Electronic device unit

Abstract

To provide an electronic device unit capable of efficiently cooling a first electronic component.SOLUTION: A power conversion section 10 of an electronic device unit 100 includes a substrate 20, a switching element 30 mounted on the substrate 20, and a transformer 40. The electronic device unit 100 includes a cooling section 11 for cooling the power conversion section 10. The transformer 40 is arranged between the substrate 20 and the cooling section 11. The electronic device unit 100 includes: a biasing member 50 for biasing the transformer 40 in a direction toward the cooling section 11; and a metal member 60 which is formed of a metal material having lower rigidity and higher thermal conductivity than those of the biasing member 50, and configured to absorb the heat generated from the switching element 30 and cooled by the cooling section 11. In the electronic device unit 100, the cooling section 11, the transformer 40, the metal member 60, and the substrate 20 are arranged in this order.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electronic device unit.

Background Art

[0002] The electronic device disclosed in Patent Document 1 includes a substrate on which a switching element and a coil are mounted, a metal case to which the substrate is attached, and a heat transfer member interposed between the coil and the case. The heat transfer member is inserted between the coil and the bottom wall of the case. In the electronic device, the bottom wall of the case, the heat transfer member, the coil, and the substrate are arranged in this order and are in close contact with each other. The coil and the switching element are connected by a conductive pattern formed on the substrate. Further, the coil includes a winding and a core material that encloses the winding.

[0003] The heat generated from the switching element is transmitted to the conductive pattern. The heat transmitted to the conductive pattern is transmitted to the coil. The heat transmitted to the coil is transmitted to the core material of the coil through the winding. Then, the heat transmitted to the core material is transmitted to the heat transfer member and from the heat transfer member to the case. As a result, the switching element is cooled.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the heat dissipation performance of the core material is low, the switching element cannot be sufficiently cooled only by transmitting the heat generated in the switching element to the case through the core material.

Means for Solving the Problems

[0006] An electronic device unit for solving the above problems includes a substrate, a first electronic component mounted on the substrate, a second electronic component, a power conversion unit including the first and second electronic components, and a cooling unit for cooling the power conversion unit. a used electronic device unit , the second electronic component is in a state of being placed on the cooling unit Between the substrate and the cooling unit is provided at is provided 、 a biasing member that applies a biasing force to the second electronic component in a direction toward the cooling unit, and a metal member that is formed of a metal material having a lower rigidity and a higher thermal conductivity than the biasing member, absorbs heat generated from the first electronic component, and is cooled by the cooling unit. The cooling unit, the second electronic component, the metal member, and the substrate are arranged in this order.

[0007] According to this, the metal member absorbs heat generated from the first electronic component and is cooled by the cooling unit. Therefore, the first electronic component can be efficiently cooled. Regarding the electronic device unit, the biasing member and the metal member may be fastened to the cooling unit by the same fastening member.

[0008] According to this, both the biasing member and the metal member can be fastened to the cooling unit collectively. Compared with the case where the biasing member and the metal member are separately fastened to the cooling unit, the fastening work of the biasing member and the metal member becomes easier.

[0009] Regarding the electronic device unit, a heat dissipation member may be provided between the substrate and the metal member. According to this, heat generated from the first electronic component is transmitted to the metal member through the substrate and the heat dissipation member. Even if the separation distance between the substrate and the metal member differs from a preset value, the difference can be absorbed by the heat dissipation member.

Advantages of the Invention

[0010] According to the present invention, the first electronic component can be efficiently cooled.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0012] Hereinafter, an embodiment in which the electronic device unit is embodied will be described with reference to FIGS. 1 to 2. <Electronic device unit> As shown in FIGS. 1 and 2, the electronic device unit 100 includes a power conversion unit 10, a cooling unit 11 for cooling the power conversion unit 10, a biasing member 50, and a metal member 60.

[0013] <Cooling unit> The cooling unit 11 is formed of, for example, aluminum. The cooling unit 11 includes a main body portion 12 having a cooling surface 12b, and a plurality of first bosses 13 and a plurality of second bosses 14 protruding from the cooling surface 12b. A refrigerant flow path 12a is provided in the main body portion 12. Refrigerant flows through the refrigerant flow path 12a. The refrigerant may be a gaseous substance such as air or a liquid substance such as cooling water. Since the main body portion 12 is cooled by the refrigerant, the first bosses 13 and the second bosses 14 are also cooled.

[0014] Each of the first bosses 13 and the second bosses 14 is cylindrical. The first boss 13 has a tip surface 13a, and the second boss 14 has a tip surface 14a. Female threads (not shown) extending from the tip surface 13a toward the cooling surface 12b are formed in the first boss 13. Female threads (not shown) extending from the tip surface 14a toward the cooling surface 12b are formed in the second boss 14. The length from the cooling surface 12b to the tip surface 13a of the first boss 13 is longer than the length from the cooling surface 12b to the tip surface 14a of the second boss 14. A substrate 20 described later is placed on the tip surfaces 13a of the plurality of first bosses 13, and a substrate fastening member 15 passing through the substrate 20 is screwed into the female threads of each first boss 13. Thereby, the substrate 20 is fastened to the cooling unit 11.

[0015] The plurality of second bosses 14 are arranged at positions sandwiching a transformer 40 as a second electronic component described later. An urging member 50 and a metal member 60 described later are placed on the front end surfaces 14a of the plurality of second bosses 14, and a fastening member 70 penetrating through the urging member 50 and the metal member 60 is screwed into the female screw of each second boss 14. Thereby, the urging member 50 and the metal member 60 are integrally fastened to the cooling unit 11 by the fastening member 70. Therefore, the urging member 50 and the metal member 60 are cooled by the cooling unit 11.

[0016] <Power conversion unit> The power conversion unit 10 is, for example, a DC-DC converter. The power conversion unit 10 includes a substrate 20, a plurality of switching elements 30 as first electronic components, and a transformer 40 as second electronic components. In addition to the switching elements 30 and the transformer 40, the power conversion unit 10 includes a smoothing capacitor, a rectifying circuit, etc. (not shown).

[0017] <Substrate and switching element> The substrate 20 includes a first mounting surface 21 and a second mounting surface 22. The first mounting surface 21 and the second mounting surface 22 are surfaces opposite to each other in the thickness direction of the substrate 20. The switching elements 30 are mounted on the first mounting surface 21. That is, the switching elements 30 are connected to a wiring pattern (not shown) provided on the first mounting surface 21. The second mounting surface 22 of the substrate 20 includes a wiring pattern (not shown) to which a winding 41 of the transformer 40 described later is connected.

[0018] The substrate 20 is placed on the front end surfaces 13a of the plurality of first bosses 13 described above. That is, among the second mounting surface 22 of the substrate 20, the portion placed on the front end surface 13a of the first boss 13 is in contact with the cooling unit 11. The portion of the second mounting surface 22 of the substrate 20 other than the portion placed on the front end surface 13a of the first boss 13 is separated from the cooling unit 11.

[0019] <Transformer> The transformer 40 is provided between the substrate 20 and the cooling unit 11. That is, the transformer 40 is provided between the second mounting surface 22 and the cooling surface 12b of the cooling unit 11. The transformer 40 is a magnetic component including a winding 41 and a core 42 made of a magnetic material around which the winding 41 is wound. The core 42 is an EI core. The core 42 includes a first core 44 and a second core 45. The first core 44 is an I core. The first core 44 is flat. The first core 44 includes a first surface 44a and a second surface 44b. The first surface 44a and the second surface 44b are surfaces that are opposite to each other in the plate thickness direction of the first core 44. The first surface 44a is in contact with the cooling surface 12b. Therefore, the transformer 40 is placed on the cooling unit 11 and is cooled by the cooling unit 11. Note that a heat dissipation grease may be interposed between the first surface 44a of the first core 44 and the cooling surface 12b.

[0020] The second core 45 is an E core. The second core 45 includes a flat base portion 46, a first protruding portion 47, a second protruding portion 48, and a third protruding portion 49 that protrude from the base portion 46. The first protruding portion 47, the second protruding portion 48, and the third protruding portion 49 protrude from the base portion 46 in the plate thickness direction of the base portion 46. The first protruding portion 47, the second protruding portion 48, and the third protruding portion 49 are provided side by side with a space therebetween. The second protruding portion 48 is shorter in the protruding direction from the base portion 46 than the first protruding portion 47 and the third protruding portion 49.

[0021] The tip surfaces of the first protruding portion 47 and the third protruding portion 49 are in contact with the second surface 44b of the first core 44. The tip surface of the second protruding portion 48 is separated from the second surface 44b of the first core 44. The winding 41 is wound around the second protruding portion 48. The second core 45 has dimensions for winding the winding 41.

[0022] <Biasing member> The biasing member 50 is a flat member. The biasing member 50 is a member that applies a biasing force to the transformer 40 in the direction toward the cooling unit 11. The biasing member 50 of the present embodiment is formed so that the planar shape is U-shaped, but the shape of the biasing member 50 can be appropriately changed.

[0023] The biasing member 50 is made of a metal material that is higher in rigidity and lower in thermal conductivity than the metal member 60 described later. For example, the biasing member 50 is made of stainless steel. The biasing member 50 of the present embodiment is formed by molding a strip-shaped stainless steel plate.

[0024] The biasing member 50 includes a mounting portion 51 and a pair of spring portions 54. The biasing member 50 functions as a leaf spring. The mounting portion 51 of the present embodiment is formed so as to have a U-shaped planar shape. More specifically, the mounting portion 51 includes a connecting portion 52 having a through hole 51a near the center, and a pair of extending portions 53 extending from both end portions of the connecting portion 52 toward the second core 45. The mounting portion 51 is fastened to the cooling portion 11 by screwing a fastening member 70 inserted through the through hole 51a into the female screw of the second boss 14.

[0025] The pair of spring portions 54 extend from each of the pair of extending portions 53. The spring portion 54 includes a first curved portion 54a that curves so as to bulge toward the substrate 20 from an end portion of the extending portion 53 on the side opposite to the connecting portion 52, and a second curved portion 54b that curves so as to bulge toward the second core 45 from an end portion of the first curved portion 54a on the side opposite to the extending portion 53. That is, the first curved portion 54a has a convex shape from the extending portion 53 toward the substrate 20, and the second curved portion 54b has a convex shape from the first curved portion 54a toward the second core 45.

[0026] The top 54c of the second bent portion 54b of the spring portion 54 presses against the end face 45a of the second core 45. Specifically, one of the pair of biasing members 50 presses against the portion between the first protrusion 47 and the second protrusion 48 on the end face 45a of the second core 45. One of the biasing members 50 applies a biasing force to the second core 45 in the direction toward the first core 44. The remaining biasing member 50 of the pair of biasing members 50 presses against the portion between the third protrusion 49 and the second protrusion 48 on the end face 45a of the second core 45. The remaining biasing member 50 applies a biasing force to the second core 45 in the direction toward the first core 44. Due to the biasing forces of the pair of biasing members 50, the first protrusion 47 and the third protrusion 49 are in contact with the second surface 44b of the first core 44. That is, it can be said that the pair of biasing members 50 applies a biasing force to the transformer 40 in the direction toward the cooling portion 11.

[0027] <Metal member> The metal member 60 is a flat member. The metal member 60 is a member that absorbs heat generated from the switching element 30 and is cooled by the cooling portion 11. The metal member 60 is formed of a metal material having a lower rigidity and a higher thermal conductivity than the biasing member 50. For example, the metal member 60 is formed of copper. The metal member 60 of the present embodiment is formed by shaping a strip-shaped copper plate.

[0028] The metal member 60 includes a pair of mounting portions 61 that are the ends of the metal member 60, a pair of protrusions 62, and a rectangular plate-shaped connecting portion 63 that connects the pair of protrusions 62. The mounting portion 61 is rectangular plate-shaped. The mounting portion 51 in the present embodiment is rectangular flat plate-shaped. The mounting portion 61 is provided with a through hole 61a. The mounting portion 61 is sandwiched between the mounting portion 51 of the biasing member 50 and the second boss 14 such that the through hole 51a of the biasing member 50 and the through hole 61a communicate with each other. Then, the mounting portion 61 is fastened to the cooling portion 11 together with the biasing member 50 by screwing a fastening member 70 inserted through the through hole 51a and the through hole 61a of the biasing member 50 into the female thread of the second boss 14. Therefore, the biasing member 50 and the metal member 60 are fastened to the cooling portion 11 by the same fastening member 70 and are cooled by the cooling portion 11. Further, the metal member 60 is arranged to contact the tip surface 14a of the second boss 14 without passing through the biasing member 50 so as to be easily cooled by the cooling portion 11. It can be said that the metal member 60 spans the pair of second bosses 14. Also, the metal member 60 is arranged between the pair of extending portions 53 and the spring portions 54 of the biasing member 50.

[0029] Each of the pair of protrusions 62 includes a first extending portion 62a that extends from the mounting portion 61 toward the substrate 20, a second extending portion 62b that extends from the end of the first extending portion 62a on the side opposite to the mounting portion 61 side toward the other side, and a third extending portion 62c that extends from the end of the second extending portion 62b on the side opposite to the first extending portion 62a side toward the transformer 40. That is, each of the pair of protrusions 62 can be said to have a convex shape from the mounting portion 61 toward the substrate 20.

[0030] The second extending portion 62b and the third extending portion 62c are provided between the substrate 20 and the transformer 40. Specifically, the second extending portion 62b and the third extending portion 62c are located between the second mounting surface 22 of the substrate 20 and the end face 45a of the second core 45. More specifically, one of the second extending portions 62b is provided at a position overlapping with one of the switching elements 30 via the substrate 20 when viewed from above. Also, the other second extending portion 62b is provided at a position overlapping with the other switching element 30 via the substrate 20 when viewed from above. Further, the second extending portion 62b is spaced apart from the end face 45a of the second core 45. That is, a gap K exists between the second extending portion 62b and the end face 45a of the second core 45. The length of the first extending portion 62a is longer than the length of the third extending portion 62c. A heat dissipation member 80, which will be described later, is interposed between the second extending portion 62b and the substrate 20. Therefore, the heat generated from the switching element 30 is absorbed by the metal member 60 (the second extending portion 62b) via the heat dissipation member 80 and the substrate 20.

[0031] The connecting portion 63 connects between the ends of the pair of third extending portions 62c on the side opposite to the second extending portion 62b side. The connecting portion 63 has a square plate shape. The connecting portion 63 is in contact with the end face 45a of the second core 45. Since the second extending portion 62b receives the force from the substrate 20 via the heat dissipation member 80, it is likely to be deformed. Therefore, the connecting portion 63 is brought into contact with the end face 45a of the second core 45, and the lengths of the first extending portion 62a, the second extending portion 62b, the third extending portion 62c, and the plate thickness of the metal member 60 are adjusted.

[0032] <Heat dissipation member> The heat dissipation member 80 has heat conductivity. The heat dissipation member 80 is deformed by the force from the substrate 20. The heat dissipation member 80 is provided between the substrate 20 and the second extending portion 62b. The heat dissipation member 80 is in contact with the second extending portion 62b and the substrate 20. The heat dissipation member 80 insulates the conductive portion of the substrate 20 and the transformer 40.

[0033] <The whole of the electronic device unit> In the electronic device unit 100, the cooling unit 11, the transformer 40, the metal member 60, the heat dissipation member 80, and the substrate 20 are arranged in this order. Since the second boss 14 is a part of the cooling unit 11, it is cooled. Therefore, the heat generated from the switching element 30 is absorbed by the metal member 60 via the substrate 20 and the heat dissipation member 80, and then absorbed by the cooling unit 11. That is, the heat generated from the switching element 30 is absorbed by the cooling unit 11 without passing through the transformer 40.

[0034] [Operation of the Embodiment] As the power conversion unit 10 is driven, the switching element 30 is driven. As the switching element 30 is driven, heat is generated from the switching element 30. The heat generated from the switching element 30 is transmitted from the substrate 20 to the second extension portion 62b of the metal member 60 via the heat dissipation member 80. The heat transmitted to the second extension portion 62b is transmitted to the second boss 14 via the first extension portion 62a and the attachment portion 61. The heat transmitted to the second boss 14 is transmitted to the main body portion 12 and released to the refrigerant flowing through the refrigerant flow path 12a. As a result, the metal member 60 absorbs the heat generated from the switching element 30 and is cooled by the cooling unit 11.

[0035] According to the above embodiment, the following effects can be obtained. (1) The metal member 60 absorbs the heat generated from the switching element 30 and is cooled by the cooling unit 11. Therefore, the switching element 30 can be efficiently cooled.

[0036] (2) In the case of a configuration in which a transformer 40 is provided between the substrate 20 and the cooling unit 11, since the transformer 40 is a large-sized electronic component, the distance between the substrate 20 and the cooling unit 11 becomes wide. For this reason, the metal member used to absorb the heat generated from the switching element 30 mounted on the substrate 20 by the cooling unit 11 becomes large. Therefore, in the electronic device unit 100, the metal member 60 is provided between the transformer 40 and the substrate 20. With this configuration, the size of the portion of the metal member 60 between the substrate 20 and the transformer 40 can be reduced.

[0037] (3) The biasing member 50 and the metal member 60 are fastened to the second boss 14 of the cooling part 11 by the same fastening member 70. Therefore, both the biasing member 50 and the metal member 60 can be fastened to the second boss 14 of the cooling part 11 together. Compared with the case where the biasing member 50 and the metal member 60 are separately fastened to the cooling part 11, the fastening operation of the biasing member 50 and the metal member 60 becomes easier.

[0038] (4) Since the biasing member 50 is provided to press and hold the transformer 40 on the cooling part 11 side, rigidity is required. Generally, a material with high rigidity has poor thermal conductivity. Therefore, when the biasing member 50 is interposed, the cooling performance deteriorates. Thus, in the electronic device unit 100, the metal member 60 and the biasing member 50 are arranged in this order on the second boss 14. According to this configuration, the metal member 60 can be cooled by the cooling part 11 without passing through the biasing member 50, so that the switching element 30 can be efficiently cooled.

[0039] (5) A heat dissipation member 80 is provided between the substrate 20 and the second extension part 62b. Therefore, the heat generated from the switching element 30 is transmitted to the second extension part 62b through the substrate 20 and the heat dissipation member 80. Due to tolerances such as the thickness of the substrate 20, the height of the first boss 13, and the thickness of the metal member 60, the separation distance between the substrate 20 and the second extension part 62b may be different from a preset value. Even if such a difference in the separation distance occurs, the difference can be absorbed by the heat dissipation member 80.

[0040] (6) The metal member 60 has the second extension part 62b and the connecting part 63. Therefore, a gap K can be formed between the second extension part 62b and the transformer 40. According to this configuration, the force applied from the substrate 20 to the metal member 60 can be absorbed.

[0041] (7) The metal member 60 is formed of a copper plate. The copper plate has lower rigidity than stainless steel. According to this configuration, the force applied from the substrate 20 to the metal member 60 can be absorbed.

[0042] Note that this embodiment can be implemented with the following modifications. This embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range. ○ The metal member 60 may have any shape as long as it can absorb the heat generated from the first electronic component and is cooled by the cooling unit 11.

[0043] ○ The biasing member 50 and the metal member 60 may be separately fastened to the cooling unit 11. In this case, the cooling unit 11 separately includes a boss for fastening the biasing member 50 and a boss for fastening the metal member 60.

[0044] ○ The first electronic component may be other than the switching element 30 as long as it is mounted on the substrate 20 and generates heat. ○ The second electronic component may be a component larger in size than the first electronic component, and may be a capacitor or an inductor.

[0045] ○ The shape of the core 42 may be other than the EI core, and may be an EE core, an EER core, a toroidal core, a UI core, a drum core, etc. ○ The power conversion unit 10 may be an inverter. In short, as long as the power conversion unit 10 includes the substrate 20, the first electronic component that generates heat, and the second electronic component, its type may be appropriately changed.

[0046] ○ The cooling unit 11 may not include the refrigerant flow path 12a. In that case, it is preferable that the cooling unit 11 includes heat - radiating fins. ○ The heat - radiating member 80 may not be provided.

[0047] ○ The substrate 20 includes the first mounting surface 21 and the second mounting surface 22, but only one of them may be provided. ○ The winding 41 of the transformer 40 is connected to the wiring pattern on the second mounting surface 22, but it is not limited to this, and it may be connected to the wiring pattern on the first mounting surface 21, or may be connected to the wiring pattern of a substrate different from the substrate 20. That is, the second electronic component may be connected to the wiring pattern on the first mounting surface provided with the wiring pattern to which the first electronic component is connected, or may be connected to the wiring pattern on the second mounting surface different from the first mounting surface provided with the wiring pattern to which the first electronic component is connected, or may be connected to the wiring pattern provided on a substrate different from the substrate on which the first electronic component is mounted.

[0048] ○ The switching element 30 may be mounted on the second mounting surface 22 of the substrate 20. Next, the technical ideas that can be grasped from the above embodiments and alternative examples are added below. (a) The electronic device unit is characterized in that the metal member applies a biasing force to the second electronic component in a direction toward the cooling unit.

Description of Reference Numerals

[0049] 10... Power conversion unit, 11... Cooling unit, 20... Substrate, 30... Switching element as the first electronic component, 40... Transformer as the second electronic component, 50... Biasing member, 60... Metal member, 70... Fastening member, 80... Heat dissipation member, 100... Electronic device unit.

Claims

1. An electronic device unit comprising a substrate, a first electronic component mounted on the substrate, and a second electronic component, and a cooling unit for cooling the power conversion unit, wherein the second electronic component is provided between the substrate and the cooling unit while being placed on the cooling unit, a biasing member that applies a biasing force to the second electronic component in a direction toward the cooling unit, and a metal member that is formed of a metal material having lower rigidity and higher thermal conductivity than the biasing member, absorbs heat generated from the first electronic component, and is cooled by the cooling unit. The electronic device unit is characterized in that the cooling unit, the second electronic component, the metal member, and the substrate are arranged in this order.

2. The electronic device unit according to claim 1, wherein the biasing member and the metal member are fastened to the cooling unit by the same fastening member.

3. The electronic device unit according to claim 1 or claim 2, wherein a heat dissipation member is provided between the substrate and the metal member. ​ ​

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