Circuit design

Abstract

Circuit device (1) comprising: a heat dissipation element (23); several conductors (20, 21, 22) placed on a placement surface (23a) of the heat dissipation element (23), with an insulating element (24) made of an epoxy resin and containing a thermally conductive filler arranged between them; a thermal insulation element (26) arranged at a location on the placement surface (23a) that differs from the locations where the insulating element (24) and the several conductors (20, 21, 22) are placed; a printed circuit board (25) provided with an opening (25a); a semiconductor switch (3, 4) passing through the opening (25a), electrically connected to two of the several conductors (20, 21, 22) and generating heat;a control element (51) located on the printed circuit board (25) opposite the thermal insulation element (26), with the printed circuit board (25) positioned between them, and outputting a control signal for controlling the operation of the semiconductor switch (3, 4); and a drive circuit (50) that switches the semiconductor switch (3, 4) on or off according to a control signal output by the control element (51); wherein the control signal is a signal to switch the semiconductor switch (3, 4) on or off; an element in the drive circuit (50) located on the printed circuit board (25) opposite the thermal insulation element (26), with the printed circuit board (25) positioned between them, the printed circuit board (25) having a conductor pattern connecting the drive circuit (50) and the semiconductor switch (3, 4), and each of the conductors (20, 21, 22) being a bus bar.

Description

TECHNICAL AREA

[0001] The present invention relates to a circuit device.

[0002] The present application is based on Japanese patent application No. 2017-068331 filed with the Japanese Patent Office on March 30, 2017, the entire content of which is deemed to be incorporated by reference. TECHNICAL BACKGROUND

[0003] Patent document No. 1 discloses an electrical distribution box connected to a battery and a load, such as a headlight or windshield wiper. In this electrical distribution box, several plate-shaped conductors are placed on a mounting surface of a heat dissipation element, with an insulating element positioned between them, and the plate surfaces on one side of the conductors facing the mounting surface. One end and the other end of a semiconductor switch are each connected to one of the two conductors. One end of the semiconductor switch is connected to the battery via one of the two conductors, and the other end of the semiconductor switch is connected to the load via the other of the two conductors.

[0004] A printed circuit board (PCB) is arranged on plate areas on the opposite side of the multiple conductors, and one plate area of ​​the PCB faces the plate areas on the opposite side of the conductors. A control element is located on the other plate area of ​​the PCB, and the control element outputs control signals to turn the semiconductor switch on or off. When the control element outputs a control signal to turn the semiconductor switch on, the semiconductor switch is turned on, and the load is supplied with power from the battery, with current flowing through the semiconductor switch. When the control element outputs a control signal to turn the semiconductor switch off, the semiconductor switch is turned off, and the power supply from the battery to the load is terminated by interrupting the current flow through the semiconductor switch.

[0005] When current flows through the semiconductor switch, the semiconductor switch generates heat. The heat generated by the semiconductor switch is first conducted via the conductors and then the heat dissipation element, and is then dissipated by the heat dissipation element. PREVIOUSLY KNOWN TECHNICAL DOCUMENTS PATENT DOCUMENTS

[0006] Patent Document No. 1: JP 2003-164040A OVERVIEW OF THE INVENTION

[0007] A circuit device according to one aspect of the present invention comprises a heat dissipation element, a conductor placed on a placement surface of the heat dissipation element, wherein an insulating element is arranged between them, a thermal insulation element arranged at a location on the placement surface that differs from the location where the conductor is placed, a circuit component electrically connected to the conductor and generating heat, a printed circuit board, and a control element placed on the printed circuit board opposite the thermal insulation element, wherein the printed circuit board is arranged between them, and outputs a control signal for controlling the operation of the circuit component. List of characters Fig. Figure 1 is a circuit diagram of an electrical distribution box according to an exemplary embodiment. Fig. Figure 2 is a perspective view of the electrical distribution box. Fig. 3 is a cross-sectional view along the line A-A in Fig. 2. Fig. Figure 4 is a perspective view of the electrical distribution box with the cover removed. Fig. Figure 5 is a top view of the electrical distribution box without the cover. Fig. 6 is a cross-sectional view along the line B-B in Fig. 5. Fig. 7 is an enlarged view of the in Fig. Section 6, labelled C. Fig. Figure 8 is a diagram illustrating the manufacturing of the electrical distribution box. TASKS TO BE SOLVED FROM THE INVENTION

[0008] In the electrical distribution box described in patent document No. 1, the heat dissipation element, the conductors, the circuit board, and the control element are arranged in precisely that order. Therefore, heat generated by the semiconductor switch is conducted to the control element via the conductors and the circuit board. Consequently, as the temperature of the semiconductor switch increases, the temperature of the control element also increases at a rate that is essentially the same as the rate at which the temperature of the semiconductor switch increases.

[0009] The control element has low thermal resistance. Therefore, the upper temperature limit of the semiconductor switch, up to which its normal operation is ensured, is typically higher than the upper temperature limit of the control element. In this case, the operation of the semiconductor switch is controlled such that its temperature does not exceed the upper temperature limit of the control element. For example, if the temperature of the semiconductor switch approaches the upper temperature limit of the control element, the control element outputs a control signal to turn off the semiconductor switch and terminate the power supply through the semiconductor switch.

[0010] As described above, the problem arises with the electrical distribution box described in patent document No. 1 that the upper limit of a permissible temperature of the semiconductor switch is lower than the actual upper limit of the temperature of the semiconductor switch.

[0011] Circuit devices in which such a problem occurs are not limited to the electrical distribution box described in patent document No. 1. Similar problems arise in circuit devices in which a heat dissipation element, a conductor, a circuit board, and a control element are arranged in that same order, and a heat-generating circuit component is connected to the conductor.

[0012] In such a circuit arrangement, the control element outputs control signals to regulate the operation of the circuit component, and the upper temperature limit of the circuit component, up to which its normal operation is ensured, is higher than the upper temperature limit of the control element, up to which its normal operation is ensured. Therefore, the upper limit of a permissible temperature of the circuit component is lower than the actual upper temperature limit of the circuit component.

[0013] The present disclosure therefore aims to provide a circuit device in which the upper limit of a permissible temperature of a circuit component is high. EFFECT OF INVENTION

[0014] According to the present disclosure, the upper limit of a permissible temperature of a circuit component is high. FORMS OF EXECUTION OF THE INVENTION

[0015] First, aspects of the implementation of the present invention are listed and described. At least some of the embodiments described below can be combined as required.

[0016] (1) A circuit device according to one aspect of the present invention comprises a heat dissipation element, a conductor placed on a placement surface of the heat dissipation element, an insulating element arranged between them, a thermal insulation element arranged at a location on the placement surface that differs from the location where the conductor is placed, a circuit component electrically connected to the conductor and generating heat, a printed circuit board, and a control element placed on the printed circuit board opposite the thermal insulation element, the printed circuit board being arranged between them and outputting a control signal for controlling the operation of the circuit component.

[0017] As described above, the control element is positioned opposite the thermal insulation element, with the printed circuit board (PCB) between them. Therefore, heat generated by the circuit component is barely transferred to the control element via the conductor or heat dissipation element. Consequently, the temperature of the control element hardly increases, even when the temperature of the circuit component increases. As a result, the upper limit of the permissible temperature of the circuit component is high, since this value is not limited by the upper temperature limit of the control element up to which its normal operation is ensured.

[0018] (2) In a circuit device according to a further aspect of the present invention, the thermal insulation element is formed by a fleece containing silicate aerogel particles.

[0019] According to this aspect, the thermal insulation element is formed by a nonwoven fabric containing silicate aerogel particles, and therefore it is less likely that heat will be conducted from the conductor or heat dissipation element to the control element via the thermal insulation element.

[0020] (3) A circuit arrangement according to a further aspect of the present invention further comprises a frame arranged along a circumferential edge of the placement surface of the heat dissipation element and surrounding the circuit component, the printed circuit board and the control element, and a cover arranged opposite the placement surface of the heat dissipation element and covering the interior of the frame, wherein the conductor, the circuit component, the printed circuit board and the control element are arranged between the placement surface and the cover.

[0021] From this perspective, the circuit component is covered by the heat dissipation element, the frame, and the cover, and therefore it is unlikely that any air in contact with the circuit component will escape from the circuit assembly. Consequently, most of the heat generated by the circuit component is conducted through the conductor and the heat dissipation element. The thermal insulation element functions more effectively in a design where the frame and cover are provided.

[0022] (4) In a circuit device according to a further aspect of the present invention, the circuit device comprises several of the conductors, the circuit component is a semiconductor switch which is electrically connected to two of the several conductors, and the control signal is a signal to switch the circuit component on or off.

[0023] According to this view, current flows through the two conductors and the semiconductor switch, which serves as the circuit component. When the semiconductor switch is on, current can flow through the two conductors; conversely, when the semiconductor switch is off, no current flows through the two conductors. EXAMPLES OF THE PRESENT INVENTION

[0024] A specific example of an electrical distribution box (a circuit device) according to an embodiment of the present invention is explained below with reference to the accompanying drawings. It should be noted that the present invention is not limited to this example, but is defined by the claims and is intended to include all modifications that are equivalent in meaning and scope to the claims.

[0025] Fig. Figure 1 is a circuit diagram of an electrical distribution box. 1according to this exemplary embodiment. The electrical distribution box 1 is preferably installed in a vehicle and features ladders 20 , 21 and 22 , six n-channel field-effect transistors (FETs) 3 and 4 , a control circuit 50 and a microcomputer 51 up. Each of the leaders 20 , 21 and 22 It is a so-called busbar and is made, for example, of a copper alloy. The electrical distribution box 1 It serves as a circuit device.

[0026] Each of the FETs 3 features a FET main body 3a and a diode 3b up, and the diode 3b is between the drain and the source of the FET main body 3a switched. Each of the FETs 4 features a FET main body 4a and a diode 4b up, and the diode 4bis between the drain and the source of the FET main body 4a switched. The diodes 3b and 4b are parasitic diodes.

[0027] The three main FET bodies 3a are between the ladders 20 and 21 connected in parallel, and the three FET main bodies 4a are between the ladders 21 and 22 The drains of the three FET main bodies are connected in parallel. 3a are with the leader 20 connected, the sources of the six main FET bodies 3a and 4a are with the leader 21 connected and the drains of the three main FET bodies 4a are with the leader 22 connected. The gates of the six main FET bodies 3a and 4a are connected to the control circuit 50 connected. Furthermore, the microcomputer 51 with the control circuit 50 tied together.

[0028] Each of the FETs 3and 4 It serves as a semiconductor switch. The control circuit 50 regulates the voltage at the gate of the six FETs 3 and 4 related to a fixed potential. The control circuit 50 This switches the six FETs 3 and 4 on or off.

[0029] Are the six FETs 3 and 4 When switched on, electricity can flow through the conductors 20 , 21 and 22 and the six FETs 3 and 4 flow. Are the six FETs 3 and 4 When switched off, no current flows through the conductors. 20 , 21 and 22 and the six FETs 3 and 4 .

[0030] When current flows between the drain and source of the FETs 3 The FETs generate flow. 3 Heat. When current flows between the drain and source of the FETs. 4 The FETs generate flow. 4 Heat. Each of the FETs 3and 4 It also serves as a circuit component.

[0031] The anodes of the three diodes 3b are over the ladder 21 with the anodes of the three diodes 4b connected. Therefore, no current flows through the six diodes. 3b and 4b , when the six FETs 3 and 4 are switched off.

[0032] A switch-on signal that activates the six FETs 3 and 4 switches on, and a switch-off signal that activates the six FETs 3 and 4 when switched off, the microcomputer 51 entered. Depending on the signal entered, the microcomputer outputs 51 a control signal that controls the six FETs 3 and 4 switches on or off, to the control circuit 50 out of.

[0033] In detail, the microcomputer 51, when a power-on signal is input, a control signal to switch on the six FETs 3 and 4 to the control circuit 50 off, and the control circuit 50 then switches the six FETs 3 and 4 a. When a shutdown signal is input, the microcomputer outputs 51 a control signal to switch off the six FETs 3 and 4 to the control circuit 50 off, and the control circuit 50 then switches the six FETs 3 and 4 out of.

[0034] The control signals are signals for controlling the operation of each of the six FETs. 3 and 4 .

[0035] Fig. Figure 2 is a perspective view of the electrical distribution box. 1 The electrical distribution box 1 It also features a box-shaped housing 6 up, and the six FETs 3 and4 , the control circuit 50 and the microcomputer 51 are in the case 6 housed the case 6 has a rectangular frame 60 and a lid 61 open. The lid 61 is on the top of the electrical distribution box 1 arranged, is within the frame 60 fitted and covers the inside of the frame 60 away.

[0036] The ladder 20 and 22 are plate-shaped. A plate surface of the conductor 20 covers the top of one side section of the frame 60 off, and a plate surface of the conductor 22 covers the top of another side section of the frame 60 off. The one from the leader 20 covered one side section of the frame 60 and the one from the leader 22 covered other side section of the frame 60are arranged side by side in a left-right direction and run in a front-back direction. Accordingly, the one controlled by the conductor 20 covered one side section of the frame 60 opposite the one led by the manager 22 covered other side section of the frame 60 arranged. The following description refers to the one ordered by the leader. 20 covered one side section of the frame 60 referred to as the left lateral section, and the one led by the head 22 covered other side section of the frame 60 is referred to as the right sidebar.

[0037] A cylindrical stud bolt 52 protrudes from an upper surface of the left side section of the frame 60 upwards. The ladder 20 has a through hole 20a up, which leads through it in an up-down direction, and the stud screw 52 runs through the through hole20a A cylindrical stud screw protrudes in a similar manner. 53 from an upper surface of the right side section of the frame 60 upwards. The ladder 22 has a through hole 22a up, which leads through it in an up-down direction, and the stud screw 53 runs through the through hole 22a The two stud screws 52 and 53 are arranged opposite each other in a left-right direction and in each of the stud screws 52 and 53 A thread is formed.

[0038] On the stud screw 52 A connection (not shown) is attached, which has an opening. Specifically, it is in a state where the stud screw 52 through the opening of the connection, a nut (not shown) runs onto the stud bolt. 52 attracted. As a result, the leader 20and the connection in contact with each other, and the leader 20 is electrically connected to the terminal.

[0039] In a similar way, the stud screw 53 A connection (not shown) is attached, which has an opening. Specifically, it is in a state where the stud screw 53 through the opening of the connection, a nut (not shown) runs onto the stud bolt. 53 attracted. As a result, the leader 22 and the connection in contact with each other, and the leader 22 is electrically connected to the terminal.

[0040] The one on the stud screw 52 The attached connection is, for example, connected to a positive electrode of the battery, and the one on the stud screw 53 The attached connection is, for example, connected to one end of the load. The load is connected via the electrical distribution box. 1powered by the battery.

[0041] The electrical distribution box 1 has a connector 54 up, and into the connector 54 A connector (not shown) is fitted to the end of a signal line (not shown). The power-on and power-off signals are transmitted to the microcomputer via this signal line. 51 of the electrical distribution box 1 entered.

[0042] Fig. 3 is a cross-sectional view along the line A-A in Fig. 2. Within that framework 60 is a plate-shaped heat dissipation element 23 housed. The heat dissipation element 23 The frame is made of aluminum, for example. 60 covers a left edge section and a right edge section of an upper surface 23a of the heat dissipation element 23 off. The leader 20is bent multiple times, and the plate surface of the conductor 20 It does not only cover the upper surface of the left side section of the frame. 60 , but also a left side section of the upper surface 23a of the heat dissipation element 23 within the framework 60 and an inner surface of the left side section of the frame 60 off. The leader is similarly 22 bent several times and the plate surface of the conductor 22 does not only cover the upper surface of the right side section of the frame. 60 , but also a right side section of the upper surface 23a of the heat dissipation element 23 within the framework 60 and an inner surface of the right side section of the frame 60 away.

[0043] The leader 21 It is also plate-shaped. The conductor 21 is between the ladders 20 and 22on the upper surface 23a of the heat dissipation element 23 placed. The upper surface 23a of the heat dissipation element 23 is the lower surface of the ladder 20 , 21 and 22 facing, and the upper surface 23a of the heat dissipation element 23 is using an insulating element 24 (see Fig. 7), which serves as an adhesive, with the lower surfaces of the ladder 20 , 21 and 22 glued together.

[0044] As described above, the ladders 20 , 21 and 22 on the upper surface 23a of the heat dissipation element 23 placed, with the insulating element 24 is arranged in between. The upper surface 23a of the heat dissipation element 23 serves as a placement area.

[0045] Within the framework 60 are the FETs 3 and 4, which are chip-shaped, on the top of the ladder 20 , 21 and 22 arranged. As described above, the drains of the FETs are 3 electrically connected to the conductor 20 connected, the sources of the FETs 3 and 4 are electrically connected to the conductor 21 connected, and the drains of the FETs 4 are electrically connected to the conductor 22 connected. Within the framework 60 is a printed circuit board 25 on the upper surfaces of the ladder 20 , 21 and 22 arranged. A lower surface of the circuit board 25 is the upper surfaces of the ladder 20 , 21 and 22 facing, and six openings 25a are in the circuit board 25 provided (see Fig. 4) The six FETs 3 and 4 each pass through one of the six openings 25a .

[0046] Heat dissipated by the FETs 3 The generated process is only carried out via the conductor 20 , then the insulating element 24 and then the heat dissipation element 23 directed or only via the leader 21 , then the insulating element 24 and then the heat dissipation element 23 Heat conducted through the FETs 4 The generated process is only carried out via the conductor 21 , then the insulating element 24 and then the heat dissipation element 23 directed or only via the leader 22 , then the insulating element 24 and then the heat dissipation element 23 directed to the heat dissipation element. 23 Conducted heat is removed by the heat dissipation element. 23 from the electrical distribution box 1 carried out.

[0047] Fig. Figure 4 is a perspective view of the electrical distribution box. 1 with the lid removed 61, and Fig. 5 is a top view of the electrical distribution box 1 without the lid 61 The circuit board 25 It has a rectangular shape and runs in a front-to-back direction. The six openings 25b are in the circuit board 25 Provided in a grid pattern. Three openings. 25a are arranged in a front-to-back direction and have two openings 25a are arranged in a left-right direction.

[0048] The three FETs 3 are each in one of three openings 25a arranged in a left side section of the circuit board 25 are provided. The three FETs 4 are each in one of three openings 25a arranged in a right side section of the circuit board 25 are provided. The gates of the FETs 3 and 4are electrically connected to a conductor pattern (not shown) located on a top surface of the circuit board 25 is provided.

[0049] The microcomputer 51 is chip-shaped and is located in a front side section of the upper surface of the circuit board 25 arranged. Furthermore, the connector 54 in the front side section of the upper surface of the circuit board 25 provided. The control circuit 50 is on the upper surface of the circuit board 25 trained. It is pointed out that the control circuit 50 in Fig. 4 and Fig. 5 is not shown.

[0050] The microcomputer 51 is via the conductor track pattern that is on the upper surface of the circuit board 25 is provided individually with the control circuit 50 and the connector 54 electrically connected. The control circuit50 is via the conductor track pattern that is on the upper surface of the circuit board 25 is provided, electrically connected to the gates of the six FETs 3 and 4 tied together.

[0051] As described above, the connector of the signal line is in the connector 54 fitted. The power-on and power-off signals are transmitted to the microcomputer via the signal line and the conductor pattern. 51 input. Control signals are also received from the microcomputer. 51 via the conductor pattern to the control circuit 50 entered. The control circuit 50 Furthermore, it applies a voltage to the gates of the six FETs via the conductor pattern. 3 and 4 and regulates the voltage at these gates relative to a fixed potential.

[0052] As described above, the microcomputer 51, when a power-on signal is input, a control signal to switch on the six FETs 3 and 4 to the control circuit 50 off, and the control circuit 50 then switches the six FETs 3 and 4 a. When a shutdown signal is input, the microcomputer outputs 51 a control signal to switch off the six FETs 3 and 4 to the control circuit 50 off, and the control circuit 50 then switches the six FETs 3 and 4 out of.

[0053] As in Fig. 3 and Fig. As shown in section 4, the lid is shown. 61 opposite the upper surface 23a of the heat dissipation element 23 arranged and covers the six FETs 3 and 4 , the circuit board 25 and the microcomputer 51 off. The six FETs 3 and 4 , the three ladders 20 ,21 and 22 , the circuit board 25 and the microcomputer 51 are between the upper surface 23a of the heat dissipation element 23 and the lid 61 arranged.

[0054] Fig. 6 is a cross-sectional view along the line B-B in Fig. 5. As in Fig. 4, Fig. 5 and Fig. Figure 6 shows a rectangular, foil-shaped thermal insulation element. 26 on the front side section of the upper surface 23a of the heat dissipation element 23 within the framework 60 arranged. The thermal insulation element 26 is in a place that is different from the places where the three ladders 20 , 21 and 22 are placed on the upper surface 23a of the heat dissipation element 23 placed. The thermal insulation element 26is formed by a fleece containing silicate aerogel particles. The circuit board 25 runs along the three ladders 20 , 21 and 22 past forwards, and an extension section of the circuit board 25 is on the top side of the thermal insulation element 26 arranged. The microcomputer 51 is located on an upper surface of the extension section of the circuit board 25 arranged, and the microcomputer 51 is in contrast to the thermal insulation element 26 arranged, with the circuit board 25 is located in between. The microcomputer 51 serves as a control element.

[0055] As in Fig. 3 and Fig. The frame shown in section 6 is... 60 along the circumferential edge of the upper surface 23a of the heat dissipation element 23 arranged and surrounds the six FETs 3 and 4 , the circuit board 25and the microcomputer 51 .

[0056] Fig. 7 is an enlarged view of the in Fig. Section 6, labelled C. As described above, the lower surfaces of the ladder are 20 , 21 and 22 with the upper surface 23a of the heat dissipation element 23 using the insulating element 24 bonded, which serves as an adhesive, and the insulating element 24 It has the form of a layer. Specifically, the insulating element 24 on the upper surface 23a of the heat dissipation element 23 upset, and the ladder 20 , 21 and 22 are located on the top side of the insulation element 24 arranged. In this state, the insulating element is 24 Heated. As a result, the insulating element is 24 hardened and all ladders 20 , 21 and 22are via the insulating element 24 with the upper surface 23a of the heat dissipation element 23 glued together.

[0057] No current flows through the insulating element. 24 , and consequently no current flows from the conductors. 20 , 21 and 22 to the heat dissipation element 23 The insulating element 24 It exhibits heat dissipation properties. Therefore, heat is dissipated from each of the conductors. 20 , 21 and 22 about the insulating element 24 to the heat dissipation element 23 guided. The insulating element 24 It is made, for example, from an epoxy resin containing a thermally conductive filler. Aluminum oxide is used as a thermally conductive filler, for instance.

[0058] The electrical distribution box set up as described above 1 is the microcomputer 51compared to the thermal insulation element 26 arranged, with the circuit board 25 is positioned in between, and therefore is affected by the six FETs 3 and 4 The generated heat barely passed through one of the conductors 20 , 21 and 22 or the heat dissipation element 23 to the microcomputer 51 therefore the temperature of the microcomputer 51 even then hardly at all if the temperature of the six FETs 3 and 4 increases.

[0059] The microcomputer 51 It has low heat resistance. Therefore, the upper temperature limit of the FETs is 3 and 4 , up to which its normal operation is ensured, higher than the upper limit of the microcomputer's temperature 51 , up to which its normal operation is ensured. Even if the temperature of the six FETs 3 and 4As the temperature of the microcomputer increases, so does its temperature. 51 hardly at all. The upper limit of the permissible temperature of the FETs. 3 and 4 is correspondingly large, since this value is not limited by the upper temperature limit of the microcomputer. 51 is restricted, up to which its normal operation is ensured.

[0060] The ladder 20 , 21 and 22 and the heat dissipation element 23 They are made of metal and therefore have high thermal conductivity. The circuit board 25 In contrast, it is formed by an insulating plate on which the conductor pattern is formed, and the thermal conductivity of the insulating plate is sufficiently lower than the thermal conductivity of the conductors. 20 , 21 and 22 and the heat dissipation element 23 Therefore, very little heat is generated by the six FETs. 3 and 4 via the circuit board 25to the microcomputer 51 guided.

[0061] There may be a case where the electrical distribution box 1 - except for the microcomputer 51 - has a low-temperature element whose upper limit of the temperature up to which its normal operation is ensured - that is, whose upper limit of an adequate temperature - is lower than the upper limit of the adequate temperature of the FETs 3 and 4 Examples of such low-temperature elements include control ICs (integrated circuits), aluminum electrolytic capacitors, and the like. If, besides the microcomputer... 51 a low-temperature element is included - for example, if a low-temperature element is included in the control circuit 50 is included - then the low-temperature element, which is supplied by the microcomputer 51 is different, preferably also in this way on the upper surface of the circuit board25 arranged so that it is opposite the thermal insulation element 26 is arranged and the circuit board 25 is located in between.

[0062] As described above, the thermal insulation element 26 formed by a fleece containing silicate aerogel particles, and therefore the thermal conductivity of the thermal insulation element is 26 lower than the thermal conductivity of air. As a result, it is unlikely that heat will be transferred through either conductor. 20 , 21 and / or 22 and the heat dissipation element 23 to the microcomputer 51 is being managed.

[0063] The six FETs 3 and 4 , the circuit board 25 , the control circuit 50 and the microcomputer 51 are through the heat dissipation element 23 , the frame 60 and the lid 61covered. It is therefore unlikely that air coming into contact with the six FETs would be covered. 3 and 4 located, from the electrical distribution box 1 escapes. Accordingly, most of the heat generated by the six FETs is lost. 3 and 4 is generated via one of the conductors 20 , 21 and 22 and the heat dissipation element 23 conducted. The thermal insulation element 26 This therefore works in a design where the framework 60 and the lid 61 are provided, more effectively.

[0064] It should be noted that the six FETs 3 and 4 , the circuit board 25 , the control circuit 50 and the microcomputer 51 through the heat dissipation element 23 , the frame 60 , the lid 61 and similar items are sealed to be liquid-tight.

[0065] Next, a manufacturing process for the electrical distribution box will be described. 1 described. Fig. Figure 8 is a diagram showing the manufacturing of the electrical distribution box. 1 illustrated. First, the ladders are shown. 20 , 21 and 22 manufactured by cutting and bending metal sheets made from a copper alloy. Next, the circuit board is... 25 on the ladders 20 , 21 and 22 fixed and the six FETs 3 and 4 will be at one of the six openings each 25a attached to the circuit board 25 are provided. After that, several elements, including the microcomputer, are installed. 51 , on the upper surface of the circuit board 25 The insulating element is attached next. 24 , which serves as an adhesive, onto the upper surface 23a of the heat dissipation element 23applied, and the heat dissipation element 23 is attached to the inside of the frame 60 attached, the one with the two stud screws 52 and 53 is provided.

[0066] Next, the insulating element will be installed. 26 on the front side section of the upper surface 23a of the heat dissipation element 23 arranged and the three ladders 20 , 21 and 22 and the circuit board 25 are thus located on the top side of the heat dissipation element 23 arranged that the microcomputer 51 compared to the thermal insulation element 26 is arranged, with the circuit board 25 is positioned in between. Then the insulating element is... 24 hardened by heating. As a result, the lower surfaces of the ladder are 20 , 21 and 22 with the upper surface 23a of the heat dissipation element 23glued. Then the lid is... 61 from above into the frame 60 fitted.

[0067] It should be noted that a configuration is also possible in which the sources of the three FETs 3 with the leader 20 are connected, the drains of the six FETs 3 and 4 with the leader 21 are connected and the sources of the three FETs 4 with the leader 22 are connected. In this case too, no current flows through the six diodes. 3b and 4b , as long as the six FETs 3 and 4 are switched off.

[0068] The number of FETs 3 and the number of FETs 4 are not limited to three, but can number one, two, four, or more. A configuration is also possible in which the number of FETs 3 unequal to the number of FETs 4 is. Furthermore, the FETs are 3and the FETs 4 not limited to the n-channel type. The FETs 3 and the FETs 4 They can also be of the p-channel type. The type of FETs 3 However, it is the same as the type of FETs. 4 .

[0069] The FETs 3 and 4 They only need to serve as semiconductor switches, and therefore bipolar transistors, insulated gate bipolar transistors (IGBTs) or the like can be used instead of FETs. 3 and 4 are used. If no parasitic diodes are formed in semiconductor switches, no current flows through the semiconductor switches when the semiconductor switches are switched off. Therefore, if no parasitic diodes are formed in semiconductor switches, a design is also possible which does not have any semiconductor switches that are electrically connected between the conductors. 21 and 22 are switched. In this case, the conductors are 21 and 22They are formed in one piece and treated as a single conductor. There is no possibility of current flowing from the conductor. 22 first via the ladder 21 and then the ladder 20 Furthermore, it is not necessary to install the electrical distribution box. 1 the FETs 4 to provide. In this case too, the ladders 21 and 22 They are formed in one piece and treated as a single conductor. If the conductors are 21 and 22 Treated as a single conductor, the number of conductors is two.

[0070] The thermal insulation element 26 It merely needs to be an element with a sufficiently low thermal conductivity and does not necessarily have to be formed by a fleece containing silicate aerogel particles. Furthermore, the circuit components connected to the conductors 20 , 21 and 22are connected, not limited to semiconductor switches, as long as they are components that generate heat. The microcomputer 51 Furthermore, it only needs to serve as a control element that outputs control signals. Therefore, instead of the microcomputer, 51 An element that outputs control signals can be used. The number of conductors is not limited to two or three and can also be one, four, or more.

[0071] The disclosed embodiment is in all aspects an illustrative example and is not to be considered limiting. The scope of protection of the present invention is not defined by the foregoing description, but by the claims; it is intended to encompass all modifications made in the area that are equivalent in meaning and scope to the claims. Reference symbol list 1 electrical distribution box (switching device) 3.4 FET (circuit component, semiconductor switch) 3a, 4a FET main body 3b, 4b diode 6 cases 20, 21, 22 ladder 20a, 22a Through hole 23 Heat dissipation element 23a upper surface (placement area) 24 Insulation element 25 circuit boards 25a Opening 26 Thermal insulation element 50 Control circuit 51 Microcomputer (control element) 52, 53 Stud bolt 54 connectors 60 frames 61 lids QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2017

[0002] JP 068331

[0002] JP 2003164040 A

[0006]

Claims

[1] Circuit device with: a heat dissipation element; a conductor placed on a placement surface of the heat dissipation element, with an insulating element arranged between them; a thermal insulation element that is located at a position on the placement surface that differs from the position where the conductor is placed; a circuit component that is electrically connected to the conductor and generates heat; a circuit board; and a control element that is placed on the circuit board opposite the thermal insulation element, with the circuit board positioned between them, and outputs a control signal to control the operation of the circuit component. [2] Circuit device according to claim 1, wherein the thermal insulation element is formed by a fleece containing silicate aerogel particles. [3] Circuit device according to claim 1 or 2, further comprising: a frame arranged along a circumferential edge of the placement surface of the heat dissipation element, surrounding the circuit component, the printed circuit board, and the control element; and a cover that is positioned opposite the placement surface of the heat dissipation element and covers the inside of the frame, wherein the conductor, the circuit component, the printed circuit board and the control element are arranged between the placement surface and the cover. [4] Circuit device according to one of claims 1 to 3, wherein the circuit device has several of the conductors, the circuit component is a semiconductor switch that is electrically connected to two of the multiple conductors, and The control signal is a signal to switch the circuit component on or off.