JP4831702B2 - Power semiconductor device - Google Patents

Description

  The present invention relates to a power semiconductor device, and more particularly to a power semiconductor device having a power semiconductor element.

  2. Description of the Related Art Power semiconductor devices that can generate a pulse current having a desired frequency are widely used for applications such as motor speed control. This power semiconductor device has power semiconductor elements such as an IGBT (Insulated Gate Bipolar Transistor) and a power MOSFET (Metal Oxide Silicon Field Effect Transistor). These power semiconductor elements are semiconductor switching elements capable of turning on / off current.

  When these semiconductor switching elements are short-circuited due to a failure, a continuous current is generated instead of a pulse current, so that the device receiving the current from the power semiconductor device may be destroyed by an excessive current. . In this case, since the current value itself is the same as the pulse current at the time of normal operation and the continuous current at the time of failure, it is difficult to protect with a fuse having the current value as a threshold, and other types of protection elements are required.

For example, according to Japanese Patent Laid-Open No. 10-261353 (Patent Document 1), the protective element has a configuration in which a low melting point soluble alloy piece and a resistor are provided on an insulating substrate. The low-melting-point soluble alloy piece (low-melting-point metal part) is melted by heat generated by energizing this resistor. As a result, the protected device is disconnected from the power source.
Japanese Patent Laid-Open No. 10-261353

  However, the technique disclosed in the above publication has a problem in that when the low melting point metal part is melted, an arc is generated and the current is not cut off.

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a power semiconductor device in which current is more reliably interrupted when a power semiconductor element fails by preventing the occurrence of an arc when a low melting point metal part is melted. It is.

The power semiconductor device of the present invention includes a power semiconductor element, a first electric wiring, a second electric wiring, a low melting point metal part, a heater, and at least one high resistance part. The first electric wire has a first end which is electrically connected to a power semiconductor device, comprising the first metal. The second electrical wiring has a second end facing the first end with a gap, and is made of a second metal that is either the same metal as the first metal or a metal different from the first metal. The low melting point metal portion is made of a metal having a melting point lower than that of each of the first metal and the second metal, and electrically connects the first end portion and the second end portion to each other. The heater is capable of heating at least a part of the low melting point metal part to a temperature equal to or higher than the melting point of the low melting point metal part. The at least one high resistance portion is provided between the first end portion and the second end portion, and is made of a material having a resistivity higher than the resistivity of each of the first metal and the second metal. At least one high resistance part consists of an insulator. The at least one high resistance part is provided on the tip of at least one of the first end and the second end.

  According to the power semiconductor device of the present invention, since the high resistance portion having a high resistivity is provided between the first end portion and the second end portion, the first end portion and the second end portion By suppressing the occurrence of arcs between the currents, the current is more reliably interrupted.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a perspective view schematically showing a configuration of a power semiconductor device according to the first embodiment of the present invention. FIG. 2 is a front view schematically showing a configuration of a connection element included in the power semiconductor device according to the first embodiment of the present invention. 3 and 4 are schematic sectional views taken along lines III-III and IV-IV in FIG. 2, respectively. FIG. 5 is a schematic cross-sectional view taken along line VV in FIGS. 3 and 4. FIG. 6 is a schematic cross-sectional view taken along lines VI-VI in FIGS. 4 and 5.

  1 and 2, power semiconductor device SD of the present embodiment includes power semiconductor element SE, bus bar Wb0, connection element CE, power supply PS, and power supply control switch SW. ing.

  The power semiconductor element SE is, for example, a transfer mold type power module having an IGBT. The power semiconductor element SE includes a bus bar Wb0, a first bus bar Wb1, and a failure signal terminal MT. The bus bar Wb0 and the first bus bar Wb1 have a function as an N terminal and a P terminal, which are a pair of main terminals of the power semiconductor element SE, for example. The failure signal terminal MT is a terminal that outputs a failure signal when the power semiconductor element SE fails.

  The power supply control switch SW is normally in an off state and has a function of being turned on when receiving a failure signal from the failure signal terminal MT. The power supply PS is connected to the connection element CE together with the power supply control switch SW. With this configuration, it is possible to apply a voltage generated by the power source PS to the connection element CE when the power semiconductor element SE fails.

  Referring mainly to FIG. 3 to FIG. 6, the connection element CE includes a second bus bar Wb2 (second electrical wiring), a low melting point metal part LM, a heater HT, a first high resistance part Rb1, and a second It has a high resistance portion Rb2, a housing CS, a first support column CL1, and a second support column CL2. The connection element CE shares the first bus bar Wb1 (first electrical wiring) with the power semiconductor element SE (FIG. 1). Therefore, the entire first bus bar Wb1 is electrically connected to the power semiconductor element SE.

  The first bus bar Wb1 is made of a highly conductive metal (first metal). The second bus bar Wb2 is a second end Eb2 (the left end in each of FIGS. 3 to 5) facing the first end Eb1 (the right end in each of FIGS. 3 to 5) of the first bus bar Wb1 with a space therebetween. Part). The second bus bar Wb2 is made of a highly conductive metal (second metal) that is the same as or different from the first metal.

  The low melting point metal part LM electrically connects the first end Eb1 and the second end Eb2 to each other. The low melting point metal portion LM is made of a metal material having a melting point lower than the melting points of the first metal and the second metal. Specifically, this material is a material containing tin (Sn), and preferably a solder material.

  The heater HT is embedded in the low melting point metal portion LM and wired so that a voltage generated by the power source PS can be applied between both ends of the heater HT when the power control switch SW is in an ON state. Yes. With this configuration, the heater HT can heat at least a part of the low melting point metal part LM to a temperature higher than the melting point of the low melting point metal part LM.

  Each of the first high resistance portion Rb1 and the second high resistance portion Rb2 covers the tips of the first end portion Eb1 and the second end portion Eb2. That is, each of the first high resistance portion Rb1 and the second high resistance portion Rb2 is provided between the first end portion Eb1 and the second end portion Eb2. Each of the first high resistance portion Rb1 and the second high resistance portion Rb2 is made of an insulator. Therefore, each of the first high resistance portion Rb1 and the second high resistance portion Rb2 is made of a material having a resistivity higher than the resistivity of each of the first metal and the second metal.

  Each of the first column CL1 and the second column CL2 supports the first bus bar Wb1 and the second bus bar Wb2. The casing CS includes a first end Eb1, a second end Eb2, a first high resistance portion Rb1, a second high resistance portion Rb2, a low melting point metal portion LM, a heater HT, a first support column CL1, and a second support column CL2. Is provided to protect.

  FIG. 7 is a perspective view schematically showing a process of attaching the high resistance portion in the method for manufacturing the power semiconductor device according to the first embodiment of the present invention. Referring to FIG. 7, a second high resistance portion Rb2 having a recess formed on the side surface is prepared. The second high resistance portion Rb2 is formed, for example, by pouring a melt of an insulator into a mold and then curing the melt. Next, the tip of the second end Eb2 is inserted into the recess and fixed with an epoxy adhesive or the like. The process of attaching the first high resistance portion Rb1 to the tip of the first end Eb1 (not shown in FIG. 7) is the same.

Next, a method for using the power semiconductor device SD of the present embodiment will be described.
Referring to FIG. 1, a load (not shown), which is a device that receives a current supply, is attached between bus bar Wb0 and second bus bar Wb2, thereby supplying a pulse current from power semiconductor element SE. Is called. When a continuous abnormal current is output from the power semiconductor element SE due to a failure, the power semiconductor device SD starts a cutoff operation. That is, a failure signal is output from the failure signal terminal MT. The power supply control switch SW is turned on by this failure signal.

  Referring to FIG. 5, the heater HT generates heat when a voltage generated by the power source PS is applied to the heater HT. When the low melting point metal part LM is heated to a temperature equal to or higher than the melting point, the low melting point metal part LM around the first end Eb1 and the second end Eb2 melts down. As a result, the first bus bar Wb1 and the second bus bar Wb2 are electrically separated. As a result, a device (not shown) that has been supplied with current from the second bus bar Wb2 is protected from abnormal current.

  Next, the function and effect of this embodiment will be described. FIG. 8 is a cross-sectional view showing a state when the low melting point metal portion of the power semiconductor device according to the first embodiment of the present invention is melted. 8 is the same as the cross-sectional position in FIG.

  Referring to FIGS. 3 and 8, as low melting point metal portion LM (FIG. 3) melts, first bus bar Wb1 and second bus bar Wb2 are electrically separated as shown in FIG. At this time, in order to generate an arc between the first bus bar Wb1 and the second bus bar Wb2, as shown by the broken line arrows in the drawing, the arc is formed of the first high resistance portion Rb1 and the second high resistance portion made of an insulator. It is necessary to extend to bypass Rb2. That is, it is necessary to generate an arc having a long arc length. However, as the arc length increases, the electric field strength along the arc length decreases. As a result, arcing is less likely to occur. Therefore, in the present embodiment, the occurrence of arc during the interruption operation is suppressed, so that the interruption of current is performed more reliably.

  Next, a comparative example of the present embodiment will be described. FIG. 9 is a cross-sectional view showing a state when the low melting point metal portion of the power semiconductor device in the comparative example of the first embodiment of the present invention is melted.

  Referring mainly to FIG. 9, in this comparative example, the first high resistance portion Rb1 and the second high resistance portion Rb2 (FIG. 8) are not provided. Therefore, when the low melting point metal part LM melts down, there is nothing that prevents the arc from being generated in the region where the first bus bar Wb1 and the second bus bar Wb2 face each other at the facing distance Lb. For this reason, an arc Ab having an arc length Lb is likely to be generated. When the arc Ab is generated, the first bus bar Wb1 and the second bus bar Wb2 are electrically connected by the arc. Therefore, since a current is continuously output from the second bus bar Wb2, a device (not shown) that receives the current cannot be protected.

  In the present embodiment, the first high resistance portion Rb1 and the second high resistance portion Rb2 are provided on the respective leading ends of the first end portion Eb1 and the second end portion Eb2. However, the present invention is not limited thereto. The present invention is not limited, and the above effect can be obtained to some extent also by the configuration in which one of the first high resistance portion Rb1 and the second high resistance portion Rb2 is provided.

(Embodiment 2)
FIG. 10 is a cross sectional view schematically showing a configuration of a connection element included in the power semiconductor device according to the second embodiment of the present invention. Referring to FIG. 10, the connecting element of the present embodiment is replaced with each of first bus bar Wb1, second bus bar Wb2, first high resistance portion Rb1, and second high resistance portion Rb2 in the first embodiment. , First electric wire Wc1, second electric wire Wc2, first high resistance portion Rc1, and second high resistance portion Rc2. In addition, each of the 1st electric wire Wc1 and the 2nd electric wire Wc2 is coat | covered with the coating | coated CV except for the edge part.

  The first electric wire Wc1 is made of a highly conductive metal (first metal). The second electric wire Wc2 has an end facing the end of the first electric wire Wc1 with a gap. The second electric wire Wc2 is made of a highly conductive metal (second metal) that is the same as or different from the first metal. The low melting point metal portion LM is made of a metal having a melting point lower than the melting points of the first metal and the second metal, and electrically connects the two end portions to each other.

  Each of the first high resistance portion Rc1 and the second high resistance portion Rc2 covers the tips of the end portions of the first electric wire Wc1 and the second electric wire Wc2. Therefore, each of the first high resistance portion Rc1 and the second high resistance portion Rc2 is provided between the two end portions. Each of the first high resistance portion Rc1 and the second high resistance portion Rc2 is made of an insulator. Therefore, each of the first high resistance portion Rc1 and the second high resistance portion Rc2 is made of a material having a resistivity higher than the resistivity of each of the first metal and the second metal.

  11 and 12 are schematic front views showing a method of attaching the high resistance portion in the manufacturing method of the power semiconductor device according to the second embodiment of the present invention in the order of steps.

  Referring to FIG. 11, a second high resistance portion Rc2 in which a female screw FS-shaped concave portion is formed and a second electric wire Wc2 having an end portion Ec2 in which an external surface of a male screw MS shape is formed are prepared. Next, as shown by the arrows in the figure, the female screw FS and the male screw MS are combined.

  Referring to FIG. 12, the second high resistance portion Rc2 that covers a part of the end portion Ec2 is attached on the tip of the end portion Ec2 of the second electric wire Wc2. In addition, the 1st high resistance part Rc1 which covers a part of this edge part is formed on the front-end | tip of the edge part of the 1st electric wire Wc1 by the same process.

  Since the configuration other than the above is substantially the same as the configuration of the first embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

  According to the present embodiment, the same effect as in the first embodiment can be obtained in the configuration in which the electric wire is used instead of the bus bar. In the present embodiment, the first high resistance portion Rc1 and the second high resistance portion Rc2 are provided on the respective tips of the first electric wire Wc1 and the second electric wire Wc2, but the present invention is not limited to this. The above effect can be obtained to some extent even by a configuration in which one of the first high resistance portion Rc1 and the second high resistance portion Rc2 is provided.

(Embodiment 3)
FIG. 13: is a front view which shows roughly the structure of the high resistance part which the power semiconductor device in Embodiment 3 of this invention has, an electric wire, and a coating | cover. FIG. 14 is a perspective view schematically showing a configuration of a high resistance portion included in the power semiconductor device according to the third embodiment of the present invention.

  Referring mainly to FIGS. 13 and 14, in the present embodiment, second high resistance portion Rc2t is provided instead of second high resistance portion Rc2 in the second embodiment. The second high resistance portion Rc2t has a shape in which a female screw is provided on the bottom surface of the truncated cone. Although not shown, a first high resistance portion (not shown) having the same shape as the second high resistance portion Rc2t is provided instead of the first high resistance portion Rc1 in the second embodiment.

  Since the configuration other than the above is substantially the same as the configuration of the second embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof will not be repeated.

  The side surfaces of the first high resistance portion (not shown) and the second high resistance portion Rc2t in the present embodiment are the side surfaces of the first high resistance portion Rc1 and the second high resistance portion Rc2 in the second embodiment (see FIG. Unlike 12), each end portion of the first electric wire Wc1 and the second electric wire Wc2 has a surface SL inclined with respect to the facing direction. Therefore, since the length of the arc length formed along each side surface of the first high resistance portion and the second high resistance portion Rc2t is increased, the generation of the arc is more effectively performed as compared with the second embodiment. Can be suppressed.

  In the present embodiment, each of the first high resistance portion (not shown) and the second high resistance portion Rc2t has a truncated cone shape, but the present invention is not limited to this. Absent. If at least one of the side surfaces of the first high resistance portion and the second high resistance portion Rc2t has a surface that is inclined with respect to the direction in which the respective ends of the first electric wire Wc1 and the second electric wire Wc2 are opposed to each other, The effect of can be obtained.

(Embodiment 4)
FIG. 15 and FIG. 16 are a plan view and a bottom view, respectively, schematically showing a configuration of a connection element included in the power semiconductor device according to the fourth embodiment of the present invention. FIG. 17 is a schematic sectional view taken along line XVII-XVII in each of FIGS. 15 and 16.

  Referring mainly to FIGS. 15 to 17, the connection element of the present embodiment includes an insulating substrate SB, a first wiring pattern Wp1 (first electric wiring), and a second wiring pattern Wp2 (second electric wiring). And a low melting point metal part LM, a heater HT, a first high resistance part Rp1, and a second high resistance part Rp2.

  The first wiring pattern Wp1 is shared by the connection element and the power semiconductor element SE (FIG. 1). Therefore, the entire first wiring pattern Wp1 is electrically connected to the power semiconductor element SE (FIG. 1). The first wiring pattern Wp1 is made of a highly conductive metal (first metal). The second wiring pattern Wp2 has a second end portion Ep2 that faces the first end portion Ep1 with a space therebetween. The second wiring pattern Wp2 is made of a highly conductive metal (second metal) that is the same as or different from the first metal. The low melting point metal part LM is made of a metal having a melting point lower than that of each of the first metal and the second metal, and electrically connects the first end part Ep1 and the second end part Ep2.

  Each of the first high resistance portion Rp1 and the second high resistance portion Rp2 covers the tips of the first end portion Ep1 and the second end portion Ep2. Therefore, each of the first high resistance portion Rp1 and the second high resistance portion Rp2 is provided between the first end portion Ep1 and the second end portion Ep2. Each of the first high resistance part Rp1 and the second high resistance part Rp2 is made of an insulator. Therefore, each of the first high resistance portion Rp1 and the second high resistance portion Rp2 is made of a material having a resistivity higher than the resistivity of each of the first metal and the second metal.

  The insulating substrate SB fixes each of the first end portion Ep1 and the second end portion Ep2. The insulating substrate SB is positioned below the low melting point metal part LM and has a hole HL. The hole HL preferably faces at least a part of the low melting point metal part LM.

  Since the configuration other than the above is substantially the same as the configuration of the first embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

Next, a method for using the power semiconductor device of this embodiment will be described.
Referring to FIG. 17, as in the first embodiment, when a continuous abnormal current is output from power semiconductor element SE due to a failure of power semiconductor element SE, a failure signal is output from failure signal terminal MT. Is output. The power supply control switch SW is turned on by this failure signal. When the voltage generated by the power source PS is applied to the heater HT, the heater HT generates heat. When the low melting point metal part LM is heated to a temperature equal to or higher than the melting point, the low melting point metal part LM around the first end Ep1 and the second end Ep2 melts through the hole HL. Thus, the first wiring pattern Wp1 and the second wiring pattern Wp2 are electrically separated. As a result, a device (not shown) that receives a current supply is protected from an abnormal current.

  Next, the function and effect of this embodiment will be described. FIG. 18 is a cross-sectional view showing a state when the low melting point metal portion of the power semiconductor device according to the fourth embodiment of the present invention is melted. The cross-sectional position in FIG. 18 is the same as the cross-sectional position in FIG.

  Referring to FIGS. 17 and 18, when low melting point metal portion LM (FIG. 17) melts through hole HL, first wiring pattern Wp1 and second wiring pattern Wp2 are formed as shown in FIG. Electrically separated. At this time, in order to generate an arc between the first wiring pattern Wp1 and the second wiring pattern Wp2, as shown by a broken line arrow in the figure, the arc is composed of the first high resistance portion Rp1 and the second high resistance made of an insulator. It is necessary to extend so as to bypass the resistance portion Rp2. That is, it is necessary to generate an arc having a long arc length. However, as the arc length increases, the electric field strength along the arc length decreases. As a result, arcing is less likely to occur. Therefore, in the present embodiment, the occurrence of arc during the interruption operation is suppressed, so that the interruption of current is performed more reliably.

  Next, a comparative example of the present embodiment will be described. FIG. 19 is a cross-sectional view showing a state when the low melting point metal portion of the power semiconductor device in the comparative example of the fourth embodiment of the present invention is melted.

  Referring mainly to FIG. 19, in this comparative example, the first high resistance portion Rp1 and the second high resistance portion Rp2 (FIG. 18) are not provided. Therefore, when the low melting point metal portion LM (not shown in FIG. 19) melts, there is nothing that prevents the arc from being generated in the region where the first wiring pattern Wp1 and the second wiring pattern Wp2 face each other. As a result, arcing is likely to occur as indicated by solid arrows in the figure. When the first wiring pattern Wp1 and the second wiring pattern Wp2 are electrically connected by this arc, a current is continuously output from the second wiring pattern Wp2, and thus a device that receives supply of current from the second wiring pattern Wp2 ( An abnormal current continues to be supplied to (not shown). That is, it is not possible to protect a device that receives a current supply.

  In the present embodiment, the first high resistance portion Rp1 and the second high resistance portion Rp2 are provided on the tips of the respective end portions of the first wiring pattern Wp1 and the second wiring pattern Wp2. The present invention is not limited to this, and even if there is a gap between the respective leading ends of the first wiring pattern Wp1 and the second wiring pattern Wp2 and the first high resistance portion Rp1 and the second high resistance portion Rp2. Good.

  In addition, the first high resistance portion Rp1 and the second high resistance portion Rp2 are provided on the respective tips of the first end portion Ep1 and the second end portion Ep2, but the present invention is not limited to this, The above effect can be obtained to some extent also by the configuration in which one of the first high resistance portion Rp1 and the second high resistance portion Rp2 is provided.

(Embodiment 5)
FIG. 20 is a plan view schematically showing a configuration of a connection element included in the power semiconductor device according to the fifth embodiment of the present invention. Referring to FIG. 20, in the present embodiment, instead of first high resistance part Rp1 and second high resistance part Rp2 in the fourth embodiment, first high resistance part Rp1t and second high resistance part Rp2t is provided. Each of the first high resistance portion Rp1t and the second high resistance portion Rp2t has a trapezoidal pattern.

  Since the configuration other than the above is substantially the same as the configuration of the fourth embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

  Each of the first high resistance part Rp1t and the second high resistance part Rp2t in the present embodiment is different from the first high resistance part Rp1 and the second high resistance part Rp2 (FIG. 15) in the fourth embodiment in the first end. The portion Ep1 and the second end portion Ep2 have side surfaces that are inclined with respect to the facing direction. Therefore, since the length of the arc length formed along each side surface of the first high resistance portion Rp1t and the second high resistance portion Rp2t is increased, the generation of the arc is more effectively generated as compared with the fourth embodiment. Can be suppressed.

  In the present embodiment, each of the first high resistance portion Rp1t and the second high resistance portion Rp2t has a trapezoidal pattern, but the present invention is not limited to this. At least one of the side surfaces of the first high resistance portion Rp1t and the second high resistance portion Rp2t has a surface that is inclined with respect to the direction in which the ends of the first wiring pattern Wp1 and the second wiring pattern Wp2 face each other. The above effects can be obtained.

(Embodiment 6)
FIG. 21 is a bottom view schematically showing a configuration of a connection element included in the power semiconductor device according to the sixth embodiment of the present invention. 22 is a schematic sectional view taken along line XXII-XXII in FIG.

  Referring mainly to FIGS. 21 and 22, the connecting element of the present embodiment has a configuration in which the connecting element of the fourth embodiment is provided upside down. Therefore, the insulating substrate SB is located above the low melting point metal part LM. However, unlike the fourth embodiment, in the present embodiment, the insulating substrate SB does not have the hole HL (FIGS. 15 to 17).

  Since the configuration other than the above is substantially the same as the configuration of the fourth embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

  According to the present embodiment, since the insulating substrate SB is located above the low melting point metal part LM as shown in FIG. 22, even if the hole HL (FIG. 17) is not provided in the insulating substrate SB. The insulating substrate SB does not prevent the low melting point metal part LM from falling. Therefore, the same effect as in the fourth embodiment can be obtained without forming the hole HL in the insulating substrate SB.

(Embodiment 7)
Each of FIG. 23 and FIG. 24 is a cross sectional view schematically showing a configuration of a connection element included in the power semiconductor device according to the seventh embodiment of the present invention. Note that the cross-sectional positions in FIGS. 23 and 24 correspond to the cross-sectional positions in FIGS. 3 and 4.

  Referring mainly to FIG. 23 and FIG. 24, the power semiconductor device according to the present embodiment replaces first high resistance portion Rb1 and second high resistance portion Rb2 (FIGS. 3 and 4) according to the first embodiment. And a high resistance portion Rb. The high resistance portion Rb is made of an insulator, is provided between the first end portion Eb1 and the second end portion Eb2, and has a first end along the direction in which the first end portion Eb1 and the second end portion Eb2 face each other. The part Eb1 and the second end part Eb2 are connected.

  Next, the configuration near the high resistance portion Rb will be further described. FIG. 25 is a perspective view schematically showing a state where each of the first and second bus bars is attached to the high resistance portion of the power semiconductor device according to the seventh embodiment of the present invention. FIG. 26 is a front view schematically showing a configuration of a high resistance portion included in the power semiconductor device according to the seventh embodiment of the present invention.

  Referring to FIGS. 25 and 26, high resistance portion Rb has a pair of recesses Hb facing each other. The tip end of the first bus bar Wb1 and the tip end of the second bus bar Wb2 are inserted into each of the pair of recesses Hb.

  Since the configuration other than the above is substantially the same as the configuration of the first embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

  Next, a method for forming the high resistance portion Rb will be described. FIG. 27 is a perspective view schematically showing one step of the method for forming the high resistance portion included in the power semiconductor device according to the seventh embodiment of the present invention.

  Referring to FIG. 27, the melted material of the insulator is poured into a mold, and then the melted material is cured to form a part Rbh. The component Rbh has one main surface (the upper surface in FIG. 27). A pair of recesses Db is formed at the edge of the one main surface. The depth of the recess Db is about half of the thickness of each of the first bus bar Wb1 and the second bus bar Wb2, and is shallower than the depth of the recess Hb.

  Referring to FIGS. 26 and 27, a pair of components Rbh are prepared, and the respective main surfaces of the pair of components Rbh are formed as shown in FIG. Combined at the position of the two-dot chain line. Thereby, the high resistance portion Rb is formed.

  According to the present embodiment, in the region where the first end Eb1 and the second end Eb2 face each other, the entire path connecting the first end Eb1 and the second end Eb2 is filled with the insulator. Yes. Therefore, compared to the first embodiment, the occurrence of an arc through this path is more reliably suppressed.

  The high resistance portion Rb is formed by combining a pair of components Rbh (FIG. 27). Since the concave portion of the component Rbh is a shallow concave portion located on the main surface of the component Rbh, the component Rbh using a mold can be easily formed. That is, there is no need to use a split mold or a slide mold, or to process and form the recess after the mold is formed.

(Embodiment 8)
FIG. 28 is a cross sectional view schematically showing a configuration of a connection element included in the power semiconductor device according to the eighth embodiment of the present invention. FIG. 29 is a front view schematically showing a configuration of a high resistance portion, an electric wire, and a coating included in the power semiconductor device according to the eighth embodiment of the present invention. FIG. 30 is an exploded view of FIG. The cross-sectional position in FIG. 28 corresponds to the cross-sectional position in FIG.

  Referring mainly to FIGS. 28 to 30, the power semiconductor device according to the present embodiment is a high-power semiconductor device instead of first high-resistance portion Rc1 and second high-resistance portion Rc2 (FIG. 10) in the second embodiment. It has a resistance portion Rc. The high resistance portion Rc is made of an insulator, is provided between the first end portion Ec1 and the second end portion Ec2, and has a first end along a direction in which the first end portion Ec1 and the second end portion Ec2 face each other. The part Ec1 and the second end part Ec2 are connected.

  Since the configuration other than the above is substantially the same as the configuration of the second embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof will not be repeated.

  According to the present embodiment, the entire path connecting the first end Ec1 and the second end Ec2 is filled with the insulator in the region where the first end Ec1 and the second end Ec2 face each other. . Therefore, compared to the second embodiment, the occurrence of an arc through this path is more reliably suppressed.

(Embodiment 9)
FIG. 31 is a front view schematically showing a configuration of a high resistance portion, an electric wire, and a coating included in the power semiconductor device according to the ninth embodiment of the present invention.

  Referring mainly to FIG. 31, in the present embodiment, high resistance portion Rcw is provided instead of high resistance portion Rc (FIG. 30) in the eighth embodiment. The high resistance portion Rcw is made of an insulator, is provided between the first end portion Ec1 and the second end portion Ec2 (FIG. 30), and extends in a direction in which the first end portion Ec1 and the second end portion Ec2 face each other. The first end Ec1 and the second end Ec2 are connected. In addition, the high resistance portion Rcw has a surface that undulates in a direction intersecting the direction in which the respective ends of the first electric wire Wc1 and the second electric wire Wc2 face each other. More specifically, the undulating surface has a surface having wavy irregularities.

  Since the configuration other than the above is substantially the same as the configuration of the above-described eighth embodiment, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

  According to the present embodiment, the arc length of the arc along the side surface of the high resistance portion Rcw is increased by the undulation on the side surface of the high resistance portion Rcw. Thereby, compared with Embodiment 8, generation | occurrence | production of an arc can be suppressed more effectively.

(Embodiment 10)
Each of FIGS. 32 to 34 is a cross sectional view schematically showing a configuration of a connection element included in the power semiconductor device according to the tenth embodiment of the present invention. The cross-sectional positions in FIGS. 32 to 34 correspond to the cross-sectional positions in FIGS.

  Referring mainly to FIG. 32 to FIG. 34, the connection element of the present embodiment includes a first high resistance portion instead of the first high resistance portion Rb1 and the second high resistance portion Rb2 in the first embodiment. Rb1r and second high resistance portion Rb2r are provided.

  Each of the first high resistance portion Rb1r and the second high resistance portion Rb2r covers the tips of the first end Eb1 and the second end Eb2. Therefore, each of the first high resistance portion Rb1r and the second high resistance portion Rb2r is provided between the first end portion Eb1 and the second end portion Eb2.

  Each of the first high resistance portion Rb1r and the second high resistance portion Rb2r is made of either a conductor or a semiconductor. This material has a resistivity higher than the resistivity of each of the first metal (the material of the first bus bar Wb1) and the second metal (the material of the second bus bar Wb2).

  FIG. 35 is a perspective view schematically showing a high resistance portion mounting step in the method for manufacturing the power semiconductor device according to the tenth embodiment of the present invention. Referring to FIG. 35, second high resistance portion Rb2r is joined to the tip of the end portion of second bus bar Wb2 by brazing. The first high resistance portion Rb1r is similarly joined on the tip of the end portion of the first bus bar Wb1.

  Since the configuration other than the above is substantially the same as the configuration of the first embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

  Next, the function and effect of this embodiment will be described. FIG. 36 is an explanatory diagram for explaining the state when the low melting point metal portion of the power semiconductor device according to the tenth embodiment of the present invention is melted together with the cross-sectional shape. The cross-sectional position in FIG. 36 is the same as the cross-sectional position in FIG.

  Referring to FIGS. 32 and 36, when low melting point metal portion LM (FIG. 32) melts, first bus bar Wb1 and second bus bar Wb2 are electrically separated as shown in FIG. At this time, an arc may occur between the first high resistance portion Rb1r on the first bus bar Wb1 and the second high resistance portion Rb2r on the second bus bar Wb2. Since the short circuit current due to the arc flows through the circuit schematically shown in FIG. 36, each of the first high resistance portion Rb1r and the second high resistance portion Rb2r acts as a resistance R against the arc current. Therefore, a part of the voltage V between the first bus bar Wb1 and the second bus bar Wb2 is divided by the resistor R. As a result, the arc voltage becomes a voltage VR smaller than the voltage V. That is, according to the present embodiment, the arc voltage is suppressed as compared with the comparative example shown in FIG. As a result, the arc is easily interrupted.

  Furthermore, when the short-circuit current is alternating current and the load is inductive or capacitive, the resistance R is provided, so that the phase difference between the current and voltage is reduced. Thereby, the possibility that the arc is re-ignited between the first high resistance portion Rb1r and the second high resistance portion Rb2r can be reduced.

(Embodiment 11)
FIG. 37 is a cross sectional view schematically showing a configuration of a connection element included in the power semiconductor device according to the eleventh embodiment of the present invention. FIG. 38 is a perspective view schematically showing a configuration of a high resistance portion, an electric wire, and a coating included in the power semiconductor device according to the eleventh embodiment of the present invention.

  Referring to FIGS. 37 and 38, the connecting element according to the present embodiment includes a first high resistance portion Rc1r and a second high resistance portion Rc2 instead of the first high resistance portion Rc1 and the second high resistance portion Rc2 according to the second embodiment. The second high resistance portion Rc2r is included.

  The first high resistance portion Rc1r covers the tip of the end portion of the first electric wire Wc1. The second high resistance portion Rc2r covers the tip of the end portion of the second electric wire Wc2. Therefore, each of the first high resistance portion Rc1r and the second high resistance portion Rc2r is provided between the end portions of the first electric wire Wc1 and the second electric wire Wc2.

  Each of the first high resistance portion Rc1r and the second high resistance portion Rc2r is made of a material of either a conductor or a semiconductor. This material has a resistivity higher than the resistivity of each of the first metal (the material of the first electric wire Wc1) and the second metal (the second electric wire Wc2).

  As a method of attaching the second high resistance portion Rc2r onto the tip of the end portion of the second electric wire Wc2, for example, a brazing method can be used. The same applies to the attachment of the first high resistance portion Rc1r to the first electric wire Wc1.

  According to the present embodiment, the same effect as in the tenth embodiment can be obtained in the configuration in which the electric wires are used instead of the bus bars.

  Next, a modification of the present embodiment will be described. FIG. 39 is a cross sectional view schematically showing a configuration of a connection element included in a power semiconductor device according to a modification of the eleventh embodiment of the present invention. FIG. 40 is a perspective view schematically showing a configuration of a conductor portion, a high resistance portion, an electric wire, and a coating included in the power semiconductor device according to the modification of the eleventh embodiment of the present invention. Referring to FIGS. 39 and 40, in this modification, a conductor portion C1 and a conductor portion C2 are provided on the tip of the first high resistance portion Rc1r and on the tip of the second high resistance portion Rc2r, respectively. Yes. Also in this modification, the same effect as this embodiment can be obtained.

(Embodiment 12)
FIG. 41 is a cross sectional view schematically showing a configuration of a connection element included in the power semiconductor device according to the twelfth embodiment of the present invention. The cross-sectional position in FIG. 41 corresponds to the cross-sectional position in FIG.

  Referring to FIG. 41, the connection element of the present embodiment has a high resistance portion Rc1s instead of the first high resistance portion Rc1 (FIG. 10) in the second embodiment, and the second element in the second embodiment. The high resistance portion Rc2 (FIG. 10) is not provided. The high resistance portion Rc1s covers the tip of the end portion of the first electric wire Wc1. Therefore, the high resistance portion Rc1s is provided between the end portions of the first electric wire Wc1 and the second electric wire Wc2. The high resistance portion Rc1s is made of either a conductor or a semiconductor. This material has a resistivity higher than the resistivity of each of the first metal (material of the first electric wire Wc1) and the second metal (material of the second electric wire Wc2).

  Next, the function and effect of this embodiment will be described. FIG. 42 is an explanatory diagram for explaining the state when the low melting point metal portion of the power semiconductor device according to the twelfth embodiment of the present invention is melted together with the cross-sectional shape. 42 is the same as the cross-sectional position in FIG.

  Referring to FIG. 41 and FIG. 42, when low melting point metal portion LM (FIG. 41) melts, first electric wire Wc1 and second electric wire Wc2 are electrically separated as shown in FIG. At this time, an arc may occur between the high resistance portion Rc1s on the first electric wire Wc1 and the second electric wire Wc2. Since the short-circuit current due to this arc flows through the circuit schematically shown in FIG. 42, the high resistance portion Rc1s acts as a resistance 2R against the arc current. For this reason, a part of the voltage V between the first electric wire Wc1 and the second electric wire Wc2 is divided by the resistor 2R. As a result, the arc voltage becomes a voltage VR smaller than the voltage V. That is, the arc voltage is suppressed as compared with the case where the high resistance portion Rc1s is not provided. Thereby, the same effect as in the tenth embodiment can be obtained.

  Further, the high resistance portion such as the high resistance portion Rc1s is not provided on the second electric wire Wc2. That is, the configuration of the present embodiment can be manufactured more easily because there are fewer components compared to the configuration in which the high resistance portion is also provided on the second electric wire Wc2.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be applied particularly advantageously to a power semiconductor device having a power semiconductor element.

1 is a perspective view schematically showing a configuration of a power semiconductor device according to a first embodiment of the present invention. It is a front view which shows roughly the structure of the connection element which the power semiconductor device in Embodiment 1 of this invention has. It is a schematic sectional drawing in alignment with line III-III of FIG. It is a schematic sectional drawing in alignment with line IV-IV of FIG. FIG. 5 is a schematic cross-sectional view taken along line VV in each of FIGS. 3 and 4. FIG. 6 is a schematic sectional view taken along lines VI-VI in FIGS. 4 and 5. It is a perspective view which shows roughly the attachment process of the high resistance part in the manufacturing method of the semiconductor device for electric power in Embodiment 1 of this invention. It is sectional drawing which shows a mode when the low melting metal part of the semiconductor device for electric power in Embodiment 1 of this invention melt | dissolved. It is sectional drawing which shows a mode when the low melting-point metal part of the semiconductor device for electric power in the comparative example of Embodiment 1 of this invention melt | dissolved. It is sectional drawing which shows schematically the structure of the connection element which the power semiconductor device in Embodiment 2 of this invention has. It is a schematic front view which shows the 1st process of the attachment method of the high resistance part in the manufacturing method of the semiconductor device for electric power in Embodiment 2 of this invention. It is a schematic front view which shows the 2nd process of the attachment method of the high resistance part in the manufacturing method of the semiconductor device for electric power in Embodiment 2 of this invention. It is a front view which shows roughly the structure of the high resistance part which the power semiconductor device in Embodiment 3 of this invention has, an electric wire, and a coating | cover. It is a perspective view which shows roughly the structure of the high resistance part which the power semiconductor device in Embodiment 3 of this invention has. It is a top view which shows roughly the structure of the connection element which the power semiconductor device in Embodiment 4 of this invention has. It is a bottom view which shows roughly the structure of the connection element which the power semiconductor device in Embodiment 4 of this invention has. It is a schematic sectional drawing which follows each line XVII-XVII of FIG. 15 and FIG. It is sectional drawing which shows a mode when the low melting metal part of the semiconductor device for electric power in Embodiment 4 of this invention melt | dissolved. It is sectional drawing which shows a mode when the low melting metal part of the semiconductor device for electric power in the comparative example of Embodiment 4 of this invention melt | dissolved. It is a top view which shows roughly the structure of the connection element which the power semiconductor device in Embodiment 5 of this invention has. It is a bottom view which shows roughly the structure of the connection element which the power semiconductor device in Embodiment 6 of this invention has. FIG. 22 is a schematic sectional view taken along line XXII-XXII in FIG. 21. It is sectional drawing which shows schematically the structure of the connection element which the power semiconductor device in Embodiment 7 of this invention has. It is sectional drawing which shows schematically the structure of the connection element which the power semiconductor device in Embodiment 7 of this invention has. It is a perspective view which shows roughly a mode that each of the 1st and 2nd bus bar is attached to the high resistance part which the power semiconductor device in Embodiment 7 of this invention has. It is a front view which shows roughly the structure of the high resistance part which the power semiconductor device in Embodiment 7 of this invention has. It is a perspective view which shows roughly 1 process of the formation method of the high resistance part which the power semiconductor device in Embodiment 7 of this invention has. It is sectional drawing which shows schematically the structure of the connection element which the power semiconductor device in Embodiment 8 of this invention has. It is a front view which shows roughly the structure of the high resistance part which the power semiconductor device in Embodiment 8 of this invention has, an electric wire, and a coating | cover. FIG. 30 is an exploded view of FIG. 29. It is a front view which shows roughly the structure of the high resistance part which the power semiconductor device in Embodiment 9 of this invention has, an electric wire, and a coating | cover. It is sectional drawing which shows schematically the structure of the connection element which the power semiconductor device in Embodiment 10 of this invention has. It is sectional drawing which shows schematically the structure of the connection element which the power semiconductor device in Embodiment 10 of this invention has. It is sectional drawing which shows schematically the structure of the connection element which the power semiconductor device in Embodiment 10 of this invention has. It is a perspective view which shows roughly the attachment process of the high resistance part in the manufacturing method of the semiconductor device for electric power in Embodiment 10 of this invention. It is explanatory drawing explaining a mode when the low melting metal part of the semiconductor device for electric power in Embodiment 10 of this invention melt | dissolved with a cross-sectional shape. It is sectional drawing which shows schematically the structure of the connection element which the power semiconductor device in Embodiment 11 of this invention has. It is a perspective view which shows roughly the structure of the high resistance part which the power semiconductor device in Embodiment 11 of this invention has, an electric wire, and a coating | cover. It is sectional drawing which shows schematically the structure of the connection element which the power semiconductor device in the modification of Embodiment 11 of this invention has. It is a perspective view which shows roughly the structure of the conductor part, high resistance part, electric wire, and coating | cover which the power semiconductor device in the modification of Embodiment 11 of this invention has. It is sectional drawing which shows schematically the structure of the connection element which the power semiconductor device in Embodiment 12 of this invention has. It is explanatory drawing explaining a mode when the low melting-point metal part of the power semiconductor device in Embodiment 12 of this invention melt | dissolved with a cross-sectional shape.

Explanation of symbols

  Eb1 first end, Eb2 second end, HT heater, LM low melting point metal part, MT fault signal terminal, PS power supply, Rb1 first high resistance part, Rb2 second high resistance part, SW power control switch, Wb1 first 1 busbar (first electrical wiring), Wb2 second busbar (second electrical wiring).

Claims (5)

A power semiconductor element;
And electrically connected to the having a first end, a first electric wire made of a first metal to said power semiconductor device,
A second electrical wiring having a second end facing the first end with a gap and made of a second metal that is either the same metal as the first metal or a metal different from the first metal When,
A low melting point metal part made of a metal having a melting point lower than the melting point of each of the first metal and the second metal, and electrically connecting the first end part and the second end part to each other;
A heater capable of heating at least a part of the low melting point metal part to a melting point or higher of the low melting point metal part;
At least one high resistance portion made of a material provided between the first end portion and the second end portion and having a resistivity higher than the resistivity of each of the first metal and the second metal; Prepared ,
The at least one high resistance portion is made of an insulator,
The power semiconductor device, wherein the at least one high resistance portion is provided on a tip of at least one of the first end and the second end . 2. The power semiconductor device according to claim 1 , wherein the at least one high resistance portion has a surface inclined with respect to a direction in which the first end portion and the second end portion face each other. Wherein said at least one high-resistance portion, the first end and the second end portion has a surface that undulations in a direction crossing the opposing directions, power semiconductor device according to claim 1 or 2. It said first end and fixed to each of said second end, said further comprising a substrate having a hole in at least a portion facing the region of the low-melting-point metal portion, to any of the claims 1-3 The power semiconductor device described. Wherein located above the low melting point metal portion, the provided first end and further the substrate for fixing each of said second end, power semiconductor device according to any one of claims 1-3.

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