JPH11186478A - Semiconductor module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor module which can be assembled without requiring connecting work of a wire for fixing potential. SOLUTION: In a semiconductor module having a semiconductor stack constituted by alternately connecting thyristors 1A and 1B and heat sinks 5A, 5B, and 5C in series, branch cooling water pipes 8A-8I and 9 which distribute cooling water to the heat sinks 5A, 5B, and 5C, resistors 2A and 2B, a reactor 4, etc., are provided. Of the pipes 8A-8I and 9, the pipe 9 which supplies the cooling water to the intermediate heat sink 5B from a cooling water pipe 6B which is maintained at the same potential as that at a frame 7 is made to have electrical conductivity. Therefore, the potential at the frame 7 can be fixed to the intermediate potential of the semiconductor module without connecting any wire for fixing potential.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled semiconductor module used for converting large-capacity AC power and DC power.

[0002]

2. Description of the Related Art Thyristors, optical thyristors, GTO thyristors, IGBTs and the like are used as semiconductors for semiconductor modules used for large-capacity power conversion. Here, a method of fixing the potential of a thyristor module will be described using a thyristor as an example. I do.

In a thyristor module used for large-capacity power conversion, a plurality of thyristor elements connected in series and in parallel are used, so that the voltage applied to one module becomes large. It is necessary to secure a sufficient insulation distance.

It is assumed that a thyristor module having a thyristor stack in which two thyristor elements are connected in series has 4
Considering the case where a voltage of kV is applied, when one end of the thyristor stack is fixed to the frame, the insulation distance in the module requires a maximum of 4 kV, but the frame potential is fixed to the middle potential of the thyristor stack. In this case, an insulation distance of 2 kV, which is half of the potential fixing method, is sufficient.

Therefore, conventionally, a method of fixing the frame potential to the intermediate potential of the thyristor stack has been adopted. However, since the electric wires are used for fixing the potential, an extra operation of connecting the electric wires has occurred.

Here, the configuration of a conventional thyristor module will be described with reference to the drawings. FIG. 8 shows two thyristors 1
A and 1B are connected in series, and a snubber circuit composed of a series connection of a resistor 2A and a capacitor 3A or a resistor 2B and a capacitor 3B is connected in parallel with each of the thyristors 1A and 1B, and the anode reactor 4 is connected to the thyristors 1A and 1B. FIG. 3 is a circuit diagram of a water-cooled thyristor module in which are connected in series.

Here, the thyristors 1A and 1B and the resistor 2
A, 2B and the anode reactor 4 are water-cooled. FIG. 7 also shows the electrical connection and the cooling piping system in this case. The thyristors 1A and 1B are sandwiched and cooled by water-cooled heat sinks 5A, 5B and 5C from both sides. The cooling water is guided to each component in the thyristor module through the conductive cooling water pipes 6A and 6B, and takes out the respective heat and is discharged. Usually, a plurality of thyristor modules are used to constitute a thyristor valve. Although not shown here, cooling water is supplied to and discharged from each thyristor module in parallel.

Various systems are used for the cooling system of the water-cooled thyristor module. Here, the two systems will be described. The cooling water is a water-cooled heat sink 5A, 5B,
The system branches to a system of 5C and a system of resistors 2A and 2B and an anode reactor 4. Water-cooled heat sink 5A, 5B, 5
The system C cools the thyristors 1A and 1B from the conductive cooling water pipe 6A through the cooling water pipe connection portion 12.
The other system cools the resistors 2A and 2B and the anode reactor 4 from the conductive cooling water pipe 6A through the cooling water pipe connection portion 12. The frame potential of the thyristor module is fixed to an intermediate potential of two thyristors 2A and 2B connected in series by a potential fixing wire 15.

[0009]

In the conventional method of fixing a potential in a semiconductor module, in assembling the semiconductor module, an electric wire support is attached in consideration of an insulation distance from a component on the semiconductor module, and a screw hole for fixing to a frame is formed. Therefore, work for connecting the electric potential fixing wires was required. An object of the present invention is to provide a semiconductor module that can reduce the work related to connection of the electric potential fixing wires during assembly.

[0010]

To achieve the above object, the present invention provides a semiconductor stack in which a plurality of semiconductor elements and a plurality of heat sinks for cooling the semiconductor elements are connected alternately in series, A series circuit of a connected resistor and capacitor, a reactor connected in series with the semiconductor element, a cooling water pipe having conductivity, a cooling water branch pipe for branching the cooling water to a heat sink, a resistor, and the reactor A cooling water branch pipe that branches cooling water to a heat sink at an intermediate position among heat sinks in a semiconductor module provided on a metal frame having the same potential as a cooling water pipe. The electric potential fixing cooling water branch pipe to be fixed is characterized by having conductivity.

With this configuration, it is possible to reduce the work related to the connection of the electric potential fixing wires when assembling the semiconductor module. Also, the present invention
A semiconductor stack in which a plurality of semiconductor elements and a plurality of heat sinks for cooling the semiconductor elements are alternately connected in series,
A series circuit of a resistor and a capacitor connected in parallel to the semiconductor element, and a reactor connected in series to the semiconductor element,
A cooling water pipe having conductivity, a heat sink, a resistor,
And a cooling water branch pipe for branching the cooling water to the reactor, and a cooling water pipe for branching the cooling water to a heat sink at an intermediate position among a plurality of heat sinks in a semiconductor module provided on a metal frame having the same potential as the cooling water pipe. The branch pipe is a potential fixing cooling water branch pipe for fixing the metal frame potential to the intermediate potential of the semiconductor stack, and has conductivity and flexibility.

With this configuration, it is possible to reduce the work related to the connection of the electric potential fixing wires when assembling the semiconductor module, and when the power is turned on, the conductive element is expanded due to the expansion of the semiconductor element and the heat sink. It is possible to prevent an excessive force from being applied to the potential fixing cooling water branch pipe.

Here, an orifice may be provided at a predetermined position of the potential fixing cooling water branch pipe. Also, a valve may be connected in series to the potential fixing cooling water branch pipe.

Further, the inside diameter of the potential fixing cooling water branch pipe may be different from the inside diameter of the other cooling water branch pipes. Thus, in the potential fixing cooling water branch pipe,
By providing an orifice, connecting valves in series, or making the inside diameter of the potential fixing cooling water branch pipe different, the flow rate of cooling water in the semiconductor module can be adjusted.

Furthermore, one end of the potential fixing cooling water branch pipe having flexibility may be welded or brazed to a cooling water pipe or a heat sink at an intermediate position. With such a configuration, the potential fixing operation can be performed more easily.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the drawings below, the same reference numerals indicate the same or corresponding parts, including the figures showing the conventional example.

FIGS. 1A and 1B are actual arrangement diagrams showing a first embodiment of the present invention, wherein FIG. 1A is a plan view and FIG. 1B is a front view. In the drawings, some parts that are not necessary for description are omitted.

In FIG. 1, various components such as thyristors 1A and 1B are mounted on a frame 7. The cooling water is supplied from the conductive cooling water pipe 6A, which is a cooling water main pipe, to the insulating cooling water branch pipes 8D, 8D.
Thyristor 1 on the frame via E, 8F, 8G
A, 1B, resistors 2A, 2B, and the anode reactor 4. After cooling these components, they pass through insulating cooling water branch pipes 8A, 8H, 8I and conductive cooling water branch pipe 9A having flexibility. Conductive cooling water piping 6
Collected by B.

Here, one end of the conductive cooling water branch pipe 9A is connected to a heat sink 5B at an intermediate position corresponding to an intermediate potential portion of the semiconductor stack, and the other end is a conductive cooling water pipe fixed to the frame 7. 6B, the frame potential can be fixed to the intermediate potential of the semiconductor module without connecting the potential fixing wire.

Since the conductive cooling water branch pipe 9A has flexibility, the thyristors 1A and 1B and the heat sink 5 can be connected to the semiconductor module when power is supplied to the semiconductor module.
A, 5B, 5C and the expansion of the holding members at both ends absorb the force applied to the conductive cooling water branch pipe 9A due to its flexibility, and an excessive force is applied to the conductive cooling water branch pipe 9A. Can be prevented.

That is, the insulating cooling water branch pipes 8H and 8I
Are usually made of a flexible material such as Teflon, so that the thyristors 1A and 1B, the heat sinks 5A and 5B,
There is no problem even if the 5C and the holding members at both ends expand. On the other hand, the conductive cooling water branch pipe 9A
Is made of, for example, a material such as copper, stainless steel, or aluminum, so that when the thyristors 1A and 1B, the heat sinks 5A, 5B and 5C, and the holding members at both ends expand, the conductive cooling water branch pipe Since an excessive force is applied to the 9A, it is preferable to prevent it from being applied by absorbing it by its flexibility.

In order to impart flexibility to the conductive cooling water branch pipe 9A, for example, the thickness of the pipe may be reduced, or the entire pipe or a part thereof may be made bellows. It is conceivable to use a method such as using annealed copper.

In FIG. 1, reference numeral 10 denotes a drain-side pipe joint, 11 denotes an inlet-side pipe joint, and 12 denotes a cooling water branch pipe joint. Next, a second embodiment of the present invention will be described.

For example, when the pipes are arranged as shown in FIG. 2, in order to make the flow rates of the insulating cooling water branch pipes 8H and 8I and the conductive cooling water branch pipe 9B uniform, the conductive cooling water branch pipe is used. It is necessary to adjust the flow rate of 9B.

Therefore, in this embodiment, as shown in FIG. 3, the orifice 1 for adjusting the flow rate is provided in the middle of the cooling water branch pipe 9B having flexibility.
3 is provided. With such a configuration, the frame potential can be fixed to the intermediate potential of the semiconductor module without connecting the potential fixing wires, and the flow balance in the semiconductor module can be adjusted.

The position where the orifice 13 is provided is not located in the middle of the cooling water branch pipe 9B but in the cooling water branch pipe 9B.
B may be any end. Next, the third aspect of the present invention
An embodiment will be described. Fig. 4 shows the configuration of the main part.
Shown in In this embodiment, a valve 14 for adjusting the flow rate is provided in the middle of the flexible cooling water branch pipe 9C, and the frame potential can be fixed at the intermediate potential of the semiconductor module without connecting the potential fixing wire. At the same time, the cooling water flow rate can be adjusted.

The position of the valve 14 may not be in the middle of the cooling water branch pipe 9C but may be at any end of the cooling water branch pipe 9C. Next, a fourth embodiment of the present invention will be described. FIG. 5 shows the configuration of the main part. In this embodiment, the inside diameter of the cooling water branch pipe 9D having flexibility is different from the inside diameters of the other cooling water branch pipes 8H and 8I. That is, the inside diameter of the cooling water branch pipe 9D is smaller than the inside diameters of the other cooling water branch pipes 8H and 8I. Accordingly, the frame potential can be fixed at the intermediate potential of the semiconductor module without connecting the potential fixing wire, and the flow rate of cooling water in the semiconductor module can be adjusted.

Next, a fifth embodiment of the present invention will be described. In this embodiment, one end of a conductive cooling water branch pipe having flexibility is welded or brazed to a conductive cooling water pipe or a heat sink corresponding to an intermediate potential of a semiconductor stack to form an integral structure.

FIG. 6 shows the structure of the main part of this embodiment. FIG. 5A shows a structure in which one end of a conductive cooling water branch pipe 9E having flexibility is brazed or welded to a conductive cooling water pipe 6B to form an integral structure.

FIG. 2B shows an integrated structure in which one end of a conductive cooling water branch pipe 9F having flexibility is brazed or welded to a heat sink 5B corresponding to an intermediate potential of the semiconductor stack. Things.

With such a configuration, the operation of fixing the potential of the semiconductor module can be performed more easily than in the first to fourth embodiments. That is, by previously brazing or welding one end of the conductive cooling water branch pipe to a conductive cooling water pipe or a heat sink corresponding to an intermediate potential of the semiconductor stack to form an integrated structure, other potential fixing work is performed. It is only necessary to fix only the end to the conductive cooling water pipe or the heat sink corresponding to the intermediate potential of the semiconductor stack with the cap nut of the joint 12 or the like. Therefore, when both ends of the conductive cooling water branch pipe are fixed to the heat sink corresponding to the intermediate potential of the conductive cooling water pipe and the semiconductor stack, respectively, as in the above-described first to fourth embodiments. The work becomes easier as compared to

[0032]

As described above, according to the semiconductor module of the present invention, the frame of the semiconductor module used for converting large-capacity AC power and DC power can be connected without connecting the electric potential fixing wire. Can be fixed to the intermediate potential of.

[Brief description of the drawings]

FIG. 1 is a plan view and a front view showing a configuration of a semiconductor module according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an electrical connection and a cooling piping system of a semiconductor module according to a second embodiment of the present invention.

FIG. 3 is a front view showing a configuration of a main part of a semiconductor module according to a second embodiment of the present invention.

FIG. 4 is a front view showing a configuration of a main part of a semiconductor module according to a third embodiment of the present invention.

FIG. 5 is a front view showing a configuration of a main part of a semiconductor module according to a fourth embodiment of the present invention.

FIG. 6 is a side view showing a configuration of a main part of a semiconductor module according to a fifth embodiment of the present invention.

FIG. 7 is a diagram showing an electrical connection and a cooling piping system of a conventional semiconductor module.

FIG. 8 is a circuit diagram of a semiconductor module.

[Explanation of symbols]

 1A, 1B: Thyristor 2A, 2B: Resistor 3A, 3B: Capacitor 4: Anode reactor 5A, 5B, 5C: Heat sink 6A, 6B: Conductive cooling water pipe 7: Frame 8A-8I: Insulating cooling water branch pipe 9A- 9F: Conductive cooling water branch pipe 10: Drain-side pipe joint 11: Inlet-side pipe joint 12 ... Cooling water branch pipe joint 13: Orifice 14: Valve 15: Potential fixing wire

Claims (6)

[Claims] A semiconductor stack in which a plurality of semiconductor elements and a plurality of heat sinks for cooling the semiconductor elements are alternately connected in series; a series circuit of a resistor and a capacitor connected in parallel to the semiconductor elements; A reactor connected in series with the element, a cooling water pipe having conductivity, the heat sink, the resistor, and a cooling water branch pipe for branching the cooling water to the reactor, the same potential of the cooling water pipe and In a semiconductor module provided on a metal frame, a cooling water branch pipe for branching cooling water to a heat sink at an intermediate position among the heat sinks,
A semiconductor module having conductivity as a potential fixing cooling water branch pipe for fixing the metal frame potential to an intermediate potential of the semiconductor stack. 2. A semiconductor stack in which a plurality of semiconductor elements and a plurality of heat sinks for cooling the semiconductor elements are alternately connected in series, a series circuit of a resistor and a capacitor connected in parallel to the semiconductor elements, and A reactor connected in series with the element, a cooling water pipe having conductivity, the heat sink, the resistor, and a cooling water branch pipe for branching the cooling water to the reactor, the same potential of the cooling water pipe and In a semiconductor module provided on a metal frame, a cooling water branch pipe for branching cooling water to a heat sink at an intermediate position among the heat sinks,
A semiconductor module, wherein the potential fixing cooling water branch pipe for fixing the metal frame potential to the intermediate potential of the semiconductor stack has conductivity and flexibility. 3. The semiconductor module according to claim 1, wherein an orifice is provided at a predetermined position of the potential fixing cooling water branch pipe. 4. The valve according to claim 1, wherein a valve is connected in series to said potential fixing cooling water branch pipe.
A semiconductor module according to item 1. 5. The semiconductor module according to claim 1, wherein an inner diameter of the potential fixing cooling water branch pipe is different from an inner diameter of another cooling water branch pipe. 6. An electric potential fixing cooling water branch pipe having one end welded or brazed to the cooling water pipe or a heat sink at an intermediate position.
A semiconductor module according to item 1.