JP2001326324A - Method of connecting conductors of stack structure, and stack structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily connect the conductors of electric parts constituting the stacks without increasing the setup time, the number of parts, the storage space, etc. SOLUTION: A stack structure is composed of an inverter stack consisting of the stack of GTO thyristors 10 and 12 equipped with inflexible conductors 10A, 10K, 12A, and 12K and cooling bodies 22-24. The conductor 10A of the GTO thyristor 10 and the conductor 12K of the GTO thyristor 12 are connected with each other. In this connection method, one end face of a flexible lead 40 and the end face of the conductor 10A are connected with each other by electric beam welding, and the other end face of the flexible lead 40 and the end face of the conductor 12K are connected with each other by electronic beam welding, using the flexible lead 40 being a flexible conductor having an end in sectional form roughly equivalent to the sectional form of the conductors 10A and 12K.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of connecting conductors of a stack structure for connecting conductors of two electric components of a stack structure composed of a laminate of a plurality of components, and more particularly to a semiconductor element and a cooling component. The present invention relates to a method of connecting conductors of a stack structure for connecting conductors of semiconductor elements of a semiconductor stack in which are stacked alternately. In addition, the present invention
The present invention relates to a stack structure composed of a laminate of electric components connected by this conductor connection method.

[0002]

2. Description of the Related Art In order to operate electric components under a large current or a high voltage, a stack is formed by stacking a plurality of electric components via other components, and a conductor between the electric components in the stack is formed. Are generally used by electrically connecting them in series or in parallel. For example, as an inverter for performing pulse width modulation control, a plurality of gate turn-off thyristors (GTO
A thyristor) and a cooling body are alternately stacked to form an inverter stack. That is, GTO
The thyristor loses its function due to thermal destruction when the junction temperature exceeds a predetermined temperature during energization.Therefore, the cooling body of the boiling cooling device and the GTO thyristor are alternately arranged so that the junction temperature does not become higher than the predetermined temperature. To form an inverter stack.

FIG. 2 is a schematic diagram showing how semiconductor elements are connected in a conventional inverter stack. In the figure, two flat GTO thyristors 1
0 and 12 are aluminum nitride (ALN) to be the insulating plate
Cooling bodies 22-of boiling cooling device 20 via plates 14-17
24, the cooling body 22, AL
N plate 14, GTO thyristor 10, ALN plate 15, cooling body 23, ALN plate 16, GTO thyristor 12, ALN
A laminated body including the plate 17 and the cooling body 24, that is, an inverter stack is configured. The evaporative cooling device 20 includes a common condenser 25 and connecting pipes 26 to 2 including bellows gas phase pipes.
8. It is composed of liquid return pipes 29 to 31 and cooling bodies 22 to 24. Heat generated by the GTO thyristors 10 and 12 is transmitted to the cooling bodies 22 to 24 via the ALN plates 14 to 17. In the cooling bodies 22 to 24, the heat causes the refrigerant to boil and vaporize. The vaporized refrigerant rises up the connection pipes 26 to 28 and is led to the common condenser 25, where it is liquefied. The liquefied refrigerant is temporarily stored in the common condenser 25, and falls back to the cooling bodies 22 to 24 via the liquid return pipes 29 to 31 to return. The boiling cooling device suppresses an increase in the temperature of the GTO thyristors 10 and 12 by boiling and vaporizing the refrigerant in the cooling bodies 22 to 24 and liquefying the refrigerant in the common condenser 25.

[0004] As described above, the semiconductor element which is an electric component constituting the inverter stack, that is, the GTO thyristor 1
When the 0 and 12 conductors are connected to each other, it is necessary for the connecting conductors to secure a good contact state and a good contact area after absorbing dimensional errors of individual parts. On the other hand, the anode conductors 10A and 12A and the cathode conductors 10K and 12K of the GTO thyristors 10 and 12 are required to have their flatness, flatness, and the like defined and not change their state over time. In general, it is composed of a single inflexible copper plate that does not exhibit flexibility. Therefore,
As shown in FIG. 2, when the GTO thyristors 10 and 12 are pressed into contact with the cooling bodies 22 to 24 and are connected to each other in series, the end of the anode conductor 10 </ b> A of the GTO thyristor 10 and the GTO thyristor 12 are connected. Cathode conductor 1
It is bent so that the 2K ends are parallel to each other,
Further, the other anode conductor 12A and cathode conductor 10K are also bent in order to secure an insulation distance between the bolt 55 and the nut 56 for tightening the anode conductor 10A and the cathode conductor 12K. In such a configuration, a gap is previously secured between the anode conductor 10A and the cathode conductor 12K in consideration of the manufacturing error of each component, and the anode conductor 10A and the cathode conductor 12K are secured.
A spacer 13 is inserted between the ends so that no stress is applied to K, and the spacer 13 is tightened and connected by bolts 55 and nuts 56.

FIG. 3 is another schematic diagram showing how semiconductor elements are connected in a conventional inverter stack. 3, the same components as those in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted. In this inverter stack, the GTO thyristor 1
0, 12 anode conductor 10A and cathode conductor 12K
Is not processed, and its ends are tightened and connected by bolts 55 and 57 and nuts 56 and 58 via a flexible lead 40 having flexibility. Note that G
The cathode conductor 10 </ b> K of the TO thyristor 10 and the anode conductor 12 </ b> A of the GTO thyristor 12 are bent in a stepwise manner as shown in the figure in order to secure an insulation distance between the bolts 55 and 57 for fastening. 2 and 3, the cathode conductor 10K of the GTO thyristor 10 and the anode conductor 12A of the GTO thyristor 12 are shown.
Are connected to the outer conductor by bolts 51 and 53 and nuts 52 and 54, respectively.

[0006]

In the prior art shown in FIG.
The spacer 1 is inserted into the gap formed between the anode conductor 10A and the cathode conductor 12K when the inverter stack is formed by bending the anode conductor 10A and the cathode conductor 12K of the GTO thyristors 10 and 12 in consideration of the gap in advance.
3 is inserted while adjusting it in kind and bolted. In the prior art shown in FIG. 3, the GTO thyristor 1
The both ends of the flexible lead 40 are connected to the leading ends of the anode conductor 10A of the No. 0 and the cathode conductor 12K of the GTO thyristor 12 by bolting. Therefore, it takes time to process the shape of the conductor and tighten the bolts,
The problem is that the overall assembly time of the stack increases. In the case of FIG. 2, parts such as spacers, bolts, nuts, and washers are required. In the case of FIG. 3, parts such as bolts, nuts, and washers are required at both ends of the flexible lead 40. There is also a problem that the number of parts is increased. Furthermore, in order to secure the insulation distance between conductors and between bolts and nuts,
There is also a problem that storage space and the like increase.

[0007] The present invention has been made in view of the above points, and can easily connect conductors of electric components constituting a stack without increasing the assembling time, the number of parts, the storage space, and the like. An object of the present invention is to provide a method for connecting conductors of a stack structure and a stack structure.

[0008]

According to a first aspect of the present invention, there is provided a method for connecting a conductor of a stack structure to a plurality of electrical components having an inflexible conductor and a plurality of components other than the electrical component. In a conductor connection method for a stack structure, wherein said inflexible conductors of two electric components of a stack structure comprising a laminate are electrically connected to each other, an end of a cross-sectional shape substantially equivalent to a cross-sectional shape of said inflexible conductor Using a flexible conductor having a portion, connecting one end face of the flexible conductor to the end face of the inflexible conductor of the one electric component by electron beam welding, and connecting the other end of the flexible conductor And the end face of the inflexible conductor of the other electric component is connected by electron beam welding. According to the present invention, since the flexible conductor is connected by electron beam welding, the assembling time can be shortened, and parts for tightening such as bolts and nuts can be omitted. In addition, by connecting by electron beam welding, it is possible to maintain a good contact surface state between the inflexible conductor and the flexible conductor of the electric component. In addition, since the components are connected by the flexible conductor, it is possible to absorb a dimensional error of each component and to minimize a storage space.

According to a second aspect of the invention, there is provided a method of connecting a conductor to a stack structure, wherein the flexible conductor is formed of a laminate of a plurality of thin plates. According to the width and the number of thin plates to be laminated, the cross-sectional shape can be made to be a rectangle of an arbitrary size. A flexible conductor can be easily created.

According to a third aspect of the present invention, there is provided a method of connecting a conductor of a stack structure according to the first aspect, wherein the stack structure is formed by stacking a semiconductor element means and a cooling means for cooling the semiconductor element means. And a semiconductor stack composed of: There are stack structures in which various electric components are stacked, but in the present invention, the electric components are limited to semiconductor elements requiring cooling. This is because many semiconductor elements requiring cooling have a large current and a high voltage and often have an inflexible conductor.

According to a fourth aspect of the present invention, in the first aspect, the flexible conductor has a U-shape as a whole. When the flexible conductor is entirely U-shaped by electron beam welding, this flexible conductor has an effect that no useless space is generated.

According to a fifth aspect of the present invention, there is provided a stack structure comprising a laminate of a plurality of electrical components having an inflexible conductor and a plurality of components other than the electrical components. A flexible conductor having an end having a cross-sectional shape substantially equivalent to the cross-sectional shape of the inflexible conductor, wherein one end surface of the flexible conductor is connected to an end surface of the inflexible conductor of the one electric component. The inflexibility of the two electrical components is connected by electron beam welding, and the other end face of the flexible conductor is connected to the end face of the inflexible conductor of the other electrical component by electron beam welding. It has a flexible conductor for electrically connecting the conductors. The present invention relates to a stack structure having a flexible conductor constituted by the method for connecting a conductor of a stack structure according to claim 1. Therefore, various effects similar to those of the first aspect of the invention can be obtained.

According to a sixth aspect of the present invention, there is provided a stack structure according to the fifth aspect, wherein the flexible conductor is constituted by a laminate of a plurality of thin plates. This is claimed in claim 2
It is possible to easily produce a flexible conductor having an end having a cross section substantially equivalent to the cross section of the inflexible conductor of the electric component.

According to a seventh aspect of the present invention, in the semiconductor device according to the fifth aspect, the stack structure comprises a stacked body of a semiconductor element means and a cooling means for cooling the semiconductor element means. It consists of. This is the same as the third aspect of the present invention, in which the electric components constituting the stack structure are limited to semiconductor elements requiring cooling.

According to an eighth aspect of the present invention, in the fifth aspect of the present invention, the flexible conductor is entirely U-shaped.
It is shaped like a letter. This is the same as the fourth aspect of the present invention, and has an effect that useless space is not generated by the flexible conductor.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing a method for connecting conductors of a stack structure according to the present invention and a schematic configuration of the stack structure. In the figure, two flat GTO thyristors 10,
12 is an aluminum nitride (ALN) plate 14 serving as an insulating plate
To the cooling bodies 22 to 24 of the boiling cooling device 20 through the cooling body 22, the ALN plate 1
4, GTO thyristor 10, ALN plate 15, cooling body 2
3, ALN plate 16, GTO thyristor 12, ALN plate 1
7. A laminated body composed of the cooling body 24, that is, an inverter stack is configured. The boiling cooling device 20 includes a common condenser 25, connecting pipes 26 to 28 including bellows gas phase pipes, liquid return pipes 29 to 31, and cooling bodies 22 to 24. The common condenser 25 exchanges heat with the atmosphere to condense and liquefy the vaporized refrigerant, and stores it inside. The cooling bodies 22 to 24 have a configuration in which a metal block such as copper or aluminum is cut into a box shape by machining and has a large number of fins and partitioning plates for heat dissipation therein, and the coolant is stored therein. ing. As the refrigerant, a conductive refrigerant such as an aqueous solution of ethylene glycol is used. Accordingly, ALN plates 14 to 17 for insulation are inserted between the GTO thyristors 10 and 12 and the cooling bodies 22 to 24. Therefore, when an insulating refrigerant such as chlorofluorocarbon or fluorocarbon is used as the refrigerant, the ALN plates 14 to 17 can be omitted.

The cooling bodies 22 to 24 and the common condenser 25 are connected by connecting pipes 26 to 28 and liquid return pipes 29 to 31. The connection pipes 26 to 28 and the liquid return pipes 29 to 31
The refrigerant, which has a double pipe structure, is heated and boiled by the cooling bodies 22 to 24, and the vaporized refrigerant rises between the connecting pipes 26 to 28 of the outer pipe and the liquid return pipes 29 to 31 of the inner pipe to form a common condensate. Table 25
It is led to. The bellows gas-phase tube provided in a part of the connecting tubes 26 to 28 absorbs expansion and contraction of each part due to a temperature change. In addition, in addition to the bellows gas phase tube, an insulating tube for insulating between the cooling bodies 22 to 24 and the common condenser 25 may be provided in the middle of the connecting tubes 26 to 28.

Heat generated from the GTO thyristors 10 and 12 is transmitted to cooling bodies 22 to 24 via ALN plates 14 to 17. In the cooling bodies 22 to 24, the heat causes the refrigerant to boil and vaporize. The vaporized refrigerant is connected to the connecting pipes 26 to
It rises between 28 and the liquid return pipes 29 to 31 of the inner pipe and is led to the common condenser 25 where it is liquefied. The liquefied refrigerant is temporarily stored in the common condenser 25, and is returned to the liquid return pipe 2
It falls to cooling bodies 22-24 via 9-31 and returns. In this way, the ebullient cooling device 20
The refrigerant is boiled and vaporized by the cooling bodies 22 to 24, and liquefied by the common condenser 25, thereby suppressing the temperature rise of the GTO thyristors 10 and 12.

In the method for connecting the conductors of the stack structure according to the present embodiment, a plurality of thin plates having a cross-sectional shape substantially equivalent to the cross-sectional shapes of the anode conductor 10A and the cathode conductor 12K drawn from the GTO thyristors 10, 12 are used. The flexible lead 40 thus configured is welded to each conductor so as to form a U-shape by electron beam welding.
Electron beam welding is performed by irradiating an electron beam in parallel to a butt portion between a conductor end face to be welded and an end face formed by a group of thin plates, and melting both the conductor metal and the thin plate metal at the butt portion to form a weld. It is to be bonded. It is desirable that the gap formed between the butted portions of the two metals be as small as possible. Therefore, it is necessary to polish the surface of the butted portion of both metals and to process in advance so that the gap is minimized.

By joining the flexible leads 40 into a U-shape using electron beam welding in this manner, the anode conductors 10A, the cathode conductors 12K and the flexible leads 4 of the GTO thyristors 10, 12 are formed.
It is possible to maintain a good contact surface state with zero and to absorb a dimensional error of each part. In addition, joining of both can be performed by brazing, TIG welding, or the like. However, in these joining methods, the anode conductor 10A
And the contact surface of the cathode conductor 12K must be plated for the purpose of preventing oxidation. If the respective conductor surfaces are plated first, the plated portion will be peeled off by the heat of brazing or TIG welding, and if plating is attempted after welding, Further, there is a problem that the plating solution infiltrates between the thin plates of the flexible lead 40 due to the capillary phenomenon, making it very difficult to remove the plating solution and corroding from the conductor surface over time. On the other hand, by employing electron beam welding having a large heat density, the conductor can be plated first, and the thin plate and the conductor can be welded without damaging the plating.

In the above-described embodiment, an inverter stack composed of a stack of a GTO thyristor and a cooling body has been described as an example of the stack structure. However, the present invention is not limited to this. The present invention can be similarly applied to a case where conductors of electric components constituting each stack such as a battery stack, a diode rectifier stack, a power semiconductor stack, and a semiconductor switch stack are connected. Further, in the above-described embodiment, the individual cooling method for individually cooling the heating elements has been described as an example, but the present invention can be similarly applied to the collective cooling method. In the above-described embodiment, the inverter stack has two GTOs.
The case where the thyristors are configured by the thyristors 10 and 12 and three cooling bodies 22 to 24 has been described. However, the present invention can be similarly applied to an inverter stack including more GTO thyristors and cooling bodies. In the above-described embodiment, the case where the connecting pipe has a double pipe structure of a gas phase pipe and a return pipe has been described as an example, but the present invention can be similarly applied to a case where the gas phase pipe and the return pipe are separately arranged. it can.

[0022]

According to the method for connecting conductors of a stack structure and the stack structure of the present invention, conductors of electric components constituting a stack can be easily connected to each other without increasing the assembling time, the number of parts, and the storage space. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for connecting conductors of a stack structure according to the present invention and a schematic configuration of the stack structure;

FIG. 2 is a schematic diagram showing how semiconductor elements are connected in a conventional inverter stack;

FIG. 3 is another schematic diagram showing how semiconductor elements are connected in a conventional inverter stack.

[Explanation of symbols]

 10, 12 GTO thyristor 13 spacer 14 to 17 cooling body 20 boiling cooling device 22 to 24 cooling body 25 common condenser 26 to 28 connecting pipe 29 to 31 liquid return pipe 10A, 12A anode conductor 10K, 12K cathode conductor 51, 53, 55 bolt 52, 54, 56 nut 40 flexible lead

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02M 7/48 H01L 23/46 A // B23K 101: 38

Claims (8)

[Claims] An electrical connection between the inflexible conductors of two electrical components of a stack structure comprising a laminate of a plurality of electrical components having an inflexible conductor and a plurality of components other than the electrical component. In the method for connecting a conductor of a stack structure connected to a flexible conductor having an end having a cross-sectional shape substantially equivalent to the cross-sectional shape of the inflexible conductor, one end face of the flexible conductor and the An end face of the inflexible conductor of one electric component is connected by electron beam welding, and another end face of the flexible conductor and an end face of the inflexible conductor of the other electric component are connected by electron beam welding. A method for connecting a conductor of a stack structure, wherein the conductor is connected. 2. The method according to claim 1, wherein the flexible conductor is formed of a laminate of a plurality of thin plates. 3. The stack structure according to claim 1, wherein the stack structure is constituted by a semiconductor stack composed of a stack of semiconductor element means and cooling means for cooling the semiconductor element means. Conductor connection method. 4. The method according to claim 1, wherein the flexible conductor has a U-shape as a whole. 5. A stack structure comprising a laminate of a plurality of electric components having an inflexible conductor and a plurality of components other than the electric component, wherein a cross-section substantially equivalent to a cross-sectional shape of the inflexible conductor is provided. A flexible conductor having a shaped end, wherein one end face of the flexible conductor is connected to an end face of the inflexible conductor of the one electric component by electron beam welding, A flexible conductor that electrically connects the inflexible conductors of the two electric components by connecting the other end surface of the non-flexible conductor to the end surface of the inflexible conductor of the other electric component by electron beam welding. A stack structure comprising: 6. The stack structure according to claim 5, wherein the flexible conductor is constituted by a laminate of a plurality of thin plates. 7. The stack structure according to claim 5, wherein the stack structure is a semiconductor stack composed of a stack of semiconductor element means and cooling means for cooling the semiconductor element means. . 8. The stack structure according to claim 5, wherein the flexible conductor has a U-shape as a whole.