Semiconductor stack and power supply device

Abstract

To provide a semiconductor stack and a power supply device that can be easily and suitably held with a member disposed between holding members.SOLUTION: An input electrode 7 and an output electrode 8 are arranged apart from each other in the axial direction so as to sandwich thyristors 1A to 1C. A holding plate 4A is arranged to face the thyristors 1A to 1C with the input electrode 7 in between. A holding plate 4B is arranged to face the thyristors 1A to 1C with the output electrode 8 in between. An insulating plate 5 is arranged on the side of the holding plate 4B with respect to the output electrode 8. Rods 6A and 6B extend in the axial direction and connect the holding plates 4A and 4B. A hydraulic bellows 3 is inserted between the insulating plate 5 and the holding plate 4B, and can be expanded and contracted in the axial direction by being supplied with fluid thereinto.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a semiconductor stack and a power supply device. [Background technology]

[0002] A thyristor stack in which thyristors are arranged in series is known as a component used in a power conversion device (Patent Documents 1 and 2).

[0003] In such a thyristor stack, multiple stacked thyristors are placed between two holding members, which are connected by multiple rods that pass through them, and the multiple thyristors are held between the two holding members by tightening nuts attached to the ends of each rod.

[0004] As an example of a general semiconductor stack, the semiconductor stack disclosed in Patent Document 1 will be described. Fig. 10 schematically shows an example of the configuration of a general semiconductor stack. The semiconductor stack 900 in Fig. 10 is configured as a thyristor stack. The semiconductor stack 900 includes a thyristor 91, a cooling fin 92, an insulator 93, a holding plate 94, a capacitor 95, electrodes 95A and 95B of the capacitor 95, conductors 95C and 95D connected to the electrodes 95A and 95B of the capacitor 95, a rod 96, and a nut 97.

[0005] The thyristors 91 and the cooling fins 92 are arranged alternately. The alternately arranged thyristors 91 and cooling fins 92, insulators 93, capacitors 95, and electrodes 95A and 95B of the capacitor 95 are arranged between two holding plates 94. A plurality of rods 96 are inserted through the two holding plates 94, and nuts 97 are attached to both ends of each rod 96. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-200128 [Patent Document 2] Japanese Patent Application Publication No. 2018-98969 Summary of the Invention [Problem to be solved by the invention]

[0007] In the semiconductor stack described above, it is necessary to uniformly apply pressure to the contact surfaces of each thyristor with its neighboring thyristors, so multiple rods must be inserted axially symmetrically into the two holding members, with nuts attached to both ends of each rod, and all nuts must be tightened with the same torque.

[0008] However, tightening all nuts with the same torque requires tedious checks such as checking the torque value each time a nut is tightened and making sure the retaining member is not tilted, etc. Therefore, it takes a great deal of effort and time to tighten all nuts with the same torque.

[0009] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0010] In one embodiment, the semiconductor stack comprises: a plurality of semiconductor elements arranged in a first direction; first and second electrodes arranged to be spaced apart in the first direction so as to sandwich the plurality of semiconductor elements; an insulating first holding member disposed opposite the plurality of semiconductor elements along the first direction so as to sandwich the first electrode therebetween; an insulating second holding member disposed opposite the plurality of semiconductor elements along the first direction so as to sandwich the second electrode therebetween; and an insulating member disposed on the second holding member side with respect to the second electrode; a plurality of connecting members extending in the first direction and connecting the first holding member and the second holding member; an extension member that is inserted between the insulating member and the second holding member and that exerts a force to extend the member along the first direction. [Effects of the Invention]

[0011] According to one embodiment, it is possible to provide a semiconductor stack and a power supply device that can easily and suitably hold a member placed between holding members. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram schematically illustrating a configuration of a semiconductor stack according to a first embodiment. [Figure 2] FIG. 2 is a diagram schematically illustrating the semiconductor stack according to the first embodiment when viewed from the -Z side. [Figure 3] FIG. 2 is a diagram schematically illustrating the semiconductor stack according to the first embodiment when viewed from the +Z side. [Figure 4] 1 is a diagram schematically illustrating a configuration of a pressure oil supply system according to a first embodiment. [Figure 5] 1 is a diagram illustrating a schematic configuration of a power supply device according to a first embodiment. [Figure 6] FIG. 10 is a diagram illustrating a configuration of a power supply device according to a second embodiment. [Figure 7] FIG. 10 is a diagram showing the current flow from when thyristors 1A to 1C are turned on until the current becomes zero in the power supply device according to the second embodiment. [Figure 8] FIG. 10 is a diagram showing the flow of current after thyristors 1A to 1C are turned off in the power supply device according to the second embodiment. [Figure 9] FIG. 10 is a diagram schematically illustrating a configuration of a power supply device 3000 according to a third embodiment. [Figure 10] FIG. 1 is a diagram schematically illustrating an example of the configuration of a general semiconductor stack. DETAILED DESCRIPTION OF THE INVENTION

[0013] Specific embodiments will be described in detail below with reference to the drawings. However, the present invention is not limited to the following embodiments. For clarity of explanation, the following description and drawings have been simplified as appropriate. The same elements are given the same reference numerals, and duplicate explanations will be omitted.

[0014] Embodiment 1 A semiconductor stack according to a first embodiment will be described. FIG. 1 schematically shows the configuration of a semiconductor stack 100 according to the first embodiment. A semiconductor stack is configured by stacking a plurality of semiconductor elements, but here, the semiconductor stack 100 will be described as being configured by stacking a plurality of thyristors. In the following, the Z direction (also referred to as the first direction), which is the vertical direction from bottom to top on the paper in the figure, is defined as the axial direction of the semiconductor stack 100. The horizontal direction perpendicular to the Z direction and extending from left to right on the paper is defined as the X direction, and the normal direction perpendicular to the X and Z directions and extending from the front to the back of the paper is defined as the Y direction.

[0015] In the semiconductor stack 100, a plurality of conductive cooling fins 2 are arranged in the Z direction, which is the axial direction of the semiconductor stack 100, and a thyristor 1 is disposed between two adjacent cooling fins. In other words, the contact surfaces of the thyristor 1 and the cooling fins 2, i.e., the main surfaces, are the XY plane, which is a plane perpendicular to the Z direction. Here, as an example, a configuration is shown in which four cooling fins 2A to 2D and three thyristors 1A to 1C are stacked alternately from the -Z side to the +Z side.

[0016] An input electrode 7 (also referred to as a first electrode) is arranged at one end of the stack of thyristors 1 and cooling fins 2, i.e., between the -Z side of cooling fin 2A and an insulating holding plate 4A (also referred to as a first holding member). An insulating plate 5 (also referred to as an insulating member), an output electrode 8 (also referred to as a second electrode), and a hydraulic bellows 3 (also referred to as an expansion member) are arranged in this order at the other end of the stack of thyristors 1 and cooling fins 2, i.e., between the +Z side of cooling fin 2D and an insulating holding plate 4B (also referred to as a second holding member).

[0017] The cooling fins 2A to 2D are connected to, for example, cooling pipes 30, and are configured so that the cooling fins 2A to 2D can be cooled by circulating a fluid through the cooling pipes 30.

[0018] A plurality of rods 6A to 6D (also referred to as connecting members) extending in the axial direction (Z direction) are inserted through the holding plates 4A and 4B. Nuts 9A to 9D are fitted to the ends of the rods 6A to 6D on the holding plate 4A side (-Z side), respectively. Nuts 10A to 10D are fitted to the ends of the rods 6A to 6D on the holding plate 4B side (+Z side), respectively. When viewed along the axial direction (Z direction), the rods 6A to 6D are arranged symmetrically with respect to the central axis. FIG. 2 schematically shows the semiconductor stack 100 as viewed from the -Z side. FIG. 3 schematically shows the semiconductor stack 100 as viewed from the +Z side. As shown in FIGS. 2 and 3, the rods 6A to 6D are arranged at the vertices of a square symmetrical with respect to the central axis 101 of the semiconductor stack 100. By tightening nuts 9A to 9D and 10A to 10D, the stack of thyristors 1 and cooling fins 2, hydraulic bellows 3, insulating plate 5, input electrode 7 and output electrode 8 arranged between holding plate 4A and holding plate 4B can be clamped by holding plate 4A and holding plate 4B.

[0019] The hydraulic bellows 3 has a hollow bellows section 3A, a plate 3B arranged on the -Z side, a plate 3C arranged on the +Z side, and a pressure oil supply port 3D. The pressure oil supply port 3D is configured to supply pressure oil supplied from the outside to a space closed by the bellows section 3A and the plates 3B and 3C.

[0020] As a result, when pressure oil is supplied through the pressure oil supply port 3D, the hydraulic bellows 3 expands and contracts in the axial direction (Z direction). Needless to say, the bellows portion 3A does not expand and contract in the X and Y directions that are perpendicular to the axial direction (Z direction). However, if the plates 3B and 3C are not coaxial, the bellows portion 3A can deform in the direction perpendicular to the axial direction (Z direction).

[0021] In this configuration, by extending the hydraulic bellows 3, pressure can be applied to the contact surface between the components arranged between the retaining plates 4A and 4B, and these components can be clamped between the retaining plates 4A and 4B.

[0022] Furthermore, in this configuration, by supplying pressure oil to the hydraulic bellows 3, pressure is applied evenly to the contact surface between the plate 3B and the insulating plate 5. Similarly, pressure is applied evenly to the contact surface between the plate 3C and the holding plate 4B.

[0023] Needless to say, even if the main surfaces of holding plates 4A and 4B are not parallel, the deformation of bellows portion 3A will apply even pressure to the contact surface of plate 3B with insulating plate 5, and even pressure will be applied to the contact surface of plate 3C with holding plate 4B.

[0024] Here, we have described the hydraulic bellows 3, but it is possible to use other components than the hydraulic bellows as long as they can be supplied with any pressurized fluid such as pressure oil, have an enclosed container capable of sealing the supplied fluid, and the axial (Z-direction) end of the enclosed container can make surface contact with components such as the insulating plate 5 and the retaining plate 4B.

[0025] Alternatively, as described above, a sealing member may be used in which a path for supplying pressurized fluid to the sealed container is not connected, the closed sealed container is filled with fluid, and the axial (Z-direction) end can be in surface contact with components such as the insulating plate 5 and the retaining plate 4B. For example, the above-mentioned sealing member applies when pressure oil is supplied to the bellows portion 3A, which is a sealed container, from a pipe connected to the pressure oil supply port 3D, and then the pipe is disconnected from the pressure oil supply port 3D and the end of the pressure oil supply port 3D is blocked. Even in this case, by pressurizing the fluid in the container above atmospheric pressure, pressure can be applied evenly to the contact surface between the plate 3C and the retaining plate 4B. Note that blocking the end of the pressure oil supply port 3D is expected to effectively prevent oil leakage from the hydraulic bellows 3 when the semiconductor stack 100 is used.

[0026] In other words, regardless of whether there is a fluid supply path or not, it is sufficient that a fluid sealing member whose inside is filled with pressurized fluid and whose end in the axial direction (Z direction) is in surface contact with other adjacent members is inserted between adjacent members, in this example, between the insulating plate 5 and the holding plate 4B. Note that hereinafter, the above-mentioned fluid sealing member which is capable of applying pressure in the axial direction (Z direction) to other adjacent members, in other words, which is subjected to a force that stretches it in the axial direction (Z direction) while inserted between adjacent members, is also referred to as an extension member.

[0027] Next, a pressure oil supply system that supplies pressure oil to the semiconductor stack 100 will be described. FIG. 4 schematically shows the configuration of a pressure oil supply system 110 according to the first embodiment. The pressure oil supply system 110 includes a control unit 111, a pressure oil supply unit 112, and a pressure gauge 113. The pressure oil supply unit 112 includes an accumulator that pressurizes hydraulic oil, a pump that delivers pressure oil, a valve that opens and closes a pressure oil supply path, and the like. The pressure oil supply unit 112 is connected to a pressure oil supply port 3D via a pipe 114 and supplies pressure oil to the hydraulic bellows 3. The pressure gauge 113 is provided in, for example, the pipe 114 and measures the pressure of the pressure oil supplied to the hydraulic bellows 3. The control unit 111 monitors the hydraulic pressure measured by the pressure gauge 113 and controls the pressure oil supply unit 112 by providing a control signal C1 so that the hydraulic pressure of the hydraulic bellows 3 becomes a desired value.

[0028] Therefore, by connecting the pressurized oil supply system 110 to the semiconductor stack 100, it is possible to control the pressurized oil in the hydraulic bellows 3 to an appropriate value and continuously maintain the components between the holding plates 4A and 4B in an appropriate state.

[0029] Furthermore, since the hydraulic pressure of the hydraulic bellows 3 can be constantly controlled, it is possible to omit maintenance work such as retightening nuts, which is required for general semiconductor stacks.

[0030] Next, a power supply device using the semiconductor stack 100 will be described. FIG. 5 schematically shows the configuration of the power supply device 1000 according to the first embodiment. The power supply device 1000 has the semiconductor stack 100, a capacitor 11, and a control unit 12. The input electrode 7 is connected to one end of the capacitor 11. The output electrode 8 and the capacitor 11 are connected via a load 13. The control unit 12 controls the operations of the thyristors 1A to 1C using a control signal C2.

[0031] The operation of the power supply device 1000 will now be described. The capacitor 11 is charged in advance by a charging device (not shown) so that the end connected to the input electrode 7 is positive and the end connected to the load 13 is negative. Then, when the control unit 12 turns on the thyristors 1A to 1C using a control signal C2, a current begins to flow in the forward direction of the thyristors 1A to 1C and continues to flow until the current reaches zero. This makes it possible to supply a relatively large current to the load 13.

[0032] Embodiment 2 A power supply device according to a second embodiment will now be described. Fig. 6 schematically shows the configuration of a power supply device 2000 according to the second embodiment. The power supply device 2000 has a configuration in which the semiconductor stack 100 of the power supply device 1000 is replaced with a semiconductor stack 200. The semiconductor stack 200 has a configuration in which three diodes 14A to 14C, four cooling fins 2E to 2H, and a ground-side electrode 15 are added between the output electrode 8 of the semiconductor stack 100 and the insulating plate 5. The cooling fins 2E to 2H have the same configuration as the cooling fins 2A to 2D.

[0033] In the semiconductor stack 200, diodes 14A to 14C are arranged between each two adjacent ones of the four cooling fins 2E to 2H from the output electrode 8 toward the insulating plate 5, and an earth side electrode 15 is inserted between the cooling fin 2H and the insulating plate 5.

[0034] Next, the operation of the power supply device 2000 will be described. Fig. 7 shows the current flow from when the thyristors 1A to 1C are turned on until the current becomes zero. When the control unit 12 turns on the thyristors 1A to 1C, a forward current I1 starts to flow. The current I1 flows forward from the capacitor 11 through the input electrode 7 and through the thyristors 1A to 1C. It then flows through the output electrode 8 and the load 13 to the capacitor 11. This current I1 flows until the current flowing through the thyristors 1A to 1C becomes zero and the thyristors 1A to 1C are turned off.

[0035] FIG. 8 shows the current flow after thyristors 1A to 1C are turned off. Even after thyristors 1A to 1C are turned off, an induced voltage is generated due to the inductor component of load 13. Therefore, current I2 flows in the same direction as current I1, i.e., in the forward direction of diodes 14A to 14C, through the circuit formed by load 13, output electrode 8, earth side electrode 15, and diodes 14A to 14C. The value of current I2 decreases as the energy of the inductor component is released.

[0036] As described above, with this configuration, even when a power supply device is configured using a semiconductor stack made up of thyristors and current flows through the thyristors, it is possible to prevent a high reverse voltage from being applied when the thyristors are turned off, thereby making it possible to avoid damage to the thyristors.

[0037] Embodiment 3 A power supply device according to a third embodiment will now be described. Fig. 9 schematically shows the configuration of a power supply device 3000 according to the third embodiment. The power supply device 3000 is a modified example of the power supply device 2000, and has a configuration in which the control unit 12 is integrated with the semiconductor stack 200 and the capacitor 11.

[0038] In this configuration, the output electrode of capacitor 11 is attached near input electrode 7, and semiconductor stack 200 and capacitor 11 are integrated together. Capacitor 11 is provided, for example, below semiconductor stack 200 and housed inside support base 20 that mechanically supports semiconductor stack 200. This allows power supply device 3000 to have a more compact configuration than power supply device 2000.

[0039] In FIG. 9, the input electrode of the capacitor 11 is connected to the earth electrode 15 via two paths, but the circuit configuration and current paths are substantially the same as those of the power supply device 2000, so a description thereof will be omitted.

[0040] As described above, according to this configuration, as in the second embodiment, even when a power supply device is configured using a semiconductor stack made up of thyristors and current flows through the thyristors, it is possible to prevent a high reverse voltage from being applied when the thyristors are turned off, thereby making it possible to avoid damage to the thyristors.

[0041] Furthermore, by integrating the semiconductor stack and the capacitor, a more compact power supply device can be provided.

[0042] Other embodiments The present invention is not limited to the above-described embodiments, and modifications can be made as appropriate without departing from the spirit of the present invention. For example, for simplicity, a configuration in which the semiconductor stack has three thyristors and four cooling fins has been described, but this is merely an example. A semiconductor stack may be configured with two or more thyristors and cooling fans arranged alternately with respect to the thyristors. In this case, any number of cooling fins may be used as long as the two or more thyristors can be appropriately cooled. In other words, any number of cooling fins may be arranged in the Z direction for multiple thyristors. The above also applies to multiple diodes according to the second and third embodiments.

[0043] In the above embodiment, the cooling fins are described as being liquid-cooled cooling fins, but this is merely an example. For example, the cooling fins may be configured as any cooling member, such as air-cooled cooling fins.

[0044] In the above embodiment, four rods are described as being arranged symmetrically with respect to the central axis when viewed along the axial direction (Z direction), but this is merely an example. Any number of rods greater than three may be arranged as long as they can be arranged symmetrically with respect to the central axis. Also, in the above embodiment, an example was described in which the holding plate is square, but any shape, such as a polygon, circle, or ellipse, may be used as long as they can be arranged symmetrically with respect to the central axis.

[0045] Furthermore, although the description has been given of the holding plates 4A and 4B being connected by a plurality of rods and a plurality of nuts, other connecting members may be used as appropriate as long as they can fix the positional relationship between the holding plates 4A and 4B.

[0046] In the above-described first embodiment, the anode of the thyristor is configured to face the -Z side and the cathode is configured to face the +Z side, but the anode of the thyristor may be configured to face the +Z side and the cathode is configured to face the -Z side. Also, in the above-described second and third embodiments, the anode of the thyristor is configured to face the -Z side and the anode of the diode is configured to face the +Z side, but the anode of the thyristor may be configured to face the +Z side and the anode of the diode is configured to face the -Z side. In this case, the positions of the input electrode 7 and the output electrode 8 are swapped, and the input electrode 7 becomes the second electrode and the output electrode 8 becomes the first electrode. Also, the polarity when charging capacitor 11 is reversed.

[0047] In the above description, it has been explained that pressure oil is supplied to the hydraulic bellows 3, but a pressurized liquid other than pressure oil may be sealed in the fluid sealing member including the hydraulic bellows 3. Furthermore, the fluid is not limited to liquid, and may be any of various gases. [Explanation of symbols]

[0048] 1, 1A~1C, 91 Thyristor 2, 2A~2H, 92 Cooling fins 3 Hydraulic bellows 3A Bellows section 3B, 3C plates 3D pressure oil supply port 4A, 4B, 94 Holding plate 5. Insulating plate 6A~6D, 96 rods 7 Input electrodes 8 Output Electrodes 9A~9D, 10A~10D, 97 Nut 11, 95 capacitor 12 Control Unit 13 Load 14A~14C diode 15 Earth electrode 20 Support stand 30 Cooling piping 93 Insulator 95A, 95B electrode 95C, 95D conductor 96 Rod 100, 200, 900 semiconductor stacks 101 Center axis 110 Pressure Oil Supply System 111 Control Unit 112 Pressure oil supply unit 113 Pressure Gauge 114 Piping 1000, 2000, 3000 power supplies I1, I2 current C1, C2 control signals

Claims

1. a plurality of semiconductor elements arranged in a first direction; first and second electrodes arranged to be spaced apart in the first direction so as to sandwich the plurality of semiconductor elements; an insulating first holding member disposed opposite the plurality of semiconductor elements along the first direction so as to sandwich the first electrode therebetween; an insulating second holding member disposed opposite the plurality of semiconductor elements along the first direction so as to sandwich the second electrode therebetween; and an insulating member disposed on the second holding member side with respect to the second electrode; a plurality of connecting members extending in the first direction and connecting the first holding member and the second holding member; an extension member that is inserted between the insulating member and the second holding member and that exerts a force to extend the extension member along the first direction, Semiconductor stack.

2. the extension member is a member that can expand and contract due to the pressure of an internal fluid, the extension force is exerted by the pressure of the fluid supplied to the extension member, and a load is applied to the second holding member and the insulating member, whereby the plurality of semiconductor elements, the first and second electrodes, the insulating member, and the extension member are sandwiched between the first holding member and the second holding member. The semiconductor stack of claim 1 .

3. a passage for supplying the fluid is connected to the extension member; an external oil supply means for adjusting the pressure of the fluid inside the extension member via the passage; The semiconductor stack of claim 2 .

4. The extension member has a closed container with the fluid enclosed therein. The semiconductor stack of claim 2 .

5. the extension member is in surface contact with a surface of the insulating member that is perpendicular to the first direction; A semiconductor stack according to any one of claims 1 to 4.

6. the extension member is a hydraulic bellows that can expand and contract in the first direction when pressure oil is supplied thereto; A semiconductor stack according to any one of claims 1 to 5.

7. the plurality of connecting members are arranged at positions symmetrical with respect to a central axis of the semiconductor stack in a plane perpendicular to the first direction. A semiconductor stack according to any one of claims 1 to 6.

8. the semiconductor device further includes a conductive first cooling member that is arranged between the first electrode and the second electrode and aligned with the semiconductor elements in the first direction, and that cools the semiconductor elements; A semiconductor stack according to any one of claims 1 to 7.

9. the plurality of first cooling members and the plurality of semiconductor elements are alternately arranged in the first direction; The semiconductor stack of claim 8 .

10. The semiconductor element is a thyristor. A semiconductor stack according to any one of claims 1 to 9.

11. The semiconductor stack of claim 10; a capacitor having one end connected to one of the first and second electrodes; a control unit that applies a control signal to the plurality of thyristors; a load is connected between the other end of the capacitor and the other of the first and second electrodes; When the capacitor is charged, the control unit turns on the plurality of thyristors using the control signal, causing a current to flow in the forward direction of the plurality of thyristors. power supply.

12. a plurality of diodes arranged in the first direction with polarity opposite to that of the plurality of thyristors, so as to face the plurality of thyristors across the electrode, with the cathode facing the electrode of the first and second electrodes that is arranged on the cathode side of the plurality of thyristors; a third electrode disposed on the anode side of the plurality of diodes; the third electrode and the end of the capacitor on the load side are connected; 12. The power supply device of claim 11.

13. the plurality of diodes are arranged alternately in the first direction, and the plurality of second cooling members are electrically conductive and cool the plurality of diodes.

13. The power supply device of claim 12.

Images