Semiconductor device and manufacturing method for the semiconductor device

Abstract

To provide a semiconductor device and a manufacturing method of the same, which are capable of improving a bonding state of a conductive member to each of a plurality of electrodes of a semiconductor element while coping with a larger current.SOLUTION: A semiconductor device A10 includes a die pad, a semiconductor element 20, bonding layers 21 and 22, a first conductive member 31, and a second conductive member 32. The semiconductor element includes a first electrode provided to face a main surface of the die pad, a second electrode 202 provided on a side opposite to the first electrode in a thickness direction, and a third electrode 203. The first electrode is electrically bonded to the main surface. Each bonding layer electrically bonds the first electrode and the main surface. The first conductive member is electrically bonded to the second electrode. The second conductive member is electrically bonded to the third electrode. When viewed along a thickness direction, an area of the third electrode is smaller than an area of the second electrode. A Young ratio of the second conductive member is smaller than a Young ratio of the first conductive member.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present disclosure relates to a semiconductor device including a semiconductor element such as a MOSFET, and a method for manufacturing the semiconductor device. [Background technology]

[0002] Semiconductor devices equipped with semiconductor elements such as MOSFETs that convert current based on electrical signals are widely known. Such semiconductor devices are used in electronic devices equipped with power conversion circuits, such as DC-DC converters. Patent Document 1 discloses an example of a semiconductor device incorporating a MOSFET. The semiconductor device includes a drain lead to which a power supply voltage is applied, a gate lead for inputting an electrical signal to the MOSFET, and a source lead through which a current corresponding to the power supply voltage is converted based on the electrical signal and then flows. The MOSFET has a drain electrode connected to the drain lead, a gate electrode connected to the gate lead, and a source electrode connected to the source lead. The drain electrode is electrically connected to the drain lead by solder. Metal clips are electrically connected to the gate electrode and gate lead, and to the source electrode and source lead, respectively. This allows a larger current to flow through the semiconductor device.

[0003] In recent years, semiconductor devices equipped with MOSFETs including compound semiconductor substrates made of materials such as silicon carbide have become increasingly popular. Compared to conventional MOSFETs, these MOSFETs offer the advantage of being able to improve current conversion efficiency while reducing the device size. When using the MOSFET in the semiconductor device disclosed in Patent Document 1, misalignment of the MOSFET with respect to the drain lead may occur when electrically connecting the drain electrode to the drain lead with solder. This is due to the relatively small weight of the MOSFET and the fact that the solder is melted by reflow. Furthermore, the area of ​​the gate electrode is smaller than the area of ​​the source electrode when viewed along the thickness direction of the drain lead. Therefore, misalignment of the MOSFET with respect to the die pad may significantly reduce the bonding area of ​​the metal clip to the gate electrode. This deteriorates the bonding condition of the metal clip to the gate electrode, resulting in a decrease in the yield of the semiconductor device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-274206 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above circumstances, the present disclosure aims to provide a semiconductor device that can accommodate larger currents while improving the bonding state of a conductive member to each of multiple electrodes of a semiconductor element, and a manufacturing method thereof. [Means for solving the problem]

[0006] A first aspect of the present disclosure provides a semiconductor device having a die pad having a main surface facing a thickness direction, a first electrode provided opposite the main surface, and a second electrode and a third electrode provided on the opposite side of the first electrode in the thickness direction and positioned apart from each other, and further comprising: a semiconductor element in which the first electrode is electrically connected to the main surface; a first bonding layer electrically connecting the first electrode to the main surface; a first conductive member electrically connected to the second electrode; and a second conductive member electrically connected to the third electrode, wherein, when viewed along the thickness direction, the area of ​​the third electrode is smaller than the area of ​​the second electrode, and the Young's modulus of the second conductive member is smaller than the Young's modulus of the first conductive member.

[0007] A second aspect of the present disclosure provides a method for manufacturing a semiconductor device, comprising the steps of: placing a conductive bonding material on a main surface of a die pad facing a thickness direction; a semiconductor element having a first electrode and a second electrode facing opposite each other in the thickness direction and a third electrode provided on the same side as the second electrode in the thickness direction and spaced apart from the second electrode; placing the semiconductor element on the bonding material so that the first electrode faces the bonding material; electrically bonding the first electrode to the main surface by melting and solidifying the bonding material; electrically bonding a first conductive member to the second electrode; and electrically bonding a second conductive member to the third electrode; wherein, when viewed along the thickness direction, an area of ​​the third electrode is smaller than an area of ​​the second electrode, and a Young's modulus of the second conductive member is smaller than that of the first conductive member. [Effects of the Invention]

[0008] The semiconductor device and the manufacturing method thereof according to the present disclosure can accommodate a larger current while improving the bonding state of the conductive member to each of the multiple electrodes of the semiconductor element.

[0009] Other features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view of a semiconductor device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a plan view of the semiconductor device shown in FIG. [Figure 3] FIG. 3 is a plan view corresponding to FIG. 2, seen through the sealing resin. [Figure 4] FIG. 2 is a bottom view of the semiconductor device shown in FIG. [Figure 5] FIG. 2 is a front view of the semiconductor device shown in FIG. [Figure 6] FIG. 2 is a right side view of the semiconductor device shown in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. [Figure 10] FIG. 4 is a cross-sectional view taken along line XX in FIG. [Figure 11] FIG. 4 is a partially enlarged view of FIG. [Figure 12] FIG. 8 is a partially enlarged view of FIG. [Figure 13] FIG. 8 is a partially enlarged view of FIG. [Figure 14] FIG. 9 is a partially enlarged view of FIG. 8. [Figure 15] 2 is a plan view illustrating a manufacturing process of the semiconductor device shown in FIG. [Figure 16] 2 is a plan view illustrating a manufacturing process of the semiconductor device shown in FIG. [Figure 17] 2 is a plan view illustrating a manufacturing process of the semiconductor device shown in FIG. [Figure 18] 2A to 2C are partially enlarged cross-sectional views illustrating a manufacturing process of the semiconductor device shown in FIG. [Figure 19] 2 is a plan view illustrating a manufacturing process of the semiconductor device shown in FIG. [Figure 20]2A to 2C are partially enlarged cross-sectional views illustrating a manufacturing process of the semiconductor device shown in FIG. [Figure 21] 2A to 2C are partially enlarged cross-sectional views illustrating a manufacturing process of the semiconductor device shown in FIG. [Figure 22] 2 is a plan view illustrating a manufacturing process of the semiconductor device shown in FIG. [Figure 23] 2 is a plan view illustrating a manufacturing process of the semiconductor device shown in FIG. [Figure 24] 2 is a plan view illustrating the function and effect of the semiconductor device shown in FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0012] A semiconductor device A10 according to one embodiment of the present disclosure will be described with reference to FIGS. 1 to 14. The semiconductor device A10 is used in electronic devices equipped with a power conversion circuit, such as a DC-DC converter. The semiconductor device A10 includes a die pad 10, a first lead 11, a second lead 12, a third lead 13, a semiconductor element 20, a first bonding layer 21, a second bonding layer 22, a third bonding layer 23, a first conductive member 31, a second conductive member 32, and a sealing resin 40. For ease of understanding, FIG. 3 shows the sealing resin 40 in a perspective view. In FIG. 3, the transmitted sealing resin 40 is indicated by an imaginary line (a two-dot chain line).

[0013] In describing the semiconductor device A10, for convenience, the thickness direction of the die pad 10 will be referred to as the "thickness direction z." The direction perpendicular to the thickness direction z will be referred to as the "first direction x." The direction perpendicular to both the thickness direction z and the first direction x will be referred to as the "second direction y." When viewed along the thickness direction z, the first direction x corresponds to the longitudinal direction of the semiconductor device A10. When viewed along the thickness direction z, the second direction y corresponds to the lateral direction of the semiconductor device A10.

[0014] As shown in FIG. 3 and FIGS. 7 to 9, the die pad 10 is a conductive member on which a semiconductor element 20 is mounted. The die pad 10, together with a first lead 11, a second lead 12, and a third lead 13, is formed from the same lead frame. The lead frame is made of copper (Cu) or a copper alloy. Therefore, the die pad 10, the first lead 11, the second lead 12, and the third lead 13 each contain copper (i.e., each member contains copper). As shown in FIG. 9, the die pad 10 has a main surface 101, a back surface 102, and a through hole 103. The main surface 101 faces the thickness direction z. The semiconductor element 20 is mounted on the main surface 101. The back surface 102 faces the opposite side to the main surface 101 in the thickness direction z. The back surface 102 is plated with, for example, tin (Sn). The through hole 103 penetrates the die pad 10 from the main surface 101 to the back surface 102 in the thickness direction z. The through hole 103 has a circular shape when viewed along the thickness direction z. As shown in FIG. 7 , the thickness T of the die pad 10 is 1 / 2 times the maximum thickness t of the first lead 11. max is greater than

[0015] As shown in FIG. 3 and FIGS. 7 to 9, the semiconductor element 20 is mounted on the main surface 101 of the die pad 10. The semiconductor element 20 is, for example, a vertical-structure metal-oxide-semiconductor field-effect transistor (MOSFET). In the description of the semiconductor device A10, the semiconductor element 20 is an n-channel, vertical-structure MOSFET. The semiconductor element 20 includes a compound semiconductor substrate. The main material of the compound semiconductor substrate is silicon carbide (SiC). Alternatively, gallium nitride (GaN) may be used as the main material of the compound semiconductor substrate. In the semiconductor device A10, the area of ​​the semiconductor element 20, as viewed along the thickness direction z, is 40% or less of the area of ​​the main surface 101 of the die pad 10. As viewed along the thickness direction z, the area of ​​the semiconductor element 20 may be 20% or less, or even 10% or less, of the area of ​​the main surface 101. This ratio may vary depending on the transition between the area of ​​the semiconductor element 20 and the area of ​​the main surface 101. As shown in Figures 11, 12 and 14, the semiconductor element 20 has a first electrode 201, a second electrode 202 and a third electrode 203.

[0016] 12 and 14, the first electrode 201 is provided opposite the main surface 101 of the die pad 10. A DC power supply voltage to be converted into power is applied to the first electrode 201. In other words, the first electrode 201 corresponds to a drain electrode.

[0017] 12 and 14, the second electrode 202 is provided on the opposite side to the first electrode 201 in the thickness direction z. A current converted by the semiconductor element 20 flows through the second electrode 202. In other words, the second electrode 202 corresponds to a source electrode.

[0018] 11 and 14, the third electrode 203 is provided on the opposite side of the first electrode 201 in the thickness direction z and is located away from the second electrode 202. A gate voltage for driving the semiconductor element 20 is applied to the third electrode 203. That is, the third electrode 203 corresponds to a gate electrode. Based on the gate voltage, the semiconductor element 20 converts a current corresponding to the power supply voltage applied to the first electrode 201. When viewed along the thickness direction z, the area of ​​the third electrode 203 is smaller than the area of ​​the second electrode 202.

[0019] As shown in FIGS. 12 and 14 , the first bonding layer 21 includes a portion interposed between the main surface 101 of the die pad 10 and the first electrode 201 of the semiconductor element 20. The first bonding layer 21 is conductive. The first bonding layer 21 electrically bonds the first electrode 201 to the main surface 101. As a result, in the semiconductor device A10, the first electrode 201 is electrically bonded to the main surface 101 and is electrically connected to the die pad 10. The first bonding layer 21 contains tin. The material of the first bonding layer 21 is, for example, lead-free solder. The first bonding layer 21 may also be lead solder.

[0020] As shown in FIGS. 3 and 7 , the first lead 11 is located away from the die pad 10. The first lead 11 extends along the first direction x. The first lead 11 is electrically connected to the second electrode 202 of the semiconductor element 20. Therefore, the first lead 11 corresponds to the source terminal of the semiconductor device A10. The first lead 11 has a covering portion 111, an exposed portion 112, and a first bonding surface 113. The covering portion 111 is covered with the sealing resin 40. The exposed portion 112 is connected to the covering portion 111 and is exposed from the sealing resin 40. The exposed portion 112 extends away from the die pad 10 in the first direction x. The surface of the exposed portion 112 is, for example, tin-plated. The first bonding surface 113 faces the same side as the main surface 101 of the die pad 10 in the thickness direction z. The first bonding surface 113 is included in part of the covering portion 111. In the thickness direction z, the first bonding surface 113 is located closer to the semiconductor element 20 than the main surface 101.

[0021] As shown in FIGS. 3 and 8 , the second lead 12 is located away from both the die pad 10 and the first lead 11. The second lead 12 extends along the first direction x. In the semiconductor device A10, the second lead 12 is located on the opposite side of the first lead 11 with respect to the third lead 13 in the second direction y. The second lead 12 is electrically connected to the third electrode 203 of the semiconductor element 20. Therefore, the second lead 12 corresponds to the gate terminal of the semiconductor device A10. The second lead 12 has a covering portion 121, an exposed portion 122, and a second bonding surface 123. The covering portion 121 is covered with the sealing resin 40. The exposed portion 122 is connected to the covering portion 121 and is exposed from the sealing resin 40. The exposed portion 122 extends away from the die pad 10 in the first direction x. The surface of the exposed portion 122 is tin-plated. The second bonding surface 123 faces the same side as the main surface 101 of the die pad 10 in the thickness direction z. The second bonding surface 123 is included in part of the covering portion 121. In the thickness direction z, the second bonding surface 123 is located closer to the semiconductor element 20 than the main surface 101. As shown in FIG. 10 , the position of the second bonding surface 123 is the same as the position of the first bonding surface 113 of the first lead 11 in the thickness direction z.

[0022] As shown in FIGS. 3 and 9 , the third lead 13 includes a portion extending in the first direction x and is connected to the die pad 10. The material of the third lead 13 is the same as the material of the die pad 10. The third lead 13 has a covering portion 131 and an exposed portion 132. The covering portion 131 is connected to the die pad 10 and is covered with the sealing resin 40. When viewed along the second direction y, the covering portion 131 is bent. The exposed portion 132 is connected to the covering portion 131 and is exposed from the sealing resin 40. The exposed portion 132 extends away from the die pad 10 in the first direction x. The surface of the exposed portion 132 is tin-plated.

[0023] 5, in the semiconductor device A10, the height h of the exposed portion 112 of the first lead 11, the exposed portion 122 of the second lead 12, and the exposed portion 132 of the third lead 13 are all the same. Therefore, when viewed along the second direction y, at least a portion of the third lead 13 (exposed portion 132) overlaps with each of the first lead 11 and the second lead 12 (see FIG. 6).

[0024] As shown in FIGS. 3 and 7 , the first conductive member 31 is electrically connected to the second electrode 202 of the semiconductor element 20 and the first bonding surface 113 of the first lead 11. This electrically connects the first lead 11 to the second electrode 202. The first conductive member 31 contains copper. In the semiconductor device A10, the first conductive member 31 is a fixed-length metal clip. As shown in FIGS. 12 and 13 , the first conductive member 31 has a first bonding portion 311 and a second bonding portion 312. The first bonding portion 311 is located at one end of the first conductive member 31 and electrically connects the first conductive member 31 to the second electrode 202. The second bonding portion 312 is located at the other end of the first conductive member 31 and electrically connects the first conductive member 31 to the first bonding surface 113.

[0025] As shown in FIG. 12 , the second bonding layer 22 includes a portion interposed between the second electrode 202 of the semiconductor element 20 and the first bonding portion 311 of the first conductive member 31. The second bonding layer 22 is conductive. The second bonding layer 22 electrically bonds the first bonding portion 311 and the second electrode 202. As a result, in the semiconductor device A10, the first conductive member 31 is electrically bonded to the second electrode 202, and the first conductive member 31 is electrically connected to the second electrode 202. The second bonding layer 22 contains tin. The second bonding layer 22 is made of the same material as the first bonding layer 21. Furthermore, the thickness t1 of the first bonding layer 21 is greater than the thickness t2 of the second bonding layer 22.

[0026] 13 , the third bonding layer 23 includes a portion interposed between the first bonding surface 113 of the first lead 11 and the second bonding portion 312 of the first conductive member 31. The third bonding layer 23 is conductive. The third bonding layer 23 electrically bonds the second bonding portion 312 and the first bonding surface 113. As a result, in the semiconductor device A10, the first conductive member 31 is electrically bonded to the first bonding surface 113, and the first conductive member 31 is electrically connected to the first lead 11. The third bonding layer 23 is made of the same material as the first bonding layer 21.

[0027] As shown in FIGS. 3 and 8 , the second conductive member 32 is electrically connected to the third electrode 203 of the semiconductor element 20 and the second bonding surface 123 of the second lead 12. This electrically connects the second lead 12 to the third electrode 203. The second conductive member 32 contains aluminum (Al). In the semiconductor device A10, the second conductive member 32 is a wire. The second conductive member 32 is formed by wire bonding. As shown in FIG. 8 , the second conductive member 32 has a third bonding portion 321 and a fourth bonding portion 322. As shown in FIG. 14 , the third bonding portion 321 is located at one end of the second conductive member 32 and electrically connects the second conductive member 32 to the third electrode 203. When the second conductive member 32 is formed by wire bonding, the third bonding portion 321 corresponds to the starting point of the bonding. The fourth joint portion 322 is located at the other end of the second conductive member 32 and electrically joins the second conductive member 32 to the second bonding surface 123. When the second conductive member 32 is formed by wire bonding, the fourth joint portion 322 corresponds to the end point of the bonding.

[0028] The differences between the first conductive member 31 and the second conductive member 32 will be described below. The Young's modulus (elastic modulus) of the second conductive member 32 is smaller than that of the first conductive member 31. As described above, this is because the first conductive member 31 contains copper and the second conductive member 32 contains aluminum. Therefore, the linear expansion coefficient of the second conductive member 32 is larger than that of the first conductive member 31. In addition, the thermal conductivity of the second conductive member 32 is smaller than that of the first conductive member 31. Furthermore, as shown in FIG. 11 , the width B of the first conductive member 31 is larger than the width (diameter) D of the second conductive member 32.

[0029] As shown in FIG. 3 and FIGS. 7 to 10, the sealing resin 40 covers the semiconductor element 20, the first conductive member 31, the second conductive member 32, the die pad 10, and portions of the first lead 11, the second lead 12, and the third lead 13. The sealing resin 40 has electrical insulation properties. The sealing resin 40 is made of a material containing, for example, black epoxy resin. The sealing resin 40 has a top surface 41, a bottom surface 42, a pair of first side surfaces 43, a pair of second side surfaces 44, a pair of openings 45, and a mounting hole 46.

[0030] 7 to 10, the top surface 41 faces the same side as the main surface 101 of the die pad 10 in the thickness direction z. As shown in Figures 7 to 9, the bottom surface 42 faces the opposite side to the top surface 41 in the thickness direction z. The back surface 102 of the die pad 10 is exposed from the bottom surface 42.

[0031] 2, 4, and 6, the pair of first side surfaces 43 are spaced apart from each other in the first direction x. Each of the pair of first side surfaces 43 is connected to the top surface 41 and the bottom surface 42. As shown in FIG. 5, an exposed portion 112 of the first lead 11, an exposed portion 122 of the second lead 12, and an exposed portion 132 of the third lead 13 are exposed from one of the pair of first side surfaces 43.

[0032] As shown in FIGS. 2, 4, and 5, the pair of second side surfaces 44 are spaced apart from each other in the second direction y. Each of the pair of second side surfaces 44 is connected to the top surface 41 and the bottom surface 42. As shown in FIGS. 2, 6, and 8, the pair of openings 45 are spaced apart from each other in the second direction y. Each of the pair of openings 45 is recessed inward into the sealing resin 40 from both the top surface 41 and one of the pair of second side surfaces 44. A portion of the main surface 101 of the die pad 10 is exposed from each of the pair of openings 45. As shown in FIGS. 2, 4, and 9, the mounting hole 46 penetrates the sealing resin 40 from the top surface 41 to the bottom surface 42 in the thickness direction z. When viewed along the thickness direction z, the mounting hole 46 is contained within the through hole 103 of the die pad 10. The peripheral surface of the die pad 10 that defines the through hole 103 is covered with the sealing resin 40. As a result, the maximum dimension of the attachment hole 46 is smaller than the dimension of the through hole 103 when viewed along the thickness direction z.

[0033] Next, an example of a manufacturing method of the semiconductor device A10 will be described with reference to Figures 15 to 23. Here, the cross-sectional positions of Figures 18 and 20 are the same as the cross-sectional position of Figure 12. The cross-sectional position of Figure 21 is the same as the cross-sectional position of Figure 13.

[0034] First, as shown in FIG. 15 , a first bonding material 81 is placed on the main surface 101 of the die pad 10. Here, the first lead 11, the second lead 12, and the third lead 13 are connected to one another by tie bars 80 that form a lead frame. The tie bars 80 extend along the second direction y. The first bonding material 81 is conductive. The first bonding material 81 is cream solder or wire solder. When the first bonding material 81 is wire solder, the first bonding material 81 is temporarily attached to the main surface 101.

[0035] 16 , the semiconductor element 20 is placed on the first bonding material 81. At this time, the first electrode 201 of the semiconductor element 20 faces the first bonding material 81. When the first bonding material 81 is wire solder, the first electrode 201 is temporarily attached to the first bonding material 81.

[0036] 17 and 18 , the first bonding material 81 is melted by reflow and then solidified by cooling, thereby electrically bonding the first electrode 201 of the semiconductor element 20 to the main surface 101 of the die pad 10. In this step, the first bonding material 81 solidified by cooling becomes the first bonding layer 21.

[0037] Next, as shown in FIGS. 20 and 21 , a second bonding material 82 is placed on the second electrode 202 of the semiconductor element 20, and a third bonding material 83 is placed on the first bonding surface 113 of the first lead 11. The second bonding material 82 and the third bonding material 83 are each made of the same bonding material as the first bonding material 81. The second bonding material 82 and the third bonding material 83 are each conductive. If the second bonding material 82 and the third bonding material 83 are each made of cream solder, a dispenser or the like is used to place them. Thereafter, the first conductive member 31 is electrically bonded to the second electrode 202 and the first bonding surface 113 by clip bonding. For this clip bonding, the first bonding portion 311 of the first conductive member 31 is placed on the second bonding material 82. Additionally, the second bonding portion 312 of the first conductive member 31 is placed on the third bonding material 83. Thereafter, the second bonding material 82 and the third bonding material 83 are melted by reflow and then solidified by cooling, thereby electrically bonding the first bonding portion 311 to the second electrode 202. At the same time, the second bonding portion 312 is electrically bonded to the first bonding surface 113. As a result, as shown in FIG. 19 , the first conductive member 31 is electrically bonded to the second electrode 202 and the first bonding surface 113. In this process, the second bonding material 82 solidified by cooling becomes the second bonding layer 22. At the same time, the third bonding material 83 solidified by cooling becomes the third bonding layer 23.

[0038] 22, the second conductive member 32 is electrically joined to the third electrode 203 of the semiconductor element 20 and the second bonding surface 123 of the second lead 12. In this step, the second conductive member 32 is electrically joined to the third electrode 203 and the second bonding surface 123 by wire bonding. Therefore, the second conductive member 32 is formed by this wire bonding.

[0039] Next, as shown in FIG. 23 , a sealing resin 84 is formed to cover the semiconductor element 20, the first conductive member 31, the second conductive member 32, and portions of the die pad 10, the first lead 11, the second lead 12, and the third lead 13. The sealing resin 84 is formed by transfer molding. As the sealing resin 84 is formed, a resin burr 841 is formed. The resin burr 841 is blocked by the exposed portion 112 of the first lead 11, the exposed portion 122 of the second lead 12, the exposed portion 132 of the third lead 13, and the tie bar 80. The resin burr 841 is then removed using high-pressure water or the like. Thereafter, tin plating is applied by electrolytic plating using the tie bar 80 as a conductive path, covering the surfaces of the exposed portion 112 of the first lead 11, the exposed portion 122 of the second lead 12, and the exposed portion 132 of the third lead 13, as well as the back surface 102 of the die pad 10. Finally, the tie bars 80 are cut to obtain the semiconductor device A10.

[0040] Next, the effects of the semiconductor device A10 will be described.

[0041] The semiconductor device A10 includes a first bonding layer 21, a first conductive member 31, and a second conductive member 32. The first bonding layer 21 is conductive and electrically bonds a first electrode 201 of the semiconductor element 20 to a main surface 101 of the die pad 10. The first conductive member 31 is electrically bonded to a second electrode 202 of the semiconductor element 20. The second conductive member 32 is electrically bonded to a third electrode 203 of the semiconductor element 20. When viewed along the thickness direction z, the area of ​​the third electrode 203 is smaller than the area of ​​the second electrode 202. Furthermore, the Young's modulus of the second conductive member 32 is smaller than the Young's modulus of the first conductive member 31.

[0042] In the manufacturing process of the semiconductor device A10 shown in FIGS. 17 and 18, when the first bonding material 81 that forms the first bonding layer 21 is melted, the position of the semiconductor element 20 may shift relative to the die pad 10, as shown in FIG. 24. As a result, the positions of the second electrode 202 and the third electrode 203 of the semiconductor element 20 shift from their original positions. In this case, the area of ​​the second electrode 202 is relatively large when viewed along the thickness direction z, so the bonding state of the first conductive member 31 to the second electrode 202 can be maintained in a good state. However, the area of ​​the third electrode 203 is smaller than the area of ​​the second electrode 202 when viewed along the thickness direction z. Therefore, if the second conductive member 32 is a fixed-length metal clip, the bonding area of ​​the second conductive member 32 to the third electrode 203 may be significantly reduced. Therefore, in the manufacturing process of the semiconductor device A10 shown in FIG. 22, the second conductive member 32 is formed by wire bonding. As a result, the second conductive member 32, which is a wire, is accurately aimed at the misaligned third electrode 203 and bonded thereto, thereby preventing a reduction in the bonding area of ​​the second conductive member 32 to the third electrode 203. Therefore, even if the semiconductor element 20 is misaligned with respect to the die pad 10, the bonding state of the second conductive member 32 to the third electrode 203 is good. In this state, if the Young's modulus of the second conductive member 32 is smaller than that of the first conductive member 31, the impact force acting on the third electrode 203 due to the formation of the second conductive member 32 can be reduced. As described above, the semiconductor device A10 can improve the bonding state of the conductive members (the first conductive member 31 and the second conductive member 32) to each of the multiple electrodes (the second electrode 202 and the third electrode 203) of the semiconductor element 20 while accommodating a larger current.

[0043] The first conductive member 31 contains copper. This allows the electrical resistance of the first conductive member 31 to be reduced compared to aluminum wire. This is advantageous for passing a larger current through the semiconductor element 20.

[0044] The linear expansion coefficient of the second conductive member 32 is greater than the linear expansion coefficient of the first conductive member 31. In contrast, the thermal conductivity of the second conductive member 32 is smaller than the thermal conductivity of the first conductive member 31. As a result, when the semiconductor device A10 is in use, heat generated from the semiconductor element 20 is more likely to be conducted to the second electrode 202 than to the third electrode 203. As a result, it is possible to reduce thermal stress at the interface between the third electrode 203 and the second conductive member 32 while suppressing an increase in on-resistance at the third electrode 203.

[0045] The thickness t1 of the first bonding layer 21 is greater than the thickness t2 of the second bonding layer 22. This allows the heat generated from the semiconductor element 20 to be conducted more quickly to the die pad 10 when the semiconductor device A10 is in use. Furthermore, by using wire solder as the first bonding material 81 in the manufacturing process of the semiconductor device A10, the first bonding layer 21 can be formed with a uniform thickness.

[0046] In the thickness direction z, the first bonding surface 113 of the first lead 11 is located closer to the semiconductor element 20 than the main surface 101 of the die pad 10. This reduces the length of the first conductive member 31, thereby reducing the inductance of the first conductive member 31.

[0047] In the thickness direction z, the second bonding surface 123 of the second lead 12 is located closer to the semiconductor element 20 than the main surface 101 of the die pad 10. This shortens the length of the second conductive member 32, thereby reducing the inductance of the second conductive member 32. This is advantageous for reducing the on-resistance of the third electrode 203 of the semiconductor element 20.

[0048] The die pad 10 contains copper. Furthermore, the thickness T of the die pad 10 is smaller than the maximum thickness t max This makes it possible to improve the efficiency of heat conduction in the direction perpendicular to the thickness direction z while improving the thermal conductivity of the die pad 10. This contributes to improving the heat dissipation performance of the die pad 10.

[0049] The semiconductor device A10 includes a sealing resin 40 that covers the semiconductor element 20, the first conductive member 31, the second conductive member 32, and a portion of the die pad 10. The back surface 102 of the die pad 10 is exposed from the sealing resin 40. This makes it possible to protect the semiconductor element 20, the first conductive member 31, and the second conductive member 32 from the outside while avoiding a decrease in the heat dissipation performance of the semiconductor device A10.

[0050] The semiconductor device A10 further includes a second bonding layer 22 and a third bonding layer 23. The second bonding layer 22 is conductive and electrically bonds the first conductive member 31 to the second electrode 202 of the semiconductor element 20. The third bonding layer 23 is conductive and electrically bonds the first conductive member 31 to the first bonding surface 113 of the first lead 11. The second bonding layer 22 and the third bonding layer 23 are each made of the same material as the first bonding layer 21, which contains tin. As a result, in the manufacturing process of the semiconductor device A10 shown in FIGS. 20 and 21 , when the second bonding material 82 that becomes the second bonding layer 22 is melted, the third bonding material 83 that becomes the third bonding layer 23 is simultaneously melted. Therefore, in the manufacturing process of the semiconductor device A10, when the first conductive member 31 is electrically bonded to the second electrode 202, the first conductive member 31 can be electrically bonded to the first bonding surface 113 at the same time, thereby improving the manufacturing efficiency of the semiconductor device A10.

[0051] The present disclosure is not limited to the above-described embodiment, and the specific configuration of each part of the present disclosure can be freely modified in various ways.

[0052] The present disclosure includes the configurations described in the following appendices. Appendix 1. a die pad having a main surface facing in a thickness direction; a semiconductor element including a first electrode provided opposite to the main surface, and a second electrode and a third electrode provided on the opposite side of the first electrode in the thickness direction and positioned apart from each other, the first electrode being electrically connected to the main surface; a first bonding layer that electrically bonds the first electrode and the main surface; a first conductive member electrically connected to the second electrode; a second conductive member electrically connected to the third electrode; When viewed along the thickness direction, the area of ​​the third electrode is smaller than the area of ​​the second electrode; The semiconductor device, wherein the Young's modulus of the second conductive member is smaller than the Young's modulus of the first conductive member. Appendix 2. 2. The semiconductor device according to claim 1, wherein the first bonding layer contains tin. Appendix 3. a second bonding layer that electrically bonds the first conductive member and the second electrode; 3. The semiconductor device according to claim 2, wherein the second bonding layer is made of the same material as the first bonding layer. Appendix 4. 4. The semiconductor device according to claim 3, wherein the second conductive member has a linear expansion coefficient greater than the linear expansion coefficient of the first conductive member. Appendix 5. 5. The semiconductor device according to claim 4, wherein the second conductive member has a thermal conductivity lower than the thermal conductivity of the first conductive member. Appendix 6. 6. The semiconductor device according to claim 5, wherein the width of the first conductive member is greater than the width of the second conductive member. Appendix 7. the first conductive member contains copper; 7. The semiconductor device according to claim 4, wherein the second conductive member contains aluminum. Appendix 8. 8. The semiconductor device according to claim 4, wherein the area of ​​the semiconductor element is 40% or less of the area of ​​the main surface when viewed along the thickness direction. Appendix 9. 9. The semiconductor device according to claim 8, wherein the semiconductor element includes a compound semiconductor substrate. Appendix 10. a first lead having a first bonding surface facing the same side as the main surface in the thickness direction and positioned away from the die pad; a third bonding layer that electrically bonds the first conductive member and the first bonding surface, the first lead contains copper; 10. The semiconductor device according to any one of claims 3 to 9, wherein the third bonding layer is made of the same material as the first bonding layer. Appendix 11. 11. The semiconductor device according to claim 10, wherein the first bonding surface is located closer to the semiconductor element than the main surface in the thickness direction. Appendix 12. 12. The semiconductor device according to claim 11, wherein the thickness of the die pad is greater than the maximum thickness of the first lead. Appendix 13. a second lead having a second bonding surface facing the same side as the main surface in the thickness direction and positioned away from both the die pad and the first lead; 13. The semiconductor device according to claim 10, wherein the second conductive member is electrically connected to the second bonding surface. Appendix 14. 14. The semiconductor device according to claim 13, wherein the second bonding surface is located closer to the semiconductor element than the main surface in the thickness direction. Appendix 15. each of the first lead and the second lead extends along a first direction perpendicular to the thickness direction; a third lead including a portion extending along the first direction and connected to the die pad; the material of the third lead is the same as the material of the die pad; A semiconductor device as described in Appendix 13 or 14, wherein, when viewed along a second direction perpendicular to both the thickness direction and the first direction, at least a portion of the third lead overlaps each of the first lead and the second lead. Appendix 16. a sealing resin that covers the semiconductor element, the first conductive member, the second conductive member, and a portion of the die pad; the die pad has a back surface facing the opposite side to the main surface in the thickness direction, 16. The semiconductor device according to any one of claims 1 to 15, wherein the back surface is exposed from the sealing resin. Appendix 17. a step of disposing a conductive bonding material on a main surface of a die pad having a main surface facing a thickness direction; a step of placing a semiconductor element on a bonding material such that the first electrode faces the bonding material, the semiconductor element having a first electrode and a second electrode facing opposite sides in the thickness direction, and a third electrode provided on the same side as the second electrode in the thickness direction and positioned apart from the second electrode; melting and solidifying the bonding material to electrically bond the first electrode to the main surface; electrically joining a first conductive member to the second electrode; and electrically connecting the second conductive member to the third electrode; When viewed along the thickness direction, the area of ​​the third electrode is smaller than the area of ​​the second electrode; The method for manufacturing a semiconductor device, wherein the second conductive member has a Young's modulus smaller than the Young's modulus of the first conductive member. Appendix 18. In the step of electrically joining the first conductive member, the first conductive member is electrically joined to the second electrode by clip bonding using the same bonding material as the bonding material; 18. The method for manufacturing a semiconductor device according to claim 17, wherein in the step of electrically joining the second conductive member, the second conductive member is electrically joined to the third electrode by wire bonding. Appendix 19. 19. The method for manufacturing a semiconductor device according to claim 18, wherein the bonding material is wire solder. [Explanation of symbols]

[0053] A10: Semiconductor device 10: Die pad 101: Main surface 102: Back surface 103: Through hole 11: First lead 111: Covered portion 112: Exposed portion 113: First bonding surface 12: Second lead 121: Covered portion 122: Exposed portion 123: Second bonding surface 13: Third lead 131: Covering portion 132: exposed portion 19: plating layer 20: semiconductor element 201: 1st electrode 202: 2nd electrode 203: 3rd electrode 21: First bonding layer 22: Second bonding layer 23: Third bonding layer 31: First conductive member 311: First joint 312: Second joint 32: Second conductive member 321: Third joint 322: Fourth joint 40: Sealing resin 41: Top surface 42: Bottom surface 43: First side 44: Second side 45: Opening 46: Mounting hole 80: Tie bar 81: First joining material 82: Second bonding material 83: Third bonding material z: Thickness direction x: 1st direction y: 2nd direction

Claims

1. a die pad having a main surface facing in a thickness direction; a semiconductor element including a first electrode provided opposite to the main surface, and a second electrode and a third electrode provided on the opposite side of the first electrode in the thickness direction and positioned apart from each other, the first electrode being electrically connected to the main surface; a first bonding layer that electrically bonds the first electrode and the main surface; a first conductive member electrically connected to the second electrode; a second conductive member electrically connected to the third electrode; When viewed along the thickness direction, an area of ​​the third electrode is smaller than an area of ​​the second electrode, The semiconductor device, wherein the second conductive member has a Young's modulus smaller than the Young's modulus of the first conductive member.

2. The semiconductor device according to claim 1 , wherein the first bonding layer contains tin.

3. a second bonding layer that electrically bonds the first conductive member and the second electrode; The semiconductor device according to claim 2 , wherein the second bonding layer is made of the same material as the first bonding layer.

4. 4. The semiconductor device according to claim 3, wherein the second conductive member has a linear expansion coefficient greater than that of the first conductive member.

5. 5. The semiconductor device according to claim 4, wherein the thermal conductivity of said second conductive member is lower than the thermal conductivity of said first conductive member.

6. 6. The semiconductor device according to claim 5, wherein a width of said first conductive member is greater than a width of said second conductive member.

7. the first conductive member contains copper; 7. The semiconductor device according to claim 4, wherein said second conductive member contains aluminum.

8. 8. The semiconductor device according to claim 4, wherein the area of ​​said semiconductor element is 40% or less of the area of ​​said main surface when viewed along said thickness direction.

9. a first lead having a first bonding surface facing the same side as the main surface in the thickness direction and positioned away from the die pad; a third bonding layer that electrically bonds the first conductive member and the first bonding surface, the first lead contains copper; 9. The semiconductor device according to claim 3, wherein the third bonding layer is made of the same material as the first bonding layer.

10. The semiconductor device according to claim 9 , wherein the first bonding surface is located closer to the semiconductor element than the main surface in the thickness direction.

11. 11. The semiconductor device according to claim 10, wherein the thickness of said die pad is greater than the maximum thickness of said first lead.

12. a second lead having a second bonding surface facing the same side as the main surface in the thickness direction and positioned away from both the die pad and the first lead; 12. The semiconductor device according to claim 9, wherein the second conductive member is electrically connected to the second bonding surface.

13. The semiconductor device according to claim 12 , wherein the second bonding surface is located closer to the semiconductor element than the main surface in the thickness direction.

14. a sealing resin that covers the semiconductor element, the first conductive member, the second conductive member, and a portion of the die pad; the die pad has a back surface facing the opposite side to the main surface in the thickness direction, 14. The semiconductor device according to claim 1, wherein the back surface is exposed from the sealing resin.

15. a step of disposing a conductive bonding material on a main surface of a die pad having a main surface facing a thickness direction; a step of placing the semiconductor element on a bonding material such that the first electrode faces the bonding material, the first electrode facing in opposite directions in the thickness direction, and a third electrode provided on the same side as the second electrode in the thickness direction and spaced apart from the second electrode; melting and solidifying the bonding material to electrically bond the first electrode to the main surface; electrically joining a first conductive member to the second electrode; and electrically connecting the second conductive member to the third electrode; When viewed along the thickness direction, an area of ​​the third electrode is smaller than an area of ​​the second electrode, The method for manufacturing a semiconductor device, wherein the second conductive member has a Young's modulus smaller than the Young's modulus of the first conductive member.

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