Patent Application
20240162117
This disclosure relates to cooling systems for power electronics assemblies.
Effective thermal management of power electronics assemblies or packages is needed for increasing power density and improving reliability in many applications (e.g., in electric drive vehicles). For example, electric and hybrid electric vehicles utilize high voltage battery packs or fuel cells that deliver high power direct current to drive vehicle motors, electric traction systems and other vehicle systems. In addition, these vehicles can include power electronics assemblies (e.g., inverters) to convert the direct current provided by, for example, the battery packs, to alternating current for use by electric motors and other electric devices and systems of the vehicle. A power electronics assembly can include heat-generating semiconductor devices such an insulated-gate bipolar transistor (IGBT) and a fast recovery diode (FRD). Compact packaging of power electronics assemblies creates thermal management challenges that need to be addressed for power-dense systems.
In a general aspect, a package includes a frame having a first sidewall and a second sidewall opposite the first sidewall, the frame having at least one opening in the first sidewall and at least one opening in the second sidewall. A first power electronics module covers the at least one opening in the first sidewall with a surface of a substrate in the first power electronics module being exposed to an interior of the frame through the at least one opening in the first sidewall, and a second power electronics module covers the at least one opening in the second sidewall with a surface of a substrate in the second power electronics module being exposed to an interior of the frame through the at least one opening in the second sidewall. The first sidewall, the surface of the substrate of the first power electronics module, the second sidewall, and the surface of the substrate of the second power electronics module collectively define a cooling fluid channel through the frame.
In a general aspect, a package includes a frame having a cooling fluid channel therethrough. The cooling fluid channel is formed between a first sidewall and a second sidewall opposite the first sidewall. The frame includes a first plurality of openings disposed in a first row in the first sidewall alongside the cooling fluid channel and a second plurality of openings disposed in a second row in the second sidewall alongside the cooling fluid channel opposite the first sidewall. A first plurality of power electronics modules are disposed alongside the first sidewall over the first plurality of openings in the first sidewall with each of the first plurality of openings exposing a surface of a substrate in a corresponding one of the first plurality of power electronics modules to the cooling fluid channel in the frame. A second plurality of power electronics modules are disposed alongside the second sidewall over the second plurality of openings in the second sidewall with each of the second plurality of openings exposing a surface of a substrate in a corresponding one of the second plurality of power electronics modules to the cooling fluid channel in the frame.
In a general aspect, a method, includes forming a cooling fluid channel between a first sidewall and a second sidewall in a frame. The frame includes at least one opening in the first sidewall alongside the cooling fluid channel and at least one opening in the second sidewall alongside the cooling fluid channel. The method further includes disposing a first power electronics module to cover the at least one opening in the first sidewall with a surface of a substrate in the first power electronics module being exposed to the cooling fluid channel in the frame through the at least one opening in the first sidewall, and disposing a second power electronics module to cover the at least one opening in the second sidewall with a surface of a substrate in the second power electronics module being exposed to the cooling fluid channel in the frame through the at least one opening in the second sidewall.
In a general aspect, a package includes a frame having a cooling fluid channel therethrough. The cooling fluid channel is formed between a first sidewall and a second sidewall opposite the first sidewall. The frame has at least one opening in the first sidewall alongside the cooling fluid channel and at least one opening in the second sidewall alongside the cooling fluid channel. A first power electronics module covers the at least one opening in the first sidewall with a surface of a substrate in the first power electronics module being exposed to the cooling fluid channel in the frame through the at least one opening in the first sidewall, and a second power electronics module covers the at least one opening in the second sidewall with a surface of a substrate in the second electronics module being exposed to the cooling fluid channel in the frame through the at least one opening in the second sidewall.
In the drawings, which are not necessarily drawn to scale, like reference symbols and or alphanumeric identifiers may indicate like and/or similar components (elements, structures, etc.) in different views. The drawings illustrate, by way of example, but not by way of limitation, various implementations discussed in the present disclosure. Reference symbols and or alphanumeric identifiers shown in one drawing may not be repeated for the same, and/or similar elements in related views in other drawings. Reference symbols and or alphanumeric identifiers that are repeated in multiple drawings may not be specifically discussed with respect to each of those drawings but are provided for convenience in cross reference between related views. Also, not all like elements in the drawings are specifically referenced with a reference symbol and or an alphanumeric identifier when multiple instances of an element are illustrated.
The present disclosure is directed a heat management system for a power electronics package. The power electronics package (e.g., an integrated power module package) may be modular and may include multiple power electronics modules (or sub-packages).
A power electronics module (or sub-package) may, for example, include power electronic devices (e.g., silicon-controlled rectifiers (SCRs), insulated-gate bipolar transistors (IGBTs), field effect transistors (FETs), etc.) to provide AC power to loads. The power electronic devices can be silicon based or based on wide band gap (WBG) semiconductors. The power electronic devices can generate heat which has to be removed to keep the devices at acceptable operating temperatures. For high power density applications (e.g., power density at or greater than 240 kW) the demands for efficient heat removal can be severe.
In example implementations, the power electronics module may include at least a semiconductor die (e.g., an IGBT and/or an FRD). The semiconductor die may be mounted on a top surface of substrate (e.g., a printed circuit board, a direct bonded metal (DBM) substrate, a direct bonded copper (DBC) substrate, etc.). The semiconductor die or dies may be packaged (e.g., encapsulated in a molding compound), for example, as a single side direct cooled (SSDC) power electronics module with signal pins and power terminals extending from the module. The power electronics module may have a width (WM) and a height (HM) along a surface of the substrate, and a thickness (TM) perpendicular (generally perpendicular) to the substrate (in the direction of the semiconductor die mounted on the top surface of substrate). In example implementations, for an IGBT power electronics module, height HM and width WM may be measured in centimeters, while thickness TM may be in the range of a few millimeters or less.
Heat generated by the semiconductor die or dies flows perpendicularly through the substrate for dissipation from a bottom surface of the substrate. In some instances, a heat sink (e.g., a baseplate, or a baseplate with fins) may be attached to the bottom surface of the substrate to aid in dispersal of the heat generated in the power electronics module. The baseplate with fins may include pin fins (i.e., fins shaped like pins). The power electronics module may be further configured with either forced air and liquid cooled options to remove the heat generated in the power electronics module.
In example implementations, an integrated power electronics package may be modular and may include multiple power electronics modules (or sub-packages) in a single package for use in various applications (e.g., three-phase inverters; DC/DC convertors; choppers; half or full bridge; and power supply applications, etc.). For example, an integrated power electronics package for many automotive applications may integrate six IGBT modules in a 6-pack configuration. The multiple power electronics modules (or sub-packages) (e.g., the six IGBT modules) may be placed electrically in parallel.
In example implementations, the integrated power electronics package may include (or be integrated with) a heat management system. The heat management system may utilize a cooling fluid (e.g., water, or a water-glycol mixture) to remove heat generated in the integrated power electronics package. The heat management system may include a manifold or jacket (e.g., a tube or container) including a cooling fluid passageway or channel. The multiple power electronics modules of the integrated power electronics package can be disposed on a side or sides of the cooling fluid channel in contact with the cooling fluid. In example implementations, the manifold or jacket may have a rectangular cylinder shape with a length L between an input end and an output end, and a width W and a height H in a cross-section perpendicular to the length. The manifold or jacket including the cooling fluid channel may be formed in a three-dimensional rectangular frame (a hollow rectangular frame) with an input port and an output port disposed in opposing end plates of the frame. The frame may include windows (e.g., rectangular openings) in a sidewall of the frame. The power electronic modules may be placed over the windows to seal the windows (e.g., using O-rings or other elastomers) and to thereby confine the cooling fluids to the cooling fluid channel within the three-dimensional rectangular frame.
A stream of the cooling fluid can enter the manifold through the inlet port, pass over the multiple power electronics modules placed along the cooling fluid channel in the manifold to remove heat generated by the power electronics modules, and exit the manifold through the output port. The stream of the cooling fluid may be driven by a recirculating pump (not shown).
In some example implementations, an integrated power electronics package may include a multiplicity of power electronics modules placed in sequence in a row. The widths of the multiplicity of power electronics modules placed in sequence in the row in the integrated power electronics package may, for example, extend sequentially module-by-module along a direction of the row while the heights and thicknesses of the power electronics modules may be perpendicular to the direction of the row, in accordance with the principles of the present disclosure.
The multiplicity of power electronics modules placed in sequence in the row may be supported on the frame. The frame may extend in the direction of the row and have windows (openings) exposing the bottom surfaces of the substrates (on the front surfaces of which semiconductor dies are mounted in the power electronics modules) to the interior of the frame (i.e., the cooling fluid channel). Baseplates (e.g., baseplates with pin-fins) if attached to the bottom surfaces of the substrates may protrude (at least the pin fins) on one side of the frame through the windows.
Power terminals and signal pins of each of the multiplicity of power electronics modules placed in the manifold may extend to an outside of the manifold/integrated power electronics package.
In some example implementations, the multiplicity of power electronics modules in the integrated power electronics package may be placed in sequence in two rows (i.e., a first row and a second row) on opposing sides of the frame. The first row and the second row may be separated, for example, by an inter-row distance RD. A first power electronics module placed in the first row may be placed back-to-back with (e.g., opposing) a corresponding second power electronics module placed in the second row. The windows in the frame may expose the bottom surfaces of the substrates on which semiconductor dies are mounted (or the bottom surfaces of the baseplates attached to the substrates) in the power electronics modules disposed on opposing sides of the frame.
A space (defined, e.g., by an inter-row distance) between the first row and the second row in the frame may form a cooling fluid channel for a stream of the cooling fluid from the input port to the output port passing over the backsides of the multiple power electronics modules placed in the first row and the backsides of the multiple power electronics modules placed in the second row on opposing sides of the frame. The cooling fluid channel may provide a single straight continuous path for the stream of the cooling fluid to flow over the backsides of multiple power electronics modules (i.e., without requiring bifurcation or turning of the path to flow over individual power electronics modules).
Baseplate pin fins of the first power electronics module placed in the first row and the baseplate pin fins of the opposing second power electronics module placed in the second row may protrude through the windows or openings in the frame into the cooling fluid channel. The baseplate pin fins of the first power electronics module placed in the first row and the baseplate pin fins of the second power electronics module placed in the second row protruding into the cooling fluid channel may be aligned with each other. In some example implementations, the ends (e.g., a top end) of the pin fins of the opposing power electronics modules may be close to each other in distance (e.g., no greater than 5%-10% of a pin height of the pins), and in some example implementations, the ends of the pin fins of the opposing power electronics modules may even contact or touch each other.
As shown in
With reference to
In example implementations, multiple individual power electronics modules (e.g., power electronics module 200A) may disposed (e.g., in rows R1 and R2) along two sides of frame 140. In the view shown in
In some example implementations, the various structural components of integrated power electronics package 100 (e.g., beams, cover plates, end plates, etc.) may be assembled using, for example, nut-and-bolt assemblies (e.g., nut-and-bolt assembly 130). In some example implementations, the various structural components of integrated power electronics package 100 may also be assembled using, adhesives, O-ring and groove arrangements, or other coupling members (not shown in
As shown in
As shown in
In some implementations, the cooling fluid channel 115 can be defined at least in part by the frame 140 and the sidewalls of the power modules 200A, which are coupled to the frame 140. In some implementations, the cooling fluid channel 115 can be defined at least in part by the frame 140 and pairs of the power modules 200A on opposing sides of the frame 140. In some implementations, less power modules can be included in the device.
Beam 141 and beam 142 may held apart (in the y direction) by the vertical posts (e.g., end post 144, end post 143) having a height H. End post 144 and end post 143 may be attached to beam 141 and 142 at the ends of frame 140 separated the length L of the frame. Further, vertical side posts (e.g., side post 145 and side post 146) may be attached to beam 141 and 142 along the length L of frame 140 to define areas for openings or windows (e.g., window 147) in the sidewalls (e.g., sidewall S1) of frame 140. The windows (e.g., window 147) may be open to the interior of frame 140, which includes the cooling fluid channel (cooling fluid channel 155). Further, the end posts (e.g., end post 143 and end post 144) may include openings (e.g., slot 150) that provide access to the interior of frame from directions (e.g., x direction) along the length of frame 140.
In some implementations, the slot 150 can have a rectangular profile. Multiple slots, similar to slot 150, can be defined within the frame 140. In example implementations, frame 140 may have a modular structure. For example, frame 140 may include a modules M,1, M2, M3, etc., arranged in a row. The cooling fluid channel (cooling fluid channel 155) may pass through each of the modules in sequence. The modules (e.g., modules M,1, M2, M3, etc.) may be interconnected by slots (like slot 150) through which the cooling fluid channel (cooling fluid channel 155) can pass from one module to the next module (e.g., module M1 to module M2, etc.).
Each module (e.g., module M1) may include a window (e.g., window 147) formed in a sidewall (e.g., sidewall S1) on one side of the frame and a corresponding window (e.g., window 149) formed in another sidewall (e.g., sidewall S2 parallel to sidewall S1) on an opposite side of the frame. Windows 147 and window 149 may be aligned with each other (e.g., aligned to be parallel to each other).
Each individual power electronics module (e.g., power electronics module 200A) disposed (e.g., in rows R1 and R2) along two sides of frame 140 may cover (close) and seal a respective opening or window (e.g., window 147) in the sidewalls (e.g., sidewall S1) of frame 140. In example implementations, an O-ring-and-groove arrangement (e.g., O-ring-and-groove arrangement 148) may be disposed around a perimeter P of the opening or window (e.g., window 147). The O-ring-and-groove arrangement between the power electronics module (e.g., power electronics module 200A) and the sidewall (e.g., sidewall S1) of frame 140 may be utilized to seal the opening or window (e.g., window 147) to confine cooling fluids to the cooling fluid channel (cooling fluid channel 155,
The cover plates 112, 114 may, for example, be aligned along planes that are generally parallel to cooling fluid channel 155 (e.g., a longitudinal direction along the fluid channel) in frame 140.
In some implementations, openings (e.g., lumen) associated with the input port 124 and/or the output port 122 define at least some portion of the cooling fluid channel 115. In some implementations, the input port 124 and/or the output port 122 define at least some portion of the cooling fluid channel 115.
The pin fins (on the baseplates attached to substrates of the power electronics modules) that intrude into the stream of the cooling fluid passing through frame 140 provide additional surface contact areas for transfer of heat from the baseplate to the cooling fluid.
In example implementations, the pin fins (on the baseplates of the power electronics modules) that intrude into the stream of the cooling fluid passing through frame 140 may have hydrodynamic shapes. The hydrodynamic shapes of the pin fins may be designed to encourage laminar flow (e.g., non-turbulent flow) of cooling fluid across the baseplates (e.g., baseplate 230) and through the array of pin fins of the power electronics modules disposed on either side of cooling fluid channel 155 in frame 140.
In some example implementations, the hydrodynamic shape of a pin fin may be a fish-like (or a teardrop-like) shape.
A direction of flow of cooling fluids (in cooling fluid channel 155) across the baseplate, over and through the pin fins (e.g., pin fin 232), is indicated in
In some example implementations, the hydrodynamic shape of a pin fin may include a frustoconical portion (i.e., a frustrum). The pin fin may include a cylindrical shaft, a portion of which is tapered to form a truncated cone portion (i.e., the frustrum) at one end of the cylindrical shaft.
In example assemblies of integrated power electronics package 100, the power electronic modules (e.g., power electronics module 200A) may be positioned so that the top surfaces (e.g., surface PS) of the pin fins (e.g., pin fin 232, or pin fin 242) associated with a pair power electronic modules disposed on opposite sides of frame 140 are close in distance in frame 140 and may even touch each other (as shown, e.g., in
In example implementations, a package includes a frame having a first sidewall and a second sidewall opposite the first sidewall. The frame has at least one opening in the first sidewall and at least one opening in the second sidewall. The frame may be made of metal, plastic, or composite material.
A first power electronics module covers (e.g., closes, seals) the at least one opening in the first sidewall with a surface of a substrate in the first power electronics module. The surface of the substrate in the first power electronics module is exposed to an interior of the frame through the at least one opening in the first sidewall. Further, a second power electronics module covers (e.g., closes, seals) the at least one opening in the second sidewall with a surface of a substrate in the second power electronics module. The surface of the substrate in the second power electronics module is exposed to the interior of the frame through the at least one opening in the second sidewall.
The first sidewall, the surface of the substrate of the first power electronics module, the second sidewall, and the surface of the substrate of the second power electronics module collectively define a cooling fluid channel through the frame. A stream of cooling fluid can flow in the cooling fluid channel over the surface of the substrate of the first power electronics module and the surface of the substrate of the second power electronics module to remove heat from the power electronics modules.
In some example implementations, a package includes a frame having a cooling fluid channel therethrough. The cooling fluid channel is formed between a first sidewall and a second sidewall opposite the first sidewall. The frame includes a first plurality of openings disposed in a first row in the first sidewall alongside the cooling fluid channel and a second plurality of openings disposed in a second row in the second sidewall alongside the cooling fluid channel opposite the first sidewall.
In the package, a first plurality of power electronics modules may be disposed alongside the first sidewall over the first plurality of openings in the first sidewall with each of the first plurality of openings exposing a surface of a substrate in a corresponding one of the first plurality of power electronics modules to the cooling fluid channel in the frame. Furthermore, a second plurality power electronics modules may be disposed alongside the second sidewall over the second plurality of openings in the second sidewall with each of the second plurality of openings exposing a surface of a substrate in a corresponding one of the second plurality power electronics modules to the cooling fluid channel in the frame.
In some example implementations, a package includes a frame having a cooling fluid channel therethrough. The cooling fluid channel is formed between a first sidewall and a second sidewall opposite the first sidewall. The frame has at least one opening in the first sidewall alongside the cooling fluid channel and at least one opening in the second sidewall alongside the cooling fluid channel.
The package further includes a first power electronics module covering the at least one opening in the first sidewall with a surface of a substrate in the first power electronics module being exposed to the cooling fluid channel in the frame through the at least one opening in the first sidewall, and a second power electronics module covering the at least one opening in the second sidewall with a surface of a substrate in the second electronics module being exposed to the cooling fluid channel in the frame through the at least one opening in the second sidewall.
Method 400 includes forming a cooling fluid channel t between a first sidewall and a second sidewall in a frame (410). The frame has at least one opening in the first sidewall alongside the cooling fluid channel and at least one opening in the second sidewall alongside the cooling fluid channel Method further includes disposing a first power electronics module to cover the at least one opening in the first sidewall with a surface of a substrate in the first power electronics module being exposed to the cooling fluid channel in the frame through the at least one opening in the first sidewall (420), and Disposing a second power electronics module to cover the at least one opening in the second sidewall with a surface of a substrate in the second power electronics module being exposed to the cooling fluid channel in the frame through the at least one opening in the second sidewall (430). The first power electronics module and the second power electronics module may, for example, be SSDC packages.
Forming the cooling fluid channel through the hollow frame may include disposing an inlet port on a first end of the hollow frame and an outlet port of a second end of the hollow frame opposite the first end.
Disposing the at least one power electronics module over the at least one opening or window 420 may include sealing of the opening or window by the substrate surface of the power electronics module. Sealing the opening or window may involve disposing an O-ring-and-groove arrangement around a perimeter of the opening or window on the at least one sidewall of the rectangular cylindrical structure. In some implementations, an adhesive (sealant) disposed around the perimeter of the opening or window on the at least one sidewall of the rectangular cylindrical structure may be used to seal the opening.
Disposing the at least one power electronics module over the at least one opening or window 420 may also include attaching a heat sink or baseplate to the substrate surface of the power electronics module. Further, attaching the heat sink or baseplate to the substrate surface of the power electronics module may include exposing the baseplate to the cooling fluid channel in the hollow frame. In example implementations, the baseplate may include at least one pin fin extending from the baseplate. In some example implementations, the at least one pin fin may have a teardrop-like shape. In some example implementations, the at least one pin fin may include a truncated cone portion.
In example implementations, where the at least one sidewall of the rectangular cylindrical structure is a first sidewall, the at least one opening or window is a first window, and the at least one power electronics module is a first power electronic module, method 400 may further include disposing at a second power electronics module over a second window in a second sidewall opposite the first window in the first sidewall so that a substrate surface of second power electronics module covers second window and is exposed to the cooling fluid channel in the hollow frame.
In some example implementations, method 400 may further include aligning a pin fin on a baseplate of the first power electronics module and a pin fin on a baseplate of the second power electronics module so that top end surfaces of the two pin fins touch each other.
In some example implementations, method 400 may further include aligning a pin fin on a baseplate of the first power electronics module and a pin fin on a baseplate of the second power electronics module so that top end surfaces of the two pin fins are separated by a distance no greater than 5% to 10% percent of a pin height.
The various implementations described herein are given only by way of example and only for purposes of illustration. It will understood, for purposes of this disclosure, that when an element, such as a layer, a region, a component, or a substrate, is referred to as being on, mechanically connected to, electrically connected to, coupled to, or electrically coupled to another element, it may be directly on, connected or coupled to the other element, or one or more intervening elements may be present. In contrast, when an element is referred to as being directly on, directly connected to or directly coupled to another element or layer, there are no intervening elements or layers present. Although the terms directly on, directly connected to, or directly coupled to may not be used throughout the detailed description, elements that are shown as being directly on, directly connected or directly coupled can be referred to as such. The claims of the application may be amended to recite exemplary relationships described in the specification and or shown in the figures.
As used in this specification, a singular form may, unless indicating a particular case in the context, include a plural form. Spatially relative terms (e.g., over, above, upper, under, beneath, below, lower, and so forth) are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. In some implementations, the relative terms above and below can, respectively, include vertically above and vertically below. In some implementations, the term adjacent can include laterally adjacent to or horizontally adjacent to.
Some implementations may be implemented using various semiconductor processing and/or packaging techniques. Some implementations may be implemented using various types of semiconductor processing techniques associated with semiconductor substrates including, but not limited to, for example, silicon (Si), silicon carbide (SiC), gallium arsenide (GaAs), gallium nitride (GaN), and/or so forth.
While certain features of the described implementations have been illustrated as described herein, many modifications, substitutions, changes, and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the scope of the implementations. It should be understood that they have been presented by way of example only, not limitation, and various changes in form and details may be made. Any portion of the apparatus and/or methods described herein may be combined in any combination, except mutually exclusive combinations. The implementations described herein can include various combinations and/or sub-combinations of the functions, components and/or features of the different implementations described.
