Semiconductor device, power conversion device, and method for manufacturing the semiconductor device

Abstract

Provided is, for example, a semiconductor device having high reliability. The semiconductor device comprises a semiconductor element and an electrode plate electrically connected to the semiconductor element. The rear surface of the electrode plate is bonded to a terminal serving as a conductive member via a bonding material having a thermosetting property. A recess is formed in a main surface of the electrode plate. The recess formed in the main surface of the electrode plate is separated from the bonding material.

Description

[Technical Field]

[0001] The present disclosure relates to a semiconductor device that uses an electrode plate, a power conversion device, and a method for manufacturing a semiconductor device. [Background technology]

[0002] Power modules are becoming increasingly popular as modules mounted in industrial equipment, home appliances, information terminals, etc., and high productivity is required for these products. For example, modules mounted in electric vehicles require high reliability.

[0003] In semiconductor devices such as power modules, lead terminals must be firmly bonded to conductive members via a thermosetting bonding material, such as solder. The lead terminals are lead electrodes.

[0004] Patent Document 1 discloses a configuration (hereinafter also referred to as "related configuration A") in which a lead pin as a gull-wing lead is firmly bonded to a land as a conductive member via a thermosetting bonding material. In related configuration A, a groove that acts as a capillary action is provided in the lead pin to improve the fluidity of the solder that is the bonding material. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-351066 Summary of the Invention [Problem to be solved by the invention]

[0006] Among semiconductor devices, there are devices configured such that an electrode plate electrically connected to a semiconductor element is bonded to a conductive member via a thermosetting bonding material. In such semiconductor devices, the electrode plate is bonded to the conductive member by heating the bonding material via the electrode plate. The bonding material is heated, for example, by irradiating the electrode plate with laser light.

[0007] The semiconductor device is required to have a configuration in which the electrode plate can be firmly bonded to the conductive member via a thermosetting bonding material, i.e., a highly reliable semiconductor device is required.

[0008] The present disclosure has been made to solve such problems, and has an object to provide a semiconductor device and the like having high reliability. [Means for solving the problem]

[0009] To achieve the above object, a semiconductor device according to one embodiment of the present disclosure uses an electrode plate electrically connected to a conductive member having conductivity. The semiconductor device includes a semiconductor element and an electrode plate electrically connected to the semiconductor element, the electrode plate having a first surface that is one side and a second surface that is the other side of the electrode plate, the second surface of the electrode plate being the surface of the electrode plate opposite to the first surface, a recess formed in the first surface of the electrode plate, the second surface of the electrode plate being bonded to the conductive member via a thermosetting bonding material, and the recess formed in the first surface of the electrode plate being separated from the bonding material. [Effects of the Invention]

[0010] According to the present disclosure, a recess is formed on the first surface of the electrode plate. This reduces the heat capacity of the electrode plate. As a result, for example, when the electrode plate is heated by irradiating the recess with laser light, the heat of the electrode plate can be efficiently transferred to the bonding material. Therefore, the electrode plate is firmly bonded to the conductive member via the thermosetting bonding material.

[0011] Furthermore, the depressions formed on the first surface of the electrode plate are separated from the bonding material. Therefore, even if, for example, laser light is irradiated onto the depressions on the first surface of the electrode plate to heat the electrode plate, the following problem can be prevented from occurring: For example, the bonding material may be scattered when the laser light is directly irradiated onto the bonding material.

[0012] As a result, a highly reliable semiconductor device can be provided.

[0013] The objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description and the accompanying drawings. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram for explaining a configuration of a semiconductor device according to a first embodiment. [Figure 2] FIG. 2 is a diagram for explaining a characteristic configuration of the first embodiment. [Figure 3] 3 is a flowchart of a manufacturing method according to the first embodiment. [Figure 4] FIG. 2 is a cross-sectional view illustrating a manufacturing method according to the first embodiment. [Figure 5] FIG. 10 is a cross-sectional view illustrating another embodiment of the joining method. [Figure 6] FIG. 10 is a cross-sectional view showing another configuration of the recess. [Figure 7] FIG. 10 is a diagram for explaining the configuration of a semiconductor device according to a second embodiment. [Figure 8] FIG. 10 is a cross-sectional view illustrating a manufacturing method according to the second embodiment. [Figure 9] FIG. 10 is a cross-sectional view illustrating the configuration of a semiconductor device according to a third embodiment. [Figure 10] 10 is a flowchart of a manufacturing method according to a third embodiment. [Figure 11] 10A and 10B are cross-sectional views illustrating a manufacturing method according to a third embodiment. [Figure 12]FIG. 10 is a cross-sectional view illustrating the configuration of a semiconductor device according to a fourth embodiment. [Figure 13] 10 is a flowchart of a manufacturing method according to a fourth embodiment. [Figure 14] 10A and 10B are cross-sectional views illustrating a manufacturing method according to a fourth embodiment. [Figure 15] FIG. 10 is a block diagram showing a configuration of a power conversion system to which a power conversion device according to a fifth embodiment is applied. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments will be described with reference to the drawings. In the following drawings, the same components are assigned the same reference numerals. The names and functions of components assigned the same reference numerals are the same. Therefore, detailed descriptions of some of the components assigned the same reference numerals may be omitted.

[0016] The dimensions, materials, shapes, and relative positions of the components illustrated in the embodiments may be changed as appropriate depending on the configuration of the device, various conditions, etc. The dimensions of the components in the drawings may differ from the actual dimensions.

[0017] <First Embodiment> (composition) 1 is a diagram illustrating the configuration of a semiconductor device 100 according to a first embodiment. The semiconductor device 100 is, for example, a power module that operates at a high voltage. Note that the semiconductor device 100 is not limited to a power module and may be, for example, a semiconductor module that operates at a low voltage.

[0018] Fig. 1(a) is a cross-sectional view of a semiconductor device 100 according to embodiment 1. Fig. 1(a) shows a terminal 64, which will be described later and which is not included in the semiconductor device 100.

[0019] In FIG. 1(a), the X direction, Y direction, and Z direction are perpendicular to one another. The X direction, Y direction, and Z direction shown in the following figures are also perpendicular to one another. Hereinafter, the direction including the X direction and the direction opposite to the X direction (-X direction) will also be referred to as the "X-axis direction." Hereinafter, the direction including the Y direction and the direction opposite to the Y direction (-Y direction) will also be referred to as the "Y-axis direction." Hereinafter, the direction including the Z direction and the direction opposite to the Z direction (-Z direction) will also be referred to as the "Z-axis direction."

[0020] In the following, the plane including the X-axis direction and the Y-axis direction will also be referred to as the "XY plane." In the following, the plane including the X-axis direction and the Z-axis direction will also be referred to as the "XZ plane." In the following, the plane including the Y-axis direction and the Z-axis direction will also be referred to as the "YZ plane."

[0021] Fig. 1(b) is a plan view of the semiconductor device 100 according to the first embodiment. In Fig. 1(b), the outline of the sealing resin 83 is indicated by a dotted line in order to make it easier to understand the internal configuration of the sealing resin 83 (described later). Fig. 1(b) also shows a terminal 64 (described later) that is not included in the semiconductor device 100.

[0022] As shown in FIGS. 1(a) and 1(b), the semiconductor device 100 includes a heat spreader 70, a plurality of semiconductor elements S1, an insulating sheet 73, an electrode plate E1, lead terminals 62, wires W1, and a sealing resin 83.

[0023] The heat spreader 70 is made of, for example, copper. The thickness of the heat spreader 70 is, for example, 2 mm. The shape of the heat spreader 70 in plan view is rectangular. The size of the rectangle that is the shape of the heat spreader 70 is, for example, a size expressed as "25 mm x 40 mm."

[0024] A semiconductor element S1 is mounted on the upper surface of the heat spreader 70. Specifically, two adjacent semiconductor elements S1 are bonded to the upper surface of the heat spreader 70 via a bonding material b1.

[0025] The bonding material b1 is a thermosetting material. The bonding material b1 is, for example, solder. The melting point of the solder that is the bonding material b1 is, for example, 217°C. The solder is composed of tin, silver, and copper. The composition ratio of the solder that is the bonding material b1 is expressed as "96.5% tin, 3% silver, and 0.5% copper."

[0026] As an example, the semiconductor device 100 is provided with two heat spreaders 70. Therefore, the semiconductor device 100 includes a plurality of semiconductor elements S1, each of which has two adjacent semiconductor elements S1.

[0027] Each of the plurality of semiconductor elements S1 is, for example, a semiconductor chip. Each of the plurality of semiconductor elements S1 has a plate shape. Each of the semiconductor elements S1 is, for example, a power semiconductor element that operates at a high voltage. Note that each of the semiconductor elements S1 is not limited to a power semiconductor element, and may be, for example, a semiconductor element that operates at a low voltage.

[0028] An electrode e5 is provided on the top surface of each semiconductor element S1. That is, the electrode e5 is an electrode provided on each semiconductor element S1. The electrode e5 is a main electrode. The electrode e5 is a conductive member having conductivity.

[0029] Hereinafter, the two adjacent semiconductor elements S1 will also be referred to as semiconductor elements S1a and S1b, respectively. The semiconductor element S1a is, for example, a diode. The semiconductor element S1b is, for example, an IGBT (Insulated Gate Bipolar Transistor).

[0030] The material constituting the semiconductor element S1a is, for example, silicon. The thickness of the semiconductor element S1a is, for example, 0.2 mm. The shape of the semiconductor element S1a in plan view is rectangular. The size of the rectangle that is the shape of the semiconductor element S1a is, for example, a size expressed as "13 mm x 10 mm."

[0031] The material constituting the semiconductor element S1b is, for example, silicon. The thickness of the semiconductor element S1b is, for example, 0.2 mm. The shape of the semiconductor element S1b in plan view is rectangular. The size of the rectangle that is the shape of the semiconductor element S1b is, for example, a size expressed as "13 mm x 13 mm."

[0032] The electrode plate E1 is made of, for example, copper. The thickness of the electrode plate E1 is, for example, 0.64 mm. The electrode plate E1 has one surface, a main surface E1s, and the other surface, a back surface E1r. The main surface E1s is the first surface. The back surface E1r is the second surface. The back surface E1r is the surface of the electrode plate E1 opposite to the main surface E1s. FIG. 1(a) shows a curved electrode plate E1 as an example. Note that the electrode plate E1 does not have to be curved.

[0033] The semiconductor device 100 operates using the electrode plate E1. That is, the semiconductor device 100 uses the electrode plate E1.

[0034] Furthermore, the electrode e5 of the semiconductor element S1a and the electrode e5 of the semiconductor element S1b are connected to the electrode plate E1 via the bonding material b2. That is, the electrode plate E1 is electrically connected to the semiconductor element S1. This forms, for example, a main circuit. The bonding material b2 is in contact with the back surface E1r of the electrode plate E1 and the electrode e5 of the semiconductor element S1.

[0035] The bonding material b2 has the same configuration as the bonding material b1. The bonding material b2 has thermosetting properties. The bonding material b2 is, for example, solder. The material constituting the bonding material b2 is the same as the material constituting the bonding material b1.

[0036] As shown in FIG. 1(b), a signal electrode g1 is provided on the upper surface of the semiconductor element S1b. The signal electrode g1 of the semiconductor element S1b is connected to a lead terminal 62 by a wire W1. The lead terminal 62 is a signal terminal. The lead terminal 62 is made of, for example, copper. The lead terminal 62 has a thickness of 0.64 mm. The wire W1 is made of, for example, aluminum. The thickness of the wire W1 is, for example, 0.15 mm.

[0037] An insulating sheet 73 is disposed on the lower surface of the heat spreader 70. The insulating sheet 73 has a rectangular shape in plan view. The size of the rectangular shape of the insulating sheet 73 is expressed as, for example, "62 mm x 44 mm."

[0038] The insulating sheet 73 is made of copper foil 72 and a thermally conductive resin layer 71. The copper foil 72 has a thickness of, for example, 0.1 mm. The thermally conductive resin layer 71 has a thickness of, for example, 0.05 mm. The thermally conductive resin layer 71 is provided on the copper foil 72.

[0039] The sealing resin 83 is a resin that seals multiple components included in the semiconductor device 100. The sealing resin 83 is produced by a transfer molding method. The sealing resin 83 is an epoxy resin in which silica filler is dispersed.

[0040] The insulating sheet 73, the heat spreader 70, the semiconductor elements S1, the electrode plate E1, the lead terminals 62, the wires W1, etc. are mainly sealed with the sealing resin 83. Part of the electrode plate E1 and part of the lead terminals 62 are exposed to the outside of the sealing resin 83.

[0041] A part of the electrode plate E1 is a lead terminal 61. That is, the lead terminal 61 is the electrode plate E1. The lead terminal 61 in the semiconductor device 100 is a part of the electrode plate E1 that is exposed to the outside of the sealing resin 83. Note that the entire electrode plate E1 may be the lead terminal 61.

[0042] The lead terminal 61, which is the electrode plate E1, has a main surface E1s and a back surface E1r. The lead terminal 61 functions as an external terminal. The width of the lead terminal 61 is, for example, 10 mm.

[0043] 1(b), the semiconductor device 100 is provided with two heat spreaders 70 on which semiconductor elements S1a and S1b are mounted. The semiconductor elements S1a and S1b mounted on the two heat spreaders 70 form two pairs of 2-in-1 modules. The number of electrode plates E1 provided on the semiconductor device 100 is, for example, three. The number of lead terminals 61 provided on the semiconductor device 100 is, for example, three.

[0044] The number of electrode plates E1 provided in the semiconductor device 100 may be 1, 2, or 4 or more. The number of lead terminals 61 provided in the semiconductor device 100 may be 1, 2, or 4 or more.

[0045] (Characteristic configuration) Next, a characteristic configuration of this embodiment will be described. Fig. 2 is a diagram for explaining a characteristic configuration of embodiment 1. Fig. 2 is an enlarged view of the vicinity of lead terminal 61, which is electrode plate E1.

[0046] In this embodiment, the semiconductor device 100 is electrically connected to a terminal 64 of a device A (not shown). Specifically, the lead terminal 61, which is an electrode plate E1, is joined to the terminal 64 of the device A.

[0047] Device A is, for example, an external device. The external device is, for example, a device that operates using a semiconductor device. The external device is, for example, a transportation device such as an electric vehicle. Terminal 64 functions as an external terminal of device A.

[0048] The terminal 64 of the device A is a conductive member having electrical conductivity. The terminal 64 is made of, for example, copper. The thickness of the terminal 64 is, for example, 1 mm. The width of the terminal 64 is, for example, 12 mm.

[0049] 2, a recess V1 is formed in a main surface E1s of the lead terminal 61, which is the electrode plate E1.

[0050] The depth of the depression V1 is, for example, 0.3 mm. The shape of the depression V1 in plan view is rectangular. The size of the rectangle that is the shape of the depression V1 is, for example, a size expressed as "width 8 mm x 6 mm."

[0051] The recess V1 is spaced apart from the outer periphery of the main surface E1s of the lead terminal 61, which is the electrode plate E1. In other words, the recess V1 is spaced apart from the edge of the main surface E1s.

[0052] The lead terminal 61 is joined to a terminal 64 of the device A via a bonding material b6. Specifically, a back surface E1r of the lead terminal 61, which is the electrode plate E1, is joined to the terminal 64, which is a conductive member, via the bonding material b6. The bonding material b6 is present between the lead terminal 61 and the terminal 64. The bonding material b6 is in contact with the back surface E1r of the lead terminal 61, which is the electrode plate E1, and the terminal 64. In other words, the lead terminal 61, which is the electrode plate E1, is electrically connected to the terminal 64, which is a conductive member.

[0053] The bonding material b6 is a thermosetting material. The configuration of the bonding material b6 is the same as the configuration of the bonding material b1. The bonding material b6 is, for example, solder. The material constituting the bonding material b6 is the same as the material constituting the bonding material b1.

[0054] Furthermore, the recess V1 formed on the main surface E1s of the lead terminal 61, which is the electrode plate E1, is spaced apart from the bonding material b6.

[0055] Hereinafter, the state of the electrode plate E1 will also be referred to as “state St1.” In state St1, a bonding state Stc exists.

[0056] The bonded state Stc includes a state St1a in which the back surface E1r of the electrode plate E1 is bonded to a conductive member via a bonding material. The bonding material is, for example, a bonding material b6. The conductive member is, for example, a terminal 64. The electrode plate E1 in the state St1a is, for example, the electrode plate E1 serving as a lead terminal 61 shown in FIGS. 1(a) and 2.

[0057] The bonding state Stc also includes a state St1b in which the recess V1 formed on the main surface E1s of the electrode plate E1 is separated from the bonding material, which is the bonding material b6.

[0058] The bonded state Stc of this embodiment includes a state St1a and a state St1b. The electrode plate E1 in the bonded state Stc is, for example, the electrode plate E1 serving as the lead terminal 61 shown in FIGS.

[0059] As will be described in detail later, laser light L1 emitted from, for example, a YAG laser is used to bond the lead terminal 61, which is the electrode plate E1. The depression V1 is the area to be irradiated with the laser light L1. The output of the YAG laser is, for example, 20 W. The wavelength of the laser light L1 is, for example, 1.064 nm.

[0060] Furthermore, a recess V4 is formed in the terminal 64 of the device A. Specifically, as shown in FIG. 1(a), the recess V4 is formed on the bottom surface of the terminal 64. The depth of the recess V4 is, for example, 0.5 mm. The shape of the recess V4 in a plan view is rectangular. The size of the rectangle that is the shape of the recess V4 is, for example, a size expressed as "width 8 mm x 6 mm."

[0061] In a plan view, the recess V1 of the lead terminal 61 overlaps with the recess V4 of the terminal 64.

[0062] (Manufacturing method) Next, an example of a method for manufacturing the semiconductor device 100 will be described with reference to FIGS. 3 and 4. Hereinafter, the method for manufacturing the semiconductor device 100 will also be referred to as a "manufacturing method Pr." FIG. 3 is a flowchart of the manufacturing method Pr according to the first embodiment. FIG. 3 shows only the main steps included in the multiple steps of the manufacturing method Pr. FIG. 4 is a cross-sectional view for explaining the manufacturing method Pr according to the first embodiment. Hereinafter, to make the explanation of the manufacturing method Pr easier to understand, each of the semiconductor elements S1a and S1b will be explained as a semiconductor element S1.

[0063] In the manufacturing method Pr, an initial step is first performed. In the initial step, a plurality of components used in manufacturing the semiconductor device 100 are prepared. The plurality of components are shown in FIG. 4(a). The plurality of components include a heat spreader 70, a lead frame 60, a semiconductor element S1, bonding materials b1 and b2, a lead terminal 62, and an electrode plate E1. Each of the prepared bonding materials b1 and b2 has a plate shape.

[0064] An electrode plate E1 and lead terminals 62 are connected to the lead frame 60. The electrode plate E1 connected to the lead frame 60 is a member in which a portion of the electrode plate E1 will become the lead terminals 61 in a process described below. A recess V1 is formed in advance on the main surface E1s of the electrode plate E1. The recess V1 is formed, for example, by etching or the like.

[0065] Next, an element placement step is performed (step S110). In the element placement step, the semiconductor element S1 is placed on the upper surface of the heat spreader 70 via a plate-shaped bonding material b1.

[0066] Next, a bonding material placement process is performed (step S120). The bonding material placement process is a process of placing a bonding material b2 on the upper surface of a conductive member. The bonding material b2 has thermosetting properties. The conductive member is the electrode e5 provided on the upper surface of the semiconductor element S1. In other words, the conductive member is the electrode e5 provided on the semiconductor element S1. In the bonding material placement process, a plate-shaped bonding material b2 is placed on the upper surface of the electrode e5 of the semiconductor element S1.

[0067] Next, an electrode plate arrangement process is performed (step S130). The electrode plate arrangement process is a process of arranging the electrode plate E1 on the bonding material b2 so that the back surface E1r of the electrode plate E1 contacts the bonding material b2. In the electrode plate arrangement process, the electrode plate E1 is arranged on the bonding material b2 so that the back surface E1r of the electrode plate E1 contacts the bonding material b2.

[0068] Next, a heating step N is performed. In the heating step N, the bonding materials b1 and b2 are heated. Specifically, the bonding materials b1 and b2 are heated so as to melt. The bonding materials b1 and b2 are heated using a reflow furnace. The bonding materials b1 and b2 are heated so that the temperature of the bonding materials b1 and b2 rises to 280°C. As a result, as shown in FIG. 4(b), the semiconductor element S1 is bonded to the upper surface of the heat spreader 70 by the bonding material b1. The electrode plate E1 is also bonded to the electrode e5 of the semiconductor element S1.

[0069] Next, a terminal connecting step is performed in which the lead terminal 62 is electrically connected to the signal electrode g1 (not shown) of the semiconductor element S1b, which is the semiconductor element S1, by the wire W1 (see FIG. 4(b)).

[0070] Next, the bonding step is performed in which an insulating sheet 73 is bonded to the lower surface of the heat spreader 70.

[0071] Next, an encapsulation process is performed (step S140). In the encapsulation process, a transfer molding method is performed so that multiple components are encapsulated in encapsulating resin 83. The multiple components include insulating sheet 73, heat spreader 70, semiconductor element S1, electrode plate E1, lead terminals 62, and wires W1.

[0072] Next, a frame removing step is performed in which the lead frame 60 is removed.

[0073] Next, a lead forming process is performed in which pressure is applied to the lead terminals 62 so that the lead terminals 62 are bent.

[0074] In this way, the semiconductor device 100 shown in Fig. 4(c) is manufactured. In Fig. 4(c), the portion of the electrode plate E1 that is exposed to the outside of the sealing resin 83 is the lead terminal 61.

[0075] (Joining method) Hereinafter, the method of joining the electrode plate E1 to the conductive member will also be referred to as the “joining method Pc.” The joining method Pc of this embodiment is a method of joining the lead terminal 61, which is the electrode plate E1 included in the semiconductor device 100 of FIG. 4(c), to the terminal 64 (i.e., the conductive member) of the device A.

[0076] Next, the joining method Pc will be described with reference to Fig. 2. In the joining method Pc, a joining step N is performed. The joining step N is a step of irradiating a laser beam L1 onto a recess V1 formed on a main surface E1s of the electrode plate E1 so that the state of the electrode plate E1 becomes the above-mentioned joined state Stc.

[0077] The bonded state Stc of this embodiment includes a state St1a and a state St1b. In the state St1a of this embodiment, the back surface E1r of the electrode plate E1 is bonded to the terminal 64, which is a conductive member, via the bonding material b6. In the state St1b of this embodiment, the recess V1 formed on the main surface E1s of the electrode plate E1 is separated from the bonding material b6.

[0078] In the bonding step N, first, as shown in FIG. 2, a plate-shaped bonding material b6 is placed on the upper surface of the terminal 64, which is a conductive member.

[0079] Next, the lead terminal 61, which is the electrode plate E1, is positioned so that the depression V1 of the lead terminal 61 overlaps the bonding material b6 in plan view.

[0080] Next, in the bonding step N, an irradiation process A is performed. In the irradiation process A, a laser beam L1 is irradiated onto the bottom of the depression V1. Hereinafter, the irradiation of the laser beam L1 is also referred to as "laser beam irradiation." The laser beam irradiation in the bonding method Pc is the irradiation of the laser beam L1 onto the bottom of the depression V1.

[0081] Specifically, in the irradiation process A, the bonding material b6 is heated by laser light irradiation so as to melt the bonding material b6. The heating of the bonding material b6 is performed so that the bonding material b6 is melted by heat generated in the lead terminal 61, which is the electrode plate E1, by the laser light irradiation. The heating of the bonding material b6 (i.e., the laser light irradiation) is terminated after the bonding material b6 is melted. When the heating of the bonding material b6 is terminated, the bonding material b6 hardens again.

[0082] This completes the irradiation process A. As a result, as shown in Fig. 1(a), the back surface E1r of the lead terminal 61, which is the electrode plate E1, is bonded to the terminal 64, which is the conductive member, via the bonding material b6.

[0083] (summary) As described above, according to this embodiment, the recess V1 is formed on the main surface E1s of the electrode plate E1. This reduces the heat capacity of the electrode plate E1. As a result, for example, when the electrode plate E1 is heated by irradiating the recess V1 of the electrode plate E1 with laser light L1, the heat of the electrode plate E1 can be efficiently transferred to the bonding material b6. Therefore, the electrode plate E1 is firmly bonded to the terminal 64, which is a conductive member, via the thermosetting bonding material b6.

[0084] Furthermore, the depression V1 formed on the main surface E1s of the electrode plate E1 is separated from the bonding material b6. Therefore, even if, for example, laser light L1 is irradiated onto the depression V1 on the main surface E1s of the electrode plate E1 to heat the electrode plate E1, the following problem can be prevented from occurring: For example, the laser light L1 is directly irradiated onto the bonding material b6, causing the bonding material b6 to scatter.

[0085] As a result, a highly reliable semiconductor device can be provided.

[0086] According to the present embodiment, a depression V1 is formed on the main surface E1s of the lead terminal 61, which is the electrode plate E1. In the bonding step N, the bottom of the depression V1 is irradiated with laser light L1 so as to melt the bonding material b6 in contact with the back surface E1r of the lead terminal 61.

[0087] Because the recess V1 is formed in the lead terminal 61, which is the electrode plate E1, the thickness of the portion of the lead terminal 61 where the recess V1 is present is thin. As a result, the heat capacity of the lead terminal 61 is smaller than that of a lead terminal without the recess V1. This makes it possible to increase the thermal conductivity of the lead terminal 61. In other words, the lead terminal 61 has the property that the temperature of the lead terminal 61 easily rises.

[0088] This improves the thermal conduction to the rear surface E1r of the lead terminal 61. This improves the thermal conduction to the bonding material b6 that contacts the rear surface E1r of the lead terminal 61. This has the effect of improving the solderability of the lead terminal 61.

[0089] Furthermore, according to the present embodiment, the recess V1 is located away from the outer periphery of the main surface E1s of the lead terminal 61. This makes it possible to prevent the following problem from occurring: For example, the solder serving as the bonding material b6 flows to the recess V1, and then the solder is irradiated with laser light, causing the solder to splash.

[0090] Furthermore, according to this embodiment, the recess V1 is formed in the lead terminal 61, which is the electrode plate E1. The lead terminal 61 is joined to the terminal 64 of the device A via the joining material b6.

[0091] As a result, the lead terminal 61 is joined by irradiating a laser beam onto a portion of the lead terminal 61 that is to be joined to the terminal 64. That is, the joining of the lead terminal 61 can be achieved by localized irradiation of the laser beam. Therefore, by irradiating the lead terminal 61 with the laser beam, the range to which the heat generated in the lead terminal 61 is transferred can be limited.

[0092] Furthermore, according to this embodiment, a recess V4 is formed on the lower surface of the terminal 64. This reduces the heat capacity of the terminal 64. Furthermore, the heat conduction to the bonding material b6 sandwiched between the lead terminal 61 and the terminal 64 can be improved.

[0093] Meanwhile, with growing awareness of environmental issues, power modules are becoming more common in situations where electrical energy is used for power generation, transmission, regeneration, etc. Power modules used in equipment A, such as transportation equipment, are required to be particularly reliable. For this reason, instead of conventional wire bonding, a structure is becoming more common in which a copper lead frame is used to solder the main circuit of a semiconductor element to the external terminals of equipment A. The main circuit of the semiconductor element is provided in a power module.

[0094] When connecting such a power module to the external terminals of device A via a lead frame, soldering is often used. However, because lead frames have excellent thermal conductivity, the following problem is likely to occur. This problem is that heat spreads over a wide area in the lead frame. When this problem occurs, the temperature of the part to be joined does not rise sufficiently, resulting in insufficient soldering.

[0095] If the heat input to the lead frame is excessively large, the heat is transferred through the lead frame, which can easily cause the following problems: For example, the solder inside the module melts, affecting the reliability of the joints. When this problem occurs, the solder expands and cracks form in the sealing resin.

[0096] Therefore, a method of soldering using localized heat input using a laser beam as a heat source has been investigated. In the related configuration A mentioned above, the grooves that act on capillary action improve the fluidity of the solder. This allows the molten solder to wet the lead pins as gull-wing leads.

[0097] In this related configuration A, it is possible to apply a heating method using laser light. In this case, the heat input by irradiating the lead pin with a groove with laser light is easily conducted to the back surface of the lead pin. This may improve solderability. However, the following problems may occur.

[0098] This problem occurs when the solder that has been wetted is directly irradiated with laser light, causing the solder with a low melting point to splatter around. When this problem occurs, problems such as short circuits and reduced insulation properties may occur.

[0099] Therefore, the semiconductor device 100 of this embodiment has a configuration for achieving the above-mentioned effects, and therefore, the semiconductor device 100 of this embodiment can solve the above-mentioned problems.

[0100] In addition, SiC semiconductor elements made of silicon carbide (SiC) have a high operating temperature and excellent power conversion efficiency. For this reason, SiC semiconductor elements have become mainstream in recent years. Therefore, there is a demand for power modules that can accommodate SiC semiconductor elements.

[0101] The semiconductor device 100 of this embodiment has a configuration for achieving the above-mentioned effects. Therefore, the semiconductor element S1 mounted on the semiconductor device 100 can be a SiC semiconductor element.

[0102] As described above, it is possible to provide a semiconductor device that can be used in various situations where power generation, power transmission, efficient energy utilization, energy regeneration, and the like are performed.

[0103] In the joining method Pc, the terminal 64 of the device A is joined to the back surface E1r of the lead terminal 61, which is the electrode plate E1, but the present invention is not limited to this.

[0104] 5, a configuration may be adopted in which a terminal 64 is bonded to a main surface E1s of a lead terminal 61. In this configuration, a recess V4 is formed on the upper surface of the terminal 64, and a recess V1 is formed on the rear surface E1r of the lead terminal 61. In this configuration, a laser beam is irradiated onto the recess V4 of the terminal 64. This provides the same effect as the bonding method Pc of the first embodiment.

[0105] Hereinafter, a configuration in which the shape of the recess in plan view is rectangular will also be referred to as a “configuration Cs1.” The recess V1 in the configuration Cs1 is, for example, the recess V1 in FIG.

[0106] It should be noted that the recess V1 is not limited to the recess V1 in the configuration Cs1. Fig. 6 is a cross-sectional view showing another configuration of the recess V1.

[0107] As shown in Fig. 6(a), the depression V1 may be composed of a plurality of grooves V1a. Hereinafter, a configuration in which a depression is composed of a plurality of grooves V1a will also be referred to as "configuration Cs2." The depression V1 to which configuration Cs2 is applied is composed of a plurality of grooves V1a.

[0108] The shape of each groove V1a is linear. The depth of each groove V1a is, for example, 0.3 mm. The shape of each groove V1a in plan view is rectangular. The size of the rectangle that is the shape of each groove V1a is, for example, a size expressed as "width 8 mm x 1.2 mm."

[0109] As a result, the configuration Cs2 can suppress the decrease in rigidity of the electrode plate E1 more effectively than the configuration Cs1. Therefore, the flatness of the electrode plate E1 can be easily ensured. The shape of each groove V1a is not limited to a linear shape and may be, for example, a square shape.

[0110] Hereinafter, a configuration in which the cross-sectional shape of the depression along the depth direction of the depression is triangular is also referred to as "configuration Cs3." When configuration Cs3 is applied to depression V1, the cross-sectional shape of depression V1 along the depth direction of depression V1 is triangular, as shown in FIG. 6(b).

[0111] The depression V1 to which the structure Cs3 is applied is a groove. The shape of the depression V1 is linear. Furthermore, as shown in FIG. 6(b), a plurality of depressions V1 to which the structure Cs3 is applied may be formed.

[0112] 6(b) has a rectangular shape in plan view. The rectangular shape of the recess V1, which is a groove, has a size that can be expressed as, for example, "width 8 mm x 1.2 mm."

[0113] Due to the configuration of the recess V1 in the configuration Cs3, the laser light L1 is diffusely reflected in the above-described irradiation process A. This reduces the reflectance of the laser light L1 on the electrode plate E1. This makes it possible to more reliably increase the temperature of the electrode plate E1 in the irradiation process A.

[0114] The shape of the depression V1 in the structure Cs3 is not limited to a linear shape, and may be, for example, a square shape.

[0115] Concerning the shape of the depressions V1, making them into multiple cylinders or cones can ensure diffuse reflection of the laser light L1. The most efficient way to increase absorption is to make the diameter of the cylinders or cones about 1x the fiber diameter or spot diameter of the laser light L1. Furthermore, the deeper the cylinders or cones, the more likely they are to cause diffuse reflection. It is desirable for the aspect ratio of depth / diameter to be 0.5 or greater.

[0116] In this embodiment, a through hole may be provided in a part of the bottom of the recess V1. With this configuration, the bonding state of the part of the lead terminal 61 that is in contact with the bonding material b6 can be inspected by observing it from above the recess V1.

[0117] In this configuration, it is desirable to provide a structure in the through hole that prevents solder wetting. For example, this structure is a structure in which a resin that prevents solder wetting is applied to the inner wall of the through hole, the periphery of the through hole, etc. Alternatively, this structure is a structure in which the inner wall of the through hole, the periphery of the through hole, etc. are plated with a metal that does not easily cause solder wetting.

[0118] In the present embodiment, the material constituting the electrode plate E1, heat spreader 70, etc. is not limited to copper. The material constituting the electrode plate E1, heat spreader 70, etc. may be, for example, a copper alloy. The material constituting the electrode plate E1, heat spreader 70, etc. may be, for example, aluminum with a nickel-plated surface.

[0119] In this embodiment, the material constituting the semiconductor element S1 is not limited to silicon. The material constituting the semiconductor element S1 may be, for example, a wide bandgap semiconductor material such as silicon carbide, silicon carbide (SiC), gallium nitride, or diamond. A wide bandgap semiconductor material is a material having a bandgap wider than that of silicon.

[0120] In addition, in this embodiment, the composition ratio of the solders that are the bonding materials b1, b2, b6, etc. is expressed as "96.5% tin, 3% silver, 0.5% copper" and the melting point of the solder is 217°C, but this is not limiting. For example, the composition ratio of the solders that are the bonding materials b1, b2, b6, etc. may be expressed as "99.3% tin, 0.7% copper" and the melting point of the solder may be 224°C.

[0121] In this embodiment, the bonding materials b1, b2, b6, etc. are not limited to solder. The bonding materials b1, b2, b6, etc. may be materials having better heat resistance than solder. The bonding materials b1, b2, b6, etc. may be, for example, a silver sintered material, a brazing material, etc.

[0122] Furthermore, the material of the wire W1 is not limited to aluminum. The material of the wire W1 may be, for example, an aluminum alloy, copper, or the like. The aluminum alloy contains a small amount of additive. The additive is, for example, iron.

[0123] Furthermore, the sealing resin 83 is not limited to an epoxy resin in which a silica filler is dispersed. For example, the sealing resin 83 may be an epoxy resin in which a filler such as alumina is dispersed. For example, the sealing resin 83 may be an epoxy resin in which a silicone resin is mixed with an epoxy resin.

[0124] Furthermore, although the terminal 64 of the device A has been described as having the recess V4 formed therein, the present invention is not limited to this. The terminal 64 of the device A does not necessarily have to have the recess V4 formed therein.

[0125] <Embodiment 2> (composition) 7A and 7B are diagrams illustrating the configuration of a semiconductor device 100A according to a second embodiment. FIG. 7A is a cross-sectional view of the semiconductor device 100A according to the second embodiment. FIG. 7A shows a terminal 64 of the device A, which is not included in the semiconductor device 100A. FIG. 7B is a plan view of the semiconductor device 100A according to the first embodiment. FIG. 7B shows a terminal 64, which is not included in the semiconductor device 100A.

[0126] 1, the semiconductor device 100A differs in that it includes a sealing material 84 instead of the sealing resin 83, an insulating substrate 10 instead of the heat spreader 70, a case 5, and does not include the insulating sheet 73. The other configurations of the semiconductor device 100A are the same as those of the semiconductor device 100. Below, the differences between the semiconductor device 100A and the semiconductor device 100 will be mainly described.

[0127] The case 5 has, for example, a cylindrical shape. The case 5 has a closed loop shape in plan view. The case 5 is made of, for example, PPS (Poly Phenylene Sulfide) resin.

[0128] The electrode plate E1 and the lead terminals 62 are fixed to the case 5 by insert molding. The electrode plate E1 and the lead terminals 62 are integrated with the case 5. The electrode plate E1 is made of, for example, copper. The thickness of the electrode plate E1 is, for example, 0.64 mm. The outline of the case 5 in plan view is, for example, rectangular.

[0129] The case 5 houses multiple components included in the semiconductor device 100A. The multiple components include an insulating substrate 10, multiple semiconductor elements S1, electrode plates E1, wires W1, etc. That is, the case 5 houses at least the semiconductor element S1. The case 5 is joined to the insulating substrate 10 with an adhesive 80.

[0130] The insulating substrate 10 is a substrate having insulating properties. The insulating substrate 10 is, for example, a ceramic substrate. The insulating substrate 10 includes a base material 11, a plurality of conductor layers 12, and a conductor layer 13. The base material 11 is made of, for example, aluminum nitride. The base material 11 has a plate-like shape. The thickness of the base material 11 is, for example, 2 mm. The shape of the base material 11 in a plan view is rectangular. The size of the rectangle that is the shape of the base material 11 is, for example, a size expressed as "40 mm x 40 mm".

[0131] Two conductor layers 12 are formed on the upper surface of the substrate 11. Each conductor layer 12 is made of, for example, copper. The thickness of each conductor layer 12 is, for example, 0.8 mm. The shape of the conductor layer 12 in plan view is rectangular. The size of the rectangle that is the shape of the conductor layer 12 is, for example, a size expressed as "17 mm x 37 mm."

[0132] A conductor layer 13 is formed on the lower surface of the substrate 11. The conductor layer 13 is made of, for example, copper. The thickness of the conductor layer 13 is, for example, 0.8 mm. The shape of the conductor layer 13 in plan view is rectangular. The size of the rectangle that is the shape of the conductor layer 13 is, for example, a size expressed as "37 mm x 37 mm."

[0133] A semiconductor element S1 is mounted on the insulating substrate 10. Specifically, semiconductor elements S1a and S1b, which are the semiconductor element S1, are mounted on each conductor layer 12 of the insulating substrate 10 with a bonding material b1.

[0134] The semiconductor device 100A operates using the electrode plate E1, that is, the semiconductor device 100A uses the electrode plate E1.

[0135] Furthermore, the electrode e5 of the semiconductor element S1a and the electrode e5 of the semiconductor element S1b are connected to the electrode plate E1 via the bonding material b2. That is, the electrode plate E1 is electrically connected to the semiconductor element S1. The bonding material b2 is in contact with the back surface E1r of the electrode plate E1 and the electrode e5 of the semiconductor element S1.

[0136] The signal electrode g1 of the semiconductor element S1b is connected to the lead terminal 62 by a wire W1.

[0137] Furthermore, a sealant 84 is provided inside the case 5. The sealant 84 is, for example, silicone gel. The sealant 84 mainly seals the insulating substrate 10, the plurality of semiconductor elements S1, the electrode plate E1, the wires W1, etc.

[0138] A part of the electrode plate E1 in the semiconductor device 100A is a lead terminal 61. That is, the lead terminal 61 is the electrode plate E1. The lead terminal 61 in the semiconductor device 100A is a part of the electrode plate E1 that is exposed to the outside of the case 5. Note that the entire electrode plate E1 may be the lead terminal 61. The lead terminal 61, which is the electrode plate E1, has a main surface E1s and a back surface E1r.

[0139] The semiconductor device 100A is electrically connected to a terminal 64 of a device A (not shown). Specifically, a lead terminal 61, which is an electrode plate E1, is joined to the terminal 64 of the device A.

[0140] A recess V1 is formed in the main surface E1s of the lead terminal 61, which is the electrode plate E1.

[0141] The configuration of the recess V1 in this embodiment is the same as the configuration of the recess V1 in embodiment 1. For example, in this embodiment, the shape of the recess V1 in plan view is rectangular.

[0142] The recess V1 of this embodiment is located away from the outer periphery of the main surface E1s of the lead terminal 61, which is the electrode plate E1. In other words, the recess V1 is located away from the edge of the main surface E1s.

[0143] The lead terminal 61 is joined to a terminal 64 of the device A via a bonding material b6. Specifically, the back surface E1r of the lead terminal 61, which is the electrode plate E1, is joined to the terminal 64, which is a conductive member, via the bonding material b6. In other words, the lead terminal 61, which is the electrode plate E1, is electrically connected to the terminal 64, which is a conductive member.

[0144] The bonding material b6 is a thermosetting material. The configuration of the bonding material b6 is the same as the configuration of the bonding material b1. The bonding material b6 is, for example, solder.

[0145] Moreover, the depression V1 formed in the main surface E1s is spaced apart from the bonding material b6.

[0146] Furthermore, the terminal 64 of the device A is formed with a recess V4.

[0147] (Manufacturing method) Next, an example of a manufacturing method for the semiconductor device 100A will be described with reference to Fig. 8. Hereinafter, the manufacturing method for the semiconductor device 100A will also be referred to as "manufacturing method Pra." Except for some processing, the manufacturing method Pra is the same as the manufacturing method Pr for the semiconductor device 100. Fig. 8 is a cross-sectional view for explaining the manufacturing method Pra according to the second embodiment.

[0148] Here, the manufacturing method Pra of the semiconductor device 100A will be described, focusing on the differences from the manufacturing method Pr of FIG. 3 in the first embodiment. In the following, to make the description of the manufacturing method Pra easier to understand, each of the semiconductor elements S1a and S1b will be described as the semiconductor element S1.

[0149] In the manufacturing method Pra, an initial step A is first performed. In the initial step A, a plurality of components used in manufacturing the semiconductor device 100A are prepared. FIG. 8(a) shows the plurality of components. The plurality of components include a case 5, an insulating substrate 10, a semiconductor element S1, bonding materials b1 and b2, a lead terminal 62, an electrode plate E1, etc. Each of the prepared bonding materials b1 and b2 has a plate shape.

[0150] Next, an element placement step is performed (step S110). In the element placement step of the manufacturing method Pra, a semiconductor element S1 is placed on the upper surface of the conductor layer 12 of the insulating substrate 10 via a plate-shaped bonding material b1.

[0151] Next, a heating step A1 is performed. In the heating step A1, the bonding material b1 is heated so as to melt the bonding material b1. The bonding material b1 is heated using a reflow furnace. The bonding material b1 is heated so that the temperature of the bonding material b1 rises to 280°C. As a result, the semiconductor element S1 is bonded to the upper surface of the conductor layer 12 of the insulating substrate 10 by the bonding material b1.

[0152] Next, as in the first embodiment, a bonding material placement step is performed (step S120). As a result, a thermosetting bonding material b2 is placed on the upper surface of the conductive member. The conductive member is the electrode e5 provided on the upper surface of the semiconductor element S1.

[0153] Next, an insert molding process is performed. In the insert molding process, the electrode plate E1 and the lead terminal 62 are fixed to the case 5 by insert molding. In FIG. 8(a), the portion of the electrode plate E1 that is exposed to the outside of the case 5 is the lead terminal 61.

[0154] The timing of performing the insert molding step is not limited to the timing after the bonding material placement step, and the insert molding step may be performed in parallel with the element placement step, for example.

[0155] Next, a heating step A2 is performed. In the heating step A2, the bonding material b2 is heated so as to melt the bonding material b2. The heating step A2 may be performed after the following electrode plate arrangement step.

[0156] Next, an electrode plate arrangement step and a case joining step are carried out in parallel.

[0157] In the electrode plate arrangement step, the electrode plate E1 is arranged on the bonding material b2 so that the back surface E1r of the electrode plate E1 contacts the bonding material b2, thereby bonding the electrode plate E1 to the electrode e5 of the semiconductor element S1 (see FIG. 8(b)).

[0158] The case joining process is a process of joining the case 5 to the insulating substrate 10 via an adhesive 80. In the case joining process, the case 5, which has the adhesive 80 applied to its inner surface as shown in Fig. 8(a), is joined to the insulating substrate 10 via the adhesive 80 (see Fig. 8(b)).

[0159] Next, a terminal connecting step is performed as in embodiment 1. In the terminal connecting step of manufacturing method Pra, lead terminal 62 fixed to case 5 is electrically connected to signal electrode g1 (not shown) of semiconductor element S1b, which serves as semiconductor element S1, by wire W1.

[0160] Next, the sealing process F is performed. In the sealing process F, a fluid sealing material 84 is injected into the case 5. The sealing material 84 is then cured. As a result, a plurality of components are sealed within the sealing material 84. The plurality of components include the insulating substrate 10, the semiconductor element S1, the lead terminals 62, the electrode plate E1, the wire W1, etc.

[0161] In this way, the semiconductor device 100A shown in FIG. 8(c) is manufactured.

[0162] (Joining method) Next, a description will be given of the bonding method Pc. The bonding method Pc of the present embodiment is a method for bonding a lead terminal 61, which is an electrode plate E1 included in the semiconductor device 100A of FIG. 8(c), to a terminal 64 (i.e., a conductive member) of the device A.

[0163] Next, a joining method Pc of the present embodiment will be described with reference to Fig. 7(a). In the joining method Pc, a joining step N is performed as in embodiment 1. In the joining step N, a laser beam L1 is irradiated onto a recess V1 formed on a main surface E1s of the electrode plate E1 so that the state of the electrode plate E1 becomes the above-mentioned joined state Stc.

[0164] In the bonding step N, as shown in FIG. 7(a), the back surface E1r of the lead terminal 61, which is the electrode plate E1, is bonded to the terminal 64, which is the conductive member, via the bonding material b6.

[0165] (summary) As described above, according to this embodiment, the semiconductor device 100A using the case 5 can achieve the same effects as those of the first embodiment. For example, a highly reliable semiconductor device can be provided. In addition, for example, the solderability of the lead terminals 61 can be improved.

[0166] <Third Embodiment> (composition) Fig. 9 is a cross-sectional view for explaining the configuration of a semiconductor device 100B according to embodiment 3. Fig. 9 shows a terminal 64 of the device A described above, which is not included in the semiconductor device 100B.

[0167] Hereinafter, the two electrode plates E1 joined together by the bonding material will also be referred to as "joined electrode plates." The shape of the joined electrode plates of this embodiment is similar to the shape of the electrode plate E1 in the semiconductor device 100A of FIG. 7(a), for example. The size of the joined electrode plates of this embodiment is equivalent to the size of the electrode plate E1 in the semiconductor device 100A.

[0168] The bonded electrode plate includes two electrode plates E1 bonded to each other. Each electrode plate E1 included in the bonded electrode plate has a main surface E1s and a back surface E1r. Each electrode plate E1 included in the bonded electrode plate is made of, for example, copper. The size of each electrode plate E1 included in the bonded electrode plate is smaller than the size of the electrode plate E1 included in the semiconductor device 100A.

[0169] Hereinafter, the two electrode plates E1 included in the joining electrode plate will also be referred to as electrode plates E1a and E1b, respectively. Each of the electrode plates E1a and E1b is a conductive member. Each of the electrode plates E1a and E1b has a plate-like shape. The electrode plates E1a and E1b are not bent. The size of each of the electrode plates E1a and E1b is smaller than the size of the electrode plate E1 included in the semiconductor device 100A.

[0170] The semiconductor device 100B differs from the semiconductor device 100A of FIG. 7(a) in that a bonding electrode plate is used instead of the electrode plate E1 of the semiconductor device 100A. That is, the semiconductor device 100B has a configuration using a bonding electrode plate. The other configurations of the semiconductor device 100B are the same as those of the semiconductor device 100A. Below, the differences between the semiconductor device 100B and the semiconductor device 100A will be mainly described.

[0171] The electrode plate E1a is joined to an electrode plate E1b, which is a conductive member, via a bonding material b3. The joined electrode plate is formed by joining the electrode plate E1a to the electrode plate E1b via the bonding material b3.

[0172] The electrode plate E1a is electrically connected to the electrode plate E1b. Specifically, the back surface E1r of the electrode plate E1a is joined to the electrode plate E1b via a bonding material b3. The bonding material b3 is in contact with the back surface E1r of the electrode plate E1a and the electrode plate E1b.

[0173] The bonding material b3 has the same configuration as the bonding material b1. The bonding material b3 has thermosetting properties. The bonding material b3 is, for example, solder. The material constituting the bonding material b3 is the same as the material constituting the bonding material b1.

[0174] The electrode plate E1a and the lead terminal 62 are fixed to the case 5 by insert molding. The electrode plate E1a and the lead terminal 62 are integrated with the case 5.

[0175] The case 5 accommodates multiple components included in the semiconductor device 100B. The multiple components are the insulating substrate 10, multiple semiconductor elements S1, electrode plates E1a and E1b, wires W1, etc. That is, the case 5 accommodates at least the semiconductor element S1.

[0176] Semiconductor elements S1a and S1b, which are part of the semiconductor element S1, are mounted on each conductor layer 12 of the insulating substrate 10 of the semiconductor device 100B with a bonding material b1.

[0177] The semiconductor device 100B operates using the electrode plates E1a and E1b, which are the electrode plate E1. That is, the semiconductor device 100B uses the electrode plates E1a and E1b.

[0178] Furthermore, the electrode e5 of the semiconductor element S1a and the electrode e5 of the semiconductor element S1b are connected to the electrode plate E1b via the bonding material b2. That is, the electrode plate E1b is bonded to the semiconductor element S1. That is, the electrode plate E1b is electrically connected to the semiconductor element S1. The bonding material b2 is in contact with the back surface E1r of the electrode plate E1b and the electrode e5 of the semiconductor element S1.

[0179] As described above, the electrode plate E1a is electrically connected to the electrode plate E1b, and therefore the electrode plate E1a is electrically connected to the semiconductor element S1.

[0180] The signal electrode g1 of the semiconductor element S1b is connected to the lead terminal 62 by a wire W1.

[0181] Furthermore, a sealing material 84 is provided inside the case 5. The sealing material 84 mainly seals the insulating substrate 10, the plurality of semiconductor elements S1, the electrode plates E1a and E1b, the wires W1, and the like.

[0182] A part of the electrode plate E1a in the semiconductor device 100B is a lead terminal 61. That is, the lead terminal 61 is the electrode plate E1a as the electrode plate E1. The lead terminal 61 in the semiconductor device 100B is a part of the electrode plate E1a as the electrode plate E1 that is exposed to the outside of the case 5. Note that the entire electrode plate E1a may be the lead terminal 61. The lead terminal 61, which is the electrode plate E1a as the electrode plate E1, has a main surface E1s and a back surface E1r.

[0183] The semiconductor device 100B is electrically connected to a terminal 64 of the device A (not shown). Specifically, the lead terminal 61, which is the electrode plate E1a, is joined to the terminal 64 of the device A.

[0184] A recess V1 is formed in the main surface E1s of the lead terminal 61, which is the electrode plate E1a.

[0185] The configuration of the recess V1 in this embodiment is the same as the configuration of the recess V1 in embodiment 1. For example, in this embodiment, the shape of the recess V1 in plan view is rectangular.

[0186] Hereinafter, the portion of the electrode plate E1a that is joined to the electrode plate E1b will also be referred to as the "electrode junction portion." The electrode junction portion is an end portion of the electrode plate E1a. A recess V2 is formed in the electrode junction portion of the electrode plate E1a. Specifically, the recess V2 is formed in the main surface E1s of the electrode junction portion of the electrode plate E1a. That is, the recess V1 and the recess V2 are formed in the main surface E1s of the electrode plate E1a.

[0187] The configuration of the recess V2 is the same as the configuration of the recess V1. The depth of the recess V2 is, for example, 0.3 mm. The shape of the recess V2 in plan view is rectangular. The size of the rectangle that is the shape of the recess V2 is, for example, a size expressed as "width 8 mm x 6 mm."

[0188] The recess V2 is located away from the outer periphery of the main surface E1s of the electrode plate E1a, that is, away from the edge of the main surface E1s.

[0189] (Manufacturing method) Next, an example of a manufacturing method for the semiconductor device 100B will be described with reference to Figures 10 and 11. Hereinafter, the manufacturing method for the semiconductor device 100B will also be referred to as "manufacturing method Prb." Except for some processing steps, the manufacturing method Prb is similar to the manufacturing method Pra for the semiconductor device 100A.

[0190] Fig. 10 is a flowchart of a manufacturing method Prb according to embodiment 3. Fig. 10 shows only main steps included in the manufacturing method Prb. Fig. 11 is a cross-sectional view for explaining the manufacturing method Prb according to embodiment 3.

[0191] Here, the method for manufacturing the semiconductor device 100B Prb will be described, focusing on the differences from the manufacturing method Pra in embodiment 2. In the following, to make the description of the manufacturing method Prb easier to understand, each of the semiconductor elements S1a and S1b will be described as the semiconductor element S1.

[0192] In the manufacturing method Prb, an initial step B is first performed. In the initial step B, a plurality of components used in manufacturing the semiconductor device 100B are prepared. FIG. 11(a) shows some of the plurality of components. The plurality of components include an insulating substrate 10, a semiconductor element S1, bonding materials b1 and b2, an electrode plate E1b, and the like. Each of the prepared bonding materials b1 and b2 has a plate shape.

[0193] 11(b) shows the case 5, the lead terminal 62, the electrode plate E1a, etc. as other parts of the plurality of members to be prepared. Recesses V1 and V2 are formed in advance on the main surface E1s of the prepared electrode plate E1a.

[0194] Next, an element placement step is performed (step S110). In the element placement step of the manufacturing method Prb, a semiconductor element S1 is placed on the upper surface of the conductor layer 12 of the insulating substrate 10 via a plate-shaped bonding material b1.

[0195] Next, a bonding material placement process is performed (step S120). The bonding material placement process is a process of placing a bonding material b2 on the upper surface of a conductive member. The bonding material b2 has thermosetting properties. The conductive member is an electrode e5 provided on the upper surface of the semiconductor element S1. In the bonding material placement process, a plate-shaped bonding material b2 is placed on the upper surface of the electrode e5 of the semiconductor element S1.

[0196] Next, an electrode plate arrangement process B is performed (step S130B). The electrode plate arrangement process B is a process of arranging the electrode plate E1b, which is the electrode plate E1, on the bonding material b2 so that the back surface E1r of the electrode plate E1b contacts the bonding material b2. In the electrode plate arrangement process B, the electrode plate E1b is arranged on the bonding material b2 so that the back surface E1r of the electrode plate E1b contacts the bonding material b2.

[0197] Next, the heating step N is performed as in the first embodiment. In the heating step N, the bonding materials b1 and b2 are heated so as to melt the bonding materials b1 and b2. As a result, the semiconductor element S1 is bonded to the upper surface of the conductor layer 12 of the insulating substrate 10 by the bonding material b1 (see FIG. 11(b)). In addition, the electrode plate E1b is bonded to the electrode e5 of the semiconductor element S1. That is, the electrode plate E1b is bonded to the semiconductor element S1.

[0198] Next, an insert molding process B is performed. In the insert molding process B, the electrode plate E1a and the lead terminal 62 are fixed to the case 5 by insert molding (see FIG. 11(b)). Here, the portion of the electrode plate E1a, which is the electrode plate E1, that is exposed to the outside of the case 5 is the lead terminal 61.

[0199] The timing at which the insert molding step B is performed is not limited to the timing after the electrode plate arrangement step B. The insert molding step B may be performed in parallel with the element arrangement step, for example.

[0200] Next, a bonding material placement process B is performed (step S131B). The bonding material placement process B is a process of placing a bonding material b3 on the upper surface of a conductive member. The bonding material b3 has thermosetting properties. The conductive member is an electrode plate E1b that is bonded to the semiconductor element S1. In the bonding material placement process B, a plate-shaped bonding material b3 is placed on the main surface E1s, which is the upper surface of the electrode plate E1b.

[0201] Next, the electrode plate arrangement process Ba is performed (step S132B). Also, the case joining process is performed in parallel with the electrode plate arrangement process Ba.

[0202] The electrode plate arrangement process Ba is a process of arranging the electrode plate E1a, which is the electrode plate E1, on the bonding material b3 so that the back surface E1r of the electrode plate E1a contacts the bonding material b3. The electrode plate E1a is an electrode fixed to the case 5 by the insert molding process B described above.

[0203] In the electrode plate arrangement process Ba, the electrode plate E1a is arranged on the bonding material b3 so that the back surface E1r of the electrode plate E1a contacts the bonding material b3. Furthermore, the electrode plate E1a is arranged so that the recess V2 of the electrode plate E1a overlaps the bonding material b3 in a plan view. As a result, the bonding material b3 is sandwiched between the electrode plates E1a and E1b.

[0204] In addition, in the case joining process of manufacturing method Prb, the case 5, which has adhesive 80 applied to its inner surface as shown in Figure 11(b), is joined to the insulating substrate 10 via the adhesive 80 (see Figure 11(c)).

[0205] Next, the joining process B is performed (step S133B). The joining process B is a process of irradiating the laser light L1 onto the recess V2 formed on the main surface E1s of the electrode plate E1a so that the state of the electrode plate E1a becomes the above-mentioned joined state Stc.

[0206] The bonded state Stc of this embodiment includes a state St1a and a state St1b. In the state St1a of this embodiment, the back surface E1r of the electrode plate E1a is bonded to the electrode plate E1b, which is a conductive member, via the bonding material b3. In the state St1b of this embodiment, the recess V2 formed on the main surface E1s of the electrode plate E1a is separated from the bonding material b3.

[0207] Specifically, in the joining step B, an irradiation process B is performed. In the irradiation process B, a laser beam L1 is irradiated onto the bottom of the recess V2. As described above, the irradiation of the laser beam L1 is also referred to as "laser beam irradiation." The laser beam irradiation in the manufacturing method Prb is the irradiation of the laser beam L1 onto the bottom of the recess V2.

[0208] Specifically, in the irradiation process B, the bonding material b3 is heated by laser light irradiation so as to melt the bonding material b3. The heating of the bonding material b3 is performed so that the bonding material b3 is melted by the heat generated in the electrode plate E1a by the laser light irradiation. The heating of the bonding material b3 (i.e., the laser light irradiation) is terminated after the bonding material b3 is melted. When the heating of the bonding material b3 is terminated, the bonding material b3 hardens again.

[0209] This completes the irradiation process B. As a result, the rear surface E1r of the electrode plate E1a is bonded to the electrode plate E1b, which is a conductive member, via the bonding material b3, as shown in FIG.

[0210] Next, a terminal connecting step is performed in the same manner as in embodiment 2. In the terminal connecting step, the lead terminal 62 fixed to the case 5 is electrically connected to the signal electrode g1 (not shown) of the semiconductor element S1b as the semiconductor element S1 by the wire W1 (see FIG. 9).

[0211] Next, similarly to the second embodiment, the sealing process F is performed (step S140B). In the sealing process F, the sealant 84 having fluidity is injected into the case 5. Thereafter, the sealant 84 is hardened. As a result, the plurality of components are sealed in the sealant 84.

[0212] In this way, the semiconductor device 100B shown in FIG. 9 is manufactured.

[0213] (Joining method) Next, a description will be given of the bonding method Pc. The bonding method Pc of the present embodiment is a method for bonding a lead terminal 61, which is an electrode plate E1a included in the semiconductor device 100B of FIG. 9, to a terminal 64 (i.e., a conductive member) of the device A.

[0214] Next, a joining method Pc of the present embodiment will be described with reference to Fig. 9. In the joining method Pc, a joining step N is performed as in embodiment 2. In the joining step N, a laser beam L1 is irradiated onto a recess V1 formed on a main surface E1s of an electrode plate E1a, which is an electrode plate E1, so that the state of the electrode plate E1a becomes the above-described joined state Stc.

[0215] In the bonding step N, as shown in FIG. 9, the back surface E1r of the lead terminal 61, which is the electrode plate E1a (ie, the electrode plate E1), is bonded to the terminal 64, which is a conductive member, via the bonding material b6.

[0216] (summary) As described above, according to this embodiment, the semiconductor device 100B can also achieve the same effects as those of the first embodiment. The semiconductor device 100B has a configuration using a bonded electrode plate. The bonded electrode plate is formed by bonding an electrode plate E1a to an electrode plate E1b via a bonding material b3. The electrode plate E1a is fixed to the case 5 by insert molding. The electrode plate E1b is bonded to the semiconductor element S1 mounted on the insulating substrate 10.

[0217] This ensures a degree of tolerance for vertical positional deviation of the electrode plate E1b due to warping of the insulating substrate 10, for example.

[0218] <Fourth Embodiment> (composition) Fig. 12 is a cross-sectional view for explaining the configuration of a semiconductor device 100C according to embodiment 4. Fig. 12 shows a terminal 64 of the device A described above, which is not included in the semiconductor device 100C.

[0219] 7(a) in that the semiconductor device 100C has a plurality of recesses formed in the electrode plate E1. The rest of the configuration of the semiconductor device 100C is the same as that of the semiconductor device 100A. Below, the differences between the semiconductor device 100C and the semiconductor device 100A will be mainly described.

[0220] Hereinafter, the electrode plate E1 included in the semiconductor device 100C will also be referred to as "electrode plate E1c." The electrode plate E1c has a main surface E1s and a back surface E1r. The electrode plate E1c is curved. However, the electrode plate E1c does not have to be curved.

[0221] Electrode plate E1c differs from electrode plate E1 in Fig. 7(a) in that recesses V3 are further formed on the main surface E1s. Other configurations of electrode plate E1c are the same as those of electrode plate E1 in Fig. 7(a). Two recesses V3 are formed on the main surface E1s of electrode plate E1c. The number of recesses V3 formed on the main surface E1s of electrode plate E1c is not limited to two, and may be one or three or more.

[0222] The configuration of the recess V3 is the same as the configuration of the recess V1. The depth of the recess V3 is, for example, 0.3 mm. The shape of the recess V3 in plan view is rectangular. The size of the rectangle that is the shape of the recess V3 is, for example, a size expressed as "width 8 mm x 6 mm."

[0223] The recess V3 is located away from the outer periphery of the main surface E1s of the electrode plate E1c, which is the electrode plate E1. In other words, the recess V3 is located away from the edge of the main surface E1s.

[0224] Furthermore, the recess V3 formed on the main surface E1s of the electrode plate E1c is located above the semiconductor element S1. That is, in a plan view, the recess V3 overlaps with the semiconductor element S1.

[0225] Hereinafter, the two recesses V3 formed on the main surface E1s of the electrode plate E1c will also be referred to as recesses V3a and V3b, respectively. The recess V3a, which is recess V3, is located above the semiconductor element S1a, which is the semiconductor element S1. The recess V3b, which is recess V3, is located above the semiconductor element S1b, which is the semiconductor element S1.

[0226] The electrode plate E1c is bonded to the semiconductor element S1 via a bonding material b2. That is, the electrode plate E1c is electrically connected to the semiconductor element S1. The bonding material b2 is in contact with the back surface E1r of the electrode plate E1c and the electrode e5 of the semiconductor element S1.

[0227] (Manufacturing method) Next, an example of a manufacturing method of the semiconductor device 100C will be described with reference to Figures 13 and 14. Hereinafter, the manufacturing method of the semiconductor device 100C will also be referred to as "manufacturing method Prc." Except for some processing, the manufacturing method Prc is similar to the manufacturing method Pra of the semiconductor device 100A.

[0228] Fig. 13 is a flowchart of a manufacturing method Prc according to embodiment 4. Fig. 13 shows only main steps included in the manufacturing method Prc. Fig. 14 is a cross-sectional view for explaining the manufacturing method Prc according to embodiment 4.

[0229] Here, the manufacturing method Prc of the semiconductor device 100C will be described, focusing on the differences from the manufacturing method Pra in the second embodiment. Hereinafter, for ease of understanding of the manufacturing method Prc, each of the semiconductor elements S1a and S1b will be described as a semiconductor element S1. Also, each of the recesses V3a and V3b will be described as a recess V3.

[0230] In the manufacturing method Prc, an initial step C is first performed. In the initial step C, a plurality of components used in manufacturing the semiconductor device 100C are prepared. FIG. 14(a) shows some of the plurality of components. The plurality of components include an insulating substrate 10, a semiconductor element S1, and bonding materials b1 and b2. Each of the prepared bonding materials b1 and b2 has a plate shape.

[0231] 14(b) shows the case 5, the lead terminal 62, the electrode plate E1c, etc. as other parts of the plurality of members to be prepared. Recesses V1 and V3 are formed in advance on the main surface E1s of the prepared electrode plate E1c.

[0232] Next, an element placement step is performed (step S110) in the same manner as in the second embodiment. In the element placement step of the manufacturing method Prc, a semiconductor element S1 is placed on the upper surface of the conductor layer 12 of the insulating substrate 10 via a plate-shaped bonding material b1.

[0233] Next, a heating step A1 is performed. In the heating step A1, the bonding material b1 is heated so as to melt the bonding material b1. The bonding material b1 is heated using a reflow furnace. The bonding material b1 is heated so that the temperature of the bonding material b1 rises to 280°C. As a result, the semiconductor element S1 is bonded to the upper surface of the conductor layer 12 of the insulating substrate 10 by the bonding material b1.

[0234] Next, as in the second embodiment, a bonding material placement step is performed (step S120). The bonding material placement step of manufacturing method Prc is a step of placing a bonding material b2 on the upper surface of a conductive member. The bonding material b2 has thermosetting properties. The conductive member is an electrode e5 provided on the upper surface of the semiconductor element S1. In the bonding material placement step of manufacturing method Prc, a plate-shaped bonding material b2 is placed on the upper surface of the electrode e5, which is a conductive member provided on the semiconductor element S1.

[0235] Next, an insert molding process C is performed. In the insert molding process C, the electrode plate E1c and the lead terminal 62 are fixed to the case 5 by insert molding. In FIG. 14(b), the portion of the electrode plate E1c that is exposed to the outside of the case 5 is the lead terminal 61.

[0236] The timing of performing the insert molding step C is not limited to the timing after the bonding material arranging step, and the insert molding step C may be performed in parallel with the element arranging step, for example.

[0237] Next, a heating step A2 is performed. In the heating step A2, the bonding material b2 is heated so as to melt the bonding material b2. The heating step A2 may be performed after the electrode plate arrangement step C described below.

[0238] Next, the electrode plate arrangement step C is performed (step S130C). In addition, the case joining step is performed in parallel with the electrode plate arrangement step C.

[0239] The electrode plate arrangement process C is a process of arranging the electrode plate E1c, which is the electrode plate E1, on the bonding material b2 so that the back surface E1r of the electrode plate E1c contacts the bonding material b2. The electrode plate E1c is an electrode fixed to the case 5 by the insert molding process C described above.

[0240] In the electrode plate arrangement process C, the electrode plate E1c is arranged on the bonding material b2 so that the back surface E1r of the electrode plate E1c contacts the bonding material b2. Furthermore, the electrode plate E1c is arranged so that the recess V3 of the electrode plate E1c overlaps the bonding material b2 in a plan view. That is, the recess V3 and the bonding material b2 are positioned. Furthermore, the electrode plate E1c is arranged so that the recess V3 of the electrode plate E1c overlaps the semiconductor element S1 in a plan view.

[0241] In addition, in the case joining process of manufacturing method Prc, the case 5, which has adhesive 80 applied to its inner surface as shown in Figure 14(b), is joined to the insulating substrate 10 via the adhesive 80 (see Figure 14(c)).

[0242] Next, the joining process C is performed (step S133C). The joining process C is a process of irradiating the laser light L1 onto the recess V3 formed on the main surface E1s of the electrode plate E1c so that the state of the electrode plate E1c becomes the above-mentioned joined state Stc.

[0243] The bonding state Stc of this embodiment includes a state St1a and a state St1b. In the state St1a of this embodiment, the back surface E1r of the electrode plate E1c is bonded to the electrode e5, which is a conductive member, via the bonding material b2. The electrode e5 is an electrode provided on the upper surface of the semiconductor element S1.

[0244] In the state St1b of this embodiment, the recess V3 formed on the main surface E1s of the electrode plate E1c is separated from the bonding material b2.

[0245] Specifically, in the joining step C, an irradiation process C is performed. In the irradiation process C, a laser beam L1 is irradiated onto the bottom of the recess V3. As described above, the irradiation of the laser beam L1 is also referred to as "laser beam irradiation." The laser beam irradiation in the manufacturing method Prc is the irradiation of the laser beam L1 onto the bottom of the recess V3.

[0246] Specifically, in the irradiation process C, the bonding material b2 is heated by laser light irradiation so as to melt the bonding material b2. The heating of the bonding material b2 is performed so that the bonding material b2 is melted by the heat generated in the electrode plate E1c by the laser light irradiation. The heating of the bonding material b2 (i.e., the laser light irradiation) is terminated after the bonding material b2 is melted. When the heating of the bonding material b2 is terminated, the bonding material b2 hardens again.

[0247] This completes the irradiation process C. As a result, as shown in Fig. 14(c), the back surface E1r of the electrode plate E1c is bonded to the electrode e5, which is a conductive member, via the bonding material b2. The electrode e5 is an electrode provided on the upper surface of the semiconductor element S1.

[0248] Next, a terminal connecting step is performed in the same manner as in embodiment 2. In the terminal connecting step, the lead terminal 62 fixed to the case 5 is electrically connected to the signal electrode g1 (not shown) of the semiconductor element S1b as the semiconductor element S1 by the wire W1 (see FIG. 12).

[0249] Next, similarly to the second embodiment, the sealing process F is performed (step S140B). In the sealing process F, the sealant 84 having fluidity is injected into the case 5. Thereafter, the sealant 84 is hardened. As a result, the plurality of components are sealed in the sealant 84.

[0250] In this way, the semiconductor device 100C shown in FIG. 12 is manufactured.

[0251] (Joining method) Next, a description will be given of the bonding method Pc. The bonding method Pc of the present embodiment is a method for bonding a lead terminal 61, which is an electrode plate E1c included in the semiconductor device 100C of FIG. 12, to a terminal 64 (i.e., a conductive member) of the device A.

[0252] Next, a joining method Pc of the present embodiment will be described with reference to Fig. 12. In the joining method Pc, a joining step N is performed as in embodiment 2. In the joining step N, a laser beam L1 is irradiated onto a recess V1 formed on a main surface E1s of an electrode plate E1c, which is an electrode plate E1, so that the state of the electrode plate E1c becomes the above-described joined state Stc.

[0253] In the bonding step N, as shown in FIG. 12, the back surface E1r of the lead terminal 61, which is the electrode plate E1c (ie, the electrode plate E1), is bonded to the terminal 64, which is a conductive member, via the bonding material b6.

[0254] (summary) As described above, according to this embodiment, the recess V3 formed on the main surface E1s of the electrode plate E1c is located above the semiconductor element S1. Hereinafter, the portion of the electrode plate E1c located above the semiconductor element S1 will also be referred to as the "element corresponding portion." The element corresponding portion is a part of the electrode plate E1c. The back surface E1r of the element corresponding portion of the electrode plate E1c contacts the bonding material b2.

[0255] A recess V3 is formed on the main surface E1s of the element-corresponding portion of the electrode plate E1c. This reduces the heat capacity of the element-corresponding portion of the electrode plate E1c. Furthermore, when the above-mentioned irradiation process C is performed in which the bottom of the recess V3 is irradiated with laser light L1, the heat conduction to the bonding material b2 can be improved.

[0256] <Fifth Embodiment> Here, a power conversion device to which any one of the above-described semiconductor devices 100, 100A, 100B, and 100C is applied will be described. Although the present disclosure is not limited to a specific power conversion device, a case in which any one of the semiconductor devices 100, 100A, 100B, and 100C is applied to a three-phase inverter will be described below as a fifth embodiment.

[0257] Fig. 15 is a block diagram showing the configuration of a power conversion system to which a power conversion device according to embodiment 5 is applied. The power conversion system shown in Fig. 15 includes a power supply Pw1, a power conversion device 200, and a load 300. The power supply Pw1 is a DC power supply. The power supply Pw1 supplies DC power to the power conversion device 200. The power supply Pw1 may be made up of various elements. The power supply Pw1 may be made up of, for example, a DC system, a solar cell, a storage battery, or the like.

[0258] The power supply Pw1 may also be configured by a rectifier circuit or an AC / DC converter connected to an AC system, or a DC / DC converter that converts DC power output from a DC system into a predetermined power.

[0259] The power conversion device 200 is a three-phase inverter connected between a power source Pw1 and a load 300. The power conversion device 200 converts DC power supplied from the power source Pw1 into AC power and supplies the AC power to the load 300. As shown in FIG. 15 , the power conversion device 200 includes a main conversion circuit 201 and a control circuit 203. The main conversion circuit 201 converts and outputs power input to the main conversion circuit 201. Specifically, the main conversion circuit 201 converts DC power into AC power and outputs the AC power.

[0260] The control circuit 203 outputs a control signal for controlling the main conversion circuit 201 to the main conversion circuit 201 .

[0261] The load 300 is a three-phase motor driven by AC power supplied from the power conversion device 200. The load 300 is not limited to a specific application and may be a motor mounted on various types of electrical equipment. The load 300 is used, for example, as a motor for a hybrid vehicle, an electric vehicle, a railroad car, an elevator, or an air conditioning device.

[0262] The power conversion device 200 will be described in detail below. The main conversion circuit 201 includes a switching element (not shown) and a free wheel diode (not shown). When the switching element is switched, DC power supplied from the power source Pw1 is converted into AC power, and the AC power is supplied to the load 300.

[0263] There are various specific circuit configurations for the main conversion circuit 201. The main conversion circuit 201 according to this embodiment is a two-level three-phase full-bridge circuit. The main conversion circuit 201 is composed of, for example, six switching elements and six freewheeling diodes. The six switching elements are connected in anti-parallel to the six freewheeling diodes.

[0264] At least one of the switching elements and freewheeling diodes of the main conversion circuit 201 is configured by a semiconductor module 202. The semiconductor module 202 corresponds to any one of the semiconductor devices 100, 100A, 100B, and 100C described above. That is, the main conversion circuit 201 includes a semiconductor module 202 corresponding to any one of the semiconductor devices 100, 100A, 100B, and 100C.

[0265] The main conversion circuit 201 includes three upper and lower arms configured using six switching elements. Each of the three upper and lower arms is configured with two switching elements connected in series. The three upper and lower arms correspond to the U phase, V phase, and W phase of the full-bridge circuit, respectively. The output terminals of the three upper and lower arms correspond to the three output terminals of the main conversion circuit 201. The three output terminals of the main conversion circuit 201 are connected to the load 300.

[0266] The main conversion circuit 201 also includes a drive circuit (not shown) that drives each switching element. The drive circuit may be built into the semiconductor module 202. The main conversion circuit 201 may also include a drive circuit separate from the semiconductor module 202.

[0267] The drive circuit generates drive signals that drive the switching elements of the main conversion circuit 201 and supplies the drive signals to the control electrodes of the switching elements of the main conversion circuit 201. Specifically, the drive circuit outputs a drive signal that turns the switching element on and a drive signal that turns the switching element off to the control electrodes of each switching element in accordance with control signals from a control circuit 203, which will be described later.

[0268] When the switching element is maintained in the ON state, the drive signal is a voltage signal equal to or greater than the threshold voltage of the switching element (i.e., an ON signal). When the switching element is maintained in the OFF state, the drive signal is a voltage signal less than the threshold voltage of the switching element (i.e., an OFF signal).

[0269] The control circuit 203 controls the switching elements of the main conversion circuit 201 so that a desired power is supplied to the load 300. Specifically, the control circuit 203 calculates the on-time, which is the time for which each switching element of the main conversion circuit 201 should be in the on-state, based on the power to be supplied to the load 300. The control circuit 203 can control the main conversion circuit 201, for example, by PWM control. The PWM control is a control that modulates the on-time of the switching elements according to the voltage to be output.

[0270] The control circuit 203 then outputs a control signal as a control command to the drive circuit included in the main conversion circuit 201. This control signal is a signal for outputting an ON signal to a switching element that should be in an ON state at each point in time. The control signal is also a signal for outputting an OFF signal to a switching element that should be in an OFF state at each point in time. In accordance with this control signal, the drive circuit outputs an ON signal or an OFF signal as a drive signal to the control electrode of each switching element.

[0271] In the power conversion device according to this embodiment, at least one of the switching elements and free wheel diodes of the main conversion circuit 201 is configured by a semiconductor module 202. The semiconductor module 202 corresponds to any one of the semiconductor devices 100, 100A, 100B, and 100C described above. Therefore, the high reliability of the semiconductor module 202 can improve the reliability of the power conversion device.

[0272] In this embodiment, an example has been described in which any one of semiconductor devices 100, 100A, 100B, and 100C is applied to a two-level three-phase inverter, but the present disclosure is not limited to this, and any one of semiconductor devices 100, 100A, 100B, and 100C can be applied to various power conversion devices.

[0273] Although the present embodiment describes a two-level power conversion device, it may also be a three-level or multi-level power conversion device. When supplying power to a single-phase load, any of the semiconductor devices 100, 100A, 100B, and 100C may be applied to a single-phase inverter. When supplying power to a DC load or the like, any of the semiconductor devices 100, 100A, 100B, and 100C may also be applied to a DC / DC converter or an AC / DC converter.

[0274] Furthermore, the configuration of a power conversion device using any of semiconductor devices 100, 100A, 100B, and 100C is not limited to the configuration in which load 300 is an electric motor. Load 300 may be, for example, an electric discharge machine, a laser processing machine, an induction heating cooker, or a power supply device for a contactless power supply system. Furthermore, a power conversion device using any of semiconductor devices 100, 100A, 100B, and 100C may be used as a power conditioner for a solar power generation system, a power storage system, or the like.

[0275] (Other variations) It should be noted that the embodiments can be freely combined, and each embodiment can be modified or omitted as appropriate.

[0276] For example, any one of the semiconductor devices 100, 100A, 100B, and 100C is not limited to a power module, and any one of the semiconductor devices 100, 100A, 100B, and 100C may be, for example, a semiconductor module that operates at a low voltage.

[0277] Furthermore, for example, the above-described structure Cs2 may be applied to both or one of the recesses V2 and V3. The structure Cs2 is a structure in which the recess is formed of a plurality of grooves V1a.

[0278] Furthermore, for example, the aforementioned configuration Cs3 may be applied to both or one of the recesses V2 and V3. The configuration Cs3 is a configuration in which the cross-sectional shape of the recess along the depth direction of the recess is triangular. Furthermore, a plurality of recesses V2 to which the configuration Cs3 is applied may be formed. Furthermore, a plurality of recesses V3 to which the configuration Cs3 is applied may be formed.

[0279] Although the present disclosure has been described in detail, the above description is illustrative in all respects and is not restrictive. It is understood that countless variations not illustrated can be envisioned.

[0280] Various aspects of the present disclosure are summarized below as appendices.

[0281] (Appendix 1) A semiconductor device using an electrode plate electrically connected to a conductive member having conductivity, A semiconductor element; the electrode plate is electrically connected to the semiconductor element, the electrode plate has a first surface that is one surface and a second surface that is the other surface, the second surface of the electrode plate is a surface of the electrode plate opposite to the first surface, A recess is formed on the first surface of the electrode plate, the second surface of the electrode plate is joined to the conductive member via a thermosetting bonding material, The depression formed on the first surface of the electrode plate is spaced apart from the bonding material. Semiconductor device.

[0282] (Appendix 2) the recess is spaced from the outer periphery of the first surface of the electrode plate; 2. The semiconductor device according to claim 1.

[0283] (Appendix 3) the semiconductor device is electrically connected to a terminal of the device; the conductive member is the terminal of the device, A part or all of the electrode plates are lead terminals, the recess is formed in the lead terminal, the lead terminal is joined to the terminal of the device via the joining material; 3. The semiconductor device according to claim 1 or 2.

[0284] (Appendix 4) The terminal of the device has another recess formed therein. 4. The semiconductor device according to claim 3.

[0285] (Appendix 5) The semiconductor device further comprises: a case for accommodating at least the semiconductor element; The electrode plate is integrated with the case. 5. The semiconductor device according to claim 1.

[0286] (Appendix 6) the electrode plate is joined to another electrode plate, which is the conductive member, via the joining material; the other electrode plate is bonded to the semiconductor element, The semiconductor device further comprises: a case for accommodating at least the semiconductor element; the electrode plate is integrated with the case, The recess is formed in a portion of the electrode plate that is joined to the other electrode plate. 3. The semiconductor device according to claim 2.

[0287] (Appendix 7) the conductive member is an electrode provided on the semiconductor element, the recess formed on the first surface of the electrode plate is located above the semiconductor element; 3. The semiconductor device according to claim 2.

[0288] (Appendix 8) The cross-sectional shape of the depression along the depth direction of the depression is triangular. 8. The semiconductor device according to any one of claims 1 to 7.

[0289] (Appendix 9) a main conversion circuit including the semiconductor device according to any one of Supplementary Notes 1 to 8, which converts input power and outputs the converted power; a control circuit that outputs a control signal to the main conversion circuit to control the main conversion circuit; Power conversion device.

[0290] (Appendix 10) A method of manufacturing a semiconductor device using an electrode plate electrically connected to a conductive member having conductivity, comprising: The semiconductor device includes: A semiconductor element; the electrode plate is electrically connected to the semiconductor element, the electrode plate has a first surface that is one surface and a second surface that is the other surface, the second surface of the electrode plate is a surface of the electrode plate opposite to the first surface, A recess is formed on the first surface of the electrode plate, The manufacturing method includes: (a) placing a thermosetting bonding material on an upper surface of the conductive member; (b) placing the electrode plate on the bonding material such that the second surface of the electrode plate contacts the bonding material; (c) irradiating the recess formed on the first surface of the electrode plate with laser light so that the electrode plate is in a bonded state; The bonding state is a state in which the second surface of the electrode plate is joined to the conductive member via the joining material; the depression formed on the first surface of the electrode plate is separated from the bonding material. A method for manufacturing a semiconductor device.

[0291] (Appendix 11) the conductive member is a separate electrode plate joined to the semiconductor element; 11. A method for manufacturing a semiconductor device according to claim 10.

[0292] (Appendix 12) the conductive member is an electrode provided on the semiconductor element; 11. A method for manufacturing a semiconductor device according to claim 10. [Explanation of symbols]

[0293] 5 Case, 10 Insulating substrate, 61 Lead terminal, 64 Terminal, 100, 100A, 100B, 100C Semiconductor device, 200 Power conversion device, 201 Main conversion circuit, 202 Semiconductor module, 203 Control circuit, b1, b2, b3, b6 Bonding material, E1, E1a, E1b, E1c Electrode plate, e5 Electrode, S1, S1a, S1b Semiconductor element, V1, V2, V3, V3a, V3b, V4 Depression.

Claims

1. A semiconductor device using an electrode plate electrically connected to a conductive member having conductivity, A semiconductor element; the electrode plate is electrically connected to the semiconductor element, the electrode plate has a first surface that is one surface and a second surface that is the other surface, the second surface of the electrode plate is a surface of the electrode plate opposite to the first surface, A recess is formed on the first surface of the electrode plate, the second surface of the electrode plate is joined to the conductive member via a thermosetting bonding material, The depression formed on the first surface of the electrode plate is spaced apart from the bonding material. Semiconductor device.

2. the recess is spaced from the outer periphery of the first surface of the electrode plate; The semiconductor device according to claim 1 .

3. the semiconductor device is electrically connected to a terminal of the device; the conductive member is the terminal of the device, A part or all of the electrode plates are lead terminals, the recess is formed in the lead terminal, the lead terminal is joined to the terminal of the device via the joining material; The semiconductor device according to claim 1 .

4. The terminal of the device has another recess formed therein. The semiconductor device according to claim 3 .

5. The semiconductor device further comprises: a case for accommodating at least the semiconductor element; The electrode plate is integrated with the case. The semiconductor device according to claim 1 .

6. the electrode plate is joined to another electrode plate, which is the conductive member, via the joining material; the other electrode plate is bonded to the semiconductor element, The semiconductor device further comprises: a case for accommodating at least the semiconductor element; the electrode plate is integrated with the case, The recess is formed in a portion of the electrode plate that is joined to the other electrode plate. The semiconductor device according to claim 2 .

7. the conductive member is an electrode provided on the semiconductor element, the recess formed on the first surface of the electrode plate is located above the semiconductor element; The semiconductor device according to claim 2 .

8. The cross-sectional shape of the depression along the depth direction of the depression is triangular. The semiconductor device according to claim 1 .

9. a main conversion circuit including the semiconductor device according to any one of claims 1 to 8, which converts input power and outputs the converted power; a control circuit that outputs a control signal to the main conversion circuit to control the main conversion circuit; Power conversion device.

10. A method of manufacturing a semiconductor device using an electrode plate electrically connected to a conductive member having conductivity, comprising: The semiconductor device includes: A semiconductor element; the electrode plate is electrically connected to the semiconductor element, the electrode plate has a first surface that is one surface and a second surface that is the other surface, the second surface of the electrode plate is a surface of the electrode plate opposite to the first surface, A recess is formed on the first surface of the electrode plate, The manufacturing method includes: (a) placing a thermosetting bonding material on an upper surface of the conductive member; (b) placing the electrode plate on the bonding material such that the second surface of the electrode plate contacts the bonding material; (c) irradiating the recess formed on the first surface of the electrode plate with laser light so that the electrode plate is in a bonded state; The bonding state is a state in which the second surface of the electrode plate is joined to the conductive member via the joining material; the depression formed on the first surface of the electrode plate is separated from the bonding material. A method for manufacturing a semiconductor device.

11. the conductive member is a separate electrode plate joined to the semiconductor element; The method for manufacturing a semiconductor device according to claim 10.

12. the conductive member is an electrode provided on the semiconductor element; The method for manufacturing a semiconductor device according to claim 10.

Images