JP2013073945A - Electrode terminal with wiring sheet, wiring structure, semiconductor device, and manufacturing method of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode terminal with a wiring sheet which allows a small switching element to be mounted without using wire connection, a wiring structure, a semiconductor device, and a manufacturing method of the semiconductor device.SOLUTION: In an electrode terminal with a wiring sheet 45, a switching element 10, in which a source electrode 14 and a gate electrode 15 are formed on a first main surface 11, is disposed, and the electrode terminal has the following structure. The electrode terminal with the wiring sheet 45 includes: a first conductor 31 connecting with a source electrode 14; a wiring sheet 60 where a gate terminal 67 connecting with the gate electrode 15 and a connection part 61A are provided; and a third electrode terminal 81 connecting with the connection part 61A. The wiring sheet 60 is bonded to a first electrode terminal 40 to be integrated therewith.

Description

  The present invention relates to an electrode terminal with a wiring sheet on which a switching element is disposed, a wiring structure, a semiconductor device, and a method for manufacturing the semiconductor device.

  A semiconductor device for power control includes a switching element, a wiring structure in which the switching element is disposed, and a sealing portion that seals the switching element. The wiring structure includes a wiring body connected to the first electrode of the switching element, a wiring body connected to the second electrode of the switching element, and a wiring body connected to the control electrode of the switching element.

  At present, silicon (Si) IGBTs (Insulated Gate Bipolar Transistors) are mainly used as switching elements for high withstand voltage. In recent years, field effect transistors, SiC-based MOSFETs (Metal-Oxide-) using wide band gap semiconductor materials capable of higher breakdown voltage and lower loss than Si, such as silicon carbide (SiC) and gallium nitride (GaN), etc. Semiconductor Field-Effect Transistor), GaN-based MESFETs, and the like have been developed. Along with the development of these elements, studies are being made on power control semiconductor devices on which these elements are mounted.

  For example, in the technique described in FIG. 1 of Patent Document 1, the gate electrode (control electrode) and the main electrode (first electrode) formed on the main surface of the switching element are formed on one insulating substrate. Each is connected to two electrodes (wiring bodies).

  In the technique described in FIG. 10 of Patent Document 1, the gate electrode (control electrode) and the main electrode (first electrode) formed on the main surface of the switching element are connected to separate wiring bodies. That is, the main electrode is connected to an electrode (wiring body) facing the main electrode. The control electrode is connected to the lead electrode by a wire.

JP 2009-117428 A

By the way, the area of each electrode tends to be reduced by downsizing the switching element.
For example, since a MOSFET using SiC has a higher breakdown voltage than an IGBT using Si, the chip can be made smaller than an IGBT using Si. For this reason, the area of the source electrode and the area of the gate electrode are smaller than those of the Si-type switching element having the conventional structure. In addition, even Si-based switching elements tend to have a higher breakdown voltage and a smaller size due to a deep trench method or the like, and each electrode is made smaller accordingly.

When the electrode area is reduced, there are the following problems.
Due to the miniaturization of the switching element, the distance between the source electrode and the gate electrode (control electrode) is shortened. For this reason, it is necessary to reduce the distance between the electrode (wiring body) connected to the source electrode and the electrode (wiring body) connected to the gate electrode.

  However, in the case of a wiring structure in which an electrode connected to a high-current source electrode and an electrode connected to a small-current gate electrode are formed on an insulating substrate, it is difficult to reduce the distance between the two electrodes. This is because it is necessary to increase the electrode thickness in order to pass a large current, and it is difficult to significantly reduce the distance between the two electrodes depending on the electrode thickness in the etching process.

  On the other hand, as in the technique described in FIG. 10 of Patent Document 1, it is conceivable to connect each electrode of the switching element and each wiring body of the wiring structure by wire bonding. However, such a connection structure has the following problems. That is, the wire used for wire bonding is made of aluminum, and the maximum diameter is 500 μm in order to obtain the flexibility required for wire bonding. With the miniaturization of the switching element, the current density of the switching element increases, and naturally, the wire bonding wire also increases in current density. As a result, there is a possibility that the wire is blown by an electric current.

  The present invention has been made in view of such a situation, and an object thereof is to provide an electrode terminal with a wiring sheet, a wiring structure, a semiconductor device, and a semiconductor device capable of mounting a small switching element regardless of wire connection. An object of the present invention is to provide a method for manufacturing the semiconductor device.

  (1) The invention according to claim 1 is a wiring in which at least one switching element having at least a first electrode and a control electrode formed on a first main surface and a second electrode formed on a second main surface is disposed. An electrode terminal with a sheet, which is provided with an electrode terminal connected to the first electrode, a control terminal connected to the control electrode, and a connection portion connected to the control terminal via a wiring A sheet electrode and a control electrode terminal connected to the connection portion of the wiring sheet, the wiring sheet being attached to a surface of the electrode terminal to which the first electrode is connected, and the electrode terminal and the wiring The gist is that the sheet is integrated.

  With the downsizing of a switching element in which an electrode through which a large current flows and a control electrode through which a small current are present on the same surface, the following matters are required for the wiring structure. That is, it is required to secure insulation between the electrode terminal for large current and the electrode terminal for small current and to reduce the distance between them. However, in the conventional wiring structure, it is difficult to satisfy the above requirement due to the limitation in processing of the wiring structure, that is, the distance between both terminals due to the electrode thickness.

  In the present invention, the electrode terminal for large current and the electrode terminal for small current are configured as separate members. And the electrode terminal for small electric current is formed on the wiring sheet. Since the wiring sheet can be made thin and electrode terminals can be arranged at the edge of the wiring sheet, the distance between the electrode terminal for large current and the electrode terminal for small current must be reduced. Can do.

  Further, the control electrode and the control electrode terminal of the switching element are connected via the wiring sheet. In other words, the control electrode of the switching element and the control electrode terminal are connected without using a wire.

  (2) The invention according to claim 2 is the electrode terminal with a wiring sheet according to claim 1, wherein the electrode terminal is interposed between the electrode terminal and the first electrode of the switching element. The gist is that conductors are connected to each other. In the present invention, a conductor is interposed between the electrode terminal and the first electrode of the switching element. Thereby, it is possible to select a conductor made of a material different from that of the electrode terminal.

  (3) The invention according to claim 3 is a wiring in which at least one switching element having at least a first electrode and a control electrode formed on the first main surface and a second electrode formed on the second main surface is disposed. A first electrode terminal to which a conductor connected to the first electrode is attached; a second electrode terminal connected to the second electrode; a control terminal connected to the control electrode; The gist includes a wiring sheet on which a connection portion connected to the control terminal is formed, and a control electrode terminal connected to the connection portion of the wiring sheet.

  Since a large current flows through the first electrode and the second electrode of the switching element for power control, the wiring body connected to the first electrode and the wiring body connected to the second electrode do not become resistors. The cross-sectional area is set. On the other hand, since the amount of current flowing through the control electrode is small, the cross-sectional area of the wiring body connected to the control electrode may be smaller than that of the wiring body connected to the first electrode and the second electrode.

  In the conventional wiring structure, the first wiring body connected to the first electrode and the second wiring body connected to the control electrode are formed on the insulating substrate. In this case, since both wiring bodies are formed on one insulating substrate, the wiring body thickness of the first wiring body and the second wiring body is limited to the thickness of the first wiring body through which a large current flows. And it is difficult to make the space | interval between both wiring bodies smaller than wiring body thickness by the restriction | limiting of an etching process. For this reason, it is difficult to form a wiring structure suitable for a small switching element in which the distance between the first electrode and the second electrode is small in the conventional wiring structure.

  In the present invention, the conductor (wiring body) connected to the first electrode and the control terminal (wiring body) connected to the control electrode are configured as separate members. That is, the conductor corresponds to the first wiring body. A control terminal of the wiring sheet corresponds to the second wiring body. Since the conductor and the wiring sheet are parts of different forms, both members are not subject to processing restrictions from the other member. In addition, the wiring sheet can be made thin, and the distance between the control terminal (wiring body) and the conductor (wiring body) of the wiring sheet can be made narrower than in the conventional structure. For this reason, it is possible to mount a small switching element that is difficult to mount with the conventional wiring structure.

  Moreover, the connection part of the wiring sheet is connected to the control electrode terminal. That is, the control electrode of the switching element and the control electrode terminal are connected. For this reason, it is possible to accommodate a wiring sheet in a semiconductor device by using a control electrode terminal as an external terminal. When the wiring sheet is configured to be accommodated in the semiconductor device, the boundary surface between the sealing resin and the wiring sheet is not exposed to the outside, so that the withstand voltage is increased.

  (4) The invention according to claim 4 is the wiring structure according to claim 3, wherein the arrangement relationship between the conductor and the control terminal is such that the first electrode on the first main surface of the switching element. The wiring sheet is fixed to the first electrode terminal so as to correspond to the positional relationship between the first electrode terminal and the control electrode.

  In the present invention, the arrangement relationship between the conductor and the control terminal is matched with the arrangement relationship between the first electrode of the switching element and the control electrode. For this reason, the 1st electrode and conductor of a switching element and the control electrode and control terminal of a switching element can be connected accurately.

  (5) The invention according to claim 5 is the wiring structure according to claim 3 or 4, wherein the wiring sheet has a through hole corresponding to the first electrode, and the conductor is The gist is that it is attached to the first electrode terminal through the through hole.

  According to this invention, the conductor is positioned by the through hole of the wiring sheet. For this reason, positioning of a conductor can be performed easily. In addition, since the movement of the conductor is restricted by the through hole, the arrangement relationship between the conductor and the control terminal does not greatly deviate. That is, it is possible to suppress the frequency of positional deviation in the connection between the first electrode of the switching element and the conductor and the connection between the control electrode of the switching element and the control terminal.

  (6) The invention according to claim 6 is the wiring structure according to any one of claims 3 to 5, wherein the conductor is formed of a buffer material that relieves stress. . According to this invention, since the conductor is formed of the buffer material, the stress generated between the first electrode terminal and the switching element or inside these members can be reduced.

  (7) The invention according to claim 7 is the wiring structure according to any one of claims 3 to 6, wherein the conductor connected to the first electrode is the first conductor. The gist is that the two-electrode terminal is provided with a second conductor connected to the second electrode.

  (8) The invention according to claim 8 is the wiring structure according to claim 7, wherein the first electrode terminal is provided with a third conductor connected to another semiconductor element, and the second electrode terminal is provided with the second conductor. The gist is that the electrode terminal is provided with a fourth conductor connected to another semiconductor element.

  (9) The invention according to claim 9 is the wiring structure according to claim 8, wherein a thermal expansion coefficient of the first conductor is larger than a thermal expansion coefficient of the switching element and the first electrode terminal. The thermal expansion coefficient of the second conductor is larger than the thermal expansion coefficient of the switching element and smaller than the thermal expansion coefficient of the second electrode terminal, the third conductor. The thermal expansion coefficient of the fourth conductor is larger than the thermal expansion coefficient of the other semiconductor element and smaller than the thermal expansion coefficient of the first electrode terminal, and the thermal expansion coefficient of the fourth conductor is the other semiconductor element. The thermal expansion coefficient of the second electrode terminal is smaller than the thermal expansion coefficient of the second electrode terminal.

  When the difference between the thermal expansion coefficients between the two members is large, stress is generated due to the difference in expansion coefficient between the two members due to the temperature rise. The stress causes a crystal structure defect or delamination between both members. For this reason, it is preferable that the stress is small.

  In the present invention, the first conductor having a thermal expansion coefficient between the thermal expansion coefficient of the switching element and the thermal expansion coefficient of the first electrode terminal, and the thermal expansion coefficient of the switching element and the thermal expansion coefficient of the second electrode terminal A second conductor having a thermal expansion coefficient between is used. The third conductor having a thermal expansion coefficient between the thermal expansion coefficient of the other semiconductor element and the thermal expansion coefficient of the first electrode terminal, and the thermal expansion coefficient of the other semiconductor element and the thermal expansion of the second electrode terminal A fourth conductor having a coefficient of thermal expansion between the coefficients is used. For this reason, the difference in thermal expansion coefficient between two members adjacent to each other is reduced. Thereby, the stress which arises between each member can be made small.

  (10) The invention according to claim 10 is the wiring structure according to any one of claims 3 to 9, wherein the first main surface, the control electrode, and at least one other electrode are provided on the first main surface. And a switching element in which the second electrode is formed on the second main surface is disposed, and further includes another electrode terminal, and the wiring sheet includes another corresponding to the other electrode. The gist is that a terminal is provided, and a connection portion corresponding to the other terminal is connected to the other electrode terminal.

  In the present invention, the wiring sheet is provided with other terminals in addition to the control terminals. The other terminals are connected to other electrode terminals. For this reason, the switching element provided with another electrode in addition to the first electrode and the control electrode can be disposed on the wiring sheet. In addition, a signal can be input or output through another electrode terminal.

  (11) The invention according to claim 11 is the wiring structure according to any one of claims 3 to 10, wherein the first electrode terminal has a surface opposite to the surface facing the switching element. The gist is that an insulating layer is provided, and an insulating layer is provided on a surface of the second electrode terminal opposite to the surface facing the switching element.

  According to the present invention, when a semiconductor device is formed using a wiring structure, when the switching element placement side is sealed with the sealing resin, the surface side on which the insulating layer is formed can be exposed to the outside. For this reason, it is possible to attach a heat radiating device to the part in which the insulating layer was formed, and heat can be transmitted to a heat radiating device without going through sealing resin. That is, it is possible to provide a wiring structure that can be directly attached to a heat dissipation device.

  (12) The invention according to claim 12 is a semiconductor device including the electrode terminal with a wiring sheet according to claim 1 or 2. In the present invention, the semiconductor device includes the electrode terminal with the wiring sheet having the above-described configuration. That is, a switching element smaller than the conventional one can be mounted, and the semiconductor device can be downsized.

  (13) A thirteenth aspect of the invention is a semiconductor device including the wiring structure according to any one of the third to eleventh aspects. In the present invention, the semiconductor device includes the wiring structure having the above structure. That is, a switching element smaller than the conventional one can be mounted, and the semiconductor device can be downsized.

  (14) The invention described in claim 14 is a wiring sheet including a first electrode terminal, a second electrode terminal, a control electrode terminal, a control terminal and a connection portion, a first conductor, and a wiring including the second conductor. A method of manufacturing a semiconductor device including a structure and a switching element disposed in the wiring structure, the step of disposing the wiring sheet on a lead frame including the first electrode terminal and the control electrode terminal; A step of connecting the connection portion of the wiring sheet and the control electrode terminal, a step of connecting the first electrode terminal and the first conductor, and the second electrode terminal and the second conductor. Connecting, a connection between the control electrode of the switching element and the control terminal of the wiring sheet, a connection between the first electrode of the switching element and the first conductor, and a second electrode of the switching element and the first A step of connecting with a conductor, a step of sealing the switching element and the wiring sheet, a step of removing unnecessary portions of the lead frame and making the first electrode terminal and the control electrode terminal independent. It is made to include.

  When wire connection is included in the manufacturing process, the number of wires connected increases as the number of switching elements mounted increases, and the man-hour increases accordingly. The manufacturing method of the present invention does not include a wire connection step. For this reason, even when the number of mounted switching elements is large, the number of man-hours does not increase significantly.

  (15) According to a fifteenth aspect of the present invention, in the method of manufacturing a semiconductor device according to the fourteenth aspect, the first electrode terminal and the first electrode are formed on the assumption that the melting point of the first solder is higher than the melting point of the second solder. Using the first solder for connection with one conductor and for connection between the second electrode terminal and the second conductor, and connection between the control electrode of the switching element and the control terminal of the wiring sheet; The gist is to use the second solder for connection between the first electrode of the switching element and the first conductor and for connection between the second electrode of the switching element and the second conductor.

  In the present invention, for the sake of convenience, the step A for connecting the first electrode terminal and the first conductor and the step for connecting the second electrode terminal and the second conductor are performed for the sake of convenience. The connection between the control electrode of the switching element and the control terminal of the wiring sheet, the connection between the first electrode of the switching element and the first conductor, and the connection between the second electrode of the switching element and the second conductor are referred to as B process. .

  In the present invention, in the step A, the first solder having a melting point higher than that of the second solder used in the step B is used. For this reason, the second solder melts during the heating in the process B, but the first solder melts little. That is, as compared with the case where the types of solder used in each process are unified, the positional deviation between the members connected in the A process can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the electrode terminal with a wiring sheet which can mount a small switching element irrespective of wire connection, a wiring structure, a semiconductor device, and the manufacturing method of the semiconductor device can be provided.

Sectional drawing which shows the cross-sectional structure about the semiconductor device of one Embodiment of this invention. The top view of an electrode terminal with a wiring sheet. Sectional drawing along the AA line of FIG. The perspective view which shows the manufacturing method of a semiconductor device. The enlarged view which shows mounting of a switching element.

An embodiment of a semiconductor device of the present invention will be described with reference to FIG.
The semiconductor device 1 described below is used in a switching circuit such as an inverter, for example.

  The semiconductor device 1 includes a switching element 10, a flywheel diode 20, a wiring structure 30 in which these two elements are arranged, and a sealing unit 100 that seals these two elements.

The circuit configuration of the semiconductor device 1 is as follows.
The switching element 10 and the flywheel diode 20 are connected in parallel.
That is, the source electrode 14 of the switching element 10 and the anode electrode of the flywheel diode 20 are connected, and the drain electrode 13 of the switching element 10 and the cathode electrode of the flywheel diode 20 are connected.

  A signal wiring (wiring 61) is connected to the gate electrode 15 of the switching element 10. The flywheel diode 20 is an element for escaping electric power generated in the reverse direction of the switching element 10. This suppresses overpower from being applied to the switching element 10.

Hereinafter, each component of the semiconductor device 1 will be described.
The switching element 10 is formed of an n-type MOSFET.
On the first main surface 11 of the switching element 10, a source electrode 14 (first electrode), a gate electrode 15 (control electrode), a first monitor electrode 16, a second monitor electrode 17, and a third monitor electrode 18. And the 4th monitor electrode 19 is formed (refer FIG. 5). A drain electrode 13 (second electrode) is formed on the second main surface 12 of the switching element 10.

  The first monitor electrode 16 is connected to the anode of a temperature characteristic monitoring diode formed in the switching element 10 for temperature monitoring. The second monitor electrode 17 is connected to the cathode of the temperature characteristic monitoring diode. Note that the temperature of the switching element 10 is estimated based on the potential difference between the first monitor electrode 16 and the second monitor electrode 17.

  The third monitor electrode 18 is connected to the drain layer in the switching element 10. That is, a part of the drain current is output. For example, 1/10000 of the drain current is shunted.

  The fourth monitor electrode 19 is connected to the source layer in the switching element 10. A signal input to the gate electrode 15 of the switching element 10 is formed with reference to the potential of the source layer, that is, the potential of the fourth monitor electrode 19.

  The source electrode 14 is larger than the gate electrode 15 and the first to fourth monitor electrodes 16 to 19. The gate electrode 15 and the first to fourth monitor electrodes 16 to 19 are arranged in a line on the end side of the first main surface 11. These electrodes 15-19 are formed in substantially the same size.

The flywheel diode 20 is made of Si.
The sealing unit 100 seals the switching element 10 and the flywheel diode 20. As the sealing resin, for example, filler-containing epoxy resin such as silicon oxide, PPS resin (polyphenylene sulfide resin), or the like is used.

Next, the wiring structure 30 will be described in detail.
The wiring structure 30 includes a first electrode terminal 40, a second electrode terminal 50, a wiring sheet 60, a control electrode terminal array 80, four conductors (first to fourth conductors 31 to 34), and It has. The control electrode terminal array 80 includes five electrode terminals, that is, third to seventh electrode terminals 81 to 85. In the following description, in FIG. 1, the lower electrode terminal of the wiring structure 30, that is, the first electrode terminal 40, the third to seventh electrode terminals 81 to 85, the wiring sheet 60, the first conductor 31, and The structure including the third conductor 33 is referred to as an electrode terminal 45 with a wiring sheet (see FIG. 2).

The first electrode terminal 40 will be described.
The first electrode terminal 40 constitutes a terminal of the semiconductor device 1.
The first electrode terminal 40 is formed of a good conductor having a thickness of several hundred μm to several mm. Since some switching elements 10 can control current of several tens of A to 100 A, the first electrode terminal 40 is set to the above thickness.

  A first conductor 31 and a third conductor 33 are provided on the first surface 41 of the first electrode terminal 40. The first conductor 31 is disposed where the switching element 10 is disposed. The first main surface 31 </ b> A of the first conductor 31 is connected to the first electrode terminal 40 by a first solder 91. The third conductor 33 is disposed where the flywheel diode 20 is disposed. The first main surface 33 </ b> A of the third conductor 33 is connected to the first electrode terminal 40 by the first solder 91. Note that lead-free solder is used as the first solder 91. The first solder 91 is higher than the melting point of the second solder 92 described later.

  An insulating sheet 43 is attached to the second surface 42 of the first electrode terminal 40 and the back surface 80 </ b> B of the control electrode terminal array 80. The insulating sheet 43 is made of a polyimide resin. The insulating sheet 43 has a three-layer structure. That is, the intermediate layer of the insulating sheet 43 is a non-thermoplastic polyimide layer, and a thermoplastic polyimide layer is formed on both surfaces of the non-thermoplastic polyimide layer. That is, a thermoplastic polyimide layer is laminated on the surface of the insulating sheet 43 that adheres to the second surface 42. Non-thermoplastic refers to the property that there is no clear glass transition temperature, softening at high temperature is small, and elastic modulus is small.

  A metal sheet 44 is attached to the insulating sheet 43. The edge 44 </ b> A of the metal sheet 44 is disposed on the inner side than the edge 43 </ b> A of the insulating sheet 43. That is, the area of the insulating sheet 43 is larger than the area of the metal sheet 44. The metal sheet 44 is made of, for example, copper foil.

  The portion where the insulating sheet 43 and the metal sheet 44 are attached is exposed when the wiring structure 30 is sealed with resin to form the semiconductor device 1. That is, the first surface 41 side of the first electrode terminal 40 is sealed with the sealing resin, while the second surface 42 side of the first electrode terminal 40 is exposed to the outside.

  In addition, the laminated body (henceforth insulating protective layer) of the insulating sheet 43 (insulating layer) and the metal sheet 44 (protective layer) is formed with a copper clad polyimide laminated sheet. As the copper-clad polyimide laminated sheet, a sheet whose adhesive surface is a thermoplastic polyimide layer is used. This is because the copper-clad polyimide laminated sheet can be attached to the first electrode terminal 40 by thermocompression bonding.

The surface of the first electrode terminal 40 is subjected to electroless Ni—P plating treatment to prevent rust.
As the material of the first electrode terminal 40, copper is used from the viewpoints of conductivity and thermal conductivity. For example, it is made of high-purity copper such as tough pitch copper or oxygen-free copper. In addition, aluminum may be used for weight reduction.

The second electrode terminal 50 will be described.
The second electrode terminal 50 constitutes a terminal of the semiconductor device 1.
The second electrode terminal 50 is made of the same material as the first electrode terminal 40 and is subjected to the same surface treatment.

  A second conductor 32 and a fourth conductor 34 are provided on the first surface 51 of the second electrode terminal 50. The second conductor 32 is disposed where the switching element 10 is disposed. The first main surface 32 </ b> A of the second conductor 32 is connected to the second electrode terminal 50 by the first solder 91. The fourth conductor 34 is disposed where the flywheel diode 20 is disposed. The first main surface 34 </ b> A of the fourth conductor 34 is connected to the second electrode terminal 50 by the first solder 91.

  An insulating sheet 53 is attached to the second surface 52 of the second electrode terminal 50, that is, the surface opposite to the surface facing the switching element 10. A metal sheet 54 is attached to the insulating sheet 53. The structure of the laminated body of the insulating sheet 53 and the metal sheet 54 is the same as the structure of the insulating protective layer of the first electrode terminal 40. Note that when the semiconductor device 1 is formed by sealing the wiring structure 30 with resin, the first surface 51 side of the second electrode terminal 50 is sealed, while the second surface 52 side of the second electrode terminal 50 is sealed. Exposed to the outside.

  The material of the second electrode terminal 50 is the same material as that of the first electrode terminal 40 in view of the balance of stress applied to the entire semiconductor device 1. Note that the first electrode terminal 40 and the second electrode terminal 50 may be made of different materials.

The control electrode terminal array 80 will be described.
The thicknesses of the electrode terminals 81 to 85 of the control electrode terminal array 80 are substantially the same as the thickness of the first electrode terminal 40. The first surface 41 of the first electrode terminal 40 and the connection surface 80A of the wiring 61 of the control electrode terminal array 80 form the same plane. That is, it is possible to form the control electrode terminal array 80 and the first electrode terminal 40 from a single copper material. The distance (dimension) between the control electrode terminal array 80 and the first electrode terminal 40 is 0.7 times or more of these thicknesses. The same is true for the spacing (dimensions) between the electrode terminals constituting the control electrode terminal array 80.

  The electrode terminals 81 to 85 of the control electrode terminal array 80 are connected to the electrodes 15 to 19 of the switching element 10 via the wiring 61. That is, the third electrode terminal 81 (control electrode terminal) is connected to the gate electrode 15 through the wiring 61. The fourth electrode terminal 82 is connected to the first monitor electrode 16 via the wiring 61. The fifth electrode terminal 83 is connected to the second monitor electrode 17 via the wiring 61. The sixth electrode terminal 84 is connected to the third monitor electrode 18 via the wiring 61. The seventh electrode terminal 85 is connected to the fourth monitor electrode 19 via the wiring 61.

The first to fourth conductors 31 to 34 will be described.
The 1st-4th conductors 31-34 are formed in the substantially rectangular parallelepiped.
The thermal expansion coefficient of the first conductor 31 is larger than the thermal expansion coefficient of the switching element 10 and smaller than the thermal expansion coefficient of the first electrode terminal 40. The thermal expansion coefficient of the second conductor 32 is larger than the thermal expansion coefficient of the switching element 10 and smaller than the thermal expansion coefficient of the second electrode terminal 50.

  That is, the first conductor 31 and the second conductor 32 are caused by the difference between the function as a conductor and the thermal expansion coefficient of the switching element 10 and the thermal expansion coefficient of the first electrode terminal 40 or the second electrode terminal 50. It has a function as a cushioning material that relieves stress generated.

  The thermal expansion coefficient of the third conductor 33 is larger than the thermal expansion coefficient of the flywheel diode 20 and smaller than the thermal expansion coefficient of the first electrode terminal 40. The thermal expansion coefficient of the fourth conductor 34 is larger than the thermal expansion coefficient of the flywheel diode 20 and smaller than the thermal expansion coefficient of the second electrode terminal 50.

  That is, the third conductor 33 and the fourth conductor 34 are caused by the difference between the function as a conductor and the thermal expansion coefficient of the flywheel diode 20 and the thermal expansion coefficient of the first electrode terminal 40 or the second electrode terminal 50. Thus, it has a function as a cushioning material to relieve the stress generated.

  The first main surface 31A and the second main surface 31B of the first conductor 31 are formed to have approximately the same size as the source electrode 14 of the switching element 10. The second main surface 31 </ b> B of the first conductor 31 is plated with the second solder 92.

  The first main surface 32A and the second main surface 32B of the second conductor 32 are formed to have substantially the same size as the drain electrode 13 of the switching element 10. The second main surface 32 </ b> B of the second conductor 32 is plated with the second solder 92.

  The first main surface 33A and the second main surface 33B of the third conductor 33 are formed to have substantially the same size as the first main surface 21 of the flywheel diode 20. The second main surface 33 </ b> B of the third conductor 33 is plated with the second solder 92.

  The first main surface 34A and the second main surface 34B of the fourth conductor 34 are formed to have substantially the same size as the second main surface 22 of the flywheel diode 20. The second main surface 34 </ b> B of the fourth conductor 34 is plated with the second solder 92.

  In addition, as the 1st-4th conductors 31-34, the conductor by which the 1st main surface and the 2nd main surface are gold-plated etc. can also be used. Further, a conductor not subjected to solder plating can also be used. In these cases, a solder preform or a solder paste is used to connect the first to fourth conductors 31 to 34 and the first electrode terminal 40 or the second electrode terminal 50.

  The first conductor 31, the second conductor 32, the third conductor 33, and the fourth conductor 34 are, for example, a Cu / Mo / Cu laminated plate, a Cu—Mo alloy (Cu—Mo composite material), Cu— W alloy (Cu-W composite), Al-SiC alloy, Kovar (Fe-Ni-Co), tungsten (W), molybdenum (Mo), iron (Fe), 42 alloy (Fe-Ni), etc. ing. These materials satisfy the conditions of the thermal expansion coefficient. Among these materials, Cu / Mo / Cu laminated plates, Cu-Mo alloys (Cu-Mo composite materials), and Cu-W alloys (Cu-W composite materials) have thermal conductivity as compared with other materials. Since it is high, it is preferable from the viewpoint of heat dissipation. The Cu—Mo composite material indicates a material in which copper (Cu) is impregnated with molybdenum (Mo) or a material in which molybdenum (Mo) is impregnated with copper (Cu). The Cu—W composite material indicates a material obtained by impregnating copper (Cu) with tungsten (W) or a material obtained by impregnating tungsten (W) with copper (Cu).

The wiring sheet 60 will be described with reference to FIGS.
2 shows a planar structure of the electrode terminal 45 with a wiring sheet, and FIG. 3 shows a cross-sectional structure of the electrode terminal 45 with a wiring sheet.

The wiring sheet 60 is formed of a flexible printed board. Specifically, it has the following configuration.
The wiring sheet 60 includes five wirings 61, a reinforcing plate 62, a first polyimide layer 63A that covers one surface of the wiring 61 and the reinforcing plate 62, and a second polyimide layer 63B that covers the other surface of the wiring 61 and the reinforcing plate 62. And. The first polyimide layer 63 </ b> A is an insulating layer that contacts the first electrode terminal 40.

  The first polyimide layer 63A has a three-layer structure. That is, the intermediate layer of the first polyimide layer 63A is a non-thermoplastic polyimide layer, and a thermoplastic polyimide layer is formed on both surfaces of the non-thermoplastic polyimide layer.

The wiring 61 and the reinforcing plate 62 are made of a copper material and are formed on the first polyimide layer 63A.
The second polyimide layer 63 </ b> B covers the wiring 61 and the reinforcing plate 62. The second polyimide layer 63B is formed by applying a non-thermoplastic resin to the first polyimide layer 63A on which the wiring 61 and the reinforcing plate 62 are formed.

  As described above, in the wiring sheet 60, the surface that contacts the wiring 61, the surface that contacts the reinforcing plate 62, and the surface that contacts the first electrode terminal 40 are formed of the thermoplastic polyimide resin. The thermoplastic polyimide resin includes high-temperature adhesion between the first polyimide layer 63A and the wiring 61, high-temperature adhesion between the first polyimide layer 63A and the reinforcing plate 62, and high temperature between the first polyimide layer 63A and the first electrode terminal 40. Improve adhesion.

  The wiring sheet 60 is divided into a fixing portion 60 </ b> A fixed to the first electrode terminal 40 and a lead portion 60 </ b> B including the wiring 61. As shown in FIG. 2, a part of the lead portion 60 </ b> B contacts the first electrode terminal 40 and is fixed to the first electrode terminal 40 at this contact portion.

  The fixed portion 60 </ b> A surrounds the switching element 10 and the flywheel diode 20. A first through hole 64 and a second through hole 65 are formed in the fixing portion 60A. The first through hole 64 is formed to be slightly larger than the first conductor 31. The second through hole 65 is formed slightly larger than the third conductor 33. A reinforcing plate 62 is provided around the first through hole 64 and the second through hole 65.

  The lead portion 60B indicates a range from a portion adjacent to the first through hole 64 of the fixing portion 60A to the tip portions of the third to seventh electrode terminals 81 to 85. The portions where the lead portion 60B and the tip portions of the third to seventh electrode terminals 81 to 85 overlap are bonded to each other by thermocompression bonding.

  In the lead portion 60 </ b> B, each wiring 61 is formed from the vicinity of the first through hole 64 toward the third to seventh electrode terminals 81 to 85. A connection portion 61 </ b> A for connecting the end portion of the wiring 61 and each of the third to seventh electrode terminals 81 to 85 is formed in a portion overlapping with the third to seventh electrode terminals 81 to 85. The connecting portion 61A and the third to seventh electrode terminals 81 to 85 are connected by electrolytic plating. The connecting portion 61A is, for example, a through hole that penetrates the first polyimide layer 63A and the second polyimide layer 63B with the same diameter, or a through via that has a diameter of the second polyimide layer 63B larger than the diameter of the first polyimide layer 63A. It is formed.

  In the lead portion 60B, an opening 66 from which a part of the second polyimide layer 63B is removed is formed in the vicinity of the first through hole 64. Five terminals 67 to 71 are formed in the opening 66. Each terminal 67-71 and each connection part 61A are connected by the wiring 61 one-on-one.

  The five terminals 67 to 71 are composed of a gate terminal 67 (control terminal) and four monitor terminals 68 to 71. The gate terminal 67 is connected to the gate electrode 15. The first monitor terminal 68 is connected to the first monitor electrode 16. The second monitor terminal 69 is connected to the second monitor electrode 17. The third monitor terminal 70 is connected to the third monitor electrode 18. The fourth monitor terminal 71 is connected to the fourth monitor electrode 19.

  That is, the wiring sheet 60 connects the small pitch electrodes 15 to 19 and the large pitch third to seventh electrode terminals 81 to 85 to each other. This structure will be described in comparison with a lead frame on which an IC (Integrated Circuit) is mounted. The lead frame for IC has a large number of electrode terminals, and the tip of the electrode terminal is tapered toward the IC chip and extends to the vicinity of the IC chip. Each electrode and each electrode terminal of the IC chip are wire-connected. The reason why such a structure is possible is that the lead frame thickness can be reduced because the current flowing through each electrode terminal is small. On the other hand, in the case of the switching element 10, since the current flowing through the first electrode terminal 40 is large, the lead frame cannot be thinned. For this reason, the pitches of the third to seventh electrode terminals 81 to 85 other than the first electrode terminal 40 are increased, and the third to seventh electrode terminals 81 to 85 are disposed at positions away from the first electrode terminal 40. The Therefore, the wiring sheet 60 is used to connect the electrodes 15 to 19 and the third to seventh electrode terminals 81 to 85 of the switching element 10. Moreover, in the wiring sheet 60, the back surface side of the terminals 67-71 is fixed to the 1st electrode terminal 40 by thermocompression bonding, and the part which overlaps with each electrode terminal 81-85 is fixed to each electrode terminal 81-85 by thermocompression bonding. . Thus, since the wiring sheet 60 is also fixed at a portion other than the connection portion, even if a force is applied to the wiring sheet 60, almost no force is applied to the connection portion.

The arrangement relationship between the five terminals 67 to 71 and the first through holes 64 is as follows.
The first through hole 64 is provided at a position facing the source electrode 14 of the switching element 10. Each of the five terminals 67 to 71 is provided for the corresponding electrodes 15 to 19. That is, the arrangement relationship between the first through hole 64 and the five terminals 67 to 71 and the arrangement relationship between the source electrode 14 and the five electrodes 15 to 19 are the same.

  A solder layer is formed on these five terminals 67 to 71. The solder layer is formed by the second solder 92. The height of the surface of the five terminals (the surface of the solder layer) is substantially the same as the height of the second main surface 31B (the surface of the solder plating) of the first conductor 31. That is, when the switching element 10 is disposed on the second main surface 31B of the first conductor 31, the switching element 10 is configured not to tilt.

Next, the structural features of the wiring structure 30 will be described.
The wiring structure 30 includes a wiring body and a wiring body corresponding to each electrode of the switching element 10. In the present embodiment, the wiring structure 30 includes a first conductor 31 (wiring body) corresponding to the source electrode 14 and five terminals 67 to 71 corresponding to the five electrodes 15 to 19. A wiring sheet 60 (wiring body) is provided.

  In recent years, the distance between the source electrode 14 and the five electrodes 15 to 19 has been reduced due to the miniaturization of the switching element 10. For this reason, it is necessary to reduce the distance between the first conductor 31 and the five terminals 67 to 71. However, in the case of the conventional wiring structure, it is difficult to narrow between terminals (between electrodes). This is because it is difficult to make the terminal interval (electrode interval) larger than the terminal thickness (electrode thickness) in the etching process.

  On the other hand, in the embodiment, the wiring body connected to the source electrode 14 and the wiring body connected to the five electrodes 15 to 19 are members of different forms. That is, the first conductor 31 connected to the source electrode 14 is connected to the first electrode terminal 40, and the gate terminal 67 connected to the gate electrode 15 is formed on the wiring sheet 60. Since the wiring sheet 60 is processed regardless of the first conductor 31 and can form a terminal near the edge, the terminal formed near the edge is brought closer to the first conductor 31. Is possible.

Moreover, it has the following characteristics.
The first conductor 31 is positioned with respect to the five terminals 67 to 71 by the first through hole 64 of the wiring sheet 60. That is, the movement of the first conductor 31 is restricted by the first through hole 64. For this reason, the positional relationship between the first conductor 31 and the terminals 67 to 71 does not greatly deviate. In particular, when the first conductor 31 is fixed with solder, the first conductor 31 may be displaced from a predetermined position due to the surface tension of the solder, but the movement of the first conductor 31 is restricted by the first through hole 64, The positional relationship between the first conductor 31 and the terminals 67 to 71 on the wiring sheet 60 is maintained in a predetermined positional relationship. Thereby, the positional relationship between the first conductor 31 and the gate terminal 67 is maintained so as to correspond to the positional relationship between the source electrode 14 and the gate electrode 15 of the switching element 10. For this reason, the source electrode 14 and each electrode 15-19 of the switching element 10, and the 1st conductor 31 and each terminal 67-71 are connected in an appropriate state.

Furthermore, it has the following characteristics.
A wiring 61 connecting the electrodes 15 to 19 and the terminals 67 to 71 of the switching element 10 is protected by a polyimide layer. In the case of wire connection, a force due to expansion and contraction of the sealing resin may be directly applied to the wire, but in this configuration, a force due to expansion and contraction of the sealing resin or the like is directly applied to the wiring 61. There is no.

  In addition, since the wiring sheet 60 is fixed to the first electrode terminal 40 by thermocompression bonding, the distance between the electrodes 15 to 19 of the switching element 10 and the terminals 67 to 71 of the wiring sheet 60 (hereinafter referred to as electrode terminal spacing). ) Is maintained. Thereby, since the fluctuation | variation of the said electrode terminal space | interval resulting from the thermal expansion / contraction of surrounding sealing resin is suppressed, generation | occurrence | production of the crack of each electrode 15-19, each terminal 67-71, and a connection part is suppressed. Can do.

  Further, since the wiring sheet 60 is fixed by being thermocompression bonded to the third to seventh electrode terminals 81 to 85, the direction in which the third to seventh electrode terminals 81 to 85 and each connection portion 61 </ b> A of the wiring sheet 60 are separated. The force (hereinafter referred to as peeling force) acting on the surface is reduced. This suppresses the peeling force caused by the thermal expansion and contraction of the surrounding sealing resin, thereby suppressing the occurrence of cracks at the connection portions between the third to seventh electrode terminals 81 to 85 and the connection portions 61A. can do.

<Method for Manufacturing Semiconductor Device>
An example of a method for manufacturing the semiconductor device 1 will be described with reference to FIGS.
Here, a semiconductor device 1 in which six switching elements 10 and six flywheel diodes 20 are connected in parallel will be described.

[Each member]
A lead frame 200 including the first electrode terminal 40 and the control electrode terminal array 80 is used.
A lead frame 200 is formed by etching or stamping a 2 mm thick copper plate.

The lead frame 210 including the second electrode terminal 50 is formed in the same manner as the lead frame 200.
The following copper-clad polyimide laminate sheet (hereinafter, polyimide sheet 90) is used as an insulating protective sheet for forming the insulating protective layer of the first electrode terminal 40 and the control electrode terminal row 80 or the insulating protective layer of the second electrode terminal 50. Is used. That is, it is a two-layer material in which a copper foil and a polyimide layer are laminated, and a polyimide sheet 90 is used in which an adhesive is not used for bonding the two layers and the outermost surface of the polyimide layer is a thermoplastic polyimide layer.

  For example, the copper foil (metal sheets 44 and 54) is a rolled copper foil of 18 μm, and the polyimide sheet 90 having a polyimide layer (insulating sheets 43 and 53) of 25 μm is used. Further, the copper foil is etched to a position set back 5 mm from the edges 43A and 53A of the polyimide layer. That is, a distance of 5 mm between the edge 43A, 53A of the polyimide layer and the edge 44A, 54A of the copper foil is secured. Furthermore, the copper foil is subjected to Ni-P plating.

  A Cu / Mo / Cu laminated plate having a thickness of 0.15 mm is used as the first conductor 31, the second conductor 32, the third conductor 33, and the fourth conductor 34. The first main surface of the Cu / Mo / Cu laminate is plated with the first solder 91. Further, the second main surface of the Cu / Mo / Cu laminated plate is plated with the second solder 92. The first main surface is a surface connected to the first electrode terminal 40 or the second electrode terminal 50. The second main surface is a surface connected to the switching element 10 or the flywheel diode 20.

  As the first solder 91, solder having a melting point higher than that of the second solder 92 is used. Each solder is selected from the following group. For example, the first solder 91 is selected from a SnAgCu-based or SnCu-based solder group. The second solder 92 is selected from a SnZn-based or SnZnBi-based solder group.

A Si-MOSFET having a thickness of 0.2 mm and 13.6 mm × 13.6 mm is used as the switching element 10.
As the flywheel diode 20, a Si semiconductor element having a thickness of 0.2 mm and 13.6 mm × 13.6 mm is used.

As the wiring sheet 60, a sheet having a first polyimide layer 63A of 25 μm, a second polyimide layer 63B of 3.5 μm, and a copper foil thickness of 35 μm is used.
The wiring sheet 60 is manufactured as follows.

  In the first step, a laminated material (two-layer material without an adhesive layer) of a copper foil and a three-layer structure polyimide sheet is prepared. The three-layer structure polyimide sheet corresponds to the first polyimide layer 63A. In the second step, the wiring 61 and the reinforcing plate 62 are formed by etching the copper foil. In the third step, in the two-layer material, in addition to the terminal forming portion, a thermoplastic polyimide resin or a precursor thereof is applied and dried to form a layer corresponding to the second polyimide layer 63B. In the fourth step, the first through hole 64, the second through hole 65, and the through hole for the through hole (connection portion 61A) are formed. Further, electroless plating and electrolytic plating are performed to complete the through hole 61B. In the fifth step, the terminals 67 to 71 are plated or dipped with the second solder 92.

[assembly]
In the first step, a polyimide sheet 90 (insulation protection sheet) and a wiring sheet 60 are attached to the lead frame 200. Specifically, the polyimide sheet 90, the lead frame 200, and the wiring sheet 60 are laminated in order and aligned with each other. And it presses on conditions of 300 degreeC and 3 Mpa using a vacuum hot press apparatus.

  Next, copper plating of 30 μm is applied to the lead frame 200 to which the wiring sheet 60 is bonded. Thereby, the through hole 61B of the wiring sheet 60 and the electrode terminals 81 to 85 of the lead frame 200 are connected to each other. Then, in order to prevent rust and improve solderability, the lead frame 200 is subjected to electroless Ni—P plating having a thickness of 5 μm.

In the second step, a polyimide sheet 90 (insulation protection sheet) is attached to the lead frame 210. This pasting operation is performed by the same method as in the first step.
In the third step, the first conductor 31 and the third conductor 33 are fixed to the first electrode terminal 40. Specifically, the wiring sheet 60 is turned upward, the first conductor 31 is disposed in the first through hole 64, and the third conductor 33 is disposed in the second through hole 65. Next, solder melting is performed in an oven to fix the first conductor 31 and the third conductor 33 to the first electrode terminal 40. The temperature of the oven is set to a temperature at which the first solder 91 is melted.

  In the fourth step, the second conductor 32 and the fourth conductor 34 are disposed on the second electrode terminal 50, and are soldered and melted in an oven to fix the second conductor 32 and the fourth conductor 34. The oven temperature is the same as in the third step.

  In the fifth step, the switching element 10 and the flywheel diode 20 are arranged in the first assembly formed in the third step. Specifically, as shown in FIG. 5, the source electrode 14 of the switching element 10 and the second main surface 31 </ b> B of the first conductor 31 are opposed to each other, and each of the electrodes 15 to 19 of the switching element 10 and the wiring sheet 60. The terminals 67 to 71 are opposed to each other. Further, the flywheel diode 20 and the third conductor 33 are opposed to each other. Further, the second assembly formed in the fourth step is disposed on these elements. At this time, the second conductor 32 and the drain electrode 13 of the switching element 10 are opposed to each other, and the fourth conductor 34 and the flywheel diode 20 are opposed to each other. Then, the solder is melted in an oven to fix each member. The temperature of the oven is lower than the heating temperature in the second step and the third step, and is a temperature at which the second solder 92 melts.

  In the sixth step, the switching element 10 and the flywheel diode 20 are sealed with a sealing resin. Specifically, a sealing resin is filled between the first electrode terminal 40 and the second electrode terminal 50 with a molding machine to form the semiconductor device 1. As the sealing resin, for example, an epoxy resin containing silicon oxide filler is used. Further, tie bar cutting of the lead frame 200 and the lead frame 210 is performed.

The fifth step can be divided into two steps as follows.
Specifically, the switching element 10 and the flywheel diode 20 are arranged in the first assembly in the third step. Then, using the solder X, the switching element 10 and the flywheel diode 20 are fixed to the first assembly. This laminate is referred to as a third assembly. As the solder X, one having a melting point lower than that of the first solder 91 is used.

  Next, the second assembly of the fourth step is arranged on the third assembly. Then, using the solder Y, the second assembly is fixed to the third assembly. As the solder Y, a solder having a melting point lower than that of the solder X is used.

  According to such a process, the switching element 10 and the flywheel diode 20 are soldered to the first assembly in a movable state. For this reason, the switching element 10 and the flywheel diode 20 can be positioned by self-alignment.

[module]
The module includes a case including the semiconductor device 1, a water cooling jacket, a control circuit, and a bus bar. The module is manufactured as follows.

A water cooling jacket (heat radiating device) is attached to the semiconductor device 1.
A water cooling jacket is fixed to each of the outer surface of the first electrode terminal 40 and the control electrode terminal row 80 and the outer surface of the second electrode terminal 50. Filler-containing silicone thermal grease is used for fixing the water cooling jacket.

  Next, the semiconductor device 1 with the water cooling jacket is placed in the case, and the first electrode terminal 40 and the second electrode terminal 50 are welded to the corresponding bus bars. Then, the third to seventh electrode terminals 81 to 85 are solder-connected to corresponding terminals of the control circuit.

According to the present embodiment, the following effects can be obtained.
(1) In the above embodiment, the semiconductor device 1 includes the electrode terminal 45 with a wiring sheet and the second electrode terminal 50. The electrode terminal 45 with a wiring sheet includes a first electrode terminal 40, a wiring sheet 60, and a control electrode terminal array 80. And the wiring sheet 60 is affixed on the 1st surface 41 of the 1st electrode terminal 40, and the 1st electrode terminal 40 and the wiring sheet 60 are united.

  In the present invention, in the wiring structure 30, the first electrode terminal 40 through which a large current flows and the terminals 67 to 71 through which a small current flows are separate members. Then, terminals 67 to 71 for small current are formed on the wiring sheet 60. Since the wiring sheet 60 can be made thin, and the terminals 67 to 71 can be disposed on the edge of the wiring sheet 60, the distance between the first electrode terminal 40 and the terminals 67 to 71 is reduced. be able to. Thereby, the small switching element 10 can be arranged.

  Further, the electrodes 15 to 19 of the switching element 10 and the third to seventh electrode terminals 81 to 85 (control electrode terminals) are connected via the wiring sheet 60. That is, the electrodes 15 to 19 of the switching element 10 and the third to seventh electrode terminals 81 to 85 (control electrode terminals) are connected without using a wire.

  (2) The first electrode terminal 40 and the source electrode 14 of the switching element 10 are connected via the first conductor 31. With this structure, the first electrode terminal 40 and the source electrode 14 can be connected with a material different from that of the first electrode terminal 40.

(3) The wiring structure 30 is configured as follows.
The wiring structure 30 includes a first electrode terminal 40 connected to the source electrode 14 via the first conductor 31, a second electrode terminal 50 connected to the drain electrode 13, a gate terminal 67, and a connection portion 61A. The wiring sheet 60 which has and the 3rd-7th electrode terminal 81-85 are included. That is, the wiring structure 30 includes the electrode terminal 45 with the wiring sheet. For this reason, the effect similar to (1) is acquired.

  The electrodes 15 to 19 of the switching element 10 and the third to seventh electrode terminals 81 to 85 are connected via the wiring sheet 60. The wiring sheet 60 is accommodated inside the semiconductor device 1.

(4) In the above embodiment, the arrangement relationship between the first conductor 31 and the terminals 67 to 71 and the arrangement relationship between the source electrode 14 of the switching element 10 and the electrodes 15 to 19 are the same.
According to this configuration, the source electrode 14 and the first conductor 31 of the switching element 10 and the electrodes 15 to 19 and the terminals 67 to 71 of the switching element 10 can be accurately connected.

  (5) In the embodiment, the first through hole 64 is formed in the wiring sheet 60 at a location corresponding to the source electrode 14. The first conductor 31 is attached to the first electrode terminal 40 through the first through hole 64.

  According to this configuration, the first conductor 31 is positioned by the first through hole 64 of the wiring sheet 60. For this reason, it is possible to suppress the frequency of occurrence of displacement in the connection between the source electrode 14 of the switching element 10 and the first conductor 31 and the connection between the gate electrode 15 of the switching element 10 and the gate terminal 67.

  Further, since the gate terminal 67 and the first through-hole 64 of the wiring sheet 60 are formed by a series of structural steps of the wiring sheet 60, the positional deviation between them with respect to the design dimension is small. That is, the interval between the gate terminal 67 and the first through-hole 64 is accurately set to a certain distance or more. For this reason, there is little possibility that the first conductor 31 and the gate terminal 67 are short-circuited.

  (6) In the said embodiment, the 1st-4th conductors 31-34 are formed of the buffer material which relieves stress. According to this configuration, the stress generated between the first electrode terminal 40, the second electrode terminal 50, the switching element 10 and the flywheel diode 20, or the stress generated inside these members can be relaxed.

  (7) In the said embodiment, the member which satisfy | fills the following conditions is used as the 1st-4th conductors 31-34. That is, the thermal expansion coefficient of the first conductor 31 is larger than the thermal expansion coefficient of the switching element 10 and smaller than the thermal expansion coefficient of the first electrode terminal 40. The thermal expansion coefficient of the second conductor 32 is larger than the thermal expansion coefficient of the switching element 10 and smaller than the thermal expansion coefficient of the second electrode terminal 50. The thermal expansion coefficient of the third conductor 33 is larger than the thermal expansion coefficient of the flywheel diode 20 and smaller than the thermal expansion coefficient of the first electrode terminal 40. The thermal expansion coefficient of the fourth conductor 34 is larger than the thermal expansion coefficient of the flywheel diode 20 and smaller than the thermal expansion coefficient of the second electrode terminal 50. According to such a configuration, the difference in coefficient of thermal expansion between two adjacent members is reduced. Thereby, the stress which arises between each member can be made small.

  (8) In the above embodiment, the wiring sheet 60 is provided with monitor terminals (other terminals) 68 to 71 corresponding to the plurality of monitor electrodes (other electrodes) 16 to 19. Further, fourth to seventh electrode terminals (other electrode terminals) 82 to 85 are provided corresponding to the monitor terminals 68 to 71, respectively. For this reason, the switching element 10 provided with a monitor electrode in addition to the source electrode 14 and the gate electrode 15 can be mounted.

  (9) In the above embodiment, the insulating sheet 43 (insulating layer) is provided on the surface (second surface 42) on the opposite side of the surface facing the switching element 10 of the first electrode terminal 40. In addition, an insulating sheet 53 (insulating layer) is provided on a surface (second surface 52) opposite to the surface facing the switching element 10 of the second electrode terminal 50.

  According to this configuration, when the semiconductor device 1 is formed using the wiring structure 30, the insulating sheets 43 and 53 are formed when the surface side on which the switching element 10 is disposed is sealed with the sealing resin. The surface side can be exposed to the outside. For this reason, it is possible to attach a heat radiating device to the part in which the insulating sheets 43 and 53 are formed, and heat can be transmitted to the heat radiating device without using a sealing resin. That is, it is possible to provide the wiring structure 30 to which the heat dissipation device can be directly attached.

  (10) In the above embodiment, the height of the surface of each terminal 67 to 71 of the wiring sheet 60 (the surface of the solder layer) and the height of the second main surface 31B (the surface of the solder plating) of the first conductor 31 Are approximately the same. For this reason, it is suppressed that the switching element 10 inclines at the time of mounting of the switching element 10. As a result, the production yield can be increased.

(11) The semiconductor device 1 of the above embodiment includes the wiring structure 30 having the above configuration. That is, the semiconductor device 1 includes an electrode terminal 45 with a wiring sheet.
According to this structure, the switching element 10 smaller than before can be mounted. For this reason, the semiconductor device 1 can be made smaller than before in a package that does not use wire connection.

  (12) The manufacturing method of the semiconductor device 1 of the above embodiment does not include a wire connection process. Each member can be connected by reflow or the like. For this reason, even when the number of mounted switching elements 10 is large, the man-hour is not significantly increased.

  (13) In the method of manufacturing the semiconductor device 1 according to the above embodiment, the process A connected by the first solder 91 is performed before the process B connected by the second solder 92. The process A includes the connection between the first conductor 31 and the third conductor 33 and the first electrode terminal 40, and the connection between the second conductor 32 and the fourth conductor 34 and the second electrode terminal 50. It is. The process B includes the connection between the first conductor 31 and the second conductor 32 and the switching element 10 and the connection between the third conductor 33 and the fourth conductor 34 and the flywheel diode 20. A solder having a higher melting point than the second solder 92 is used as the first solder 91.

  According to such a manufacturing method, since the solder having a higher melting point than the solder used in the B process is used in the A process, the second solder 92 is melted in the B process performed after the A process. The melting of the first solder 91 is small. For this reason, the position shift of the members connected in the A process is suppressed.

(Other embodiments)
In addition, the embodiment of the present invention is not limited to the embodiment shown in each of the above-described embodiments, and the embodiment can be modified as shown below, for example. In addition, the following modifications can be implemented by combining different modifications with each other.

  In the above embodiment, the first conductor 31 and the third conductor 33 are configured as separate members, but may be configured as a single member. According to this configuration, it is not necessary to mount the first conductor 31 and the third conductor 33 on the first electrode terminal 40 individually. For this reason, compared with the case where the 1st conductor 31 and the 3rd conductor 33 are comprised as a separate member, the manufacturing process of the wiring structure 30 can be simplified.

  Similarly, the second conductor 32 and the fourth conductor 34 are configured as separate members, but may be configured as a single member. Also by this, the manufacturing process of the wiring structure 30 can be simplified.

  In the above embodiment, the first conductor 31, the second conductor 32, the third conductor 33, and the fourth conductor 34 are replaced with the thermal expansion coefficient of the switching element 10 and the first electrode terminal 40 (or the second electrode terminal). It is made of a material having an intermediate value of the thermal expansion coefficient of 50), but a simple metal plate can be used instead. For example, any or all of the first to fourth conductors 31 to 34 may be formed of copper or a copper alloy.

-In the said embodiment, although the sheet | seat formed with the polyimide resin is used as the insulating sheets 43 and 53, the material of the insulating sheets 43 and 53 is not limited to this. For example, as materials for the insulating sheets 43 and 53, epoxy resin, PPS resin, PET resin (polyethylene terephthalate resin), PEEK resin (polyether ether ketone resin), silicone resin, fluororesin, liquid crystal polymer, insulating fillers for these resins A resin containing can be used. A ceramic substrate may also be used. As the ceramic substrate, for example, SiN, AlN, Al ₂ O ₃ , SiC, SiO ₂ or the like can be used.

  In the above embodiment, two types of solder having different melting points are used, but instead of this configuration, the types of solder may be unified. When unifying the kind of solder, it is preferable to perform solder connection of each member collectively.

  In the above embodiment, each member is solder-connected using a solder-plated member, but the solder connection is not limited to this method. For example, each member may be connected by using a solder paste, a solder preform, or the like. In this case, the solder plating applied to the first conductor 31 to the fourth conductor 34 may be omitted.

  In the above embodiment, the connecting portion 61A of the wiring sheet 60 and each of the electrode terminals 81 to 85 are connected by electrolytic plating, but can be connected by solder. In consideration of the solder connection step of the switching element 10 performed in a later step, it is preferable to perform the solder connection between the connection portion 61A and the electrode terminals 81 to 85 with the first solder.

  In the above embodiment, the present invention is applied to the wiring structure 30 of the semiconductor device 1 in which the switching element 10 and the flywheel diode 20 are connected in parallel, but the wiring structure of the semiconductor device 1 including only the switching element 10 The present invention can be applied to 30.

  In the above embodiment, SiC-MOSFET or Si-MOSFET is used as the switching element 10, but the type of the switching element 10 is not limited. In other words, the present invention can be applied to a wiring structure of a semiconductor device including the switching element 10 having two or more electrodes. Other examples of the switching element 10 include a MOSFET using a group III nitride material such as GaN, Si-IGBT (n-channel IGBT), SiC-IGBT, and the like.

  In the above embodiment, in the method of manufacturing a semiconductor device, first, the wiring sheet 60, the first conductor 31, and the third conductor 33 are fixed to the lead frame 200 to form the first assembly, and the lead frame 210 The second conductor 32 and the fourth conductor 34 are fixed to form the second assembly. Next, the first assembly, the second assembly, the switching element 10 and the flywheel diode 20 are fixed.

  Instead of such an assembly order, the following assembly order may be employed. First, the first assembly is formed in the same manner as described above. Next, the switching element 10 and the flywheel diode 20 are fixed to the first assembly to form a third assembly. Next, the second conductor 32 and the fourth conductor 34 are fixed to the third assembly to form the fourth assembly. Next, the lead frame 210 is fixed to the fourth assembly.

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor device, 10 ... Switching element, 11 ... 1st main surface, 12 ... 2nd main surface, 13 ... Drain electrode, 14 ... Source electrode, 15 ... Gate electrode, 16 ... 1st monitor electrode, 17 ... 2nd Monitor electrode, 18 ... third monitor electrode, 19 ... fourth monitor electrode, 20 ... flywheel diode, 21 ... first main surface, 22 ... second main surface, 30 ... wiring structure, 31 ... first conductor, 31A ... first main surface, 31B ... second main surface, 32 ... second conductor, 32A ... first main surface, 32B ... second main surface, 33 ... third conductor, 33A ... first main surface, 33B ... 2nd main surface, 34 ... 4th conductor, 34A ... 1st main surface, 34B ... 2nd main surface, 40 ... 1st electrode terminal, 41 ... 1st surface, 42 ... 2nd surface, 43 ... insulating sheet 43A ... edge, 44 ... metal sheet, 44A ... edge, 45 ... electrode terminal with wiring sheet, 50 ... second Electrode terminal, 51 ... first surface, 52 ... second surface, 53 ... insulating sheet, 53A ... edge, 54 ... metal sheet, 54A ... edge, 60 ... wiring sheet, 60A ... fixed portion, 60B ... lead portion, 61 ... wiring, 61A ... connecting portion, 61B ... through hole, 62 ... reinforcing plate, 63A ... first polyimide layer, 63B ... second polyimide layer, 64 ... first through hole, 65 ... second through hole, 66 ... opening 67: Gate terminal, 68: First monitor terminal, 69: Second monitor terminal, 70: Third monitor terminal, 71: Fourth monitor terminal, 80: Control electrode terminal row, 80A: Connection surface, 80B: Back surface , 81 ... third electrode terminal, 82 ... fourth electrode terminal, 83 ... fifth electrode terminal, 84 ... sixth electrode terminal, 85 ... seventh electrode terminal, 90 ... polyimide sheet, 91 ... first solder, 92 ... first 2 solder, 100 ... sealed portion, 200 ... lead hook Over-time, 210 ... lead frame.

Claims (15)

An electrode terminal with a wiring sheet in which at least one switching element in which at least a first electrode and a control electrode are formed on a first main surface and a second electrode is formed on a second main surface is disposed;
An electrode terminal connected to the first electrode; a control sheet connected to the control electrode; and a wiring sheet provided with a connection portion connected to the control terminal via a wiring; and the wiring sheet A control electrode terminal connected to the connection part,
The electrode terminal with a wiring sheet, wherein the wiring sheet is attached to a surface of the electrode terminal to which the first electrode is connected, and the electrode terminal and the wiring sheet are integrated. In the electrode terminal with a wiring sheet according to claim 1,
The electrode terminal with a wiring sheet, wherein the electrode terminal is provided with a conductor that is interposed between the electrode terminal and the first electrode of the switching element and connects the two to each other. A wiring structure in which at least one switching element having at least a first electrode and a control electrode formed on a first main surface and a second electrode formed on a second main surface is disposed,
A first electrode terminal to which a conductor connected to the first electrode is attached; a second electrode terminal connected to the second electrode; a control terminal connected to the control electrode; and the control terminal. A wiring structure comprising: a wiring sheet on which a connecting portion is formed; and a control electrode terminal connected to the connecting portion of the wiring sheet. The wiring structure according to claim 3,
The wiring sheet is connected to the first electrode terminal so that the arrangement relationship between the conductor and the control terminal corresponds to the arrangement relationship between the first electrode and the control electrode on the first main surface of the switching element. A wiring structure characterized by being fixed to the wire. In the wiring structure according to claim 3 or 4,
A through hole is formed in the wiring sheet at a location corresponding to the first electrode,
The wiring structure, wherein the conductor is attached to the first electrode terminal through the through hole. In the wiring structure according to any one of claims 3 to 5,
The wiring structure is characterized in that the conductor is formed of a buffer material that relieves stress. In the wiring structure according to any one of claims 3 to 6,
The conductor connected to the first electrode as a first conductor,
The wiring structure according to claim 1, wherein the second electrode terminal is provided with a second conductor connected to the second electrode. The wiring structure according to claim 7,
The first electrode terminal is provided with a third conductor connected to another semiconductor element,
The second electrode terminal is provided with a fourth conductor connected to another semiconductor element. The wiring structure according to claim 8,
A thermal expansion coefficient of the first conductor is larger than a thermal expansion coefficient of the switching element and smaller than a thermal expansion coefficient of the first electrode terminal;
A thermal expansion coefficient of the second conductor is larger than a thermal expansion coefficient of the switching element and smaller than a thermal expansion coefficient of the second electrode terminal;
The thermal expansion coefficient of the third conductor is larger than the thermal expansion coefficient of the other semiconductor element and smaller than the thermal expansion coefficient of the first electrode terminal, and the thermal expansion coefficient of the fourth conductor is A wiring structure having a coefficient of thermal expansion greater than that of the other semiconductor element and smaller than that of the second electrode terminal. In the wiring structure according to any one of claims 3 to 9,
A switching element in which the first electrode, the control electrode, and at least one other electrode are formed on the first main surface and the second electrode is formed on the second main surface;
Further provided with other electrode terminals,
The wiring sheet is provided with another terminal corresponding to the other electrode, and a connection portion corresponding to the other terminal is connected to the other electrode terminal. In the wiring structure according to any one of claims 3 to 10,
An insulating layer is provided on the surface of the first electrode terminal opposite to the surface facing the switching element,
An insulating layer is provided on the surface of the second electrode terminal opposite to the surface facing the switching element.   A semiconductor device comprising the electrode terminal with a wiring sheet according to claim 1.   The semiconductor device containing the wiring structure as described in any one of Claims 3-11. A first electrode terminal, a second electrode terminal, a control electrode terminal, a wiring sheet including a control terminal and a connection portion, a first conductor, a wiring structure including the second conductor, and the wiring structure A method of manufacturing a semiconductor device including a switching element,
Disposing the wiring sheet on a lead frame including the first electrode terminal and the control electrode terminal;
Connecting the connection portion of the wiring sheet and the control electrode terminal;
Connecting the first electrode terminal and the first conductor;
Connecting the second electrode terminal and the second conductor;
The connection between the control electrode of the switching element and the control terminal of the wiring sheet, the connection between the first electrode of the switching element and the first conductor, and the second electrode of the switching element and the second conductor Connecting, and
Sealing the switching element and the wiring sheet;
And removing the unnecessary portion of the lead frame to make the first electrode terminal and the control electrode terminal independent. A method for manufacturing a semiconductor device, comprising: In the manufacturing method of the semiconductor device according to claim 14,
As the melting point of the first solder is higher than the melting point of the second solder,
The first solder is used for connection between the first electrode terminal and the first conductor and between the second electrode terminal and the second conductor, and the control electrode and the wiring sheet of the switching element The second solder for connection to the control terminal of the switching element, connection of the first electrode of the switching element to the first conductor, and connection of the second electrode of the switching element to the second conductor. A method for manufacturing a semiconductor device, comprising:

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