DIRECT POWER MODULE COOLING

A power module assembly includes a frame assembly and a bus bar assembly. The frame assembly includes an upper frame body and a lower frame body coupled to the upper frame body, at least one of the upper and lower frame bodies including at least one jet orifice formed therethrough, the jet orifice configured to receive coolant at a first end and discharge the coolant at a second end, the upper and lower frame bodies at least partially defining a chamber therebetween. The bus bar assembly is arranged in the chamber and includes a bus bar arranged adjacent to the second end of the jet orifice. The jet orifice is configured to discharge the coolant directly onto the bus bar so as to reduce an operating temperature of the bus bar.

BACKGROUND

The present disclosure relates to electronic systems, in particular electronic systems having more power dense solutions and improving the operation of such systems.

SUMMARY

According to a first aspect of the present disclosure, a power module assembly includes a frame assembly and a bus bar assembly. The frame assembly includes an upper frame body and a lower frame body coupled to the upper frame body, at least one of the upper and lower frame bodies including at least one first jet orifice formed therethrough. The at least one first jet orifice is configured to receive coolant at a first end and discharge the coolant at a second end opposite the first end. The upper and lower frame bodies at least partially define a chamber therebetween. The bus bar assembly is arranged in the chamber and includes a first bus bar arranged adjacent to the second end of the at least one first jet orifice. The at least one first jet orifice is configured to discharge the coolant directly onto the first bus bar so as to reduce an operating temperature of the first bus bar.

According to a further aspect of the present disclosure, a power module assembly includes a frame assembly and a bus bar assembly. The frame assembly includes a first frame body including a first jet orifice formed therethrough and a second frame body coupled to the first frame body. The bus bar assembly is arranged at least partially within the second frame body and includes a first bus bar arranged adjacent to an outlet of the first jet orifice. The first jet orifice is configured to discharge coolant from the outlet directly onto the first bus bar so as to reduce an operating temperature of the first bus bar.

According to a further aspect of the present disclosure, a method includes coupling a lower frame body to an upper frame body to form a frame assembly, the upper and lower frame bodies at least partially defining a chamber therebetween, forming at least one first jet orifice through at least one of the upper and lower frame bodies, directing coolant to a first end of the at least one first jet orifice, arranging a bus bar assembly in the chamber, the bus bar assembly including a first bus bar arranged adjacent to a second end of the at least one first jet orifice opposite the first end, and discharging the coolant at the second end of the at least one first jet orifice directly onto the first bus bar so as to reduce an operating temperature of the first bus bar.

DETAILED DESCRIPTION

FIGS.1-8illustrate a power module assembly10according to a first aspect of the present disclosure.FIGS.9-15Billustrate a power module assembly110according to a further aspect of the present disclosure.FIGS.16-18illustrate a power module assembly210according to a further aspect of the present disclosure.FIGS.19A-23illustrate a power module assembly310according to a further aspect of the present disclosure.

As can be seen inFIG.1, the power module assembly10includes a frame assembly12including a top lid14, a bottom lid19, an upper plenum body24, a lower plenum body30, and a frame body36. A bus bar assembly50is arranged within the frame body36and includes dies60,62and other electrical components (seeFIGS.3B and4, extended surfaces90E,92E,52E,56E formed as pin fins) arranged on bus bars52,54,56of the bus bar assembly50. When assembled together such that the frame body36is sandwiched between the upper and lower plenum bodies24,30, and the upper and lower plenum bodies24,30sandwiched between the top and bottom lids14,19, the combination of the top lid14and the upper plenum body24and the bottom lid19and the lower plenum body30each define an integrated cooling fluid manifold configured to transport coolant98,99from a source (not shown) to the bus bar assembly50, in particular the electrical components arranged on the bus bars52,54,56. Specifically, the coolant98,99can be discharged directly onto the electrical components of the bus bar assembly50, thus resulting in a significant reduction of thermal impedance between the electrical components and the coolant98,99. It is noted that the power module assembly10shown inFIGS.1-8may be referred to as a type of “floating bus power module.”

The term “frame body” as used herein, whether in isolation or in conjunction with the terms “first,” “second,” and the like, may refer to any body that comprises a frame assembly, such as, for example, the top lid14, the bottom lid19, the upper plenum body24, the lower plenum body30, and the frame body36described herein. A “frame body” can also include other bodies associated with frame assemblies123,223,323described herein, such as the upper and lower frame bodies124,130, the top and bottom lids324,330, and the main frame body336.

Illustratively, the top lid14of the power module assembly10is a generally planar plate, as shown inFIGS.1and2. In some embodiments, the top lid14may be formed of metal, such as aluminum, although other suitable materials may be used. In some embodiments, the top lid14, the bottom lid19, the upper plenum body24, the lower plenum body30, and the frame body36being formed of metal may provide mechanical robustness and chemical compatibility in certain applications. The top lid14, as well as the bottom lid19, the upper plenum body24, the lower plenum body30, and the frame body36, each include at least one mounting hole15,20,25,31,44extending through a thickness of the respective component, through which fasteners (not shown) may extend to couple the top lid14, the bottom lid19, the upper plenum body24, the lower plenum body30, and the frame body36to each other to form the power module assembly10. In the illustrative embodiment, each of the top lid14, the bottom lid19, the upper plenum body24, the lower plenum body30, and the frame body36includes four mounting holes15,20,25,31,44.

Similar to the top lid14, the bottom lid19of the power module assembly10is a generally planar plate, as shown inFIGS.1and2. In some embodiments, the bottom lid19may be formed of metal, such as aluminum, although other suitable materials may be used.

The top lid14further includes an inlet16and an outlet17each formed as an opening extending through a thickness of the top lid14, as shown inFIGS.1and2. The inlet16is spaced apart from the outlet17in the longitudinal direction of the top lid14. The inlet16is aligned with a jet orifice recess26formed in the upper plenum body24and the outlet17is aligned with a vapor outlet27formed in the upper plenum body24. Similarly, the bottom lid19further includes an inlet22and an outlet23each formed as an opening extending through a thickness of the bottom lid19, as shown inFIGS.1and2. The inlet22is spaced apart from the outlet23in the longitudinal direction of the bottom lid19. The inlet22is aligned with a jet orifice recess32formed in the lower plenum body30and the outlet23is aligned with a vapor outlet33formed in the lower plenum body30.

Each of the top and bottom lids14,19further includes a seal groove18,23extending generally around a perimeter of an inwardly facing surface14S,19S of the top and bottom lid14,19, respectively, as shown inFIGS.1and2. The seal groove18,23receives a seal29,35therein, which may be formed as an O-ring seal. The seals29,35cooperate with other seals42,43described herein to hermetically seal the bus bar assembly50from the outside environment.

Illustratively, the upper plenum body24, also referred to as an upper frame body, is a generally planar plate, as shown inFIGS.1and2. In some embodiments, the upper plenum body24may be formed of metal, such as aluminum, although other suitable materials may be used. In order to route coolant98,99from the inlet16of the top lid14to the electrical components on an upper side50A of the bus bar assembly50, the upper plenum body24includes the first jet orifice recess26formed therein. Specifically, the first jet orifice recess26is formed to open outwardly toward the inlet16so as to receive inlet coolant98therein from the inlet16. Although a rectangular recess26is shown inFIG.1, other shapes may be used based on the cooling needs of the bus bar assembly50. The size and shape of the first jet orifice recess26maybe configured to meet the size and shape of the electrical components on the bus bar assembly50, as well as the number of jet orifices28included in the first jet orifice recess26.

The first jet orifice recess26further includes jet orifices28that extend through the bottom surface26A of the first jet orifice recess26, as shown inFIGS.1and2. The jet orifices28can be arranged in any arrangement on the surface26A based on the cooling needs of the power module assembly10, such as the shape and size of the electrical components on the upper side50A of the bus bar assembly50or the location of hot spots of the components on the upper side50A of the bus bar assembly50. For example, the jet orifices28may be arranged in parallel lines, as shown inFIGS.1and2, in order to direct inlet coolant98to locations of the dies60,62arranged on the bus bar assembly50, as shown inFIGS.3-6. Any suitable number, arrangement, and size of jet orifices28may be included on the upper plenum body24in order to meet the cooling needs of the power module assembly10. The number and diameter of jet orifices28can be balanced to provide adequate flow to the top and bottom sides of the module10in parallel.

In some embodiments, as can be seen inFIG.2, the inner surface26S of the first jet orifice recess26that faces the bus bar assembly50may be raised away from a main surface24S of the upper plenum body24. In this way, the jet orifices28can be arranged directly adjacent to the electrical components that need cooling, which can be, for example, the extended surfaces90E,92E, as shown inFIG.2.

The upper plenum body24further includes the first vapor outlet27spaced apart from the first jet orifice recess26, as shown inFIGS.1and2. The first vapor outlet27is formed as a large hole through the body24, and is sized and shaped to receive spent coolant99that has passed over and cooled the electrical components on the upper side50A of the bus bar assembly50. The spent coolant99is routed from the first vapor outlet27and to the outlet17formed in the top lid14.

Similar to the upper plenum body24, the lower plenum body30, also referred to as a lower frame body, is a generally planar plate, as shown inFIGS.1and2. In some embodiments, the lower plenum body30may be formed of metal, such as aluminum, although other suitable materials may be used. In order to route coolant98,99from the inlet21of the bottom lid19to the electrical components on the bottom side50B of the bus bar assembly50, the lower plenum body30includes a second jet orifice recess32formed therein. Specifically, the second jet orifice recess32is formed to open outwardly toward the inlet21so as to receive inlet coolant98therein from the inlet21. Although a rectangular recess32is shown inFIG.1, other shapes may be used based on the cooling needs of the bus bar assembly50.

The size and shape of the second jet orifice recess32can be configured to meet the size and shape of the electrical components on the bus bar assembly50, as well as the number of jet orifices34included in the recess32. Illustratively, the second jet orifice recess32can be formed to be larger than the first jet orifice recess26(i.e. includes a longer longitudinal extent than the first jet orifice recess26, as shown inFIGS.1and2) so as to cool a larger area than the first jet orifice recess26. For example,FIG.2illustrates first extended surfaces90E,92E arranged above and second extended surfaces52E,56E arranged below the DC+ bus bar52and the output bus bar56of the bus bar assembly50, respectively. Because the second extended surfaces52E,56E occupy a greater amount of space than first extended surfaces90E,92E, the second jet orifice recess32is longer and larger than the first jet orifice recess26in order to effectively cool the second extended surfaces52E,56E.

The second jet orifice recess32further includes jet orifices34that extend through the bottom surface32A of the recess32, as shown inFIGS.1and2. The jet orifices34can be arranged in any arrangement on the surface32A based on the cooling needs of the power module assembly10, such as the shape and size of the electrical components on the bottom side50B of the bus bar assembly50or the location of hot spots of components on the bottom side50B of the bus bar assembly50. For example, the jet orifices34may be arranged in parallel lines, as shown inFIGS.1and2, in order to direct inlet coolant98to locations of the extended surfaces52E,56E arranged on the bus bar assembly50, as shown inFIGS.3-6. Any suitable number, arrangement, and size of jet orifices34may be included on the lower plenum body30in order to meet the cooling needs of the power module assembly10. As a non-limiting example, the jet orifices34of the second jet orifice recess32may be more spaced apart in the longitudinal direction than the jet orifices28of the first jet orifice recess26so as to effectively cool the second extended surfaces52E,56E.

In some embodiments, as can be seen inFIG.2, the inner surface32S of the second jet orifice recess32that faces the bus bar assembly50may be raised away from a main surface30S of the lower plenum body30. In this way, the jet orifices34can be arranged directly adjacent to the electrical components that need cooling, which can be, for example, the extended surfaces52E,56E, as shown inFIG.2.

The lower plenum body30further includes the second vapor outlet33spaced apart from the second jet orifice recess32, as shown inFIGS.1and2. The second vapor outlet33is formed as a large hole through the body30, and is sized and shaped to receive spent coolant99that has passed over and cooled the electrical components on the bottom side50B of the bus bar assembly50. The spent coolant99is routed from the second vapor outlet33and to the outlet22formed in the bottom lid19.

As shown inFIGS.1and2, and in greater detail inFIGS.3A-6, the frame body36is a generally planar plate and is formed to provide a rigid housing to hold the bus bar assembly50in a fixed position. In some embodiments, the frame body36may be formed of metal, such as aluminum, although other suitable materials may be used. The frame body36may be formed to be thicker than the top lid14, the bottom lid19, the upper plenum body24, and the lower plenum body30in order to effectively house all components of the bus bar assembly50. Illustratively, the top lid14, the bottom lid19, the upper plenum body24, the lower plenum body30, and the frame body36are formed with identical lengths and widths so as to align with each other when assembled into the power module assembly10, as shown inFIG.2. The top lid14, the bottom lid19, the upper plenum body24, the lower plenum body30, and the frame body36need not be formed identically in all embodiments in order for the power module assembly10to operate effectively.

Similar to the top and bottom lids14,19, the frame body36further includes seal grooves40,41on upper and bottom surfaces40S,41S of the frame body36, as shown inFIGS.3A and3B. The seal grooves40,41extend generally around a perimeter of the frame body36. The seal grooves40,41each receive a seal42,43therein, which may be formed as an O-ring seal. The seals42,43cooperate with other seals29,35described herein to hermetically seal the bus bar assembly50from the outside environment.

As will be described in greater detail below, for external electrical connections, a DC+ bus bar52, a DC− bus bar54, and an output bus bar56are passed through respective walls36W of the frame body36and are sealed by polymer flanges84,85,86arranged on the bus bars52,54,56. Illustratively, the walls36W of the frame body36define a large central opening36C within which the components of the bus bar assembly50are housed. The upper and lower plenum bodies24,30enclose the central opening36C, which may also be referred to as a chamber36C when enclosed by the upper and lower plenum bodies24,30.

As shown inFIGS.3A and3B, the bus bar assembly50includes a DC+ bus bar52, a DC− bus bar54, and an output bus bar56. In some embodiments, the bus bars52,54,56may be arranged parallel to each other, and in some embodiments, the DC+ bus bar52and the DC− bus bar54may extend out of the frame body36on one side of the body36and the output bus bar56may extend out of the frame body36on an opposing side of the body36. In some embodiments, the DC− bus bar54may include a bend55external to the frame body36. In some embodiments, the bus bars52,54,56may be formed of copper or another suitable material.

Illustratively, the bus bar assembly50includes a first plurality of dies60arranged on an upper surface52A of the DC+ bus bar52within the opening36C of the frame body36, as shown inFIG.3A. The bus bar assembly50further includes a second plurality of dies62arranged on an upper surface56A of the output bus bar56within the opening36C of the frame body36. A printed circuit board (PCB)64is arranged on the DC+ bus bar52and the output bus bar56and extends between and interconnects the DC+ bus bar52and the output bus bar56. The PCB is illustrated to represent connections to a gate and kelvin pads on the dies, which may be included in some embodiments.

Wires66,68can be included to electrically connect the PCB64to the dies60,62. Wire bonds70,72can also be included to electrically connect the dies60,62to the adjacent bus bars54,56, specifically first wire bonds70that connect the dies62to the DC− bus bar54on an upper surface54A thereof, and second wire bonds72that connect the dies60to the output bus bar56on the upper surface56A. The wire bonds70,72provide flexibility to prevent mechanical failure due to thermal expansion and varying coefficients of thermal expansion (CTE). Copper ribbon bonds, which are used in other embodiments described herein, or any other electrical connector suitable for this purpose could be used as an alternative to wire bonds.

In the illustrative embodiment, the first plurality of dies60and the second plurality of dies62each include five dies60,62. This embodiment is merely exemplary, and other combinations of electrical components may be arranged on the bus bars52,54,56, including the first and second pluralities of dies60,62having the same or different numbers of dies, as used by the particular applications of the power module assembly10.FIG.3Aalso shows that the dies60,62may be formed as bare dies that are directly exposed to the coolant98,99with no extended surfaces (i.e. the extended surfaces52E,56E formed as pin fins shown inFIG.3B) attached to the top of the dies60,62. As will be described in detail below, the dies60,62may be covered in other configurations of the bus bar assembly50.

As shown inFIG.3B, some bus bars52,54,56may include extended surfaces that extend away from the bus bar and receive coolant98,99to cool the bus bars52,54,56. Illustratively, the DC+ bus bar52may include a plurality of extended surfaces52E that extend away from a bottom surface52B of the DC+ bus bar52. Similarly, the output bus bar56may include a plurality of extended surfaces56E that extend away from a bottom surface56B of the output bus bar56. The ends of the extended surfaces52E,56E can be directly exposed to the impinging jets of coolant98received from the jet orifices34of the lower plenum body30. Any suitable arrangement and/or number of extended surfaces52E,56E may be arranged on the bus bars52,56depending on the cooling needs of the bus bar assembly50, including arranging additional extended surfaces on the DC− bus bar54. In some embodiments, the extended surfaces52E,56E may be formed as pin fins machined into the bus bars52,56in order to provide extended heat transfer surfaces. Other suitable enhanced heat transfer surfaces which increase heat transfer efficiency, also referred to herein as surface enhancements, could be fabricated on the bus bars52,54,56and copper blocks90,92on top of the dies60,62depending on the cooling needs and design specifications of the power module assembly10, such as, for example, parallel walls of a heat sink forming channels, honeycomb pins, porous coatings, increased surface roughness, and the like.

Illustratively, the bus bar assembly50further includes insulating flanges84,85,86that are arranged in respective openings37A,37B,37C formed in the walls36W of the frame body34and surround the portions of the respective bus bars52,54,56that pass through the openings37A,37B,37C, as shown inFIGS.3A and3B. In some embodiments, the insulating flanges84,85,86are formed of a non-conductive material, such as a polymer, so as to insulate the bus bars52,54,56from the frame body36. Moreover, the ends of the DC+ and DC− bus bars52,54that do not extend through the frame body36may rest within recesses37D,37E that do not extend fully through the frame body36. Further insulating flanges87,88may be arranged within these recesses37D,37E in order to insulate the ends of the DC+ and DC− bus bars52,54. A similar recess and flange may be provided for the opposing end of the output bus bar56(not shown). In some embodiments, the insulating flanges84,85,86,87,88may be formed by permanently bonding the polymer material to the bus bars52,54,56using an overmolding process where a plastic is injection molded directly onto a substrate.

In some embodiments, as shown inFIG.4, the bus bar assembly50can include separate copper blocks90,92arranged on a top side of the bare dies60,62. The copper blocks90,92may be formed as individual flat blocks of copper that substantially cover the dies60,62. The copper blocks90,92may be thermally conductive. In some embodiments, extended surfaces90E,92E can extend away from the flat blocks of copper90,92, in particular extended surfaces90E,92E formed as machined pin fins for increased heat transfer area. The ends of the extended surfaces90E,92E can be directly exposed to the impinging jets of coolant98received from the jet orifices28of the upper plenum body24. It is noted thatFIG.11shows a more detailed view of a possible structure and arrangement of the flat blocks of copper90,92and the extended surfaces90E,92E ofFIG.4, although it is also noted that the arrangement inFIG.11slightly differs from that shown inFIG.4in that the blocks90,92have a smaller footprint and are attached to opposing bus bars using ribbon bonds instead of wire bods. In some embodiments, the individual flat blocks of copper90,92can be soldered onto the source pads of each individual die60,62(this can be seen more clearly inFIG.2, which shows the source pads of the dies60,62underneath the blocks90,92).

Instead of separate copper blocks90,92or in place of one of the sets of copper blocks90,92, the bus bar assembly50can include an elongated copper block90′,92′ arranged on and extending over all of respective bare dies60,62of the bus bar assembly50, as shown inFIG.5. Similar to the separate copper blocks90,92, the elongated copper blocks90′,92′ can include extended surfaces90E′,92E′ formed as machined pin fins for increased heat transfer area. This configuration may provide increased heat spreading and thermal coupling between dies60,62.

In some embodiments, instead of including multiple insulating flanges on each side of the frame body36as shown inFIGS.3A and3B, the bus bar assembly50can include only a single insulating flange84′,85′ on each side of the frame body36, as shown inFIG.6. Instead of multiple openings, each side of the frame body36only includes a single opening37A′,37B′. Accordingly, a first insulating flange84′ is formed to include two openings84A′,84B′ that each surround a portion of a respective bus bar52,54that passes through the opening37A′. A second insulating flange85′ is formed to include a single full opening85A′ that surrounds a portion of the output bus bar56that passes through the opening37B′. Moreover, the ends of the DC+ and DC− bus bars52,54that do not extend through the frame body36may rest within recesses85B′,85C′ that do not extend fully through the second insulating flange85′. This configuration may mitigate electrical losses due to the presence of conductive material inside the loop formed by the DC+ and DC− bus bars52,54.

Referring again toFIG.2, in operation, liquid inlet coolant98enters through the input16(also referred to as a “top liquid inlet”) of the top lid14and into the first jet orifice recess26of the upper plenum body24. The coolant98is directed through the jet orifices28and onto the electrical components of the bus bar assembly50. Similarly, liquid inlet coolant98enters through the input21(also referred to as a “bottom liquid inlet”) of the bottom lid19and into the second jet orifice recess32of the lower plenum body30. The coolant98is directed through the jet orifices34and onto the electrical components of the bus bar assembly50to cool the components, or in other words, reduce an operating temperature of the bus bar assembly50and its components. Specifically, the coolant98will boil as it absorbs heat from the dies60,62, extended surfaces90E,92E,52E,56E, and bus bars52,54,56. The spent coolant99, which is a two-phase mixture after having boiled, is routed through the two outlets17,22(also referred to as a “top vapor outlet” and a “bottom vapor outlet”) located on the top and bottom lids14,19after passing over the DC− bus bar54(shown on the left inFIG.2) and through the vapor outlets27,33of the plenum bodies24,30.

In one example, the cooling fluid may be a dielectric coolant. The cooling fluid may be deionized water, Ethylene Glycol Water (EGW), or any other suitable fluid may be used. One potential concern is that the cooling fluid may ionize quickly due to number of dissimilar metals. In another example, the cooling fluid may be a dielectric fluid such as tetrafluoroethane, also referred to as R134a, available from Linde Inc. Another example of a dielectric fluid is Honeywell Solstice® zd refrigerant, also referred to as R1233zd, available from Honeywell Belgium N.V.

FIG.7shows a first configuration94of arranging multiple power module assemblies10to operate in parallel. As shown inFIG.7, three module assemblies10are mounted between two manifolding plates95,96which include fluid passages (not shown) therein so as to provide inlet coolant98routing to the top and bottom sides of each module assembly10in a planar, horizontal configuration. Specifically, a liquid inlet97A,97B is fluidically connected to each manifolding plate95,96and provides the coolant98,99to the fluid passages and subsequently to the inlets16,21of the top and bottom lids14,19of each power module assembly10. The module assemblies10are hydrodynamically connected in parallel, reducing overall pressure drop. The spent coolant99is routed out of the configuration94via the vapor outlets98A,98B.

FIG.8shows a second configuration94′ of arranging multiple power module assemblies10to operate in parallel. As shown inFIG.8, three module assemblies10are mounted vertically relative to each other with separation plates95′ arranged between each module assembly10and below the lowermost module assembly10. A first vertical manifolding plate96′ can be arranged on one side of the configuration94′, and a second vertical manifolding plate97′ can be arranged on an opposing side of the configuration94′. Each manifolding plate96′,97′ can include fluid passages (not shown) therein so as to provide inlet coolant98to the module assemblies10from a liquid inlet96A′ of the first manifolding plate96′ and transport spent coolant99away from the module assemblies10and to a vapor outlet97A′ of the second manifolding plate97′.

Another embodiment of a power module assembly110is shown inFIGS.9-15B. The power module assembly110is similar to the power module assembly10shown inFIGS.1-8and described herein. Accordingly, similar reference numbers in the100series indicate features that are common between the power module assembly110and the power module assembly10. The description of the power module assembly10is incorporated by reference to apply to the power module assembly110, except in instances when it conflicts with the specific description and the drawings of the power module assembly110.

Similar to the power module assembly10, the power module assembly110includes a bus bar assembly150including two DC bus bars152,154and an output bus bar156arranged within a frame. Unlike the power module assembly10, the power module assembly110does not include top and bottom lids nor separate plenum bodies, but instead includes two frame bodies124,130that couple to each other and enclose the bus bar assembly150, as shown inFIG.9. It is noted that the power module assembly110shown inFIGS.9-15Bmay be referred to as another type of “floating bus power module” similar to the floating bus power module shown inFIGS.1-8.

As can be seen inFIGS.9-14, the power module assembly110includes a frame assembly123which includes a top frame body124and a bottom frame body130coupled to the top frame body124via fasteners (not shown) extending through mounting holes125,131. As shown inFIG.9and in more detail inFIG.13A, the top frame body124, also referred to as an upper frame body and similar to the upper plenum body24, includes a first jet orifice recess126and a first vapor outlet127formed adjacent to the first jet orifice recess126. The first jet orifice recess126is formed similarly to the first jet orifice recess26to include jet orifices128in a jet orifice area124J arranged to discharge coolant198,199directly onto the electrical components of the bus bar assembly150. As shown inFIG.9and in more detail inFIG.13B, the bottom frame body130, similar to the bottom plenum body30, includes a second jet orifice recess132and a second vapor outlet133formed adjacent to the second jet orifice recess132. The second jet orifice recess132is formed similarly to the second jet orifice recess32to include jet orifices134in a jet orifice area130J arranged to discharge coolant198,199directly onto the electrical components of the bus bar assembly150.

FIG.11shows a view of the bottom frame body130and the bus bar assembly150without the top frame body124. The bus bar assembly150is formed similarly to the bus bar assembly50described herein, in particular to include the DC+ and DC− bus bars152,154and an output bus bar156arranged parallel and adjacent to each other. The bus bar assembly150further includes a PCB164similar to the PCB64to facilitate gate connections, and dies160,162, similar to the dies60,62, arranged on the DC+ bus bar152and the output bus bar156. The bus bar assembly150further includes extended surfaces190E,192E extending away from the dies160,162and ribbon bonds170,172used instead of the wire bonds described herein.

In some embodiments, as shown in detail inFIG.12A, the bus bar assembly150can include MOSFET dies162arranged only on the output bus bar156or MOSFET dies160,162arranged on both of the DC+ bus bar152and the output bus bar156. Drains of the MOSFET dies160,162are bonded onto the top surfaces152A,156A of the DC+ and output bus bars152,156. In some embodiments, the ribbon bonds170,172extending from each of the MOSFET dies160,162extend into slots171A,171B formed in respective DC+ and output bus bars152,156, as shown inFIG.12A. Arranging the bonds170,172within the slots171A,171B may increase mechanical strength and lower electrical resistance as compared to other components such as wire bonds.

Illustratively, as shown inFIG.12B, the DC+ bus bar152may include a plurality of extended surfaces152E that extend away from a bottom surface152B of the DC+ bus bar152. Similarly, the output bus bar156may include a plurality of extended surfaces156E that extend away from a bottom surface156B of the output bus bar156. The ends of the extended surfaces152E,156E can be directly exposed to the impinging jets of coolant198received from the jet orifices134.

Similar to the bus bar assembly50, the bus bar assembly150further includes insulating flanges184,185,186that surround the portions of the respective bus bars152,154,156that extend out of the frame assembly123, as shown inFIGS.11-12B. The insulating flanges84,85,86are formed of a non-conductive material, such as a polymer, so as to insulate the bus bars152,154,156from the frame bodies124,130. The ends of the DC+ and DC− bus bars152,154and the output bus bar156that do not extend out of the frame assembly123may include non-conductive end caps187,188,189formed of a non-conductive material such as a polymer. The end caps187,188,189insulate the ends of the bus bars152,154,156from the frame bodies124,130. In some embodiments, ridges184R,185R,186R can be included in the flanges184,185,186(and in the end caps187,188,189in some embodiments) to provide surface creepage resistance and pins molded into the flanges184,185,186, as shown inFIGS.11-12B.

As can be seen inFIGS.11-13B, the bus bar assembly150rests on portions of the bottom frame body130so as to secure the assembly150between the top and bottom frame bodies124,130. Specifically, the bottom frame body130, also referred to herein as a lower frame body, includes walls130W that extend around a perimeter of the body130and define a shallow cavity130C therebetween. In some embodiments, the walls130W may be supported by frame support gussets130S staggered around the extent of the walls130W. A first wall130W on a first side of the bottom frame body130includes two notches136A,136B formed therein. The notches136A,136B provide a surface within which the DC+ and DC− bus bars152,154can be arranged and, in some embodiments, bonded to the bottom frame body130via permanent epoxy or similar means. An opposing wall130W on a second opposing side of the bottom frame body130includes a single notch136C formed therein. The notch136C provides a surface within which the output bus bar156can be arranged and, in some embodiments, bonded to the bottom frame body130via permanent epoxy or similar means.

Key slots137A,138A,139A can be formed opposite each notch136A,136B,136C, as shown inFIG.13B. The key slots137A,138A,139A can each be formed by two opposing ridges137B,137C,138B,138C,139B,139C that protrude away from the bottom surface130A of the body130and contact the adjacent wall130W. A corresponding key187A,188A,189A, as shown inFIG.12B, can be formed in each respective end cap187,188,189, the key187A,188A,189A being formed to fit securely within the respective key slot137A,138A,139A. This arrangement provides additional mechanical rigidity to the bus bars152,154,156to prevent damage during attachment of electrical connections to the external ends of the bus bars152,154,156.

As shown inFIG.13A, the top frame body124is formed similarly to the upper plenum body24, but instead is formed to include perimeter walls124W extending away from an upper surface124A of the body124and defining a shallow cavity124C into which the first jet orifice recess126protrudes (as this “recess” is recessed from the opposing surface of the body124, i.e. the bottom of the body124as viewed inFIG.13A). The jet orifices128are arranged on the first jet orifice recess126in the jet orifice area124J. The top frame body124includes notches129A,129B,129C that correspond to the notches136A,136B,136C of the bottom frame body130, and further includes end supports129D,129E,129F that are aligned with the ridges137B,137C,138B,138C,139B,139C and support the side of the respective end cap187,188,189opposite the side supported by the ridges137B,137C,138B,138C,139B,139C.

Illustratively, the power module assembly110can be assembled by first arranging the bus bar assembly150on the bottom frame body130such that the insulating flanges184,185,186of the bus bars152,154,156rest in the notches136A,136B,136C. The flanges184,185,186can then be epoxied to the surfaces of the notches136A,136B,136C. The top frame body124can then placed on top of the bottom frame body130, and fasteners (not shown) can be inserted through the mounting holes125,131. Epoxy can also be used between the surfaces of the notches129A,129B,129C of the top frame body124and the tops of the flanges184,185,186, and then the fasteners can be tightened so as to secure the components together, resulting in an assembled power module assembly110. As can be seen inFIG.14, the power module assembly110operates similar to the power module assembly10, with inlet coolant198flowing from an external source to jet orifice recesses126,132, through the jet orifices128,134, onto a corresponding electrical component of the bus bar assembly150, and then out of the power module assembly110via the vapor outlets127,133.

FIGS.15A and15Bshow an alternative arrangement of a bus bar assembly150′ that may be used in the power module assembly110. An important electrical design objective of the power module assemblies described herein is to minimize the parasitic induction in the DC current loop path. While the planar configuration of the bus bar assembly150shown inFIGS.9-12Bprovides many advantages, that configuration may lead to DC loop induction. One example of an alternative bus bar design that may aid in reducing and/or minimizing DC loop induction is shown inFIGS.15A and15B.

InFIGS.15A and15B, the DC+ and DC− bus bars152′,154′ are stacked vertically. The DC+ bus bar152′ remains in the same orientation as shown in the configuration ofFIGS.9-12B, while the output bus bar156′ is flipped vertically, and the DC− bus bar154′ is arranged below the DC+ bus bar152′. In order to accommodate this arrangement, the bottom frame body130may include an opening similar to the openings formed in the frame body36below the notch136A for the DC+ bus bar152′, the opening being configured to receive the DC− bus bar154′ therethrough.

A first plurality of dies160′ is arranged on an upper surface152A′ of the DC+ bus bar152′, and a second plurality of dies162′ is arranged on the bottom surface156B′ of the output bus bar156′. Ribbon bonds may be used to interconnect the dies160′ to the output bus bar156and to interconnect the dies162′ to the DC− bus bar154′. Since no dies are bonded onto the DC− bus bar154′, the cross section of the DC− bus bar154′ only needs to be large enough to carry current and the bus bar154′ can be shaped to maintain access for liquid jets to impinge on the DC+ bus bar152′. The DC+ bus bar152′ and the output bus bar156′ shown inFIGS.15A and15Balso have extended wings152W′,156W′ for additional heat spreading to reduce heat fluxes if necessary.

An extended surface191E′ could be machined on at least a portion of the main body156M′ of the output bus bar156′ and extending out onto the wing156W′. An additional extended surface152E′ could be machined on the bottom side152B′ of at least a portion of the main body152M′ of the DC+ bus bar152′ and extending out on to the wing152W′. Smaller extended surfaces156E′ and193E′ could be machined on the bottom side156B′ of the wing156W′ and the upper surface152A′ of the bus bar152′. These extended surfaces191E′,193E′,152E′,156E′ further increase available surface area for cooling purposes.

Similar to the power module assembly110, the power module assembly210includes a bus bar assembly250including two DC bus bars252,254and an output bus bar256arranged within a frame assembly223. Unlike the top and bottom frame bodies124,130of the power module assembly110, the top and bottom frame bodies224,230are not made of metal, but instead are made of a non-conductive material such as a polymer, which may include, for example, Nylon or PEEK. Because the top and bottom frame bodies224,230are not conductive, the bus bars252,254,256can be arranged directly in contact with the bodies224,230, thus eliminating the need for the insulating flanges184,185,186and end caps187,188of the power module assembly110. It is noted that the power module assembly210shown inFIGS.16-18may be referred to as another type of “floating bus power module” similar to the floating bus power modules shown inFIGS.1-15B.

The bus bar assembly250is formed substantially similarly to the bus bar assembly150, but instead does not include the insulating flanges184,185,186and end caps187,188, as described above. Instead, each bus bar252,254,256includes holes284at opposing sides of the bus bar that are formed to align with corresponding pins285of the bottom frame body230in order to secure the bus bar252,254,256in position with respect to the bottom frame body230. As can be seen inFIG.17, each bus bar252,254,256includes two holes284through which the pins285extend.

Another difference between the bus bar assembly150and the bus bar assembly250is that the PCB264is formed to extend over the DC− bus bar254in addition to the DC+ bus bar252and the output bus bar256. The PCB264may also be formed to rest on and be secured to stepped pegs264A that extend upwardly from a bottom surface230S of the bottom frame body230. The top ends of the pegs264A are stepped and extend through holes264B formed in the four corners of the PCB264so as to allow the PCB264to rest on the ledges of the stepped portions of the pegs264A. Other suitable methods of supporting the PCB264are contemplated, such as supporting the PCB264directly on the bus bars252,254,256or via other supporting structures within the frame assembly223.

As can be seen inFIGS.17and18, the top and bottom frame bodies224,230may be formed substantially similarly to the top and bottom frame bodies124,130, for example, with regard to their shape, size, and arrangement of the orifices228,234and vapor outlets227,233. The bottom frame body230differs in that the walls230W of the body230include a plurality of holes286formed in the top surface of the wall230W around the perimeter of the body230. The holes286are configured to receive the pins285which extend through and secure the bus bars252,254,256to the bottom frame body230. The walls230W also include recesses283formed therein to receive free ends of the bus bars252,254,256, as opposed to the insulating end caps187,188described herein.

Another embodiment of a power module assembly310is shown inFIGS.19A-23. The power module assembly310is similar to the power module assemblies10,110,210shown inFIGS.1-18and described herein. Accordingly, similar reference numbers in the300series indicate features that are common between the power module assembly310and the power module assemblies10,110,210. The descriptions of the power module assemblies10,110,210are incorporated by reference to apply to the power module assembly310, except in instances when they conflict with the specific description and the drawings of the power module assembly310.

The power module assembly310is constructed similarly to the power module assembly10ofFIGS.1-8, in particular to include a central, main frame body336and top and bottom lids324,330enclosing the main frame body336. The top and bottom lids324,330include the jet orifices328,334through which coolant398,399is directed to the bus bar assembly350, as will be described in greater detail below.

The power module assembly310differs from the power modules10,110,210in that the module assembly310is a “folded bus bar configuration,” which includes the DC+ and DC− bus bars352,354in an aligned, stacked arrangement on one side of the main frame body336, and the output bus bar356on an opposing side of the main frame body336, as shown inFIGS.19A-21B. The folded bus bar configuration of the power module assembly310may provide certain advantages over the floating bus power module of the power module assemblies10,110,210. For example, although the floating bus power module of the power module assemblies10,110,210may provide design simplicity and ease of manufacturing benefits, the folded bus bar configuration of the power module assembly310may reduce noise and losses due to parasitic inductance, and can reduce the size of the DC current path through the module, which would likely reduce losses that may be caused by such a large DC current path. This could also lead to increased switching performance.

As shown inFIGS.19A-21B, the main frame body336is formed similarly to the frame body36, in particular having walls336W that define a large central opening3360within which the components of the bus bar assembly350are housed. The main frame body336further includes ridges336A that extend from opposing walls336W1,336W2toward each other and into the opening3360. The ridges336A define an output bus bar opening336B between the wall336W3and a plane extending between the ends of the ridges336A and a DC+ bus bar opening336C between the wall336W4and the plane extending between the ends of the ridges336A. Opposing ends of the output bus bar356are configured to be tightly surrounded and secured within the boundaries of the output bus bar opening336B, and opposing ends of the DC+ bus bar352are configured to be tightly surrounded and secured within the boundaries of the DC+ bus bar opening336C. In some embodiments, ledges336B1,336C1,336B2,336C2may be arranged within the ends of the output bus bar opening336B and/or the DC+ bus bar opening336C on which the bus bars352,356rest, as shown inFIG.20.

Unlike the top and bottom frame bodies124,130of the power module assembly110, the main frame body336, as well as the top and bottom lids324,330, are not made of metal, but instead are made of a non-conductive material such as a polymer, which may include, for example, Nylon or PEEK. Because the top and bottom lids324,330and the main frame body336are not conductive, the bus bars352,354,356can be arranged directly in contact with the lids324,330and the main frame body336, thus eliminating the need for the insulating flanges184,185,186and end caps187,188of the power module assembly110.

In some embodiments, similar to the frame body36, the main frame body336further includes seal grooves340,341extending generally around a perimeter of an outwardly facing surface3405,3415of the main frame body336, respectively, as shown inFIGS.21A and21B. The seal grooves340,341each receive a seal therein (not shown, similar to the O-ring seals described herein). The seals hermetically seal the bus bar assembly350from the outside environment.

As shown in detail in19B-21B, the bus bar assembly350includes two DC bus bars352,354and an output bus bar356arranged within the main frame body336. The bus bars352,354,356are shaped differently than the bus bars in other embodiments described herein, and are arranged differently with respect to each other as well. For example, as can be seen inFIG.21A, the DC+ bus bar352is arranged in parallel with the output bus bar356, with each extending along a longitudinal extent of the main frame body336. In some embodiments, the DC+ bus bar352may be wider than the output bus bar356.

With reference toFIG.21A, the DC+ bus bar352may include a first plurality of dies360arranged on an upper surface352A of the bus bar352, and may include extended surfaces390E formed of copper and extending from each of the dies360. A first PCB364A may be arranged on the upper surface352A. The dies360may be interconnected with the output bus bar356via copper ribbon bonds372, as shown inFIG.21A. The output bus bar356may include extended surfaces392E that extend away from the upper surface356A of the bus bar356.

With reference toFIG.21B, the output bus bar356may include a second plurality of dies362arranged on a bottom surface356B of the bus bar356, and may include extended surfaces356E formed of copper and extending from each of the dies362. A second PCB364B may be arranged on the bottom surface356B. The dies362may be interconnected with the DC+ bus bar352via copper ribbon bonds370, as shown inFIG.21B. The DC+ bus bar352may include extended surfaces352E that extend away from the bottom surface352B of the bus bar352. As shown inFIG.20, the DC− bus bar354is arranged below the DC+ bus bar352and the output bus bar356, and is formed to be much thinner than the bus bars352,356, and can include end flanges354A for supporting the DC− bus bar354on platforms332D of the bottom lid330. By reducing the size of the DC− bus bar354, the larger DC+ bus bar352and output bus bar356, which experience the majority of heat losses in the module assembly310, can be exposed directly to the coolant398,399.

The bus bar assembly350further includes bus bar extensions353,355,357that extend out of the main frame body336and are configured to be electrically connected to external terminals, as shown in detail inFIG.20. Each bus bar extension353,355,357includes an end tab353A,355A,357A and an extension rod353B,355B,357B extending from the end tab353A,355A,357A, the end of the extension rod353B,355B,357B opposite the end tab353A,355A,357A being a threaded end353C,355C,357C.

Each bus bar extension353,355,357is coupled to a respective bus bar352,354,356by screwing the threaded end353C,355C,357C into a corresponding threaded bores352C,354C,356C formed in the bus bar352,354,356, as shown inFIGS.20-21B. When assembled, the extension rod353B,355B,357B extends through a corresponding hole338A,338B,338C formed in the wall336W of the main frame body336. Standard O-ring seals (not shown) may be arranged in the holes338A,338B,338C to hermetically seal the bus bar assembly350from the outside environment.

As shown inFIG.20, the main frame body336further includes a first tab cover342that surrounds the output bus bar end tab357A on a first tab cover ledge342A formed within the tab cover342. The main frame body336also includes a second tab cover346that surrounds the DC+ and DC− bus bar end tabs353A,355A. A second tab cover ledge346A formed within the tab cover346extends between the DC+ and DC− bus bar end tabs353A,355A. This second tab cover ledge346A can provide insulation between the DC+ and DC− bus bar end tabs353A,355A.

As shown inFIGS.22A and22B, the top and bottom lids324,330can be formed to include jet orifices328A,328B,332A,332B similar to the jet orifices of the other embodiments described herein. In particular, the top lid324may be formed as a planar plate that includes jet orifices328A,328B formed therethrough, as well as a first vapor outlet327. A first plurality of jet orifices328A align with the extended surfaces392E of the output bus bar356, and a second plurality of jet orifices328B are spaced apart from the first plurality of jet orifices328A and align with the extended surfaces390E of the first plurality of dies360. The top lid324may further include multiple bus bar retention platforms329configured to contact and secure the bus bars352,356in a fixed position within the main frame body336.

Similar to the top lid324, the bottom lid330may be formed as a planar plate that includes jet orifices332A,332B formed therethrough, as well as a second vapor outlet333. The bottom lid330includes two first bus bar retention platforms332C that are generally aligned with the DC+ bus bar352such that the DC+ bus bar352can rest on and be secured by the platforms332C. Each platform332C can include some of the jet orifices332A, which align with the extended surfaces352E of the DC+ bus bar352. Additional platforms332D may extend away from the first bus bar retention platforms332C and can support the DC− bus bar354thereon, as described above.

The bottom lid330further includes a second bus bar retention platform332E spaced apart from the two first bus bar retention platforms332C, as shown inFIG.22B. The second plurality of jet orifices332B are arranged on the second bus bar retention platform332E and align with the extended surfaces356E of the second plurality of dies362arranged on the bottom surface356B of the output bus bar356.

In some embodiments, the power module assembly310may be assembled by placing the DC+ and output bus bars352,356into the main frame body336before the corresponding bus bar extensions353,357are inserted into the holes338A,338B and threaded to the bus bars352,356. The partially assembled module assembly310is then be inverted and the DC− bus bar354is placed into the main frame body336. The locating features machined into the bottom lid330, such as the platforms332C,332D,332E, allow the DC− bus bar354to slide along the length of the module assembly310, providing clearance for the DC− bus bar extension355to be threaded into the bus bar354before sliding into its final position. The platforms329,332C,332D,332E machined into the top and bottom lids324,330provide additional bus bar352,354,356retention once die bonding is complete. As can be seen inFIG.23, the power module assembly310operates similar to the power module assembly10, with inlet coolant398flowing from an external source to the jet orifices328A,328B,332A,332B and then onto a corresponding electrical component of the bus bar assembly350, and then out of the power module assembly310via the vapor outlets327,333.

FIG.24shows a comparison of finite element analysis results of parasitic inductance for the bus bar assembly shown inFIGS.9-18(“floating bus power module”) and the bus bar assembly shown inFIGS.19A-23(“folded bus bar configuration”). This analysis was carried out using Ansys Q3D software. The CAD models for each concept were imported into Ansys and appropriately de-featured to retain the critical features of the geometry while improving simulation speed. Both modules were configured with all MOSFET dies in the conducting state, and the impedance was evaluated from the DC+ terminal to the DC− terminal. The resulting FEA-predicted impedance data was used to generate a plot of commutation inductance over frequency for each module concept. Commutation inductance is widely considered to be the most important parasitic figure of merit for WBG-based power modules.

A summary of the results400of this analysis is presented inFIG.24. As expected, the floating bus-bar concept (line410) demonstrates higher commutation inductance than the folded bus-bar concept (line420) across the entire frequency range considered in this study (1 Hz-100 MHz). The inductance trend over frequency for both designs correspond to the expected profile for this type of structure, with two regions of relatively constant inductance separated by a transition region in the high kHz range [1]. At low frequency, the folded bus-bar concept achieves a reduction of approximately 32% in commutation inductance relative to the floating bus-bar concept (16.3 nH vs. 24.0 nH). At high-frequency, the folded bus-bar concept achieves a reduction of approximately 23% in commutation inductance relative to the floating bus-bar concept (10.3 nH vs. 13.4 nH). This reduction is expected to yield at least some benefit in terms of switching performance.

Electric power modules should be cooled to function properly. In power electronic architectures where electrically conductive fluids are used as the coolant medium, voltage standoff requirements between the die, bus bars, and eventual coolant medium should be established.

In comparative module architectures, this is accomplished using the expensive direct bond copper (DBC) material processing approach, which grows copper on a ceramic substrate providing an electrically conductive pathway with the necessary voltage standoff between internal electrical component and external cooling. Dies are soldered to the DBC layer which are then attached to a copper baseplate to improve heat transfer. These multiple interface layers increase thermal resistance between the semiconductor die and cooling medium and result in increased electrical losses due to limitations in growth size of the copper layer.

If, instead, a dielectric fluid is used as the coolant medium, the need for voltage isolation between the internal electrical components and the coolant medium is eliminated. This may be used in cases where the heat sink is integral to the current carrying path, such as in press-pack packaging. By using dielectric coolants in comparative module architectures, several layers within the module can be removed, including the ceramic insulator, the baseplate, and the associated solder interfaces between these layers. This results in a significant reduction of thermal impedance between the die junction and the coolant medium. In addition, because a DBC layer is no longer used, the thickness of the copper layers which the dies are attached to are not restricted by the DBC manufacturing process. Thicker copper layers reduce electrical resistance, maintain heat spreading from the dies, and increase thermal mass for transient thermal events. In comparative module architectures, the DBC layer is one of the most expensive components, comprising up to 20% of the total module cost, and its elimination is therefore also attractive from a cost reduction standpoint.

The following numbered clauses include embodiments that are contemplated and non-limiting:

Clause 1. A power module assembly, comprising a frame assembly including an upper frame body and a lower frame body coupled to the upper frame body, at least one of the upper and lower frame bodies including at least one first jet orifice formed therethrough, the at least one first jet orifice configured to receive coolant at a first end of the at least one first jet orifice and discharge the coolant at a second end opposite the first end, the upper and lower frame bodies at least partially defining a chamber therebetween.

Clause 2. The power module assembly of clause 1, any other clause, or combination of clauses, further comprising a bus bar assembly arranged in the chamber and including a first bus bar arranged adjacent to the second end of the at least one first jet orifice.

Clause 3. The power module assembly of clause 1, any other clause, or combination of clauses, wherein the at least one first jet orifice is configured to discharge the coolant directly onto the first bus bar so as to reduce an operating temperature of the first bus bar.

Clause 4. The power module assembly of clause 1, any other clause, or combination of clauses, wherein the first bus bar extends at least partially away from the chamber and is exposed to an outside environment such that at least a portion of the first bus bar is configured to electrically connect to an external electronic device.

Clause 5. The power module assembly of clause 4, any other clause, or combination of clauses, wherein the at least one of the upper and lower frame bodies including at least one first jet orifice further includes a first vapor outlet formed as an opening therein.

Clause 6. The power module assembly of clause 5, any other clause, or combination of clauses, wherein a first portion of the coolant is configured to flow from the at least one first jet orifice, over and around the first bus bar, transfer heat from the first bus bar to the coolant, and subsequently flow away from the first bus bar and the at least one of the upper and lower frame bodies via the first vapor outlet.

Clause 7. The power module assembly of clause 6, any other clause, or combination of clauses, wherein the at least one of the upper and lower frame bodies including at least one first jet orifice is the upper frame body.

Clause 8. The power module assembly of clause 7, any other clause, or combination of clauses, wherein the lower frame body includes at least one second jet orifice configured to receive the coolant at a first end of the at least one second jet orifice and discharge the coolant at a second end opposite the first end.

Clause 9. The power module assembly of clause 8, any other clause, or combination of clauses, wherein the first bus bar is arranged adjacent to the second end of the at least one second jet orifice.

Clause 10. The power module assembly of clause 9, any other clause, or combination of clauses, wherein the at least one second jet orifice is configured to discharge the coolant directly onto the first bus bar at a second location different than a first location at which the at least one first jet orifice is configured to discharge the coolant.

Clause 11. The power module assembly of clause 8, any other clause, or combination of clauses, wherein the bus bar assembly further includes a second bus bar arranged adjacent to the first bus bar.

Clause 12. The power module assembly of clause 11, any other clause, or combination of clauses, wherein the at least one second jet orifice is configured to discharge the coolant directly onto the second bus bar so as to reduce an operating temperature of the second bus bar.

Clause 13. The power module assembly of clause 12, any other clause, or combination of clauses, wherein the second bus bar extends at least partially away from the chamber and is exposed to an outside environment such that at least a portion of the second bus bar is configured to electrically connect to an external electronic device.

Clause 14. The power module assembly of clause 8, any other clause, or combination of clauses, wherein the lower frame body further includes a second vapor outlet.

Clause 15. The power module assembly of clause 14, any other clause, or combination of clauses, wherein a second portion of the coolant is configured to flow from the at least one second jet orifice, over and around the first bus bar, transfer heat from the first bus bar to the coolant, and subsequently flow away from the first bus bar and the lower frame body via the second vapor outlet.

Clause 16. The power module assembly of clause 4, any other clause, or combination of clauses, wherein the bus bar assembly further includes a second bus bar arranged adjacent to the first bus bar.

Clause 17. The power module assembly of clause 16, any other clause, or combination of clauses, wherein the first bus bar is a DC+ bus bar and the second bus bar is an output bus bar.

Clause 18. The power module assembly of clause 17, any other clause, or combination of clauses, wherein the DC+ bus bar includes a first plurality of dies arranged on an upper surface of the DC+ bus bar.

Clause 19. The power module assembly of clause 18, any other clause, or combination of clauses, wherein the output bus bar includes a second plurality of dies arranged on an upper surface of the output bus bar.

Clause 20. The power module assembly of clause 19, any other clause, or combination of clauses, wherein the bus bar assembly further includes at least one first electrical connector connecting the first plurality of dies to the output bus bar.

Clause 21. The power module assembly of clause 20, any other clause, or combination of clauses, wherein the at least one first electrical connector is one of a wire bond or a ribbon bond.

Clause 22. The power module assembly of clause 20, any other clause, or combination of clauses, wherein the bus bar assembly further includes a third bus bar arranged adjacent to the output bus bar such that the output bus bar is arranged between the DC+ bus bar and the third bus bar.

Clause 23. The power module assembly of clause 22, any other clause, or combination of clauses, wherein the third bus bar is a DC− bus bar, and wherein the bus bar assembly further includes at least one second electrical connector connecting the second plurality of dies to the DC− bus bar.

Clause 24. The power module assembly of clause 23, any other clause, or combination of clauses, wherein the at least one second electrical connector is one of a wire bond or a ribbon bond.

Clause 25. The power module assembly of clause 24, any other clause, or combination of clauses, wherein a slot is formed in an upper surface of the DC− bus bar, and wherein a terminal end of the at least one second electrical connector is arranged in the slot.

Clause 26. The power module assembly of clause 4, any other clause, or combination of clauses, wherein at least one of an upper surface of the first bus bar or a lower surface of the first bus bar opposite the upper surface is arranged adjacent to and faces the second end of the at least one first jet orifice.

Clause 27. The power module assembly of clause 26, any other clause, or combination of clauses, wherein the at least one of an upper surface or the lower surface includes at least one surface enhancement including one or more of extended surfaces, porous coatings, or increased surface roughness in order to increase heat transfer efficiency between the coolant and the first bus bar.

Clause 28. The power module assembly of clause 18, any other clause, or combination of clauses, wherein the bus bar assembly further includes at least one thermally conductive block arranged above and soldered to at least one die of the first plurality of dies that is configured increase heat transfer efficiency between the coolant and the first bus bar and increase heat spreading.

Clause 29. The power module assembly of clause 28, any other clause, or combination of clauses, wherein the at least one thermally conductive block is soldered to a source pad of the at least one die.

Clause 30. The power module assembly of clause 29, any other clause, or combination of clauses, wherein first bus bar is comprised of copper.

Clause 31. The power module assembly of clause 30, any other clause, or combination of clauses, wherein the at least one thermally conductive block is comprised of copper.

Clause 32. The power module assembly of clause 28, any other clause, or combination of clauses, wherein the at least one thermally conductive block includes a plurality of thermally conductive blocks.

Clause 33. The power module assembly of clause 32, any other clause, or combination of clauses, wherein each thermally conductive block of the plurality of thermally conductive blocks is arranged above and is soldered to a corresponding die of the first plurality of dies.

Clause 34. The power module assembly of clause 28, any other clause, or combination of clauses, wherein the at least one thermally conductive block includes a single thermally conductive blocks.

Clause 35. The power module assembly of clause 34, any other clause, or combination of clauses, wherein the single thermally conductive block extends across all dies of the first plurality of dies.

Clause 36. The power module assembly of clause 28, any other clause, or combination of clauses, wherein the at least one thermally conductive block includes at least one surface enhancement including one or more of extended surfaces, porous coatings, or increased surface roughness in order to increase heat transfer efficiency between the coolant and the first bus bar.

Clause 37. The power module assembly of clause 6, any other clause, or combination of clauses, wherein the lower frame body includes a bottom surface and bottom walls extending around a perimeter of the bottom surface.

Clause 38. The power module assembly of clause 37, any other clause, or combination of clauses, wherein the upper frame body includes an upper surface and upper walls extending around a perimeter of the upper surface.

Clause 39. The power module assembly of clause 38, any other clause, or combination of clauses, wherein the upper walls, the upper surface, the bottom walls, and the bottom surface define the chamber within which the bus bar assembly is arranged.

Clause 40. The power module assembly of clause 39, any other clause, or combination of clauses, wherein the at least one first jet orifice and the first vapor outlet extend through the upper surface.

Clause 41. The power module assembly of clause 40, any other clause, or combination of clauses, wherein the bus bar assembly further includes a second bus bar arranged adjacent to the first bus bar.

Clause 42. The power module assembly of clause 41, any other clause, or combination of clauses, wherein the lower frame body includes a first notch formed in a first wall of the bottom walls configured to receive the first bus bar and a second notch formed in a second wall of the bottom walls opposite the first wall and configured to receive the second bus bar.

Clause 43. The power module assembly of clause 42, any other clause, or combination of clauses, wherein the upper frame body includes a third notch formed in a third wall of the upper walls aligned with the first notch so as to form a first bus bar opening in the frame assembly and configured to receive the first bus bar and a fourth notch formed in a fourth wall of the upper walls opposite the third wall, the fourth notch aligned with the second notch so as to form a second bus bar opening in the frame assembly, and configured to receive the second bus bar.

Clause 44. The power module assembly of clause 43, any other clause, or combination of clauses, wherein a first insulating flange is arranged within the first bus bar opening so as to insulate the first bus bar from the upper and lower frame bodies.

Clause 45. The power module assembly of clause 44, any other clause, or combination of clauses, wherein a second insulating flange is arranged within the second bus bar opening so as to insulate the second bus bar from the upper and lower frame bodies.

Clause 46. A power module assembly, comprising a frame assembly including a first frame body including a first jet orifice formed therethrough and a second frame body coupled to the first frame body.

Clause 47. The power module assembly of clause 46, any other clause, or combination of clauses, further comprising a bus bar assembly arranged at least partially within the second frame body and including a first bus bar arranged adjacent to an outlet of the first jet orifice.

Clause 48. The power module assembly of clause 47, any other clause, or combination of clauses, wherein the first jet orifice is configured to discharge coolant from the outlet directly onto the first bus bar so as to reduce an operating temperature of the first bus bar.

Clause 49. The power module assembly of clause 48, any other clause, or combination of clauses, wherein the first bus bar extends at least partially away from the second frame body and is exposed to an outside environment such that at least a portion of the first bus bar is configured to electrically connect to an external electronic device.

Clause 50. The power module assembly of clause 49, any other clause, or combination of clauses, wherein the bus bar assembly further includes a second bus bar arranged adjacent to the first bus bar.

Clause 51. The power module assembly of clause 50, any other clause, or combination of clauses, wherein the first bus bar is a DC+ bus bar and the second bus bar is an output bus bar.

Clause 52. The power module assembly of clause 51, any other clause, or combination of clauses, wherein the DC+ bus bar includes a first plurality of dies arranged on an upper surface of the DC+ bus bar.

Clause 53. The power module assembly of clause 52, any other clause, or combination of clauses, wherein the output bus bar includes a second plurality of dies arranged on an upper surface of the output bus bar.

Clause 54. The power module assembly of clause 53, any other clause, or combination of clauses, wherein the bus bar assembly further includes at least one first electrical connector connecting the first plurality of dies to the output bus bar.

Clause 55. The power module assembly of clause 54, any other clause, or combination of clauses, wherein the at least one first electrical connector is one of a wire bond or a ribbon bond.

Clause 56. The power module assembly of clause 54, any other clause, or combination of clauses, wherein the bus bar assembly further includes a third bus bar arranged adjacent to the output bus bar such that the output bus bar is arranged between the DC+ bus bar and the third bus bar.

Clause 57. The power module assembly of clause 56, any other clause, or combination of clauses, wherein the third bus bar is a DC− bus bar.

Clause 58. The power module assembly of clause 57, any other clause, or combination of clauses, wherein the bus bar assembly further includes at least one second electrical connector connecting the second plurality of dies to the DC− bus bar.

Clause 59. The power module assembly of clause 58, any other clause, or combination of clauses, wherein the at least one second electrical connector is one of a wire bond or a ribbon bond.

Clause 60. The power module assembly of clause 59, any other clause, or combination of clauses, wherein the at least one second electrical connector is one of a wire bond or a ribbon bond.

Clause 61. The power module assembly of clause 60, any other clause, or combination of clauses, wherein a slot is formed in an upper surface of the DC− bus bar.

Clause 62. The power module assembly of clause 61, any other clause, or combination of clauses, wherein a terminal end of the at least one second electrical connector is arranged in the slot.

Clause 63. The power module assembly of clause 48, any other clause, or combination of clauses, wherein the second frame body defines a large opening within which the bus bar assembly is housed.

Clause 64. The power module assembly of clause 63, any other clause, or combination of clauses, wherein the frame assembly further includes a third frame body.

Clause 65. The power module assembly of clause 64, any other clause, or combination of clauses, wherein the first frame body and the third frame body are arranged on opposing sides of the second frame body so as to enclose the large opening and define a chamber therewithin.

Clause 66. The power module assembly of clause 63, any other clause, or combination of clauses, wherein the first bus bar is arranged entirely within the large opening.

Clause 67. The power module assembly of clause 66, any other clause, or combination of clauses, wherein the bus bar assembly further includes a second bus bar arranged adjacent to the first bus bar and arranged entirely within the large opening.

Clause 68. The power module assembly of clause 67, any other clause, or combination of clauses, wherein the bus bar assembly further includes a first bus bar extension coupled to and extending away from the first bus bar and a second bus bar extension coupled to and extending away from the second bus bar.

Clause 69. The power module assembly of clause 68, any other clause, or combination of clauses, wherein at least a portion of the first bus bar extension extends through a first wall of the second frame body.

Clause 70. The power module assembly of clause 69, any other clause, or combination of clauses, wherein at least a portion of the second bus bar extension extends through a second wall of the second frame body opposite the first wall.

Clause 71. The power module assembly of clause 70, any other clause, or combination of clauses, wherein a longitudinal extent of each of the first and second bus bars extends perpendicular to a longitudinal extent of each of the first and second bus bar extensions.

Clause 72. The power module assembly of clause 70, any other clause, or combination of clauses, wherein the at least a portion of the first and second bus bar extensions are threadably engaged with corresponding threaded bores formed in the first and second bus bars, respectively.

Clause 73. A method comprises coupling a lower frame body to an upper frame body to form a frame assembly, the upper and lower frame bodies at least partially defining a chamber therebetween.

Clause 74. The method of clause 73, any other clause, or combination of clauses, further comprising forming at least one first jet orifice through at least one of the upper and lower frame bodies.

Clause 75. The method of clause 74, any other clause, or combination of clauses, further comprising directing coolant to a first end of the at least one first jet orifice.

Clause 76. The method of clause 75, any other clause, or combination of clauses, further comprising arranging a bus bar assembly in the chamber, the bus bar assembly including a first bus bar arranged adjacent to a second end of the at least one first jet orifice opposite the first end.

Clause 77. The method of clause 76, any other clause, or combination of clauses, further comprising discharging the coolant at the second end of the at least one first jet orifice directly onto the first bus bar so as to reduce an operating temperature of the first bus bar.

Clause 78. The method of clause 77, any other clause, or combination of clauses, wherein the first bus bar extends at least partially away from the chamber and is exposed to an outside environment such that at least a portion of the first bus bar is configured to electrically connect to an external electronic device.

Clause 79. The method of clause 78, any other clause, or combination of clauses, further comprising directing a first portion of the coolant from the at least one first jet orifice over and around the first bus bar.

Clause 80. The method of clause 79, any other clause, or combination of clauses, further comprising transferring heat from the first bus bar to the coolant.

Clause 81. The method of clause 80, any other clause, or combination of clauses, subsequently directing the coolant away from the first bus bar and at least one of the upper and lower frame bodies via a first vapor outlet formed in the at least one of the upper and lower frame bodies.

Clause 82. The method of clause 81, any other clause, or combination of clauses, wherein the at least one of the upper and lower frame bodies including at least one first jet orifice is the upper frame body.

Clause 83. The method of clause 82, any other clause, or combination of clauses, wherein the lower frame body includes at least one second jet orifice configured to receive the coolant at a first end of the at least one second jet orifice and discharge the coolant at a second end opposite the first end.

Clause 84. The method of clause 83, any other clause, or combination of clauses, wherein the first bus bar is arranged adjacent to the second end of the at least one second jet orifice.

Clause 85. The method of clause 84, any other clause, or combination of clauses, further comprising discharging, via the at least one second jet orifice, the coolant directly onto the first bus bar at a second location different than a first location at which the at least one first jet orifice is configured to discharge the coolant.

Clause 86. The method of clause 83, any other clause, or combination of clauses, wherein the bus bar assembly further includes a second bus bar arranged adjacent to the first bus bar.

Clause 87. The method of clause 86, any other clause, or combination of clauses, further comprising discharging, via the at least one second jet orifice, the coolant directly onto the second bus bar so as to reduce an operating temperature of the second bus bar.