Semiconductor module

Abstract

The present application provides a semiconductor module that improves temperature detection accuracy of a semiconductor element without affecting the original performance of the semiconductor element. The semiconductor module (1) includes: a laminated substrate (2) formed by disposing a circuit board (22) on an upper surface of an insulating board (20) and a heat sink (21) on a lower surface of the insulating board; a semiconductor element (3) disposed on an upper surface of the circuit board; a metal wiring board (4) disposed on an upper surface of the semiconductor element; and a temperature sensor (6) disposed on an upper surface of the metal wiring board for detecting a temperature of the semiconductor element. The metal wiring board has a cutout portion (40) that shields heat of the semiconductor element.

Description

TECHNICAL FIELD

[0001] The present application relates to a semiconductor module. BACKGROUND

[0002] A semiconductor device having a substrate provided with a semiconductor element such as an IGBT (Insulated Gate Bipolar Transistor), a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor), a FWD (Free Wheeling Diode), and the like is used for an inverter device and the like.

[0003] An inverter device widely used for a motor drive for household / industrial use and the like is composed of a semiconductor switching element (switching element) such as a MOSFET, an IGBT, and an IC chip for driving the semiconductor switching element. In addition, as a unit for miniaturizing a device and built-in protection circuit, an IPM (Intelligent Power Module) in which the above-mentioned switching element and IC chip are one-packaged is used.

[0004] In such a semiconductor device (semiconductor module), a temperature sensor (thermistor) for detecting the temperature of a semiconductor element is provided. For example, in Patent Literature 1, a semiconductor element and a thermistor are disposed on a circuit substrate in which a copper circuit is formed on the surface of a metal base via an insulating layer. The semiconductor element and the thermistor are respectively disposed on independent copper circuits, and the thermistor is connected to the gate of the semiconductor element via a bonding wire. In addition, in Patent Literature 2, a power semiconductor chip and a thermistor are disposed on a base plate. Further, in Patent Literature 3, a temperature sensor is mounted on a semiconductor chip.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Literature 1: Japanese Patent Application Laid-Open No. 2003-188336

[0008] Patent Literature 2: Japanese Patent Application Laid-Open No. 2017-4999

[0009] Patent Literature 3: Japanese Patent Application Laid-Open No. 2004-127983 SUMMARY

[0010] Problems to be Solved by the Invention

[0011] However, in Patent Document 1, the semiconductor element and the thermistor are positioned separately on independent copper circuits, thus separating them. Therefore, the thermistor cannot directly receive heat from the semiconductor element, potentially affecting sensing accuracy. Furthermore, in Patent Document 2, where the semiconductor element and thermistor are positioned on the same substrate, the layout of the circuit board on the substrate is limited. Additionally, Patent Document 3 has considered directly mounting the temperature sensor on the semiconductor element to improve sensing accuracy; however, this reduces the active area of ​​the semiconductor element by an amount equivalent to the dedicated area of ​​the temperature sensor. In other words, a portion of the active area of ​​the semiconductor element is sacrificed, potentially impacting the performance of the semiconductor device.

[0012] The present invention was made in view of the aforementioned problems, and one of its objectives is to provide a semiconductor module that can improve the temperature detection accuracy of a semiconductor element without affecting the inherent performance of the semiconductor element.

[0013] Means for Solving the Problems

[0014] One aspect of the present invention provides a semiconductor module comprising: a laminated substrate having a circuit board disposed on an upper surface of an insulating plate and a heat sink disposed on a lower surface of the insulating plate; a semiconductor element disposed on the upper surface of the circuit board; a metal wiring board disposed on the upper surface of the semiconductor element; and a temperature sensor disposed on the upper surface of the metal wiring board for detecting the temperature of the semiconductor element, wherein the metal wiring board has a heat shield portion that shields the semiconductor element from heat.

[0015] Effects of the Invention

[0016] According to the present invention, the temperature detection accuracy of semiconductor devices can be improved without affecting the original performance of the semiconductor devices. Attached Figure Description

[0017] FIG. 1 This is a plan view illustrating an example of a semiconductor module involved in this embodiment.

[0018] FIG. 2 It is along FIG. 1 A schematic diagram of the cross-section obtained by cutting line AA.

[0019] FIG. 3 It is along FIG. 1 A schematic diagram of the cross-section obtained by cutting the BB line.

[0020] FIG. 4 It means FIG. 1 A magnified view of a portion of the heat shield.

[0021] FIG. 5 is a plan view showing a heat shield portion according to a modification.

[0022] FIG. 6 is a plan view showing a heat shield portion according to another modification.

[0023] Fig. 7 is a plan view showing a variation of the configuration of the heat shield portion.

[0024] Fig. 8 is a view showing the positional relationship between the temperature sensor and the heat shield portion.

[0025] FIG. 9 is a plan view showing a semiconductor module according to another example of the embodiment.

[0026] FIG. 10 is a cross-sectional view taken along the C-C line of FIG. 9 .

[0027] FIG. 11 is an enlarged view of a portion of the heat shield portion of FIG. 9 .

[0028] Fig. 12 is a view showing a semiconductor module according to another embodiment.

[0029] Explanation of Reference Numerals

[0030] 1: semiconductor module; 2: laminated substrate; 3: semiconductor element; 3a: electrode pad; 3b: electrode pad; 4: metal wiring board; 4a: first end portion; 4b: second end portion; 5: metal wiring board; 6: temperature sensor; 7: sealing resin; 10: housing member; 11: annular wall portion; 12: recessed portion; 13: stepped portion; 14: main terminal; 15: main terminal; 16: control terminal; 17: temperature sensor terminal; 20: insulating board; 21: heat dissipation plate; 22: circuit board; 40: cutout portion; 41: cutout portion; 42: cutout portion; 43: cutout portion; 44: cutout portion; Dl: width of cutout portion; D2: distance; S: bonding material; T: heat transfer path; θl: angle range; θ2: angle range; θ3: angle range. DETAILED DESCRIPTION

[0031] Hereinafter, a semiconductor module to which the present application can be applied will be described. FIG. 1 is a plan view showing an example of a semiconductor module according to the embodiment. FIG. 2 is a cross-sectional view taken along the A-A line of FIG. 1 . FIG. 3 is a cross-sectional view taken along the B-B line of FIG. 1a cross-sectional view of the B-B line cut. Furthermore, the semiconductor module shown below is merely an example and is not limited thereto and can be appropriately changed.

[0032] In addition, in the following drawings, the long side direction of the semiconductor module (the direction in which the metal wiring board described later extends from the semiconductor element) is defined as the X direction, the short side direction (the direction orthogonal to the X direction) is defined as the Y direction, and the height direction is defined as the Z direction. The respective axes of X, Y, and Z shown in the drawings are orthogonal to each other and form a right-hand system. In addition, depending on the situation, the X direction is sometimes referred to as the left-right direction, the Y direction is sometimes referred to as the front-rear direction, and the Z direction is sometimes referred to as the up-down direction. These directions (front-rear, left-right, up-down directions) are words used for convenience of explanation and depending on the mounting posture of the semiconductor module, the correspondence relationship with the respective directions of the XYZ directions is sometimes changed. For example, the side of the heat dissipation surface (the side of the cooler) of the semiconductor module is taken as the lower surface side, and the opposite side thereof is taken as the upper surface side. In addition, in the present specification, plan view means a case where the upper surface of the semiconductor module is observed from the Z direction positive side.

[0033] The semiconductor module 1 is applied, for example, to a power conversion device such as a power module. As shown in FIG. 1, the semiconductor module 1 is configured to dispose the laminated substrate 2, the semiconductor element 3, the metal wiring boards 4 and 5, the temperature sensor 6, and the like within the housing member 10. FIGS. 1 to 3

[0034] The laminated substrate 2 is formed by laminating a metal layer and an insulating layer and is configured, for example, by a DCB (Direct Copper Bonding) substrate, an AMB (Active Metal Brazing) substrate, or a metal base substrate (Japanese: base plate). Specifically, the laminated substrate 2 has an insulating plate 20, a heat dissipation plate 21 disposed on the lower surface of the insulating plate 20, and a plurality of circuit boards 22 disposed on the upper surface of the insulating plate 20. The laminated substrate 2 is formed, for example, in a rectangular shape in plan view in which the X direction is longer than the Y direction.

[0035] The insulating plate 20 is formed in a flat plate shape having a prescribed thickness in the Z direction and having an upper surface and a lower surface. The insulating plate 20 is formed, for example, of a ceramic material such as aluminum oxide (AI2O3), aluminum nitride (AIN), silicon nitride (Si3N4), a resin material such as epoxy, or an epoxy resin material in which a ceramic material is used as a filler, or the like insulating material. In addition, the insulating plate 20 can also be referred to as an insulating layer or an insulating film.

[0036] The heat dissipation plate 21 is formed to have a prescribed thickness in the Z direction and covers the entire lower surface of the insulating plate 20. The heat dissipation plate 21 is formed, for example, of a metal plate such as copper or aluminum having good thermal conductivity. The lower surface of the heat dissipation plate 21 is a heat dissipation surface on which a cooler not shown is mounted.​

[0037] On the main surface of the insulating board 20, multiple circuit boards 22 are formed in an island-like pattern (in a mutually electrically insulated state). FIG. 1 For convenience, only one circuit board 22 is shown in the diagram. The circuit board 22 is composed of a metal layer of a specified thickness, which is formed from copper foil or the like.

[0038] On the upper surface of the circuit board 22, a semiconductor element 3 is disposed using a bonding material S such as solder. The semiconductor element 3 is formed from a semiconductor substrate such as silicon (Si) or silicon carbide (SiC) in a square shape when viewed from above. In this embodiment, the semiconductor element 3 is composed of an RC (Reverse Conducting)-IGBT element, which integrates the functions of an IGBT (Insulated Gate Bipolar Transistor) element and an FWD (Free Wheeling Diode) element.

[0039] Furthermore, semiconductor element 3 is not limited to this; it can also be constructed by combining switching elements such as IGBTs and power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) and diodes such as FWDs (Free Wheeling Diodes). Additionally, RB (Reverse Blocking)-IGBTs, which have sufficient withstand voltage to reverse bias, can also be used as semiconductor element 3. Semiconductor element 3 can be a vertically oriented switching element or diode. Furthermore, the shape, number, and placement of semiconductor element 3 can be appropriately modified.

[0040] Additionally, a frame-shaped outer shell member 10 is disposed on the upper surface of the outer periphery of the laminated substrate 2. The outer shell member 10 is molded, for example, from synthetic resin and is bonded to the upper surface of the insulating plate 20 by means of an adhesive (not shown). The outer shell member 10 has an annular wall portion 11 surrounding the outer periphery of the laminated substrate 2. The annular wall portion 11 is formed into a square ring shape when viewed from above along the outline of the laminated substrate 2.

[0041] The annular wall portion 11 rises along the thickness direction (Z direction) of the semiconductor module 1. A recess 12 of a predetermined depth is formed on the lower surface of the annular wall portion 11, allowing the outer periphery of the laminated substrate 2 to engage. The recess 12 has a depth corresponding to the thickness of the laminated substrate 2 (the combined thickness of the insulating plate 20 and the heat sink 21). With the laminated substrate 2 engaged in the recess 12, the circuit board 22 is located inside the annular wall portion 11.

[0042] Furthermore, a stepped portion 13 is formed on the inner circumferential side of the upper surface of the annular wall portion 11, which descends by one step. The stepped portion 13 is formed by a square annular protrusion, and the stepped portion 13 is located at a position where the upper surface (bottom surface) of the stepped portion 13 is lower than the upper surface of the annular wall portion 11.

[0043] Terminal components are integrally embedded in the housing component 10. Specifically, the terminal components include main terminals 14 and 15, control terminals 16, and temperature sensor terminals 17. These terminal components are composed of plate-like bodies formed from metallic materials such as copper, copper alloys, aluminum alloys, and iron alloys.

[0044] Main terminals 14 and 15 are embedded in a pair of opposing walls of the annular wall portion 50 along its long side (X direction). The side connected to the emitter side of the semiconductor element 3 ( FIG. 1 The terminal component on the left side of the paper is the main terminal 14, which is connected to the collector side of the semiconductor element 3 via the circuit board 22. FIG. 1 The terminal component on the right side of the paper is the main terminal 15.

[0045] Main terminals 14 and 15 are formed, for example, by elongated strips extending in the X direction. One end of main terminal 14 protrudes from the inside of the annular wall portion 11 to the upper surface (bottom surface) of the stepped portion 13. The other end of main terminal 14 protrudes through the annular wall portion 11 and extends to the outside of the housing member 10. Similarly, one end of main terminal 15 protrudes from the inside of the annular wall portion 11 to the upper surface (bottom surface) of the stepped portion 13. The other end of main terminal 15 protrudes through the annular wall portion 11 and extends to the outside of the housing member 10.

[0046] The control terminal 16 and the temperature sensor terminal 17 are embedded in a wall portion of the annular wall portion 11 extending in the X direction. The control terminal 16 and the temperature sensor terminal 17 are formed, for example, by an elongated body extending in the Y direction, and are arranged in pairs, each in an X-direction arrangement. One end of the control terminal 16 and the temperature sensor terminal 17 protrudes from the inner side of the annular wall portion 11 to the upper surface (bottom surface) of the stepped portion 13. The other end of the control terminal 16 and the temperature sensor terminal 17 protrudes through the annular wall portion 11 and extends to the outer side of the housing member 10.

[0047] The semiconductor element 3 and the main terminal 14 are electrically connected by the metal wiring board 4. Also, the circuit board 22 and the main terminal 15 are electrically connected by the metal wiring board 5. The metal wiring boards 4, 5 are composed of a plate-like body having an upper surface and a lower surface, and are formed of a metal material such as a copper material, a copper alloy system material, an aluminum alloy system material, an iron alloy system material, or the like. The metal wiring boards 4, 5 are formed into a prescribed shape by, for example, press working. Further, the shapes of the metal wiring boards 4, 5 shown below are merely for illustrating one example, and can be appropriately changed. Also, the metal wiring boards can be referred to as lead frames.

[0048] The metal wiring board 4 is an elongated body long in the X direction, and has a shape bent in an L shape in a side view. One end side (a first end portion 4a described later) of the metal wiring board 4 is joined to the upper surface of the semiconductor element 3 via a joining material (not shown) such as solder. The upper surface electrode of the semiconductor element 3 joined to the metal wiring board 4 is an emitter electrode or an anode electrode. In the case where the semiconductor element 3 is a MOSFET or a diode, the upper surface electrodes can be a source electrode and an anode electrode, respectively. The joining material can also be a sintered material. The other end side (a second end portion 4b described later) of the metal wiring board 4 is bent downward in the upward direction of the main terminal 14 to be joined to the upper surface of the main terminal 14. Also, the width of the metal wiring board 4 in the Y direction is the same size from the first end portion 4a to the second end portion 4b.

[0049] In particular, the width of the first end portion 4a in the Y direction is smaller than the width of the semiconductor element 3, as described in detail later. Further, the width of the first end portion 4a is not limited thereto, and can be set to be the same as or larger than the width of the semiconductor element 3 after the main electrode and the edge structure of the semiconductor element 3 have been processed so as not to cause short circuiting, for example. Also, in the case where the semiconductor element 3 is a MOSFET, the width of the first end portion 4a in the Y direction can be set to be the same as or larger than the width of the semiconductor element 3. FIG. 1 In the embodiment, the case where the width of the metal wiring board 4 in the Y direction is the same from the first end portion 4a to the second end portion 4b is exemplified, but is not limited thereto. The width of the metal wiring board 4 in the Y direction can also be locally changed between the first end portion 4a and the second end portion 4b. The same also applies to the metal wiring board 5 shown below.

[0050] The metal wiring board 5 is an elongated body long in the X direction, and has a crank shape bent multiple times in a side view. One end side of the metal wiring board 5 is joined to the upper surface of the circuit board 22. The other end side of the metal wiring board 5 is joined to the upper surface of the main terminal 15. As described above, the width of the metal wiring board 5 in the Y direction is the same size from one end side to the other end side, but is not limited thereto, and can be locally changed in the middle.

[0051] As described above, the metal wiring boards 4, 5 are formed of a metal material, and are joined to the semiconductor element 3 and the main terminal 14, 15 via a joining material such as solder. Thus, the metal wiring boards 4, 5 can be electrically connected to the semiconductor element 3 and the main terminal 14, 15. FIG. 1As shown, electrode pads 3a, 3b are provided on the upper surface of the semiconductor element 3 exposed from the metal wiring board 4. The electrode pads 3a, 3b are electrically connected to the control terminal 16 via the wiring member Wl, respectively.

[0052] On the upper surface of the metal wiring board 4, the temperature sensor 6 is provided with the bonding material S. In this case, it is preferable that the two electrodes of the temperature sensor 6 are separated from each other, and the temperature sensor 6 is electrically insulated from the metal wiring board 4, for example, by the bonding material S. In addition, the bonding material S that bonds the metal wiring board 4 and the temperature sensor 6 can also be an adhesive.

[0053] The temperature sensor 6 is provided on the one end side (first end portion 4a side) of the metal wiring board 4 so as to overlap the semiconductor element 3 when viewed from above. That is, the temperature sensor 6 is positioned directly above the semiconductor element 3. The temperature sensor 6 is used to detect the temperature of the semiconductor element 3. Specifically, the temperature sensor 6 is constituted by a thermistor. In addition, the temperature sensor 6 is not limited to a thermistor, and can also be constituted by other types of temperature measuring resistors or thermocouples.

[0054] The temperature sensor 6 has a sufficiently small area compared to the semiconductor element 3, and has, for example, an elongated shape that is long in the X direction when viewed from above. The temperature sensor 6 is provided, for example, at the center in the width direction (X direction or Y direction) of the semiconductor element 3 (metal wiring board 4). In addition, the shape and the position of the temperature sensor 6 are not limited thereto, and can be appropriately changed.

[0055] The one end side (for example, one end portion in the X direction) of the temperature sensor 6 is electrically connected to one temperature sensor terminal 17 via the wiring member W2. The other end side (the other end portion on the opposite side in the X direction) of the temperature sensor 6 is electrically connected to the other temperature sensor terminal 17 via the wiring member W2.

[0056] The above-described wiring members Wl, W2 (also including the wiring member W3 described later) use a conductor wire (bonding wire). As for the material of the conductive wire, any one of gold, copper, aluminum, gold alloy, copper alloy, aluminum alloy, or a combination thereof can be used. In addition, a member other than the conductive wire can also be used as the wiring member. For example, a ribbon cable can be used as the wiring member.

[0057] Further, the method of taking out the electric output of the temperature sensor 6 is not limited to the above-described wiring method and can be appropriately changed. For example, two electrode pads corresponding to the cathode electrode and the anode electrode of the semiconductor element 3 can be formed on the metal wiring board 4. The two electrode pads are arranged in an electrically independent state from the metal wiring board 4. For example, it is preferable that an insulating board be arranged between each electrode pad and the lead frame. In this case, one end of the temperature sensor 6 is electrically connected to one electrode pad, and the other end of the temperature sensor 6 is electrically connected to the other electrode pad.

[0058] In addition, the inside space of the housing member 10 defined by the annular wall portion 11 is filled with a sealing resin 7. Thereby, the stacked substrate 2, the semiconductor element 3, the main terminal 14, the main terminal 15, the metal wiring boards 4, 5, the temperature sensor 6, and the wiring members W1, W2 are sealed. The housing member 10 defines a space for housing the stacked substrate 2, the semiconductor element 3, the metal wiring boards 4, 5, the temperature sensor 6, the wiring members W1, W2, and the sealing resin 7. Further, the sealing resin 7 can use an epoxy resin, a silicone gel. The filling amount to the housing member 10 is appropriately set according to the kind of the sealing resin 7. For example, in the case where the sealing resin 7 is a non-soft resin such as an epoxy, the sealing resin 7 is often filled to reach the upper surface of the annular wall portion 11, and in the case where the sealing resin 7 is a soft resin such as a silicone gel, the sealing resin 7 is often filled to embed the internal members.

[0059] In addition, the structure is not limited to the above-described structure, and a full-mold (Japanese: full mold) structure in which the housing member 10 is integrated with the sealing resin 7 can be used. In this case, the housing member 10 forms the annular wall portion 11 of the semiconductor module, and the stacked substrate, the semiconductor element 3, the main terminal 14, the main terminal 15, the metal wiring boards 4, 5, and the temperature sensor 6 are sealed. Such a full-mold structure can be formed by transfer molding or the like. Further, the housing member 10 integrated with the sealing resin 7 preferably uses an epoxy resin.

[0060] In addition, generally, in a semiconductor module, the temperature of a semiconductor element needs to be detected to appropriately control the operation of the semiconductor element. As a temperature sensor that detects the temperature of the semiconductor element, for example, a thermistor is used. The temperature sensor is arranged on, for example, a stacked substrate on which a plurality of circuit boards are formed on the upper surface. More specifically, the temperature sensor is arranged on a circuit board that is independent of the circuit board on which the semiconductor element is arranged. In addition, the temperature sensor is sometimes arranged on a prescribed region on the semiconductor element.

[0061] However, in the case where the temperature sensor is arranged on a circuit board separate from the semiconductor element, the temperature sensor is separated from the semiconductor element. Therefore, the temperature sensor cannot directly receive heat from the semiconductor element, and there is a possibility that the sensing accuracy is affected. In addition, in the case where the temperature sensor is arranged inside the semiconductor element, the active area of the semiconductor element is reduced by an amount equivalent to the dedicated area of the temperature sensor. That is, a part of the active area of the semiconductor element is sacrificed, and as a result, there is a possibility that the performance of the semiconductor device is affected.

[0062] On the other hand, in the past, the electrical connection of the semiconductor element to the circuit board on the insulating substrate has been achieved by a wiring member such as a bonding wire. Recently, a semiconductor module in which a metal wiring board configuration is adopted instead of the wiring of the wire has been developed. With the metal wiring board configuration, the surface area is increased, and thus the amount of heat dissipation is expanded, and it is possible to reduce the chip temperature. Also, compared to the wire wiring, there are advantages such as simple connection and excellent productivity.

[0063] Therefore, the present inventors have conceived the present application by focusing on the following aspect: the metal wiring board is formed of a plate-shaped body, and thus if the metal wiring board is arranged on the upper surface of the semiconductor element, a prescribed space is ensured on the upper surface of the metal wiring board. In the present embodiment, the temperature sensor 6 is arranged on the upper surface of the metal wiring board 4 arranged on the upper surface of the semiconductor element 3.

[0064] According to this structure, it is possible to arrange the temperature sensor 6 close to the semiconductor element 3, and the heat of the semiconductor element 3 easily passes to the temperature sensor 6 via the metal wiring board 4. Thus, the loss of heat is small, and it is possible to improve the detection accuracy of the temperature sensor 6.

[0065] However, since the metal wiring board 4 is formed of a metal material having good thermal conductivity, there is a concern that the heat of the semiconductor element 3 diffuses toward the main terminal 14 on the downstream side of the heat transfer direction of the metal wiring board 4, and the temperature of the semiconductor element deviates from the temperature of the temperature sensor. Therefore, in the present embodiment, a cutout portion 40 is also formed in the metal wiring board 4 as a heat shield portion for suppressing the diffusion of the heat of the semiconductor element 3.

[0066] According to this structure, the heat transferred from the semiconductor element 3 to the metal wiring board 4 is shielded by the cutout portion 40. As a result, the diffusion of the heat is suppressed, and the heat of the semiconductor element 3 stagnates around the temperature sensor 6. Therefore, the temperature of the metal wiring board 4 on the semiconductor element 3 approaches the temperature of the semiconductor element 3, and it is possible to improve the temperature detection accuracy of the temperature sensor 6.

[0067] As such, in the present embodiment, the temperature sensor 6 is arranged on the upper surface of the metal wiring board 4, whereby the space on the metal wiring board 4 is effectively utilized. Thus, it is not necessary to arrange the temperature sensor 6 directly on the semiconductor element 3. Therefore, a part of the active area of the semiconductor element 3 is not sacrificed, and the active area can be utilized to the maximum, thereby improving the performance of the semiconductor element 3. Further, the notch portion 40 is provided on the metal wiring board 4 as a heat shielding portion, whereby the spread of heat around the temperature sensor 6 can be prevented. That is, the temperature detection accuracy of the semiconductor element 3 can be improved without affecting the original performance of the semiconductor element 3.

[0068] Here, the specific shape and layout of the notch portion 40 as a heat shielding portion will be described. FIG. 4 is a partial enlarged view of the heat shielding portion of FIG. 1 As described above, the width of the metal wiring board 4 in the Y direction as the first end portion 4a on one end side is smaller than the width of the semiconductor element 3 in the Y direction. As shown in FIGS. 1 to 4 , the notch portion 40 is formed of a rectangular hole that penetrates the metal wiring board 4 in the thickness direction (Z direction) and extends in the Y direction. At least a part of the notch portion 40 is arranged at a position on the heat transfer direction downstream side from the temperature sensor 6.

[0069] The heat transfer direction downstream side means the downstream side of the direction (the direction of the arrow T of FIG. 3 ) in which heat of the semiconductor element 3 as a heat generation source is transferred along the extending direction of the metal wiring board 4. In other words, the heat transfer direction indicates the direction from the first end portion 4a to the second end portion 4b of the metal wiring board 4. As described above, the first end portion 4a is located directly above the semiconductor element 3 and is joined to the semiconductor element 3 via a joining material (not shown). The second end portion 4b is located on the opposite side of the first end portion 4a with the notch portion 40 interposed therebetween. In the present embodiment, the direction from the semiconductor element 3 to the main terminal 14 (the negative side of the X direction) is the heat transfer direction. Further, the heat transfer direction is not limited to the above-described example, and is a concept that is appropriately changed in correspondence with the shape, arrangement position, and the like of the metal wiring board 4 and the notch portion 40. In addition, in the present embodiment, the temperature sensor 6 is arranged so as to overlap the semiconductor element 3 when viewed from above, and the notch portion 40 is arranged on the heat transfer direction downstream side from the temperature sensor 6 and is arranged so as not to overlap the semiconductor element 3 when viewed from above. FIGS. 1 to 4

[0070] Further, in the present embodiment, the notch portion 40 is long in the Y direction, and the notch portion 40 is formed with a width smaller than the width of the metal wiring board 4 in the Y direction, so as to leave both end portions in the width direction (Y direction) of the metal wiring board 4. As such, the notch portion 40 is formed so as to shield a part of the heat transfer path of the semiconductor element 3. FIG. 4

[0071] ​​The cutout portion 40 is provided at a position downstream of the temperature sensor 6 in the heat transfer direction, whereby heat transferred from the semiconductor element 3 to the metal wiring board 4 is allowed to remain around the temperature sensor 6 at a position upstream of the cutout portion 40 in the heat transfer direction, i.e., in the vicinity of the temperature sensor 6 and the semiconductor element 3, so that heat diffusion is prevented. Thus, the temperature sensor 6 can detect the temperature of the metal wiring board 4 close to the temperature of the semiconductor element 3, so that the detection accuracy thereof can be improved.

[0072] In addition, the cutout portion 40 is formed so as to leave both end portions of the metal wiring board 4. That is, the cutout portion 40 is formed so as not to shield the entire heat transfer path in the width direction of the metal wiring board 4, but to shield only a part of the heat transfer path and leave the other part. Thus, it is possible to release a part of the heat to a position downstream of the cutout portion 40 in the heat transfer direction while retaining heat around the temperature sensor 6, so that overheating of the semiconductor element 3 is prevented. That is, FIG. 4 the arrow T indicates the remaining other part of the heat transfer path T. Further, it is preferable that the width of the cutout portion 40 be set to a degree that does not hinder the heat dissipation property of the semiconductor element 3 while improving the temperature detection accuracy of the temperature sensor 6, as will be described later. In addition, the heat transfer path indicates a path along which heat generated in the semiconductor element 3 due to driving of the module is transferred within the metal wiring board 4. In FIG. 4 In the embodiment, the cutout portion 40 is formed so as to extend in a direction (Y direction) intersecting a direction (X direction) from the first end portion 4a to which the semiconductor element 3 is joined toward the second end portion 4b. Further, the cutout portion 40 can not extend in a direction orthogonal to the X direction, but can extend in a different direction.

[0073] Further, in the above embodiment, a case where the cutout portion 40 is formed so as to leave both end portions in the metal wiring board 4 is described, but the structure is not limited to this. For example, it can be configured so that FIG. 5 and FIG. 6 such a structure. FIG. 5 is a plan view schematically showing a heat shielding portion according to a modification. FIG. 6 is a plan view schematically showing a heat shielding portion according to another modification.

[0074] In FIG. 5In the modification shown, a pair of cutout portions 41 extending in the Y direction is formed in the metal wiring board 4. The pair of cutout portions 41 is disposed at a position downstream of the heat transfer direction from the temperature sensor 6, and is disposed so as not to overlap the semiconductor element 3 in plan view. In addition, the pair of cutout portions 41 is formed so as to extend from the end portion of the metal wiring board 4 in the Y direction toward the center, and so as to leave the central portion of the metal wiring board 4. That is, the pair of cutout portions 41 is disposed facing each other in the Y direction. Thus, a heat transfer path T of a prescribed width is formed in the center in the Y direction of the metal wiring board 4. In this structure, the same effects as FIG. 4 are also obtained.

[0075] In addition, in FIG. 6 the modification shown, a plurality of cutout portions 42 is formed in the metal wiring board 4, the plurality of cutout portions 42 being arranged in the Y direction and being disposed intermittently. The plurality of cutout portions 42 is disposed at a position downstream of the heat transfer direction from the temperature sensor 6, and is disposed so as not to overlap the semiconductor element 3 in plan view. A heat transfer path T of a prescribed width is formed between two cutout portions 42 adjacent to each other in the Y direction. In addition, the number of cutout portions 42 can be changed as appropriate. In this structure, the same effects as FIG. 4 and FIG. 5 are also obtained. The plurality of cutout portions 42 can each be a hole that is rectangular in plan view, or can each be a hole that is circular in plan view.

[0076] In addition, it is preferable that FIGS. 4 to 6 the width of the heat transfer path T be a width that ensures the electrical conductivity on the metal wiring board 4. That is, the heat transfer path T is a heat dissipation path for the semiconductor element 3, and is also a current path that allows current to flow on the metal wiring board 4.

[0077] In addition, in FIGS. 4 to 6 the example shown, the case where the cutout portions 40 to 42 as heat shielding portions are disposed so as not to overlap the semiconductor element 3 in plan view is described, but the structure is not limited to this. In addition, in the example described above, the case where the width of the metal wiring board 4 in the Y direction is smaller than the width of the semiconductor element 3 in the Y direction is described, but the structure is not limited to this. For example, the structure shown in Fig. 7 can be provided. Fig. 7 FIG. 7A and FIG. 7B is a plan view schematically showing a variation of the disposition example of the heat shielding portions.

[0078] As FIG. 7A and FIG. 7B shown, the width of the metal wiring board 4 in the Y direction is greater than the width of the semiconductor element 3 in the Y direction. In addition, a plurality of cutout portions 43 is formed in the metal wiring board 4 so as to surround the periphery of the temperature sensor 6. The plurality of cutout portions 43 is disposed so as to overlap the semiconductor element 3 in plan view. Each cutout portion 43 can be a hole that is rectangular in plan view, or can be a hole that is circular in plan view.FIG. 7A It can also be formed by a through hole in the shape of a long strip extending in a specified direction, or as... FIG. 7B As shown, it is formed by an L-shaped through-hole when viewed from above. The temperature sensor 6 is surrounded by multiple cutouts 43, which allows heat to easily remain around the temperature sensor 6, thereby improving the temperature detection accuracy of the temperature sensor 6. Furthermore, Figure 7 illustrates the case where multiple cutouts 43 are formed to surround the temperature sensor 6, i.e., multiple cutouts 43 are formed intermittently, but this structure is not limited. Alternatively, the cutouts 43 can be formed as a continuous ring to surround the temperature sensor 6. That is, in Figure 7, "surrounding the temperature sensor 6" means not only the way the temperature sensor 6 is surrounded by continuously formed annular cutouts 43, but also the way the temperature sensor 6 is surrounded by multiple intermittently formed cutouts 43. Therefore, the temperature sensor 6 does not need to be completely surrounded by the cutouts 43, as long as at least a part of it is surrounded. Additionally, in the case of FIG7, at least a portion of the plurality of cutouts 43 are located downstream of the temperature sensor 6 in the heat transfer direction (downstream of the direction from the first end 4a to the second end 4b).

[0079] Furthermore, in the above embodiment, it is preferable to set the width of the cut portion 40 to a degree that improves the temperature detection accuracy of the temperature sensor 6 without hindering the heat dissipation of the semiconductor element 3. Here, the width D1 of the cut portion 40 and the distance D2 between the cut portion 40 and the temperature sensor 6 will be explained with reference to FIG8. FIG8 is a schematic diagram showing the positional relationship between the temperature sensor and the heat shield. Specifically, FIG. 8A This is a plan view of the area surrounding the heat shield. FIG. 8B This is a cross-sectional schematic diagram of the area surrounding the heat shield.

[0080] like FIG. 8A and FIG. 8B As shown, the heat generated in semiconductor element 3 has a defined diffusion range. For example, in FIG. 8A As shown in the top view, the heat transferred from the semiconductor element 3 to the temperature sensor 6 via the metal wiring board 4, i.e., the heat of the semiconductor element 3 after passing through the temperature sensor 6, tends to diffuse from the end near the cutout 40 at a predetermined angle range θ1. The angle range θ1 is, for example, 90 degrees.

[0081] In this case, it is preferable that the width Dl of the cutout portion 40 be equal to or greater than the angle range θl as viewed from the temperature sensor 6. According to this structure, it is possible to suppress the diffusion of heat through the temperature sensor 6 while allowing the diffusion of heat from the semiconductor element 3, thereby effectively improving the temperature detection accuracy. Further, it is also possible to give priority to the diffusion of heat from the semiconductor element 3 over the temperature detection accuracy of the temperature sensor 6, thereby converging the width Dl of the cutout portion 40 to the inside of the angle range θl.

[0082] In this case, when the width Dl of the cutout portion 40 is extremely small compared to the angle range θl, the shielding of heat can be insufficient. On the other hand, when the width Dl of the cutout portion 40 is equal to or greater than the angle range θl and approaches the width in the Y direction of the metal wiring board 4, there is a concern that heat exceeding that required for sensing will be shielded, also hindering heat dissipation. Thus, it is preferable that the width Dl of the cutout portion 40 be set within a range that takes into account the diffusion of heat from the semiconductor element 3 and ensures the temperature detection accuracy of the temperature sensor 6 described above.

[0083] Further, in FIG. 8B In the cross section shown in FIG. 6, heat from the semiconductor element 3 has a tendency to diffuse in a prescribed angle range θ2 toward the upper side with respect to the metal wiring board 4 disposed on the upper surface side. The angle range θ2 is, for example, 90 degrees.

[0084] In this case, it is preferable that the facing interval (distance D2) of the cutout portion 40 and the temperature sensor 6 be set so that the cutout portion 40 is disposed at a position further outside than the angle range θ2. According to this structure, it is possible to suppress the diffusion of heat through the temperature sensor 6 while allowing the diffusion of heat from the semiconductor element 3, thereby effectively improving the temperature detection accuracy. Further, it is also possible to give priority to the prevention of the diffusion of heat through the temperature sensor 6 over the heat dissipation of the semiconductor element 3, and to dispose the cutout portion 40 so as to converge within the angle range θ2.

[0085] Next, a semiconductor module according to another example will be described with reference to FIGS. 9 to 11 FIG. 9 is a plan view schematically showing a semiconductor module according to another example of the present embodiment. FIG. 10 is a cross-sectional view obtained by cutting along the C-C line of FIG. 9 FIG. 11 is a partial enlarged view showing a heat shielding portion of FIG. 9 FIGS. 9 to 11 In the manner of FIGS. 1 to 4 the semiconductor module shown in FIG. 6, the layout of the circuit board and a part of the terminal member is different, and a part of the shape of the metal wiring board is different. Therefore, only the main points will be described, the same reference numerals will be attached to common structures, and the description will be omitted as appropriate.

[0086] In​​​FIGS. 9 to 11 In the semiconductor module 1 shown, two circuit boards 22a and 22b are formed in an island-like pattern on the main surface of the insulating plate 20. The two circuit boards 22a and 22b are rectangular in shape, elongated in the Y direction, and arranged along the X direction. A semiconductor element 3 is disposed on the upper surface of the circuit board 22a using a bonding material S. A rectangular main electrode 30, slightly smaller than the outer shape of the semiconductor element 3, is formed on the upper surface of the semiconductor element 3. Furthermore, electrode pads 3a and 3b are formed on the upper surface of the semiconductor element 3 and outside the main electrode 30.

[0087] A metal wiring board 4 is disposed on the upper surface of the semiconductor element 3. The metal wiring board 4 is an elongated strip extending in the X direction across two circuit boards 22a and 22b when viewed from above, and has a crank shape formed by multiple bends when viewed from the side. One end of the metal wiring board 4 (first end 4a) is electrically bonded to the upper surface of the main electrode 30 of the semiconductor element 3 via a bonding material S such as solder. The other end of the metal wiring board 4 (second end 4b) is electrically bonded to the upper surface of the circuit board 22b via a bonding material S such as solder. The metal wiring board 4 is formed such that, when viewed from above, the width of the first end 4a in the Y direction is smaller than the width of the semiconductor element 3 (main electrode 30) in the Y direction, and the width of the second end 4b in the Y direction is larger than the width of the first end 4a.

[0088] A cutout 40 extending through the thickness direction is formed on the upper surface of the metal wiring board 4 at its first end 4a. The cutout 40 has an elongated shape extending in the Y direction and is positioned directly above the semiconductor element 3 (main electrode 30). Additionally, a temperature sensor 6 is disposed on the upper surface of the metal wiring board 4 at its first end 4a using a bonding material (not shown). The cutout 40 and the temperature sensor 6 are configured to overlap with the semiconductor element 3 (main electrode 30) when viewed from above. Furthermore, the cutout 40 is positioned downstream of the temperature sensor 6 in the direction from the first end 4a to the second end 4b of the metal wiring board 4.

[0089] In particular, at least a portion of the cut-out portion 40 is filled with the bonding material S, the upper surface of which is in the shape of a weld bead (see reference). FIG. 10 In this structure, since the cutout 40 is positioned downstream of the temperature sensor 6 in the heat transfer direction, and the thermal conductivity of the bonding material S (solder) filling the cutout 40 is lower than that of the metal wiring board 4, it is possible to shield against heat generated from the semiconductor element 3 located directly below the temperature sensor 6. That is, the cutout 40 and the bonding material S entering the cutout 40 function as a heat shield.

[0090] In addition, such as FIG. 11As shown, the width of the metal wiring board 4 in the Y direction is set to a width W, and the distances from both end portions of the metal wiring board 4 in the Y direction to the end portions of the cutout portion 40 are set to Yl and Y2, respectively. In addition, the facing interval of the cutout portion 40 and the temperature sensor 6 is set to XI, and the distance from the first end portion 4a of the metal wiring board 4 to one end portion of the temperature sensor 6 is set to X2. Further, the angle formed by a pair of straight lines connecting the end portion on the negative side of the X direction of the temperature sensor 6 and the end portion of the cutout portion 40 is set to Θ3. In this case, it is preferable that XI ≤ X2, 85° ≤ Θ3 ≤ 95°, Yl ≥ XI, and Y2 ≥ XI. These ranges indicate ranges in which the heat diffusion of the semiconductor element 3 and the temperature detection accuracy of the temperature sensor 6 can be both taken into account when the size and the arrangement position of the cutout portion 40 are set.

[0091] Next, another embodiment will be described with reference to FIG. 12. FIG. 12 is a schematic view of a semiconductor module according to the other embodiment.

[0092] In the example of FIG. 11, the case where the temperature sensor 6 is arranged on the upper surface of the metal wiring board 4 is described. In contrast, in the example shown in FIG. 12, a cutout portion 44 (an opening) as a heat shielding portion is formed in the metal wiring board 4 at a position corresponding to the temperature sensor 6. The cutout portion 44 has an area larger than that of the temperature sensor 6. The temperature sensor 6 is directly joined to the semiconductor element 3 via the joining material S within the cutout portion 44. FIGS. 1 to 11 According to this structure, since the temperature sensor 6 is directly joined to the semiconductor element 3, the temperature sensor 6 can directly receive heat from the semiconductor element 3. Therefore, the temperature detection accuracy of the temperature sensor 6 can be improved. In addition, the cutout portion 44 larger than the temperature sensor 6 is formed in the metal wiring board 4 corresponding to the temperature sensor 6, and thus the temperature sensor 6 does not directly contact the metal wiring board 4. Therefore, heat transmitted from the semiconductor element 3 to the temperature sensor 6 can be prevented from diffusing to the metal wiring board 4. Therefore, as in the above, the temperature detection accuracy of the temperature sensor 6 can be further improved.

[0093] As described above, according to the present application, the heat transmitted from the semiconductor element 3 to the temperature sensor 6 is shielded from diffusing via the metal wiring board by the heat shielding portion, and thus the temperature detection accuracy of the semiconductor element can be improved without affecting the original performance of the semiconductor element.

[0094] Further, in the above-described embodiments, the number and arrangement position of the semiconductor element 3 arranged on the laminated substrate 2 and the temperature sensor 6 arranged on the metal wiring board 4 are not limited to the above-described structures, and can be appropriately changed.

[0095]

[0096] ​Also, in the above-described embodiment, the number and layout of the circuit boards 22 are not limited to the above-described structure and can be appropriately changed.

[0097] Also, in the above-described embodiment, the structure in which the semiconductor element 3 is formed in a rectangular shape in plan view is described, but the structure is not limited thereto. The semiconductor element 3 can also be formed in a polygonal shape other than a rectangular shape.

[0098] Also, in the above-described embodiment, the case in which the temperature sensor 6 has an elongated shape long in the X direction is described, but the structure is not limited thereto. The temperature sensor 6 can also have an elongated shape long in the Y direction, and the shape and the arrangement position thereof can be appropriately changed, not limited to the elongated shape.

[0099] Also, the above-described embodiment and the modified example can be combined as a whole or partially to be another embodiment.

[0100] Also, the present embodiment is not limited to the above-described embodiment and the modified example, and various changes, substitutions, and modifications can be made within the scope of the gist of the technical idea. Also, if another method can be used to achieve the technical idea due to progress of technology or other technology derived therefrom, the method can also be used to implement. Thus, the claims cover all embodiments included in the scope of the technical idea.

[0101] Next, the characteristic points in the above-described embodiment are summarized.

[0102] The semiconductor module described in the above-described embodiment includes: a laminated substrate formed by disposing a circuit board on an upper surface of an insulating board and disposing a heat dissipation board on a lower surface of the insulating board; a semiconductor element disposed on an upper surface of the circuit board; a metal wiring board disposed on an upper surface of the semiconductor element; and a temperature sensor disposed on an upper surface of the metal wiring board for detecting a temperature of the semiconductor element, wherein the metal wiring board has a heat shielding portion that shields heat of the semiconductor element.

[0103] Also, in the semiconductor module described in the above-described embodiment, the metal wiring board has a first end portion engaged with the semiconductor element and a second end portion located on a side opposite to the first end portion, and at least a part of the heat shielding portion is disposed at a position on a downstream side from the temperature sensor in a direction from the first end portion to the second end portion.

[0104] Also, in the semiconductor module described in the above-described embodiment, the heat shielding portion is formed by a cutout portion extending in a direction intersecting a direction from the first end portion to the second end portion.

[0105] Further, in the semiconductor module described in the above embodiment, the temperature sensor is arranged to overlap the semiconductor element in plan view.

[0106] Further, in the semiconductor module described in the above embodiment, the heat shield portion is arranged to overlap the semiconductor element in plan view.

[0107] Further, in the semiconductor module described in the above embodiment, the heat shield portion is arranged to surround the temperature sensor.

[0108] Further, in the semiconductor module described in the above embodiment, the heat shield portion is arranged within a heat diffusion range of the semiconductor element in plan view.

[0109] Further, in the semiconductor module described in the above embodiment, the heat shield portion is arranged at a position outside the heat diffusion range of the semiconductor element in cross-sectional view.

[0110] Further, the semiconductor module described in the above embodiment includes: a laminated substrate formed by arranging a circuit board on an upper surface of an insulating board and arranging a heat sink on a lower surface of the insulating board; a semiconductor element arranged on an upper surface of the circuit board; a metal wiring board arranged on an upper surface of the semiconductor element; and a temperature sensor arranged at an opening of the metal wiring board provided on the upper surface of the semiconductor element, for detecting a temperature of the semiconductor element.

[0111] Industrial Applicability

[0112] As described above, the present application has an effect that it is possible to improve the temperature detection accuracy of a semiconductor element without affecting the original performance of the semiconductor element, and is particularly useful for a semiconductor module.

Claims

1. A semiconductor module comprising: a laminated substrate formed by disposing a circuit board on an upper surface of an insulating board and disposing a heat dissipation board on a lower surface of the insulating board; a semiconductor element disposed on an upper surface of the circuit board; a metal wiring board disposed on an upper surface of the semiconductor element; and a temperature sensor disposed on an upper surface of the metal wiring board for detecting a temperature of the semiconductor element, wherein the metal wiring board has a heat shield portion that shields heat of the semiconductor element, wherein the metal wiring board further has: a first end portion that is joined to the semiconductor element; and a second end portion that is located on a side opposite to the first end portion, and wherein at least a portion of the heat shield portion is disposed at a position on a downstream side from the temperature sensor in a direction from the first end portion to the second end portion.

2. The semiconductor module according to claim 1, wherein the heat shield portion is formed by a cutout portion that extends in a direction intersecting a direction from the first end portion to the second end portion.

3. The semiconductor module according to claim 1 or 2, wherein the temperature sensor is disposed so as to overlap the semiconductor element in plan view.

4. The semiconductor module according to claim 3, wherein the heat shield portion is disposed so as to overlap the semiconductor element in plan view.

5. The semiconductor module according to claim 4, wherein the heat shield portion is disposed so as to surround a periphery of the temperature sensor.

6. The semiconductor module according to claim 1 or 2, wherein the heat shield portion is disposed within a range of diffusion of heat of the semiconductor element in plan view.

7. The semiconductor module according to claim 6, wherein the heat shield portion is disposed at a position on an outer side from the range of diffusion of heat of the semiconductor element in cross-sectional view. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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