Semiconductor Devices

Abstract

To provide a semiconductor device configured to maintain a proper bonding status between a semiconductor element and a conductive member, to thereby improve reliability on the bonding status.SOLUTION: A semiconductor device A10 includes: a conductive portion 20 having a main surface 20A; a semiconductor element 40 mounted on the main surface 20A; and a conductive bonding material 49 interposed between the conductive portion 20 and the semiconductor element 40 to conductively bond the conductive portion 20 and the semiconductor element 40 to each other. The conductive bonding material 49 includes a metal base layer 490, a first bonding layer 491, and a second bonding layer 492. The first bonding layer 491 is interposed between the metal base layer 490 and the semiconductor element 40 and is bonded to the semiconductor element 40 by metal solid phase diffusion. The second bonding layer 492 is interposed between the metal base layer 490 and the conductive portion 20 and is bonded to the conductive portion 20 by metal solid phase diffusion.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Conventionally, semiconductor devices incorporating semiconductor elements such as MOSFETs and IGBTs have been 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 support substrate (insulating substrate). The semiconductor element is bonded to the metal pattern via a conductive bonding material.

[0003] When the semiconductor device disclosed in Patent Document 1 is used, heat is generated from the semiconductor element, causing an increase in the ambient temperature. In particular, the conductive bonding material may be exposed to high temperatures. Repeated exposure to high temperatures changes the state of the conductive bonding material. As a result, the electrical continuity between the semiconductor element and the metal pattern may be impaired. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-158787 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above circumstances, one objective of the present disclosure is to provide a semiconductor device that is suitable for improving the reliability of a bonding state by maintaining an appropriate bonding state between a semiconductor element and a conductive portion. [Means for solving the problem]

[0006] A semiconductor device provided by one aspect of the present disclosure comprises a conductive portion having a main surface, a semiconductor element mounted on the main surface, and a conductive bonding material interposed between the conductive portion and the semiconductor element and electrically bonding the conductive portion and the semiconductor element, the conductive bonding material including a metal base layer, a first bonding layer, and a second bonding layer, the first bonding layer being interposed between the metal base layer and the semiconductor element and bonded to the semiconductor element by solid-state diffusion of metal, and the second bonding layer being interposed between the metal base layer and the conductive portion and bonded to the conductive portion by solid-state diffusion of metal.

[0007] Other features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a semiconductor device according to a first embodiment. [Figure 2] FIG. 2 is a plan view of the semiconductor device shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2. [Figure 5] FIG. 4 is a partially enlarged view of FIG. [Figure 6] FIG. 6 is a partially enlarged view of FIG. 5. [Figure 7] FIG. 7 is an enlarged view of part A in FIG. 6. [Figure 8] FIG. 7 is an enlarged view of part B in FIG. 6. [Figure 9] FIG. 7 is an enlarged view of part C in FIG. 6. [Figure 10] FIG. 7 is an enlarged view of part D in FIG. 6. [Figure 11] 10A to 10C are diagrams for explaining a method of joining a semiconductor element and a conductive portion. [Figure 12] FIG. 10 is a plan view showing a semiconductor device according to a second embodiment. [Figure 13] FIG. 13 is a bottom view of the semiconductor device shown in FIG. [Figure 14]FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. [Figure 15] FIG. 15 is a partially enlarged view of FIG. [Figure 16] FIG. 16 is a partially enlarged view of FIG. [Figure 17] FIG. 17 is an enlarged view of part A in FIG. [Figure 18] FIG. 17 is an enlarged view of part B in FIG. [Figure 19] FIG. 17 is an enlarged view of part C in FIG. [Figure 20] FIG. 17 is an enlarged view of part D in FIG. [Figure 21] FIG. 10 is a plan view showing a semiconductor device according to a third embodiment. [Figure 22] FIG. 22 is a cross-sectional view taken along line XXII-XXII in FIG. 21. [Figure 23] FIG. 23 is a partially enlarged view of FIG. 22. [Figure 24] FIG. 24 is a partially enlarged view of FIG. 23. [Figure 25] FIG. 25 is an enlarged view of part A in FIG. 24. [Figure 26] FIG. 25 is an enlarged view of part B in FIG. 24. [Figure 27] FIG. 25 is an enlarged view of part C in FIG. 24. [Figure 28] FIG. 25 is an enlarged view of part D in FIG. 24. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present disclosure will now be described in detail with reference to the drawings.

[0010] Terms such as "first," "second," and "third" in this disclosure are used merely as labels and are not necessarily intended to dictate any ordering of their objects.

[0011] A semiconductor device A10 according to a first embodiment will be described with reference to FIGS. 1 to 10. The illustrated semiconductor device A10 includes a support substrate 10, multiple conductive portions 20, a first input terminal 31, a second input terminal 32, a first output terminal 33, a second output terminal 34, multiple semiconductor elements 40, and a sealing resin 80 (not shown in FIG. 1). In addition, the semiconductor device A10 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 the semiconductor device A10 is, for example, a power conversion device (power module). The semiconductor device A10 is used as a driving source for a motor, an inverter device for various electrical appliances, a DC / DC converter, and the like. In FIGS. 2 to 4, the sealing resin 80 is shown in a see-through manner (see the two-dot chain line).

[0012] In describing the semiconductor device A10, for example, as shown in FIG. 1, the direction extending through the thickness of the support substrate 10 (or the conductive portion 20) is referred to as the "direction z" (sometimes referred to as the "thickness direction"). A direction perpendicular to the direction z is referred to as the "direction x," and a direction perpendicular to both the direction z and the direction x is referred to as the "direction y." As shown in FIG. 2, the semiconductor device A10 is rectangular when viewed in the direction z (in other words, in a plan view). The direction x is parallel to one side of the semiconductor device A10 (for example, the left side in FIG. 2), and the direction y is parallel to another side of the semiconductor device A10 (for example, the bottom side in FIG. 2). In describing the semiconductor device A10, when there are two members A and B (or two groups A and B) spaced apart from each other in an arbitrary direction, it may be described as "member A is on one side of the direction (relative to member B)" or "member B is on the other side of the direction (relative to member A)." 2, for example, it is stated that "the first input terminal 31 and the second input terminal 32 are arranged on one side of the direction x, and the first output terminal 33 and the second output terminal 34 are arranged on the other side of the direction x." Note that "one side" and "the other side" may be reversed in this example.

[0013] As shown in FIGS. 1 to 4, the support substrate 10 supports a plurality of conductive portions 20. In the illustrated example, the support substrate 10 is square when viewed in the direction z. The support substrate 10 has a support surface 10A and a bottom surface 10B that face opposite each other (are spaced apart from each other) in the direction z. The support surface 10A faces each of the conductive portions 20. As shown in FIGS. 3 and 4, the bottom surface 10B is exposed from the sealing resin 80. When the semiconductor device A10 is attached to, for example, a heat sink, the bottom surface 10B faces the heat sink. In the illustrated example, the support substrate 10 includes a first support plate 11, a second support plate 12, and a bottom plate 13.

[0014] 3 and 4, the first support plate 11 is located between the second support plate 12 and the bottom plate 13 in the direction z. The first support plate 11 has electrical insulation properties. The first support plate 11 is made of ceramics with excellent thermal conductivity. An example of such ceramics is aluminum nitride (AlN).

[0015] Each second support plate 12 is laminated on the first support plate 11 and has a support surface 10A. A corresponding conductive portion 20 is bonded to the second support plate 12. The second support plate 12 is made of metal, for example, metal foil. The second support plate 12 is made of copper (Cu) or a copper alloy and is conductive. In the example shown in the figure, 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 spaced apart from one another.

[0016] The bottom plate 13 is laminated 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 like the second support plate 12, and is formed of, for example, a metal foil made of copper or a copper alloy. The second support plate 12 is conductive. As can be seen from FIGS. 3 and 4, the area of ​​the bottom plate 13 is smaller than the area of ​​the first support plate 11 when viewed in direction z. The periphery of the first support plate 11 is located outward from the periphery of the bottom plate 13. As a result, when viewed in direction z, a recess 13A surrounding the bottom plate 13 is provided in the support substrate 10. The recess 13A is covered with a sealing resin 80.

[0017] The support substrate 10 can be formed, for example, by using a DBC (Direct Bonded Copper) substrate. The DBC substrate is composed of a ceramic plate and a pair of copper foils that sandwich the ceramic plate from both sides in the z direction. The ceramic plate becomes the first support plate 11. The pair of copper foils are each partially removed by etching to form the second support plate 12 and the bottom plate 13.

[0018] 3 and 4, bonding members 19 are provided so as to cover the support surface 10A of each 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.

[0019] 3 and 4 , each conductive portion 20 is joined to a corresponding second support plate 12 via a joining member 19. The plurality of conductive portions 20, together with a first input terminal 31, a second input terminal 32, a first output terminal 33, and a 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 direction z, and the back surface 20B faces the support surface 10A of the support substrate 10.

[0020] In the semiconductor device A10, the conductive portion 20 is formed, for example, by a metal plate. The metal plate is made of, for example, copper or a copper alloy. As shown in FIGS. 3 and 4, the thickness of the conductive portion 20 is greater than the thickness of the second support plate 12. The conductive portion 20 may be formed by plating the surface of the metal plate with, for example, silver or a multi-type metal plating in which an aluminum layer, a nickel (Ni) layer, and a silver layer are stacked in this order. Details will be described later (see FIGS. 9 and 10), but in this embodiment, the conductive portion 20 includes a metal base material 24 and a conductor layer 25 formed on the base material 24.

[0021] 2 to 4, the multiple 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 joined to a first region 121 of the second support plate 12. The second conductive portion 202 is joined to a second region 122 of the second support plate 12. The third conductive portion 203 is joined to a 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 spaced apart from one another.

[0022] As shown in FIGS. 1, 2, and 4, a pair of insulating layers 26 are disposed on the main surface 20A of each of the first conductive portion 201 and the second conductive portion 202. The pair of insulating layers 26 are spaced apart from each other in the direction y. The pair of insulating layers 26 are strip-shaped and extend in the direction x. The insulating layers 26 are made of, for example, ceramics or glass epoxy resin. Furthermore, at least the surface of the insulating layer 26 may be formed of insulating SiC or the like.

[0023] A pair of gate wiring layers 271 are disposed separately on the pair of insulating layers 26. The pair of gate wiring layers 271 are strip-shaped extending in the direction x. The pair of detection wiring layers 272 are disposed separately on the pair of insulating layers 26. The pair of detection wiring layers 272 are strip-shaped extending in the direction x. The gate wiring layer 271 and the detection wiring layer 272 are disposed side by side on each insulating layer 26. The gate wiring layer 271 and the detection wiring layer 272 are made of metal foil made of, for example, copper or a copper alloy.

[0024] As shown in FIGS. 1 and 2, the first input terminal 31 and the second input terminal 32 are located on one side in the direction x. The first input terminal 31 and the second input terminal 32 are spaced apart from each other in the direction y. DC power (voltage) to be converted is input to the first input terminal 31 and the second input terminal 32. The first input terminal 31 is a positive electrode (P terminal). The second input terminal 32 is a negative electrode (N terminal). The first input terminal 31 and the second input terminal 32 are made of metal plates. The metal plates are made of copper or a copper alloy.

[0025] The first input terminal 31 has a bent portion 311 bent in a stepwise manner at its end on the other side in the direction x. This bent portion 311 is connected to the main surface 20A of the first conductive portion 201 by solder bonding, ultrasonic bonding, or the like. This provides 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 in a stepwise manner at its end on the other side in the direction x. This bent portion 321 is connected to the main surface 20A of the third conductive portion 203 by solder bonding, ultrasonic bonding, or the like. This provides electrical continuity between the second input terminal 32 and the third conductive portion 203.

[0026] As shown in FIGS. 1 and 2 , the first output terminal 33 and the second output terminal 34 are located on the other side in the direction x. The first output terminal 33 and the second output terminal 34 are spaced apart from each other in the direction y. AC power (voltage) converted by the multiple 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 made of a metal plate. The metal plate is made of copper or a copper alloy. The first output terminal 33 and the second output terminal 34 have bent portions 331 and 341 bent in a step-like manner at their ends on one side in the direction x. The bent portions 331 and 341 are connected to the main surface 20A of the second conductive portion 202 by soldering, ultrasonic bonding, or the like. This provides electrical continuity between the first output terminal 33 and the second output terminal 34 and the second conductive portion 202. In the illustrated example, two output terminals (first output terminal 33 and second output terminal 34) are provided, but these may be combined into one output terminal.

[0027] The pair of gate terminals 35 and the pair of detection terminals 36 are arranged corresponding to the pair of gate wiring layers 271 and the pair of detection wiring layers 272, respectively. The pair of gate terminals 35 and the pair of detection terminals 36 are made of metal plates and extend in the direction y. The metal plates are made of copper or a copper alloy.

[0028] Each end of the pair of gate terminals 35 and the pair of detection terminals 36 is bent in a stepped shape. The end of each gate terminal 35 is connected to the corresponding gate wiring layer 271 by solder bonding, ultrasonic bonding, or the like. The end of each detection terminal 36 is connected to the corresponding detection wiring layer 272 by solder bonding, ultrasonic bonding, or the like.

[0029] The semiconductor element 40 is, for example, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) made of a semiconductor material mainly composed of silicon carbide (SiC). The semiconductor element 40 is not limited to a MOSFET, and may 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). In the description of the semiconductor device A10, the semiconductor element 40 is a switching element, and is an n-channel MOSFET.

[0030] 5, the semiconductor element 40 has an element body 41, a main surface electrode 42, a back surface electrode 43, and a gate electrode (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 each other in the direction z. The element main surface 411 faces the same side as the main surface 20A of the conductive portion 20 in the direction z. Therefore, the element back surface 412 faces the main surface 20A.

[0031] As shown in FIG. 5 , the principal surface electrode 42 is provided on the element principal surface 411. A source current flows through the principal surface electrode 42 from inside the element body 41. The back surface electrode 43 is provided on the element back surface 412. The back surface electrode 43 is configured by laminating multiple metal layers, such as silver, or nickel and silver. A drain current flows through the back surface electrode 43 toward the inside of the element body 41. The back surface electrode 43 is electrically joined to the principal surface 20A of the conductive portion 20 by a conductive bonding material 49. The gate electrode is provided on the element principal surface 411, and a gate voltage for driving the semiconductor element 40 is applied to the gate electrode.

[0032] The conductive bonding material 49 is interposed between the conductive section 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 entire semiconductor element 40 overlaps with the conductive bonding material 49 when viewed in the z direction. The conductive bonding material 49 is configured by stacking multiple metal layers. As shown in FIGS. 5 and 6, 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. As shown in FIGS. 7 to 10, the conductive bonding material 49 further includes a first intermediate layer 493 and a second intermediate layer 494.

[0033] 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 constituent material of the metal base layer 490 includes, for example, at least one of aluminum (Al), titanium (Ti), zinc (Zn), hafnium (Hf), and erbium (Er). In this embodiment, the constituent material of the metal base layer 490 includes aluminum. When the constituent material of the metal base layer 490 is aluminum, the Young's modulus of the metal base layer 490 is 70.3 GPa.

[0034] The first bonding layer 491 is interposed between the metal base layer 490 and the semiconductor element 40. In this embodiment, as shown in FIGS. 7 and 8, 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 (rear electrode 43) by solid-state diffusion of the metal. The constituent material of the rear electrode 43 includes, for example, silver. The thickness of the rear electrode 43 is smaller than the thickness of the first bonding layer 491, and the rear electrode 43 is formed by, for example, a sputtering method.

[0035] The second bonding layer 492 is interposed between the metal base layer 490 and the conductive portion 20. In this embodiment, as shown in FIGS. 9 and 10, 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 (the conductor layer 25) by solid-state diffusion of the metal. In this embodiment, the conductive portion 20 includes a base material 24 and a conductor layer 25 formed on the base material 24, and the second bonding layer 492 and the conductor layer 25 are bonded to each other by solid-state diffusion. The constituent material of the conductor layer 25 includes, for example, silver.

[0036] When first bonding layer 491 and second bonding layer 492 are each made of silver, first bonding layer 491 and second bonding layer 492 each have a Young's modulus of 82.7 GPa. Therefore, as indicated by the Young's modulus (70.3 GPa) of metal base layer 490 described above, metal base layer 490 has a smaller Young's modulus than first bonding layer 491 and second bonding layer 492. First bonding layer 491 and second bonding layer 492 each have a thickness of, for example, about 2 to 5 μm, which is smaller than the thickness of metal base layer 490.

[0037] As shown in FIGS. 7 and 8, the first intermediate layer 493 is interposed 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. As shown in FIGS. 9 and 10, the second intermediate layer 494 is interposed 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 material of each of the first intermediate layer 493 and the second intermediate layer 494 includes, for example, nickel (Ni). When the constituent material of each of the first intermediate layer 493 and the second intermediate layer 494 is 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.

[0038] The laminated structure of the conductive bonding material 49 is formed by, for example, sputtering or plating. In the case of sputtering, for example, 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 both the front and back surfaces of an aluminum sheet material corresponding to the metal base layer 490. In the case of plating, plating layers made of the materials constituting the first intermediate layer 493 and the second intermediate layer 494, and plating layers made of the materials constituting the first bonding layer 491 and the second bonding layer 492 are sequentially formed on the entire surface of the aluminum sheet material. By cutting the sheet-like laminated structure thus produced, a plurality of conductive bonding materials 49 are obtained.

[0039] Next, a method for joining the conductive portion 20 and the semiconductor element 40 will be described.

[0040] 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 (conductor layer 25) and the second bonding layer 492, and the first bonding layer 491 and the semiconductor element 40 (rear surface electrode 43) are in contact with each other.

[0041] Next, the conductive portion 20 (conductor layer 25) and the second bonding layer 492, and the first bonding layer 491 and the semiconductor element 40 (rear electrode 43) are bonded to each other by solid-phase diffusion. Bonding by solid-phase diffusion is performed under high temperature and high pressure. For example, as shown in FIG. 11, bonding by solid-phase diffusion is performed while pressing the stacked semiconductor elements 40 with a flat pressing member 9. Conditions for solid-phase diffusion include a temperature of about 350°C and a pressure of about 40 MPa. However, the temperature and pressure conditions for solid-phase diffusion can be selected appropriately. The solid-phase diffusion bonding is assumed to be performed in the atmosphere, but may also be performed in a vacuum.

[0042] When the conductive portion 20 and the semiconductor element 40 are bonded by the conductive bonding material 49 through solid-state diffusion, the portion of the conductive bonding material 49 that overlaps with the semiconductor element 40 as viewed in the z direction is slightly recessed by pressure from the semiconductor element 40. As a result, as shown in Fig. 6 , a step is formed in the conductive bonding material 49 at the boundary between the portion that overlaps with the semiconductor element 40 as viewed in the z direction and the portion that does not overlap with the semiconductor element 40 as viewed in the z direction.

[0043] 6, 8, and 10, near the boundary between the portion where conductive bonding material 49 overlaps with semiconductor element 40 and the portion where it does not overlap with semiconductor element 40 as viewed in direction z, voids 495 may occur at the boundary surface between first bonding layer 491 and back surface electrode 43 (semiconductor element 40) and at the boundary surface between second bonding layer 492 and conductor layer 25 (conductive portion 20). On the other hand, as shown in FIGS. 6, 7, and 9, slightly inside the boundary portion between the portion where conductive bonding material 49 overlaps with semiconductor element 40 and the portion where it does not overlap with semiconductor element 40 as viewed in direction z (the portion where conductive bonding material 49 overlaps with semiconductor element 40 as viewed in direction z), the boundary surface between first bonding layer 491 and back surface electrode 43 (semiconductor element 40) and the boundary surface between second bonding layer 492 and conductor layer 25 (conductive portion 20) are difficult to see. This is because first bonding layer 491 and back electrode 43, and second bonding layer 492 and conductor layer 25 are both made of silver, which is a solid-state diffusion bonding of the same metal. In the enlarged views of FIGS. 8 and 10, the boundary surface between first bonding layer 491 and back electrode 43 (semiconductor element 40) and the boundary surface between second bonding layer 492 and conductor layer 25 (conductive portion 20) are schematically represented by dotted lines. As can be seen from this, first bonding layer 491 and back electrode 43, and second bonding layer 492 and conductor layer 25 are each firmly bonded by solid-state diffusion. The strong bonded state achieved by solid-state diffusion can be confirmed, for example, by an enlarged photograph (e.g., an SEM photograph) of the cross section of the bonded portion.

[0044] The plurality of semiconductor elements 40 include a plurality of first elements 401 and a plurality of second elements 402. As shown in FIGS. 1, 2, and 4, the plurality of first elements 401 are electrically connected to the main surface 20A of the first conductive portion 201. The plurality of first elements 401 are arranged at predetermined intervals along the direction x. The plurality of first elements 401 constitute an upper arm circuit of the semiconductor device A10.

[0045] 1 to 4, the plurality of second elements 402 are electrically connected to the main surface 20A of the second conductive portion 202. The plurality of second elements 402 are arranged at predetermined intervals along the direction x. The plurality of second elements 402 constitute a lower arm circuit of the semiconductor device A10.

[0046] 2, the multiple first elements 401 are arranged to be shifted in the direction x with respect to the multiple second elements 402. In the example shown in the figure, three first elements 401 and three second elements 402 are provided. The number of each of the first elements 401 and second elements 402 is not limited to this configuration and can be freely set depending on, for example, the performance required of the semiconductor device A10.

[0047] Each of the principal surface electrodes 42 of the multiple first elements 401 and the principal surface 20A of the second conductive portion 202 are connected via, for example, a wire 70a (for simplicity, only one wire 70a is shown in FIG. 2). This allows each of the principal surface electrodes 42 of the multiple first elements 401 to be electrically connected to the second conductive portion 202 via the wire. Therefore, the first output terminal 33 is electrically connected to each of the principal surface electrodes 42 of the multiple first elements 401 via the second conductive portion 202 and the wire. The first output terminal 33 corresponds to the source terminal of the multiple first elements 401.

[0048] Each of the back electrodes 43 of the multiple first elements 401 and the first conductive section 201 are electrically connected via the conductive bonding material 49. Therefore, the first input terminal 31 is electrically connected to each of the back electrodes 43 of the multiple first elements 401 via the first conductive section 201. The first input terminal 31 corresponds to the drain terminals of the multiple first elements 401.

[0049] Each of the principal surface electrodes 42 of the multiple second elements 402 and the principal surface 20A of the third conductive portion 203 are connected via, for example, a wire 70b (for simplicity, only one wire 70b is shown in FIG. 2). This allows each of the principal surface electrodes 42 of the multiple second elements 402 to be electrically connected to the third conductive portion 203 via the wire. Therefore, the second input terminal 32 is electrically connected to each of the principal surface electrodes 42 of the multiple second elements 402 via the third conductive portion 203 and the wire. The second input terminal 32 corresponds to the source terminal of the multiple second elements 402.

[0050] Each of the back electrodes 43 of the second elements 402 and the second conductive portion 202 are electrically connected via the conductive bonding material 49. Therefore, the second output terminal 34 is electrically connected to each of the back electrodes 43 of the second elements 402 via the second conductive portion 202. The second output terminal 34 corresponds to the drain terminals of the second elements 402.

[0051] The semiconductor device A10 includes gate wires and detection wires (not shown). A plurality of the gate wires are provided corresponding to the plurality of first elements 401 and the plurality of second elements 402. Each gate wire corresponding to the first element 401 is connected to a gate electrode (not shown) of the first element 401 and one of the gate wiring layers 271 located above the first conductive section 201. Each gate wire corresponding to the second element 402 is connected to a gate electrode (not shown) of the second element 402 and the other of the gate wiring layers 271 located above the second conductive section 202. A gate voltage for driving either the plurality of first elements 401 or the plurality of second elements 402 is applied to each of a pair of gate terminals 35 connected to the pair of gate wiring layers 271.

[0052] A plurality of the detection wires are provided corresponding to the plurality of first elements 401 and the plurality of second elements 402. Each detection wire corresponding to the first element 401 is connected to the principal surface electrode 42 of the first element 401 and one detection wiring layer 272 located on the first conductive section 201. Each detection wire corresponding to the second element 402 is connected to the principal surface electrode 42 of the second element 402 and the other detection wiring layer 272 located on the second conductive section 202. A voltage (a voltage corresponding to the source current) is applied to the plurality of principal surface electrodes 42 corresponding to either the plurality of first elements 401 or the plurality of second elements 402 from each of a pair of detection terminals 36 connected to the pair of detection wiring layers 272.

[0053] 2 to 4, the 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, the conductive portion 20, and the semiconductor elements 40. The sealing resin 80 covers the pair of insulating layers 26, the pair of gate wiring layers 271, the pair of detection wiring layers 272, and the wires. Furthermore, the sealing resin 80 covers portions of the pair of gate terminals 35 and the pair of detection terminals 36. The sealing resin 80 is made of a material such as black epoxy resin.

[0054] 3 and 4, 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 direction z. The resin bottom surface 82 faces the opposite side to the resin main surface 81 in the direction z. The bottom surface 10B of the bottom plate 13 (support substrate 10) is exposed from the resin bottom surface 82. The resin bottom surface 82 has a frame shape that surrounds the bottom plate 13. Note that the portions of the pair of gate terminals 35 and the pair of detection terminals 36 that are exposed from the sealing resin 80 are bent as appropriate depending on the usage form of the semiconductor device A10.

[0055] Next, the effects of the semiconductor device A10 will be described.

[0056] In semiconductor device A10, conductive bonding material 49 interposed between conductive portion 20 and semiconductor element 40 includes metal base layer 490, first bonding layer 491, and second bonding layer 492, with metal base layer 490 interposed between first bonding layer 491 and second bonding layer 492. With this configuration, intermediate metal base layer 490 functions as a cushion when bonding first bonding layer 491 and semiconductor element 40 (rear electrode 43) and when bonding second bonding layer 492 and conductive portion 20 (conductor layer 25). This uniformizes the pressure acting on the boundary between first bonding layer 491 and semiconductor element 40 (rear electrode 43) and the boundary between second bonding layer 492 and conductive portion 20 (conductor layer 25). Furthermore, the first bonding layer 491 and the semiconductor element 40 (rear electrode 43), and the second bonding layer 492 and the conductive portion 20 (conductor layer 25), are firmly bonded together by solid-state diffusion bonding. As a result, even if the conductive bonding material 49 is repeatedly exposed to high temperatures due to heat generated in 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, the semiconductor device A10 including the conductive bonding material 49 can improve the reliability of the bonding state between the semiconductor element 40 and the conductive portion 20.

[0057] In this embodiment, the Young's modulus of metal base layer 490 is smaller than the Young's modulus of each of the constituent materials of first bonding layer 491 and second bonding layer 492. With this configuration, when conductive bonding material 49 is bonded to semiconductor element 40 (rear electrode 43) and conductive portion 20 (conductor layer 25) by solid-state diffusion, stress is alleviated by relatively soft metal base layer 490, and the bonded boundary can be smoothed. As a result, first bonding layer 491 and semiconductor element 40 (rear electrode 43), and second bonding layer 492 and conductive portion 20 (conductor layer 25) are more firmly bonded by solid-state diffusion.

[0058] In this embodiment, the thickness of metal base layer 490 is greater than the thickness of each of first bonding layer 491 and second bonding layer 492. This allows for more uniform pressing forces to be applied to the boundary between first bonding layer 491 and semiconductor element 40 (rear surface electrode 43) and the boundary between second bonding layer 492 and conductive section 20 (conductor layer 25) during bonding by solid-state diffusion. This allows for stronger conductive bonding between first bonding layer 491 and semiconductor element 40 (rear surface electrode 43) and between second bonding layer 492 and conductive section 20 (conductor layer 25).

[0059] Conductive bonding material 49 includes first intermediate layer 493 and second intermediate layer 494. First intermediate layer 493 is interposed between metal base layer 490 and first bonding layer 491, and second intermediate layer 494 is interposed between metal base layer 490 and second bonding layer 492. The configuration including first intermediate layer 493 and second intermediate layer 494 is suitable for uniforming the pressing force acting on the boundary between first bonding layer 491 and semiconductor element 40 (rear electrode 43) and the boundary between second bonding layer 492 and conductive portion 20 (conductor layer 25) during bonding by solid-state diffusion. Furthermore, when first intermediate layer 493 and second intermediate layer 494 are each made of nickel, the Young's moduli of first intermediate layer 493 and second intermediate layer 494 are relatively large. In this case, the pressure acting on the bonding boundary during solid-state diffusion bonding 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 portion 20 (conductor layer 25) can be in a stronger conductive bond state.

[0060] In this embodiment, the constituent material of each of first bonding layer 491 and second bonding layer 492 contains silver. With this configuration, oxidation of first bonding layer 491 and second bonding layer 492 is suppressed during bonding by solid-state diffusion using conductive bonding material 49, enabling good solid-state diffusion bonding. Furthermore, back surface electrode 43 and conductor layer 25, which are bonded to first bonding layer 491 and second bonding layer 492, each contain silver, enabling better solid-state diffusion bonding.

[0061] The specific configuration of the bonding member 19 shown in FIGS. 3 and 4 and interposed between the conductive portion 20 and the support substrate 10 (second support plate 12) is not particularly limited, but may be the same as the previously described conductive bonding material 49. The bonding member 19 has a configuration in which, for example, multiple metal layers are stacked, including multiple metal layers bonded by solid-state diffusion. Like the conductive bonding material 49, the bonding member 19 may include 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 these metal base layer, first bonding layer, second bonding layer, first intermediate layer, and second intermediate layer are the same as the metal base layer 490, first bonding layer 491, second bonding layer 492, first intermediate layer 493, and second intermediate layer 494 of the conductive bonding material 49, respectively. In this case, the first bonding layer of the bonding member 19 is bonded to the conductive portion 20 by solid-state 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-state diffusion of the metal.

[0062] 12 to 20, a semiconductor device A20 according to the second embodiment will 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 wire 71, a second wire 72, a third wire 73, and a light-transmitting resin 8. The semiconductor device A20 is used, for example, as a pulsed laser light source for LiDAR, which is an example of two-dimensional distance measurement, but the present disclosure is not limited to this.

[0063] As shown in Fig. 12, the semiconductor device A20 has a rectangular shape when viewed in direction z. The light-transmitting resin 8 is omitted in Fig. 12. In Fig. 12, reference numerals 84 to 87 in parentheses indicate 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, which will be described later).

[0064] 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. There are no particular limitations on the material of the support member 1, and examples of the material include epoxy resin and glass epoxy resin. In the following explanation, an example will be described in which the support member 1 is made of ceramics. 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 is, for example, rectangular when viewed in the z direction.

[0065] The support surface 1A faces one side in the direction z and is a flat surface in the illustrated example. The bottom surface 1B faces the other side in the direction z opposite the support surface 1A and is a flat surface in the illustrated example. The first surface 14 faces one side in the direction x and is a flat surface in the illustrated example. The second surface 15 faces the other side in the direction x opposite the first surface 14 and is a flat surface in the illustrated example. The third surface 16 faces one side in the direction y and is a flat surface in the illustrated example. The fourth surface 17 faces the other side in the direction x opposite the third surface 16 and is a flat surface in the illustrated example.

[0066] The conductive portion 2 is a portion that constitutes a conductive path to the semiconductor laser element 4, the switching element 5, etc. The material of the conductive portion 2 is not particularly limited, and examples thereof include metals such as copper (Cu), nickel (Ni), titanium (Ti), and gold (Au). The method for forming the conductive portion 2 is also not particularly limited, and in the illustrated example, the conductive portion 2 is formed by plating, for example.

[0067] The illustrated conductive portion 2 includes a main surface portion 21, a bottom surface portion 22, and a connecting portion .

[0068] The main surface portion 21 is disposed on the support surface 1A of the support member 1. The main surface portion 21 is a thin plate with its thickness direction aligned in the z direction. The main surface portion 21 includes a plurality of portions, and in the illustrated example, includes 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.

[0069] As shown in FIGS. 12 and 14 , the first main surface portion 211 is disposed on the fourth surface 17 side in the direction y of the support member 1. The first main surface portion 211 has a main surface 211A facing one side in the direction z. The shape of the first main surface portion 211 is not particularly limited, but in the illustrated example, it has a shape in which a protrusion 211B is combined with an elongated rectangle whose longitudinal direction is the direction x. The protrusion 211B is a portion of the first main surface portion 211 on the third surface 16 side in the direction y that protrudes toward the third surface 16 in the direction y. The protrusion 211B is located at the center of the first main surface portion 211 in the direction x. The first main surface portion 211 is spaced apart from the first surface 14, the second surface 15, and the fourth surface 17.

[0070] As shown in FIGS. 12 and 14 , the second principal surface portion 212 is disposed closer to the third surface 16 in the direction y than the first principal surface portion 211. The second principal surface portion 212 has a principal surface 212A facing one side in the direction z. The dimension in the direction x of the second principal surface portion 212 is substantially the same as the dimension in the direction x of the first principal surface portion 211. The dimension in the direction y of the second principal surface portion 212 is greater than the dimension in the direction y of the first principal surface portion 211. The second principal surface portion 212 overlaps with the first principal surface portion 211 when viewed in the direction y. The shape of the second principal surface portion 212 is not particularly limited, but in the illustrated example, it has a rectangular shape with a partially recessed shape. The second principal surface portion 212 has a recessed portion 212B. The recessed portion 212B is a portion of the second principal surface portion 212 on the fourth surface 17 side in the direction y that is recessed toward the third surface 16 in the direction y. The recess 212B is located at the center of the second main surface portion 212 in the x direction. The recess 212B overlaps with the protrusion 211B when viewed in the y direction. The area of ​​the second main surface portion 212 is larger than the areas of 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 spaced apart from the first surface 14 and the second surface 15.

[0071] As shown in FIGS. 12 and 14 , the third main surface portion 213 is disposed closer to the third surface 16 in the direction y than the second main surface portion 212. The third main surface portion 213 is disposed on the first surface 14 side of the support member 1 in the direction x, and on the third surface 16 side in the direction y. The third main surface portion 213 has a main surface 213A facing one side in the direction z. The shape of the third main surface portion 213 is not particularly limited, and in the illustrated example, it is an elongated rectangle with the direction x as its longitudinal direction. The illustrated third main surface portion 213 is spaced apart from the first surface 14 and the third surface 16.

[0072] As shown in FIG. 12 , the fourth principal surface portion 214 is located closer to the second surface 15 in the direction x than the third principal surface portion 213, and is located closer to the third surface 16 in the direction y than the second principal surface portion 212. The fourth principal surface portion 214 has a principal surface 214A facing one side in the direction z. The shape of the fourth principal surface portion 214 is not particularly limited, and in the illustrated example, it is rectangular. In the illustrated example, the y dimension of the fourth principal surface portion 214 is approximately the same as the y dimension of the third principal surface portion 213. Furthermore, the x dimension of the fourth principal surface portion 214 is smaller than the x dimension of the third principal surface portion 213. The area of ​​the fourth principal surface portion 214 is smaller than the area of ​​the third principal surface portion 213. The fourth principal surface portion 214 overlaps with the third principal surface portion 213 when viewed in the direction x. Furthermore, the fourth main surface portion 214 overlaps with the first main surface portion 211 and the second main surface portion 212 when viewed in the direction y. The illustrated fourth main surface portion 214 is spaced apart from the second surface 15 and the third surface 16.

[0073] 13 and 14, the bottom surface portion 22 is disposed on the bottom surface 1B of the support member 1. In the illustrated example, the bottom surface portion 22 includes a first bottom surface portion 221, a second bottom surface portion 222, a third bottom surface portion 223, and a fourth bottom surface portion 224. In this embodiment, the bottom surface portion 22 is used as a mounting terminal when mounting the semiconductor device A20 on a circuit board (not shown) or the like.

[0074] 13 and 14, the first bottom surface portion 221 is disposed on the fourth surface 17 side of the support member 1 in the direction y. The shape of the first bottom surface portion 221 is not particularly limited, and in the illustrated example, it is an elongated rectangle with the direction x as its longitudinal direction. The illustrated first bottom surface portion 221 is spaced apart from the first surface 14, the second surface 15, and the fourth surface 17.

[0075] As shown in FIGS. 13 and 14 , the second bottom surface portion 222 is disposed closer to the third surface 16 in the direction y than the first bottom surface portion 221. The dimension in the x direction of the first bottom surface portion 221 is substantially the same as the dimension in the x direction of the first bottom surface portion 221. The dimension in the y direction of the second bottom surface portion 222 is larger than the dimension in the y direction of the first bottom surface portion 221. The second bottom surface portion 222 overlaps with the first bottom surface portion 221 when viewed in the y direction. The shape of the second bottom surface portion 222 is not particularly limited, and in the illustrated example, it is rectangular. The area of ​​the second bottom surface portion 222 is larger than the areas of the first bottom surface portion 221, the third bottom surface portion 223, and the fourth bottom surface portion 224. The illustrated second bottom surface portion 222 is spaced apart from the first surface 14 and the second surface 15.

[0076] 13 and 14, the third bottom surface portion 223 is disposed closer to the third surface 16 in the direction y than the second bottom surface portion 222. The third bottom surface portion 223 is disposed on the first surface 14 side of the support member 1 in the direction x and on the third surface 16 side in the direction y. The shape of the third bottom surface portion 223 is not particularly limited, and in the illustrated example, it is an elongated rectangle with the direction x as its longitudinal direction. The illustrated third bottom surface portion 223 is spaced apart from the first surface 14 and the third surface 16.

[0077] As shown in FIG. 13 , the fourth bottom surface portion 224 is located closer to the second surface 15 in the direction x than the third bottom surface portion 223, and is located closer to the third surface 16 in the direction y than the second bottom surface portion 222. The shape of the fourth bottom surface portion 224 is not particularly limited, and in the illustrated example, it is rectangular. In the illustrated example, the y-direction dimension of the fourth bottom surface portion 224 is approximately the same as the y-direction dimension of the third bottom surface portion 223. Furthermore, the x-direction dimension of the fourth bottom surface portion 224 is smaller than the x-direction dimension of the third bottom surface portion 223. The area of ​​the fourth bottom surface portion 224 is smaller than the area of ​​the third bottom surface portion 223. The fourth bottom surface portion 224 overlaps with the third bottom surface portion 223 when viewed in the direction x. Furthermore, the fourth bottom surface portion 224 overlaps with the first bottom surface portion 221 and the second bottom surface portion 222 when viewed in the direction y. The illustrated fourth bottom portion 224 is spaced apart from the second surface 15 and the third surface 16 .

[0078] The connecting portion 23 provides electrical continuity between each portion of the main surface portion 21 and each portion of the bottom surface portion 22. The specific configuration of the connecting portion 23 is not particularly limited, and in the illustrated example, as shown in Figures 12 and 13, it includes a first connecting portion 231, a plurality of second connecting portions 232, a plurality of third connecting portions 233, and a fourth connecting portion 234. The numbers of the first connecting portion 231, second connecting portion 232, third connecting portion 233, and fourth connecting portion 234 are not particularly limited.

[0079] The specific configurations of the first connecting portion 231, the second connecting portion 232, the third connecting portion 233, and the fourth connecting portion 234 are not particularly limited. In this embodiment, as shown in FIGS. 12 to 14 , the first connecting portion 231, the second connecting portion 232, the third connecting portion 233, and the fourth connecting portion 234 penetrate the support member 1 in the thickness direction in an inner region of the support member 1 as viewed in direction z (a region spaced from the first surface 14, the second surface 15, the third surface 16, and the fourth surface 17). The first connecting portion 231, the second connecting portion 232, the third connecting portion 233, and the fourth connecting portion 234 are provided by forming a metal plating layer on the inner surface of a 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 portion 231, the second connecting portion 232, the third connecting portion 233, and the fourth connecting portion 234 are filled with resin, but may also be filled with, for example, metal.

[0080] As shown in FIGS. 12 to 14, the first connecting portion 231 is connected to the first main surface portion 211 and the first bottom surface portion 221, and connects the first main surface portion 211 and the first bottom surface portion 221 together.

[0081] 12 to 14, the plurality of second connecting portions 232 are connected to the second main surface portion 212 and the second bottom surface portion 222, and connect the second main surface portion 212 and the second bottom surface portion 222. In the illustrated example, the plurality of second connecting portions 232 are arranged in a matrix along the direction x and the direction y.

[0082] 12 to 14, the plurality of third connecting portions 233 are connected to the third main surface portion 213 and the third bottom surface portion 223, and connect 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 direction x. The plurality of third connecting portions 233 are arranged closer to the third surface 16 in the direction y.

[0083] 12 and 13, the fourth connecting portion 234 is connected to the fourth main surface portion 214 and the fourth bottom surface portion 224, and connects 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 may be used.

[0084] The semiconductor laser element 4 is a light source of the semiconductor device A20 and includes an active layer made of a semiconductor. In this embodiment, as shown in FIG. 14 , the semiconductor laser element 4 has an element body 41, a first laser electrode 44, and a second laser electrode 45. The element body 41 has an element principal surface 411 and an element rear surface 412. The element principal surface 411 and the element rear surface 412 face opposite each other in the direction z. The element principal surface 411 faces the same side as the principal surface 211A in the direction z. The element rear surface 412 faces opposite the principal surface 211A.

[0085] The first laser electrode 44 is disposed on the main surface 411 of the element. The second laser electrode 45 is disposed on the rear surface 412 of the element. The first laser electrode 44 is omitted in FIG. 12. 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 configured by laminating multiple metal layers, such as silver, nickel, and silver.

[0086] 12 and 14, in this embodiment, the semiconductor laser element 4 is disposed on the first principal surface portion 211. Specifically, the second laser electrode 45 of the semiconductor laser element 4 is electrically joined to the principal surface 211A of the first principal surface portion 211 by a conductive bonding material 49. In the example shown, the semiconductor laser element 4 overlaps with the convex portion 211B and the concave portion 212B when viewed in the direction y. The semiconductor laser element 4 emits laser light L toward the side toward which the fourth surface 17 faces in the direction y. Furthermore, in the example shown, the semiconductor laser element 4 overlaps with the first connecting portion 231 when viewed in the direction z.

[0087] The conductive bonding material 49 is interposed between the conductive portion 2 (the first principal surface portion 211 of the principal 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 entire semiconductor laser element 4 overlaps with the conductive bonding material 49 when viewed in the z direction. The conductive bonding material 49 is configured by stacking multiple metal layers. As shown in FIGS. 15 and 16, 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. In the present embodiment, as shown in FIGS. 17 to 20, the conductive bonding material 49 further includes a first intermediate layer 493 and a second intermediate layer 494.

[0088] 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 constituent material of the metal base layer 490 includes, for example, at least one of aluminum, titanium, zinc, hafnium, and erbium. In this embodiment, the constituent material of the metal base layer 490 includes aluminum. When the constituent material of the metal base layer 490 is aluminum, the Young's modulus of the metal base layer 490 is 70.3 GPa.

[0089] The first bonding layer 491 is interposed between the metal base layer 490 and the semiconductor laser element 4. In this embodiment, as shown in FIGS. 17 and 18, 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-state 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 the thickness of the first bonding layer 491, and the second laser electrode 45 is formed by, for example, a sputtering method.

[0090] The second bonding layer 492 is interposed between the metal base layer 490 and the conductive portion 2 (first main surface portion 211). In this embodiment, as shown in FIGS. 19 and 20, 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-state diffusion of the metal.

[0091] When first bonding layer 491 and second bonding layer 492 are each made of silver, first bonding layer 491 and second bonding layer 492 each have a Young's modulus of 82.7 GPa. Therefore, as indicated by the Young's modulus (70.3 GPa) of metal base layer 490 described above, metal base layer 490 has a smaller Young's modulus than first bonding layer 491 and second bonding layer 492. Furthermore, first bonding layer 491 and second bonding layer 492 each have a thickness of, for example, about 2 to 5 μm, which is smaller than the thickness of metal base layer 490.

[0092] As shown in FIGS. 17 and 18 , the first intermediate layer 493 is interposed 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. As shown in FIGS. 19 and 20 , the second intermediate layer 494 is interposed 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 material of each of the first intermediate layer 493 and the second intermediate layer 494 includes, for example, nickel. When the constituent material of each of the first intermediate layer 493 and the second intermediate layer 494 is nickel, the Young's modulus of each of the first intermediate layer 493 and the second intermediate layer 494 is 200 GPa. Furthermore, the thickness of each of the first intermediate layer 493 and the second intermediate layer 494 is, for example, approximately 0.2 to 2 μm, which is smaller than the thickness of the first bonding layer 491 and the second bonding layer 492.

[0093] The laminated 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 for the conductive bonding material 49 in the semiconductor device A10 described above. The method for bonding the conductive portion 2 (first main surface portion 211) and the semiconductor laser element 4 using the conductive bonding material 49 is also the same as the method described with reference to FIG. 11 for the semiconductor device A10 described above.

[0094] When the conductive portion 2 and the semiconductor laser element 4 are bonded by solid-state diffusion with the conductive bonding material 49, the portion of the conductive bonding material 49 that overlaps with the semiconductor laser element 4 as viewed in the z direction is slightly recessed by the pressure applied from the semiconductor laser element 4. Then, as shown in Fig. 16 , a step is formed in the conductive bonding material 49 at the boundary between the portion that overlaps with the semiconductor laser element 4 as viewed in the z direction and the portion that does not overlap with the semiconductor laser element 4 as viewed in the z direction.

[0095] 16, 18, and 20, near the boundary between a portion where the conductive bonding material 49 overlaps with the semiconductor laser element 4 and a portion where it does not overlap with the semiconductor laser element 4, a gap 495 may be generated 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 shown in FIGS. 16, 17, and 19, slightly inside the boundary between the portion where the conductive bonding material 49 overlaps with the semiconductor laser element 4 and a portion where it does not overlap with the semiconductor laser element 4 as viewed in the z direction (the portion where the conductive bonding material 49 overlaps with the semiconductor laser element 4 as viewed in the z direction), no gap is present 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). As can be understood from this, 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 together by solid-phase diffusion.

[0096] The switching element 5 is an element for turning on and off the current to the semiconductor laser element 4. The switching element 5 is a transistor such as an FET made of, for example, Si, SiC, or GaN. When the switching element 5 is made of SiC, it is suitable for achieving high-speed switching. As shown in FIGS. 12 and 14 , the switching element 5 has an element body 51, a gate electrode 52, a source electrode 53, and a drain electrode 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 faces the same side as the main surface 212A in the direction z. The element back surface 512 faces the same side as the bottom surface 1B in the direction z and faces the main surface 212A.

[0097] The gate electrode 52 is disposed on the element principal surface 511. In the illustrated example, the gate electrode 52 is disposed closer to the second surface 15 in the direction x and closer to the third surface 16 in the direction y. The shape of the gate electrode 52 is not particularly limited, and in the illustrated example, it is rectangular when viewed in the direction z.

[0098] The source electrode 53 is disposed on the element principal surface 511. In the illustrated example, the source electrode 53 is L-shaped when viewed in the direction z, and is disposed in a region on the first surface 14 side in the direction x with respect to the gate electrode 52 and in a region closer to the fourth surface 17 in the direction y.

[0099] The drain electrode 54 is disposed on the rear surface 512 of the device, and in the example shown, covers substantially the entire surface of the rear surface 512 of the device.

[0100] 12 and 14, 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 joined to the main surface 212A of the second main surface portion 212 by a conductive bonding material 59. In this embodiment, the switching element 5 is disposed on the second main surface portion 212 closer to the first surface 14 in the direction x. The switching element 5 overlaps with all of the multiple second connection portions 232 when viewed in the direction z. The switching element 5 overlaps with the semiconductor laser element 4 when viewed in the direction y.

[0101] The conductive bonding material 59 is interposed 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 direction z, and the entire switching element 5 overlaps with the conductive bonding material 59 when viewed in the direction z. The conductive bonding material 59 is configured by laminating multiple 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 configurations of these metal base layer, first bonding layer, second bonding layer, first intermediate layer, and second intermediate layer are the same as the metal base layer 490, first bonding layer 491, second bonding layer 492, first intermediate layer 493, and second intermediate layer 494 of the conductive bonding material 49, respectively. A first bonding layer of the conductive bonding material 59 is bonded to the switching element 5 (drain electrode 54) by solid-state diffusion of metal, and a second bonding layer of the conductive bonding material 59 is bonded to the conductive portion 2 (second main surface portion 212) by solid-state diffusion of metal. The method for forming the conductive bonding material 59 is similar to that for the conductive bonding material 49 in the semiconductor device A10 described above. The method for bonding the conductive portion 2 (second main surface portion 212) and the switching element 5 using the conductive bonding material 59 is also similar to the method described with reference to FIG. 11 for the semiconductor device A10 described above.

[0102] The capacitor 6 is for temporarily storing charge that will become a current that flows through the semiconductor laser element 4. As shown in FIG. 12, in the illustrated example, the capacitor 6 has an electrode 61 and an electrode 62. The electrode 61 is conductively joined to the first main surface 211 by a joining member (not shown). The electrode 62 is conductively joined to the second main surface 212 by a joining member (not shown). The joining member is, for example, solder. In this embodiment, the semiconductor device A20 includes two capacitors 6. The two capacitors 6 are connected in parallel with each other. In this embodiment, the two capacitors 6 are arranged on both sides of the semiconductor laser element 4 in the direction x. The two capacitors 6 do not overlap with the recessed portion 212B and the protruding portion 211B when viewed in the direction y.

[0103] As shown in FIGS. 12 and 14 , the multiple first wires 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 wires 71 are made of a metal such as Au, Cu, or Al, and are made of Au in this embodiment. The number of the multiple first wires 71 is not particularly limited, and is three in the illustrated example. The multiple first wires 71 are connected to a portion of the source electrode 53 closer to the fourth surface 17 in the direction y. The multiple first wires 71 are connected to the first laser electrode 44 of the semiconductor laser element 4 so as to be aligned in the direction y.

[0104] As shown in FIGS. 12 and 14 , the multiple second wires 72 are connected to the source electrode 53 of the switching element 5 and the third main surface portion 213 of the main surface portion 21 of the conductive portion 2. The second wires 72 are made of a metal such as Au, Cu, or Al, and in this embodiment, are made of Au, the same as the first wires 71. The number of the multiple second wires 72 is not particularly limited, and in the illustrated example, there are two, which is fewer than the number of the multiple first wires 71. Therefore, the resistance value of the multiple first wires 71 is smaller than the resistance value of the multiple second wires 72. The multiple second wires 72 are connected to a portion of the source electrode 53 closer to the third surface 16 in the direction y. The multiple second wires 72 are connected to the third main surface portion 213 so as to be aligned in the direction x.

[0105] 12, the third wire 73 is connected to the gate electrode 52 of the switching element 5 and the fourth main surface portion 214 of the main surface portion 21 of the conductive portion 2. The third wire 73 is made of a metal such as Au, Cu, or Al, and is made of Au in this embodiment. The number of third wires 73 is not particularly limited, and is one in the example shown.

[0106] The light-transmitting resin 8 is disposed on the support surface 1A of the support member 1, and covers the support surface 1A, the semiconductor laser element 4, the switching element 5, the plurality of capacitors 6, the plurality of first wires 71, the plurality of second wires 72, and the third wires 73. The light-transmitting resin 8 is made of a material that transmits the laser light L from the semiconductor laser element 4, and is made of, for example, a transparent epoxy resin or silicone resin.

[0107] The shape of the translucent resin 8 is not particularly limited, and in this embodiment, as shown in Figures 12 and 14, the translucent 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.

[0108] The resin main surface 81 is a surface facing the same side as the support surface 1A in the direction z, and in the illustrated example, is a flat surface. The resin first surface 84 is a surface facing the same side as the first surface 14 in the direction x. In the illustrated example, the resin first surface 84 is a flat surface and is flush with the first surface 14. The resin second surface 85 is a surface facing the same side as the second surface 15 in the direction x. In the illustrated example, the resin second surface 85 is a flat surface and is flush with the second surface 15. The resin third surface 86 is a surface facing the same side as the third surface 16 in the direction y. In the illustrated example, the resin third surface 86 is a flat surface and is flush with the third surface 16. The resin fourth surface 87 is a surface facing the same side as the fourth surface 17 in the direction y. In the illustrated example, the resin fourth surface 87 is a flat surface and is flush with the resin fourth surface 87. In this embodiment, the laser light L from the semiconductor laser element 4 is emitted from a fourth resin surface 87 of the light-transmitting resin 8. By making the fourth resin surface 87 a flat and smooth surface, scattering of the laser light L can be suppressed and the emission efficiency can be increased.

[0109] Next, the operation of the semiconductor device A20 will be described.

[0110] In the semiconductor device A20, the conductive bonding material 49 interposed 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-state diffusion of metal, and the metal base layer 490 is interposed between the first bonding layer 491 and the second bonding layer 492. With this configuration, the metal base layer 490 functions as a cushion 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-state diffusion, respectively. This uniformizes the pressing force 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). 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 together by solid-state diffusion bonding. As a result, even if the conductive bonding material 49 is repeatedly exposed to high temperatures due to heat generated in the semiconductor laser element 4 during use of the semiconductor device A20, changes in the bonding state of the conductive bonding material 49 are suppressed. Therefore, the semiconductor device A20 including the conductive bonding material 49 can improve the reliability of the bonding state between the semiconductor laser element 4 and the conductive portion 2.

[0111] In this embodiment, the Young's modulus of the metal base layer 490 is smaller than the Young's modulus of each 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 semiconductor laser element 4 (second laser electrode 45) and the conductive portion 2 (first main surface portion 211) by solid-state diffusion, stress is alleviated by the relatively soft metal base layer 490, and the bonding boundary 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 by solid-state diffusion.

[0112] 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. This allows the 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) to be more uniform during bonding by solid-state diffusion. This allows 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) to be in a stronger conductive bonded state.

[0113] The conductive bonding material 49 includes a first intermediate layer 493 and a second intermediate layer 494. The first intermediate layer 493 is interposed between the metal base layer 490 and the first bonding layer 491, and the second intermediate layer 494 is interposed between the metal base layer 490 and the second bonding layer 492. The configuration including the first intermediate layer 493 and the second intermediate layer 494 is suitable for uniforming the pressing force acting on the boundary between the first bonding layer 491 and the semiconductor laser element 4 (the second laser electrode 45) and the boundary between the second bonding layer 492 and the conductive portion 2 (the first principal surface portion 211) during bonding by solid-state diffusion. Furthermore, when the constituent material of each of the first intermediate layer 493 and the second intermediate layer 494 is nickel, the Young's moduli of the first intermediate layer 493 and the second intermediate layer 494 are relatively large. In this case, the pressure acting on the bonding boundary during solid-state diffusion bonding becomes more uniform, and 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) can be in a stronger conductive bond state.

[0114] In this embodiment, the constituent material of each of first bonding layer 491 and second bonding layer 492 contains silver. With this configuration, oxidation of first bonding layer 491 and second bonding layer 492 is suppressed during bonding by solid-phase diffusion using conductive bonding material 49, enabling good solid-phase diffusion bonding.

[0115] The conductive bonding material 59 interposed between the conductive section 2 and the switching element 5 includes a metal base layer, a first bonding layer, a second bonding layer, a first intermediate layer, and a second intermediate layer, similar to the conductive bonding material 49. 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 of the conductive bonding material 49, respectively. Therefore, the conductive bonding material 59 can also improve the reliability of the bonded state between the switching element 5 and the conductive section 20. The provision of the conductive bonding material 59 provides the same effects as those described above for the conductive bonding material 49.

[0116] 21 to 28, a semiconductor device A30 according to the third embodiment will be described. The illustrated semiconductor device A30 includes a support member 1, a dam portion 18, a conductive portion 2, an LED element 400, a wire 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.

[0117] 21, the semiconductor device A30 has a rectangular shape when viewed in direction z. Directions x and y correspond to directions along the sides of the rectangular shape of the semiconductor device A20. The light-transmitting resin 8 is omitted in FIG.

[0118] 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 include epoxy resin and glass epoxy resin. In the following explanation, an example in which the support member 1 is made of ceramic will be described. In this embodiment, the support member 1 has a support surface 1A and a bottom surface 1B, and is, for example, rectangular when viewed in the direction z. The support surface 1A is a surface facing one side in the direction z and is flat in the illustrated example. The bottom surface 1B is a surface facing the other side in the direction z opposite the support surface 1A and is flat in the illustrated example.

[0119] The conductive portion 2 is a portion that constitutes a conductive path to the LED element 400. The material of the conductive portion 2 is not particularly limited, and examples thereof include metals such as copper (Cu), nickel (Ni), titanium (Ti), and gold (Au). The method for forming the conductive portion 2 is also not particularly limited, and in the illustrated example, the conductive portion 2 is formed by plating, for example.

[0120] The illustrated conductive portion 2 includes a main surface portion 21, a bottom surface portion 22, and a connecting portion .

[0121] The main surface portion 21 is disposed on the support surface 1A of the support member 1. The main surface portion 21 is a thin plate with its thickness direction aligned in the z direction. In the illustrated example, the main surface portion 21 includes a first main surface portion 211 and a second main surface portion 212.

[0122] 21 and 22, the first main surface portion 211 is disposed in the center of the support member 1 when viewed in direction z. The first main surface portion 211 has a main surface 211A facing one side in direction z. The shape of the first main surface portion 211 is not particularly limited, but in the illustrated example, it is rectangular.

[0123] 21 and 22, the second principal surface portion 212 is disposed closer to one side in the direction x than the first principal surface portion 211. The shape of the second principal surface portion 212 is not particularly limited, and in the illustrated example, it is rectangular. The area of ​​the second principal surface portion 212 is smaller than that of the first principal surface portion 211.

[0124] 22, the bottom surface portion 22 is disposed on the bottom surface 1B of the support member 1. In the illustrated example, the bottom surface portion 22 includes a first bottom surface portion 221 and a second bottom surface portion 222. In this embodiment, the bottom surface portion 22 is used as a mounting terminal when mounting the semiconductor device A30 on a circuit board (not shown) or the like.

[0125] 22, the first bottom surface portion 221 is disposed in the center of the support member 1 as viewed in the z direction. The shape of the first bottom surface portion 221 is not particularly limited, and in this embodiment it is rectangular.

[0126] 22, the second bottom surface portion 222 is disposed closer to one side in the x direction than the first bottom surface portion 221. The shape of the second bottom surface portion 222 is not particularly limited, and in this embodiment, it is rectangular. The area of ​​the second bottom surface portion 222 is smaller than that of the first bottom surface portion 221.

[0127] The connecting portion 23 provides electrical continuity between each portion of the main surface portion 21 and each portion of the bottom surface portion 22. The specific configuration of the connecting portion 23 is not particularly limited, and in the illustrated example, it includes a first connecting portion 231 and a second connecting portion 232, as shown in Figures 21 and 22. In the illustrated example, one first connecting portion 231 is provided, but the number of first connecting portions 231 is not particularly limited.

[0128] The specific configurations of the first connecting portion 231 and the second connecting portion 232 are not particularly limited, and in this embodiment, as shown in Figures 21 and 22, they penetrate the support member 1 in the thickness direction in an inner region of the support member 1 when viewed in direction z. Such first connecting portion 231 and second connecting portion 232 are provided by filling a metal into a through hole formed in the support member 1, and reach the support surface 1A and the bottom surface 1B. Unlike the example shown in the figures, the first connecting portion 231 and second connecting portion 232 may be provided by forming a metal plating layer on the inner surface of a through hole formed in the support member 1, in which case the inside of the first connecting portion 231 and the second connecting portion 232 is filled with resin.

[0129] 22 , the first connecting portion 231 is connected to the first main surface portion 211 and the first bottom surface portion 221, and connects the first main surface portion 211 and the first bottom surface portion 221. The second connecting portion 232 is connected to the second main surface portion 212 and the second bottom surface portion 222, and connects the second main surface portion 212 and the second bottom surface portion 222.

[0130] The LED element 400 is a light source for the semiconductor device A30 and includes an active layer made of a semiconductor layer. In this embodiment, as shown in FIG. 22 , the LED element 400 has an element body 41, an electrode pad 421, and a back electrode 43. The element body 41 is made of, for example, a GaN-based semiconductor and emits, for example, blue light. 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 each other in the direction z. The element main surface 411 faces the same side as the main surface 211A in the direction z. The element back surface 412 faces the same side as the bottom surface 1B in the direction z and faces the main surface 211A.

[0131] The electrode pad 421 is disposed on the element principal surface 411. The back surface electrode 43 is disposed on the element rear surface 412. In this embodiment, the electrode pad 421 is an anode electrode and the back surface electrode 43 is a cathode electrode. The back surface electrode 43 is made of, for example, silver.

[0132] 21 and 22, in this embodiment, the LED element 400 is disposed on the first main surface portion 211. Specifically, the back electrode 43 of the LED element 400 is electrically joined to the main surface 211A of the first main surface portion 211 by a conductive bonding material 49. In the LED element 400, light emitted from the element body 41 is emitted toward the side toward which the element main surface 411 faces (one side in the direction z). In the illustrated example, the LED element 400 overlaps with the first connecting portion 231 when viewed in the direction z.

[0133] The conductive bonding material 49 is interposed between the conductive portion 2 (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 configured by laminating multiple metal layers. As shown in FIGS. 23 and 24, 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. As shown in FIGS. 25 to 28, the conductive bonding material 49 further includes a first intermediate layer 493 and a second intermediate layer 494.

[0134] 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 constituent material of the metal base layer 490 includes, for example, at least one of aluminum, titanium, zinc, hafnium, and erbium. In this embodiment, the constituent material of the metal base layer 490 includes aluminum. When the constituent material of the metal base layer 490 is aluminum, the Young's modulus of the metal base layer 490 is 70.3 GPa.

[0135] The first bonding layer 491 is interposed between the metal base layer 490 and the LED element 400. In this embodiment, as shown in FIGS. 25 and 26, 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 (rear electrode 43) by solid-state diffusion of the metal. The constituent material of the rear electrode 43 includes, for example, silver. The thickness of the rear electrode 43 is smaller than the thickness of the first bonding layer 491, and the rear electrode 43 is formed by, for example, a sputtering method.

[0136] The second bonding layer 492 is interposed between the metal base layer 490 and the conductive portion 2 (first main surface portion 211). In this embodiment, as shown in FIGS. 27 and 28, 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-state diffusion of the metal.

[0137] When first bonding layer 491 and second bonding layer 492 are each made of silver, first bonding layer 491 and second bonding layer 492 each have a Young's modulus of 82.7 GPa. Therefore, as indicated by the Young's modulus (70.3 GPa) of metal base layer 490 described above, metal base layer 490 has a smaller Young's modulus than first bonding layer 491 and second bonding layer 492. Furthermore, first bonding layer 491 and second bonding layer 492 each have a thickness of, for example, about 2 to 5 μm, which is smaller than the thickness of metal base layer 490.

[0138] As shown in FIGS. 25 and 26 , the first intermediate layer 493 is interposed 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. As shown in FIGS. 27 and 28 , the second intermediate layer 494 is interposed 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 material of each of the first intermediate layer 493 and the second intermediate layer 494 includes, for example, nickel. When the constituent material of each of the first intermediate layer 493 and the second intermediate layer 494 is nickel, the Young's modulus of each of the first intermediate layer 493 and the second intermediate layer 494 is 200 GPa. Furthermore, the thickness of each of the first intermediate layer 493 and the second intermediate layer 494 is, for example, approximately 0.2 to 2 μm, which is smaller than the thickness of the first bonding layer 491 and the second bonding layer 492.

[0139] The laminated 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 for the conductive bonding material 49 in the semiconductor device A10 described above. The method for bonding the conductive portion 2 (first main surface portion 211) and the LED element 400 using the conductive bonding material 49 is also the same as the method described with reference to FIG. 11 for the semiconductor device A10 described above.

[0140] When the conductive part 2 and the LED element 400 are bonded by the conductive bonding material 49 through solid-state diffusion, the portion of the conductive bonding material 49 that overlaps with the semiconductor laser element 4 as viewed in the z direction is slightly recessed by the pressure applied from the semiconductor laser element 4. Then, as shown in Fig. 24 , a step is formed in the conductive bonding material 49 at the boundary between the portion that overlaps with the LED element 400 as viewed in the z direction and the portion that does not overlap with the LED element 400 as viewed in the z direction.

[0141] 24, 26, and 28, near the boundary between the portion where conductive bonding material 49 overlaps with LED element 400 and the portion where it does not overlap with LED element 400 as viewed in direction z, voids 495 may occur at the boundary between first bonding layer 491 and back electrode 43 (LED element 400) and at the boundary between second bonding layer 492 and first main surface portion 211 (conductive portion 2). On the other hand, as shown in FIGS. 24, 25, and 27, slightly inside the boundary between the portion where conductive bonding material 49 overlaps with LED element 400 and the portion where it does not overlap with LED element 400 as viewed in direction z (the portion where conductive bonding material 49 overlaps with LED element 400 as viewed in direction z), no voids exist at the boundary between first bonding layer 491 and back electrode 43 (LED element 400) and at the boundary between second bonding layer 492 and first main surface portion 211 (conductive portion 2). As can be understood from this, first bonding layer 491 and rear surface electrode 43, and second bonding layer 492 and first principal surface portion 211 are firmly bonded together by solid-phase diffusion.

[0142] 21 and 22, the 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 wire 7 is made of a metal such as Au, Cu, or Al, and in this embodiment, is made of Au.

[0143] The dam portion 18 is disposed on the support surface 1A of the support member 1. When viewed in the z direction, the dam portion 18 has a closed frame shape with a rectangular outer edge and a circular inner edge. When viewed in the z direction, the dam portion 18 surrounds the LED element 400 and the translucent resin 8. The dam portion 18 is made of, for example, a white silicone resin.

[0144] The translucent resin 8 fills the space surrounded by the dam portion 18 and covers part of the support surface 1A of the support member 1, the LED element 400, and the wire 7. The translucent resin 8 is made of a material that transmits light from the LED element 400, such as a transparent silicone resin or epoxy resin mixed with a fluorescent material. The fluorescent material may be one that emits yellow light when excited by blue light from the LED element 400. This causes white light to be emitted from the semiconductor device A30.

[0145] Next, the operation of the semiconductor device A30 will be described.

[0146] In semiconductor device A30, conductive bonding material 49 interposed between conductive portion 2 and LED element 400 includes metal base layer 490, first bonding layer 491, and second bonding layer 492. First bonding layer 491 and LED element 400 (rear surface electrode 43), and second bonding layer 492 and conductive portion 2 (first main surface portion 211), are conductively bonded by solid-state diffusion of metal, and metal base layer 490 is interposed between first bonding layer 491 and second bonding layer 492. With this configuration, metal base layer 490 functions as a cushion when first bonding layer 491 and LED element 400 (rear surface electrode 43), and second bonding layer 492 and conductive portion 2 (first main surface portion 211), are bonded by solid-state diffusion. This uniformizes the pressure acting on the boundary between first bonding layer 491 and LED element 400 (rear electrode 43) and the boundary between second bonding layer 492 and conductive portion 2 (first main surface portion 211). Therefore, first bonding layer 491 and LED element 400 (rear electrode 43), and second bonding layer 492 and conductive portion 2 (first main surface portion 211), are firmly bonded together by solid-state diffusion bonding. As a result, even if conductive bonding material 49 is repeatedly exposed to high temperatures due to heat generated by LED element 400 during use of semiconductor device A30, changes in the bonding state of conductive bonding material 49 are suppressed. Therefore, semiconductor device A30 including conductive bonding material 49 can improve the reliability of the bonding state between LED element 400 and conductive portion 2.

[0147] In this embodiment, the Young's modulus of metal base layer 490 is smaller than the Young's modulus of each of the constituent materials of first bonding layer 491 and second bonding layer 492. With this configuration, when conductive bonding material 49 is bonded to LED element 400 (rear electrode 43) and conductive portion 2 (first main surface portion 211) by solid-state diffusion, stress is alleviated by relatively soft metal base layer 490, and the bonded boundary can be smoothed. As a result, first bonding layer 491 and LED element 400 (rear electrode 43), and second bonding layer 492 and conductive portion 2 (first main surface portion 211) are more firmly bonded by solid-state diffusion.

[0148] In this embodiment, the thickness of metal base layer 490 is greater than the thickness of each of first bonding layer 491 and second bonding layer 492. This allows for more uniform pressing forces to be applied to the boundary between first bonding layer 491 and LED element 400 (rear surface electrode 43) and the boundary between second bonding layer 492 and conductive portion 2 (first main surface portion 211) during bonding by solid-state diffusion. This allows for stronger conductive bonding between first bonding layer 491 and LED element 400 (rear surface electrode 43), and between second bonding layer 492 and conductive portion 2 (first main surface portion 211).

[0149] Conductive bonding material 49 includes first intermediate layer 493 and second intermediate layer 494. First intermediate layer 493 is interposed between metal base layer 490 and first bonding layer 491, and second intermediate layer 494 is interposed between metal base layer 490 and second bonding layer 492. The configuration including first intermediate layer 493 and second intermediate layer 494 is suitable for uniforming the pressing force acting on the boundary between first bonding layer 491 and LED element 400 (rear electrode 43) and the boundary between second bonding layer 492 and conductive portion 2 (first principal surface portion 211) during bonding by solid-state diffusion. When first intermediate layer 493 and second intermediate layer 494 are each made of nickel, the Young's moduli of first intermediate layer 493 and second intermediate layer 494 are relatively large. In this case, the pressure acting on the bonding boundary during solid-state diffusion bonding becomes more uniform, and the first bonding layer 491 and the LED element 400 (rear electrode 43), and the second bonding layer 492 and the conductive portion 2 (first main surface portion 211) can be in a stronger conductive bond state.

[0150] In this embodiment, the constituent material of each of first bonding layer 491 and second bonding layer 492 contains silver. With this configuration, oxidation of first bonding layer 491 and second bonding layer 492 is suppressed during bonding by solid-phase diffusion using conductive bonding material 49, enabling good solid-phase diffusion bonding.

[0151] 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 ways.

[0152] The materials and thicknesses of the layers constituting the conductive bonding material of the present disclosure are not limited to those described in the above embodiments. In the above embodiments, the conductive bonding material has a metal base layer, a first bonding layer, a second bonding layer, a first intermediate layer, and a second intermediate layer. However, the conductive bonding material may have, for example, no first intermediate layer or no second intermediate layer. In addition to the metal base layer, the first bonding layer, the second bonding layer, the first intermediate layer, and the second intermediate layer, the conductive bonding material may have, for example, another metal layer interposed between the metal base layer and the first bonding layer or between the metal base layer and the second bonding layer 492.

[0153] The present disclosure includes the configurations described in the following appendices.

[0154] Appendix 1. a conductive portion having a main surface; a semiconductor element mounted on the main surface; a conductive bonding material interposed between the conductive portion and the semiconductor element to electrically bond the conductive portion and the semiconductor element, The semiconductor device includes a conductive bonding material including a metal base layer, a first bonding layer, and a second bonding layer, the first bonding layer being interposed between the metal base layer and the semiconductor element and bonded to the semiconductor element by solid-state diffusion of metal, and the second bonding layer being interposed between the metal base layer and the conductive portion and bonded to the conductive portion by solid-state diffusion of metal. Appendix 2. 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. Appendix 3. 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. Appendix 4. 4. The semiconductor device according to claim 3, wherein the metal base layer is made of a material containing at least one of aluminum, titanium, zinc, hafnium, and erbium. Appendix 5. 5. The semiconductor device according to claim 4, wherein the first bonding layer and the second bonding layer are each made of a material containing at least one of silver, copper, and gold. Appendix 6. the semiconductor element has an element body and a back surface electrode formed on the element body, 6. The semiconductor device according to claim 1, wherein the back electrode and the first bonding layer are bonded to each other by solid-state diffusion. Appendix 7. 7. The semiconductor device according to claim 6, wherein the first bonding layer and the second bonding layer each have a thickness greater than a thickness of the back electrode. Appendix 8. A semiconductor device described in any one of Appendixes 1 to 7, wherein the conductive bonding material includes a first intermediate layer and a second intermediate layer, the first intermediate layer being interposed between the metal base layer and the first bonding layer, and the second intermediate layer being interposed between the metal base layer and the second bonding layer. Appendix 9. 9. The semiconductor device according to claim 8, wherein the first intermediate layer and the second intermediate layer each include nickel. Appendix 10. 10. The semiconductor device according to any one of claims 1 to 9, further comprising a support substrate having a support surface facing the conductive portion. Appendix 11. a bonding member that bonds the conductive portion to the support substrate, 11. The semiconductor device of claim 10, wherein the bonding member includes a plurality of metal layers bonded by solid-state diffusion. Appendix 12. 12. The semiconductor device according to claim 10, further comprising a sealing resin that covers the conductive portion, the semiconductor element, and a portion of the support substrate, the support substrate having a bottom surface opposite the support surface, the bottom surface being exposed from the sealing resin. Appendix 13. 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, the conductive portion includes a first conductive portion to which the first switching element is conductively connected and a second conductive portion to which the second switching element is conductively connected, 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; 13. The semiconductor device according to claim 12, wherein 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. Appendix 14. a support member having a support surface for supporting the semiconductor element; 10. The semiconductor device according to claim 1, wherein 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. Appendix 15. the semiconductor element includes a semiconductor laser element and a switching element, the conductive portion includes a first portion and a second portion spaced apart from each other; 15. The semiconductor device according to claim 14, wherein the semiconductor laser element is conductively joined to the first portion, and the switching element is conductively joined to the second portion. Appendix 16. 16. The semiconductor device according to claim 15, further comprising a light-transmitting resin that covers the semiconductor laser element, the switching element, and the support surface of the support member. Appendix 17. Further comprising a light-transmitting resin, the semiconductor element includes an LED element, 15. The semiconductor device according to claim 14, wherein the translucent resin covers the LED element and at least a portion of the support surface of the support member. Appendix 18. The support member further includes a frame-shaped dam portion disposed on the support surface, 18. The semiconductor device according to claim 17, wherein the dam portion surrounds the translucent resin when viewed in a thickness direction of the support member. [Explanation of symbols]

[0155] A10, A20, A30 Semiconductor devices 1 Support member 1A Support surface 1B bottom 10 Support base board 10A support surface 10B bottom 11. 1st support plate 12 Second support plate 121 First Area 122 Second Domain 123 The Third Realm 13 bottom plate 13A recess Page 14 15 Page 2 16 Page 3 17 Page 4 18 Weir 19 Joining parts 2 Conductive part 20 conductive part 20A main surface 20B inside 201 1st conductive part 202 Second conductive part 203 Third conductive part 21 Main face 21A Main surface 211 1st main face 211A main surface 211B convex part 212 Second Main Face 212A main surface 212B concave part 213 3rd Main Face 213A main surface 214 4th Main Face 214A main surface 22 bottom part 221 1st bottom part 222 Second bottom part 223 3rd bottom part 224 4th bottom part 23 Liaison Department 231 First Liaison Department 232 Liaison Department 2 233 Liaison Department 3 234 Liaison Department 4 24 substrate 25 conductor layer 26 Insulation layer 271 Gato wiring layer 272 Detection wiring layer 31 First input terminal 311 Bend 32 Second input terminal 321 Bend 33 First output terminal 331 Bend 34 Second output terminal 341 Bend 35 Gate terminal 36 Detection terminal 4. Semiconductor laser element 40 Semiconductor elements 400 LED elements 401 1st element 402 Second element 41 Element body 411 Element main surface 412 Back side of element 42 Main surface electrode 421 Electrode Pads 43 Back electrode 44 First laser electrode 45 Second laser electrode (back electrode) 49 Conductive bonding material 490 Metal base layer 491 1st bonding layer 492 2nd bonding layer 493 First Middle Class 494 Second Middle Class 495 void 5 Switching elements 51 Element body 511 Element main surface 512 Back side of element 52 gate electrode 53 Source electrode 54 Drain electrode (rear electrode) 59 Conductive bonding material 6 capacitors 61 Electrode 62 electrodes 7 wire 71 First Wire 72 Second Wire 73 Third Wire 8 Translucent resin 80 Sealing resin 81 Resin main surface 82 Resin bottom 84 Resin first side 85 Resin 2nd side 86 Resin 3rd side 87 Resin 4th side 9 Pressing member L laser light x direction y direction z direction (thickness direction)

Claims

1. a conductive portion having a main surface; a semiconductor element mounted on the main surface; a conductive bonding material interposed between the conductive portion and the semiconductor element to electrically bond the conductive portion and the semiconductor element, the conductive bonding material includes a metal base layer and a first bonding layer, the first bonding layer being interposed between the metal base layer and the semiconductor element and being bonded to the semiconductor element by solid-state diffusion of a metal; the conductive bonding material is larger than the semiconductor element when viewed in a thickness direction, and the entire semiconductor element is overlapped with the conductive bonding material when viewed in the thickness direction; a constituent material of the metal base layer including aluminum, and a constituent material of the first bonding layer including silver; The semiconductor device, wherein the first bonding layer has a step formed at a boundary between a portion that overlaps with the semiconductor element in the thickness direction and a portion that does not overlap with the semiconductor element in the thickness direction.

2. The conductive bonding material includes a second bonding layer, 2. The semiconductor device according to claim 1, wherein the second bonding layer is interposed between the metal base layer and the conductive portion, and is bonded to the conductive portion by solid-phase diffusion of metal.

3. A semiconductor device as described in Claim 2, wherein the constituent material of the second bonding layer includes silver.

4. A semiconductor device as described in claim 2 or 3, 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.

5. A semiconductor device as described in Claim 4, 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.

6. The semiconductor element has an element body and a back surface electrode formed on the element body, 6. The semiconductor device according to claim 2, wherein the back electrode and the first bonding layer are bonded to each other by solid-phase diffusion.

7. A semiconductor device as described in 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 electrode.

8. The conductive bonding material includes a first intermediate layer and a second intermediate layer, the first intermediate layer is interposed between the metal base layer and the first bonding layer, 8. The semiconductor device according to claim 2, wherein the second intermediate layer is interposed between the metal base layer and the second bonding layer.

9. A semiconductor device as described in Claim 8, wherein the constituent material of each of the first intermediate layer and the second intermediate layer includes nickel.

10. A semiconductor device as described in claim 8 or 9, wherein the thickness of each of the first intermediate layer and the second intermediate layer is smaller than the thickness of each of the first bonding layer and the second bonding layer.

11. A semiconductor device described in any one of claims 2 to 10, further comprising a support substrate having a support surface facing the conductive portion.

12. Further comprising a joining member joining the conductive portion to the support substrate, The semiconductor device according to claim 11 , wherein the bonding member includes a plurality of metal layers bonded by solid-state diffusion.

13. The semiconductor device further includes a sealing resin that covers the conductive portion, the semiconductor element, and a portion of the support substrate, 13. The semiconductor device according to claim 11, wherein the support substrate has a bottom surface opposite to the support surface, the bottom surface being exposed from the sealing resin.

14. 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, the conductive portion includes a first conductive portion to which the first switching element is conductively connected and a second conductive portion to which the second switching element is conductively connected, 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; 14. The semiconductor device according to claim 13, wherein 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.

15. The semiconductor device according to claim 1, further comprising a support member having a support surface for supporting the semiconductor element.

10. The semiconductor device according to claim 2, wherein said conductive portion includes a main surface portion, a bottom surface portion, and a connecting portion that electrically connects said main surface portion and said bottom surface portion.

16. The semiconductor element includes a semiconductor laser element and a switching element, the conductive portion includes a first portion and a second portion spaced apart from each other; 16. The semiconductor device according to claim 15, wherein the semiconductor laser element is conductively joined to the first portion, and the switching element is conductively joined to the second portion.

17. A semiconductor device as described in Claim 16, further comprising a translucent resin covering the semiconductor laser element, the switching element, and the support surface of the support member.

18. Further comprising a translucent resin, the semiconductor element includes an LED element, The semiconductor device according to claim 15 , wherein the light-transmitting resin covers the LED element and at least a part of the support surface of the support member.

19. The support member further includes a frame-shaped dam portion disposed on the support surface, The semiconductor device according to claim 18 , wherein the dam portion surrounds the translucent resin when viewed in a thickness direction of the support member.

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