JP5111592B2 - Power semiconductor device having shut-off mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power semiconductor device equipped with a circuit breaking mechanism having a thermal fuse fusible at low temperatures while having a small resistance value. <P>SOLUTION: This circuit breaking mechanism 10 includes: one primary wiring conductor 2 and the other primary wiring conductor 2 provided on the upper side of a substrate 1 and each connected to a prescribed electronic circuit; and heater conductors 4 provided on the primary surface of the substrate 1 so as to generate heat when a current flows in it. The circuit breaking mechanism 10 also includes one low-melting point metal conductor 5 for connecting the one primary wiring conductor 2 to an electrode film 3, and the other low-melting point metal conductor 5 for electrically connecting the other primary wiring conductor 2 to the electrode film 3. Each of the one low-melting point metal conductor 5 and the other low-melting point metal conductor 5 has a melting point lower than that of either of the one primary wiring conductor 2 and the other primary wiring conductor 2. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a power semiconductor device having a mechanism for interrupting a current flowing in an electronic circuit.

Power semiconductor devices include IGBT (Insulated Gate Bipolar Transistor) and MOS
An electronic device that integrates a plurality of semiconductor switches called FETs (Metal Oxide Silicon Field Effect Transistors). By turning on / off at a predetermined timing, an alternating current of a desired frequency is generated and the motor can be freely controlled. Used for speed control.

  In addition, the semiconductor switch can block the current flowing through the electronic circuit without forming a portion that is not physically connected. Specifically, a semiconductor switch applies a minute voltage signal to a gate electrode provided on a semiconductor substrate with a thin insulating layer as a medium, and blocks a large current flowing between the source electrode and the drain electrode. . Therefore, the semiconductor switch is less likely to be damaged than a switch that switches between physical contact and non-contact.

  However, in this semiconductor switch, when the density of the current flowing between the source electrode and the drain electrode exceeds a predetermined value, a high density energy is locally given to the channel region and may be damaged by melting. In this case, the semiconductor switch is short-circuited, that is, is always connected. Such a situation is said to occur even when cosmic rays hit a semiconductor device.

  Usually, since an electronic circuit has a fuse, a breaker, or the like, the entire semiconductor circuit is prevented from being destroyed due to damage to the semiconductor switch.

  However, in the power semiconductor device for controlling the motor of the moving body, there is a demand for a power semiconductor device that does not have a fuse or a breaker in order to reduce the cost. In other words, a power semiconductor device having a mechanism capable of actively interrupting a current flowing in an electric circuit is demanded. More specifically, there is a demand for a power semiconductor device having a cutoff mechanism that can intentionally cut off a current flowing through an electronic circuit even when a current having a value smaller than a rated current value flows.

  Conventionally, as a breaker mechanism as described above, for example, as disclosed in Japanese Patent No. 3552539, when a predetermined part of an electronic circuit reaches a predetermined temperature, a thermal fuse that blows off and cuts off a current is provided. It is used.

JP 2001-118481 A JP 2000-251598 A JP 2000-260280 A JP 2001-135213 A Japanese Patent Laid-Open No. 07-230747 Japanese Patent No. 3552539

In general, a conductive metal is used as an example of a blocking mechanism. When the metal melts, it deforms so that the free energy of the surface is minimized, so it basically approaches a spherical shape. When heat is generated by energization of the metal conductor bridged between the two electrodes, the central portion becomes the highest temperature. A metal conductor that is at a temperature exceeding the melting point tends to be spherical, but when the range of the molten metal conductor increases, the molten metal moves from the center to the electrode, and the sphere becomes larger accordingly. Become. When the total diameter of each sphere when the molten metal conductor is divided into two spheres is smaller than the distance between the molten metals, the energy of the separated metal conductor is not separated metal. It is larger than the energy of the conductor. At this time, the metal conductor is easily separated.

  Therefore, it is desirable that the low melting point conductor used as the thermal fuse has a length of several times the width and thickness. Therefore, a low-melting-point conductor having an elongated shape is used as the material for the thermal fuse. On the other hand, the electric resistance value of the low melting point conductor (hereinafter referred to simply as “resistance value”) is inversely proportional to the cross-sectional area and proportional to the length. For this reason, an elongated low-melting-point conductor is easily cut at a low temperature, but its resistance value is increased.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a power semiconductor device including a breaking mechanism having a thermal fuse that is easily divided at a low temperature and has a small resistance value.

  A power semiconductor device having a blocking mechanism according to one aspect of the present invention includes an insulating substrate and an electrode film provided on one main surface of the substrate. In addition, the apparatus is provided near the electrode conductor and the heater conductor provided on the other main surface of the substrate so as to generate heat when an electric current flows, and each one is connected to a predetermined electronic circuit. Main wiring conductor and the other main wiring conductor. The apparatus further includes one low-melting-point conductor that connects one main wiring conductor and the electrode film, and the other low-melting-point conductor that electrically connects the other main wiring conductor and the electrode film. . Each of the one low-melting-point conductor and the other low-melting-point conductor has a melting point lower than the melting point of either the one main wiring conductor or the other main wiring conductor.

  According to the above configuration, the fusing of one low melting point conductor and the other low melting point conductor is promoted by the action of gravity on the substrate, the electrode film, and the heater conductor. Therefore, the blocking mechanism is easily divided at a low temperature.

  A power semiconductor device having a blocking mechanism according to another aspect of the present invention includes an insulating substrate and an electrode film provided on one main surface of the substrate. In addition, the apparatus is provided on the other main surface of the substrate, and generates a heater conductor when current flows, one main wiring conductor electrically connected to a predetermined electronic circuit and an electrode film, and And the other main wiring conductor. Further, the electrode film has a plurality of broken line-shaped through-holes extending so as to cross a region between one main wiring conductor and the other main wiring conductor as viewed in a plan view.

  According to said structure, an electrode film and a board | substrate are easy to fracture | rupture along several through-holes of a fractured line shape. Therefore, the blocking mechanism is easily divided at a low temperature.

  A power semiconductor device having a blocking mechanism according to still another aspect of the present invention includes an insulating substrate and an electrode film provided on one main surface of the substrate. In addition, the apparatus is provided on the other main surface of the substrate, and generates a heater conductor when current flows, one main wiring conductor electrically connected to a predetermined electronic circuit and an electrode film, and And the other main wiring conductor. Furthermore, the apparatus includes one conductor layer that electrically connects one main wiring conductor and the electrode film, and the other conductor layer that electrically connects the other main wiring conductor and the electrode film. Yes. Also, one conductor layer and the other conductor layer are provided separately on both sides of the imaginary line.

  According to said structure, a board | substrate and an electrode film become easy to be fractured | ruptured along the virtual line crossing the area | region between one conductor apparatus and the other conductor layer. Therefore, the occurrence of a problem that one of the low-melting-point conductors and the other low-melting-point conductor are difficult to melt is suppressed.

  A power semiconductor device having a blocking mechanism according to still another aspect of the present invention includes an insulating substrate and an electrode film provided on one main surface of the substrate. Further, the apparatus is provided on the other main surface of the substrate and generates heat when current flows, one main wiring conductor and the other main wiring conductor each connected to a predetermined electronic circuit. It has. Further, the apparatus includes one low melting point conductor that electrically connects one main wiring conductor and the electrode film, and the other low melting point conductor that electrically connects the other main wiring conductor and the electrode film. I have. The device is provided between one low melting point conductor and the other low melting point conductor, and another low melting point conductor that causes a eutectic reaction with each of the one low melting point conductor and the other low melting point conductor, It has.

  According to the above configuration, when a eutectic reaction occurs, the one low melting conductor and the other low melting conductor are liquefied at a temperature lower than the melting points of one of the low melting conductor and the other low melting conductor. Therefore, each of the one low-melting-point conductor and the other low-melting-point conductor is easily melted at a low temperature.

  A power semiconductor device having a blocking mechanism according to another aspect of the present invention includes an insulating substrate and an electrode film provided on one main surface of the substrate. In addition, the apparatus is provided on the other main surface of the substrate, and generates a heater conductor when current flows, one main wiring conductor electrically connected to a predetermined electronic circuit and an electrode film, and And the other main wiring conductor. The heater conductor is disposed only in the region on the other main surface on the back side of the region where one main wiring conductor and the other main wiring conductor are projected on one main surface.

  Also with the above configuration, the occurrence of a problem that each of the one low-melting-point conductor and the other low-melting-point conductor is difficult to melt is suppressed.

  A power semiconductor device having a blocking mechanism according to still another aspect of the present invention includes an insulating substrate and an electrode film provided on one main surface of the substrate. Further, the apparatus is provided on the other main surface of the substrate and generates heat when current flows, one main wiring conductor and the other main wiring conductor each connected to a predetermined electronic circuit. It has. Further, the apparatus includes a low melting point conductor that is connected to each of the one main wiring conductor and the other main wiring conductor and melts due to heat generated by the heater conductor. The low melting point conductor has a thickness at the center portion larger than the thickness at both end portions.

  According to said structure, a interruption | blocking mechanism is easy to be blown out at low temperature, and the resistance value becomes small.

  According to the present invention, it is possible to obtain a power semiconductor device including a breaking mechanism having a thermal fuse that is easily divided at a low temperature and has a small resistance value.

3 is a surface view of a cutoff mechanism of the power semiconductor device according to the first embodiment. FIG. 2 is a rear view of the power semiconductor device according to the first embodiment. FIG. It is the III-III sectional view taken on the line of FIG. 1 and FIG. It is a figure which shows the state immediately after the low melting metal conductor of Embodiment 1 fuse | melted and divided | segmented. It is a figure which shows the power semiconductor device of Embodiment 1, Comprising: It is a fragmentary sectional view which shows the state by which the interruption | blocking mechanism is connected to the electronic circuit. It is a figure which shows the power semiconductor device of Embodiment 1, Comprising: It is a fragmentary sectional view which shows the state by which the interruption | blocking mechanism is not connected to the electronic circuit. It is sectional drawing of the power semiconductor device of Embodiment 2, Comprising: It is a fragmentary sectional view which shows the state by which the interruption | blocking mechanism is connected to the electronic circuit. It is sectional drawing of the semiconductor device for electric power of Embodiment 2, Comprising: It is a fragmentary sectional view which shows the state where the interruption | blocking mechanism is not connected to the electronic circuit. It is sectional drawing of the semiconductor device for electric power of Embodiment 3, Comprising: It is a fragmentary sectional view which shows the state by which the interruption | blocking mechanism is connected to the electronic circuit. It is sectional drawing of the semiconductor device for electric power of Embodiment 3, Comprising: It is a fragmentary sectional view which shows the state in which the interruption | blocking mechanism is not connected to the electronic circuit. FIG. 6 is a cross-sectional view of a cutoff mechanism of a power semiconductor device according to a fourth embodiment. FIG. 10 is a cross-sectional view of a cutoff mechanism of a power semiconductor device according to a fifth embodiment. FIG. 10 is a surface view of a cutoff mechanism of a power semiconductor device according to a sixth embodiment. FIG. 23 is a rear view of a cutoff mechanism of the power semiconductor device according to the sixth embodiment. It is sectional drawing of the XV-XV line | wire of FIG. 13 and FIG. FIG. 24 is a surface view of a cutoff mechanism of a power semiconductor device according to a seventh embodiment. It is sectional drawing of the XVII-XVII line of FIG. It is sectional drawing which shows the state which the interruption | blocking mechanism of the power semiconductor device of Embodiment 7 fractured | ruptured. FIG. 20 is a cross-sectional view of a power shut-off mechanism for a power semiconductor device according to an eighth embodiment. FIG. 38 is a rear view of the cutoff mechanism of the power semiconductor device according to the ninth embodiment. FIG. 38 is a cross-sectional view of a power semiconductor device blocking mechanism according to the ninth embodiment. It is sectional drawing which shows the state which the interruption | blocking mechanism of the semiconductor device for electric power of Embodiment 9 fractured | ruptured. FIG. 38 is a cross-sectional view of the power semiconductor device blocking mechanism according to the tenth embodiment. It is sectional drawing which shows the state which two types of low melting metal conductors of the interruption | blocking mechanism of the semiconductor device for electric power of Embodiment 10 integrated. FIG. 38 is a surface view of a cutoff mechanism of a power semiconductor device according to an eleventh embodiment. FIG. 38 is a rear view of the cutoff mechanism of the power semiconductor device according to the eleventh embodiment. It is sectional drawing of the XXVII-XXVII line of FIG. 25 and FIG. FIG. 38 is a surface view of a cutoff mechanism of a power semiconductor device according to a twelfth embodiment. FIG. 38 is a rear view of the cutoff mechanism of the power semiconductor device according to the twelfth embodiment. FIG. 30 is a sectional view taken along line XXX-XXX in FIGS. 28 and 29. FIG. 38 is a cross-sectional view of a power shut-off mechanism for a power semiconductor device in a thirteenth embodiment.

  Hereinafter, a power semiconductor device including a blocking mechanism according to an embodiment of the present invention will be described with reference to the drawings. In each embodiment, portions having the same function are denoted by the same reference numerals, and the description thereof will not be repeated unless particularly necessary.

(Embodiment 1)
FIG. 1 is a plan view showing one main surface of the shut-off mechanism of the power semiconductor device of the present embodiment, and FIG. 2 shows the other main surface of the shut-off mechanism of the power semiconductor device of the present embodiment. FIG. 3 and 4 are cross-sectional views showing a state where the thermal fuse constituting the breaking mechanism is not blown and a state immediately after the thermal fuse constituting the breaking mechanism is blown.

  The interruption mechanism 10 is connected in series to another electronic circuit through the main wiring conductor 2 of the power semiconductor device. As shown in FIGS. 1 to 3, the blocking mechanism 10 faces the insulating substrate 1, the electrode film 3 formed on one main surface of the substrate 1, and one main surface of the substrate 1. And a heater conductor 4 formed on the other main surface. The electrode film 3 is made of a thick film material such as AgPd, AgPt, or tungsten. In addition, as shown in FIG. 3, one end and the other end of the electrode film 3 of the blocking mechanism 10 are used as brazing materials at the end of one main wiring conductor 2 and the other main wiring conductor 2, respectively. The low melting point metal conductor 5 is connected as a medium.

The substrate 1 is preferably made of a ceramic substrate such as alumina from the viewpoint of insulation and heat resistance. Therefore, in the present embodiment, the substrate 1 is an alumina substrate. As the thickness of the substrate, a value of about 0.5 mm to 1 mm is often used in the industry, and if it is this value, sufficient strength can be easily obtained. The size of the substrate is preferably about 10 mm square to 20 mm square.

  The electrode film 3 is formed by patterning and baking a mixture of a glass powder binder and a metal powder on the substrate surface by a method such as printing. Therefore, the electrode film 3 can be easily formed. The thickness of the electrode film 3 is about several μm to several tens of μm.

The blocking mechanism 10 is formed by the following manufacturing method.
First, a solidified alumina fine powder and binder mixture called a green sheet is prepared. This is fired to form a substrate 1 made of alumina. Next, the heater conductor 4 and the electrode film 3 are made of AgPd, AgPt, tungsten, or the like, and these are patterned and fired by using a method such as printing on a substrate surface with a glass powder binder and a metal powder mixture. Formed by. Therefore, the substrate 1 is easily formed. If the thickness of the substrate is about several μm to several tens of μm, it can be realized. Thereafter, the substrate 1 is baked and hardened for several hours at a high temperature of about several thousand or more degrees. Thereby, a metal conductor such as tungsten is formed in a desired shape on each of the front surface and the back surface of the substrate 1. That is, it is possible to obtain the substrate 1 in which the electrode film 3 and the heater conductor 4 are formed on one main surface and the other main surface, respectively.

  For example, the width of each pattern of the electrode film 3 and the heater conductor 4 is about 100 μm to several mm, and the minimum value of the interval between the portions of each pattern is 100 μm or more. Furthermore, the thickness of the pattern may be adjusted to a desired thickness by applying Ni plating or the like on each of the metal material constituting the electrode film 3 and the metal material constituting the heater conductor 4.

  Instead of the aforementioned method, the aforementioned pattern may be formed by a method called MoMn method. The MoMn method is a method of forming a desired pattern by firing the substrate 1 on which a mixture of Mo and manganese oxide is printed. In this method, for example, a pattern having a width of 200 μm or more can be formed, and a pattern having a minimum interval of about 200 μm can be formed.

  Further, the heater conductor 4 has a pattern width of 100 μm and a pattern interval of 100 μm, for example, and as shown in FIG. Can be small. For example, if the heater conductor 4 has a shape in which a straight portion having a length of 10 mm is connected via 50 bent portions, an elongated conductor having a length of 500 mm can be formed in a small region. For example, if the thickness of the pattern is about 10 μm, the resistance value of the heater conductor 4 can be about 100Ω.

  In general, the resistance value of the heater conductor 4 is desirably high, but the resistance value of the electrode film 3 is desirably low. This is because the amount of heat generated by the power semiconductor device can be reduced while the function of the shut-off mechanism is exhibited in a short time. For example, when a large current of several hundreds A flows through the electrode film 3, if the resistance value of the electrode film 3 is 0.1Ω, a potential difference of 10 V per 100 A occurs in the electrode film 3. Therefore, the amount of heat generated in the electrode film 3 is 1000 W. Such large heat generation is not preferable for a power semiconductor device.

  Moreover, the resistance value of the electrode film 3 having a width of 0.1 mm and a length of 500 mm is 100Ω, which means that the resistance value of the electrode film 3 having a width of 10 mm and a length of 1 mm is 0.002Ω. If the value of the current flowing through the electrode film 3 is 100 A, the potential difference in the electrode film 3 is 0.2 V, and the calorific value is 20 W. This value is barely acceptable.

  Thus, the resistance value required for the electrode film 3 and the resistance value required for the heater conductor 4 are different, and it is desirable that the resistivity of the electrode film 3 is small and the resistivity of the heater conductor 4 is large. For example, the heater conductor 4 may be made of a carbon-based conductive material.

  In the present embodiment, the length of the electrode film 3 is 1 mm. This is easily realized if the distance between the pair of main wiring conductors 2 connected to both ends of the electrode film 3 is 1 mm. Can be done.

  The main wiring conductor 2 is preferably made of copper or a copper alloy having a thickness of about 1 mm to 2 mm, for example. According to this, the resistance value of the main wiring conductor 2 can be lowered. According to the blocking mechanism 10 in which the main wiring conductor 2 is electrically connected to the electrode film 3 through a low melting point metal conductor 5 made of a brazing material such as solder, for example, between the main wiring conductors 2. The resistance value in the path can be reduced. Therefore, a blocking mechanism in which the resistance value of the electrode film 3 is small and the resistance value of the heater conductor 4 is large can be obtained.

Next, the operation of the blocking mechanism 10 will be described.
When a shut-off command is output from a rectifying mechanism not shown, current flows to the heater conductor 4 through wiring connected to the heater conductor 4 not shown. For example, when a current flows from a 200V battery to the heater conductor 4, a current of 2A flows through the heater conductor 4 having a resistance value of 100Ω, and 400W of heat is generated. This heat raises the temperature of the substrate 1. At this time, the temperature of the substrate 1 rises to 300 ° C. or more in a few seconds and rises to about 700 ° C. in a few tens of seconds.

  When the low-melting-point metal conductor 5 is made of, for example, solder, the melting point is approximately 200 ° C., so that it melts on the substrate 1 and the electrode film 3. In the present embodiment, since the substrate 1 is disposed below the main wiring conductor 2, the substrate 1, the electrode film 3, and the heater conductor 4 are integrally dropped according to gravity.

In the present embodiment, solder is used as an example of the low melting point metal conductor 5, but other low melting point metal may be used instead of the solder. The low melting point metal conductor 5 has electrical conductivity and has a lower melting point than the main wiring conductor 2, the substrate 1, the electrode film 3, and the heater conductor 4. Can function as a thermal fuse.

  As described above, in the blocking mechanism 10 of the present embodiment, the electrode film 3 and the heater conductor 4 are provided on one main surface and the other main surface of the substrate 1, respectively, and the electrode film 3 is The low-melting-point metal conductor 5 and the other low-melting-point metal conductor 5 are electrically connected to the one main wiring conductor 2 and the other main-wiring conductor 2, respectively. According to this structure, the interruption | blocking mechanism 10 can be made very small, and the resistance value can be made very small.

  Next, referring to FIGS. 5 and 6, a power semiconductor device using the blocking mechanism 10 of the present embodiment will be described.

  In the power semiconductor device of the present embodiment, as shown in FIG. 5, a resin-encapsulated power module 6 containing a power semiconductor element (not shown) is disposed on a base plate 7. The power module 6 includes a signal terminal 8 and a main terminal 9. The extended portion of the main terminal 9 constitutes one main wiring conductor 2 of the blocking mechanism 10.

  Further, the extended portion of the other main wiring conductor 2 forms a terminal block 11 for external connection. At this time, the blocking mechanism 10 is housed in a resin casing 12 having a lid, thereby being protected from being exposed to the external space.

  When the shut-off mechanism 10 is operated, the low melting point metal conductor 5 is melted by the heat generated by the heater conductor 4 in the space inside the housing 12, so that there is no support for the substrate 1. Therefore, as shown in FIG. 6, the substrate 1 falls according to gravity, and the current flowing between the main terminal 9 and the terminal block 11 of the power module 6 is interrupted.

  Note that the terminal block 11 is fixed to a predetermined position of the resin of the housing 12 in which the blocking mechanism 10 is built in by a bolt 13 inserted into a through hole provided in the main wiring conductor 2. Thus, since the interruption | blocking mechanism 10 and the terminal block 11 are integrated, the power semiconductor device is reduced in size and weight.

  Although not shown, for example, a resin casing 12 including the blocking mechanism 10 and the terminal block 11 may be integrated with the power module 6. In this case, if there is no decrease in performance such as heat dissipation, the conductor device for electric power may not have the base plate 7. The power semiconductor device may have a heat sink for cooling instead of the base plate 7. As the material of the resin casing 12, it is preferable to use a heat-resistant resin such as PPS (polyphenylene sulfide) or epoxy.

  In addition, since the housing 12 with the built-in blocking mechanism 10 has a lid and is blocked from the outside air, it is not only protected from dust, but also arc discharge generated when the blocking mechanism 10 operates. The components around the housing 12 are protected from the above. As a material for the lid of the housing 12, a portion in contact with the conductor such as the main terminal 9 of the power module 6 needs to have insulation, and for example, a heat-resistant resin such as PPS is used. Is preferred.

  As described above, according to the power semiconductor device of the present embodiment, the blocking mechanism 10 is provided between the external terminal block 11 and the main terminal 9 of the power module 6, and the low melting point is controlled by controlling the heat generation from the outside. Since the heater conductor 4 capable of melting the conductor 5 is provided, not only when an overcurrent flows through the interrupting mechanism 10 but also when a failure occurs, a current is passed through the heater conductor 4, It is possible to make the blocking mechanism 10 function actively.

  In the power semiconductor device according to the present embodiment, the shut-off mechanism 10 is disposed on the side of the power module 6 and above the base plate 7, but the terminal block 11 having external connection terminals and the power Any arrangement may be adopted as long as it is provided between the main terminal 9 of the semiconductor element.

  In many cases, the main terminal 9 of the power module 6 and the control board on which electronic components are mounted on the printed wiring board are fixed. However, as in the power semiconductor device of the present embodiment, they are horizontal. When arranged side by side in the direction, since there is no restriction on the area of the printed wiring board, the degree of freedom in designing the power semiconductor device is high. On the other hand, when the main terminal 9 of the power module 6 and the control board on which electronic components are mounted on the printed wiring board are arranged side by side in the vertical direction, the planar area of the power semiconductor device is small, and There is an advantage that there is no restriction on the area where the printed wiring board can be arranged.

  In the present embodiment, the main terminal 9 of the power module 6 constitutes the main wiring conductor 2 of the breaking mechanism 10, but each may be composed of separate and independent components. If the main terminal 9 of the power module 6 and the main wiring conductor 2 of the blocking mechanism 10 are an integral part, the power semiconductor device can be reduced in size and weight. On the other hand, if each of the main terminal 9 of the power module 6 and the main wiring conductor 2 of the shut-off mechanism 10 is a separate component, it is easy to suppress heat escape from the shut-off mechanism 10. The degree of freedom increases.

(Embodiment 2)
Next, the power semiconductor device according to the third embodiment of the present invention will be described with reference to FIGS. Since the power semiconductor device of the present embodiment is substantially the same as the semiconductor device of the first embodiment, the difference between the power semiconductor device of the present embodiment and the semiconductor device of the first embodiment will be described below. Mainly explained.

  As shown in FIGS. 7 and 8, in the power semiconductor device according to the present embodiment, the substrate 1 is pressed so as to be separated from the one main wiring conductor 2 and the other main wiring conductor 2. A mechanism is provided on the lower surface of the lid of the housing 12. A spring 16 is used as an example of the pressing mechanism. In addition to the spring 16, the pressing mechanism may be an elastic body such as rubber. In addition, the elastic body is connected to the lower surface of the substrate 1 and the bottom surface of the housing 12 in an extended state, and the substrate 1 is pulled from one main wiring conductor 2 and the other main wiring conductor 2 by pulling the substrate 1. It may be separated.

  Since the lid of the housing 12 is required to have insulating properties, it is desirable that the metal 12 be covered with an insulating material such as resin. In the present embodiment, when the low-melting point metal conductor 5 is melted, the substrate 1 is pushed downward by the force that the spring 16 tries to expand. Therefore, even if the amount of heat given to the low melting point metal conductor 5 is small, the electrode film 3 on the substrate 1 can be easily separated from the main wiring conductor 2.

  Although not shown, an insulating material such as silica sand may be filled in the space around the blocking mechanism 10. In that case, since the force of the spring 16 usually receives a reaction force from the silica sand, an excessively large force does not act on the low melting point metal conductor 5. Therefore, it is possible to suppress the occurrence of a problem that the low melting point metal conductor 5 is broken only by the force received from the spring 16. Therefore, the period during which the reliability of the power semiconductor device can be guaranteed can be extended.

In other words, according to the above-described configuration, in addition to gravity, the pressing mechanism presses the insulating substrate 1 away from the one main wiring conductor 2 and the other main wiring conductor 2, so that one low melting point metal The fusing of the conductor 5 and the other low melting point metal conductor 5 is promoted.

The foregoing will be described more specifically.
In general, it is known that a metal material is a material that causes recrystallization at a temperature higher than about half the melting point marked in absolute temperature. For example, it is known that the melting point of Pd-free solder is about 217 ° C. This is about 490K when expressed in absolute temperature. Therefore, recrystallization of Pb-free solder occurs at a temperature of 245K = 28 ° C. or higher below zero. Within the temperature range where recrystallization occurs, the Pb-free solder is easily deformed. Therefore, when a force is constantly applied to the Pb-free solder, the Pb-free solder may be gradually deformed by the force. Therefore, when the force is constantly applied to the Pb-free solder, the period during which the reliability of the shut-off mechanism of the power semiconductor device can be guaranteed is short.

  Therefore, it is preferable that the blocking mechanism 10 is sealed with silica sand or the like as in the power semiconductor device of the present embodiment. In the above description, a power semiconductor device in which the shut-off mechanism 10 is enclosed in silica sand is mentioned, but other materials can be used instead of silica sand as long as it is a flame-retardant and insulating material. In addition, there is an effect that the period during which the reliability of the power semiconductor device can be ensured can be extended.

(Embodiment 3)
Next, the power semiconductor device of the third embodiment will be described with reference to FIGS. 9 and 10. Since the power semiconductor device of the present embodiment is substantially the same as the semiconductor device of the first embodiment, the difference between the power semiconductor device of the present embodiment and the semiconductor device of the first embodiment will be described below. Mainly explained.

  As shown in FIGS. 9 and 10, in the power semiconductor device of the present embodiment, the resin 14 a and 14 b are filled in the space around the blocking mechanism 10 in the housing 12. The space above the blocking mechanism 10 is filled with the resin 14a, and the space below the blocking mechanism 10 is filled with the resin 14b.

In the present embodiment, the thermal expansion coefficient of the upper resin 14 a of the blocking mechanism 10 is larger than the thermal expansion coefficient of the lower resin 14 b of the blocking mechanism 10. For example, the thermal expansion coefficient of epoxy, which is widely used as a flame-retardant heat-resistant resin, is about 15 × 10 ⁻⁶ / ° C., whereas the thermal expansion coefficient of PPS (polyphenylene sulfide) is 22 × 10 ⁻⁶ / It is about ℃. Therefore, if the upper resin 14a of the blocking mechanism 10 is made of PPS and the lower resin 14b of the blocking mechanism 10 is made of epoxy resin, the thermal expansion coefficient of the upper resin 14a of the blocking mechanism 10 is A configuration larger than the thermal expansion coefficient of the lower resin 14b can be realized.

  In the present embodiment, the PPS resin and the epoxy resin are used as the resins 14a and 14b, respectively, but other resins may be used as the resins 14a and 14b, respectively.

In the present embodiment, as described above, the thermal expansion coefficient of the resin 14a on the upper side of the blocking mechanism 10, that is, the side where the heater conductor 4 is not provided is lower than the resin 14b, that is, the heater conductor 4 is provided. It is larger than the thermal expansion coefficient of the resin 14b on the other side. For this reason, when the blocking mechanism 10 is operated by passing a current through the heater conductor 4, the degree of expansion of the resin 14a is greater than the degree of expansion of the resin 14b. As a result, due to the difference in the degree of expansion between the resin 14a and the resin 14b, a force acts so that the substrate 1 is separated from the main wiring conductor 2. Therefore, the blocking mechanism 10 functions reliably. That is, the state shown in FIG. 9 changes to the state shown in FIG. 10, and the current flow between one main wiring conductor 2 and the other main wiring conductor 2 is interrupted. The power semiconductor device may include not only the two types of resins 14a and 14b as described above but also the spring 16 described in the second embodiment.

(Embodiment 4)
Next, the power semiconductor device according to the fourth embodiment will be described with reference to FIG. Since the power semiconductor device of the present embodiment is substantially the same as the semiconductor device of the first embodiment, the difference between the power semiconductor device of the present embodiment and the semiconductor device of the first embodiment will be described below. Mainly explained.

  As shown in FIG. 11, in the breaking mechanism 10 of the power semiconductor device of the present embodiment, a conductor layer 15 made of, for example, Cu or Al is provided on the electrode film 3. The conductor layer 15 has an electric resistance value smaller than that of the electrode film 3. The low melting point metal conductor 5 and the electrode film 3 are electrically connected through the conductor layer 15.

The manufacturing method of the interruption | blocking mechanism 10 of this Embodiment is as follows.
For example, when a technique called a casting method is used, first, the substrate 1 is mounted on a mold having a cavity corresponding to the shape of the conductor layer 15. Next, a molten metal conductor material such as aluminum is injected into the cavity. Thereafter, the metal conductor material is cooled. Next, the mold is opened. Thereafter, the blocking mechanism 10 in which the metal conductor material is formed as the conductor layer 15 is taken out from the mold.

  When a method called an active metal brazing method is used, a brazing material such as an Ag-Cu-Ti, Cu-Sn-Ti, Co-Ti, Ni-Ti, or aluminum alloy is used. In use, a metal layer such as Cu is brazed to the substrate 1 to obtain the blocking mechanism 10 in which the metal layer is formed as the conductor layer 15.

  According to such a method, the substrate 1 is greatly warped. However, when the substrate 1 is used as a component of the shut-off mechanism 10 of the power semiconductor device, the warp does not reduce the function of the shut-off mechanism 10. Therefore, even if the substrate 1 is slightly warped, it is desirable to adopt the above-described method.

  In addition, since the conductor layer 15 and the main wiring conductor 2 are electrically connected by the low melting point metal conductor 5, similarly to the blocking mechanism 10 of each of the above-described embodiments, when the blocking mechanism 10 operates, The low melting point metal conductor 5 is melted by the heat generated by the heater conductor 4, and the main wiring conductor 2 and the conductor layer 15 are electrically separated, so that the current flowing through the electronic circuit is interrupted.

  According to the present embodiment, by using the conductor layer 15, the resistance value in the blocking mechanism 10 is reduced from 1/10 to several tenths of the resistance value of the blocking mechanism 10 not using the conductor layer 15. The For example, when the resistance value is reduced to 0.1 mΩ, when a current of 100 A flows through the electronic circuit, the voltage drop in the cutoff mechanism 10 is about 0.01V. Therefore, the loss of power generated in the cutoff mechanism 10 is a very small value of about 1W.

  According to the above configuration, the electric resistance value between the one main wiring conductor 2 and the other main wiring conductor 2 does not depend on the electric resistance value of the electrode film 3, and the electric resistance value is higher than that of the electrode film 3. Depends on the small conductor layer 15. Therefore, the electrical resistance value between one main wiring conductor 2 and the other main wiring conductor 2 can be further reduced. Further, the heat generated by the heater conductor 4 is conducted to the main wiring conductor 2 through the conductor layer 15. Therefore, the escape of heat generated by the heater conductor 4 is suppressed as compared with the case where the conductor layer 15 is not provided. Therefore, the low melting point metal conductor 5 can be fused with a small energy.

(Embodiment 5)
Next, the power semiconductor device of the fifth embodiment will be described with reference to FIG. Since the power semiconductor device of the present embodiment is substantially the same as the semiconductor device of the first embodiment, the difference between the power semiconductor device of the present embodiment and the semiconductor device of the first embodiment will be described below. Mainly explained.

  As shown in FIG. 12, the conductor layer 15 is fixed on the electrode film 3. One low-melting-point conductor 5 and the other low-melting-point conductor 5 are perpendicular to each other on the side end face of one main wiring conductor 2 and on the side end face of the other main wiring conductor 2. It is provided so that it may extend. According to such a configuration, the heat generated by the heater conductor 4 passes from the conductor layer 15 through the one low melting point conductor 5 and the other low melting point conductor 5 to the side end face of the one main wiring conductor 2 and the other. It is transmitted to the side end face of the main wiring conductor 2. Therefore, heat conduction from the heater conductor 4 to the main wiring conductor 2 can be suppressed.

  The main material constituting the main wiring conductor 2 is copper or a copper alloy, and its thermal conductivity is very large among metals. In general, metals with high thermal conductivity have low electrical resistivity. It is desirable that the material of the main wiring conductor has a low electrical resistivity. This is because the heat of the heater conductor 4 escapes through the joint between the main wiring conductor 2 and the low melting point metal conductor 5. If the heat of the heater conductor 4 escapes, the temperature increase rate of the heater conductor 4 tends to be slow. This tendency becomes more prominent as the cross-sectional area of the main wiring conductor 2 increases. In this case, if a large current of several hundreds of A flows through the cutoff mechanism 10, the temperature rise rate of the heater conductor 4 is very small.

  On the other hand, according to the blocking mechanism 10 of the present embodiment, the low melting point conductor 5 is in contact only with the end surface of the main wiring conductor 2 having a very small thickness. Therefore, the heat from the heater conductor 4 to the main wiring conductor 2 is compared with the blocking mechanism or the like of the first embodiment in which a joint having a large area is formed by the lower surface of the main wiring conductor 2 and the upper surface of the low melting point conductor 5. Can be prevented.

(Embodiment 6)
Next, the power semiconductor device of the sixth embodiment will be described with reference to FIGS. Since the power semiconductor device of the present embodiment is substantially the same as the semiconductor device of the first embodiment, the difference between the power semiconductor device of the present embodiment and the semiconductor device of the first embodiment will be described below. Mainly explained.

  As shown in FIG. 13 to FIG. 15, in the interruption mechanism 10 of the power semiconductor device of the present embodiment, the main wiring conductor 2 and the electrode film 3 are electrically connected via the ribbon-shaped low melting point metal conductor 5. Connected. The ribbon-shaped low melting point metal conductor 5 is made of, for example, aluminum (Al) or aluminum (Al) alloy foil, and has a width of about 1 mm to 2 mm and a thickness of about 100 μm to 200 μm. The ribbon-shaped low melting point metal conductor 5 is bonded to each of the main wiring conductor 2 and the electrode film 3 by ultrasonic bonding.

  In general, the melting point of Al is 660 ° C. Therefore, the joint surface with the electrode film 3 of the ribbon-like low melting point metal conductor 5 made of Al is melted by heat released from the heater conductor 4. Thereby, the electric current which flows through an electronic circuit is interrupted | blocked.

  In the present embodiment, a ribbon-like low melting point metal conductor 5 is used, but instead, a wire (wire) -like low melting point metal conductor 5 made of Al or an Al alloy and having a diameter of about 100 μm is used. May be. Also in this case, the linear low melting point metal conductor 5 is joined to each of the main wiring conductor 2 and the electrode film 3 by ultrasonic joining.

The ultrasonic bonding used in the present embodiment is solid phase bonding. On the other hand, the solder bonding used in each of the above-described embodiments is liquid phase bonding. According to solder bonding, recrystallization of solder proceeds at room temperature. Generally, when a metal material is used in an atmosphere having a temperature higher than the recrystallization temperature, the fatigue life tends to be short. Therefore, when the solder is used in an environment exposed to thermal stress for a long time, the period during which the reliability of the power semiconductor device can be guaranteed is shortened. Therefore, it may be necessary to increase the bonding area between the solder and the main wiring conductor 2 in order to suppress the generation of a large thermal stress in the solder. In this case, since the metal fatigue of the joint portion between the solder and the main wiring conductor 2 is large, it is necessary to set a short period for guaranteeing the reliability of the interruption mechanism.

  On the other hand, when the Al-based material is used as the low melting point metal conductor 5 as in the present embodiment, the recrystallization temperature is 200 ° C. Can be set longer. However, since the melting point of the low-melting-point metal conductor 5 made of Al is 660 ° C., if a structure such as the blocking mechanism 10 of the first embodiment described with reference to FIGS. Therefore, an extremely large facility is required, which is not desirable from the viewpoint of production efficiency. More specifically, Cu or Cu alloy used as the material of the main wiring conductor 2 has a high thermal conductivity, and it is difficult to locally heat only the low melting point metal conductor 5. The main wiring conductor 2 and the electrode film 3 are brazed by the low melting point conductor 5 unless the temperature of the main wiring conductor 2 is raised to at least 600 ° C. which is the melting temperature of the Al-based brazing material together with the temperature of the metal conductor 5. I can't. Therefore, a large heating device for heating to 600 ° C. or higher is required.

  On the other hand, according to the Al-based ribbon or wire ultrasonic bonding technique used in the manufacture of the blocking mechanism 10 of the present embodiment, basically, the main wiring conductor 2 and the electrode film are not heated. 3 and the low melting point metal conductor 5 can be joined.

  Therefore, the period during which the reliability of the blocking mechanism 10 can be guaranteed can be made sufficiently long, and the degree of freedom in design can be improved without causing a reduction in production efficiency as described above.

  If a material such as W or MoMn is used as the heater conductor material, the melting point of the heater conductor 4 is higher than the melting point of Al constituting the low-melting-point metal conductor 5, so that the low-melting-point metal conductor is up to the temperature at which Al melts. Even if 5 is heated, the function of the blocking mechanism 10 is not hindered.

(Embodiment 7)
Next, the power semiconductor device of the seventh embodiment will be described with reference to FIGS. Since the power semiconductor device of the present embodiment is substantially the same as the semiconductor device of the first embodiment, the difference between the power semiconductor device of the present embodiment and the semiconductor device of the first embodiment will be described below. Mainly explained.

  Note that the blocking mechanism 10 of the present embodiment is similar to the blocking mechanisms of the first to sixth embodiments described above, because the low melting point metal conductor 5 is melted and the substrate 1 and the like move downward, so The electrical connection between the wiring conductor 2 and the other main wiring conductor 2 is not interrupted. The blocking mechanism 10 according to the present embodiment blocks the electrical connection between one main wiring conductor 2 and the other main wiring conductor 2 when the electrode film 3 and the substrate 1 are broken.

  As shown in FIGS. 16 to 18, in the breaking mechanism 10 of the power semiconductor device of the present embodiment, a plurality of through holes 16 are provided in the electrode film 3 in a broken line shape in a plan view. ing. Each of the plurality of through holes 16 has a rectangular shape when seen in a plan view, and penetrates the conductor film 3.

  When the electrode film 3 having such a plurality of broken line-shaped through holes 16 is formed on the substrate 1 made of ceramic such as alumina by firing, an electrode film is formed in the vicinity of the plurality of through holes 16. A large residual stress is generated due to the difference between the linear expansion coefficient of 3 and the linear expansion coefficient of the substrate 1. For this reason, the board | substrate 1 which consists of ceramics can be divided along the several through-hole 16 of a broken line by an impact, a mechanical load, or a rapid temperature change, for example.

  In order to reduce the thickness of a part of the substrate 1, the substrate 1 is broken when the surface of the substrate 1 is overlapped with a continuous line of the through-holes 16 provided in the electrode film 3 and scribed by a laser or the like. Can be facilitated, and thereby favorable results can be obtained.

  Therefore, according to the cutoff mechanism 10 of the power semiconductor device of the present embodiment, the ceramic constituting the substrate 1 is easily divided along the fracture line. Moreover, the electrode film 3 is also easily divided along the breaking line. That is, one main wiring conductor 2 and the other main wiring conductor 2 are reliably electrically separated. Also by such a method, the interruption | blocking mechanism 10 can interrupt | block the flow of the electric current between the one main wiring conductor 2 and the other main wiring conductor 2. FIG.

(Embodiment 8)
Next, the power semiconductor device of the eighth embodiment will be described with reference to FIG. Since the power semiconductor device of the present embodiment is substantially the same as the semiconductor device of the fifth embodiment, the difference between the power semiconductor device of the present embodiment and the semiconductor device of the first embodiment will be described below. Mainly explained.

  Note that, similarly to the blocking mechanism of the fifth embodiment, the blocking mechanism 10 of the present embodiment also melts the low melting point metal conductor 5 like the blocking mechanism of the first to sixth embodiments, and the substrate 1 or the like. Does not cut off the electrical connection between the one main wiring conductor 2 and the other main wiring conductor 2. The blocking mechanism 10 according to the present embodiment blocks the electrical connection between one main wiring conductor 2 and the other main wiring conductor 2 when the electrode film 3 and the substrate 1 are broken.

  As shown in FIG. 19, in the breaking mechanism 10 of the power semiconductor device of the present embodiment, one conductor layer 25 and the other conductor layer 25 are on one electrode film 3 on both sides of the virtual line. They are arranged separately. One main wiring conductor 2 and the other main wiring conductor 2 are electrically connected to one conductor layer 25 and the other conductor layer 25 through the one low melting point metal conductor 5 and the other low melting point metal conductor 5, respectively. It is connected.

  According to the blocking mechanism 10 of the present embodiment, since the one conductor layer 25 and the other conductor layer 25 are separated and arranged, the substrate 1 and the electrode are utilized by utilizing a large internal stress generated in the substrate 1. The film 3 can be broken along an imaginary line extending in a region between one conductor layer 25 and the other conductor layer 25.

(Embodiment 9)
Next, the power semiconductor device of the ninth embodiment will be described with reference to FIGS. Since the power semiconductor device of the present embodiment is substantially the same as the semiconductor device of the first embodiment, the difference between the power semiconductor device of the present embodiment and the semiconductor device of the first embodiment will be described below. Mainly explained.

Note that, similarly to the blocking mechanism of the fifth embodiment, the blocking mechanism 10 of the present embodiment also melts the low melting point metal conductor 5 like the blocking mechanism of the first to sixth embodiments, and the substrate 1 or the like. Does not cut off the electrical connection between the one main wiring conductor 2 and the other main wiring conductor 2. The blocking mechanism 10 according to the present embodiment blocks the electrical connection between one main wiring conductor 2 and the other main wiring conductor 2 when the electrode film 3 and the substrate 1 are broken.

  As can be seen from FIG. 20, in the power semiconductor device shut-off mechanism 10 of the present embodiment, the heater conductors are separated from one heater conductor 4a and the other heater conductor 4b, which are independently connected to the electronic circuit. It has become. That is, each of the one heater conductor 4a and the other heater conductor 4b constitutes an independent electronic circuit. In the present embodiment, it is assumed that the substrate 1 and the electrode film 3 are broken along a virtual line extending between one heater conductor 4a and the other heater conductor 4b.

  In the present embodiment, the heater conductor is prevented from being divided when the substrate 1 and the electrode film 3 are broken, as compared with the case where the heater conductor is composed of one circuit. Therefore, it is possible to prevent a problem that the current does not flow through the heater conductor and the substrate 1 and the electrode 3 are not completely broken.

  In the present embodiment, the low melting point metal conductor 5 is made of an Al or Al alloy ribbon conductor or wire. One low melting point metal conductor 5 and the other low melting point metal conductor 5 are bonded to the electrode film 3 and the main wiring conductor 2 by ultrasonic bonding, respectively. Also in the blocking mechanism 10 of the present embodiment, the substrate 1 changes from the state shown in FIG. 21 to the state shown in FIG. 22 due to internal stress, as in the blocking mechanisms 10 of the seventh and eighth embodiments. That is, the substrate 1 and the electrode film 3 are divided. As a result, the flow of current between one main wiring conductor 2 and the other main wiring conductor 2 is interrupted.

(Embodiment 10)
Next, the power semiconductor device according to the tenth embodiment will be described with reference to FIGS. Since the power semiconductor device of the present embodiment is substantially the same as the semiconductor device of the first embodiment, the difference between the power semiconductor device of the present embodiment and the semiconductor device of the first embodiment will be described below. Mainly explained.

  As shown in FIG. 23, in the power semiconductor device blocking mechanism 10 of the present embodiment, one electrode film 3 and the other electrode film 3 are divided into one position and the other position on the substrate 1. Is provided. One electrode film 3 and the other electrode film 3 are electrically connected through a low-melting point metal conductor 17.

  In the blocking mechanism 10 of the present embodiment, when the heater conductor 4 generates heat, the low melting point metal conductor 17 is melted. As described above, the low melting point metal conductor 17 is deformed so as to minimize the surface area. Therefore, the low melting point metal conductor 17 approaches each of the one main wiring conductor 2 and the other main wiring conductor 2 and is divided into two. As a result, as shown in FIG. 24, one low melting point metal conductor 17 and the other low melting point metal conductor 17 are integrated with one low melting point conductor 5 and the other low melting point metal conductor 5, respectively. That is, the low melting point conductor 17 having a low melting point flows toward the low melting point conductor 5 having a relatively high melting point and is integrated with the low melting point conductor 5. In the present embodiment, since the melting point of the low melting point metal conductor 17 is lower than the melting point of the low melting point metal conductor 5, the low melting point metal conductor 17 flows toward the low melting point metal conductor 5. 5 is lower than the melting point of the low melting point metal conductor 17, the low melting point metal conductor 5 melts and flows toward the low melting point metal conductor 17, and the low melting point conductor 5 is integrated with the low melting point conductor 17.

  Note that when the low-melting point metal conductor 5 and the low-melting point metal conductor 17 come into contact with each other during the operation of the shut-off mechanism 10, the melting reaction of the low-melting point metal conductors 5 and 17 proceeds at a stroke at the contact position. At this time, the low melting point metal conductors 5 and 17 are deformed so as to reduce the surface area of the molten metal. As a result, as shown in FIG. 24, the low melting point metal conductor 17 is integrated with the low melting point metal conductor 5. Accordingly, the blocking mechanism 10 can reliably perform its function.

  Further, in order to surely realize the integration as described above, it is desirable that the distance between the low melting point metal conductor 17 and the low melting point metal conductor 5 is small in the state shown in FIG.

  Moreover, it is desirable that the low melting point metal conductor 17 and the main wiring conductor 2 or the low melting point metal conductor 5 have a composition that causes a eutectic reaction with each other, such as Sn and Zn, or Sn and In. According to this, the temperature at which the low melting point metal conductors 5 and 17 are liquefied can be made lower than the respective melting points of the low melting point metal conductors 5 or 17 by utilizing the eutectic reaction. Therefore, the function of the blocking mechanism 10 can be exhibited at a lower temperature.

  Further, according to the blocking mechanism 10 of the present embodiment, the low melting point metal conductors 5 and 17 are connected to the one electrode film 3 and the other electrode film 3 after the higher melting point metal conductors 5 and 17 are connected. The lower one of the melting points 5 and 17 can be connected to one electrode film 3 and the other electrode film 3. Therefore, the degree of freedom of the manufacturing method is improved.

(Embodiment 11)
Next, the power semiconductor device according to the eleventh embodiment will be described with reference to FIGS. Since the power semiconductor device of the present embodiment is substantially the same as the semiconductor device of the fifth embodiment, the difference between the power semiconductor device of the present embodiment and the semiconductor device of the first embodiment will be described below. Mainly explained.

  Note that, similarly to the blocking mechanism of the fifth embodiment, the blocking mechanism 10 of the present embodiment also melts the low melting point metal conductor 5 like the blocking mechanism of the first to sixth embodiments, and the substrate 1 or the like. Does not cut off the electrical connection between the one main wiring conductor 2 and the other main wiring conductor 2. The blocking mechanism 10 according to the present embodiment blocks the electrical connection between one main wiring conductor 2 and the other main wiring conductor 2 when the electrode film 3 and the substrate 1 are broken.

  As shown in FIGS. 25 to 27, in the power semiconductor device blocking mechanism 10 of the present embodiment, the region where the heater conductors 4 a and 4 b and the substrate 1 are in contact with each other is the main wiring conductor 2 and the electrode film. 3 is smaller than the area in contact with 3. That is, all of the heater conductors 4a and 4b are included in a region where the main wiring conductor 2 and the electrode film 3 are in contact with each other in plan view. In other words, the heater conductors 4 a and 4 b are provided in a region corresponding to the shadow when the main wiring conductor 2 and the electrode film 3 are projected onto the substrate 1.

  In general, when nothing is formed on the main surface of the substrate 1 opposite to the heater conductor 4, the heat generated by the heater conductor 4 is transmitted to the outside through the substrate 1. On the other hand, if the electrode film 3 and the main wiring conductor 2 are provided on the main surface opposite to the heater conductor 4 of the substrate 1, the temperature of the substrate 1 is a region where the electrode film 3 and the main wiring conductor 2 are in contact with each other. The higher you move away from. For example, when the electrode film 3 and the main wiring conductor 2 are in contact with two positions on the substrate 1, the temperature at a position equidistant from each of the two positions is the highest.

  In consideration of the matters as described above, when heat is generated in the heater conductor 4 in order to melt the low melting point metal conductor 5 (brazing material), the temperature of the heater conductor 4 becomes the critical temperature (of the heater conductor 4). If the melting point is exceeded, it is considered that a part of the heater conductor 4 may melt. In this case, electricity cannot flow through the heater conductor 4. Therefore, in the case of the above-described example, the amount of heat that can be supplied using the heater conductor 4 is such that all of the main surface on the back side of the main surface of the substrate 1 on which the heater conductor 4 is formed is an electrode. It is necessary to make the size smaller than the blocking mechanism covered with the film 3 and the main wiring conductor 2.

Compared to the example as described above, according to the blocking mechanism 10 of the present embodiment, the heat generated from the heater conductor 4 is easily released to the outside through the main wiring conductor 2 and the low melting point metal conductor 5. . Therefore, the temperature of the heater conductor 4 does not become extremely high. As a result, even if the heat generation amount of the heater conductor 4 increases, the heater conductor 4 is difficult to melt. Therefore, the degree of freedom in designing the heater conductor 4 increases, and the function of the blocking mechanism is easily exhibited.

  Further, when the main wiring conductor 2 and the low melting point metal conductor 5 are divided into a plurality of parts, a portion corresponding to a portion of the heater conductor 4 where the main wiring conductor 2 and the low melting point metal conductor 5 overlap each other. It is desirable to increase only the resistance of the electrode film 3 and lower the resistance value of the electrode film 3 positioned between the main wiring conductors 2. Further, it is desirable to provide the heater conductor 4 having a high resistivity only in a region where a shadow is present when the main wiring conductor 2 and the low melting point metal conductor 5 are projected onto the substrate 1.

  According to this, since it is not necessary to consider the melting of the heater conductor 4, the degree of freedom in designing the blocking mechanism 10 increases. For example, by increasing the amount of heat generated by the heater conductor 4, the time until the electric circuit is interrupted can be shortened.

  According to the above configuration, one of the low-melting-point metal conductors 5 and the other low-melting-point metal conductor can efficiently generate heat from the heater conductor 4 while minimizing a region where the adverse effect caused by the temperature rise of the heater conductor 4 is minimized. 5 can be transmitted.

  The plurality of through holes 16 similar to those of the fifth embodiment are not necessarily provided, and the function of the blocking mechanism of the present embodiment described above can be exhibited, but the plurality of through holes 16 are electrodes. If the film 3 is provided in a broken line shape, the electrode film 3 and the substrate 1 can be easily broken along the broken line.

(Embodiment 12)
Next, the power semiconductor device of the twelfth embodiment will be described with reference to FIGS. Since the power semiconductor device of the present embodiment is substantially the same as the semiconductor device of the first embodiment, the difference between the power semiconductor device of the present embodiment and the semiconductor device of the first embodiment will be described below. Mainly explained.

  As shown in FIGS. 28 to 30, in power supply semiconductor device blocking mechanism 10 of the present embodiment, connection pads 14 a and 14 b to which other wirings can be connected are connected to both ends of heater conductor 4 a and the heater, respectively. It is provided at both ends of the conductor 4b. Each of the connection pads 14a and 14b is provided in a region included in a projection shadow of the main wiring conductor 2 on the substrate 1 and at the outermost position of the heater conductors 4a and 4b.

  According to the breaking mechanism 10 of the present embodiment, when current flows through the heater conductor 4, the temperature of the connection pads 14a and 14b can be made lower than the temperature of other regions. This is because in the blocking mechanism 10 of the present embodiment, the heat generated by the heater conductor 4 is mainly transmitted to the main wiring conductor 2, thereby suppressing the temperature rise of the connection pads 14a and 14b.

  That is, the temperature of the shadowed area when the main wiring conductor 2 is projected onto the substrate 1 is lower than the other areas. Therefore, in order to reduce the temperature of the connection pads 14a and 14b most, the region where the connection pads 14a and 14b are provided is included in the region where the main wiring conductor 2 of the substrate 1 is projected. And provided on the outermost side of the substrate 1. Thereby, the temperature of the connection pads 14a and 14b can be maintained at the lowest value among the substrates 1.

As described above, by reducing the temperature of the connection pads 14a and 14b, even when a current flows through the heater conductor 4 and the heater conductor 4 generates heat at, for example, 400 ° C. or higher, the temperature of the connection pads 14a and 14b. Can be suppressed to 200 ° C. or lower. Therefore, the reliability of connection between the connection pads 14a and 14b and other wiring can be improved. Therefore, it is possible to prevent other wirings from being disconnected from the connection pads 14a and 14b before the blocking mechanism 10 operates.

(Embodiment 13)
Next, the power semiconductor device of the thirteenth embodiment will be described with reference to FIG. Since the power semiconductor device of the present embodiment is substantially the same as the semiconductor device of the first embodiment, the difference between the power semiconductor device of the present embodiment and the semiconductor device of the first embodiment will be described below. Mainly explained.

  Note that, in the same manner as the blocking mechanisms of the first to sixth embodiments, the blocking mechanism of the present embodiment is such that one main wiring conductor 2 and the other main wiring conductor 2 are electrically connected by melting and dividing the low melting point material 17. Are separated. In addition, if the low melting-point metal conductor 17 is arrange | positioned below the board | substrate 1, that is, if the interruption | blocking mechanism 10 shown by FIG. When 17 is melted, it falls by gravity. Therefore, the electrical connection between one main wiring conductor 2 and the other main wiring conductor 2 can be more easily interrupted. The dropping of the low-melting point metal conductor 17 using the action of gravity is realized even when the substrate 1 is arranged so as to extend along the vertical direction, for example.

  As shown in FIG. 31, in the power semiconductor device blocking mechanism 10 of the present embodiment, the low melting point metal conductor 17 is arranged to face the heater conductor 4 with the substrate 1 interposed. Yes. The low melting point metal conductor 17 has a melting point lower than that of the low melting point conductor 5. Furthermore, the low melting point metal conductor 17 has a thickness distribution. In the low melting point metal conductor 17 of the present embodiment, the thickness is small at both end portions in contact with the main wiring conductor 2, and the thickness is large at the central portion.

  Generally, a low melting point metal powder is mixed with a powder metal as a binder, printed on the substrate 1, and fired to form a low melting point metal conductor. On the other hand, the low-melting-point metal conductor 17 of the present embodiment has a shape that can be formed by a method such as pouring molten solder into a frame made of a material having low leakage to the solder.

  According to the low melting point metal conductor 17 of the present embodiment described above, the cross-sectional area of the central portion is larger than the cross-sectional area of the main wiring conductor connected to both ends thereof, so The resistance value can be made very small. That is, the shape of the low melting point metal conductor 17 of the present embodiment is suitable for interrupting a circuit through which a large current flows.

  In general, the heat released from the main wiring conductor 2 to the outside hinders the temperature rise of the low melting point metal conductor 17 due to the heat generated by the heater conductor 4, but the low melting point metal conductor 17 of the blocking mechanism 10 of the present embodiment. If the thickness of the portion in contact with the main wiring conductor 2 is smaller than the thickness of the central portion, the heat flow from the low melting point metal conductor 17 to the main wiring conductor 2 is reduced. The thickness is suppressed as compared with the case where the thickness is uniform. Therefore, the temperature of the low melting point metal conductor 17 is likely to rise. As a result, the time until the electronic circuit is cut off is shortened. Therefore, the energy consumed for the heat generation of the heater conductor 4 can be reduced. This leads to an increase in the degree of freedom in designing the blocking mechanism 10.

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.

  1 Substrate, 2 Main wiring conductor, 3 Electrode film, 4, 4a, 4b Heater conductor, 6 Power module, 7 Base plate, 8 Signal terminal, 9 Main terminal, 10 Shut-off mechanism, 11 Terminal block, 12 Housing, 14a, 14b Connection pads, 5, 17 low melting point metal conductors, 15, 25 conductor layers.

Claims (1)

An insulating substrate;
An electrode film provided on one main surface of the substrate;
A heater conductor which is provided on the other main surface of the substrate and generates heat when a current flows;
Each comprising a predetermined electronic circuit and one main wiring conductor and the other main wiring conductor electrically connected to the electrode film;
The electrode film may have a plurality of through holes break line shape extending across the region between the plan view, the one with the main wiring conductor and the other main conductor,
The power semiconductor device having a blocking mechanism , wherein the heater conductor includes one heater conductor provided on one side of the break line and the other heater conductor provided on the other side of the break line .

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