Power module having cooling fin, and manufacturing method therefor

Abstract

The present invention relates to a power module having a cooling fin, and a manufacturing method therefor, and, more specifically, to a power module and a manufacturing method therefor, the power module having cooling fins directly formed on a surface of a substrate so as to have an improved cooling effect. The power module according to one embodiment of the present invention may comprise: a substrate; a plurality of cooling fins directly formed on one surface of the substrate; and a power conversion chip bonded to the surface opposite to the one surface of the substrate.

Description

Power module equipped with cooling fins and manufacturing method thereof

[0001] The present invention relates to a power module equipped with cooling fins and a method for manufacturing the same, and more particularly, to a power module capable of improving a cooling effect by directly forming cooling fins on the surface of a substrate and a method for manufacturing the same.

[0002] The power conversion device of an electric vehicle receives DC current from a high-voltage battery, converts it into AC current, supplies it to the motor, and controls the torque and rotational speed of the motor by adjusting the size and phase of the AC current.

[0003] The power module is a key sub-component of the inverter that converts DC current received from a high-voltage battery into AC current. Heat is generated during the switching process, and damage may occur if the temperature rises above a certain level.

[0004] Therefore, the power module requires cooling, and as the cooling performance improves, the power loss due to heat is reduced, and the performance of the power conversion device is also improved because the power module can convert higher specification currents.

[0005] That is, the main core technology development point of the above power module is to improve cooling performance.

[0006] In relation to this, technology development for improving the cooling performance of the power module is currently being actively conducted. For example, technology development is being conducted for single-sided cooling, double-sided cooling, shape design of effective coolers, and bonding.

[0007] As a prior art for improving the cooling performance of the above power module, Korean Patent Publication No. 10-2018-0031502 (hereinafter referred to as “prior art 1”) discloses “power module and manufacturing method thereof.”

[0008] Figure 1 is a cross-sectional view of a power module according to the above prior art 1.

[0009] Referring to FIG. 1, the power module according to the prior art 1 includes a substrate (1, 2), a power conversion chip (3), and a heat dissipation member (4, 5).

[0010] The power conversion chip (3) has a double-sided cooling structure in which a substrate (1, 2) is provided on each of the upper and lower sides, a heat dissipation member (4) is placed on the lower surface of the lower substrate (1), and a heat dissipation member (5) is placed on the upper surface of the upper substrate (2).

[0011] In addition, the lower surface of the power conversion chip (3) is bonded to the lower substrate (1) through solder (S), and the upper surface of the power conversion chip (3) is bonded to the lower surface of the upper substrate (2) through a spacer (6).

[0012] The above substrate (1, 2) is a base material for arranging a power conversion chip (3) and forming a double-sided cooling structure on the upper and lower sides, and is manufactured by bonding a metal layer (8) made of a metal material to each of the two sides of a dielectric layer (7) having a dielectric component (e.g., ceramic or FRP, etc.), and the metal layer (8) forms contact with a heat dissipation member (4, 5).

[0013] The above heat dissipation member (4,5) is intended to dissipate heat emitted from the power conversion chip (3) to the outside of the power module, and includes a plate-shaped base plate (9) that forms a contact surface with the metal layer (8) of the substrate (1,2), and a plurality of heat dissipation fins (10) protruding from the base plate (9).

[0014] However, the power module according to the above prior art 1 has a problem in that it is difficult to expect satisfactory cooling efficiency because it basically has a structure in which the heat dissipation member (4,5) is bonded to the substrate (1,2) using a bonding material, and thus includes a heterogeneous material interface. In particular, there is a problem in that damage occurs to the power conversion chip (3) in the process of bonding the heat dissipation member (4,5) to the substrate (1,2) using heat and pressure.

[0015] Meanwhile, Korean Patent Publication No. 10-2020-0124577 (hereinafter referred to as “prior art 2”) discloses a “cooling system for a power conversion device.”

[0016] FIG. 2 is a drawing showing the overall configuration of a cooling system for a power conversion device according to the above prior art 2, and FIG. 3 is a drawing showing an internal cross-section of a cooling system for a power conversion device according to the above prior art 2.

[0017] Referring to FIGS. 2 and 3, the cooling system for the power conversion device according to the prior art 2 includes an upper part of a cooling tube (11), a power conversion module (12), a cooling fin plate (13), and a lower part of a cooling tube (14).

[0018] The upper part of the cooling tube (11) is arranged on both sides of the power conversion module (12) in such a way that the cooling water flowing in from the cooling water inlet (16) allows the cooling water to cool the power conversion module (12) on both sides.

[0019] The above cooling fin plate (13) has a plate shape and has cooling fins (15) formed on one surface. The cooling fin plate (13) is arranged on one surface of the power conversion module (12) so that the cooling fins (15) face in opposite directions with respect to the power conversion module (12).

[0020] The cooling fin (15) of the above cooling fin plate (13) is inserted into the open hole (17) of the lower part of the cooling tube (14) and comes into contact with the upper part of the cooling tube (11) through which cooling water flows, and the opposite side of the cooling plate (13) on which the cooling fin (15) is not formed comes into contact with both sides of the power conversion module (12), thereby cooling the power conversion module (12).

[0021] However, the cooling system for a power conversion device according to the above prior art 2 has a structure in which a cooling fin plate (13) is basically bonded to a power conversion module (12) using a bonding material, similar to the power module according to the above prior art 1, and therefore has a problem in that it is difficult to expect satisfactory cooling efficiency because it includes a heterogeneous material interface.

[0022] The present invention is intended to solve the above-mentioned problems, and provides a power module in which cooling fins are directly formed on the surface of a substrate to improve the cooling effect.

[0023] In addition, the present invention provides a power module in which cooling fins are directly formed and arranged at a surface location of a substrate to maximize the cooling effect.

[0024] In addition, the present invention provides a method for manufacturing a power module capable of directly forming a plurality of cooling fins at a surface location of a substrate that can maximize the cooling effect.

[0025] In addition, the present invention provides a method for manufacturing a power module capable of directly forming a robust cooling fin on the surface of the power module that is not damaged by the hydraulic pressure of the supplied cooling water.

[0026] A power module according to one embodiment of the present invention may include: a substrate; a plurality of cooling fins formed directly on one surface of the substrate; and a power conversion chip bonded to the opposite surface of one surface of the substrate.

[0027] In addition, the power module according to one embodiment of the present invention may include a plurality of cooling fins formed on the outermost projection line of the power conversion chip.

[0028] In addition, the power module according to one embodiment of the present invention may include cooling fins formed on the projection line, which are formed on the corners of the projection line.

[0029] In addition, a power module according to one embodiment of the present invention includes a plurality of cooling fins including cooling fins formed in an inner region of the projection line, and a height of the cooling fins formed in the inner region of the projection line may decrease from the center of the inner region toward the projection line.

[0030] In addition, in a power module according to one embodiment of the present invention, the plurality of cooling fins can be formed only on the outermost projection line of the power conversion chip and in the inner region of the projection line.

[0031] In addition, in a power module according to one embodiment of the present invention, the height of the cooling fin may decrease from the center of the inner region toward the projection line.

[0032] In addition, in a power module according to one embodiment of the present invention, the plurality of cooling fins can be formed directly on one surface of the substrate by applying an electrochemical additive manufacturing (ECAM) method.

[0033] In addition, a power module according to one embodiment of the present invention includes a substrate including a dielectric layer and a first metal layer and a second metal layer formed on each of both sides of the dielectric layer, the cooling fins are formed on the surface of the first metal layer, and the power conversion chip can be bonded to the surface of the second metal layer.

[0034] Meanwhile, a power module according to one embodiment of the present invention may include: a substrate; a plurality of cooling fins formed directly on one surface of the substrate; a spacer bonded to an opposite surface of one surface of the substrate; and a power conversion chip bonded to the spacer.

[0035] In addition, the power module according to one embodiment of the present invention may include a plurality of cooling fins formed on the outermost projection line of the spacer.

[0036] In addition, the power module according to one embodiment of the present invention may include cooling fins formed on the projection line, which are formed on the corners of the projection line.

[0037] In addition, a power module according to one embodiment of the present invention includes a plurality of cooling fins including cooling fins formed in an inner region of the projection line, and a height of the cooling fins formed in the inner region of the projection line may decrease from the center of the inner region toward the projection line.

[0038] In addition, in a power module according to one embodiment of the present invention, the plurality of cooling fins can be formed only on the outermost projection line of the spacer and in the inner region of the projection line.

[0039] In addition, in a power module according to one embodiment of the present invention, the height of the cooling fin may decrease from the center of the inner region toward the projection line.

[0040] In addition, in a power module according to one embodiment of the present invention, the plurality of cooling fins can be formed directly on one surface of the substrate by applying an electrochemical additive manufacturing (ECAM) method.

[0041] In addition, a power module according to one embodiment of the present invention includes a substrate including a dielectric layer and a first metal layer and a second metal layer formed on each of both sides of the dielectric layer, the cooling fins are formed on the surface of the first metal layer, and the spacer can be bonded to the surface of the second metal layer.

[0042] Meanwhile, a method for manufacturing a power module according to an embodiment of the present invention may include a power module manufacturing method including a substrate having a power conversion chip or spacer bonded to an opposite surface of one surface, wherein cooling fins are formed on one surface of the power module, the method comprising: a power module fixing step of fixing the power module so that one surface of the substrate faces upward; a multi-electrode aligning step of aligning a multi-electrode having a plurality of electrodes corresponding to cooling fins to be formed on one surface of the substrate above the power module so that the plurality of electrodes face each other at a predetermined distance from the positions of the cooling fins to be formed on one surface of the substrate; an electrolyte immersion step of immersing the plurality of electrodes and one surface of the substrate in an electrolyte; and a power applying step of applying power using the plurality of electrodes as anodes and the one surface of the substrate as a cathode.

[0043] In addition, a method for manufacturing a power module according to an embodiment of the present invention includes a substrate including a dielectric layer, a first metal layer provided on one surface of the dielectric layer and on which the cooling fins are formed, and a second metal layer provided on an opposite surface of the one surface of the dielectric layer and on which the power conversion chip or spacer is bonded, and the electrolyte may include the same metal ion as that of the first metal layer.

[0044] In addition, in a method for manufacturing a power module according to one embodiment of the present invention, the position of the cooling fin to be formed on one surface of the substrate may be on the outermost projection line of the power conversion chip or spacer and an area inside the projection line.

[0045] According to an embodiment of the present invention, a power module having the above-described configuration can improve the cooling effect by directly forming cooling fins on the surface of the power module.

[0046] In addition, according to a power module according to one embodiment of the present invention, cooling fins are formed at an optimal position to maximize the cooling effect.

[0047] In addition, according to a method for manufacturing a power module according to an embodiment of the present invention, cooling fins can be selectively formed at a location where the cooling effect can be maximized.

[0048] In addition, according to a method for manufacturing a power module according to an embodiment of the present invention, a strong cooling fin that is not damaged even by the water pressure of the supplied cooling water can be formed directly on the surface of the power module.

[0049] The effects according to the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art to which the present invention pertains from the description of the claims and detailed description.

[0050] Figure 1 is a cross-sectional view of a power module according to prior art 1,

[0051] Figure 2 is a drawing showing the overall configuration of a cooling system for a power conversion device according to prior art 2.

[0052] Figure 3 is a drawing showing an internal cross-section of a cooling system for a power conversion device according to prior art 2.

[0053] Figure 4 is a schematic cross-sectional view of a power module according to one embodiment of the present invention.

[0054] Figure 5 shows a plan view of one surface of a substrate on which cooling fins are formed.

[0055] Figure 6 is a drawing showing the flow of heat on the outermost projection line of a power conversion chip according to the formation position of the cooling fin.

[0056] FIGS. 7 to 9 are drawings showing the movement of an isothermal curve on the edge of a projection line according to the formation position of a cooling fin. FIG. 7 shows the movement of an isothermal curve when a cooling fin is formed on the inside of the edge of a projection line. FIG. 8 shows the movement of an isothermal curve when a cooling fin is formed on the outside of the edge of a projection line. FIG. 9 shows the movement of an isothermal curve when a cooling fin is formed on the edge of a projection line.

[0057] Figure 10 is a cross-sectional view taken along line AA of Figure 5,

[0058] Figure 11 is a diagram showing the amount of heat generated and the amount of heat extracted according to the distance from the center of the power conversion chip.

[0059] Figure 12 is a drawing schematically showing a state in which cooling water is supplied to cooling fins formed over the entire surface of a substrate.

[0060] Figure 13 is a drawing schematically showing a state in which cooling water is supplied to cooling fins formed only on the outermost projection line of a power conversion chip on one surface of a substrate and in the inner area of ​​the projection line.

[0061] FIG. 14 is a schematic cross-sectional view of a power module according to another embodiment of the present invention;

[0062] FIG. 15 is a flowchart showing a method for manufacturing a power module according to an embodiment of the present invention, which forms cooling fins on the surface of a power module by applying an electrochemical additive manufacturing method.

[0063] Figure 16 is a schematic diagram showing a state in which cooling fins are formed on the surface of a power module by applying an electrochemical additive manufacturing method.

[0064] Hereinafter, embodiments according to the present invention will be described with reference to the attached drawings.

[0065] While the present invention is susceptible to numerous modifications and variations, specific embodiments thereof are illustrated in the drawings and will be described in detail below. However, the invention is not intended to be limited to the particular forms disclosed; rather, the invention includes all modifications, equivalents, and alternatives consistent with the spirit of the invention as defined by the claims.

[0066] When explaining with reference to the attached drawings, identical components are given the same drawing reference numerals, and duplicate explanations thereof are omitted.

[0067] The thickness or size of each layer (film), area, pattern or structure in the drawings may be modified or exaggerated for clarity and convenience of explanation, and the present invention is not limited by the relative sizes or thicknesses shown in the attached drawings.

[0068] Meanwhile, each embodiment may be implemented independently or together, and some components may be excluded in accordance with the purpose of the invention.

[0069] Additionally, directional terms such as 'upper', 'lower', 'upper side', 'lower side', 'one side', 'the other side', 'top', 'bottom', 'upper', 'lower', 'front', 'rear', and the like may be used in connection with the orientation of the disclosed drawings. Since the components of embodiments of the present invention may be positioned in various orientations, directional terms are used for illustrative purposes and not for limitation.

[0070] Additionally, terms such as first, second, etc. may be used to describe various components, but the components are not limited to the terms and may be used for the purpose of distinguishing one component from another.

[0071] Figure 4 is a schematic cross-sectional view of a power module according to one embodiment of the present invention.

[0072] Referring to FIG. 4, a power module (100) according to one embodiment of the present invention may include a substrate (110), a plurality of cooling fins (200) formed directly on one surface (111) of the substrate (110), and a power conversion chip (SiC, GaN, etc.) (130) bonded to the opposite surface (112) of one surface (111) of the substrate (110).

[0073] The above power module (100) is configured to include a plurality of switching elements and can receive direct current from a capacitor that receives direct current from a high-voltage battery mounted on a vehicle.

[0074] In addition, the power module (100) extracts heat generated when converting direct current supplied from a capacitor into alternating current through switching of multiple switching elements and releases the heat to the outside.

[0075] The above substrate (110) may include a dielectric layer (113), a first metal layer (114) formed on one surface of the dielectric layer (113), and a second metal layer (115) formed on the opposite surface of one surface of the dielectric layer (113).

[0076] At this time, the cooling fin (200) may be formed directly on the surface of the first metal layer (114), and the power conversion chip (130) may be bonded to the surface of the second metal layer (115) by a bonding layer (131). That is, one surface (111) of the substrate (110) may be the surface of the first metal layer (114), and the opposite surface (112) of one surface (111) of the substrate (110) may be the surface of the second metal layer (115).

[0077] The above power conversion chip (130) is bonded to the opposite surface (112) of one surface (111) of the substrate (110) and can be manufactured through a semiconductor process or the like as an electrical element for generating an electrical flow for power conversion.

[0078] The above-mentioned plurality of cooling fins (200) are configured to release heat emitted from the power conversion chip (130) to the outside of the power module (100), and the above-mentioned plurality of cooling fins (200) can be formed directly on one surface (111) of the substrate (110).

[0079] For example, the plurality of cooling fins (200) can be formed directly on one surface (111) of the substrate (110) using a photoresist process or by applying an electrochemical additive manufacturing (ECAM) method.

[0080] In this way, when the plurality of cooling fins (200) are directly formed on one surface (111) of the substrate (110), cooling efficiency can be further improved because there is no heterogeneous material bonding interface compared to bonding a cooling plate with cooling fins formed thereon to the substrate as in prior art 1 and 2.

[0081] Preferably, the plurality of cooling fins (200) can be formed directly on one surface (111) of the substrate (110) by applying electrochemical additive manufacturing (ECAM).

[0082] When the cooling fin (200) is formed on one surface (111) of the substrate (110) using the above photoresist process, the upper part of the column shape of the cooling fin (200) is likely to be formed as a three-dimensional column in the shape of an inverted triangle due to excessive exposure and insufficient exposure at the lower part, and the photoresist pattern (hole, etc.) is too thick to make it difficult to remove the remaining film, and this remaining film interferes with the stable formation of the plating layer.

[0083] In particular, when the cooling fin (200) is formed on one surface (111) of the substrate (110) using the photoresist process, the mechanical strength (shear stress, etc.) of the cooling fin (200) is weak, so there is a possibility of problems such as damage due to the water pressure of the supplied cooling water.

[0084] On the other hand, since the above-described additive manufacturing method (ECAM) does not use any photoresist at all, there is no deviation in exposure or residual film phenomenon, so that the growth of a metal layer can be achieved without any special interference on one surface (111) of the substrate (110), and accordingly, in the case of a cooling fin (200) of the same diameter and thickness, the mechanical strength (shear stress, etc.) is superior to that of the case where the above-described photoresist process is used.

[0085] Therefore, when the cooling fin (200) is formed on one surface (111) of the substrate (110) using the above-described additive manufacturing method (ECAM), a solid cooling fin (200) that is not damaged even by the water pressure of the supplied cooling water can be formed directly on one surface (111) of the substrate (110).

[0086] Figure 5 shows a plan view of one surface of a substrate on which cooling fins are formed.

[0087] Referring to FIG. 5, the cooling fin (200) may include a cooling fin (210) formed on the outermost projection line (133) of the power conversion chip (130).

[0088] The outermost projection line (133) of the power conversion chip (130) can be defined as a line that vertically penetrates the outermost line of the power conversion chip (130) by the thickness of the substrate (110) and is projected onto one surface (111) of the substrate (110).

[0089] The heat generated from the power conversion chip (130) is transferred to the edge of the power conversion chip (130) and is collected at the outermost line of the power conversion chip (130). Therefore, if a cooling fin (210) is formed on the projection line (133), the cooling efficiency can be improved.

[0090] Figure 6 is a drawing showing the flow of heat on the outermost projection line of a power conversion chip according to the formation position of the cooling fins.

[0091] Figure 6 shows the heat flow on the projection line (133) when the cooling fin is formed inside the projection line (133) (210-1), when the cooling fin is formed on the projection line (133) (210), and when the cooling fin is formed outside the projection line (133) (210-2).

[0092] In the diagram of FIG. 6, the Y-axis represents the temperature at one surface (111) of the substrate (110), and the X-axis represents the distance from the center of the power conversion chip (130).

[0093] Additionally, the direction and size of the arrows shown on the substrate (110) in FIG. 6 indicate the direction and size of heat flow from the power conversion chip (130) to the substrate (110).

[0094] As shown in Fig. 6, when the cooling fin is formed inside the projection line (133) (210-1), since the cooling fin is installed before the end of the heat affected zone (130a) of the power conversion chip (130), it can be seen that the temperature rises again in the area where the cooling effect by the cooling fin ends (210-1a), and then gradually drops in the flat area (210-1b) where there is no cooling fin after passing the heat affected zone (130a) of the power conversion chip (130). That is, when the cooling fin is formed inside the projection line (133) (210-1), the cooling effect by the cooling fin decreases as it passes the projection line (133).

[0095] In addition, in the case where the cooling fins are formed outside the projection line (133) (210-2), it can be seen that the cooling effect by the cooling fins occurs late after the heat generated in the heat affected zone (130a) of the power conversion chip (130) has spread to the area past the projection line (133) (210-2a). That is, in the case where the cooling fins are formed outside the projection line (133) (210-2), the cooling effect by the cooling fins occurs too late.

[0096] On the other hand, in the case where the cooling fin is formed on the projection line (133) (210), the cooling effect by the cooling fin is generated on the projection line (133), which is the outermost point of the heat-affected zone (130a) of the power conversion chip (130), thereby concentrating cooling on the boundary point where heat is transferred and increasing the cooling gradient (inclination), thereby improving the cooling efficiency.

[0097] In addition, referring to FIG. 5, the cooling fin (210) formed on the projection line (133) may include a cooling fin (215) formed on the edge of the projection line (133).

[0098] By forming a cooling fin (215) on the edge of the projection line (133), the cooling area at the edge of the projection line (133) is expanded, and the overall isothermal curve is moved inside the projection line (133), thereby improving the cooling efficiency.

[0099] FIGS. 7 to 9 are drawings showing the movement of an isothermal curve on the edge of a projection line according to the formation position of a cooling fin. FIG. 7 shows the movement of an isothermal curve when a cooling fin is formed on the inside of the edge of a projection line, FIG. 8 shows the movement of an isothermal curve when a cooling fin is formed on the outside of the edge of a projection line, and FIG. 9 shows the movement of an isothermal curve when a cooling fin is formed on the edge of a projection line.

[0100] In FIGS. 7 to 9, the solid lines formed inside the projection lines represent isothermal curves in a state where cooling fins are not formed, and the dotted lines represent isothermal curves moved by cooling fins.

[0101] As shown in Fig. 7, when the cooling fin (215-1) is formed on the inner side of the corner of the projection line (133), the heat at the corner end of the projection line (133) is not completely removed, so the isothermal curve moves toward the corner end, which is disadvantageous in maintaining a balanced heat distribution.

[0102] In addition, as shown in Fig. 8, when the cooling fins are formed outside the corner of the projection line (133), the cooling effect is relatively reduced as the isothermal curve moves outside the projection line (133) because the cooling area exists far from the corner.

[0103] On the other hand, as shown in Fig. 9, when the cooling fins are formed on the corners of the projection line (133), the cooling effect can be improved by expanding the corner cooling area while moving the overall isothermal curve inside the projection line (133).

[0104] In addition, referring to FIG. 5, the cooling fin (200) may include a cooling fin (220) formed in an inner area (134) of the projection line (133).

[0105] Fig. 10 is a cross-sectional view taken along line AA of Fig. 5.

[0106] Referring to FIG. 10, the height of the cooling fin (200) may decrease from the center of the inner region (134) toward the projection line (133).

[0107] For example, the height of the cooling fin (221) formed at the center of the inner region (134) may be the largest, the height of the cooling fin (210) formed on the projection line (133) may be the smallest, and the cooling fin (223) formed between the highest cooling fin (221) and the lowest cooling fin (210) may have a height approximately in the middle.

[0108] Figure 11 is a diagram showing the amount of heat generated and the amount of heat extracted according to the distance from the center of the power conversion chip.

[0109] In the diagram of Fig. 11, the Y-axis represents the amount of heat generated, the Y'-axis represents the amount of heat extracted, and the X-axis represents the distance from the center of the power conversion chip (130).

[0110] As shown in the heat generation graph (y) of FIG. 11, heat generation occurs throughout the entire power conversion chip (130), but cooling is fast at the edge of the power conversion chip (130) and relatively slow in the heat affected zone (130a, y1) at the center of the power conversion chip (130). Therefore, the heat generation trend is high at the center of the power conversion chip (130) and low toward the edge of the power conversion chip (130), and the heat movement is relatively small in the area portion (y2) of the substrate (110) compared to the heat extraction graph (y').

[0111] In addition, as shown in the heat extraction graph (y') of FIG. 11, when a height difference is applied to the cooling fins (200) formed in the heat-affected zone (130a, y'1) region at the center of the power conversion chip (130), i.e., the inner region of the projection line (133), the heat extraction increases at the center of the power conversion chip (130) and decreases at the edge of the power conversion chip (130). Therefore, by adjusting the height of the cooling fins, i.e., adjusting the cross-sectional area in response to the heat generation trend, the cooling efficiency can be improved compared to when cooling fins of the same height are used, by balancing the heat extraction trend. In the area portion (y'2) of the substrate (110), the heat extracted from one surface (111) of the substrate (110) is well transferred to the substrate, so that the heat accumulation is relatively slightly higher compared to the heat generation graph (y).

[0112] In addition, the cooling fin (200) can be formed only on the outermost projection line (133) of the power conversion chip (130) and in the inner area of ​​the projection line (133).

[0113] Fig. 12 is a drawing schematically showing a state in which cooling water is supplied to cooling fins formed on the entire surface of a substrate, and Fig. 13 is a drawing schematically showing a state in which cooling water is supplied to cooling fins formed only on the outermost projection line of a power conversion chip and in the inner region of the projection line on one surface of a substrate.

[0114] As shown in Fig. 12, the cooling fins formed on the conventional cooling fin plate are formed over the entire surface of the substrate. If the cooling fins (200) are formed over the entire surface of the substrate (111) in this way, when the cooling water (101) is supplied to the cooling fins (200), the jet flow may not be able to quickly escape after colliding with the hot spot (102) and may be delayed, thereby reducing the cooling effect. In addition, when the space between the cooling fins (200) is narrow or the viscosity of the cooling water (101) is high, the cooling water (101) may not be able to escape between the cooling fins (200) and may stagnate, resulting in recirculation (103).

[0115] On the other hand, as shown in FIG. 13, if the cooling fin (200) is formed only on the outermost projection line (133) of the power conversion chip (130) and in the inner region (134) of the projection line (133), when the cooling water (101) is supplied to the cooling fin (200), the jet flow quickly leaves the hot spot (102) as soon as it extracts the heat amount of the hot spot, so that the flow out speed increases and the cooling water with the increased temperature can quickly flow out of the cooling fin (200) area, thereby maximizing the cooling effect.

[0116] In addition, even if the cooling fin (200) is formed only on the outermost projection line (133) of the power conversion chip (130) and in the inner region of the projection line (133), the height of the cooling fin (200) may decrease from the center of the inner region (134) toward the projection line (133). A detailed description thereof is based on the detailed descriptions in FIGS. 10 and 11.

[0117] FIG. 14 is a schematic cross-sectional view of a power module according to another embodiment of the present invention.

[0118] Referring to FIG. 14, a power module (100) according to the present embodiment may include a substrate (110), a plurality of cooling fins (200) formed directly on one surface (111) of the substrate (110), a spacer (140) bonded to the opposite surface (112) of one surface (111) of the substrate (100), and a chip (SiC, GaN, etc.) (130) for contact conversion bonded to the spacer (150).

[0119] The above substrate (110) may include a dielectric layer (113), a first metal layer (114) formed on one surface of the dielectric layer (113), and a second metal layer (115) formed on the opposite surface of one surface of the dielectric layer (113).

[0120] At this time, the cooling fin (200) can be formed directly on the surface of the first metal layer (114), the spacer (140) can be bonded to the surface of the second metal layer (115) by a bonding layer (141), and the power conversion chip (130) can be bonded to the surface of the spacer (140) by a bonding layer (131).

[0121] The above-described plurality of cooling fins (200) can be formed directly on one surface (111) of the substrate (110) using a photoresist process or an electrochemical additive manufacturing (ECAM) method. Preferably, the above-described plurality of cooling fins (200) can be formed directly on one surface (111) of the substrate (110) using an electrochemical additive manufacturing (ECAM) method. A detailed description thereof is based on the detailed description in FIG. 4.

[0122] Additionally, the cooling fin (200) may include a cooling fin (210) formed on the outermost projection line of the spacer (140).

[0123] The outermost projection line of the spacer (140) can be defined as a line that vertically penetrates the outermost line of the spacer (140) by the thickness of the substrate (110) and is projected onto one surface (111) of the substrate (110).

[0124] The heat generated from the power conversion chip (130) is transferred to the edge of the power conversion chip (130), collected at the outermost line of the power conversion chip (130), and then transferred to the outermost line of the spacer (140). Therefore, if cooling fins (210) are formed on the projection line, cooling efficiency can be improved. A detailed description thereof is based on the detailed description in FIG. 6.

[0125] Additionally, the cooling fin (210) formed on the projection line may include a cooling fin formed on an edge of the projection line.

[0126] By forming cooling fins on the corners of the projection lines, the cooling area at the corners of the projection lines is expanded, while the overall isothermal curve is moved within the projection lines, thereby improving cooling efficiency. A detailed description thereof is provided in reference to the detailed descriptions in FIGS. 7 to 9 above.

[0127] In addition, the cooling fin (200) may include a cooling fin (220) formed in an inner region of the projection line, and the height of the cooling fin (200) may decrease from the center of the inner region toward the projection line. A detailed description thereof is based on the detailed description in FIG. 11.

[0128] In addition, the cooling fin (200) may be formed only on the outermost projection line of the spacer (140) and in the inner region of the projection line. A detailed description thereof is provided in reference to the detailed descriptions in FIGS. 12 and 13.

[0129] In addition, even if the cooling fin (200) is formed only on the outermost projection line of the spacer (140) and in the inner region of the projection line, the height of the cooling fin (200) may decrease from the center of the inner region toward the projection line.

[0130] Hereinafter, a method for manufacturing a power module in which the cooling fins (200) are formed directly on one surface (111) of the substrate (110) by applying an electrochemical additive manufacturing (ECAM) method will be described in detail with reference to the drawings.

[0131] FIG. 15 is a flowchart showing a method for manufacturing a power module according to an embodiment of the present invention for forming cooling fins on the surface of a power module by applying an electrochemical additive manufacturing method, and FIG. 16 is a drawing schematically showing a state in which cooling fins are formed on the surface of a power module by applying an electrochemical additive manufacturing method.

[0132] Referring to FIGS. 15 and 16, a method (S100) for manufacturing a power module according to an embodiment of the present invention for forming cooling fins (200) on the surface of a power module (100) by applying an electrochemical additive manufacturing method may include a power module fixing step (S110), a multi-electrode alignment step (S120), an electrolyte immersion step (S130), and a power application step (S140).

[0133] The above power module (100) may include a substrate (110) having a spacer (140) bonded to the opposite surface (112) of one surface (111), and a power conversion chip (130) bonded to the spacer (140).

[0134] In another embodiment, as described above, the power module (100) may be directly bonded to the opposite side (112) of the substrate (110) without the spacer (140).

[0135] The above power module fixing step (S110) is a step of fixing the power module (100) so that one surface (111) of the substrate (110) faces upward.

[0136] The above multi-electrode alignment step (S120) is a step of aligning a multi-electrode (250) having a plurality of electrodes (270) corresponding to cooling fins (200) to be formed on one surface (111) of the substrate (110) above the power module (100), and the multi-electrode (250) can be aligned above the power module (100) so that the plurality of electrodes (270) face the positions of the cooling fins (200) to be formed on one surface (111) of the substrate (110) at a predetermined distance apart from each other.

[0137] The above electrolyte immersion step (S130) is a step of immersing the plurality of electrodes (270) and one surface (111) of the substrate (110) in the electrolyte (252).

[0138] For example, the electrolyte immersion step (S130) may be performed by fixing the power module (100) in a predetermined bath, aligning and fixing the multi-electrode (250) above the power module (100) at a predetermined distance apart, and supplying the electrolyte (252) into the bath so that the plurality of electrodes (270) and one surface (111) of the substrate (110) are immersed in the electrolyte (252).

[0139] The above power supply step (S140) is a step of supplying power by using the plurality of electrodes (270) as anodes and one surface (110) of the substrate (110) as a cathode.

[0140] Then, a cooling fin (200) can be formed as the metal ions included in the electrolyte (252) are deposited on a surface (110) of the substrate (110) facing the plurality of electrodes (270).

[0141] The substrate (110) includes a dielectric layer (113), a first metal layer (114) provided on one surface of the dielectric layer (113) to form the cooling fin (200), and a second metal layer (115) provided on the opposite surface of the one surface of the dielectric layer (113) to which the power conversion chip (130) or spacer (140) is bonded, and the electrolyte (252) may include the same metal ion as the first metal layer (114). Then, the cooling fin (200) may be firmly formed on the surface of the first metal layer (114).

[0142] Here, as described above, the position of the cooling fin (200) to be formed on one surface (111) of the substrate (110) may be on the outermost projection line of the power conversion chip (130) or spacer (140) and the inner area of ​​the projection line.

[0143] As described above, the present invention relates to a power module and a manufacturing method thereof, wherein cooling fins are directly formed on one surface of a substrate to enhance cooling effects. The embodiments of the power module and the manufacturing method thereof may be modified in various ways. Therefore, the present invention is not limited to the embodiments disclosed herein, and all modifications that can be made by a person skilled in the art to which the present invention pertains are also within the scope of the present invention.

Claims

1. Substrate; a plurality of cooling fins formed directly on one surface of the substrate; and A power module including a power conversion chip bonded to the opposite surface of one surface of the substrate.

2. In paragraph 1, A power module characterized in that the plurality of cooling fins include cooling fins formed on the outermost projection line of the power conversion chip.

3. In paragraph 2, A power module characterized in that the cooling fins formed on the projection line include cooling fins formed on the corners of the projection line.

4. In paragraph 2, The above plurality of cooling fins include cooling fins formed in the inner region of the projection line, A power module characterized in that the height of cooling fins formed in the inner area of ​​the projection line decreases from the center of the inner area toward the projection line.

5. In paragraph 1, A power module characterized in that the plurality of cooling fins are formed only on the outermost projection line of the power conversion chip and in the inner area of ​​the projection line.

6. In paragraph 5, A power module characterized in that the height of the cooling fins decreases from the center of the inner region toward the projection line.

7. In paragraph 1, A power module characterized in that the above-mentioned plurality of cooling fins are formed directly on one surface of the substrate by applying an electrochemical additive manufacturing (ECAM) method.

8. In paragraph 7, A power module characterized in that the substrate includes a dielectric layer and a first metal layer and a second metal layer formed on each side of the dielectric layer, the cooling fins are formed on the surface of the first metal layer, and the power conversion chip is bonded to the surface of the second metal layer.

9. Substrate; A plurality of cooling fins formed directly on one surface of the substrate; a spacer bonded to the opposite surface of one surface of the substrate; and A power module including a power conversion chip connected to the above spacer.

10. In paragraph 9, A power module characterized in that the plurality of cooling fins include cooling fins formed on the outermost projection line of the spacer.

11. In Article 10, A power module characterized in that the cooling fins formed on the projection line include cooling fins formed on the corners of the projection line.

12. In paragraph 10, The above plurality of cooling fins include cooling fins formed in the inner region of the projection line, A power module characterized in that the height of cooling fins formed in the inner area of ​​the projection line becomes smaller as they go from the center of the inner area to the projection line.

13. In paragraph 9, A power module characterized in that the above-mentioned plurality of cooling fins are formed only on the outermost projection line of the spacer and in the inner area of ​​the projection line.

14. In paragraph 13, A power module characterized in that the height of the cooling fins decreases from the center of the inner region toward the projection line.

15. In paragraph 9, A power module characterized in that the above-mentioned plurality of cooling fins are formed directly on one surface of the substrate by applying an electrochemical additive manufacturing (ECAM) method.

16. In paragraph 15, A power module characterized in that the substrate includes a dielectric layer and a first metal layer and a second metal layer formed on each side of the dielectric layer, the cooling fins are formed on the surface of the first metal layer, and the spacer is bonded to the surface of the second metal layer.

17. A method for manufacturing a power module, comprising forming cooling fins on one surface of a power module including a substrate on which a power conversion chip or spacer is bonded to the opposite surface of the surface, A power module fixing step for fixing the power module so that one surface of the substrate faces upward; A multi-electrode alignment step of aligning a multi-electrode having a plurality of electrodes corresponding to cooling fins to be formed on one surface of the substrate above the power module so that the plurality of electrodes face each other at a predetermined distance from the position of the cooling fins to be formed on one surface of the substrate; An electrolyte immersion step of immersing the plurality of electrodes and one surface of the substrate in an electrolyte; and A method for manufacturing a power module, comprising: a power application step of applying power by using the plurality of electrodes as anodes and one surface of the substrate as a cathode.

18. In paragraph 17, The substrate includes a dielectric layer, a first metal layer provided on one surface of the dielectric layer and on which the cooling fins are formed, and a second metal layer provided on the opposite surface of the dielectric layer and on which the power conversion chip or spacer is bonded. A method for manufacturing a power module, characterized in that the electrolyte contains the same metal ion as the first metal layer.

19. In paragraph 17, A method for manufacturing a power module, characterized in that the position of a cooling fin to be formed on one surface of the substrate is on the outermost projection line of the power conversion chip or spacer and in an area inside the projection line.

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