Power module

Abstract

The invention relates to a power module. The power module includes an insulating layer, a first metal layer disposed on a first surface of the insulating layer and including a first intaglio pattern, and a second metal layer disposed on a second surface of the insulating layer and including a second intaglio pattern. The second intaglio pattern is formed such that the second metal layer has a volume corresponding to a volume of the first metal layer.

Description

Technical Field

[0001] The present invention relates to a power module with improved durability in terms of balanced metal layer volume. Background Art

[0002] Recently, as concerns about the environment increase, the number of environmentally friendly vehicles equipped with electric motors as a power source is increasing. Environmentally friendly vehicles are also called motor vehicles, and representative examples thereof include electric vehicles (EVs) and hybrid electric vehicles (HEVs).

[0003] An electric vehicle is equipped with an inverter for converting direct current into alternating current when driving a motor, and the inverter is generally composed of one or more power modules equipped with semiconductor chips that perform a switching function.

[0004] During the operation of the power module as described above, along with the heat generated by the semiconductor chip provided in the power module, if a high temperature condition caused by the heat generation is not resolved, the operation performance of the power module may be degraded.

[0005] Therefore, various methods are applied to improve the operation performance while dissipating the heat generated by the power module, among which a method of connecting a cooling channel in which a cooling fluid flows to an outer portion of the power module may be referred to as an example.

[0006] In this case, a heat sink for dissipating heat may be provided in the power module, and the heat sink may be separately attached to an outer portion of the power module, or may be integrally provided to a substrate of the power module.

[0007] The information included in this Background section of the present invention is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgment or any form of suggestion that this information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0008] Various aspects of the present invention are directed to providing a heat sink integrated power module with lower processing cost and improved durability.

[0009] Problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art through the following description.

[0010] In order to achieve the above problem, according to an exemplary embodiment of the present invention, there is provided a power module, comprising: an insulating layer; a first metal layer, which is arranged on a first surface of the insulating layer and includes a first intaglio pattern; and a second metal layer, which is arranged on a second surface of the insulating layer and includes a second intaglio pattern, wherein the second intaglio pattern can be formed so that the second metal layer has a volume corresponding to the volume of the first metal layer.

[0011] For example, the first intaglio pattern and the second intaglio pattern may be formed such that the first metal layer and the second metal layer have different planar shapes from each other.

[0012] For example, the first intaglio pattern and the second intaglio pattern may be formed such that the first metal layer and the second metal layer have different cross-sectional shapes from each other.

[0013] For example, the first intaglio pattern may form an electrical path in the first metal layer.

[0014] For example, the first intaglio pattern may be formed by penetrating a portion of the first metal layer to expose the insulating layer toward the penetrated portion of the first metal layer.

[0015] For example, the power module may include a semiconductor chip disposed at a first peripheral portion that relatively protrudes outside a portion of the first metal layer having the first intaglio pattern.

[0016] For example, the second intaglio pattern may be formed on the second metal layer to prevent the insulating layer from being exposed in a direction toward the second metal layer.

[0017] For example, the second intaglio pattern may be formed to form the second peripheral portion, which relatively protrudes to the outside of the portion of the second metal layer where the intaglio is formed, into a needle shape.

[0018] For example, the power module may include a cooling channel in which a cooling fluid in contact with the second peripheral portion flows.

[0019] For example, a first intaglio pattern may be formed by penetrating a portion of the first metal layer to expose the insulating layer through the penetrated portion in a direction toward the first metal layer, and a second intaglio pattern may be formed on the second metal layer to prevent the insulating layer from being exposed in a direction toward the second metal layer.

[0020] For example, the first intaglio pattern may be formed to gradually reduce the thickness of the cross section of the first metal layer in a direction toward a central portion of the intaglio.

[0021] For example, the second intaglio pattern may be formed to gradually reduce the thickness of the cross section of the second metal layer in a direction toward a central portion of the intaglio.

[0022] For example, the first intaglio pattern and the second intaglio pattern may be formed by removing a portion of the first metal layer and a portion of the second metal layer by etching.

[0023] For example, at least one of the first intaglio pattern and the second intaglio pattern may be formed by wet etching using a chemical reaction.

[0024] For example, the first and second intaglio patterns may be formed by etching the first and second metal layers after the first and second metal layers are respectively bonded to both surfaces of the insulating layer.

[0025] According to various embodiments of the present invention described above, the volumes of metal layers on opposite surfaces of the insulating layer are balanced with each other, thereby alleviating durability degradation such as substrate bending due to volume asymmetry, crack occurrence in a semiconductor chip, etc.

[0026] In addition, the present invention can provide a heat sink integrated structure through simple process and low processing cost.

[0027] The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art through the following description.

[0028] The methods and apparatus of the present invention have other features and advantages, which will be apparent from or will be described in more detail in the accompanying drawings and subsequent detailed descriptions incorporated herein, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic cross-sectional view showing a power module according to an exemplary embodiment of the present invention.

[0030] Figure 2 is a plan view showing a portion of a first metal layer of a power module according to an exemplary embodiment of the present invention.

[0031] Figure 3 is a plan view showing a portion of a second metal layer of a power module according to an exemplary embodiment of the present invention.

[0032] Figure 4 is a schematic diagram illustrating a manufacturing process of a power module according to an exemplary embodiment of the present invention.

[0033] It is to be understood that the accompanying drawings are not drawn to scale, but are appropriately simplified drawings of various features that illustrate the basic principles of the present invention. The predetermined design features of the present invention included herein (including, for example, specific size, direction, position and shape) will be determined in part by the specific environment to be applied and used.

[0034] In the drawings, like reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. DETAILED DESCRIPTION

[0035] Reference will now be made in detail to various embodiments of the present invention, examples of which are shown in the accompanying drawings and described below. Although the present invention will be described in conjunction with the exemplary embodiments of the present invention, it will be understood that this specification is not intended to limit the present invention to those exemplary embodiments of the present invention. On the other hand, the present invention is intended to include not only the exemplary embodiments of the present invention, but also various alternative embodiments, modified embodiments, equivalent embodiments and other embodiments that may be included in the spirit and scope of the present invention as defined by the appended claims.

[0036] In the following description, structural or functional descriptions assigned to exemplary embodiments according to the concepts of the present invention are intended to describe exemplary embodiments of the present invention, and thus it should be understood that the present invention can be implemented in various ways without being limited to the exemplary embodiments of the present invention.

[0037] The embodiments described herein can be changed in various ways and various shapes, so specific embodiments are shown in the drawings and will be described in detail in this specification. However, it should be understood that the exemplary embodiments according to the inventive concept are not limited to the exemplary embodiments described below with reference to the attached drawings, but all modified embodiments, equivalent embodiments and alternative embodiments are included in the scope and spirit of the present invention.

[0038] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. It is understood that the terms defined by dictionaries have the same meaning as in the context of the relevant technology, and unless the context clearly dictates otherwise, the terms should not be ideally or overly formally defined.

[0039] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or similar components are given the same reference numerals regardless of the numbers of the drawings, and the description is not repeated.

[0040] In the following description, if it is determined that the detailed description of the known technology related to the present invention makes the subject matter of the exemplary embodiment described herein unclear, the detailed description is omitted. In addition, the attached drawings are provided only for easy understanding of the exemplary embodiments included in the specification, and the technical spirit included in the specification is not limited by the attached drawings, and all changed embodiments, equivalent embodiments and replacement embodiments should be understood to be included in the spirit and scope of the present invention.

[0041] Terms including ordinal numbers such as "first", "second", etc. may be used to describe various components, but these components are not interpreted as being limited by the terms. These terms are only used to distinguish one component from another.

[0042] It should be understood that when an element is referred to as being “connected to” or “engaged to” another element, it may be directly connected to or directly engaged to the other element, or connected to or engaged to the other element with other elements interposed therebetween. On the other hand, it should be understood that when an element is referred to as being “directly connected to” or “directly engaged to” another element, it may be connected to or engaged to the other element without other elements interposed therebetween.

[0043] Singular forms are intended to include plural forms unless the context clearly indicates otherwise.

[0044] It will be further understood that the terms “including” or “having” used in this specification specify the presence of stated features, steps, operations, components, parts or a combination thereof, but do not exclude the presence or addition of one or more other features, values, steps, operations, components, parts or a combination thereof.

[0045] The power module according to an exemplary embodiment of the present invention is configured to form an intaglio pattern on a metal layer arranged at opposite surfaces of an insulating layer to achieve a balance in volume thereof, and is thus configured to mitigate a decrease in durability of the power module due to bending of a substrate, cracks of a semiconductor chip, etc.

[0046] In the following, reference will be made to Figure 1 , Figure 2 and Figure 3 A configuration of a power module according to an exemplary embodiment of the present invention is described.

[0047] Figure 1 is a schematic cross-sectional view showing a power module according to an exemplary embodiment of the present invention. Figure 2 is a plan view showing a portion of a first metal layer of a power module according to an exemplary embodiment of the present invention. Figure 3 is a plan view showing a portion of a second metal layer of a power module according to an exemplary embodiment of the present invention.

[0048] refer to Figure 1 , Figure 2 and Figure 3 , a power module according to an exemplary embodiment of the present invention may include an insulating layer 10, a first metal layer 100, a second metal layer 200, a semiconductor chip 300, and a cooling channel 400. However, Figure 1Components related to the description of the exemplary embodiment of the present invention are mainly shown, and the power module can actually be implemented with more or less components than those shown. Hereinafter, each component will be described in detail.

[0049] First, the insulating layer 10 may be made of an insulator such as ceramic and may have a plate shape.

[0050] The first metal layer 100 and the second metal layer 200 may be disposed on the first surface and the second surface of the insulating layer 10 , respectively, may be insulated from each other by the insulating layer 10 , for example, and may be made of copper.

[0051] The first metal layer 100 and the second metal layer 200 may include a first intaglio pattern 110 and a second intaglio pattern 210, respectively. The second intaglio pattern may be formed such that the second metal layer 200 has a volume corresponding to that of the first metal layer 100.

[0052] At this time, the first and second intaglio patterns 110 and 210 may be formed at the first and second metal layers 100 and 200 and may have a reduced thickness compared to surrounding portions thereof.

[0053] In addition, in the case where the volume of the first metal layer 100 and the volume of the second metal layer 200 correspond to each other, the first metal layer 100 and the second metal layer 200 can have the same volume, and although the volumes of the first metal layer 100 and the second metal layer 200 are not exactly the same, they can be at similar levels of volume.

[0054] For example, the volume of the first metal layer 100 and the volume of the second metal layer 200 may be formed to correspond to each other in a ratio of 4 to 6:6 to 4.

[0055] The first intaglio pattern 110 and the second intaglio pattern 210 may be formed so that the first metal layer 100 and the second metal layer 200 have different planar shapes from each other, or so that the first metal layer 100 and the second metal layer 200 have different cross-sectional shapes from each other. For example, the first metal layer 100 may have a planar shape such as Figure 2 The plane shape shown in FIG. 1 and the second metal layer 200 may have a Figure 3 The planar shape shown, and may have Figure 1 The cross-sectional shape shown.

[0056] However, when the first metal layer 100 and the second metal layer 200 have different planar shapes or different cross-sectional shapes, the first intaglio pattern 110 and the second intaglio pattern 210 may be formed so that the first metal layer 100 and the second metal layer 200 have volumes corresponding to each other. On the basis of the volume of the first metal layer 100 formed by the first intaglio pattern 110, the second intaglio pattern 210 may be formed so that the second metal layer 200 has a volume corresponding to the volume of the first metal layer 100.

[0057] On the other hand, the first intaglio pattern 110 may form an electrical path in the first metal layer 100. In other words, the first intaglio pattern 110 may be used as a circuit pattern forming an electrical path inside the power module.

[0058] In this case, the first intaglio pattern 110 may be formed by penetrating the first metal layer 100 to expose the insulating layer 10 toward the first metal layer 100. In other words, the first intaglio pattern 110 may be formed such that the cross-sectional thickness of the first metal layer 100 is completely reduced to expose the insulating layer 10 in direct contact with the first metal layer 100 through the first intaglio pattern 110.

[0059] In addition, the semiconductor chip 300 is arranged at the first peripheral portion 120 to be electrically connected to the first metal layer 100, and the first peripheral portion 120 relatively protrudes to the outside of the portion of the first metal layer 100 on which the first intaglio pattern 110 is formed. In this case, the semiconductor chip 300 may be bonded to the first peripheral portion 120, and the bonding may be performed, for example, by welding, sintering, or the like.

[0060] On the other hand, the second intaglio pattern 210 may be formed on the second metal layer 200 to prevent the insulating layer 10 from being exposed toward the second metal layer 200. In other words, unlike the first intaglio pattern 110, the second intaglio pattern 210 may be formed without completely penetrating the surface of the second metal layer 200. Alternatively, the second intaglio pattern 210 may be formed by recessing the surface of the second metal layer 200 so that the recessed surface of the second metal layer 200 is spaced apart from the top surface of the second metal layer 200.

[0061] In this case, the second intaglio pattern 210 may be formed such that the second peripheral portion 220 is formed in a needle shape and the second peripheral portion 220 relatively protrudes outside the portion of the second metal layer 200 where the intaglio is formed. However, the second peripheral portion 220 is not limited to the above shape and may include a microchannel form, etc.

[0062] In other words, the second peripheral portion 220 may have a suitable shape for use as a heat sink, and the second intaglio pattern 210 may allow the heat sink to be integrally formed with the second metal layer 200. In this case, the area of ​​the second metal layer 200 exposed to the outside is increased by the second intaglio pattern 210, thereby improving heat dissipation performance.

[0063] In addition, the power module according to the exemplary embodiment of the present invention may include a cooling channel 400 in which a cooling fluid in contact with the second peripheral portion 220 flows. In this case, the cooling performance is improved compared to when the cooling channel 400 is not provided, and the cooling efficiency through the cooling channel 400 can be improved by increasing the contact area between the cooling fluid and the second metal layer 200.

[0064] On the other hand, in the exemplary embodiment of the present invention, the characteristics caused by the above-mentioned first intaglio pattern 110 and second intaglio pattern 210 can be simultaneously applied. In other words, the first intaglio pattern 110 is formed by penetrating the first metal layer 100 so that the insulating layer 10 is exposed outward in the direction toward the first metal layer 100, and the second intaglio pattern 210 can be formed on the second metal layer 200 so that the insulating layer 10 is not exposed outward in the direction toward the second metal layer 200.

[0065] Therefore, the first metal layer 100 may include a circuit pattern through the first intaglio pattern 110, and the second metal layer 200 may have a heat sink through the second intaglio pattern 210. In this case, since the first metal layer 100 and the second metal layer 200 are also formed such that their volumes correspond to each other, a decrease in durability that occurs when the substrate may bend due to volume asymmetry or cracks occur in the semiconductor chip 300 may be alleviated.

[0066] like Figure 1 As shown, the first intaglio pattern 110 is formed to gradually reduce the thickness of the cross section of the first metal layer 100 in a direction toward the central portion of the intaglio portion of the first metal layer so that the first intaglio pattern 110 has an elliptical shape, a parabolic shape or a semicircular shape in the cross section, and the second intaglio pattern 210 can also be formed in a shape similar to the first intaglio pattern 110.

[0067] When the first metal layer 100 and the second metal layer 200 are formed so that the thickness of the cross section of each of the first metal layer 100 and the second metal layer 200 gradually decreases, the thermal stress applied to the end of each of the first and second intaglio patterns 110 and 210 (i.e., applied to each of the first peripheral portion 120 and the second peripheral portion 220) can be reduced compared to when the thickness of the cross section is uniformly reduced at the same time, and thus the decrease in the durability of the power module can be effectively alleviated.

[0068] However, both or at least one of the first and second intaglio patterns 110 and 210 may have a shape that is vertically bent from each of the first and second peripheral portions 120 and 220 in its cross section as the thickness of the first or second metal layer 100 or 200 uniformly decreases.

[0069] On the other hand, the first and second intaglio patterns 110 and 210 may be formed by etching a portion of the first and second metal layers 100 and 200. In this case, the processing cost may be reduced compared to the case where the circuit pattern or the heat sink is formed by mechanical processing.

[0070] As an etching method, dry etching using a reactive gas or the like may be used, and wet etching using a chemical reaction may be used. When the first and second intaglio patterns 110 and 210 are formed by wet etching, the cross-sections of the first and second intaglio patterns 110 and 210 may have the same cross-sections as described above with reference to FIG. Figure 1 The oval shape described can effectively alleviate the degradation of durability caused by thermal stress.

[0071] On the other hand, the first and second intaglio patterns 110 and 210 may be formed by bonding the first and second metal layers 100 and 200 on opposite surfaces of the insulating layer 10 and then etching the first and second metal layers 100 and 200 .

[0072] In this case, compared with the method of forming a circuit pattern, a heat sink, etc. on the first metal layer 100 and the second metal layer 200 and then combining the first metal layer 100 and the second metal layer 200, the occurrence of cracks in the insulating layer 10 caused by the asymmetry of the relative surfaces of the insulating layer 10 during processing, the occurrence of alignment failure of the first metal layer 100 and the second metal layer 200, etc. can be alleviated, thereby reducing the processing difficulty and cost.

[0073] In the following, reference will be made to Figure 4 A manufacturing process of a power module according to an exemplary embodiment is described.

[0074] Figure 4 is a schematic diagram illustrating a manufacturing process of a power module according to an exemplary embodiment of the present invention.

[0075] refer to Figure 4First, at S410, the insulating layer 10, the first metal layer 100, and the second metal layer 200 are respectively provided, and then at S420, before processing the first metal layer 100 and the second metal layer 200, the first metal layer 100 and the second metal layer 200 are bonded on opposite surfaces of the insulating layer 10. In this case, the bonding of the first metal layer 100 and the second metal layer 200 at S420 may be performed under conditions of high temperature and high pressure.

[0076] The first metal layer 100 and the second metal layer 200 are processed at S430 only after the first metal layer 100 and the second metal layer 200 are bonded to the insulating layer 10. In this case, the processing of the first metal layer 100 and the second metal layer 200 may be performed by etching, by wet etching. The above process may be formed so that a circuit pattern is formed at the first metal layer 100 and a heat sink is formed at the second metal layer 200, and as a result of the processing, the volume of the first metal layer 100 and the volume of the second metal layer 200 correspond to each other.

[0077] According to various embodiments of the present invention described above, the volumes of the metal layers on opposite surfaces of the insulating layer are balanced with each other, thereby alleviating durability degradation such as bending of the substrate due to volume asymmetry, crack occurrence in the semiconductor chip, etc.

[0078] In addition, the present invention can provide an integrated heat sink structure through simple processes and lower processing costs.

[0079] For ease of interpretation and accurate definition of the appended claims, the terms "upper", "lower", "inner", "outer", "above", "below", "upward", "downward", "front", "rear", "back", "inner", "outer", "inwardly", "outwardly", "interior", "exterior", "inside", "outside", "forward" and "rearward" are used to describe the features of the exemplary embodiments with reference to the positions of such features shown in the accompanying drawings. It will be further understood that the term "connected" or its derivatives refer to both direct and indirect connections.

[0080] The term "and / or" may include a combination of a plurality of related listed items or any one of a plurality of related listed items. For example, "A and / or B" includes all three situations such as "A", "B" and "A and B".

[0081] In this specification, unless otherwise stated, a singular expression includes a plural expression unless the context clearly indicates otherwise.

[0082] In an exemplary embodiment of the present invention, “at least one of A and B” may mean “at least one of A or B” or “at least one of a combination of at least one of A and B”. Furthermore, “one or more of A and B” may mean “one or more of A or B” or “one or more of a combination of one or more of A and B”.

[0083] In exemplary embodiments of the present invention, it should be understood that terms such as “include” or “have” are intended to specify that the features, values, steps, operations, elements, parts, or a combination thereof described in the specification are present, and do not exclude the possibility of adding or existing one or more other features, values, steps, operations, elements, parts, or a combination thereof.

[0084] According to the exemplary embodiments of the present invention, components may be combined with each other to be implemented as one, or some components may be omitted.

[0085] The foregoing descriptions of specific exemplary embodiments of the present invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise form disclosed, and it is apparent that many modified embodiments and variations of the embodiments are possible in view of the above teachings. The exemplary embodiments are selected and described in order to explain the specific principles of the present invention and their practical applications, so that other persons skilled in the art can realize and utilize various exemplary embodiments of the present invention and various alternative implementations and modified embodiments thereof. The scope of the present invention is intended to be limited by the appended claims and their equivalents.

Claims

1. A power module, comprising: Insulation layer; a first metal layer disposed on a first surface of the insulating layer and comprising a first intaglio pattern; as well as a second metal layer disposed on the second surface of the insulating layer and comprising a second intaglio pattern, The second intaglio pattern is formed so that the second metal layer has a volume corresponding to the volume of the first metal layer.

2. The power module according to claim 1, wherein: The first intaglio pattern and the second intaglio pattern are formed so that the first metal layer and the second metal layer have different planar shapes from each other.

3. The power module according to claim 1, wherein: The first intaglio pattern and the second intaglio pattern are formed such that the first metal layer and the second metal layer have different cross-sectional shapes from each other.

4. The power module according to claim 1, wherein: The first intaglio pattern forms an electrical path in the first metal layer.

5. The power module according to claim 4, wherein: The first intaglio pattern is formed by penetrating a portion of the first metal layer to expose the insulating layer toward the penetrated portion of the first metal layer.

6. The power module according to claim 5, further comprising: A semiconductor chip is arranged at a first peripheral portion that relatively protrudes outside a portion of the first metal layer where the first intaglio pattern is formed.

7. The power module according to claim 1, wherein: The second intaglio pattern is formed on the second metal layer to prevent the insulating layer from being exposed in a direction toward the second metal layer.

8. The power module according to claim 7, wherein: The second intaglio pattern is formed by recessing a surface of the second metal layer and spacing the recessed surface of the second metal layer apart from a top surface of the second metal layer.

9. The power module according to claim 7, wherein: The second intaglio pattern is formed to include a needle-shaped second peripheral portion relatively protruding to the outside of a portion of the second metal layer where the intaglio of the second intaglio pattern is formed.

10. The power module according to claim 9, further comprising: A cooling passage in which the second peripheral portion is located and in which a cooling fluid in contact with the second peripheral portion flows.

11. The power module according to claim 1, wherein: forming the first intaglio pattern by penetrating a portion of the first metal layer to expose the insulating layer in a direction toward the first metal layer through the penetrated portion, The second intaglio pattern is formed on the second metal layer to prevent the insulating layer from being exposed in a direction toward the second metal layer.

12. The power module according to claim 11, wherein: The second intaglio pattern is formed by recessing a surface of the second metal layer and spacing the recessed surface of the second metal layer apart from a top surface of the second metal layer.

13. The power module according to claim 1, wherein: The first intaglio pattern is formed to reduce a thickness of a cross section of the first metal layer in a direction toward a central portion of an intaglio in the first intaglio pattern.

14. The power module according to claim 1, wherein: The second intaglio pattern is formed to reduce the thickness of a cross section of the second metal layer in a direction toward a central portion of an intaglio in the second intaglio pattern.

15. The power module according to claim 1, wherein: The first and second intaglio patterns are formed by removing a portion of the first metal layer and a portion of the second metal layer by etching.

16. The power module according to claim 15, wherein: At least one of the first intaglio pattern and the second intaglio pattern is formed by wet etching using a chemical reaction.

17. The power module according to claim 15, wherein: The first and second intaglio patterns are formed by etching the first and second metal layers after the first and second metal layers are bonded to the first and second surfaces of the insulating layer, respectively.

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