Semiconductor device

Abstract

This semiconductor device is provided with a plurality of leads, a semiconductor element, and a sealing resin. A first lead includes: a first main part; and a plurality of first branch parts which are arranged along a first direction and which extend in a second direction from the first main part. The first branch parts each have: a first root section which connects to the first main part; and a first connection section conductively bonded to a first electrode. A first width, which is the width in the first direction of an end of the first connection section, is narrower than a second width, which is the width in the first direction of a boundary between the first root section and the first main part.

Description

Semiconductor Devices

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

[0002] Semiconductor devices using III-V nitride semiconductors (hereinafter sometimes referred to as "nitride semiconductors") such as gallium nitride (GaN) have been developed. Patent Document 1 discloses a semiconductor device using a nitride semiconductor. The semiconductor device disclosed in this document includes a device body made of a semiconductor, and a nitride semiconductor layer and electrodes stacked on the main surface side of the device body. The electrodes include a source electrode, a drain electrode, and a gate electrode disposed on the nitride semiconductor layer. This semiconductor device is configured as a GaN-HEMT (High Electron Mobility Transistor) device.

[0003] JP 2018-82011 A

[0004] There is a concern that the larger the current flowing through the semiconductor element, the more likely it is that current concentration will occur in the conduction path connected to the semiconductor element.

[0005] 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 that can alleviate current concentration in a conduction path.

[0006] A semiconductor device A1 according to one aspect of the present disclosure includes a plurality of leads, a semiconductor element, and a sealing resin covering at least some of the leads and the semiconductor element. The plurality of leads include a first lead. The semiconductor element has a main surface facing one side in a thickness direction and a back surface facing the other side, and a plurality of first electrodes arranged on the main surface along a first direction intersecting the thickness direction. The first lead includes a first main portion and a plurality of first branch portions extending from the first main portion in a second direction intersecting the thickness direction and the first direction and arranged along the first direction. The first branch portions have a first root portion connected to the first main portion and a first connection portion conductively joined to the first electrode. A first width, which is the width in the first direction of a tip of the first connection portion, is narrower than a second width, which is the width in the first direction of a boundary between the first root portion and the first main portion.

[0007] According to the above configuration, current concentration in the conduction path can be alleviated.

[0008] Other features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0009] FIG. 1 is a plan view showing a semiconductor device according to a first embodiment of the present disclosure. FIG. 2 is a partial plan view showing a semiconductor device according to a first embodiment of the present disclosure. FIG. 3 is a bottom view showing a semiconductor device according to a first embodiment of the present disclosure. FIG. 4 is a front view showing a semiconductor device according to a first embodiment of the present disclosure. FIG. 5 is a rear view showing a semiconductor device according to a first embodiment of the present disclosure. FIG. 6 is a left side view showing a semiconductor device according to a first embodiment of the present disclosure. FIG. 7 is a right side view showing a semiconductor device according to a first embodiment of the present disclosure. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 1. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 1. FIG. 10 is a cross-sectional view taken along line X-X in FIG. 1. FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. 1. FIG. 12 is a partial enlarged plan view showing a semiconductor device according to a first embodiment of the present disclosure. FIG. 13 is a partial enlarged plan view showing a first modified example of the semiconductor device according to the first embodiment of the present disclosure. FIG. 14 is a partial enlarged plan view showing a second modified example of the semiconductor device according to the first embodiment of the present disclosure. 15 is a partially enlarged plan view showing a third modified example of the semiconductor device according to the first embodiment of the present disclosure. FIG. 16 is a plan view showing a semiconductor device according to a second embodiment of the present disclosure. FIG. 17 is a cross-sectional view taken along line XVII-XVII in FIG. 16. FIG. 18 is a cross-sectional view taken along line XVIII-XVIII in FIG. 16. FIG. 19 is a cross-sectional view showing a first modified example of the semiconductor device according to the second embodiment of the present disclosure. FIG. 20 is a cross-sectional view showing a second modified example of the semiconductor device according to the second embodiment of the present disclosure.

[0010] Preferred embodiments of the present disclosure will now be described in detail with reference to the drawings.

[0011] The terms "first," "second," "third," etc. in this disclosure are used for identification purposes only and are not intended to impose any ranking on their objects.

[0012] 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.

[0013] 1 to 12 show a semiconductor device according to a first embodiment of the present disclosure. The semiconductor device A1 of this embodiment includes a plurality of leads 1 to 6, a semiconductor element 7, a wire 99, and a sealing resin 8. The semiconductor device A1 is intended to perform current switching by being mounted on a substrate, for example, but the specific use of the semiconductor device A1 is not limited in any way.

[0014] In these figures, the thickness direction of the present disclosure is defined as the thickness direction z. One side of the thickness direction z is referred to as the z1 side, and the side opposite the z1 side of the z direction is referred to as the z2 side. Furthermore, a direction perpendicular to the thickness direction z is defined as the first direction x. One side of the first direction x is referred to as the x1 side, and the side opposite the x1 side is referred to as the x2 side. Furthermore, a direction perpendicular to the thickness direction z and the first direction x is defined as the second direction y. One side of the second direction y is defined as the y1 side, and the side opposite the y1 side is defined as the y2 side.

[0015] Leads 1-6: The multiple leads 1-6 are intended to appropriately fulfill functions such as supporting the semiconductor element 7 and forming conductive paths that are electrically connected to the semiconductor element 7. The multiple leads 1-6 are made of metal such as copper (Cu), nickel (Ni), iron (Fe), etc. The multiple leads 1-6 are formed, for example, by subjecting a metal plate material to a process selected from punching, bending, etching, etc. Furthermore, a plating layer made of silver (Ag), Ni, gold (Au), etc. may be provided in appropriate locations on each of the multiple leads 1-6, as needed.

[0016] In this embodiment, the multiple leads 1 to 6 will be described as a first lead 1, a second lead 2, a third lead 3, a fourth lead 4, a fifth lead 5, and an island lead 6. That is, the multiple leads 1 to 6 include a first lead 1, a second lead 2, a third lead 3, a fourth lead 4, a fifth lead 5, and an island lead 6. As will be described later, in this embodiment, the fourth lead 4 and the island lead 6 are connected to each other. Depending on the conduction state of each lead 1 to 6, the leads may be configured as separate pieces, or some of the leads may be connected to each other. In the following description, an example will be given in which the first lead 1 and the second lead 2 are formed by punching and bending a metal plate material, and the third lead 3, the fourth lead 4, the fifth lead 5, and the island lead 6 are formed by etching the metal plate material.

[0017] Island lead 6: As shown in FIGS. 1 to 3 and 8 to 11 , the island lead 6 has a main surface 601, a back surface 602, a thick portion 61, a thin portion 62, and multiple extending portions 63. The main surface 601 faces the z1 side in the z direction, and in the illustrated example, is a smooth surface perpendicular to the z direction. The island lead 6 may have, for example, a recess or groove recessed from the main surface 601 as appropriate. The back surface 602 faces the z2 side in the z direction, and is opposite to the main surface 601. In the illustrated example, the back surface 602 is a smooth surface perpendicular to the z direction. A plating layer made of Ni, titanium (Ti), or the like may be provided on the back surface 602 as appropriate.

[0018] The thick portion 61 is a portion where the main surface 601 and the back surface 602 overlap when viewed in the z direction, and in the example shown, is a rectangular portion when viewed in the z direction. The shape of the thick portion 61 is not limited in any way. The thickness of the thick portion 61 in the z direction is the distance between the main surface 601 and the back surface 602. The thin portion 62 is a portion that overlaps the main surface 601 when viewed in the z direction but does not overlap the back surface 602, and in the example shown, is connected to the thick portion 61 so as to extend to both sides in the x direction and both sides in the y direction when viewed in the z direction. The thickness of the thin portion 62 in the z direction is smaller than the distance between the main surface 601 and the back surface 602. The thicknesses of the thick portion 61 and the thin portion 62 are not limited in any way. For example, the thickness of the thick portion 61 is approximately 0.2 mm to 0.5 mm, and the thickness of the thin portion 62 is 0.1 mm to 0.4 mm. In the illustrated example, the portion of the thin portion 62 extending from the thick portion 61 toward the y1 side in the y direction is larger than the portion extending toward the y2 side.

[0019] The multiple extension portions 63 are portions extending from the ends of the thin-walled portion 62. In the illustrated example, the multiple extension portions 63 extend from the thin-walled portion 62 on both sides in the x-direction. The number of extension portions 63 is not limited and may be multiple or one. In the illustrated example, two extension portions 63 are provided on the x1 side in the x-direction, and two extension portions 63 are provided on the x2 side. The extension portions 63 have end faces 631. The end faces 631 are surfaces facing the opposite side from the thin-walled portion 62 in the x-direction; in other words, they are surfaces facing outward in the x-direction. The illustrated end faces 631 are surfaces perpendicular to the x-direction. The positions in the x-direction of the two end faces 631 located on the x1 side of the x-direction are the same (or approximately the same). Furthermore, the positions in the x-direction of the two end faces 631 located on the x2 side of the x-direction are the same (or approximately the same).

[0020] 1, 7, and 8 to 12, the first lead 1 is arranged on the z1 side in the z direction relative to the third lead 3, the fourth lead 4, the fifth lead 5, and the island lead 6. The first lead 1 of this embodiment has a first main portion 11, a plurality of first branch portions 12, a first extending portion 13, a third extending portion 14, and a first standing portion 15.

[0021] The first main portion 11 is a plate-like portion along the xy plane, and in the illustrated example, has a substantially rectangular shape with the x direction as the longitudinal direction. The first main portion 11 in the illustrated example has a through hole 111. The through hole 111 penetrates the first main portion 11 in the z direction. The number of through holes 111 is not limited and may be one or more. In the illustrated example, the first main portion 11 has two through holes 111. The shape of the through holes 111 is not limited in any way and may be a circle, an ellipse, a rectangle, a polygon, or the like, as appropriate. In the illustrated example, the through hole 111 has an elliptical shape with the x direction as the longitudinal direction when viewed in the z direction.

[0022] The multiple first branch portions 12 extend from the first main portion 11 to the y2 side in the y direction. There is no limitation on the number of first branch portions 12, and in the example shown, three first branch portions 12 are provided. The multiple first branch portions 12 are arranged side by side in the x direction. The first branch portion 12 has a first connection portion 121 and a first root portion 122.

[0023] The first connecting portion 121 is a portion located on the y2 side of the first main portion 11 in the y direction. The first connecting portion 121 is located on the z2 side of the first main portion 11 in the z direction. The shape of the first connecting portion 121 is not limited in any way, and in the example shown, it has a shape whose longitudinal direction is the y direction when viewed in the z direction. The first connecting portion 121 is perpendicular to the z direction.

[0024] The first root portion 122 is located between the first connection portion 121 and the first main portion 11, and is connected to the first connection portion 121 and the first main portion 11. The first root portion 122 is inclined so as to approach the semiconductor element 7 in the z direction (toward the z2 side) as it moves from the first main portion 11 toward the first connection portion 121 in the y direction (as it moves from the y1 side toward the y2 side).

[0025] In the illustrated example, the three first branches 12 include first branches 12 having different lengths in the y direction. The first branch 12 located closest to the x2 side in the x direction has a shorter length in the y direction than the other first branches 12. The first branch 12 located closest to the x2 side in the x direction is disposed in a position close to a third electrode 73 and a wire 99, which will be described later. However, the multiple first branches 12 may have the same length.

[0026] 12 , a first width W11, which is the width in the first direction x of the tip of the first connection portion 121 on the y2 side in the y direction, is narrower than a second width W12, which is the width in the first direction x of the boundary between the first root portion 122 and the first main portion 11. The first connection portion 121 of this example has a shape in which the width in the first direction x decreases from the tip on the y2 side in the y direction toward the first root portion 122. This first connection portion 121 is composed only of the first tapered portion of the present disclosure.

[0027] In the illustrated example, a third width W13, which is the width in the first direction x of the boundary between the first root portion 122 and the first connection portion 121, is smaller than the second width W12. In the illustrated example, the first root portion 122 has a tapered shape in which the width in the first direction x increases in the y direction from the first connection portion 121 side (y2 side) toward the first main portion 11 side (y1 side). In addition, the first branch portion 12 in the illustrated example has a tapered shape in which the width in the first direction x increases as the width increases from the y2 side toward the y1 side in the y direction. In other words, the first connection portion 121 and the first root portion 122 have a continuous tapered shape when viewed in the z direction.

[0028] The first extending portion 13 is a portion extending from the first main portion 11. The first extending portion 13 extends toward the x1 side from the end of the first main portion 11 on the x1 side in the x direction. The first extending portion 13 has a first end face 131. The first end face 131 is a surface facing the opposite side from the first main portion 11 in the x direction, in other words, a surface facing the x1 side, which is the outer side in the x direction. The illustrated first end face 131 is a surface perpendicular to the x direction. The position of the first end face 131 in the x direction is the same (or approximately the same) as the position in the x direction of the multiple end faces 631 located on the x1 side in the x direction.

[0029] The third extending portion 14 is a portion extending from the first main portion 11. The third extending portion 14 extends toward the x2 side from the end of the first main portion 11 on the x2 side in the x direction. The third extending portion 14 has a third end face 141. The third end face 141 is a surface facing the opposite side from the first main portion 11 in the x direction; in other words, it is a surface facing the x2 side, which is the outer side in the x direction. The illustrated third end face 141 is a surface perpendicular to the x direction. Furthermore, the position of the third end face 141 in the x direction is the same (or approximately the same) as the position in the x direction of the multiple end faces 631 located on the x2 side in the x direction.

[0030] The first upright portion 15 is connected to the end of the first main portion 11 on the y1 side in the y direction, opposite the first branch portion 12. The first upright portion 15 extends from the first main portion 11 to the z2 side in the z direction. The shape of the first upright portion 15 is not limited in any way, and in the example shown, it is rectangular with the x direction as the longitudinal direction. In the example shown, the center of the first upright portion 15 in the x direction is the same as (or approximately the same as) the center of the first main portion 11 in the x direction.

[0031] 8 to 10, the tip of the first upstanding portion 15 of the first lead 1 on the z2 side in the z direction is conductively joined to the third lead 3 via a fourth conductive joint 94. The fourth conductive joint 94 is, for example, solder, Ag paste material, Ag sintered material, Cu sintered material, or the like.

[0032] Second lead 2: As shown in FIGS. 1, 7, and 8 to 12, the second lead 2 is arranged on the z1 side in the z direction relative to the third lead 3, the fourth lead 4, the fifth lead 5, and the island lead 6. The second lead 2 is also arranged on the y2 side in the y direction relative to the first lead 1. The second lead 2 of this embodiment has a second main portion 21, a plurality of second branch portions 22, second extending portions 23, a fourth extending portion 24, a second standing portion 25, and a connecting portion 29.

[0033] The second main portion 21 is a plate-like portion along the xy plane, and in the illustrated example, has a substantially rectangular shape with the x direction as the longitudinal direction. The first main portion 11 and the second main portion 21 are disposed on opposite sides of each other in the y direction with respect to the semiconductor element 7. In the illustrated example, the second main portion 21 has a through hole 211. The through hole 211 penetrates the second main portion 21 in the z direction. The number of through holes 211 is not limited and may be one or more. In the illustrated example, the second main portion 21 has two through holes 211. The shape of the through holes 211 is not limited and may be a circle, an ellipse, a rectangle, a polygon, or the like, as appropriate. In the illustrated example, the through hole 211 has an elliptical shape with the x direction as the longitudinal direction when viewed in the z direction. In this embodiment, the second main portion 21 is disposed at the same (or substantially the same) position as the first main portion 11 in the z direction.

[0034] The multiple second branch portions 22 extend from the second main portion 21 toward the y1 side in the y direction. There is no limitation on the number of second branch portions 22, and in the example shown, two second branch portions 22 are provided. The multiple second branch portions 22 are arranged side by side in the x direction. The second branch portion 22 has a second connection portion 221 and a second root portion 222.

[0035] The second connecting portion 221 is a portion located on the y1 side in the y direction relative to the second main portion 21. The second connecting portion 221 is located on the z2 side of the second main portion 21 in the z direction. The shape of the second connecting portion 221 is not limited in any way, and in the example shown, it has a shape whose longitudinal direction is the y direction when viewed in the z direction. The second connecting portion 221 is perpendicular to the z direction.

[0036] The second root portion 222 is located between the second connecting portion 221 and the second main portion 21, and is connected to the second connecting portion 221 and the second main portion 21. The second root portion 222 is inclined so as to approach the semiconductor element 7 in the z direction (toward the z2 side) as it moves from the second main portion 21 toward the second connecting portion 221 in the y direction (as it moves from the y2 side toward the y1 side).

[0037] In the illustrated example, the lengths of the two second branch portions 22 in the y direction are equal. However, the lengths of the multiple second branch portions 22 in the y direction may be different from each other.

[0038] 12 , a fourth width W21, which is the width in the first direction x of the tip of the second connection portion 221 on the y1 side in the y direction, is narrower than a fifth width W22, which is the width in the first direction x of the boundary between the second root portion 222 and the second main portion 21. The second connection portion 221 in this example has a shape in which the width in the first direction x decreases from the tip on the y1 side in the y direction toward the second root portion 222. This second connection portion 221 is composed only of the second tapered portion of the present disclosure.

[0039] In the illustrated example, a sixth width W23, which is the width in the first direction x of the boundary between the second root portion 222 and the second connection portion 221, is smaller than the fifth width W22. In the illustrated example, the second root portion 222 has a tapered shape in which the width in the first direction x increases in the y direction from the second connection portion 221 side (y1 side) toward the second main portion 21 side (y2 side). In addition, the second branch portion 22 in the illustrated example has a tapered shape in which the width in the first direction x increases overall from the y1 side toward the y2 side in the y direction. In other words, the second connection portion 221 and the second root portion 222 have a continuous tapered shape when viewed in the z direction.

[0040] The second extending portion 23 is a portion extending from the second main portion 21. The second extending portion 23 extends toward the x1 side from the end of the second main portion 21 on the x1 side in the x direction. The second extending portion 23 has a second end face 231. The second end face 231 is a surface facing the opposite side from the second main portion 21 in the x direction; in other words, it is a surface facing the x1 side, which is the outer side in the x direction. The illustrated second end face 231 is a surface perpendicular to the x direction. The position of the second end face 231 in the x direction is the same (or approximately the same) as the first end face 131 and the end face 631 located on the x1 side in the x direction.

[0041] The fourth extension portion 24 is connected to the second main portion 21 via a connecting portion 29. The dimension of the connecting portion 29 in the y direction is smaller than that of the second main portion 21 and the fourth extension portion 24. As such, the fourth extension portion 24 in the present disclosure is not limited to a configuration in which it is directly connected to the second main portion 21, but also includes a configuration in which it is connected to the second main portion 21 via another portion. This also applies to the second extension portion 23. Furthermore, the first extension portion 13 and the third extension portion 14 described above are not limited to a configuration in which they are directly connected to the first main portion 11, but also include a configuration in which they are connected to the first main portion 11 via another portion. The fourth extension portion 24 extends along the y direction. The fourth extension portion 24 has a fourth end surface 241. The fourth end surface 241 is a surface facing away from the second main portion 21 in the y direction; in other words, a surface facing the y2 side, which is outward in the y direction. The illustrated fourth end surface 241 is a surface perpendicular to the y direction.

[0042] The second upright portion 25 is connected to an end of the second main portion 21 on the y2 side in the y direction, opposite the second branch portion 22. The second upright portion 25 extends from the second main portion 21 to the z2 side in the z direction. The shape of the second upright portion 25 is not limited in any way, and in the example shown, it is rectangular with the x direction as the longitudinal direction. In the example shown, the center of the second upright portion 25 in the x direction is the same as (or approximately the same as) the center of the second main portion 21 in the x direction.

[0043] 8 to 10, the tip of the second upstanding portion 25 of the second lead 2 on the z2 side in the z direction is conductively joined to the fourth lead 4 via a fifth conductive joint 95. The fifth conductive joint 95 is, for example, solder.

[0044] Third lead 3: As shown in Figures 1 to 3, the third lead 3 is arranged on the y1 side in the y direction away from the island lead 6. The center of the third lead 3 in the x direction is at the same (or approximately the same) position in the x direction as the center of the island lead 6 in the x direction. As shown in Figures 1 to 3 and 8 to 10, the third lead 3 has a main surface 301, a back surface 302, a thick portion 31, a thin portion 32, and a plurality of extending portions 33.

[0045] The main surface 301 is a surface facing the z1 side in the z direction, and in the illustrated example, is a smooth surface perpendicular to the z direction. The third lead 3 may have, for example, a recess or groove recessed from the main surface 301 as appropriate. The first upright portion 15 described above is joined to the main surface 301 via a fourth conductive joint 94. The back surface 302 is a surface facing the z2 side in the z direction, facing the opposite side to the main surface 301. In the illustrated example, the back surface 302 is a smooth surface perpendicular to the z direction. A plating layer made of Ni, Ti, or the like may be appropriately provided on the back surface 302. In this embodiment, the main surface 301 is located at the same (or approximately the same) position as the main surface 601 in the z direction, and the back surface 302 is located at the same (or approximately the same) position as the back surface 602.

[0046] The thick portion 31 is a portion where the main surface 301 and the back surface 302 overlap when viewed in the z direction. In the illustrated example, the thick portion 31 is a rectangular portion with the longitudinal direction in the x direction when viewed in the z direction. The shape of the thick portion 31 is not limited in any way. The thickness of the thick portion 31 in the z direction is the distance between the main surface 301 and the back surface 302. The thin portion 32 is a portion that overlaps the main surface 301 when viewed in the z direction but does not overlap the back surface 302 when viewed in the z direction. In the illustrated example, the thin portion 32 is connected to the thick portion 31 so as to extend to both sides in the x direction and to the y2 side in the y direction when viewed in the z direction. Furthermore, the thin portion 32 has a portion that is connected to the thick portion 31 so as to extend to the y1 side in the y direction when viewed in the z direction, and this portion is sandwiched between the extending portions 33 in the x direction. The thickness of the thin portion 32 in the z direction is smaller than the distance between the main surface 301 and the back surface 302. There are no limitations on the thickness of the thick portion 31 and the thin portion 32. In this embodiment, the thickness of the thick portion 31 is the same as (or approximately the same as) the thickness of the thick portion 61, and the thickness of the thin portion 32 is the same as (or approximately the same as) the thickness of the thin portion 62.

[0047] The multiple extending portions 33 are portions extending from the end of the thick portion 31. In the illustrated example, the multiple extending portions 33 extend from the thick portion 31 toward the y1 side in the y direction. There is no limitation on the number of extending portions 33, and there may be multiple extending portions 33 or just one extending portion. In the illustrated example, four extending portions 33 are provided. The extending portion 33 has an end face 331. The end face 331 is a surface facing the opposite side to the thick portion 31 in the y direction, in other words, a surface facing the y1 side, which is the outside in the y direction. The illustrated end face 331 is a surface perpendicular to the y direction. The positions of the multiple end faces 331 in the y direction are the same (or approximately the same).

[0048] Fourth lead 4: As shown in FIGS. 1 to 3, the fourth lead 4 is disposed on the y2 side in the y direction relative to the island lead 6. The center of the fourth lead 4 in the x direction is located on the x1 side in the x direction relative to the center of the island lead 6 in the x direction. In the semiconductor device A1, the fourth lead 4 and the island lead 6 are connected by a relay portion 49. Alternatively, the fourth lead 4 may be separated from the island lead 6. As shown in FIGS. 1 to 3 and 8 to 10, the fourth lead 4 has a main surface 401, a back surface 402, a thick portion 41, a thin portion 42, and a plurality of extending portions 43.

[0049] The main surface 401 is a surface facing the z1 side in the z direction, and in the illustrated example, is a smooth surface perpendicular to the z direction. The fourth lead 4 may have, for example, a recess or groove recessed from the main surface 401 as appropriate. The aforementioned second upright portion 25 is joined to the main surface 401 via a fifth conductive joint 95. The back surface 402 is a surface facing the z2 side in the z direction, facing the opposite side from the main surface 401. In the illustrated example, the back surface 402 is a smooth surface perpendicular to the z direction. A plating layer made of Ni, Ti, or the like may be appropriately provided on the back surface 402. In this embodiment, the main surface 401 is located at the same (or approximately the same) position as the main surface 601 in the z direction, and the back surface 402 is located at the same (or approximately the same) position as the back surface 602.

[0050] The thick portion 41 is a portion where the main surface 401 and the back surface 402 overlap when viewed in the z direction. In the illustrated example, the thick portion 41 is a rectangular portion with the longitudinal direction in the x direction when viewed in the z direction. The shape of the thick portion 41 is not limited in any way. The thickness of the thick portion 41 in the z direction is the distance between the main surface 401 and the back surface 402. In this embodiment, the dimension of the thick portion 41 in the x direction is smaller than the dimension of the thick portion 31 in the x direction. The thin portion 42 is a portion that overlaps the main surface 401 when viewed in the z direction but does not overlap the back surface 402. In the illustrated example, the thin portion 42 is connected to the thick portion 41 when viewed in the z direction so as to extend to both sides in the x direction and to the y1 side in the y direction. Furthermore, the thin portion 42 has a portion that is connected to the thick portion 41 when viewed in the z direction so as to extend to the y2 side in the y direction, and this portion is sandwiched between the extending portions 43 in the x direction. The thickness of the thin portion 42 in the z direction is smaller than the distance between the main surface 401 and the back surface 402. The thicknesses of the thick portion 41 and the thin portion 42 are not limited in any way. In this embodiment, the thickness of the thick portion 41 is the same as (or approximately the same as) the thickness of the thick portion 61, and the thickness of the thin portion 42 is the same as (or approximately the same as) the thickness of the thin portion 62.

[0051] The multiple extending portions 43 are portions extending from the end of the thick portion 41. In the illustrated example, the multiple extending portions 43 extend from the thick portion 41 toward the y2 side in the y direction. The number of extending portions 43 is not limited and may be multiple or may be one. In the illustrated example, three extending portions 43 are provided. The positions in the x direction of these three extending portions 43 are the same (or approximately the same) as the positions in the x direction of three extending portions 33 among the multiple extending portions 33 that are located on the x1 side in the x direction. The extending portion 43 has an end surface 431. The end surface 431 is a surface that faces the opposite side from the thick portion 41 in the y direction, in other words, a surface that faces the y2 side, which is outward in the y direction. The illustrated end surface 431 is a surface perpendicular to the y direction. The positions in the y direction of the multiple end surfaces 431 are the same (or approximately the same) as one another. Furthermore, the positions of the multiple end faces 431 in the y direction are the same as (or approximately the same as) the fourth end face 241 .

[0052] Fifth lead 5: As shown in FIGS. 1 to 3, the fifth lead 5 is arranged on the y2 side in the y direction with respect to the island lead 6. The center of the fifth lead 5 in the x direction is located on the x2 side in the x direction with respect to the center of the island lead 6 in the x direction. The fifth lead 5 is arranged on the x2 side in the x direction with respect to the fourth lead 4. As shown in FIGS. 1 to 3 and 10, the fifth lead 5 has a main surface 501, a back surface 502, a thick portion 51, a thin portion 52, and an extending portion 53.

[0053] The main surface 501 is a surface facing the z1 side in the z direction, and in the illustrated example, is a smooth surface perpendicular to the z direction. The fifth lead 5 may have, for example, a recess or groove recessed from the main surface 501 as appropriate. A wire 99 is bonded to the main surface 501. The back surface 502 is a surface facing the z2 side in the z direction, and faces the opposite side to the main surface 501. In the illustrated example, the back surface 502 is a smooth surface perpendicular to the z direction. A plating layer made of Ni, Ti, or the like may be provided on the back surface 502 as appropriate. In this embodiment, the main surface 501 is located at the same (or approximately the same) position as the main surface 601 in the z direction, and the back surface 502 is located at the same (or approximately the same) position as the back surface 602.

[0054] The thick portion 51 is a portion where the main surface 501 and the back surface 502 overlap when viewed in the z direction. In the illustrated example, the thick portion 51 is a rectangular portion when viewed in the z direction. The shape of the thick portion 51 is not limited in any way. The thickness of the thick portion 51 in the z direction is the distance between the main surface 501 and the back surface 502. In this embodiment, the dimension of the thick portion 51 in the x direction is smaller than the dimensions of the thick portions 31 and 41 in the x direction. The thin portion 32 is a portion that overlaps with the main surface 301 when viewed in the z direction but does not overlap with the back surface 302. In the illustrated example, the thin portion 32 is connected to the thick portion 51 so as to extend to both sides in the x direction and to the y1 side in the y direction when viewed in the z direction. The thickness of the thin portion 52 in the z direction is smaller than the distance between the main surface 501 and the back surface 502. The thickness of the thick portion 51 and the thin portion 52 is not limited in any way. In this embodiment, the thickness of the thick portion 51 is the same as (or approximately the same as) the thickness of the thick portion 61 , and the thickness of the thin portion 52 is the same as (or approximately the same as) the thickness of the thin portion 62 .

[0055] The extending portion 53 is a portion extending from the end of the thick portion 51. In the illustrated example, the extending portion 53 extends from the thick portion 51 toward the y2 side in the y direction. The number of extending portions 53 is not limited and may be multiple or may be one. In the illustrated example, one extending portion 53 is provided. The position of the extending portion 53 in the x direction is the same (or approximately the same) as the position in the x direction of the extending portion 33 among the multiple extending portions 33 that is located closest to the x2 side in the x direction. The extending portion 53 has an end face 531. The end face 531 is a surface facing the opposite side from the thick portion 51 in the y direction. In other words, it is a surface facing the y2 side, which is the outside in the y direction. The illustrated end face 531 is a surface perpendicular to the y direction. The position of the end face 531 in the y direction is the same (or approximately the same) as the fourth end face 241 and the multiple end faces 431.

[0056] Semiconductor element 7: The semiconductor element 7 is a component that performs the electrical functions of the semiconductor device A1. The specific configuration of the semiconductor element 7 is not limited. In this embodiment, the semiconductor element 7 is a transistor using a nitride semiconductor, more specifically, a GaN-HEMT (High Electron Mobility Transistor) element using gallium nitride (GaN). The semiconductor element 7 is not limited to a nitride semiconductor, and other semiconductors such as silicon (Si) and silicon carbide (SiC) may also be used. Furthermore, the semiconductor element 7 is not limited to a HEMT, and may be other transistors such as a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) and an IGBT (Insulated Gate Bipolar Transistor). The semiconductor element 7 is mounted on the thick portion 61 of the island lead 6. As shown in FIGS. 1, 2, and 8 to 12, the semiconductor element 7 includes an element body 70, a plurality of first electrodes 71, a plurality of second electrodes 72, and a third electrode 73.

[0057] The element body 70 is, for example, a portion in which a substrate layer, a buffer layer, and a nitride layer (all not shown) are stacked. The element body 70 has an element main surface 701 and an element back surface 702. The element main surface 701 faces the z1 side in the z direction. The element back surface 702 faces the z2 side in the z direction, facing the opposite side to the element main surface 701. In the illustrated example, a metal layer is provided on the element back surface 702. As shown in FIGS. 12 to 14 , this metal layer and the main surface 601 of the island lead 6 are joined by a first conductive joint 91. The first conductive joint 91 is, for example, solder, Ag paste material, Ag sintered material, Cu sintered material, or the like. The above-mentioned metal layer is provided for joining by the first conductive joint 91, but the metal layer may not be provided. Alternatively, the metal layer may be at the same potential as, for example, the second electrode 72. In the illustrated example, the semiconductor element 7 is disposed at a position overlapping a part of the thick portion 61 and a part of the thin portion 62 of the island lead 6 when viewed in the z direction.

[0058] A plurality of first electrodes 71, a plurality of second electrodes 72, and a third electrode 73 are arranged on the element principal surface 701. The number of the plurality of first electrodes 71 and the plurality of second electrodes 72 is not limited in any way. In the illustrated example, three first electrodes 71 and two second electrodes 72 are provided. The number of the plurality of first electrodes 71 is the same as the number of the plurality of first branch portions 12, and the number of the plurality of second electrodes 72 is the same as the number of the plurality of second branch portions 22. The first electrode 71 is an electrode that functions as a drain electrode. The second electrode 72 is an electrode that functions as a source electrode. The plurality of first electrodes 71 and the plurality of second electrodes 72 are arranged alternately in the x direction. The shapes of the first electrodes 71 and the second electrodes 72 are not limited in any way. In the illustrated example, they are shaped such that the longitudinal direction is in the y direction, more specifically, they are tapered.

[0059] As shown in Figures 1, 2, 8, and 10 to 12, the first connection portions 121 of the multiple first branch portions 12 of the first lead 1 are individually conductively joined to the multiple first electrodes 71 via second conductive joint portions 92. The second conductive joint portions 92 are, for example, solder, Ag paste material, Ag sintered material, Cu sintered material, etc. As shown in Figures 1, 2, 9, 11, and 12, the second connection portions 221 of the multiple second branch portions 22 of the second lead 2 are individually conductively joined to the multiple second electrodes 72 via third conductive joint portions 93. The third conductive joint portions 93 are, for example, solder, Ag paste material, Ag sintered material, Cu sintered material, etc.

[0060] The third electrode 73 functions as a gate electrode. The number of third electrodes 73 is not limited and may be one or more. In the illustrated example, one third electrode 73 is provided. The third electrode 73 is disposed, for example, at one of the four corners of the element principal surface 701. In the illustrated example, the third electrode 73 is disposed near the corner of the element principal surface 701 that is on the x2 side in the x direction and the y2 side in the y direction. The third electrode 73 is disposed on the y2 side in the y direction relative to the first electrode 71 that is on the x2 side in the x direction of the two first electrodes 71. A wire 99 is joined to the third electrode 73, and the third electrode 73 is electrically connected to the fifth lead 5 via the wire 99. Note that instead of the wire 99, a conductive member made of a metal plate material may be used to electrically connect the third electrode 73 and the fifth lead 5.

[0061] Sealing resin 8: The sealing resin 8 covers a portion of each of the plurality of leads 1 to 6, the semiconductor element 7, and the wires 99, and is made of an insulating material such as epoxy resin. As shown in Figures 1 to 11, the sealing resin 8 has a first surface 81, a second surface 82, a third surface 83, a fourth surface 84, a fifth surface 85, and a sixth surface 86, and is shaped like a rectangular parallelepiped.

[0062] The first surface 81 is a surface facing the z1 side in the z direction. In the example shown, the first surface 81 is a plane perpendicular to the z direction. The second surface 82 is a surface facing the z2 side in the z direction. In the example shown, the second surface 82 is a plane perpendicular to the z direction. The third surface 83 is a surface facing the y1 side in the y direction. In the example shown, the third surface 83 is a plane perpendicular to the y direction. The fourth surface 84 is a surface facing the y2 side in the y direction. In the example shown, the fourth surface 84 is a plane perpendicular to the y direction. The fifth surface 85 is a surface facing the x1 side in the x direction. In the example shown, the fifth surface 85 is a plane perpendicular to the x direction. The sixth surface 86 is a surface facing the x2 side in the x direction. In the example shown, the sixth surface 86 is a plane perpendicular to the x direction.

[0063] A back surface 602 of the island lead 6, a back surface 302 of the third lead 3, a back surface 402 of the fourth lead 4, and a back surface 502 of the fifth lead 5 are exposed on the z2 side in the z direction from the second surface 82. The second surface 82, the back surface 602 of the island lead 6, the back surface 302 of the third lead 3, the back surface 402 of the fourth lead 4, and the back surface 502 of the fifth lead 5 are flush with one another. However, all or any of the back surface 602 of the island lead 6, the back surface 302 of the third lead 3, the back surface 402 of the fourth lead 4, and the back surface 502 of the fifth lead 5 may protrude slightly from the second surface 82.

[0064] A plurality of end faces 331 of the third lead 3 are exposed on the y1 side in the y direction from the third surface 83. The third surface 83 and the plurality of end faces 331 of the third lead 3 are flush with each other. However, all or any of the plurality of end faces 331 may slightly protrude from the third surface 83.

[0065] From the fourth surface 84, the fourth end face 241 of the second lead 2, the multiple end faces 431 of the fourth lead 4, and the end face 531 of the fifth lead 5 are exposed on the y2 side in the y direction. The fourth surface 84, the fourth end face 241 of the second lead 2, the multiple end faces 431 of the fourth lead 4, and the end face 531 of the fifth lead 5 are flush with one another. However, all or any of the fourth end face 241 of the second lead 2, the multiple end faces 431 of the fourth lead 4, and the end face 531 of the fifth lead 5 may protrude slightly from the fourth surface 84.

[0066] From the fifth surface 85, the first end face 131 of the first lead 1, the second end face 231 of the second lead 2, and the multiple end faces 631 of the island lead 6 are exposed on the x1 side in the x direction. The fifth surface 85, the first end face 131 of the first lead 1, the second end face 231 of the second lead 2, and the multiple end faces 631 of the island lead 6 are flush with one another. However, all or any of the first end face 131 of the first lead 1, the second end face 231 of the second lead 2, and the multiple end faces 631 of the island lead 6 may slightly protrude from the fifth surface 85.

[0067] From the sixth surface 86, the third end face 141 of the first lead 1 and the multiple end faces 631 of the island lead 6 are exposed on the x2 side in the x direction. The sixth surface 86, the third end face 141 of the first lead 1, and the multiple end faces 631 of the island lead 6 are flush with one another. However, all or any of the third end face 141 of the first lead 1 and the multiple end faces 631 of the island lead 6 may protrude slightly from the sixth surface 86.

[0068] The semiconductor device A1 is mounted on a circuit board (not shown) or the like using the back surfaces 302, 402, and 502 exposed from the second surface 82 of the sealing resin 8 as mounting terminals. That is, the mounting surface of the semiconductor device A1 is the z2 side, which is opposite to the z1 side, which is the side to which the element main surface 701 of the semiconductor element 7 faces in the z direction. The back surface 602 is used as a heat dissipation surface for dissipating heat from the semiconductor element 7.

[0069] Next, the operation of the semiconductor device A1 will be described.

[0070] According to this embodiment, as shown in Fig. 12, the first width W11 of the first branch portion 12 is narrower than the second width W12. The first connection portion 121 is conductively joined to the first electrode 71. Therefore, a current flows in the y direction in the first branch portion 12. This current becomes larger as it moves toward the first main portion 11 in the y direction. The first branch portion 12, which is the conduction path of this current, has a larger width in the y direction on the side where the first main portion 11 is located. Therefore, current concentration in the current path can be alleviated.

[0071] Furthermore, in the manufacturing process of semiconductor device A1, first branch portion 12 is in a cantilever state with one side supported by first main portion 11. If the length of first branch portion 12 in the y direction becomes longer or the thickness in the thickness direction z becomes thinner, there is a concern that the entire first branch portion 12 will bend so that the tip of first branch portion 12 is positioned on the z2 side in the thickness direction z. In this embodiment, because second width W12 is larger than first width W11, it is possible to suppress bending of first branch portion 12, and semiconductor device A1 can be manufactured more appropriately.

[0072] The first connection portion 121 has a tapered shape in which the width in the first direction x increases toward the first root portion 122 in the y direction. Such a shape is preferable for alleviating current concentration. In this example, the entire first connection portion 121 has a tapered shape. Such a configuration is preferable for alleviating current concentration.

[0073] Furthermore, the first root portion 122 has a tapered shape. This can further reduce current concentration and suppress bending. The fourth width W21 of the second branch portion 22 is narrower than the fifth width W22. The second connection portion 221 is conductively joined to the second electrode 72. Therefore, a current flows through the second branch portion 22 in the y direction. This current becomes larger as it moves toward the first main portion 11 in the y direction. The second branch portion 22, which is the conduction path of this current, has a larger width on the side where the first main portion 11 is located in the y direction. This can reduce current concentration in the current path.

[0074] Furthermore, in the manufacturing process of semiconductor device A1, second branch portion 22 is in a cantilever state with one side supported by first main portion 11. If the length of second branch portion 22 in the y direction becomes longer or the thickness in the thickness direction z becomes thinner, there is a concern that the entire second branch portion 22 will bend so that the tip of second branch portion 22 is positioned on the z2 side in the thickness direction z. In this embodiment, by making fifth width W22 larger than fourth width W21, it is possible to suppress bending of second branch portion 22, and semiconductor device A1 can be manufactured more appropriately.

[0075] The second connection portion 221 has a tapered shape in which the width in the first direction x increases in the y direction toward the first root portion 122. This shape is preferable for alleviating current concentration. In this example, the entire second connection portion 221 has a tapered shape. This configuration is preferable for alleviating current concentration.

[0076] In addition, the first root portion 122 has a tapered shape, which can further promote the relaxation of current concentration and the suppression of bending.

[0077] 13 to 20 show other embodiments of the present disclosure. In these figures, elements that are the same as or similar to those in the above embodiment are given the same reference numerals. Furthermore, the configurations of the various parts in each of the modified examples and embodiments can be combined with each other as appropriate within the scope of not causing technical contradictions.

[0078] 13 shows a first modification of the semiconductor device A1. In the semiconductor device A11 of this modification, the configurations of the first branch portion 12 and the second branch portion 22 are different from those of the semiconductor device A1.

[0079] In this modification, the second width W12 and the third width W13 of the first branch portion 12 are equal. That is, the first root portion 122 has a shape with a constant width in the first direction x. Furthermore, the fifth width W22 and the sixth width W23 of the second branch portion 22 are equal. That is, the second root portion 222 has a shape with a constant width in the first direction x.

[0080] This modification also makes it possible to alleviate current concentration in the current path and to suppress bending of the first branch portion 12 and the second branch portion 22 during the manufacturing process. Furthermore, as can be seen from this modification, the first branch portion 12 and the first extending portion 13 are not limited to having a tapered shape as a whole.

[0081] 14 shows a second modification of the semiconductor device A1. In the semiconductor device A12 of this modification, the configurations of the first branch portion 12 and the second branch portion 22 are different from those in the above-described example.

[0082] In this modification, the first root portion 122 and the second root portion 222 both have a shape with a constant width in the first direction x.

[0083] The first connecting portion 121 includes a first tapered portion 1211 and a first equal width portion 1212 .

[0084] The first tapered portion 1211 has a shape in which its width in the first direction x increases from its tip on the y2 side toward the first root portion 122 (y1 side). The first constant width portion 1212 is interposed between the first tapered portion 1211 and the first root portion 122. The first constant width portion 1212 has a constant width in the first direction x. In the illustrated example, the width in the first direction x of the first constant width portion 1212 is the same as (or approximately the same as) the width in the first direction x of the first root portion 122 (second width W12, third width W13). A first length L11, which is the length in the y direction of the first tapered portion 1211, is longer than a second length L12, which is the length in the y direction of the first constant width portion 1212.

[0085] The second connecting portion 221 includes a second tapered portion 2211 and a second equal width portion 2212 .

[0086] The second tapered portion 2211 has a shape in which its width in the first direction x increases from its tip on the y1 side toward the second root portion 222 (y2 side). The second constant width portion 2212 is interposed between the second tapered portion 2211 and the second root portion 222. The second constant width portion 2212 has a constant width in the first direction x. In the illustrated example, the width in the first direction x of the second constant width portion 2212 is the same as (or approximately the same as) the width in the first direction x of the second root portion 222 (fifth width W22, sixth width W23). A third length L21, which is the length in the y direction of the second tapered portion 2211, is longer than a fourth length L22, which is the length in the y direction of the second constant width portion 2212.

[0087] This modification also makes it possible to alleviate current concentration in the current path and to suppress bending of the first branch portion 12 and the second branch portion 22 during the manufacturing process. Furthermore, as can be seen from this modification, the first connection portion 121 and the first root portion 122 are not limited to configurations consisting of only tapered portions.

[0088] 15 shows a third modification of the semiconductor device A1. In the semiconductor device A13 of this modification, the configurations of the first branch portion 12 and the second branch portion 22 are different from those in the above-described example.

[0089] The first root portion 122 of this modified example includes a first wide portion 1221 and a second narrow portion 1222. The first wide portion 1221 has a width in the first direction x greater than that of the second narrow portion 1222, and is interposed between the second narrow portion 1222 and the first main portion 11. The second narrow portion 1222 is interposed between the first wide portion 1221 and the first connection portion 121. In the illustrated example, the width of the first wide portion 1221 in the first direction x is a second width W12, and the width of the second narrow portion 1222 in the first direction x is a third width W13. When viewed in the thickness direction z, the first wide portion 1221 does not overlap with the first electrode 71.

[0090] The second root portion 222 of this modified example includes a first wide portion 2221 and a second narrow portion 2222. The first wide portion 2221 has a width in the first direction x greater than that of the second narrow portion 2222, and is interposed between the second narrow portion 2222 and the second main portion 21. The second narrow portion 2222 is interposed between the first wide portion 2221 and the second connection portion 221. In the illustrated example, the width of the first wide portion 2221 in the first direction x is a fifth width W22, and the width of the second narrow portion 2222 in the first direction x is a sixth width W23. When viewed in the thickness direction z, the first wide portion 2221 does not overlap the second electrode 72.

[0091] This modification also alleviates current concentration in the current path and suppresses bending of the first branch portion 12 and the second branch portion 22 during the manufacturing process. As can be seen from this modification, the shapes of the first root portion 122 and the second root portion 222 are not limited in any way. The inclusion of the first wide portion 1221 and the first wide portion 2221 can further alleviate current concentration in the current path and suppress bending of the first branch portion 12 and the second branch portion 22 during the manufacturing process. Furthermore, if the first wide portion 1221 does not overlap the first electrode 71 and the first wide portion 2221 does not overlap the second electrode 72 when viewed in the thickness direction z, insulation between the first wide portion 1221 and the first electrode 71 and insulation between the first wide portion 2221 and the second electrode 72 can be more reliably ensured.

[0092] 16 to 18 show a semiconductor device according to a second embodiment of the present disclosure. A semiconductor device A2 of this embodiment includes a first lead 1, a second lead 2, a fifth lead 5, a semiconductor element 7, and a sealing resin 8.

[0093] The semiconductor element 7 of this embodiment is disposed with its element principal surface 701 facing the z2 side in the z direction and its element rear surface 702 facing the z1 side in the z direction. The plurality of first electrodes 71, the plurality of second electrodes 72, and the third electrode 73 are formed by a plurality of metal bumps. The plurality of first electrodes 71 are groups of a plurality of metal bumps (two or three in the figure) arranged in the y direction. A plurality of sets (three sets) of first electrodes 71 are arranged in the first direction x. The plurality of second electrodes 72 are groups of a plurality of metal bumps (three in the figure) arranged in the y direction. A plurality of sets (two sets) of second electrodes 72 are arranged in the first direction x. The plurality of sets of first electrodes 71 and the plurality of sets of second electrodes 72 are alternately arranged in the first direction x.

[0094] The first lead 1 has a main surface 101 and a back surface 102. The main surface 101 faces the z1 side in the z direction and faces the element main surface 701 of the semiconductor element 7. The back surface 102 faces the z2 side in the z direction and is exposed from the second surface 82 of the sealing resin 8. In this example, the thickness of the first lead 1 in the z direction is constant.

[0095] The second lead 2 has a main surface 201 and a back surface 202. The main surface 201 faces the z1 side in the z direction and faces the element main surface 701 of the semiconductor element 7. The back surface 202 faces the z2 side in the z direction and is exposed from the second surface 82 of the sealing resin 8. In this example, the thickness of the second lead 2 in the z direction is constant.

[0096] The shapes of the plurality of first branches 12 of the first lead 1 and the plurality of second branches 22 of the second lead 2 when viewed in the z direction are similar to, for example, the plurality of first branches 12 and the plurality of second branches 22 in the semiconductor device A1 described above. However, the plurality of first branches 12 and the plurality of second branches 22 may have the shapes in the semiconductor devices A11, A12, and A13, or may also have other shapes. The plurality of first branches 12 and the plurality of second branches 22 are located on the z2 side in the z direction with respect to the semiconductor element 7.

[0097] The plurality of first branch portions 12 are individually conductively joined to the plurality of sets of first electrodes 71 via second conductive joints 92. The plurality of second branch portions 22 are conductively joined to the plurality of sets of second electrodes 72 via third conductive joints 93.

[0098] The fifth lead 5 has a third connection portion 55. A third electrode 73 is electrically connected to the third connection portion 55 by a conductive joint portion (not shown). One surface of the fifth lead 5 is exposed from the second surface 82 of the sealing resin 8.

[0099] The semiconductor device A2 of this embodiment has a configuration in which a semiconductor element 7 is flip-chip bonded to the first lead 1, the second lead 2, and the third lead 3. Furthermore, the back surface 102 of the first lead 1, the back surface 202 of the second lead 2, and one surface of the fifth lead 5 (the surface exposed from the second surface 82) are used as mounting terminals when the semiconductor device A2 is mounted on a circuit board (not shown) or the like.

[0100] This embodiment also makes it possible to alleviate current concentration in the current path and to suppress bending of the first branch portion 12 and the second branch portion 22 during the manufacturing process. Furthermore, as can be understood from this embodiment, the bonding form between the first lead 1 and the second lead 2 and the semiconductor element 7 is not limited in any way.

[0101] Second Embodiment - First Modification: Figure 19 shows a first modification of the semiconductor device A2. In a semiconductor device A21 of this modification, the first branch portion 12 of the first lead 1 is thinner than the first main portion 11. The first branch portion 12 is not exposed on the z2 side in the z direction from the second surface 82 of the sealing resin 8. Furthermore, the second branch portion 22 of the second lead 2 is thinner than the second main portion 21. The second branch portion 22 is not exposed on the z2 side in the z direction from the second surface 82 of the sealing resin 8. Such first lead 1 and second lead 2 can be formed, for example, by etching a metal plate material from both sides in the z direction.

[0102] This modification also makes it possible to alleviate current concentration in the current path and to suppress bending of the first branch portion 12 and the second branch portion 22 during the manufacturing process. Furthermore, as can be seen from this modification, the first lead 1 and the second lead 2 may not have a constant thickness.

[0103] Second Modification of Second Embodiment: FIG. 20 shows a second modification of the semiconductor device A2. In this modification, the semiconductor device A22 has a first lead 1 in which the first branch 12 is located closer to the z1 side in the z direction than the first main portion 11. The first branch 12 is not exposed on the z2 side in the z direction from the second surface 82 of the sealing resin 8. The first main portion 11 and the first branch 12 have the same (or approximately the same) thickness in the thickness direction z. Furthermore, in the second lead 2, the second branch 22 is located closer to the z1 side in the z direction than the second main portion 21. The second branch 22 is not exposed on the z2 side in the z direction from the second surface 82 of the sealing resin 8. The second main portion 21 and the second branch 22 have the same (or approximately the same) thickness in the thickness direction z. Such a first lead 1 and a second lead 2 can be formed, for example, by bending a metal plate material.

[0104] This modification also makes it possible to alleviate current concentration in the current path and to suppress bending of the first branch portion 12 and the second branch portion 22 during the manufacturing process. As can be seen from this modification, the first lead 1 and the second lead 2 may be configured to be bent in the thickness direction z.

[0105] The semiconductor device according to the present disclosure is not limited to the above-described embodiment. The specific configuration of each part of the semiconductor device according to the present disclosure can be freely designed in various ways. The present disclosure includes the embodiments described in the following appendices.

[0106] Supplementary Note 1. A semiconductor device comprising: a plurality of leads; a semiconductor element; and a sealing resin covering at least some of the plurality of leads and the semiconductor element, wherein the plurality of leads include a first lead, the semiconductor element has a main surface facing one side in a thickness direction and a back surface facing the other side, and a plurality of first electrodes arranged on the main surface of the element along a first direction intersecting the thickness direction, the first lead includes a first main portion and a plurality of first branch portions extending from the first main portion in a second direction intersecting the thickness direction and the first direction and arranged along the first direction, the first branch portions have a first root portion connected to the first main portion and a first connection portion conductively joined to the first electrode, and a first width that is the width in the first direction of a tip of the first connection portion is narrower than a second width that is the width in the first direction of a boundary between the first root portion and the first main portion. Supplementary Note 2. The semiconductor device according to Appendix 1, wherein the first connection portion includes a first tapered portion whose width in the first direction increases from the tip toward the first root portion. Appendix 3. The semiconductor device according to Appendix 2, wherein the first connection portion includes only the first tapered portion. Appendix 4. The semiconductor device according to Appendix 2, wherein the first connection portion includes a first constant width portion interposed between the first tapered portion and the first root portion. Appendix 5. The semiconductor device according to Appendix 4, wherein a first length which is the length in the second direction of the first tapered portion is longer than a second length which is the length in the second direction of the first constant width portion. Appendix 6. The semiconductor device according to Appendix 1, wherein a third width which is the width in the first direction of the boundary between the first root portion and the first connection portion is the same as the second width. Appendix 7. The semiconductor device according to Appendix 1, wherein the third width which is the width in the first direction of the boundary between the first root portion and the first connection portion is smaller than the second width and larger than the first width. Appendix 8. 8. The semiconductor device of claim 7, wherein the first base portion includes a first wide portion and a first narrow portion, the first wide portion having a width in the first direction greater than that of the first narrow portion, and the first wide portion is interposed between the first narrow portion and the first main portion.Supplementary Note 9. The semiconductor device according to any one of Supplementary Notes 1 to 8, wherein the plurality of leads include a second lead, the semiconductor element has a plurality of second electrodes arranged along the first direction on the element main surface, the plurality of first electrodes and the plurality of second electrodes being arranged alternately in the first direction, the second lead includes a second main portion located on the opposite side of the first main portion in the second direction with the plurality of first electrodes and the plurality of second electrodes sandwiched between them when viewed in the thickness direction, and a plurality of second branch portions extending in the second direction from the second main portion and arranged along the first direction, the second branch portions having a second root portion connected to the second main portion and a second connection portion conductively joined to the second electrode, and a fourth width which is the width in the first direction of a tip of the second connection portion is narrower than a fifth width which is the width in the first direction of a boundary between the second root portion and the second main portion. The semiconductor device according to Appendix 9, wherein the second connection portion includes a second tapered portion whose width in the first direction increases from the tip toward the second root portion. Appendix 11. The semiconductor device according to Appendix 10, wherein the second connection portion includes only the second tapered portion. Appendix 12. The semiconductor device according to Appendix 10, wherein the second connection portion includes a second equal width portion interposed between the second tapered portion and the second root portion. Appendix 13. The semiconductor device according to Appendix 12, wherein a third length which is the length in the second direction of the second tapered portion is longer than a fourth length which is the length in the second direction of the second equal width portion. Appendix 14. The semiconductor device according to Appendix 9, wherein a sixth width which is the width in the first direction of the boundary between the second root portion and the second connection portion is the same as the fifth width. Appendix 15. The semiconductor device according to Appendix 9, wherein the sixth width which is the width in the first direction of the boundary between the second root portion and the second connection portion is smaller than the fifth width and larger than the fourth width. Appendix 16. The semiconductor device according to Appendix 15, wherein the second root portion includes a second wide portion and a second narrow portion, the second wide portion having a width in the first direction greater than that of the second narrow portion, and being interposed between the second narrow portion and the second main portion. Appendix 17. The semiconductor device according to any one of claims 1 to 16, wherein the semiconductor element is a GaN-HEMT element.

[0107] A1, A11, A12, A13, A2, A21, A22: semiconductor device 1: first lead 2: second lead 3: third lead 4: fourth lead 5: fifth lead 6: island lead 7: semiconductor element 8: sealing resin 11: first main portion 12: first branch portion 13: first extending portion 14: third extending portion 15: first standing portion 21: second main portion 22: second branch portion 23: second extending portion 24: fourth extending portion 25: second standing portion 29: connecting portion 31: thick portion 32: thin portion 33: extending portion 41: thick portion 42: thin portion 43: extending portion 49: relay portion 51: thick portion 52: thin portion 53: extending portion 55: third connecting portion 61: Thick portion 62: Thin portion 63: Extension portion 70: Element body 71: First electrode 72: Second electrode 73: Third electrode 81: First surface 82: Second surface 83: Third surface 84: Fourth surface 85: Fifth surface 86: Sixth surface 91: First conductive joint 92: Second conductive joint 93: Third conductive joint 94: Fourth conductive joint 95: Fifth conductive joint 99: Wire 101: Main surface 102: Back surface 111: Through hole 121: First connection portion 122: First root portion 131: First end surface 141: Third end surface 201: Main surface 202: Back surface 211: Through hole 221: Second connection portion 222: Second root portion 231: Second end surface 241: Fourth end face 301: Main surface 302: Reverse surface 331: End face 401: Main surface 402: Reverse surface 431: End face 501: Main surface 502: Reverse surface 531: End face 601: Main surface 602: Reverse surface 631: End face 701: Element main surface 702: Element reverse surface 1211: First tapered portion 1212: First constant width portion 1221: First wide width portion 1222: Second narrow width portion 2211: Second tapered portion 2212: Second constant width portion 2221: First wide width portion 2222: Second narrow width portion W11: First width W12: Second width W13: Third width W21: Fourth width W22: Fifth width W23: Sixth width x: First direction y: second direction z: thickness direction

Claims

1. Multiple leads and A semiconductor element; a sealing resin that covers at least a portion of the leads and the semiconductor element, the plurality of leads includes a first lead; the semiconductor element has a main surface facing one side in a thickness direction and a back surface facing the other side, and a plurality of first electrodes arranged on the main surface of the element along a first direction intersecting the thickness direction; the first lead includes a first main portion and a plurality of first branch portions extending from the first main portion in a second direction intersecting the thickness direction and the first direction and arranged along the first direction; the first branch portion has a first root portion connected to the first main portion and a first connection portion conductively joined to the first electrode, A semiconductor device, wherein a first width, which is the width in the first direction of a tip of the first connection portion, is narrower than a second width, which is the width in the first direction of a boundary between the first root portion and the first main portion.

2. The semiconductor device according to claim 1 , wherein said first connection portion includes a first tapered portion whose width in said first direction increases from said tip toward said first base portion.

3. The semiconductor device according to claim 2 , wherein said first connection portion includes only said first tapered portion.

4. The semiconductor device according to claim 2 , wherein said first connection portion includes a first equal width portion interposed between said first tapered portion and said first base portion.

5. 5 . The semiconductor device according to claim 4 , wherein a first length which is a length in the second direction of said first tapered portion is longer than a second length which is a length in the second direction of said first constant width portion.

6. The semiconductor device according to claim 1 , wherein a third width, which is a width in the first direction of a boundary between said first base portion and said first connection portion, is equal to said second width.

7. 2 . The semiconductor device according to claim 1 , wherein a third width, which is a width in the first direction of a boundary between said first base portion and said first connection portion, is smaller than said second width and larger than said first width.

8. the first root portion includes a first wide portion and a first narrow portion; The semiconductor device according to claim 7 , wherein the first wide portion has a width in the first direction greater than that of the first narrow portion, and is interposed between the first narrow portion and the first main portion.

9. the plurality of leads includes a second lead; the semiconductor element has a plurality of second electrodes arranged along the first direction on the element main surface, the first electrodes and the second electrodes are alternately arranged in the first direction, the second lead includes: a second main portion located on the opposite side in the second direction to the first main portion with the plurality of first electrodes and the plurality of second electrodes interposed therebetween when viewed in the thickness direction; and a plurality of second branch portions extending in the second direction from the second main portion and arranged along the first direction, the second branch portion has a second root portion connected to the second main portion and a second connection portion conductively joined to the second electrode, 9. The semiconductor device according to claim 1, wherein a fourth width, which is the width in the first direction of a tip of the second connection portion, is narrower than a fifth width, which is the width in the first direction of a boundary between the second root portion and the second main portion.

10. The semiconductor device according to claim 9 , wherein said second connection portion includes a second tapered portion whose width in said first direction increases from said tip toward said second base portion.

11. The semiconductor device according to claim 10 , wherein the second connection portion includes only the second tapered portion.

12. The semiconductor device according to claim 10 , wherein the second connection portion includes a second equal width portion interposed between the second tapered portion and the second base portion.

13. 13 . The semiconductor device according to claim 12 , wherein a third length which is a length in the second direction of said second tapered portion is longer than a fourth length which is a length in the second direction of said second constant width portion.

14. The semiconductor device according to claim 9 , wherein a sixth width, which is a width in the first direction of a boundary between said second base portion and said second connection portion, is equal to said fifth width.

15. 10. The semiconductor device according to claim 9, wherein a sixth width that is a width in the first direction of a boundary between said second base portion and said second connection portion is smaller than said fifth width and larger than said fourth width.

16. the second root portion includes a second wide portion and a second narrow portion; The semiconductor device according to claim 15 , wherein the second wide portion has a width in the first direction greater than that of the second narrow portion, and is interposed between the second narrow portion and the second main portion.

17. 2. The semiconductor device according to claim 1, wherein the semiconductor element is a GaN-HEMT element.