Semiconductor module and manufacturing method

Abstract

To provide a thin semiconductor module including a switching element.SOLUTION: A semiconductor device 200 includes a switching element 10 having a first main electrode (metal plate 14) on one surface, a connection conductor 20 connected to the first main electrode of the switching element, a sealing part 260 that seals a space between the switching element and the connection conductor, and an insulating layer 280 disposed overlapping with the sealing part between at least a part of the switching element and the connection conductor.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a semiconductor module and a manufacturing method.

Background Art

[0002] Patent Document 1 states that "a semiconductor module 100 including a semiconductor assembly 110 including a plurality of semiconductor chips 30 can constitute a power device such as an inverter or an IPM (Intelligent Power Module) including a control circuit as a whole" (paragraph 0031), "as an example, the PCB 40 is electrically connected to the semiconductor chip 30 by a bonding wire 55" (paragraph 0032), "the external connection portion 50 may be nickel-plated. By connecting a copper bus bar to the external connection portion 50, a large current can be applied to each main terminal 52 of the semiconductor assembly 110" (paragraph 0033), and "the semiconductor assembly 110 may have a metal wiring board 70 that electrically connects the semiconductor chip 30 and the main terminal 52. Instead of the metal wiring board 70, the semiconductor chip 30 and the main terminal 52 may be electrically connected by a conductive member such as a wire or a ribbon" (paragraph 0035).

[0003] In Patent Document 2, it is described that "The two semiconductor elements 3 are electrically connected by the wiring member W1. One semiconductor element 3 is electrically connected to the second circuit layer 24 via the wiring member W2. The second circuit layer 24 is electrically connected to an external terminal 27 described later via the wiring member W3. The other semiconductor element 3 is electrically connected to the third circuit layer 25 via the wiring member W4. The third circuit layer 25 is electrically connected to another external terminal 27 via the wiring member W5." (Paragraph 0023), "In addition, a conductor wire is used for each of the above-described wiring members. As the material of the conductive wire, any one of gold, copper, aluminum, gold alloy, copper alloy, and aluminum alloy or a combination thereof can be used. It is also possible to use a member other than the conductive wire as the wiring member. For example, a ribbon can be used as the wiring member." (Paragraph 0024), "The insulating circuit board 2 and the semiconductor element 3 are covered by a case 11 as a housing portion surrounding the periphery. The case 11 is composed of an annular wall portion 12 surrounding the outer peripheral side of the insulating circuit board 2 and a lid portion 13 covering the upper side of the insulating circuit board 2 and the semiconductor element 3, and is formed of, for example, a synthetic resin." (Paragraph 0025). [Prior Art Documents] [Patent Documents] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2021-2610 [Patent Document 2] International Publication No. 2020 / 121680 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] Thin down a semiconductor module including a switching element. [Means for Solving the Problems]

[0005] In a first aspect of the present invention, there is provided a semiconductor device including a switching element having a first main electrode on one surface, a connection conductor connected to the first main electrode of the switching element, a sealing portion that seals a space between the switching element and the connection conductor, and an insulating layer disposed overlapping the sealing portion between at least a part of the switching element and the connection conductor.

[0006] In the semiconductor device described above, the insulating layer may have a higher electrical resistivity than the sealing material of the sealing portion.

[0007] In any of the semiconductor devices described above, the insulating layer may be laminated on the surface of the connection conductor on the switching element side.

[0008] In any of the semiconductor devices described above, the insulating layer may be disposed on the surface of the connection conductor on the switching element side so as to face a region including at least a part of the outer edge of the outer edge portion of the switching element to the outer edge portion of the conductor exposed on the surface of the switching element on the connection conductor side.

[0009] In any of the semiconductor devices described above, the region of the connection conductor connected to the first main electrode may protrude toward the first main electrode side with respect to the region where the insulating layer is disposed.

[0010] In any of the semiconductor devices described above, the connection conductor may have a groove between the region connected to the first main electrode and the region where the insulating layer is disposed.

[0011] In any of the semiconductor devices described above, the insulating layer may be laminated on the surface of the switching element on the connection conductor side.

[0012] In any of the semiconductor devices described above, the connection conductor may have a plurality of bumps that contact the first main electrode.

[0013] Any of the semiconductor devices described above may include a mounting substrate having the connection conductor on a mounting surface on which the switching element is mounted, and having a first main electrode plate connected to the connection conductor in a region of the mounting surface where the switching element is not disposed.

[0014] Any of the semiconductor devices described above may include a second main electrode plate connected to the second main electrode of the switching element. The mounting substrate may have a control electrode plate connected to the control electrode of the switching element. The first main electrode plate, the second main electrode plate, and the control electrode plate may be exposed on one surface of the semiconductor device.

[0015] In any of the semiconductor devices described above, the mounting substrate may have a heat conduction plate formed on a surface opposite to the mounting surface.

[0016] In any of the semiconductor devices described above, the switching element may be a power MOSFET, an IGBT, or a SiC semiconductor element.

[0017] In a second aspect of the present invention, there is provided a method of manufacturing a semiconductor device, including preparing a switching element having a first main electrode on one surface, disposing an insulating layer at a location between at least a part of the switching element and a connection conductor to be connected to the first main electrode, connecting the connection conductor to the first main electrode of the switching element, and sealing a space between the switching element and the connection conductor with a sealing material.

[0018] In the manufacturing method described above, disposing the insulating layer may include laminating the insulating layer on a surface of the connection conductor on the switching element side.

[0019] In any of the manufacturing methods described above, laminating the insulating layer on a surface of the connection conductor on the switching element side may include placing an insulating sheet to be the insulating layer on a surface of the connection conductor on the switching element side.

[0020] In any of the above manufacturing methods, laminating the insulating layer on the surface of the connection conductor on the switching element side may include applying an insulating material that becomes the insulating layer on the surface of the connection conductor on the switching element side.

[0021] In any of the above manufacturing methods, the connection conductor may have a step that prevents the insulating material from spreading to the region to be connected to the first main electrode between the region to be connected to the first main electrode and the region where the insulating layer is to be disposed.

[0022] In any of the above manufacturing methods, the connection conductor may have a groove that prevents the insulating material from spreading to the region to be connected to the first main electrode between the region to be connected to the first main electrode and the region where the insulating layer is to be disposed.

[0023] In any of the above manufacturing methods, applying the insulating material may include applying a part of the insulating material that becomes the insulating layer on the surface of the connection conductor on the switching element side to form a boundary wall of the insulating material at the boundary between the region to be connected to the first main electrode and the region where the insulating layer is to be disposed in the connection conductor, and applying the other part of the insulating material to the region where the insulating layer is to be disposed with respect to the boundary wall to form the insulating layer.

[0024] Note that the above summary of the invention does not list all the features of the present invention. Also, sub-combinations of these feature groups can also be inventions.

Brief Description of the Drawings

[0025]

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Mode for Carrying Out the Invention

[0026] Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution means of the invention.

[0027] FIG. 1 is a perspective view of a switching element 10 according to the present embodiment. The switching element 10 is a semiconductor switching element such as a MOSFET (metal oxide semiconductor field effect transistor). The switching element 10 may be a vertical power MOSFET. The switching element 10 may be a Si semiconductor element such as a Si-MOSFET, may be a SiC semiconductor element such as a SiC-MOSFET that can switch at a higher speed, or may use a wide bandgap semiconductor such as GaN, diamond, gallium nitride-based materials, gallium oxide-based materials, AlN, AlGaN, or ZnO. Alternatively, the switching element 10 may be a semiconductor switching element such as an IGBT (insulated gate bipolar transistor), or may be a SiC-IGBT. Further, the switching element 10 may be a HEMT (high electron mobility transistor).

[0028] The switching element 10 may be a semiconductor chip, having a first main electrode 100 and a control electrode 110 on one surface (the upper surface in the figure), and a second main electrode 120 on the opposite surface. In the example of this figure, the switching element 10 further has a sense electrode 130 on the upper surface in the figure. When the switching element 10 is a MOSFET, the switching element 10 has a source and a drain as the first main electrode 100 and the second main electrode 120, has a gate as the control electrode 110, and has a sense source as the sense electrode 130. When the switching element 10 is an IGBT, the switching element 10 has an emitter and a collector as the first main electrode 100 and the second main electrode 120, has a gate as the control electrode 110, and has a sense emitter as the sense electrode 130. In the present embodiment, for convenience of explanation, the case where the switching element 10 is a MOSFET is shown.

[0029] Note that the names "first main electrode" and "second main electrode" are given for convenience of explanation to distinguish between the two main electrodes of the switching element 10. Therefore, the switching element 10 may be regarded as having, on one surface, a symbol 100 which is the second main electrode and a control electrode 110, and on the opposite surface, a symbol 120 which is the first main electrode. Further, the switching element 10 used in the semiconductor device 200 shown below may adopt a configuration in which it does not have the second main electrode 120 on the surface opposite to the first main electrode 100, or it may have the second main electrode 120 on the surface on the first main electrode 100 side.

[0030] FIG. 2 is a cross section of the semiconductor device 200 according to the reference example. A semiconductor module using a switching element such as the switching element 10 shown in FIG. 1 generally has a structure in which one surface of the switching element (for example, the surface on the second main electrode 120 side) is joined to a wiring pattern on a substrate, and each electrode on the other surface (for example, the first main electrode 100, the control electrode 110, and the sense electrode 130) is electrically connected to another wiring pattern by wire bonding. Such a semiconductor module is realized as an integrated module by resin-sealing a substrate on which the switching element is mounted, each bonding wire, and each metal plate connected to the positive terminal, the negative terminal, and the output terminal.

[0031] On the other hand, in the semiconductor device 200 according to the reference example, one surface of the switching element 10 (for example, the surface on the side of the second main electrode 120) is exposed to the surface of the semiconductor device 200 directly or via the second main electrode plate 230, so that it can be joined to a wiring pattern on a substrate outside the semiconductor device 200. On the other side surface of the switching element 10, each electrode (for example, the first main electrode 100, the control electrode 110, and the sense electrode 130) is directly connected to a connection conductor such as a wiring pattern provided on a substrate within the semiconductor device 200. Such a connection conductor electrically connects each electrode on the other side surface of the switching element 10 to an external electrode such as an electrode plate exposed outside the semiconductor device 200. Alternatively, the semiconductor device 200 may adopt a structure in which the surfaces on the sides of the first main electrode 100, the control electrode 110, and the sense electrode 130 are exposed to the surface of the semiconductor device 200, and the surface on the side of the second main electrode 120 is directly connected to the connection conductor. With such a structure, it is not necessary to connect each electrode of the switching element 10 inside the semiconductor device 200 by wire bonding, so that the semiconductor device 200 can be thinned. Further, by using such a semiconductor device 200, the semiconductor module can be thinned or miniaturized.

[0032] The semiconductor device 200 according to the reference example includes a switching element 10, a mounting substrate 210, a second main electrode plate 230, and a sealing portion 260. In this figure, for the switching element 10, the surface on the side of the first main electrode 100 etc. is arranged downward in the figure, and the surface on the side of the second main electrode 120 is arranged upward in the figure. The switching element 10 has an element structure including a metal film 14, an interlayer insulating film 16, etc. on the chip substrate 12 (lower side in the figure) in cross section. Note that in this figure, the part focused on in the present application in the element structure to be formed on the chip substrate 12 is shown as the center, and the more detailed structure is omitted from the illustration and description.

[0033] The metal film 14 is exposed on one surface (the lower surface in the figure) of the switching element 10 and functions as an electrode of the switching element 10. In the example of this figure, the metal film 14 may be the first main electrode 100 in FIG. 1. Alternatively, the metal film 14 may be the control electrode 110 or the sense electrode 130. Further, the metal film 14 may be the second main electrode 120 in FIG. 1.

[0034] The interlayer insulating film 16 is an insulating film such as a silicon oxide film, a silicon nitride film, or the like, which is formed integrally with the switching element 10 using a semiconductor process during the manufacture of the switching element 10. The interlayer insulating film 16 may be formed integrally with the switching element 10 before the singulation of the switching element 10 during the semiconductor process for manufacturing the switching element 10.

[0035] The mounting substrate 210 mounts the switching element 10 on the mounting surface (the upper surface in the figure). The mounting substrate 210 includes an insulating substrate 500 and a connection conductor 20 formed on the mounting surface of the insulating substrate 500 for the switching element 10. The connection conductor 20 is connected to the first main electrode 100 of the switching element 10. The connection conductor 20 may include a conductor pattern 22 and one or more pillars 24. The conductor pattern 22 may be formed on the insulating substrate 500 by a conductive metal film or metal plate such as copper. As an example, the conductor pattern 22 is a wiring pattern for connecting between an external electrode arranged at a position not overlapping with the chip substrate 12 in a top view of the semiconductor device 200. One or more pillars 24 are arranged in a region of the conductor pattern 22 facing the metal film 14 and connect the conductor pattern 22 to the metal film 14 by contacting the metal film 14. The pillar 24 is formed of a conductive metal. In the example of this figure, the pillar 24 is a pillar such as a cylindrical shape. Although the pillar 24 is used in the example of this figure, not limited to the pillar, protrusions (bumps) of any shape may be used.

[0036] The mounting substrate 210 may have a heat conduction plate 270 formed on the surface of the insulating substrate 500 opposite to the mounting surface of the switching element 10. The heat conduction plate 270 may be a heat conduction component such as a copper plate, which has higher thermal conductivity than the insulating substrate 500.

[0037] The second main electrode plate 230 is electrically connected to the second main electrode 120 of the switching element 10. The sealing portion 260 seals the space between the switching element 10 and the connection conductor 20. The sealing portion 260 may be formed, for example, by injecting a resin material such as epoxy or silicon between the switching element 10 and the connection conductor 20 and curing it.

[0038] With the configuration shown above, the semiconductor device 200 can be thinned. However, depending on the application destination of the semiconductor module using the semiconductor device 200, a high voltage of several hundred V or one thousand several hundred V etc. may be applied between the main electrodes of the switching element 10. Here, the surface on the side of the second main electrode plate 230 of the switching element 10 and the outer edge portion of the switching element 10 (i.e., the outer edge portion of the chip substrate 12) are at substantially the same potential as the second main electrode 120, and the connection conductor 20 is at substantially the same potential as the first main electrode 100. Therefore, insulation such as between the outer edge portion of the switching element 10 (more specifically, the edge on the side of the connection conductor 20 on the side surface of the chip substrate 12) and the connection conductor 20 as shown by the arrow in the figure becomes a problem. For example, when the distance between the switching element 10 and the conductor pattern 22 is set to several tens of μm to one hundred several tens of μm etc. due to the thinning of the semiconductor device 200, the insulation distance may become insufficient only by separating the outer edge portion of the chip substrate 12 and the conductor pattern 22 by the sealing portion 260.

[0039] Figure 3 is a cross-section of the semiconductor device 200 according to the present embodiment. Since the semiconductor device 200 shown in this figure is obtained by adding an insulating layer 280 to the semiconductor device 200 of the reference example shown in Figure 2, the description will be omitted except for the following differences.

[0040] The semiconductor device 200 according to this embodiment includes an insulating layer 280 disposed overlapping a sealing portion 260 between at least a part of the switching element 10 and the connection conductor 20. The insulating layer 280 may be disposed between the outer edge portion and the connection conductor 20 over the entire outer edge portion of the switching element 10, or may be disposed between the outer edge portion and the connection conductor 20 at least in a part of the outer edge portion of the switching element 10. The insulating layer 280 may be disposed between at least a part (for example, a part having the same potential as the second main electrode 120) where the potential difference between the connection conductor 20 and the surface of the switching element 10 on the first main electrode 100 side exceeds a predetermined limit voltage and the connection conductor 20. In the example of this figure, the insulating layer 280 is laminated on the surface of the connection conductor 20 on the switching element 10 side.

[0041] The insulating layer 280 may be formed of a material having a higher electrical resistivity than the sealing material of the sealing portion 260. As an example, the insulating layer 280 may be a polyimide, a polyester, a liquid crystal polymer, etc., or a layer, film, sheet (for example, an insulating adhesive sheet) based on at least one of these. The insulating layer 280 may have a thickness of 1 / 2 or less, or 1 / 4 or less of the distance between the outer edge portion of the switching element 10 and the connection conductor 20. By reducing the thickness of the insulating layer 280, it is possible to make it easier for the sealing material to flow between the switching element 10 and the connection conductor 20. The insulating layer 280 may have a thickness of 1 / 20 or more, 1 / 10 or more, or 1 / 8 or more of the distance between the outer edge portion of the switching element 10 and the connection conductor 20. By using a material having a high electrical resistivity as the insulating layer 280, sufficient insulation can be obtained even if the thickness of the insulating layer 280 is relatively small.

[0042] The range where the insulating layer 280 is provided may be determined according to the structure of the semiconductor device 200 and the required breakdown voltage. The range where the insulating layer 280 is provided is determined on the condition that the sum of the distance between the outer edge of the switching element 10 and the insulating layer 280 and the creepage distance from the location directly below the outer edge of the switching element 10 in the insulating layer 280 through the surface of the insulating layer 280 to the conductor pattern 22 is a sufficient insulation distance for the required breakdown voltage. In the example of this figure, such a creepage distance may be the length of the shortest path among the paths from the location directly below the outer edge of the switching element 10 in the sealing portion 260 through the surface of the sealing portion 260 to the exposed portion from the insulating layer 280 in the conductor pattern 22 (in the example of this figure, the upper surface portion of the conductor pattern 22 exposed from the insulating layer 280 on the right end side of the insulating layer 280, the side surface portion of the conductor pattern 22 exposed from the insulating layer 280 on the left end side of the insulating layer 280). Further, when the length of the path from the location directly below the outer edge of the switching element 10 in the sealing portion 260 through the surface of the sealing portion 260 to the exposed portion from the insulating layer 280 in the conductor pattern 22 at the right end in the figure of the sealing portion 260 is relatively short, it is required that there is a sufficient insulation distance when the length of this path is taken as the creepage distance.

[0043] Further, the insulating layer 280 may be disposed to face a region including at least a part of the outer edge of the switching element 10 to the outer edge of a conductor (for example, the metal film 14) exposed on the surface of the switching element 10 on the side of the connection conductor 20. In the example of this figure, since the metal film 14 is connected to the connection conductor 20, the metal film 14 and the connection conductor 20 are substantially at the same potential. Therefore, the insulating layer 280 may not be disposed between the metal film 14 and the conductor pattern 22.

[0044] Further, when the switching element 10 is a vertical semiconductor element such as a power MOSFET or an IGBT, a guard ring that surrounds the element structure provided on the surface on the connection conductor 20 side is provided near the outer edge of the surface on the connection conductor 20 side of the chip substrate 12. On the surface of the switching element 10 on the connection conductor 20 side, the region outside the guard ring can be substantially at the same potential as the opposite surface of the switching element 10. Therefore, the insulating layer 280 may be disposed to face a region including at least a part of the outer edge of the switching element 10 to the guard ring of the switching element 10. Note that the insulating layer 280 need only be disposed within the minimum range in which insulation can be ensured, and may be provided in a range smaller than the range shown above as long as the required insulation can be ensured.

[0045] According to the semiconductor device 200 described above, it is possible to sufficiently ensure the insulation between the switching element 10 and the connection conductor 20 while thinning the semiconductor device 200.

[0046] FIG. 4 is a cross-section of the semiconductor device 200 according to the first modification of the present embodiment. Since the semiconductor device 200 shown in this figure is a modified example of the semiconductor device 200 shown in FIG. 3, the description will be omitted except for the following differences.

[0047] The semiconductor device 200 according to this modification includes an insulating layer 280 disposed to overlap with the sealing portion 260 between the outer edge of the switching element 10 and the connection conductor 20, similar to the semiconductor device 200 shown in FIG. 3. The insulating layer 280 may be disposed between the outer edge and the connection conductor 20 over the entire outer edge of the switching element 10, or may be disposed between the outer edge and the connection conductor 20 at least in a part of the outer edge of the switching element 10. In this modification, the insulating layer 280 is laminated on the surface of the switching element 10 on the connection conductor 20 side.

[0048] In this modification example, the insulating layer 280 covers the entire thickness direction of the switching element 10 on the side surface of the switching element 10 in order to ensure an insulating distance between the edge of the switching element 10 and the connection conductor 20. Alternatively, if a sufficient insulating distance can be ensured, the insulating layer 280 may cover only at least a partial range on the connection conductor 20 side in the thickness direction of the switching element 10 on the side surface of the switching element 10. The thickness of the insulating layer 280 and the range where the insulating layer 280 is provided may be determined according to the structure of the semiconductor device 200 and the required withstand voltage, similar to the semiconductor device 200 in FIG. 3.

[0049] FIG. 5 is a perspective view of the semiconductor device 200 according to the present embodiment. The semiconductor device 200 according to the present embodiment has a structure in which each electrode plate electrically connected to each electrode of the switching element 10 is exposed on one surface of the plate-shaped semiconductor device 200. In the present embodiment, the semiconductor device 200 includes a mounting substrate 210, a first main electrode plate 220, a second main electrode plate 230, a control electrode plate 240, a sub-electrode plate 250, and a sealing portion 260.

[0050] The mounting substrate 210 mounts the switching element 10 on the mounting surface (the upper surface in the figure). The first main electrode plate 220 is electrically connected to the first main electrode 100 of the switching element 10. The second main electrode plate 230 is electrically connected to the second main electrode 120 of the switching element 10. The control electrode plate 240 is electrically connected to the control electrode 110 of the switching element 10. The sub-electrode plate 250 is electrically connected to the first main electrode 100 of the switching element 10. Here, the first main electrode plate 220, the second main electrode plate 230, the control electrode plate 240, and the sub-electrode plate 250 are exposed on the surface of the semiconductor device 200 opposite to the mounting substrate 210 side (the switching element 10 mounting surface side of the mounting substrate 210). The sealing portion 260 covers the mounting surface of the switching element 10 on the mounting substrate 210 while exposing the first main electrode plate 220, the second main electrode plate 230, the control electrode plate 240, and the sub-electrode plate 250.

[0051] Instead of modularizing the switching element such as the switching element 10 as described above, each electrode plate on one surface of the semiconductor device 200 of the present embodiment is joined to a wiring pattern on the substrate, so that all the necessary electrodes in the switching element 10 can be electrically connected to the wiring on the substrate without wire bonding.

[0052] Note that the semiconductor device 200 may further have an electrode plate electrically connected to the sense electrode 130 on the same surface as the first main electrode plate 220 and the like. Also, although both the first main electrode plate 220 and the sub-electrode plate 250 are electrically connected to the first main electrode 100 of the switching element 10, the first main electrode plate 220 has a large area and is used for flowing a large current, and the sub-electrode plate 250 is used for controlling the switching element 10 in a pair with the control electrode plate 240. In other forms, the semiconductor device 200 may not include the sub-electrode plate 250. In this case, the first main electrode plate 220 is also used for controlling the switching element 10.

[0053] FIG. 6 shows a manufacturing method of the semiconductor device 200 according to the present embodiment. Hereinafter, the manufacturing method of the semiconductor device 200 will be described with reference to FIGS. 7 to 11 showing the configurations during the manufacturing of the semiconductor device 200. In S300 (step 300), a switching element 10 having the first main electrode 100 and the control electrode 110 on one surface and the second main electrode 120 on the opposite surface is prepared.

[0054] In S310, a second main electrode plate 230 is joined to the surface of the switching element 10 on the side of the second main electrode 120. FIG. 7 is a perspective view of a configuration in which the second main electrode plate 230 is joined to the switching element 10 according to the present embodiment. The second main electrode plate 230 is a conductive plate such as a copper plate. The second main electrode plate 230 may be joined to the second main electrode 120 using a sintering agent of nano silver, or may be joined by direct gold-gold bonding. Thereby, the second main electrode plate 230 is electrically connected to the second main electrode 120 of the switching element 10. In addition to the above, the second main electrode plate 230 may be joined by a soldering material or by direct copper-copper bonding. Further, a plurality of bumps arranged regularly or irregularly on the second main electrode plate 230 may be joined to the second type electrode of the switching element 10.

[0055] In S320, a mounting substrate 210 is fabricated. FIG. 8 is a perspective view of the mounting substrate 210 according to the present embodiment. In this step, a mounting substrate 210 having wiring patterns of a first main electrode wiring 510, a control wiring 520, and a sub-wiring 530 is fabricated on a mounting surface of an insulating substrate 500 such as Si, silicon nitride, or aluminum nitride where the switching element 10 is to be mounted. The insulating substrate 500 may be made of a ceramic material or the like including the above.

[0056] The first main electrode wiring 510 is formed of a conductive metal film or metal plate such as copper. The first main electrode wiring 510 is an example of the connection conductor 20 in FIGS. 2 to 4. The first main electrode wiring 510 includes a first main electrode contact 513, a wiring 515, and a first main electrode plate contact 517. The first main electrode contact 513 is an area connected to the first main electrode 100 of the switching element 10. The wiring 515 corresponds to the conductor pattern 22 in FIGS. 2 to 4 and electrically connects between the first main electrode contact 513 and the first main electrode plate contact 517. The first main electrode plate contact 517 is an area connected to the first main electrode plate 220.

[0057] The control wiring 520 is formed of a conductive metal film or metal plate such as copper, similar to the first main electrode wiring 510. The control wiring 520 includes a control electrode contact 523, a wiring 525, and a control electrode plate contact 527. The control electrode contact 523 is an area connected to the control electrode 110 of the switching element 10. The wiring 525 electrically connects between the control electrode contact 523 and the control electrode plate contact 527. The control electrode plate contact 527 is an area connected to the control electrode plate 240. The control wiring 520 may also be treated as the connection conductor 20 in FIGS. 2 to 4.

[0058] The sub-wiring 530 is formed of a conductive metal film or metal plate such as copper, similar to the first main electrode wiring 510. The sub-wiring 530 includes a first main electrode contact 513, a wiring 535, and a sub-electrode plate contact 537. The first main electrode contact 513 is shared with the first main electrode wiring 510. The sub-wiring 530 may utilize a part of the first main electrode contact 513 used by the first main electrode wiring 510. The wiring 535 electrically connects between the first main electrode contact 513 and the sub-electrode plate contact 537. The wiring 535 may have a smaller wiring width compared to the wiring 515. The sub-electrode plate contact 537 is an area connected to the sub-electrode plate 250. The sub-wiring 530 may also be treated as the connection conductor 20 in FIGS. 2 to 4.

[0059] Here, regions where each electrode of the switching element 10, such as the first main electrode contact 513 and the first main electrode plate contact 517 of the first main electrode wiring 510, the control electrode contact 523 and the control electrode plate contact 527 of the control wiring 520, and the sub - electrode plate contact 537 of the sub - wiring 530, or each electrode plate such as the first main electrode plate 220, the second main electrode plate 230, the control electrode plate 240, and the sub - electrode plate 250 are joined may each have a plurality of bumps arranged regularly or irregularly. The pillar 24 shown in FIGS. 2 to 4 is an example of such a bump. These plurality of bumps may be bumps made of a conductive metal such as gold. These plurality of bumps may be formed, for example, by arranging a bump precursor of a conductive metal in each region by transfer or the like and then baking and curing the bump precursor.

[0060] In S325, at the entire or at least a part of the outer edge of the switching element 10, an insulating layer 280 is disposed at a location between the outer edge and a connection conductor 20 (such as the first main electrode wiring 510 in FIGS. 2 to 4) to be connected to the first main electrode 100. FIG. 9 shows a state where the insulating layer 280 is disposed on the mounting substrate 210 according to this embodiment. In the example of this figure, the insulating layer 280 is disposed by laminating the insulating layer 280 on the surface of the first main electrode wiring 510 and the like on the side of the switching element 10.

[0061] In the example of this figure, the insulating layer 280 is disposed in a region surrounding the first main electrode contact 513 where a plurality of pillars 24 are formed on the first main electrode wiring 510. In the example of this figure, the insulating layer 280 is disposed by placing or pasting an insulating sheet that becomes the insulating layer 280 on the surface of the first main electrode wiring 510 on the side of the switching element 10. In this step, an insulating sheet piece obtained by cutting a tape-shaped insulating sheet to a required length is placed along each side of the outer periphery of the first main electrode contact 513, so that the insulating sheet may be disposed in a region surrounding the first main electrode contact 513. Alternatively, an insulating sheet having a shape surrounding the first main electrode contact 513 may be created and placed on the connection conductor 20. Here, in a portion where the insulating layer 280 does not face the connection conductor 20 such as the first main electrode wiring 510 at the outer edge of the switching element 10, the insulating layer 280 may not be disposed as long as sufficient insulation can be obtained.

[0062] Note that electrodes such as the control electrode 110 are provided on the surface of the switching element 10 on the mounting substrate 210 side in addition to the first main electrode 100. The insulating layer 280 may be disposed in a region that collectively surrounds the periphery of the control electrode contact 523 in the control wiring 520 in addition to the first main electrode contact 513.

[0063] In S330, the switching element 10 is mounted on the mounting surface of the mounting substrate 210 where each wiring pattern is formed. FIG. 10 is a perspective view of a configuration in which the switching element 10 to which the second main electrode plate 230 is joined is joined to the mounting substrate 210 according to the present embodiment. As shown in FIG. 7, the switching element 10 to which the second main electrode plate 230 is joined is joined to the mounting surface of the mounting substrate 210 with the upper surface of the switching element 10 in FIG. 7 facing downward. Thereby, the first main electrode 100 of the switching element 10 is joined to the first main electrode contact 513 of the first main electrode wiring 510 and the sub-wiring 530, and the control electrode 110 of the switching element 10 is joined to the control electrode contact 523 of the control wiring 520. This joining method may be the same as the joining method of the second main electrode plate 230 to the second main electrode 120. As a result, an insulating layer 280 is disposed between the outer edge portion of the switching element 10 and the connection conductor 20.

[0064] In S340, each electrode plate is joined to each wiring of the mounting substrate 210. FIG. 11 is a perspective view of a configuration in which the first main electrode plate 220, the control electrode plate 240, and the sub-electrode plate 250 are joined to the mounting substrate 210 according to the present embodiment. As shown in FIG. 11, the first main electrode plate contact 517 of the first main electrode wiring 510, the control electrode plate contact 527 of the control wiring 520, and the sub-electrode plate contact 537 of the sub-wiring 530 are located in a region where the switching element 10 is not disposed on the mounting surface of the mounting substrate 210 where the switching element 10 is to be mounted. In this step, the first main electrode plate 220, the control electrode plate 240, and the sub-electrode plate 250 are respectively joined to such first main electrode plate contact 517, control electrode plate contact 527, and sub-electrode plate contact 537. This joining method may be the same as the joining method of the second main electrode plate 230 to the second main electrode 120.

[0065] As a result, the first main electrode plate 220, the control electrode plate 240, and the sub - electrode plate 250 are located in the region on the mounting surface of the switching element 10 where the switching element 10 is not disposed, and are electrically connected to the first main electrode wiring 510, the control wiring 520, and the sub - wiring 530, respectively. In this way, the mounting substrate 210 having the insulating substrate 500 and the first main electrode wiring 510, the first main electrode plate 220, the control wiring 520, the control electrode plate 240, the sub - wiring 530, and the sub - electrode plate 250 formed on the insulating substrate 500 is manufactured.

[0066] Here, in the semiconductor device 200 according to the present embodiment, on the mounting surface of the switching element 10 on the mounting substrate 210, the switching element 10 is disposed between the first main electrode plate 220 and the control electrode plate 240. The sub - electrode plate 250 may be disposed on the same side as the control electrode plate 240 with respect to the switching element 10. As a result, the semiconductor device 200 can have a configuration in which control - use wirings can be connected to the control electrode plate 240 and the sub - electrode plate 250 located at one end of the semiconductor device 200.

[0067] In S350, the mounting surface of the mounting substrate 210 is sealed with a sealing material so that each electrode plate is exposed, thereby forming a sealing portion 260 to obtain the semiconductor device 200 shown in FIG. 5. Here, the sealing portion 260 covers the mounting surface of the switching element 10 on the mounting substrate 210 and the surface of the switching element 10 on the side of the mounting substrate 210, and exposes the first main electrode plate 220, the second main electrode plate 230, the control electrode plate 240, and the sub - electrode plate 250 on the terminal surface (the upper surface in FIG. 2) of the semiconductor device 200. This sealing may be resin sealing with a molding material. By sealing the mounting surface of the mounting substrate 210, the space between the switching element 10 and the connection conductor 20 can be sealed with a sealing material. As a result, the semiconductor device 200 has a structure in which the sealing portion 260 and the insulating layer 280 are disposed overlappingly between the outer edge portion of the switching element 10 and the first main electrode wiring 510 (conductor pattern 22 in FIGS. 2 to 4).

[0068] In this process, after performing encapsulation so as to cover the mounting surface of the switching element 10 on the mounting substrate 210 and the surface of the switching element 10 on the side of the mounting substrate 210, the terminal surface of the semiconductor device 200 may be polished to scrape off the excess encapsulation material to expose each electrode plate. In other embodiments, the encapsulation process may be omitted, and the semiconductor device 200 may not include the encapsulation portion 260. Note that, after this process, an antioxidant film may be formed by plating the exposed surface of each electrode plate with Sn or the like.

[0069] According to the manufacturing method described above, it is possible to manufacture the semiconductor device 200 in which each terminal electrically connected to each electrode of the switching element 10 is exposed on one surface. Note that, in the manufacturing method described above, the second main electrode plate 230 is joined to the surface of the switching element 10 on the side of the second main electrode 120 in S310, but this process may be omitted. In this case, the second main electrode 120 may be directly exposed on the terminal surface of the semiconductor device 200.

[0070] In addition, in the manufacturing method described above, the order of each process may be changed within a possible range. For example, S340 may be performed before S330, and after joining each electrode plate to each wiring of the mounting substrate 210, the switching element 10 may be mounted on the mounting substrate 210. Alternatively, S310 may be performed after S330, and after mounting the mounting substrate 210 on the switching element 10, the second main electrode plate 230 may be joined to the surface of the switching element 10 on the side of the second main electrode 120. Also, either S300 and S310 or S320 may be performed first, or they may be performed in parallel.

[0071] Note that the semiconductor device 200 may include a temperature-sensing diode or other temperature sensor for measuring the temperature of the semiconductor device 200 or the switching element 10. In this case, the semiconductor device 200 may further have, on the same surface as the first main electrode plate 220 or the like, an electrode plate connected to the electrodes of the temperature sensor such as the anode electrode and the cathode electrode of the temperature-sensing diode.

[0072] Also, the number of electrode plates arranged on the same surface as the first main electrode plate 220 and the like in the semiconductor device 200, as well as the size, shape, type, etc. of each electrode plate, may be appropriately selected according to the usage form of the semiconductor device 200, the temperature sensor added to the semiconductor device 200, or other additional circuits. For example, in the semiconductor device 200, the area of the control electrode plate 240 may be further reduced, and a new electrode plate may be provided in the area thus vacated. Examples of the newly provided electrode plate include, for example, a sense electrode plate electrically connected to the sense electrode 130, one or more temperature sense electrode plates respectively connected to the electrodes of a temperature sensor such as the switching element 10 as described above, or an electrode plate having the same potential as the second main electrode plate 230 (such as a sub-electrode plate), etc. At least one of them may be mentioned. Also, for example, other electrode plates such as the second main electrode plate 230 may be extended to the area vacated by reducing the area of the control electrode plate 240.

[0073] Such additional electrodes may be used for measuring electrical quantities for monitoring the state of the semiconductor device 200 or the switching element 10. Such additional electrodes may be arranged at positions away from the large-current conduction paths such as the first main electrode plate 220 and the second main electrode plate 230, and the main wirings connected to these main electrode plates, for example, near the sides on the side where the control electrode plate 240 and the sub-electrode plate 250 are provided in the semiconductor device 200. Thereby, the semiconductor device 200 can reduce the influence of at least one of the noise or heat generation caused by the flow of a large current on the additional electrodes.

[0074] Further, for example, a second sub-electrode plate different from the sub-electrode plate 250 may be provided in the area where space is created by reducing the area of the control electrode plate 240. The sub-electrode plate 250 (also referred to as the "first sub-electrode plate") and the second sub-electrode plate may be disposed on both sides of the control electrode plate 240 so as to sandwich the control electrode plate 240 between the sub-electrode plates. To achieve such an arrangement, in addition to the sub-wiring 530, the mounting substrate 210 may have a second sub-wiring on the mounting surface of the switching element 10 that electrically connects between the first main electrode 100 of the switching element 10 and the second sub-electrode plate. The sub-wiring 530 (also referred to as the "first sub-wiring") and the second sub-wiring may be disposed on both sides of the control wiring 520 so as to sandwich the control wiring 520 between the sub-wirings. In this way, by adopting a configuration in which the control electrode plate 240 is sandwiched between two sub-electrode plates, the semiconductor device 200 can reduce the wiring inductance in the path through which the current for driving the semiconductor device 200 (i.e., the current of the control signal flowing through the control electrode 110 of the switching element 10) flows.

[0075] FIG. 12 shows a state in which an insulating layer 280 is disposed on the mounting substrate 210 according to the second modification of the present embodiment. In S325 of FIG. 6, instead of placing the insulating sheet that becomes the insulating layer 280 on the mounting substrate 210 as shown in FIG. 9, the insulating layer 280 may be laminated on the surface of the first main electrode wiring 510 and the like on the side of the switching element 10 by the method shown in this figure.

[0076] In the example of this figure, a liquid insulating material that becomes the insulating layer 280 is applied to the surface of the mounting substrate 210 on the side of the switching element 10. Such an insulating material may be, for example, a thermosetting polyimide material. After applying the insulating material to the surface of the connection conductor 20 on the side of the switching element 10, the insulating layer 280 may be formed by heating the mounting substrate 210 to thermally cure the insulating material.

[0077] FIG. 13 is a cross-section of a semiconductor device 200 according to a third modification of the present embodiment. When forming the insulating layer 280 by applying an insulating material in S325 of FIG. 6, depending on the amount and fluidity of the insulating material, the insulating material may spread to the regions where a plurality of pillars 24 are formed on the mounting substrate 210 (for example, the first main electrode contact 513, the control electrode contact 523, etc.). Therefore, the region of the connection conductor 20 such as the first main electrode wiring 510 and the control wiring 520 connected to the first main electrode 100 may have a structure that protrudes toward the first main electrode 100 side with respect to the region where the insulating layer 280 is disposed. Thereby, the connection conductor 20 can have a step that prevents the insulating material from spreading to the region to be connected to the first main electrode 100 between the region to be connected to the first main electrode 100 and the region where the insulating layer 280 is to be disposed.

[0078] By providing such a step, it is possible to prevent the insulating material from spreading to the region where a plurality of pillars 24 are provided. Also, such a step can more accurately define the range where the insulating layer 280 is disposed.

[0079] FIG. 14 shows a state in which the insulating layer 280 is disposed on the mounting substrate 210 according to a fourth modification of the present embodiment. In the example of this figure, the connection conductor 20 such as the first main electrode wiring 510 and the control wiring 520 has a groove 285 that prevents the insulating material from spreading to the region to be connected to the first main electrode 100 and the control electrode 110, etc. between the regions such as the first main electrode contact 513 and the control electrode contact 523 to be connected to the first main electrode 100 and the control electrode 110 of the switching element 10 and the regions such as the wiring 515 and the wiring 525 where the insulating layer 280 is to be disposed. Such a groove 285 may be shallower compared to the thickness of the conductor pattern 22 in the connection conductor 20 and may not hinder the conductivity of the connection conductor 20.

[0080] By providing such a groove 285, even when the insulating material is applied slightly more on the mounting substrate 210, it is possible to suppress the spread of the insulating material to the region where a plurality of pillars 24 are provided.

[0081] FIG. 15 shows a state in which a boundary wall 290 is arranged on a mounting substrate 210 according to a fifth modification of the present embodiment. In the example of this figure, the application of the insulating material in S325 of FIG. 6 is performed in two or more times.

[0082] This figure shows a state in which a part of an insulating material that becomes an insulating layer 280 is applied to the surface of the switching element 10 side in the connection conductors 20 such as the first main electrode wiring 510 and the control wiring 520, and a boundary wall 290 made of the insulating material is formed at the boundary between the region to be connected to the first main electrode 100 in the connection conductor 20 and the region where the insulating layer 280 is to be arranged. When forming the boundary wall 290, the insulating material may be once applied to a portion such as 1 / 2 or less or 1 / 4 or less of the region where the insulating layer 280 is finally to be arranged. After applying a part of the insulating material in this way, the boundary wall 290 is formed by thermally curing the insulating material. When the viscosity of the insulating material is high enough to function as the boundary wall 290 without thermal curing, the thermal curing for forming the boundary wall 290 may be omitted.

[0083] After forming the boundary wall 290, another part of the insulating material is applied to the side of the region where the insulating layer 280 is to be arranged with respect to the boundary wall 290, thereby forming the insulating layer 280. In this step, the insulating material applied to the side of the region where the insulating layer 280 is to be arranged rather than the boundary wall 290 is blocked by the boundary wall 290. Therefore, according to this modification, it is possible to prevent the insulating material from spreading to the region to be connected to the first main electrode 100 in the connection conductor 20.

[0084] As described above, the present invention has been described using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. It is obvious from the description of the claims that the forms with such changes or improvements can also be included in the technical scope of the present invention.

[0085] The execution order of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the specification, and the drawings is not explicitly stated as "earlier" or "preceding" etc., and it should be noted that it can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the specification, and the drawings, even if it is described for convenience using "first," "next," etc., it does not mean that it is essential to implement in this order.

Explanation of Reference Signs

[0086] 10 Switching element 12 Chip substrate 14 Metal film 16 Insulating film 20 Connection conductor 22 Conductor pattern 24 Pillar 100 First main electrode 110 Control electrode 120 Second main electrode 130 Sense electrode 200 Semiconductor device 210 Mounting substrate 220 First main electrode plate 230 Second main electrode plate 240 Control electrode plate 250 Sub - electrode plate 260 Sealing part 270 Heat conduction plate 280 Insulating layer 285 Groove 290 Boundary wall 500 Insulating substrate 510 First main electrode wiring 513 First main electrode contact 515 Wiring 517 First main electrode plate contact 520 Control wiring 523 Control electrode contact 525 Wiring 527 Control electrode plate contact 530 Sub - wiring 535 Wiring 537 Sub - electrode plate contact

Claims

1. A semiconductor device comprising: a switching element having a first main electrode on one surface; a connection conductor connected to the first main electrode of the switching element; a sealing portion for sealing a space between the switching element and the connection conductor; an insulating layer disposed overlapping the sealing portion between at least a part of the switching element and the connection conductor.

2. The semiconductor device according to claim 1, wherein the insulating layer has a higher electrical resistivity than the sealing material of the sealing portion.

3. The semiconductor device according to claim 1, wherein the insulating layer is laminated on the surface of the connection conductor on the switching element side.

4. The semiconductor device according to claim 3, wherein the insulating layer is disposed on the surface of the connection conductor on the switching element side so as to face a region including at least a part of an outer edge portion of the switching element to an outer edge portion of a conductor exposed on the surface of the switching element on the connection conductor side.

5. The semiconductor device according to claim 3, wherein a region of the connection conductor connected to the first main electrode protrudes toward the first main electrode side with respect to the region where the insulating layer is disposed.

6. The semiconductor device according to claim 3, wherein the connection conductor has a groove between a region connected to the first main electrode and a region where the insulating layer is disposed.

7. The semiconductor device according to claim 1, wherein the insulating layer is laminated on the surface of the switching element on the connection conductor side.

8. The semiconductor device according to claim 1, wherein the connection conductor has a plurality of bumps in contact with the first main electrode.

9. The semiconductor device according to claim 1, further comprising a mounting substrate having a connection conductor on a mounting surface on which the switching element is mounted, and a first main electrode plate connected to the connection conductor in a region of the mounting surface where the switching element is not disposed.

10. Comprising a second main electrode plate connected to a second main electrode of the switching element, the mounting substrate has a control electrode plate connected to a control electrode of the switching element, The semiconductor device according to claim 9, wherein the first main electrode plate, the second main electrode plate, and the control electrode plate are exposed on one surface of the semiconductor device.

11. The semiconductor device according to claim 9, wherein the mounting substrate has a heat conduction plate formed on a surface opposite to the mounting surface.

12. The semiconductor device according to claim 1, wherein the switching element is a power MOSFET, an IGBT, or a SiC semiconductor element.

13. Preparing a switching element having a first main electrode on one surface; Disposing an insulating layer at a location between at least a part of the switching element and a connection conductor to be connected to the first main electrode; Connecting the connection conductor to the first main electrode of the switching element; Sealing a space between the switching element and the connection conductor with a sealing material A method for manufacturing a semiconductor device comprising.

14. The manufacturing method according to claim 13, wherein disposing the insulating layer includes laminating the insulating layer on a surface of the connection conductor on the switching element side.

15. The manufacturing method according to claim 14, wherein laminating the insulating layer on a surface of the connection conductor on the switching element side includes placing an insulating sheet serving as the insulating layer on a surface of the connection conductor on the switching element side.

16. The manufacturing method according to claim 14, wherein laminating the insulating layer on a surface of the connection conductor on the switching element side includes applying an insulating material serving as the insulating layer on a surface of the connection conductor on the switching element side.

17. The manufacturing method according to claim 16, wherein the connection conductor has a step for preventing the insulating material from spreading into a region to be connected to the first main electrode between a region to be connected to the first main electrode and a region where the insulating layer is to be disposed.

18. The manufacturing method according to claim 16, wherein the connection conductor has a groove for preventing the insulating material from spreading into a region to be connected to the first main electrode between a region to be connected to the first main electrode and a region where the insulating layer is to be disposed.

19. Applying the insulating material includes Applying a part of the insulating material serving as the insulating layer on a surface of the connection conductor on the switching element side to form a boundary wall made of the insulating material at a boundary between a region to be connected to the first main electrode in the connection conductor and a region where the insulating layer is to be disposed; Applying another part of the insulating material on a side of the boundary wall where the insulating layer is to be disposed to form the insulating layer The manufacturing method according to claim 16, including.

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