3D power module with double-sided cooling per semiconductor chip

Abstract

Power module (600), which includes: a first layer stack (608); a second layer stack (610); a third layer stack arranged between the first layer stack (608) and the second layer stack (610) and comprising a first semiconductor chip (602), a second semiconductor chip (604) and a first intermediate spacer layer (605) arranged between the first semiconductor chip (602) and the second semiconductor chip (604); a first heat conduction tube (606) that extends at least partially into the first intermediate spacer layer (605); and at least one cooling plate (611) that absorbs heat energy from the first layer stack (608) and from the second layer stack (610), wherein the first layer stack (608), the second layer stack (610), the first heat guide tube (606) and the at least one cooling plate (611) enable double-sided cooling of both the first semiconductor chip (602) and the second semiconductor chip (604); characterized by the fact that the cooling plate (611) has a 'C'-shaped form with two sections, between which the three layer stacks (608, 610) are located, the two sections of the cooling plate (611) being connected to each other by a further section through which the heat conduction tube (606) extends.

Description

INTRODUCTION

[0001] The present invention relates to the cooling of power modules containing semiconductor chips, and in particular to a power module according to the preamble of claim 1, as is known essentially from US 2020 / 0375061A1.

[0002] Further details of the state of the art can be found in the publications JP 2018 - 37 545 A and US 2005 / 0 183 847 A.

[0003] A power module can contain circuit components of various types of power converters or power inverters, such as a boost converter, a buck converter, a voltage-source converter, or a current-source converter. For example, power modules can be used to supply power to vehicle motors for propulsion, providing high voltages (e.g., 100–1600 V) and operating them at high power levels (e.g., 100 kilowatts (kW) to 1 megawatt (MW)). The power modules may contain voltage-source converter components for converting direct current (DC) voltage to alternating current (AC) voltage to drive the motors. Each converter and / or inverter may contain switching pairs (e.g., metal-oxide-semiconductor field-effect transistor pairs (MOSFET pairs) or insulated-layer bipolar transistor pairs (IGBT pairs)).As an example, a power converter can contain three pairs of switches, each pair containing a high-side switch and a low-side switch, together providing a half-bridge structure. The three pairs of switches together provide a full-bridge structure. SUMMARY

[0004] According to the invention, a power module is presented which is characterized by the features of claim 1.

[0005] According to other characteristics, the first layer stack contains a first conductive layer, a second conductive layer, and a first dielectric layer located between the first and second conductive layers. The second layer stack contains a third conductive layer, a fourth conductive layer, and a second dielectric layer located between the first and second conductive layers.

[0006] According to other features, the power module also includes a cooling circuit configured to circulate a coolant to and from at least one cooling plate or heat sink.

[0007] According to other features, the first heat conduction tube contains: a wick structure arranged between the first semiconductor chip and the second semiconductor chip; and a vapor chamber arranged at least partially between the first semiconductor chip and the second semiconductor chip.

[0008] According to other features, the first heat conduction tube contains: a wick structure located between the first semiconductor chip and the second semiconductor chip; and a vapor chamber not located between the first semiconductor chip and the second semiconductor chip.

[0009] According to other features, the power module further includes: a first mounting layer located between the first semiconductor chip and the second layer stack; and a second mounting layer located between the second semiconductor chip and the third layer stack.

[0010] According to other features, the power module further includes: a third mounting layer located between the first semiconductor chip and the first intermediate spacer layer; and a fourth mounting layer located between the second semiconductor chip and the first intermediate spacer layer.

[0011] According to other characteristics, the first intermediate spacer layer is a conductive layer that connects a first switch of the first semiconductor chip in series with a second switch of the second semiconductor chip. The first and second switches are designed to provide a half-bridge structure.

[0012] According to other features, the power module further comprises a fourth layer stack, a fifth layer stack, a sixth layer stack, and a second heat pipe. The sixth layer stack is arranged between the fourth and fifth layer stacks and includes a third semiconductor chip, a fourth semiconductor chip, and a second intermediate spacer layer located between the third and fourth semiconductor chips. The second heat pipe extends at least partially into the second intermediate spacer layer. The at least one cooling plate or heat sink absorbs thermal energy from the fourth and fifth layer stacks. The fourth layer stack, the fifth layer stack, the second heat pipe, and the at least one cooling plate or heat sink enable double-sided cooling of both the third and fourth semiconductor chips.

[0013] According to other characteristics, the first semiconductor chip, the second semiconductor chip, the third semiconductor chip and the fourth semiconductor chip together provide a full bridge converter.

[0014] Another power module comprises a first layer stack, a first heat pipe, a second layer stack, and a third layer stack. The first layer stack includes a first semiconductor chip, a second semiconductor chip, and a first intermediate spacer layer located between the first and second semiconductor chips. The first heat pipe extends at least partially into the first intermediate spacer layer and absorbs heat energy from the first and second semiconductor chips. The third layer stack transfers heat energy away from the first semiconductor chip and comprises a first conductive layer, a second conductive layer, and a first dielectric layer located between the first and second conductive layers.The third layer stack transfers heat energy away from the second semiconductor chip and contains a third conductive layer, a fourth conductive layer, and a second dielectric layer positioned between the third and fourth conductive layers. The first layer stack is located between the second and third layer stacks. The second layer stack, the third layer stack, and the first heat pipe enable double-sided cooling of both the first and second semiconductor chips.

[0015] According to other features, the power module further includes at least one cooling plate or heat sink configured to absorb thermal energy from the second layer stack and from the third layer stack in order to cool the first semiconductor chip and the second semiconductor chip.

[0016] According to other features, the power module also includes a cooling circuit configured to circulate a coolant to and from at least one cooling plate or heat sink.

[0017] According to other features, the first heat conduction tube contains: a wick structure arranged between the first semiconductor chip and the second semiconductor chip; and a vapor chamber arranged at least partially between the first semiconductor chip and the second semiconductor chip.

[0018] According to other features, the first heat conduction tube contains: a wick structure located between the first semiconductor chip and the second semiconductor chip; and a vapor chamber not located between the first semiconductor chip and the second semiconductor chip.

[0019] According to other features, the power module further includes: a first mounting layer located between the first semiconductor chip and the second layer stack; and a second mounting layer located between the second semiconductor chip and the third layer stack.

[0020] According to other features, the power module further includes: a third mounting layer located between the first semiconductor chip and the first intermediate spacer layer; and a fourth mounting layer located between the second semiconductor chip and the first intermediate spacer layer.

[0021] According to other characteristics, the first intermediate spacer layer is a conductive layer that connects a first switch of the first semiconductor chip in series with a second switch of the second semiconductor chip. The first and second switches are designed to provide a half-bridge structure.

[0022] According to other features, the power module further includes a fourth layer stack, a second heat pipe, a fifth layer stack, and a sixth layer stack. The fourth layer stack contains a third semiconductor chip, a fourth semiconductor chip, and a second intermediate spacer layer located between the third and fourth semiconductor chips. The second heat pipe extends at least partially into the second intermediate spacer layer and absorbs heat energy from the third and fourth semiconductor chips. The fifth layer stack transfers heat energy away from the third semiconductor chip. The sixth layer stack transfers heat energy away from the fourth semiconductor chip. The fourth layer stack is located between the fifth and sixth layer stacks.At least one cooling plate or heat sink absorbs heat energy from the second layer stack, the third layer stack, the fifth layer stack, and the sixth layer stack. The first semiconductor chip, the second semiconductor chip, the third semiconductor chip, and the fourth semiconductor chip together form a full bridge converter.

[0023] According to other features, the first layer stack contains a third semiconductor chip, a fourth semiconductor chip, and a second intermediate spacer layer located between the third and fourth semiconductor chips. The second heat pipe extends at least partially into the second intermediate spacer layer and absorbs heat energy from the third and fourth semiconductor chips. The third layer stack transfers heat energy away from the third semiconductor chip. The fourth layer stack transfers heat energy away from the fourth semiconductor chip. At least one cooling plate or heat sink absorbs heat energy from the second layer stack, the third layer stack, the fifth layer stack, and the sixth layer stack. The first, second, third, and fourth semiconductor chips together form a full bridge converter.

[0024] Further areas of application of the present invention will become apparent from the detailed description, the claims, and the drawings. The detailed description and the specific examples are for illustrative purposes only. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be more fully understood from the detailed description and the accompanying drawings; these show: Fig. 1 A perspective view of a half-bridge power module containing stacked chips with double-sided cooling per chip and stacked DC connectors; Fig. 2 another perspective view of the half-bridge power module from Fig. 1; Fig. 3 an exploded view of the half-bridge power module from Fig. 1; Fig. 4 a perspective view of a half-bridge power module containing stacked chips with double-sided cooling per chip and separate DC connectors; Fig. 5 an exploded view of the half-bridge power module from Fig. 4; Fig. 6 a lateral cross-sectional view of a half-bridge power module containing stacked chips with double-sided cooling per chip, and a corresponding cooling circuit according to the present invention; Fig. 7 a front cross-sectional view of a first example of a half-bridge power module made of Fig. 6, seen along the section line AA, and which represents a heat conduction tube containing a steam structure arranged in a middle spacer layer, according to an embodiment of the present invention; Fig. 8 a front cross-sectional view of a second example of the half-bridge power module from Fig. 6, seen along the section line AA, and which represents a heat conduction tube containing a vapor structure outside a mean spacer layer, according to another embodiment of the present invention; Fig. 9 a side cross-sectional view of a full bridge power module; Fig. 10 a schematic view of a boost converter configured with a power module according to the present invention; Fig. 11 a schematic view of a buck converter configured with a power module according to the present invention; Fig. 12 a schematic view of a MOSFET voltage source power converter configured with power modules according to the present invention; Fig. 13 a schematic view of an IGBT voltage source power converter configured with power modules according to the present invention; Fig. 14 a schematic view of an IGBT power source converter configured with power modules according to the present invention; Fig. 15 a schematic diagram of a thermal structure of each of the power modules Fig. 1-9; Fig. 16A a side cross-sectional view of a half-bridge power module made of Fig. 6, which represents a commutation loop representation; Fig. Figure 16B shows an exemplary representation of the inductance frequency response of the half-bridge power module. Fig. 6; and Fig. 17 an exemplary vehicle system comprising a power converter configured with power modules containing stacked chips with double-sided cooling per chip according to the present invention.

[0026] This refers to Fig. 6 on a power module with all the features of claim 1.

[0027] Reference symbols may be used multiple times in the drawings to identify similar and / or identical elements. DETAILED DESCRIPTION

[0028] Conventional power modules typically contain a single chip layer sandwiched between conductive layers. These conductive layers are part of direct-bonded copper (DBC) stacks attached to heat sinks to transfer heat energy from the chip to the heat sinks. Alternatively, a chip can be attached to the first side of a single DBC stack. A heat pipe can be placed adjacent to the chip on the first side of the DBC stack. The second side of the DBC stack, opposite the first, can be mounted on a base plate attached to a heat sink. These and other conventional power module configurations have large package sizes and limited cooling capabilities.Because of the arrangement of the power modules and the large assembly sizes, the power modules and the corresponding circuits tend to have large assembly sizes, low power densities, high parasitic inductances and parasitic resistances, and high power losses.

[0029] The examples presented here include three-dimensional power modules (3D power modules) with stacked chips featuring double-sided cooling per chip. Each stacked power module structure includes a middle spacer layer positioned between stacked chips, the middle spacer layer containing at least a section of a heat pipe. The sides of the chips facing the middle spacer layer are attached to DBC stacks or the like, which in turn are attached to at least one cooling plate. The heat pipe is an integral part of the stacked structure, is positioned at least partially between the chips, and provides passive, fully enclosed cooling. The cooling plate is actively cooled by the flow of a coolant into and out of the cooling plate.

[0030] The disclosed 3D-stacked power module structures are compact, exhibit low corresponding commutation loop area and inductance, low parasitic inductance, low parasitic resistance, and low losses. Due to their compact design, the power modules offer high power density. Compared to conventional power module structures, these structures exhibit improved thermal management (or cooling) and thus enhanced reliability. The 3D-stacked power modules incorporate heat pipe structures that, as further described below, function as thermal connections analogous to electrical connections.

[0031] The Fig. Figures 1-3 show a half-bridge power module 100 containing stacked chips 102, 104, a middle spacer layer 105, a heat pipe 106, and DBC stacks 108, 110. Furthermore, the half-bridge power module 100 can include a cooling plate, for which an example is shown in Fig. Figure 6 shows that although a cooling plate is shown, the cooling plate can be replaced by a heat sink and / or attached to one. This applies to other cooling plates of the embodiments and examples disclosed herein. The cooling plates and heat sinks can be interchangeable or used together to provide enhanced cooling. The middle spacer layer 105 is arranged between the chips 102 and 104. The heat pipe 106 extends at least partially into the middle spacer layer 105 between the chips 102 and 104. The chips 102 and 104, the middle spacer layer 105, and a section of the heat pipe 106 are arranged between the DBC stacks 108 and 110. The DBC stacks 108 and 110 are arranged between sections of the cooling plate.Heat energy is transferred (i) from the first sides of the chips 102, 104 to the middle spacer layer 105 and to the heat guide tube 106 and (ii) from the second sides of the chips 102, 104, which are opposite the first sides of the chips 102, 104, to the DBC stacks 108, 110, which transfer the heat energy to the cooling plate.

[0032] Chips 102 and 104 can form one or more switches, either completely or partially. Furthermore, each chip 102 and 104 can contain one or more diodes. According to one embodiment, each chip 102 and 104 contains a switch and can also contain a diode. Chip 102 can contain a high-side switch. Chip 104 can contain a low-side switch connected in series with the high-side switch to provide a half-bridge structure. Exemplary converter structures are shown in Fig. 10-14 shown. Chips 102, 104 can be made of silicon, silicon carbide, diamond and / or gallium nitride.

[0033] The middle spacer layer 105 can be in direct contact with the chips 102, 104, or, as shown, it can be in contact with first tethering layers 120, 122, which separate the chips 102, 104 from the middle spacer layer 105. The chips 102, 104 can be connected by second tethering layers (tethering layer 124 is in Fig. 3 between the chip 104 and the DBC stacks 110) are separated from the DBC stacks 108, 110. The middle spacer layer 105 can be a 'C'-shaped or cup-shaped layer and include an open end 112 for receiving a section 114 of the heat pipe 106. The heat pipe 106 can generally be cylindrical, except for the section 114, which: can be flattened to be compatible with power module assembly; can be positioned between the chips 102, 104; and can provide improved heat energy transfer from the chips 102, 104 to the heat pipe 106. According to another embodiment, a large section of the heat pipe 106 or the entire heat pipe is flattened.

[0034] Furthermore, the power module can contain 100 stacked DC connectors 130, one AC connector 132, and other connectors 134. The other connectors 134 can include gate pins of the switches of chips 102 and 104, temperature sensing pins for detecting temperatures within the power module 100, drains (or return lines), etc. Mounting layers 140, 142, and 144 can be arranged between the ends of the connectors 134 and the DBC stacks 108 and 110.

[0035] The Fig. Figures 4-5 show a half-bridge power module 400 containing stacked chips 402, 404, a middle spacer layer 405, a heat pipe 406, and DBC stacks 408, 410. The half-bridge power module 400 can further include a cooling plate, an example of which is shown in Fig. Figure 6 shows the intermediate spacer layer 405 arranged between the chips 402 and 404. The heat pipe 406 extends at least partially into the intermediate spacer layer 405 between the chips 402 and 404. The chips 402 and 404, the intermediate spacer layer 405, and a section of the heat pipe 406 are arranged between the DBC stacks 408 and 410. The DBC stacks 408 and 410 are arranged between sections of the cooling plate. Heat energy is transferred (i) from the first sides of the chips 402, 404 to the middle spacer layer 405 and to the heat guide tube 406 and (ii) from the second sides of the chips 402, 404, which are opposite the first sides of the chips 402, 404, to the DBC stacks 408, 410, which transfer the heat energy to the cooling plate.

[0036] The middle spacer layer 405 can be in direct contact with chips 402, 404 or, as shown, in contact with first affixing layers 420, 422, which separate chips 402, 404 from the middle spacer layer 405. Chips 402, 404 can be separated from DBC stacks 408, 410 by second affixing layers (in Fig. Figure 3 shows the mounting layer 424 between the chip 404 and the DBC stacks 410. The middle spacer layer 405 can be a 'C'-shaped or cup-shaped layer and include an open end 412 for receiving a section 414 of the heat pipe 406. The heat pipe 406 can generally be cylindrical, except for the section 414, which: can be flattened to be compatible with power module assembly; can be positioned between the chips 402, 404; and can provide improved heat energy transfer from the chips 402, 404 to the heat pipe 406.

[0037] Apart from the fact that it contains separate DC 430 connectors, the 400 power module is similar to the 100 power module. Fig. 1-3. The power module 400 may further include an AC terminal 432 and other terminals 434. The other terminals may include gate terminal pins of the switches of chips 402, 404, temperature sensing terminal pins for detecting temperatures within the power module 400, drain (or return), etc. Mounting layers 440, 442, 444 may be arranged between the ends of the terminals 434 and the DBC stacks 408, 410.

[0038] The power modules from Fig. Figures 1-5 contain 3D structures with current paths in the X, Y, and Z directions, as opposed to only in the X and Y directions. The 3D structures allow for more current flow in the Z direction for a given small area of ​​each power module.

[0039] Fig. Figure 6 shows a half-bridge power module 600 according to the invention, comprising stacked chips 602, 604, a middle spacer layer 605, a heat guide tube 606, DBC stacks 608, 610, and a cooling plate 611. The half-bridge power module 600 can be used to power the power modules from Fig. 1-5 replace and / or represent. The middle spacer layer 605 is arranged between the chips 602 and 604. The heat pipe 606 extends into the middle spacer layer 605 between the chips 602 and 604. The chips 602 and 604, the middle spacer layer 605, and a section of the heat pipe 606 are arranged between the DBC stacks 608 and 610. The DBC stacks 608 and 610 are arranged between sections of the cooling plate 611. Thermal energy is transferred (i) from the first sides of the chips 602, 604 to the middle spacer layer 605 and to the heat pipe 606, and (ii) from the second sides of the chips 602, 604, which are opposite the first sides of the chips 602, 604, to the DBC stacks 608, 610, which transfer the thermal energy to the cooling plate 611. The cooling plate 611 can contain one or more coolant channels (an exemplary coolant channel 613 is shown) through which a coolant flows.The chips 602, 604, the heat guide tube 606 and the DBC stacks 608, 610 are stacked and arranged in such a way as to provide double-sided cooling for each of the chips 602, 604.

[0040] The intermediate spacer layer 605 can be in direct contact with chips 602 and 604, or, as shown, in contact with first mounting layers 620 and 622 that separate chips 602 and 604 from the intermediate spacer layer 605. The intermediate spacer layer 605 is a conductive layer and connects one or more components of the first chip 602 to one or more components of the second chip 604. Chips 602 and 604 can be separated from the DBC stacks 608 and 610 by second spacer layers 624 and 626. The mounting layers 620, 622, 624, and 626 can contain a thermal paste material, nanosilver, solder, or another suitable mounting material.

[0041] The middle spacer layer 605 can be C-shaped, cup-shaped, and / or surround a section 614 of the heat pipe 606. The middle spacer layer 605 can include an open end 612 for receiving the section 614 of the heat pipe 606. The heat pipe 606 can generally be cylindrical, except for the section 614, which: can be flattened to be compatible with power module assembly; can be positioned between the chips 602 and 604; and can provide improved heat energy transfer from the chips 602 and 604 to the heat pipe 606. The middle spacer layer 605 can be formed from a conductive material such as copper (Cu), aluminum (Al), or an alloy.

[0042] The heat pipe 606 can be made of and / or contain a metallic material such as copper. A layer 630 of an electrical insulating material can be arranged between the middle spacer layer 605 and the heat pipe 606. The heat pipe 606 can be coated, for example, with an electrical insulating material that may be a ceramic such as SiN, Al₂O₃, and / or Al₂O₃. The coating may contain a polymer with ceramic doping. The heat pipe 606 is a sealed vessel containing a fluid that is heated, evaporates, cools back to a fluid state, and then reheated. This cycle is repeated iteratively within the heat pipe 606. The heat pipe 606 acts as a thermal connection to the power module 600. Fig. 7 and Fig. Figure 8 shows cross-sectional examples of the heat pipe 606. The heat pipe 606 contains the flattened section 614, which is located within the middle spacer layer 605, and a non-flattened section 634, which is located within the cooling plate 611. The flattened section 614 is shaped for thermal contact with components of the power circuit provided by the chips 602 and 604. The thickness T1 of the flattened section 614 is less than the thickness T2 of the non-flattened section 634.

[0043] The DBC stacks 608, 610 can be referred to as substrates and contain corresponding conductive layers 635, 636, 637, 638 and intermediate dielectric layers 639, 641, which are arranged between pairs of the conductive layers 635, 636, 637, 638. The conductive layers 635, 636, 637, 638 can be made of and / or contain copper (Cu). The dielectric layers 639, 641 can be made of and / or contain ceramics such as silicon nitride (SiN), aluminum nitride (AlN), and / or aluminum oxide (Al₂O₃). The DBC stacks 608, 610 can be implemented as direct bond aluminum layers (DMA layers), insulated metal substrate layers (IMS layers), or as other layered stacks, each containing one or more conductive layers.

[0044] The conductive layers 636 and 637 provide connections from the circuit components of chips 602 and 604 to other circuit components of other power modules. Layers 636 and 637 can extend externally and make contact with other similar layers of one or more other power modules and / or provide connections to other circuit components of the other power modules and / or to a corresponding converter / power inverter. An example of this is shown in Fig. Figure 9 shows that the conductive layers 635 and 638 may be included to compensate for the equilibrium of the conductive layers 636 and 637 and a mechanical coefficient of thermal expansion. The conductive layers 635 and 638 do not connect to electrical circuit components. The middle dielectric layers 639 and 641 insulate the electrical circuit of the power module 600 and associated high voltages.

[0045] The cooling plate 611 is C-shaped and may be made of and / or contain copper (Cu) or aluminum (Al). A cooling circuit 640 is provided to control the flow of coolant through the coolant channel 613 and / or through other coolant channels contained in the cooling plate 611 and / or in other cooling plates, if included. Although a single cooling plate with a single coolant channel is shown, one or more cooling plates may be included, each containing one or more coolant channels. One or more cooling channels may be arranged above, below, and on the sides of the heat pipe 606.

[0046] The cooling circuit 640 can include a pump 642, a control module 644, and a reservoir 646. The pump 642 is controlled by the control module 644, which can operate based on temperatures detected by the power module 600 via sensors 648. Although shown separately, the sensors can be (i) located in and / or attached to the cooling plate 611 and / or (ii) located elsewhere in the power module 600. The pump 642 circulates coolant to and from the reservoir 646 via one or more coolant channels. The control module 644 can adjust the coolant flow based on a predetermined target operating temperature.

[0047] According to one embodiment, a coolant channel is provided above the first DBC stack 608 and another coolant channel is provided below the DBC stack 610, each coolant channel having a respective inlet and outlet connected to the pump. The vertical structure of the stacks (i.e., the chip stack containing the chips 602, 604 and the intermediate spacer layer 605, and the DBC stacks 608, 610) provides a significant reduction in parasitic dimensions. The heat pipe 606 in the vertical structure, together with the DBC stacks and the top and bottom cooling plates, provides double-sided cooling per chip for a substantial improvement in thermal management.

[0048] Fig. Figure 7 shows an example of the half-bridge power module 600' according to the invention. Fig. 6 for a first embodiment, wherein it comprises a heat-conducting tube structure 701, which includes a wick structure (or wick chamber) 703 and a vapor structure (or vapor chamber) 705, which is arranged within a central spacer layer 605'. The half-bridge power module 600' is similar to the power module 600 from Fig. 6 is configured and contains chips 602, 604 and DBC stacks 608, 610. A coolant (e.g., water) in the heat conduction tube structure 701 is heated and evaporated in the wick structure 703 and transferred to the vapor structure 705, where the coolant is cooled and returned to a liquid state. The cooled coolant is then transferred back to the wick structure 703. The wick structure 703 contains a honeycomb structure, cooling fins, and / or other structural elements configured to enable capillary action. The vapor structure 705 may contain one or more channels and / or chambers for cooling the evaporated coolant.

[0049] Fig. Figure 8 shows an example of the 600" half-bridge power module according to the invention. Fig. 6 for a second embodiment, comprising a heat-conducting tube structure 800, which includes a wick structure (or wick chamber) 802 within a central spacer layer 605" and a vapor structure (or vapor chamber) 804 outside the central spacer layer 605". A coolant (e.g., water) in the heat-conducting tube structure 800 is heated and evaporated in the wick structure 802 and transferred to the vapor structure 804, where the coolant is cooled and returned to a liquid state. The cooled coolant is then transferred back to the wick structure 802. The wick structure 802 may include a honeycomb structure, cooling fins, and / or other structural elements configured to perform capillary action. The vapor structure 804 may include one or more channels and / or chambers for cooling the evaporated coolant.

[0050] The stacking structures from Fig. 7-8 can be optimized for heat transfer. Wick and vapor structures and / or wick and vapor elements thereof can be dimensioned for the maximum thermal contact area and for maximum heat energy transfer. The amount of heat transfer can be adjusted, for example, by determining the size and location of the vapor structures 703, 804. The vapor structures 703, 804 can be located within, partially within, and / or partially outside a region between the chips 602, 604.

[0051] Although in Fig. Figures 1-6 show a single stack containing a half-bridge structure; however, multiple stacks can also be included to provide a full-bridge structure containing two or three half-bridge structures connected in parallel. An example of this is shown in Figure 1-6. Fig. Figure 9 shows. According to another exemplary embodiment, each switch is composed of several chips arranged in a stacked structure with a repeating pattern. As a result, in this exemplary embodiment, several versions of the disclosed double-sided cooling structures are stacked to form a single half-bridge, each double-sided cooling structure containing two chips, each cooled on two opposite sides. The resulting stack can contain multiple heat pipe structures, one for each adjacent pair of chips in the resulting stack. Each chip in the stack can be cooled (i) on two opposite sides by two heat pipes or (ii) on a first side by a heat pipe and on a second side, opposite the first side, by a cooling plate and / or a heat sink.

[0052] Fig. Figure 9 shows a full-bridge power module 900, which includes two versions of a power module structure similar to that in Fig. The full-bridge power module 900 contains two half-bridge structures 902 and 904, which are positioned opposite each other. The half-bridge structures 902 and 904 contain intermediate spacer layers 906 and 908, heat pipes 909 and 911, chips 910, 912, 914, and 916, DBC stacks 918, 920, 922, and 924, and a shared cooling plate 926. Although the power module 900 is shown as containing two half-bridge structures, it may also contain one or more additional half-bridge structures, which may be located adjacent to and / or opposite the two half-bridge structures 902 and 904.

[0053] Fig. Figure 10 shows a boost converter 1000 configured with a power module 1002, which, as revealed here, can be configured to contain stacked chips with double-sided cooling per chip, each chip containing one of the switches 1004, 1006. Fig. Figure 11 shows a buck converter 1100 configured with a power module 1102, which, as revealed here, can be configured to contain stacked chips with double-sided cooling per chip, each chip containing one of the switches 1104, 1106.

[0054] Fig. Figure 12 shows a MOSFET voltage source power converter 1200 configured with power modules 1202, 1204, 1206 which, as revealed here, can be configured to contain stacked chips with double-sided cooling per chip, each chip containing one of the switches 1208, 1210, 1212, 1214, 1216, 1218. Fig. Figure 13 shows an IGBT voltage source power converter 1300 configured with power modules 1302, 1304, 1306 which, as revealed here, can be configured to contain stacked chips with double-sided cooling per chip, each chip containing one of the switch diode pairs 1308, 1310, 1312, 1314, 1316, 1318. Fig. Figure 14 shows an IGBT power source converter 1400 configured with power modules 1402, 1404, 1406 which, as revealed here, can be configured to contain stacked chips with double-sided cooling per chip, each chip containing one of the switch-diode pairs 1408, 1410, 1412, 1414, 1416, 1418.

[0055] The vertical stacks of power modules made of Fig. 10-14 can reduce the size of the corresponding planar solder pads of the converters and power converters by up to half. Power electronic converters and power electronic power converters used for propulsion and accessories include high-side and low-side switches that can be implemented in the power modules disclosed here. The vertical structures allow for the straightforward series connection of switching devices to form converters and power converters.

[0056] Fig. Figure 15 shows a thermal structure 1500, which each of the power modules consists of Fig. Figures 1-9 represent the thermal structure 1500, which includes a high-side and a low-side heat flow, represented by current sources 1502 and 1504. The thermal structure 1500 also includes coolant and DBC stack resistors 1506 and 1508, and heat pipe resistors 1510 and 1512, which are connected in series between sections of a cooling plate, represented by ground references 1514 and 1516. The high-side heat flow (or the first current source output) is supplied to a point connected between resistors 1506 and 1510. The low-side heat flow (or the second current source output) is supplied to a point connected between resistors 1508 and 1512. A heat pipe coolant resistor 1517 is connected to a point between resistors 1510 and 1512 and to a ground reference 1518.The heat transfer ratio between the DBC stacks and the heat pipe of a power module, as disclosed here, can vary depending on the size, shape, and material of the power module. For example, the DBC stacks can transfer 70% of the total heat energy drawn by the chips of the power module, and the heat pipe can transfer 30%. This ratio can be adjusted by modifying the size, shape, and material of the DBC stacks and the heat pipe, as well as the arrangement of the heat pipe. The effective thermal conductivity of the heat pipes is 10 to 50 times that of copper alone. Thus, heat pipes provide effective thermal diffusivity and effective thermal resistance.The number of heat pipes and the geometric dimensions of the power modules can be adjusted for each specific application to maximize heat transfer and thus maximize chip cooling.

[0057] Fig. 16A shows the 600 half-bridge power module. Fig. Figure 6, which represents a commutation loop diagram 1600. The commutation loop shown refers to the switches connected in series (e.g., the high-side and low-side switches in Fig. 10-14), which are contained in chips 602, 604, which are connected to a capacitor 1602 (e.g., one of the capacitors in Fig. 10-14) can be connected in parallel. The stacked arrangement of the 600 power module contains a parasitic impedance and a parasitic resistance. Due to the compact arrangement of the 600 power module, the size of the commutation loop is reduced, and the parasitic impedance and parasitic resistance are minimized. The vertical stacking contains antiparallel current paths in the commutation loop, represented by arrows 1604, which provides a low inductance due to field cancellation. The commutation loop inductance is low (e.g., less than 2.5 nanohenries (nH)). Fig. Figure 16B shows an exemplary graphical representation of the inductance frequency response of the half-bridge power module. Fig. 6.

[0058] Fig.Figure 17 shows an exemplary vehicle propulsion system 1700, which includes a power converter configured with power modules 1701, 1703, and 1705, as disclosed herein, containing stacked chips with double-sided cooling per chip. The propulsion system 1700 may include a motor 1702. Although the motor 1702 is shown as an internal permanent magnet (IPM) motor, it may be a surface-mounted permanent magnet motor or another type of electric motor. Although various examples relating to a motor are disclosed herein, the examples are applicable to other electrical working machines.

[0059] The propulsion system 1700 can be used to power a vehicle 1710 and further includes a power source 1712 (e.g., a battery bank), a power converter 1714, a shaft 1716, an axle 1718 containing a differential 1721, and wheels 1723. The power converter 1714 contains the power modules 1701, 1703, and 1705 and converts a direct current (DC) voltage into a three-phase alternating current (AC) to power the motor 1702. The motor 1702 drives the shaft 1716, which in turn drives the axle 1718.

[0060] Furthermore, the propulsion system 1700 includes a vehicle control module 1720, a current control module 1722, and a driver 1724. The vehicle control module 1720 can generate a torque request signal. This torque request signal can be generated based on a torque command, for example, by an accelerator pedal 1726, if included. The current control module 1722 can control the driver 1724 based on the torque request signal. The driver 1724 can, for example, generate pulse-width modulation (PWM) signals based on the output of the current control module 1722 to control the states of transistors in the power converter 1714.

[0061] The current control module 1722 controls the driver 1724 based on sensor outputs. The sensors can include current sensors (e.g., Hall effect sensors 1730), a resolver 1732, a temperature sensor 1734, and / or other sensors (e.g., an accelerometer). The current sensors can be other than Hall effect sensors.

[0062] The current control module transforms the current phase signals Ia, Ib, and Ic for the three phases of the motor into current vector signals Id and Iq. The current control module 1722 determines the current flow and the current required (or requested) and modifies the input current levels of the motor 1702 by adjusting the output current vector voltage signals supplied to the driver 1724. This is based on (i) the current vector signals Id and Iq, (ii) the position signal from the resolver 1732, and (iv) the torque request signal from the vehicle control module 1720.

[0063] A propulsion system 1700 can contain one or more electric motors. Each electric motor can be used to drive one or more axles and / or one or more wheels of the vehicle 1710. For example, an electric motor can be used to drive one axle of the vehicle 1710 via a differential. The vehicle control module 1720 can signal the electric motor, based on a torque request, to rotate an input gear of the differential and, as a result, the wheels attached to the axle. The control module 1720 can adjust the current, voltage, and / or power levels of the electric motor to control the acceleration, deceleration, and / or speed of the vehicle 1710.

[0064] The examples revealed above include 3D power modules with vertical stacks of semiconductor chips to achieve compact enclosures and solder pads. The power module arrays feature a small, corresponding commutation loop area with low inductance. The arrays incorporate vertically oriented drain-source or emitter-collector connections to reduce the solder pads of the power electronics converter and power electronics inverter. The power modules include heat pipes for enhanced heat transfer, with vapor channels and / or vapor chambers located within and / or outside the areas between chips.

Claims

[1] Power module (600), which includes: a first layer stack (608); a second layer stack (610); a third layer stack arranged between the first layer stack (608) and the second layer stack (610) and comprising a first semiconductor chip (602), a second semiconductor chip (604) and a first intermediate spacer layer (605) arranged between the first semiconductor chip (602) and the second semiconductor chip (604); a first heat conduction tube (606) that extends at least partially into the first intermediate spacer layer (605); and at least one cooling plate (611) that absorbs heat energy from the first layer stack (608) and from the second layer stack (610), wherein the first layer stack (608), the second layer stack (610), the first heat guide tube (606) and the at least one cooling plate (611) enable double-sided cooling of both the first semiconductor chip (602) and the second semiconductor chip (604); characterized by , that the cooling plate (611) has a 'C'-shaped form with two sections, between which the three layer stacks (608, 610) are located, the two sections of the cooling plate (611) being connected to each other by a further section through which the heat conduction tube (606) extends. [2] Power module (600) according to claim 1, wherein: the first layer stack (608) comprises a first conductive layer (635), a second conductive layer (636) and a first dielectric layer (639) arranged between the first conductive layer (635) and the second conductive layer (636); and the second layer stack (610) comprises a third conductive layer (637), a fourth conductive layer (638) and a second dielectric layer (641) arranged between the third conductive layer (637) and the fourth conductive layer (638). [3] Power module (600) according to claim 1, further comprising a cooling circuit (640) configured to circulate a coolant to and from the at least one cooling plate (611). [4] Power module (600) according to claim 1, wherein the first heat conduction tube (606) comprises: a wick structure (703) arranged between the first semiconductor chip (602) and the second semiconductor chip (604); and a vapor chamber (705) which is at least partially arranged between the first semiconductor chip (602) and the second semiconductor chip (604). [5] Power module (600) according to claim 1, wherein the first heat conduction tube (606) comprises: a wick structure (802) arranged between the first semiconductor chip (602) and the second semiconductor chip (604); and a vapor chamber (804) that is not located between the first semiconductor chip (602) and the second semiconductor chip (604). [6] Power module (600) according to claim 1, wherein: the first intermediate spacer layer (605) is a conductive layer that connects a first switch of the first semiconductor chip (602) in series with a second switch of the second semiconductor chip (604); and The first switch and the second switch are designed to provide a half-bridge structure.

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