Radiator

Abstract

Provided is a heat sink capable of reducing the temperature difference between heating elements. The heat sink is provided with: a first member having a flat plate-shaped base part through which heat generated by a heating element is transferred, and a fin part protruding from the base part in a direction intersecting a plate surface of the base part; and a second member which is disposed around the first member and in which an inner peripheral portion, which is a portion inside, is joined to the first member, and in which a heat passage area of an outer peripheral portion, which is a portion from the inner peripheral portion toward the outside, of the second member is smaller than a contact area between the second member and the first member.

Description

Technical Field

[0001] The utility model relates to a radiator. Background Art

[0002] Conventionally, a cooler has been proposed that is bonded to a substrate on which a semiconductor element is mounted in order to dissipate heat generated by the semiconductor element.

[0003] For example, the cooler described in Patent Document 1 includes a box-shaped container body having an opening on its upper surface, and a base plate having a plurality of heat sinks formed on the lower surface of its inner circumference and capable of arranging a heating element on the upper surface of said inner circumference. Furthermore, while the heat sinks are housed within the container body through its upper surface opening, the outer periphery of the base plate is fixed to the peripheral edge of the upper surface opening of the container body via a sealing member. Thus, the base plate is assembled to the container body in such a manner as to seal the upper surface opening of the container body.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-61399 Utility Model Content

[0007] Issues to be solved by the utility model

[0008] Sometimes, multiple IC (Integrated Circuit) chips are mounted on an insulating substrate. Since the characteristics of an IC chip change with temperature, it is desirable to minimize the temperature difference between the multiple IC chips.

[0009] The purpose of the utility model is to provide a radiator capable of reducing the temperature difference of a heating element.

[0010] Means for solving problems

[0011] The utility model completed based on the above-mentioned purpose is a radiator comprising: a first component, the first component having a flat base portion for transferring heat generated by a heating element and a heat dissipation fin portion protruding from the base portion in a direction intersecting the plate surface of the base portion; and a second component, the second component being arranged around the first component and the inner peripheral portion of the second component being the inner portion being joined to the first component, the heat path area of the outer peripheral portion of the second component being the portion extending from the inner peripheral portion to the outer side being smaller than the contact area between the second component and the first component.

[0012] Here, the base portion of the first member and the inner peripheral portion of the second member may be joined in a stacked and surface-contact state.

[0013] Furthermore, the size of the inner peripheral portion of the second member in the stacking direction of the first member and the second member may be smaller than the size of the outer peripheral portion in the stacking direction.

[0014] In addition, the surfaces of the inner peripheral portion and the outer peripheral portion on the base portion side of the first component may be flat, and the surface of the outer peripheral portion on the side opposite to the base portion may protrude toward the side opposite to the base portion more than the surface of the inner peripheral portion on the side opposite to the base portion.

[0015] Furthermore, the heat dissipation fin portion of the first member may protrude toward the second member.

[0016] Furthermore, a portion of the outer peripheral portion of the second member on the opposite side to the inner peripheral portion may be molded from resin.

[0017] Furthermore, the first member and the second member may be joined by laser welding.

[0018] Utility model effect

[0019] According to the present invention, a heat sink capable of reducing the temperature difference of a heating element can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is an example of an exploded view of components constituting the semiconductor device according to the first embodiment.

[0021] Figure 2 This is a diagram showing an example of a cross section of the semiconductor device according to the first embodiment.

[0022] Figure 3 This is an example of a partially exploded view of components constituting the semiconductor device according to the second embodiment.

[0023] Figure 4 This is a diagram showing an example of a cross section of a semiconductor device according to the second embodiment.

[0024] Figure 5 This is an example of an enlarged view of a portion of a cross-sectional view of the semiconductor device according to the third embodiment.

[0025] Figure 6 This is an example of a diagram when the second member of the third embodiment is viewed from below.

[0026] Description of Reference Numerals

[0027] 1, 2, 3...semiconductor device, 20...cooling device, 50, 250...semiconductor module, 53...IC chip, 100, 200, 300...heat sink, 110, 210...first component, 111, 211...base portion, 112, 212...heat sink portion, 120, 220, 320...second component, 122, 222...inner peripheral portion, 123, 223, 323...outer peripheral portion. DETAILED DESCRIPTION

[0028] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0029] <First embodiment>

[0030] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

[0031] Figure 1 This is an example of an exploded view of components constituting the semiconductor device 1 according to the first embodiment.

[0032] Figure 2 This is a diagram showing an example of a cross section of the semiconductor device 1 according to the first embodiment. Figure 2 This is an example of a cross-sectional view when the semiconductor device 1 is cut along a plane perpendicular to the front-back direction.

[0033] The semiconductor device 1 includes a semiconductor module 50 and a cooling device 20 for cooling the semiconductor module 50 .

[0034] The cooling device 20 is a liquid-cooled cooling device that uses a coolant and a heat sink 100 to cool the semiconductor module 50. The cooling device 20 includes the heat sink 100 and a bottomed, concave housing 21 that, together with the heat sink 100, forms a space for the coolant to flow. The heat sink 100 and the housing 21 are stacked. The housing 21 can be made of aluminum, for example.

[0035] The cooling device 20 also includes an O-ring 22 for sealing between the radiator 100 and the housing 21, and bolts 23 for joining the radiator 100 and the housing 21. The cooling device 20 also includes an inlet pipe 24 for allowing coolant to flow into the housing 21, and an outlet pipe 25 for allowing coolant to flow out of the housing 21.

[0036] Hereinafter, the stacking direction of the heat sink 100 and the housing 21 may be referred to as the "upper and lower directions," the heat sink 100 side may be referred to as the "upper side," and the housing 21 side may be referred to as the "lower side." Furthermore, the direction perpendicular to the upper and lower directions and extending from the inlet pipe 24 to the outlet pipe 25 may be referred to as the "left-right direction," and the direction perpendicular to the upper and lower directions may be referred to as the "forward-backward direction." Furthermore, when the distinction between the left-right and forward-backward directions is unnecessary, these two directions may be collectively referred to as the "horizontal direction."

[0037] The semiconductor module 50 includes an insulating substrate 51, a wiring layer 52 provided on the insulating substrate 51, and a plurality of (in the embodiment of FIG. 5 ) solder layers 54 mounted on the wiring layer 52. Figure 1 (three in the figure) IC chips 53 (an example of a heating element). The plurality of IC chips 53 are arranged in the left-right direction. In addition, the semiconductor module 50 has a heat transfer layer 55 that transfers heat from the insulating substrate 51 to the heat sink 100. Furthermore, the heat transfer layer 55 is bonded to the upper surface of the base portion 111 of the heat sink 100, which will be described later. Examples of methods for bonding the heat transfer layer 55 to the heat sink 100 include brazing, soldering, sintering, resin-based bonding, and attachment using thermally conductive grease.

[0038] (Radiator 100)

[0039] The heat sink 100 includes a first member 110 and a second member 120 that is disposed around the first member 110 and bonded to the first member 110. The material of the heat sink 100 may be metal such as aluminum or copper.

[0040] The first member 110 includes a flat plate-shaped base portion 111 and fin portions 112 protruding from the base portion 111 in a direction intersecting the plate surface of the base portion 111. The base portion 111 and the fin portions 112 are integrally formed.

[0041] The base portion 111 is in the shape of a rectangular parallelepiped.

[0042] The fin section 112 includes a plurality of columnar fins 113 protruding vertically from the base section 111. The fin section 112 is provided in a region extending inwardly from the outer edge of the base section 111 by a predetermined length when viewed in the vertical direction.

[0043] The cross-sectional shape of the heat sink 113, taken along a plane perpendicular to the protruding direction, can be a quadrilateral such as a circle, an ellipse, a square, a rectangle, or a rhombus. Furthermore, the heat sink 113 can also be a flat plate. In the case of a flat plate, it can be parallel to the left-right direction (in other words, the direction from the inlet pipe 24 to the outlet pipe 25), or it can be wavy with portions inclined relative to the left-right direction.

[0044] The second member 120 includes an inner peripheral portion 122 having a through-hole 121 formed in the center and extending around the entire periphery of the through-hole 121, and an outer peripheral portion 123 disposed around the inner peripheral portion 122. The inner peripheral portion 122 and the outer peripheral portion 123 are integrally formed. When viewed from above and below, the through-hole 121 can be exemplified as having a rectangular shape. The outer peripheral portion 123 includes a bolt hole 123h extending therethrough for the bolt 23 to pass therethrough.

[0045] The second member 120 is joined to the first member 110 in a state where the heat sink portion 112 of the first member 110 passes through the through-hole 121 and the base portion 111 is stacked on the inner peripheral portion 122. Examples of the joining method include welding or bonding. Examples of welding methods include laser welding and friction stir welding. In the case of laser welding, for example, the laser head is moved along the shape of the inner peripheral portion 122 around the heat sink portion 112 while irradiating the inner peripheral portion 122 with a laser.

[0046] When viewed in the vertical direction, the first member 110 is positioned inward of the outer periphery 123 of the second member 120. That is, the base 111 of the first member 110 contacts only the inner periphery 122 of the second member 120 and does not contact the outer periphery 123. As a result, heat generated by the semiconductor module 50 is transferred to the inner periphery 122 of the second member 120 via the base 111 of the first member 110. Furthermore, the heat transferred to the inner periphery 122 of the second member 120 is transferred to the outer periphery 123.

[0047] The inner peripheral portion 122 is arranged in a manner that the size in the vertical direction is uniform throughout the entire horizontal area. Similarly, the outer peripheral portion 123 is arranged in a manner that the size in the vertical direction is uniform throughout the entire horizontal area (except for the portion where the bolt hole 123h is formed). In addition, the size of the inner peripheral portion 122 in the vertical direction is smaller than the size of the outer peripheral portion 123 in the vertical direction. In addition, the heat path area from the inner peripheral portion 122 to the outer peripheral portion 123 of the second component 120 is smaller than the contact area between the second component 120 and the first component 110 (in other words, the contact area between the base portion 111 and the inner peripheral portion 122). In other words, the boundary surface 124 between the inner peripheral portion 122 and the outer peripheral portion 123, which is a surface parallel to the vertical direction, becomes the heat path from the inner peripheral portion 122 to the outer peripheral portion 123, and the area of the boundary surface 124 is set to be smaller than the contact area between the base portion 111 and the inner peripheral portion 122 of the first component 110.

[0048] As described above, the heat sink 100 includes: a first member 110 having a flat base portion 111 and a fin portion 112 protruding from the base portion 111 in a direction intersecting the plate surface of the base portion 111; and a second member 120 disposed around the first member 110, with an inner peripheral portion 122 of the second member 120 being joined to the first member 110. Furthermore, the heat path area of the outer peripheral portion 123 of the second member 120, which extends outward from the inner peripheral portion 122, is smaller than the contact area between the second member 120 and the first member 110.

[0049] The heat path area from the inner peripheral portion 122 to the outer peripheral portion 123 is preferably less than 1 / 2 of the contact area between the first member 110 and the second member 120, more preferably less than 1 / 3, and even more preferably less than 1 / 4. The lower limit of the heat path area from the inner peripheral portion 122 to the outer peripheral portion 123 is determined by the mechanical strength of the heat sink 100.

[0050] According to the heat sink 100 configured as described above, the heat generated by the semiconductor module 50 that is transferred to the inner peripheral portion 122 of the second member 120 via the base portion 111 of the first member 110 is retained in the path from the inner peripheral portion 122 to the outer peripheral portion 123 (in other words, the boundary surface 124), making it difficult to transfer from the inner peripheral portion 122 to the outer peripheral portion 123. As a result, the temperature difference between the multiple IC chips 53 mounted on the insulating substrate 51 can be reduced. This will be described in detail below.

[0051] Here, a heat sink of a comparative example is used in which, unlike the heat sink 100 , the heat path area from the inner peripheral portion 122 to the outer peripheral portion 123 of the second member 120 is equal to or larger than the contact area between the second member 120 and the first member 110 .

[0052] The heat generated by the IC chip 53 among the multiple IC chips 53, which is arranged at a position close to the inner peripheral portion 122 of the second member 120, is transferred to the heat sink portion 112 via the base portion 111 of the first member 110, and is also easily transferred to the inner peripheral portion 122. On the other hand, the heat generated by the IC chip 53, which is arranged at a position far from the inner peripheral portion 122 of the second member 120, is transferred to the heat sink portion 112 via the base portion 111 of the first member 110, but is difficult to transfer to the inner peripheral portion 122. For example, in Figure 1 In the illustrated configuration where the three IC chips 53 are arranged in the left-right direction, the IC chips 53 arranged at the left-right end portions are located closer to the inner peripheral portion 122 extending in the front-back direction of the inner peripheral portion 122 provided around the heat sink 112 than the IC chip 53 arranged in the center portion. Therefore, heat generated by the IC chips 53 arranged at the left-right end portions is more easily transferred to the inner peripheral portion 122 extending in the front-back direction than heat generated by the IC chip 53 arranged in the center portion.

[0053] Therefore, in the heat sink of the comparative example, where the heat path area from the inner peripheral portion 122 to the outer peripheral portion 123 of the second member 120 is greater than the contact area between the second member 120 and the first member 110, heat is more easily transferred from the inner peripheral portion 122 to the outer peripheral portion 123 than in the case of the heat sink 100, where the heat path area is smaller than the contact area. Consequently, in the heat sink of the comparative example, heat generated by the IC chip 53 located closer to the inner peripheral portion 122 of the second member 120 is transferred to a wider area of the heat sink 100 than heat generated by the IC chip 53 located farther from the inner peripheral portion 122 of the second member 120. Consequently, in the heat sink of the comparative example, the IC chip 53 located closer to the inner peripheral portion 122 of the second member 120 is more easily cooled than the IC chip 53 located farther from the inner peripheral portion 122. In contrast, according to the heat sink 100, the heat generated by the IC chip 53 located near the inner peripheral portion 122 of the second member 120 and transferred to the inner peripheral portion 122 of the second member 120 via the base portion 111 of the first member 110 is retained in the path from the inner peripheral portion 122 to the outer peripheral portion 123, and is less likely to be transferred from the inner peripheral portion 122 to the outer peripheral portion 123. As a result, in the heat sink 100, the difference in the amount of heat dissipated between the heat generated by the IC chip 53 located near the inner peripheral portion 122 of the second member 120 and the heat generated by the IC chip 53 located far from the inner peripheral portion 122 can be reduced compared to the heat sink of the comparative example, thereby reducing the temperature difference among the plurality of IC chips 53 mounted on the insulating substrate 51.

[0054] Furthermore, in the heat sink 100, the base portion 111 of the first member 110 and the inner peripheral portion 122 of the second member 120 are joined in a stacked, surface-contact state. This allows for a more reliable joining of the first and second members 110, 120, compared to, for example, a butt-joined state. Furthermore, by laser welding the stacked, surface-contact joints, the joining can be simplified.

[0055] Furthermore, in the heat sink 100, the size of the inner peripheral portion 122 of the second member 120 in the stacking direction (in other words, the vertical direction) of the first member 110 and the second member 120 is smaller than the size of the outer peripheral portion 123 in the stacking direction. This reliably reduces the heat path area from the inner peripheral portion 122 to the outer peripheral portion 123 of the second member 120.

[0056] Furthermore, the surfaces of the inner peripheral portion 122 and the outer peripheral portion 123 on the side of the base portion 111 of the first member 110 (in other words, the upper surface) are flat, and the surface of the outer peripheral portion 123 on the side opposite to the base portion 111 protrudes more than the surface of the inner peripheral portion 122 on the side opposite to the base portion 111. Here, assuming that the upper surface of the inner peripheral portion 122 is located below the upper surface of the outer peripheral portion 123, the distance between the outer peripheral surface of the base portion 111 of the first member 110 and the inner peripheral surface of the outer peripheral portion 123 becomes smaller, and heat is easily transferred from the first member 110 to the second member 120 via the base portion 111 and the outer peripheral portion 123 without passing through the inner peripheral portion 122. In contrast, according to the heat sink 100, heat can be transferred from the first component 110 to the outer peripheral portion 123 of the second component 120 with high reliability through the contact area between the base portion 111 of the first component 110 and the inner peripheral portion 122 of the second component 120, and the boundary surface 124 between the inner peripheral portion 122 and the outer peripheral portion 123, thereby making it difficult for heat to be transferred from the first component 110 to the second component 120 with high reliability.

[0057] Furthermore, in the heat sink 100, the fin portion 112 of the first member 110 protrudes toward the second member 120. Thus, even in a configuration where the second member 120 is placed on the housing 21 and the heat sink 100 covers the opening of the housing 21, the fin portion 112 can be housed within the concave housing 21, allowing the fin portion 112 to come into contact with the coolant.

[0058] <Second embodiment>

[0059] Figure 3 This is an example of a partially exploded view of components constituting the semiconductor device 2 according to the second embodiment.

[0060] Figure 4 This is a diagram showing an example of a cross section of a semiconductor device 2 according to the second embodiment. Figure 4 This is an example of a cross-sectional view when the semiconductor device 2 is cut along a plane perpendicular to the front-back direction.

[0061] The semiconductor device 2 of the second embodiment differs from the semiconductor device 1 of the first embodiment in a semiconductor module 250 corresponding to the semiconductor module 50 and a heat sink 200 corresponding to the heat sink 100. The differences from the first embodiment will be described below. In the first and second embodiments, the same reference numerals are used for the same components, and detailed descriptions thereof will be omitted.

[0062] The semiconductor module 250 differs from the semiconductor module 50 in that it includes a single IC chip 53. Specifically, the semiconductor module 250 includes an insulating substrate 51, a wiring layer 52, a single IC chip 53 mounted on the wiring layer 52 via a solder layer 54, and a heat transfer layer 55.

[0063] Furthermore, in the semiconductor device 2, a plurality of ( Figure 4 The semiconductor modules 250 (three in the figure) are arranged in the left-right direction.

[0064] The heat sink 200 includes a first member 210 and a second member 220 that is disposed around the first member 210 and bonded to the first member 210 .

[0065] The first member 210 includes a base portion 211 corresponding to the base portion 111 and a heat sink portion 212 corresponding to the heat sink portion 112 .

[0066] The semiconductor device 2 includes a plurality of semiconductor modules 250 (in Figure 3 The heat transfer layer 55 of the semiconductor module 250 is bonded to the upper surface of the base portion 211 of the first member 210 .

[0067] The second member 220 is formed with a plurality of Figure 3 The through-holes 221 (three in total) are each provided for the heat sink fins 212 of the plurality of first members 210 to pass through. Furthermore, the second member 220 includes a plurality of inner peripheral portions 222 disposed around each of the plurality of through-holes 221, and an outer peripheral portion 223 disposed around the inner peripheral portions 222. The inner peripheral portions 222 and the outer peripheral portion 223 are integrally formed. When viewed from above and below, the through-holes 221 can be exemplified as being rectangular. Bolt holes 223h are formed in the outer peripheral portion 223 for the passage of the bolts 23.

[0068] The second member 220 is joined to the first member 210 in a state where the heat sink portion 212 of the first member 210 passes through the through-hole 221 and the base portion 211 is stacked on the inner peripheral portion 222. When the joining method is laser welding, for example, the laser head is moved along the shape of the inner peripheral portion 222 around the heat sink portion 212 while irradiating the inner peripheral portion 222 with laser light.

[0069] When viewed in the vertical direction, the first member 210 is arranged inward of the outer peripheral portion 223 of the second member 220. In other words, the base portion 211 of the first member 210 contacts only the inner peripheral portion 222 of the second member 220 and does not contact the outer peripheral portion 223. As a result, heat generated by the semiconductor module 250 is transferred to the inner peripheral portion 222 of the second member 220 via the base portion 211 of the first member 210 and then to the outer peripheral portion 223.

[0070] The inner circumference 222 is arranged in a manner that the size in the vertical direction is uniform throughout the entire horizontal area. Similarly, the outer circumference 223 is arranged in a manner that the size in the vertical direction is uniform throughout the entire horizontal area (except for the portion where the bolt hole 223h is formed). In addition, the size of the inner circumference 222 in the vertical direction is smaller than the size of the outer circumference 223 in the vertical direction. In addition, compared to the contact area between the second member 220 and the first member 210, the heat path area from the inner circumference 222 of the second member 220 in contact with the first member 210 to the outer circumference 223 is smaller. In other words, the boundary surface 224 between the inner circumference 222 and the outer circumference 223, which is a surface parallel to the vertical direction, becomes the heat path from the inner circumference 222 to the outer circumference 223, and the area of the boundary surface 224 is set to be smaller than the contact area between the base portion 211 of the first member 210 and the inner circumference 222.

[0071] As described above, the heat sink 200 includes: a first member 210 having a flat base portion 211 and a fin portion 212 protruding from the base portion 211 in a direction intersecting the plate surface of the base portion 211; and a second member 220 disposed around the first member 210, with the inner peripheral portion 222 of the second member 220 being joined to the first member 210. Furthermore, the heat path area of the outer peripheral portion 223 of the second member 220 extending from the inner peripheral portion 222 to the outside is smaller than the contact area between the second member 220 and the first member 210.

[0072] The heat path area from the inner peripheral portion 222 to the outer peripheral portion 223 is preferably less than 1 / 2, more preferably less than 1 / 3, and even more preferably less than 1 / 4 of the contact area between the first member 210 and the second member 220. The lower limit of the heat path area from the inner peripheral portion 222 to the outer peripheral portion 223 is determined by the mechanical strength of the heat sink 200.

[0073] According to the heat sink 200 configured as described above, the heat generated by the semiconductor module 250 and transferred to the inner peripheral portion 222 of the second member 220 via the base portion 211 of the first member 210 is retained in the path (in other words, the boundary surface 224) from the inner peripheral portion 222 to the outer peripheral portion 223, and is less likely to be transferred from the inner peripheral portion 222 to the outer peripheral portion 223. As a result, the temperature difference between the semiconductor modules 250 arranged at the left and right ends of the heat sink 200 and the semiconductor module 250 arranged in the center can be reduced.

[0074] <Third embodiment>

[0075] Figure 5This is an example of an enlarged view of a portion of the cross-sectional view of the semiconductor device 3 according to the third embodiment. Figure 5 This is an example of a cross-sectional view when the semiconductor device 3 is cut along a plane perpendicular to the front-rear direction.

[0076] Figure 6 This is an example of a diagram when the second member 320 of the third embodiment is viewed from below.

[0077] The semiconductor device 3 of the third embodiment differs from the semiconductor device 1 of the first embodiment in a heat sink 300 corresponding to the heat sink 100. The differences from the first embodiment will be described below. In the first and third embodiments, the same reference numerals are used for the same components, and detailed descriptions thereof will be omitted.

[0078] The heat sink 300 according to the third embodiment is different from the heat sink 100 according to the first embodiment in a second member 320 corresponding to the second member 120 .

[0079] The second member 320 includes an inner peripheral portion 122 and an outer peripheral portion 323 provided around the inner peripheral portion 122 .

[0080] The outer peripheral portion 323 includes an inner portion 330 provided around the inner peripheral portion 122 and an outer portion 340 provided around the inner portion 330 .

[0081] The inner portion 330 includes a surrounding portion 331 surrounding the inner peripheral portion 122 and a convex portion 332 protruding outward from the surrounding portion 331 .

[0082] The size of the surrounding portion 331 in the vertical direction is larger than that of the inner peripheral portion 122 , and the size of the surrounding portion 331 in the horizontal direction is formed to be equal to the size of the inner peripheral portion 122 in the vertical direction.

[0083] The convex portion 332 is provided at the vertical center of the surrounding portion 331. The vertical size of the convex portion 332 is formed to be equal to the vertical size of the inner peripheral portion 122. The convex portion 332 is provided so that its vertical size is uniform across the entire horizontal area.

[0084] The inner peripheral portion 122 and the inner side portion 330 of the outer peripheral portion 323 are integrally formed of a metal such as aluminum or copper.

[0085] The outer portion 340 is formed by insert molding in which a resin heated to a softening temperature (for example, polyphenylene sulfide (PPS)) is filled into a mold while the inner portion 330 is held in the mold.

[0086] The size of the outer portion 340 in the vertical direction is the same as the size of the surrounding portion 331 of the inner portion 330 in the vertical direction. The outer portion 340 is provided so that the size in the vertical direction is uniform over the entire area in the horizontal direction.

[0087] A recessed portion 341 is formed on the inner side of the outer portion 340 and is recessed outward from the inner peripheral surface, into which the convex portion 332 is fitted.

[0088] As described above, the heat sink 300 includes: a first member 110 having a flat base portion 111 and a fin portion 112 protruding from the base portion 111 in a direction intersecting the plate surface of the base portion 111; and a second member 320 disposed around the first member 110, with the inner peripheral portion 122 of the second member 320 being joined to the first member 110. Furthermore, the heat path area of the outer peripheral portion 323 of the second member 320, which extends outward from the inner peripheral portion 122, is smaller than the contact area between the second member 320 and the first member 110.

[0089] According to the heat sink 300 configured as described above, the semiconductor module 50 (see Figure 1 ) of the heat generated, the heat transferred to the inner peripheral portion 122 of the second member 320 via the base portion 111 of the first member 110 is transferred to the outer peripheral portion 323 as a path from the inner peripheral portion 122, Figure 5 The boundary surface 324 shown in FIG. 1 is retained and is difficult to be transferred from the inner peripheral portion 122 to the outer peripheral portion 323. As a result, the amount of material mounted on the insulating substrate 51 (see FIG. 1 ) can be reduced. Figure 1 ) of multiple IC chips 53 (refer to Figure 1 ) temperature difference.

[0090] Furthermore, in the second member 320, since the outer portion 340 is formed of resin, electrical insulation can be improved and weight reduction can be achieved compared to a case where the outer portion 340 is formed of metal. Furthermore, resin has a lower thermal conductivity than metal, so heat is less likely to be transferred, further reducing the temperature difference between the plurality of IC chips 53 mounted on the insulating substrate 51.

[0091] Furthermore, the second member 320 having an outer peripheral portion 323 formed of an inner portion 330 molded from metal and an outer portion 340 molded from resin around the inner peripheral portion 122, as in the heat sink 300, may be applied to the heat sink 200 of the second embodiment. This improves the electrical insulation of the second member 220 of the second embodiment and reduces its weight.

[0092] Furthermore, in the semiconductor device 1 of the first embodiment, the semiconductor device 2 of the second embodiment, and the semiconductor device 3 of the third embodiment described above, a liquid-cooled cooling device (e.g., cooling device 20) is provided, in which the fin portion (e.g., fin portion 112) of a heat sink (e.g., heat sink 100) is mounted and used in such a manner that the fin portion is in contact with the coolant. However, the semiconductor device 1 of the first embodiment, the semiconductor device 2 of the second embodiment, and the semiconductor device 3 of the third embodiment may also include an air-cooled cooling device in which a heat sink (e.g., heat sink 100) is disposed in a space for air circulation.

Claims

1. A radiator, characterized in that: have: a first member having a flat base portion for transferring heat generated by a heating element and a heat dissipation fin portion projecting from the base portion in a direction intersecting a plate surface of the base portion; and a second member disposed around the first member and having an inner peripheral portion of the second member joined to the first member; A heat passage area of an outer peripheral portion of the second member, which is a portion extending from the inner peripheral portion to the outside, is smaller than a contact area between the second member and the first member.

2. The radiator according to claim 1, characterized in that The base portion of the first member and the inner peripheral portion of the second member are joined in a stacked and surface-contact state.

3. The radiator according to claim 2, characterized in that The size of the inner peripheral portion of the second member in the stacking direction of the first member and the second member is smaller than the size of the outer peripheral portion in the stacking direction.

4. The radiator according to claim 3, characterized in that The surfaces of the inner and outer peripheral portions on the base portion side of the first member are flat, and the surface of the outer peripheral portion on the side opposite to the base portion protrudes further than the surface of the inner peripheral portion on the side opposite to the base portion.

5. The radiator according to claim 3, characterized in that The heat dissipation fin portion of the first member protrudes toward the second member.

6. The radiator according to claim 1, characterized in that A portion of the outer peripheral portion of the second member on the opposite side to the inner peripheral portion is molded from resin.

7. The radiator according to any one of claims 1 to 6, characterized in that: The first member and the second member are joined by laser welding.

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