficiency experienced due to the raise in temperature of the coolant fluid do to the absorbed heat energy. This “third-dimension” flow balancing has been shown to achieve increased thermal efficiency both theoretically through Computational Fluid Dynamics (CFD) and during actual testing. It is important to note that to achieve such results the flow rate and channel restriction must be properly calibrated to the material properties of the coolant fluid such that the coolant fluid experiences transition while flowing through the channel 114.

[0043] FIG. 5 illustrates another embodiment of the manifold wherein gate features 115 at the exit of the channel 114 are used instead of at the beginning of the channel as illustrated in FIG. 4. Alternative embodiments are possible so long as the flow balancing features cause the cooling fluid to experience transition from laminar to turbulent flow during its journey across the heat transfer surface.

[0044] The enablements described in detail above are considered novel over the prior art of record and are considered critical to the operation of at least one aspect of the apparatus and its method of use, and to the achievement of the above-described objectives. The words used in this specification to describe the instant embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification: structure, material, or acts beyond the scope of the commonly defined meanings. Thus, if an element can be understood in the context of this specification as including more than one meaning, then its use must be understood as being generic to all possible meanings supported by the specification and by the word(s) describing the element.

[0045] The definitions of the words or drawing elements described herein are meant to include not only the combination of elements which are literally set forth, but all equivalent structures, materials or acts for performing substantially the same function in substantially the same way to obtain substantially the same result. In this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements described and its various embodiments or that a single element may be substituted for two or more elements in a claim.

[0046] Changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalents within the scope intended and its various embodiments. Therefore, substitutions, now or later known to one with ordinary skill in the art, are defined to be within the scope of the defined elements. This disclosure is thus meant to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, what can be obviously substituted, and also what incorporates the essential ideas.

[0047] The scope of this description is to be interpreted only in conjunction with the appended claims and it is made clear, here, that each named inventor believes that the claimed subject matter is what is intended to be patented.