Electric circuit body, power conversion device, and manufacturing method for electric circuit body

Abstract

To suppress the increase in inductance while improving the productivity.SOLUTION: An electric circuit body includes: a first assembly formed having an upper arm semiconductor element held between a first conductive plate and a second conductive plate in a thickness direction; a second assembly formed having a lower arm semiconductor element held between a third conductive plate and a fourth conductive plate in the thickness direction; and a sealing material for sealing the first assembly and the second assembly. The first conductive plate and the fourth conductive plate are mechanically and electrically connected to each other at a junction part formed at a side where these plates face each other. The first conductive plate and the fourth conductive plate are disposed on a first substantially same plane. The second conductive plate and the third conductive plate are disposed on a second substantially same plane, which is different from the first substantially same plane. The upper arm semiconductor element and the lower arm semiconductor element are in a front-back inverse relation.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an electric circuit body, a power conversion device, and a method for manufacturing an electric circuit body.

Background Art

[0002] In recent years, in-vehicle power conversion devices have been required to have higher output and higher density. In order to achieve both higher output and higher density, it is necessary to reduce losses and suppress heat generation. A method of reducing switching losses by increasing the switching speed is known. However, a problem occurs in that the surge voltage increases as the switching speed increases. Patent Document 1 discloses a power semiconductor module including a power semiconductor element, a conductor plate electrically connected to the power semiconductor element, a metal case housing the power semiconductor element and the conductor plate, a front surface side cover joined to one outer surface of the metal case, a back surface side cover joined to the other outer surface of the metal case, an inlet portion disposed on one side of the metal case, and an outlet portion disposed on the one side of the metal case. The metal case has a first heat radiating portion and a second heat radiating portion facing the first heat radiating portion with the conductor plate interposed therebetween. The front surface side cover is disposed at a position facing the first heat radiating portion so as to form a space for a front surface side flow path between the front surface side cover and the first heat radiating portion. The back surface side cover is disposed at a position facing the second heat radiating portion so as to form a space for a back surface side flow path between the back surface side cover and the second heat radiating portion. The inlet portion is connected to the front surface side flow path and the back surface side flow path, and the outlet portion is connected to the front surface side flow path and the back surface side flow path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the invention described in Patent Document 1, there is room for improvement in productivity and reduction of inductance.

Means for Solving the Problems

[0005] An electric circuit body according to a first aspect of the present invention includes a first assembly formed by sandwiching an upper arm semiconductor element in a thickness direction between a first conductor plate and a second conductor plate, a second assembly formed by sandwiching a lower arm semiconductor element in the thickness direction between a third conductor plate and a fourth conductor plate, and a sealing material for sealing the first assembly and the second assembly. The first conductor plate and the fourth conductor plate are mechanically and electrically connected at a joint formed on sides facing each other, the first conductor plate and the fourth conductor plate are arranged on a first substantially identical plane, the second conductor plate and the third conductor plate are arranged on a second substantially identical plane different from the first substantially identical plane, and the upper arm semiconductor element and the lower arm semiconductor element are in a relationship of front-back inversion. A power conversion device according to a second aspect of the present invention includes one or more of the above-described electric circuit bodies and converts DC power into AC power. A method for manufacturing an electric circuit body according to a third aspect of the present invention includes a first forming step of forming a first assembly by sandwiching an upper arm semiconductor element in a thickness direction between a first conductor plate and a second conductor plate, a second forming step of forming a second assembly by sandwiching a lower arm semiconductor element in the thickness direction between a third conductor plate and a fourth conductor plate, and after the first forming step and the second forming step, arranging the first assembly and the second assembly such that the first conductor plate and the fourth conductor plate exist on a first substantially identical plane, the second conductor plate and the third conductor plate exist on a second substantially identical plane different from the first substantially identical plane, and the upper arm semiconductor element and the lower arm semiconductor element are in a state of front-back inversion, and a joining step of mechanically and electrically joining the first conductor plate and the fourth conductor plate.

Advantages of the Invention

[0006] According to the present invention, it is possible to suppress an increase in inductance while improving productivity.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Embodiments for Carrying Out the Invention

[0008] - The First Embodiment - Hereinafter, embodiments of an electric circuit body and a method for manufacturing the same will be described with reference to FIGS. 1 to 10. The following description and drawings are examples for explaining the present invention, and for the sake of clarity of explanation, appropriate omissions and simplifications are made. The present invention can be implemented in various other forms. Unless otherwise particularly limited, each component may be singular or plural.

[0009] The positions, sizes, shapes, ranges, etc. of the respective components shown in the drawings may not represent the actual positions, sizes, shapes, ranges, etc. in order to facilitate understanding of the invention. For this reason, the present invention is not necessarily limited to the positions, sizes, shapes, ranges, etc. disclosed in the drawings. When there are a plurality of components having the same or similar functions, they may be described with the same reference numeral and different subscripts. However, when it is not necessary to distinguish these plurality of components, the subscripts may be omitted in the description.

[0010] FIG. 1 is a plan view of an electric circuit body 400. In the present embodiment, XYZ axes orthogonal to each other are described in order to clarify the correlation between the drawings. In FIG. 1, the right side in the drawing is the plus side of the X axis, the upper side in the drawing is the plus side of the Y axis, and the back side in the drawing is the plus side of the Z axis. The electric circuit body 400 includes a semiconductor device 300 and a cooling member 340. The electric circuit body 400 includes three semiconductor devices 300 having exactly the same configuration. Therefore, hereinafter, only one of the three semiconductor devices 300 may be given a reference numeral. The cooling member 340 includes an upper cooling member 340U on the plus side of the Z axis and a lower cooling member 340L on the minus side of the Z axis.

[0011] The semiconductor device 300 encapsulates and incorporates therein a first element 155 and a second element 157, which will be described later, with a sealing material 360. Terminals connected to the first element 155 and the second element 157 are led out from the sealing material 360 on the side surface of the semiconductor device 300 to the plus side and the minus side of the Y-axis. These terminals are power terminals through which a large current flows, such as a positive terminal 315B and a negative terminal 319B connected to a capacitor module 500 (see FIG. 16) of a DC circuit, and an AC-side terminal 320B connected to a first motor generator 192 and a second motor generator 194 (see FIG. 16) of an AC circuit.

[0012] Further, the following signal terminals protrude from the sealing material 360 on the side surface of the plus side of the Y-axis of the semiconductor device 300. That is, signal terminals used for controlling a semiconductor module, such as a lower arm gate terminal 325L, a first mirror emitter signal terminal 325M-1, a second mirror emitter signal terminal 325M-2, a first Kelvin emitter signal terminal 325K-1, a second Kelvin emitter signal terminal 325K-2, and an upper arm gate terminal 325U, protrude from the sealing material 360.

[0013] The electric circuit body 400 functions as a power conversion device that converts a DC current and an AC current by the switching operations of the first element 155 and the second element 157. Note that the number of semiconductor devices 300 included in the electric circuit body 400 is not limited to three, and can be arbitrarily set according to various forms of the electric circuit body 400.

[0014] The cooling member 340 is disposed to face the heat dissipation surface 301 (see FIG. 2) of the semiconductor device 300 and cools the heat generated by the switching operations of the first element 155 and the second element 157. Specifically, the cooling member 340 has a flow path formed therein through which a refrigerant circulates, and cools the heat generated by the semiconductor device 300 with the refrigerant flowing through the flow path. As the refrigerant, water or an antifreeze obtained by mixing ethylene glycol into water can be used. The cooling member 340 can be made of a copper-based material having a high thermal conductivity, and an aluminum-based material having a higher thermal conductivity and being lighter than copper is desirable. The cooling member 340 can be manufactured by extrusion molding, forging, brazing, or the like.

[0015] FIG. 2 is a cross-sectional view taken along line II-II of the electric circuit body 400 shown in FIG. 1, and FIG. 3 is a perspective cross-sectional view taken along line III-III of the electric circuit body 400 shown in FIG. 1. However, an enlarged view of a joint portion 330 described later is shown at the lower part of FIG. 3. The electric circuit body 400 includes a pressurizing mechanism that pressurizes the cooling members 340 provided on both sides of the semiconductor device 300 by sandwiching them from both sides. Although not shown in the drawing, the pressurizing mechanism is, for example, a mechanism that connects the cooling members 340 on both sides to each other with screws or the like and pressurizes them toward the semiconductor device 300 side.

[0016] As shown in FIG. 2, a first element 155 and a first diode 156 that form the upper arm circuit of the power conversion device 200 are provided (see FIGS. 4 and 5 described later). However, the body diode of the first element 155 may be used as the first diode 156. The collector side of the first element 155 is joined to the second conductor plate 431. For this joining, solder may be used, or sintered metal may be used. A first conductor plate 430 is joined to the emitter side of the first element 155.

[0017] As shown in FIG. 3, a second element 157 is arranged on the plus side of the X axis of the first element 155. The second element 157 forms the lower arm circuit of the power conversion device 200. Since the first element 155 is a semiconductor element that constitutes the upper arm circuit, it can also be called an "upper arm semiconductor element". Since the second element 157 is a semiconductor element that constitutes the lower arm circuit, it can also be called a "lower arm semiconductor element". Although not shown in FIGS. 2 and 3, a second diode 158 that forms the lower arm circuit together with the second element 157 is arranged on the plus side of the Y axis of the second element 157.

[0018] Si, SiC, GaN, GaO, C, etc. can be used for the first element 155 and the second element 157. The first element 155 and the second element 157 are, for example, power semiconductor elements such as IGBT (Insulated Gate Bipolar Transistor) and MOSFET (Metal Oxide Semiconductor Field Effect Transistor). When MOSFETs are used as the first element 155 and the second element 157, the first diode 156 and the second diode 158 become unnecessary.

[0019] Hereinafter, the first conductor plate 430, the second conductor plate 431, the third conductor plate 432, and the fourth conductor plate 433 are collectively referred to as the conductor plate 435. The conductor plate 435 is not particularly limited as long as it is a material with high electrical conductivity and high thermal conductivity. However, it is desirable to use a metal-based material such as a copper-based or aluminum-based material, or a composite material such as a metal-based material and diamond, carbon, or ceramic with high thermal conductivity. These metals may be used alone for the conductor plate 435, or plating such as Ni or Ag may be applied to enhance the bonding property with solder or sintered metal.

[0020] As shown in FIGS. 2 and 3, in addition to the role of conducting current, the conductor plate 435 also serves as a heat transfer member that transfers the heat generated by the first element 155, the second element 157, the first diode 156, and the second diode 158 to the cooling member 340. Since the potential of the conductor plate 435 and the cooling member 340 is different, it is desirable to dispose an upper insulating sheet 440 and a lower insulating sheet 441 therebetween. The first element 155, the second element 157, the first diode 156, the second diode 158, the conductor plate 435, the upper insulating sheet 440, and the lower insulating sheet 441 are sealed with a sealing material 360 by transfer molding to form the semiconductor device 300. In order to reduce the contact thermal resistance between the semiconductor device 300 and the cooling member 340, a heat conducting member 453 is disposed between the semiconductor device 300 and the cooling member 340.

[0021] The upper insulating sheet 440 may include an upper resin insulating layer 442 and an upper metal foil 444. The lower insulating sheet 441 may include a lower resin insulating layer 443 and a lower metal foil 445. The upper resin insulating layer 442 and the lower resin insulating layer 443 are not particularly limited as long as they have adhesiveness to the heat sink. However, an epoxy resin-based resin insulating layer in which a powdery inorganic filler is dispersed is desirable. This is because the balance between adhesiveness and heat dissipation is good. The upper insulating sheet 440 and the lower insulating sheet 441 may be a single resin insulating layer, but it is desirable to provide an upper metal foil 444 and a lower metal foil 445 on the side in contact with the heat conducting member 453.

[0022] In the transfer molding process, when mounting the upper insulating sheet 440 and the lower insulating sheet 441 on the mold, a release sheet is provided on the contact surface of the upper insulating sheet 440 and the lower insulating sheet 441 with the mold to prevent adhesion to the mold. However, the upper metal foil 444 and the lower metal foil 445 may be used instead of the release sheet.

[0023] Since the release sheet has a low thermal conductivity, a process of peeling it off after transfer molding is required. However, when using the upper metal foil 444 and the lower metal foil 445, by selecting a metal with a high thermal conductivity such as copper-based or aluminum-based, it can be used without peeling off after transfer molding. By performing transfer molding including the upper insulating sheet 440 and the lower insulating sheet 441, the ends of the upper insulating sheet 440 and the lower insulating sheet 441 are covered with the sealing material 360, which has the effect of improving reliability.

[0024] As the heat conductive member 453, those having fluidity at normal temperature or high temperature such as grease, gel grease, and phase change sheet can be used. However, in order to ensure workability and long-term reliability, it is desirable to use a heat conductive material of a curable type that has fluidity when uncured and loses fluidity after curing for the heat conductive member 453. The curable heat conductive member has the advantage that its viscosity is low during application, resulting in excellent workability, and its mechanical properties can be improved by curing. Curing can utilize heat curing, moisture curing, ultraviolet curing, etc., but heat curing is desirable for deep curing.

[0025] The heat conduction member 453 is not particularly limited as long as it is a material with high thermal conductivity. However, it is preferable to use a high thermal conductivity material such as metal, ceramics, or carbon-based material in combination with a resin material. This is because the resin material fills the gaps between the high thermal conductivity materials, between the high thermal conductivity material and the cooling member 340, and between the heat conduction member and the upper insulating sheet 440 and the lower insulating sheet 441, reducing the contact thermal resistance. The resin material is not particularly limited. The resin is most preferably a silicone resin with a small change in elastic modulus from around -40°C to around 200°C. Also, the heat conduction member 453 is preferably an insulating material. This is to prevent the reduction of insulation due to the adhesion of a conductive material near the terminal. The thermal conductivity of the heat conduction member 453 is about 5 to 10 W / (m·K). The method for measuring the thermal conductivity is not particularly limited. For example, it is obtained by measuring the density, specific gravity, and thermal diffusivity of the heat conduction member 453 and multiplying them together (density × specific gravity × thermal diffusivity).

[0026] The electric circuit body 400 is subjected to a so-called cold-heat cycle in which heat generation and cooling are repeated according to the switching operations of the first element 155 and the second element 157. Due to this cold-heat cycle, since the thermal expansion coefficients of the semiconductor device 300 and the cooling member 340 are different, the heat conduction member 453 tends to be compressed and flow out of the semiconductor device 300.

[0027] As shown in FIG. 3, the semiconductor device 300 is mechanically and electrically connected by a joining member 331 at a joining portion 330 formed on the sides of the first conductor plate 430 and the fourth conductor plate 433 that face each other. It can also be said that the first conductor plate 430 and the fourth conductor plate 433 are connected in a single plate shape. As a result, the first conductor plate 430 and the fourth conductor plate 433 are arranged on the same plane, and the semiconductor elements are connected in a state where the front and back are reversed so that the second conductor plate 431 and the third conductor plate 432 are arranged on another same plane. As shown in the lower part of FIG. 3, the first conductor plate 430 includes a protruding portion 330A that protrudes on the plus side of the X-axis on the minus side of the Z-axis. The joining portion 330 is formed by joining the protruding portion 330A of the first conductor plate 430 and the surface on the minus side of the Z-axis of the fourth conductor plate 433 with the joining member 331.

[0028] For the joining member 331, solder, sintered metal, or a conductive adhesive may be used. More preferably, any one of solder, sintered metal, and a conductive adhesive, which is a joining member having a melting point lower than that of the solder or sintered metal used for the joining member of the semiconductor element, is used for the joining member 331.

[0029] FIG. 4 is a semi-transparent plan view of a set of upper and lower arms in the semiconductor device 300. FIG. 5 is a circuit diagram of a set of upper and lower arms in the semiconductor device 300. Hereinafter, the circuit constituting the upper arm is referred to as the upper arm circuit body 381 or the "first assembly", and the circuit constituting the lower arm is referred to as the lower arm circuit body 382 or the "second assembly". In FIG. 4, the left side in the drawing is the upper arm circuit body 381, and the right side in the drawing is the lower arm circuit body 382.

[0030] As shown in FIGS. 4 and 5, the positive terminal 315B outputs from the collector side of the upper arm circuit and is connected to the positive side of the battery or capacitor. The upper arm gate terminal 325U outputs from the gate of the first element 155 of the upper arm circuit. The negative terminal 319B outputs from the emitter side of the lower arm circuit and is connected to the negative side of the battery or capacitor, or GND. The lower arm gate terminal 325L outputs from the gate of the second element 157 of the lower arm circuit. The AC side terminal 320B outputs from the collector side of the lower arm circuit and is connected to the motor. When neutral point grounding is performed, the lower arm circuit is connected to the negative side of the capacitor instead of GND.

[0031] A first conductor plate 430 is disposed on the emitter side of the upper arm circuit, a second conductor plate 431 is disposed on the collector side of the upper arm circuit, a third conductor plate 432 is disposed on the emitter side of the lower arm circuit, and a fourth conductor plate 433 is disposed on the collector side of the lower arm circuit. The first conductor plate 430 and the second conductor plate 431 sandwich the first element 155 and the first diode 156 in the Z-axis direction. The third conductor plate 432 and the fourth conductor plate 433 sandwich the second element 157 and the second diode 158 in the Z-axis direction.

[0032] The first conductor plate 430 and the fourth conductor plate 433 are mechanically and electrically connected via the joint portion 330. The end face on the positive Z-axis side of the first conductor plate 430 and the end face on the positive Z-axis side of the fourth conductor plate 433 have the same Z-axis coordinate. The end face on the negative Z-axis side of the second conductor plate 431 and the end face on the negative Z-axis side of the third conductor plate 432 have the same Z-axis coordinate. The first element 155 and the second element 157 are in a relationship where the front and back are reversed when rotated around the Y-axis. The first element 155 and the second element 157 are the same type of semiconductor element, and since they are arranged with the front and back reversed, the order of the terminals is reversed and the direction of the current flow is also reversed.

[0033] The semiconductor device 300 has a 2-in-1 structure in which two arm circuits, an upper arm circuit and a lower arm circuit, are integrated into one module. A plurality of upper arm circuits and lower arm circuits may be included in one semiconductor device 300. In this case, the number of output terminals from the semiconductor device 300 can be reduced and the size can be minimized.

[0034] FIG. 6 is a semi-transparent plan view of a comparative example semiconductor device 300Z which is a comparative example. As shown in FIG. 6, the upper arm circuit on the left side of the figure and the lower arm circuit on the right side of the figure are connected via a comparative example joint portion 332Z between the comparative example first conductor plate 430Z and the comparative example fourth conductor plate 433Z. The comparative example joint portion 332Z also has a role of absorbing the difference in the Z-direction positions of the comparative example first conductor plate 430Z and the comparative example fourth conductor plate 433Z.

[0035] The comparative example fourth conductor plate 433Z and the comparative example third conductor plate 432Z are connected via a semiconductor element, and the third conductor plate 432 and the negative terminal 319B are connected via a comparative example connection portion 333Z. In this way, the upper arm circuit composed of the comparative example first conductor plate 430Z and the comparative example second conductor plate 431Z and the lower arm circuit composed of the comparative example third conductor plate 432Z and the comparative example fourth conductor plate 433Z are connected in a state where the semiconductor elements of each other have the same front and back direction.

[0036] Compared with this comparative example semiconductor device 300Z, the semiconductor device 300 described above has the following advantages. First, in the semiconductor device 300, the negative electrode side terminal 319B and the third conductor plate 432 are integrated, and the comparative example connection portion 333Z as in the comparative example is unnecessary. Therefore, the current path of the semiconductor device 300 is shorter than that of the comparative example semiconductor device 300Z, and an effect of reducing inductance can be expected. Second, in the semiconductor device 300, the currents flowing through the semiconductor elements of the upper arm circuit and the lower arm circuit are in opposite directions, and an effect of reducing inductance can be expected.

[0037] (Manufacturing method) Figures 7 to 9 are diagrams showing a manufacturing method of the electric circuit body 400. The manufacturing method of the electric circuit body 400 includes a first forming step, a second forming step, an assembly arranging step, a sheet arranging step, a transfer molding step, and a bonding step. Figure 7 is a diagram for explaining the manufacturing method of the semiconductor device 300. Specifically, Figure 7 is a plan view for explaining the soldering step and the wire bonding step of the upper arm circuit body 381 and the lower arm circuit body 382 of the semiconductor device 300.

[0038] Figure 7(a) shows the first forming step of manufacturing the upper arm circuit body 381. First, the collector side of the first element 155 and the cathode side of the first diode 156 are connected to the second conductor plate 431. Next, each of the upper arm gate terminal 325U, the mirror emitter signal terminal 325M, and the Kelvin emitter signal terminal 325K is connected to the first element 155 by wire bonding. Further, the emitter side of the first element 155 and the anode side of the first diode 156 are connected to the first conductor plate 430 to produce a circuit body on the upper arm side.

[0039] Figure 7(b) shows the second forming process for manufacturing the lower arm circuit body 382. Similar to the manufacturing process of the upper arm circuit body 381, first, the collector side of the second element 157 and the cathode side of the second diode 158 are connected to the fourth conductor plate 433. Next, each of the lower arm gate terminal 325L, mirror emitter signal terminal 325M, and Kelvin emitter signal terminal 325K is connected to the second element 157 by wire bonding. Further, the emitter side of the second element 157 and the anode side of the second diode 158 are connected to the third conductor plate 432 to fabricate the lower arm circuit body 382. Note that the processes in FIGS. 7(a) and 7(b) may be in reverse order.

[0040] After the process shown in FIG. 7(b), as shown in FIG. 7(c), the lower arm circuit body 382 shown in FIG. 7(b) is turned over. FIG. 7(d) shows the assembly arrangement process. As shown in FIG. 7(d), the upper arm circuit body 381 of FIG. 7(a) and the lower arm circuit body 382 of FIG. 7(c) are arranged. At this time, the first element 155 and the second element 157 are in a relationship of being turned over. Also, as shown later in FIG. 10, the first conductor plate 430 and the fourth conductor plate 433 are on a first substantially identical plane extending in the XY plane, and the second conductor plate 431 and the third conductor plate 432 are on a second substantially identical plane extending in the XY plane. Although a joining member 331 is arranged at the joining portion 330, at this stage, the first conductor plate 430 and the fourth conductor plate 433 may be joined by solder, sintered metal, conductive adhesive, etc., which are the joining member 331, or may be joined in the transfer molding process shown in FIGS. 8(c) and 8(d). Therefore, the first conductor plate 430 and the fourth conductor plate 433 do not necessarily have to be actively joined yet.

[0041] FIGS. 8 and 9 are cross-sectional views for explaining the manufacturing process of the electric circuit body 400. In FIGS. 8 and 9, the same viewing angle as in FIG. 2 is adopted. The electric circuit body 400 is manufactured by going through the processes from FIG. 8(a) to FIG. 9(c) in order. The first FIG. 8(a) shows the semiconductor device 300 shown in FIG. 7(d) above. That is, FIG. 8(a) is a view with the viewing angle of FIG. 7(d) changed.

[0042] FIG. 8(b) shows the placement process, and FIGS. 8(c) and 8(d) show the transfer molding process. In FIG. 8(b), the semiconductor device 300 shown in FIG. 8(a) is placed in the transfer molding device 601, and the upper insulating sheet 440 and the lower insulating sheet 441 are arranged so as to sandwich the semiconductor device 300 from both sides of the Z axis. The transfer molding device 601 includes a spring 602, an upper mold 603U, and a lower mold 603L. The transfer molding device 601 also includes a mechanism for vacuum-sucking the upper insulating sheet 440 and the lower insulating sheet 441 and a vacuum degassing mechanism.

[0043] As shown in FIG. 8(b), the semiconductor device 300 is temporarily placed between the upper mold 603U and the lower mold 603L that have been preheated to a constant temperature of 175° C. in advance, and the upper insulating sheet 440 and the lower insulating sheet 441 are held by vacuum suction. The semiconductor device 300 has been preheated to 175° C. in advance, and the semiconductor device 300 is arranged between the upper mold 603U and the lower mold 603L and at a position away from the upper insulating sheet 440 and the lower insulating sheet 441.

[0044] Next, as shown in FIG. 8(c), the upper mold 603U and the lower mold 603L are clamped. The space between the upper mold 603U and the lower mold 603L after clamping is referred to as a “mold cavity” 610. At this time, due to the spring 602, the upper insulating sheet 440 and the lower insulating sheet 441 and the first conductor plate 430 and the second conductor plate 431 are pressurized and brought into close contact. Next, the mold cavity 610 is evacuated to a predetermined atmospheric pressure or less. When the evacuation is completed, the upper mold 603U and the lower mold 603L are further crushed and completely clamped. At this time, the upper insulating sheet 440 and the lower insulating sheet 441 come into contact with the semiconductor device 300. Since the upper insulating sheet 440 and the lower insulating sheet 441 are in contact with the semiconductor device 300 in a vacuum state and are brought into close contact by the pressing force of the spring 602, they can be brought into close contact without entraining voids.

[0045] Then, as shown in FIG. 8(d), the sealing material 360 is injected into the mold cavity. Note that the peripheral end portions of the upper insulating sheet 440 and the lower insulating sheet 441 are buried in the sealing material 360. In the transfer molding process shown in FIGS. 8(c) and 8(d), since the joining member 331 is at a high temperature and high pressure, the first conductor plate 430 and the fourth conductor plate 433 are joined by solder, sintered metal, conductive adhesive, etc., which are the joining member 331.

[0046] Thereafter, as shown in FIG. 9(a), the semiconductor device 300 sealed with the sealing material 360 is taken out from the transfer molding apparatus 601, and post-curing is performed at 175° C. for 2 hours or more. Thereafter, as shown in FIG. 9(b), a coating process of applying the heat conductive member 453 to the cooling member 340 is performed. Although the heat conductive member 453 is shown above and below in FIG. 9(b), the same reference numerals are given because the same material is used. If we emphasize that they are members arranged at different positions, they can also be called the "first heat conductive member" and the "second heat conductive member". Finally, it is the adhesion curing process shown in FIG. 9(c). In the adhesion curing process, the cooling member 340 coated with the heat conductive member 453 is brought into close contact with the semiconductor device 300. Then, the cooling member 340 is pressed against the semiconductor device 300 through the heat conductive member 453, and the heat conductive member 453 is cured to fabricate the electric circuit body 400.

[0047] FIG. 10 is a cross-sectional view of the semiconductor device 300. FIG. 10 has substantially the same viewing point as FIG. 3, and the upper insulating sheet 440, the lower insulating sheet 441, and the sealing material 360 are omitted for drawing convenience. The central coordinates obtained by projecting the first conductor plate 430 onto the Z-axis are called the first conductor plate central coordinates Zc1. The central coordinates obtained by projecting the second conductor plate 431 onto the Z-axis are called the second conductor plate central coordinates Zc2. The central coordinates obtained by projecting the third conductor plate 432 onto the Z-axis are called the third conductor plate central coordinates Zc3. The central coordinates obtained by projecting the fourth conductor plate 433 onto the Z-axis are called the fourth conductor plate central coordinates Zc4. The central coordinates obtained by projecting the first element 155 onto the Z-axis are called the first element central coordinates Zs1. The central coordinates obtained by projecting the second element 157 onto the Z-axis are called the second element central coordinates Zs2.

[0048] The Z-axis coordinates of the end face on the plus side of the Z-axis of the first conductor plate 430 and the Z-axis coordinates of the end face on the plus side of the Z-axis of the fourth conductor plate 433 are the same upper end face coordinate Z2. The Z-axis coordinates of the end face on the minus side of the Z-axis of the second conductor plate 431 and the Z-axis coordinates of the end face on the minus side of the Z-axis of the third conductor plate 432 are the same lower end face coordinate Z1.

[0049] Since the first conductor plate 430, the first element 155, and the second conductor plate 431 are arranged in the Z-axis direction, they are arranged in the order of the lower end face coordinate Z1, the second conductor plate center coordinate Zc2, the first element center coordinate Zs1, the first conductor plate center coordinate Zc1, and the upper end face coordinate Z2 from the minus side of the Z-axis toward the plus side of the Z-axis. Similarly, since the fourth conductor plate 433, the second element 157, and the third conductor plate 432 are arranged in the Z-axis direction, they are arranged in the order of the lower end face coordinate Z1, the third conductor plate center coordinate Zc3, the second element center coordinate Zs2, the fourth conductor plate center coordinate Zc4, and the upper end face coordinate Z2 from the minus side of the Z-axis toward the plus side of the Z-axis.

[0050] The first conductor plate center coordinate Zc1 and the fourth conductor plate center coordinate Zc4 are substantially the same. Therefore, it can be said that the first conductor plate 430 and the fourth conductor plate 433 are arranged on the first substantially identical plane. The second conductor plate center coordinate Zc2 and the third conductor plate center coordinate Zc3 are substantially the same. Therefore, it can be said that the second conductor plate 431 and the third conductor plate 432 are arranged on the second substantially identical plane.

[0051] According to the first embodiment described above, the following operational effects can be obtained. (1) The electric circuit body 400 includes an upper arm circuit body 381 formed by sandwiching a first element 155 in the Z-axis direction between a first conductor plate 430 and a second conductor plate 431, a lower arm circuit body 382 formed by sandwiching a second element 157 in the Z-axis direction between a third conductor plate 432 and a fourth conductor plate 433, and a sealing material 360 that seals the upper arm circuit body 381 and the lower arm circuit body 382. The first conductor plate 430 and the fourth conductor plate 433 are mechanically and electrically connected at a joint 330 formed on the sides facing each other. The first conductor plate 430 and the fourth conductor plate 433 are arranged on a first substantially identical plane. The second conductor plate 431 and the third conductor plate 432 are arranged on a second substantially identical plane different from the first substantially identical plane. The first element 155 and the second element 157 are in a relationship of front-back inversion. Therefore, the current path of the semiconductor device 300 is shorter than that of the comparative example semiconductor device 300Z, and an effect of reducing inductance can be expected. Further, in the semiconductor device 300, the currents flowing through the semiconductor elements of the upper arm circuit and the lower arm circuit are in opposite directions, and an effect of reducing inductance can be expected. Also, since there are few joining locations, it is excellent in productivity.

[0052] (2) The upper arm gate terminal 325U that controls the first element 155 and the lower arm gate terminal 325L that controls the second element 157 are integrally formed with the first conductor plate 430, the second conductor plate 431, the third conductor plate 432, and the fourth conductor plate 433 by the sealing material 360.

[0053] (3) The end faces on the side opposite to the first element 155 in the first conductor plate 430 and the end faces on the side opposite to the second element 157 in the fourth conductor plate 433 have the same position in the Z-axis direction at the upper end face coordinate Z2. The end faces on the side opposite to the first element 155 in the second conductor plate 431 and the end faces on the side opposite to the second element 157 in the third conductor plate 432 have the same position in the Z-axis direction at the lower end face coordinate Z1. Therefore, the semiconductor device 300 can be easily cooled by being sandwiched from both sides of the Z-axis.

[0054] (4) The joint portion 330 is a material joint, specifically realized by soldering or joining using a conductive adhesive. Therefore, the joint portion 330 is excellent in conductivity and joinability.

[0055] (5) At least one of the first conductor plate 430 and the fourth conductor plate 433 has a protrusion 330A protruding toward the other on the side facing the other, and the protrusion 330A constitutes the joint portion 330. Therefore, it can be firmly joined using the protrusion 330A.

[0056] (6) The electric circuit body 400 includes an upper cooling member 340U in contact with the first conductor plate 430 and the fourth conductor plate 433 via at least a heat conduction member 453, and a lower cooling member 340L in contact with the second conductor plate 431 and the third conductor plate 432 via at least the heat conduction member 453. Therefore, the heat generated by the first element 155 and the second element 157 can be efficiently dissipated using the upper cooling member 340U and the lower cooling member 340L.

[0057] (7) The thermal conductivity of the heat conduction member 453 is 5 to 10 W / (m·K).

[0058] (8) The electric circuit body 400 includes an upper cooling member 340U in contact with the first conductor plate 430 and the fourth conductor plate 433 via the heat conduction member 453 and an upper insulating sheet 440, and a lower cooling member 340L in contact with the second conductor plate 431 and the third conductor plate 432 via the heat conduction member 453 and a lower insulating sheet 441.

[0059] (9) The manufacturing method of the electric circuit body 400 includes a first forming step, a second forming step, an assembly arranging step, and a joining step. In the first forming step, as shown in Fig. 7(a), the upper arm circuit body 381 is formed by sandwiching the first element 155 in the Z-axis direction between the first conductor plate 430 and the second conductor plate 431. In the second forming step, as shown in Fig. 7(b), the lower arm circuit body 382 is formed by sandwiching the second element 157 in the thickness direction between the third conductor plate 432 and the fourth conductor plate 433. In the assembly arranging step, after the first forming step and the second forming step, as shown in Fig. 7(d), the first conductor plate 430 and the fourth conductor plate 433 are on the first substantially same plane, and the second conductor plate 431 and the third conductor plate 432 are on the second substantially same plane, and the upper arm circuit body 381 and the lower arm circuit body 382 are arranged such that the first element 155 and the second element 157 are in a state of being reversed front and back. In the joining step, the first conductor plate 430 and the fourth conductor plate 433 are joined mechanically and electrically. Therefore, the manufacturing of the electric circuit body 400 is easy and the inductance can be reduced.

[0060] (10) The manufacturing method of the electric circuit body 400 includes a sheet arranging step of arranging the upper insulating sheet 440 and the lower insulating sheet 441 so as to sandwich the first substantially same plane and the second substantially same plane, and a sealing material forming step of arranging the upper mold 603U and the lower mold 603L so as to cover the upper insulating sheet 440 and the lower insulating sheet 441, and injecting the sealing material 360 into the mold cavity 610 while pressurizing the upper insulating sheet 440 and the lower insulating sheet 441 using the upper mold 603U and the lower mold 603L.

[0061] (11) In the assembly arranging step, a solder material or a conductive adhesive is arranged between the first conductor plate 430 and the fourth conductor plate 433. The sealing material forming step also serves as the joining step. Therefore, the joining step can be reduced.

[0062] (Modification Example 1) FIG. 11 is a plan view of the electric circuit body 400A in Modification 1. FIG. 11 corresponds to FIG. 1 in the above-described embodiment. The electric circuit body 400A includes three semiconductor devices 300A connected in parallel and a cooling member 340 that sandwiches the semiconductor device 300A from both sides of the Z-axis.

[0063] FIG. 12 is a cross-sectional view taken along line XII-XII of the electric circuit body 400A shown in FIG. 11, and FIG. 13 is a perspective cross-sectional view taken along line XIII-XIII of the electric circuit body 400A shown in FIG. 12. FIG. 14 is a semi-transparent plan view of the semiconductor device 300A. That is, FIGS. 11 to 14 correspond to FIGS. 1 to 4 in the embodiment.

[0064] As shown in FIG. 13, the positive terminal 315B outputs from the collector side of the upper arm circuit and is connected to the positive side of the battery or capacitor. The upper arm gate terminal 325U outputs from the gate of the first element 155 of the upper arm circuit. The negative terminal 319B outputs from the emitter side of the lower arm circuit and is connected to the negative side of the battery or capacitor or GND. The lower arm gate terminal 325L outputs from the gate of the second element 157 of the lower arm circuit. The AC side terminal 320B outputs from the collector side of the lower arm circuit and is connected to the motor. When performing neutral point grounding, the lower arm circuit is connected to the negative side of the capacitor instead of GND.

[0065] The point that the first conductor plate 430 is arranged on the emitter side of the upper arm circuit, the second conductor plate 431 is arranged on the collector side of the upper arm circuit, the third conductor plate 432 is arranged on the emitter side of the lower arm circuit, and the fourth conductor plate 433 is arranged on the collector side of the lower arm circuit is the same as in the embodiment. That is, also in this modification, the first conductor plate 430 and the second conductor plate 431 sandwich the first element 155 and the first diode 156 in the Z-axis direction. Further, the third conductor plate 432 and the fourth conductor plate 433 sandwich the second element 157 and the second diode 158 in the Z-axis direction.

[0066] The first conductor plate 430 and the fourth conductor plate 433 are mechanically and electrically connected via the joint portion 330. The end face on the plus side of the Z-axis of the first conductor plate 430 and the end face on the plus side of the Z-axis of the fourth conductor plate 433 have the same Z-axis coordinate. The end face on the minus side of the Z-axis of the second conductor plate 431 and the end face on the minus side of the Z-axis of the third conductor plate 432 have the same Z-axis coordinate. The first element 155 and the second element 157 have a relationship where the front and back are reversed when rotated around the Y-axis.

[0067] FIG. 15 is a diagram for explaining a manufacturing method of the semiconductor device 300A, corresponding to FIG. 7 of the embodiment. FIG. 15(a) shows the soldering process and the wire bonding process of the upper arm circuit. In FIGS. 15 and 7, mainly the arrangement of the terminals is different, but the manufacturing method is the same. For the sake of description, the outline is as follows. As shown in FIGS. 15(a) and 15(b), the upper arm circuit and the lower arm circuit are created respectively, and the lower arm circuit is inverted front and back as shown in FIG. 15(c). Then, as shown in FIG. 15(d), they are joined at the joint portion 330 using the joining member 331.

[0068] (Modification 2) The above-described electric circuit body 400 and electric circuit body 400A may be incorporated into a power conversion device. Hereinafter, for simplicity of explanation, an example of incorporating the electric circuit body 400 into a power conversion device will be described, taking the electric circuit body 400 and the electric circuit body 400A as representatives.

[0069] FIG. 16 is a circuit diagram of the power conversion device 200 including the electric circuit body 400 in the second modification. The power conversion device 200 includes a first inverter circuit section 140, a second inverter circuit section 142, an auxiliary machine inverter circuit section 43, and a capacitor module 500. The first inverter circuit section 140 and the second inverter circuit section 142 include a plurality of semiconductor devices 300, and a three-phase bridge circuit is configured by connecting them. When a larger current capacity is required, additional semiconductor devices 300 are added and connected in parallel, and these parallel connections are made corresponding to each phase of the three-phase inverter circuit, so that an increase in the current capacity can be accommodated. Also, an increase in the current capacity can be accommodated by connecting in parallel the first element 155 and the second element 157, which are power semiconductor elements incorporated in the semiconductor device 300, and the first diode 156 and the second diode 158.

[0070] The first inverter circuit section 140 and the second inverter circuit section 142 have the same basic circuit configuration, and their control methods and operations are basically the same. Since the outline of the circuit operation of the first inverter circuit section 140 and the like is well known, a detailed description thereof is omitted here.

[0071] As described above, the upper arm circuit includes the first element 155 and the first diode 156 as power semiconductor elements for switching, and the lower arm circuit includes the second element 157 and the second diode 158 as power semiconductor elements for switching. The first element 155 and the second element 157 receive a drive signal output from one or the other of two driver circuits constituting the driver circuit 174 and perform a switching operation to convert the DC power supplied from the battery 136 into three-phase AC power.

[0072] As described above, the first element 155 and the second element 157 include a collector electrode, an emitter electrode, and a gate electrode. The first diode 156 and the second diode 158 include two electrodes, a cathode electrode and an anode electrode. As shown in FIG. 3, the cathode electrodes of the first diode 156 and the second diode 158 are connected to the collector electrodes of the first element 155 and the second element 157, and the anode electrodes are electrically connected to the emitter electrodes of the first element 155 and the second element 157, respectively. Thereby, the flow of current from the emitter electrodes to the collector electrodes of the first element 155 and the second element 157 is in the forward direction.

[0073] The positive terminal 315B and the negative terminal 319B of the semiconductor device 300 are respectively connected to the DC terminals for capacitor connection of the capacitor module 500. AC power is generated at the connection parts of the upper arm circuit and the lower arm circuit. In each semiconductor device 300, the connection part of the upper arm circuit and the lower arm circuit is connected to the AC side terminal 320B. The AC side terminals 320B of each semiconductor device 300 in each phase are respectively connected to the AC output terminals of the power conversion device 200, and the generated AC power is supplied to the stator windings of the first motor generator 192 or the second motor generator 194.

[0074] The control circuit 172 generates a timing signal for controlling the switching timing of the first element 155 and the second element 157 based on input information from a control device, sensors, such as a current sensor 180, etc., of the device equipped with the power conversion device 200. The driver circuit 174 generates a drive signal for causing the first element 155 and the second element 157 to perform a switching operation based on the timing signal output from the control circuit 172. Note that the reference numerals 181, 182, and 188 indicate connectors.

[0075] The semiconductor device 300 in this modification example includes a temperature sensor (not shown), and the temperature data of the semiconductor device 300 is input to the microcomputer. Also, voltage information on the DC positive electrode side of the semiconductor device 300 is input to the microcomputer. The microcomputer performs over-temperature detection and over-voltage detection based on this information, and when over-temperature or over-voltage is detected, it stops the switching operations of all the first elements 155 and the second elements 157 to protect the semiconductor device 300 from over-temperature or over-voltage.

[0076] FIG. 17 is an external perspective view of the power conversion device 200 shown in FIG. 16, and FIG. 18 is a cross-sectional view taken along line XVIII-XVIII of the power conversion device 200 shown in FIG. 17. The power conversion device 200 includes a housing 12 having a substantially rectangular parallelepiped shape. The housing 12 includes an upper case 10 that can also be called an upper lid, and a lower case 11 that forms a substantially rectangular parallelepiped when combined with the upper case 10.

[0077] Inside the housing 12, an electric circuit body 400, a capacitor module 500, etc. are accommodated. The electric circuit body 400 has a cooling flow path, and from one side surface of the housing 12, a cooling water inflow pipe 13 and a cooling water outflow pipe 14 communicating with the cooling flow path protrude. As shown in FIG. 17, the lower case 11 has an opening on the upper side shown in the figure, and the upper case 10 closes the opening of the lower case 11 and is attached to the lower case 11. The upper case 10 and the lower case 11 are formed of an aluminum alloy or the like and are sealed and fixed to the outside. However, the upper case 10 and the lower case 11 may be integrally configured. Since the housing 12 has a simple rectangular parallelepiped shape, it has the advantages of being easy to attach to a vehicle or the like and easy to manufacture.

[0078] A connector 17 is attached to one side surface in the longitudinal direction of the housing 12, and an AC terminal 18 is connected to this connector 17. Also, a connector 21 is provided on the surface from which the cooling water inflow pipe 13 and the cooling water outflow pipe 14 are led out.

[0079] As shown in FIG. 18, an electric circuit body 400 is accommodated in the housing 12. Above the electric circuit body 400, a control circuit 172 and a driver circuit 174 are arranged, and a capacitor module 500 is accommodated on the DC terminal side of the electric circuit body 400. By arranging the capacitor module 500 at the same height as the semiconductor device 300, the power conversion device 200 can be made thinner, and the degree of freedom in installation on the vehicle is improved. The AC side terminal 320B of the electric circuit body 400 passes through the current sensor 180 and is joined to the bus bar 361. Also, the positive terminal 315B and the negative terminal 319B, which are the DC terminals of the semiconductor device 300, are joined to the positive terminal 362A and the negative terminal 362B of the capacitor module 500, respectively.

[0080] (12) The power conversion device 200 includes a plurality of electric circuit bodies 400 and converts DC power into AC power.

[0081] (Modification 3) FIG. 19 is a diagram showing the shape of the joint portion 330 in Modification 3. The joint portion 330 is not limited to the shape shown at the bottom of FIG. 3 in the embodiment. The joint portion 330 shown in FIG. 19(a) is provided with protrusions 330A on both the first conductor plate 430 and the fourth conductor plate 433, and a joining member 331 is arranged between the two protrusions 330A.

[0082] The joint portion 330 shown in FIG. 19(b) is provided with protrusions 330A on both the first conductor plate 430 and the fourth conductor plate 433, and joining members 331 are arranged at two locations between the two protrusions 330A. In the joint portion 330 shown in FIG. 19(c), a clamping portion formed by parallel plates that clamp the fourth conductor plate 433 is provided on the side surface of the first conductor plate 430. Specifically, the tip portion of the fourth conductor plate 433 is inserted between the parallel plates of the clamping portion provided on the first conductor plate 430. The fourth conductor plate 433 clamped between the parallel plates is electrically connected by a joining member 331.

[0083] (Modification 4) In the above-described embodiments, material bonding such as solder, sintered metal, and conductive adhesive was used for the joint portion 330. However, mechanical bonding may be used for the joint portion 330. For example, fixing with screws, press-fitting, shrink fitting, caulking, etc. may be used for the joint portion 330.

[0084] Each of the above-described embodiments and modifications may be combined. Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other aspects conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention.

Explanation of Reference Numerals

[0085] 155: First element 157: Second element 200: Power conversion device 300: Semiconductor device 325L: Lower arm gate terminal 325U: Upper arm gate terminal 330: Joint portion 330A: Protrusion 331: Joint member 340: Cooling member 360: Sealing material 381: Upper arm circuit body 382: Lower arm circuit body 400: Electric circuit body 430: First conductor plate 431: Second conductor plate 432: Third conductor plate 433: Fourth conductor plate 440: Upper insulating sheet 441: Lower insulating sheet 453: Heat conductive member

Claims

1. A first assembly formed by sandwiching an upper arm semiconductor element in the thickness direction between a first conductor plate and a second conductor plate; A second assembly formed by sandwiching a lower arm semiconductor element in the thickness direction between a third conductor plate and a fourth conductor plate; A sealing material for sealing the first assembly and the second assembly, and comprising: The first conductor plate and the fourth conductor plate are mechanically and electrically connected at a joint formed on sides facing each other; The first conductor plate and the fourth conductor plate are arranged on a first substantially identical plane; The second conductor plate and the third conductor plate are arranged on a second substantially identical plane different from the first substantially identical plane; The upper arm semiconductor element and the lower arm semiconductor element are in a relationship of front-back inversion, an electric circuit body.

2. In the electric circuit body according to Claim 1, A first control terminal for controlling the upper arm semiconductor element and a second control terminal for controlling the lower arm semiconductor element are integrally formed with the first conductor plate, the second conductor plate, the third conductor plate, and the fourth conductor plate by the sealing material, an electric circuit body.

3. In the electric circuit body according to Claim 1, End faces of the first conductor plate on the side opposite to the upper arm semiconductor element and end faces of the fourth conductor plate on the side opposite to the lower arm semiconductor element have the same position in the thickness direction; End faces of the second conductor plate on the side opposite to the upper arm semiconductor element and end faces of the third conductor plate on the side opposite to the lower arm semiconductor element have the same position in the thickness direction, an electric circuit body.

4. In the electric circuit body according to Claim 1, The joint is a mechanical joint or a material joint, an electric circuit body.

5. In the electric circuit body according to Claim 1, The joint is a joint using a solder material or a conductive adhesive, an electric circuit body.

6. In the electric circuit body according to Claim 1, At least one of the first conductor plate and the fourth conductor plate has a protrusion protruding toward the other on the side facing the other; The protrusion constitutes the joint, an electric circuit body.

7. In the electric circuit body according to Claim 1, An upper cooling member in contact with the first conductor plate and the fourth conductor plate via at least a first heat conducting member; A lower cooling member in contact with the second conductor plate and the third conductor plate via at least a second heat conducting member, and further comprising an electric circuit body.

8. In the electric circuit body according to Claim 7, An electric circuit body, wherein the thermal conductivities of the first heat conducting member and the second heat conducting member are 5 to 10 W / (m·K).

9. In the electric circuit body according to claim 1, an upper cooling member that is in contact with the first conductor plate and the fourth conductor plate via a first heat conducting member and a first insulating sheet; a lower cooling member that is in contact with the second conductor plate and the third conductor plate via a second heat conducting member and a second insulating sheet, the electric circuit body further comprising the lower cooling member.

10. A power conversion device that includes one or more electric circuit bodies according to claim 1 and converts direct current power into alternating current power.

11. A first forming step of forming a first assembly by sandwiching an upper arm semiconductor element in a thickness direction between a first conductor plate and a second conductor plate; A second forming step of forming a second assembly by sandwiching a lower arm semiconductor element in the thickness direction between a third conductor plate and a fourth conductor plate; After the first forming step and the second forming step, the first conductor plate and the fourth conductor plate are on a first substantially identical plane, and the second conductor plate and the third conductor plate are on a second substantially identical plane different from the first substantially identical plane, and an assembly arranging step of arranging the first assembly and the second assembly so that the upper arm semiconductor element and the lower arm semiconductor element are in a state of being front-back reversed; A manufacturing method of an electric circuit body, including a joining step of mechanically and electrically joining the first conductor plate and the fourth conductor plate.

12. In the manufacturing method of the electric circuit body according to claim 11, a sheet arranging step of arranging an upper insulating sheet and a lower insulating sheet so as to sandwich the first substantially identical plane and the second substantially identical plane; A sealing material forming step of arranging a mold so as to cover the upper insulating sheet and the lower insulating sheet, and injecting a sealing material into the mold while pressurizing the upper insulating sheet and the lower insulating sheet using the mold. The manufacturing method of the electric circuit body further includes the sealing material forming step.

13. In the manufacturing method of the electric circuit body according to claim 12, in the assembly arranging step, a soldering material or a conductive adhesive is disposed between the first conductor plate and the fourth conductor plate; The sealing material forming step also serves as the joining step. The manufacturing method of the electric circuit body.

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