JP2007324626A - Power module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power module that can reduce circuit inductance, can be miniaturized and made light, and also has vibration resistance. <P>SOLUTION: A box-like smoothing capacitor 20 for smoothing a DC supply voltage applied to a power semiconductor device 5 externally comes into contact with the side of a case frame 6 including a second side (namely, a side where an N terminal 8N and a P terminal 8P are arranged) on the upper surface of the case frame 6, and is arranged while the height of the upper surface of a smoothing capacitor 20 is aligned to the upper surface of the case frame 6. An N electrode 21N and a P electrode 21P of the smoothing capacitor 20 are arranged at locations close to the N terminal 8N and the P terminal 8P at a power module body 99 on the upper surface of the smoothing capacitor 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a structure of a power module, and more particularly to a structure of a power module including a smoothing capacitor for smoothing a DC power supply voltage applied to a power semiconductor element such as an IGBT from the outside.

  FIG. 28 is a top view schematically showing the structure of a conventional power module main body 100. Output terminals 111U, 111V, and 111W are arranged side by side along the first side of the upper surface of the case frame 106, and P along the second side of the upper surface of the case frame 106 parallel to the first side. A terminal 108P and an N terminal 108N are arranged side by side.

  FIG. 29 is a cross-sectional view showing a cross-sectional structure at a position along the line X100 shown in FIG. A resin case frame 106 is disposed on the metal base plate 101, and a resin case lid 116 is disposed on the case frame 106. On the base plate 101, a ceramic insulating substrate 102 is disposed by solder 103. A plurality of power semiconductor elements 105 such as IGBTs are disposed on the insulating substrate 102 by solder 104. A circuit element (not shown) such as a switching element is mounted on the upper surface of the insulating substrate 102, and a predetermined circuit pattern (not shown) is formed.

  In the case frame 106, a control board 114 on which a control circuit for controlling the power semiconductor element 105 is formed is disposed. The control board 114 is soldered to one end of the relay electrode 112. The other end of the relay electrode 112 is connected to the power semiconductor element 105 through an aluminum wire 109. A shield plate 113 for preventing noise is disposed between the control board 114 and the insulating board 102 in the case frame 106. The inside of the case frame 106 at a lower part than the shield plate 113 is filled with a silicone gel 115.

  An N terminal 108 </ b> N is disposed on the upper surface of the case frame 106. The N terminal 108N is connected to one end of the N electrode 107N. The other end of the N electrode 107N is connected to the power semiconductor element 105 through an aluminum wire 109. A P terminal 108P (not shown in FIG. 29) is disposed on the upper surface of the case frame 106. The P terminal 108P is connected to one end of the P electrode 107P. The other end of the P electrode 107P is connected to the power semiconductor element 105 through a circuit pattern formed on the aluminum wire 109 and the insulating substrate 102. An output terminal 111 </ b> V is disposed on the upper surface of the case frame 106. The output terminal 111 </ b> V is connected to one end of the output electrode 110. The other end of the output electrode 110 is connected to the power semiconductor element 105 through an aluminum wire 109.

  FIG. 30 is a cross-sectional view schematically showing the overall configuration of a conventional power module when viewed from the side. A smoothing capacitor 120 for smoothing a DC power supply voltage applied to the power semiconductor element 105 from the outside is disposed above the power module main body 100. N electrode 121N and P electrode 121P (reference numeral 121 in FIG. 30) of smoothing capacitor 120 and N terminal 108N and P terminal 108P (reference numeral 108 in FIG. 30) of power module main body 100 are connected to each other by a connecting conductor 124. ing. The connection conductor 124 includes conductor plates 122N and 122P that are opposed to each other with the insulating plate 123 interposed therebetween. The conductor plates 122N and 122P and the N terminal 108N and the P terminal 108P are fixed by screws 125, respectively.

  FIG. 31 is a cross-sectional view schematically showing the structure of the connection portion between the smoothing capacitor 120 and the connection conductor 124 when viewed from the upper surface side. The conductive plate 122N is in contact with the N electrode 121N, and the conductive plate 122P is in contact with the P electrode 121P. The conductive plate 122N is partially provided with an opening 126 in order to avoid contact with the P electrode 121P, and the conductive plate 122P has an opening 127 in order to avoid contact with the N electrode 121N. Partially provided.

  However, according to such a conventional power module, in order to connect the N electrode 121N and the P electrode 121P of the smoothing capacitor 120 and the N terminal 108N and the P terminal 108P of the power module main body 100, respectively, the conductor plates 122N, There is a problem that the connection conductor 124 including 122P and the insulating plate 123 is required, the number of parts is large, and the assembly is complicated.

  In addition, since the wiring path between the smoothing capacitor 120 and the power semiconductor element 105 is long, there is a problem that the inductance of the circuit increases. In the operation of the power module, when the power semiconductor element 105 is switched at a high speed, a large pulsed current proportional to the current change (di / dt) flows between the smoothing capacitor 120 and the power semiconductor element 105. A voltage proportional to the inductance of the circuit is generated and applied to the power semiconductor element 105 as noise. Further, when the inductance of the circuit is increased, it is necessary to increase the capacitance of the smoothing capacitor 120 in order to suppress the ripple voltage. As a result, the smoothing capacitor 120 is increased in size, and consequently the power module itself is increased in size. Therefore, it is desirable that the inductance of the circuit is small.

  Furthermore, since the conventional power module has a configuration in which a large smoothing capacitor 120 is disposed above the power module main body 100, the vibration resistance is low for use as, for example, an in-vehicle power module. There was also a problem.

  The present invention has been made to solve these problems, and it is possible to reduce the inductance of a circuit, to reduce the size and weight, and to obtain a power module excellent in vibration resistance. It is the purpose.

  According to a first aspect of the present invention, a power module includes: a substrate on which a power semiconductor element is mounted; a case in which the substrate is disposed; a cooling fin on which the substrate and the case are mounted; Smoothing for smoothing the voltage supplied to the power semiconductor element from the outside, which is disposed on the surface of the cooling fin opposite to the surface on which it is placed and is electrically connected to the power semiconductor element And a capacitor.

  A power module according to a second aspect of the invention is the power module according to the first aspect, wherein the smoothing capacitor is a ceramic capacitor.

  According to the first aspect of the present invention, since the smoothing capacitor can be effectively cooled by the cooling fins, the reliability of the power module can be improved.

  According to the second aspect of the present invention, the operation of the power module can be speeded up by employing a ceramic capacitor having excellent charge / discharge characteristics.

Embodiment 1 FIG.
FIG. 1 is a top view schematically showing the structure of the power module main body 99 according to Embodiment 1 of the present invention. Along the first side of the upper surface of the case frame 6, output terminals 11 U, 11 V, and 11 W corresponding to the three phases of the U phase, the V phase, and the W phase are arranged side by side. An N terminal 8N and a P terminal 8P are arranged side by side along the second side of the upper surface of the case frame 6 parallel to the first side.

  FIG. 2 is a cross-sectional view showing a cross-sectional structure at a position along line X1 shown in FIG. A resin case frame 6 is disposed on a metal base plate 1 that functions as a heat radiating plate, and a resin case lid 16 is disposed on the case frame 6. A ceramic insulating substrate 2 is disposed on the base plate 1 by solder 3. A plurality of power semiconductor elements 5 such as IGBTs are mounted on the insulating substrate 2 by solder 4. A circuit element (not shown) such as a switching element (IGBT) is mounted on the upper surface of the insulating substrate 2 and a predetermined circuit pattern (not shown) is formed.

  A control board 14 on which a control circuit for controlling the power semiconductor element 5 is formed is disposed in the case frame 6. The control board 14 is soldered to one end of the relay electrode 12. The other end of the relay electrode 12 is connected to the power semiconductor element 5 through an aluminum wire 9. In the case frame 6, a shield plate 13 for preventing noise is disposed between the control board 14 and the insulating board 2. The inside of the case frame 6 below the shield plate 13 is filled with a silicone gel 15.

  An N terminal 8N is disposed on the upper surface of the case frame 6. The N terminal 8N is connected to one end of an N electrode 7N embedded in the case frame 6. The other end of the N electrode 7N is connected to the power semiconductor element 5 through an aluminum wire 9. A P terminal 8P (not shown in FIG. 2) is disposed on the upper surface of the case frame 6. The P terminal 8P is connected to one end of a P electrode 7P embedded in the case frame 6. The other end of the P electrode 7P is connected to the power semiconductor element 5 through a circuit pattern formed on the aluminum wire 9 and the insulating substrate 2.

  An output terminal 11V is disposed on the upper surface of the case frame 6. The output terminal 11 </ b> V is connected to one end of the output electrode 10 embedded in the case 6. The other end of the output electrode 10 is connected to the power semiconductor element 5 through an aluminum wire 9. Although not appearing in FIG. 2, the output terminals 11U and 11W are also connected to the power semiconductor element 5 via the output electrode 10 and the aluminum wire 9, respectively, similarly to the output terminal 11V.

  FIG. 3 is a top view schematically showing the overall configuration of the power module according to the first embodiment, and FIG. 4 is an enlarged view of the connection portion between the power module main body 99 and the smoothing capacitor 20 shown in FIG. It is sectional drawing shown. The box-shaped smoothing capacitor 20 for smoothing the DC power supply voltage applied from the outside to the power semiconductor element 5 is the second side (that is, the side where the N terminal 8N and the P terminal 8P are arranged) on the upper surface of the case frame 6. ) In contact with the side surface of the case frame 6, and the upper surface of the smoothing capacitor 20 is arranged with the height of the upper surface of the case frame 6 aligned.

  Further, the N electrode 21N and the P electrode 21P of the smoothing capacitor 20 are disposed on the upper surface of the smoothing capacitor 20 at locations close to the N terminal 8N and the P terminal 8P of the power module main body 99, respectively. Referring to FIG. 4, N electrode 21 </ b> N and P electrode 21 </ b> P (denoted by reference numeral 21 in FIG. 4) are plate-like electrodes protruding from the upper surface of smoothing capacitor 20. The N electrode 21N and the P electrode 21P are bent toward the case frame 6 and overlapped with the N terminal 8N and the P terminal 8P (indicated by reference numeral 8 in FIG. 4), respectively. The terminal 8N, the P electrode 21P, and the P terminal 8P are fixed. As a result, the N electrode 21N and the P electrode 21P of the smoothing capacitor 20 and the N terminal 8N and the P terminal 8P of the power module main body 99 are directly connected without using any other connection body such as a connection cable. can do.

  Thus, according to the power module according to the first embodiment, the smoothing capacitor 20 is disposed in contact with the side surface of the case frame 6 and with the height of the upper surface of the case frame 6 aligned. The N electrode 21N and the P electrode 21P of the smoothing capacitor 20 are disposed at locations close to the N terminal 8N and the P terminal 8P of the power module main body 99, respectively. Therefore, the N electrode 21N and the P electrode 21P and the N terminal 8N and the P terminal 8P can be directly connected without using the conventional connection conductor 124. As a result, the number of parts can be reduced, the wiring path between the smoothing capacitor 20 and the power semiconductor element 5 can be shortened, and the inductance of the circuit can be reduced.

  Moreover, vibration resistance can also be improved by making the side surface of the smoothing capacitor 20 and the side surface of the power module main body 99 contact each other.

  In the above description, an example in which one smoothing capacitor 20 is provided has been described, but a plurality of smoothing capacitors may be provided. For example, three smoothing capacitors may be provided corresponding to the U phase, V phase, and W phase. 5 and 6 are top views schematically showing the configuration of the power module in which three smoothing capacitors 20a to 20c are arranged.

  In FIG. 5, each of the N electrodes 22Na to 22Nc of the smoothing capacitors 20a to 20c is a pad-like electrode, and is commonly connected to the N terminal 8N of the power module main body 99 by a connection conductor 23N. The connection conductor 23N is insulated from the P electrodes 22Pa to 22Pc. Each of the P electrodes 22Pa to 22Pc of the smoothing capacitors 20a to 20c is a pad-like electrode, and is commonly connected to the P terminal 8P of the power module main body 99 by the connection conductor 23P. The connection conductor 23P is insulated from the connection conductor 23N and the N electrodes 22Na to 22Nc.

  In FIG. 6, the N electrodes 21Na to 21Nc of the smoothing capacitors 20a to 20c are directly connected to the N terminals 8Na to 8Nc of the power module main body 99, respectively. Further, the P electrodes 21Pa to 21Pc of the smoothing capacitors 20a to 20c are directly connected to the P terminals 8Pa to 8Pc of the power module main body 99, respectively.

  According to the power modules shown in FIGS. 5 and 6, since the smoothing capacitors 20a to 20c are divided and arranged corresponding to each of the three phases, when any of the smoothing capacitors 20a to 20c fails. In addition, since only the defective smoothing capacitor has to be repaired or replaced, the cost can be reduced. Furthermore, according to the power module shown in FIG. 6, since the smoothing capacitors 20a to 20c can be arranged at the shortest and equal distances with respect to each of the three phases, the imbalance between the phases can be reduced and the inductance of the circuit can be reduced. Can be further reduced.

Embodiment 2. FIG.
FIG. 7 is a top view schematically showing the overall configuration of the power module according to Embodiment 2 of the present invention, and FIGS. 8 and 9 are cross sections taken along lines X2 and X3 shown in FIG. 7, respectively. It is sectional drawing which shows a structure. Referring to FIG. 7, a plurality of capacitor elements 30 a to 30 e are arranged side by side within a smoothing capacitor housing 32. Referring to FIG. 8, N electrodes 35 a to 35 e are provided on the bottom surfaces of capacitor elements 30 a to 30 e, respectively, and N electrodes 35 a to 35 e are in contact with plate-shaped N electrode 21 </ b> N in common. Part of the N electrode 21 </ b> N is pulled out to the upper surface of the housing 32, and is fixed to the N terminal 8 </ b> N of the power module main body 99 by screws 25.

  Referring to FIG. 9, capacitor elements 30a to 30e are provided with P electrodes 36a to 36e on their upper surfaces, respectively, and P electrodes 36a to 36e are in contact with plate-like P electrode 21P in common. A part of the P electrode 21 </ b> P is pulled out to the upper surface of the housing 32, and is fixed to the P terminal 8 </ b> P of the power module main body 99 by a screw 25.

  Similar to the smoothing capacitor 20 according to the first embodiment, the housing 32 is disposed in contact with the side surface of the case frame 6 and with the height of the upper surface of the case frame 6 aligned. An insulator 31 is provided between the side surface of the capacitor element 30a and the N electrode 21N, and the bottom surface of the housing 32 is constituted by a heat radiating plate 33 for radiating heat generated in the capacitor elements 30a to 30e to the outside. Has been. The capacitor elements 30a to 30e are pressed and fixed to the bottom surface of the housing 32 via the N electrode 21N by the pressing force of the pressing plate 34 screwed to the upper surface of the housing 32.

  As described above, according to the power module according to the second embodiment, in addition to the effects obtained by the power module according to the first embodiment, the following effects can be obtained. That is, in order to fix the plurality of capacitor elements 30a to 30e in the housing 32, it is only necessary to screw the pressing plate 34 to the upper surface of the housing 32, so that the mounting process of the plurality of capacitor elements is facilitated. .

  In addition, since the bottom surface of the housing 32 is constituted by a single heat radiating plate 33 for radiating the heat generated in the capacitor elements 30a to 30e to the outside, the cooling effect on each of the plurality of capacitor elements 30a to 30e is uniform. Can increase the sex.

  Note that at least one of the N electrodes 35a to 35e and the P electrodes 36a to 36e may be made elastic by using an elastic material as an electrode material. Thereby, it is possible to prevent damage to the capacitor elements 30a to 30e due to the pressing force by the pressing plate 34 and the thermal stress accompanying the heat generation of the capacitor elements 30a to 30e. Further, the N electrode 21N and the N electrodes 35a to 35e, and the P electrode 21P and the P electrodes 36a to 36e can be reliably brought into contact with each other.

  FIG. 10 is a top view schematically showing an overall configuration of a power module according to a modification of the second embodiment of the present invention. Three smoothing capacitors having the same configuration as the smoothing capacitors shown in FIGS. 7 to 9 are individually arranged corresponding to the three phases. 10, reference numerals 32a to 32c are housings, reference numerals 21Na to 21Nc are N electrodes, reference numerals 21Pa to 21Pc are P electrodes, reference numerals 8Na to 8Nc are N terminals, and reference numerals 8Pa to 8Pc are P terminals.

Embodiment 3 FIG.
FIG. 11 is a top view schematically showing the overall configuration of the power module according to Embodiment 3 of the present invention, and FIG. 12 is a cross-sectional view showing a cross-sectional structure at a position along line X4 shown in FIG. It is. The case frame 6 has a recess formed in a part of its outer surface. Of the two side surfaces of the recesses facing each other, an N terminal 8N is disposed on one side surface, and a P terminal 8P is disposed on the other side surface. As shown in FIG. 12, the N terminal 8 </ b> N and the P terminal 8 </ b> P are formed so as to extend to a part of the upper surface of the case frame 6 around the recess.

  The smoothing capacitor 40 has a shape that fits into the recess. The N electrode 43N is disposed on the side surface of the recess that faces the one side surface, and the P electrode 43P is disposed on the side surface of the recess that faces the other side surface. It is installed. The smoothing capacitor 40 is fitted in the recess, and the N electrode 43N and the N terminal 8N, and the P electrode 43P and the P terminal 8P are joined by the solder 41, and the smoothing capacitor 40 and the case frame 6 are fixed to each other. ing. On the smoothing capacitor 40, a lid 44 fixed on the upper surface of the case frame 6 is disposed.

  As described above, according to the power module according to the third embodiment, the recess is formed in the outer surface of the case frame 6, and the smoothing capacitor 40 is fitted into the recess and fixed by the solder 41. Therefore, the N electrode 43N and the N terminal 8N, and the P electrode 43P and the P terminal 8P can be directly connected without using the conventional connection conductor 124. As a result, the number of parts can be reduced, the wiring path between the smoothing capacitor 40 and the power semiconductor element 5 can be shortened, and the inductance of the circuit can be reduced.

  Further, since the smoothing capacitor 40 is disposed in the recess of the case frame 6, the power module can be reduced in size.

Embodiment 4 FIG.
FIG. 13 is a top view schematically showing the overall configuration of the power module according to Embodiment 4 of the present invention, and FIG. 14 shows the smoothing capacitor 40 and the elastic body 45 before being fixed to the case frame 6. It is sectional drawing. FIG. 15 is a cross-sectional view showing a cross-sectional structure at a position along the line X5 shown in FIG. In the power module according to the fourth embodiment, the N electrode 43N and the N terminal 8N and the P electrode 43P and the P terminal 8P are not joined by the solder 41 on the basis of the power module according to the third embodiment. A conductive elastic body 45 such as a leaf spring is disposed between the N electrode 43N and the N terminal 8N and between the P electrode 43P and the P terminal 8P. The smoothing capacitor 40 and the case frame 6 are fixed to each other by the repulsive force of the pressed elastic body 45. However, the elastic body 45 only needs to be disposed between at least one of the N electrode 43N and the N terminal 8N and between the P electrode 43P and the P terminal 8P.

  Thus, according to the power module according to the fourth embodiment, in addition to the effects obtained by the power module according to the third embodiment, the following effects can be obtained. That is, it is possible to prevent the smoothing capacitor 40 from being damaged due to the pressing force when the smoothing capacitor 40 is fitted in the recess and the thermal stress accompanying the heat generation of the smoothing capacitor 40. Further, the N electrode 43N and the N terminal 8N, and the P electrode 43P and the P terminal 8P can be reliably brought into contact with each other.

Embodiment 5 FIG.
FIG. 16 is a cross-sectional view showing a cross-sectional structure of a portion where an N terminal 54N is provided in the power module according to Embodiment 5 of the present invention. The smoothing capacitor 50 is attached on the back surface of the case lid 51 (the surface on the side facing the control board 14). The N terminal 54N is formed on the upper surface of the case frame 6 so as to extend from the outside of the case lid 51 to the inside. An N electrode 52N is formed on the upper surface of the smoothing capacitor 50 (the surface in contact with the back surface of the case lid 51). The N electrode 52N is connected via a connection electrode 53N formed on the back surface of the case lid 51. , N terminal 54N. The N terminal 54N is connected to the power semiconductor element 5 through the N electrode 7N and the aluminum wire 9.

  FIG. 17 is a cross-sectional view showing a cross-sectional structure of a portion where the P terminal 54P is provided in the power module according to Embodiment 5 of the present invention. The P terminal 54 </ b> P is formed on the upper surface of the case frame 6 so as to extend from the outside of the case lid 51 to the inside. A P electrode 52P is formed on the upper surface of the smoothing capacitor 50, and the P electrode 52P is connected to a P terminal 54P via a connection electrode 53P formed on the back surface of the case lid 51. The P terminal 54P is connected to the power semiconductor element 5 via a P electrode 7P, the aluminum wire 9, and a circuit pattern formed on the insulating substrate 2.

  As described above, according to the power module of the fifth embodiment, the smoothing capacitor 50 is disposed on the back surface of the case lid 51 in the case including the case frame 6 and the case lid 51. Therefore, the wiring path between the smoothing capacitor 50 and the power semiconductor element 5 can be shortened, and the inductance of the circuit can be reduced.

  Moreover, since the smoothing capacitor 50 is isolated from the external environment outside the case, it is possible to suppress the adhesion of dust to the smoothing capacitor 50 and the generation of rust caused by the external environment. That is, the environment resistance can be improved.

  Further, since the smoothing capacitor 50 is attached in contact with the case lid 51, heat generated in the smoothing capacitor 50 can be radiated to the outside through the case lid 51. 16 and 17 show the flat case lid 51, the heat dissipation can be further improved by making the outer shape of the case lid 51 into a fin shape.

Embodiment 6 FIG.
FIG. 18 is a cross-sectional view showing a cross-sectional structure of a portion where the N terminal 8N is provided in the power module according to Embodiment 6 of the present invention. A shield plate 56 is disposed between the control substrate 14 and the insulating substrate 2, and a stepped structure that contacts a part of the periphery of the shield plate 56 is provided on the inner surface of the case frame 6. A terminal 59N is formed on the upper surface of the stepped structure, and the terminal 59N is connected to the N electrode 7N1 through a connection electrode 7N2 embedded in the case frame 6. One end of the N electrode 7N1 is connected to the N terminal 8N, and the other end is connected to the power semiconductor element 5 through the aluminum wire 9.

  The smoothing capacitor 55 is attached on the back surface of the shield plate 56 (the surface on the side facing the insulating substrate 2). An N electrode 57N is formed on the upper surface of the smoothing capacitor 55 (the surface in contact with the back surface of the shield plate 56), and the N electrode 57N is connected via a connection electrode 58N formed on the back surface of the shield plate 56. Are connected to the terminal 59N.

  FIG. 19 is a cross-sectional view showing a cross-sectional structure of a portion where the P terminal 8P is provided in the power module according to Embodiment 6 of the present invention. A terminal 59P is formed on the upper surface of the stepped structure, and the terminal 59P is connected to the P electrode 7P1 via a connection electrode 7P2 embedded in the case frame 6. One end of the P electrode 7P1 is connected to the P terminal 8P, and the other end is connected to the power semiconductor element 5 via the aluminum wire 9 and a circuit pattern formed on the insulating substrate 2. A P electrode 57P is formed on the upper surface of the smoothing capacitor 55, and the P electrode 57P is connected to a terminal 59P via a connection electrode 58P formed on the back surface of the shield plate 56.

  As described above, according to the power module of the sixth embodiment, the smoothing capacitor 55 is disposed on the back surface of the shield plate 56 in the case made up of the case frame 6 and the case lid 16. Therefore, the wiring path between the smoothing capacitor 55 and the power semiconductor element 5 can be shortened and the inductance of the circuit can be further reduced as compared with the power module according to the fifth embodiment. Further, since the smoothing capacitor 55 is isolated from the external environment, it is possible to improve the environmental resistance.

Embodiment 7 FIG.
FIG. 20 is a cross-sectional view showing a cross-sectional structure of a portion where the N terminal 8N is provided in the power module according to Embodiment 7 of the present invention. The power module according to the seventh embodiment employs a shield plate 63 made of a printed circuit board as the shield plate 56 on the basis of the power module according to the sixth embodiment. The case frame 6 is provided with a stepped structure that contacts the periphery of the shield plate 63 along the inner surface thereof. The entire back surface of the shield plate 63 is covered with a heat conductive sheet 64, and the smoothing capacitor 60 is disposed on the heat conductive sheet 64 in the center of the shield plate 63.

  The N electrode 61N provided on the first side surface of the smoothing capacitor 60 is in contact with the N electrode 61N, is formed on the upper surface of the connection electrode 62N1 penetrating the shield plate 63, and the shield plate 63, and is in contact with the connection electrode 62N1. The conductor pattern 62N2 and the connection electrode 62N3 that contacts the conductor pattern 62N2 and penetrates the shield plate 63 are connected to the terminal 59N through this order.

  FIG. 21 is a cross-sectional view showing a cross-sectional structure of a portion where the P terminal 8P is provided in the power module according to Embodiment 7 of the present invention. The P electrode 61P provided on the second side surface of the smoothing capacitor 60 facing the first side surface is formed on the connection electrode 62P1 that contacts the P electrode 61P and penetrates the shield plate 63, and on the upper surface of the shield plate 63. The conductor pattern 62P2 in contact with the connection electrode 62P1 and the connection electrode 62P3 in contact with the conductor pattern 62P2 and penetrating the shield plate 63 are connected to the terminal 59P in this order.

  The other structure of the power module according to the seventh embodiment is the same as the structure of the power module according to the sixth embodiment shown in FIGS.

  As described above, according to the power module according to the seventh embodiment, similarly to the power module according to the sixth embodiment, it is possible to reduce the inductance of the circuit and improve the environmental resistance. Further, since the smoothing capacitor 60 is disposed on the back surface of the shield plate 63 via the heat conductive sheet 64, heat generated in the smoothing capacitor 60 can be effectively radiated to the outside via the heat conductive sheet 64 and the case frame 6. Also, the stress accompanying heat generation can be relaxed.

Embodiment 8 FIG.
FIG. 22 is a cross-sectional view showing a cross-sectional structure of a portion where N terminal 8N is provided in the power module according to Embodiment 8 of the present invention. The power module according to the eighth embodiment employs, in particular, a metal shield plate 65 as the shield plate 56 based on the power module according to the sixth embodiment. The N electrode 57N of the smoothing capacitor 55 and the terminal 59N provided on the upper surface of the stepped structure are connected to each other via a connection conductor 66N provided on the back surface of the shield plate 65 and covered with an insulating thin film. Yes.

  FIG. 23 is a cross-sectional view showing a cross-sectional structure of a portion where the P terminal 8P is provided in the power module according to Embodiment 8 of the present invention. The P electrode 57P of the smoothing capacitor 55 and the terminal 59P provided on the top surface of the stepped structure are connected to each other via a connection conductor 66P provided on the back surface of the shield plate 65 and covered with an insulating thin film. Yes.

  The other structure of the power module according to the eighth embodiment is the same as that of the power module according to the sixth embodiment shown in FIGS.

  Thus, according to the power module according to the eighth embodiment, similarly to the power module according to the sixth embodiment, it is possible to reduce the inductance of the circuit and improve the environmental resistance. Further, since the smoothing capacitor 55 is disposed on the back surface of the metal shield plate 65, heat generated in the smoothing capacitor 55 can be effectively radiated to the outside through the shield plate 65 and the case frame 6.

Embodiment 9 FIG.
FIG. 24 is a cross-sectional view showing a cross-sectional structure of a power module according to Embodiment 9 of the present invention. The smoothing capacitor 70 is arranged vertically on the upper surface of the insulating substrate 2 where the power semiconductor element 5 is not mounted. An N electrode 71N is formed on the upper surface of the smoothing capacitor 70. A connection electrode 72 is disposed so as to cover the N electrode 71N and not to contact the P electrode 71P. One end of the connection electrode 72 is connected to the N electrode 7 </ b> N via the aluminum wire 9, and the other end is connected to the power semiconductor element 5 via the aluminum wire 9.

  A P electrode 71P is formed on the bottom surface of the smoothing capacitor 70, and the P electrode 71P is connected to the power semiconductor element 5 through a circuit pattern formed on the insulating substrate 2. Further, the P electrode 71P is connected to the P electrode 7P through the circuit pattern and the aluminum wire 9 (in reality, it does not appear on the same cross section as the N electrode 7N, and is shown by a broken line in FIG. 24). It is connected.

  As described above, according to the power module according to the ninth embodiment, the smoothing capacitor 70 is disposed in the case made up of the case frame 6 and the case lid 16, and therefore the power according to the fifth to eighth embodiments. As with the module, environmental resistance can be improved.

  Since the smoothing capacitor 70 is disposed on the insulating substrate 2, the wiring path between the smoothing capacitor 70 and the power semiconductor element 5 can be remarkably shortened, and the inductance of the circuit can be greatly reduced.

  The smoothing capacitor 70 may be made of the same material as that of the insulating substrate 2. For example, when the insulating substrate 2 is made of ceramic, a ceramic capacitor is employed as the smoothing capacitor 70. Thereby, since the thermal expansion coefficients of the smoothing capacitor 70 and the insulating substrate 2 can be made equal to each other, various inconveniences due to differences in the thermal expansion coefficients can be avoided, and the reliability of the power module can be improved.

Embodiment 10 FIG.
FIG. 25 is a cross-sectional view showing a cross-sectional structure of the power module according to Embodiment 10 of the present invention. The smoothing capacitor 80 is disposed vertically on the upper surface of the base plate 1 where the insulating substrate 2 is not disposed. In particular, in the structure shown in FIG. 25, the smoothing capacitor 80 is disposed in a state of being embedded in the case frame 6. An N electrode 81N is formed on the upper surface of the smoothing capacitor 80. The N electrode 81N is in contact with and fixed to the N electrode 7N by a conductive adhesive, solder, or the like.

  Further, a P electrode 81P is formed on the bottom surface of the smoothing capacitor 80. The P electrode 81P is made of a P electrode 7P (actually on the same cross section as the N electrode 7N) by a conductive adhesive or solder. Since it does not appear, it is in contact with and fixed to (indicated by a broken line in FIG. 25). The P electrode 7P and the base plate 1 are insulated from each other.

  As described above, according to the power module according to the tenth embodiment, the environment resistance can be improved similarly to the power modules according to the fifth to ninth embodiments, and the smoothing capacitor 80 is made of a metal base. Since it is disposed on the plate 1, the heat generated in the smoothing capacitor 80 can be effectively radiated to the outside via the base plate 1.

  Further, the following effects can be obtained by adopting a configuration in which the N electrode 81N and the P electrode 81P of the smoothing capacitor 80 are in direct contact with and fixed to the N electrode 7N and the P electrode 7P, respectively. That is, compared with the case where both electrodes are connected via a connection electrode or the like, a member for connecting the electrodes is not necessary, and thus the weight and cost can be reduced. Further, compared with a configuration in which the connection electrodes connected to the N electrode 81N and the P electrode 81P of the smoothing capacitor 80 and the terminals connected to the N electrode 7N and the P electrode 7P, respectively, are fixed by screwing, the screwing portion The generation of contact resistance can be avoided and energy loss as a whole power module can be suppressed. At the same time, heat generation due to generation of contact resistance is suppressed, and the cooling mechanism can be downsized.

Embodiment 11 FIG.
FIG. 26 is a cross-sectional view showing a cross-sectional structure of a portion where N electrode 95N is provided in the power module according to Embodiment 11 of the present invention. The case frame 6 and the insulating substrate 2 are disposed horizontally on a water cooling fin 90 having a cooling water flow passage 91 therein. Smoothing capacitor 92 is disposed on the back surface of water-cooling fin 90 (the surface opposite to the surface on which insulating substrate 2 is disposed). An N electrode 95N penetrating from the inner side surface of the case frame 6 to the outer side surface is embedded in the case frame 6. The N electrode 93N formed on the side surface of the smoothing capacitor 92 is connected to the N electrode 95N via the connection conductor 94N. The connection conductor 94 </ b> N is formed on the bottom surface, side surface, and part of the outer surface of the case frame 6 of the water cooling fin 90.

  FIG. 27 is a cross-sectional view showing a cross-sectional structure of a portion where P electrode 95P is provided in the power module according to Embodiment 11 of the present invention. In the case frame 6, a P electrode 95P penetrating from the inner surface to the outer surface of the case frame 6 is embedded. The P electrode 93P formed on the side surface of the smoothing capacitor 92 is connected to the P electrode 95P through the connection conductor 94P. The connection conductor 94 </ b> P is formed on the bottom surface, side surface, and part of the outer surface of the case frame 6 of the water cooling fin 90.

  Thus, according to the power module according to the eleventh embodiment, the smoothing capacitor 92 is disposed on the back surface of the water-cooled fin 90. Therefore, the heat generated in the smoothing capacitor 92 can be effectively radiated by the water-cooled fins 90, and the reliability of the power module can be improved.

  In the first to eleventh embodiments, the operation of the power module can be speeded up by using a ceramic capacitor having excellent charge / discharge characteristics as a smoothing capacitor.

It is a top view which shows typically the structure of the power module main-body part which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the cross-section in the position along the line X1 shown in FIG. It is a top view which shows typically the whole structure of the power module which concerns on Embodiment 1 of this invention. It is sectional drawing which expands and shows the connection part of the power module main-body part shown in FIG. 3, and a smoothing capacitor. It is a top view which shows typically the structure of the power module by which three smoothing capacitors are arrange | positioned. It is a top view which shows typically the structure of the power module by which three smoothing capacitors are arrange | positioned. It is a top view which shows typically the whole structure of the power module which concerns on Embodiment 2 of this invention. It is sectional drawing which shows the cross-section in the position along the line X2 shown in FIG. It is sectional drawing which shows the cross-section in the position along the line X3 shown in FIG. It is a top view which shows typically the whole structure of the power module which concerns on the modification of Embodiment 2 of this invention. It is a top view which shows typically the whole structure of the power module which concerns on Embodiment 3 of this invention. It is sectional drawing which shows the cross-section in the position along line X4 shown in FIG. It is a top view which shows typically the whole structure of the power module which concerns on Embodiment 4 of this invention. It is sectional drawing which shows the smoothing capacitor and elastic body before being fixed to a case frame. It is sectional drawing which shows the cross-section in the position along line X5 shown in FIG. It is sectional drawing which shows the cross-section of the part by which N terminal is arrange | positioned regarding the power module which concerns on Embodiment 5 of this invention. It is sectional drawing which shows the cross-section of the part by which P terminal is arrange | positioned regarding the power module which concerns on Embodiment 5 of this invention. It is sectional drawing which shows the cross-section of the part by which N terminal is arrange | positioned regarding the power module which concerns on Embodiment 6 of this invention. It is sectional drawing which shows the cross-section of the part by which P terminal is arrange | positioned regarding the power module which concerns on Embodiment 6 of this invention. It is sectional drawing which shows the cross-section of the part by which N terminal is arrange | positioned regarding the power module which concerns on Embodiment 7 of this invention. It is sectional drawing which shows the cross-section of the part by which P terminal is arrange | positioned regarding the power module which concerns on Embodiment 7 of this invention. It is sectional drawing which shows the cross-section of the part by which N terminal is arrange | positioned regarding the power module which concerns on Embodiment 8 of this invention. It is sectional drawing which shows the cross-section of the part by which P terminal is arrange | positioned regarding the power module which concerns on Embodiment 8 of this invention. It is sectional drawing which shows the cross-section of the power module which concerns on Embodiment 9 of this invention. It is sectional drawing which shows the cross-section of the power module which concerns on Embodiment 10 of this invention. It is sectional drawing which shows the cross-section of the part by which N electrode is arrange | positioned regarding the power module which concerns on Embodiment 11 of this invention. It is sectional drawing which shows the cross-section of the part by which P electrode is arrange | positioned regarding the power module which concerns on Embodiment 11 of this invention. It is a top view which shows typically the structure of the conventional power module main-body part. It is sectional drawing which shows the cross-section in the position along line X100 shown in FIG. It is sectional drawing which shows typically the whole structure of the conventional power module at the time of seeing from the side surface side. It is sectional drawing which shows typically the structure of the connection part of a smoothing capacitor and a connection conductor at the time of seeing from the upper surface side.

Explanation of symbols

  1 base plate, 2 insulating substrate, 5 power semiconductor element, 6 case frame, 8N N terminal, 8PP terminal, 14 control board, 20, 40, 50, 55, 60, 70, 80, 92 smoothing capacitor, 21N, 35a -35e, 43N N electrode, 21P, 36a-36e, 43P P electrode, 30a-30e Capacitor element, 32 Housing, 33 Heat sink, 34 Holding plate, 45 Elastic body, 51 Case lid, 56, 65 Shield plate, 64 Thermal conductive sheet, 90 water-cooled fins.

Claims (2)

A substrate on which a power semiconductor element is mounted;
A case in which the substrate is disposed;
A cooling fin on which the substrate and the case are placed;
A voltage, which is disposed on the surface of the cooling fin opposite to the surface on which the substrate is placed, is electrically connected to the power semiconductor element, and is supplied to the power semiconductor element from the outside. A power module comprising a smoothing capacitor for smoothing.   The power module according to claim 1, wherein the smoothing capacitor is a ceramic capacitor.

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