Electronic circuit device

Abstract

The electronic circuit device includes: a circuit board on which a wiring layer is formed; a conductor electrically connected to the wiring layer; a flow path forming body that, together with the circuit board, forms a flow path for a refrigerant that flows in contact with the circuit board; a fastening member for fastening the circuit board and the conductor; and a sealing member for sealing the flow path. A first through hole is formed in the circuit board and penetrates between a cooling surface on which the flow path is formed and a back surface on the opposite side of the cooling surface. A second through hole communicating with the first through hole is formed in the conductor. The fastening member fastens the circuit board and the conductor via the first through hole and the second through hole. By using the fastening member to fasten the circuit board and the conductor, the sealing member blocks the first through hole to seal the flow path.

Description

Technical Field

[0001] The present invention relates to an electronic circuit device. Background Art

[0002] In recent years, in industrial machinery and vehicles (e.g., automobiles, railway vehicles), from the viewpoints of energy saving and precise driving control, the electrification and electronic control of power sources have been rapidly developing. Along with this, the importance of a power conversion device equipped with a power module for controlling the electric power of such a power source and an electronic circuit device for controlling the power module has increased. A motor driven by AC power generated by converting DC power of a storage battery through such a power conversion device functions as a driving device of a vehicle.

[0003] In an electric vehicle equipped with the above-described power conversion device, storage battery, and motor, in order to expand the space inside the vehicle, thinning of the power conversion device is desired. In the thinning of the power conversion device, in order to cope with the heat generated by the electronic circuit device, an efficient cooling method is required.

[0004] As an attempt to efficiently cool a heat-generating body of an electronic device, for example, an electronic device described in Patent Document 1 is known. Patent Document 1 discloses an electronic device including: a circuit board on which a heat-generating body is mounted; a first frame mounted on a first main surface so as to enclose the heat-generating body and a refrigerant between the first main surface of the circuit board; and a deformation suppression portion that suppresses deformation of the circuit board, and the heat-generating body and the refrigerant are sealed in a space surrounded by the circuit board and the frame.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2019-145749 Summary of the Invention

[0008] -Problems to be Solved by the Invention-

[0009] In an electronic circuit device mounted on a power conversion device, a large amount of power for driving a motor is supplied to wirings formed on the surface and inside of a circuit board. If the wiring is made thinner, the cross-sectional area becomes smaller, the resistance becomes larger, and thus the heat generation increases. Therefore, it is necessary to cool the circuit board. In particular, since current concentrates on a portion where input / output terminals for connecting the wiring to the outside are provided, the necessity of cooling becomes higher. However, depending on the size of the input / output terminals, strong fastening with screws is effective, so through-holes for the screws need to be provided in the circuit board, and the refrigerant leaks from these through-holes, making forced cooling with the refrigerant impossible. That is, in a conventional electronic circuit device mounted on a power conversion device, in order to make it thinner, it is necessary to cool the circuit board with a refrigerant, but due to the low sealing performance of the refrigerant flow path provided in contact with the circuit board having through-holes, there is a problem of refrigerant leakage.

[0010] Therefore, an object of the present invention is to provide an electronic circuit device capable of effectively cooling a circuit board while ensuring the sealing performance of a refrigerant flow path.

[0011] Means for Solving the Problem

[0012] The electronic circuit device of the present invention includes: a circuit board forming a wiring layer; a conductor electrically connected to the wiring layer; a flow path forming body forming, together with the circuit board, a flow path for a refrigerant flowing in contact with the circuit board; a fastening member for fastening the circuit board and the conductor; and a sealing member for sealing the flow path. A first through-hole is formed in the circuit board penetrating between a cooling surface forming the flow path and the back surface on the opposite side of the cooling surface, and a second through-hole communicating with the first through-hole is formed in the conductor. The fastening member fastens the circuit board and the conductor via the first through-hole and the second through-hole, and the sealing member closes the first through-hole to seal the flow path.

[0013] Advantages of the Invention

[0014] According to the present invention, it is possible to provide an electronic circuit device capable of effectively cooling a circuit board while ensuring the sealing performance of a refrigerant flow path. Description of the Drawings

[0015] Figure 1 is an exploded perspective view of an inverter.

[0016] Figure 2 is a top view of the inverter.

[0017] Figure 3 is a cross-sectional view of the inverter.

[0018] Figure 4 It is a cross-sectional view showing an example of the structure of a circuit board in an electronic circuit device according to the first embodiment of the present invention.

[0019] Figure 5 It is a cross-sectional view showing an example of the structure in which a conductor is mounted on a circuit board in an electronic circuit device according to the first embodiment of the present invention.

[0020] Figure 6 It is a cross-sectional view showing the structure of an electronic circuit device according to the first embodiment of the present invention.

[0021] Figure 7 It is a cross-sectional view showing the structure of an electronic circuit device according to the second embodiment of the present invention.

[0022] Figure 8 It is a cross-sectional view showing an example of the structure in which a conductor is mounted on a circuit board in an electronic circuit device according to the third embodiment of the present invention.

[0023] Figure 9 It is a cross-sectional view showing the structure of an electronic circuit device according to the third embodiment of the present invention.

[0024] Figure 10 It is a cross-sectional view showing an example of the structure of a circuit board and a flow path forming body in an electronic circuit device according to the fourth embodiment of the present invention.

[0025] Figure 11 It is a cross-sectional view showing the structure of an electronic circuit device according to the fourth embodiment of the present invention.

[0026] Figure 12 It is a cross-sectional view showing the structure of an electronic circuit device according to the fifth embodiment of the present invention.

[0027] Figure 13 It is a cross-sectional view showing the structure of an electronic circuit device according to the sixth embodiment of the present invention. Detailed Embodiment

[0028] [Structure of Inverter]

[0029] Hereinafter, with reference to Figures 1 to 3 , the structure of an inverter 100 including the electronic circuit device according to the present invention will be described. Figure 1 It is an exploded perspective view of the inverter 100. The inverter 100 is used in combination with an in-wheel motor provided in a wheel of an electric vehicle such as an electric car, and converts DC power supplied from a battery (not shown) into AC power and outputs it to the motor.

[0030] As Figure 1As shown in the figure, the inverter 100 is configured to include: a stator housing 70 having a cylindrical shape; an electronic circuit device 1 disposed on the bottom surface of the stator housing 70; and a flow path forming body 50 disposed to cover the electronic circuit device 1. A stator constituting a motor (not shown) is disposed inside the stator housing 70, and three recesses 71 recessed more than other portions are formed on the bottom surface of the stator housing 70. In addition, a hole for passing a vehicle axle is formed at the center of the stator housing 70. The motor is rotationally driven about the vehicle axle inserted into the hole, whereby the electric vehicle travels.

[0031] In the electronic circuit device 1, three power modules 60 are mounted on a circuit board 10. When the electronic circuit device 1 is disposed at a predetermined position with respect to the bottom surface of the stator housing 70, each power module 60 is disposed at a position overlapping with the recess 71 of the stator housing 70, respectively. Thereby, a flow path for a refrigerant for cooling each power module 60 is formed between the flow path forming body 50 and the recess 71. A flow inlet 55 for allowing the refrigerant 50 to flow in is provided in the flow path forming body 50.

[0032] High-power DC power is supplied from a battery (not shown) to each power module 60 via a conductor 20 provided in the electronic circuit device 1. Each power module 60 corresponds to a three-phase leg of the inverter 100 and has a switching element for the upper arm and a switching element for the lower arm, respectively. Each switching element is switched and driven according to a gate drive signal input from a control device (not shown), whereby the DC power is converted into AC power of each phase, respectively. In addition, the switching element is constituted by a semiconductor element such as an IGBT or a MOSFET, for example.

[0033] Figure 2 is a top view of the inverter 100. In addition, in Figure 2 , in order to represent the structure of the inverter 100 in an easily understandable manner, the illustration of the flow path forming body 50 is omitted. In Figure 2 , the dotted line 56 indicates the flow path of the refrigerant flowing on the circuit board 10. As Figure 2 shown, the refrigerant flowing in from the flow inlet 55 (refer to Figure 1 ) reaches each power module 60 through the flow path indicated by the dotted line 56, cools each power module 60, and reaches the back side of the circuit board 10 via the openings 15a and 15b provided in the circuit board 10. Thereafter, it flows out to the motor side through an unillustrated flow outlet provided on the back side of the circuit board 10.

[0034] In addition, through holes 14 for connecting the conductor 20 are formed in the circuit board 10. The conductor 20 is mounted on the circuit board 10 by the structure described below so that the refrigerant flowing in the flow path does not leak from the through holes 14.

[0035] Figure 3 is Figure 2 a cross-sectional view of the inverter 100 in cross-section A-A. As Figure 3 shown, a flow path 51 is formed between the circuit board 10 and the flow path forming body 50. The refrigerant flowing in from the inlet 55 flows in this flow path 51. A hollow portion 72 is formed in the stator housing 70.

[0036] A fastening member 30 is installed via a sealing member 40 for preventing leakage of the refrigerant in the through hole 14 of the circuit board 10, and a conductor 20 is connected by this fastening member 30. In the following embodiments, the details of the fastening member 30 and the sealing member 40 will be described.

[0037] [First Embodiment]

[0038] Figure 4 is a cross-sectional view showing an example of the structure of the circuit board in the electronic circuit device according to the first embodiment of the present invention. Figure 4 In the circuit board 10 shown, a wiring layer 12 such as a copper foil is formed in the insulator 11. In addition, the circuit board 10 may be formed by embedding the wiring layer 12 inside the insulator 11, or the circuit board 10 may be formed by overlapping the layer of the insulator 11 and the wiring layer 12.

[0039] An insulating film 13 for protecting the wiring layer 12 is provided on the surface of the circuit board 10. In addition, in Figure 4 the example of, the entire surface of the circuit board 10 is covered with the insulating film 13, but only a part of the surface of the circuit board 10 may be covered with the insulating film 13, or the insulating film 13 may not be provided.

[0040] A through hole 14 penetrating between both surfaces is formed in the circuit board 10. The wiring layer 12 is exposed inside and around the through hole 14.

[0041] Figure 5 is a cross-sectional view showing an example of the structure in which a conductor is mounted on the circuit board in the electronic circuit device according to the first embodiment of the present invention. In Figure 4 the circuit board 10 shown, a conductor 20 is mounted using a fastening member 30. The fastening member 30 is composed of a bolt 31 and a nut 32, and a through hole 21 is formed in the conductor 20. As Figure 5 shown, the circuit board 10 and the conductor 20 are arranged at positions where the through hole 14 of the circuit board 10 and the through hole 21 of the conductor 20 communicate with each other, and the nut 32 is screwed onto the bolt 31 through these through holes 14 and 21, whereby the circuit board 10 and the conductor 20 are fastened to each other. Thereby, the wiring layer 12 of the circuit board 10 is joined to the conductor 20 and electrically connected.

[0042] A sealing member 40, which is formed of an elastic member such as a rubber washer, is disposed between the circuit board 10 and the bolt 31. The sealing member 40 is disposed around the through-hole 14 in a state of being sandwiched between the head 33 of the bolt 31 and the circuit board 10. Therefore, when the circuit board 10 and the conductor 20 are fastened by the fastening member 30 (the bolt 31 and the nut 32), the sealing member 40 is in close contact with the circuit board 10. As a result, the gap between the sealing member 40 and the circuit board 10 is filled to block the through-hole 14.

[0043] The conductor 20 is connected to a load device such as an external storage battery (not shown) or a winding of a motor (not shown). By mounting the conductor 20 on the circuit board 10 as described above, these load devices are connected to the wiring layer 12 of the circuit board 10 via the conductor 20, and a large amount of power is input to and output from the wiring layer 12, generating heat in the wiring layer 12. In particular, since the power is concentrated near the through-hole 14, the temperature tends to be higher than other parts. Therefore, it is necessary to efficiently cool the circuit board 10.

[0044] Figure 6 It is a cross-sectional view showing the structure of the electronic circuit device according to the first embodiment of the present invention. Figure 6 The illustrated electronic circuit device 1 is constituted by further combining a flow path forming body 50 with the combination of the circuit board 10, the conductor 20, the fastening member 30, and the sealing member 40 described in Figure 5 .

[0045] The flow path forming body 50 and the circuit board 10 together form a flow path for the refrigerant 51 for cooling the circuit board 10. In order to prevent leakage of the refrigerant 51, the flow path forming body 50 is in close contact with the circuit board 10 by a known method such as sandwiching an O-ring. Thus, in the space sealed by the circuit board 10 and the flow path forming body 50, for example, by flowing the refrigerant 51 in the direction from the front side near the paper surface toward the inside, the circuit board 10 can be forcibly cooled by the refrigerant 51 flowing in contact with the circuit board 10.

[0046] In the circuit board 10, the thinner the wiring layer 12 is, the greater the resistance of the wiring layer 12 becomes, and the greater the amount of heat generated during energization. However, in the electronic circuit device of the present embodiment, by forcibly cooling the circuit board 10 using the refrigerant 51, particularly the peripheral portion of the through-hole 14 where the conductor 20 is mounted via the bolt 31, the temperature of the wiring layer 12 in the circuit board 10 can be effectively reduced. Therefore, even if the circuit board 10 is made thin, the function of the wiring layer 12 can be maintained.

[0047] In addition, in a state where the contact surface between the surface of the circuit board 10 and the head 33 of the bolt 31 is not smooth, the bolt 31 penetrates through the surface of the circuit board 10 where the flow path of the refrigerant 51 is formed, that is, Figure 6 between the upper surface (hereinafter referred to as the "cooling surface") and the surface on the opposite side of the cooling surface (hereinafter referred to as the "back surface"), the nut 32 is screwed to fasten the circuit board 10 and the conductor 20. In this case, since a gap is formed in the contact surface between the circuit board 10 and the head 33 of the bolt 31, the refrigerant 51 may leak to the outside through the through hole 14 from this gap. Therefore, in the present embodiment, the sealing member 40 is disposed between the circuit board 10 and the head 33 of the bolt 31, and the through hole 14 is blocked by the sealing member 40 for sealing. Thus, the space surrounded by the circuit board 10 and the flow path forming body 50 can be used as the flow path of the refrigerant 51, and the refrigerant 51 can be sealed in the flow path to prevent the refrigerant 51 from leaking to the outside.

[0048] As described above, in the electronic circuit device 1 of the present embodiment, it is possible to achieve both efficient cooling of the circuit board 10 and prevention of leakage of the refrigerant 51, so that a thin electronic circuit device can be constructed.

[0049] According to the first embodiment of the present invention, the following effects are achieved.

[0050] (1) The electronic circuit device 1 includes: a circuit board 10 formed with a wiring layer 12; a conductor 20 electrically connected to the wiring layer 12; a flow path forming body 50 that forms a flow path of the refrigerant 51 that flows in contact with the circuit board 10 together with the circuit board 10; a fastening member 30 for fastening the circuit board 10 and the conductor 20; and a sealing member 40 for sealing the flow path of the refrigerant 51. A through hole 14 is formed in the circuit board 10, and the through hole penetrates between the cooling surface where the flow path of the refrigerant 51 is formed and the back surface on the opposite side of the cooling surface. A through hole 21 communicating with the through hole 14 is formed in the conductor 20. The fastening member 30 fastens the circuit board 10 and the conductor 20 through the through hole 14 and the through hole 21. By fastening the circuit board 10 and the conductor 20 by the fastening member 30, the sealing member 40 blocks the through hole 14 to seal the flow path of the refrigerant 51. In this way, an electronic circuit device 1 that can effectively cool the circuit board 10 while ensuring the sealing performance of the refrigerant flow path can be provided.

[0051] (2) The fastening member 30 includes: a bolt 31 having a head 33 disposed on the cooling surface side of the circuit board 10 and penetrating through the through hole 14 and the through hole 21; and a nut 32 disposed on the conductor 20 side and screwed to the bolt 31. The sealing member 40 is disposed between the circuit board 10 and the head 33. In this way, the through hole 14 can be reliably blocked to ensure the sealing performance of the refrigerant flow path.

[0052] [Second Embodiment]

[0053] Figure 7 It is a cross-sectional view showing the structure of the electronic circuit device according to the second embodiment of the present invention. Figure 7 The shown electronic circuit device 1a, Figure 6 similarly to the electronic circuit device 1 shown, forms a space by closely adhering the flow path forming body 50 to the circuit board 10, and cools the circuit board 10 by causing the refrigerant 51 to flow through this space. The difference between the electronic circuit device 1a of the present embodiment and the electronic circuit device 1 described in the first embodiment is that Figure 6 the nut 32 and the sealing member 40 are respectively replaced with Figure 7 the nut 32a and the sealing member 40a.

[0054] The nut 32a is a cap nut that closes without penetrating the threaded hole for mounting the bolt 31. The sealing member 40a is disposed on the conductor 20 side and has a convex portion that inserts into the through hole 21 of the conductor 20 and abuts against the back surface of the circuit board 10, and a base portion that is disposed between the conductor 20 and the nut 32a. The convex portion of the sealing member 40a is thicker than the conductor 20 and has elasticity.

[0055] If there are gaps between the bolt 31 and the circuit board 10 and between the conductor 20 and the circuit board 10, there is a possibility that the refrigerant 51 leaks to the outside through these gaps and the through hole 14. Therefore, in the present embodiment, although it has a thickness compared to the conductor 20, when pressure is applied, the sealing member 40a having an elastic convex portion thinner than the conductor 20 is disposed between the conductor 20 and the nut 32a, and with the convex portion inserted into the through hole 21 of the conductor 20, the nut 32a is screwed onto the bolt 31 and tightened. Thus, the conductor 20 and the circuit board 10 are fastened by the fastening member 30a composed of the bolt 31 and the nut 32a, and the convex portion of the sealing member 40a is compressed by the nut 32a and the circuit board 10 and its thickness becomes smaller. As a result, the gap between the conductor 20 and the circuit board 10 is filled by the convex portion of the sealing member 40a, and the through hole 14 is blocked and sealed.

[0056] In the electronic circuit device 1a of the present embodiment, with the above structure, the space surrounded by the circuit board 10 and the flow path forming body 50 can be used as the flow path of the refrigerant 51, and the refrigerant 51 can be sealed in this flow path to prevent the refrigerant 51 from leaking to the outside. Therefore, similarly to the first embodiment, it is possible to achieve both efficient cooling of the circuit board 10 and prevention of refrigerant 51 leakage, and thus a thin electronic circuit device can be constructed.

[0057] According to the second embodiment of the present invention, the same effects as those of the first embodiment are achieved. Furthermore, the fastening member 30a includes: a bolt 31 having a head 33 disposed on the cooling surface side of the circuit board 10 and passing through the through-hole 14 and the through-hole 21; and a nut 32a disposed on the conductor 20 side and screwed with the bolt 31. The sealing member 40a is thicker than the conductor 20 and elastic, and has a convex portion passing through the through-hole 21 and a base portion disposed between the conductor 20 and the nut 32a. Therefore, the through-hole 14 can be reliably blocked to ensure the sealing performance of the refrigerant flow path.

[0058] [Third Embodiment]

[0059] Figure 8 FIG. is a cross-sectional view showing an example of a structure in which a conductor is mounted on a circuit board in an electronic circuit device according to the third embodiment of the present invention. The electronic circuit device of the present embodiment has the same structure as the electronic circuit device 1a described in the second embodiment. Figure 8 The difference between the structure shown and the structure described in the second embodiment is the orientation of the fastening member 30a and the structure of the sealing member. Specifically, in the present embodiment, as shown in Figure 8 FIG., the head 33 of the bolt 31 is disposed on the conductor 20 side, the nut 32a is disposed on the cooling surface side of the circuit board 10, and a sealing member 40b having the shape shown in Figure 8 FIG. is disposed around the through-hole 14 in a state of being sandwiched between the circuit board 10 and the nut 32a. The sealing member 40b is made of an elastic member such as rubber.

[0060] By fastening the circuit board 10 and the conductor 20 with the fastening member 30a (bolt 31 and nut 32a), the sealing member 40b is compressed and closely attached to the circuit board 10. Thus, similarly to the first embodiment, the gap between the sealing member 40b and the circuit board 10 is filled to block the through-hole 14.

[0061] Figure 9 FIG. is a cross-sectional view showing the structure of an electronic circuit device according to the third embodiment of the present invention. Figure 9 The shown electronic circuit device 1b is in Figure 8It is constituted by further combining a flow path forming body 50 with the combination of the circuit board 10, the conductor 20, the fastening member 30a, and the sealing member 40b described in [the foregoing]. In the present embodiment, the sealing member 40b is disposed between the circuit board 10 and the nut 32a, and the through hole 14 is blocked by the sealing member 40b for sealing. Thus, the space surrounded by the circuit board 10 and the flow path forming body 50 can be used as a flow path for the refrigerant 51, and the refrigerant 51 can be sealed in this flow path to prevent the refrigerant 51 from leaking to the outside. Therefore, similar to the first and second embodiments, it is possible to achieve both efficient cooling of the circuit board 10 and prevention of leakage of the refrigerant 51, and thus a thin electronic circuit device can be constructed.

[0062] According to the third embodiment of the present invention, the same effects as those of the first embodiment are achieved. Further, the fastening member 30a includes: a bolt 31 having a head 33 disposed on the conductor 20 side and passing through the through hole 21 and the through hole 14; and a nut 32a disposed on the cooling surface side of the circuit board 10 and screwed with the bolt 31. The sealing member 40b is disposed between the circuit board 10 and the nut 32a. In this way, the through hole 14 can be reliably blocked to ensure the sealing performance of the refrigerant flow path.

[0063] [Fourth Embodiment]

[0064] Figure 10 It is a cross-sectional view showing an example of the structure of a circuit board and a flow path forming body in an electronic circuit device according to the fourth embodiment of the present invention. The electronic circuit device of the present embodiment includes a circuit board 10 and a flow path forming body 50a having the same structure as the structure described in the first to third embodiments. The flow path forming body 50a has a protruding portion 52 protruding toward the cooling surface of the circuit board 10, and a threaded hole 53 is formed at a position corresponding to the through hole 14 of the circuit board 10 in the protruding portion 52. In addition, similar to the flow path forming body 50 in the first to third embodiments, the flow path forming body 50a forms a flow path for the refrigerant 51 for cooling the circuit board 10 together with the circuit board 10, and in order to prevent leakage of the refrigerant 51, it is brought into close contact with the circuit board 10 by a known method such as sandwiching an O-ring in the middle.

[0065] Figure 11 It is a cross-sectional view showing the structure of an electronic circuit device according to the fourth embodiment of the present invention. Figure 11 The illustrated electronic circuit device 1c is in Figure 10The combination of the circuit board 10 and the flow path forming body 50a described in [the above] is further combined with the conductor 20 and the bolt 31 to form a structure. In the present embodiment, the bolt 31 as a fastening member penetrates through the through hole 21 of the conductor 20 and the through hole 14 of the circuit board 10 from the conductor 20 side, and is screwed into the threaded hole 53 provided in the protruding portion 52 of the flow path forming body 50a. Thus, in a state where the through hole 14 is covered by the protruding portion 52, the circuit board 10 and the conductor 20 are fastened, so that the protruding portion 52 can function as a sealing member to block the through hole 14 for sealing.

[0066] According to the above structure, although the flow of the refrigerant 51 is divided by the protruding portion 52, the space surrounded by the circuit board 10 and the flow path forming body 50a is used as the flow path of the refrigerant 51, and the refrigerant 51 is sealed in the flow path, so that the refrigerant 51 can be prevented from leaking to the outside. Therefore, similar to the first to third embodiments, it is possible to achieve both efficient cooling of the circuit board 10 and prevention of leakage of the refrigerant 51, so that a thin electronic circuit device can be constructed. In addition, since a part of the fastening member for fastening the circuit board 10 and the conductor 20 can be used as the protruding portion 52 of the flow path forming body 50a, the number of components of the electronic circuit device can be reduced. Furthermore, since the bolt 31 can be removed in a state where the flow path forming body 50a and the circuit board 10 are combined to disassemble the conductor 20, the replacement of the conductor 20 becomes easy, and the maintainability can be improved.

[0067] According to the fourth embodiment of the present invention, the same effects as those of the first embodiment are achieved. Furthermore, the flow path forming body 50a has a protruding portion 52 protruding toward the cooling surface of the circuit board 10, and the flow path forming body 50a and the circuit board 10 together form a flow path for the refrigerant 51, so that the protruding portion 52 is configured to cover the through hole 14. The bolt 31 as a fastening member penetrates through the through hole 21 and the through hole 14 from the conductor 20 side, and is screwed into the threaded hole 53 provided in the protruding portion 52 of the flow path forming body 50a. By screwing the bolt 31 into the threaded hole 53, the protruding portion 52 functions as a sealing member. In this way, the number of components can be reduced, and the through hole 14 can be reliably blocked to ensure the sealing performance of the refrigerant flow path.

[0068] [Fifth Embodiment]

[0069] Figure 12 It is a cross-sectional view showing the structure of the electronic circuit device according to the fifth embodiment of the present invention. Figure 12 The shown electronic circuit device 1d is the same as Figure 11Similarly, in the illustrated electronic circuit device 1c, the bolt 31 as a fastening member penetrates through the through-hole 21 and the through-hole 14 from the conductor 20 side and is screwed into the threaded hole 53 of the protrusion 52 provided on the flow path forming body 50a, thereby forming the flow path of the refrigerant 51. The difference between the electronic circuit device 1d of the present embodiment and the electronic circuit device 1c described in the fourth embodiment is that the sealing member 40 described in the first embodiment is disposed while being sandwiched between the circuit board 10 and the protrusion 52.

[0070] In the present embodiment, the sealing member 40 is disposed around the through-hole 14 in a state of being sandwiched between the circuit board 10 and the protrusion 52. Therefore, the circuit board 10 and the conductor 20 are fastened by the bolt 31 as a fastening member, so that the sealing member 40 is in close contact with the circuit board 10 and the protrusion 52, respectively. Thereby, the gap between the sealing member 40 and the circuit board 10 is filled to block the through-hole 14. Therefore, compared with the case where the protrusion 52 functions as a sealing member as in the fourth embodiment, even if the insulating film 13 is not provided around the through-hole 14 on the cooling surface of the circuit board 10, the sealing property of the refrigerant flow path can be ensured. Further, the dimensional accuracy in the height direction of the protrusion 52 and the surface roughness of the contact surface of the protrusion 52 with the circuit board 10 do not affect the sealing property, so that the manufacturing cost can be reduced.

[0071] According to the above configuration, similarly to the first to fourth embodiments, it is possible to achieve both efficient cooling of the circuit board 10 and prevention of leakage of the refrigerant 51, so that a thin electronic circuit device can be constructed. In addition, similarly to the fourth embodiment, a part of the fastening member for fastening the circuit board 10 and the conductor 20 can be used as the protrusion 52 of the flow path forming body 50a, so that the number of components of the electronic circuit device can be reduced. Further, since the bolt 31 can be removed in a state where the flow path forming body 50a and the circuit board 10 are combined to disassemble the conductor 20, the replacement of the conductor 20 becomes easy, and the maintainability can be improved.

[0072] According to the fifth embodiment of the present invention, the same effects as those of the first embodiment are achieved. Further, the flow path forming body 50a has a protrusion 52 protruding toward the cooling surface of the circuit board 10, and the flow path forming body 50a and the circuit board 10 together form the flow path of the refrigerant 51, so that the protrusion 52 is configured to cover the through-hole 14. The bolt 31 as a fastening member penetrates through the through-hole 21 and the through-hole 14 from the conductor 20 side and is screwed into the threaded hole 53 of the protrusion 52 provided on the flow path forming body 50a. The sealing member 40 is disposed while being sandwiched between the circuit board 10 and the protrusion 52. In this way, the number of components can be reduced, and the through-hole 14 can be reliably blocked to ensure the sealing property of the refrigerant flow path.

[0073] [Sixth Embodiment]

[0074] Figure 13 FIG. 204 is a cross-sectional view showing the structure of the electronic circuit device according to the sixth embodiment of the present invention. Figure 13 The main difference between the shown electronic circuit device 1e and the electronic circuit device 1 described in the first embodiment is that the bolt 31 described in the first embodiment is replaced with a two-sided bolt member having bolt portions 31a and 31b with a common head 33a formed at both ends.

[0075] The heads 33a of the two-sided bolt member are arranged in the flow path of the refrigerant 51 formed by the circuit board 10 and the flow path forming body 50b. One bolt portion 31a extending downward in the figure from the head 33a penetrates the through hole 14 of the circuit board 10 and the through hole 21 of the conductor 20. In addition, the other bolt portion 31b extending upward in the figure from the head 33a penetrates the through hole 54 formed in the flow path forming body 50b. A nut 32 disposed on the side of the conductor 20 is screwed onto the bolt portion 31a, and a nut 32 disposed on the outer surface side of the flow path forming body 50b, that is, on the side opposite to the flow path surface where the flow path is formed, is screwed onto the bolt portion 31b. In the present embodiment, in this way, the circuit board 10 and the conductor 20 are fastened by the fastening member 30b constituted by the two bolt portions 31a and 31b having the common head 33a and the two nuts 32 corresponding to these bolt portions.

[0076] In addition, in the present embodiment, the sealing member 40 described in the first embodiment is arranged around the through hole 14 of the circuit board 10 in a state of being sandwiched between the circuit board 10 and the head 33a, and is also arranged around the through hole 54 of the flow path forming body 50b in a state of being sandwiched between the flow path forming body 50b and the head 33a. Therefore, by fastening the circuit board 10 and the conductor 20 by the fastening member 30b, one sealing member 40 is closely attached to the circuit board 10, and by fastening the circuit board 10 and the flow path forming body 50b by the fastening member 30b, the other sealing member 40 is closely attached to the flow path forming body 50b. As a result, the gaps between the sealing member 40 and the circuit board 10 and between the sealing member 40 and the flow path forming body 50b are respectively filled, and the through hole 14 and the through hole 54 are blocked.

[0077] In the electronic circuit device 1e of the present embodiment, with the above structure, the space surrounded by the circuit board 10 and the flow path forming body 50b can be used as the flow path of the refrigerant 51, and the refrigerant 51 can be sealed in the flow path to prevent the refrigerant 51 from leaking to the outside. Therefore, similarly to the first to fifth embodiments, it is possible to achieve both efficient cooling of the circuit board 10 and prevention of leakage of the refrigerant 51, and thus a thin electronic circuit device can be constructed.

[0078] According to the sixth embodiment of the present invention, the same effects as those of the first embodiment are achieved. Furthermore, a through-hole 54 is formed in the flow path forming body 50b, and the through-hole 54 penetrates between the flow path surface where the flow path of the refrigerant 51 is formed and the outer surface on the side opposite to the flow path surface. The fastening member 30b has: a head 33a disposed within the flow path of the refrigerant 51; a bolt portion 31a extending from the head 33a and penetrating through the through-hole 14 and the through-hole 21; a bolt portion 31b extending from the head 33a and penetrating through the through-hole 54; a nut 32 disposed on the side of the conductor 20 and screwed with the bolt portion 31a; and a nut 32 disposed on the outer surface side of the flow path forming body 50b and screwed with the bolt portion 31b. The sealing member 40 has a member disposed between the circuit board 10 and the head 33a, and a member disposed between the flow path forming body 50b and the head 33a. In this way, the through-hole 14 can be reliably blocked to ensure the sealing of the refrigerant flow path.

[0079] In addition, the above-described various embodiments are described to facilitate the understanding of the present invention, and the present invention is not limited to the specific structures described. For example, a part of the structure of the embodiment can be replaced with the structure of the common technical knowledge of those skilled in the art, and in addition, the structure of the common technical knowledge of those skilled in the art can also be added to the structure of the embodiment. That is, the present invention can delete a part of the structure of the embodiment in the present specification, replace it with other structures, or add other structures without departing from the technical idea of the invention.

[0080] The embodiments and modification examples described above are only examples, and the present invention is not limited to these as long as the features of the invention are not impaired. In addition, in the above content, various embodiments and modification examples are described, but the present invention is not limited to these. Other ways considered within the technical idea of the present invention are also included within the scope of the present invention.

[0081] Reference Signs

[0082] 1, 1a, 1b, 1c, 1d, 1e ··· electronic circuit device

[0083] 10 ··· circuit board

[0084] 11 ··· insulator

[0085] 12 ··· wiring layer

[0086] 13 ··· insulating film

[0087] 14 ··· through-hole

[0088] 20 ··· conductor

[0089] 21 ··· through-hole

[0090] 30, 30a, 30b ··· fastening members

[0091] 31 ··· bolts

[0092] 31a, 31b ··· bolt portions

[0093] 32, 32a ··· nuts

[0094] 33, 33a ··· heads

[0095] 40, 40a, 40b ··· sealing members

[0096] 50, 50a, 50b ··· flow path forming bodies

[0097] 51 ··· refrigerant

[0098] 52 ··· protruding portions

[0099] 53 ··· threaded holes

[0100] 54 ··· through holes.

Claims

1. An electronic circuit device, comprising: A circuit board, forming a wiring layer; A conductor, electrically connected to the wiring layer; A flow path forming body, forming a flow path of a refrigerant that contacts and flows on the circuit board together with the circuit board; A fastening member, for fastening the circuit board and the conductor; And A sealing member, for sealing the flow path, A first through hole is formed in the circuit board, penetrating between the cooling surface forming the flow path and the back surface on the opposite side of the cooling surface; Inside the first through hole, the wiring layer is exposed to the back surface; A second through hole communicating with the first through hole is formed in the conductor; The fastening member fastens the circuit board and the conductor through the first through hole and the second through hole; By fastening the circuit board and the conductor with the fastening member, the wiring layer is electrically connected to the conductor through the first through hole, DC power is input and output to the wiring layer through the conductor, and the sealing member blocks the first through hole to seal the flow path.

2. The electronic circuit device according to claim 1, wherein The fastening member has: a bolt, the head of which is disposed on the cooling surface side of the circuit board and penetrates through the first through hole and the second through hole; And a nut, disposed on the conductor side and screwed with the bolt, The sealing member is disposed between the circuit board and the head.

3. The electronic circuit device according to claim 1, wherein The fastening member has: a bolt, the head of which is disposed on the cooling surface side of the circuit board and penetrates through the first through hole and the second through hole; And a nut, disposed on the conductor side and screwed with the bolt, The sealing member has: a convex portion, thicker than the conductor and having elasticity, and penetrating through the second through hole; and a base portion, disposed between the conductor and the nut.

4. The electronic circuit device according to claim 1, wherein The fastening member has: a bolt, the head of which is disposed on the conductor side and penetrates through the second through hole and the first through hole; And a nut, disposed on the cooling surface side of the circuit board and screwed with the bolt, The sealing member is disposed between the circuit board and the nut.

5. The electronic circuit device according to claim 1, wherein The flow path forming body has a protruding portion that protrudes toward the cooling surface of the circuit board as a part of the flow path forming body, The flow path forming body and the circuit board together form the flow path, so that the protruding portion is configured to cover the first through hole, The fastening member penetrates through the second through hole and the first through hole from the conductor side, and is screwed with a threaded hole provided in the protruding portion of the flow path forming body, By screwing the fastening member with the threaded hole, the protruding portion functions as the sealing member.

6. The electronic circuit device according to claim 1, wherein The flow path forming body has a protruding portion that protrudes toward the cooling surface of the circuit board as a part of the flow path forming body, The flow path forming body and the circuit board together form the flow path, so that the protruding portion is configured to cover the first through hole. The fastening member penetrates through the second through hole and the first through hole from the conductor side and is screwed into the threaded hole of the protruding portion provided on the flow path forming body. The sealing member is disposed sandwiched between the circuit board and the protruding portion.

7. The electronic circuit device according to claim 1, wherein A third through hole is formed in the flow path forming body, penetrating between the flow path surface forming the flow path and the outer surface on the opposite side of the flow path surface. The fastening member has: a head portion disposed in the flow path; a first bolt portion extending from the head portion and penetrating through the first through hole and the second through hole; a second bolt portion extending from the head portion and penetrating through the third through hole; a first nut disposed on the conductor side and screwed to the first bolt portion; and a second nut disposed on the outer surface side of the flow path forming body and screwed to the second bolt portion. The sealing member has: a first sealing member disposed sandwiched between the circuit board and the head portion; and a second sealing member disposed sandwiched between the flow path forming body and the head portion.

Images