POWER MODULE WITH ONE POWER CHIP, ONE SUBSTRATE AND ONE COOLING BLOCK
Patent Information
- Application Number
- DE112023005234
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-12-16
- Filing Date
- 2023-12-15
- Publication Date
- 2025-10-16
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The invention relates to the field of cooling blocks for dissipating heat from a heat source, such as a power chip.
[0002] The present invention particularly relates to a power module comprising a power chip, a substrate and a cooling block provided with a vapor chamber. TECHNICAL BACKGROUND
[0003] Power modules are generally well known in technology. According to a Fig. In the example shown in Figure 1, a power module 1 comprises the following: - a power chip 20 and - a substrate 3 with at least one: ◯ electrical connection layer 32, which comprises an outer side 324 connected to the power chip 20 to supply it with energy, and an inner side 322 opposite the power chip 20, and ◯ an electrically insulating layer 33 which is in contact with the inner side 322 of the electrical connection layer 32, with: - a contact surface 334 covering the entire inner side 322, and - a chamber surface 332 opposite the electrical connection layer 32, and - a cooling block 4 with: ◯ a steam chamber housing 43 enclosing a steam chamber 430, ◯ a liquid cooling block 50 comprising a heat sink 52 and a cooling channel 54 through which cooling liquid flows, and ◯ a working fluid in the vapor chamber housing 43, wherein the working fluid is in a liquid or a gaseous state.
[0004] According to the Fig. 1, the power chip 20 is located below the substrate 3, which is located below the cooling block 4 of the power module 1, in a vertical direction V of a VLT reference.
[0005] The power chip 20 corresponds to an electrical component that forms the heat source of the power module 1, such as a power electronics switch or a processor or an LED.
[0006] The substrate 3 corresponds to a direct bonded copper (DBC) substrate, which provides the connections for forming an electrical circuit. In particular, the electrical connection layer 32 of the substrate 3 (in Fig. 1) that are held in position on the electrically insulating layer 33 of the substrate 3 for connection to various terminals of the power chip 20. Generally, the electrical connection layer 32 of the substrate 3 is made of a thermally conductive material, such as copper, and the electrically insulating layer 33 of the substrate 3 is made of an electrically non-conductive material, such as ceramic.
[0007] The cooling block 4 is intended for cooling the electronic components, ie the power chip 20 of the power module 1.
[0008] According to a Fig. 1, the heat sink 52 of the liquid cooling block 50 of the cooling block 4 comprises several parts (in Fig. 1 (only two are shown), including a first part 52A comprising a contact surface 524A opposite the vapor chamber 430 and an inner surface 522A defining the cooling channel 54 of the liquid cooling block 50, and a second part 52B comprising a first inner surface 522B defining the cooling channel 54 opposite the inner surface 522A of the first part 52A of the heat sink 52. The second part 52B also comprises a second surface 524B opposite the first inner surface 522B, which may be an outer surface with air or an inner surface of another cooling channel.
[0009] The vapor chamber 430 is enclosed in a vacuum-tight manner by the vapor chamber housing 43 of the cooling block 4, in which the working fluid is accommodated. The vapor chamber 430 is delimited in the vertical direction V between the chamber surface 332 of the electrically insulating layer 33 and the contact surface 524A of the first part 52A of the heat sink 52 of the liquid cooling block 50. In general, the vapor chamber housing 43 of the cooling block 4 is made of a thermally conductive material, preferably metal. The working fluid is preferably a cooling liquid such as untreated water, which is electrically conductive water. Thus, the electrically insulating layer 33 electrically insulates the electrical connection layer 32 of the cooling block 4.
[0010] The process of cooling the power chip 20 of the power module 1 includes the following steps: - Heat diffusion from the power chip 20 to the substrate 3 of the power module 1 and to the vapor chamber housing 43, - Increasing the temperature of the working fluid in the liquid state contained in the steam chamber 430, - Heat diffusion from the steam chamber housing 43 to the liquid cooling block 50 and conversion of the working fluid into the gaseous state, - Cooling of the working fluid in the steam chamber housing 43 in the gaseous state into a liquid state due to the heat exchange between the cooling block 50 cooled by the cooling liquid flows and the steam chamber housing 43, - Distributing the working fluid in the liquid state by gravity to the part of the vapor chamber housing 43 which is in contact with the chamber surface 332 of the electrically insulating layer 33 of the substrate 3 and which is opposite to the power chip 20 in order to cool the power chip 20.
[0011] All these steps are executed in a loop or even simultaneously.
[0012] However, the thermal conductivity of the electrically insulating layer 33 of the substrate 3 of the power module 1 is relatively low, which affects the heat transfer from the power chip 20 to the cooling block 4, and therefore the cooling of the power chip 20 is not optimal. As a result, the price of the power chip increases because it must have a higher temperature limit. DISCLOSURE OF THE INVENTION
[0013] The invention proposes a solution to the problems mentioned by providing a power module comprising a power chip, a substrate and a cooling block with a specific architecture.
[0014] The invention relates to a power module comprising: - at least one performance chip and - a substrate with at least one: ◯ electrical connection layer connected to the power chip to supply it with energy and comprising an inner side opposite to the power chip, and ◯ an electrically insulating layer arranged adjacent to the inside of the electrical connection layer and comprising a chamber surface opposite to the electrical connection layer, - a cooling block comprising: ◯ a steam chamber boundary wall with a condensation surface, ◯ a first part of a vapor chamber which is delimited in a first direction between the condensation surface of the vapor chamber boundary wall and the chamber surface of the electrically insulating layer, ◯ an opening forming a second part of the vapor chamber, which extends from the first part through the electrically insulating layer to an evaporator surface of the inside of the electrical connection layer opposite the power chip, ◯ an electrically insulating support separating the vapor chamber boundary wall from the electrically insulating layer and comprising an inner side defining the first part of the vapor chamber in a second direction through the electrically insulating support, ◯ a liquid cooling block comprising a heat sink and a cooling channel through which cooling liquid flows, and ◯ an electrically insulating fluid in the vapor chamber.
[0015] The power module according to the invention improves the thermal conductivity of the substrate, particularly in a region of the electrical connection layer opposite the power chip, due to the presence of an opening formed in the electrically insulating layer opposite the power chip. The heating part (the region of the electrical connection layer) of the substrate is therefore in direct contact with the vapor chamber. The use of an electrically insulating fluid makes it possible to insulate the electrical connection layer from the vapor chamber boundary wall.
[0016] Preferably, the electrically insulating layer of the substrate comprises an inner side defining the vapor chamber, which extends from the inner side of the electrical connection layer to the inner side of the electrically insulating support of the cooling block 40. The electrical insulation comprises a contact surface of the electrically insulating layer that is in contact with the inner side of the electrical connection layer.
[0017] In one example, the inner side extends from the contact surface of the electrically insulating layer to the inner side of the electrically insulating carrier.
[0018] Advantageously, the vapor chamber boundary wall of the cooling block is made of copper, as is the electrical connection layer of the substrate. This feature prevents electrolysis phenomena within the vapor chamber between the electrically insulating layer and the vapor chamber boundary wall.
[0019] According to an example of a first embodiment, the cooling block comprises an additional insulating plate arranged on a condensation surface of the vapor chamber boundary wall opposite the opening of the cooling block. This feature prevents the formation of arcs between the electrical connection layer of the substrate and the vapor chamber boundary wall of the cooling block.
[0020] Preferably, the additional insulating plate of the steam chamber boundary wall of the cooling block according to the previous example completely covers the condensation surface of the steam chamber boundary wall and has a thickness that is less than the thickness of the steam chamber boundary wall.
[0021] Advantageously, the electrically insulating fluid is pure water, such as treated water without any impurities, i.e., a non-conductive fluid. Using pure water in the vapor chamber allows proper electrical insulation to be maintained in the power module.
[0022] Preferably, the heat sink of the liquid cooling block is made of aluminum, which is a highly effective heat conductor.
[0023] Advantageously, the heat sink of the liquid cooling block comprises fins that extend outward to be cooled by the air surrounding the liquid cooling block. The presence of fins cools the heat sink, which cools the cooling fluid streams and thus the vapor chamber boundary wall and the electrically insulating fluid in the cooling channel. In particular, the fins can be hollow and form part of the cooling channel of the liquid cooling block.
[0024] According to a second embodiment, the vapor chamber boundary wall and the electrically insulating support of the cooling block form a single part. This feature reduces the total number of parts in the power module.
[0025] According to a third embodiment, the power module comprises a wick material arranged in the vapor chamber of the cooling block. The presence of a wick material allows the electrically insulating fluid in the liquid state to be distributed by capillary action onto the evaporator surface of the electrical connection layer of the substrate, thus cooling the power chip of the power module.
[0026] According to a first example of the third embodiment, the wick material fills the first and second parts of the vapor chamber of the cooling block.
[0027] According to a second example of the third embodiment, the wick material covers all surfaces within the vapor chamber of the cooling block. SHORT DESCRIPTION OF THE CHARACTERS
[0028] The invention is further explained in the description illustrated by the accompanying figures, in which: - Fig. 1, already described, is a sectional view of a power module with a power chip, a substrate and a cooling block according to the prior art, - Fig. 2 is a sectional view of a power module including a power chip, a substrate, and a cooling block according to a first example of a first embodiment of the invention, - Fig. 3 is a sectional view of a power module including a power chip, a substrate, and a cooling block according to a second example of the first embodiment of the invention, - Fig. 4 is a perspective sectional view of a power module including a power chip, a substrate, and a cooling block according to a third example of the first embodiment of the invention, - Fig. 5 is a sectional view of a power module including a power chip, a substrate, and a cooling block according to a fourth example of the first embodiment of the invention, - Fig. 6 is a sectional view of a power module including a power chip, a substrate and a cooling block according to a second embodiment of the invention, - Fig. 7 is a sectional view of a power module including a power chip, a substrate, and a cooling block according to a first example of a third embodiment of the invention, - Fig. 8 is a sectional view of a power module including a power chip, a substrate, and a cooling block according to a second example of the third embodiment of the invention. DETAILED DESCRIPTION
[0029] An example of a power module according to the invention will be described in detail below with reference to the accompanying figures. This example illustrates the features and advantages of the invention.
[0030] Unless otherwise stated, the same element has a unique reference in different figures.
[0031] To understand the invention, the vertical, longitudinal and transverse alignment are adopted according to the VLT reference shown in the figures, wherein the longitudinal axis L and the transverse axis T extend in a horizontal plane.
[0032] In the Fig. 2 to 8, a power module 10 is shown, wherein the Fig. 2 to 5 correspond to different examples of a first embodiment, Fig. 6 corresponds to a second embodiment and the Fig. 7 and Fig. 8 correspond to two examples of a third embodiment.
[0033] The power modules 10 according to the first, second and third embodiments comprise at least one power chip 20 and a substrate 30 having at least one: - electrical connection layer 32, which comprises an outer side 324 connected to the power chip 20 to supply it with energy, and an inner side 322 opposite the power chip 20, and - electrically insulating layer 34, which comprises a contact surface 344 arranged adjacent to the inner side 322 of the electrical connection layer 32, and a chamber surface 342 opposite the electrical connection layer 32.
[0034] The power modules 10 according to the first, second and third embodiments also comprise a cooling block 40 which comprises a vapor chamber boundary wall 42 with a condensation surface 424 and a contact surface 422 and a vapor chamber 44 bounded by the vapor chamber boundary wall 42.
[0035] The steam chamber 44 comprises the following: - a first part 442 which is defined in the vertical direction V between the chamber surface 342 of the electrically insulating layer 34 and the condensation surface 424 of the steam chamber boundary wall 42, - an opening 46 forming a second part 444 of the vapor chamber 44, which extends from the first part 442 through the electrically insulating layer 34 to an evaporator surface 322V of the inner side 322 of the electrical connection layer 32 opposite the power chip 20.
[0036] The cooling block 40 of each power module 10 according to the first, second and third embodiments further comprises: - an electrically insulating support 48 that separates the vapor chamber boundary wall 42 from the electrically insulating layer 34. The electrically insulating support 48 comprises an inner side 480 that delimits the first part 442 of the vapor chamber 44 in the longitudinal direction L through the electrically insulating support 48.
[0037] The cooling block 40 of each power module 10 according to the first, second and third embodiments further comprises: - a liquid cooling block 50 comprising a heat sink 52 and a cooling channel 54 through which cooling liquid flows, and - an electrically insulating fluid in the vapor chamber 44, wherein the electrically insulating fluid is in a liquid or a gaseous state.
[0038] Each power chip 20 corresponds to an electrical component that forms the heat source of the power module 10, such as a power electronics switch or a processor or an LED.
[0039] The contact between the power chip(s) 20 and the outer side 324 of the electrical connection layer 32 of the substrate 30 defines a contact surface on the outer side 324 of a thermal contact region of the electrical connection layer 32. The thermal contact region of the electrical connection layer 32 extends from this contact surface of the outer side 324 to at least a part of the evaporator surface 322V by allowing this contact surface to protrude vertically. This thermal contact region extends in the longitudinal direction L along a length L10, which is Fig. 2 and Fig. 3 (but is also limited by a length in the transverse direction T not shown).
[0040] The substrate 3 corresponds to a direct bonded copper (DBC) substrate, which provides the connections for forming an electrical circuit. In particular, the electrical connection layer 32 of the substrate 30 (in Fig. 4) which are held in position on the electrically insulating layer 34 of the substrate 30 to be connected to various connectors of the power chip 20.
[0041] The electrically insulating layer 34 of the substrate 30 includes an inner surface 346 extending from the contact surface 344 of the electrically insulating layer 34, which is in contact with the inner surface 322 of the electrical connection layer 32, to the chamber surface 342 of the electrically insulating layer 34. The inner surface 346 defines the opening 46, which forms a second portion 444 of the vapor chamber 44.
[0042] The chamber surface 342 of the electrically insulating layer 34 faces the condensation surface 424 of the vapor chamber boundary wall 42 of the cooling block 40.
[0043] The first part 444 extends from the second part 442 of the vapor chamber 44 and comprises a vertically delimited section between the chamber surface 342 of the electrically insulating layer 34 and the condensation surface 424 of the vapor chamber boundary wall 42.
[0044] Preferably, the electrical connection layer 32 of the substrate 30 is made of a thermally conductive material, such as copper, and the electrically insulating layer 34 of the substrate 30 is made of an electrically non-conductive material, such as ceramic.
[0045] The cooling block 40 is designed to cool the electronic components, ie the power chip 20 of the power module 10.
[0046] According to a report published in Fig. 2 to 8, the heat sink 52 of the liquid cooling block 50 of the cooling block 4 comprises several parts (in Fig. 2, only two are shown), including a first part 52A and a second part 52B, which form the cooling channel 54 between them.
[0047] The first part 52A includes a contact surface 524A in contact with the vapor chamber boundary wall 42 and an inner side 522A which defines the cooling channel 54 of the liquid cooling block 50.
[0048] The second part 52B comprises a first inner side 522B, which faces the inner side 522A and together with it defines the cooling channel 54 of the liquid cooling block 50, and a second inner side 524B opposite the inner side 522B of the second part 52B of the heat sink 52.
[0049] The first part 52A and the steam chamber boundary wall 42 separate the cooling channel 54 with respect to the steam chamber 44.
[0050] The vapor chamber 44 is a sealed vacuum in which the electrically insulating fluid is contained. The first part 442 of the vapor chamber 44 extends in a longitudinal direction L over a length L1 between two surfaces of the inner side 480 of the electrically insulating carrier 48.
[0051] The inner side 480 of the electrically insulating support 48 may be circular in section, for example cylindrical or conical, or it may be polygonal in section, for example rectangular, and be a polyhedron.
[0052] The opening 46, which forms the second part 444 of the vapor chamber 44, is delimited in the longitudinal direction L between two surfaces of the inner side 346 of the electrically insulating layer 34 of the substrate 30 along a length L2.
[0053] Furthermore, the length L2 of the opening 46 is greater than or equal to the length L10 of the contact area between the power chip(s) 20 and the outer side 324 of the electronic interconnect layer 32 of the substrate 30.
[0054] Therefore, the thermal contact area includes at least a portion of the evaporator surface 322V of the inner side 322 of the electrical connection layer 32, corresponds to the heating part of the substrate 30, is in direct contact with the first part 442 of the vapor chamber 44. The length L1 of the first part 442 of the vapor chamber 44 is greater than the length L2 of the second part 442 of the vapor chamber 44 to provide a large vapor chamber 44.
[0055] The opening 46 may be circular in section, for example cylindrical or conical, or it may be polygonal in section, for example rectangular, and be a polyhedron.
[0056] The inner side 480 of the electrically insulating support 48 of the cooling block 40 extends from the chamber surface 342 of the electrically insulating layer 34 to the condensation surface 424 of the vapor chamber boundary wall 42.
[0057] Advantageously, the vapor chamber boundary wall 42 of the cooling block 40 is made of a thermally conductive material, such as copper, and the electrically insulating support 48 is made of an electrically non-conductive material, such as plastic. Preferably, the electrically insulating fluid is a cooling liquid, such as treated water without any impurities, which is electrically non-conductive water.
[0058] According to the first and second embodiments shown in the Fig. 1 to 6, each power chip 20 is located in the vertical direction V below the substrate 30, which is located below the cooling block 40 of the power module 10. Therefore, the electrically insulating fluid in the liquid state is distributed by gravity onto the evaporation surface 322V of the electrical connection layer 32 to cool the power chip 20 of the power module 10.
[0059] Fig. 2 shows a power module 10 according to a first example of a first embodiment, comprising only one power chip 20. The length L10 of the contact area between the power chip 20 and the outer side 324 of the electronic interconnect layer 32 of the substrate 30 corresponds to the length of the single power chip 20 of the power module 10. Furthermore, the evaporator area 322V of the inner side 322 of the electrical interconnect layer 32 of the substrate 30 is opposite to the single power chip 20. In particular, the evaporator area 322V corresponds to the surface (the inner side 322) of the thermal contact area of the electronic interconnect layer 32. Consequently, the length L2 is equal to the length L10.
[0060] In Fig. Figure 3 shows a power module 10 according to a second example of the first embodiment. This example differs from the first example of the first embodiment in that it includes three power chips 20 and an additional insulation plate 45.
[0061] In this example, the three power chips 20 are arranged longitudinally on the outer side 324 of the electrical connection layer 32 of the substrate such that a central power chip 20 is located between two lateral power chips 20 separated by a gap. Therefore, the length L10 of the contact area between the power chips 20 and the outer side 324 of the electronic connection layer 32 of the substrate 30 corresponds to the addition of the length of the three power chips 20 and the length of the gaps between them. Furthermore, the evaporator area 322V of the inner side 322 of the electrical connection layer 32 of the substrate 30 is located opposite the three power chips 20. In particular, the evaporator area 322V is larger than the area (of the inner side 322) of the thermal contact region of the electronic connection layer 32, but encompasses it. Consequently, the length L2 is greater than the length L10.
[0062] The additional insulating plate 45 is arranged on the condensation surface 424 of the vapor chamber boundary wall 42 opposite the opening 46 of the cooling block 40. In the case where the vapor chamber boundary wall 42 is directly adjacent to the heat sink 52 of the liquid cooling block 50, the use of an additional insulating plate 45 prevents the formation of arcs between the electrical connection layer 32 of the substrate 30 and the vapor chamber boundary wall 42 of the cooling block 40. Preferably, the additional insulating plate 45 has a thickness that is less than the thickness of the vapor chamber boundary wall 42 and must be as thin as possible. Furthermore, the additional insulating plate 45 is made of an electrically non-conductive material such as ceramic.
[0063] In Fig. Figure 4 shows a power module 10 according to a third example of the first embodiment. This example differs from the second example of the first embodiment in that the additional insulating plate 45 of the vapor chamber boundary wall 42 of the cooling block 40 completely covers the condensation surface 424 of the vapor chamber boundary wall 42. This figure also shows the conductive traces 326 of the electrical connection layer 32 of the substrate 30.
[0064] In Fig. 5 shows a power module 10 according to a fourth example of the first embodiment. This example differs from the first example of the first embodiment in that the electrically insulating carrier 48 of the cooling block 40 has a specific architecture in which it encloses the electrical connection layer 32 and the electrically insulating layer 34 of the substrate 30, as well as the heat sink 52 of the liquid cooling block 50. The electrically insulating carrier 48 includes recesses 482, 484, 486 for assembling the substrate 30 and the cooling block 50 with the electrically insulating carrier 48.In particular, the electrically insulating support 48 includes a first recess 482 configured to receive the electrical connection layer 32 of the substrate 30, a second recess 484 configured to receive the electrically insulating layer 34 of the substrate 30, and a third recess 486 configured to receive the first portion 522A of the heat sink 52 of the liquid cooling block 52. In this example, the inner surface 480 of the electrically insulating support 48 extends from the second recess 484, which engages the chamber surface 342 of the electrically insulating layer 34, to the third recess 486, which engages the condensation surface 424 of the vapor chamber boundary wall 42.
[0065] Furthermore, this fourth example differs from the first example of the first embodiment in that the first part 52A of the heat sink 52 of the liquid cooling block 50 has a specific architecture in which it envelops the vapor chamber boundary wall 42 of the cooling block 40. The first part 52A of the heat sink 52 of the liquid cooling block 50 includes a recess 526 for assembling the vapor chamber boundary wall 42 of the cooling block 40 with the first part 52A of the heat sink 52. In particular, the recess 526 of the first part 52A of the heat sink 52 is designed to receive the vapor chamber boundary wall 42 along its entire length in the longitudinal direction L.
[0066] In Fig. Figure 6 shows a power module 10 according to a second embodiment. This embodiment differs from the first embodiment in that the vapor chamber boundary wall 42 and the electrically insulating support 48 of the cooling block 4 form a monoblock assembly 428 in a single part, enclosing the entire substrate 30. Advantageously, the monoblock assembly 428 is made of an electrically non-conductive material, such as plastic.
[0067] In the Fig. 7 and Fig. Figure 8 shows a power module 10 according to a third embodiment. This embodiment differs from the second embodiment in that the power chip 20 is located in the vertical direction V above the substrate 30, which is located above the cooling block 40 of the power module 10. Therefore, the power module 10 includes a wick material 49 arranged in the vapor chamber 44 of the cooling block 40. The wick material 49 is designed to absorb the electrically insulating fluid in the liquid state and distribute it by capillary action to the evaporator surface 322V of the electrical connection layer 32 in order to cool the power chip 20 of the power module 10.
[0068] In Fig. 7 shows a first example of the third embodiment in which the wick material 49 fills the first and second parts 442, 444 of the vapor chamber 44 of the cooling block 40.
[0069] In Fig.Figure 8 shows a second example of the third embodiment, in which the wicking material 49 coats all surfaces in the vapor chamber 44 of the cooling block 40. Specifically, the wicking material 49 is a coating that covers the evaporator surface 322V of the inner surface 322 of the electrical connection layer 32, the chamber surface 342 and the inner surface 346 of the electrically insulating layer 34 of the substrate 30, the condensation surface 424 of the vapor confinement wall 42, and the inner surface 480 of the electrically insulating support 48 of the cooling block 40.
[0070] The wick material 49 used in the third embodiment can be made of sintered copper, fiber material, sintered plastic powder, and microfiber-like materials. Furthermore, since copper is a thermally conductive material, it cannot be used in the wick material 49 if the vapor chamber 44 of the cooling block 40 needs to be electrically insulated.
[0071] According to a further embodiment not shown in the figures, the heat sink 52 of the liquid cooling block 50 comprises fins extending into the cooling channel 54 of the liquid cooling block 50 to cool the electrically insulating fluid of the cooling channel 54.
[0072] The process of cooling the power chip 20 of the power module 10 according to the invention comprises the following steps: - Heat diffusion from each power chip 20 to the substrate 30 of the power module 10, in particular in the thermal contact area of the electrical connection layer 32, - increasing the temperature of the electrically insulating fluid in the liquid state contained in the steam chamber 44 in the second part 444 of the steam chamber 44 until a part of the electrically insulating fluid in the liquid state changes into a gaseous state, - Cooling the electrically insulating fluid in the first part 442 of the vapor chamber 44 in the gaseous state by the liquid cooling block 50 until a part of the electrically insulating fluid in the gaseous state changes into a liquid state, - Distributing the electrically insulating fluid in the liquid state by gravity (when each power chip 20 is located below) or by capillary action (when each power chip 20 is located above and when a wick material 49 is arranged in the vapor chamber 44) onto the evaporator surface 322V of the electrical connection layer 32 in order to cool the power chip 20 of the power module 10.
[0073] All these steps are executed in a loop or even simultaneously.
[0074] Such a power module 10 according to the invention makes it possible to improve the heat transfer from the power chip 20 to the cooling block 40 and to optimize the cooling of the power chip 20. Furthermore, with such an architecture of the power module 10, the ratio of heat transfer to the effective thermal conductivity of the power module 10 is improved due to the presence of the opening 46 formed in the electrically insulating layer 34 opposite the power chip 20 and the use of a non-conductive fluid such as pure water.
Claims
[1] Power module (10) comprising: - at least one power chip (20) and - a substrate (30) with at least one: ◯ electrical connection layer (32) connected to the power chip (20) to supply it with energy and comprising an inner side (322) opposite the power chip (20), and ◯ an electrically insulating layer (34) which is arranged adjacent to the inner side (322) of the electrical connection layer (32) and comprises a chamber surface (342) opposite the electrical connection layer (32), - characterized by that it comprises a cooling block (40) comprising: ◯ a steam chamber boundary wall (42) with a condensation surface (424), ◯ a steam chamber (44) having a first part (442) defined in a first direction between the condensation surface (424) of the steam chamber boundary wall (42) and the chamber surface (342) of the electrically insulating layer (34), ◯ an opening (46) forming a second part (444) of the vapor chamber (44) which extends from the first part (442) through the electrically insulating layer (34) to an evaporator surface (322V) of the inner side (322) of the electrical connection layer (32) opposite the power chip (20), ◯ an electrically insulating support (48) which separates the vapor chamber boundary wall (42) from the electrically insulating layer (34) and comprises an inner side (480) which delimits the first part (442) of the vapor chamber (44) in a second direction through the electrically insulating support (48), ◯ a liquid cooling block (50) comprising a heat sink (52) and a cooling channel (54) through which cooling liquid flows, and ◯ an electrically insulating fluid in the steam chamber (44). [2] Power module (10) according to claim 1, characterized by that the vapor chamber boundary wall (42) of the cooling block (40) is made of copper, as is the electrical connection layer (32) of the substrate (30). [3] Power module (10) according to one of claims 1 to 2, characterized by that the cooling block (40) comprises an additional insulating plate (45) which is arranged on a condensation surface (424) of the steam chamber boundary wall (42) opposite the opening (46) of the cooling block (40). [4] Power module (10) according to claim 3, characterized bythat the additional insulating plate (45) of the steam chamber boundary wall (42) of the cooling block (40) completely covers the condensation surface (424) of the steam chamber boundary wall (42) and has a thickness which is less than the thickness of the steam chamber boundary wall (42). [5] Power module (10) according to one of claims 1 to 4, characterized by that the electrically insulating fluid is pure water. [6] Power module (10) according to one of claims 1 to 5, characterized by that the heat sink (52) of the liquid cooling block (50) is made of aluminum. [7] Power module (10) according to claims 1 to 6, characterized by that the heat sink (52) of the liquid cooling block (50) comprises fins which extend outwards so that they are cooled by the air surrounding the liquid cooling block (50). [8] Power module (10) according to claims 1 to 7, characterized bythat it comprises a wick material (49) which is arranged in the steam chamber (44) of the cooling block (40). [9] Power module (10) according to claim 8, characterized by that the wick material (49) fills the first and second parts (442, 444) of the vapor chamber (44) of the cooling block (40). [10] Power module (10) according to claim 8, characterized by that the wick material (49) covers all surfaces (322V, 342, 346, 424, 480) within the vapor chamber (44) of the cooling block (40).