JP2017174951A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device capable of improving radiation performance while ensuring reliability.SOLUTION: A semiconductor device comprises: a first lead 21 including a first pad 211 having a pad principal surface 211a and a pad rear face 211 which face opposite to each other in a first direction Z indicating a thickness direction, and a first terminal 212 extending along a second direction X perpendicular to the first direction Z; a semiconductor element 11 which has an element principal surface 111 and an element rear face 112 which face opposite to each other in the first direction Z and is mounted in such a manner that the element rear face 112 faces the pad principal surface 211a; a radiation member 3 including a pair of sidewall parts 31 which erect from the pad principal surface 211a and are arranged away from each other in a third direction Y perpendicular to both of the first direction Z and the second direction X, and a head slab part 32 with both ends in the third direction Y being fastened to the pair of sidewall parts 31, respectively, which has a radiation surface 321 facing the same direction with the pad principal surface 211a; and an encapsulation resin 4 covering the semiconductor element 11.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a semiconductor device in which a semiconductor element to be mounted is a power semiconductor (such as a power MOSFET and an IGBT).

  Power semiconductors such as power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) and IGBTs (Insulated Gate Bipolar Transistors) have low on-resistance, low loss, high-speed switching characteristics in the high-frequency region, and high breakdown voltage against rising drive voltage. Etc. are required.

  Power semiconductors that meet these requirements tend to generate a lot of heat when used. In a semiconductor device on which a semiconductor element that is the power semiconductor is mounted, the device may be damaged by such heat. Therefore, in order to ensure the reliability of the semiconductor device, the release (removal) of heat generated from the semiconductor element is an important issue.

  Therefore, for example, as disclosed in Patent Document 1, a semiconductor device having a structure in which a conductive member conducting to a semiconductor element is exposed from both an upper surface and a lower surface of a sealing resin has been proposed. The semiconductor device has a configuration in which a die pad portion on which a semiconductor element is mounted is exposed from the lower surface of the sealing resin, and a metal clip that forms a conduction path between the semiconductor element and the terminal portion is exposed from the upper surface of the sealing resin. . Moreover, the connection part with the terminal part of the said metal clip becomes a structure pinched | interposed by sealing resin from the upper and lower sides. By adopting such a configuration, even if the metal clip is exposed from the sealing resin, there is no concern that the metal clip will fall off the sealing resin when the semiconductor device is used, and the reliability of the semiconductor device is ensured. Is done. However, in the thickness direction of the semiconductor device, since the connection portion with the terminal portion of the metal clip is located in the center and is covered with sealing resin thickly on the upper and lower sides, heat dissipation at the connection portion There is a problem that the performance is not fully exhibited.

JP 2015-142077 A

  In view of the above circumstances, an object of the present invention is to provide a semiconductor device capable of improving heat dissipation performance while ensuring reliability.

  A semiconductor device provided by the present invention includes a first pad having a pad main surface and a pad back surface that are opposite to each other in a first direction that is a thickness direction, and a second direction that is perpendicular to the first direction. A first lead including a first terminal extending along the first direction, an element main surface facing the opposite side in the first direction, and an element back surface, and the element back surface faces the pad main surface And a pair of side wall portions that stand up from the pad main surface and are spaced apart from each other in a third direction perpendicular to either the first direction or the second direction, A heat radiating member including a top plate portion having both ends in the third direction fixed to the pair of side wall portions and a heat radiating surface facing the same direction as the pad main surface; and a sealing resin covering the semiconductor element; Characterized by comprising It is.

  In the embodiment of the present invention, preferably, the pad back surface and the heat radiating surface are both exposed from the sealing resin.

  In the embodiment of the present invention, preferably, part of both ends of the top plate portion in the third direction are fixed to the pair of side wall portions.

  In the embodiment of the present invention, preferably, both ends of the top plate portion in the third direction are all fixed to the pair of side wall portions.

  Preferably, in the embodiment of the present invention, the top plate portion is formed with a plurality of engaging claws that engage with the side wall portion at each part of both ends in the third direction.

  Preferably, in the embodiment of the present invention, the top plate portion is formed with a plurality of engaging claws that engage with the side wall portion at each of both ends in the third direction.

  In an embodiment of the present invention, preferably, the plurality of engaging claws are all covered with the sealing resin.

  In the embodiment of the present invention, preferably, the pair of side wall portions are formed with side wall through holes penetrating in the third direction.

  In the embodiment of the present invention, preferably, the pair of side wall portions are both disposed along the second direction.

  Preferably, in the embodiment of the present invention, in the plan view as the first direction, the top plate portion overlaps the entire semiconductor element.

  In the embodiment of the present invention, preferably, both the first lead and the heat dissipation member are made of the same metal.

  In an embodiment of the present invention, preferably, the sealing resin is a thermosetting synthetic resin having electrical insulation.

  In an embodiment of the present invention, the sealing resin is preferably an epoxy resin.

  In an embodiment of the present invention, preferably, the sealing resin has a resin main surface and a resin back surface facing to opposite sides in the first direction, and the sealing resin includes the resin in the first direction. A main body insertion hole extending from the main surface to the resin back surface is formed.

  In the embodiment of the present invention, preferably, in the first direction, a pad through hole is formed in the first pad, and a top plate through hole is formed in the top plate portion.

  Preferably, in the embodiment of the present invention, the first lead includes an intermediate connecting portion connected to the first pad and the first terminal, and the intermediate connecting portion includes the first pad and the first terminal. Inclined with respect to both.

  In an embodiment of the present invention, it is preferable that the second lead and the third lead are provided apart from the first lead and extend along the second direction. Both leads are electrically connected to the element main surface, and the positions of the first terminal, the second lead, and the third lead in the first direction are all equal.

  In an embodiment of the present invention, preferably, the first terminal, the second lead, and the third lead are all arranged along the third direction, and the first terminal is connected to the second lead and the third lead. It is located between the third lead.

  In an embodiment of the present invention, preferably, the first terminal, the second lead, and the third lead all have a portion exposed from the sealing resin, and is formed by covering the portion. With layers.

  In the embodiment of the present invention, preferably, the exterior plating layer is made of an alloy containing Sn as a main component.

  In an embodiment of the present invention, preferably, a first bonding wire that connects the second lead and the element main surface, and a second bonding wire that connects the third lead and the element main surface are provided. The first bonding wire and the second bonding wire are both made of the same metal.

  In the embodiment of the present invention, preferably, both the first bonding wire and the second bonding wire are made of Al.

  Preferably, in the embodiment of the present invention, the cross-sectional area of the second bonding wire is larger than the cross-sectional area of the first bonding wire.

  In an embodiment of the present invention, preferably, an inner plating layer formed on each part of the pad main surface, the second lead, and the third lead is provided.

  In the embodiment of the present invention, preferably, the interior plating layer is made of Ag.

  In an embodiment of the present invention, the semiconductor element is preferably a power MOSFET or an IGBT.

  A semiconductor device according to the present invention includes a pair of side walls that stand from a pad main surface of a first pad on which a semiconductor element is mounted and are spaced apart in a third direction, and a pair of side walls that are opposite in the third direction. And a heat radiating member including a top plate portion having a heat radiating surface which is fixed to the portion and faces the same direction as the pad main surface. With such a configuration, heat generated from the semiconductor element during use of the semiconductor device is radiated from the heat radiation surface to the outside through the pair of side wall portions in addition to the pad back surface of the first pad. The heat radiation surface has a larger area than a conventional semiconductor device and is in a state in which heat radiation performance is exhibited over the entire surface. Moreover, since both ends of the top plate portion in the third direction are fixed to the pair of side wall portions, the top plate portion is prevented from falling off from the sealing resin, and the reliability of the semiconductor device is ensured. Therefore, according to the semiconductor device of the present invention, it is possible to improve the heat dissipation performance while ensuring reliability.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

1 is a perspective view of a semiconductor device according to a first embodiment of the present invention. 2 is a plan view of the semiconductor device shown in FIG. 1 in which a sealing resin is omitted. FIG. FIG. 2 is a plan view of the semiconductor device shown in FIG. 1 in which a sealing resin and a top plate portion of a heat dissipation member are omitted. FIG. 2 is a bottom view of the semiconductor device shown in FIG. 1. FIG. 2 is a right side view of the semiconductor device shown in FIG. 1 with a sealing resin omitted. It is a perspective view (a side wall part is abbreviate | omitted) of the heat radiating member of the semiconductor device shown in FIG. It is sectional drawing which follows the VII-VII line of FIG. FIG. 7B is a cross-sectional view of FIG. 7A of a modification of the semiconductor device shown in FIG. 1. It is sectional drawing which follows the VIII-VIII line of FIG. It is sectional drawing which follows the IX-IX line of FIG. It is a perspective view of the semiconductor device concerning 2nd Embodiment of this invention. FIG. 11 is a plan view of the semiconductor device shown in FIG. 10 in which a sealing resin is omitted. 11 is a plan view of the semiconductor device shown in FIG. 10 in which a sealing resin and a top plate portion of a heat dissipation member are omitted. FIG. FIG. 11 is a right side view of the semiconductor device shown in FIG. 10 with a sealing resin omitted. It is a perspective view (omission of a side wall part) of the heat radiating member of the semiconductor device shown in FIG. It is sectional drawing which follows the XV-XV line | wire of FIG.

  Embodiments of the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
A semiconductor device A10 according to the first embodiment of the present invention will be described with reference to FIGS. For convenience of explanation, the thickness direction of the semiconductor device A10 is defined as the first direction Z, the vertical direction of the plan view perpendicular to the first direction Z is defined as the second direction X, the first direction Z, and the second direction X. On the other hand, the left-right direction of the plan view, which is a right angle, is defined as a third direction Y.

  The semiconductor device A10 shown in these drawings is of a type that is surface-mounted on, for example, a circuit board of automobile electrical equipment. The semiconductor device A10 of this embodiment includes a semiconductor element 11, a bonding layer 12, a first lead 21, a second lead 22, a third lead 23, a heat dissipation member 3, a sealing resin 4, an exterior plating layer 51, and an interior plating layer 52. The first bonding wire 61 and the second bonding wire 62 are provided. The portion of the semiconductor device A10 covered with the sealing resin 4 has a rectangular shape in plan view (hereinafter referred to as “plan view”) as viewed in the first direction Z.

  FIG. 1 is a perspective view of the semiconductor device A10. 2 and 3 are plan views of the semiconductor device A10. FIG. 4 is a bottom view of the semiconductor device A10. FIG. 5 is a right side view of the semiconductor device A10. FIG. 6 is a perspective view of the heat dissipation member 3. 7A is a cross-sectional view taken along line VII-VII in FIG. FIG. 7B is a cross-sectional view of the semiconductor device A11, which is a modification of the semiconductor device A10, with respect to FIG. 7A. 8 is a cross-sectional view taken along line VIII-VIII in FIG. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. Here, for convenience of understanding, FIGS. 2, 5 and 8 are views in which the sealing resin 4 is omitted. FIG. 3 is a view in which the top plate portion 32 of the heat radiating member 3 is further omitted from FIG. 2. Moreover, the side wall part 31 mentioned later is abbreviate | omitted in FIG. Note that the omitted sealing resin 4 and side wall 31 are indicated by imaginary lines (two-dot chain lines).

  The semiconductor element 11 is an element that becomes the center of the function of the semiconductor device A10. The semiconductor element 11 according to the present embodiment is a power MOSFET or IGBT. The semiconductor element 11 has an element main surface 111 and an element back surface 112.

  The element main surface 111 is the upper surface of the semiconductor element 11 shown in FIGS. 7A and 8. As shown in FIG. 3, a part of the element main surface 111 is a second electrode pad 111a and a third electrode pad 111b. When the semiconductor element 11 is a power MOSFET, the second electrode pad 111a is a gate electrode, the third electrode pad 111b is a source electrode, and when the semiconductor element 11 is an IGBT, the second electrode pad 111a is a gate electrode, The electrode pad 111b is an emitter electrode. The area of the second electrode pad 111a is smaller than the area of the third electrode pad 111b. The first bonding wire 61 is connected to the second electrode pad 111a, and the second bonding wire 62 is connected to the third electrode pad 111b.

  The element back surface 112 is the bottom surface of the semiconductor element 11 shown in FIGS. 7A and 8. The main part of the element back surface 112 is the first electrode pad 112a. When the semiconductor element 11 is a power MOSFET, the first electrode pad 112a is a drain electrode, and when the semiconductor element 11 is an IGBT, the first electrode pad 112a is a collector electrode. The element main surface 111 and the element back surface 112 face each other in the first direction Z.

  As shown in FIGS. 7A and 8, the bonding layer 12 is a member that is interposed between the semiconductor element 11 and a first pad 211 of the first lead 21 described later and has conductivity. By the bonding layer 12, the semiconductor element 11 is mounted on the first pad 211 by die bonding, and conduction between the first electrode pad 112 a of the semiconductor element 11 and the first lead 21 is ensured. The bonding layer 12 is made of, for example, an Ag paste.

  The first lead 21, the second lead 22, and the third lead 23 are members that form a conductive path between the semiconductor device A 10 and the circuit board by being bonded to the circuit board and have conductivity. The first lead 21, the second lead 22, and the third lead 23 are all members derived from the same lead frame, and the lead frame according to the present embodiment is made of an alloy containing Cu as a main component.

  The first lead 21 includes a first pad 211 (die pad), a first terminal 212 and an intermediate connecting portion 213. As shown in FIGS. 7A, 8, and 9, the first pad 211 has a pad main surface 211 a and a pad back surface 211 b that face opposite sides in the first direction Z. The pad main surface 211a is the upper surface of the first pad 211 shown in FIGS. 7A, 8 and 9. The pad back surface 211b is the bottom surface of the first pad 211 shown in FIGS. 7A, 8 and 9. The pad main surface 211a and the pad back surface 211b are both flat. As shown in FIG. 3, the pad main surface 211a is a surface on which the semiconductor element 11 is mounted. As shown in FIGS. 7A and 8, the element back surface 112 faces the pad main surface 211a. As shown in FIG. 3, an inner plating layer 52 having an area larger than that of the semiconductor element 11 is formed on the pad main surface 211 a. Therefore, the bonding layer 12 is in contact with the interior plating layer 52 and the first electrode pad 112 a formed on the element back surface 112. Moreover, as shown in FIG. 4, the pad back surface 211b according to the present embodiment is exposed from the sealing resin 4 over the entire surface. In this case, as shown in FIGS. 7A, 8, and 9, the pad back surface 211 b is covered with the exterior plating layer 51. Note that the sealing resin 4 may thinly cover the entire surface of the pad back surface 211b as in a semiconductor device A11 that is a modification of the semiconductor device A10 illustrated in FIG. 7B. Further, as shown in FIG. 3 and FIG. 7A, the first pad 211 is formed with a pad through hole 211 c extending from the pad main surface 211 a to the pad back surface 211 b so as to be separated from the semiconductor element 11.

  As shown in FIGS. 1 to 3, the first terminal 212 is a portion that extends along the second direction X and is partially exposed from the sealing resin 4. As shown in FIG. 7A, the portion exposed from the sealing resin 4 of the first terminal 212 is covered with the exterior plating layer 51. The first terminal 212 is electrically connected to the first electrode pad 112a through the intermediate connecting portion 213, the first pad 211, and the bonding layer 12. Therefore, when the semiconductor element 11 is a power MOSFET, the first terminal 212 is a drain terminal of the semiconductor device A10, and when the semiconductor element 11 is an IGBT, the first terminal 212 is a collector terminal.

  The intermediate connecting portion 213 is a portion connected to the first pad 211 and the first terminal 212 as shown in FIGS. 3 and 7A. As shown in FIG. 7A, in the first direction Z, the positions of the first pad 211 and the first terminal 212 are different, and the first pad 211 is located below the first terminal 212 in FIG. 7A. Therefore, the intermediate connection part 213 is inclined with respect to the first pad 211 and the first terminal 212. The intermediate connecting portion 213 is covered with the sealing resin 4 throughout.

  As shown in FIGS. 1 to 3, the second lead 22 is a member that is spaced apart from the first lead 21 and extends along the second direction X. In the third direction Y, the second lead 22 is located on one side of the first terminal 212. The second lead 22 includes a second pad 221 and a second terminal 222. As shown in FIGS. 2 and 3, the second pad 221 is a portion whose length in the third direction Y is longer than that of the second terminal 222 and is entirely covered with the sealing resin 4. An interior plating layer 52 is formed on the upper surface of the second pad 221 shown in FIG. 8, and a first bonding wire 61 is further connected.

  The second terminal 222 is a portion connected to the second pad 221 as shown in FIGS. 2 and 3. The second terminal 222 extends along the second direction X, and a part thereof is exposed from the sealing resin 4. The part exposed from the sealing resin 4 of the second terminal 222 is covered with the exterior plating layer 51 as in the first terminal 212 shown in FIG. 7A. The second terminal 222 is electrically connected to the second electrode pad 111 a that is a part of the element main surface 111 via the second pad 221 and the first bonding wire 61. Therefore, when the semiconductor element 11 is a power MOSFET or IGBT, the second terminal 222 is a gate terminal of the semiconductor device A10.

  As shown in FIGS. 1 to 3, the third lead 23 is a member that is spaced apart from the first lead 21 and extends along the second direction X. In the third direction Y, the third lead 23 is located on the side opposite to the second lead 22 with respect to the first terminal 212. The third lead 23 includes a third pad 231 and a third terminal 232. As shown in FIGS. 2 and 3, the third pad 231 is a portion whose length in the third direction Y is longer than that of the third terminal 232 and is entirely covered with the sealing resin 4. An interior plating layer 52 is formed on the upper surface of the third pad 231 shown in FIG. 8, and further, a second bonding wire 62 is connected.

  As shown in FIGS. 2 and 3, the third terminal 232 is a portion connected to the third pad 231. The third terminal 232 extends along the second direction X, and a part thereof is exposed from the sealing resin 4. The portion exposed from the sealing resin 4 of the third terminal 232 is covered with the exterior plating layer 51 as in the first terminal 212 shown in FIG. 7A. The third terminal 232 is electrically connected to the third electrode pad 111 b which is a part of the element main surface 111 via the second pad 221 and the second bonding wire 62. Therefore, when the semiconductor element 11 is a power MOSFET, the third terminal 232 is a source terminal of the semiconductor device A10, and when the semiconductor element 11 is an IGBT, the third terminal 232 is an emitter terminal.

  As shown in FIGS. 1 to 3, the first terminal 212, the second lead 22, and the third lead 23 are all arranged along the third direction Y. In the third direction Y, the first terminal 212 is It is sandwiched between the two leads 22 and the third lead 23. Further, as shown in FIGS. 1 and 8, the positions of the first terminal 212, the second lead 22, and the third lead 23 in the first direction Z are all equal.

  As shown in FIGS. 2 and 3, the heat radiating member 3 is a member provided on the first pad 211 and functions to radiate heat generated from the semiconductor element 11 to the outside of the semiconductor device A10. The heat radiating member 3 has a gate shape surrounding the semiconductor element 11, and a part thereof is exposed from the sealing resin 4. In the present embodiment, the heat dissipation member 3 includes a pair of side wall portions 31 and a top plate portion 32. The heat dissipation member 3 according to the present embodiment is made of the same metal as the first lead 21, the second lead 22, and the third lead 23, that is, an alloy containing Cu as a main component.

  As shown in FIGS. 3 and 5, the pair of side wall portions 31 are portions that stand from the pad main surface 211 a of the first pad 211 and are spaced apart in the third direction Y. Side wall through holes 311 are formed in the pair of side wall portions 31 so as to penetrate both in the third direction Y. The shape of the side wall through hole 311 according to the present embodiment in the third direction Y view (side view) is a rectangular shape. In addition, a plurality of side wall through holes 311 according to the present embodiment are formed, and these are arranged along the second direction X. The pair of side wall portions 31 are disposed on the pad main surface 211a by welding and covered with the sealing resin 4 throughout. Further, the pair of side wall portions 31 are both disposed along the second direction X.

  As shown in FIGS. 2, 5, and 6, the top plate portion 32 is a portion in which both ends in the third direction Y are fixed to the pair of side wall portions 31. In the present embodiment, part of both ends of the top plate portion 32 in the third direction Y are fixed to the pair of side wall portions 31. In plan view, the top plate portion 32 overlaps the entire semiconductor element 11. The top plate portion 32 has a heat radiation surface 321 and an inner surface 322. The heat radiating surface 321 is a surface facing the same direction as the pad main surface 211a, as shown in FIGS. The heat radiating surface 321 according to the present embodiment is exposed from the sealing resin 4 over the entire surface in the same manner as the pad back surface 211 b and is covered with the exterior plating layer 51. Note that the sealing resin 4 may thinly cover the entire surface of the heat radiation surface 321 as in a semiconductor device A11 that is a modification of the semiconductor device A10 illustrated in FIG. 7B. The inner surface 322 is a lower surface of the top plate portion 32 shown in FIGS. 7A, 8, and 9, and is a surface facing the pad main surface 211 a and the semiconductor element 11. Therefore, the heat radiating surface 321 and the inner surface 322 face in opposite directions in the first direction Z. Both the heat radiating surface 321 and the inner surface 322 are flat. 7A and 9, the inner surface 322 is in contact with the sealing resin 4 over the entire surface.

  As shown in FIGS. 2, 5, and 6, a plurality of engagement claws 323 are formed at both ends in the third direction Y of the top plate portion 32. In the present embodiment, the plurality of engaging claws 323 are formed on each of both ends of the top plate portion 32 in the third direction Y. The top plate portion 32 is fixed to the pair of side wall portions 31 by the plurality of engaging claws 323 engaging with the upper ends of the side wall portions 31 shown in FIG. The side wall 31 and the plurality of engaging claws 323 may be further welded together. The plurality of engaging claws 323 are all covered with the sealing resin 4. Further, the top plate portion 32 is formed with a pair of recesses 324 that are recessed from the both ends in the third direction Y of the top plate portion 32 where the plurality of engaging claws 323 are not formed, respectively. ing. Furthermore, a top plate through-hole 325 extending from the heat radiation surface 321 to the inner surface 322 is formed in the top plate portion 32 so as to be sandwiched between a pair of recesses 324. In the present embodiment, the center and diameter of the top plate through hole 325 are the same as those of the pad through hole 211c.

  The sealing resin 4 includes a part of each of the first lead 21, the second lead 22, and the third lead 23, the semiconductor element 11, the pair of side wall portions 31, the plurality of engaging claws 323 of the top plate portion 32, It is a member that covers the first bonding wire 61 and the second bonding wire 62. The sealing resin 4 is a thermosetting synthetic resin having electrical insulation. The synthetic resin according to this embodiment is a black epoxy resin. The sealing resin 4 is formed, for example, by transfer molding using a mold. The sealing resin 4 has a resin main surface 41, a resin back surface 42, a pair of resin first side surfaces 43, and a pair of resin second side surfaces 44.

  The resin main surface 41 is an upper surface of the sealing resin 4 shown in FIGS. 7A and 9. The resin back surface 42 is the bottom surface of the sealing resin 4 shown in FIGS. 7A and 9. The resin main surface 41 and the resin back surface 42 face opposite sides in the first direction Z. In the present embodiment, the heat radiation surface 321 is exposed from the resin main surface 41, and the pad back surface 211 b is exposed from the resin back surface 42.

  The pair of first resin side surfaces 43 are surfaces that are spaced apart in the second direction X as shown in FIGS. 1, 4, and 7 </ b> A. The pair of resin first side surfaces 43 face opposite sides in the second direction X. The upper end of the resin first side surface 43 shown in FIG. 7A is connected to the resin main surface 41, and the lower end of the resin first side surface 43 shown in FIG. 7A is connected to the resin back surface 42. In the present embodiment, a part of each of the first terminal 212, the second lead 22 (second terminal 222), and the third lead 23 (third terminal 232) is exposed from one resin first side surface 43. .

  The pair of resin second side surfaces 44 are surfaces formed in the third direction Y so as to be separated from each other as shown in FIGS. 1, 4, and 9. The pair of resin second side surfaces 44 face opposite sides in the third direction Y. The upper end of the resin second side surface 44 shown in FIG. 1 is connected to the resin main surface 41, and the lower end of the resin second side surface 44 shown in FIG. 1 is connected to the resin back surface 42.

  In the sealing resin 4, a pair of recesses 45 that are recessed from the upper portions of the pair of second resin side surfaces 44 shown in FIG. 1 into the sealing resin 4 are formed. As shown in FIGS. 1, 4, 7A, and 9, the main body insertion hole 46 extending from the resin main surface 41 to the resin back surface 42 is formed in the sealing resin 4 in the first direction Z. . In the present embodiment, the center of the main body insertion hole 46 is the same as the centers of the pad through hole 211 c and the top plate through hole 325. Further, the diameter of the main body insertion hole 46 is smaller than the diameters of the pad through hole 211 c and the top plate through hole 325. Accordingly, the hole walls of the main body insertion hole 46 are all formed by the sealing resin 4.

  As shown in FIGS. 7A, 8 and 9, the exterior plating layer 51 includes a pad back surface 211b exposed from the sealing resin 4, a heat radiation surface 321, a first terminal 212, a second lead 22 (second terminal 222), and It is formed so as to cover the third lead 23 (third terminal 232). The exterior plating layer 51 according to the present embodiment is made of an alloy containing Sn as a main component. Specifically, the alloy is a lead-free solder such as a Sn—Sb alloy or a Sn—Ag alloy. The exterior plating layer 51 is formed by electrolytic plating.

  The interior plating layer 52 is a part of the pad main surface 211 a shown in FIG. 3, a top surface of the second pad 221 shown in FIG. 8 that is a part of the second lead 22, and a part of the third lead 23. 8 is formed on the upper surface of the third pad 231 shown in FIG. The interior plating layer 52 according to the present embodiment is made of Ag. The interior plating layer 52 is formed by electrolytic plating.

  As shown in FIG. 3, the first bonding wire 61 is a conductive member that connects the second pad 221 of the second lead 22 and the second electrode pad 111 a of the element main surface 111. Further, as shown in FIG. 3, the second bonding wire 62 connects the third pad 231 of the third lead 23 and the third electrode pad 111 b of the element main surface 111 and is a conductive member. Both the first bonding wire 61 and the second bonding wire 62 are made of the same metal, and the metal according to the present embodiment is Al. In the present embodiment, the cross-sectional area of the second bonding wire 62 is larger than the cross-sectional area of the first bonding wire 61.

  Next, functions and effects of the semiconductor device A10 will be described.

  The semiconductor device A10 according to the present embodiment includes a pair of side wall portions 31 that are erected from the pad main surface 211a of the first pad 211 on which the semiconductor element 11 is mounted and are spaced apart from each other in the third direction Y. A heat radiating member 3 including a top plate portion 32 having both ends in the three directions Y fixed to the pair of side wall portions 31 and having a heat radiating surface 321 facing the same direction as the pad main surface 211a is provided. By adopting such a configuration, heat generated from the semiconductor element 11 when the semiconductor device A10 is used is not only from the pad back surface 211b of the first pad 211 but also from the heat radiating surface 321 through the pair of side wall portions 31 to the outside. Heat is dissipated. The heat dissipating surface 321 has a larger area than the conventional semiconductor device and is in a state where the heat dissipating performance is exhibited over the entire surface. Further, since both ends of the top plate portion 32 in the third direction Y are fixed to the pair of side wall portions 31, the top plate portion 32 is prevented from falling off from the sealing resin 4, and the reliability of the semiconductor device A10 is ensured. Is done. Therefore, the semiconductor device A10 can improve the heat dissipation performance while ensuring the reliability.

  A plurality of engaging claws 323 are formed on each part of both ends in the third direction Y of the top plate portion 32. The top plate portion 32 is fixed to the pair of side wall portions 31 by the plurality of engaging claws 323 engaging with the respective tips of the pair of side wall portions 31. By taking such a configuration, the top plate portion 32 can be fixed to the pair of side wall portions 31 at an accurate position. Since the plurality of engaging claws 323 are all covered with the sealing resin 4, the plurality of engaging claws 323 are sandwiched between the side wall portion 31 and the sealing resin 4. By adopting such a configuration, the top plate portion 32 is firmly fixed by the pair of side wall portions 31, and thus the reliability of the semiconductor device A10 is further improved.

  Side wall through holes 311 are formed in the pair of side wall portions 31 so as to penetrate both in the third direction Y. By adopting such a configuration, it is possible to suppress the generation of voids due to poor filling in the sealing resin 4 in the process of forming the sealing resin 4.

  In the present embodiment, the pad back surface 211b and the heat radiating surface 321 are both exposed from the sealing resin 4, and the main body insertion hole extending from the resin main surface 41 to the resin back surface 42 in the sealing resin 4 in the first direction Z. 46 is formed. By adopting such a configuration, a fastening member such as a screw is inserted into the main body insertion hole 46, and a member having a heat radiation function such as a heat spreader is attached to the pad back surface 211b and the heat radiation surface 321 via an electrical insulating sheet. Therefore, it is possible to further improve the heat dissipation performance.

  In the first direction Z, the top plate portion 32 overlaps the entire semiconductor element 11. Taking such a configuration is suitable for radiating heat generated from the semiconductor element 11 to the outside from the top plate portion 32 evenly when the semiconductor device A10 is used.

  By forming the exterior plating layer 51, each of the first terminal 212, the second lead 22, and the third lead 23 exposed from the sealing resin 4 when the semiconductor device A10 is surface-mounted on the circuit board by solder bonding. It is possible to prevent erosion of the part due to solder joining while improving the solder attached to the part.

  By forming the interior plating layer 52, the second bonding wire to the third pad 231 at the time of die bonding of the semiconductor element 11 to the pad main surface 211a, the wire bonding of the first bonding wire 61 to the second pad 221, and the like. The first pad 211, the second pad 221, and the third pad 231 can be protected from each thermal shock during bonding to 62.

[Second Embodiment]
A semiconductor device A20 according to the second embodiment of the present invention will be described with reference to FIGS. In these drawings, the same or similar elements as those of the semiconductor device A10 described above are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 10 is a perspective view of the semiconductor device A20. 11 and 12 are plan views of the semiconductor device A20. FIG. 13 is a right side view of the semiconductor device A20. FIG. 14 is a perspective view of the heat dissipation member 3, and the side wall portion 31 is omitted. 15 is a cross-sectional view taken along line XV-XV in FIG. Here, for convenience of understanding, FIGS. 11 and 13 are views in which the sealing resin 4 is omitted. FIG. 12 is a view in which the top plate portion 32 of the heat radiating member 3 is further omitted from FIG. 11.

  In the present embodiment, the configurations of the heat dissipation member 3 and the sealing resin 4 are different from the configuration of the semiconductor device A10 described above. As shown in FIGS. 11 to 15, the heat radiating member 3 according to the present embodiment has a configuration in which both ends of the top plate portion 32 in the third direction Y are fixed to a pair of side wall portions 31. Therefore, the length of the side wall portion 31 according to the present embodiment is set to be longer than the length of the side wall portion 31 of the semiconductor device A10, and the pad through hole 211c formed in the first pad 211 is formed in the pair of side wall portions 31. It is sandwiched. Further, the plurality of engaging claws 323 according to the present embodiment are formed on all of both ends in the third direction Y of the top plate portion 32. The plurality of engaging claws 323 are all covered with the sealing resin 4 as in the semiconductor device A10.

  As shown in FIGS. 11 and 14, unlike the semiconductor device A <b> 10, the pair of recesses 324 are not formed in the top plate portion 32 according to the present embodiment. Further, as shown in FIG. 10, unlike the semiconductor device A10, the pair of recesses 45 are not formed in the sealing resin 4 according to the present embodiment.

  Next, functions and effects of the semiconductor device A20 will be described.

  Similar to the semiconductor device A10, the semiconductor device A20 according to the present embodiment includes the heat dissipating member 3 including a pair of side wall portions 31 and a top plate portion 32 having both ends in the third direction Y fixed to the pair of side wall portions 31. It is configured to be equipped. Therefore, the semiconductor device A20 can improve the heat dissipation performance while ensuring the reliability.

  In the heat dissipation member 3 according to the present embodiment, since both ends of the top plate portion 32 in the third direction Y are all fixed to the pair of side wall portions 31, the length of the side wall portion 31 is the side wall portion of the semiconductor device A10. It is set longer than the length of 31. By adopting such a configuration, the amount of heat transferred from the semiconductor element 11 to the top plate portion 32 when the semiconductor device A20 is used is larger than that of the semiconductor device A10. Therefore, the heat dissipation performance of the semiconductor device A20 is further improved as compared with the semiconductor device A10.

  The present invention is not limited to the embodiment described above. The specific configuration of each part of the present invention can be changed in various ways.

A10, A11, A20: Semiconductor device 11: Semiconductor element (power MOSFET / IGBT)
111: Element main surface 111a: Second electrode pad 111b: Third electrode pad 112: Element back surface 112a: First electrode pad 12: Bonding layer 21: First lead 211: First pad 211a: Pad main surface 211b: Pad back surface 211c: pad through hole 212: first terminal 213: intermediate connecting portion 22: second lead 221: second pad 222: second terminal 23: third lead 231: third pad 232: third terminal 3: heat dissipation member 31 : Side wall part 311: Side wall through hole 32: Top plate part 321: Heat radiation surface 322: Inner surface 323: Engaging claw 324: Recess 325: Top plate through hole 4: Sealing resin 41: Resin main surface 42: Resin back surface 43: Resin first side surface 44: Resin second side surface 45: Recess 46: Body insertion hole 51: Exterior plating layer 52: Interior plating layer 61: First bonding wire 62 Second bonding wires Z: the first direction X: the second direction Y: the third direction

Claims (26)

A first pad having a pad main surface and a pad back surface facing opposite to each other in a first direction which is a thickness direction; a first terminal extending along a second direction perpendicular to the first direction; A first lead including
A semiconductor element having an element main surface and an element back surface facing opposite to each other in the first direction, and the element back surface facing the pad main surface;
A pair of side wall portions standing from the pad main surface and spaced apart in a third direction perpendicular to either the first direction or the second direction, and both ends in the third direction are A top plate portion fixed to a pair of side wall portions and having a heat radiating surface facing the same direction as the pad main surface, and a heat radiating member,
A semiconductor device comprising: a sealing resin that covers the semiconductor element.   The semiconductor device according to claim 1, wherein both the pad back surface and the heat dissipation surface are exposed from the sealing resin.   3. The semiconductor device according to claim 1, wherein a part of each of both ends of the top plate portion in the third direction is fixed to the pair of side wall portions.   3. The semiconductor device according to claim 1, wherein both ends of the top plate portion in the third direction are fixed to the pair of side wall portions.   4. The semiconductor device according to claim 3, wherein the top plate portion is formed with a plurality of engaging claws that engage with the side wall portion at a part of each of both ends in the third direction.   The semiconductor device according to claim 4, wherein a plurality of engaging claws that engage with the side wall portion are formed on each of both ends in the third direction in the top plate portion.   The semiconductor device according to claim 5, wherein each of the plurality of engaging claws is covered with the sealing resin.   The semiconductor device according to claim 1, wherein side wall through holes penetrating in the third direction are formed in the pair of side wall portions.   The semiconductor device according to claim 1, wherein both of the pair of side wall portions are disposed along the second direction.   The semiconductor device according to claim 1, wherein the top plate portion overlaps all of the semiconductor elements in a plan view as the first direction view.   The semiconductor device according to claim 1, wherein both the first lead and the heat dissipation member are made of the same metal.   The semiconductor device according to claim 1, wherein the sealing resin is a thermosetting synthetic resin having electrical insulation.   The semiconductor device according to claim 12, wherein the sealing resin is an epoxy resin.   The sealing resin has a resin main surface and a resin back surface facing opposite sides in the first direction, and the sealing resin in the first direction includes a main body extending from the resin main surface to the resin back surface. The semiconductor device according to claim 12 or 13, wherein an insertion hole is formed.   The semiconductor device according to claim 14, wherein a pad through hole is formed in the first pad and a top plate through hole is formed in the top plate portion in the first direction.   The first lead includes an intermediate connecting portion connected to the first pad and the first terminal, and the intermediate connecting portion is inclined with respect to both the first pad and the first terminal. Item 16. A semiconductor device according to any one of Items 1 to 15.   The second lead and the third lead are disposed apart from the first lead and extend along the second direction, and both the second lead and the third lead are electrically connected to the element main surface. The semiconductor device according to claim 16, wherein the positions of the first terminal, the second lead, and the third lead in the first direction are all equal.   The first terminal, the second lead, and the third lead are all arranged along the third direction, and in the third direction, the first terminal is connected between the second lead and the third lead. The semiconductor device according to claim 17, which is located in between.   The first terminal, the second lead, and the third lead all have a portion exposed from the sealing resin, and include an exterior plating layer formed to cover the portion. The semiconductor device described.   The semiconductor device according to claim 19, wherein the exterior plating layer is made of an alloy containing Sn as a main component.   A first bonding wire that connects the second lead and the element main surface; and a second bonding wire that connects the third lead and the element main surface; and the first bonding wire and the second bonding wire. 21. The semiconductor device according to claim 17, wherein both bonding wires are made of the same metal.   The semiconductor device according to claim 21, wherein both the first bonding wire and the second bonding wire are made of Al.   23. The semiconductor device according to claim 21, wherein a cross-sectional area of the second bonding wire is larger than a cross-sectional area of the first bonding wire.   24. The semiconductor device according to claim 21, further comprising an interior plating layer formed on each part of the pad main surface, the second lead, and the third lead.   The semiconductor device according to claim 24, wherein the interior plating layer is made of Ag.   The semiconductor device according to claim 17, wherein the semiconductor element is a power MOSFET or an IGBT.

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