Resistor mounting structure

Abstract

This mounting structure comprises a substrate, a conductive part (first conductive part and second conductive part), a resistor that is disposed on the route along which current flows in the conductive part, and a detection wiring part (first detection wiring and second detection wiring) that is electrically connected to the resistor. The first conductive part has a first pad part that is disposed to one side in a first direction. The second conductive part has a second pad part that is disposed separated from the first pad part and toward the other side in the first direction. A first conductive joining material that joins a first pad main surface and the resistor (first part), and a second conductive joining material that joins a second pad main surface and the resistor (second part) are provided. A first wiring main surface (second wiring main surface) is positioned further to the other side in the thickness direction than the first pad main surface (second pad main surface).

Description

Resistor mounting structure

[0001] The present disclosure relates to a resistor mounting structure.

[0002] Conventionally, semiconductor devices including power switching elements such as MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) and IGBTs (Insulated Gate Bipolar Transistors) have been known. Such semiconductor devices are installed in a wide variety of electronic devices, from industrial equipment to home appliances, information terminals, and automotive equipment. Patent Document 1 discloses a conventional semiconductor device. The semiconductor device described in Patent Document 1 includes a base material (substrate), a conductive plate (conductive portion), and a semiconductor element. The conductive plate is supported by the base material and forms a conduction path for carrying current through the semiconductor element. The semiconductor element is supported by the base material and is electrically connected to the conductive plate.

[0003] When the semiconductor device is mounted on a circuit board such as a PCB (Printed Circuit Board), a shunt resistor is separately mounted on the circuit board and used as a shunt to detect current. However, since the shunt resistor must be separately mounted on the circuit board and wiring for the resistor must be routed, the space occupied by the current detection device increases, which is a factor in increasing costs.

[0004] Japanese Patent Application Laid-Open No. 2015-220429

[0005] An object of the present disclosure is to provide an improved semiconductor device. In particular, in view of the above-mentioned circumstances, an object of the present disclosure is to provide a resistor mounting structure suitable for detecting current with high accuracy.

[0006] A resistor mounting structure provided by one aspect of the present disclosure includes a substrate, a conductive portion supported by the substrate, a resistor disposed in a path through which current flows in the conductive portion, and a detection wiring portion conducting to the resistor. The substrate has a first main surface facing one side in a thickness direction. The conductive portion includes a first conductive portion and a second conductive portion, each disposed on the first main surface. The first conductive portion has a first pad portion disposed on one side in a first direction perpendicular to the thickness direction. The second conductive portion has a second pad portion disposed spaced apart from the first pad portion on the other side in the first direction. The resistor has a first portion overlapping the first pad portion when viewed in the thickness direction and a second portion overlapping the second pad portion when viewed in the thickness direction. The first pad portion has a first pad main surface facing one side in the thickness direction. The second pad portion has a second pad main surface facing one side in the thickness direction, and includes: a first conductive bonding material interposed between the first pad main surface and the first portion and bonding the first pad main surface and the first portion; and a second conductive bonding material interposed between the second pad main surface and the second portion and bonding the second pad main surface and the second portion. The detection wiring portion includes a first detection wiring that is electrically connected to the first pad portion and a second detection wiring that is electrically connected to the second pad portion. The first detection wiring has a first wiring main surface facing one side in the thickness direction. The second detection wiring has a second wiring main surface facing one side in the thickness direction. The first wiring main surface is located on the other side in the thickness direction of the first pad main surface. The second wiring main surface is located on the other side in the thickness direction of the second pad main surface.

[0007] According to the above configuration, it is possible to provide a structure that is preferable for detecting current with high accuracy.

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

[0009] FIG. 1 is a diagram showing a schematic configuration example of a mounting structure including a resistor mounting structure according to the present disclosure. FIG. 2 is an enlarged plan view of a main portion of the mounting structure according to the first embodiment of the present disclosure. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is an enlarged plan view of a main portion of a mounting structure according to a first modified example of the first embodiment. FIG. 5 is a cross-sectional view taken along line V-V in FIG. 4. FIG. 6 is an enlarged plan view of a main portion of a mounting structure according to a second modified example of the first embodiment. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. FIG. 8 is an enlarged plan view of a main portion of a mounting structure according to a third modified example of the first embodiment. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 8.

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

[0011] The terms "first," "second," "third," etc. in this disclosure are used merely for identification purposes and are not intended to necessarily assign any order to their objects.

[0012] In this disclosure, unless otherwise specified, "a certain object A is formed on a certain object B" and "a certain object A is formed on a certain object B" include "a certain object A is formed directly on a certain object B" and "a certain object A is formed on a certain object B with another object interposed between the certain object A and the certain object B." Similarly, "a certain object A is disposed on a certain object B" and "a certain object A is disposed on a certain object B" include "a certain object A is disposed directly on a certain object B" and "a certain object A is disposed on a certain object B with another object interposed between the certain object A and the certain object B" unless otherwise specified. Similarly, "a certain object A is located on a certain object B" includes "a certain object A is located on a certain object B with a certain object A in contact with the certain object B" and "a certain object A is located on a certain object B with another object interposed between the certain object A and the certain object B." Furthermore, unless otherwise specified, the phrase "an object A overlaps an object B when viewed in a certain direction" includes "an object A overlaps the entire object B" and "an object A overlaps a part of an object B." Furthermore, in the present disclosure, "a surface A faces in (one side or the other side of) direction B" is not limited to the case where the angle of surface A with respect to direction B is 90°, but also includes the case where surface A is tilted with respect to direction B.

[0013] First embodiment: Figures 1 to 3 show a mounting structure including a resistor mounting structure according to a first embodiment of the present disclosure. Figure 1 is a diagram showing a schematic configuration of the mounting structure A1. Figure 2 is an enlarged plan view of a main portion of the mounting structure A1. Figure 3 is a cross-sectional view taken along line III-III in Figure 2.

[0014] The mounting structure A1 of this embodiment includes a substrate 1, a conductive portion 2, a resistor 5, a detection wiring portion 6, terminals 71 and 72, detection terminals 73 and 74, and a sealing resin 8. The mounting structure A1 is used to detect a current flowing through the conductive portion 2 between the two terminals 71 and 72.

[0015] In the description of the mounting structure A1, the thickness direction (direction in a plan view) of the substrate 1 is an example of the "thickness direction" of the present disclosure and is referred to as the "thickness direction z." The direction perpendicular to the thickness direction z is an example of the "first direction" of the present disclosure and is referred to as the "first direction x." The direction perpendicular to both the thickness direction z and the first direction x is an example of the "second direction" of the present disclosure and is referred to as the "second direction y." Furthermore, in FIG. 2 , the left side of the figure is an example of the "one side of the first direction" of the present disclosure and is referred to as the "x1 side of the first direction x," and the right side of the figure is an example of the "other side of the first direction" of the present disclosure and is referred to as the "x2 side of the first direction x." In FIG. 2 , the lower side of the figure is an example of the "one side of the second direction" of the present disclosure and is referred to as the "y1 side of the second direction y," and the upper side of the figure is an example of the "other side of the second direction" of the present disclosure and is referred to as the "y2 side of the second direction y." In Figure 3, the upper side of the figure is an example of "one side in the thickness direction" in the present disclosure and is called the "z1 side in the thickness direction z," and the lower side of the figure is an example of "the other side in the thickness direction" in the present disclosure and is called the "z2 side in the thickness direction z."

[0016] The substrate 1 has electrical insulation properties. The substrate 1 is made of ceramics containing, for example, alumina (Al2O3). The constituent material of the substrate 1 is preferably a material with relatively high thermal conductivity. As shown in Figures 2 and 3, the substrate 1 has a first main surface 101. The first main surface 101 faces the z1 side in the thickness direction z.

[0017] The conductive portion 2 constitutes a path for current to flow. A current to be detected flows through the conductive portion 2 between the two terminals 71 and 72. As shown in FIGS. 2 and 3 , the conductive portion 2 is supported on the substrate 1. The conductive portion 2 is formed, for example, from a lead frame. The lead frame is made of a material containing Cu (copper) or a Cu alloy. In this embodiment, the conductive portion 2 includes a first conductive portion 2A and a second conductive portion 2B. Each of the first conductive portion 2A and the second conductive portion 2B is disposed on the first main surface 101 of the substrate 1. Details of the first conductive portion 2A and the second conductive portion 2B will be described later.

[0018] The resistor 5 is a passive element that serves to detect current in the mounting structure A1. The resistor 5 is disposed in a path through which current flows in the conductive portion 2. Details of the resistor 5 will be described later.

[0019] The detection wiring section 6 is electrically connected to the resistor 5 and is a wiring portion that divides and flows a detection current by being connected in parallel with the resistor 5. The detection wiring section 6 includes first detection wiring 6A and second detection wiring 6B. Details of the detection wiring section 6 (first detection wiring 6A and second detection wiring 6B) will be described later.

[0020] The terminals 71 and 72 are each connected to the conductive portion 2. Devices for passing a current through the conductive portion 2 are connected to the terminals 71 and 72.

[0021] The detection terminals 73 and 74 are connected to the first detection wiring 6A and the second detection wiring 6B, respectively, and are connected to, for example, a voltmeter for measuring current.

[0022] The sealing resin 8 covers the substrate 1, at least a portion of the conductive portion 2, at least a portion of the detection wiring portion 6, and the resistor 5. The external connection terminals 71 and 72 and the detection terminals 73 and 74 include portions that are exposed from the sealing resin 8. The sealing resin 8 is omitted in Figures 2 and 3.

[0023] As shown in FIGS. 2 and 3 , the first conductive portion 2A has a first pad portion 21A. The first pad portion 21A is arranged on the x1 side in the first direction x. The first pad portion 21A has a first pad main surface 210a. The first pad main surface 210a faces the z1 side in the thickness direction z. The second conductive portion 2B has a second pad portion 21B. The second pad portion 21B is arranged spaced apart from the conductive portion 21 on the x2 side in the first direction x. The second pad portion 21B has a second pad main surface 210b. The second pad main surface 210b faces the z1 side in the thickness direction z.

[0024] In this embodiment, the mounting structure A1 includes a first bonding layer 25A and a second bonding layer 25B. The first bonding layer 25A is interposed between the first main surface 101 and the first pad portion 21A, bonding the first main surface 101 and the first pad portion 21A together. The second bonding layer 25B is interposed between the first main surface 101 and the second pad portion 21B, bonding the first main surface 101 and the second pad portion 21B together. The first bonding layer 25A and the second bonding layer 25B are each electrically conductive. The first bonding layer 25A and the second bonding layer 25B are made of a material containing Ag (silver), for example, and are baked silver. The first bonding layer 25A (second bonding layer 25B) has an area on the first bonding layer 25A (second bonding layer 25B) where the first conductive portion 2A (second conductive portion 2B) is not arranged, and plays the role of wiring formed on the first main surface 101.

[0025] The resistor 5 is a plate-like member having a predetermined thickness. When viewed in the thickness direction z, the resistor 5 has a rectangular shape with the longer side extending in the first direction x. The resistor 5 is made of a metal plate, specifically, an NI (nickel)-Cr (chromium) alloy, a Cu-Mn (manganese) alloy, a Cu-Ni alloy, a Cu-Mn-Sn (tin) alloy, or an Fe (iron)-Cr alloy. Note that the constituent material of the resistor 5 is not limited to these, as long as it is a metal plate.

[0026] The resistor 5 is disposed across the first pad portion 21A and the second pad portion 21B. The resistor 5 has a first portion 5A and a second portion 5B. The first portion 5A and the second portion 5B are located at both ends of the resistor 5 in the longitudinal direction (first direction x). The first portion 5A is located on the x1 side in the first direction x and overlaps the first pad portion 21A in the thickness direction z. The second portion 5B is located on the x2 side in the first direction x and overlaps the second pad portion 21B in the thickness direction z.

[0027] The mounting structure A1 includes a first conductive bonding material 29A and a second conductive bonding material 29B. The resistor 5 is bonded to the first pad portion 21A and the second pad portion 21B via the first conductive bonding material 29A and the second conductive bonding material 29B. The first conductive bonding material 29A is interposed between the first pad main surface 210a and the first portion 5A, bonding the first pad main surface 210a to the first portion 5A. The second conductive bonding material 29B is interposed between the second pad main surface 210b and the second portion 5B, bonding the second pad main surface 210b to the second portion 5B. The first conductive bonding material 29A and the second conductive bonding material 29B are made of, for example, solder.

[0028] In this embodiment, the first bonding layer 25A includes first detection wires 6A. The first detection wires 6A have first wiring main surfaces 60a. The first wiring main surfaces 60a face the z1 side in the thickness direction z. The first wiring main surface 60a is located closer to the z2 side in the thickness direction z than the first pad main surfaces 210a of the first pad portions 21A.

[0029] The first detection wire 6A has a first extension portion 611 and a third extension portion 613. As shown in FIGS. 2 and 3 , the first extension portion 611 extends from the first pad portion 21A toward the x2 side in the first direction x as viewed in the thickness direction z. The first extension portion 611 overlaps the resistor 5 as viewed in the thickness direction z. The third extension portion 613 is connected to the first extension portion 611 and extends toward the y1 side in the second direction y. The third extension portion 613 has a portion that overlaps the resistor 5 and a portion that does not overlap the resistor 5 as viewed in the thickness direction z. With the above configuration, the first detection wire 6A (first extension portion 611) is electrically connected to the first pad portion 21A. The first detection wire 6A is electrically connected to the first portion 5A of the resistor 5 via the first pad portion 21A and the first conductive bonding material 29A. The first detection wire 6A (third extension portion 613) is electrically connected to a detection terminal 73 (see FIG. 1) not shown.

[0030] In this embodiment, the second bonding layer 25B includes second detection wires 6B. The second detection wires 6B have second wiring main surfaces 60b. The second wiring main surfaces 60b face the z1 side in the thickness direction z. The second wiring main surface 60b is located closer to the z2 side in the thickness direction z than the second pad main surfaces 210b of the second pad portions 21B.

[0031] The second detection wire 6B has a second extension portion 612 and a fourth extension portion 614. As shown in FIGS. 2 and 3 , the second extension portion 612 extends from the second pad portion 21B toward the x1 side in the first direction x as viewed in the thickness direction z. The second extension portion 612 overlaps the resistor 5 as viewed in the thickness direction z. The fourth extension portion 614 is connected to the second extension portion 612 and extends toward the y1 side in the second direction y. The fourth extension portion 614 has a portion that overlaps the resistor 5 and a portion that does not overlap the resistor 5 as viewed in the thickness direction z. With the above configuration, the second detection wire 6B (second extension portion 612) is electrically connected to the second pad portion 21B. The second detection wire 6B is electrically connected to the second portion 5B of the resistor 5 via the second pad portion 21B and the second conductive bonding material 29B. The second detection wire 6B (fourth extension 614) is electrically connected to a detection terminal 74 (see FIG. 1) not shown.

[0032] Next, the operation of this embodiment will be described.

[0033] The mounting structure A1 includes a substrate 1, a conductive portion 2, a resistor 5, and a detection wiring portion 6. The resistor 5 is disposed in a path through which a current flows in the conductive portion 2. The detection wiring portion 6 is electrically connected to the resistor 5. By incorporating the resistor 5, the mounting structure A1 can detect a current flowing through the conductive portion 2. Furthermore, on a circuit board on which the mounting structure A1 is mounted, there is no need to route a separate resistor or wiring for the resistor, thereby saving space.

[0034] The conductive portion 2 includes a first conductive portion 2A and a second conductive portion 2B arranged on the first main surface 101 of the substrate 1. The first conductive portion 2A has a first pad portion 21A arranged on the x1 side in the first direction x, and the second conductive portion 2B has a second pad portion 21B arranged on the x2 side in the first direction x and spaced apart from the first pad portion 21A. The resistor 5 has a first portion 5A overlapping the first pad portion 21A as viewed in the thickness direction z and a second portion 5B overlapping the second pad portion 21B as viewed in the thickness direction z. A first conductive bonding material 29A is interposed between the first pad portion 21A (first pad main surface 210a) and the first portion 5A, and the first conductive bonding material 29A bonds the first pad portion 21A (first pad main surface 210a) and the first portion 5A. A second conductive bonding material 29B is interposed between the second pad portion 21B (second pad main surface 210b) and the second portion 5B, and the second conductive bonding material 29B bonds the second pad portion 21B (second pad main surface 210b) and the second portion 5B. With this configuration, the resistor 5 can be appropriately positioned on the path through which a current flows in the conductive portion 2.

[0035] A conductive first bonding layer 25A is interposed between the first main surface 101 and the first pad portion 21A, and the first bonding layer 25A bonds the first main surface 101 and the first pad portion 21A. The first bonding layer 25A includes a first detection wire 6A. The first detection wire 6A has a first extension portion 611, and the first extension portion 611 extends from the first pad portion 21A to the x2 side in the first direction x as viewed in the thickness direction z. A conductive second bonding layer 25B is interposed between the first main surface 101 and the second pad portion 21B, and the second bonding layer 25B bonds the first main surface 101 and the second pad portion 21B. The second bonding layer 25B includes a second detection wire 6B. The second detection wire 6B has a second extending portion 612, and the second extending portion 612 extends from the second pad portion 21B to the x1 side in the first direction x when viewed in the thickness direction z.

[0036] According to the above configuration, a conductive path is formed from the first portion 5A of the resistor 5 through the first conductive bonding material 29A and the first pad portion 21A to the first extension portion 611. The first detection wire 6A has a first wiring main surface 60a facing the z1 side in the thickness direction z. The first wiring main surface 60a is located closer to the z2 side in the thickness direction z than the first pad main surface 210a of the first pad portion 21A. According to this configuration, as shown in FIG. 3 , at the end of the first pad portion 21A on the x2 side in the first direction x, there is a step in the thickness direction z between the end and the first extension portion 611 (first detection wire 6A). This prevents the first conductive bonding material 29A made of solder from flowing unduly toward the x2 side in the first direction x on the first pad portion 21A during melt bonding. Similarly, a conductive path is formed on the second portion 5B side of the resistor 5, extending from the second portion 5B through the second conductive bonding material 29B and the second pad portion 21B to the second extension portion 612. The second detection wire 6B has a second wiring main surface 60b facing the z1 side in the thickness direction z. The second wiring main surface 60b is located closer to the z2 side in the thickness direction z than the second pad main surface 210b of the second pad portion 21B. At the end of the second pad portion 21B on the x1 side in the first direction x, there is a step in the thickness direction z between the end and the second extension portion 612 (second detection wire 6B). This prevents the second conductive bonding material 29B made of solder from flowing unduly toward the x1 side in the first direction x on the second pad portion 21B during melt bonding. With this configuration, the contact point between the first conductive bonding material 29A and the first portion 5A (resistor 5) on the x2 side in the first direction x can be set based on the position of the end of the first pad portion 21A on the x2 side in the first direction x. Also, the contact point between the second conductive bonding material 29B and the second portion 5B (resistor 5) on the x1 side in the first direction x can be set based on the position of the end of the second pad portion 21B on the x1 side in the first direction x. Therefore, the resistance value of the resistor 5 appears correctly, and the current flowing through the conductive portion 2 can be accurately detected.

[0037] The first detection wire 6A has a third extension portion 613. The third extension portion 613 is connected to the first extension portion 611 and extends toward the y1 side in the second direction y. The second detection wire 6B has a fourth extension portion 614. The fourth extension portion 614 is connected to the second extension portion 612 and extends toward the y1 side in the second direction y. With this configuration, the first detection wire 6A and the second detection wire 6B can be appropriately routed from below the resistor 5 to its periphery while preventing short-circuiting. Note that in this embodiment, the third extension portion 613 and the fourth extension portion 614 are configured to extend to the same side in the second direction y (the y1 side in the second direction y), but the third extension portion 613 and the fourth extension portion 614 may be configured to extend to opposite sides in the second direction y.

[0038] First Modification of First Embodiment: Figures 4 and 5 show a mounting structure according to a first modification of the first embodiment. Figure 4 is an enlarged plan view of a main portion of a mounting structure A11 according to this modification. Figure 5 is a cross-sectional view taken along line V-V in Figure 4. In Figures 4 and subsequent figures, elements that are the same as or similar to those in the mounting structure A1 of the above embodiment are given the same reference numerals as in the above embodiment, and descriptions thereof will be omitted where appropriate. Furthermore, the configurations of the various parts in each of the modifications and embodiments shown in Figure 4 and subsequent figures can be combined with each other as appropriate within the scope of not causing technical contradictions.

[0039] In comparison with the mounting structure A1 of the above embodiment, the mounting structure A11 of this modified example is additionally provided with an insulating film 9. The specific configuration of the insulating film 9 is not limited in any way, and it may be formed of, for example, a resist layer or polyimide resin.

[0040] The insulating film 9 is disposed in predetermined regions on the first main surface 101 and the detection wiring portion 6 (the first detection wiring 6A and the second detection wiring 6B). As shown in FIG. 5 , the insulating film 9 is interposed between the first extension portion 611 (the first detection wiring 6A) and the resistor 5, and between the second extension portion 612 (the second detection wiring 6B) and the resistor 5. The insulating film 9 contacts the end of the first pad portion 21A on the x2 side in the first direction x and the end of the second pad portion 21B on the x1 side in the first direction x. The first conductive bonding material 29A and the second conductive bonding material 29B are each in contact with the insulating film 9. The insulating film 9 having the above configuration is formed before the resistor 5 is disposed on the first pad portion 21A and the second pad portion 21B.

[0041] According to the mounting structure A11 of this modification, the resistor 5 is built in, thereby enabling detection of the current flowing through the conductive portion 2. Furthermore, a circuit board on which the mounting structure A11 is mounted does not require a separate resistor or wiring for the resistor, thereby saving space. The mounting structure A11 additionally includes an insulating film 9. The insulating film 9 is interposed between the first extension 611 (first detection wiring 6A) and the resistor 5, and between the second extension 612 (second detection wiring 6B) and the resistor 5. The first conductive bonding material 29A and the second conductive bonding material 29B are in contact with the insulating film 9. This configuration allows the contact point of the first conductive bonding material 29A with the first portion 5A (resistor 5) on the x2 side in the first direction x and the contact point of the second conductive bonding material 29B with the second portion 5B (resistor 5) on the x1 side in the first direction x to be more accurately determined based on the formation position of the insulating film 9. Therefore, the resistance value of the resistor 5 appears more appropriately, and it is possible to more accurately detect the current flowing through the conductive portion 2. In addition, the same effects as those of the mounting structure A1 of the above embodiment are achieved.

[0042] Second Modification of First Embodiment: Figures 6 and 7 show a mounting structure according to a second modification of the first embodiment. Figure 6 is an enlarged plan view of a main portion of a mounting structure A12 according to this modification. Figure 7 is a cross-sectional view taken along line VII-VII in Figure 6. In the mounting structure A12 according to this modification, the configurations of the substrate 1, conductive portion 2, and detection wiring portion 6 differ from those of the mounting structure A1 according to the above embodiment.

[0043] In the mounting structure A12, the conductive portion 2 is directly bonded to the first main surface 101 of the substrate 1. Therefore, unlike the embodiment A1, this modification does not include the first bonding layer 25A and the second bonding layer 25B. A back surface metal layer 23 is bonded to the surface of the substrate 1 opposite the first main surface 101 (the surface facing the z2 side in the thickness direction z). The conductive portion 2 is a metal layer formed on the front side (first main surface 101) of the substrate 1, and the back surface metal layer 23 is a metal layer formed on the back side (the surface opposite the first main surface 101) of the substrate 1. The substrate 1 is made of, for example, ceramics with excellent thermal conductivity. Examples of such ceramics include SiN (silicon nitride) and alumina. The conductive portion 2 and the back surface metal layer 23 are made of a material that includes, for example, Cu. The material may also include, for example, Al (aluminum) in addition to Cu. The substrate 1, conductive portion 2, and rear surface metal layer 23 having such a configuration can be configured by, for example, a DBC (Direct Bonded Copper) substrate or an AMB (Active Metal Brazing) substrate.

[0044] In the mounting structure A12, the conductive portion 2 is patterned to form a conductive path for current flow. In this modification, the first conductive portion 2A has a first detection wiring 6A. As shown in FIG. 7 , the first detection wiring 6A is connected to the first pad portion 21A and has a smaller thickness (dimension in the thickness direction z) than the first pad portion 21A. The first wiring main surface 60a of the first detection wiring 6A is located on the z2 side in the thickness direction z of the first pad main surface 210a of the first pad portion 21A. The second conductive portion 2B has a second detection wiring 6B. The second detection wiring 6B is connected to the second pad portion 21B and has a smaller thickness than the second pad portion 21B. The second wiring main surface 60b of the second detection wiring 6B is located on the z2 side in the thickness direction z of the second pad main surface 210b of the second pad portion 21B. In the illustrated example, the thickness of the first detection wires 6A (second detection wires 6B) is approximately half the thickness of the first pad portion 21A (second pad portion 21B). The first detection wires 6A and the second detection wires 6B are formed by, for example, half-etching the conductive portion 2.

[0045] The first detection wire 6A has a fifth extension portion 615 and a seventh extension portion 617. As shown in FIGS. 6 and 7 , the fifth extension portion 615 is connected to the first pad portion 21A and extends from the first pad portion 21A toward the x2 side in the first direction x in the thickness direction z. The fifth extension portion 615 overlaps the resistor 5 in the thickness direction z. The seventh extension portion 617 is connected to the fifth extension portion 615 and extends toward the y1 side in the second direction y. The seventh extension portion 617 has a portion that overlaps the resistor 5 and a portion that does not overlap the resistor 5 in the thickness direction z. With the above configuration, the first detection wire 6A (fifth extension portion 615) is electrically connected to the first pad portion 21A. The first detection wire 6A is electrically connected to the first portion 5A of the resistor 5 via the first pad portion 21A and the first conductive bonding material 29A. The first detection wire 6A (seventh extending portion 617) is electrically connected to a detection terminal 73 (see FIG. 1) not shown.

[0046] The second detection wire 6B has a sixth extension portion 616 and an eighth extension portion 618. As shown in FIGS. 6 and 7 , the sixth extension portion 616 is connected to the second pad portion 21B and extends from the second pad portion 21B toward the x1 side in the first direction x as viewed in the thickness direction z. The sixth extension portion 616 overlaps the resistor 5 as viewed in the thickness direction z. The eighth extension portion 618 is connected to the sixth extension portion 616 and extends toward the y1 side in the second direction y. The eighth extension portion 618 has a portion that overlaps the resistor 5 and a portion that does not overlap the resistor 5 as viewed in the thickness direction z. With the above configuration, the second detection wire 6B (sixth extension portion 616) is electrically connected to the second pad portion 21B. The second detection wire 6B is electrically connected to the second portion 5B of the resistor 5 via the second pad portion 21B and the second conductive bonding material 29B. The second detection wire 6B (eighth extending portion 618) is electrically connected to a detection terminal 74 (see FIG. 1) not shown.

[0047] According to the mounting structure A12 of this modified example, by incorporating the resistor 5, it is possible to detect the current flowing through the conductive portion 2. Furthermore, on the circuit board on which the mounting structure A12 is mounted, there is no need to install a separate resistor or route wiring for the resistor, which allows for space saving.

[0048] The conductive portion 2 includes a first conductive portion 2A and a second conductive portion 2B arranged on the first main surface 101 of the substrate 1. The first conductive portion 2A has a first pad portion 21A arranged on the x1 side in the first direction x, and the second conductive portion 2B has a second pad portion 21B arranged on the x2 side in the first direction x and spaced apart from the first pad portion 21A. The resistor 5 has a first portion 5A overlapping the first pad portion 21A as viewed in the thickness direction z and a second portion 5B overlapping the second pad portion 21B as viewed in the thickness direction z. A first conductive bonding material 29A is interposed between the first pad portion 21A (first pad main surface 210a) and the first portion 5A, and the first conductive bonding material 29A bonds the first pad portion 21A (first pad main surface 210a) and the first portion 5A. A second conductive bonding material 29B is interposed between the second pad portion 21B (second pad main surface 210b) and the second portion 5B, and the second conductive bonding material 29B bonds the second pad portion 21B (second pad main surface 210b) and the second portion 5B. With this configuration, the resistor 5 can be appropriately positioned on the path through which a current flows in the conductive portion 2.

[0049] The first conductive portion 2A has a first detection wire 6A. The first detection wire 6A has a fifth extension portion 615, which extends from the first pad portion 21A to the x2 side in the first direction x as viewed in the thickness direction z. The second conductive portion 2B has a second detection wire 6B. The second detection wire 6B has a sixth extension portion 616, which extends from the second pad portion 21B to the x1 side in the first direction x as viewed in the thickness direction z. With the above configuration, a conductive path is formed from the first portion 5A of the resistor 5 to the fifth extension portion 615 via the first conductive bonding material 29A and the first pad portion 21A. The first detection wire 6A has a smaller thickness (dimension in the thickness direction z) than the first pad portion 21A, and the first wiring main surface 60a of the first detection wire 6A is located closer to the z2 side in the thickness direction z than the first pad main surface 210a of the first pad portion 21A. With this configuration, as shown in FIG. 7 , at the end of the first pad portion 21A on the x2 side in the first direction x, there is a step in the thickness direction z between the fifth extension portion 615 (first detection wire 6A). This prevents the first conductive bonding material 29A made of solder from flowing unduly toward the x2 side in the first direction x on the first pad portion 21A during melt bonding. Similarly, on the second portion 5B side of the resistor 5, a conductive path is formed from the second portion 5B to the sixth extension portion 616 via the second conductive bonding material 29B and the second pad portion 21B. The second detection wire 6B is thinner than the second pad portion 21B, and the second wiring main surface 60b of the second detection wire 6B is located closer to the z2 side in the thickness direction z than the second pad main surface 210b of the second pad portion 21B. At the end of the second pad portion 21B on the x1 side in the first direction x, there is a step in the thickness direction z between the sixth extension portion 616 (the second detection wire 6B). This prevents the second conductive bonding material 29B, which is made of solder, from flowing unduly toward the x1 side in the first direction x on the second pad portion 21B during melt bonding. With this configuration, the contact point of the first conductive bonding material 29A with the first portion 5A (resistor 5) on the x2 side in the first direction x can be set based on the position of the end of the first pad portion 21A on the x2 side in the first direction x.Furthermore, the contact point between the second conductive bonding material 29B and the second portion 5B (resistor 5) on the x1 side in the first direction x can be set based on the position of the end of the second pad 21B on the x1 side in the first direction x. Therefore, the resistance value of the resistor 5 appears properly, and the current flowing through the conductive portion 2 can be detected accurately.

[0050] The first detection wire 6A has a seventh extension portion 617. The seventh extension portion 617 is connected to the fifth extension portion 615 and extends toward the y1 side in the second direction y. The second detection wire 6B has an eighth extension portion 618. The eighth extension portion 618 is connected to the sixth extension portion 616 and extends toward the y1 side in the second direction y. With this configuration, the first detection wire 6A and the second detection wire 6B can be appropriately routed from below the resistor 5 to its periphery while preventing short-circuiting. Note that in this embodiment, the seventh extension portion 617 and the eighth extension portion 618 are configured to extend to the same side in the second direction y (the y1 side in the second direction y), but the seventh extension portion 617 and the eighth extension portion 618 may be configured to extend to opposite sides in the second direction y.

[0051] Third Modification of First Embodiment: Figures 8 and 9 show a mounting structure according to a third modification of the first embodiment. Figure 8 is an enlarged plan view of a main portion of a mounting structure A13 of this modification. Figure 9 is a cross-sectional view taken along line IX-IX in Figure 8. In the mounting structure A13 of this modification, an insulating film 9 is additionally provided compared to the mounting structure A12 of the second modification. The specific configuration of the insulating film 9 is not limited in any way, and it may be formed of, for example, a resist layer or polyimide resin.

[0052] The insulating film 9 is disposed in predetermined regions on the first main surface 101 and the detection wiring portion 6 (the first detection wiring 6A and the second detection wiring 6B). As shown in FIG. 9 , the insulating film 9 is interposed between the fifth extension portion 615 (the first detection wiring 6A) and the resistor 5, and between the sixth extension portion 616 (the second detection wiring 6B) and the resistor 5. The insulating film 9 contacts the end of the first pad portion 21A on the x2 side in the first direction x and the end of the second pad portion 21B on the x1 side in the first direction x. The first conductive bonding material 29A and the second conductive bonding material 29B are each in contact with the insulating film 9. The insulating film 9 having the above configuration is formed before the resistor 5 is disposed on the first pad portion 21A and the second pad portion 21B.

[0053] According to the mounting structure A13 of this modification, the resistor 5 is built in, thereby enabling detection of the current flowing through the conductive portion 2. Furthermore, a circuit board on which the mounting structure A13 is mounted does not require a separate resistor or resistor wiring, thereby saving space. The mounting structure A13 additionally includes an insulating film 9. The insulating film 9 is interposed between the fifth extension 615 (first detection wiring 6A) and the resistor 5, and between the sixth extension 616 (second detection wiring 6B) and the resistor 5. The first conductive bonding material 29A and the second conductive bonding material 29B are in contact with the insulating film 9. This configuration allows the contact point of the first conductive bonding material 29A with the first portion 5A (resistor 5) on the x2 side in the first direction x and the contact point of the second conductive bonding material 29B with the second portion 5B (resistor 5) on the x1 side in the first direction x to be more accurately determined based on the formation position of the insulating film 9. Therefore, the resistance value of the resistor 5 appears more appropriately, and it is possible to more accurately detect the current flowing through the conductive portion 2. In addition, the same effects as those of the mounting structure A12 of the above-described modified example are achieved.

[0054] The mounting structure (resistor mounting structure) according to the present disclosure is not limited to the above-described embodiment. The specific configuration of each part of the resistor mounting structure according to the present disclosure can be freely modified in various ways.

[0055] In the above embodiment, the resistor 5 has two terminals corresponding to the first portion 5A and the second portion 5B, but it may also have four terminals including two additional terminals for detection. The resistor 5 can be modified as appropriate regardless of the number of terminals. When the resistor 5 has four terminals, the configurations of the first pad portion 21A and the second pad portion 21B and the detection wiring portion 6 (the first detection wiring 6A and the second detection wiring 6B) can be modified as appropriate to suit the configuration of the resistor 5.

[0056] The present disclosure includes configurations relating to the following notes.

[0057] Supplementary Note 1: A semiconductor device comprising: a substrate; a conductive portion supported by the substrate; a resistor arranged in a path through which a current flows in the conductive portion; and a detection wiring portion conducting to the resistor, wherein the substrate has a first main surface facing one side in a thickness direction, the conductive portion includes a first conductive portion and a second conductive portion each arranged on the first main surface, the first conductive portion has a first pad portion arranged on one side in a first direction perpendicular to the thickness direction, the second conductive portion has a second pad portion arranged spaced apart from the first pad portion on the other side in the first direction, the resistor has a first portion overlapping the first pad portion when viewed in the thickness direction and a second portion overlapping the second pad portion when viewed in the thickness direction, the first pad portion has a first pad main surface facing one side in the thickness direction, and the second pad portion has a second pad main surface facing one side in the thickness direction, a first conductive bonding material interposed between the first pad main surface and the first portion and bonding the first pad main surface and the first portion together, and a second conductive bonding material interposed between the second pad main surface and the second portion and bonding the second pad main surface and the second portion together; the detection wiring portion includes a first detection wiring that is conductive to the first pad portion and a second detection wiring that is conductive to the second pad portion; the first detection wiring has a first wiring main surface facing one side in the thickness direction; the second detection wiring has a second wiring main surface facing one side in the thickness direction; the first wiring main surface is located on the other side in the thickness direction of the first pad main surface; and the second wiring main surface is located on the other side in the thickness direction of the second pad main surface. Supplementary Note 2: The resistor mounting structure according to Supplementary Note 1, further comprising: a first bonding layer interposed between the first main surface and the first pad portion and bonding the first main surface and the first pad portion together; and a second bonding layer interposed between the first main surface and the second pad portion and bonding the first main surface and the second pad portion together. Supplementary Note 3: The resistor mounting structure according to Supplementary Note 2, wherein the first bonding layer and the second bonding layer are each conductive, the first bonding layer includes the first detection wiring, and the second bonding layer includes the second detection wiring.Supplementary Note 4: The resistor mounting structure according to Supplementary Note 3, wherein the first detection wire has a first extension portion extending from the first pad portion to the other side in the first direction when viewed in the thickness direction, and the second detection wire has a second extension portion extending from the second pad portion to one side in the first direction when viewed in the thickness direction. Supplementary Note 5: The resistor mounting structure according to Supplementary Note 4, wherein the first detection wire has a third extension portion connected to the first extension portion and extending in a second direction perpendicular to the thickness direction and the first direction, and the second detection wire has a fourth extension portion connected to the second extension portion and extending in the second direction. Supplementary Note 6: The resistor mounting structure according to any of Supplements 2 to 5, wherein a constituent material of the substrate is ceramics. Supplementary Note 7: The resistor mounting structure of Supplementary Note 1, wherein the first conductive portion has the first detection wiring, The second conductive portion has the second detection wiring, The first detection wiring is connected to the first pad portion and has a thickness smaller than that of the first pad portion, The second detection wiring is connected to the second pad portion and has a thickness smaller than that of the second pad portion. Supplementary Note 8: The resistor mounting structure of Supplementary Note 7, wherein the first detection wiring is connected to the first pad portion and has a fifth extension portion extending from the first pad portion to the other side in the first direction, The second detection wiring is connected to the second pad portion and has a sixth extension portion extending from the second pad portion to one side in the first direction. Supplementary Note 9: The resistor mounting structure according to Supplementary Note 8, wherein the first detection wiring has a seventh extension portion connected to the fifth extension portion and extending in a second direction perpendicular to the thickness direction and the first direction, and the second detection wiring has an eighth extension portion connected to the sixth extension portion and extending in the second direction.Supplementary Note 10: The resistor mounting structure according to any one of Supplementary Notes 7 to 9, further comprising a backside metal layer bonded to a surface of the substrate facing opposite to the first main surface, and wherein a constituent material of the substrate is ceramics.Supplementary Note 11: The resistor mounting structure according to any one of Supplementary Notes 1 to 10, further comprising an insulating film interposed between the first detection wiring and the resistor, and between the second detection wiring and the resistor, wherein the first conductive bonding material and the second conductive bonding material are in contact with the insulating film. Supplementary Note 12: The resistor mounting structure according to any one of Supplementary Notes 1 to 11, wherein the first conductive bonding material and the second conductive bonding material are made of solder.

[0058] A1, A11, A12, A13: mounting structure 1: substrate 2: conductive portion 2A: first conductive portion 2B: second conductive portion 21A: first pad portion 21B: second pad portion 210a: first pad main surface 210b: second pad main surface 23: back surface metal layer 25A: first bonding layer 25B: second bonding layer 29A: first conductive bonding material 29B: second conductive bonding material 5: resistor 5A: first portion 5B: second portion 6: detection wiring portion 6A: first detection wiring 6B: second detection wiring 60a: first wiring main surface 60b: second wiring main surface 611: first extension portion 612: second extension portion 613: third extension portion 614: fourth extension portion 615: fifth extension portion 616: Sixth extending portion 617: Seventh extending portion 618: Eighth extending portion 71, 72: Terminals 73, 74: Detection terminals 8: Sealing resin 9: Insulating film

Claims

1. A substrate; A conductive portion supported by the substrate; a resistor disposed in a path through which a current flows in the conductive portion; A detection wiring portion that is electrically connected to the resistor, The substrate has a first main surface facing one side in a thickness direction, the conductive portion includes a first conductive portion and a second conductive portion each disposed on the first main surface; the first conductive portion has a first pad portion arranged on one side in a first direction perpendicular to the thickness direction, the second conductive portion has a second pad portion disposed on the other side in the first direction and spaced apart from the first pad portion, the resistor has a first portion overlapping the first pad portion when viewed in the thickness direction, and a second portion overlapping the second pad portion when viewed in the thickness direction, the first pad portion has a first pad main surface facing one side in the thickness direction, the second pad portion has a second pad main surface facing one side in the thickness direction, a first conductive bonding material interposed between the first pad main surface and the first portion and bonding the first pad main surface and the first portion; and a second conductive bonding material interposed between the second pad main surface and the second portion and bonding the second pad main surface and the second portion, the detection wiring section includes a first detection wiring that is electrically connected to the first pad section and a second detection wiring that is electrically connected to the second pad section; the first detection wiring has a first wiring main surface facing one side in the thickness direction, the second detection wiring has a second wiring main surface facing one side in the thickness direction, the first wiring main surface is located on the other side in the thickness direction than the first pad main surface, A mounting structure of a resistor, wherein the second wiring main surface is located on the other side in the thickness direction than the second pad main surface.

2. 2. The resistor mounting structure of claim 1, further comprising: a first bonding layer interposed between the first main surface and the first pad portion and bonding the first main surface and the first pad portion; and a second bonding layer interposed between the first main surface and the second pad portion and bonding the first main surface and the second pad portion.

3. the first bonding layer and the second bonding layer each have electrical conductivity; the first bonding layer includes the first detection wiring, The resistor mounting structure according to claim 2 , wherein the second bonding layer includes the second detection wiring.

4. the first detection wiring has a first extension portion extending from the first pad portion to the other side in the first direction as viewed in the thickness direction, The resistor mounting structure according to claim 3 , wherein the second detection wire has a second extension portion extending from the second pad portion to one side in the first direction when viewed in the thickness direction.

5. the first detection wiring has a third extension portion connected to the first extension portion and extending in a second direction perpendicular to the thickness direction and the first direction; The resistor mounting structure according to claim 4 , wherein the second detection wiring has a fourth extension portion connected to the second extension portion and extending in the second direction.

6. 6. The resistor mounting structure according to claim 2, wherein the material of said substrate is ceramic.

7. the first conductive portion has the first detection wiring, the second conductive portion includes the second detection wiring, the first detection wiring is connected to the first pad portion and has a thickness smaller than that of the first pad portion; 2. The resistor mounting structure according to claim 1, wherein the second detection wire is connected to the second pad portion and has a thickness smaller than that of the second pad portion.

8. the first detection wiring has a fifth extension portion connected to the first pad portion and extending from the first pad portion to the other side in the first direction, 8. The resistor mounting structure according to claim 7, wherein the second detection wiring has a sixth extension portion connected to the second pad portion and extending from the second pad portion to one side in the first direction.

9. the first detection wiring has a seventh extension portion connected to the fifth extension portion and extending in a second direction perpendicular to the thickness direction and the first direction; The resistor mounting structure according to claim 8 , wherein the second detection wiring has an eighth extension portion connected to the sixth extension portion and extending in the second direction.

10. a back metal layer bonded to a surface of the substrate facing away from the first main surface, 10. The resistor mounting structure according to claim 7, wherein the material of the substrate is ceramic.

11. an insulating film is provided between the first detection wiring and the resistor and between the second detection wiring and the resistor; 8. The resistor mounting structure according to claim 1, wherein the first conductive bonding material and the second conductive bonding material are in contact with the insulating film.

12. 8. The resistor mounting structure according to claim 1, wherein the first conductive bonding material and the second conductive bonding material are made of solder.