Semiconductor Devices

Abstract

To provide a semiconductor device that can be suppressed in degradation of electrical connection reliability.SOLUTION: A semiconductor device 10 has: a lower substrate 20; a semiconductor element 30 that has an electrode electrically connected to a wiring pattern 22 having a current input terminal 22A, and an electrode 32 provided at a side opposite to the electrode; and an upper substrate 40 provided at the electrode 32 side of the semiconductor element 30. The semiconductor device 10 has: a plurality of via wirings 80 penetrating through the upper substrate 40 in a thickness direction and connected to the electrode 32; a wiring pattern 62 provided on a top face of the upper substrate 40 and electrically connected to the electrode 32 via the plurality of via wirings 80; and a current output terminal 23A outputting current. The plurality of via wirings 80 have one or more via wirings 81 arranged at positions closest to the current output terminal 23A in an X-axis direction, and one or more via wirings 82 provided adjacent to the via wirings 81. A planar shape of the via wirings 81 is formed to be larger than a planar shape of the via wirings 82.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a semiconductor device. [Background technology]

[0002] Conventionally, a power semiconductor device (power module) that controls and supplies electric power has been known as a semiconductor device. This type of semiconductor device includes a semiconductor element mounted between a lower substrate and an upper substrate, a sealing resin provided between the lower substrate and the upper substrate and sealing the semiconductor element, and a wiring layer formed on the upper surface of the upper substrate. The wiring layer formed on the upper surface of the upper substrate is electrically connected to electrodes of the semiconductor element through a plurality of via wirings that penetrate the upper substrate in the thickness direction.

[0003] Incidentally, Patent Document 1 is disclosed as a prior art related to the above conventional technology. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-120902 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional semiconductor devices, when a current flows through a semiconductor element, current density may concentrate in some via wirings. This may cause heat generation in the via wiring where the current density is concentrated, which may lead to localized rupture of the via wiring. This localized rupture of the via wiring may result in a decrease in the reliability of the electrical connection between the wiring layer and the electrode of the semiconductor element. [Means for solving the problem]

[0006] According to one aspect of the present invention, a semiconductor device includes a lower substrate, a current input terminal to which a current is input, a first wiring pattern provided on an upper surface of the lower substrate, a first electrode electrically connected to the first wiring pattern, and a second electrode provided on the opposite side of the first electrode, the semiconductor device mounted on the upper surface of the lower substrate, an upper substrate provided on the second electrode side of the semiconductor element, a plurality of via wirings penetrating the upper substrate in a thickness direction and connected to the second electrode, a second wiring pattern provided on the upper surface of the upper substrate and electrically connected to the second electrode via the plurality of via wirings, and a current output terminal for outputting the current, the second wiring pattern being electrically connected to the current output terminal and extending from the second electrode toward the current output terminal in a first direction which is one of planar directions, the plurality of via wirings including one or more first via wirings arranged at a position closest to the current output terminal in the first direction and one or more second via wirings provided adjacent to the first via wiring, the planar shape of the first via wiring being formed larger than the planar shape of the second via wiring. [Effects of the Invention]

[0007] According to one aspect of the present invention, an effect is achieved in that a decrease in the reliability of electrical connection can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic plan view illustrating a semiconductor device according to an embodiment; [Figure 2] 1 is an enlarged plan view of a portion of a semiconductor device according to an embodiment; [Figure 3] 1 is a schematic cross-sectional view (cross-sectional view taken along line 3-3 in FIG. 1) illustrating a semiconductor device according to an embodiment. [Figure 4] 4 is a schematic cross-sectional view (cross-sectional view taken along line 4-4 in FIG. 1) illustrating a semiconductor device according to one embodiment. [Figure 5] FIG. 2 is a schematic plan view showing a current path of the semiconductor device according to the embodiment; [Figure 6] FIG. 10 is a schematic plan view showing a semiconductor device of a comparative example. [Figure 7] 10 is a graph showing simulation results of current density. [Figure 8] FIG. 10 is an enlarged plan view showing a part of a semiconductor device according to a modified example. [Figure 9] FIG. 10 is a schematic cross-sectional view showing a semiconductor device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment will be described below with reference to the accompanying drawings. For convenience, the accompanying drawings may show characteristic portions enlarged to make the features easier to understand, and the dimensional ratios of each component may differ from one drawing to another. Furthermore, in cross-sectional views, the hatching of some components is replaced with a matte finish, and some components are omitted, to make the cross-sectional structure of each component easier to understand. Each drawing illustrates mutually orthogonal X-, Y-, and Z-axes. In the following description, for convenience, the direction extending along the X-axis is referred to as the X-axis direction, the direction extending along the Y-axis is referred to as the Y-axis direction, and the direction extending along the Z-axis is referred to as the Z-axis direction. Furthermore, in this specification, "planar view" refers to viewing an object from the Z-axis direction, and "planar shape" refers to the shape of an object viewed from the Z-axis direction.

[0010] (Overall configuration of semiconductor device 10) First, the overall configuration of a semiconductor device 10 will be described with reference to FIGS. 1 to 4 is, for example, a power semiconductor device (power module) that controls and supplies power. An example of the semiconductor device 10 is a DC-DC converter.

[0011] The semiconductor device 10 has a lower substrate 20, one or more (one in this embodiment) semiconductor elements 30 mounted on the upper surface of the lower substrate 20, and an upper substrate 40 provided on the upper surface of the semiconductor element 30. The semiconductor device 10 has a wiring layer 21 provided on the upper surface of the lower substrate 20.

[0012] 3 and 4, the semiconductor device 10 includes a sealing resin 50 that is provided between the lower substrate 20 and the upper substrate 40 and seals the semiconductor element 30, and a wiring layer 60 that is electrically connected to the semiconductor element 30 and is provided on the upper surface of the upper substrate 40. The semiconductor element 30 is provided between the upper surface of the lower substrate 20 and the lower surface of the upper substrate 40. In the semiconductor device 10, the semiconductor element 30 is embedded between the lower substrate 20 and the upper substrate 40.

[0013] (Configuration of semiconductor element 30) The semiconductor element 30 is formed of, for example, silicon (Si) or silicon carbide (SiC). The semiconductor element 30 is, for example, a power semiconductor element, i.e., a power semiconductor element. For example, the semiconductor element 30 may be an insulated gate bipolar transistor (IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET), a diode, or the like. The semiconductor element 30 of this embodiment is a MOSFET. The planar shape of the semiconductor element 30 may be any shape and any size. The planar shape of the semiconductor element 30 is, for example, rectangular. The planar size of the semiconductor element 30 may be, for example, approximately 5 mm × 5 mm. The thickness of the semiconductor element 30 may be, for example, in the range of 50 μm to 600 μm.

[0014] 4, the semiconductor element 30 has, for example, an electrode 31 provided on the bottom surface side, and electrodes 32 and 33 provided on the top surface side. The semiconductor element 30 has, for example, a main body 34. The electrodes 32 and 33 are provided on the opposite side to the electrode 31. The electrode 31 is, for example, a drain electrode of a MOSFET. The electrode 32 is, for example, a source electrode of the MOSFET. The electrode 33 is, for example, a gate electrode of the MOSFET.

[0015] The electrodes 31, 32, and 33 may be made of a metal such as aluminum (Al) or copper (Cu), or an alloy containing at least one metal selected from these metals. If necessary, a surface treatment layer may be formed on the surfaces of the electrodes 31, 32, and 33. Examples of the surface treatment layer include a gold (Au) layer, a nickel (Ni) layer / Au layer (a metal layer formed by laminating a Ni layer and an Au layer in this order), and a Ni layer / palladium (Pd) layer / Au layer (a metal layer formed by laminating a Ni layer, a Pd layer, and an Au layer in this order). The Au layer, Ni layer, and Pd layer may be, for example, a metal layer formed by electroless plating (electroless plated metal layer). The Au layer is a metal layer made of Au or an Au alloy, the Ni layer is a metal layer made of Ni or an Ni alloy, and the Pd layer is a metal layer made of Pd or a Pd alloy.

[0016] The electrode 31 is formed, for example, on the lower surface of the main body portion 34. For example, the electrode 31 is formed so as to cover the entire lower surface of the main body portion 34. As shown in FIG. 2, the electrodes 32 and 33 are formed, for example, on the upper surface of the main body 34. In this embodiment, two electrodes 32 and one electrode 33 are provided on the upper surface of the main body 34. The two electrodes 32 are provided spaced apart from each other on the upper surface of the main body 34. The two electrodes 32 are provided side by side, for example, along the X-axis direction. Each electrode 32 has a recess 32X, for example, in the lower part of the figure. The electrode 33 is provided, for example, spaced apart from the electrode 32 on the upper surface of the main body 34. The electrode 33 is provided, for example, so as to fit inside the two recesses 32X in a plan view.

[0017] (Configuration of lower substrate 20) As shown in Fig. 1, the lower substrate 20 is formed in a flat plate shape. The lower substrate 20 is a ceramic substrate made of ceramics such as oxide ceramics or non-oxide ceramics. Examples of oxide ceramics include aluminum oxide (Al2O3) and zirconia (ZrO2). Examples of non-oxide ceramics include aluminum nitride (AlN) and silicon nitride (Si3N4).

[0018] The planar shape of the lower substrate 20 can be any shape and any size. For example, the planar shape of the lower substrate 20 is rectangular. The thickness of the lower substrate 20 can be, for example, in the range of 200 μm to 400 μm. FIG. 1 is a plan view of the semiconductor device 10 shown in FIGS. 3 and 4 as viewed from above. FIG. 2 is an enlarged plan view of a portion of the semiconductor device 10 shown in FIG. 1. In FIG. 2, the upper substrate 40, the sealing resin 50, and the wiring layer 60 are depicted in a perspective manner.

[0019] (Configuration of wiring layer 21) 1, the wiring layer 21 has, for example, a large number of wiring patterns. The wiring layer 21 of this embodiment has a wiring pattern 22, a wiring pattern 23, a wiring pattern 24, and a wiring pattern 25.

[0020] The wiring patterns 22, 23, 24, and 25 may be made of, for example, copper or a copper alloy. If necessary, a surface treatment layer may be formed on the surfaces (top and side surfaces, or only the top surfaces) of the wiring patterns 22, 23, 24, and 25. Examples of the surface treatment layer include a metal layer such as an Au layer, a Ni layer / Au layer, or a Ni layer / Pd layer / Au layer. The thickness of the wiring patterns 22, 23, 24, and 25 may be, for example, in the range of 100 μm to 800 μm.

[0021] The wiring patterns 22, 23, 24, and 25 are provided separately from one another on the upper surface of the lower substrate 20. The planar shapes of the wiring patterns 22, 23, 24, and 25 can be any shape and any size.

[0022] The planar shape of the wiring pattern 22 is formed, for example, in a rectangular shape. The wiring pattern 22 is formed, for example, in a strip shape having a predetermined width in the Y-axis direction, which is one of the planar directions, and extending in the X-axis direction, which is also one of the planar directions. The wiring pattern 22 is provided, for example, so that a portion of the wiring pattern 22 overlaps with the upper substrate 40 in a planar view, and the remaining portion of the wiring pattern 22 is exposed from the upper substrate 40. As shown in FIG. 3 , the wiring pattern 22 is electrically connected, for example, to an electrode 31 of the semiconductor element 30. That is, the wiring pattern 22 is electrically connected to the electrode 31, which serves as a drain electrode.

[0023] The wiring pattern 22 has, for example, a current input terminal 22A. The current input terminal 22A is provided, for example, on the upper surface of the wiring pattern 22 in a portion exposed from the upper substrate 40 and the sealing resin 50. The current input terminal 22A is electrically connected, for example, to an external electrode provided outside the semiconductor device 10. The current input terminal 22A is, for example, a connection terminal to which a current I1 is input from a circuit or a power supply provided outside the semiconductor device 10. The current input terminal 22A in this embodiment is a drain electrode terminal.

[0024] As shown in FIG. 1 , the planar shape of the wiring pattern 23 is, for example, rectangular. The wiring pattern 23 is, for example, formed in a strip shape having a predetermined width in the Y-axis direction and extending in the X-axis direction. The wiring pattern 23 is, for example, provided below the wiring pattern 22 in the drawing. The wiring pattern 23 is, for example, formed to extend parallel to the wiring pattern 22. The wiring pattern 23 is, for example, formed to have the same length as the wiring pattern 22 in the X-axis direction. The wiring pattern 23 is, for example, provided so that a portion of the wiring pattern 23 overlaps with the upper substrate 40 in a planar view, and the remaining portion of the wiring pattern 23 is exposed from the upper substrate 40. The wiring pattern 23 is, for example, electrically connected to the electrode 32 of the semiconductor element 30. That is, the wiring pattern 22 is electrically connected to the electrode 32 serving as a source electrode.

[0025] The wiring pattern 23 has, for example, a current output terminal 23A. The current output terminal 23A is provided, for example, on the upper surface of the wiring pattern 23 in a portion exposed from the upper substrate 40 and the sealing resin 50. The current output terminal 23A is electrically connected, for example, to an external electrode provided outside the semiconductor device 10. The current output terminal 23A is, for example, a connection terminal that outputs a current I1 (see FIG. 3 ) to a circuit or the like provided outside the semiconductor device 10. The current output terminal 23A in this embodiment is a source electrode terminal.

[0026] The planar shape of the wiring pattern 24 is, for example, rectangular. The wiring pattern 24 is, for example, formed in a strip shape having a predetermined width in the Y-axis direction and extending in the X-axis direction. The wiring pattern 24 is, for example, provided below the wiring pattern 23 in the figure. The wiring pattern 24 is, for example, formed so as to extend parallel to the wiring patterns 22 and 23. The wiring pattern 24 is, for example, formed longer in the X-axis direction than the wiring patterns 23 and 24. The wiring pattern 24 is, for example, provided so that a portion of the wiring pattern 24 overlaps with the upper substrate 40 in a plan view, and the remaining portion of the wiring pattern 24 is exposed from the upper substrate 40. The wiring pattern 24 is, for example, electrically connected to the electrode 33 of the semiconductor element 30. That is, the wiring pattern 24 is electrically connected to the electrode 33 serving as a gate electrode.

[0027] The wiring pattern 24 has, for example, a connection terminal 24A. The connection terminal 24A is provided on the upper surface of the wiring pattern 24 in a portion exposed from the upper substrate 40 and the sealing resin 50. The connection terminal 24A is electrically connected to, for example, an external electrode provided outside the semiconductor device 10. The connection terminal 24A is, for example, a gate electrode terminal.

[0028] The planar shape of the wiring pattern 25 is formed, for example, in a rectangular shape. The wiring pattern 25 is formed, for example, larger than the planar shapes of the wiring patterns 23, 24, and 25. The wiring pattern 25 is formed, for example, in a solid shape. For example, the wiring pattern 25 is formed on the upper surface of the lower substrate 20 so as to extend entirely over the right half region in the figure. The wiring pattern 25 is provided, for example, so as to entirely overlap with the upper substrate 40 in a planar view. The wiring pattern 25 is provided, for example, so as to overlap with the semiconductor element 30 in a planar view. The wiring pattern 25 is electrically connected, for example, to the electrodes 31 of the semiconductor element 30 (see FIG. 3).

[0029] (Configuration of joint 71) 3, the semiconductor element 30 is bonded to the upper surface of the wiring pattern 25 via a conductive bonding portion 71. The bonding portion 71 is bonded to the wiring pattern 25 and also to the electrode 31. The bonding portion 71 electrically connects the wiring pattern 25 and the electrode 31 of the semiconductor element 30.

[0030] 1, the semiconductor element 30 is provided, for example, so that its entirety overlaps the wiring pattern 25 in a planar view. The semiconductor element 30 is provided, for example, so that its entirety overlaps the upper substrate 40 in a planar view.

[0031] (Configuration of joint 72) As shown in FIG. 3, a conductive bonding portion 72 is formed on the upper surface of the wiring pattern 22. As shown in FIG. 4, a bonding portion 72 is formed on the upper surface of the wiring pattern 23. Although detailed illustration is omitted, a bonding portion 72 is also formed on the upper surface of the wiring pattern 24 shown in FIG. 1. A connection member 75 is formed on the upper surface of each bonding portion 72. The bonding portion 72 is bonded to the wiring pattern 22 (see FIG. 3), the wiring pattern 23, or the wiring pattern 24 (see FIG. 1), and is also bonded to the connection member 75. As shown in FIG. 3, the bonding portion 72 electrically connects the wiring pattern 22 and the connection member 75. As shown in FIG. 4, the bonding portion 72 electrically connects the wiring pattern 23 and the connection member 75. The bonding portion 72 electrically connects the wiring pattern 24 (see FIG. 1) and the connection member 75.

[0032] The bonding portions 71, 72 may be made of, for example, a metal sintered material. Examples of the sintered material include a sintered material (silver sintered material) primarily composed of silver (Ag) particles and a sintered material (copper sintered material) primarily composed of copper particles. The bonding portions 71, 72 may also be made of, for example, solder, conductive paste such as silver paste, or a metal brazing material. The thickness of the bonding portions 71, 72 may be, for example, in the range of 10 μm to 60 μm.

[0033] (Configuration of connecting member 75) The connection member 75 is electrically connected to the wiring layer 60 formed on the upper surface of the upper substrate 40. As a result, the wiring patterns 22, 23, and 24 are electrically connected to the wiring layer 60 via the joints 72 and the connection member 75. The connection member 75 is formed, for example, in a columnar shape extending along the stacking direction of the semiconductor device 10 (here, the Z-axis direction). The connection member 75 is, for example, a metal post. The connection member 75 is formed, for example, to have the same thickness as the semiconductor element 30. The thickness of the connection member 75 can be, for example, in the range of 50 μm to 775 μm. Note that the connection member 75 can be made of, for example, copper or a copper alloy.

[0034] (Configuration of upper substrate 40) The upper substrate 40 is provided on the electrode 32, 33 side of the semiconductor element 30. The upper substrate 40 is provided on the upper surface of the semiconductor element 30 and the upper surface of the connecting member 75. The upper substrate 40 is formed in a flat plate shape. The planar shape of the upper substrate 40 can be any shape and any size. As shown in FIG. 1 , the planar shape of the upper substrate 40 is formed, for example, in a rectangular shape. The planar shape of the upper substrate 40 is formed, for example, to be smaller than the planar shape of the lower substrate 20. For example, the dimension of the upper substrate 40 in the X-axis direction is formed smaller than the dimension of the lower substrate 20 in the X-axis direction. For example, the dimension of the upper substrate 40 in the Y-axis direction is formed smaller than the dimension of the lower substrate 20 in the Y-axis direction. The upper substrate 40 is provided, for example, so that its entirety overlaps with the lower substrate 20 in a planar view.

[0035] As shown in FIG. 4, the upper substrate 40 includes, for example, a substrate main body 41 and an adhesive layer 42 formed on the lower surface of the substrate main body 41. The substrate main body 41 may be made of an insulating resin such as a polyimide resin or a polyester resin. The adhesive layer 42 may be made of an epoxy, polyimide, or silicone adhesive. The thickness of the substrate main body 41 may be, for example, in the range of 30 μm to 50 μm. The thickness of the adhesive layer 42 may be, for example, in the range of 15 μm to 45 μm.

[0036] The substrate body 41 is adhered to the semiconductor element 30 and the connecting member 75 by, for example, an adhesive layer 42. The adhesive layer 42 is adhered to the upper surface of the semiconductor element 30 and also to the lower surface of the substrate body 41. The adhesive layer 42 is adhered to the upper surface of the connecting member 75 and also to the lower surface of the substrate body 41. The adhesive layer 42 is provided, for example, to incorporate a portion of the semiconductor element 30. In other words, a portion of the semiconductor element 30 is embedded in the adhesive layer 42. For example, a portion of the electrodes 32, 33 of the semiconductor element 30 is embedded in the adhesive layer 42.

[0037] The upper substrate 40 has a plurality of openings 43 formed therein, penetrating the upper substrate 40 in the thickness direction (here, the Z-axis direction). Each opening 43 is formed, for example, by penetrating the substrate main body 41 and the adhesive layer 42 in the thickness direction. Each opening 43 is formed, for example, in a tapered shape in which the opening width (opening diameter) decreases from the upper side (the upper surface side of the upper substrate 40) to the lower side (the lower substrate 20 side) in FIG. 4. For example, each opening 43 is formed in an inverted truncated cone shape in which the opening diameter at the lower opening end is smaller than the opening diameter at the upper opening end. Some of the openings 43 are formed, for example, so as to expose part of the upper surfaces of the electrodes 32, 33. Some of the openings 43 are formed, for example, so as to expose part of the upper surface of the connection member 75.

[0038] (Configuration of wiring layer 60) The wiring layer 60 is formed on the upper surface of the upper substrate 40. As shown in FIG. 1, the wiring layer 60 has a wiring pattern 61, a wiring pattern 62, and a wiring pattern 63. The wiring patterns 61, 62, and 63 may be made of, for example, copper or a copper alloy. If necessary, a surface treatment layer may be formed on the surfaces (top and side surfaces, or only the top surfaces) of the wiring patterns 61, 62, and 63. Examples of the surface treatment layer include a metal layer such as an Au layer, a Ni layer / Au layer, or a Ni layer / Pd layer / Au layer. The thickness of the wiring patterns 61 and 62 may be, for example, in the range of 50 μm to 200 μm.

[0039] The wiring patterns 61, 62, and 63 are provided apart from one another on the upper surface of the upper substrate 40. The planar shapes of the wiring patterns 61, 62, and 63 can be any shape and any size.

[0040] (Configuration of wiring pattern 61) The wiring pattern 61 is formed, for example, to electrically connect the wiring pattern 22 and the wiring pattern 25. The wiring pattern 61 is formed, for example, to extend in the X-axis direction in a plan view. The wiring pattern 61 is formed, for example, to extend from the wiring pattern 22 to the wiring pattern 25 in a plan view.

[0041] The wiring pattern 61 is formed, for example, to partially overlap the wiring pattern 22 in a plan view. The wiring pattern 61 is formed, for example, to overlap the right end of the wiring pattern 22 in the figure in a plan view. As shown in FIG. 3 , the wiring pattern 61 is electrically connected to a connection member 75 provided on the wiring pattern 22, for example, via one or more (two in this embodiment) via wirings V1 that penetrate the upper substrate 40 in the thickness direction. The wiring pattern 61 is electrically connected to the wiring pattern 22, for example, via the via wirings V1, the connection member 75, and a joint 72. The wiring pattern 61 is formed, for example, integrally with the via wirings V1. Each via wiring V1 is formed, for example, in an opening 43 that exposes a portion of the upper surface of the connection member 75 provided on the wiring pattern 22. Each via wiring V1 is formed, for example, to fill the opening 43. Two via wirings V1 are connected to one connection member 75, for example. The two via wirings V1 are arranged side by side, for example, along the X-axis direction.

[0042] As shown in FIG. 1, the wiring pattern 61 is formed, for example, to partially overlap the wiring pattern 25 in a plan view. The wiring pattern 61 is formed, for example, to overlap an upper portion of the wiring pattern 25 in a plan view. As shown in FIG. 3, the wiring pattern 61 is electrically connected to a connection member 75 provided on the wiring pattern 25, for example, via one or more via wirings V2 penetrating the upper substrate 40 in the thickness direction. As shown in FIG. 1, the wiring pattern 61 of this embodiment is electrically connected to two connection members 75 provided on the wiring pattern 25 via four via wirings V2. The four via wirings V2 are arranged, for example, side by side along the X-axis direction. The four via wirings V2 are arranged, for example, so that two via wirings V2 are connected to one connection member 75. As shown in FIG. 3, each via wiring V2 is formed, for example, in an opening 43 that exposes a portion of the upper surface of the connection member 75 provided on the wiring pattern 25. Each via wiring V2 is formed, for example, to fill the opening 43. The wiring pattern 61 is formed integrally with, for example, the via wiring V2. The wiring pattern 61 is electrically connected to the wiring pattern 25 via the via wiring V2, the connection member 75, and the joint 72. As a result, the wiring pattern 22 is electrically connected to the electrode 31 of the semiconductor element 30 via the joint 72, the connection member 75, the via wiring V1, the wiring pattern 61, the via wiring V2, the connection member 75, the joint 72, the wiring pattern 25, and the joint 71. In other words, the wiring pattern 22 having the current input terminal 22A is electrically connected to the electrode 31, which is the drain electrode, via the wiring patterns 61, 25, etc.

[0043] (Configuration of wiring pattern 62) 1, the wiring pattern 62 is formed, for example, to electrically connect the wiring pattern 23 and the electrode 32 of the semiconductor element 30. The wiring pattern 62 is formed, for example, to electrically connect the current output terminal 23A of the wiring pattern 23 and the electrode 32 of the semiconductor element 30. The wiring pattern 62 is formed, for example, to extend in the X-axis direction in a plan view. The wiring pattern 62 is formed, for example, to extend in the X-axis direction from the electrode 32 toward the current output terminal 23A.

[0044] The wiring pattern 62 is formed, for example, to partially overlap the wiring pattern 23 in a plan view. The wiring pattern 62 is formed, for example, to overlap the right end of the wiring pattern 23 in the figure in a plan view. As shown in FIG. 4 , the wiring pattern 62 is electrically connected to a connection member 75 provided on the wiring pattern 23, for example, via one or more (two in this embodiment) via wirings V3 that penetrate the upper substrate 40 in the thickness direction. The wiring pattern 62 is electrically connected to the wiring pattern 23, for example, via the via wirings V3, the connection member 75, and the joint portion 72. The wiring pattern 62 is formed, for example, integrally with the via wirings V3. Each via wiring V3 is formed, for example, in an opening 43 that exposes a portion of the upper surface of the connection member 75 provided on the wiring pattern 23. Each via wiring V3 is formed, for example, to fill the opening 43. Two via wirings V3 are connected to one connection member 75, for example. The two via wirings V3 are arranged side by side, for example, along the X-axis direction.

[0045] As shown in FIG. 1 , the wiring pattern 62 is formed, for example, to partially overlap the semiconductor element 30 in a planar view. The wiring pattern 62 is formed, for example, to overlap the electrode 32 of the semiconductor element 30 in a planar view. The wiring pattern 62 is formed, for example, to overlap two electrodes 32 in a planar view. As shown in FIG. 4 , the wiring pattern 62 is electrically connected to the electrode 32, for example, via a plurality of via wirings 80 that penetrate the upper substrate 40 in the thickness direction. As a result, the wiring pattern 62 is electrically connected to the electrode 32 through the via wirings 80, and is also electrically connected to the wiring pattern 23 through the via wiring V3, the connecting member 75, and the joint 72. In other words, the wiring pattern 23 having the current output terminal 23A is electrically connected to the electrode 32, which is the source electrode, via the joint 72, the connecting member 75, the via wiring V3, the wiring pattern 62, and the via wiring 80. The wiring pattern 62 is formed, for example, integrally with the via wiring 80. As shown in FIG. 2, the wiring pattern 62 of this embodiment is electrically connected to two electrodes 32 through 20 via wirings 80.

[0046] (Configuration of via wiring 80) As shown in Fig. 3, each via wiring 80 penetrates the upper substrate 40 in the thickness direction and is connected to an electrode 32. Each via wiring 80 is formed, for example, in an opening 43 that exposes a portion of the upper surface of the electrode 32. Each via wiring 80 is formed, for example, to fill the opening 43. As shown in Fig. 2, for example, a plurality of via wirings 80 are connected to each electrode 32. In this embodiment, the 20 via wirings 80 are provided such that 10 via wirings 80 are connected to one electrode 32. The 20 via wirings 80 are provided, for example, side by side along the X-axis direction and also side by side along the Y-axis direction.

[0047] As shown in FIG. 1 , the via wirings 80 of this embodiment are arranged in six rows in the X-axis direction. The via wirings 80 include one or more (four in this embodiment) via wirings 81 arranged at a position closest to the current output terminal 23A in the X-axis direction. The four via wirings 81 are arranged, for example, along the side that is closest to the current output terminal 23A in the X-axis direction among the four sides that form the outer shape of the rectangular semiconductor element 30, that is, the side that is located on the left side in the drawing and extends in the Y-axis direction. The four via wirings 81 are arranged spaced apart from each other in the Y-axis direction. In the following description, for convenience, the four via wirings 81 may be referred to as the "first row of via wirings 81." The via wirings 80 include one or more via wirings 82 in a second row that are arranged adjacent to the first row of via wirings 81 in the X-axis direction, and one or more via wirings 83 in a third row that are arranged adjacent to the second row of via wirings 82 in the X-axis direction. The via wiring 80 has one or more via wirings 84 in a fourth row arranged adjacent to the via wirings 83 in the third row in the X-axis direction, and one or more via wirings 85 in a fifth row arranged adjacent to the via wirings 84 in the fourth row. The via wiring 80 has one or more via wirings 86 in a sixth row arranged adjacent to the via wirings 85 in the fifth row in the X-axis direction. The via wiring 80 of this embodiment has three via wirings 82, three via wirings 83, three via wirings 84, three via wirings 85, and four via wirings 86. As shown in FIG. 2 , the via wirings 81, 82, and 83 in the first to third rows are connected to one electrode 32, and the via wirings 84, 85, and 86 in the fourth to sixth rows are connected to the other electrode 32. The via wirings 81, 82, and 83 in the first to third rows are arranged, for example, in a staggered pattern on the upper surface of the electrode 32. For example, the via wirings 81 in the first row and the via wirings 83 in the third row are arranged at positions where they overlap each other in the X-axis direction. For example, the via wirings 82 in the second row are arranged at positions where they are shifted from the via wirings 81 in the first row and the via wirings 83 in the third row in the Y-axis direction. The via wirings 84, 85, and 86 in the fourth to sixth rows are arranged, for example, in a staggered pattern on the upper surface of the electrode 32. For example, the via wirings 84 in the fourth row and the via wirings 86 in the sixth row are arranged at positions where they overlap each other in the X-axis direction.The fifth row of via wirings 85 is provided, for example, at a position offset in the Y-axis direction from the fourth row of via wirings 84 and the sixth row of via wirings 86. The third row of via wirings 83 and the fourth row of via wirings 84 are provided at positions overlapping each other in the X-axis direction.

[0048] The planar shape of each of the via wirings 81 to 86 can be formed to any shape and any size. The planar shapes of the via wirings 81 to 86 may be the same as each other or may be different from each other. In this embodiment, the planar shapes of the via wirings 81 to 86 are formed to be the same as each other, specifically, circular.

[0049] The planar shape of the via wirings 81 in the first row is larger than the planar shape of the via wirings 82 in the second row. The planar shape of each via wiring 81 is larger than, for example, the planar shape of the via wirings 80 other than the via wiring 81, specifically, the planar shape of each of the via wirings 82 to 86 in the second to sixth rows. The via diameter (diameter) of the via wirings 81 in the first row is larger than, for example, the via diameter of the via wirings 82 in the second row. The via diameter of each via wiring 81 is larger than, for example, the via diameter of each of the via wirings 82 to 86 in the second to sixth rows. The planar shapes of the four via wirings 81 are, for example, formed to have the same size. For example, the planar shapes of the via wirings 82 to 86 in the second to sixth rows are formed to have the same size. In the multiple via wirings 80 of this embodiment, only the planar shape of the via wirings 81 in the first row is formed to have a larger size among the via wirings 81 to 86. The size of the planar shape of the via wiring 81 can be set, for example, in the range of 1.2 to 2 times the size of the planar shape of the other via wirings 82 to 86. For example, the via diameter of the via wirings 82 to 86 can be set in the range of 300 μm to 600 μm, and the diameter of the via wiring 81 can be set in the range of 360 μm to 1200 μm.

[0050] (Configuration of wiring pattern 63) 1, the wiring pattern 63 is formed, for example, to electrically connect the wiring pattern 24 and the electrode 33 of the semiconductor element 30. The wiring pattern 63 is formed, for example, to extend in the X-axis direction in a plan view. The wiring pattern 63 is formed, for example, to extend from the wiring pattern 24 to the semiconductor element 30 in a plan view.

[0051] The wiring pattern 63 is formed, for example, to partially overlap the wiring pattern 24 in a plan view. The wiring pattern 63 is formed, for example, to overlap the right end of the wiring pattern 24 in the figure in a plan view. The wiring pattern 63 is electrically connected to a connection member 75 provided on the wiring pattern 24, for example, via one or more via wirings V4 that penetrate the upper substrate 40 in the thickness direction. The wiring pattern 63 of this embodiment is electrically connected to two connection members 75 provided on the wiring pattern 24 via four via wirings V4. Although detailed illustration is omitted, the wiring pattern 63 is electrically connected to the wiring pattern 24, for example, via the via wirings V4 and the connection member 75. The wiring pattern 63 is formed, for example, integrally with the via wirings V4. The four via wirings V4 are provided, for example, so that two via wirings V4 are connected to one connection member 75. The four via wirings V4 are provided, for example, side by side along the X-axis direction.

[0052] The wiring pattern 63 is formed, for example, to partially overlap the semiconductor element 30 in a plan view. The wiring pattern 63 is formed, for example, to overlap the electrode 33 of the semiconductor element 30 in a plan view. As shown in FIG. 4, the wiring pattern 63 is electrically connected to the electrode 33, for example, via one or more via wirings V5 (one in this embodiment) that penetrate the upper substrate 40 in the thickness direction. The wiring pattern 63 is formed, for example, integrally with the via wiring V5. The via wiring V5 is formed, for example, in an opening 43 that exposes a portion of the upper surface of the electrode 33. The via wiring V5 is formed, for example, to fill the opening 43.

[0053] 1, the wiring pattern 63 is electrically connected to the electrode 33 through the via wiring V5, and is also electrically connected to the wiring pattern 24 through the via wiring V4 and the connecting member 75. In other words, the electrode 33, which is the gate electrode, is electrically connected to the wiring pattern 24 through the via wiring V5, the wiring pattern 63, the via wiring V4, and the connecting member 75.

[0054] (Configuration of sealing resin 50) 3, the sealing resin 50 is formed to seal, for example, the semiconductor element 30, the connection member 75, and the bonding portions 71 and 72 provided between the lower substrate 20 and the upper substrate 40. The sealing resin 50 is formed to cover, for example, the side surfaces of the semiconductor element 30, the side surfaces of the connection member 75, the upper surface of the bonding portion 71 exposed from the semiconductor element 30, the side surfaces of the bonding portion 71, the upper surface of the bonding portion 72 exposed from the connection member 75, and the side surfaces of the bonding portion 72. The sealing resin 50 is formed to cover, for example, the entire lower surface of the upper substrate 40. The sealing resin 50 is formed to cover, for example, the upper surface of the wiring layer 21 exposed from the bonding portions 71 and 72, the side surfaces of the wiring layer 21, and the upper surface of the lower substrate 20 exposed from the wiring layer 21 in the portion overlapping with the upper substrate 40 in a plan view.

[0055] The material for the sealing resin 50 may be, for example, a non-photosensitive insulating resin containing a thermosetting resin as its main component. The material for the sealing resin 50 may be, for example, an insulating resin such as an epoxy resin or a polyimide resin, or a resin material in which a filler such as silica or alumina is mixed into such a resin. The sealing resin 50 may be, for example, a mold resin.

[0056] Electrode 31 is drawn out beyond sealing resin 50 via wiring patterns 25, 61, and 22. As shown in Fig. 1, electrode 32 is drawn out beyond sealing resin 50 via wiring patterns 62 and 23. Electrode 33 is drawn out beyond sealing resin 50 via wiring patterns 63 and 24.

[0057] (Current path) Next, the path of the current I1 that flows through the semiconductor device 10 when the semiconductor element 30 is driven will be described with reference to FIGS.

[0058] As shown in FIGS. 3 and 5, when a current I1 is input to the current input terminal 22A, the current I1 flows from the wiring pattern 22 through the connection member 75 and the via wiring V1 to the wiring pattern 61. Subsequently, the current I1 flows from the via wiring V1 side of the wiring pattern 61 toward the via wiring V2. Next, the current I1 flows from the wiring pattern 61 through the via wiring V2 and the connection member 75 to the wiring pattern 25. Then, as shown in FIG. 3, the current I1 flows from the wiring pattern 25 through the joint 71 to the electrode 31. Next, the current I1 flows from the electrode 32 through the via wiring 80 to the wiring pattern 62. Next, as shown in FIGS. 4 and 5, the current I1 flows from the via wiring 80 side of the wiring pattern 62 toward the via wiring V3. Then, the current I1 flows from the wiring pattern 62 through the via wiring V3 and the connection member 75 to the wiring pattern 23. The current I1 is then output from the current output terminal 23A of the wiring pattern 23.

[0059] Here, through intensive research by the present inventors, it has been found that, among the multiple via wirings 80 connected to the electrode 32 serving as the source electrode, the current density tends to concentrate on the via wirings arranged on the outlet side of the current I1, specifically the via wirings 81 in the first row. In other words, it has been found that, among the multiple via wirings 80, the current density tends to concentrate on the via wirings 81 in the first row arranged at a position closest to the current output terminal 23A in the X-axis direction.

[0060] Therefore, in the semiconductor device 10 of this embodiment, the planar size of the via wirings 81 in the first row arranged at positions where current density is likely to concentrate is made larger than the planar sizes of the other via wirings 82 to 86. This makes it possible to increase the volume of each via wiring 81 compared to when the planar sizes of each via wiring 81 and each via wiring 82 to 86 are formed to be the same. This makes it possible to distribute the current density in the via wirings 81, and effectively suppress the current density from concentrating on the via wirings 81.

[0061] In this embodiment, electrode 31 is an example of a first electrode, electrode 32 is an example of a second electrode, electrode 33 is an example of a third electrode, wiring pattern 22 is an example of a first wiring pattern, wiring pattern 62 is an example of a second wiring pattern, and the X-axis direction is an example of a first direction. Also, via wiring 81 is an example of a first via wiring, via wiring 82 is an example of a second via wiring, and via wiring 83 is an example of a third via wiring.

[0062] (About the simulation) A simulation analysis of current density was carried out for the semiconductor device 10 (sample 1) shown in FIGS. 1 to 4 and the semiconductor device 100 (sample 2) of the comparative example shown in FIG.

[0063] (Simulation conditions) In the semiconductor device 10 of Sample 1, the via diameter of the via wirings 82 to 86 in the second to sixth rows was set to 500 μm. A simulation of current density distribution was performed when the via diameter of each via wiring 81 in the first row in the semiconductor device 10 of Sample 1 was changed to 300 μm, 500 μm, 650 μm, and 700 μm. Comparative Example 1 corresponds to a case where the via diameter of each of the four via wirings 81 is set to 300 μm, which is smaller than the via diameter of the via wirings 82 to 86. Comparative Example 2 corresponds to a case where the via diameter of each of the four via wirings 81 is set to 500 μm, the same as the via diameter of the via wirings 82 to 86. Example 1 corresponds to a case where the via diameter of each of the four via wirings 81 is set to 650 μm, which is larger than the via diameter of the via wirings 82 to 86. Example 2 corresponds to a case where the via diameter of each of the four via wirings 81 is set to 700 μm, which is larger than the via diameter of the via wirings 82 to 86. In the simulation, the maximum current of the standard current, here 95 A, was input to the current input terminal 22A of the semiconductor device 10 in Comparative Examples 1 and 2 and Examples 1 and 2, and the maximum current density was measured in the multiple via wirings 80. Then, the rate of change in the maximum current density in Comparative Example 1 and Examples 1 and 2 relative to the maximum current density in Comparative Example 2, in which the via diameter of each via wiring 81 was set to 500 μm, was calculated. Specifically, the maximum current density in Comparative Example 1 and Examples 1 and 2 when the maximum current density in Comparative Example 2 was set to 0% was calculated as the rate of change in the maximum current density.

[0064] In the semiconductor device 100 of Sample 2, the via diameter of the via wirings 81 to 85 in the first to fifth rows was set to 500 μm. Then, a simulation of current density distribution was performed in the semiconductor device 100 of Sample 2, in which the via diameter of each via wiring 86 in the sixth row was changed to 300 μm, 500 μm, 650 μm, and 700 μm. That is, in the semiconductor device 100 of Sample 2, the via diameter of the via wiring 86 provided at the position farthest from the current output terminal 23A in the X-axis direction was varied. Here, Comparative Example 3 is a case in which the via diameter of each of the four via wirings 86 is set to 300 μm, and Comparative Example 4 is a case in which the via diameter of each of the four via wirings 86 is set to 500 μm. Comparative Example 5 is a case in which the via diameter of each of the four via wirings 86 is set to 650 μm, and Comparative Example 6 is a case in which the via diameter of each of the four via wirings 86 is set to 700 μm. Then, a simulation was performed on the semiconductor devices 100 of Comparative Examples 3 to 6 under the same conditions as in the case of the semiconductor device 10 of Sample 1. For the semiconductor devices 100 of Comparative Examples 3 to 6, the maximum current densities in Comparative Examples 3, 5, and 6 were calculated as the maximum current density change rate when the maximum current density in Comparative Example 4 was set to 0%.

[0065] (Simulation results) The simulation results of the current density change rate are shown in Fig. 7. The horizontal axis of Fig. 7 indicates the via diameter of the via wiring 81 in the case of Sample 1, and indicates the via diameter of the via wiring 82 in the case of Sample 2. The vertical axis of Fig. 7 indicates the maximum current density change rate. In Fig. 7, the maximum current density change rate indicated by the solid line is the maximum current density change rate of Sample 1, and the maximum current density change rate indicated by the dashed dotted line is the maximum current density change rate of Sample 2. Although not shown in the drawings, in all of Comparative Examples 1 to 6 and Examples 1 and 2, the current density of a part of the via wiring 81 in the first row was the maximum current density.

[0066] 7, it was confirmed that in the semiconductor device 10 of Sample 1, the maximum current density decreased in inverse proportion to the via diameter of the via wiring 81. Specifically, it was confirmed that by setting the via diameter of the via wiring 81 larger than the via diameters of the other via wirings 82 to 86 (Examples 1 and 2), the maximum current density could be lowered compared to Comparative Example 2 in which the via diameter of the via wiring 81 and the via diameters of the via wirings 82 to 86 were set to the same diameter. In other words, it was confirmed that by setting the via diameter of the via wiring 81 larger than the via diameters of the other via wirings 82 to 86, the current density in the via wiring 81 could be dispersed more than in Comparative Example 2, and concentration of the current density in the via wiring 81 could be suppressed. Furthermore, as is clear from the results of Examples 1 and 2, it was confirmed that the larger the via diameter of the via wiring 81, the lower the maximum current density could be.

[0067] On the other hand, in the semiconductor device 100 of Sample 2, it was confirmed that the maximum current density hardly changed even when the via diameter of the via wiring 86 was varied. That is, it was confirmed that there was no correlation between the via diameter of the via wiring 86 and the maximum current density, i.e., the current density in the via wiring 81. Specifically, it was confirmed that even when the via diameter of the via wiring 86 was set larger than the via diameters of the other via wirings 81 to 85, the maximum current density in the plurality of via wirings 80 could not be reduced. That is, it was confirmed that even when the via diameter of the via wiring 86 was increased to increase the overall volume of the plurality of via wirings 80, the maximum current density in the plurality of via wirings 80 could not be reduced.

[0068] These results show that the current density in the via wiring 81 can be dispersed by increasing the via diameter of the via wiring 81 arranged on the outlet side of the current I1 where the current density is concentrated among the multiple via wirings 80. This makes it possible to suppress the concentration of the current density in the via wiring 81, and therefore, it is possible to suitably suppress local breakage of the via wiring 81.

[0069] Next, the effects of this embodiment will be described. (1) The plurality of via wirings 80 connecting the electrodes 32 of the semiconductor element 30 and the wiring pattern 62 includes one or more via wirings 81 arranged at a position closest to the current output terminal 23A in the X-axis direction, and a via wiring 82 arranged adjacent to the via wiring 81. The planar shape of the via wiring 81 is formed to be larger than the planar shape of the via wiring 82.

[0070] According to this configuration, the planar shape of the via wiring 81, which is arranged on the outlet side of the current I1, where the current density is likely to concentrate, among the multiple via wirings 80, can be made large. As a result, the current density in the via wiring 81 can be dispersed and the concentration of the current density in the via wiring 81 can be suppressed compared to when the planar shapes of the via wiring 81 and the via wiring 82 are formed to be the same size. Therefore, localized heat generation in the via wiring 81 due to the concentration of the current density can be suppressed, and local breakage of the via wiring 81 can be suppressed. As a result, a decrease in the reliability of the electrical connection between the electrode 32 of the semiconductor element 30 and the wiring pattern 62 can be suppressed.

[0071] (2) The semiconductor element 30 has a rectangular planar shape. The via wiring 80 has a plurality of (four in this embodiment) via wirings 81 arranged side by side along the side that is closest to the current output terminal 23A in the X-axis direction among the four sides of the semiconductor element 30. The planar shape of each of the four via wirings 81 is formed to be larger than the planar shape of the via wiring 82.

[0072] According to this configuration, the planar shape of all the via wirings 81 provided at positions where current density is likely to concentrate can be made large. This allows the current density in all the via wirings 81 to be dispersed, and current density concentration in all the via wirings 81 can be suppressed.

[0073] (3) However, if the planar shapes of the via wirings 82 to 86 in the second to sixth rows are also formed large along with the via wirings 81 in the first row, the contact area between the adhesive layer 42 of the upper substrate 40 and the electrodes 32 will be reduced. Therefore, if the planar shapes of the via wirings 80 are made larger overall, there is a problem that the upper substrate 40 will be more likely to peel off from the semiconductor element 30. In contrast, in the semiconductor device 10 of this embodiment, the planar shape of the via wirings 81 in the first row is formed larger than the planar shapes of the via wirings 80 other than the via wiring 81, i.e., the via wirings 81 in the second to sixth rows. According to this configuration, only the planar shape of the via wirings 81 in the first row among the multiple via wirings 80 is formed large. This prevents the contact area between the adhesive layer 42 of the upper substrate 40 and the electrodes 32 from being reduced, thereby effectively preventing the upper substrate 40 from peeling off from the semiconductor element 30. Therefore, while suppressing current density concentration in the via wirings 81 in the first row, peeling of the upper substrate 40 can be effectively prevented.

[0074] (Other embodiments) The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0075] 8, the planar shape of the second row of via wirings 82 may be formed smaller than the planar shape of the third row of via wirings 83. In this modified example, the planar shape of each via wiring 82 is formed smaller than the planar shape of each of the third to sixth rows of via wirings 83 to 86.

[0076] According to this configuration, the planar shape of the via wiring 82 provided next to the via wiring 81, which has a larger planar shape than the via wirings 82 to 86, is smaller than the planar shapes of the via wirings 83 to 86. This makes it possible to secure a wide area for expanding the planar shape of the via wiring 81. Furthermore, while expanding the planar shape of the via wiring 81, it is possible to prevent the contact area between the adhesive layer 42 of the upper substrate 40 and the electrode 32 from becoming smaller.

[0077] The number and arrangement of the via wirings 80 in the above embodiment can be changed as appropriate. For example, the number of via wirings 81 arranged closest to the current output terminal 23A in the X-axis direction may be one to three, or may be five or more. For example, in the above embodiment, the multiple via wirings 80 are arranged in six rows in the X-axis direction. However, the multiple via wirings 80 may be arranged in two to five rows, or seven or more rows in the X-axis direction.

[0078] In the above embodiment, the current input terminal 22A is provided on the upper surface of the lower substrate 20, but the position where the current input terminal 22A is formed is not limited to this. For example, the current input terminal 22A may be provided on the upper surface of the upper substrate 40. For example, the wiring pattern 61 provided on the upper surface of the upper substrate 40 may have the current input terminal 22A.

[0079] In the above embodiment, the current output terminal 23A is provided on the upper surface of the lower substrate 20, but the position where the current output terminal 23A is formed is not limited to this. For example, the current output terminal 23A may be provided on the upper surface of the upper substrate 40. For example, the wiring pattern 62 provided on the upper surface of the upper substrate 40 may have the current output terminal 23A.

[0080] In the above embodiment, the connection terminals 24A are provided on the upper surface of the lower substrate 20, but the formation position of the connection terminals 24A is not limited to this. For example, the connection terminals 24A may be provided on the upper surface of the upper substrate 40. For example, the wiring pattern 63 provided on the upper surface of the upper substrate 40 may have the connection terminals 24A.

[0081] The area where the sealing resin 50 is formed in the above embodiment can be changed as appropriate. For example, the sealing resin 50 may be formed so as to cover the side surfaces of the upper substrate 40. For example, the sealing resin 50 may be formed so as to cover the upper surface of the upper substrate 40. For example, the sealing resin 50 may be formed so as to cover a portion of the upper surface of the wiring layer 60.

[0082] The sealing resin 50 in the above embodiment may be omitted. In the above embodiment, the upper substrate 40 is formed so that its planar shape is smaller than that of the lower substrate 20, but this is not limiting. For example, the planar shape of the upper substrate 40 may be formed so that it is larger than that of the lower substrate 20. For example, the planar shape of the upper substrate 40 may be formed so that it is the same size as that of the lower substrate 20.

[0083] A metal plate serving as a heat sink may be provided on the lower surface of the lower substrate 20 in the above embodiment. In the above embodiment, the substrate body 41 of the upper substrate 40 has a single-layer structure, but is not limited to this. For example, the substrate body 41 may have a laminated structure in which one or more wiring layers and multiple insulating layers are laminated.

[0084] In the above embodiment, the semiconductor element 30 is embodied as a MOSFET, but the present invention is not limited to this. For example, as shown in FIG. 9 , the semiconductor element 30 may be embodied as a diode having an electrode 91 serving as an anode electrode and an electrode 92 serving as a cathode electrode. The semiconductor element 30 has, for example, a main body 94. The electrode 91 is provided on, for example, the lower surface of the main body 94. The electrode 91 is formed, for example, so as to cover the entire lower surface of the main body 94. The electrode 92 is provided on, for example, the upper surface of the main body 94. The electrode 92 is formed, for example, so as to cover the entire upper surface of the main body 94. In this case, the wiring pattern 62 is electrically connected to the electrode 92 via a plurality of via wirings 80 that penetrate the upper substrate 40 in the thickness direction. Even in this case, the planar shape of the via wiring 81, which is arranged on the outlet side of the current I1 among the plurality of via wirings 80, is formed larger than the planar shapes of the via wirings 80 other than the via wiring 81.

[0085] In the above embodiment, the semiconductor device 10 is embodied as a power semiconductor device, but is not limited to this. For example, the semiconductor device 10 may be embodied as various semiconductor devices other than power semiconductor devices.

[0086] In the above embodiment, the semiconductor element 30 is embodied as a power semiconductor element, but is not limited to this. For example, the semiconductor element 30 may be embodied as various semiconductor elements other than power semiconductor elements. [Explanation of symbols]

[0087] 10 Semiconductor device 20 Lower board 22 Wiring Pattern 22A current input terminal 23 Wiring Pattern 23A current output terminal 24 Wiring Pattern 24A connection terminal 25 Wiring Pattern 30 Semiconductor elements 31 electrode 32 electrodes 33 electrode 34 Main body 40 Upper board 50 Sealing resin 61 Wiring Pattern 62 Wiring Pattern 63 Wiring Pattern 80 via wiring 81 Via wiring 82 via wiring 83 Via wiring 84, 85, 86 Via wiring 91 Electrode 92 electrodes 94 Main body V1, V2, V3, V4, V5 via wiring I1 current

Claims

1. A lower substrate; a first wiring pattern provided on the upper surface of the lower substrate, the first wiring pattern having a current input terminal to which a current is input; a semiconductor element mounted on the upper surface of the lower substrate, the semiconductor element having a first electrode electrically connected to the first wiring pattern and a second electrode provided on the opposite side to the first electrode; an upper substrate provided on the second electrode side of the semiconductor element; a plurality of via wirings that penetrate the upper substrate in a thickness direction and are connected to the second electrodes; a second wiring pattern provided on the upper surface of the upper substrate and electrically connected to the second electrode through the plurality of via wirings; a current output terminal for outputting the current, the second wiring pattern is electrically connected to the current output terminal and extends from the second electrode toward the current output terminal in a first direction that is one of planar directions, the plurality of via wirings include one or more first via wirings arranged at positions closest to the current output terminal in the first direction and one or more second via wirings provided adjacent to the first via wirings, The semiconductor device is configured such that the planar shape of the first via wiring is larger than the planar shape of the second via wiring.

2. The semiconductor element has a rectangular planar shape, 2. The semiconductor device according to claim 1, wherein the via wirings include a plurality of the first via wirings arranged side by side along the side of the semiconductor element that is positioned closest to the current output terminal in the first direction.

3. 2. The semiconductor device according to claim 1, wherein the planar shape of the first via wiring is larger than the planar shapes of the via wirings other than the first via wiring.

4. the via wiring includes one or more third via wirings provided adjacent to the second via wiring in the first direction, a planar shape of the first via wiring is formed to be larger than a planar shape of the third via wiring; The semiconductor device according to claim 1 , wherein the second via wiring has a planar shape smaller than the planar shape of the third via wiring.

5. a sealing resin provided between the lower substrate and the upper substrate and sealing the semiconductor element; the current input terminal is provided at a position exposed from the sealing resin, 2. The semiconductor device according to claim 1, wherein the current output terminal is provided at a position exposed from the sealing resin.

6. 2. The semiconductor device according to claim 1, wherein the semiconductor element is a power semiconductor element.

7. 7. The semiconductor device according to claim 6, wherein the semiconductor element is a metal oxide semiconductor field effect transistor having the first electrode which is a drain electrode, the second electrode which is a source electrode, and a third electrode which is a gate electrode.

8. 7. The semiconductor device according to claim 6, wherein the semiconductor element is a diode having the first electrode as an anode electrode and the second electrode as a cathode electrode.

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