Semiconductor equipment

Abstract

This semiconductor device comprises a semiconductor element, a first lead that conducts to the semiconductor element, and a connection member that is connected to the semiconductor element and the first lead. The connection member includes a core section including a first material, and a surface section. The surface section includes a first metal, and covers the core section. The first material includes an alloy resulting from adding at least a third metal to a second metal, and has a higher corrosion resistance than the second metal. The third metal has the highest composition ratio among the added metal or metals, and has a higher atomic number than the second metal.

Description

Technical Field

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

Background Art

[0002] Semiconductor devices including semiconductor elements have been proposed in various configurations. As an example of a semiconductor device, there is a semiconductor device in which a semiconductor element mounted on a die pad is connected to a lead by a wire, and these are covered with a sealing resin. For example, Patent Document 1 discloses such a semiconductor device. The semiconductor device includes a semiconductor element, first to fifth leads, bonding wires, and a sealing resin. The semiconductor element is mounted on the main surface of the mounting portion of the first lead. Each electrode of the semiconductor element and the second to fifth leads are connected by bonding wires, respectively. The sealing resin covers a part of each of the first to fifth leads, the semiconductor element, and the bonding wires. The sealing resin is made of a black epoxy resin.

[0003] Generally, the sealing resin contains a sulfur component in order to improve the adhesiveness with the lead. Also, Cu is used as a constituent material of the bonding wire. In this case, the bonding wire is easily corroded by the sulfur component and halogen contained in the sealing resin. Also, the surface of the bonding wire is easily oxidized, and the oxide film becomes a factor inhibiting the bonding with the lead. As a method for preventing these, a method of using a bonding wire in which a core material made of Cu is coated with Pd or the like can be considered. In the case of the bonding wire, the coating film protects the core material made of Cu from the sulfur component and halogen in the sealing resin, and also prevents the oxidation of the core material.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005] However, during the formation of bonding wires, a portion of the coating may peel off, exposing the core material. In such cases, the Pd in ​​the coating acts as a catalyst for sulfur corrosion, accelerating the corrosion process. [Overview of the project] [Problems that the invention aims to solve]

[0006] This disclosure was conceived under the circumstances described above, and one of its objectives is to provide a semiconductor device that can suppress corrosion of connecting members by sulfur. [Means for solving the problem]

[0007] A semiconductor device provided by this disclosure comprises a semiconductor element, a first lead that conducts to the semiconductor element, and a connecting member connected to the semiconductor element and the first lead. The connecting member includes a core material portion containing a first material and a surface layer portion containing a first metal and covering the core material portion. The first material includes an alloy in which at least a third metal is added to a second metal, and has higher corrosion resistance than the second metal. The third metal has the highest composition ratio among the added metals and has a larger atomic number than the second metal. [Effects of the Invention]

[0008] The semiconductor device described herein can suppress corrosion of connecting members caused by sulfur.

[0009] Other features and advantages of this disclosure will become more apparent from the detailed description below, with reference to the accompanying drawings. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a plan view showing a semiconductor device according to a first embodiment of the present disclosure. [Figure 2] Figure 2 is a plan view of the semiconductor device shown in Figure 1, and is a view seen through the resin component. [Figure 3]FIG. 3 is a front view of the semiconductor device shown in FIG. 1. [Figure 4] FIG. 4 is a front view of the semiconductor device shown in FIG. 1 and is a view through the resin member. [Figure 5] FIG. 5 is a left side view of the semiconductor device shown in FIG. 1. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 2 [Figure 7] FIG. 7 is a partially enlarged view of FIG. 6. [Figure 8] FIG. 8 is a partially enlarged view of FIG. 6. [Figure 9] FIG. 9 is a schematic cross-sectional view showing an electronic component according to the first embodiment. [Figure 10] FIG. 10 is a circuit diagram showing an example of the circuit configuration of the semiconductor device shown in FIG. 1. [Figure 11] FIG. 11 is a plan view showing a semiconductor device according to the second embodiment of the present disclosure and is a view through the resin member. [Figure 12] FIG. 12 is a cross-sectional view taken along line XII-XII of FIG. 11. [Figure 13] FIG. 13 is a partially enlarged view of FIG. 12. [Figure 14] FIG. 14 is a partially enlarged view of FIG. 12. [Figure 15] FIG. 15 is a plan view showing a semiconductor device according to the third embodiment of the present disclosure and is a view through the resin member. [Figure 16] FIG. 16 is a plan view showing a semiconductor device according to the fourth embodiment of the present disclosure and is a view through the resin member. [Figure 17] FIG. 17 is a plan view showing a semiconductor device according to the fifth embodiment of the present disclosure and is a view through the resin member.

MODE FOR CARRYING OUT THE INVENTION

[0011] Hereinafter, preferred embodiments of the present disclosure will be specifically described with reference to the accompanying drawings.

[0012] Based on FIGS. 1 to 9, the semiconductor device A10 according to the first embodiment of the present disclosure will be described. The semiconductor device A10 is surface-mounted on a circuit board of various electronic devices or the like. The semiconductor device A10 is, for example, a package called SOP (Small Outline Package). Note that the package form of the semiconductor device A10 is not limited. The semiconductor device A10 is, for example, a power IC. Note that the use and function of the semiconductor device A10 are not limited. The shape of the semiconductor device A10 in the thickness direction view is rectangular (or substantially rectangular). Each dimension of the semiconductor device A10 is not particularly limited. The semiconductor device A10 includes an electronic component 1, a conductive support member 4, a connection member 5, and a resin member 6.

[0013] FIG. 1 is a plan view showing the semiconductor device A10. FIG. 2 is a plan view showing the semiconductor device A10. In FIG. 2, for convenience of understanding, the outer shape of the resin member 6 is shown by an imaginary line (two-dot chain line) through the resin member 6. FIG. 3 is a front view showing the semiconductor device A10. FIG. 4 is a front view showing the semiconductor device A10. In FIG. 4, for convenience of understanding, the outer shape of the resin member 6 is shown by an imaginary line (two-dot chain line) through the resin member 6. Note that in FIG. 4, a plurality of connection members 5 are omitted. FIG. 5 is a left side view showing the semiconductor device A10. FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. 2. FIG. 7 is a partial enlarged view of FIG. 6. FIG. 8 is a partial enlarged view of FIG. 6. FIG. 9 is a schematic cross-sectional view showing the electronic component 1 (first semiconductor elements 2A and 2B described later).

[0014] For convenience of explanation, the thickness direction of the semiconductor device A10 is defined as the z direction, the direction along one side of the semiconductor device A10 orthogonal to the z direction (the left-right direction in FIGS. 1 to 2) is defined as the x direction, and the direction orthogonal to the z direction and the x direction (the up-down direction in FIGS. 1 to 2) is defined as the y direction. Note that in the following description, one side in the z direction (up in the front view shown in FIG. 3) may be referred to as the upper side, and the other side in the z direction (down in the front view shown in FIG. 3) may be referred to as the lower side, but the posture of the semiconductor device A10 is not limited.

[0015] Electronic component 1 serves as the functional core of semiconductor device A10. Electronic component 1 is bonded to a conductive support member 4 (die pad 46, described later) via a bonding material (not shown). Electronic component 1 includes two first semiconductor elements 2A and 2B and a second semiconductor element 3.

[0016] Each of the first semiconductor elements 2A and 2B is, for example, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor). However, each of the first semiconductor elements 2A and 2B is not limited to MOSFETs, and may be other transistors such as bipolar transistors or IGBTs (Insulated Gate Bipolar Transistors), or diodes, etc.

[0017] As shown in Figures 2 and 9, the first semiconductor device 2A includes a semiconductor substrate 21A, a wiring layer 23A, a protective film 24A, and a plurality of electrode pads 251A, 252A (not shown in Figure 9).

[0018] The semiconductor substrate 21A is made of a semiconductor material such as Si (silicon), SiC (silicon carbide), GaN (gallium nitride), and Ga2O3 (gallium oxide). As shown in Figure 9, the semiconductor substrate 21A has a main substrate surface 211A and a back substrate surface 212A. The main substrate surface 211A and the back substrate surface 212A are spaced apart in the z direction. The main substrate surface 211A faces upward. The back substrate surface 212A faces downward.

[0019] As shown in Figure 9, the semiconductor substrate 21A has an active region 220A formed on the main surface 211A side of the substrate. The active region 220A includes semiconductor regions 221A, 222A, and 223A. Semiconductor region 221A is, for example, the drain region. Semiconductor region 222A is, for example, the source region. Semiconductor region 223A is, for example, the gate region.

[0020] As shown in Figure 9, the wiring layer 23A is formed on the main substrate surface 211A of the semiconductor substrate 21A. The wiring layer 23A is formed by alternately stacking, for example, a plurality of conductive layers 231 and a plurality of insulating layers 232. Each conductive layer 231 is electrically connected through vias 233 formed to penetrate each insulating layer 232. Note that the wiring layer 23A shown in Figure 9 is just an example and is not limited thereto.

[0021] As shown in Figure 9, the protective film 24A is formed on the wiring layer 23A and covers the upper surface of the wiring layer 23A. As shown in Figure 2, the protective film 24A has an opening in part, and several electrode pads 251A and 252A are exposed from this opening. The protective film 24A is, for example, a Si3N4 layer or an SiO2 layer formed by plasma CVD, or a polyimide resin layer formed by coating. The protective film 24A may also be formed by a combination of these.

[0022] Each of the electrode pads 251A and 252A is a terminal of the first semiconductor element 2A. Each of the electrode pads 251A is conductive to the semiconductor region 221A via the wiring layer 23A. Therefore, each electrode pad 251A is the drain terminal of the first semiconductor element 2A. Each electrode pad 251A is connected to one of the multiple connecting members 5 (wire 51 described later). Electrode pad 252A is conductive to the semiconductor region 222A via the wiring layer 23A. Therefore, electrode pad 252A is the source terminal of the first semiconductor element 2A. Electrode pad 252A is connected to one of the multiple connecting members 5 (wire 53 described later).

[0023] As shown in Figures 2 and 9, the first semiconductor device 2B includes a semiconductor substrate 21B, a wiring layer 23B, a protective film 24B, and a plurality of electrode pads 251B (not shown in Figure 9), 252B.

[0024] The semiconductor substrate 21B is made of a semiconductor material such as Si (silicon), SiC (silicon carbide), GaN (gallium nitride), and Ga2O3 (gallium oxide). As shown in Figure 9, the semiconductor substrate 21B has a main substrate surface 211B and a back substrate surface 212B. The main substrate surface 211B and the back substrate surface 212B are spaced apart in the z direction. The main substrate surface 211B faces upward. The back substrate surface 212B faces downward.

[0025] As shown in Figure 9, the semiconductor substrate 21B has an active region 220B formed on the main surface 211B side. The active region 220B includes semiconductor regions 221B, 222B, and 223B. Semiconductor region 221B is, for example, the drain region. Semiconductor region 222B is, for example, the source region. Semiconductor region 223B is, for example, the gate region.

[0026] As shown in Figure 9, the wiring layer 23B is formed on the main substrate surface 211B of the semiconductor substrate 21B. The wiring layer 23B is configured similarly to the wiring layer 23A. That is, the wiring layer 23B is made up of, for example, multiple conductive layers 231 and multiple insulating layers 232 stacked alternately. Each conductive layer 231 is electrically connected through vias 233 formed to penetrate each insulating layer 232. Note that the wiring layer 23B shown in Figure 9 is just an example and is not limited thereto.

[0027] As shown in Figure 9, the protective film 24B is formed on the wiring layer 23B and covers the upper surface of the wiring layer 23B. As shown in Figure 2, the protective film 24B has an opening in part, and several electrode pads 251B, 252B are exposed from this opening. The protective film 24B is, for example, a Si3N4 layer or SiO2 layer formed by plasma CVD, or a polyimide resin layer formed by coating. The protective film 24B may also be formed by a combination of these. In addition, the protective film 24A and the protective film 24B may be formed integrally.

[0028] Each of the electrode pads 251B and 252B is a terminal of the first semiconductor element 2B. Electrode pad 251B is conductive to the semiconductor region 221B via the wiring layer 23B. Therefore, each electrode pad 251B is the drain terminal of the first semiconductor element 2B. One of the multiple connecting members 5 (wire 54 described later) is attached to electrode pad 251B. Each of the multiple electrode pads 252B is conductive to the semiconductor region 222B via the wiring layer 23B. Therefore, electrode pad 252B is the source terminal of the first semiconductor element 2B. One of the multiple connecting members 5 (wire 52 described later) is attached to electrode pad 252B.

[0029] The second semiconductor element 3 is, for example, a driver IC. The second semiconductor element 3 controls the driving of multiple first semiconductor elements 2A and 2B. The second semiconductor element 3 is conductive to each of the first semiconductor elements 2A and 2B. For example, the second semiconductor element 3 is conductive to the semiconductor region 223A (gate region) of the first semiconductor element 2A, and controls the first semiconductor element 2A by outputting a control signal to the semiconductor region 223A (gate region). Similarly, the second semiconductor element 3 is conductive to the semiconductor region 223B (gate region) of the first semiconductor element 2B, and controls the first semiconductor element 2B by outputting a control signal to the semiconductor region 223B (gate region).

[0030] The second semiconductor element 3 has an upward-facing main surface 301. The main surface 301 is covered with a protective film 32 similar to the protective films 24A and 24B. The protective film 32 has an opening in part, and the electrode pads 31 are exposed from the opening. In this embodiment, the second semiconductor element 3 has a plurality of electrode pads 31 formed thereon. Each electrode pad 31 is joined to one of a plurality of connecting members 5 (a plurality of wires 55 described later).

[0031] The conductive support member 4 forms an electrical path between the electronic component 1 and the circuit board when the semiconductor device A10 is mounted on the circuit board of an electronic device or the like. The conductive support member 4 supports the electronic component 1. The constituent material of the conductive support member 4 is, for example, Cu (copper) or a Cu alloy. However, the constituent material of the conductive support member 4 is not limited. The conductive support member 4 consists of a lead frame formed by stamping or etching a metal plate. The thickness of the conductive support member 4 is, for example, about 0.2 mm. As shown in Figure 2, the conductive support member 4 includes leads 41, leads 42, leads 43, leads 44, a plurality of leads 45, and a die pad 46. The leads 41, leads 42, leads 43, leads 44, the plurality of leads 45, and the die pad 46 are spaced apart from each other.

[0032] As shown in Figure 2, the lead 41 includes two terminal portions 411 and a pad portion 412. In a plan view, the pad portion 412 is a long rectangle with a notch in the corner in the direction in which the lead 42 is located (the lower right corner in Figure 2). This notch is provided so as not to come into contact with the lead 42. Note that if it does not come into contact with the lead 42, the notch does not need to be provided. The wire 51 is joined to the pad portion 412. As shown in Figure 8, the pad portion 412 has a metal layer 49. The metal layer 49 is located on the upper side of the pad portion 412 (the side to which the wire 51 is joined). The metal layer 49 is in contact with the resin member 6. The metal layer 49 contains, for example, Ag and is formed, for example, by plating.

[0033] Each terminal portion 411 is partially exposed from the resin member 6. Each terminal portion 411 connects to the pad portion 412 in the portion covered by the resin member 6. Each terminal portion 411 is bent in the z direction in the portion exposed from the resin member 6. The surface of each terminal portion 411 may be plated with, for example, Sn.

[0034] As shown in Figure 2, the lead 42 includes a terminal portion 421 and a pad portion 422. In a plan view, the pad portion 422 is an elongated rectangle that is long in the x-direction. In a plan view, the pad portion 422 has a larger dimension in the x-direction than the terminal portion 421. The pad portion 422 is covered by a resin member 6. The pad portion 422 is not connected to any of the multiple connecting members 5. The pad portion 422 is electrically insulated from the electronic component 1. Part of the terminal portion 421 is exposed from the resin member 6. The terminal portion 421 connects to the pad portion 422 in the portion covered by the resin member 6. The terminal portion 421 bends in the z-direction in the portion exposed from the resin member 6. The surface of the terminal portion 421 may be plated with, for example, Sn.

[0035] As shown in Figure 2, the lead 43 includes two terminal portions 431 and a pad portion 432. In a plan view, the pad portion 432 is a long rectangle with a notch in the corner in the direction in which the lead 42 is located (the lower left corner in Figure 2). This notch is provided so as not to come into contact with the lead 42. Note that if it does not come into contact with the lead 42, the notch does not need to be provided. The wire 52 is joined to the pad portion 432. The pad portion 432 has a metal layer 49. The metal layer 49 is located on the upper side of the pad portion 432 (the side to which the wire 52 is joined).

[0036] Each terminal portion 431 is partially exposed from the resin member 6. Each terminal portion 431 connects to the pad portion 432 in the portion covered by the resin member 6. Each terminal portion 431 is bent in the z direction in the portion exposed from the resin member 6. The surface of each terminal portion 431 may be plated with, for example, Sn.

[0037] As shown in Figure 2, the lead 44 includes three terminal portions 441 and a pad portion 442. In plan view, the pad portion 442 is an elongated rectangle that is long in the x-direction. Wires 53 and 54 are joined to the pad portion 442. The pad portion 442 has a metal layer 49. The metal layer 49 is located on the upper side of the pad portion 442 (the side to which wires 53 and 54 are joined).

[0038] Each terminal portion 441 is partially exposed from the resin member 6. Each terminal portion 441 connects to the pad portion 442 in the portion covered by the resin member 6. Each terminal portion 441 is bent in the z direction in the portion exposed from the resin member 6. The surface of each terminal portion 441 may be, for example, coated with Sn plating.

[0039] As shown in Figure 2, each of the multiple leads 45 includes a terminal portion 451 and a pad portion 452. In a plan view, the pad portion 452 has a constricted shape in the central part in the y direction. A wire 55, which will be described later, is joined to the pad portion 452. The pad portion 452 has a metal layer 49. The metal layer 49 is located on the upper side of the pad portion 452 (the side to which the wire 55 is joined).

[0040] A portion of the terminal portion 451 is exposed from the resin member 6. The portion of the terminal portion 451 covered by the resin member 6 connects to the pad portion 452. The portion of the terminal portion 451 exposed from the resin member 6 is bent in the z direction. The surface of the terminal portion 451 may be plated with, for example, Sn.

[0041] The die pad 46 is on which the electronic component 1 is mounted. In this embodiment, the die pad 46 is not electrically connected to the electronic component 1, but it may be configured to be electrically connected to the electronic component 1. As shown in Figure 2, the die pad 46 includes a pad portion 461 and a plurality of extension portions 462.

[0042] As shown in Figure 2, the pad portion 461 has an upward-facing die pad main surface 461a. An electronic component 1 is bonded to the center of the die pad main surface 461a.

[0043] Each of the multiple extensions 462 extends from the pad portion 461. The end face 462a of each extension 462 is exposed from the resin member 6. In this embodiment, the downward-facing back surface of the pad portion 461 is covered by the resin member 6, but this back surface may be exposed from the resin member 6.

[0044] In the conductive support member 4, as shown in Figure 2, leads 41, 42, 43, and some leads 45 are located on one side of the die pad 46 in the y-direction in a plan view. The terminal portions 411, 421, 431, and 451 of these leads overlap when viewed in the x-direction. Leads 44 and other leads 45 are located on the other side of the die pad 46 in the y-direction in a plan view. The terminal portions 441 and 451 of these leads overlap when viewed in the x-direction. As shown in Figure 2, the terminal portion 411 of lead 41, the terminal portion 421 of lead 42, and the terminal portion 431 of lead 43 are aligned in the x-direction in a plan view. The terminal portion 421 of lead 42 is sandwiched between the terminal portion 411 of lead 41 and the terminal portion 431 of lead 43 in a plan view.

[0045] Each of the multiple connecting members 5 provides electrical conductivity to the spaced-apart members. Each connecting member 5 provides electrical conductivity between the electronic component 1 (either the first semiconductor elements 2A, 2B or the second semiconductor element 3) and one of the conductive support members 4. The multiple connecting members 5 may include those used for electrical conductivity within the electronic component 1 (for example, electrical conductivity between the first semiconductor elements 2A, 2B and the second semiconductor element 3). Each connecting member 5 is a linear member with a circular cross-section. Each connecting member 5 is a so-called bonding wire. As shown in Figure 2, the multiple connecting members 5 include two wires 51, two wires 52, wire 53, wire 54, and multiple wires 55.

[0046] The two wires 51 each provide electrical connections between the electrode pads 251A of the first semiconductor element 2A and the pad portions 412 of the lead 41. As shown in Figure 2, one end of each wire 51 is joined to the electrode pad 251A and the other end is joined to the pad portion 412. The thickness (wire diameter) of the wires 51 is not limited, but is approximately φ15 μm to 50 μm. As shown in Figures 7 and 8, each wire 51 includes a core material portion 51A and a surface layer portion 51B that covers the core material portion 51A.

[0047] The core material 51A is an alloy in which Pt is added as an additive metal to Cu, which is the main component metal. This alloy is an alloy in which Pt is added to Cu to improve corrosion resistance to sulfur, and has higher corrosion resistance to sulfur than Cu. In addition, other metals may be added to this alloy. In this alloy, Pt has the highest composition ratio among the additive metals, and its content is not limited, but is approximately 50 ppm to 300 ppm by mass. In addition, the additive metal for improving corrosion resistance to sulfur is not limited to Pt, but may be other metals. In this case, it is desirable that the other metal has an atomic number greater than Cu. In addition, the main component metal of the core material 51A is not limited to Cu, but may be other metals.

[0048] The constituent material of the surface layer 51B includes, for example, Pd. The surface layer 51B is provided to protect the core material 51A from corrosion by sulfur and halogens, and to prevent oxidation of the core material 51A. Furthermore, as shown in Figure 8, the surface layer 51B is in contact with the metal layer 49 of the pad portion 412 of the lead 41. Since the Pd constituent material of the surface layer 51B has a larger bonding area with the metal layer 49 of the pad portion 412 than the constituent material of the core material 51A (an alloy of Cu with added Pt), the bonding strength with the lead 41 is higher. In other words, the surface layer 51B also has the function of increasing the bonding strength between the wire 51 and the lead 41. Note that the constituent material of the surface layer 51B is not limited to Pd, but any metal having the above functions is acceptable.

[0049] As shown in Figure 8, each wire 51 has a main portion 511 and an end portion 512. The end portion 512 is interposed between the main portion 511 and the pad portion 412 of the lead 41. The end portion 512 has a tapered portion 512A and a tip portion 512B. The tapered portion 512A is connected to the main portion 511, and its dimension d in the z direction decreases as it moves away from the main portion 511. The bonding interface 412A between the pad portion 412 and the wire 51 straddles the main portion 511 and the end portion 512 in a z-direction view (also called a plan view). The tip portion 512B is connected to the tapered portion 512A and protrudes from the tapered portion 512A in the z direction.

[0050] The wire 51 is formed by wire bonding using a wire material in which a coating made of the constituent material of the surface layer 51B is formed on the surface of a wire made of the constituent material of the core material 51A. The method for forming the coating on the surface of the wire material is not limited to plating, vapor deposition, or melting. The wire 51 is formed as follows, for example. First, the tip of the wire material is melted to form a ball, and this ball is pressed against the electrode pad 251A of the first semiconductor element 2A to perform first bonding. Since the surface layer 51B melts into the core material 51A when the ball is formed, as shown in Figure 7, the surface layer 51B does not cover the core material 51A in the portion of the wire 51 that is joined to the electrode pad 251A. Depending on the discharge conditions and the type of wire material, the surface layer 51B may cover part or all of the core material 51A. In this case, the thickness (dimension in the z direction) of the joined portion becomes smaller. Next, the wire material is fed out and pressed against the pad portion 412 of the lead 41 to perform second bonding. This second bonding forms the end portion 512.

[0051] The two wires 52 each connect the respective electrode pads 252B of the first semiconductor element 2B to the pad portion 432 of the lead 43. As shown in Figure 2, one end of each wire 52 is joined to the respective electrode pad 252B and the other end is joined to the pad portion 432. Wire 53 connects the electrode pad 252A of the first semiconductor element 2A to the pad portion 442 of the lead 44. As shown in Figure 2, one end of wire 53 is joined to the electrode pad 252A and the other end is joined to the pad portion 442. Wire 54 connects the electrode pad 251B of the first semiconductor element 2B to the pad portion 442 of the lead 44. As shown in Figure 2, one end of wire 54 is joined to the electrode pad 251B and the other end is joined to the pad portion 442. The configuration of wires 52 to 54 is the same as that of wire 51.

[0052] Each of the multiple wires 55 provides electrical conductivity between the electrode pads 31 of the second semiconductor element 3 and the pad portions 452 of each lead 45. As shown in Figure 2, one end of each wire 55 is joined to the electrode pad 31, and the other end is joined to the pad portion 452 of each lead 45. Each wire 55 does not include the portion corresponding to the surface layer 51B of the wire 51, and consists only of the portion corresponding to the core material portion 51A. The constituent material of the wire 55 is Cu without the addition of other metals. The constituent material of the wire 55 is not limited. For example, the constituent material of the wire 55 may be a metal (for example, Au) with a higher electrical resistivity than Cu, which is the main component metal of the core material portion 51A of the wire 51. The thickness (wire diameter) of the multiple wires 55 is not limited, but is for example, approximately φ15 μm to 50 μm.

[0053] Each wire 51-54 is connected to either the drain terminals (electrode pads 251A, 251B) or source terminals (electrode pads 252A, 252B) of the first semiconductor elements 2A and 2B. Relatively large currents flow through these drain and source terminals, and therefore relatively large currents also flow through each wire 51-54. On the other hand, each wire 55 is connected to each electrode pad 31 of the second semiconductor element 3. Relatively small currents flow through each electrode pad 31 compared to the currents flowing through the drain and source terminals. Therefore, the current flowing through each wire 55 is smaller than the currents flowing through each wire 51-54. Generally, the larger the current flowing through a wire, the more easily the wire is corroded by sulfur. Therefore, in this embodiment, only wires 51-54, which have relatively large currents flowing through them and are therefore more susceptible to corrosion by sulfur, have a configuration in which the surface layer 51B covers the core material 51A. Wire 55, which has a relatively small current flowing through it, does not have a surface layer.

[0054] The resin member 6 covers the electronic component 1, a part of the conductive support member 4, and a plurality of connecting members 5, respectively. The resin member 6 is made of an insulating resin material. The constituent material of the resin member 6 is, for example, black epoxy resin. However, the material and color of the resin member 6 are not limited. The resin member 6 contains a sulfur component to improve adhesion with the conductive support member 4. The sulfur content of the resin member 6 is 5 ppm to 30 ppm by mass. The above-mentioned sulfur content can be measured, for example, by the following method: The resin composition of the resin member 6 is heat-cured at 175°C for 4 hours, and the cured product is pulverized to obtain a pulverized material. Next, the gas generated when the pulverized material is heat-treated at 150°C for 8 hours is collected with hydrogen peroxide solution. Then, the sulfur content relative to the total amount of the resin composition is calculated from the amount of sulfate ions in the hydrogen peroxide solution.

[0055] The resin member 6 is, for example, rectangular in plan view. The resin member 6 is formed, for example, by transfer molding using a mold. The constituent materials, shape, and formation method of the resin member 6 are not limited. The resin member 6 has a resin main surface 61, a resin back surface 62, and a plurality of resin side surfaces 63.

[0056] The main resin surface 61 and the back resin surface 62 are spaced apart in the z direction. The main resin surface 61 is the upper surface of the resin member 6. The back resin surface 62 is the lower surface of the resin member 6. Multiple resin side surfaces 63 are connected to both the main resin surface 61 and the back resin surface 62 and are sandwiched between them in the z direction. The resin member 6 has a pair of resin side surfaces 631 spaced apart in the x direction and a pair of resin side surfaces 632 spaced apart in the y direction. Each lead 41-45 protrudes from one of the pair of resin side surfaces 632.

[0057] Figure 10 is a circuit diagram showing an example of the circuit configuration of semiconductor device A10. Figure 10 is a circuit diagram when semiconductor device A10 is configured as a DC / DC converter.

[0058] In Figure 10, sw1 and sw2 represent switching elements. Dr represents a control circuit that controls the switching operation of switching elements sw1 and sw2, as well as various protection function operations. R1 to R3 represent resistors, Vref represents an internal reference voltage circuit, ss represents a soft-start circuit, pgd represents a power-good circuit, and amp represents an error amplifier that takes the Vref output voltage and FB terminal voltage as inputs. For example, one of the switching elements sw1 and sw2 corresponds to the first semiconductor element 2A, and the other corresponds to the first semiconductor element 2B. Furthermore, the internal reference voltage circuit Vref, soft-start circuit ss, power-good circuit pgd, error amplifier amp, and control circuit Dr correspond to the second semiconductor element 3.

[0059] Terminal PVIN is the power input terminal of the DC / DC converter. Terminal PVIN is connected to the high-potential terminal of a DC power supply (not shown). Terminal PVIN corresponds to lead 41 of semiconductor device A10. Terminal PGND is the ground terminal of the DC / DC converter. Terminal PGND is connected to the low-potential terminal of a DC power supply (not shown). Terminal PGND corresponds to lead 43 of semiconductor device A10. Terminal SW is the output terminal of the DC / DC converter. Terminal SW corresponds to lead 44 of semiconductor device A10.

[0060] Terminal AVIN is the analog section power input terminal. Terminal AGND is the analog section ground terminal. Terminal EN is the device control terminal. Terminal FB is the output voltage feedback terminal. Terminal SS is the soft start time setting terminal. Terminal COMP is the ERRAMP output terminal. Terminal PGD is the power good terminal. Terminal CTL is a terminal for various function controls. Note that terminal MODE may be used instead of terminal CTL. Terminal MODE is a terminal for various mode switching. Terminals AVIN, AGND, EN, FB, SS, COMP, PGD, and CTL (or terminal MODE) each correspond to one of the multiple leads 45.

[0061] The connection between terminal PVIN and the drain electrode of switching element sw1 corresponds to wire 51, and the connection between terminal PGND and the source electrode of switching element sw2 corresponds to wire 52. The connection between terminal SW and the source electrode of switching element sw1 corresponds to wire 53, and the connection between terminal SW and the drain electrode of switching element sw2 corresponds to wire 54. The connections to the other terminals each correspond to wire 55. In semiconductor device A10, a large current flows from terminal PVIN to terminal PGND, so a large current flows through wires 51 to 54. On the other hand, the current flowing through the other terminals is small, so the current flowing through each wire 55 is small.

[0062] Next, we will explain the effects and benefits of semiconductor device A10.

[0063] According to this embodiment, the wire 51 includes a core material portion 51A and a surface layer portion 51B that covers the core material portion 51A. This protects the core material portion 51A from corrosion by sulfur and halogens, and also prevents oxidation of the core material portion 51A. The constituent material of the surface layer portion 51B includes Pd. Therefore, the surface layer portion 51B prevents corrosion and oxidation of the core material portion 51A and improves the bonding strength of the wire 51 to the lead 41. Furthermore, according to this embodiment, the constituent material of the core material portion 51A is an alloy in which an additive metal is added to Cu, the main component metal, to improve corrosion resistance to sulfur. Therefore, even if a part of the surface layer portion 51B peels off in the wire 51 and the core material portion 51A is exposed, corrosion of the core material portion 51A by sulfur can be suppressed. According to this embodiment, Pt is used as the additive metal. This appropriately suppresses corrosion of the core material portion 51A by sulfur. The same applies to wires 52-54.

[0064] Furthermore, according to this embodiment, wire 55 does not include a portion corresponding to the surface layer 51B of wire 51, and consists only of a portion corresponding to the core material portion 51A. Since only a relatively small current flows through wire 55, corrosion by sulfur is less likely to be accelerated. In semiconductor device A10, only wires 51-54, which carry a large current and are susceptible to accelerated corrosion by sulfur, are configured such that the surface layer 51B covers the core material portion 51A. In this way, semiconductor device A10 has appropriately improved resistance to corrosion by sulfur. If the constituent material of wire 55 is Cu without other metals added, the cost of wire 55 can be reduced compared to wires 51-54. Therefore, semiconductor device A10 can achieve both improved resistance to corrosion by sulfur and cost reduction. Also, if the constituent material of wire 55 is Au, the cost of semiconductor device A10 can be reduced compared to when wires 51-54 have the same configuration as wire 55. Furthermore, because the main component of wires 51-54 through which high currents flow is Cu, resistance losses can be suppressed compared to the case where Au, which has a higher electrical resistivity than Cu, is used. Therefore, semiconductor device A10 can achieve both improved corrosion resistance to sulfur and suppression of resistance losses and costs.

[0065] Furthermore, according to this embodiment, the wire 51 has a core material portion 51A covered by a surface layer portion 51B. The surface layer portion 51B has a higher bonding strength with the lead 41 than the core material portion 51A. As a result, the semiconductor device A10 can suppress deterioration of the bonding state of the wire 51 to the lead 41 (such as the occurrence of cracks and peeling). The same applies to wires 52 to 54.

[0066] Furthermore, according to this embodiment, the wire 51 has a main portion 511 and an end portion 512 located between the main portion 511 and the pad portion 412. The end portion 512 has a tapered portion 512A in which the dimension d in the z direction (see Figure 8) decreases as it moves away from the main portion 511. This facilitates the transmission of tensile stress generated in the end portion 512 when joining with the pad portion 412, thereby reducing stress concentration at the end portion 512. Moreover, the joining interface 412A (see Figure 8) between the pad portion 412 and the wire 51 spans both the main portion 511 and the end portion 512 in a view in the z direction. As a result, the joining of the wire 51 to the pad portion 412 is shared not only by the end portion 512 but also by the main portion 511, thus more effectively reducing stress concentration at the end portion 512. The same applies to wires 52 to 54.

[0067] Furthermore, according to this embodiment, the sulfur content of the resin member 6 is 5 ppm to 50 ppm by mass. As described above, the wires 52 to 54 have high resistance to corrosion by sulfur, so the resin member 6 can contain a certain amount of sulfur. This allows the resin member 6 to suppress corrosion of the wires 52 to 54 by sulfur components while improving adhesion to the conductive support member 4.

[0068] In this embodiment, the case described is one in which the multiple wires 55 do not include a portion corresponding to the surface layer 51B of the wire 51, and consist only of a portion corresponding to the core material portion 51A, but the invention is not limited to this. The wire 55 may have a structure in which, for example, a core material portion made of Cu without other metals added is covered with a surface layer similar to the surface layer 51B of the wire 51. In this case, the bonding strength of the wire 55 to the lead 45 can be improved.

[0069] In this embodiment, the semiconductor device A10 has been described as having bonding wires 51-54 as connecting members 5, but it is not limited to this. The semiconductor device A10 may also have a wide bonding ribbon as connecting member 5, with a configuration similar to that of wires 51-54 (including a core material portion 51A and a surface layer portion 51B covering the core material portion 51A). Furthermore, the connecting member 5 is not limited to these.

[0070] Figures 11 to 17 illustrate other embodiments of the present disclosure. In these figures, elements identical or similar to those in the above embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0071] Figures 11 to 14 are diagrams illustrating a semiconductor device A20 according to a second embodiment of the present disclosure. Figure 11 is a plan view of the semiconductor device A20 and corresponds to Figure 2. In Figure 11, for ease of understanding, the outline of the resin member 6 is shown by dashed lines (double-dotted lines) through the resin member 6. Figure 12 is a cross-sectional view along line XII-XII in Figure 11. Figure 13 is a partially enlarged view of Figure 12. Figure 14 is a partially enlarged view of Figure 12. The semiconductor device A20 according to this embodiment differs from the semiconductor device A10 according to the first embodiment in that it is equipped with connecting leads 56-58 instead of wires 51-54. The configuration and operation of other parts of this embodiment are the same as in the first embodiment.

[0072] The semiconductor device A20 according to this embodiment is equipped with connecting leads 56-58 instead of wires 51-54. The connecting leads 56-58 provide electrical conductivity between the first semiconductor elements 2A, 2B and leads 41, 43, 44. The connecting leads 56-58 are plate-shaped conductors formed by bending a metal plate. The shape and thickness of the connecting leads 56-58 are not limited.

[0073] As shown in Figures 11 and 12, the connecting lead 56 provides electrical conductivity between each electrode pad 251A of the first semiconductor element 2A and the pad portion 412 of the lead 41. As shown in Figure 13, the connecting lead 56 is joined to the electrode pad 251A via a bonding material 7, such as solder, and as shown in Figure 14, it is joined to the pad portion 412 via the bonding material 7. The connecting lead 56 includes a main body portion 56A and a surface layer portion 56B that covers the main body portion 56A.

[0074] The main body 56A is an alloy in which Pt is added as an additive metal to Cu, which is the main component metal. This alloy is an alloy in which Pt is added to Cu to improve corrosion resistance to sulfur, and has higher corrosion resistance to sulfur than Cu. In addition, other metals may be added to this alloy. In this alloy, Pt has the highest composition ratio among the additive metals, and its content is not limited, but is approximately 50 ppm to 300 ppm in parts per million by mass. In addition, the additive metal for improving corrosion resistance to sulfur is not limited to Pt, but may be other metals. In this case, it is preferable that the other metal has an atomic number greater than Cu. In addition, the main component metal of the main body 56A is not limited to Cu, but may be other metals.

[0075] The constituent material of the surface layer 56B includes, for example, Pd. The surface layer 56B is provided to protect the main body 56A from corrosion by sulfur and halogens, and to prevent oxidation of the main body 56A. The constituent material of the surface layer 56B is not limited to Pd, but any metal having the above functions is acceptable. The surface layer 56B is formed on the surface of the main body 56A, for example, by plating. The method of forming the connecting lead 56 is not limited.

[0076] As shown in Figure 11, the connecting lead 57 connects the electrode pads 252B of the first semiconductor element 2B with the pad portion 432 of the lead 43. As shown in Figures 11 and 12, the connecting lead 58 connects the electrode pad 252A of the first semiconductor element 2A and the electrode pad 251B of the first semiconductor element 2B with the pad portion 442 of the lead 44. The configuration of connecting leads 57 and 58 is the same as that of connecting lead 56.

[0077] According to this embodiment, the connecting lead 56 includes a main body portion 56A and a surface layer portion 56B that covers the main body portion 56A. This protects the main body portion 56A from corrosion by sulfur and halogens, and also prevents oxidation of the main body portion 56A. The material of the surface layer portion 56B includes Pd. Therefore, the surface layer portion 56B can prevent corrosion and oxidation of the main body portion 56A. Furthermore, according to this embodiment, the material of the main body portion 56A is an alloy in which an additive metal is added to Cu, the main component metal, to improve corrosion resistance to sulfur. Therefore, even if a part of the surface layer portion 56B peels off in the connecting lead 56, exposing the main body portion 56A, corrosion of the main body portion 56A by sulfur can be suppressed. According to this embodiment, Pt is used as the additive metal. This appropriately suppresses corrosion of the main body portion 56A by sulfur. The same applies to connecting leads 57 and 58.

[0078] Furthermore, in this embodiment as well, the wire 55 does not include the portion corresponding to the surface layer 51B of the wire 51, and consists only of the portion corresponding to the core material 51A. Since only a relatively small current flows through the wire 55, corrosion by sulfur is less likely to be accelerated. The semiconductor device A20 employs connecting leads 56-58 only in the connecting members where a large current flows and corrosion by sulfur is easily accelerated. In this way, the corrosion resistance of the semiconductor device A20 is appropriately improved. Moreover, the semiconductor device A20 has a configuration common to the semiconductor device A10 and therefore achieves the same effects as the semiconductor device A10.

[0079] Figure 15 is a diagram illustrating a semiconductor device A30 according to a third embodiment of the present disclosure. Figure 15 is a plan view of the semiconductor device A30 and corresponds to Figure 2. In Figure 15, for ease of understanding, the outline of the resin member 6 is shown by dashed lines (double-dotted lines) through the resin member 6. The configuration of each wire 55 in the semiconductor device A30 according to this embodiment differs from that of the semiconductor device A10 according to the first embodiment. The configuration and operation of other parts of this embodiment are the same as in the first embodiment. Note that the parts of the first and second embodiments described above may be combined in any way.

[0080] The wire 55 in this embodiment has the same configuration as the wire 51. All connecting members 5 (wires 51 to 55) provided in the semiconductor device A30 have a configuration that includes a core material portion 51A and a surface layer portion 51B that covers the core material portion 51A.

[0081] According to this embodiment, wires 51-55 include a core material portion 51A and a surface layer portion 51B that covers the core material portion 51A. This protects the core material portion 51A from corrosion by sulfur and halogens, and also prevents oxidation of the core material portion 51A. The constituent material of the surface layer portion 51B includes Pd. Therefore, the surface layer portion 51B prevents corrosion and oxidation of the core material portion 51A and improves the bonding strength of wires 51-55 to the conductive support member 4. Furthermore, according to this embodiment, the constituent material of the core material portion 51A is an alloy in which an additive metal is added to Cu, which is the main component metal, to improve corrosion resistance to sulfur. Therefore, even if a part of the surface layer portion 51B peels off in wires 51-55 and the core material portion 51A is exposed, corrosion of the core material portion 51A by sulfur can be suppressed. According to this embodiment, Pt is used as the additive metal. This effectively suppresses sulfur-induced corrosion of the core material 51A. Furthermore, semiconductor device A30, having a configuration common to semiconductor device A10, achieves the same effects as semiconductor device A10. Moreover, according to this embodiment, the wire material for forming wires 51 to 55 is all the same. In the wire bonding process, there is no need to change the wire material and bonding method depending on the wire being formed, thus simplifying the manufacturing process.

[0082] Figure 16 is a diagram illustrating a semiconductor device A40 according to a fourth embodiment of the present disclosure. Figure 16 is a plan view of the semiconductor device A40 and corresponds to Figure 2. In Figure 16, for ease of understanding, the outline of the resin member 960 is shown by dashed lines (double-dotted lines) through the resin member 960. The semiconductor device A40 according to this embodiment differs from the semiconductor device A10 according to the first embodiment in that it is equipped with a semiconductor element 920 instead of an electronic component 1. The configuration and operation of other parts of this embodiment are the same as in the first embodiment. Note that the parts of the first to third embodiments described above may be combined arbitrarily.

[0083] The semiconductor device A40 according to this embodiment is a package called, for example, DFN (Dual Flatpack No-leaded). However, the package type of the semiconductor device A40 is not limited. The semiconductor device A40 includes a semiconductor element 920 instead of an electronic component 1. The semiconductor device A40 also includes leads 941 to 943 as conductive support members 4, wires 951 and 952 as connecting members 5, and a resin member 960.

[0084] Lead 941 is located at one end of semiconductor device A40 in the y-direction (upper side in Figure 16) and extends across the entire x-direction. Lead 942 is located at the corner on the other side of semiconductor device A40 in the y-direction (lower side in Figure 16) in the x-direction (left side in Figure 16). Lead 943 is located at the corner on the other side of semiconductor device A40 in the y-direction (right side in Figure 16) in the x-direction. Leads 942 and 943 are spaced apart from lead 941 in the y-direction and spaced apart from each other in the x-direction. Lead 941 supports semiconductor element 920. Leads 941 to 943 are each electrically connected to semiconductor element 920.

[0085] The semiconductor element 920 is, for example, a MOSFET. However, the semiconductor element 920 may also be another transistor, such as an IGBT. The semiconductor element 920 has a source electrode 921 and a gate electrode 922 on its main surface, and a drain electrode on its back surface. The drain electrode of the semiconductor element 920 is electrically connected to a lead 941 via a bonding material. Thus, the lead 941 functions as the drain terminal. The source electrode 921 of the semiconductor element 920 is electrically connected to a lead 942 via a wire 951. Thus, the lead 942 functions as the source terminal. The gate electrode 922 of the semiconductor element 920 is electrically connected to a lead 943 via a wire 952. Thus, the lead 943 functions as the gate terminal.

[0086] Wire 951 connects the source electrode 921 and lead 942 of the semiconductor element 920. One end of wire 951 is joined to the source electrode 921, and the other end is joined to the lead 942. Wire 951 has the same configuration as wire 51 according to the first embodiment, and includes a core material portion 51A and a surface layer portion 51B that covers the core material portion 51A. Wire 952 connects the gate electrode 922 and lead 943 of the semiconductor element 920. One end of wire 952 is joined to the gate electrode 922, and the other end is joined to the lead 943. Wire 952 has the same configuration as wire 55 according to the first embodiment. A relatively large current flows through the source electrode 921, so a relatively large current also flows through wire 951. On the other hand, a relatively small current flows through the gate electrode 922 compared to the current flowing through the source electrode 921. Therefore, the current flowing through wire 952 is smaller than the current flowing through wire 951. In this embodiment, only wire 951, through which a relatively large current flows and which is susceptible to corrosion by sulfur, has a configuration in which the surface layer 51B covers the core material 51A. On the other hand, wire 952, through which a relatively small current flows, does not have a surface layer.

[0087] According to this embodiment, the wire 951 includes a core material portion 51A and a surface layer portion 51B that covers the core material portion 51A. This protects the core material portion 51A from corrosion by sulfur and halogens, and also prevents oxidation of the core material portion 51A. The constituent material of the surface layer portion 51B includes Pd. Therefore, the surface layer portion 51B prevents corrosion and oxidation of the core material portion 51A and improves the bonding strength of the wire 951 to the lead 942. Furthermore, according to this embodiment, the constituent material of the core material portion 51A is an alloy in which an additive metal is added to Cu, the main component metal, to improve corrosion resistance to sulfur. Therefore, even if a part of the surface layer portion 51B peels off in the wire 951 and the core material portion 51A is exposed, corrosion of the core material portion 51A by sulfur can be suppressed. According to this embodiment, Pt is used as the additive metal. This appropriately suppresses corrosion of the core material portion 51A by sulfur.

[0088] Furthermore, according to this embodiment, wire 952 does not include the portion corresponding to the surface layer 51B of wire 951, and consists only of the portion corresponding to the core material 51A. Since only a relatively small current flows through wire 952, corrosion by sulfur is less likely to be accelerated. In semiconductor device A40, only wire 951, which carries a large current and is susceptible to accelerated corrosion by sulfur, is configured such that the surface layer 51B covers the core material 51A. In this way, semiconductor device A40 has appropriately improved resistance to corrosion by sulfur. If the constituent material of wire 952 is Cu without other metals added, the cost of wire 952 can be reduced compared to wire 951. Therefore, semiconductor device A40 can achieve both improved resistance to corrosion by sulfur and cost reduction. Also, if the constituent material of wire 952 is Au, the cost of semiconductor device A40 can be reduced compared to when wire 951 has the same configuration as wire 952. Furthermore, because the main component of wire 951, through which high current flows, is Cu, losses due to resistance can be suppressed compared to the case where Au, which has a higher electrical resistivity than Cu, is used. Therefore, semiconductor device A40 can achieve both improved corrosion resistance due to sulfur and suppression of resistance losses and costs. In addition, semiconductor device A40 has a configuration common to semiconductor device A10 and therefore achieves the same effects as semiconductor device A10.

[0089] In this embodiment, an example in which the semiconductor element 920 is a transistor has been described, but it is not limited to this. The type of semiconductor element 920 is not limited. Furthermore, the number, shape, and arrangement of each conductive support member 4 are not limited, nor is the number of each connecting member 5.

[0090] Figure 17 is a diagram illustrating a semiconductor device A50 according to a fifth embodiment of the present disclosure. Figure 17 is a plan view of the semiconductor device A50 and corresponds to Figure 2. In Figure 17, for ease of understanding, the outline of the resin member 960 is shown by dashed lines (double-dotted lines) through the resin member 960. The semiconductor device A50 according to this embodiment differs from the semiconductor device A10 according to the first embodiment in that it includes a semiconductor element 970 instead of the electronic component 1. The configuration and operation of other parts of this embodiment are the same as in the first embodiment. Note that the parts of the first to fourth embodiments described above may be combined in any way.

[0091] The semiconductor device A50 according to this embodiment includes a semiconductor element 970 instead of an electronic component 1. The semiconductor device A50 also includes a lead 944 and a plurality of leads 945 as conductive support members 4, wires 951 and 952 as connecting members 5, and a resin member 960.

[0092] Lead 944 is located in the center of the semiconductor device A50 in the x-direction and extends throughout the y-direction. Multiple leads 945 are arranged on both sides of lead 944 in the x-direction, five on each side, and spaced equally in the y-direction. Each lead 945 is spaced apart from lead 944 and also spaced apart from one another. Lead 944 supports the semiconductor element 970. Each lead 945 is electrically connected to the semiconductor element 970. In this embodiment, lead 945 includes leads 945a and leads 945b. Lead 945a is located at the top left of Figure 17, and lead 945b is located at the bottom left of Figure 17.

[0093] The semiconductor element 970 is, for example, an LSI (Large Scale Integration). Note that the semiconductor element 970 may be other electronic components. The semiconductor element 970 is bonded to the lead 944 via a bonding material. The semiconductor element 970 has a plurality of electrode pads 971 arranged on its main surface. These electrode pads 971 include electrode pad 971a and electrode pad 971b. Electrode pad 971a is a power electrode. Electrode pad 971b is a ground electrode. In this embodiment, electrode pad 971a is located at the top left of the main surface in Figure 17, and electrode pad 971b is located in Figure 17. It is located at the bottom left of the main surface. Note that the placement of each electrode pad 971 is not limited. Each electrode pad 971 other than electrode pads 971a and 971b is connected to a different lead 945 via wire 952. Electrode pad 971a is connected to lead 945a via wire 951. As a result, lead 945a functions as a power terminal. Electrode pad 971b is connected to lead 945b via wire 951. As a result, lead 945b functions as a ground terminal.

[0094] One wire 951 connects the electrode pad 971a and lead 945a of the semiconductor element 970. One end of this wire 951 is joined to the electrode pad 971a and the other end is joined to lead 945a. Another wire 951 connects the electrode pad 971b and lead 945b of the semiconductor element 970. One end of this wire 951 is joined to the electrode pad 971b and the other end is joined to lead 945b. Each wire 951 has the same configuration as the wire 51 according to the first embodiment and includes a core material portion 51A and a surface layer portion 51B that covers the core material portion 51A. Multiple wires 952 connect each electrode pad 971 other than electrode pads 971a and 971b, and each lead 945 other than lead 945a and lead 945b. Each wire 952 has one end joined to an electrode pad 971 and the other end joined to a lead 945. Each wire 952 has the same configuration as wire 55 according to the first embodiment. Since a relatively large current flows through electrode pads 971a and 971b, a relatively large current also flows through wire 951. On the other hand, since a relatively small current flows through each electrode pad 971 other than electrode pads 971a and 971b, a relatively small current also flows through wire 952. In this embodiment, only wire 951, which has a relatively large current flowing through it and is prone to corrosion by sulfur, has a configuration in which the surface layer 51B covers the core material 51A. On the other hand, wire 952, which has a relatively small current flowing through it, does not have a surface layer.

[0095] According to this embodiment, the wire 951 includes a core material portion 51A and a surface layer portion 51B that covers the core material portion 51A. This protects the core material portion 51A from corrosion by sulfur and halogens, and also prevents oxidation of the core material portion 51A. The constituent material of the surface layer portion 51B includes Pd. Therefore, the surface layer portion 51B prevents corrosion and oxidation of the core material portion 51A and improves the bonding strength of the wire 951 to the leads 945a and 945b. Furthermore, according to this embodiment, the constituent material of the core material portion 51A is an alloy in which an additive metal is added to Cu, the main component metal, to improve corrosion resistance to sulfur. Therefore, even if a part of the surface layer portion 51B peels off in the wire 951 and the core material portion 51A is exposed, corrosion of the core material portion 51A by sulfur can be suppressed. According to this embodiment, Pt is used as the additive metal. This effectively suppresses sulfur-induced corrosion of the core material 51A.

[0096] Furthermore, according to this embodiment, wire 952 does not include the portion corresponding to the surface layer 51B of wire 951, and consists only of the portion corresponding to the core material 51A. Since only a relatively small current flows through wire 952, corrosion by sulfur is less likely to be accelerated. In semiconductor device A50, only wire 951, which carries a large current and is susceptible to corrosion by sulfur, is configured such that the surface layer 51B covers the core material 51A. In this way, semiconductor device A50 has appropriately improved resistance to corrosion by sulfur. If the constituent material of wire 952 is Cu without other metals added, the cost of wire 952 can be reduced compared to wire 951. Therefore, semiconductor device A50 can achieve both improved resistance to corrosion by sulfur and cost reduction. Also, if the constituent material of wire 952 is Au, the cost of semiconductor device A50 can be reduced compared to when wire 951 has the same configuration as wire 952. Furthermore, because the main component of wire 951, through which high current flows, is Cu, losses due to resistance can be suppressed compared to the case where Au, which has a higher electrical resistivity than Cu, is used. Therefore, semiconductor device A50 can achieve both improved corrosion resistance due to sulfur and suppression of resistance losses and costs. In addition, semiconductor device A50 has a configuration common to semiconductor device A10 and therefore achieves the same effects as semiconductor device A10.

[0097] In this embodiment, an example in which the semiconductor element 970 is an LSI has been described, but it is not limited to this. The type of semiconductor element 970 is not limited. Furthermore, the number, shape, and arrangement of each conductive support member 4 are not limited, nor is the number of each connecting member 5.

[0098] The semiconductor device described herein is not limited to the embodiments described above. The specific configuration and processing of each part of the semiconductor device described herein can be modified in various ways. This disclosure includes the embodiments described in the following appendix.

[0099] Note 1. Semiconductor device (2A), The first lead (41) that conducts to the semiconductor element, A connecting member (51) connected to the semiconductor element and the first lead, Equipped with, The connecting member includes a core material portion (51A) containing a first material, and a surface layer portion (51B) containing a first metal (Pd) and covering the core material portion. The first material comprises an alloy in which at least a third metal (Pt) is added to a second metal (Cu), and has higher corrosion resistance than the second metal. The third metal has the highest composition ratio among the added metals and has a larger atomic number than the second metal, in a semiconductor device. Note 2. The semiconductor device described in Appendix 1, wherein the second metal is Cu. Note 3. The semiconductor device according to Appendix 1 or 2, wherein the third metal is Pt. Note 4. The semiconductor device according to any one of the appendices 1 to 3, wherein the bonding strength with the first lead is higher for the first metal than for the first material. Note 5. The semiconductor device according to any one of the appendices 1 to 4, wherein the first metal is Pd. Note 6. The aforementioned connecting member is a wire, as described in any one of appendices 1 to 5. Appendix 7. (Embodiments 1-3, Figure 2) The second semiconductor element (3) and A second lead (45) that conducts to the second semiconductor element, A second connecting member (55) is connected to the second semiconductor element and the second lead, and the current flowing from the connecting member is small. Furthermore, The semiconductor device according to any one of the appendices 1 to 6, wherein the second connecting member consists only of a second core material portion containing a second material (Cu). Note 8. The aforementioned semiconductor device is a transistor, The semiconductor device described in Appendix 7, wherein the second semiconductor element is a drive IC that drives and controls the transistor. Note 9. (Fourth embodiment, Figure 16) A second lead (943) that conducts to the semiconductor element (920), A second connecting member (952) is connected to the semiconductor element and the second lead, and the current flowing from the connecting member is small. Furthermore, The semiconductor device according to any one of the appendices 1 to 6, wherein the second connecting member consists only of a second core material portion including the second material. Note 10. The semiconductor device described in Appendix 9 is a transistor. Note 11. The semiconductor device according to any one of appendices 7 to 10, wherein the second material consists solely of the second metal (Cu) without any other metals added. Note 12. The semiconductor device according to any one of appendices 7 to 10, wherein the second material contains a fourth metal (Au) with a higher electrical resistivity than the second metal (Cu). Note 13. The semiconductor device described in Appendix 12, wherein the fourth metal is Au. Note 14. The resin member (6) covering the connecting member is further provided. The aforementioned resin component is a semiconductor device according to any one of the appendices 1 to 13, wherein the sulfur content is 5 ppm or more. [Explanation of symbols]

[0100] A10, A20, A30, A40: Semiconductor equipment 1: Electronic components 2A, 2B: First semiconductor element; 21A, 21B: Semiconductor substrate 211A, 211B: Main surface of the board 212A, 212B: Back surface of the board 220A, 220B: Active region; 221A, 221B: Semiconductor region 222A, 222B: Semiconductor area 223A, 223B: Semiconductor area 23A, 23B: Wiring layer 231: Conductive layer 232: Insulating layer 233: Via 24A, 24B: Protective film 251A, 251B, 252A, 252B: Electrode pads 3: Second semiconductor element 301: Main surface of the element 31: Electrode pad 32: Protective film 4: Conductive support member 41: Lead 411: Terminal section 412: Pad section 412A: Joint interface 42: Lead 421: Terminal section 422: Pad section 43: Lead 431: Terminal part 432: Pad part 44: Lead 441: Terminal part 442: Pad part 45: Lead 451: Terminal part 452: Pad part 46: Die pad 461: Pad section 461a: Main surface of die pad 462: Extension portion 462a: End surface 49: Metal layer 5: Connecting member 51~55: Wire 51A: Core material part 51B: Surface layer part 511: Main part 512: End portion 512A: Tapered portion 512B: Tip portion 56-58: Connecting leads 56A: Main body 56B: Surface layer 6: Resin component 61: Main surface of resin 62: Back surface of resin 63,631,632: Resin side 7: Bonding material 920, 970: Semiconductor element; 921: Source electrode 922: Glycol 971, 971a, 971b: Electrode pads 941~945,945a,945b: Reeds 951, 952: Wire 960: Resin component

Claims

1. Semiconductor elements and A first lead that conducts to the aforementioned semiconductor element, A connecting member connected to the semiconductor element and the first lead, Equipped with, The connecting member includes a core material portion containing a first material and a surface layer portion containing a first metal and covering the core material portion. The first material comprises an alloy in which at least a third metal is added to a second metal, and has higher corrosion resistance than the second metal. The third metal has the highest composition ratio among the added metals and has a larger atomic number than the second metal. The connecting member is a wire, and comprises a main part and an end part. The end portion is interposed between the main portion and the first lead and comprises a tapered portion connected to the main portion and a tip portion connected to the tapered portion. The tapered portion has a smaller dimension in the thickness direction of the first lead as it moves away from the main portion. Semiconductor equipment.

2. The core material portion at the tip and the core material portion at the tapered portion are separated by the surface portion. The semiconductor device according to claim 1.

3. The second metal is Cu. The semiconductor device according to claim 1.

4. The third metal is Pt. The semiconductor device according to claim 1.

5. The bonding strength with the first lead is higher for the first metal than for the first material. The semiconductor device according to claim 1.

6. The first metal is Pd. The semiconductor device according to claim 1.

7. The second semiconductor element, A second lead that conducts to the second semiconductor element, A second connecting member connected to the second semiconductor element and the second lead, and having a small current flowing from the connecting member, Furthermore, The second connecting member consists only of a second core material portion including the second material. The semiconductor device according to claim 1.

8. The aforementioned semiconductor device is a transistor, The second semiconductor element is a drive IC that drives and controls the semiconductor element. The semiconductor device according to claim 7.

9. A second lead that conducts to the aforementioned semiconductor element, A second connecting member is connected to the semiconductor element and the second lead, and the current flowing from the connecting member is small. Furthermore, The second connecting member consists only of a second core material portion including the second material. The semiconductor device according to claim 1.

10. The aforementioned semiconductor device is a transistor. The semiconductor device according to claim 9.

11. The second material consists solely of the second metal, with no other metals added. The semiconductor device according to any one of claims 7 to 10.

12. The second material contains a fourth metal with a higher electrical resistivity than the second metal. The semiconductor device according to any one of claims 7 to 10.

13. The fourth metal is Au. The semiconductor device according to claim 12.

14. The connecting member further comprises a resin member covering the aforementioned connecting member, The aforementioned resin component has a sulfur content of 5 ppm or more and 50 ppm or less in parts per million by mass. The semiconductor device according to claim 1.

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