HIGH PRESSURE HEAT DISSIPATION APPARATUS FOR POWER SEMICONDUCTOR DEVICES

Abstract

An improved power semiconductor heat dissipation apparatus for regulating the temperature of multiple power semiconductors featuring increased structural integrity for high pressure applications, a more robust heat exchange fin design to accommodate particulates or other solid contaminants that may be present in less refined coolant fluids, and a modified construction for increased durability and ease of automated assembly.

Claims

1. An improved power semiconductor heat dissipation apparatus, said apparatus comprising: a liquid heat exchange manifold comprising: a first and second plenum; an influent allowing cooling fluid ingress to said manifold to said first plenum; an effluent allowing cooling fluid egress from said manifold from said second plenum; and at least one copper plate having an internal and external surface; a heat exchange surface in thermal communication with said internal surface of said copper plate; at least one power semiconductor in thermal communication with said external surface of said copper plate; wherein said heat exchange surface is situated within said manifold between said first plenum and said second plenum such that cooling liquid much pass through said heat exchange surface to flow from said first plenum to said second plenum; wherein said copper plate is a structural member that defines said manifold, which is capable of withstanding coolant fluid pressure up to at least 400 kPa.

2. An apparatus as in claim 1 wherein said heat exchange surface is a thermally conductive material with a thickness of no more than 0.3 mm featuring a plurality of serpentine folds with a gap of at least 1 mm between each folds to allow coolant fluid flow.

3. An apparatus as in claim 1 further including a plurality of power semiconductor devices, wherein said power semiconductor devices are electrically isolated from each other by a direct bond copper substrate;

4. An apparatus as in claim 1 further including at least one thermistor in thermal communication with said copper plate.

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 an exemplary embodiment of the presently disclosed heat dissipation apparatus.

[0030] FIG. 2 is an cross-sectional view of the presently disclosed heat dissipation apparatus illustrating the novel groove and snap design manifold that increases the structural integrity of the apparatus while also increasing ease of assembly automation.

[0031] FIG. 3 is an exploded view of the wall of the presently disclosed apparatus illustrating each layer in order from inner most to outermost, the heat exchange surface, copper plate, direct bond copper layer, exemplar power semiconductors, and exemplar thermistors.

[0032] FIG. 4 is a perspective view of an exemplary embodiment of the legacy design of the presently disclosed heat dissipation apparatus shown for comparison purposes.

[0033] FIG. 5 is a perspective view of an exemplary embodiment of a heat exchange surface featuring 0.3 mm thick heat exchange surface and 1 mm gaps designed to better accommodate particulates and other solid contaminants in the cooling fluid, also featuring louver design to increase dissipation efficiency.

[0034] FIG. 6 is a perspective view of an exemplary embodiment a heat exchange surface featuring 0.3 mm heat exchange surface and 1 mm gaps designed to better accommodate particulates and other solid contaminants in the cooling fluid, also featuring a wave design to increase thermal efficiency.

[0035] FIG. 7 is a plan view of a plurality of power semiconductor devices depicting a thermistor directly sintered or vacuum soldered on the direct bonded copper substrate which is in turned bonded to a copper plate providing improved structural integrity, thermal spreading, thermal monitoring, and ease of assembly.

[0036] FIG. 8 is a plan view of the heat dissipation profile of power semiconductor devices mounted on the presently disclosed construction comprising direct bonded copper substrate bonded to a copper plate, demonstrating better heat dissipation than the legacy design illustrated in FIG. 9 (lighter shades represent higher temperatures).

[0037] FIG. 9 is a plan view of the heat dissipation profile of power semiconductor devices mounted on the legacy design construction comprising only direct bonded copper substrate backed by epoxy laminate substrate such as FR-4, demonstrating poorer heat dissipation than the presently disclosed improved design illustrated in FIG. 8 (lighter shades represent higher temperatures).

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT

[0038] The above described drawing figures illustrate an exemplary embodiment of the 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.

[0039] Described now in detail is a high pressure heat dissipation apparatus featuring fortified structural integrity, increased capacity to pass coolant fluid continents, and an improved design to simplified assembly.

[0040] FIG. 1 illustrates an exemplary embodiment of the presently disclosed high pressure power semiconductor heat dissipation apparatus 100 featuring a manifold with an influent 110 for ingress of coolant fluid and an effluent 120 for egress of cooling fluid. FIG. 1 is shown with multiple power semiconductor devices 160 bonded to direct bond copper substrate pads (DBC) 155 to provide the power semiconductor devices 160 electrical isolation. The DBC substrate pads 155 are sintered or vacuum soldered to a copper plate 140. In applications that do not require electrical isolation, power semiconductors can be bonded directly to the copper plate 140.

[0041] Regardless of whether DBC substrate 155 is utilized, the copper plate 140 provides greatly improved structural integrity to the apparatus in comparison to legacy designs that utilized epoxy laminate substrate such as FR-4. The improved structural integrity allows the presently disclosed apparatus to accommodate applications that require high pressure cooling fluids. In testing the presently disclosed apparatus demonstrated both static and dynamic operational integrity with cooling fluid pressure of at least 400 kPa.

[0042] FIG. 1 also features mechanical mounting points 130 to allow for more robust mounting options and for better vibration tolerance thereby increasing the range of environments the presently disclosed apparatus can endure.

[0043] FIG. 2 illustrates a cross-section of the presently disclosed improved apparatus 100 showing a power semiconductor device 160 bonded to a DBC substrate pad 155 which in turn is bonded to a copper plate 140. The angle of the illustration depicts how the copper plate 140 is secured to the manifold frame 175 by a groove 180 along the inferior edge of the manifold frame 175 and a snap 170 along the superior edge of the manifold frame 175. FIG. 2 also depict the gasket 190 that provides a robust seals along the junction between the copper plate 140 and the manifold frame 175.

[0044] During assembly, the inferior edge of the copper plate 140 is placed in the grove 180 located along the inferior edge of the manifold frame 175 and then the copper plate 140 is pressed laterally toward the manifold frame 175 until the superior edge of the copper plate 140 is secured by the snap 170 that is molded along the superior edge of the manifold frame 175. This assembly procedure is much simpler than the assembly procedure of legacy designs that involved installing clips 135 shown in FIG. 4, more importantly, the simpler design is possible to automate which can yield significant manufacturing cost savings.

[0045] FIG. 3 illustrates an exploded perspective view the heat transfer path between the power semiconductor 160 and the heat transfer surface 200. The illustration shows six power semiconductor 160 devices that are electrically isolated on the DBC substrate pads 155 that are bonded to the copper plate 140 which is in direct thermal contact with the heat transfer surface 200. The illustration also shows multiple NTC thermistors 150 directly soldered to the DBC substrate pad 155 providing one more manufacturing advantage over legacy designs that utilized manual application of adhesives to the secure NTC thermistors 150. Another exemplar configuration illustrating two NTC thermistors soldered directly to a separate DBC substrate pad is depicted in FIG. 7.

[0046] FIGS. 8 and 9 illustrate the superior heat spreading performance of the copper plate 140. The illustrations depict testing in which the power semiconductor devices were each operating at 560 ARMS. In FIG. 8 the power semiconductor devices were bonded to DBC substrate pads 155 bonded to a copper plate 140, whereas in FIG. 9 the power semiconductor devices were bonded to DBC substrate pads 155 mounted on legacy epoxy laminate substrate. The superior heat spreading of the improved design in FIG. 8 is visually apparent. The improved design also presented a lower steady state temperature by 1.5%.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.