JP2017183430A - Switching element unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a switching element unit that is able to appropriately ensure the cooling performance of a switching element disposed such that an external face provided with both a main terminal and a control terminal face an insulation substrate.SOLUTION: A first electrode pattern 51 is provided so as to be exposed from an element arrangement face 41, and is electrically connected to a first terminal 31 of the first switching element 11 on the element arrangement surface 41. A control electrode pattern 54 is provided so as to be exposed from the element arrangement face 41, and is electrically connected to a control terminal 34 of the first switching element 11 on the element arrangement face 41. If a direction in which the first electrode pattern 51 extends to the control electrode pattern 54 along the element arrangement face 41 is assumed as an object direction A, the first electrode pattern 51 is formed so as to extend in the object direction A toward a cooling face 42 from the element arrangement face 41.SELECTED DRAWING: Figure 2

Description

  The present invention includes a switching element unit including an insulating substrate and a switching element disposed on an element arrangement surface of the insulating substrate, and a surface opposite to the element arrangement surface of the insulating substrate is a cooling surface cooled by the cooling unit. About.

  As a switching element unit provided with a switching element, what was described in Unexamined-Japanese-Patent No. 2013-38848 (patent document 1) is known. In the description of the background art section, reference numerals in Patent Document 1 are quoted in []. 2 to 4 of Patent Document 1, a positive electrode terminal [80] and a negative electrode terminal [82] are formed on an insulating substrate [100, 102] disposed on a heat sink [106], and the positive electrode terminal or the negative electrode terminal is formed. A configuration is described in which switching elements [50a to 50d, 54a to 54d] are arranged so as to be electrically connected to each other. The switching element includes a positive electrode [72] and a negative electrode [76] that are a pair of main terminals, and a gate electrode [78] that is a control terminal, and as shown in FIG. A positive electrode is formed on the first surface [70], and a negative electrode and a gate electrode are formed on the second surface [74] of the switching element. The switching elements [50a to 50d] constituting the upper arm [32] of the inverter circuit are arranged so that the first surface on which the positive electrode is formed is placed on the positive terminal on the insulating substrate, The switching elements [54a to 54d] constituting the arm [38] are arranged such that the second surface on which the negative electrode and the gate electrode are formed is placed on the negative terminal on the insulating substrate via the spacer [60a to 60d]. Is arranged.

  By the way, since the switching element generates heat with the on / off operation, it is necessary to cool the switching element. Generally, it is possible to appropriately cool the switching element by appropriately ensuring heat dissipation from the main terminal through which a large current flows. In the configuration described in Patent Document 1, the switching element that constitutes the upper arm is disposed such that the first surface on which the positive electrode is formed is opposed to the insulating substrate that is cooled by the heat sink. The switching element constituting the arm is arranged so that the second surface on which both the negative electrode and the gate electrode are formed faces the insulating substrate cooled by the heat sink. Therefore, for the switching element constituting the lower arm, the area of the main terminal on the outer surface facing the insulating substrate constitutes the upper arm by the amount of the gate electrode formation region and the region for ensuring insulation around the gate electrode. The heat dissipation from the main terminal to the insulating substrate is likely to be reduced by that amount. As a result, the cooling performance of the switching element (the switching element constituting the lower arm in the example of Patent Document 1) arranged so that the outer surface on which both the main terminal and the control terminal are provided faces the insulating substrate is appropriately set. It may be difficult to ensure. However, Patent Document 1 does not mention this point.

JP 2013-38848 A (FIGS. 2 to 5 etc.)

  Therefore, it is desired to realize a switching element unit that can appropriately ensure the cooling performance of the switching element that is arranged so that the outer surface on which both the main terminal and the control terminal are provided faces the insulating substrate.

  In view of the above, an insulating substrate formed of an electrically insulating material and a switching element disposed on an element arrangement surface of the insulating substrate, the opposite side of the insulating substrate from the element arrangement surface The characteristic configuration of the switching element unit is a cooling surface cooled by the cooling unit. The switching element includes a pair of main terminals electrically connected to a DC voltage supply source, and control of the switching element. A first terminal that is one of the pair of main terminals and the control terminal are provided on a first surface of the outer surface of the switching element and are the other of the pair of main terminals. Two terminals are provided on the second surface of the outer surface of the switching element facing away from the first surface, and the first surface faces the element arrangement surface as the switching element. A first switching element arranged so as to be provided; and the insulating substrate includes a first electrode pattern and a control electrode pattern, and the first electrode pattern is provided so as to be exposed on the element arrangement surface. And is electrically connected to the first terminal of the first switching element on the element arrangement surface, and the control electrode pattern is provided to be exposed on the element arrangement surface, and the first electrode is arranged on the element arrangement surface. The first electrode pattern is electrically connected to the control terminal of one switching element and the direction from the first electrode pattern toward the control electrode pattern along the element arrangement surface is a target direction. It is in the point formed so that it may spread to the said object direction side as it goes to the said cooling surface side.

In the above characteristic configuration, the first switching element is arranged such that the first surface on which both the first terminal (one of the pair of main terminals) and the control terminal are provided is opposed to the element arrangement surface of the insulating substrate. The first electrode pattern electrically connected to the first terminal on the element arrangement surface is formed so as to spread toward the target direction side from the element arrangement surface to the cooling surface side cooled by the cooling unit in the insulating substrate. Is done. Therefore, the heat dissipation efficiency through the first electrode pattern from the first terminal to the cooling surface side can be improved by the amount that the first electrode pattern spreads toward the target direction, and the cooling performance of the first switching element Can be secured appropriately. Since the target direction is a direction from the first electrode pattern toward the control electrode pattern along the element arrangement surface, a cooling surface with respect to the control electrode pattern is suppressed while suppressing an increase in size of the insulating substrate toward the target direction. There is also an advantage that the first electrode pattern can be formed so as to spread toward the target direction as it goes from the element arrangement surface to the cooling surface side by effectively using the space on the side.
As described above, according to the above-described characteristic configuration, it is possible to appropriately ensure the cooling performance of the switching element arranged so that the outer surface on which both the main terminal and the control terminal are provided faces the insulating substrate. It becomes.

  Further features and advantages of the switching element unit will become more apparent from the following description of embodiments described with reference to the drawings.

The top view of the switching element unit which concerns on 1st embodiment Sectional drawing of the switching element unit which concerns on 1st embodiment Configuration diagram of the inverter circuit according to the first embodiment The top view of the switching element unit which concerns on 2nd embodiment Sectional drawing of the switching element unit which concerns on 2nd embodiment Sectional drawing of the switching element unit which concerns on other embodiment Sectional drawing of the switching element unit which concerns on other embodiment Sectional drawing of the switching element unit which concerns on other embodiment Sectional drawing of the switching element unit which concerns on other embodiment

1. First Embodiment A first embodiment of a switching element unit will be described with reference to FIGS. In the following description, unless otherwise specified, “upper” refers to the Z direction in FIG. 2, and “lower” refers to the −Z direction in FIG. The Z direction is a direction from the element arrangement surface 41 toward the switching element 10 arranged on the element arrangement surface 41 along a direction (vertical direction) orthogonal to the element arrangement surface 41 as shown in FIG. (That is, the direction of the normal vector toward the outside of the element arrangement surface 41).

  As shown in FIGS. 1 and 2, the switching element unit 1 includes an insulating substrate 40 formed of an electrically insulating material, and a switching element 10 arranged on an element arrangement surface 41 of the insulating substrate 40. I have. The material forming the insulating substrate 40 is, for example, ceramic or resin (epoxy resin or the like). A surface of the insulating substrate 40 opposite to the element arrangement surface 41 (a lower surface of the insulating substrate 40) is a cooling surface 42 that is cooled by the cooling unit 2. In the present embodiment, both the element arrangement surface 41 and the cooling surface 42 are formed flat. In the present embodiment, the element arrangement surface 41 and the cooling surface 42 are parallel to each other. In the example shown in FIG. 2, the cooling unit 2 includes a heat sink 2a, and the cooling surface 42 of the insulating substrate 40 is configured to be cooled by the heat sink 2a. That is, the heat of the switching element 10 arranged on the element arrangement surface 41 is transmitted to the heat sink 2a via the insulating substrate 40, whereby the switching element 10 is cooled. The cooling surface 42 is cooled directly or indirectly by the cooling unit 2. In the example shown in FIG. 2, the substrate 3 having both electrical insulation and thermal conductivity is disposed between the cooling surface 42 and the heat sink 2 a, and the heat of the insulation substrate 40 is transmitted through the substrate 3. It is transmitted to the heat sink 2a. That is, in the example shown in FIG. 2, the insulating substrate 40 is supported by the substrate 3 that is cooled by the cooling unit 2. The material forming the substrate 3 is, for example, ceramic or resin (epoxy resin or the like).

  In the present embodiment, the switching element 10 is used in an inverter circuit (DC AC conversion circuit) that performs power conversion between DC power and AC power. Specifically, as shown in FIG. 3, the switching element 10 is used in an inverter circuit for controlling the rotating electrical machine 93. This inverter circuit is between DC power transferred to and from a DC power source B such as a battery or a capacitor, and AC power (three-phase AC power in this embodiment) transferred to or from the rotating electrical machine 93. Power conversion. As the switching element 10, for example, a power semiconductor element such as an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is used. In the example illustrated in FIG. 3, a case where an IGBT is used as the switching element 10 is illustrated. In this specification, the “rotary electric machine” is used as a concept including any of a motor (electric motor), a generator (generator), and a motor / generator functioning as both a motor and a generator as necessary. The rotating electrical machine 93 is, for example, a rotating electrical machine provided as a driving force source for wheels in an electric vehicle, a hybrid vehicle, or the like. In the present embodiment, the DC power source B corresponds to a “DC voltage supply source”.

  One arm (leg) constituting the inverter circuit (bridge circuit) includes one or a plurality of parallel-connected positive-side switching elements 10 (in the present embodiment, the first switching element 11) and one or a plurality of parallel elements. The switching element 10 (in this embodiment, the 2nd switching element 12) of the connected negative electrode side (for example, ground side) has the structure electrically connected in series. In this embodiment, a single positive-side switching element 10 (first switching element 11) and a single negative-side switching element 10 (second switching element 12) are electrically connected in series in one arm. Have a configuration. Each switching element 10 is connected in parallel with a diode element 92 (free wheel diode) whose forward direction is from the negative electrode to the positive electrode. As the switching element 10, a switching element in which the diode element 92 is incorporated can be used. A smoothing capacitor 90 is electrically connected in parallel to the arm constituting the inverter circuit. The smoothing capacitor 90 suppresses fluctuations in the DC voltage supplied to the switching element 10. The smoothing capacitor 90 is electrically connected in parallel with a discharge resistor 91 for discharging the electric charge stored in the smoothing capacitor 90 when the power is turned off.

  As shown in FIG. 2, the switching element 10 includes a pair of main terminals 30 electrically connected to a DC power source B (an example of a DC voltage supply source), and a control terminal 34 (for controlling the switching element 10). Gate terminal). Each of the pair of main terminals 30 is electrically connected to the DC power supply B directly or via another circuit element (for example, another switching element 10). As shown in FIG. 2, the first terminal 31 and the control terminal 34 which are one of the pair of main terminals 30 are provided on the first surface 21 on the outer surface of the switching element 10 and are the other of the pair of main terminals 30. The second terminal 32 is provided on the second surface 22 facing away from the first surface 21 on the outer surface of the switching element 10. The control terminal 34 is disposed on the first surface 21 so as to be separated from the first terminal 31 by an insulation distance or more. In the present embodiment, as shown in FIGS. 1 and 2, the control terminal 34 is provided at an end portion of the first surface 21 in a target direction A described later, and the first terminal 31 is provided on the first surface 21. It is formed in most of the region opposite to the target direction A with respect to the control terminal 34. In the present embodiment, the second terminal 32 is formed over the entire area of the second surface 22. In the present embodiment, both the first surface 21 and the second surface 22 are formed flat. In the present embodiment, the first surface 21 and the second surface 22 are parallel to each other. In the present embodiment, the switching element 10 is formed in a rectangular parallelepiped shape.

  In the present embodiment, the first terminal 31 is the main terminal 30 on the negative side of the pair of main terminals 30 (the main terminal 30 connected to the negative electrode of the DC power supply B), and the second terminal 32 is the pair of main terminals 30. The main terminal 30 on the positive side of the main terminals 30 (the main terminal 30 connected to the positive electrode of the DC power supply B). That is, when an IGBT is used as the switching element 10, the first terminal 31 is an emitter terminal and the second terminal 32 is a collector terminal. When a MOSFET is used as the switching element 10, the first terminal 31 is a source terminal and the second terminal 32 is a drain terminal.

  As shown in FIG. 2, the switching element unit 1 is provided with a first switching element 11 arranged as a switching element 10 so that the first surface 21 faces the element arrangement surface 41 (insulating substrate 40). In the present embodiment, as shown in FIG. 3, the first switching element 11 is used as the switching element 10 constituting the upper arm, and the first switching element 11 is arranged with respect to the element arrangement surface 41 (insulating substrate 40). Are used as the switching element 10 constituting the lower arm. Although the detailed description is omitted here, the second switching element 12 is the switching element 10 that is arranged so that the second surface 22 faces the element arrangement surface 41. The second switching element 12 is disposed on the same insulating substrate 40 as the insulating substrate 40 on which the first switching element 11 is disposed, or on an insulating substrate 40 different from the insulating substrate 40 on which the first switching element 11 is disposed. Be placed. The first switching element 11 is used as the switching element 10 constituting the lower arm, or the first switching element 11 is used as the switching element 10 constituting the upper arm and the switching element 10 constituting the lower arm. It is also possible to adopt a configuration used as

  As shown in FIG. 2, the insulating substrate 40 includes a first electrode pattern 51 and a control electrode pattern 54. The first electrode pattern 51 is an electrode pattern which is provided so as to be exposed on the element arrangement surface 41 and is electrically connected to the first terminal 31 of the first switching element 11 on the element arrangement surface 41. In the present embodiment, the shape (type and size of shape) of the portion of the first electrode pattern 51 that appears on the element arrangement surface 41 in the vertical direction (plan view) is the first surface of the first switching element 11. 21 coincides with the shape of the first terminal 31 formed in 21 as viewed in the vertical direction. The control electrode pattern 54 is an electrode pattern provided so as to be exposed on the element arrangement surface 41 and electrically connected to the control terminal 34 of the first switching element 11 on the element arrangement surface 41. The control electrode pattern 54 is formed away from the first electrode pattern 51 by an insulation distance or more on both the surface and inside of the insulating substrate 40. In the present embodiment, as shown in FIG. 1, the insulating substrate 40 further includes a third electrode pattern 53. The third electrode pattern 53 is an electrode pattern provided so as to be exposed on the element arrangement surface 41 and electrically connected to the third terminal 33 of the first switching element 11 on the element arrangement surface 41. The third terminal 33 is a terminal having the same potential as the first terminal 31 provided on the first surface 21 of the switching element 10. In the present embodiment, the third terminal 33 is provided at the same position as the control terminal 34 in the target direction A described later. Each electrode pattern provided on the insulating substrate 40 is formed of a conductive material (for example, a metal material such as copper or aluminum). The material forming each electrode pattern also has thermal conductivity.

  The first switching element 11 includes a first electrode pattern 51 (specifically, a portion exposed on the element arrangement surface 41 in the first electrode pattern 51) and a control electrode pattern 54 (specifically, the control electrode pattern 54). The portion is placed (ie, placed) so as to be placed from above. Specifically, the first terminal 31 provided on the first surface 21 is placed on the first electrode pattern 51 from above, and the control terminal 34 provided on the first surface 21 is connected to the control electrode pattern 54. The first switching element 11 is arranged on the element arrangement surface 41 so as to be placed from above. In the present embodiment, the first terminal 31 and the first electrode pattern 51 are bonded to each other and the control terminal 34 and the control electrode pattern 54 are bonded to each other by a conductive bonding material such as solder or conductive paste. Has been.

  In the present embodiment, the first switching element 11 is further placed from the upper side with respect to the third electrode pattern 53 (specifically, the portion exposed to the element arrangement surface 41 in the third electrode pattern 53). Is arranged. Specifically, the first switching element 11 is arranged on the element arrangement surface 41 so that the third terminal 33 provided on the first surface 21 is placed on the third electrode pattern 53 from above. In the present embodiment, the third terminal 33 and the third electrode pattern 53 are bonded to each other by a conductive bonding material.

  The first electrode pattern 51 is an electrode pattern for electrically connecting the first terminal 31 to a component outside the first switching element 11. In the present embodiment, as shown in FIG. 3, the first terminal 31 of the first switching element 11 is electrically connected to the second terminal 32 of the second switching element 12 through the first electrode pattern 51. The first terminal 31 of the first switching element 11 is electrically connected to the coil of the rotating electrical machine 93. The control electrode pattern 54 is an electrode pattern for electrically connecting the control terminal 34 to a control circuit (driver circuit) that outputs a switching control signal (gate drive signal) of the first switching element 11. The third electrode pattern 53 is an electrode pattern for electrically connecting the third terminal 33 to the driver circuit or a higher-level control circuit (control device) than the driver circuit. That is, the control electrode pattern 54 and the third electrode pattern 53 are electrically connected to a switching control line (for example, a control line formed on a flexible printed board). As described above, the third terminal 33 is a terminal having the same potential as the first terminal 31. For example, based on information detected from the third terminal 33, the presence / absence of overcurrent can be determined.

  Here, as shown in FIG. 2, a direction from the first electrode pattern 51 toward the control electrode pattern 54 along the element arrangement surface 41 is defined as a target direction A. That is, the target direction A is a direction parallel to the element arrangement surface 41, and is directed from the exposed portion of the first electrode pattern 51 on the element arrangement surface 41 to the exposed portion of the element arrangement surface 41 of the control electrode pattern 54. Direction. The target direction A coincides with the direction from the first terminal 31 toward the control terminal 34 along the first surface 21 in a state where the first switching element 11 is disposed on the element arrangement surface 41. That is, the first switching element 11 is arranged on the element arrangement surface 41 with the control terminal 34 facing the target direction A with respect to the first terminal 31.

  Since the switching element 10 generates heat with the on / off operation, it is necessary to cool the switching element 10. In the present embodiment, as shown in FIG. 2, the first switching element 11 is arranged so that the first surface 21 faces the element arrangement surface 41 of the insulating substrate 40 and the element arrangement of the insulating substrate 40. The cooling surface 42, which is the surface opposite to the surface 41, is cooled by the cooling unit 2. Therefore, the 1st switching element 11 can be cooled appropriately by ensuring the heat dissipation from the 1st terminal 31 to the cooling surface 42 side appropriately. Since the first terminal 31 is arranged so as to be placed on the first electrode pattern 51 formed on the insulating substrate 40 from above, the heat of the first terminal 31 is mainly cooled via the first electrode pattern 51. It is diffused to the surface 42 side. That is, the first electrode pattern 51 has a function as a heat spreader in addition to a function as an electrical connection member. In view of this point, as shown in FIG. 2, the first electrode pattern 51 is formed so as to spread toward the target direction A side from the element arrangement surface 41 toward the cooling surface 42 side. Note that the spread toward the target direction A side is a continuous or stepwise spread, and in the present embodiment, the spread is stepwise. Thereby, the heat dissipation efficiency through the first electrode pattern 51 from the first terminal 31 to the cooling surface 42 side can be improved by the amount that the first electrode pattern 51 spreads in the target direction A side. The cooling performance of one switching element 11 can be appropriately ensured.

  As shown in FIG. 2, in the present embodiment, the first electrode pattern 51 is formed so as to spread on the side opposite to the target direction A as it goes from the element arrangement surface 41 to the cooling surface 42 side. The end of the first electrode pattern 51 on the target direction A side in the element arrangement surface 41 and the target electrode on the target direction A side of the first electrode pattern 51 at the position closest to the cooling surface 42 (the position of the cooling surface 42 in this embodiment). The difference (absolute value) of the position in the target direction A from the end is defined as “first spread width”, and the end of the first electrode pattern 51 opposite to the target direction A on the element arrangement surface 41 is most cooled. The difference (absolute value) of the position in the target direction A from the end of the first electrode pattern 51 opposite to the target direction A at the position on the surface 42 side (the position of the cooling surface 42 in this embodiment) In the present embodiment, the second spread width is smaller than the first spread width, assuming “double spread width”. In the present embodiment, the end of the first electrode pattern 51 opposite to the target direction A (as a whole) (in the present embodiment, the opposite side of the cooling electrode 42 from the target direction A of the first electrode pattern 51). Is aligned with the end of the first switching element 11 opposite to the target direction A and at the same position in the target direction A.

  In the present embodiment, the control electrode pattern 54 is further formed only on the surface layer 43 on the element arrangement surface 41 side of the insulating substrate 40. In the present embodiment, the first electrode pattern 51 is disposed on the surface layer 43 at an insulation distance or more away from the control electrode pattern 54, and the cross-sectional area is continuous or stepwise toward the cooling surface 42 side. It is formed continuously from the surface layer 43 to the cooling surface 42 so as to increase in a stepwise manner in the present embodiment. The cross-sectional area here is an area of a cross section perpendicular to the vertical direction. Although illustration is omitted, in the present embodiment, the width of the first electrode pattern 51 in the direction orthogonal to both the target direction A and the vertical direction is uniformly formed along the target direction A. Therefore, in the present embodiment, as the width of the first electrode pattern 51 in the target direction A increases, the cross-sectional area of the first electrode pattern 51 increases. The “surface layer 43” means a portion (surface portion) from the surface of the insulating substrate 40 (here, the element arrangement surface 41) to a certain depth. The thickness (width in the vertical direction) of the surface layer 43 is, for example, less than half the thickness of the insulating substrate 40, less than a quarter of the thickness of the insulating substrate 40, and the thickness of the insulating substrate 40. Or a thickness of 1/8 or less of the thickness.

  In the present embodiment, the portion on the lower side (cooling surface 42 side) of the control electrode pattern 54 in the insulating substrate 40, in other words, the portion of the insulating substrate 40 excluding the surface layer 43 (on the cooling surface 42 side than the surface layer 43). A portion of the first electrode pattern 51 is formed in a portion that overlaps the control electrode pattern 54 when viewed in the vertical direction. That is, the first electrode pattern 51 is formed so as to spread to a portion overlapping with the control electrode pattern 54 when viewed in the vertical direction from the element arrangement surface 41 toward the cooling surface 42 side. Therefore, the end portion on the target direction A side (as a whole) of the first electrode pattern 51 (in the present embodiment, coincides with the end portion on the target direction A side of the first electrode pattern 51 on the cooling surface 42) is the control electrode pattern. 54 is arranged closer to the target direction A than the end opposite to the target direction A. In the present embodiment, the end of the first electrode pattern 51 on the target direction A side (as a whole) is arranged at the same position in the target direction A as the end of the control electrode pattern 54 on the target direction A side. .

  As described above, the first electrode pattern 51 is disposed on the surface layer 43 at a distance greater than the insulation distance from the control electrode pattern 54. As a matter of course, the first electrode pattern 51 is disposed away from the control electrode pattern 54 by an insulation distance or more in the portion of the insulating substrate 40 closer to the cooling surface 42 than the surface layer 43. In this regard, in the present embodiment, the insulating distance required inside the insulating substrate 40 is shorter than the insulating distance (creeping distance) required on the surface of the insulating substrate 40 (here, the element arrangement surface 41). As shown in FIG. 2, the separation distance between the first electrode pattern 51 and the control electrode pattern 54 inside the insulating substrate 40 is larger than the separation distance between the first electrode pattern 51 and the control electrode pattern 54 on the element arrangement surface 41. It is shortened.

2. Second Embodiment A second embodiment of the switching element unit will be described mainly with reference to FIGS. 4 and 5. Below, it demonstrates centering around difference with said 1st embodiment, and it is the same as that of said 1st embodiment about the point which is not specified clearly.

  As shown in FIG. 5, the switching element unit 1 includes a first switching element 11 and a second switching element 12 arranged on the same insulating substrate 40. The 2nd switching element 12 is the switching element 10 arrange | positioned so that the 2nd surface 22 may oppose the element arrangement | positioning surface 41 as demonstrated in said 1st embodiment. As shown in FIGS. 3 and 5, the first switching element 11 and the second switching element 12 arranged on the same insulating substrate 40 are the first terminal 31 of the first switching element 11 and the second switching element 12. When the second terminal 32 is electrically connected, they are connected in series.

  As shown in FIG. 5, the insulating substrate 40 includes a second electrode pattern 52 in addition to the first electrode pattern 51 and the control electrode pattern 54. The second electrode pattern 52 is an electrode pattern provided so as to be exposed on the element arrangement surface 41 and electrically connected to the second terminal 32 of the second switching element 12 on the element arrangement surface 41. The 2nd switching element 12 is arrange | positioned so that it may mount from the upper side with respect to the 2nd electrode pattern 52 (specifically the part exposed to the element arrangement | positioning surface 41 in the 2nd electrode pattern 52). Specifically, the second switching element 12 is arranged on the element arrangement surface 41 so that the second terminal 32 provided on the second surface 22 is placed on the second electrode pattern 52 from above. Then, the heat of the second terminal 32 is mainly dissipated to the cooling surface 42 side through the second electrode pattern 52, whereby the second switching element 12 is cooled. In the present embodiment, the second terminal 32 and the second electrode pattern 52 are bonded to each other by a conductive bonding material.

  The second electrode pattern 52 is an electrode pattern for electrically connecting the second terminal 32 to a component outside the second switching element 12. In the present embodiment, as shown in FIG. 3, the second terminal 32 of the second switching element 12 is electrically connected to the first terminal 31 of the first switching element 11 via the second electrode pattern 52. The second terminal 32 of the second switching element 12 is electrically connected to the coil of the rotating electrical machine 93. In the example shown in FIG. 5, the insulating layer 4 is formed above the first switching element 11 and the second switching element 12. The insulating layer 4 is formed of an electrically insulating material (for example, ceramic or resin). A positive electrode pattern 55, a negative electrode pattern 56, a first signal electrode pattern 61, a second signal electrode pattern 62, a third signal electrode pattern 63, and a fourth signal electrode pattern 64 are formed on the insulating layer 4. . The positive electrode pattern 55 is an electrode pattern for electrically connecting the second terminal 32 of the first switching element 11 to the positive electrode of the DC power supply B, and the negative electrode pattern 56 is the first terminal of the second switching element 12. This is an electrode pattern for electrically connecting 31 to the negative electrode of the DC power supply B. In the example shown in FIG. 5, the positive electrode pattern 55 and the second terminal 32 of the first switching element 11 are bonded to each other by the conductive bonding material, and the negative electrode pattern 56 and the second switching element 12 are connected to each other. One terminal 31 is joined to each other.

  The first signal electrode pattern 61 is an electrode pattern for electrically connecting the control terminal 34 of the first switching element 11 to the control circuit, and the second signal electrode pattern 62 is a control of the second switching element 12. The electrode pattern for electrically connecting the terminal 34 to the control circuit, and the third signal electrode pattern 63 is an electrode pattern for electrically connecting the third terminal 33 of the first switching element 11 to the control circuit. The fourth signal electrode pattern 64 is an electrode pattern for electrically connecting the third terminal 33 of the second switching element 12 to the control circuit. In the example shown in FIGS. 4 and 5, the first signal electrode pattern 61 is electrically connected to the control terminal 34 of the first switching element 11 via the control electrode pattern 54 and is displayed on the upper surface of the insulating layer 4. It is formed to come out. The second signal electrode pattern 62 is bonded to the control terminal 34 of the second switching element 12 by a conductive bonding material and is formed so as to be exposed on the upper surface of the insulating layer 4. The third signal electrode pattern 63 is electrically connected to the third terminal 33 of the first switching element 11 through the third electrode pattern 53 and is formed so as to be exposed on the upper surface of the insulating layer 4. ing. The fourth signal electrode pattern 64 is bonded to the third terminal 33 of the second switching element 12 by a conductive bonding material and is formed so as to be exposed on the upper surface of the insulating layer 4. Switching control lines are electrically connected to portions of the first signal electrode pattern 61, the second signal electrode pattern 62, the third signal electrode pattern 63, and the fourth signal electrode pattern 64 that are exposed on the upper surface of the insulating layer 4. Connected.

  In the present embodiment, as shown in FIGS. 4 and 5, the second switching element 12 is arranged on the target direction A side with respect to the first switching element 11. In the present embodiment, the arrangement direction of the second switching element 12 is such that the first terminal 31 is on the target direction A side with respect to the control terminal 34. Accordingly, as shown in FIG. 5, the distance (the distance along the target direction A) between the control terminal 34 of the first switching element 11 and the control terminal 34 of the second switching element 12 will be described later with reference to FIG. Compared to the example shown in FIG. As a result, the distance between the first signal electrode pattern 61 and the second signal electrode pattern 62 can also be shortened. In the present embodiment, the distance between the third terminal 33 of the first switching element 11 and the third terminal 33 of the second switching element 12 can be shortened. As a result, as shown in FIG. The distance between the electrode pattern 63 and the fourth signal electrode pattern 64 can also be shortened. Accordingly, as compared with the examples illustrated in FIGS. 7 and 8, the length of the control line that electrically connects the control circuit and the control terminal 34 and the length of the control line that electrically connects the control circuit and the third terminal 33. Thus, it is possible to keep both the first switching element 11 and the second switching element 12 short. In the present embodiment, since both the first signal electrode pattern 61 and the second signal electrode pattern 62 that transmit a low voltage signal are disposed between the positive electrode pattern 55 and the negative electrode pattern 56, A strong voltage system is not interposed between the one signal electrode pattern 61 and the second signal electrode pattern 62. From this point also, the distance between the first signal electrode pattern 61 and the second signal electrode pattern 62 is shortened. It is possible.

  In the present embodiment, as shown in FIG. 5, the first electrode pattern 51 and the second electrode pattern 52 are integrally connected to the control electrode pattern 54 on the cooling surface 42 side. That is, the first terminal 31 of the first switching element 11 and the second terminal 32 of the second switching element 12 are electrically connected only by the electrode pattern provided on the insulating substrate 40. When the first switching element 11 and the second switching element 12 are arranged so that the same outer surface faces the element arrangement surface 41, the first switching element 11 and the second switching element 12 are electrically connected. However, in this embodiment, it is not necessary to arrange such a member in the space outside the element arrangement surface 41. Thereby, the first switching element 11 and the second switching element 12 are arranged close to each other, or another member (in this embodiment, in the space between the first switching element 11 and the second switching element 12, The first signal electrode pattern 61 and the second signal electrode pattern 62) can be arranged, and the entire switching element unit 1 can be reduced in size.

  In the present embodiment, the first switching element 11 and the second switching element 12 are provided on the outer surfaces opposite to each other (more specifically, the first switching element 11 is the first surface 21, and the second switching element 12 is the first switching element 12. Since the second surface 22) is arranged toward the element arrangement surface 41, the direction of the current flowing through the first switching element 11 and the direction of the current flowing through the second switching element 12 can be opposite to each other. . That is, the direction of the magnetic field generated by the current flowing through the first switching element 11 and the direction of the magnetic field generated by the current flowing through the second switching element 12 can be set to weaken each other's magnetic field. Therefore, it is possible to reduce the effective inductance of the first switching element 11 and the second switching element 12 and suppress the surge voltage accompanying the switching operation.

3. Other Embodiments Other embodiments of the switching element unit will be described. Note that the configurations disclosed in the following embodiments can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction arises.

(1) In the second embodiment described above, the switching element unit 1 includes one each of the first switching element 11 and the second switching element 12 as the plurality of switching elements 10 arranged on the same insulating substrate 40. The configuration provided is described as an example. However, without being limited to such a configuration, the switching element unit 1 includes a plurality of first switching elements 11 and a plurality of second switching elements 12 as the plurality of switching elements 10 disposed on the same insulating substrate 40. It is also possible to have a structure provided with each. For example, as in the example shown in FIG. 6, the switching element unit 1 has all the switching elements 10 (three first switching elements 11 and three elements constituting the inverter circuit shown in FIG. 3 on the same insulating substrate 40. A configuration comprising a second switching element 12) is also possible. In the example shown in FIG. 6, the switching element unit 1 shown in FIG. 5 has one unit configuration, and three unit configurations are arranged in the target direction A. Such a configuration is suitable for an inverter for driving a three-phase motor.

(2) In the second embodiment, the configuration in which the second switching element 12 is disposed on the target direction A side with respect to the first switching element 11 has been described as an example. However, the present invention is not limited to such a configuration, and the second switching element 12 is disposed on the opposite side to the target direction A with respect to the first switching element 11, for example, as in the examples illustrated in FIGS. 7 and 8. It is also possible to adopt a configuration. In the example shown in FIG. 7, the arrangement direction of the second switching element 12 is the direction in which the first terminal 31 is opposite to the target direction A with respect to the control terminal 34, whereas in FIG. In the example shown, the arrangement direction of the second switching element 12 is the direction in which the first terminal 31 is on the target direction A side with respect to the control terminal 34. In the examples shown in FIGS. 7 and 8, the first electrode pattern 51 and the second electrode pattern 52 are integrally connected as in the second embodiment.

(3) In the second embodiment, the configuration in which the arrangement direction of the second switching element 12 is the direction in which the first terminal 31 is the target direction A side with respect to the control terminal 34 has been described as an example. However, without being limited to such a configuration, in the configuration of the second embodiment, the arrangement direction of the second switching element 12 is opposite to the target direction A with respect to the control terminal 34 where the first terminal 31 is directed. It is also possible to set the direction to the side.

(4) In each of the above embodiments, the first electrode pattern 51 has been described as an example in which the first electrode pattern 51 gradually spreads toward the target direction A side from the element arrangement surface 41 toward the cooling surface 42 side. However, without being limited to such a configuration, for example, as in the example shown in FIG. 9, the first electrode pattern 51 is continuously formed in the target direction A side from the element arrangement surface 41 toward the cooling surface 42. It can also be set as the structure which spreads to. In the example shown in FIG. 9, the first electrode pattern 51 is continuously formed from the surface layer 43 to the cooling surface 42 so that the cross-sectional area continuously increases toward the cooling surface 42 side. In the example shown in FIG. 9, unlike the above-described embodiments, the first spread width and the second spread width described above are equal to each other. In the example shown in FIG. 9, unlike the above-described embodiments, the first electrode pattern 51 overlaps with the control electrode pattern 54 when viewed in the vertical direction from the element arrangement surface 41 toward the cooling surface 42. It is configured not to spread to the part. That is, in the example shown in FIG. 9, the end portion on the target direction A side of the first electrode pattern 51 is on the opposite side to the target direction A than the end portion on the opposite side to the target direction A of the control electrode pattern 54. Has been placed.

(5) In the above embodiments, the configuration in which the control electrode pattern 54 is formed only on the surface layer 43 on the element arrangement surface 41 side of the insulating substrate 40 has been described as an example. However, the configuration is not limited to such a configuration, and the control electrode pattern 54 may be formed continuously from the surface layer 43 to the cooling surface 42. In this case, for example, the end of the control electrode pattern 54 on the side opposite to the target direction A may be formed so as to be directed toward the target direction A side toward the cooling surface 42 side.

(6) In each of the above embodiments, the first terminal 31 is the negative-side main terminal 30 of the pair of main terminals 30, and the second terminal 32 is the positive-side of the pair of main terminals 30. The configuration that is the main terminal 30 has been described as an example. However, without being limited to such a configuration, the first terminal 31 is the positive-side main terminal 30 of the pair of main terminals 30, and the second terminal 32 is of the pair of main terminals 30. The main terminal 30 on the negative electrode side may be configured.

(7) In each of the above embodiments, the configuration in which the switching element 10 is used in an inverter circuit has been described as an example. However, without being limited to such a configuration, for example, the switching element 10 may be configured to be used in a booster circuit for boosting the DC voltage of the DC power supply B.

(8) Regarding other configurations, it should be understood that the embodiments disclosed herein are merely examples in all respects. Accordingly, those skilled in the art can make various modifications as appropriate without departing from the spirit of the present disclosure.

4). Outline of the above embodiment Hereinafter, an outline of the switching element unit described above will be described.

  An insulating substrate (40) formed of a material having electrical insulation, and a switching element (10) disposed on an element disposition surface (41) of the insulating substrate (40), the insulating substrate (40 ) Is a switching element unit (1) whose surface opposite to the element arrangement surface (41) is a cooling surface (42) cooled by the cooling unit (2), and the switching element (10) A pair of main terminals (30) electrically connected to a DC voltage supply source (B) and a control terminal (34) for controlling the switching element (10), the pair of main terminals ( 30), the first terminal (31) and the control terminal (34) are provided on the first surface (21) of the outer surface of the switching element (10), and the pair of main terminals (30) The other second terminal (32 Is provided on the second surface (22) facing away from the first surface (21) on the outer surface of the switching element (10), and the first surface (21) is the switching element (10). A first switching element (11) arranged to face the element arrangement surface (41) is provided, and the insulating substrate (40) includes a first electrode pattern (51), a control electrode pattern (54), and The first electrode pattern (51) is provided so as to be exposed on the element arrangement surface (41), and the first terminal of the first switching element (11) is provided on the element arrangement surface (41). The control electrode pattern (54) is electrically connected to the element placement surface (41) and is electrically connected to the first switching element (11) on the device placement surface (41). ) Said control terminal 34), and the direction from the first electrode pattern (51) toward the control electrode pattern (54) along the element arrangement surface (41) is defined as the target direction (A). A pattern (51) is formed so as to spread toward the target direction (A) as it goes from the element arrangement surface (41) toward the cooling surface (42).

In this configuration, the first surface (21) on which both the first terminal (31) (one of the pair of main terminals (30)) and the control terminal (34) are provided is the element arrangement of the insulating substrate (40). For the first switching element (11) arranged to face the surface (41), the first electrode pattern (51) electrically connected to the first terminal (31) at the element arrangement surface (41) is: The insulating substrate (40) is formed so as to spread toward the target direction (A) side from the element arrangement surface (41) toward the cooling surface (42) side cooled by the cooling unit (2). Therefore, the heat dissipation efficiency through the first electrode pattern (51) from the first terminal (31) to the cooling surface (42) side by the amount that the first electrode pattern (51) spreads toward the target direction (A) side. Therefore, it is possible to appropriately secure the cooling performance of the first switching element (11). Since the target direction (A) is a direction from the first electrode pattern (51) toward the control electrode pattern (54) along the element arrangement surface (41), the target direction (A) of the insulating substrate (40). The space on the cooling surface (42) side with respect to the control electrode pattern (54) is effectively utilized while suppressing the enlargement to the side, and the object is directed toward the cooling surface (42) side from the element arrangement surface (41). There is also an advantage that the first electrode pattern (51) can be formed so as to spread in the direction (A).
As described above, according to the above configuration, the switching element (21) arranged so that the outer surface (21) provided with both the main terminal (30) and the control terminal (34) faces the insulating substrate (40). It becomes possible to ensure the cooling performance of 11) appropriately.

  Here, the control electrode pattern (54) is formed only on the surface layer (43) on the element arrangement surface (41) side of the insulating substrate (40), and the first electrode pattern (51) is formed on the surface layer (43). 43), the surface layer is disposed so as to be separated from the control electrode pattern (54) by an insulation distance or more and the cross-sectional area increases continuously or stepwise toward the cooling surface (42). It is preferable to form continuously from (43) to the cooling surface (42).

  According to this configuration, since the control electrode pattern (54) is formed only on the surface layer (43) of the insulating substrate (40), the portion on the cooling surface (42) side of the surface layer (43) in the insulating substrate (40). The first electrode pattern (51) spreads toward the target direction (A) from the element arrangement surface (41) toward the cooling surface (42) while appropriately securing an insulation distance from the control electrode pattern (54). ). In addition, the first electrode pattern (51) is arranged on the surface layer (43) with an insulation distance or more away from the control electrode pattern (54), and the cross-sectional area is continuous toward the cooling surface (42) side. Or it forms continuously from a surface layer (43) to a cooling surface (42) so that it may become large in steps. Therefore, it is possible to appropriately ensure electrical insulation between the first electrode pattern (51) and the control electrode pattern (54) and to continuously form the surface layer (43) to the cooling surface (42). Since the cross-sectional area of the first electrode pattern (51) increases toward the cooling surface (42), the first electrode pattern (51) from the first terminal (31) to the cooling surface (42) side is interposed. The heat dissipation efficiency can be further improved.

  The switching element (10) is further provided with a second switching element (12) disposed so that the second surface (22) faces the element disposition surface (41), and the second switching element (10) is provided. The element (12) is arranged on the target direction (A) side with respect to the first switching element (11), and the arrangement direction of the second switching element (12) is the same as that of the second switching element (12). The first terminal (31) is oriented in the target direction (A) with respect to the control terminal (34) of the second switching element (12), and the insulating substrate (40) A second electrode pattern (52) provided so as to be exposed on the surface (41) and electrically connected to the second terminal (32) of the second switching element (12) on the element arrangement surface (41). ) Preferably, the first electrode pattern (51) and the second electrode pattern (52) are integrally connected to the control electrode pattern (54) on the cooling surface (42) side. is there.

According to this configuration, the first terminal (31) of the first switching element (11) and the second terminal (2) of the second switching element (12) are formed by the first electrode pattern (51) and the second electrode pattern (52). 32) are electrically connected to each other, so that a series circuit in which the first switching element (11) and the second switching element (12) are electrically connected to each other in series can be formed. Here, when the first switching element (11) and the second switching element (12) are arranged so that the same outer surface faces the element arrangement surface (41), these two switching elements (11, 12) are arranged. ) In the space outside the element arrangement surface (41), the first switching element (11) and the second switching element (12) need to be arranged in the space outside the element arrangement surface (41). The first electrode pattern (51) and the second electrode pattern (52) are electrically provided on the insulating substrate (40). Therefore, the first switching element (11) and the second switching element (12) are arranged close to each other, or another space is provided between the first switching element (11) and the second switching element (12). It becomes possible to arrange the members, and the entire switching element unit (1) can be downsized.
Moreover, according to said structure, since a 1st switching element (11) and a 2nd switching element (12) are arrange | positioned toward the element arrangement | positioning surface (41) with the outer surface on the opposite side mutually, 1st switching The direction of the current flowing through the element (11) and the direction of the current flowing through the second switching element (12) can be opposite to each other. That is, the direction of the magnetic field generated by the current flowing through the first switching element (11) and the direction of the magnetic field generated by the current flowing through the second switching element (12) are set to be directions in which the mutual magnetic fields are weakened. it can. Therefore, the effective inductance of the first switching element (11) and the second switching element (12) can be reduced, and the surge voltage associated with the switching operation can be suppressed.
Furthermore, according to said structure, while the 2nd switching element (12) is arrange | positioned with respect to the 1st switching element (11) at the object direction (A) side, arrangement | positioning of a 2nd switching element (12) The direction is such that the first terminal (31) is on the target direction (A) side with respect to the control terminal (34). Therefore, when the second switching element (12) is disposed on the side opposite to the target direction (A) with respect to the first switching element (11), the second switching element (12) Even if it is a case where it is arranged on the object direction (A) side with respect to (11), the arrangement direction of the second switching element (12) is the object of the first terminal (31) with respect to the control terminal (34). The control terminal (34) of the first switching element (11) and the control terminal (34) of the second switching element (12) are arranged closer to each other than when the direction is opposite to the direction (A). can do. Thereby, the length of the electrical connection path between the control circuit that outputs the control signal of the first switching element (11) and the second switching element (12) and the two control terminals (34) is kept short. For example, the noise tolerance of the control signal can be improved.

1: switching element unit 2: cooling unit 10: switching element 11: first switching element 12: second switching element 21: first surface 22: second surface 30: main terminal 31: first terminal 32: second terminal 34 : Control terminal 40: Insulating substrate 41: Element arrangement surface 42: Cooling surface 43: Surface layer 51: First electrode pattern 52: Second electrode pattern 54: Control electrode pattern A: Target direction B: DC power supply (DC voltage supply source )

Claims (3)

An insulating substrate formed of an electrically insulating material; and a switching element disposed on an element arrangement surface of the insulating substrate. A surface of the insulating substrate opposite to the element arrangement surface is cooled. A switching element unit which is a cooling surface cooled by the unit,
The switching element includes a pair of main terminals electrically connected to a DC voltage supply source, and a control terminal for controlling the switching element,
The first terminal which is one of the pair of main terminals and the control terminal are provided on the first surface of the outer surface of the switching element, and the second terminal which is the other of the pair of main terminals is the switching element. Provided on the second surface of the outer surface facing away from the first surface;
As the switching element, provided is a first switching element disposed so that the first surface faces the element arrangement surface,
The insulating substrate includes a first electrode pattern and a control electrode pattern,
The first electrode pattern is provided so as to be exposed on the element arrangement surface and electrically connected to the first terminal of the first switching element on the element arrangement surface,
The control electrode pattern is provided so as to be exposed on the element arrangement surface, and is electrically connected to the control terminal of the first switching element on the element arrangement surface,
The direction from the first electrode pattern toward the control electrode pattern along the element arrangement surface is a target direction, and the first electrode pattern spreads toward the target direction side from the element arrangement surface toward the cooling surface. A switching element unit formed as described above. The control electrode pattern is formed only on the surface layer on the element arrangement surface side of the insulating substrate,
The first electrode pattern is disposed at an insulating distance or more away from the control electrode pattern on the surface layer, and the cross-sectional area increases continuously or stepwise toward the cooling surface side. The switching element unit according to claim 1, wherein the switching element unit is continuously formed from a surface layer to the cooling surface. As the switching element, there is further provided a second switching element arranged so that the second surface faces the element arrangement surface,
The second switching element is disposed on the target direction side with respect to the first switching element,
The arrangement direction of the second switching element is an orientation in which the first terminal of the second switching element is on the target direction side with respect to the control terminal of the second switching element,
The insulating substrate further includes a second electrode pattern provided to be exposed on the element arrangement surface and electrically connected to the second terminal of the second switching element on the element arrangement surface,
The switching element unit according to claim 1, wherein the first electrode pattern and the second electrode pattern are integrally connected to the control electrode pattern on the cooling surface side.

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