Semiconductor device

Abstract

In the present invention, a semiconductor device comprises: a first lead that includes a die pad part having a first main surface facing one thickness-direction side and a first back surface facing the other thickness-direction side; a semiconductor element supported on the first main surface; a conductive part that is disposed on the one thickness-direction side of the semiconductor element and conductively joined to the semiconductor element; a sealing resin that covers the semiconductor element and at least a portion of the die pad part; and a first heat dissipation body that is secured to the one thickness-direction side of the conductive part, and that has higher thermal conductivity than the sealing resin. The first heat dissipation body includes a first insulation layer that overlaps the conductive part as viewed in the thickness direction, and also has a first heat dissipation surface facing the one thickness-direction side. The sealing resin has a resin main surface facing the one thickness-direction side, and the first heat dissipation surface is exposed from the resin main surface.

Description

Semiconductor Devices

[0001] The present disclosure relates to semiconductor devices.

[0002] Various configurations have been proposed for semiconductor devices including semiconductor elements. Patent Document 1 discloses an example of a conventional semiconductor device. The semiconductor device disclosed in this document includes a semiconductor element, multiple leads, and an encapsulating resin. The semiconductor element is supported by the leads. The semiconductor element is a transistor with a switching function. An electrode (source electrode) of the semiconductor element on the lead is connected to the other leads by multiple wires. The encapsulating resin covers a portion of each lead, the semiconductor element, and the multiple wires. In the semiconductor device disclosed in Patent Document 1, connecting multiple wires to the source electrode of the semiconductor element makes it suitable for passing large currents and capable of handling high output. However, as the output of semiconductor devices increases, the amount of heat generated by the semiconductor element increases, and improvements in the heat dissipation and voltage resistance of the semiconductor device are required.

[0003] Japanese Patent Application Laid-Open No. 2017-135241

[0004] An object of the present disclosure is to provide an improved semiconductor device compared to conventional semiconductor devices. In particular, in view of the above-mentioned circumstances, an object of the present disclosure is to provide a semiconductor device suitable for improving heat dissipation and voltage resistance.

[0005] One aspect of the present disclosure provides a semiconductor device comprising: a first lead including a die pad portion having a first main surface facing one side in a thickness direction and a first back surface facing the other side in the thickness direction; a semiconductor element supported on the first main surface; a conductive portion disposed on one side of the semiconductor element in the thickness direction and conductively joined to the semiconductor element; a sealing resin covering at least a portion of the die pad portion and the semiconductor element; and a first heat sink fixed to one side of the conductive portion in the thickness direction and having a higher thermal conductivity than the sealing resin. The first heat sink includes a first insulating layer overlapping the conductive portion when viewed in the thickness direction and has a first heat sink surface facing the one side in the thickness direction. The sealing resin has a resin main surface facing the one side in the thickness direction and a resin back surface spaced from the resin main surface on the other side in the thickness direction and facing the other side in the thickness direction. The first heat sink surface is exposed from the resin main surface.

[0006] According to the above configuration, it is possible to improve the heat dissipation and voltage resistance of the semiconductor device.

[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.

[0008] FIG. 1 is a plan view showing a semiconductor device according to a first embodiment of the present disclosure. FIG. 2 is a bottom view showing a semiconductor device according to a first embodiment of the present disclosure. FIG. 3 is a plan view showing a semiconductor device according to a first embodiment of the present disclosure (transparent to a sealing resin and a first heat sink). FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. FIG. 5 is a cross-sectional view taken along line V-V in FIG. 3. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 3. FIG. 7 is a cross-sectional view similar to FIG. 4, showing a semiconductor device according to a first modification of the first embodiment. FIG. 8 is a plan view showing a semiconductor device according to a second modification of the first embodiment. FIG. 9 is a plan view showing a semiconductor device according to a second modification of the first embodiment (transparent to a sealing resin and a first heat sink). FIG. 10 is a cross-sectional view taken along line X-X in FIG. 9. FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. 9. FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 9. FIG. 13 is a plan view showing a semiconductor device according to a second embodiment of the present disclosure. 14 is a bottom view showing a semiconductor device according to a second embodiment of the present disclosure. FIG. 15 is a plan view showing a semiconductor device according to a second embodiment of the present disclosure (transmitting the sealing resin and the first heat sink). FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG. 15. FIG. 17 is a cross-sectional view taken along line XVII-XVII in FIG. 15. FIG. 18 is a cross-sectional view taken along line XVIII-XVIII in FIG. 15. FIG. 19 is a cross-sectional view taken along line XIX-XIX in FIG. 15. FIG. 20 is a cross-sectional view similar to FIG. 17, showing a semiconductor device according to a first modification of the second embodiment.

[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] In this disclosure, unless otherwise specified, "a certain object A is formed on a certain object B" and "a certain object A is formed on a certain object B" include "a certain object A is formed directly on a certain object B" and "a certain object A is formed on a certain object B with another object interposed between the certain object A and the certain object B." Similarly, "a certain object A is disposed on a certain object B" and "a certain object A is disposed on a certain object B" include "a certain object A is disposed directly on a certain object B" and "a certain object A is disposed on a certain object B with another object interposed between the certain object A and the certain object B" unless otherwise specified. Similarly, "a certain object A is located on a certain object B" includes "a certain object A is located on a certain object B with a certain object A in contact with the certain object B" and "a certain object A is located on a certain object B with another object interposed between the certain object A and the certain object B." Furthermore, unless otherwise specified, the phrase "an object A overlaps an object B when viewed in a certain direction" includes "an object A overlaps the entire object B" and "an object A overlaps a part of an object B." Furthermore, in the present disclosure, "a surface A faces in (one side or the other side of) direction B" is not limited to the case where the angle of surface A with respect to direction B is 90°, but also includes the case where surface A is tilted with respect to direction B.

[0012] 1 to 6, a semiconductor device A10 according to a first embodiment of the present disclosure will be described. The semiconductor device A10 includes a first lead 1A, a second lead 1B, a third lead 1C, a semiconductor element 2, a conductive member 3, a first heat sink 4, conductive bonding materials 61, 62, and 63, a bonding material 64, and a sealing resin 7.

[0013] FIG. 1 is a plan view showing the semiconductor device A10. FIG. 2 is a bottom view showing the semiconductor device A10. FIG. 3 is a plan view showing the semiconductor device A10. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. FIG. 5 is a cross-sectional view taken along line V-V in FIG. 3. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 3. For ease of understanding, FIG. 3 shows the sealing resin 7 and the first heat sink 4 in a transparent manner. In these figures, the transparent sealing resin 7 and the first heat sink 4 are shown by imaginary lines (chain double-dashed lines).

[0014] In the description of the semiconductor device A10, the thickness direction (direction in a plan view) of the semiconductor element 2 is referred to as the "thickness direction z." The direction perpendicular to the thickness direction z (the up-down direction in FIG. 1) is referred to as the "first direction x." The direction perpendicular to the thickness direction z and the first direction x (the left-right direction in FIG. 1) is referred to as the "second direction y." As shown in FIGS. 1 and 2, the semiconductor device A10 has a substantially rectangular shape when viewed in the thickness direction z. Furthermore, in the description of the semiconductor device A10, for convenience, the upper side in FIG. 1 is referred to as the "x1 side of the first direction x," and the lower side in FIG. 1 is referred to as the "x2 side of the first direction x." In FIG. 1, the right side is referred to as the "y1 side of the second direction y," and the left side is referred to as the "y2 side of the second direction y." In Figures 4 to 6, the upper side in the figure is an example of "one side in the thickness direction" in the present disclosure and is called the "z1 side in the thickness direction z," and the lower side in the figure is an example of "the other side in the thickness direction" in the present disclosure and is called the "z2 side in the thickness direction z."

[0015] The first lead 1A, the second lead 1B, and the third lead 1C are formed, for example, by punching or bending a metal plate. The constituent material of the first lead 1A, the second lead 1B, and the third lead 1C is, for example, copper (Cu) or nickel (Ni), or an alloy thereof. The thickness of the first lead 1A, the second lead 1B, and the third lead 1C is, for example, 0.1 mm to 0.3 mm.

[0016] 3, the first lead 1A is arranged to be spaced apart from the second lead 1B and the third lead 1C in the first direction x. The second lead 1B and the third lead 1C are aligned in the second direction y. The first lead 1A, the second lead 1B, and the third lead 1C are arranged to be spaced apart from each other when viewed in the thickness direction z. The size when viewed in the thickness direction z is the largest for the first lead 1A and the smallest for the third lead 1C.

[0017] As shown in FIGS. 3 to 6 , the first lead 1A has a die pad portion 11 and multiple (four in this embodiment) terminal portions 12. The die pad portion 11 is, for example, rectangular when viewed in the thickness direction z. The die pad portion 11 has a first main surface 111 and a first back surface 112. The first main surface 111 faces the z1 side in the thickness direction z, and the first back surface 112 faces the opposite side to the first main surface 111 (the z1 side in the thickness direction z). A semiconductor element 2 is mounted on the first main surface 111. As shown in FIGS. 2 and 4 , the first back surface 112 is exposed from the sealing resin 7. The first back surface 112 is a portion to be bonded with a bonding material such as solder when the semiconductor device A10 is mounted on a circuit board (not shown).

[0018] The multiple terminal portions 12 are located on the x1 side in the first direction x with respect to the die pad portion 11. Each of the multiple terminal portions 12 is connected to the x1 side in the first direction x of the die pad portion 11 and extends toward the x1 side in the first direction x. The multiple terminal portions 12 are arranged at intervals in the second direction y. Each of the multiple terminal portions 12 has a back surface mounting portion 121. The back surface mounting portion 121 faces the z2 side in the thickness direction z (the lower side in FIG. 4 ). The back surface mounting portion 121 is exposed from the sealing resin 7. The back surface mounting portion 121 is a portion that is bonded with a bonding material such as solder when the semiconductor device A10 is mounted on a circuit board (not shown).

[0019] 3 and 4, the second lead 1B has a pad portion 13, a plurality of (three in this embodiment) terminal portions 14, and a plurality of (three in this embodiment) bent portions 15. The pad portion 13 is located on the z1 side in the thickness direction z (upper side in FIG. 4) with respect to the plurality of terminal portions 14. The pad portion 13 is also located inward in the first direction x with respect to the plurality of terminal portions 14.

[0020] The multiple terminal portions 14 are located on the x2 side in the first direction x with respect to the die pad portion 11 of the first lead 1A. The multiple terminal portions 14 are arranged at intervals in the second direction y. Each of the multiple terminal portions 14 has a back surface mounting portion 141. The back surface mounting portion 141 faces the z2 side in the thickness direction z (the lower side in FIG. 4 ). The back surface mounting portion 141 is exposed from the sealing resin 7. The back surface mounting portion 141 is a portion that is joined with a joining material such as solder when the semiconductor device A10 is mounted on a circuit board (not shown). The multiple bent portions 15 individually connect the pad portion 13 and the multiple terminal portions 14 and have a bent shape when viewed in the second direction y.

[0021] 3 and 5, the third lead 1C has a pad portion 16, a terminal portion 17, and a bent portion 18. The pad portion 16 is located on the z1 side in the thickness direction z (upper side in FIG. 5) with respect to the terminal portion 17. The pad portion 16 is also located inward in the first direction x with respect to the terminal portion 17.

[0022] The terminal portion 17 is located on the x2 side in the first direction x with respect to the die pad portion 11 of the first lead 1A. The multiple terminal portions 14 of the second lead 1B and the terminal portion 17 of the third lead 1C are arranged at intervals in the second direction y. The terminal portion 17 has a back surface mounting portion 171. The back surface mounting portion 171 faces the z2 side in the thickness direction z (the lower side in FIG. 5 ). The back surface mounting portion 171 is exposed from the sealing resin 7. The back surface mounting portion 171 is a portion that is joined with a joining material such as solder when the semiconductor device A10 is mounted on a circuit board (not shown). The bent portion 18 connects the pad portion 16 and the terminal portion 17 and has a bent shape when viewed in the second direction y.

[0023] The semiconductor element 2 is an element that performs the electrical functions of the semiconductor device A10. The type of semiconductor element 2 is not particularly limited, and in this embodiment, the semiconductor element 2 is a power semiconductor chip with a switching function, such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The semiconductor element 2 may also be a switching element such as an IGBT (Insulated Gate Bipolar Transistor) or a diode. As shown in FIGS. 3 to 5 , the semiconductor element 2 has an element body 20, a source electrode 21, a drain electrode 22, and a gate electrode 23.

[0024] The element body 20 has a rectangular shape when viewed in the thickness direction z. The element body 20 has an element main surface 201 and an element back surface 202. The element main surface 201 and the element back surface 202 face opposite each other in the thickness direction z. The element main surface 201 faces the same side as the first main surface 111 of the die pad portion 11 in the thickness direction z. Therefore, the element back surface 202 faces the first main surface 111.

[0025] The source electrode 21 and the gate electrode 23 are disposed on the main surface 201 of the device. The drain electrode 22 is disposed on the rear surface 202 of the device. The constituent materials of the source electrode 21, the drain electrode 22, and the gate electrode 23 are, for example, copper, aluminum (Al), or an alloy thereof.

[0026] In this embodiment, the source electrode 21 covers most of the device principal surface 201. Specifically, the source electrode 21 is disposed in a region of the rectangular device principal surface 201 excluding the periphery and one corner (the lower right corner in FIG. 3 ). The gate electrode 23 is disposed in one corner of the device principal surface 201 (the lower right corner in FIG. 3 ). The drain electrode 22 covers substantially the entire device rear surface 202.

[0027] The drain electrode 22 is electrically joined to the first main surface 111 (die pad portion 11) via a conductive bonding material 62. The conductive bonding material 62 electrically connects the die pad portion 11 and the drain electrode 22. The conductive bonding material 62 is, for example, solder.

[0028] The semiconductor device A10 includes a wire 68. As shown in Figures 3 and 5, the wire 68 is electrically connected to the gate electrode 23 and the pad portion 16 of the third lead 1C. The wire 68 electrically connects the gate electrode 23 and the third lead 1C.

[0029] 3 and 4 , the conductive member 3 is joined to the source electrode 21 of the semiconductor element 2 and the second lead 1B. The conductive member 3 is made of a metal plate material. The conductive member 3 is made of, for example, copper or a copper alloy. The conductive member 3 is a metal plate material that has been subjected to, for example, a punching process or a bending process. In this embodiment, the conductive member 3 has a conductive portion 31, a lead-side joint portion 32, and an intermediate portion 33. As shown in FIG. 4 , the conductive portion 31, the lead-side joint portion 32, and the intermediate portion 33 are connected by being appropriately bent when viewed in the second direction y.

[0030] The conductive portion 31 is disposed on the z1 side in the thickness direction z of the semiconductor element 2. The conductive portion 31 is joined to the source electrode 21 via a conductive bonding material 61. The conductive bonding material 61 electrically connects the conductive portion 31 (conductive member 3) and the source electrode 21. The conductive bonding material 61 is, for example, solder. The conductive portion 31 has a conductive main surface 311. The conductive main surface 311 faces the z1 side in the thickness direction z.

[0031] The lead-side joint 32 is joined to the pad 13 of the second lead 1B via a conductive bonding material 63. The conductive bonding material 63 electrically connects the lead-side joint 32 (conductive member 3) and the pad 13 (second lead 1B). The conductive bonding material 63 is, for example, solder. As shown in FIG. 4 , the lead-side joint 32 has a convex portion located on the z2 side (lower side in the figure) in the thickness direction z from the surrounding area. When the pad 13 and the lead-side joint 32 are joined, the convex portion is pressed against the pad 13, and a sufficient amount of conductive bonding material 63 is present around the convex portion. This ensures proper conductivity between the lead-side joint 32 and the pad 13.

[0032] The intermediate portion 33 is located between the conductive portion 31 and the lead-side joint portion 32 in the first direction x. The intermediate portion 33 is connected to both the conductive portion 31 and the lead-side joint portion 32. As a result, the conductive portion 31 is electrically connected to the pad portion 13 (second lead 1B) via the intermediate portion 33 and the lead-side joint portion 32. The conductive member 3 forms a path for a main current switched by the semiconductor element 2.

[0033] In this embodiment, the conductive portion 31 is thicker than the lead-side joint portion 32 and the intermediate portion 33. The intermediate portion 33 is formed integrally with the conductive portion 31. In the illustrated example, as shown in FIGS. 3 and 4 , the intermediate portion 33 is connected to an end of the conductive portion 31 closer to the y2 side in the second direction y and on the z2 side in the thickness direction z, and extends toward the x2 side in the first direction x. Note that the conductive member 3 having the conductive portion 31 is not limited to the above configuration. The conductive member 3 may be configured such that the conductive portion 31, the lead-side joint portion 32, and the intermediate portion 33 each have a substantially uniform thickness.

[0034] The first heat sink 4 is disposed on the z1 side of the conductive portion 31 in the thickness direction z. The first heat sink 4 is fixed to the conductive main surface 311 (conductive portion 31). In this embodiment, the first heat sink 4 includes a first insulating layer 41, a first metal layer 42, and a second metal layer 43 stacked on top of each other. The first heat sink 4 is formed, for example, from a DBC (Direct Bonded Copper) substrate.

[0035] The first insulating layer 41 is made of a material with relatively high thermal conductivity, such as ceramics. The material of the first insulating layer 41 is not particularly limited, and examples thereof include alumina (Al2O3), aluminum nitride (AlN), and silicon nitride (Si3N4). The first insulating layer 41 may be made of an insulating resin sheet in addition to ceramics. The first insulating layer 41 has a rectangular shape when viewed in the thickness direction z.

[0036] The first metal layer 42 is laminated on the z1 side in the thickness direction z of the first insulating layer 41. The constituent material of the first metal layer 42 is not particularly limited and may include, for example, copper. The constituent material of the first metal layer 42 may also include aluminum instead of copper.

[0037] The second metal layer 43 is laminated on the z2 side of the first insulating layer 41 in the thickness direction z. The constituent material of the second metal layer 43 is the same as the constituent material of the first metal layer 42. The second metal layer 43 is bonded to the conductive main surface 311 (conductive portion 31) via a bonding material 64. The conductive main surface 311 is an example of a fixing portion to which the second metal layer 43 (first heat sink 4) is fixed. The bonding material 64 may be conductive or insulating, and is, for example, solder.

[0038] The first metal layer 42 and the second metal layer 43 are each rectangular when viewed in the thickness direction z. The first insulating layer 41 is larger in size in a plan view (when viewed in the thickness direction z) than the first metal layer 42 and the second metal layer 43. When viewed in the thickness direction z, the first insulating layer 41 overlaps with each of the first metal layer 42, the second metal layer 43, and the conductive portion 31 of the conductive member 3. In the illustrated example, when viewed in the thickness direction z, the first insulating layer 41 overlaps with all of the first metal layer 42, the second metal layer 43, and the conductive portion 31.

[0039] The first metal layer 42 has a first heat dissipation surface 421. The first heat dissipation surface 421 faces the z1 side in the thickness direction z. The first heat dissipation surface 421 is exposed from the sealing resin 7.

[0040] The sealing resin 7 covers a portion of each of the first lead 1A, the second lead 1B, and the third lead 1C, the semiconductor element 2, the wire 68, the conductive member 3, and a portion of the first heat sink 4. The sealing resin 7 is made of, for example, a black epoxy resin. The thermal conductivity of the first heat sink 4 (each of the first insulating layer 41, the first metal layer 42, and the second metal layer 43) is higher than the thermal conductivity of the sealing resin 7.

[0041] As shown in FIGS. 1, 2, 4, and 6, the sealing resin 7 has a resin main surface 71, a resin back surface 72, and resin side surfaces 73 to 76. The resin main surface 71 and the resin back surface 72 face opposite sides in the thickness direction z. The resin main surface 71 faces the z1 side in the thickness direction z, facing the same side as the element main surface 201 and the first main surface 111. As shown in FIG. 1, the resin main surface 71 has a frame shape surrounding the first heat dissipation surface 421 of the first metal layer 42 of the first heat sink 4 in a plan view (viewed in the thickness direction z). The first heat dissipation surface 421 is exposed from this resin main surface 71. In the illustrated example, the first heat dissipation surface 421 is flush with the resin main surface 71. Note that, unlike the illustrated example, the first heat dissipation surface 421 may be located closer to the z1 side in the thickness direction z than the resin main surface 71. In this case, the first metal layer 42 including the first heat dissipation surface 421 protrudes from the resin main surface 71 toward the z1 side in the thickness direction z. Alternatively, the first heat dissipation surface 421 may be located on the z2 side in the thickness direction z from the resin main surface 71. In this case, the first metal layer 42 including the first heat dissipation surface 421 is located in a recessed position from the resin main surface 71 toward the z2 side in the thickness direction z.

[0042] The resin back surface 72 faces the z2 side in the thickness direction z, and faces the same side as the element back surface 202 and the first back surface 112. As shown in FIG. 2 , the first back surface 112 of the die pad portion 11 is exposed from the resin back surface 72. The first back surface 112 is, for example, flush with the resin back surface 72. Also, the back surface mounting portion 121 of each of the multiple terminal portions 12, the back surface mounting portion 141 of each of the multiple terminal portions 14, and the back surface mounting portion 171 of the terminal portion 17 are exposed from the resin back surface 72. Note that the first back surface 112 of the die pad portion 11 may be covered with the sealing resin 7, unlike the example shown in the drawings.

[0043] Each of the resin side surfaces 73 to 76 is connected to the resin main surface 71 and the resin back surface 72 and is sandwiched between the resin main surface 71 and the resin back surface 72 in the thickness direction z. The resin side surface 73 and the resin side surface 74 face opposite each other in the first direction x. The resin side surface 73 faces the x1 side of the first direction x, and the resin side surface 74 faces the x2 side of the first direction x. The resin side surface 75 and the resin side surface 76 face opposite each other in the second direction y. The resin side surface 75 faces the y1 side of the second direction y, and the resin side surface 76 faces the y2 side of the second direction y. As shown in FIG. 1 , a portion of each of the multiple terminal portions 12 protrudes from the resin side surface 73. Furthermore, a portion of each of the multiple terminal portions 14 and 17 protrudes from the resin side surface 74. In the illustrated example, the resin side surfaces 73 to 76 are each slightly inclined with respect to the thickness direction z. 1, 2, and 4 to 6 are merely examples, and the shape of the sealing resin 7 is not limited to the illustrated shapes.

[0044] Next, the operation of this embodiment will be described.

[0045] The semiconductor device A10 includes a semiconductor element 2 supported on a first main surface 111 of a die pad portion 11 (first lead 1A), a conductive portion 31 electrically connected to the z1 side of the semiconductor element 2 in the thickness direction z, and a first heat sink 4 fixed to the z1 side of the conductive portion 31 in the thickness direction z. The first heat sink 4 has a first heat sink surface 421 facing the z1 side of the thickness direction z, and the first heat sink surface 421 is exposed from a resin main surface 71 of the sealing resin 7. The thermal conductivity of the first heat sink 4 is higher than that of the sealing resin 7. This configuration allows heat generated in the semiconductor element 2 to be released from the first heat sink surface 421 via the conductive portion 31 and the first heat sink 4. The first heat sink surface 421 faces the opposite side to a first back surface 112, which is the mounting surface of the first lead 1A (die pad portion 11). By closely attaching a heat sink or the like (not shown) to this first heat dissipation surface 421, heat generated in the semiconductor element 2 can be efficiently dissipated from the side opposite the die pad portion 11 (the z1 side in the thickness direction z) of the semiconductor element 2. Furthermore, the first heat dissipation body 4 includes a first insulating layer 41 that overlaps with the conductive portion 31 when viewed from the z1 side in the thickness direction z. The semiconductor device A10 configured as described above can achieve improved heat dissipation properties and improved voltage resistance.

[0046] The first heat sink 4 includes a first insulating layer 41, a first metal layer 42, and a second metal layer 43 stacked one on top of the other. The first metal layer 42 is stacked on the z1 side of the first insulating layer 41 in the thickness direction z and has a first heat sink surface 421. The second metal layer 43 is stacked on the z2 side of the first insulating layer 41 in the thickness direction z and is joined to the conductive main surface 311 (conductive portion 31). The first heat sink 4 configured as described above can be formed, for example, from a DBC substrate. The semiconductor device A10 equipped with this first heat sink 4 has a structure suitable for improving heat dissipation and voltage resistance.

[0047] When viewed in the thickness direction z, the first insulating layer 41 of the first heat sink 4 overlaps the entire conductive main surface 311 to which the first heat sink 4 is fixed in the conductive portion 31. This configuration is preferable in terms of improving the voltage resistance of the semiconductor device A10.

[0048] First Modification of First Embodiment: Figure 7 shows a semiconductor device according to a first modification of the first embodiment. Figure 7 is a cross-sectional view showing a semiconductor device A11 of this modification, and shows the same cross section as Figure 4 shown in the above embodiment. In Figures from Figure 7 onwards, elements that are the same as or similar to those of the semiconductor device A10 of the above embodiment are given the same reference numerals as in the above embodiment, and descriptions thereof will be omitted as appropriate.

[0049] In the semiconductor device A11 of this modification, the configuration of the first heat sink 4 differs from that of the semiconductor device A10 of the above embodiment. In this modification, the first heat sink 4 includes a conductor plate 44 and a first insulating layer 45. The conductor plate 44 is made of, for example, a metal plate. The conductor plate 44 is made of, for example, copper or a copper alloy. The conductor plate 44 has a rectangular shape when viewed in the thickness direction z. The lower surface of the conductor plate 44 (the surface facing the z2 side in the thickness direction z) is joined to the conductive main surface 311 (conductive portion 31) via a bonding material 64.

[0050] The first insulating layer 45 is disposed on the z1 side of the conductor plate 44 in the thickness direction z and is bonded to the conductor plate 44. The first insulating layer 45 is, for example, rectangular when viewed in the thickness direction z. When viewed in the thickness direction z, the first insulating layer 45 overlaps the entire conductor plate 44 and the entire conductive main surface 311. The first insulating layer 45 covers the entire upper surface of the conductor plate 44 (the surface facing the z1 side in the thickness direction z) and a portion of the resin main surface 71 of the sealing resin 7. The first insulating layer 45 is made of a material with relatively high thermal conductivity. The configuration of the first insulating layer 45 is not particularly limited and may be made of, for example, a ceramic sheet or an insulating resin sheet.

[0051] The first insulating layer 45 has a first heat dissipation surface 451 facing the z1 side in the thickness direction z. The first heat dissipation surface 451 is exposed from the sealing resin 7. In the example shown, the first heat dissipation surface 451 is located on the z1 side in the thickness direction z of the main resin surface 71 of the sealing resin 7. The thermal conductivity of the first heat dissipation body 4 (each of the conductive plate 44 and the first insulating layer 45) is higher than the thermal conductivity of the sealing resin 7.

[0052] The semiconductor device A11 includes a semiconductor element 2 supported on a first main surface 111 of a die pad portion 11 (first lead 1A), a conductive portion 31 electrically connected to the z1 side of the semiconductor element 2 in the thickness direction z, and a first heat sink 4 fixed to the z1 side of the conductive portion 31 in the thickness direction z. The first heat sink 4 has a first heat sink surface 451 facing the z1 side of the thickness direction z, and the first heat sink surface 451 is exposed from a resin main surface 71 of the sealing resin 7. The thermal conductivity of the first heat sink 4 is higher than that of the sealing resin 7. With this configuration, heat generated in the semiconductor element 2 can be dissipated from the first heat sink surface 451 via the conductive portion 31 and the first heat sink 4. The first heat sink surface 451 faces the opposite side to a first back surface 112, which is the mounting surface of the first lead 1A (die pad portion 11). By closely attaching a heat sink or the like (not shown) to this first heat dissipation surface 451, heat generated in the semiconductor element 2 can be efficiently dissipated from the side opposite the die pad portion 11 (the z1 side in the thickness direction z) of the semiconductor element 2. Furthermore, the first heat dissipation body 4 includes a first insulating layer 45 that overlaps with the conductive portion 31 when viewed from the z1 side in the thickness direction z. The semiconductor device A11 configured as described above can achieve improved heat dissipation properties and improved voltage resistance.

[0053] When viewed in the thickness direction z, the first insulating layer 45 of the first heat sink 4 overlaps the entire conductive main surface 311 to which the first heat sink 4 is fixed in the conductive portion 31. This configuration is preferable in terms of improving the voltage resistance of the semiconductor device A11.

[0054] Second Modification of First Embodiment: Figures 8 to 12 show a semiconductor device according to a second modification of the first embodiment. Figure 8 is a plan view showing a semiconductor device A12 of this modification. Figure 9 is a plan view showing the semiconductor device A12 of this modification (with the sealing resin and first heat sink transparent). Figure 10 is a cross-sectional view taken along line X-X in Figure 9. Figure 11 is a cross-sectional view taken along line XI-XI in Figure 9. Figure 12 is a cross-sectional view taken along line XII-XII in Figure 9.

[0055] In this modification, the configurations of the first heat sink 4 and the conductive member 3 are different from those of the semiconductor device A10 of the above embodiment. In this modification, the first heat sink 4 includes a first insulating layer 46 and a third metal layer 47. The conductive member 3 has a conductive portion 35, a lead-side bonding portion 36, and an intermediate portion 37. The first heat sink 4 is disposed on the z1 side of the conductive member 3 (conductive portion 35) in the thickness direction z.

[0056] In the first heat sink 4, the first insulating layer 46 is made of a material with relatively high thermal conductivity, such as ceramics. The material of the first insulating layer 46 is not particularly limited, and examples thereof include alumina, aluminum nitride, and silicon nitride. The first insulating layer 46 may be made of an insulating resin sheet in addition to ceramics. The first insulating layer 46 has a rectangular shape when viewed in the thickness direction z.

[0057] The third metal layer 47 is laminated on the z1 side of the first insulating layer 46 in the thickness direction z. The constituent material of the third metal layer 47 is not particularly limited and may include, for example, copper. The constituent material of the third metal layer 47 may include aluminum instead of copper. The third metal layer 47 is rectangular when viewed in the thickness direction z. The third metal layer 47 has a first heat dissipation surface 471. The first heat dissipation surface 471 faces the z1 side in the thickness direction z. The first heat dissipation surface 471 is exposed from the resin main surface 71 of the sealing resin 7. In the illustrated example, the first heat dissipation surface 471 is flush with the resin main surface 71. The thermal conductivity of the first heat sink 4 (each of the first insulating layer 46 and the third metal layer 47) is higher than the thermal conductivity of the sealing resin 7.

[0058] The conductive member 3 (the conductive portion 35, the lead-side joint portion 36, and the intermediate portion 37) is laminated on the z2 side of the first insulating layer 45 in the thickness direction z. The conductive member 3 is made of the same material as the third metal layer 47. The first heat sink 4 (the first insulating layer 46 and the third metal layer 47) and the conductive member 3 are made of, for example, a DBC substrate.

[0059] The conductive portion 35 is joined to the source electrode 21 of the semiconductor element 2 via a conductive bonding material 61. The conductive bonding material 61 electrically connects the conductive portion 35 (conductive member 3) and the source electrode 21. The conductive bonding material 61 is, for example, solder. The conductive portion 35 has a conductive main surface 351. The conductive main surface 351 faces the z1 side in the thickness direction z. The conductive main surface 351 is an example of a fixing portion to which the first insulating layer 46 (first heat sink 4) is fixed.

[0060] The lead-side joint portion 36 is joined to the pad portion 13 of the second lead 1B via a conductive bonding material 63. The conductive bonding material 63 electrically connects the lead-side joint portion 32 (conductive member 3) and the pad portion 13 (second lead 1B). The conductive bonding material 63 is, for example, solder.

[0061] The intermediate portion 37 is located between the conductive portion 35 and the lead-side joint portion 36 in the first direction x. The intermediate portion 37 is connected to both the conductive portion 35 and the lead-side joint portion 36. As a result, the conductive portion 35 is electrically connected to the pad portion 13 (second lead 1B) via the intermediate portion 37 and the lead-side joint portion 36. The conductive member 3 forms a path for a main current switched by the semiconductor element 2. In the illustrated example, as shown in FIGS. 9 and 10 , the intermediate portion 37 is connected to the conductive portion 35 closer to the y2 side in the second direction y, and extends toward the x2 side in the first direction x.

[0062] The semiconductor device A12 of this modified example includes a conductive member 69 instead of the wire 68 of the above embodiment. As shown in FIGS. 9 and 11 , the conductive member 69 is bonded to the gate electrode 23 of the semiconductor element 2 and the third lead 1C. The conductive member 69 is formed, for example, of a metal plate material. The conductive member 69 is made of, for example, copper or a copper alloy. The conductive member 69 is a metal plate material that has been subjected to, for example, a punching process or a bending process. In this embodiment, the conductive member 69 has an element-side bonding portion 691, a lead-side bonding portion 692, and an intermediate portion 693. As shown in FIG. 11 , the element-side bonding portion 691, the lead-side bonding portion 692, and the intermediate portion 693 are appropriately bent and connected when viewed in the second direction y.

[0063] The element-side bonding portion 691 is bonded to the gate electrode 23 via a conductive bonding material 65. The conductive bonding material 65 electrically connects the element-side bonding portion 691 and the gate electrode 23. The conductive bonding material 65 is, for example, solder. The lead-side bonding portion 692 is bonded to the pad portion 16 of the third lead 1C via a conductive bonding material 66. The conductive bonding material 66 electrically connects the lead-side bonding portion 692 (conductive member 69) and the pad portion 16 (third lead 1C). The conductive bonding material 66 is, for example, solder. The intermediate portion 693 is located between the element-side bonding portion 691 and the lead-side bonding portion 692 in the first direction x. The intermediate portion 693 is connected to both the element-side bonding portion 691 and the lead-side bonding portion 692. As a result, the element-side bonding portion 691 is electrically connected to the pad portion 16 (third lead 1C) via the intermediate portion 693 and the lead-side bonding portion 692.

[0064] 9 to 12 , the size of the first insulating layer 46 of the first heat dissipator 4 in a plan view (as viewed in the thickness direction z) is larger than each of the third metal layer 47 and the conductive portion 35. When viewed in the thickness direction z, the first insulating layer 46 overlaps each of the third metal layer 47 and the conductive member 3 (the conductive portion 35). In the illustrated example, when viewed in the thickness direction z, the first insulating layer 46 overlaps each of the third metal layer 47 and the entire conductive portion 35.

[0065] The semiconductor device A12 includes a semiconductor element 2 supported on a first main surface 111 of a die pad portion 11 (first lead 1A), a conductive portion 35 electrically connected to the z1 side of the semiconductor element 2 in the thickness direction z, and a first heat sink 4 fixed to the z1 side of the conductive portion 31 in the thickness direction z. The first heat sink 4 has a first heat sink surface 471 facing the z1 side of the thickness direction z, and the first heat sink surface 471 is exposed from a resin main surface 71 of the sealing resin 7. The thermal conductivity of the first heat sink 4 is higher than that of the sealing resin 7. This configuration allows heat generated in the semiconductor element 2 to be released from the first heat sink surface 471 via the conductive portion 35 and the first heat sink 4. The first heat sink surface 471 faces the opposite side to a first back surface 112, which is the mounting surface of the first lead 1A (die pad portion 11). By closely attaching a heat sink or the like (not shown) to this first heat dissipation surface 471, heat generated in the semiconductor element 2 can be efficiently dissipated from the side opposite the die pad portion 11 (the z1 side in the thickness direction z) of the semiconductor element 2. Furthermore, the first heat dissipation body 4 includes a first insulating layer 46 that overlaps with the conductive portion 35 when viewed from the z1 side in the thickness direction z. The semiconductor device A12 configured as described above can achieve improved heat dissipation properties and improved voltage resistance.

[0066] The first heat sink 4 includes a first insulating layer 46 and a third metal layer 47. The third metal layer 47 is laminated on the z1 side of the first insulating layer 46 in the thickness direction z, and has a first heat sink surface 471. The conductive portion 35 is laminated on the z2 side of the first insulating layer 46 in the thickness direction z. The first heat sink 4 and conductive member 3 configured as described above can be formed, for example, from a DBC substrate. The semiconductor device A12 including this first heat sink 4 and conductive member 3 has a structure suitable for improving heat dissipation and voltage resistance.

[0067] When viewed in the thickness direction z, the first insulating layer 46 of the first heat sink 4 overlaps the entire conductive main surface 351 to which the first heat sink 4 is fixed in the conductive portion 35. This configuration is preferable in terms of improving the voltage resistance of the semiconductor device A12.

[0068] Second Embodiment: FIGS. 13 to 19 show a semiconductor device according to a second embodiment of the present disclosure. FIG. 13 is a plan view showing a semiconductor device A20 according to this embodiment. FIG. 14 is a bottom view showing the semiconductor device A20. FIG. 15 is a plan view showing the semiconductor device A20 (with the sealing resin and first heat sink transparent). FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG. 15. FIG. 17 is a cross-sectional view taken along line XVII-XVII in FIG. 15. FIG. 18 is a cross-sectional view taken along line XVIII-XVIII in FIG. 15. FIG. 19 is a cross-sectional view taken along line XIX-XIX in FIG. 15. The semiconductor device A20 includes a first lead 1A, a plurality of lead terminals 191, a plurality of lead terminals 192, a plurality of semiconductor elements 2, a plurality of conductive members 3, a first heat sink 4, a second heat sink 5, conductive bonding materials 61, 62, and 63, bonding materials 64 and 671, and a sealing resin 7.

[0069] 15 and 16 , the first lead 1A has a die pad portion 11, an extension portion 125, and a terminal portion 126. A first back surface 112 of the die pad portion 11 is exposed from the sealing resin 7. Meanwhile, in this embodiment, a fourth metal layer 52 of the second heat sink 5, which will be described later, is joined to this first back surface 112.

[0070] The extending portion 125 is located on the x2 side in the first direction x with respect to the die pad portion 11. The extending portion 125 is connected to the x2 side in the first direction x of the die pad portion 11 and extends toward the x2 side in the first direction x. The extending portion 125 is connected to the center of the die pad portion 11 in the second direction y. The terminal portion 126 is connected to the x2 side in the first direction x of the extending portion 125 and extends toward the x2 side in the first direction x. A portion of the terminal portion 126 is exposed from the sealing resin 7. The portion of the terminal portion 126 exposed from the sealing resin 7 extends from the resin side surface 74 toward the x2 side in the first direction x.

[0071] The multiple (two in this embodiment) lead terminals 191 each extend in the first direction x. The two lead terminals 191 are arranged on either side of the terminal portion 126 in the second direction y. A portion of each lead terminal 191 is exposed from the sealing resin 7. The portion of the lead terminal 191 exposed from the sealing resin 7 extends from the resin side surface 74 toward the x2 side in the first direction x.

[0072] Each of the multiple (two in this embodiment) lead terminals 192 extends in the first direction x. The two lead terminals 192 are arranged on either side of the terminal portion 126 and the two lead terminals 191 in the second direction y. A portion of each lead terminal 192 is exposed from the sealing resin 7. The portion of the lead terminal 192 exposed from the sealing resin 7 extends from the resin side surface 74 to the x2 side in the first direction x. As shown in FIGS. 15 to 18 , the portions of the terminal portion 126, the multiple lead terminals 191, and the multiple lead terminals 192 exposed from the sealing resin 7 are aligned in the thickness direction z and overlap each other when viewed in the second direction y.

[0073] A plurality of (two in this embodiment) semiconductor elements 2 are supported on the first main surface 111 of the die pad portion 11 and are spaced apart from one another in the second direction y. The type of the plurality of (two) semiconductor elements 2 is not particularly limited. In this embodiment, the semiconductor elements 2 are, for example, power semiconductor chips with switching functions, such as MOSFETs (Metal Oxide Semiconductor Field Effect Transistors). The semiconductor elements 2 may also be switching elements such as IGBTs (Insulated Gate Bipolar Transistors) or diodes. As shown in FIGS. 15 and 17 to 19 , the semiconductor elements 2 have an element body 20, a source electrode 21, a drain electrode 22, and a gate electrode 23. The configuration of each semiconductor element 2 is the same as in the above embodiment.

[0074] The source electrode 21 covers most of the device principal surface 201. Specifically, the source electrode 21 is arranged in a region of the rectangular device principal surface 201 excluding the peripheral edge and one corner. The gate electrode 23 is arranged in one corner of the device principal surface 201. The drain electrode 22 covers almost the entire device rear surface 202.

[0075] The drain electrodes 22 of the two semiconductor elements 2 are electrically joined to the first main surface 111 (die pad portion 11) via a conductive bonding material 62. The conductive bonding material 62 electrically connects the die pad portion 11 and the drain electrodes 22. Each drain electrode 22 is electrically connected to a terminal portion 126 via the die pad portion 11 and an extension portion 125.

[0076] The semiconductor device A10 includes a plurality of (two) wires 68. As shown in Figures 15 and 18, each wire 68 is electrically connected to the gate electrode 23 of one of the two semiconductor elements 2 and one of two lead terminals 192. The wire 68 electrically connects the gate electrode 23 and the lead terminal 192.

[0077] As shown in FIGS. 15 and 17 , two conductive members 3 are arranged corresponding to two semiconductor elements 2, respectively. Each conductive member 3 is bonded to the source electrode 21 of the semiconductor element 2 and a lead terminal 191. The conductive member 3 is made of a metal plate material. The conductive member 3 is made of, for example, copper or a copper alloy. The conductive member 3 is a metal plate material that has been subjected to, for example, a punching process or a bending process. The conductive member 3 has a conductive portion 31, a lead-side bonding portion 32, and an intermediate portion 33. As shown in FIG. 17 , the conductive portion 31, the lead-side bonding portion 32, and the intermediate portion 33 are connected by being appropriately bent when viewed in the second direction y.

[0078] The conductive portion 31 is disposed on the z1 side in the thickness direction z of the semiconductor element 2. The conductive portion 31 is joined to the source electrode 21 via a conductive bonding material 61. The conductive bonding material 61 electrically connects the conductive portion 31 (conductive member 3) to the source electrode 21. The conductive portion 31 has a conductive main surface 311 facing the z1 side in the thickness direction z.

[0079] The lead-side joint portion 32 is joined to the end portion of the lead terminal 191 on the x1 side in the first direction x via a conductive joint material 63. The conductive joint material 63 electrically joins the lead-side joint portion 32 (conductive member 3) and the lead terminal 191.

[0080] The intermediate portion 33 is located between the conductive portion 31 and the lead-side joint portion 32 in the first direction x. The intermediate portion 33 is connected to both the conductive portion 31 and the lead-side joint portion 32. The conductive portion 31 is electrically connected to the lead terminal 191 via the intermediate portion 33 and the lead-side joint portion 32. As a result, each source electrode 21 is electrically connected to the lead terminal 191 via the conductive member 3.

[0081] The first heat sink 4 is disposed on the z1 side of the conductive portion 31 in the thickness direction z. The first heat sink 4 is fixed to the conductive main surface 311 (conductive portion 31). In this embodiment, the first heat sink 4 includes a first insulating layer 41, a first metal layer 42, and a second metal layer 43 stacked one on top of the other. The first heat sink 4 is formed, for example, from a DBC (Direct Bonded Copper) substrate. The configuration of the first heat sink 4 is similar to that of the first heat sink 4 in the semiconductor device A10 of the above embodiment.

[0082] The second metal layer 43, which is laminated on the z2 side of the first insulating layer 41 in the thickness direction z, is bonded to the conductive main surfaces 311 (conductive portions 31) of the two conductive members 3 via a bonding material 64. The conductive main surfaces 311 are an example of a fixing portion to which the second metal layer 43 (first heat sink 4) is fixed. The bonding material 64 may be conductive or insulating, and is, for example, solder. The first metal layer 42 has a first heat dissipation surface 421. The first heat dissipation surface 421 faces the z1 side in the thickness direction z. The first heat dissipation surface 421 is exposed from the sealing resin 7.

[0083] The first insulating layer 41, the first metal layer 42, and the second metal layer 43 each have an elongated rectangular shape with the longitudinal direction extending in the second direction y when viewed in the thickness direction z. The first insulating layer 41 is larger in size than the first metal layer 42 and the second metal layer 43 when viewed in a plan view (when viewed in the thickness direction z). The first insulating layer 41 overlaps the first metal layer 42 and the second metal layer 43 and the conductive portion 31 of each of the two conductive members 3 when viewed in the thickness direction z. In the illustrated example, the first insulating layer 41 overlaps all of the first metal layer 42, the second metal layer 43, and the conductive portion 31 when viewed in the thickness direction z. Note that in the illustrated example, the second metal layer 43 is provided as a single elongated region extending in the second direction y along which the two semiconductor elements 2 are aligned, and the second metal layer 43 of this single region is bonded to the conductive main surfaces 311 (conductive portions 31) of each of the two conductive members 3, but this is not limited thereto. The second metal layer 43 may be configured to have a plurality of (two) regions separated from each other, corresponding to the conductive portions 31 of the two conductive members 3 to be joined.

[0084] 15 to 19 , the second heat dissipation body 5 is disposed on the z2 side of the die pad portion 11 in the thickness direction z. The second heat dissipation body 5 is fixed to the first back surface 112 (die pad portion 11). In this embodiment, the second heat dissipation body 5 includes a second insulating layer 51, a fourth metal layer 52, and a fifth metal layer 53, which are stacked one on top of the other. The second heat dissipation body 5 is formed, for example, from a DBC (Direct Bonded Copper) substrate.

[0085] The second insulating layer 51 is made of a material with relatively high thermal conductivity, such as ceramics. The material of the second insulating layer 51 is not particularly limited, and examples thereof include alumina, aluminum nitride, and silicon nitride. The second insulating layer 51 may be made of an insulating resin sheet in addition to ceramics. The second insulating layer 51 has a rectangular shape when viewed in the thickness direction z.

[0086] The fourth metal layer 52 is laminated on the z1 side of the second insulating layer 51 in the thickness direction z. The constituent material of the fourth metal layer 52 is not particularly limited and may include, for example, copper. The constituent material of the fourth metal layer 52 may include aluminum instead of copper. The fourth metal layer 52 is bonded to the first back surface 112 (die pad portion 11) via a bonding material 671. The bonding material 671 may be conductive or insulating, and may be, for example, solder.

[0087] The fifth metal layer 53 is laminated on the z2 side in the thickness direction z of the second insulating layer 51. The constituent material of the fifth metal layer 53 is the same as the constituent material of the fourth metal layer 52. The fifth metal layer 53 has a second heat dissipation surface 531. The second heat dissipation surface 531 faces the z2 side in the thickness direction z. The second heat dissipation surface 531 is exposed from the resin back surface 72 of the sealing resin 7.

[0088] The second insulating layer 51, the fourth metal layer 52, and the fifth metal layer 53 each have a rectangular shape when viewed in the thickness direction z. The second insulating layer 51 is larger in size in a plan view (when viewed in the thickness direction z) than the fourth metal layer 52 and the fifth metal layer 53. The second insulating layer 51 overlaps the fourth metal layer 52, the fifth metal layer 53, and the die pad portion 11 (first rear surface 112) when viewed in the thickness direction z. In the illustrated example, the second insulating layer 51 overlaps all of the fourth metal layer 52, the fifth metal layer 53, and the die pad portion 11 (first rear surface 112) when viewed in the thickness direction z. The thermal conductivity of the second heat sink 5 (each of the second insulating layer 51, the fourth metal layer 52, and the fifth metal layer 53) is higher than the thermal conductivity of the sealing resin 7.

[0089] The sealing resin 7 covers the first lead 1A, portions of the plurality of lead terminals 191 and 192, the semiconductor element 2, the plurality of wires 68, the conductive member 3, and portions of the first heat sink 4 and the second heat sink 5. The sealing resin 7 is made of, for example, black epoxy resin.

[0090] As shown in FIGS. 13 , 14 , and 16 to 19 , the sealing resin 7 has a resin main surface 71, a resin back surface 72, and resin side surfaces 73 to 76. The resin main surface 71 and the resin back surface 72 face opposite sides in the thickness direction z. The resin main surface 71 faces the z1 side in the thickness direction z, facing the same side as the element main surface 201 and the first main surface 111. As shown in FIG. 13 , the resin main surface 71 has a frame shape surrounding the first heat dissipation surface 421 of the first metal layer 42 of the first heat sink 4 in a plan view (viewed in the thickness direction z). The first heat dissipation surface 421 is exposed from this resin main surface 71. In the illustrated example, the first heat dissipation surface 421 is flush with the resin main surface 71. Note that, unlike the illustrated example, the first heat dissipation surface 421 may be located closer to the z1 side in the thickness direction z than the resin main surface 71. In this case, the first metal layer 42 including the first heat dissipation surface 421 protrudes from the resin main surface 71 toward the z1 side in the thickness direction z. Alternatively, the first heat dissipation surface 421 may be located on the z2 side in the thickness direction z from the resin main surface 71. In this case, the first metal layer 42 including the first heat dissipation surface 421 is located in a recessed position from the resin main surface 71 toward the z2 side in the thickness direction z.

[0091] The resin back surface 72 faces the z2 side in the thickness direction z, and faces the same side as the element back surface 202 and the first back surface 112. As shown in Fig. 14 , the resin back surface 72 has a frame shape in a plan view (viewed in the thickness direction z) that surrounds the second heat dissipation surface 531 of the fifth metal layer 53 of the second heat sink 5. The second heat dissipation surface 531 is exposed from this resin back surface 72. The second heat dissipation surface 531 is, for example, flush with the resin back surface 72.

[0092] Each of the resin side surfaces 73 to 76 is connected to the resin main surface 71 and the resin back surface 72 and is sandwiched between the resin main surface 71 and the resin back surface 72 in the thickness direction z. The resin side surface 73 and the resin side surface 74 face opposite each other in the first direction x. The resin side surface 73 faces the x1 side in the first direction x, and the resin side surface 74 faces the x2 side in the first direction x. The resin side surface 75 and the resin side surface 76 face opposite each other in the second direction y. The resin side surface 75 faces the y1 side in the second direction y, and the resin side surface 76 faces the y2 side in the second direction y. As shown in FIG. 13 , a portion of each of the terminal portion 126, the plurality of lead terminals 191, and the plurality of lead terminals 192 protrudes from the resin side surface 73. In the illustrated example, the resin side surfaces 73 to 76 are each slightly inclined with respect to the thickness direction z. 13, 14, 16 to 19 are merely examples, and the shape of the sealing resin 7 is not limited to the illustrated shapes.

[0093] Next, the operation of this embodiment will be described.

[0094] The semiconductor device A20 includes a plurality of semiconductor elements 2 supported on a first main surface 111 of a die pad portion 11 (first lead 1A), a conductive portion 31 electrically connected to the z1 side of the semiconductor elements 2 in the thickness direction z, and a first heat sink 4 fixed to the z1 side of the conductive portion 31 in the thickness direction z. The first heat sink 4 has a first heat sink surface 421 facing the z1 side of the thickness direction z, and the first heat sink surface 421 is exposed from a resin main surface 71 of the sealing resin 7. The thermal conductivity of the first heat sink 4 is higher than that of the sealing resin 7. With this configuration, heat generated in the plurality of semiconductor elements 2 can be dissipated from the first heat sink surface 421 via the conductive portion 31 and the first heat sink 4. By closely attaching a heat sink or the like (not shown) to the first heat sink surface 421, the heat generated in the plurality of semiconductor elements 2 can be efficiently dissipated from the side of the semiconductor elements 2 opposite the die pad portion 11 (the z1 side in the thickness direction z). The first heat sink 4 further includes a first insulating layer 41 that overlaps the conductive portion 31 when viewed from the z1 side in the thickness direction z. The semiconductor device A10 having the above configuration can improve heat dissipation and voltage resistance.

[0095] The semiconductor device A20 further includes a second heat dissipation body 5. The second heat dissipation body 5 is fixed to the first back surface 112 (the surface facing the z2 side in the thickness direction z) of the die pad portion 11. The second heat dissipation body 5 has a second heat dissipation surface 531 facing the z2 side in the thickness direction z, and the second heat dissipation surface 531 is exposed from the resin back surface 72 of the sealing resin 7. The thermal conductivity of the second heat dissipation body 5 is higher than that of the sealing resin 7. With this configuration, heat generated in the multiple semiconductor elements 2 can be dissipated from the second heat dissipation surface 531 via the die pad portion 11 and the second heat dissipation body 5. By closely attaching a heat sink or the like (not shown) to the second heat dissipation surface 531, the heat generated in the multiple semiconductor elements 2 can be efficiently dissipated from the die pad portion 11 side (the z2 side in the thickness direction z). The second heat sink 5 also includes a second insulating layer 51 that overlaps the die pad portion 11 when viewed from the z1 side in the thickness direction z. The semiconductor device A20 including the above-described second heat sink 5 is more preferable in terms of improving heat dissipation performance and voltage resistance.

[0096] The first heat sink 4 includes a first insulating layer 41, a first metal layer 42, and a second metal layer 43 stacked one on top of the other. The first metal layer 42 is stacked on the z1 side of the first insulating layer 41 in the thickness direction z and has a first heat sink surface 421. The second metal layer 43 is stacked on the z2 side of the first insulating layer 41 in the thickness direction z and is bonded to the conductive main surface 311 (conductive portion 31). The second heat sink 5 includes a second insulating layer 51, a fourth metal layer 52, and a fifth metal layer 53 stacked one on top of the other. The fourth metal layer 52 is stacked on the z1 side of the second insulating layer 51 in the thickness direction z and is bonded to the first back surface 112 of the die pad portion 11. The fifth metal layer 53 is stacked on the z2 side of the second insulating layer 51 in the thickness direction z and has a second heat sink surface 531. The first heat sink 4 and the second heat sink 5 configured as described above can each be formed using a DBC substrate, for example. The semiconductor device A20 having the above-described first heat sink 4 and second heat sink 5 has a structure suitable for improving heat dissipation and voltage resistance.

[0097] The first insulating layer 41 of the first heat sink 4 overlaps, in the thickness direction z, the entire conductive main surface 311 to which the first heat sink 4 is fixed in the conductive portion 31. The second insulating layer 51 of the second heat sink 5 overlaps, in the thickness direction z, the entire first back surface 112 to which the second heat sink 5 is fixed in the die pad portion 11. A semiconductor device A20 having such a configuration is preferable in terms of improving voltage resistance.

[0098] Although the semiconductor device A20 of this embodiment has been described as an example configuration including multiple semiconductor elements 2, a first heat sink 4 arranged on the z1 side in the thickness direction z of the semiconductor elements 2, and a second heat sink 5 arranged on the z2 side in the thickness direction z of the semiconductor elements 2, the present disclosure is not limited to this. The semiconductor device of the present disclosure may also be configured to include only one semiconductor element 2, a first heat sink 4 arranged on the z1 side in the thickness direction z of the semiconductor element 2, and a second heat sink 5 arranged on the z2 side in the thickness direction z of the semiconductor element 2.

[0099] First Modification of Second Embodiment: Fig. 20 shows a semiconductor device according to a first modification of the second embodiment. Fig. 20 is a cross-sectional view showing a semiconductor device A21 of this modification, and shows a cross section similar to that shown in Fig. 17 in the second embodiment.

[0100] The semiconductor device A21 of this modification is additionally provided with a heat sink 8 compared to the semiconductor device A20 described above. The heat sink 8 is made of, for example, copper or nickel, or an alloy thereof.

[0101] The heat sink 8 has a first surface 81 and a second surface 82. The first surface 81 faces the z1 side in the thickness direction z and faces the second heat sink surface 531 of the second heat sink 5 (fifth metal layer 53). The second heat sink surface 531 is exposed from the sealing resin 7. Meanwhile, in this modification, the second heat sink surface 531 and the first surface 81 of the heat sink 8 are bonded to each other via a bonding material 672. The bonding material 672 may be conductive or insulating, but is preferably solder, for example. The second surface 82 faces the z2 side in the thickness direction z. The second surface 82 is exposed from the resin back surface 72 of the sealing resin 7. In the illustrated example, the second surface 82 is flush with the resin back surface 72. The second surface 82 is a portion that is bonded with a bonding material such as solder when mounting the semiconductor device A21 on a circuit board (not shown), for example.

[0102] In this modification, the portion of the lead terminal 191 exposed from the sealing resin 7 has a bent shape when viewed in the second direction y. The tip of the lead terminal 191 on the x2 side in the first direction x is located closer to the z2 side in the thickness direction z than the other portions. Although not shown in detail, the tip of the lead terminal 192 electrically connected to the gate electrode 23 of the semiconductor element 2 and the terminal portion 126 electrically connected to the drain electrode 22 of the semiconductor element 2 are also bent like the lead terminal 191, with the tip of the x2 side in the first direction x being located closer to the z2 side in the thickness direction z than the other portions. The tip of each of the lead terminals 191, 192, and terminal portion 126 is to be joined with a joining material such as solder when mounting the semiconductor device A21 on a circuit board (not shown), for example.

[0103] The semiconductor device A21 of this modification achieves the same effects as the semiconductor device A20 of the second embodiment. The semiconductor device A21 includes a heat sink 8 bonded to the second heat dissipation surface 531 of the second heat sink 5. With this configuration, heat generated in the semiconductor element 2 can be efficiently dissipated to the heat sink 8 via the die pad portion 11 and the second heat sink 5. The semiconductor device A21 having this configuration is preferable for improving heat dissipation.

[0104] The semiconductor device according to the present disclosure is not limited to the above-described embodiment, and the specific configuration of each part of the semiconductor device according to the present disclosure can be freely modified in various ways.

[0105] The present disclosure includes embodiments described in the following supplementary notes. Supplementary note 1. A semiconductor device comprising: a first lead including a die pad portion having a first main surface facing one side in a thickness direction and a first back surface facing the other side in the thickness direction; a semiconductor element supported on the first main surface; a conductive portion arranged on one side of the semiconductor element in the thickness direction and conductively joined to the semiconductor element; a sealing resin covering at least a portion of the die pad portion and the semiconductor element; and a first heat sink fixed to one side of the conductive portion in the thickness direction and having a higher thermal conductivity than the sealing resin, wherein the first heat sink includes a first insulating layer overlapping the conductive portion when viewed in the thickness direction and has a first heat sink surface facing the one side in the thickness direction, and the sealing resin has a resin main surface facing the one side in the thickness direction and a resin back surface spaced from the resin main surface to the other side in the thickness direction and facing the other side in the thickness direction, and the first heat sink surface is exposed from the resin main surface. Supplementary Note 2. The semiconductor device according to Supplementary Note 1, wherein the first heat dissipation body includes the first insulating layer, a first metal layer stacked on one side of the first insulating layer in the thickness direction, and a second metal layer stacked on the other side of the first insulating layer in the thickness direction, the second metal layer being joined to the conductive portion, and the first metal layer having the first heat dissipation surface. Supplementary Note 3. The semiconductor device according to Supplementary Note 1, wherein the first heat dissipation body includes a conductor plate joined to the conductive portion, and the first insulating layer being joined to one side of the conductor plate in the thickness direction, and the first insulating layer having the first heat dissipation surface. Supplementary Note 4. The semiconductor device according to any one of Supplements 1 to 3, wherein the conductive portion is formed of a metal plate. Supplementary Note 5. The semiconductor device according to Supplementary Note 1, wherein the first heat sink includes the first insulating layer and a third metal layer stacked on one side of the first insulating layer in the thickness direction, the conductive portion is stacked on the other side of the first insulating layer in the thickness direction, and the third metal layer has the first heat dissipation surface.Supplementary Note 6. The semiconductor device according to any one of Supplementary Note 1 to 5, wherein the first heat dissipation surface is flush with the resin main surface or is located on one side of the resin main surface in the thickness direction.Appendix 7. The semiconductor device according to any one of Appendixes 1 to 6, wherein the conductive portion has a fixing portion to which the first heat sink is fixed, and the first insulating layer overlaps the entire fixing portion when viewed in the thickness direction. Appendix 8. The semiconductor device according to any one of Appendixes 1 to 7, further comprising a second lead arranged at a distance from the first lead in a direction perpendicular to the thickness direction, and the conductive portion is electrically connected to the second lead. Appendix 9. The semiconductor device according to any one of Appendixes 1 to 8, wherein the first back surface is exposed from the resin back surface. Appendix 10. The semiconductor device according to any one of Appendixes 1 to 9, further comprising a second heat sink fixed to the first back surface and having a higher thermal conductivity than the sealing resin, the second heat sink including a second insulating layer overlapping the die pad portion when viewed in the thickness direction and having a second heat sink facing the other side in the thickness direction, and the second heat sink being exposed from the resin back surface. Appendix 11. The semiconductor device according to Supplementary Note 10, wherein the second heat sink includes the second insulating layer, a fourth metal layer stacked on one side of the second insulating layer in the thickness direction, and a fifth metal layer stacked on the other side of the second insulating layer in the thickness direction, the fourth metal layer being bonded to the first back surface, and the fifth metal layer having the second heat dissipation surface. Supplementary Note 12. The semiconductor device according to Supplementary Note 10 or 11, wherein the second heat dissipation surface is flush with the resin back surface. Supplementary Note 13. The semiconductor device according to any of Supplements 10 to 12, wherein the second insulating layer overlaps the entire first back surface when viewed in the thickness direction. Supplementary Note 14. The semiconductor device according to any of Supplements 10 to 13, comprising a plurality of the semiconductor elements, the plurality of semiconductor elements being arranged on the first main surface and spaced apart from each other in a direction perpendicular to the thickness direction. Supplementary Note 15. The semiconductor device according to any of Supplementary Notes 10 to 14, wherein the semiconductor elements are switching elements.Supplementary Note 16. The semiconductor device according to Supplementary Note 15, wherein the semiconductor element has a main surface facing one side in the thickness direction, a back surface facing the other side in the thickness direction, a source electrode and a gate electrode disposed on the main surface, and a drain electrode disposed on the back surface, the drain electrode being conductively joined to the first main surface, and the conductive portion being conductively joined to the source electrode.

[0106] A10, A11, A12, A20, A21: semiconductor device 1A: first lead 1B: second lead 1C: third lead 11: die pad portion 111: first main surface 112: first back surface 12, 126, 14, 17: terminal portion 121, 141, 171: back surface mounting portion 125: extension portion 13, 16: pad portion 15, 18: bent portion 191, 192: lead terminal 2: semiconductor element 20: element body 201: element main surface 202: element back surface 21: source electrode 22: drain electrode 23: gate electrode 3: conductive member 31, 35: conductive portion 311, 351: conductive main surface 32, 36: lead side joint portion 33, 37: intermediate portion 4: first heat sink 41, 45, 46: First insulating layer 42: First metal layer 421, 451, 471: First heat dissipation surface 43: Second metal layer 44: Conductive plate 47: Third metal layer 5: Second heat dissipation body 51: Second insulating layer 52: Fourth metal layer 53: Fifth metal layer 531: Second heat dissipation surface 61, 62, 63, 65, 66: Conductive bonding material 64, 671, 672: Bonding material 68: Wire 69: Conductive member 691: Element side bonding portion 692: Lead side bonding portion 693: Intermediate portion 7: Sealing resin 71: Resin main surface 72: Resin back surface 73, 74, 75, 76: Resin side surface 8: Heat dissipation plate 81: First surface 82: Second surface

Claims

1. a first lead including a die pad portion having a first main surface facing one side in a thickness direction and a first back surface facing the other side in the thickness direction; a semiconductor element supported on the first main surface; a conductive portion disposed on one side of the semiconductor element in the thickness direction and conductively joined to the semiconductor element; a sealing resin that covers at least a portion of the die pad portion and the semiconductor element; a first heat sink fixed to one side of the conductive portion in the thickness direction and having a thermal conductivity higher than that of the sealing resin; the first heat sink includes a first insulating layer that overlaps the conductive portion when viewed in the thickness direction, and has a first heat sink surface that faces one side in the thickness direction; the sealing resin has a resin main surface facing one side in the thickness direction and a resin back surface spaced from the resin main surface toward the other side in the thickness direction and facing the other side in the thickness direction, The semiconductor device, wherein the first heat dissipation surface is exposed from the resin main surface.

2. the first heat dissipation body includes the first insulating layer, a first metal layer stacked on one side of the first insulating layer in the thickness direction, and a second metal layer stacked on the other side of the first insulating layer in the thickness direction, the second metal layer is bonded to the conductive portion; The semiconductor device according to claim 1 , wherein the first metal layer has the first heat dissipation surface.

3. the first heat dissipation body includes a conductive plate joined to the conductive portion and the first insulating layer joined to one side of the conductive plate in the thickness direction, The semiconductor device according to claim 1 , wherein said first insulating layer has said first heat dissipation surface.

4. 4. The semiconductor device according to claim 1, wherein said conductive portion is made of a metal plate material.

5. the first heat sink includes the first insulating layer and a third metal layer stacked on one side of the first insulating layer in the thickness direction, the conductive portion is laminated on the other side of the first insulating layer in the thickness direction, The semiconductor device according to claim 1 , wherein the third metal layer has the first heat dissipation surface.

6. 6. The semiconductor device according to claim 1, wherein the first heat dissipation surface is flush with the resin main surface or is positioned on one side of the resin main surface in the thickness direction.

7. the conductive portion has a fixing portion to which the first heat sink is fixed, 6. The semiconductor device according to claim 1, wherein said first insulating layer overlaps with the entirety of said fixed portion when viewed in said thickness direction.

8. a second lead disposed apart from the first lead in a direction perpendicular to the thickness direction; 6. The semiconductor device according to claim 1, wherein said conductive portion is electrically connected to said second lead.

9. 6. The semiconductor device according to claim 1, wherein said first rear surface is exposed from said resin rear surface.

10. a second heat sink fixed to the first rear surface and having a higher thermal conductivity than the sealing resin; the second heat sink includes a second insulating layer that overlaps the die pad portion when viewed in the thickness direction, and has a second heat sink surface that faces the other side in the thickness direction; 4. The semiconductor device according to claim 1, wherein said second heat dissipation surface is exposed from said resin rear surface.

11. the second heat dissipation body includes the second insulating layer, a fourth metal layer stacked on one side of the second insulating layer in the thickness direction, and a fifth metal layer stacked on the other side of the second insulating layer in the thickness direction, the fourth metal layer is bonded to the first back surface; The semiconductor device according to claim 10 , wherein the fifth metal layer has the second heat dissipation surface.

12. The semiconductor device according to claim 10 , wherein the second heat dissipation surface is flush with the rear surface of the resin.

13. The semiconductor device according to claim 10 , wherein the second insulating layer overlaps the entire first rear surface when viewed in the thickness direction.

14. a plurality of the semiconductor elements; The semiconductor device according to claim 10 , wherein the plurality of semiconductor elements are arranged on the first main surface and spaced apart from each other in a direction perpendicular to the thickness direction.

15. The semiconductor device according to claim 1 , wherein the semiconductor element is a switching element.

16. the semiconductor element has a main surface facing one side in the thickness direction, a back surface facing the other side in the thickness direction, a source electrode and a gate electrode disposed on the main surface, and a drain electrode disposed on the back surface; the drain electrode is conductively joined to the first main surface, The semiconductor device according to claim 15 , wherein the conductive portion is conductively joined to the source electrode.