SiC Semiconductor Device

Abstract

To provide a semiconductor device which prevents detachment of a sealing resin due to thermal load and thereby prevents malfunctions, and a method for manufacturing the same.SOLUTION: A SiC semiconductor device A2 includes a SiC semiconductor element 1, a leadframe 2, a conductive member (a conductive bonding material 4, a first wire 31), a resin composition 6, and a sealing resin 5. The leadframe includes a die pad 24 and leads 21, 22, and 23 separated from the die pad, and the SiC semiconductor element is mounted on the die pad. The conductive member includes a conductive bonding material 4 bonding and electrically connecting the SiC semiconductor element and the die pad. The resin composition includes a die-pad-side covering portion 61 covering a bonded portion between the conductive bonding material and the die pad. The die-pad-side covering portion includes a die-pad-side fourth portion 614 covering at least a portion of an element obverse surface 1a. The die-pad-side fourth portion is located at least at a peripheral edge of the element obverse surface.SELECTED DRAWING: Figure 15

Description

[Technical field]

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

[0002] Patent Document 1 discloses a conventional semiconductor device. The semiconductor device described in Patent Document 1 includes a semiconductor element, a lead frame, solder, wires, and a sealing resin. In this semiconductor device, the semiconductor element is, for example, a diode chip or a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) chip. The lead frame mounts the semiconductor element and is electrically connected to the semiconductor element via the solder and wires. The solder and wires are conductive members for electrically connecting the lead frame and the semiconductor element. The solder is interposed between the semiconductor element and the lead frame, and electrically connects them. The wire is joined to the semiconductor element and the lead frame, and electrically connects them. The sealing resin covers a part of the lead frame, the semiconductor element, the solder, and the wires. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-5165 A Summary of the Invention [Problem to be solved by the invention]

[0004] A semiconductor device is subjected to a thermal load, for example, due to reflow when mounted on a circuit board of an electronic device or the like, or due to heat generated by a semiconductor element during operation. This thermal load causes thermal stress to concentrate at a joint between a conductive member such as solder or wire and a lead frame. This concentration of thermal stress may cause peeling of the sealing resin at the interface between the joint and the sealing resin. If a thermal load is then applied again in a state where the sealing resin has peeled off, for example, a crack may occur in the solder as a conductive member. Furthermore, peeling or disconnection may occur in the wire as a conductive member. These are causes of malfunction of the semiconductor device.

[0005] The present disclosure has been devised in consideration of the above-mentioned problems, and its purpose is to provide a semiconductor device and a manufacturing method for the semiconductor device in which operational malfunctions are suppressed by suppressing peeling of the sealing resin due to thermal load. [Means for solving the problem]

[0006] A semiconductor device provided by a first aspect of the present disclosure comprises a semiconductor element having an element main surface and an element back surface spaced apart from each other in a first direction, a lead frame on which the semiconductor element is mounted, a conductive member joined to the lead frame and providing electrical conductivity between the semiconductor element and the lead frame, a resin composition covering a joint between the conductive member and the lead frame and exposing a portion of the element main surface, and an encapsulating resin covering a portion of the lead frame, the semiconductor element, and the resin composition, wherein the bonding strength of the resin composition to the lead frame is better than the bonding strength between the encapsulating resin and the lead frame, and the bonding strength of the resin composition to the conductive member is better than the bonding strength between the encapsulating resin and the lead frame.

[0007] In a preferred embodiment of the semiconductor device, the lead frame comprises a die pad having a pad main surface facing in the same direction as the element main surface and a pad back surface facing in the same direction as the element back surface, and leads spaced from the die pad, and the semiconductor element is mounted on the die pad with the pad main surface facing the element back surface.

[0008] In a preferred embodiment of the semiconductor device, the semiconductor element includes a back electrode formed on the back surface of the element, the conductive member includes a conductive bonding material that bonds the semiconductor element to the die pad and provides electrical conductivity between the back electrode and the die pad, and the resin composition includes a die pad side covering portion that covers the bonding portion between the conductive bonding material and the die pad.

[0009] In a preferred embodiment of the semiconductor device, the conductive bonding material has an element abutment surface that abuts against the back electrode, a die pad abutment surface that abuts against the die pad, and a connecting surface that connects the element abutment surface and the die pad abutment surface, and the die pad side covering portion includes a die pad side first portion interposed between the connecting surface and the sealing resin.

[0010] In a preferred embodiment of the semiconductor device, the die pad side covering portion further includes a die pad side second portion connected to the die pad side first portion and interposed between the pad main surface and the sealing resin.

[0011] In a preferred embodiment of the semiconductor device, the semiconductor element has an element side surface connected to the element main surface and the element back surface, and the die pad side covering portion further includes a die pad side third portion connected to the die pad side first portion and interposed between at least a portion of the element side surface and the sealing resin.

[0012] In a preferred embodiment of the semiconductor device, the die pad side covering portion further includes a die pad side fourth portion connected to the die pad side third portion and interposed between a portion of the element main surface and the sealing resin.

[0013] In a preferred embodiment of the semiconductor device, the conductive bonding material is solder.

[0014] In a preferred embodiment of the semiconductor device, the rear surface of the pad is exposed from the sealing resin.

[0015] In a preferred embodiment of the semiconductor device, the semiconductor element includes a principal surface electrode formed on the principal surface of the element, the conductive member includes a wire joined to the principal surface electrode and the lead for conducting electrical current between the principal surface electrode and the lead, and the resin composition includes a lead-side coating portion covering the joint between the wire and the lead.

[0016] In a preferred embodiment of the semiconductor device, the wire includes a first joint portion joined to the main surface electrode and a second joint portion joined to the lead, and the lead side covering portion includes a lead side first portion interposed between the second joint portion and the sealing resin.

[0017] In a preferred embodiment of the semiconductor device, the lead-side covering portion further includes a lead-side second portion connected to the lead-side first portion and interposed between the lead and the sealing resin.

[0018] In a preferred embodiment of the semiconductor device, the wire further includes a linear portion connecting the first joint portion and the second joint portion, and the linear portion includes a resin abutment region that contacts the sealing resin over the entire circumferential direction.

[0019] In a preferred embodiment of the semiconductor device, the semiconductor element is a power semiconductor chip.

[0020] A manufacturing method of a semiconductor device provided by a second aspect of the present disclosure includes the steps of: preparing a lead frame; preparing a semiconductor element having an element main surface and an element back surface spaced apart from each other in a first direction; an element mounting step of mounting the semiconductor element on the lead frame; a conductive member forming step of joining a conductive member to the lead frame and the semiconductor element to establish electrical conductivity between the lead frame and the semiconductor element via the conductive member; a coating step of applying a paste composition to cover a bonded portion between the conductive member and the lead frame and exposing a portion of the element main surface; a drying step of the applied paste composition; and a sealing resin covering a portion of the lead frame, the semiconductor element, and the dried paste composition, wherein the paste composition contains a resin material, and the resin material has a bonding strength with the lead frame that is better than the bonding strength between the sealing resin and the lead frame, and a bonding strength with the conductive member that is better than the bonding strength between the sealing resin and the conductive member.

[0021] In a preferred embodiment of the method for manufacturing a semiconductor device, the lead frame comprises a die pad having a pad main surface facing in the same direction as the element main surface and a pad back surface facing in the same direction as the element back surface, and leads spaced apart from the die pad, and in the element mounting process, the semiconductor element is mounted on the die pad with the pad main surface and the element back surface facing each other.

[0022] In a preferred embodiment of the method for manufacturing a semiconductor device, the semiconductor element includes a back electrode formed on a back surface of the element, and in the conductive member formation process, before the element mounting process, a conductive paste that bonds the back electrode and the die pad is applied, and after the element mounting process, the conductive paste is dried to form a conductive bonding material that bonds the semiconductor element and the die pad and provides electrical conductivity between the back electrode and the die pad, and in the application process, the paste composition is applied so as to cover at least the bonding portion between the conductive bonding material and the die pad.

[0023] In a preferred embodiment of the method for manufacturing a semiconductor device, the semiconductor element includes a principal surface electrode formed on a principal surface of the element, and in the conductive member forming step, after the element mounting step, a wire is formed that is joined to the principal surface electrode and the lead and that connects the principal surface electrode and the lead, and in the application step, the paste composition is applied so as to cover at least the joint portion between the wire and the lead. Effect of the Invention

[0024] According to the semiconductor device of the present disclosure, peeling of the sealing resin due to thermal load can be suppressed, and thus malfunctions can be suppressed. Also, according to the manufacturing method of the present disclosure, a semiconductor device in which malfunctions are suppressed can be manufactured. [Brief description of the drawings]

[0025] [Figure 1] 1 is a perspective view showing a semiconductor device according to a first embodiment. [Diagram 2] 2 is a perspective view of FIG. 1 in which the sealing resin and the resin composition are omitted. [Diagram 3] FIG. 1 is a plan view showing a semiconductor device according to a first embodiment. [Figure 4] 4 is a plan view of FIG. 3 in which the sealing resin is omitted. [Diagram 5] FIG. 1 is a front view showing a semiconductor device according to a first embodiment. [Figure 6] FIG. 2 is a bottom view showing the semiconductor device according to the first embodiment. [Figure 7] 1 is a side view (right side view) showing the semiconductor device according to the first embodiment. [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. 5 is a cross-sectional view taken along line XX in FIG. [Figure 11]FIG. 2 is a diagram showing a step in the method for manufacturing the semiconductor device according to the first embodiment. [Figure 12] FIG. 2 is a diagram showing a step in the method for manufacturing the semiconductor device according to the first embodiment. [Figure 13] FIG. 2 is a diagram showing a step in the method for manufacturing the semiconductor device according to the first embodiment. [Figure 14A] 11 is a schematic cross-sectional view showing a case where a sealing resin is directly formed on a conductive bonding material. FIG. [Figure 14B] 1 is a schematic cross-sectional view showing a case where a resin composition is interposed between a conductive bonding material and a sealing resin. FIG. [Figure 15] FIG. 11 is a plan view showing a semiconductor device according to a second embodiment (with the sealing resin omitted). [Figure 16] FIG. 11 is a cross-sectional view showing a semiconductor device according to a second embodiment. [Figure 17] FIG. 11 is a perspective view showing a semiconductor device according to a third embodiment. [Figure 18] 18 is a perspective view in which the sealing resin and the resin composition are omitted from the perspective view shown in FIG. 17. [Figure 19] FIG. 13 is a plan view showing a semiconductor device according to a third embodiment. [Figure 20] 20 is a plan view of FIG. 19 in which the sealing resin is omitted. [Figure 21] FIG. 13 is a front view showing a semiconductor device according to a third embodiment. [Figure 22] FIG. 13 is a bottom view showing the semiconductor device according to the third embodiment. [Figure 23] FIG. 23 is a cross-sectional view taken along line XXIII-XXIII in FIG. 20. [Figure 24] FIG. 24 is a cross-sectional view taken along line XXIV-XXIV in FIG. 20. [Diagram 25] FIG. 13 is a plan view showing a semiconductor device according to a fourth embodiment. [Figure 26] FIG. 26 is a partially enlarged view of FIG. [Figure 27] FIG. 26 is a cross-sectional view taken along line XXVII-XXVII in FIG. 25. [Figure 28]26 is a cross-sectional view taken along line XXVIII-XXVIII in FIG. 25. [Figure 29] FIG. 13 is a plan view showing a semiconductor device according to a fifth embodiment. [Diagram 30] 30 is a cross-sectional view taken along line XXX-XXX in FIG. 29. [Diagram 31] 30 is a cross-sectional view taken along line XXXI-XXXI in FIG. 29. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Preferred embodiments of the semiconductor device and the manufacturing method thereof according to the present disclosure will be described below with reference to the drawings.

[0027] 1 to 10 show a semiconductor device according to a first embodiment of the present disclosure. The semiconductor device A1 of the first embodiment includes a semiconductor element 1, a lead frame 2, a plurality of wires 3, a conductive bonding material 4, a sealing resin 5, and a resin composition 6. The plurality of wires 3 include a plurality of first wires 31, a second wire 32, and a third wire 33.

[0028] FIG. 1 is a perspective view showing the semiconductor device A1. FIG. 2 is a view in which the sealing resin 5 and the resin composition 6 are omitted from the perspective view shown in FIG. 1. FIG. 3 is a plan view showing the semiconductor device A1. FIG. 4 is a view in which the sealing resin 5 is omitted from the plan view shown in FIG. 3. In FIG. 4, the resin composition 6 is shown by imaginary lines (a dot pattern is added for ease of understanding). FIG. 5 is a front view showing the semiconductor device A1. FIG. 6 is a bottom view showing the semiconductor device A1. FIG. 7 is a side view (right side) showing the semiconductor device A1. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 4. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 4. FIG. 10 is a cross-sectional view taken along line XX in FIG. 4. For ease of explanation, three directions perpendicular to each other are defined as x-direction, y-direction, and z-direction. The x-direction is the left-right direction in the plan view (see FIGS. 3 and 4). The y-direction is the up-down direction in the plan view (see FIGS. 3 and 4). The z direction is the thickness (height) direction of the semiconductor device A1.

[0029] The semiconductor element 1 is an electronic component that is the core of the function of the semiconductor device A1, and is made of a semiconductor material. Examples of such semiconductor materials include, but are not limited to, Si (silicon), SiC (silicon carbide), and GaAs (gallium arsenide). The semiconductor element 1 is, for example, a power semiconductor chip such as a MOSFET. In this embodiment, the semiconductor element 1 is a MOSFET, but is not limited thereto, and may be other transistors such as an IGBT (insulated gate bipolar transistor), or diodes such as a Schottky barrier diode or a fast recovery diode. In this disclosure, a power semiconductor chip is defined as a chip that is used at a power of, for example, about 1 W or more when the product of the voltage between the input terminal and the output terminal and the current flowing through the input terminal and the output terminal is equal to or greater than 1 W. The input terminal and the output terminal refer to the drain electrode and the source electrode, respectively, in a MOSFET. As shown in FIG. 4, the semiconductor element 1 is, for example, rectangular in plan view. As shown in FIG. 4, FIG. 8, and FIG. 9, the semiconductor element 1 has an element main surface 1a, an element back surface 1b, and a plurality of element side surfaces 1c.

[0030] The element principal surface 1a and the element rear surface 1b are spaced apart in the z direction and face opposite each other. Each of the element side surfaces 1c is sandwiched between the element principal surface 1a and the element rear surface 1b. One edge of each element side surface 1c in the z direction (upper side in Figs. 8 and 9) is connected to the element principal surface 1a, and the other edge of each element side surface 1c in the z direction (lower side in Figs. 8 and 9) is connected to the element rear surface 1b. The element principal surface 1a, the element rear surface 1b, and the element side surfaces 1c are all substantially flat. In this embodiment, the semiconductor element 1 has a pair of element side surfaces 1c facing each of the x directions and a pair of element side surfaces 1c facing each of the y directions.

[0031] The semiconductor element 1 includes a plurality of principal surface electrodes 11 and a back surface electrode 12, as shown in FIG. 2, FIG. 4, FIG. 8, and FIG. 9. Thus, the semiconductor element 1 has a vertical structure. The plurality of principal surface electrodes 11 are formed on the element principal surface 1a. The plurality of principal surface electrodes 11 include a first principal surface electrode 111, a second principal surface electrode 112, and a third principal surface electrode 113, as shown in FIG. 2 and FIG. 4. The back surface electrode 12 is formed on the element back surface 1b. The first principal surface electrode 111 is a source electrode, the second principal surface electrode 112 is a gate electrode, the third principal surface electrode 113 is a source sense electrode, and the back surface electrode 12 is a drain electrode. The arrangement, size, and shape of the first principal surface electrode 111, the second principal surface electrode 112, and the third principal surface electrode 113 are not limited to those shown in the drawings. Also, the third principal surface electrode 113 (source sense electrode) may not be particularly formed. The constituent material of each of the plurality of principal surface electrodes 11 (first principal surface electrode 111, second principal surface electrode 112, and third principal surface electrode 113) and the back surface electrode 12 is, for example, Al (aluminum).

[0032] The lead frame 2 carries the semiconductor element 1 and is electrically connected to the semiconductor element 1. The lead frame 2 is mounted on a circuit board of an electronic device or the like to provide a conductive path between the semiconductor element 1 and the circuit board. The lead frame 2 is made of a conductive material. The conductive material is, for example, Cu (copper). The conductive material is not limited to Cu, and may be Ni (nickel), a Cu alloy, a Ni alloy, or a 42 alloy. The lead frame 2 is formed into an appropriate shape by punching, cutting, bending, or the like from a metal plate such as Cu having a rectangular shape in a plan view. As shown in FIG. 2 and FIG. 4, the lead frame 2 includes a first lead 21, a second lead 22, a third lead 23, and a die pad 24. These are spaced apart from each other in the lead frame 2.

[0033] The first lead 21 is a part of the lead frame 2 that is electrically connected to the first principal surface electrode 111 (source electrode) of the semiconductor element 1. The first lead 21 is electrically connected to the first principal surface electrode 111 via a first wire 31. The first lead 21 includes a wire bonding portion 211 and a plurality of terminal portions 212, as shown in FIGS. 2, 4 and 8.

[0034] One end of each of the first wires 31 is joined to the wire bonding portion 211. The wire bonding portion 211 is covered with a sealing resin 5.

[0035] Each of the terminal portions 212 is connected to a wire bonding portion 211. A portion of each of the terminal portions 212 is exposed from the sealing resin 5. The terminal portions 212 have the same shape except for one. In the first lead 21, all of the terminal portions 212 may have the same shape. The terminal portions 212 overlap each other when viewed in the y direction. Each of the terminal portions 212 is bonded to a circuit board as a source terminal of the semiconductor device A1. As shown in FIGS. 1 to 6, the first lead 21 includes five terminal portions 212. The number, length and shape of the terminal portions 212 are not limited to the examples shown in the drawings.

[0036] The second lead 22 is a part of the lead frame 2 that is electrically connected to the second principal surface electrode 112 (gate electrode) of the semiconductor element 1. The second lead 22 is electrically connected to the second principal surface electrode 112 via a second wire 32. The second lead 22 includes a wire bonding portion 221 and a terminal portion 222, as shown in FIGS. 2 and 4.

[0037] One end of a second wire 32 is joined to the wire bonding portion 221. The wire bonding portion 221 is covered with a sealing resin 5.

[0038] The terminal portion 222 is connected to the wire bonding portion 221. A portion of the terminal portion 222 is exposed from the sealing resin 5. The terminal portion 222 is partially bent at the portion exposed from the sealing resin 5. The terminal portion 222 overlaps with the multiple terminal portions 212 when viewed in the y direction. The terminal portion 222 is joined to a circuit board as a gate terminal of the semiconductor device A1.

[0039] The third lead 23 is a part of the lead frame 2 that is electrically connected to the third principal surface electrode 113 (source sense electrode) of the semiconductor element 1. The third lead 23 is electrically connected to the third principal surface electrode 113 via a third wire 33. The third lead 23 includes a wire bonding portion 231 and a terminal portion 232, as shown in FIGS. 2 and 4 .

[0040] One end of a third wire 33 is joined to the wire bonding portion 231. The wire bonding portion 231 is covered with a sealing resin 5.

[0041] The terminal portion 232 is connected to the wire bonding portion 231. A portion of the terminal portion 232 is exposed from the sealing resin 5. The terminal portion 232 is partially bent at the portion exposed from the sealing resin 5. The terminal portion 232 overlaps with the multiple terminal portions 212 and the terminal portion 222 when viewed in the y direction. The terminal portion 232 is sandwiched between the multiple terminal portions 212 and the terminal portion 222 in the x direction. The terminal portion 232 is bonded to a circuit board as a source sense terminal of the semiconductor device A1.

[0042] The die pad 24 is a part of the lead frame 2 on which the semiconductor element 1 is mounted. A part of the die pad 24 is covered with the sealing resin 5, and another part is exposed from the sealing resin 5. As shown in Fig. 8 and Fig. 9, the die pad 24 has a pad main surface 24a and a pad back surface 24b.

[0043] The pad main surface 24a and the pad back surface 24b face in opposite directions in the z direction and are spaced apart from each other. The pad main surface 24a faces the same direction as the element main surface 1a. The pad main surface 24a faces the element back surface 1b. The pad back surface 24b faces the same direction as the element back surface 1b. The pad back surface 24b is exposed from the sealing resin 5.

[0044] The die pad 24 is electrically connected to the back electrode 12 (drain electrode) via the conductive bonding material 4. The die pad 24 is bonded to a circuit board as a drain terminal of the semiconductor device A1.

[0045] The plurality of first wires 31, second wires 32, and third wires 33 are each a connection member that electrically connects the semiconductor element 1 and the lead frame 2.

[0046] The first wires 31 are bonding wires containing Al. The first wires 31 are, for example, an Al alloy to which any one of Fe (iron), Si, and Ni is added, or pure Al. Each of the first wires 31 may be a bonding wire containing Cu or Au (gold) instead of Al. Each of the first wires 31 may be a bonding ribbon instead of a bonding wire. In this embodiment, the semiconductor device A1 includes two first wires 31, but the number of the first wires 31 is not particularly limited. The wire diameter of each of the first wires 31 is, for example, about φ400 μm. Each of the first wires 31 includes a first joint portion 311, a second joint portion 312, and a linear portion 313, as shown in FIG. 2, FIG. 4, and FIG. 8.

[0047] The first joint portion 311 is one end of each of the first wires 31, and is a portion joined to the first principal surface electrode 111 of the semiconductor element 1. As shown in FIG. 2, FIG. 4, and FIG. 8, the first joint portion 311 includes a front contact portion 311a, a rear contact portion 311b, and an intermediate portion 311c. Both the front contact portion 311a and the rear contact portion 311b are in contact with the first principal surface electrode 111. The front contact portion 311a is located on the far side from the second joint portion 312, and the rear contact portion 311b is located on the near side from the second joint portion 312. The intermediate portion 311c is sandwiched between the front contact portion 311a and the rear contact portion 311b. The intermediate portion 311c is not joined to the first principal surface electrode 111, and is formed in an arch shape slightly floating above the first principal surface electrode 111. In this embodiment, the first joint portion 311 abuts against the first principal surface electrode 111 at two points (including the front abutment portion 311a and the rear abutment portion 311b), but may also abut against the first principal surface electrode 111 at one point.

[0048] The second joint portion 312 is the other end of each first wire 31, and is a portion joined to the wire bonding portion 211 of the first lead 21. The second joint portion 312 is covered with the resin composition 6.

[0049] The linear portion 313 is a portion that connects the first bonding portion 311 and the second bonding portion 312, and extends from each of the first bonding portion 311 and the second bonding portion 312. The linear portion 313 has a circular cross section perpendicular to the longitudinal direction. The linear portion 313 includes a resin composition abutting region 313a and a sealing resin abutting region 313b. The resin composition abutting region 313a is covered with the resin composition 6. The resin composition abutting region 313a abuts against the resin composition 6 over its entire circumference in the circumferential direction. The sealing resin abutting region 313b is not covered with the resin composition 6, but is covered with the sealing resin 5. The sealing resin abutting region 313b abuts against the sealing resin 5 over its entire circumference in the circumferential direction.

[0050] Each first wire 31 electrically connects the first principal surface electrode 111 to the first lead 21. In the semiconductor device A1, each first wire 31 and the first principal surface electrode 111 are both made of a metal containing Al, so that the effect of thermal stress on their joints is small.

[0051] The second wire 32 is a bonding wire containing Au. The second wire 32 may be a bonding wire containing Al or Cu instead of Au. The wire diameter of the second wire 32 is smaller than the wire diameter of the first wire 31. That is, the second wire 32 is thinner than the first wire 31. The wire diameter of the second wire 32 is, for example, about φ50 to 75 μm. The wire diameter of the second wire 32 can be appropriately changed depending on the constituent material of the second wire 32. As shown in FIG. 4, the second wire 32 includes a first joint portion 321, a second joint portion 322, and a linear portion 323.

[0052] The first joint portion 321 is one end of the second wire 32 , and is a portion joined to the second principal surface electrode 112 of the semiconductor element 1 .

[0053] The second joint portion 322 is the other end of the second wire 32 and is the portion joined to the wire bonding portion 221 .

[0054] The linear portion 323 is a portion that connects the first joint portion 321 and the second joint portion 322, and extends from each of the first joint portion 321 and the second joint portion 322. The linear portion 313 has a circular cross section perpendicular to the longitudinal direction.

[0055] The second wire 32 electrically connects the second principal surface electrode 112 and the second lead 22 .

[0056] The third wire 33 is a bonding wire containing Au. The third wire 33 may be a bonding wire containing Al or Cu instead of Au. The third wire 33 is assumed to have the same quality and diameter as the second wire 32, for example, but may be different. The wire diameter of the third wire 33 may be appropriately changed depending on the constituent material of the third wire 33. As shown in FIG. 4, the third wire 33 includes a first joint portion 331, a second joint portion 332, and a linear portion 333.

[0057] The first joint portion 331 is one end of the third wire 33, and is a portion joined to the third principal surface electrode 113 of the semiconductor element 1. When the principal surface electrode 11 does not include the third principal surface electrode 113 (source sense electrode), the source current can be detected by joining the first joint portion 331 to the first principal surface electrode 111 (source electrode).

[0058] The second joint portion 332 is the other end of the third wire 33 and is the portion joined to the wire bonding portion 231 .

[0059] The linear portion 333 is a portion that connects the first joint portion 331 and the second joint portion 332, and extends from each of the first joint portion 331 and the second joint portion 332. The linear portion 313 has a circular cross section perpendicular to the longitudinal direction.

[0060] The third wire 33 electrically connects the third principal surface electrode 113 and the third lead 23 .

[0061] The conductive bonding material 4 is for bonding the semiconductor element 1 to the lead frame 2. As shown in Figs. 8 and 9, the conductive bonding material 4 is interposed between the element back surface 1b of the semiconductor element 1 and the pad main surface 24a of the die pad 24, and electrically connects the back electrode 12 of the semiconductor element 1 and the die pad 24. The conductive bonding material 4 is, for example, solder. The material of the solder is not particularly limited, but examples thereof include lead-free solder such as Sn-Sb alloy or Sn-Ag alloy, and lead-containing solder such as Sn-Pb alloy.

[0062] As shown in FIG. 8 and FIG. 9, the conductive bonding material 4 has an element contact surface 4a, a die pad contact surface 4b, and a connection surface 4c. The element contact surface 4a is a surface that contacts the element back surface 1b of the semiconductor element 1. The element contact surface 4a is, for example, substantially flat. The die pad contact surface 4b is a surface that contacts the pad main surface 24a of the die pad 24. The die pad contact surface 4b is, for example, substantially flat. The connection surface 4c is a surface that is sandwiched between the element contact surface 4a and the die pad contact surface 4b and connects them. The connection surface 4c may be substantially flat or curved. As shown in FIG. 8 and FIG. 9, the connection surface 4c is inclined with respect to the element contact surface 4a and the die pad contact surface 4b. The angle between the element contact surface 4a and the connection surface 4c is, for example, about 0.3 to 27°. The z-direction dimension (thickness) ΔH (see FIG. 9) of the conductive bonding material 4 is, for example, about 10 to 150 μm, and each protrusion dimension ΔL (see FIG. 9) of the conductive bonding material 4 protruding outward from each element side surface 1c in a plan view is, for example, about 300 to 2000 μm. The above-mentioned angles and each dimension ΔH, ΔL are values ​​taking into consideration errors during manufacturing and are values ​​for the manufactured semiconductor device A1. As design values ​​during manufacturing, the above angle is, for example, about 1 to 15°, the z-direction dimension ΔH of the conductive bonding material 4 is, for example, about 30 to 130 μm, and each protrusion dimension ΔL of the conductive bonding material 4 is, for example, about 500 to 1500 μm.

[0063] The sealing resin 5 covers the semiconductor element 1, a part of the lead frame 2, the wires 3, and the resin composition 6. The sealing resin 5 is a thermosetting synthetic resin having electrical insulation properties. The sealing resin 5 is, for example, a black epoxy resin, and has a filler mixed therein. The filler is, for example, spherical, and has a particle size of, for example, about 75 μm. As shown in FIGS. 1, 3, and 5 to 10, the sealing resin 5 has a resin main surface 5a, a resin back surface 5b, and a plurality of resin side surfaces 5c.

[0064] The resin main surface 5a and the resin back surface 5b face in opposite directions in the z direction and are spaced apart from each other. The resin main surface 5a faces the same direction as the element main surface 1a, and the resin back surface 5b faces the same direction as the element back surface 1b. Each of the multiple resin side surfaces 5c is sandwiched between the resin main surface 5a and the resin back surface 5b. One edge of each resin side surface 5c in the z direction is connected to the resin main surface 5a, and the other edge in the z direction is connected to the resin back surface 5b. In this embodiment, the sealing resin 5 has a pair of resin side surfaces 5c spaced apart in the x direction and a pair of resin side surfaces 5c spaced apart in the y direction.

[0065] In this embodiment, the first lead 21, the second lead 22, and the third lead 23 protrude from the resin side surface 5c. Also, a part of the die pad 24 protrudes from the resin side surface 5c. In a plan view, the first lead 21, the second lead 22, the third lead 23, and the die pad 24 protrude from the resin side surface 5c located on the opposite sides to each other with the sealing resin 5 interposed therebetween. Also, the pad back surface 24b of the die pad 24 is exposed from the resin back surface 5b.

[0066] The resin composition 6 covers the joint between the conductive bonding material 4 and the die pad 24, and the joint between the first wire 31 and the first lead 21. The resin composition 6 has a better joint strength with the lead frame 2 than the joint strength between the sealing resin 5 and the lead frame 2. The resin composition 6 has a better joint strength with the conductive bonding material 4 than the joint strength between the sealing resin 5 and the conductive bonding material 4, and has a better joint strength with the multiple wires 3 than the joint strength between the sealing resin 5 and the multiple wires 3. The relative quality of the joint strength is determined based on, for example, the pudding cup strength (unit: MPa). This pudding cup strength indicates the shear strength in a state in which a pudding cup-shaped resin material (each material of the resin composition 6 and the sealing resin 5) is in close contact with a joint object (each material of the lead frame 2, the conductive bonding material 4, and the multiple wires 3). The higher the pudding cup strength, the better the joint strength, and the lower the pudding cup strength, the lower the joint strength. The resin composition 6 is made of materials including, for example, a thermoplastic resin, an epoxy resin, a coupling agent, a powdered inorganic filler, and a powder having rubber elasticity. The thickness of the resin composition 6 is, for example, about 10 to 20 μm. The materials and thickness of the resin composition 6 are not limited to those described above. As shown in FIG. 4 and FIG. 8, the resin composition 6 includes a die pad side covering portion 61 and a lead side covering portion 62. The die pad side covering portion 61 and the lead side covering portion 62 are arranged spaced apart from each other.

[0067] The die pad side covering portion 61 covers the joint portion between the conductive bonding material 4 and the die pad 24. In the following description, this joint portion is referred to as the die pad side joint portion. As shown in Figures 4, 8 and 9, the die pad side covering portion 61 includes a die pad side first portion 611, a die pad side second portion 612 and a die pad side third portion 613. The die pad side first portion 611, the die pad side second portion 612 and the die pad side third portion 613 are integrally formed.

[0068] The die pad side first portion 611 is a portion interposed between the connecting surface 4c of the conductive bonding material 4 and the sealing resin 5, as shown in FIG.

[0069] 8, the die pad side second part 612 is a part interposed between the pad main surface 24a of the die pad 24 and the sealing resin 5. The die pad side second part 612 is connected to the die pad side first part 611. Specifically, the die pad side second part 612 is connected to a lower edge in the z direction of the die pad side first part 611. In this embodiment, the die pad side second part 612 covers at least a part of the pad main surface 24a that is not in contact with the die pad contact surface 4b of the conductive bonding material 4, but may cover the entire surface of the pad main surface 24a that is not in contact with the die pad contact surface 4b of the conductive bonding material 4.

[0070] 8, the die pad side third portion 613 is a portion interposed between each element side surface 1c of the semiconductor element 1 and the sealing resin 5. The die pad side third portion 613 is connected to the die pad side first portion 611. Specifically, the die pad side third portion 613 is connected to an upper edge in the z direction of the die pad side first portion 611. In this embodiment, the die pad side third portion 613 is disposed below the element main surface 1a in the z direction when viewed in the x direction or y direction.

[0071] The lead-side covering portion 62 covers the joint portion between the first wire 31 and the first lead 21. In the following description, this joint portion is referred to as the lead-side joint portion. As shown in Fig. 4 and Fig. 8, the lead-side covering portion 62 includes a lead-side first portion 621, a lead-side second portion 622, and a lead-side third portion 623. The lead-side first portion 621, the lead-side second portion 622, and the lead-side third portion 623 are integrally formed.

[0072] The lead-side first portion 621 is a portion interposed between the second joint portion 312 of the first wire 31 and the sealing resin 5, as shown in FIG.

[0073] 8, the lead-side second portion 622 is a portion interposed between the wire bonding portion 211 of the first lead 21 and the sealing resin 5. The lead-side second portion 622 is connected to the lead-side first portion 621.

[0074] 8, the lead-side third portion 623 is a portion interposed between a part (resin composition contact region 313a) of the linear portion 313 of the first wire 31 and the sealing resin 5. Specifically, the lead-side third portion 623 is formed in a part of the linear portion 313 on the second bonding portion 312 side. The lead-side third portion 623 is connected to the lead-side first portion 621.

[0075] Next, a method for manufacturing the semiconductor device A1 will be described with reference to Figures 11 to 13. In Figures 11 to 13, elements that are the same as or similar to those shown in Figures 1 to 10 are denoted by the same reference numerals.

[0076] First, as shown in FIG. 11, a lead frame 200 and a semiconductor element 1 are prepared. The prepared lead frame 200 includes a first lead 21, a second lead 22, a third lead 23, and a die pad 24, which are connected by a frame 201. The lead frame 200 has a size that allows the manufacture of a plurality of semiconductor devices A1, for example. The prepared semiconductor element 1 is a MOSFET with a vertical structure, but may also have a horizontal structure. The semiconductor element 1 has a first principal surface electrode 111, a second principal surface electrode 112, and a third principal surface electrode 113 formed on the element principal surface 1a, and a back surface electrode 12 formed on the element back surface 1b.

[0077] Next, as shown in FIG. 12, the semiconductor element 1 is mounted on the die pad 24 via the conductive bonding material 4. In the process of mounting the semiconductor element 1 (element mounting process), a conductive paste is applied to the pad main surface 24a of the die pad 24. In this embodiment, a solder paste is used as the conductive paste. Then, the semiconductor element 1 is placed on the applied conductive paste. At this time, the semiconductor element 1 is placed with the pad main surface 24a and the element back surface 1b facing each other. Next, the conductive paste is fired. As a result, the conductive bonding material 4 is formed, and the semiconductor element 1 is mounted on the die pad 24. The conductive bonding material 4 electrically connects the lead frame 200 (die pad 24) and the semiconductor element 1 (back surface electrode 12).

[0078] Next, as shown in FIG. 12, a plurality of first wires 31, second wires 32, and third wires 33 are bonded to the semiconductor element 1 and the lead frame 200. A well-known wire bonder is used for bonding these wires 3. In this embodiment, a case where wedge bonding using a wedge tool is described, but ball bonding using a capillary may also be used. The first wire 31 is a bonding wire whose main component is Al. The second wire 32 and the third wire 33 are bonding wires whose main component is Au. One end of the first wire 31 is bonded to the first principal surface electrode 111, and the other end of the first wire 31 is bonded to the wire bonding portion 211 of the first lead 21. Also, one end of the second wire 32 is bonded to the second principal surface electrode 112, and the other end of the second wire 32 is bonded to the wire bonding portion 221 of the second lead 22. Then, one end of the third wire 33 is bonded to the third principal surface electrode 113, and the other end of the third wire 33 is bonded to the wire bonding portion 231 of the third lead 23. The bonding order of the first wire 31, the second wire 32, and the third wire 33 is not particularly limited.

[0079] For example, the process of bonding the first wire 31 is performed as follows. First, ultrasonic vibration is applied while pressing the tip of the wedge against the first principal surface electrode 111. As a result, one end of the first wire 31 is ultrasonically melted to the first principal surface electrode 111, and a front contact portion 311a is formed. Then, the first wire 31 is drawn out from the tip of the wedge, the wedge is moved slightly, and the tip of the wedge is again pressed against the first principal surface electrode 111, and ultrasonic vibration is applied. As a result, the middle portion 311c and the rear contact portion 311b are formed, and the first joint portion 311 is formed. Next, the wedge is moved while drawing out the first wire 31 from the tip of the wedge. As a result, the linear portion 313 is formed. Next, ultrasonic vibration is applied while pressing the first wire 31 against the wire bonding portion 211 of the first lead 21. As a result, the other end of the first wire 31 is ultrasonically melted to the wire bonding portion 211. Thereafter, the wedge is moved slightly, and a cutter of the wedge tool makes a slit in the first wire 31. Then, the first wire 31 is separated from the wire bonding portion 211 together with the wedge, and the first wire 31 is cut. This forms the second joint portion 312. As a result, one end (first joint portion 311) of the first wire 31 is bonded to the first principal surface electrode 111, and the other end (second joint portion 312) of the first wire 31 is bonded to the wire bonding portion 211, and the first principal surface electrode 111 and the wire bonding portion 211 (first lead 21) are electrically connected by the first wire 31. Note that the process of bonding the second wire 32 and the third wire 33 is substantially the same as the process of bonding the first wire 31 described above.

[0080] Next, as shown in FIG. 13, a resin composition 6 is formed. In forming the resin composition 6, first, a paste composition is applied to an area where the resin composition 6 is to be formed. In the step of applying the paste composition (application step), for example, a jet dispenser is used. Note that, instead of using a jet dispenser, other application methods such as spray application or spin application, or screen printing, etc. may be used. In this embodiment, the paste composition is applied to the surface of the conductive bonding material 4 around the semiconductor element 1 in a plan view. The paste composition contains at least a resin material and an organic solvent. The bonding strength of the resin material with the lead frame 200 is better than the bonding strength of the sealing resin 5 and the lead frame 200. In addition, the bonding strength of the resin material with the multiple wires 3 is better than the bonding strength of the sealing resin 5 and the multiple wires 3, and the bonding strength of the resin material with the conductive bonding material 4 is better than the bonding strength of the sealing resin 5 and the conductive bonding material 4. The paste composition in this embodiment is made of a material containing, for example, a thermoplastic resin, an epoxy resin, a coupling agent, a powdered inorganic filler, a powder having rubber elasticity, and an organic solvent. Next, the applied paste composition is dried to volatilize the organic solvent, and a hardened resin composition 6 is formed.

[0081] Next, the sealing resin 5 is formed. The sealing resin 5 is formed by, for example, molding using a metal mold. For example, an epoxy resin mixed with granular filler is used as the sealing resin 5. After the sealing resin 5 is formed, the lead frame 200 is appropriately cut and separated into individual semiconductor elements 1. Before and after cutting the lead frame 200, appropriate processes are performed, such as improving the bending strength of the lead frame 2 exposed from the sealing resin 5, improving adhesion when mounted on a printed circuit board, and exterior treatment for rust prevention, lead processing for bending the lead frame 2 exposed from the sealing resin 5 into a predetermined shape, stamping processing for stamping the company name, product name, rod number, etc. on the sealing resin 5, and inspection and selection processing for determining whether the product is good or bad. These processes may be performed appropriately according to the final specifications of the semiconductor device A1.

[0082] Through the steps described above, the semiconductor device A1 shown in FIGS. 1 to 10 is completed.

[0083] Next, the effects of the semiconductor device A1 according to the first embodiment will be described.

[0084] According to the semiconductor device A1, the resin composition 6 is provided. This resin composition 6 covers the joint portion (for example, the die pad side joint portion or the lead side joint portion) between the conductive member (for example, the conductive bonding material 4 or the first wire 31) and the lead frame 2. The joint strength between the resin composition 6 and the lead frame 2 is better than the joint strength between the sealing resin 5 and the lead frame 2, and the joint strength between the resin composition 6 and the conductive member is better than the joint strength between the sealing resin 5 and the conductive member. With this configuration, the resin composition 6 functions as an adhesive and can improve the joint strength between the joint portion and the sealing resin 5. Therefore, even when a thermal load is applied to the semiconductor device A1, the peeling between the joint portion and the sealing resin 5 can be suppressed. As a result, the semiconductor device A1 can suppress malfunctions caused by peeling of the sealing resin 5.

[0085] According to the semiconductor device A1, the element principal surface 1a of the semiconductor element 1 is exposed from the resin composition 6. That is, the element principal surface 1a is not covered with the resin composition 6. When the semiconductor device A1 is in operation, the element principal surface 1a side of the semiconductor element 1 is likely to generate heat. If the element principal surface 1a is covered with the resin composition 6, and the thermal conductivity of the resin composition 6 is lower than that of the sealing resin 5, the heat on the element principal surface 1a side is likely to be trapped. Therefore, the temperature difference at the interface between the resin composition 6 and the element principal surface 1a becomes large. The thermal stress caused by this temperature difference can cause the semiconductor device A1 to malfunction. Therefore, when the thermal conductivity of the resin composition 6 is lower than that of the sealing resin 5, the temperature difference at the interface of the element principal surface 1a can be made smaller by exposing the element principal surface 1a from the resin composition 6 than when the element principal surface 1a is covered with the resin composition 6. This allows the semiconductor device A1 to suppress malfunctions caused by the temperature difference.

[0086] According to the manufacturing method of the semiconductor device A1, the paste composition is applied by a jet dispenser. This allows the paste composition to be selectively applied, and therefore the resin composition 6 can be selectively formed. As shown in FIG. 13, when applying the paste composition, application to the element main surface 1a of the semiconductor element 1 can be avoided, and therefore, as shown in FIG. 4, the resin composition 6 to be formed can be prevented from covering the element main surface 1a. Therefore, it is possible to manufacture a semiconductor device A1 that suppresses the above-mentioned malfunction caused by the temperature difference.

[0087] According to the semiconductor device A1, the resin composition 6 includes a die pad side covering portion 61, and the die pad side covering portion 61 covers the joint portion (die pad side joint portion) between the conductive bonding material 4 and the lead frame 2 (die pad 24). With this configuration, the die pad side covering portion 61 improves the joint strength between the die pad side joint portion and the sealing resin 5, and can suppress peeling between the die pad side joint portion and the sealing resin 5. If this peeling occurs, when a thermal load is applied to the semiconductor device A1, the thermal stress on the conductive bonding material 4 increases, and there is a possibility that cracks will occur in the conductive bonding material 4. These cracks will lead to a decrease in the heat dissipation and conductivity of the conductive bonding material 4. However, since the semiconductor device A1 can suppress the peeling between the die pad side joint portion and the sealing resin 5, the thermal stress on the conductive bonding material 4 can be alleviated and the cracks occurring in the conductive bonding material 4 can be suppressed. Therefore, the semiconductor device A1 can suppress the cracks in the conductive bonding material 4, thereby suppressing the decrease in the heat dissipation and conductivity of the conductive bonding material 4. Also, it is generally known that lead-containing solder has higher physical strength against thermal stress than lead-free solder. Therefore, in conventional semiconductor devices, there has been a tendency to use lead-containing solder for the conductive bonding material 4 in order to improve resistance to thermal cycles. On the other hand, in the semiconductor device A1, as described above, the die pad side covering portion 61 (resin composition 6) can alleviate the thermal stress applied to the conductive bonding material 4, so that even if lead-free solder is used for the conductive bonding material 4, the resistance to thermal cycles can be improved. Therefore, the semiconductor device A1 can improve the resistance to thermal cycles while taking environmental conservation into consideration.

[0088] According to the semiconductor device A1, the die pad side covering portion 61 includes a die pad side first portion 611 interposed between the connecting surface 4c of the conductive bonding material 4 and the sealing resin 5. With this configuration, the die pad side first portion 611 can improve the bonding strength between the conductive bonding material 4 and the sealing resin 5.

[0089] 14A and 14B are schematic diagrams for explaining the mechanism by which the resin composition 6 (die pad side first portion 611) improves the bonding strength between the conductive bonding material 4 and the sealing resin 5. Fig. 14A shows a case in which the sealing resin 5 is formed directly on the conductive bonding material 4, i.e., a conventional semiconductor device, and Fig. 14B shows a case in which the resin composition 6 is interposed between the conductive bonding material 4 and the sealing resin 5, i.e., the semiconductor device A1 of the present disclosure.

[0090] 14A, the surface of the conductive bonding material 4 is roughened by fine grooves 40. The grooves 40 are smaller than the particle size of the filler 51 mixed into the sealing resin 5. Therefore, when the sealing resin 5 is directly formed on the surface of the conductive bonding material 4, the filler 51 mixed into the sealing resin 5 may block the opening of the groove 40, and the sealing resin 5 may not be filled into the groove 40. The grooves 40 that are not filled with the sealing resin 5 in this way generate voids at the interface between the conductive bonding material 4 and the sealing resin 5, and these voids cause a decrease in the bonding strength.

[0091] On the other hand, as shown in FIG. 14B, by interposing the resin composition 6 between the conductive bonding material 4 and the sealing resin 5, the grooves 40 on the surface of the conductive bonding material 4 are filled with the resin composition 6. Therefore, the resin composition 6 suppresses the generation of voids, and the decrease in bonding strength due to the voids is suppressed. In addition, by filling the grooves 40 with the resin composition 6, the bonding strength with the conductive bonding material 4 is improved by the anchor effect. Furthermore, hydrogen bonds are generated at the interface between the resin composition 6 and the sealing resin 5, and the bonding strength between the resin composition 6 and the sealing resin 5 is good due to the hydrogen bonds. From the above, by interposing the resin composition 6 between the conductive bonding material 4 and the sealing resin 5, the bonding strength between the conductive bonding material 4 and the sealing resin 5 can be increased.

[0092] According to the semiconductor device A1, the die pad side covering portion 61 includes a die pad side second portion 612 interposed between the pad main surface 24a of the die pad 24 and the sealing resin 5. With this configuration, the die pad side second portion 612 can improve the bonding strength between the die pad 24 and the sealing resin 5. Note that the surface of the lead frame 2 also has fine grooves, similar to the conductive bonding material 4. Therefore, the bonding strength between the die pad 24 and the sealing resin 5 is improved, similar to the principle shown in FIGS. 14A and 14B.

[0093] In the semiconductor device A1, the die pad side covering portion 61 includes a die pad side third portion 613 interposed between the element side surface 1c and the sealing resin 5. With this configuration, the die pad side third portion 613 can improve the bonding strength between the element side surface 1c and the sealing resin 5. Note that the element side surface 1c also has fine grooves, similar to the conductive bonding material 4. Therefore, the bonding strength between the element side surface 1c and the sealing resin 5 is improved, similar to the principle shown in FIGS. 14A and 14B.

[0094] According to the semiconductor device A1, the resin composition 6 includes the lead-side covering portion 62, and the lead-side covering portion 62 covers the joint portion (lead-side joint portion) between each first wire 31 (each second joint portion 312) and the lead frame 2 (wire bonding portion 211 of the first lead 21). With this configuration, the lead-side covering portion 62 improves the joint strength between the lead-side joint portion and the sealing resin 5, and peeling between the lead-side joint portion and the sealing resin 5 can be suppressed. If this peeling occurs, when a thermal load is applied to the semiconductor device A1, the thermal stress applied to the second joint portion 312 of each first wire 31 increases, and each first wire 31 may peel off from the wire bonding portion 211. However, since the semiconductor device A1 can suppress peeling between the lead-side joint portion and the sealing resin 5, the thermal stress applied to the second joint portion 312 of each first wire 31 can be reduced, and peeling of each first wire 31 from the wire bonding portion 211 can be suppressed. Furthermore, when each of the first wires 31 is a metal containing Al, a passive film (oxide coating) is formed on the surface of each of the first wires 31 to protect it from corrosion. However, when peeling occurs between the lead-side joint portion and the sealing resin 5, each of the first wires 31 and the sealing resin 5 rub against each other, and the passive film on the surface of each of the first wires 31 may be destroyed. In this case, corrosion (for example, pitting corrosion) progresses from the portion where the passive film is destroyed, resulting in a decrease in the conductivity of each of the first wires 31 and breakage of each of the first wires 31. On the other hand, in the semiconductor device A1, the lead-side coating portion 62 serves as a protective material and can suppress corrosion of the first wires 31, so that a decrease in the conductivity of the first wires 31 and breakage of the first wires 31 can be suppressed.

[0095] According to the semiconductor device A1, the lead-side covering portion 62 includes a lead-side first portion 621 interposed between the second joint portion 312 of the first wire 31 and the sealing resin 5. With this configuration, the lead-side first portion 621 can improve the bonding strength between the second joint portion 312 and the sealing resin 5.

[0096] According to the semiconductor device A1, the lead-side covering portion 62 includes a lead-side second portion 622 interposed between the wire bonding portion 211 (first lead 21) and the sealing resin 5. With this configuration, the lead-side second portion 622 can improve the bonding strength between the wire bonding portion 211 (first lead 21) and the sealing resin 5. Note that the surface of the lead frame 2 (first lead 21) also has fine grooves, similar to the conductive bonding material 4. Therefore, the bonding strength between the wire bonding portion 211 and the sealing resin 5 is improved, similar to the principle shown in FIGS. 14A and 14B.

[0097] According to the semiconductor device A1, the lead-side covering portion 62 includes a lead-side third portion 623 interposed between a part of the linear portion 313 of the first wire 31 and the sealing resin 5. With this configuration, the lead-side third portion 623 can improve the bonding strength between the linear portion 313 of the first wire 31 and the sealing resin 5.

[0098] According to the semiconductor device A1, each of the first wires 31 is made of a metal containing Al, and the first lead 21 is made of a metal containing Cu. Each of the first wires 31 is bonded to the first lead 21 (wire bonding portion 211). In the case of bonding using such dissimilar metals, the thermal stress applied to each of the first wires 31 (second bonding portion 312) increases due to the difference in thermal expansion coefficient (linear expansion coefficient) compared to bonding using the same metal, and peeling between the lead-side bonding portion and the sealing resin 5 is more likely to occur. Therefore, when each of the first wires 31 and the first lead 21 are made of dissimilar metals, the resin composition 6 containing the lead-side coating portion 62 is more effective in suppressing peeling between the lead-side bonding portion and the sealing resin 5 than when each of the first wires 31 and the first lead 21 are made of the same metal.

[0099] According to the semiconductor device A1, the pad back surface 24b of the die pad 24 is exposed from the sealing resin 5. In this way, when the die pad 24 is exposed from the sealing resin 5, the expansion coefficient due to thermal load is larger than when the die pad 24 is not exposed. As a result, the thermal stress on the die pad side bonding portion becomes larger, and the sealing resin 5 becomes more likely to peel off at the die pad side bonding portion. Therefore, in the semiconductor device A1 in which the pad back surface 24b of the die pad 24 is exposed from the sealing resin 5, by providing the die pad side covering portion 61, peeling of the sealing resin 5 due to thermal stress on the die pad side bonding portion can be more effectively suppressed.

[0100] In the semiconductor device A1, the semiconductor element 1 is a power semiconductor chip such as a MOSFET. Although the power semiconductor chip has a high resistance to relatively large currents and voltages, it generates a lot of heat. Therefore, the sealing resin 5 is likely to peel off as described above. Therefore, in the semiconductor device A1 in which the power semiconductor chip is mounted as the semiconductor element 1, by providing the resin composition 6, the sealing resin 5 can be more effectively prevented from peeling off.

[0101] In the first embodiment, the resin composition 6 includes both the die pad side covering portion 61 and the lead side covering portion 62, but only one of them may be included. For example, when the resin composition 6 includes only the die pad side covering portion 61, the resin composition 6 (die pad side covering portion 61) is interposed between the die pad side bonding portion and the sealing resin 5, thereby increasing the bonding strength between the die pad side bonding portion and the sealing resin 5. In this case, the step of applying the paste composition (application step) may be performed before the step of bonding the first wires 31, the second wires 32, and the third wires 33. On the other hand, when the resin composition 6 includes only the lead side covering portion 62, the resin composition 6 (lead side covering portion 62) is interposed between the lead side bonding portion and the sealing resin 5, thereby increasing the bonding strength between the lead side bonding portion and the sealing resin 5. Therefore, when the resin composition 6 includes only one of the die pad side covering portion 61 or the lead side covering portion 62, it is not necessary to form the other, so that it is possible to reduce costs and shorten the manufacturing process.

[0102] In the first embodiment, the lead-side covering portion 62 of the resin composition 6 covers the joint portion between the first wire 31 and the first lead 21, but the present invention is not limited to this. For example, the resin composition 6 covering the joint portion between the second wire 32 and the second lead 22 may be provided instead of or in addition to the lead-side covering portion 62. By configuring in this way, it is possible to suppress the sealing resin 5 from peeling off from the joint portion between the second wire 32 and the second lead 22. Also, the resin composition 6 covering the joint portion between the third wire 33 and the third lead 23 may be provided instead of or in addition to the lead-side covering portion 62. By configuring in this way, it is possible to suppress the sealing resin 5 from peeling off from the joint portion between the third wire 33 and the third lead 23.

[0103] 15 to 31 show other embodiments of the semiconductor device and the manufacturing method thereof according to the present disclosure. In these figures, elements that are the same as or similar to those of the semiconductor device A1 of the first embodiment are given the same reference numerals and the description thereof will be omitted.

[0104] 15 and 16 show a semiconductor device according to the second embodiment. The semiconductor device A2 of the second embodiment is different from the semiconductor device A1 in the formation region of the resin composition 6. Specifically, as shown in FIGS. 15 and 16, the resin composition 6 of the semiconductor device A2 further includes a die pad side fourth portion 614 in the die pad side covering portion 61. FIG. 15 is a plan view showing the semiconductor device A2 and corresponds to FIG. 4 in the first embodiment. FIG. 16 is a cross-sectional view taken along the line XVI-XVI shown in FIG. 15.

[0105] The die pad side fourth portion 614 covers a part of the element principal surface 1a as shown in Fig. 15 and Fig. 16. The die pad side fourth portion 614 is interposed between a part of the element principal surface 1a and the sealing resin 5. The die pad side fourth portion 614 is connected to the die pad side third portion 613 as shown in Fig. 15 and Fig. 16. In the manufacturing process (coating process) of the semiconductor device A2, the paste composition that becomes the resin composition 6 is coated by, for example, a jet dispenser. When this paste composition is coated, a part of the paste composition may be formed on the element principal surface 1a. The die pad side fourth portion 614 may be formed by a part of the paste composition coated on the element principal surface 1a.

[0106] The semiconductor device A2 includes a resin composition 6, similar to the semiconductor device A1. This resin composition 6 covers the joint (die pad side joint or lead side joint) between the conductive member (e.g., the conductive bonding material 4 or the first wire 31) and the lead frame 2. Therefore, the semiconductor device A2 can also suppress malfunctions caused by peeling of the sealing resin 5, similar to the semiconductor device A1.

[0107] In the second embodiment, the first bonding portion 311 of each first wire 31, the first bonding portion 321 of the second wire 32, and the first bonding portion 331 of the third wire 33 are exposed from the die pad side covering portion 61 (resin composition 6), but the present invention is not limited to this. For example, the die pad side covering portion 61 (resin composition 6) may cover a part or all of these. However, each first wire 31 tends to be hotter than the second wire 32 and the third wire 33 because a source current flows through each first wire 31. Therefore, each first wire 31 is more susceptible to adverse effects of a thermal load than the second wire 32 and the third wire 33. Therefore, it is desirable to expose at least the first bonding portion 331 of each first wire 31 from the die pad side covering portion 61 (resin composition 6) in terms of suppressing adverse effects of a thermal load on each first wire 31.

[0108] In the second embodiment, the die pad side fourth part 614 covers a part of the element main surface 1a, but is not limited thereto. For example, the die pad side fourth part 614 may cover the entire surface of the element main surface 1a. However, in consideration of the fact that the temperature difference at the interface of the element main surface 1a becomes large as described above when the die pad side fourth part 614 covers the entire surface of the element main surface 1a, it is preferable that the die pad side fourth part 614 does not cover the entire surface of the element main surface 1a, but covers only a part of the element main surface 1a.

[0109] 17 to 24 show a semiconductor device according to the third embodiment. A semiconductor device A3 of the third embodiment differs from the semiconductor device A1 mainly in that it does not include a source sense terminal.

[0110] FIG. 17 is a perspective view showing the semiconductor device A3. FIG. 18 is a view in which the sealing resin 5 and the resin composition 6 are omitted from the perspective view shown in FIG. 17. FIG. 19 is a plan view showing the semiconductor device A3. FIG. 20 is a view in which the sealing resin 5 is omitted from the plan view shown in FIG. 19. In FIG. 20, the resin composition 6 is shown by imaginary lines (a dot pattern is added for ease of understanding). FIG. 21 is a front view showing the semiconductor device A3. FIG. 22 is a bottom view showing the semiconductor device A3. FIG. 23 is a cross-sectional view taken along the line XXIII-XXIII in FIG. 20. FIG. 24 is a cross-sectional view taken along the line XXIV-XXIV in FIG. 20.

[0111] In the semiconductor device A3, the semiconductor element 1 includes a first principal surface electrode 111 and a second principal surface electrode 112 as the principal surface electrodes 11, as shown in Fig. 18, Fig. 20, and Fig. 24. Thus, the semiconductor element 1 according to this embodiment does not include a third principal surface electrode 113, as compared with the semiconductor element 1 according to the first embodiment. Therefore, the semiconductor device A3 does not include a third wire 33 and a third lead 23 that were provided for electrically connecting the third principal surface electrode 113 to the outside of the semiconductor device.

[0112] In the semiconductor device A3, the first lead 21 does not include a plurality of terminal portions 212, but includes one terminal portion 212. Note that the number of terminal portions 212 is not limited in the semiconductor device A3. Also, in the semiconductor device A3, as shown in FIGS. 17 to 22, the die pad 24 includes a portion protruding from the sealing resin 5 between the terminal portion 212 and the terminal portion 222. As shown in FIGS. 17 to 22, the protruding portion may be shorter than each of the terminal portions 212, 222, or, different from this, may have the same shape as each of the terminal portions 212, 222.

[0113] According to the semiconductor device A3, the joint portion (die pad side joint portion or lead side joint portion) between the conductive member (conductive bonding material 4 or first wire 31) and the lead frame 2 is covered with the resin composition 6. Therefore, in the semiconductor device A3 as well, it is possible to suppress malfunctions caused by peeling of the sealing resin 5, similarly to the semiconductor device A1.

[0114] 25 to 28 show a semiconductor device according to the fourth embodiment. The semiconductor device A4 of the fourth embodiment is different from the semiconductor device A1 in the formation region of the resin composition 6. Specifically, the resin composition 6 of the semiconductor device A4 further includes a lead-side covering portion 63 and a lead-side covering portion 64. FIG. 25 is a plan view showing the semiconductor device A4, and corresponds to FIG. 4 in the first embodiment. FIG. 26 is a partially enlarged view of a part of FIG. 25. FIG. 27 is a cross-sectional view taken along the line XXVII-XXVII in FIG. 25. FIG. 28 is a cross-sectional view taken along the line XXVIII-XXVIII in FIG. 25.

[0115] In the semiconductor device A4, the second wire 32 and the third wire 33 are both bonding wires containing Al. The wire diameter of the second wire 32 and the third wire 33 is, for example, about φ125 μm.

[0116] As shown in Figures 25, 26 and 27, the lead-side covering part 63 covers the joint part between the second wire 32 and the second lead 22. As shown in Figures 26 and 27, the lead-side covering part 63 includes a lead-side first part 631, a lead-side second part 632 and a lead-side third part 633. The lead-side first part 631, the lead-side second part 632 and the lead-side third part 633 are integrally formed.

[0117] The lead-side first portion 631 is a portion interposed between the second joint portion 322 of the second wire 32 and the sealing resin 5, as shown in FIGS.

[0118] 26 and 27, the lead-side second portion 632 is a portion interposed between the wire bonding portion 221 of the second lead 22 and the sealing resin 5. The lead-side second portion 632 is connected to the lead-side first portion 631.

[0119] 26 and 27, the lead-side third portion 633 is a portion interposed between a part of the linear portion 323 of the second wire 32 and the sealing resin 5. Specifically, the lead-side third portion 633 is formed in a part of the linear portion 323 on the second joint portion 322 side. The lead-side third portion 633 is connected to the lead-side first portion 631.

[0120] As shown in Figures 25, 26 and 28, the lead-side covering part 64 covers the joint portion between the third wire 33 and the third lead 23. As shown in Figures 26 and 28, the lead-side covering part 64 includes a lead-side first part 641, a lead-side second part 642 and a lead-side third part 643. The lead-side first part 641, the lead-side second part 642 and the lead-side third part 643 are integrally formed.

[0121] The lead-side first portion 641 is a portion interposed between the second joint portion 332 of the third wire 33 and the sealing resin 5, as shown in FIGS.

[0122] 26 and 28, the lead-side second portion 642 is a portion interposed between the wire bonding portion 231 of the third lead 23 and the sealing resin 5. The lead-side second portion 642 is connected to the lead-side first portion 641.

[0123] 26 and 28, the lead-side third portion 643 is a portion interposed between a part of the linear portion 333 of the third wire 33 and the sealing resin 5. Specifically, the lead-side third portion 643 is formed in a part of the linear portion 333 on the second joint portion 332 side. The lead-side third portion 643 is connected to the lead-side first portion 641.

[0124] The semiconductor device A4 includes a resin composition 6, similar to the semiconductor device A1. This resin composition 6 covers the joint (die pad side joint or lead side joint) between the conductive member (e.g., the conductive bonding material 4 or the first wire 31) and the lead frame 2. Therefore, the semiconductor device A4 can also suppress malfunctions caused by peeling of the sealing resin 5, similar to the semiconductor device A1.

[0125] According to the semiconductor device A4, the resin composition 6 includes the lead-side covering portion 63, and the lead-side covering portion 63 covers the joint portion between the second wire 32 and the second lead 22. With this configuration, the resin composition 6 functions as an adhesive, and the joint strength between the joint portion between the second wire 32 and the second lead 22 and the sealing resin 5 can be improved. Therefore, the semiconductor device A4 can suppress peeling between the joint portion and the sealing resin 5. If this peeling occurs, when a thermal load is applied to the semiconductor device A4, for example, thermal stress is applied to the neck portion of the second wire 32 (the connection portion between the second joint portion 322 and the linear portion 323), which may cause the neck portion to break. However, in the semiconductor device A4, peeling between the joint portion between the second wire 32 and the second lead 22 and the sealing resin 5 can be suppressed, so that the thermal stress applied to the neck portion can be alleviated. Therefore, the semiconductor device A4 can suppress malfunctions (for example, breakage of the second wire 32) caused by peeling of the sealing resin 5. In particular, in the semiconductor device A4, the second wire 32 is a metal containing Al and the second lead 22 is a metal containing Cu, so that the thermal stress acting on this neck portion is large. Therefore, using the lead-side coating 63 to alleviate the thermal stress acting on this neck portion is effective in suppressing malfunctions of the semiconductor device A4.

[0126] In the semiconductor device A4, the second wire 32 is thinner than each of the first wires 31. Therefore, the second wire 32 is more susceptible to breakage due to corrosion than each of the first wires 31. However, in the semiconductor device A4, the resin composition 6 includes the lead-side coating portion 63, which acts as a protective material, and therefore corrosion of the second wire 32 (for example, the connection portion (neck portion) between the second joint portion 322 and the linear portion 323) can be suppressed. In other words, the semiconductor device A4 can suppress breakage of the second wire 32 due to corrosion.

[0127] According to the semiconductor device A4, the resin composition 6 includes the lead-side covering portion 64, and the lead-side covering portion 64 covers the joint portion between the third wire 33 and the third lead 23. With this configuration, the resin composition 6 functions as an adhesive, and the joint strength between the joint portion between the third wire 33 and the third lead 23 and the sealing resin 5 can be improved. Therefore, the semiconductor device A4 can suppress peeling between the joint portion and the sealing resin 5. If this peeling occurs, when a thermal load is applied to the semiconductor device A4, for example, thermal stress is applied to the neck portion of the third wire 33 (the connection portion between the second joint portion 332 and the linear portion 333), which may cause the neck portion to break. However, in the semiconductor device A4, peeling between the joint portion between the third wire 33 and the third lead 23 and the sealing resin 5 can be suppressed, so that the thermal stress applied to the neck portion can be alleviated. Therefore, the semiconductor device A4 can suppress malfunctions (for example, breakage of the third wire 33) caused by peeling of the sealing resin 5. In particular, in the semiconductor device A4, the third wire 33 is a metal containing Al and the third lead 23 is a metal containing Cu, so that the thermal stress applied to this neck portion is large. Therefore, alleviating the thermal stress applied to this neck portion by the lead-side covering portion 64 is effective in suppressing malfunctions of the semiconductor device A4.

[0128] In the semiconductor device A4, the third wire 33 is thinner than each of the first wires 31. Therefore, the third wire 33 is more susceptible to breakage due to corrosion than each of the first wires 31. However, in the semiconductor device A4, the resin composition 6 includes the lead-side coating portion 64, which acts as a protective material, and therefore corrosion of the third wire 33 (for example, the connection portion (neck portion) between the second joint portion 332 and the linear portion 333) can be suppressed. In other words, the semiconductor device A4 can suppress breakage of the third wire 33 due to corrosion.

[0129] In the fourth embodiment, the second wire 32 and the third wire 33 are each made of a metal containing Al, but the present invention is not limited thereto. For example, the second wire 32 may be made of a metal containing Cu or a metal containing Au. Even in this case, the lead-side covering 63 serves as an adhesive, and the bonding strength between the bonding portion between the second wire 32 and the second lead 22 and the sealing resin 5 can be improved. Similarly, for example, the third wire 33 may be made of a metal containing Cu or a metal containing Au. Even in this case, the lead-side covering 64 serves as an adhesive, and the bonding strength between the bonding portion between the third wire 33 and the third lead 23 and the sealing resin 5 can be improved.

[0130] 29 to 31 show a semiconductor device according to the fifth embodiment. Compared with the semiconductor device A4, the semiconductor device A5 of the fifth embodiment has a different region in which the resin composition 6 is formed. Specifically, the resin composition 6 of the semiconductor device A5 further includes an element side covering portion 65. FIG. 29 is a plan view showing the semiconductor device A5, and corresponds to FIG. 25 in the fourth embodiment. FIG. 30 is a cross-sectional view taken along the line XXX-XXX in FIG. 29. FIG. 31 is a cross-sectional view taken along the line XXXI-XXXI in FIG. 29.

[0131] The element side covering portion 65 covers the joint portion between the second wire 32 and the second principal surface electrode 112 and the joint portion between the third wire 33 and the third principal surface electrode 113. In a plan view, the element side covering portion 65 spreads out from each of these joint portions to the periphery. In a plan view, the element side covering portion 65 overlaps a part of the first principal surface electrode 111 and covers a part of the first principal surface electrode 111. However, the element side covering portion 65 (resin composition 6) does not cover a part of the first principal surface electrode 111 to which each of the first wires 31 can be joined (region R1 shown in FIG. 29). In the example shown in FIG. 29, the element side covering portion 65 is connected to the die pad side covering portion 61, but the element side covering portion 65 does not have to be connected to the die pad side covering portion 61.

[0132] The semiconductor device A5 includes a resin composition 6, similar to the semiconductor device A1. This resin composition 6 covers the joint (die pad side joint or lead side joint) between the conductive member (e.g., the conductive bonding material 4 or the first wire 31) and the lead frame 2. Therefore, the semiconductor device A5 can also suppress malfunctions caused by peeling of the sealing resin 5, similar to the semiconductor device A1.

[0133] According to the semiconductor device A5, the resin composition 6 includes an element-side covering portion 65. The element-side covering portion 65 covers the joint portion between the second wire 32 and the second principal surface electrode 112 and the joint portion between the third wire 33 and the third principal surface electrode 113. With this configuration, the resin composition 6 acts as an adhesive, and the joint strength between the joint portion between the second wire 32 and the second lead 22 and the sealing resin 5, and the joint strength between the joint portion between the third wire 33 and the third lead 23 and the sealing resin 5 can be improved. Therefore, the semiconductor device A5 can suppress peeling of the sealing resin 5 from these joint portions, and thus can suppress malfunctions caused by peeling of the sealing resin 5. Although part of the element principal surface 1a (mainly the second principal surface electrode 112 and the third principal surface electrode 113) is covered with the resin composition 6 by the element side covering portion 65, during operation of the semiconductor device A5, the second principal surface electrode 112 and the third principal surface electrode 113 are less likely to generate heat than the first principal surface electrode 111. Therefore, the effect of a decrease in heat dissipation caused by part of the element principal surface 1a being covered with the resin composition 6 is small.

[0134] In the fifth embodiment, the element side covering portion 65 covers a part of the first principal surface electrode 111, but this is not limiting. For example, the element side covering portion 65 does not have to cover the first principal surface electrode 111. In other words, the entire first principal surface electrode 111 may be exposed from the resin composition 6.

[0135] In the fifth embodiment, the resin composition 6 includes the die pad side covering portion 61, the lead side covering portions 62, 63, and 64, and the element side covering portion 65, but the resin composition 6 does not need to include all of these. In other words, it is sufficient for the resin composition 6 to include at least one of these.

[0136] Either or both of the lead-side covering portion 63 shown in the fourth embodiment and the element-side covering portion 65 shown in the fifth embodiment may be added to the semiconductor device A3.

[0137] In the first to fifth embodiments, the semiconductor element 1 has a vertical structure including the principal surface electrode 11 and the back surface electrode 12, but is not limited thereto. For example, the semiconductor element 1 may have a horizontal structure that does not include the back surface electrode 12 (but includes the principal surface electrode 11). In this case, Ag paste may be used as the conductive bonding material 4 instead of solder.

[0138] In the first to fifth embodiments, the die pad 24 of the lead frame 2 has its pad back surface 24b exposed from the sealing resin 5, but this is not limited to the above and the pad back surface 24b may be covered by the sealing resin 5.

[0139] In the first to fifth embodiments, the semiconductor devices A1 to A5 are surface mount type, but are not limited to surface mount type and may be lead insertion type. Also, the semiconductor devices A1 to A5 are shown to have lead frames 2 protruding from the sealing resin 5 in plan view, but are not limited to this. For example, they may be so-called non-lead package type in which the lead frames 2 do not protrude from the sealing resin 5 in plan view. Therefore, the package shape of the semiconductor device of the present disclosure is not particularly limited and can be applied to various package types.

[0140] The semiconductor device and the manufacturing method thereof according to the present disclosure are not limited to the above-described embodiment. The specific configuration of each part of the semiconductor device and the specific processing of each step of the manufacturing method according to the present disclosure can be freely designed in various ways.

Claims

1. a SiC semiconductor element having a main surface and a rear surface spaced apart from each other in a first direction, and a side surface connected to the main surface and the rear surface; A lead frame on which the SiC semiconductor element is mounted; a conductive member joined to the lead frame to electrically connect the SiC semiconductor element and the lead frame; a resin composition that covers a joint portion between the conductive member and the lead frame and exposes a portion of the main surface of the element; a sealing resin that covers a portion of the lead frame, the SiC semiconductor element, and the resin composition, the lead frame includes a die pad and a lead spaced apart from the die pad; The SiC semiconductor element is mounted on the die pad, the conductive member includes a conductive bonding material that bonds and electrically connects the SiC semiconductor element and the die pad, the resin composition includes a die pad side covering portion that covers a bonding portion between the conductive bonding material and the die pad, the die pad side covering portion further includes a die pad side fourth portion covering at least a portion of the element main surface, the die pad side fourth portion is located at least in a peripheral portion of the element main surface, the die pad has a pad main surface facing in the same direction as the element main surface and a pad back surface facing in the same direction as the element back surface, The pad main surface and the element back surface face each other, The SiC semiconductor element includes a back surface electrode formed on a back surface of the element, the conductive bonding material bonds and conducts electricity between the back electrode and the die pad; The SiC semiconductor device, wherein the conductive bonding material is solder.

2. the conductive bonding material has an element contact surface that contacts the back electrode, a die pad contact surface that contacts the die pad, and a connecting surface that connects the element contact surface and the die pad contact surface, the die pad side covering portion includes a die pad side first portion interposed between the connecting surface and the sealing resin. The SiC semiconductor device according to claim 1 .

3. the die pad side covering portion further includes a die pad side second portion connected to the die pad side first portion and interposed between the pad main surface and the sealing resin; The SiC semiconductor device according to claim 2 .

4. the die pad side covering portion further includes a die pad side third portion connected to the die pad side first portion and interposed between at least a part of the element side surface and the sealing resin. The SiC semiconductor device according to claim 2 or 3.

5. The SiC semiconductor device according to claim 4 , wherein the die pad side fourth portion is interposed between at least a part of the element main surface and the sealing resin.

6. The rear surface of the pad is exposed from the sealing resin. The SiC semiconductor device according to claim 1 .

7. The SiC semiconductor element includes a principal surface electrode formed on the element principal surface, the conductive member includes a wire that is joined to the principal surface electrode and the lead and electrically connects the principal surface electrode and the lead; The SiC semiconductor device according to claim 1 .

8. The wire includes a first joint portion joined to the main surface electrode and a second joint portion joined to the lead. The SiC semiconductor device according to claim 7.

9. the wire further includes a linear portion connecting the first joint portion and the second joint portion, The linear portion includes a resin abutment region that contacts the sealing resin over the entire circumferential direction. The SiC semiconductor device according to claim 8.

Images