JP6053668B2 - Semiconductor module and power conversion device - Google Patents

Description

  The present invention relates to a semiconductor module and a power conversion device having an electrostatic capacitance component for noise removal, and in particular, an electrostatic capacitance generated between a semiconductor element and a conductive member (chassis conductor) as an electrostatic noise component for noise removal. TECHNICAL FIELD The present invention relates to a semiconductor module and a power conversion device that use the above.

  For the purpose of reducing radiation noise generated with the switching operation of the semiconductor element, a capacitance component may be provided between the semiconductor element and the chassis conductor. In this case, the electrostatic capacitance may be provided in equilibrium between the positive electrode side and the negative electrode side of the semiconductor element. Such a capacitance component is also called a ground-to-ground capacitor. However, when the capacitance between the semiconductor element and the chassis conductor is unbalanced between the positive electrode side and the negative electrode side, there is a problem that radiation noise increases.

  For example, in the case of a power semiconductor element, generally, one main surface of the element is brought into contact / joining with a base electrode joined via a thin insulator on a chassis conductor. That is, the power semiconductor element is connected to a cooling path composed of the base electrode, the insulator, and the chassis conductor.

  At this time, in the semiconductor element manufacturing process, for example, the collector side is joined to the base electrode in the case of an insulated gate bipolar transistor (IGBT), the drain side in the case of a MOS field effect transistor (MOSFET), and the cathode side in the case of a diode. It is common. Therefore, in the case of a semi-bridge circuit in which a high-side element (upper-arm power semiconductor element) and a low-side element (lower-arm power semiconductor element) are connected in series, the positive side of the semi-bridge circuit includes a base electrode. Therefore, a large capacitance is generated between the positive electrode side and the chassis conductor. On the other hand, since the negative electrode side of the semi-bridge circuit is not provided with a base electrode, the capacitance generated between the negative electrode side and the chassis conductor is very small. As a result, in the power semiconductor element, the capacitance between the positive electrode side of the semiconductor element of the upper arm and the chassis conductor and the capacitance between the negative electrode side of the semiconductor element of the lower arm and the chassis conductor become unbalanced, resulting in radiation. Noise cannot be reduced.

  In Japanese Patent Application Laid-Open No. 2007-142073, the area of the positive electrode and the negative electrode of the DC input of the circuit pattern arranged on the insulating substrate is made substantially the same size, so that the stray capacitance of the insulating substrate is used as a capacitor. It is described that capacity imbalance for each phase can be eliminated.

  Japanese Unexamined Patent Application Publication No. 2009-088046 describes a technique for mounting a first power semiconductor element and a second power semiconductor element on a wiring board in opposite directions.

JP 2007-142073 A JP 2009-088046 A

  However, since the power semiconductor module described in Japanese Patent Application Laid-Open No. 2007-142073 needs to provide a negative electrode on the insulating ceramic substrate with the same area as the positive electrode, there is a problem that the power conversion device becomes large. is there. Specifically, since it is necessary to newly provide a negative electrode on which no semiconductor element is mounted on an insulating ceramic substrate in addition to a circuit pattern (positive electrode etc.) on which a semiconductor element is mounted, It will increase in size.

  Further, in the power semiconductor device described in Japanese Patent Application Laid-Open No. 2009-088046, the area of the positive side wiring pattern to which the upper arm semiconductor element is bonded and the area of the negative side wiring pattern to which the lower arm semiconductor element is bonded Are usually not equivalent (from a different perspective, the area of the positive-side wiring pattern and the area of the positive-side wiring pattern to which the semiconductor element of the lower arm is bonded relative to the area of the positive-side wiring pattern to which the upper-arm semiconductor element is bonded) The ratio of the difference in the area is more than ± 10%). Specifically, all the wiring patterns to which the lower arm semiconductor elements are bonded are not formed as negative electrode wiring patterns, but are partially formed as gate wiring patterns, and are generally disclosed in JP 2009-088046 A. As described in the drawings, the two areas are not provided equally. At this time, in order to set the ratio of the difference between the two areas to the area of the wiring pattern to which the upper arm semiconductor element is bonded to ± 10% or less, the area of the wiring pattern to which the upper arm semiconductor element is bonded is reduced. However, in this case, the heat dissipation of the upper arm semiconductor element deteriorates. In addition, it is conceivable to increase the area of the wiring pattern to which the lower arm semiconductor element is bonded. In this case, however, the power converter is increased in size.

  The present invention has been made to solve the above-described problems. A main object of the present invention is to provide a semiconductor module and a power conversion device capable of sufficiently reducing radiation noise while suppressing an increase in size of the power conversion device and having high heat dissipation.

A semiconductor module according to the present invention includes a conductive member, a first insulator formed on the conductive member, a first electrode disposed on the first insulator, and a first electrode spaced from the first electrode. A second electrode disposed on one insulator; a first semiconductor element disposed on the first electrode and having a positive electrode and a negative electrode; and a second semiconductor element disposed on the second electrode and having a positive electrode and a negative electrode A semiconductor element, the positive electrode of the first semiconductor element is connected to the first electrode, the negative electrode of the first semiconductor element is connected to the positive electrode of the second semiconductor element, and the conductive member and the first element The ratio of the capacitance value generated between the conductive member and the negative electrode of the second semiconductor element to the capacitance value generated between the positive electrode of the semiconductor element is 0.9 or more and 1.1 or less. The positive electrode of the second semiconductor element is connected to the second electrode. The negative electrode of the second semiconductor element is connected to the first conductor. The conductive member and the first conductor are connected via a capacitor element.

  ADVANTAGE OF THE INVENTION According to this invention, the semiconductor module and power converter device which can fully reduce radiation noise can be provided, suppressing the enlargement of a power converter device and having high heat dissipation.

1 is a circuit diagram showing a configuration of a power conversion device according to a first embodiment. 3 is a bird's-eye view showing a state where the semiconductor module is mounted in the power conversion device according to Embodiment 1. FIG. 2 is a top view showing an internal configuration of the semiconductor module according to Embodiment 1. FIG. 2 is a cross-sectional view showing an internal configuration of the semiconductor module according to Embodiment 1. FIG. 2 is a circuit diagram showing a configuration of a semi-bridge circuit in the semiconductor module according to the first embodiment. FIG. FIG. 6 is a cross-sectional view showing an internal configuration of a semiconductor module according to a second embodiment. FIG. 10 is a bird's-eye view showing a state where a semiconductor module according to a third embodiment is mounted. FIG. 10 is a bird's-eye view showing a modification of a state where the semiconductor module according to the third embodiment is mounted. FIG. 6 is a top view showing an internal configuration of a semiconductor module according to a fourth embodiment. FIG. 6 is a cross-sectional view showing an internal configuration of a semiconductor module according to a fourth embodiment. FIG. 10 is a cross-sectional view showing a modification of the internal configuration of the semiconductor module according to the fourth embodiment. FIG. 9 is a top view showing an internal configuration of a semiconductor module according to a fifth embodiment. FIG. 9 is a cross-sectional view showing an internal configuration of a semiconductor module according to a fifth embodiment. FIG. 9 is a circuit diagram showing a configuration of a semi-bridge circuit in a semiconductor module according to a fifth embodiment. FIG. 10 is a cross-sectional view showing a modification of the internal configuration of the semiconductor module according to the fifth embodiment. FIG. 10 is a cross-sectional view showing an internal configuration of a semiconductor module according to a sixth embodiment. FIG. 9 is a cross-sectional view of a multilayer capacitor element according to a sixth embodiment. FIG. 10 is a top view showing an internal configuration of a semiconductor module according to a sixth embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
First, with reference to FIGS. 1-5, the semiconductor module 1 and the power converter device 51 which concern on Embodiment 1 of this invention are demonstrated. First, an example of a circuit diagram of the power conversion device 51 according to the first embodiment will be described with reference to FIG. The power conversion device 51 according to the first embodiment can convert the DC power input from the DC power supply 52 into an AC and supply it to the motor 53 and the like. The power conversion device 51 is configured by connecting, for example, three semi-bridge circuits in parallel as an inverter. Specifically, the power conversion device 51 includes upper arm semiconductor elements 56a, 56b, and 56c and lower arm semiconductor elements 57a, 57b, and 57c. The semiconductor element 56a and the semiconductor element 57a are connected in series to form a first semi-bridge circuit. The semiconductor element 56b and the semiconductor element 57b are connected in series to form a second semi-bridge circuit. The semiconductor element 56c and the semiconductor element 57c are connected in series to form a third semi-bridge circuit. These first to third semi-bridge circuits are connected in parallel to form a three-phase inverter circuit. Each of the semiconductor elements 56 and 57 can be an arbitrary semiconductor element such as an insulated gate bipolar transistor (IGBT) or a thyristor, but is, for example, a MOS field effect transistor (MOSFET). A diode is connected to each semiconductor element in parallel. The drain side of the semiconductor element of the upper arm is connected to the positive side of the DC power supply 52, and the source side of the semiconductor element of the lower arm is connected to the negative side of the DC power supply 52. A connection portion between the semiconductor element of the upper arm and the semiconductor element of the lower arm is connected to the motor 53.

  Each semi-bridge circuit of the power conversion device 51 is configured as a semiconductor module 1. FIG. 2 is a bird's eye view showing a mounting state of the semiconductor module 1 constituting the power conversion device 51. The semiconductor module 1 is mounted on a chassis conductor 2 as a conductive member. The semiconductor module 1 includes, for example, a positive electrode side conductor 3, a negative electrode side conductor 4, and an intermediate side conductor 5, and each conductor is drawn out from the inside of the semiconductor module 1. Although the chassis conductor 2 should just be comprised with arbitrary materials with high heat dissipation, it should just be comprised with copper, aluminum, etc., for example.

  FIG. 3 is a schematic top view for explaining the internal configuration of the semiconductor module 1. FIG. 4 is a schematic cross-sectional view for explaining the internal configuration of the semiconductor module 1. FIG. 5 is a circuit diagram of a semi-bridge circuit formed in the semiconductor module 1. FIG. 4 shows an arrangement of the constituent members shown in FIGS. 2 and 3 in order to explain the connection state of the constituent members from the positive electrode side to the negative electrode side of the semiconductor module 1 shown in FIGS. The part has been changed.

  The semiconductor module 1 includes, for example, an upper arm semiconductor element 6 (6a, 6b) as a first semiconductor element and a lower arm semiconductor element 7 (7a, 7b) as a second semiconductor element. The drain electrode of the semiconductor element 6 is connected to the positive electrode side conductor 3 connected to the positive electrode side of the DC power supply 52, and the source electrode of the semiconductor element 7 is connected to the negative electrode side conductor 4 connected to the negative electrode side of the DC power supply 52. It is connected. The source electrode of the semiconductor element 6 and the drain electrode of the semiconductor element 7 are connected to the intermediate conductor 5 connected to the motor 53. The chassis conductor 2 is grounded. The positive electrode side conductor 3, the negative electrode side conductor 4, and the intermediate side conductor 5 may be made of any material having conductivity, but are made of, for example, copper, silver, solder, or the like.

  In the semiconductor module 1, the upper arm semiconductor element 6 is mounted on a positive base electrode 8 serving as a first electrode. At this time, the drain electrode of the semiconductor element 6 is bonded to the positive electrode base electrode 8, and the positive electrode base electrode 8 is bonded to the positive electrode conductor 3. Thereby, as described above, the drain electrode of the semiconductor element 6 is connected to the positive electrode side of the DC power supply 52. The lower arm semiconductor element 7 is mounted on an intermediate base electrode 9 as a second electrode. At this time, the drain electrode of the semiconductor element 7 is joined to the intermediate base electrode 9, and the intermediate base electrode 9 is joined to the intermediate conductor 5. That is, the intermediate conductor 5 is bonded to the source electrode of the upper arm semiconductor element 6 as described above, and to the intermediate base electrode 9 bonded to the drain electrode of the lower arm semiconductor element 7. Thus, the semiconductor element 6 and the semiconductor element 7 are connected in series.

  The material constituting the positive side base electrode 8 and the intermediate side base electrode 9 may be any material having electrical conductivity, such as copper, silver, or solder. The positive base electrode 8 and the intermediate base electrode 9 are provided on a first insulator 10 formed on the chassis conductor 2.

  The material constituting the first insulator 10 can be selected from any material having electrical insulation properties, for example, a resin material such as an epoxy resin or a polyimide resin, a ceramic material such as barium titanate or alumina, or the like. It is. The material constituting the first insulator 10 and the film thickness thereof can be appropriately set according to the dielectric constant required for the first insulator 10. In the case where a power semiconductor element is used as in the present embodiment, the first insulator 10 is generally formed thin from the viewpoint of improving the heat dissipation to the chassis conductor 2.

  The positive-side base electrode 8 and the intermediate-side base electrode 9 are connected to the chassis conductor 2 via the first insulator 10, thereby forming a positive-side capacitance 101 and an intermediate-side capacitance 102, respectively. ing. The positive-side capacitance 101 and the intermediate-side capacitance 102 are such that the first insulator 10 is formed of the same material and with the same film thickness, and the positive-side base electrode 8 and the intermediate-side base electrode 9. Are formed with the same area, the respective capacitance values can be made equal.

  On the chassis conductor 2, a ground electrode 11 is formed in a region where the first insulator 10 is not formed. That is, the ground electrode 11 is grounded via the chassis conductor 2. The material constituting the ground electrode 11 may be any material having conductivity, for example, copper.

  The negative electrode side conductor 4 and the ground electrode 11 are connected via a capacitor element 100. The capacitor element 100 is selected as having a predetermined capacitance. Specifically, referring to FIGS. 4 and 5, the capacitance value of capacitor element 100 is between positive electrode base electrode 8 and chassis conductor 2 connected via first insulator 10. It is selected to be within ± 10% of the capacitance value of the positive electrode side capacitance 101 to be formed. That is, the capacitance value of the capacitor element 100 only needs to be within an error range of a general capacitance value of the capacitor with reference to the positive electrode side capacitance 101. Referring to FIG. 3, capacitor element 100 may be configured by a plurality of capacitor elements 100a, 100b, 100c, and 100d. The capacitor elements 100a, 100b, 100c, and 100d are connected in parallel to each other, for example, between the negative electrode side conductor 4 and the ground electrode 11. In this case, the ratio of the total value of the capacitance values of the capacitor elements 100a, 100b, 100c, and 100d to the capacitance value of the positive electrode side capacitance 101 is 0.9 to 1.1. It only has to be.

  Capacitor elements 100a, 100b, 100c, and 100d are multilayer capacitor elements in which two types of electrodes are alternately stacked in layers via a dielectric. For example, a multilayer ceramic capacitor or a multilayer printed board can be used. Capacitor element 100 may be a swivel capacitor element in which a dielectric sandwiched between two layers of electrodes is swirled, and for example, a film capacitor may be used. As the dielectric, a dielectric having a high dielectric constant such as ceramic may be used, or a dielectric having a low dielectric constant such as resin may be used.

  Each member (intermediate conductor 5, semiconductor element 6, semiconductor element 7, positive base electrode 8, intermediate base electrode 9, first insulator 10, ground electrode 11) formed on the chassis conductor 2 described above, A part of the positive electrode side conductor 3 and the negative electrode side conductor 4 is covered with a sealing body 12, thereby forming the semiconductor module 1. The material constituting the sealing body 12 is, for example, an epoxy resin.

  Next, functions and effects of the semiconductor module 1 and the power conversion device 51 according to the first embodiment will be described. In the semiconductor module 1 according to the first embodiment, the negative electrode side conductor 4 and the ground electrode 11 are connected via the capacitor elements 100a, 100b, 100c, and 100d. Furthermore, the ratio of the total value of the capacitance values of the capacitor elements 100a, 100b, 100c, and 100d to the capacitance value of the positive electrode side capacitance 101 is set to 0.9 or more and 1.1 or less. As a result, a capacitance (positive capacitance 101) generated between the grounded chassis conductor 2 and the positive electrode of the semiconductor element 6 and a static capacitance generated between the chassis conductor 2 and the negative electrode of the semiconductor element 7 are obtained. The electric capacity can be easily balanced. As a result, the capacitance can be used as a capacitance component for noise removal, and radiation noise can be sufficiently reduced. At this time, for example, without reducing the area of the positive electrode base electrode 8, the capacitance between the semiconductor element 6 and the semiconductor element 7 and the grounded chassis conductor 2 is reduced as described above. Therefore, high heat dissipation with respect to the semiconductor element 6 can be maintained.

  Further, by newly providing an electrode connected to the negative electrode side of the semiconductor element 7 and connected to the chassis conductor 2 via an insulator, the capacitance value with respect to the capacitance value of the positive electrode side capacitance 101 can be reduced. The semiconductor module 1 can be reduced in size as compared with a conventional semiconductor module for a power conversion device that forms a capacitance of 0.9 to 1.1.

  Such an effect can be obtained regardless of the number of parallel capacitor elements 100. However, by connecting the capacitor elements 100 in parallel as in the present embodiment, the negative conductor 4 and the ground electrode 11 are connected. Can be connected with low inductance, and the increase in size of the power converter can be more effectively suppressed, and radiation noise can be sufficiently reduced while having high heat dissipation.

Further, in the power conversion device 51 according to the first embodiment, the material constituting the first insulator 10 and the dielectric material of the capacitor element 100 have the same temperature change rate of the dielectric constant. preferable. For example, when the material constituting the first insulator 10 is low dielectric constant type alumina (Al ₂ O ₃ ), the temperature change of the dielectric constant of alumina is as small as about 100 ppm / ° C., so that the capacitor element 100 The dielectric material can be a low dielectric constant type titanium oxide or calcium zirconate having a small dielectric constant temperature change. More preferably, the material constituting the first insulator 10 and the dielectric material of the capacitor element are the same material. For example, the material constituting the first insulator 10 and the dielectric material of the capacitor element may be a high dielectric constant type barium titanate (BaTiO ₃ ). Here, the temperature change of the dielectric constant of barium titanate varies depending on the additive and the particle size. Therefore, by appropriately selecting these, it is possible to configure the first insulator 10 whose dielectric constant is reduced by 20% at 100 ° C. compared with that at normal temperature. As described above, when the material constituting the first insulator 10 is alumina, the dielectric material of the capacitor element 100 may be alumina.

  Since the dielectric constant of the dielectric generally changes with temperature, when the temperature change rate of the dielectric constant differs between the material constituting the first insulator 10 and the dielectric material of the capacitor element 100, the power conversion device 51. The difference between the positive electrode side capacitance 101 and the capacitance of the capacitor element 100 becomes larger depending on the operating temperature of the capacitor elements 100a, 100b, 100c, and 100d with respect to the capacitance value of the positive electrode side capacitance 101. The ratio of the total capacitance value is less than 0.9 or exceeds 1.1), and the effect of reducing radiation noise is impaired. On the other hand, by making the material constituting the first insulator 10 and the dielectric material of the capacitor element 100 have the same temperature change rate of the dielectric constant, it depends on the operating temperature of the power converter 51. Therefore, a radiation noise reduction effect can be obtained.

(Embodiment 2)
Next, the semiconductor module and the power conversion device 51 according to the second embodiment will be described. Referring to FIG. 6, the semiconductor module and the power conversion device according to the second embodiment basically have the same configuration as that of the semiconductor module and the power conversion device 51 according to the first embodiment. The difference is that the ground electrode 11 is formed between the chassis conductor 2 and the capacitor element 100 and between the chassis conductor 2 and the first insulator 10.

  The material constituting the ground electrode 11 may be any material having conductivity, for example, copper. In this way, the thermal conductivity between the chassis conductor 2 and the semiconductor module 1 can be improved. The ground electrode 11 may be formed by any method. For example, the ground electrode 11 may be formed by joining the ground electrode 11 to the first insulator 10 by an active metal brazing process.

  In general, thermal conductive grease or the like may be applied between the semiconductor module 1 and the chassis conductor 2 for the purpose of improving thermal conductivity, but the positive electrode side electrostatic capacitance is applied according to the coating amount (thickness) of the thermal conductive grease or the like. There is a problem that the capacity 101 (see FIG. 4) changes. For this reason, when the application amount of the thermal conductive grease or the like is not sufficiently controlled, the difference between the positive electrode side capacitance 101 and the capacitance of the capacitor element 100 becomes large, and the radiation noise reduction effect may be impaired.

  In the semiconductor module 1 and the power conversion device 51 according to the second embodiment, since the ground electrode 11 is formed in the region where the first insulator 10 is formed and the region where the capacitor element 100 is disposed, the first insulator Since there is no heat conduction grease between the ground electrode 11 and the ground electrode 11, it is possible to prevent the fluctuation of the capacitance due to the fluctuation of the application amount of the heat conduction grease. Note that thermal conductive grease is often applied between the ground electrode 11 and the chassis conductor 2, but the ground electrode 11 and the chassis conductor 2 are usually electrically connected, and the thermal conductive grease is applied here. Variation in the amount does not impair the radiation noise reduction effect.

  As a result, as described above, the difference in capacitance between the positive electrode side capacitance 101 and the capacitor element 100 is increased due to the thermal conductive grease or the like (the capacitance relative to the capacitance value of the positive electrode side capacitance 101). The ratio of the total capacitance of the elements 100a, 100b, 100c, and 100d is less than 0.9 or exceeds 1.1). That is, the semiconductor module 1 and the power conversion device 51 according to the second embodiment can have high heat dissipation due to the ground electrode 11, and the positive electrode side capacitance 101, the chassis conductor 2, and the negative electrode of the semiconductor element 7. The capacitance formed therebetween can be more reliably balanced.

  The ground electrode 11 formed between the chassis conductor 2 and the capacitor element 100 and the ground electrode 11 formed between the chassis conductor 2 and the first insulator 10 may be formed integrally. It may be formed as a separate body. Preferably, the ground electrode 11 formed between the chassis conductor 2 and the capacitor element 100 and the ground electrode 11 formed between the chassis conductor 2 and the first insulator 10 are made of the same material. It is formed at the same time. In this way, the influence of the ground electrode 11 can be eliminated.

(Embodiment 3)
Next, a semiconductor module and a power conversion device according to the third embodiment will be described. Referring to FIG. 7, the semiconductor module 1 and the power conversion device according to the third embodiment basically have the same configuration as the semiconductor module and the power conversion device 51 according to the first embodiment. The capacitor element 110, the negative electrode side conductor connecting member 111 connected to both electrodes thereof, and the chassis conductor side connecting member 112 are different.

  In the capacitor element 110, the ratio of the capacitance value of the capacitor element 110 to the capacitance value of the positive electrode side capacitance 101 formed in the semiconductor module 1 is 0.9 or more and 1.1 or less. Is provided.

  The negative electrode side conductor connection member 111 is connected to the negative electrode side conductor 4 extending to the outside of the semiconductor module 1. The negative electrode side conductor connecting member 111 may be any material having conductivity, but may be copper, for example, and may be provided integrally with the negative electrode side conductor 4. The negative electrode side conductor connection member 111 is connected to one electrode of the capacitor element 110.

  The chassis conductor side connection member 112 is formed on the chassis conductor 2 exposed outside the semiconductor module 1. The material constituting the chassis conductor side connection member 112 may be any material having electrical conductivity, for example, copper. The chassis conductor side connection member 112 may be connected to the chassis conductor 2 by an arbitrary method, but is screwed, for example. The chassis conductor side connection member 112 is connected to the other electrode of the capacitor element 110.

  The shapes and dimensions of the negative electrode side conductor connecting member 111 and the chassis conductor side connecting member 112 can be appropriately selected according to the shape and dimensions of the capacitor element 110. The dimensions of capacitor element 110, negative electrode side conductor connecting member 111, and chassis conductor side connecting member 112 are preferably smaller.

  Even in this case, the ratio of the positive electrode side capacitance 101 to the capacitance value between the chassis conductor 2 and the negative electrode (negative electrode side conductor 4) of the semiconductor module 1 on the negative electrode side of the semiconductor module 1 is 0.9. A capacitor element 110 having a capacitance value of 1.1 or less can be formed. Moreover, such a power converter can also be reduced in size compared with the conventional power converter which forms the negative electrode which has an area equivalent to the positive electrode base electrode 8. As a result, the semiconductor module 1 and the power conversion device according to the third embodiment can achieve the same effects as the semiconductor module 1 and the power conversion device 51 according to the first embodiment.

  In the power conversion device according to the third embodiment, the semiconductor module 1 may be configured as a discrete semiconductor module. Referring to FIG. 8, a semiconductor module 1 includes, for example, a first discrete semiconductor component 126 as an upper arm semiconductor element formed on a chassis conductor 2 and a second discrete semiconductor component 127 as a lower arm semiconductor element. May be formed so as to constitute a semi-bridge circuit as described above. The first discrete semiconductor component 126 and the second discrete semiconductor component 127 include, for example, an insulator formed on the chassis conductor 2 inside the semiconductor module 1 according to the first embodiment described above, A positive electrode formed on an insulator, positive electrodes 123A and 123B connected to the positive electrode, a semiconductor element having a positive electrode bonded to the positive electrode, and a negative electrode of the semiconductor element Negative electrode side terminals 124A and 124B joined to each other, and a sealing body covering them. At this time, the positive electrode side capacitance 101 is formed between the chassis conductor 2 and the positive electrode on the first discrete semiconductor component 126 via an insulator.

  In this case, the first discrete semiconductor component 126 has a positive terminal 123A, a negative terminal 124A, and a gate terminal 125A that extend to the outside, and the second discrete semiconductor component 127 has a positive terminal 123B that extends to the outside, and a negative side. A terminal 124B and a gate terminal 125B are provided.

  The negative terminal 124 </ b> A of the first discrete semiconductor component 126 is connected to the intermediate terminal 128 formed on the chassis conductor 2. The positive terminal 123 </ b> B of the second discrete semiconductor component 127 is connected to the intermediate terminal 128 formed on the chassis conductor 2. That is, the first discrete semiconductor component 126 and the second discrete semiconductor component 127 are connected in series via the intermediate terminal 128.

  The intermediate terminal 128 may be a wiring pattern made of a material having high electrical conductivity, for example. In this case, the intermediate terminal 128 is electrically insulated from the chassis conductor 2 by, for example, an insulating layer of a printed board.

  At this time, the capacitor element 121 and the chassis conductor side connection member 122 may be formed between the negative electrode side terminal 124 </ b> B of the second discrete semiconductor component 127 and the chassis conductor 2. Specifically, one electrode of the capacitor element 121 is connected to the negative terminal 124 </ b> B, and the other electrode is connected to the chassis conductor side connecting member 122. The chassis conductor side connection member 112 is connected to the chassis conductor 2.

  The capacitance value of the capacitor element 121 is set such that the ratio of the positive electrode side capacitance 101 formed in the first discrete semiconductor component 126 to the capacitance value is 0.9 or more and 1.1 or less. It only has to be done. Even if it does in this way, there can exist an effect similar to the power converter device which concerns on Embodiment 3. FIG.

  In the power conversion device according to the third embodiment, the chassis conductor side connection members 112 and 122 are configured as members made of a conductive material. For example, the mounting patterns of the capacitor elements 111 and 121 are provided. It may be configured as a printed circuit board.

(Embodiment 4)
Next, a semiconductor module and a power conversion device according to the fourth embodiment will be described. Referring to FIG. 9 and FIG. 10, the semiconductor module and the power conversion device according to the fourth embodiment basically have the same configuration as the semiconductor module and the power conversion device according to the first embodiment. The difference is that the negative electrode base electrode 130 and the second insulator 131 are provided instead of the negative electrode base electrode 130.

  Specifically, on the chassis conductor 2, the second insulator 131 is formed in a region where the first insulator 10 is not formed and is opposed to the negative electrode side conductor 4. A negative electrode base electrode 130 is formed on the second insulator 131. The negative electrode side conductor 4 is connected to the negative electrode side base electrode 130. Thereby, the chassis conductor 2 and the negative electrode side conductor 4 are connected via the electrostatic capacitance which has an electrostatic capacitance value prescribed | regulated by the dielectric constant, area, thickness, etc. of the 2nd insulator 131. .

  The capacitance value of the capacitance including the second insulator 131 is provided such that the ratio of the positive electrode side capacitance 101 to the capacitance value is 0.9 or more and 1.1 or less. In other words, the first ratio of the area (S2) of the region where the second insulator 131 and the negative electrode base electrode 130 overlap to the area (S1) of the region where the first insulator 10 and the positive electrode base electrode 8 overlap. The thickness (d2) of the second insulator 131 with respect to (S2 / S1) and the value (d1 / ε1) obtained by dividing the thickness (d1) of the first insulator 10 by the dielectric constant (ε1) of the first insulator 10 Is divided by the dielectric constant (ε2) of the second insulator 131 and the second ratio ((ε1 · d2) / (ε2 · d1)) of the value (d2 / ε2) The ratio of the second ratio to (((ε1 · S1) / d1) / ((ε2 · S2) / d2)) is 0.9 or more and 1.1 or less.

  The material constituting the second insulator 131 can be any dielectric, but preferably has a higher dielectric constant than the material constituting the first insulator 10. Thereby, the area (S2) of the 2nd insulator 131 can be made small, maintaining the said ratio. For example, when the dielectric constant (ε2) of the material constituting the second insulator 131 is twice the dielectric constant (ε1) of the material constituting the first insulator 10, the area (S2) of the negative-side base electrode 130 Can be made half the area (S1) of the positive electrode base electrode 8.

  This makes it possible to reduce the size of the semiconductor module 1 compared to a conventional semiconductor module that is connected to the chassis conductor 2 through an insulator and has an electrode having the same area as the positive base electrode 8. it can.

  The material constituting the first insulator 10 and the second insulator 131 is a capacitance of the positive-side capacitance 101 between the chassis conductor 2 and the positive-side base electrode 8 in the operating temperature range of the power converter 51. It is preferable that the difference between the value and the capacitance value of the negative-side electrostatic capacitance between the chassis conductor 2 and the negative-side base electrode 130 is within ± 10%. Thereby, even if it is a case where the operating temperature of the power converter device 51 is fluctuate | varied, the power converter device 51 can continue exhibiting the radiation noise reduction effect.

  Referring to FIG. 11, in semiconductor module 1 according to the fourth embodiment, ground electrode 11 may be formed between chassis conductor 2 and first insulator 10 and second insulator 131. . In this case, the first insulator 10 is connected to the chassis conductor 2 via the ground electrode 11 similarly to the semiconductor module 1 according to the second embodiment described above. Further, the second insulator 131 is connected to the chassis conductor 2 via the ground electrode 11 in the same manner as the capacitor element 100 in the semiconductor module 1 according to the second embodiment described above. As a result, the same effects as those of the semiconductor module 1 and the power conversion device 51 according to the second embodiment can be obtained.

(Embodiment 5)
Next, a semiconductor module and a power conversion device according to the fifth embodiment will be described. Referring to FIGS. 12 to 14, the semiconductor module and the power conversion device according to the fifth embodiment basically have the same configuration as the semiconductor module and the power conversion device according to the first embodiment. The difference is that the conductor 5 is directly joined to the source electrode of the semiconductor element 6 and the drain electrode of the semiconductor element 7 and these are connected in series.

  That is, the semiconductor element 7 in the semiconductor module 1 according to the fifth embodiment has a configuration in which the front and back surfaces of the semiconductor element 7 in the semiconductor module 1 according to the first embodiment are reversed. In this case, the source electrode of the semiconductor element 7 is connected to the negative electrode base electrode 209 formed on the first insulator 10. The negative electrode side conductor 4 is connected to the negative electrode side base electrode 209.

  In this manner, in the conventional semiconductor module of the power conversion device, the negative arm base electrode is not newly provided in a region other than the region where the upper arm semiconductor element and the lower arm semiconductor element are disposed. A capacitance can be formed between the negative electrode of the semiconductor element 7 and the chassis conductor 2.

  Here, the first insulator 10 is formed of the same material and the same film thickness in a region where the positive electrode base electrode 8 and the negative electrode base electrode 209 face the chassis conductor 2. In this case, the capacitance value of the positive-side capacitance 201 formed between the chassis conductor 2 and the positive-side base electrode 8 is the area of the positive-side base electrode 8 in contact with the first insulator 10. The capacitance value of the negative electrode-side capacitance 202 formed between the chassis conductor 2 and the negative electrode-side base electrode 209 is in the region of the negative electrode-side base electrode 209 in contact with the first insulator 10. Depends on area. Therefore, the ratio of the capacitance value of the negative electrode side capacitance 202 to the capacitance value of the positive electrode side capacitance 201 can be easily set by controlling the area ratio of the positive electrode side base electrode 8 and the negative electrode side base electrode 209. It can be 0.9 or more and 1.1 or less.

  As described above, the semiconductor module and the power conversion device according to the fifth embodiment, like the semiconductor module and the power conversion device according to the first embodiment, sufficiently reduce radiation noise while having high heat dissipation. In addition, the semiconductor module and the power conversion device can be reduced in size more effectively.

  Referring to FIG. 15, in the semiconductor module 1 according to the fifth embodiment, the ground electrode 11 is provided between the chassis conductor 2 and the first insulator 10 as in the semiconductor module 1 according to the second embodiment. It may be formed. In this way, the ground electrode 11 can have high heat dissipation, and the positive electrode side capacitance 101 and the capacitance formed between the chassis conductor 2 and the negative electrode of the semiconductor element 7 can be further increased. Equilibrium can be ensured.

(Embodiment 6)
Next, a semiconductor module and a power conversion device according to the fifth embodiment will be described. Referring to FIGS. 16 to 18, the semiconductor module and the power conversion device according to the fifth embodiment basically have the same configuration as the semiconductor module and the power conversion device according to the first embodiment. The difference is that a multilayer capacitor element 300 is provided instead of 100.

  The multilayer capacitor element 300 has a configuration in which first electrodes 301 and second electrodes 302 are alternately stacked via interelectrode insulating films 303. In the multilayer capacitor element 300, for example, the first electrode 301 is connected to the negative-side conductor 4 and the second electrode 302 is connected to the chassis conductor 2, whereby the negative electrode of the chassis conductor 2 and the lower-arm semiconductor element 7 is connected. A predetermined capacitance can be formed between the two. At this time, the ratio of the capacitance value between the first electrode 301 and the second electrode 302 of the multilayer capacitor element 300 to the capacitance value of the positive electrode side capacitance 101 is 0.9 or more and 1.1 or less. Thus, the multilayer capacitor element 300 is provided.

  Thereby, the same effect as the semiconductor module and power converter concerning Embodiment 1 can be produced. Furthermore, by appropriately selecting characteristic values in the multilayer capacitor element 300 such as the area of the first electrode 301, the area of the second electrode 302, and the dielectric constant of the interelectrode insulating film 303, the effect can be more easily achieved. Can play.

  Further, since the second electrode 302 of the multilayer capacitor element 300 plays the role of the ground electrode 11 according to the first embodiment, it is necessary to newly provide a ground electrode at a connection portion between the multilayer capacitor element 300 and the chassis conductor 2. However, the ground electrode 11 may be formed between the first insulator 10 and the chassis conductor 2. In this way, the same effects as those of the second embodiment can be obtained.

  Each member constituting the semiconductor module 1 may be connected by an arbitrary method, but is connected using, for example, solder or an adhesive.

  In addition, although the power converter device which concerns on Embodiment 1-Embodiment 6 is comprised by connecting three semibridge circuits in parallel, it is not restricted to this. The number of parallel connections can be arbitrarily selected. Moreover, although the power converter device which concerns on Embodiment 1-Embodiment 6 is comprised as an inverter, it is not restricted to this, For example, the DCDC converter circuit which has a semi-bridge circuit, and the diode bridge-connected It may be configured as a rectifier circuit.

  Although the embodiment of the present invention has been described above, the above-described embodiment can be variously modified. The scope of the present invention is not limited to the above-described embodiment. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Semiconductor module, 2 Chassis conductor, 3 Positive side conductor, 4 Negative side conductor, 5 Middle side conductor, 6 1st semiconductor element, 7 2nd semiconductor element, 8 Positive side base electrode, 9 Middle side base electrode, 10 1st insulator, 11 Ground electrode, 12 Sealing body, 51 Power converter, 52 DC power supply, 53 Motor, 100, 100a, 100b, 100c, 100d, 110, 111, 121 Capacitor element, 101, 201 Positive side static Capacitance, 102 Intermediate capacitance, 111 Negative conductor connection member, 112, 122 Chassis conductor connection member, 123A, 123B Positive terminal, 124A, 124B Negative terminal, 125A, 125B Gate terminal, 126 First Discrete semiconductor component, 127 Second discrete semiconductor component, 128 Middle terminal, 1 30, 209 Negative electrode base electrode, 131 Second insulator, 202 Negative electrode capacitance, 300 Multilayer capacitor element, 301 First electrode, 302 Second electrode, 303 Interelectrode insulating film.

Claims (4)

A conductive member;
A first insulator formed on the conductive member;
A first electrode disposed on the first insulator;
A second electrode disposed on the first insulator spaced from the first electrode;
A first semiconductor element disposed on the first electrode and having a positive electrode and a negative electrode;
A second semiconductor element disposed on the second electrode and having a positive electrode and a negative electrode;
A positive electrode of the first semiconductor element is connected to the first electrode; a negative electrode of the first semiconductor element is connected to a positive electrode of the second semiconductor element;
The ratio of the capacitance value generated between the conductive member and the negative electrode of the second semiconductor element to the capacitance value generated between the conductive member and the positive electrode of the first semiconductor element is 0.9. Ri der 1.1 or less or more,
A positive electrode of the second semiconductor element is connected to the second electrode;
A negative electrode of the second semiconductor element is connected to the first conductor;
A semiconductor module , wherein the conductive member and the first conductor are connected via a capacitor element . In the operating temperature range in which the semiconductor module operates, the ratio of the capacitance of the capacitor element to the capacitance generated between the conductive member and the positive electrode of the first semiconductor element is 0.9 or more and 1.1. to be equal to or less than, the dielectric material forming the first insulator, said being selected from the dielectric material constituting the capacitor element, the semiconductor module according to claim 1. A conductor layer is provided between the conductive member and the first insulator,
It said conductor layer, on said conductive member, and the first electrode and the second electrode and the conductive member is formed to cover a region facing the semiconductor module according to claim 1 or 2. A power converter device provided with the semiconductor module of any one of Claims 1-3 .

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