semiconductor devices

Abstract

A semiconductor device comprises: a conductive portion having a main surface, a semiconductor element mounted on the main surface, and a conductive bonding material disposed between the conductive portion and the semiconductor element to provide conductive bonding between the conductive portion and the semiconductor element. The conductive bonding material comprises a metal base layer, a first bonding layer, and a second bonding layer. The first bonding layer is disposed between the metal base layer and the semiconductor element and is bonded to the semiconductor element by solid-phase diffusion of metal. The second bonding layer is disposed between the metal base layer and the conductive portion and is bonded to the conductive portion by solid-phase diffusion of metal.

Description

Technical Field

[0001] The present disclosure relates to a semiconductor device including a semiconductor element. Background Art

[0002] Semiconductor devices equipped with semiconductor elements such as MOSFETs and IGBTs are widely known. Patent Document 1 discloses an example of such a semiconductor device. In this semiconductor device, a metal pattern (conductive portion) is formed on a supporting substrate (insulating substrate). The semiconductor element is bonded to the metal pattern via a conductive bonding material.

[0003] When using the semiconductor device disclosed in Patent Document 1, heat is generated from the semiconductor element, causing the surrounding temperature to rise. In particular, the conductive bonding material may be exposed to high temperatures. Repeated exposure to high temperatures can cause changes in the conductive bonding material's state. This can potentially impair the electrical connection between the semiconductor element and the metal pattern.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2009-158787 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] In view of the above circumstances, an object of the present disclosure is to provide a semiconductor device suitable for maintaining an appropriate bonding state between a semiconductor element and a conductive portion, thereby improving the reliability of the bonding state.

[0009] Methods for solving problems

[0010] One aspect of the present disclosure provides a semiconductor device comprising: a conductive portion having a main surface, a semiconductor element mounted on the aforementioned main surface, and a conductive bonding material present between the aforementioned conductive portion and the aforementioned semiconductor element, which enables the aforementioned conductive portion and the aforementioned semiconductor element to be conductively connected and bonded, wherein the aforementioned conductive bonding material includes a metal base layer, a first bonding layer and a second bonding layer, the aforementioned first bonding layer exists between the aforementioned metal base layer and the aforementioned semiconductor element and is bonded to the aforementioned semiconductor element through solid-phase diffusion of metal, and the aforementioned second bonding layer exists between the aforementioned metal base layer and the aforementioned conductive portion and is bonded to the aforementioned conductive portion through solid-phase diffusion of metal.

[0011] Other features and advantages of the present disclosure will be clarified from the detailed description given below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a perspective view showing the semiconductor device according to the first embodiment.

[0013] Figure 2 for Figure 1 A plan view of the semiconductor device shown.

[0014] Figure 3 For the Figure 2 Cross-sectional view along line III-III.

[0015] Figure 4 For the Figure 2 Cross-sectional view along line IV-IV.

[0016] Figure 5 for Figure 3 A partial enlarged view of .

[0017] Figure 6 for Figure 5 A partial enlarged view of .

[0018] Figure 7 for Figure 6 Magnified view of part A.

[0019] Figure 8 for Figure 6 Enlarged view of part B.

[0020] Figure 9 for Figure 6 Enlarged view of part C.

[0021] Figure 10 for Figure 6 Enlarged view of part D.

[0022] Figure 11 A diagram for explaining a method of bonding a semiconductor element and a conductive portion.

[0023] Figure 12 It is a plan view showing a semiconductor device according to a second embodiment.

[0024] Figure 13 for Figure 12 A bottom view of the semiconductor device is shown.

[0025] Figure 14 For the Figure 12 Cross-sectional view along line XIV-XIV.

[0026] Figure 15 for Figure 14 A partial enlarged view of .

[0027] Figure 16 for Figure 15 A partial enlarged view of .

[0028] Figure 17 for Figure 16 Magnified view of part A.

[0029] Figure 18 for Figure 16 Enlarged view of part B.

[0030] Figure 19 for Figure 16 Enlarged view of part C.

[0031] Figure 20 for Figure 16 Enlarged view of part D.

[0032] Figure 21 It is a plan view showing a semiconductor device according to a third embodiment.

[0033] Figure 22 For the Figure 21 Cross-sectional view along line XXII-XXII.

[0034] Figure 23 for Figure 22 A partial enlarged view of .

[0035] Figure 24 for Figure 23 A partial enlarged view of .

[0036] Figure 25 for Figure 24 Magnified view of part A.

[0037] Figure 26 for Figure 24 Enlarged view of part B.

[0038] Figure 27 for Figure 24 Enlarged view of part C.

[0039] Figure 28 for Figure 24 Enlarged view of part D. DETAILED DESCRIPTION

[0040] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0041] The terms "first," "second," and "third" in the present disclosure are simply used as labels and do not indicate the order of these objects.

[0042] according to Figures 1 to 10 , a semiconductor device A10 according to the first embodiment will be described. The illustrated semiconductor device A10 includes a supporting substrate 10, a plurality of conductive portions 20, a first input terminal 31, a second input terminal 32, a first output terminal 33, a second output terminal 34, a plurality of semiconductor elements 40, and a sealing resin 80 (in Figure 1(omitted). In addition to these, semiconductor device A10 also includes a pair of insulating layers 26, a pair of gate wiring layers 271, a pair of detection wiring layers 272, a pair of gate terminals 35, and a pair of detection terminals 36. Each semiconductor element 40 is, for example, a MOSFET, and semiconductor device A10 is, for example, a power conversion device (power module). Semiconductor device A10 is used as a drive source for a motor, inverters for various electrical products, and DC / DC converters. Figures 2 to 4 In FIG, the image is displayed through the sealing resin 80 (see the two-dot chain line).

[0043] In the description of the semiconductor device A10, for example, Figure 1 As shown, the direction extending through the thickness of the support substrate 10 (or the conductive portion 20) is referred to as the "z direction" (sometimes also referred to as the "thickness direction"). A direction perpendicular to the z direction is referred to as the "x direction", and a direction perpendicular to both the z direction and the x direction is referred to as the "y direction". Figure 2 As shown, the semiconductor device A10 is rectangular when viewed in the z direction (in other words, when viewed in a plane). In addition, the x direction is parallel to one side of the semiconductor device A10 (for example, Figure 2 The y direction is parallel to the other side of the semiconductor device A10 (e.g. Figure 2 In the description of the semiconductor device A10, when there are two components A and B (or two groups A and B) separated from each other in any direction, it is sometimes described as "component A is located on one side (relative to component B) in the direction" or "component B is located on the other side (relative to component A) in the direction". Therefore, Figure 2 For example, it is described as “the first input terminal 31 and the second input terminal 32 are arranged on one side in the x-direction, and the first output terminal 33 and the second output terminal 34 are arranged on the other side in the x-direction.” It should be noted that “one side” and “the other side” may be reversed from this example.

[0044] like Figures 1 to 4 As shown, the support substrate 10 supports a plurality of conductive portions 20. In the example shown in the figure, the support substrate 10 is square when viewed in the z direction. The support substrate 10 has a support surface 10A and a bottom surface 10B facing opposite sides (separated from each other) in the z direction. The support surface 10A faces each conductive portion 20. Figure 3 、 Figure 4 As shown, the bottom surface 10B is exposed from the sealing resin 80. When the semiconductor device A10 is mounted on a heat sink, for example, the bottom surface 10B faces the heat sink. In the example shown, the support substrate 10 includes a first support plate 11, a second support plate 12, and a base plate 13.

[0045] like Figure 3 and Figure 4As shown, the first support plate 11 is located between the second support plate 12 and the base plate 13 in the z direction. The first support plate 11 has electrical insulation properties. The first support plate 11 is made of a ceramic with excellent thermal conductivity. Examples of such ceramics include aluminum nitride (AlN).

[0046] Each second support plate 12 is stacked on the first support plate 11 and has a support surface 10A. A corresponding conductive portion 20 is bonded to each second support plate 12. The second support plate 12 is made of metal, such as metal foil. The second support plate 12 is made of copper (Cu) or a copper alloy and is electrically conductive. In the illustrated example, the second support plate 12 has three regions (support plates): a first region 121, a second region 122, and a third region 123. These three regions are separate from one another.

[0047] The bottom plate 13 is stacked on the first support plate 11 on the side opposite to the second support plate 12. The bottom plate 13 includes a bottom surface 10B. The bottom plate 13 is made of metal, such as a metal foil formed of copper or a copper alloy, like the second support plate 12. The second support plate 12 is conductive. Figure 3 and Figure 4 As can be understood, when viewed in the z-direction, the area of ​​the bottom plate 13 is smaller than that of the first support plate 11. The periphery of the first support plate 11 is located further outward than the periphery of the bottom plate 13. Thus, when viewed in the z-direction, the support substrate 10 is provided with a recessed portion 13A surrounding the bottom plate 13. The recessed portion 13A is covered with the sealing resin 80.

[0048] The support substrate 10 can be formed using, for example, a DBC (Direct Bonded Copper) substrate. A DBC substrate consists of a ceramic plate and a pair of copper foils sandwiching the ceramic plate from either side in the z-direction. The ceramic plate constitutes the first support plate 11. The pair of copper foils are partially removed by etching to form the second support plate 12 and the base plate 13.

[0049] like Figure 3 and Figure 4 As shown, bonding members 19 are provided so as to cover the support surfaces 10A of the first region 121 , the second region 122 , and the third region 123 . That is, each bonding member 19 covers at least a portion of the support surface 10A of the support substrate 10 .

[0050] like Figure 3 and Figure 4As shown, each conductive portion 20 is bonded to a corresponding second support plate 12 via a bonding member 19. The plurality of conductive portions 20, together with the first input terminal 31, the second input terminal 32, the first output terminal 33, and the second output terminal 34, form a predetermined conductive path in the semiconductor device A10. Each conductive portion 20 has a main surface 20A and a back surface 20B facing opposite sides in the z-direction. The back surface 20B faces the support surface 10A of the support substrate 10.

[0051] In the semiconductor device A10, the conductive portion 20 is formed of, for example, a metal plate. The metal plate is made of, for example, copper or a copper alloy. Figure 3 、 Figure 4 As shown, the thickness of the conductive portion 20 is greater than that of the second support plate 12. The conductive portion 20 may also be a structure in which the surface of the metal plate is plated with silver or a plurality of metals such as aluminum, nickel (Ni) and silver are sequentially laminated. Figure 9 、 Figure 10 ), in this embodiment, the conductive portion 20 includes a metal substrate 24 and a conductor layer 25 formed on the substrate 24.

[0052] like Figures 2 to 4 As shown, the plurality of conductive portions 20 include a first conductive portion 201, a second conductive portion 202, and a third conductive portion 203. The first conductive portion 201 is bonded to the first region 121 of the second support plate 12. The second conductive portion 202 is bonded to the second region 122 of the second support plate 12. The third conductive portion 203 is bonded to the third region 123 of the second support plate 12. Therefore, the first conductive portion 201, the second conductive portion 202, and the third conductive portion 203 are separated from each other.

[0053] like Figure 1 、 Figure 2 and Figure 4 As shown, a pair of insulating layers 26 are disposed on the respective principal surfaces 20A of the first conductive portion 201 and the second conductive portion 202. The pair of insulating layers 26 are separated from each other in the y-direction. The pair of insulating layers 26 are strip-shaped and extend in the x-direction. The insulating layers 26 are made of, for example, ceramic or glass epoxy resin. Alternatively, at least the surface of the insulating layers 26 may be formed of insulating SiC, for example.

[0054] A pair of gate wiring layers 271 are disposed on each of the pair of insulating layers 26. The pair of gate wiring layers 271 are strip-shaped and extend in the x-direction. A pair of detection wiring layers 272 are disposed on each of the pair of insulating layers 26. The pair of detection wiring layers 272 are strip-shaped and extend in the x-direction. The gate wiring layers 271 and the detection wiring layers 272 are disposed side by side on each of the insulating layers 26. The gate wiring layers 271 and the detection wiring layers 272 are formed, for example, from metal foil formed of copper or a copper alloy.

[0055] like Figure 1 and Figure 2 As shown, the first input terminal 31 and the second input terminal 32 are located on one side in the x-direction. The first input terminal 31 and the second input terminal 32 are separated from each other in the y-direction. The first input terminal 31 and the second input terminal 32 receive the DC power (voltage) to be converted. The first input terminal 31 is the positive terminal (P terminal). The second input terminal 32 is the negative terminal (N terminal). The first input terminal 31 and the second input terminal 32 are formed of metal plates. The metal plates are made of copper or a copper alloy.

[0056] The first input terminal 31 has a bent portion 311 bent into a stepped shape at its other end in the x-direction. This bent portion 311 is connected to the main surface 20A of the first conductive portion 201 by soldering, ultrasonic bonding, or the like. This establishes electrical continuity between the first input terminal 31 and the first conductive portion 201. The second input terminal 32 has a bent portion 321 bent into a stepped shape at its other end in the x-direction. This bent portion 321 is connected to the main surface 20A of the third conductive portion 203 by soldering, ultrasonic bonding, or the like. This establishes electrical continuity between the second input terminal 32 and the third conductive portion 203.

[0057] like Figure 1 and Figure 2 As shown, the first output terminal 33 and the second output terminal 34 are located on the other side of the x-direction. The first output terminal 33 and the second output terminal 34 are separated from each other in the y-direction. Alternating current (voltage) converted into electricity by a plurality of semiconductor elements 40 is output from the first output terminal 33 and the second output terminal 34. The first output terminal 33 and the second output terminal 34 are composed of metal plates. The constituent material of the metal plate is copper or a copper alloy. The ends on one side of the x-direction of the first output terminal 33 and the second output terminal 34 are provided with a bent portion 331 and a bent portion 341 bent into a stepped shape. The bent portion 331 and the bent portion 341 are connected to the main surface 20A of the second conductive portion 202 by soldering or ultrasonic bonding. Thus, the first output terminal 33 and the second output terminal 34 are conductive with the second conductive portion 202. In addition, in the example shown in the figure, the configuration includes two output terminals (the first output terminal 33 and the second output terminal 34 ), but these may be combined to provide a single output terminal.

[0058] The pair of gate terminals 35 and the pair of detection terminals 36 are respectively arranged corresponding to the pair of gate wiring layers 271 and the pair of detection wiring layers 272. The pair of gate terminals 35 and the pair of detection terminals 36 are formed of metal plates, each extending in the y direction. The metal plates are formed of copper or a copper alloy.

[0059] The ends of the pair of gate terminals 35 and the pair of detection terminals 36 are bent into a step-like shape. The ends of each gate terminal 35 are connected to the corresponding gate wiring layer 271 by soldering, ultrasonic bonding, or the like. The ends of each detection terminal 36 are connected to the corresponding detection wiring layer 272 by soldering, ultrasonic bonding, or the like.

[0060] The semiconductor element 40 is, for example, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) constructed using a semiconductor material primarily composed of silicon carbide (SiC). The semiconductor element 40 is not limited to a MOSFET and may also be a field-effect transistor including a MISFET (Metal-Insulator-Semiconductor Field-Effect Transistor) or a bipolar transistor such as an IGBT (Insulated Gate Bipolar Transistor). The description of the semiconductor device A10 is based on the case where the semiconductor element 40 is a switching element, an n-channel MOSFET.

[0061] like Figure 5 As shown, the semiconductor element 40 includes an element body 41, a main surface electrode 42, a back surface electrode 43, and a gate (not shown). The element body 41 has an element main surface 411 and an element back surface 412. The element main surface 411 and the element back surface 412 face opposite sides in the z-direction. The element main surface 411 faces the same side as the main surface 20A of the conductive portion 20 in the z-direction. Therefore, the element back surface 412 faces the main surface 20A.

[0062] like Figure 5 As shown, the main surface electrode 42 is provided on the main surface 411 of the element. In the main surface electrode 42, the source current flows from the inside of the element body 41. The back electrode 43 is provided on the back surface 412 of the element. The back electrode 43 is, for example, made of silver, or a structure in which multiple metal layers such as nickel and silver are stacked. In the back electrode 43, the drain current flows toward the inside of the element body 41. The back electrode 43 is electrically bonded to the main surface 20A of the conductive portion 20 through a conductive bonding material 49. The aforementioned gate is provided on the main surface 411 of the element, and a gate voltage for driving the semiconductor element 40 is applied to the gate.

[0063] The conductive bonding material 49 exists between the conductive portion 20 and the semiconductor element 40. The conductive bonding material 49 is larger than the semiconductor element 40 when viewed in the z direction, and the semiconductor element 40 as a whole overlaps with the conductive bonding material 49 when viewed in the z direction. The conductive bonding material 49 is composed of a plurality of stacked metal layers. Figure 5 and Figure 6 As shown in FIG. 1 , in the semiconductor device A10, the conductive bonding material 49 includes a metal base layer 490, a first bonding layer 491, and a second bonding layer 492. Figures 7 to 10 As shown, the conductive bonding material 49 further includes a first intermediate layer 493 and a second intermediate layer 494 .

[0064] The metal base layer 490 occupies the majority of the volume of the conductive bonding material 49. The thickness of the metal base layer 490 is, for example, approximately 10 to 200 μm. The metal base layer 490 may be made of, for example, at least one of aluminum (Al), titanium (Ti), zinc (Zn), hafnium (Hf), and erbium (Er). In this embodiment, the metal base layer 490 is made of aluminum. When the metal base layer 490 is made of aluminum, the Young's modulus of the metal base layer 490 is 70.3 GPa.

[0065] The first bonding layer 491 exists between the metal base layer 490 and the semiconductor element 40. In this embodiment, Figure 7 and Figure 8 As shown, the first bonding layer 491 is formed on the first intermediate layer 493. The constituent material of the first bonding layer 491 includes, for example, at least one of silver (Ag), copper (Cu), and gold (Au). In this embodiment, the constituent material of the first bonding layer 491 includes silver. The first bonding layer 491 is bonded to the semiconductor element 40 (back electrode 43) by solid-phase diffusion of the metal. The constituent material of the back electrode 43 includes, for example, silver. The thickness of the back electrode 43 is smaller than that of the first bonding layer 491, and the back electrode 43 is formed, for example, by sputtering.

[0066] The second bonding layer 492 exists between the metal base layer 490 and the conductive portion 20. Figure 9 and Figure 10 As shown, the second bonding layer 492 is formed on the second intermediate layer 494. The constituent material of the second bonding layer 492 includes, for example, at least one of silver, copper, and gold. In this embodiment, the constituent material of the second bonding layer 492 includes silver. The second bonding layer 492 is bonded to the conductive portion 20 (conductor layer 25) by solid-phase diffusion of the metal. In this embodiment, the conductive portion 20 includes a substrate 24 and a conductor layer 25 formed on the substrate 24, and the second bonding layer 492 and the conductor layer 25 are bonded by solid-phase diffusion. The constituent material of the conductor layer 25 includes, for example, silver.

[0067] When the first bonding layer 491 and the second bonding layer 492 are each made of silver, the Young's modulus of each of the first bonding layer 491 and the second bonding layer 492 is 82.7 GPa. Therefore, as indicated by the Young's modulus of the metal base layer 490 (70.3 GPa), the Young's modulus of the metal base layer 490 is smaller than the Young's modulus of each of the first bonding layer 491 and the second bonding layer 492. The thickness of each of the first bonding layer 491 and the second bonding layer 492 is, for example, approximately 2 to 5 μm, which is smaller than the thickness of the metal base layer 490.

[0068] like Figure 7 and Figure 8 As shown, the first intermediate layer 493 exists between the metal base layer 490 and the first bonding layer 491. In this embodiment, the first intermediate layer 493 is formed on the metal base layer 490. Figure 9 and Figure 10 As shown, the second intermediate layer 494 exists between the metal base layer 490 and the second bonding layer 492. In this embodiment, the second intermediate layer 494 is formed on the metal base layer 490. The constituent materials of the first intermediate layer 493 and the second intermediate layer 494 each contain nickel (Ni), for example. When the constituent materials of the first intermediate layer 493 and the second intermediate layer 494 are nickel, the Young's modulus of each of the first intermediate layer 493 and the second intermediate layer 494 is 200 GPa. The thickness of each of the first intermediate layer 493 and the second intermediate layer 494 is, for example, about 0.2 to 2 μm, which is smaller than the thickness of the first bonding layer 491 and the second bonding layer 492.

[0069] The laminated structure of the conductive bonding material 49 is formed, for example, by sputtering or plating. In the case of sputtering, metal layers corresponding to the first intermediate layer 493 and the first bonding layer 491, and the second intermediate layer 494 and the second bonding layer 492 are sequentially formed on the front and back surfaces of an aluminum sheet corresponding to the metal base layer 490. In the case of plating, a plating layer based on the materials constituting the first intermediate layer 493 and the second intermediate layer 494, and a plating layer based on the materials constituting the first bonding layer 491 and the second bonding layer 492 are sequentially formed over the entire surface of the aluminum sheet. The sheet-like laminated structure thus produced is cut to obtain a plurality of conductive bonding materials 49.

[0070] Next, a method of bonding the conductive portion 20 and the semiconductor element 40 will be described.

[0071] First, the conductive bonding material 49 and the semiconductor element 40 are stacked on the main surface 20A of the conductive portion 20. At this time, the conductive portion 20 (conductive layer 25) and the second bonding layer 492, and the first bonding layer 491 and the semiconductor element 40 (back surface electrode 43) are in contact with each other.

[0072] Next, the conductive portion 20 (conductor layer 25) and the second bonding layer 492, as well as the first bonding layer 491 and the semiconductor element 40 (back electrode 43) are bonded to each other by solid phase diffusion. Bonding by solid phase diffusion is performed under high temperature and high pressure. Bonding by solid phase diffusion is performed, for example, as follows: Figure 11 As shown, the stacked semiconductor elements 40 are pressed with a flat pressing member 9. Conditions for solid-phase diffusion include, for example, a temperature of approximately 350°C and a pressure of approximately 40 MPa. The temperature and pressure conditions for solid-phase diffusion can be appropriately selected. While this solid-phase diffusion bonding assumes atmospheric conditions, it can also be performed in a vacuum.

[0073] If the conductive portion 20 and the semiconductor element 40 are bonded by solid phase diffusion using the conductive bonding material 49, the portion of the conductive bonding material 49 that overlaps with the semiconductor element 40 when viewed in the z direction is slightly depressed by the pressing force from the semiconductor element 40 side. Figure 6 As shown in FIG. 1 , the conductive bonding material 49 has a height difference at the boundary between a portion overlapping with the semiconductor element 40 when viewed in the z direction and a portion not overlapping with the semiconductor element 40 when viewed in the z direction.

[0074] like Figure 6 、 Figure 8 and Figure 10 As shown, when viewed in the z direction, gaps 495 may be generated near the boundary between the portion where the conductive bonding material 49 overlaps with the semiconductor element 40 and the portion where it does not overlap, at the boundary between the first bonding layer 491 and the back electrode 43 (semiconductor element 40), and at the boundary between the second bonding layer 492 and the conductor layer 25 (conductive portion 20). Figure 6 、 Figure 7 and Figure 9 As shown, when viewed in the z-direction, the boundary between the first bonding layer 491 and the back electrode 43 (semiconductor element 40), and the boundary between the second bonding layer 492 and the conductive layer 25 (conductive portion 20), are difficult to distinguish at a position slightly inward of the boundary between the portion where the conductive bonding material 49 overlaps and the portion where the conductive bonding material 49 does not overlap when viewed in the z-direction. This is because the first bonding layer 491 and the back electrode 43, as well as the second bonding layer 492 and the conductive layer 25, are both made of silver, resulting in solid-phase diffusion bonding of the same metal. Figure 8 and Figure 10In the enlarged view of FIG, the boundary surface between the first bonding layer 491 and the back electrode 43 (semiconductor element 40), and the boundary surface between the second bonding layer 492 and the conductive layer 25 (conductive portion 20), are schematically indicated by dotted lines. This indicates that the first bonding layer 491 and the back electrode 43, and the second bonding layer 492 and the conductive layer 25, are firmly bonded by solid-phase diffusion. This firm bonding by solid-phase diffusion can be confirmed, for example, using an enlarged photograph of a cross-section of the bonded portion (e.g., a SEM photograph).

[0075] The plurality of semiconductor elements 40 include a plurality of first elements 401 and a plurality of second elements 402. Figure 1 、 Figure 2 and Figure 4 As shown, a plurality of first elements 401 are electrically bonded to the principal surface 20A of the first conductive portion 201. The plurality of first elements 401 are arranged at predetermined intervals along the x direction. The plurality of first elements 401 constitute an upper arm circuit of the semiconductor device A10.

[0076] like Figures 1 to 4 As shown, the plurality of second elements 402 are electrically bonded to the principal surface 20A of the second conductive portion 202. The plurality of second elements 402 are arranged at predetermined intervals along the x direction. The plurality of second elements 402 constitute the lower arm circuit of the semiconductor device A10.

[0077] like Figure 2 As shown, the plurality of first elements 401 are arranged in a state offset in the x-direction relative to the plurality of second elements 402. In the illustrated example, three first elements 401 and three second elements 402 are provided. The number of first elements 401 and second elements 402 is not limited to this configuration and can be freely set according to the performance required of the semiconductor device A10, for example.

[0078] The principal surface electrodes 42 of the plurality of first elements 401 are connected to the principal surface 20A of the second conductive portion 202 via, for example, wires 70a (for simplicity, Figure 2 Only one lead 70a is shown. Thus, each of the main surface electrodes 42 of the plurality of first elements 401 is electrically connected to the second conductive portion 202 via the lead. Consequently, the first output terminal 33 is electrically connected to each of the main surface electrodes 42 of the plurality of first elements 401 via the second conductive portion 202 and the lead. The first output terminal 33 serves as the source terminal of the plurality of first elements 401.

[0079] The back electrodes 43 of the plurality of first elements 401 are electrically connected to the first conductive portion 201 via the conductive bonding material 49. Therefore, the first input terminal 31 is electrically connected to the back electrodes 43 of the plurality of first elements 401 via the first conductive portion 201. The first input terminal 31 corresponds to the drain terminal of the plurality of first elements 401.

[0080] The principal surface electrodes 42 of the plurality of second elements 402 are connected to the principal surface 20A of the third conductive portion 203 via, for example, wires 70b (for simplicity, Figure 2 Only one lead 70b is shown. Thus, each of the main surface electrodes 42 of the plurality of second elements 402 is electrically connected to the third conductive portion 203 via the lead. Consequently, the second input terminal 32 is electrically connected to each of the main surface electrodes 42 of the plurality of second elements 402 via the third conductive portion 203 and the lead. The second input terminal 32 serves as the source terminal of the plurality of second elements 402.

[0081] The back electrodes 43 of the plurality of second elements 402 are electrically connected to the second conductive portion 202 via the conductive bonding material 49. Therefore, the second output terminal 34 is electrically connected to the back electrodes 43 of the plurality of second elements 402 via the second conductive portion 202. The second output terminal 34 corresponds to the drain terminal of the plurality of second elements 402.

[0082] The semiconductor device A10 includes gate leads and detection leads (not shown). A plurality of gate leads are provided, corresponding to the plurality of first elements 401 and the plurality of second elements 402. Each gate lead corresponding to a first element 401 is connected to the gate (not shown) of the first element 401 and to a gate wiring layer 271 located on the first conductive portion 201. Each gate lead corresponding to a second element 402 is connected to the gate (not shown) of the second element 402 and to another gate wiring layer 271 located on the second conductive portion 202. Furthermore, a gate voltage for driving one of the plurality of first elements 401 and the plurality of second elements 402 is applied to a pair of gate terminals 35 connected to the pair of gate wiring layers 271.

[0083] The aforementioned detection leads are provided in plurality, corresponding to the plurality of first elements 401 and the plurality of second elements 402. Each detection lead corresponding to the first element 401 is connected to the main surface electrode 42 of the first element 401 and a detection wiring layer 272 located on the first conductive portion 201. Each detection lead corresponding to the second element 402 is connected to the main surface electrode 42 of the second element 402 and another detection wiring layer 272 located on the second conductive portion 202. Furthermore, a voltage (a voltage corresponding to a source current) applied to the plurality of main surface electrodes 42 corresponding to any one of the plurality of first elements 401 and the plurality of second elements 402 is applied from a pair of detection terminals 36 connected to the pair of detection wiring layers 272.

[0084] like Figures 2 to 4As shown, sealing resin 80 covers the support substrate 10, portions of the first input terminal 31, the second input terminal 32, the first output terminal 33, and the second output terminal 34, as well as the conductive portion 20 and the plurality of semiconductor elements 40. Sealing resin 80 also covers the pair of insulating layers 26, the pair of gate wiring layers 271, the pair of detection wiring layers 272, and the aforementioned leads. Furthermore, sealing resin 80 covers portions of the pair of gate terminals 35 and the pair of detection terminals 36. Sealing resin 80 is made of, for example, black epoxy resin.

[0085] like Figure 3 and Figure 4 As shown, the sealing resin 80 has a resin main surface 81 and a resin bottom surface 82. The resin main surface 81 faces the same side as the support surface 10A of the support substrate 10 in the z direction. The resin bottom surface 82 faces the opposite side of the resin main surface 81 in the z direction. The bottom surface 10B of the base plate 13 (support substrate 10) is exposed from the resin bottom surface 82. The resin bottom surface 82 is a frame-shaped portion surrounding the base plate 13. It should be noted that the portions of the pair of gate terminals 35 and the pair of detection terminals 36 exposed from the sealing resin 80 can be appropriately bent according to the usage form of the semiconductor device A10.

[0086] Next, the effects of the semiconductor device A10 will be described.

[0087] In the semiconductor device A10, the conductive bonding material 49 between the conductive portion 20 and the semiconductor element 40 includes a metal base layer 490, a first bonding layer 491, and a second bonding layer 492. The metal base layer 490 is located between the first bonding layer 491 and the second bonding layer 492. With this configuration, when the first bonding layer 491 is bonded to the semiconductor element 40 (back electrode 43), and when the second bonding layer 492 is bonded to the conductive portion 20 (conductor layer 25), the intermediate metal base layer 490 functions as a buffer. As a result, the pressing force acting on the boundary between the first bonding layer 491 and the semiconductor element 40 (back electrode 43) and the boundary between the second bonding layer 492 and the conductive portion 20 (conductor layer 25) is uniformized. Furthermore, the first bonding layer 491 and the semiconductor element 40 (back electrode 43), and the second bonding layer 492 and the conductive portion 20 (conductor layer 25), are firmly bonded by solid-phase diffusion bonding. As a result, even when the conductive bonding material 49 is repeatedly exposed to high temperatures due to heat generated by the semiconductor element 40 during use of the semiconductor device A10, changes (deterioration) in the bonding state of the conductive bonding material 49 are suppressed. Therefore, according to the semiconductor device A10 including the conductive bonding material 49, the reliability of the bonding state between the semiconductor element 40 and the conductive portion 20 can be improved.

[0088] In this embodiment, the Young's modulus of the metal base layer 490 is smaller than the Young's modulus of the constituent materials of each of the first bonding layer 491 and the second bonding layer 492. According to such a configuration, when the conductive bonding material 49 is bonded to the semiconductor element 40 (back electrode 43) and the conductive portion 20 (conductor layer 25) by solid-phase diffusion, the stress is relieved by the relatively soft metal base layer 490, and the bonding boundary portion can be smoothed. As a result, the first bonding layer 491 and the semiconductor element 40 (back electrode 43), and the second bonding layer 492 and the conductive portion 20 (conductor layer 25) are more firmly bonded by solid-phase diffusion.

[0089] In this embodiment, the thickness of the metal base layer 490 is greater than the thickness of each of the first bonding layer 491 and the second bonding layer 492. As a result, during solid-phase diffusion bonding, the pressing force applied to the boundary between the first bonding layer 491 and the semiconductor element 40 (back electrode 43), and to the boundary between the second bonding layer 492 and the conductive portion 20 (conductive layer 25), becomes more uniform. Consequently, a more robust conductive bond can be formed between the first bonding layer 491 and the semiconductor element 40 (back electrode 43), and between the second bonding layer 492 and the conductive portion 20 (conductive layer 25).

[0090] The conductive bonding material 49 includes a first intermediate layer 493 and a second intermediate layer 494. The first intermediate layer 493 exists between the metal base layer 490 and the first bonding layer 491, and the second intermediate layer 494 exists between the metal base layer 490 and the second bonding layer 492. The structure having the first intermediate layer 493 and the second intermediate layer 494 is suitable for achieving uniform pressure acting on the boundary between the first bonding layer 491 and the semiconductor element 40 (back electrode 43) and the boundary between the second bonding layer 492 and the conductive portion 20 (conductor layer 25) during solid-phase diffusion bonding. In addition, if the constituent material of the first intermediate layer 493 and the second intermediate layer 494 is nickel, the Young's modulus of the first intermediate layer 493 and the second intermediate layer 494 is large. In this case, during solid-phase diffusion bonding, the pressing force acting on the bonding boundary becomes more uniform, and the first bonding layer 491 and the semiconductor element 40 (back electrode 43), and the second bonding layer 492 and the conductive part 20 (conductor layer 25) can form a more secure conductive bonding state.

[0091] In this embodiment, the constituent materials of the first bonding layer 491 and the second bonding layer 492 each contain silver. With this configuration, when solid-phase diffusion bonding is performed using the conductive bonding material 49, oxidation of the first bonding layer 491 and the second bonding layer 492 is suppressed, enabling good solid-phase diffusion bonding. Furthermore, since the back electrode 43 and the conductor layer 25, which are bonded to the first bonding layer 491 and the second bonding layer 492, respectively, contain silver, even better solid-phase diffusion bonding is achieved.

[0092] about Figure 3 and Figure 4 The specific structure of the bonding member 19 shown as existing between the conductive part 20 and the support substrate 10 (second support plate 12) is not particularly limited, and can be set to the same structure as the aforementioned conductive bonding material 49. The bonding member 19 is, for example, a structure composed of a plurality of stacked metal layers, including a plurality of metal layers bonded by solid-phase diffusion. The bonding member 19 can include a metal base layer, a first bonding layer, a second bonding layer, a first intermediate layer and a second intermediate layer in the same manner as the conductive bonding material 49. The specific structures of the metal base layer, the first bonding layer, the second bonding layer, the first intermediate layer and the second intermediate layer are respectively the same as the metal base layer 490, the first bonding layer 491, the second bonding layer 492, the first intermediate layer 493 and the second intermediate layer 494 in the conductive bonding material 49. In this case, the first bonding layer of the bonding member 19 is bonded to the conductive part 20 by solid-phase diffusion of the metal, and the second bonding layer of the bonding member 19 is bonded to the support substrate 10 (second support plate 12) by solid-phase diffusion of the metal.

[0093] according to Figures 12 to 20 A semiconductor device A20 according to a second embodiment will now be described. The illustrated semiconductor device A20 includes a support member 1, a conductive portion 2, a semiconductor laser element 4, a switching element 5, a capacitor 6, a first lead 71, a second lead 72, a third lead 73, and a light-transmitting resin 8. The semiconductor device A20 is used, for example, as a pulsed laser light source for LiDAR, an example of two-dimensional distance measurement, but the present disclosure is not limited thereto.

[0094] like Figure 12 As shown, the semiconductor device A20 is rectangular when viewed in the z direction. Figure 12 The light-transmitting resin 8 is omitted. Figure 12 In the figure, bracketed reference numerals 84 to 87 respectively represent four side surfaces of the light-transmitting resin 8 (a first resin surface, a second resin surface, a third resin surface, and a fourth resin surface described later).

[0095] The support member 1 supports the semiconductor laser element 4 and the switching element 5 via the conductive portion 2. The support member 1 is made of an insulating material. The material of the support member 1 is not particularly limited, and examples thereof include epoxy resin and glass epoxy resin. The following description uses the case where the support member 1 is made of ceramic as an example. In this embodiment, the support member 1 has a support surface 1A, a bottom surface 1B, a first surface 14, a second surface 15, a third surface 16, and a fourth surface 17, and has a rectangular shape when viewed in the z direction.

[0096] The support surface 1A is a surface facing one side in the z direction and is a flat surface in the example shown in the figure. The bottom surface 1B is a surface facing the other side in the z direction opposite to the support surface 1A and is a flat surface in the example shown in the figure. The first surface 14 is a surface facing one side in the x direction and is a flat surface in the example shown in the figure. The second surface 15 is a surface facing the other side in the x direction opposite to the first surface 14 and is a flat surface in the example shown in the figure. The third surface 16 is a surface facing one side in the y direction and is a flat surface in the example shown in the figure. The fourth surface 17 is a surface facing the other side in the x direction opposite to the third surface 16 and is a flat surface in the example shown in the figure.

[0097] The conductive portion 2 forms a conductive path to the semiconductor laser element 4, the switching element 5, and the like. The material of the conductive portion 2 is not particularly limited; examples thereof include metals such as copper (Cu), nickel (Ni), titanium (Ti), and gold (Au). Furthermore, the method for forming the conductive portion 2 is not particularly limited; in the illustrated example, the conductive portion 2 is formed by plating, for example.

[0098] The conductive portion 2 shown in the figure includes a main surface portion 21 , a bottom surface portion 22 , and a connecting portion 23 .

[0099] The main surface portion 21 is disposed on the support surface 1A of the support member 1. The main surface portion 21 is in the shape of a thin plate with its thickness extending in the z-direction. The main surface portion 21 comprises multiple sections, including a first main surface portion 211, a second main surface portion 212, a third main surface portion 213, and a fourth main surface portion 214 in the illustrated example.

[0100] like Figure 12 and Figure 14 As shown, the first main surface portion 211 is arranged on the side of the fourth surface 17 in the y direction of the support member 1. The first main surface portion 211 has a main surface 211A facing one side in the z direction. The shape of the first main surface portion 211 is not particularly limited. In the example shown in the figure, it is a shape in which a convex portion 211B is combined in a long rectangle with the x direction as the longitudinal direction. The convex portion 211B is a portion of the first main surface portion 211 on the side of the third surface 16 in the y direction, which protrudes toward the third surface 16 in the y direction. The convex portion 211B is located at the center of the first main surface portion 211 in the x direction. The first main surface portion 211 is separated from the first surface 14, the second surface 15 and the fourth surface 17.

[0101] like Figure 12 and Figure 14As shown, the second main surface portion 212 is arranged closer to the third surface 16 than the first main surface portion 211 in the y-direction. The second main surface portion 212 has a main surface 212A facing one side in the z-direction. The x-direction dimension of the second main surface portion 212 is substantially the same as the x-direction dimension of the first main surface portion 211. The y-direction dimension of the second main surface portion 212 is larger than the y-direction dimension of the first main surface portion 211. The second main surface portion 212 overlaps with the first main surface portion 211 when viewed in the y-direction. The shape of the second main surface portion 212 is not particularly limited; in the example shown, it is a rectangular shape with a recessed portion. The second main surface portion 212 has a recessed portion 212B. The recessed portion 212B is a portion of the second main surface portion 212 on the fourth surface 17 side in the y-direction that is recessed toward the third surface 16 in the y-direction. The recessed portion 212B is located at the center of the second main surface portion 212 in the x-direction. The concave portion 212B overlaps the convex portion 211B when viewed in the y direction. The second main surface portion 212 has a larger area than the first main surface portion 211 , the third main surface portion 213 , and the fourth main surface portion 214 . The second main surface portion 212 is separated from the first surface 14 and the second surface 15 .

[0102] like Figure 12 and Figure 14 As shown, the third main surface portion 213 is positioned closer to the third surface 16 in the y-direction than the second main surface portion 212. The third main surface portion 213 is positioned on the first surface 14 side in the x-direction and on the third surface 16 side in the y-direction of the support member 1. The third main surface portion 213 has a main surface 213A facing one side in the z-direction. The shape of the third main surface portion 213 is not particularly limited; in the illustrated example, it is an elongated rectangle with its longitudinal direction in the x-direction. The illustrated third main surface portion 213 is separated from the first surface 14 and the third surface 16.

[0103] like Figure 12 As shown, the fourth main surface portion 214 is located adjacent to the second surface 15 in the x-direction relative to the third main surface portion 213, and adjacent to the third surface 16 in the y-direction relative to the second main surface portion 212. The fourth main surface portion 214 has a main surface 214A facing one side in the z-direction. The shape of the fourth main surface portion 214 is not particularly limited; in the illustrated example, it is rectangular. In the illustrated example, the y-direction dimension of the fourth main surface portion 214 is substantially the same as the y-direction dimension of the third main surface portion 213. Furthermore, the x-direction dimension of the fourth main surface portion 214 is smaller than the x-direction dimension of the third main surface portion 213. The area of ​​the fourth main surface portion 214 is smaller than that of the third main surface portion 213. When viewed in the x-direction, the fourth main surface portion 214 overlaps with the third main surface portion 213. Furthermore, when viewed in the y-direction, the fourth main surface portion 214 overlaps with the first main surface portion 211 and the second main surface portion 212. The illustrated fourth main surface portion 214 is separated from the second surface 15 and the third surface 16.

[0104] like Figure 13 and Figure 14 As shown, the bottom portion 22 is arranged on the bottom surface 1B of the support member 1. In the example shown in the figure, the bottom portion 22 includes a first bottom portion 221, a second bottom portion 222, a third bottom portion 223, and a fourth bottom portion 224. In this embodiment, the bottom portion 22 is used as a mounting terminal when the semiconductor device A20 is mounted on a circuit board (not shown) or the like.

[0105] like Figure 13 and Figure 14 As shown, the first bottom portion 221 is disposed on the y-direction side of the support member 1, closer to the fourth surface 17. The shape of the first bottom portion 221 is not particularly limited; in the illustrated example, it is an elongated rectangle with its longitudinal direction in the x-direction. The illustrated first bottom portion 221 is separated from the first surface 14, the second surface 15, and the fourth surface 17.

[0106] like Figure 13 and Figure 14 As shown, the second bottom portion 222 is arranged closer to the third surface 16 than the first bottom portion 221 in the y-direction. The x-direction dimension of the first bottom portion 221 is substantially the same as the x-direction dimension of the first bottom portion 221. The y-direction dimension of the second bottom portion 222 is larger than the y-direction dimension of the first bottom portion 221. The second bottom portion 222 overlaps with the first bottom portion 221 when viewed in the y-direction. The shape of the second bottom portion 222 is not particularly limited; in the example shown in the figure, it is a rectangle. The area of ​​the second bottom portion 222 is larger than that of the first bottom portion 221, the third bottom portion 223, and the fourth bottom portion 224. The second bottom portion 222 shown in the figure is separated from the first surface 14 and the second surface 15.

[0107] like Figure 13 and Figure 14 As shown, the third bottom portion 223 is positioned closer to the third surface 16 than the second bottom portion 222 in the y-direction. The third bottom portion 223 is positioned on the first surface 14 side of the support member 1 in the x-direction and on the third surface 16 side in the y-direction. The shape of the third bottom portion 223 is not particularly limited; in the illustrated example, it is an elongated rectangle with its longitudinal direction in the x-direction. The illustrated third bottom portion 223 is separated from the first surface 14 and the third surface 16.

[0108] like Figure 13As shown, the fourth bottom portion 224 is located adjacent to the second surface 15 in the x-direction relative to the third bottom portion 223, and adjacent to the third surface 16 in the y-direction relative to the second bottom portion 222. The shape of the fourth bottom portion 224 is not particularly limited; in the illustrated example, it is rectangular. In the illustrated example, the y-direction dimension of the fourth bottom portion 224 is substantially the same as the y-direction dimension of the third bottom portion 223. Furthermore, the x-direction dimension of the fourth bottom portion 224 is smaller than the x-direction dimension of the third bottom portion 223. The area of ​​the fourth bottom portion 224 is smaller than the area of ​​the third bottom portion 223. When viewed in the x-direction, the fourth bottom portion 224 overlaps with the third bottom portion 223. Furthermore, when viewed in the y-direction, the fourth bottom portion 224 overlaps with the first bottom portion 221 and the second bottom portion 222. The illustrated fourth bottom portion 224 is separated from the second surface 15 and the third surface 16.

[0109] The connection portion 23 connects the parts of the main surface portion 21 with the parts of the bottom surface portion 22. The specific structure of the connection portion 23 is not particularly limited. Figure 12 and Figure 13 As shown, it includes a first communication portion 231, a plurality of second communication portions 232, a plurality of third communication portions 233, and a fourth communication portion 234. The number of the first communication portion 231, the second communication portion 232, the third communication portion 233, and the fourth communication portion 234 is not particularly limited.

[0110] The specific structures of the first communication part 231, the second communication part 232, the third communication part 233 and the fourth communication part 234 are not particularly limited. Figures 12 to 14 As shown, the inner region of the support member 1 (the region separated from the first surface 14, the second surface 15, the third surface 16, and the fourth surface 17) when viewed in the z-direction penetrates the support member 1 in the thickness direction. These first connecting portions 231, the second connecting portions 232, the third connecting portions 233, and the fourth connecting portions 234 are formed by forming a metal plating layer on the inner surface of the through-hole formed in the support member 1, and reach the support surface 1A and the bottom surface 1B. In the illustrated example, the interiors of the first connecting portions 231, the second connecting portions 232, the third connecting portions 233, and the fourth connecting portions 234 are filled with resin, but they may also be filled with metal, for example.

[0111] like Figures 12 to 14 As shown, the first connecting portion 231 is connected to the first main surface portion 211 and the first bottom surface portion 221 , thereby connecting the first main surface portion 211 and the first bottom surface portion 221 .

[0112] like Figures 12 to 14As shown, the second connecting portions 232 are connected to the second main surface portion 212 and the second bottom surface portion 222, thereby connecting the second main surface portion 212 and the second bottom surface portion 222. In the example shown, the second connecting portions 232 are arranged in a matrix along the x-direction and the y-direction.

[0113] like Figures 12 to 14 As shown, a plurality of third connecting portions 233 are connected to the third main surface portion 213 and the third bottom surface portion 223, thereby connecting the third main surface portion 213 and the third bottom surface portion 223. In this embodiment, the plurality of third connecting portions 233 are arranged along the x-direction. The plurality of third connecting portions 233 are arranged adjacent to the third surface 16 in the y-direction.

[0114] like Figure 12 and Figure 13 As shown, the fourth connecting portion 234 is connected to the fourth main surface portion 214 and the fourth bottom surface portion 224, thereby connecting the fourth main surface portion 214 and the fourth bottom surface portion 224. Unlike the illustrated example, a configuration having a plurality of fourth connecting portions 234 is also possible.

[0115] The semiconductor laser element 4 is a light source of the semiconductor device A20 and includes an active layer made of semiconductor. Figure 14 As shown, semiconductor laser element 4 includes element body 41, first laser electrode 44, and second laser electrode 45. Element body 41 has element principal surface 411 and element back surface 412. Element principal surface 411 and element back surface 412 face opposite sides in the z-direction. Element principal surface 411 faces the same side as principal surface 211A in the z-direction. Element back surface 412 faces principal surface 211A.

[0116] The first laser electrode 44 is arranged on the element main surface 411 . The second laser electrode 45 is arranged on the element rear surface 412 . Figure 12 The first laser electrode 44 is omitted in the figure. In this embodiment, the first laser electrode 44 is an anode electrode, and the second laser electrode 45 is a cathode electrode. The second laser electrode 45 is made of, for example, silver, or a laminate of multiple metal layers such as nickel and silver.

[0117] like Figure 12 and Figure 14 As shown, in this embodiment, the semiconductor laser element 4 is disposed on the first main surface portion 211. Specifically, the second laser electrode 45 of the semiconductor laser element 4 is electrically bonded to the main surface 211A of the first main surface portion 211 via a conductive bonding material 49. In the illustrated example, the semiconductor laser element 4 overlaps with the convex portion 211B and the concave portion 212B when viewed in the y-direction. The semiconductor laser element 4 emits laser light L toward the side in the y-direction toward which the fourth surface 17 faces. Furthermore, in the illustrated example, the semiconductor laser element 4 overlaps with the first connecting portion 231 when viewed in the z-direction.

[0118] The conductive bonding material 49 exists between the conductive portion 2 (the first main surface portion 211 of the main surface portion 21) and the semiconductor laser element 4. The conductive bonding material 49 is larger than the semiconductor laser element 4 when viewed in the z direction, and the semiconductor laser element 4 and the conductive bonding material 49 are entirely overlapped when viewed in the z direction. The conductive bonding material 49 is composed of a plurality of stacked metal layers. Figure 15 and Figure 16 As shown, in the semiconductor device A20, the conductive bonding material 49 includes a metal base layer 490, a first bonding layer 491, and a second bonding layer 492. Figures 17 to 20 As shown, the conductive bonding material 49 further includes a first intermediate layer 493 and a second intermediate layer 494 .

[0119] The metal base layer 490 occupies the majority of the volume of the conductive bonding material 49. The thickness of the metal base layer 490 is, for example, approximately 10 to 200 μm. The metal base layer 490 is composed of, for example, at least one of aluminum, titanium, zinc, hafnium, and erbium. In this embodiment, the metal base layer 490 is composed of aluminum. When the metal base layer 490 is composed of aluminum, the Young's modulus of the metal base layer 490 is 70.3 GPa.

[0120] The first bonding layer 491 exists between the metal base layer 490 and the semiconductor laser element 4. Figure 17 and Figure 18 As shown, the first bonding layer 491 is formed on the first intermediate layer 493. The constituent material of the first bonding layer 491 includes, for example, at least one of silver, copper, and gold. In this embodiment, the constituent material of the first bonding layer 491 includes silver. The first bonding layer 491 is bonded to the semiconductor laser element 4 (second laser electrode 45) by solid-phase diffusion of the metal. The constituent material of the second laser electrode 45 includes, for example, silver. The thickness of the second laser electrode 45 is smaller than that of the first bonding layer 491 and the second laser electrode 45 is formed, for example, by sputtering.

[0121] The second bonding layer 492 exists between the metal base layer 490 and the conductive portion 2 (the first main surface portion 211). Figure 19 and Figure 20 As shown, the second bonding layer 492 is formed on the second intermediate layer 494. The constituent material of the second bonding layer 492 includes, for example, at least one of silver, copper, and gold. In this embodiment, the constituent material of the second bonding layer 492 includes silver. The second bonding layer 492 is bonded to the conductive portion 2 (first main surface portion 211) by solid-phase diffusion of the metal.

[0122] When the first bonding layer 491 and the second bonding layer 492 are each made of silver, the Young's modulus of each of the first bonding layer 491 and the second bonding layer 492 is 82.7 GPa. Therefore, as indicated by the Young's modulus of the metal base layer 490 (70.3 GPa) described above, the Young's modulus of the metal base layer 490 is smaller than the Young's modulus of each of the first bonding layer 491 and the second bonding layer 492. Furthermore, the thickness of each of the first bonding layer 491 and the second bonding layer 492 is, for example, approximately 2 to 5 μm, which is smaller than the thickness of the metal base layer 490.

[0123] like Figure 17 and Figure 18 As shown, the first intermediate layer 493 exists between the metal base layer 490 and the first bonding layer 491. In this embodiment, the first intermediate layer 493 is formed on the metal base layer 490. Figure 19 and Figure 20 As shown, the second intermediate layer 494 exists between the metal base layer 490 and the second bonding layer 492. In this embodiment, the second intermediate layer 494 is formed on the metal base layer 490. The constituent materials of the first intermediate layer 493 and the second intermediate layer 494 each contain nickel, for example. When the constituent materials of the first intermediate layer 493 and the second intermediate layer 494 are each nickel, the Young's modulus of each of the first intermediate layer 493 and the second intermediate layer 494 is 200 GPa. In addition, the thickness of each of the first intermediate layer 493 and the second intermediate layer 494 is, for example, about 0.2 to 2 μm, which is smaller than the thickness of the first bonding layer 491 and the second bonding layer 492.

[0124] The stacked structure of the conductive bonding material 49 is formed by, for example, sputtering or plating. The method for forming the conductive bonding material 49 is the same as that of the conductive bonding material 49 in the aforementioned semiconductor device A10. The method for bonding the conductive portion 2 (first main surface portion 211) to the semiconductor laser element 4 using the conductive bonding material 49 is also the same as that in the aforementioned semiconductor device A10. Figure 11 The method of explanation is the same.

[0125] When the conductive portion 2 and the semiconductor laser element 4 are solid-phase diffusion-bonded using the conductive bonding material 49, the portion of the conductive bonding material 49 that overlaps with the semiconductor laser element 4 when viewed in the z direction is slightly depressed by the pressing force from the semiconductor laser element 4. Figure 16 As shown in FIG. 1 , a height difference is formed at the boundary between a portion of the conductive bonding material 49 that overlaps with the semiconductor laser element 4 when viewed in the z direction and a portion that does not overlap with the semiconductor laser element 4 when viewed in the z direction.

[0126] like Figure 16 、 Figure 18 and Figure 20As shown, when viewed in the z direction, gaps 495 may be generated near the boundary between the portion where the conductive bonding material 49 overlaps with the semiconductor laser element 4 and the portion where it does not overlap, at the boundary between the first bonding layer 491 and the second laser electrode 45 (semiconductor laser element 4), and at the boundary between the second bonding layer 492 and the first main surface portion 211 (conductive portion 2). On the other hand, as Figure 16 、 Figure 17 and Figure 19 As shown, when viewed in the z-direction, slightly inward of the boundary between the portion where the conductive bonding material 49 overlaps and the portion where it does not overlap (the portion where the conductive bonding material 49 overlaps with the semiconductor laser element 4 when viewed in the z-direction), there is no gap between the interface between the first bonding layer 491 and the second laser electrode 45 (semiconductor laser element 4), and between the interface between the second bonding layer 492 and the first main surface portion 211 (conductive portion 2). This indicates that the first bonding layer 491 and the second laser electrode 45, and the second bonding layer 492 and the first main surface portion 211, are firmly bonded by solid-phase diffusion.

[0127] The switch element 5 is an element for turning on / off the current flowing to the semiconductor laser element 4. The switch element 5 is, for example, a transistor such as a FET made of Si, SiC, or GaN. When the switch element 5 is made of SiC, it is suitable for achieving high-speed switching. Figure 12 and Figure 14 As shown, the switching element 5 includes an element body 51, a gate 52, a source 53, and a drain 54. The element body 51 is made of a semiconductor material such as Si or SiC and has an element main surface 511 and an element back surface 512. The element main surface 511 is the surface facing the same side as the main surface 212A in the z direction. The element back surface 512 is the surface facing the same side as the bottom surface 1B in the z direction and is opposite to the main surface 212A.

[0128] The gate 52 is arranged on the element main surface 511. In the example shown, the gate 52 is arranged next to the second surface 15 in the x direction and next to the third surface 16 in the y direction. The shape of the gate 52 is not particularly limited, but in the example shown, it is rectangular when viewed in the z direction.

[0129] The source electrode 53 is arranged on the element main surface 511. In the example shown in the figure, the source electrode 53 is L-shaped when viewed in the z direction and is arranged in a region on the first surface 14 side in the x direction and next to the fourth surface 17 in the y direction relative to the gate 52.

[0130] The drain electrode 54 is disposed on the device rear surface 512 , and in the example shown in the figure, covers substantially the entire surface of the device rear surface 512 .

[0131] like Figure 12 and Figure 14 As shown, in this embodiment, the switching element 5 is disposed on the second main surface portion 212. Specifically, the drain electrode 54 of the switching element 5 is electrically bonded to the main surface 212A of the second main surface portion 212 via a conductive bonding material 59. In this embodiment, the switching element 5 is disposed on the second main surface portion 212 adjacent to the first surface 14 in the x-direction. When viewed in the z-direction, the switching element 5 completely overlaps with the plurality of second contact portions 232. When viewed in the y-direction, the switching element 5 overlaps with the semiconductor laser element 4.

[0132] The conductive bonding material 59 exists between the conductive portion 2 (the second main surface portion 212 of the main surface portion 21) and the switching element 5. The conductive bonding material 59 is larger than the switching element 5 when viewed in the z direction, and the switching element 5 as a whole overlaps with the conductive bonding material 59 when viewed in the z direction. The conductive bonding material 59 is composed of a plurality of stacked metal layers. Like the conductive bonding material 49, the conductive bonding material 59 includes a metal base layer, a first bonding layer, a second bonding layer, a first intermediate layer, and a second intermediate layer. The specific composition of the metal base layer, the first bonding layer, the second bonding layer, the first intermediate layer, and the second intermediate layer is the same as the metal base layer 490, the first bonding layer 491, the second bonding layer 492, the first intermediate layer 493, and the second intermediate layer 494 in the conductive bonding material 49, respectively. The first bonding layer of the conductive bonding material 59 is bonded to the switching element 5 (drain 54) by solid-phase diffusion of the metal, and the second bonding layer of the conductive bonding material 59 is bonded to the conductive portion 2 (second main surface portion 212) by solid-phase diffusion of the metal. The method of forming the conductive bonding material 59 is the same as that of the conductive bonding material 49 in the aforementioned semiconductor device A10. The method of bonding the conductive portion 2 (second main surface portion 212) to the switching element 5 using the conductive bonding material 59 is also the same as that in the aforementioned semiconductor device A10. Figure 11 The method of explanation is the same.

[0133] The capacitor 6 is an element for temporarily storing electric charge to be used as a current to be supplied to the semiconductor laser element 4. Figure 12 As shown, in the example shown in the figure, the capacitor 6 has an electrode 61 and an electrode 62. The electrode 61 is conductively bonded to the first main surface 211 via a bonding member (not shown). The electrode 62 is conductively bonded to the second main surface 212 via a bonding member (not shown). The bonding member is, for example, solder. In this embodiment, the semiconductor device A20 includes two capacitors 6. The two capacitors 6 are connected in parallel to each other. In addition, in this embodiment, the two capacitors 6 are arranged on both sides of the semiconductor laser element 4 in the x direction. When viewed in the y direction, the two capacitors 6 do not overlap with 12B and the protrusion 211B.

[0134] like Figure 12 and Figure 14As shown, multiple first leads 71 ​​are connected to the source electrode 53 of the switching element 5 and the first laser electrode 44 of the semiconductor laser element 4. The first leads 71 ​​are made of a metal such as Au, Cu, or Al, and in this embodiment, are made of Au. The number of first leads 71 ​​is not particularly limited; in the illustrated example, there are three. The multiple first leads 71 ​​are connected to the portion of the source electrode 53 adjacent to the fourth surface 17 in the y direction. The multiple first leads 71 ​​are connected to the first laser electrode 44 of the semiconductor laser element 4 in a manner aligned in the y direction.

[0135] like Figure 12 and Figure 14 As shown, the plurality of second leads 72 are connected to the source 53 of the switching element 5 and the third main surface 213 of the main surface 21 of the conductive portion 2. The second lead 72 is made of a metal such as Au, Cu, or Al, and in this embodiment, is made of Au like the first lead 71. The number of the plurality of second leads 72 is not particularly limited, but in the example shown, it is two, which is less than the number of the plurality of first leads 71. Therefore, the resistance value of the plurality of first leads 71 ​​is smaller than the resistance value of the plurality of second leads 72. The plurality of second leads 72 are connected to a portion of the source 53 next to the third surface 16 in the y direction. The plurality of second leads 72 are connected to the third main surface 213 in a manner parallel to the x direction.

[0136] like Figure 12 As shown, the third lead 73 is connected to the gate 52 of the switching element 5 and the fourth main surface 214 of the main surface 21 of the conductive portion 2. The third lead 73 is made of a metal such as Au, Cu, or Al, and in this embodiment is made of Au. The number of third leads 73 is not particularly limited; in the illustrated example, there is one.

[0137] Light-transmitting resin 8 is disposed on support surface 1A of support member 1, covering support surface 1A, semiconductor laser element 4, switching element 5, multiple capacitors 6, multiple first leads 71, multiple second leads 72, and third lead 73. Light-transmitting resin 8 is made of a material that transmits laser light L from semiconductor laser element 4, such as a transparent epoxy resin or silicone resin.

[0138] The shape of the light-transmitting resin 8 is not particularly limited. Figure 12 and Figure 14 As shown, the light-transmitting resin 8 has a resin main surface 81 , a resin first surface 84 , a resin second surface 85 , a resin third surface 86 , and a resin fourth surface 87 .

[0139] The resin main surface 81 is a surface facing the same side as the support surface 1A in the z direction and is a flat surface in the example shown in the figure. The resin first surface 84 is a surface facing the same side as the first surface 14 in the x direction. In the example shown in the figure, the resin first surface 84 is a flat surface and is on the same plane as the first surface 14. The resin second surface 85 is a surface facing the same side as the second surface 15 in the x direction. In the example shown in the figure, the resin second surface 85 is a flat surface and is on the same plane as the second surface 15. The resin third surface 86 is a surface facing the same side as the third surface 16 in the y direction. In the example shown in the figure, the resin third surface 86 is a flat surface and is on the same plane as the third surface 16. The resin fourth surface 87 is a surface facing the same side as the fourth surface 17 in the y direction. In the example shown in the figure, the resin fourth surface 87 is a flat surface and is on the same plane as the resin fourth surface 87. In this embodiment, the laser light L from the semiconductor laser element 4 is emitted from the resin fourth surface 87 of the light-transmitting resin 8. Note that, by making the resin fourth surface 87 a flat and smooth surface, scattering of the laser light L can be suppressed and emission efficiency can be improved.

[0140] Next, the operation of the semiconductor device A20 will be described.

[0141] In semiconductor device A20, the conductive bonding material 49 between the conductive portion 2 and the semiconductor laser element 4 includes a metal base layer 490, a first bonding layer 491, and a second bonding layer 492. The first bonding layer 491 and the semiconductor laser element 4 (second laser electrode 45), and the second bonding layer 492 and the conductive portion 2 (first main surface portion 211), are conductively bonded by solid-phase diffusion of metal, with the metal base layer 490 being present between the first bonding layer 491 and the second bonding layer 492. With this configuration, the metal base layer 490 functions as a buffer when the first bonding layer 491 and the semiconductor laser element 4 (second laser electrode 45), and the second bonding layer 492 and the conductive portion 2 (first main surface portion 211), are bonded by solid-phase diffusion. This makes it possible to achieve uniformity in the pressing force acting on the boundary between the first bonding layer 491 and the semiconductor laser element 4 (second laser electrode 45), and on the boundary between the second bonding layer 492 and the conductive portion 2 (first main surface portion 211). Therefore, the first bonding layer 491 and the semiconductor laser element 4 (second laser electrode 45), and the second bonding layer 492 and the conductive portion 2 (first main surface portion 211), are firmly bonded by solid-phase diffusion bonding. As a result, even when the conductive bonding material 49 is repeatedly exposed to a high temperature state due to the heat generated by the semiconductor laser element 4 when the semiconductor device A20 is used, changes in the bonding state of the conductive bonding material 49 are suppressed. Therefore, according to the semiconductor device A20 having the conductive bonding material 49, the reliability of the bonding state between the semiconductor laser element 4 and the conductive portion 2 can be improved.

[0142] In this embodiment, the Young's modulus of the metal base layer 490 is smaller than the Young's modulus of the constituent materials of the first bonding layer 491 and the second bonding layer 492. According to this structure, when the conductive bonding material 49 is bonded to the semiconductor laser element 4 (second laser electrode 45) and the conductive portion 2 (first main surface portion 211) through solid-phase diffusion, the relatively soft metal base layer 490 is used to relieve stress, and the bonding boundary portion can be smoothed. As a result, the first bonding layer 491 and the semiconductor laser element 4 (second laser electrode 45), and the second bonding layer 492 and the conductive portion 2 (first main surface portion 211) are more firmly bonded through solid-phase diffusion.

[0143] In this embodiment, the thickness of the metal base layer 490 is greater than the thickness of each of the first bonding layer 491 and the second bonding layer 492. As a result, during solid-phase diffusion bonding, the pressing force applied to the boundary between the first bonding layer 491 and the semiconductor laser element 4 (second laser electrode 45), and to the boundary between the second bonding layer 492 and the conductive portion 2 (first main surface portion 211), becomes more uniform. Consequently, a more robust conductive bond can be formed between the first bonding layer 491 and the semiconductor laser element 4 (second laser electrode 45), and between the second bonding layer 492 and the conductive portion 2 (first main surface portion 211).

[0144] The conductive bonding material 49 includes a first intermediate layer 493 and a second intermediate layer 494. The first intermediate layer 493 exists between the metal base layer 490 and the first bonding layer 491, and the second intermediate layer 494 exists between the metal base layer 490 and the second bonding layer 492. The structure having the first intermediate layer 493 and the second intermediate layer 494 is suitable for achieving uniform pressure acting on the boundary between the first bonding layer 491 and the semiconductor laser element 4 (second laser electrode 45) and the boundary between the second bonding layer 492 and the conductive portion 2 (first main surface portion 211) during solid-phase diffusion bonding. In addition, if the constituent material of the first intermediate layer 493 and the second intermediate layer 494 is nickel, the Young's modulus of the first intermediate layer 493 and the second intermediate layer 494 is large. In this case, during solid-phase diffusion bonding, the pressing force acting on the bonding boundary becomes more uniform, and the first bonding layer 491 and the semiconductor laser element 4 (the second laser electrode 45), and the second bonding layer 492 and the conductive part 2 (the first main surface 211) can form a more secure conductive bonding state.

[0145] In this embodiment, the constituent materials of the first bonding layer 491 and the second bonding layer 492 each contain silver. With this configuration, when bonding is performed by solid-phase diffusion using the conductive bonding material 49, oxidation of the first bonding layer 491 and the second bonding layer 492 is suppressed, enabling good solid-phase diffusion bonding.

[0146] The conductive bonding material 59 between the conductive portion 2 and the switching element 5 includes, similarly to the conductive bonding material 49, a metal base layer, a first bonding layer, a second bonding layer, a first intermediate layer, and a second intermediate layer. The specific configurations of the metal base layer, the first bonding layer, the second bonding layer, the first intermediate layer, and the second intermediate layer are similar to the metal base layer 490, the first bonding layer 491, the second bonding layer 492, the first intermediate layer 493, and the second intermediate layer 494 in the conductive bonding material 49, respectively. Therefore, the conductive bonding material 59 can also improve the reliability of the bonding between the switching element 5 and the conductive portion 20. The inclusion of the conductive bonding material 59 achieves the same effects as those described above with respect to the conductive bonding material 49.

[0147] according to Figures 21 to 28 A semiconductor device A30 according to a third embodiment will now be described. The illustrated semiconductor device A30 includes a support member 1, a dam portion 18, a conductive portion 2, an LED element 400, leads 7, and a light-transmitting resin 8. The semiconductor device A30 is used as a light source in various lighting devices, display devices, and the like.

[0148] like Figure 21 As shown, the semiconductor device A30 is rectangular when viewed in the z direction. The x direction and the y direction correspond to directions along the sides of the rectangular semiconductor device A20. Figure 21 The light-transmitting resin 8 is omitted.

[0149] The support member 1 supports the LED element 400 via the conductive portion 2. The support member 1 is made of an insulating material. The material of the support member 1 is not particularly limited, and examples thereof include epoxy resin and glass epoxy resin. In the following description, the case where the support member 1 is made of ceramic is taken as an example. In the present embodiment, the support member 1 has a support surface 1A and a bottom surface 1B, and is, for example, rectangular when viewed in the z direction. The support surface 1A is a surface facing one side in the z direction, and is a plane in the example shown in the figure. The bottom surface 1B is a surface facing the other side in the z direction opposite to the support surface 1A, and is a plane in the example shown in the figure.

[0150] The conductive portion 2 forms a conductive path to the LED element 400. The material of the conductive portion 2 is not particularly limited; examples thereof include metals such as copper (Cu), nickel (Ni), titanium (Ti), and gold (Au). Furthermore, the method for forming the conductive portion 2 is not particularly limited; in the illustrated example, the conductive portion 2 is formed by plating, for example.

[0151] The conductive portion 2 shown in the figure includes a main surface portion 21 , a bottom surface portion 22 , and a connecting portion 23 .

[0152] The main surface portion 21 is disposed on the support surface 1A of the support member 1. The main surface portion 21 is in the shape of a thin plate with the z direction as the thickness direction. In the example shown in the figure, the main surface portion 21 includes a first main surface portion 211 and a second main surface portion 212.

[0153] like Figure 21 and Figure 22 As shown, the first main surface portion 211 is arranged at the center of the support member 1 when viewed in the z direction. The first main surface portion 211 has a main surface 211A facing one side in the z direction. The shape of the first main surface portion 211 is not particularly limited, but is rectangular in the example shown.

[0154] like Figure 21 and Figure 22 As shown, the second main surface portion 212 is located closer to the x-direction side than the first main surface portion 211. The shape of the second main surface portion 212 is not particularly limited, but is rectangular in the example shown. The area of ​​the second main surface portion 212 is smaller than that of the first main surface portion 211.

[0155] like Figure 22 As shown, the bottom portion 22 is arranged on the bottom surface 1B of the support member 1. In the example shown in the figure, the bottom portion 22 includes a first bottom portion 221 and a second bottom portion 222. In this embodiment, the bottom portion 22 is used as a mounting terminal when the semiconductor device A30 is mounted on a circuit board (not shown) or the like.

[0156] like Figure 22 As shown, the first bottom surface portion 221 is arranged at the center of the support member 1 when viewed in the z direction. The shape of the first bottom surface portion 221 is not particularly limited, but is rectangular in this embodiment.

[0157] like Figure 22 As shown, the second bottom portion 222 is disposed closer to the x-direction side than the first bottom portion 221. The shape of the second bottom portion 222 is not particularly limited, but in this embodiment, it is a rectangle. The area of ​​the second bottom portion 222 is smaller than that of the first bottom portion 221.

[0158] The connection portion 23 connects the parts of the main surface portion 21 with the parts of the bottom surface portion 22. The specific structure of the connection portion 23 is not particularly limited. Figure 21 and Figure 22 As shown, it includes a first communication portion 231 and a second communication portion 232. In the example shown in the figure, one first communication portion 231 is provided, but the number of the first communication portions 231 is not particularly limited.

[0159] The specific structure of the first communication part 231 and the second communication part 232 is not particularly limited. In this embodiment, Figure 21 and Figure 22As shown, the inner region of the support member 1, when viewed in the z-direction, penetrates the support member 1 in the thickness direction. Such first and second connecting portions 231, 232 are provided by filling a through-hole formed in the support member 1 with metal, reaching the support surface 1A and the bottom surface 1B. Unlike the illustrated example, the first and second connecting portions 231, 232 may be provided by forming a metal plating layer on the inner surface of the through-hole formed in the support member 1. In this case, the interiors of the first and second connecting portions 231, 232 are filled with resin.

[0160] like Figure 22 As shown, the first connecting portion 231 connects the first main surface portion 211 and the first bottom surface portion 221, thereby connecting the first main surface portion 211 and the first bottom surface portion 221. The second connecting portion 232 connects the second main surface portion 212 and the second bottom surface portion 222, thereby connecting the second main surface portion 212 and the second bottom surface portion 222.

[0161] The LED element 400 is a light source of the semiconductor device A30 and includes an active layer composed of a semiconductor layer. Figure 22 As shown, LED element 400 includes an element body 41, an electrode pad 421, and a back electrode 43. Element body 41 is composed of, for example, a GaN-based semiconductor and emits, for example, blue light. Element body 41 includes an element main surface 411 and an element back surface 412. Element main surface 411 and element back surface 412 face opposite sides in the z-direction. Element main surface 411 faces the same side as main surface 211A in the z-direction. Element back surface 412 faces the same side as bottom surface 1B in the z-direction and is opposite to main surface 211A.

[0162] The electrode pad 421 is arranged on the element main surface 411. The back electrode 43 is arranged on the element back surface 412. In this embodiment, the electrode pad 421 is an anode electrode, and the back electrode 43 is a cathode electrode. The back electrode 43 is made of silver, for example.

[0163] like Figure 21 and Figure 22 As shown, in this embodiment, LED element 400 is disposed on first main surface portion 211. Specifically, back electrode 43 of LED element 400 is electrically bonded to main surface 211A of first main surface portion 211 via conductive bonding material 49. In LED element 400, light emitted from element body 41 is emitted toward the side (z-direction side) toward which element main surface 411 faces. In the illustrated example, LED element 400 overlaps with first connecting portion 231 when viewed in the z-direction.

[0164] The conductive bonding material 49 exists between the conductive portion 2 (the first main surface portion 211 of the main surface portion 21) and the LED element 400. The conductive bonding material 49 is larger than the LED element 400 when viewed in the z direction, and the entire LED element 400 overlaps with the conductive bonding material 49 when viewed in the z direction. The conductive bonding material 49 is composed of a plurality of stacked metal layers. Figure 23 and Figure 24 As shown in FIG. 1 , in the semiconductor device A30, the conductive bonding material 49 includes a metal base layer 490, a first bonding layer 491, and a second bonding layer 492. Figures 25 to 28 As shown, the conductive bonding material 49 further includes a first intermediate layer 493 and a second intermediate layer 494 .

[0165] The metal base layer 490 occupies the majority of the volume of the conductive bonding material 49. The thickness of the metal base layer 490 is, for example, approximately 10 to 200 μm. The metal base layer 490 is composed of, for example, at least one of aluminum, titanium, zinc, hafnium, and erbium. In this embodiment, the metal base layer 490 is composed of aluminum. When the metal base layer 490 is composed of aluminum, the Young's modulus of the metal base layer 490 is 70.3 GPa.

[0166] The first bonding layer 491 exists between the metal base layer 490 and the LED element 400. Figure 25 and Figure 26 As shown, the first bonding layer 491 is formed on the first intermediate layer 493. The constituent material of the first bonding layer 491 includes, for example, at least one of silver, copper, and gold. In this embodiment, the constituent material of the first bonding layer 491 includes silver. The first bonding layer 491 is bonded to the LED element 400 (back electrode 43) by solid-phase diffusion of the metal. The constituent material of the back electrode 43 includes, for example, silver. The thickness of the back electrode 43 is smaller than that of the first bonding layer 491, and the back electrode 43 is formed, for example, by sputtering.

[0167] The second bonding layer 492 exists between the metal base layer 490 and the conductive portion 2 (the first main surface portion 211). Figure 27 and Figure 28 As shown, the second bonding layer 492 is formed on the second intermediate layer 494. The constituent material of the second bonding layer 492 includes, for example, at least one of silver, copper, and gold. In this embodiment, the constituent material of the second bonding layer 492 includes silver. The second bonding layer 492 is bonded to the conductive portion 2 (first main surface portion 211) by solid-phase diffusion of the metal.

[0168] When the first bonding layer 491 and the second bonding layer 492 are each made of silver, the Young's modulus of each of the first bonding layer 491 and the second bonding layer 492 is 82.7 GPa. Therefore, as indicated by the Young's modulus of the metal base layer 490 (70.3 GPa) described above, the Young's modulus of the metal base layer 490 is smaller than the Young's modulus of each of the first bonding layer 491 and the second bonding layer 492. Furthermore, the thickness of each of the first bonding layer 491 and the second bonding layer 492 is, for example, approximately 2 to 5 μm, which is smaller than the thickness of the metal base layer 490.

[0169] like Figure 25 and Figure 26 As shown, the first intermediate layer 493 exists between the metal base layer 490 and the first bonding layer 491. In this embodiment, the first intermediate layer 493 is formed on the metal base layer 490. Figure 27 and Figure 28 As shown, the second intermediate layer 494 exists between the metal base layer 490 and the second bonding layer 492. In this embodiment, the second intermediate layer 494 is formed on the metal base layer 490. The constituent materials of the first intermediate layer 493 and the second intermediate layer 494 each contain nickel, for example. When the constituent materials of the first intermediate layer 493 and the second intermediate layer 494 are each nickel, the Young's modulus of each of the first intermediate layer 493 and the second intermediate layer 494 is 200 GPa. In addition, the thickness of each of the first intermediate layer 493 and the second intermediate layer 494 is, for example, about 0.2 to 2 μm, which is smaller than the thickness of the first bonding layer 491 and the second bonding layer 492.

[0170] The stacked structure of the conductive bonding material 49 is formed by, for example, sputtering or plating. The method for forming the conductive bonding material 49 is the same as that of the conductive bonding material 49 in the aforementioned semiconductor device A10. The method for bonding the conductive portion 2 (first main surface portion 211) to the LED element 400 using the conductive bonding material 49 is also the same as that in the aforementioned semiconductor device A10. Figure 11 The method of explanation is the same.

[0171] When the conductive portion 2 and the LED element 400 are solid-phase diffusion-bonded using the conductive bonding material 49, the portion of the conductive bonding material 49 that overlaps with the semiconductor laser element 4 when viewed in the z direction is slightly depressed by the pressing force from the semiconductor laser element 4. Figure 24 As shown in FIG. 1 , a height difference is formed at the boundary between a portion of the conductive bonding material 49 that overlaps with the LED element 400 when viewed in the z direction and a portion that does not overlap with the LED element 400 when viewed in the z direction.

[0172] like Figure 24 、 Figure 26 and Figure 28As shown, when viewed in the z direction, gaps 495 may be generated near the boundary between the portion where the conductive bonding material 49 overlaps with the LED element 400 and the portion where it does not overlap, at the boundary between the first bonding layer 491 and the back electrode 43 (LED element 400), and at the boundary between the second bonding layer 492 and the first main surface portion 211 (conductive portion 2). On the other hand, as Figure 24 、 Figure 25 and Figure 27 As shown, when viewed in the z-direction, there is no gap at the interface between the first bonding layer 491 and the back electrode 43 (LED element 400), and at the interface between the second bonding layer 492 and the first main surface portion 211 (conductive portion 2), slightly inward of the boundary between the overlapping and non-overlapping portions of the conductive bonding material 49 and the LED element 400 (the portion where the conductive bonding material 49 and the LED element 400 overlap when viewed in the z-direction). This indicates that the first bonding layer 491 and the back electrode 43, and the second bonding layer 492 and the first main surface portion 211, are firmly bonded by solid-phase diffusion.

[0173] like Figure 21 and Figure 22 As shown, the lead wire 7 is connected to the electrode pad 421 of the LED element 400 and the second main surface portion 212 of the conductive portion 2. The lead wire 7 is made of a metal such as Au, Cu, or Al, and is made of Au in this embodiment.

[0174] Weir 18 is disposed on support surface 1A of support member 1. Weir 18 has a closed frame shape when viewed in the z-direction, with a rectangular outer edge and a circular inner edge. Weir 18 surrounds LED element 400 and light-transmitting resin 8 when viewed in the z-direction. Weir 18 is made of, for example, white silicone resin.

[0175] Light-transmitting resin 8 fills the space surrounded by dam 18, covering a portion of support surface 1A of support member 1, LED element 400, and lead 7. Light-transmitting resin 8 is made of a material that transmits light from LED element 400, such as a transparent silicone resin or epoxy resin mixed with a fluorescent material. For example, the fluorescent material is one that is excited by blue light from LED element 400 and emits yellow light. This causes semiconductor device A30 to emit white light.

[0176] Next, the operation of the semiconductor device A30 will be described.

[0177] In the semiconductor device A30, the conductive bonding material 49 between the conductive portion 2 and the LED element 400 includes a metal base layer 490, a first bonding layer 491, and a second bonding layer 492. The first bonding layer 491 and the LED element 400 (back electrode 43), and the second bonding layer 492 and the conductive portion 2 (first main surface 211), are conductively bonded by solid-phase diffusion of metal, and the metal base layer 490 exists between the first bonding layer 491 and the second bonding layer 492. According to this structure, when the first bonding layer 491 and the LED element 400 (back electrode 43) and the second bonding layer 492 and the conductive portion 2 (first main surface 211) are bonded by solid-phase diffusion, the metal base layer 490 functions as a buffer. This achieves uniformity in the pressing force applied to the boundary between the first bonding layer 491 and the LED element 400 (back electrode 43), and the boundary between the second bonding layer 492 and the conductive portion 2 (first main surface 211). Therefore, the first bonding layer 491 and the LED element 400 (back electrode 43), and the second bonding layer 492 and the conductive portion 2 (first main surface portion 211), are firmly bonded by solid-phase diffusion bonding. As a result, even when the conductive bonding material 49 is repeatedly exposed to high temperatures due to heat generated by the LED element 400 during use of the semiconductor device A30, changes in the bonding state of the conductive bonding material 49 are suppressed. Therefore, according to the semiconductor device A30 including the conductive bonding material 49, the reliability of the bonding state between the LED element 400 and the conductive portion 2 can be improved.

[0178] In this embodiment, the Young's modulus of the metal base layer 490 is smaller than the Young's modulus of the constituent materials of the first bonding layer 491 and the second bonding layer 492. With this configuration, when the conductive bonding material 49 is bonded to the LED element 400 (back electrode 43) and the conductive portion 2 (first main surface portion 211) through solid-phase diffusion, the relatively soft metal base layer 490 relieves stress, enabling smoothing of the bonding boundary. As a result, the first bonding layer 491 and the LED element 400 (back electrode 43), as well as the second bonding layer 492 and the conductive portion 2 (first main surface portion 211), are more firmly bonded through solid-phase diffusion.

[0179] In this embodiment, the thickness of the metal base layer 490 is greater than the thickness of each of the first bonding layer 491 and the second bonding layer 492. As a result, during solid-phase diffusion bonding, the pressing force applied to the boundary between the first bonding layer 491 and the LED element 400 (back electrode 43), and to the boundary between the second bonding layer 492 and the conductive portion 2 (first main surface portion 211), becomes more uniform. Consequently, a more secure conductive bond can be formed between the first bonding layer 491 and the LED element 400 (back electrode 43), and between the second bonding layer 492 and the conductive portion 2 (first main surface portion 211).

[0180] The conductive bonding material 49 includes a first intermediate layer 493 and a second intermediate layer 494. The first intermediate layer 493 exists between the metal base layer 490 and the first bonding layer 491, and the second intermediate layer 494 exists between the metal base layer 490 and the second bonding layer 492. The structure having the first intermediate layer 493 and the second intermediate layer 494 is suitable for achieving uniform pressure at the boundary between the first bonding layer 491 and the LED element 400 (back electrode 43) and the boundary between the second bonding layer 492 and the conductive portion 2 (first main surface portion 211) during solid-phase diffusion bonding. If the first intermediate layer 493 and the second intermediate layer 494 are each composed of nickel, the Young's modulus of the first intermediate layer 493 and the second intermediate layer 494 is large. In this case, during solid-phase diffusion bonding, the pressing force acting on the bonding boundary becomes more uniform, and the first bonding layer 491 and the LED element 400 (back electrode 43), and the second bonding layer 492 and the conductive part 2 (first main surface 211) can form a more secure conductive bonding state.

[0181] In this embodiment, the first bonding layer 491 and the second bonding layer 492 are each formed of silver. This configuration suppresses oxidation of the first bonding layer 491 and the second bonding layer 492 during solid-phase diffusion bonding using the conductive bonding material 49, enabling good solid-phase diffusion bonding.

[0182] While specific embodiments of the present disclosure have been described above, the present disclosure is not limited thereto and various modifications are possible. The specific configuration of the semiconductor device according to the present disclosure can be freely modified in various designs.

[0183] The material and thickness of each layer constituting the conductive bonding material of the present disclosure are also not limited by the above-mentioned embodiment. In the above-mentioned embodiment, the conductive bonding material is described as having a metal base layer, a first bonding layer, a second bonding layer, a first intermediate layer, and a second intermediate layer, but, for example, it can also be set to a structure without the first intermediate layer and the second intermediate layer. Regarding the conductive bonding material, in addition to the aforementioned metal base layer, the first bonding layer, the second bonding layer, the first intermediate layer, and the second intermediate layer, it can also be set to a structure in which, for example, other metal layers are present between the metal base layer and the first bonding layer, or between the metal base layer and the second bonding layer 492.

[0184] The present disclosure includes the configurations described in the following appendixes.

[0185] Appendix 1.

[0186] A semiconductor device comprising:

[0187] A conductive portion having a main surface,

[0188] A semiconductor element mounted on the main surface, and

[0189] a conductive bonding material that exists between the conductive portion and the semiconductor element and electrically connects the conductive portion and the semiconductor element;

[0190] The aforementioned conductive bonding material includes a metal base layer, a first bonding layer and a second bonding layer. The aforementioned first bonding layer exists between the aforementioned metal base layer and the aforementioned semiconductor element, and is bonded to the aforementioned semiconductor element through solid-phase diffusion of metal. The aforementioned second bonding layer exists between the aforementioned metal base layer and the aforementioned conductive part, and is bonded to the aforementioned conductive part through solid-phase diffusion of metal.

[0191] Appendix 2.

[0192] According to the semiconductor device described in Appendix 1, the Young's modulus of the metal base layer is smaller than the Young's modulus of each of the first bonding layer and the second bonding layer.

[0193] Appendix 3.

[0194] According to the semiconductor device described in Appendix 2, the thickness of the metal base layer is larger than the thickness of each of the first bonding layer and the second bonding layer.

[0195] Appendix 4.

[0196] According to the semiconductor device described in Appendix 3, the constituent material of the metal base layer contains at least any one of aluminum, titanium, zinc, hafnium, and erbium.

[0197] Appendix 5.

[0198] According to the semiconductor device described in Appendix 4, the constituent material of each of the first bonding layer and the second bonding layer contains at least any one of silver, copper, and gold.

[0199] Appendix 6.

[0200] The semiconductor device according to any one of Appendixes 1 to 5,

[0201] The semiconductor element comprises an element body and a back electrode formed on the element body.

[0202] The back electrode and the first bonding layer are bonded to each other by solid phase diffusion.

[0203] Appendix 7.

[0204] According to the semiconductor device described in Appendix 6, the thickness of each of the first bonding layer and the second bonding layer is larger than the thickness of the back electrode.

[0205] Appendix 8.

[0206] According to any one of the semiconductor devices described in Appendices 1 to 7, the conductive bonding material includes a first intermediate layer and a second intermediate layer, the first intermediate layer exists between the metal base layer and the first bonding layer, and the second intermediate layer exists between the metal base layer and the second bonding layer.

[0207] Appendix 9.

[0208] According to the semiconductor device described in Appendix 8, the constituent material of each of the first intermediate layer and the second intermediate layer contains nickel.

[0209] Appendix 10.

[0210] The semiconductor device according to any one of appendices 1 to 9, further comprising a supporting substrate having a supporting surface facing the conductive portion.

[0211] Appendix 11.

[0212] The semiconductor device according to Appendix 10, further comprising a bonding member bonding the conductive portion to the support substrate.

[0213] The bonded member includes a plurality of metal layers bonded by solid phase diffusion.

[0214] Appendix 12.

[0215] The semiconductor device according to Appendix 10 or 11 further includes a sealing resin that covers the conductive portion, the semiconductor element, and a portion of the supporting substrate, wherein the supporting substrate has a bottom surface opposite to the supporting surface, and the bottom surface is exposed from the sealing resin.

[0216] Appendix 13.

[0217] The semiconductor device according to appendix 12, further comprising a first input terminal, a second input terminal, a first output terminal, and a second output terminal,

[0218] The semiconductor element includes a first switching element and a second switching element, and the conductive portion includes a first conductive portion that conducts the first switching element and a second conductive portion that conducts the second switching element.

[0219] The first input terminal is connected to the first conductive portion, the second input terminal is connected to the second switching element, and the first output terminal and the second output terminal are connected to the second conductive portion.

[0220] The sealing resin covers a portion of each of the first input terminal, the second input terminal, the first output terminal, and the second output terminal.

[0221] Appendix 14.

[0222] The semiconductor device according to any one of Appendixes 1 to 9, further comprising a support member having a support surface for supporting the semiconductor element.

[0223] The conductive portion includes a main surface portion, a bottom surface portion, and a connecting portion that electrically connects the main surface portion and the bottom surface portion.

[0224] Appendix 15.

[0225] According to the semiconductor device described in Appendix 14, the semiconductor element includes a semiconductor laser element and a switching element,

[0226] The conductive portion includes a first portion and a second portion that are separated from each other.

[0227] The semiconductor laser element is conductively connected to the first portion, and the switching element is conductively connected to the second portion.

[0228] Appendix 16.

[0229] The semiconductor device according to appendix 15 further includes a light-transmitting resin covering the semiconductor laser element, the switching element, and the supporting surface of the supporting member.

[0230] Appendix 17.

[0231] The semiconductor device according to Appendix 14, further comprising a light-transmitting resin,

[0232] The aforementioned semiconductor element includes an LED element,

[0233] The light-transmitting resin covers the LED element and at least a portion of the supporting surface of the supporting member.

[0234] Appendix 18.

[0235] The semiconductor device according to Appendix 17, further comprising a frame-shaped weir portion arranged on the support surface of the support member,

[0236] The dam portion surrounds the light-transmitting resin when viewed in the thickness direction of the supporting member.

[0237] Explanation of symbols

[0238] A10, A20, A30 semiconductor device; 1 supporting member; 1A supporting surface; 1B bottom surface; 10 supporting substrate; 10A supporting surface; 10B bottom surface; 11 1st supporting plate; 12 2nd supporting plate; 121 1st region; 122 2nd region; 123 3rd region; 13 bottom plate; 13A recessed portion; 14 1st surface; 15 2nd surface; 16 3rd surface; 17 4th surface; 18 dam portion; 19 joining member; 2 conductive portion; 20 conductive portion; 20A main surface; 20B back surface; 201 1st conductive portion; 202 2nd conductive portion; 203 3rd conductive portion; 21 main surface portion; 21A main surface; 211 1st Main surface; 211A main surface; 211B convex portion; 212 second main surface; 212A main surface; 212B concave portion; 213 third main surface; 213A main surface; 214 fourth main surface; 214A main surface; 22 bottom surface; 221 first bottom surface; 222 second bottom surface; 223 third bottom surface; 224 fourth bottom surface; 23 contact portion; 231 first contact portion; 232 second contact portion; 233 third contact portion; 234 fourth contact portion; 24 base material; 25 conductor layer; 26 insulating layer; 271 gate wiring layer; 272 detection wiring layer; 31 first input terminal; 311 bent portion; 3 2 2nd input terminal; 321 bent portion; 33 1st output terminal; 331 bent portion; 34 2nd output terminal; 341 bent portion; 35 gate terminal; 36 detection terminal; 4 semiconductor laser element; 40 semiconductor element; 400 LED element; 401 1st element; 402 2nd element; 41 element body; 411 element main surface; 412 element back surface; 42 main surface electrode; 421 electrode pad; 43 back surface electrode; 44 1st laser electrode; 45 2nd laser electrode (back surface electrode); 49 conductive bonding material; 490 metal base layer; 491 1st bonding layer; 492 2nd bonding layer; 4 93 1st intermediate layer; 494 2nd intermediate layer; 495 Gap; 5 Switching element; 51 Element body; 511 Element main surface; 512 Element back surface; 52 Gate; 53 Source; 54 Drain (back electrode); 59 Conductive bonding material; 6 Capacitor; 61 Electrode; 62 Electrode; 7 Lead; 71 1st lead; 72 2nd lead; 73 3rd lead; 8 Transparent resin; 80 Sealing resin; 81 Resin main surface; 82 Resin bottom surface; 84 Resin 1st surface; 85 Resin 2nd surface; 86 Resin 3rd surface; 87 Resin 4th surface; 9 Pressing member; L Laser; x direction; y direction; z direction (thickness direction).

Claims

1. A semiconductor device comprising: A conductive portion having a main surface, a semiconductor element mounted on the main surface, and a conductive bonding material that exists between the conductive portion and the semiconductor element and electrically connects the conductive portion and the semiconductor element; The conductive bonding material includes a metal base layer, a first bonding layer, and a second bonding layer. The first bonding layer is present between the metal base layer and the semiconductor element and is bonded to the semiconductor element by solid-phase diffusion of metal. The second bonding layer is present between the metal base layer and the conductive portion and is bonded to the conductive portion by solid-phase diffusion of metal. The conductive bonding material includes a first intermediate layer and a second intermediate layer, the first intermediate layer exists between the metal base layer and the first bonding layer, the second intermediate layer exists between the metal base layer and the second bonding layer, and the thickness of the first intermediate layer and the thickness of the second intermediate layer are smaller than the thickness of the first bonding layer and the thickness of the second bonding layer. 2 . The semiconductor device according to claim 1 , wherein the Young's modulus of the metal base layer is smaller than the Young's modulus of each of the first bonding layer and the second bonding layer. 3 . The semiconductor device according to claim 2 , wherein the thickness of the metal base layer is greater than the thickness of each of the first bonding layer and the second bonding layer. 4 . The semiconductor device according to claim 3 , wherein a constituent material of the metal base layer includes at least one of aluminum, titanium, zinc, hafnium, and erbium. 5 . The semiconductor device according to claim 4 , wherein a constituent material of each of the first bonding layer and the second bonding layer includes at least one of silver, copper, and gold.

6. The semiconductor device according to claim 1, wherein the semiconductor element comprises an element body and a back surface electrode formed on the element body. The back electrode and the first bonding layer are bonded to each other by solid phase diffusion. 7 . The semiconductor device according to claim 6 , wherein the thickness of each of the first bonding layer and the second bonding layer is greater than the thickness of the back surface electrode. 8 . The semiconductor device according to claim 1 , wherein a constituent material of each of the first intermediate layer and the second intermediate layer contains nickel. 9 . The semiconductor device according to claim 1 , further comprising a support substrate having a support surface facing the conductive portion.

10. The semiconductor device according to claim 9, further comprising a bonding member that bonds the conductive portion to the support substrate. The bonded member includes a plurality of metal layers bonded by solid phase diffusion.

11. The semiconductor device according to claim 9, further comprising a sealing resin covering the conductive portion, the semiconductor element, and a portion of the support substrate, wherein the support substrate has a bottom surface opposite to the support surface, the bottom surface being exposed from the sealing resin.

12. The semiconductor device according to claim 11, further comprising a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The semiconductor element includes a first switching element and a second switching element, and the conductive portion includes a first conductive portion that conducts the first switching element and a second conductive portion that conducts the second switching element. The first input terminal is connected to the first conductive portion, the second input terminal is connected to the second switching element, and the first output terminal and the second output terminal are connected to the second conductive portion. The sealing resin covers a portion of each of the first input terminal, the second input terminal, the first output terminal, and the second output terminal.

13. The semiconductor device according to any one of claims 1 to 5, further comprising a support member having a support surface for supporting the semiconductor element. The conductive portion includes a main surface portion, a bottom surface portion, and a connecting portion that electrically connects the main surface portion and the bottom surface portion.

14. The semiconductor device according to claim 13, wherein the semiconductor element includes a semiconductor laser element and a switching element. The conductive portion includes a first portion and a second portion that are separated from each other, The semiconductor laser element is conductively bonded to the first portion, and the switching element is conductively bonded to the second portion. 15 . The semiconductor device according to claim 14 , further comprising a light-transmitting resin covering the semiconductor laser element, the switching element, and the supporting surface of the supporting member.

16. The semiconductor device according to claim 13, further comprising a light-transmitting resin. The semiconductor element includes an LED element, The light-transmitting resin covers the LED element and at least a portion of the supporting surface of the supporting member.

17. The semiconductor device according to claim 16, further comprising a frame-shaped weir portion arranged on the support surface of the support member, The dam portion surrounds the light-transmitting resin when viewed in the thickness direction of the supporting member.

18. The semiconductor device according to any one of claims 1 to 5, wherein the conductive bonding material includes a first portion overlapping the semiconductor element when viewed in a thickness direction perpendicular to the main surface. A gap is generated at an interface between the first bonding layer and the semiconductor element in a peripheral portion of the first portion as viewed in the thickness direction, or at an interface between the second bonding layer and the conductive portion in a peripheral portion of the first portion as viewed in the thickness direction.

19. The semiconductor device according to any one of claims 1 to 5, wherein the metal base layer comprises a thick portion and a thin portion, wherein the thick portion is connected to the thin portion. When viewed in the thickness direction perpendicular to the main surface, the thick portion is separated from the semiconductor element, and the thin portion overlaps with the semiconductor element. The thick portion is thicker than the thin portion.

20. The semiconductor device according to any one of claims 1 to 5, wherein the first bonding layer includes an outer portion, an inner portion, and a connecting portion disposed between the outer portion and the inner portion. When viewed in a thickness direction perpendicular to the main surface, the outer portion is spaced apart from the semiconductor element. The inner portion overlaps with the semiconductor element when viewed from the thickness direction. The thickness of the outer portion and the inner portion is greater than the thickness of the connecting portion.

21. The semiconductor device according to any one of claims 1 to 5, wherein the first bonding layer includes a recessed portion overlapping the semiconductor element when viewed in a thickness direction perpendicular to the main surface. The recess is configured to partially accommodate the semiconductor element. The thickness of the semiconductor element is greater than the recess of the concave portion.

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