JPH04255469A - Heat pipe type semiconductor stack - Google Patents

Abstract

PURPOSE:To increase heat time constant and improve heat cooling efficiency by sharing these boiling blocks, noticing that the semiconductor elements for power conversion and for flywheel diode generate heat alternately. CONSTITUTION:Flywheel diodes(FD) 2, which are connected in inverse parallel with the gate turn-off thyristors(GTO) 1 constituting an arm circuit, are arranged on one side of a boiling block(BB) 7. Separate GTO1' and FE2' are put side by side on the other side of the BB 7. Now, in heating of GTO1 and 1', the BB 7 receives heat, and the heat is conveyed to a heat radiating part 10 by the heat pipe(HP) 12 of a heat pipe type cooler(HC) 6. Moreover, the same occurs in heating of FD2 and 2'. Accordingly, average heat load is applied to the HC 6, and BB 7 receives the heating value suitable for the cooling capacity, and the HP 12 also conveys the heating value suitable for the heat conveying capacity, and the heat radiating part 10 also radiates heating value suitable for the heating capacity.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pipe type semiconductor stack used in a power conversion device such as an inverter using power semiconductor elements.

0003

2. Description of the Related Art Semiconductor devices used in power converters such as inverters require coolers that efficiently dissipate the heat generated by the semiconductor devices to the atmosphere. The type of cooler differs depending on the amount of heat generated by the semiconductor element.The natural cooling method uses natural convection of air between the radiating fins, and the forced air cooling method uses a blower to forcibly cool the radiating fins. Cooling methods, boiling cooling methods that utilize heat transport during the gas-liquid phase change of the refrigerant, etc. are used.

[0004] Among these, the boiling cooling method has high cooling efficiency and has been widely adopted due to the demands for increasing the capacity of semiconductor devices and miniaturizing devices. , high reliability is required, and the manufacturing technology is special, so in recent years, the advantage of high cooling efficiency that utilizes the phase change of the refrigerant liquid is taken advantage of, and high reliability is required. Heat pipe cooling methods that do not require a closed container filled with refrigerant liquid are increasingly being adopted.

FIG. 8 shows an arm circuit for one phase of an inverter as a general power conversion device, and FIGS. 9 to 11 show conventional examples of heat pipe type semiconductor stacks used in such an inverter. It shows.

As shown in FIG. 8, the arm circuit for one phase of an inverter generally includes a gate turn-off thyristor (GTO) 1, which is a self-extinguishing element as a main switching semiconductor element, and a gate turn-off thyristor (GTO) 1 in antiparallel to it. It is constructed by connecting two circuits in series, each including a flywheel diode (FD) 2 to be connected, a snubber diode 3, a snubber capacitor 4, and a snubber resistor 5 forming a snubber circuit.

Therefore, in FIG. 8, a circuit consisting of a GTO 1, a flywheel diode 2, a snubber diode 3, a snubber capacitor 4, and a snubber resistor 5;
An arm circuit for one phase is constituted by a circuit constituted by a GTO 1', a flywheel diode 2', a snubber diode 3', a snubber capacitor 4', and a snubber resistor 5'. Here, snubber diode 3'
The snubber circuit composed of the snubber capacitor 4' and the snubber resistor 5' can be configured by placing either the snubber diode 3' or the snubber capacitor 4' on the positive side.
The snubber circuit 1' has a circuit configuration in which the arrangement of the snubber diode 3' and the snubber capacitor 4' is reversed from that of the snubber circuit of the GTO1.

In such a general power conversion device, a conventional heat pipe type semiconductor stack using a heat pipe type cooler for cooling one phase arm circuit is shown in FIGS. 9 to 11. The configuration is as shown.

That is, the heat pipe type cooler 6 and the GT
O1, 1' and flywheel diodes 2, 2' are alternately stacked in series and pressed together in the axial direction. Since the snubber diodes 3 and 3' generate less heat than other semiconductor elements, they are attached to the conductor 8 connected to the boiling part block 7 constituting the heat pipe cooler 6, respectively. The wiring length between the snubber diodes 1' and the snubber diodes 3 and 3' is shortened to reduce inductance. Further, snubber capacitors 4, 4' and snubber resistors 5, 5' are also arranged near this semiconductor stack to form a low-inductance snubber circuit.

Furthermore, the conductors 8 connected to the respective boiling section blocks 7 are connected by connecting conductors 9, thereby realizing a one-layer arm circuit as shown in FIG.

On the other hand, the heat pipe type cooler 6 is divided into the boiling part block 7 and the heat radiation part 10, and several heat pipes 12, both sides of which are insulated by insulating tubes 11, are connected to the boiling part block 7. and the heat radiating section 10 are connected to perform heat transport. The heat dissipation section 10 is disposed outside the device in order to efficiently dissipate heat to the atmosphere, and the boiling section block 7 to which the semiconductor element is pressure-welded is housed inside the device in order to reduce contamination. .

[0012] In general, in such a conventional heat pipe type semiconductor stack, the flywheel diode 2
, 2' is smaller than that of the GTOs 1, 1', so in order to miniaturize the semiconductor stack, the heat pipe type cooler 6 is replaced with the flywheel diode 2, 2'.
’ is often omitted on one side.

In such a conventional heat pipe type semiconductor stack, the space for the heat dissipation section 10 is limited due to the thickness of the GTOs 1, 1', the flywheel diodes 2, 2', and the thickness of the boiling section block 7. There is also a problem in that the performance of the heat pipe type cooler 6 is also limited.

Therefore, in order to solve this problem, as shown in FIG.
By inserting the spacer 13 in series in the laminated portion with the spacer 13 and the
A configuration has also been proposed in which the heat dissipation performance of the heat dissipation section 10 is improved by appropriately selecting the length of the heat dissipation section 10.

However, such a conventional heat pipe type semiconductor stack has a problem in that the insertion of the spacer 13 increases the overall size of the device.

[0016]

[Problems to be Solved by the Invention] As mentioned above, in the conventional heat pipe type semiconductor stack, when trying to miniaturize the device, sufficient cooling performance cannot be obtained, and conversely, when trying to increase the cooling performance, the device There was a problem with the large size.

Generally, a power conversion device is a circuit in which a power conversion semiconductor element and a flywheel diode generate heat alternately. For example, in the case of an inverter as shown in FIG. 8, GTO1, 1' is activated during power running. The flywheel diodes 2 and 2' mainly generate heat during regeneration.

However, since the heat pipe cooler has a small thermal time constant, when heat is generated intermittently as described above, unlike cooling methods with a large thermal time constant such as the immersion boiling cooling method, , it is necessary to have a device that is sized to match the maximum heat generation, and because the heat dissipation section is provided individually for each semiconductor element, the overall thermal time constant is small, making it inevitable to increase the size of the device. It was a dot.

The present invention was made in view of the above-mentioned conventional problems, and it focuses on the fact that heat generation occurs alternately in semiconductor elements used for power conversion and flywheel diodes, and it is possible to solve these boiling part blocks. so that they can be shared,
To provide a heat pipe type semiconductor stack which is small in size but has good heat cooling efficiency by combining two parts into one, so that the volume of a heat dissipation part can be increased and the thermal time constant is substantially increased.

[Configuration of the invention]

[0021]

[Means for Solving the Problems] The present invention includes a self-extinguishing element as a power conversion semiconductor element, a flywheel diode connected in antiparallel to the element, and a snubber circuit including a snubber diode. In a heat pipe type semiconductor stack assembled to cool a power conversion device configured by connecting arm circuits in series using a heat pipe type cooler, one side of the boiling part block of one heat pipe type cooler is A self-extinguishing element and a flywheel diode constituting one arm circuit are attached, and another arm circuit connected in series with the one arm circuit is installed on the other side of the boiling section block. A self-arc-extinguishing element and a flywheel diode are attached, and a heat dissipation part having a size commensurate with the average amount of heat generated by the self-arc-extinguishing element and the flywheel diode, which alternately generate heat, is connected to the boiling part block. This is what I did.

Further, in the heat pipe type semiconductor stack of the present invention, snubber diodes included in snubber circuits belonging to arm circuits attached to each side are attached to one side and the other side of the boiling part block. You can also do that.

[0023]

[Operation] In the heat pipe type semiconductor stack of the present invention, a self-arc-extinguishing element and a flywheel diode constituting one arm circuit are attached to one side of the boiling part block of one heat pipe type cooler, and the above-mentioned A self-arc-extinguishing element and a flywheel diode constituting another arm circuit connected in series with the one arm circuit are attached to the other side of the boiling section block, and these self-arc-extinguishing elements By connecting a heat dissipation part of a size commensurate with the heat generation amount of the type element and the flywheel diode to the boiling part block, a heat pipe can be used for the heat generated by both the self-extinguishing type element and the flywheel diode, which generate heat alternately. can be used to efficiently dissipate heat from the heat dissipation section.

Furthermore, since these self-extinguishing elements and the flywheel diode generate heat alternately and do not generate heat at the same time, the heat dissipation is commensurate with the calorific value of the element with the larger calorific value among these elements. Only one heat dissipation section is required, and the volume of the heat dissipation section can be made smaller than in the past.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be explained in detail below with reference to the drawings.

1 and 2 show an embodiment of the present invention, in which a heat pipe type cooler 6 has a boiling part block 7 that is relatively long in the axial direction of the heat pipe 12, and the boiling part block 7 is relatively long in the axial direction of the heat pipe 12. On one side of the boiling section block 7, a GTO 1 constituting an arm circuit and a flywheel diode (FD) 2 connected antiparallel to it are arranged, and on the opposite side of the boiling section block 7, a GTO 1 constituting another arm circuit is arranged. ' and a flywheel diode 2' are lined up and mounted so that each is in pressure contact with the boiling part block 7. That is, G
TO1 and GTO1', and flywheel diode 2 and flywheel diode 2' are assembled in a state in which they are pressed into contact with each other with boiling part block 7 in between.

Furthermore, snubber diodes 3 and 3' are installed on both sides of the conductor 8 connected to the boiling section block 7, and snubber diodes 3 and 3' are installed on both sides of the conductor 8 connected to the boiling section block 7, and furthermore, snubber diodes 3 and 3' are installed on the sides of the GTO 1 and the flywheel diode 2 that are not directly pressed against the boiling section block 7. is connected to the connecting conductor 9.

Note that snubber capacitors 4, 4' and snubber resistors 5, 5 are installed near the snubber diodes 3, 3'.
′, a snubber circuit with low inductance is constructed.

Next, the operation of the heat pipe type semiconductor stack having the above structure will be explained.

This power converter has a circuit configuration in which the GTO 1 and the flywheel diode 2, and the GTO 1' and the flywheel diode 2' alternately generate heat.
When O1 and O1' are mainly generating heat, the boiling part block 7 receives heat from these elements, and transports the heat to the heat radiation part 10 by the heat pipe 12 of the heat pipe type cooler 6. Then it dissipates heat into the atmosphere.

At this time, the flywheel diode 2,
Since the heat generation of GTO 2' is smaller than that of GTO 1, 1', the heat pipe type cooler 6 mainly uses GTO 1, 1' at this time.
contributes to cooling.

When the flywheel diodes 2 and 2' mainly generate heat, the heat generated from these elements is similarly received by the boiling block 7 and transferred to the heat pipe 12.
The heat is transported to the heat radiating section 10, and is radiated from the heat radiating section 10 to the atmosphere.

At this time, the heat generated from the GTOs 1 and 1' is smaller than that from the flywheel diodes 2 and 2', and the heat pipe type cooler 6 mainly generates heat from the flywheel diodes 2 and 2'.
, 2'.

In this way, in the one-phase arm circuit shown in FIG. 8, the GTOs 1, 1' and the flywheel diodes 2, 2' alternately generate heat, but the implementation shown in FIGS. In the heat pipe type semiconductor stack of the example, a continuous average heat load is applied to the heat pipe type cooler 6, and the boiling part block 7 always receives an amount of heat suitable for its cooling capacity. The amount of heat suitable for the heat transport capacity can be continuously transported, and the heat radiating section 10 can also continuously radiate the amount of heat suitable for its heat radiating capacity.

As described above, according to the heat pipe type semiconductor stack of this embodiment, one phase of self-extinguishing semiconductor elements GTO1, 1' and flywheel diode 2
. Heat pipe cooling can be performed effectively while compensating for the shortcoming of the cooler's small thermal time constant.

Furthermore, the heat pipe type cooler 6 in the heat dissipation section 10 is not arranged in series, and one inverter can be configured for one phase, saving space including the pressure bonding mechanism section of the semiconductor stack. It can be used effectively to enhance the heat dissipation effect of the heat dissipation section.

In addition, a connecting conductor 9 connects the semiconductor elements GTO1, 1' and the flywheel diodes 2, 2'.
can be made into a simple shape, and this connecting conductor 9 does not become a factor that increases the shape of the semiconductor stack.
Furthermore, the wiring length of the arm circuit is shortened, and the inductance of the arm circuit can be reduced.

Furthermore, the GTOs 1, 1' and the flywheel diodes 2, 2' are not stacked and pressed together to form a semiconductor stack as in the conventional structure, but are individually connected to the boiling part block 7 of the heat pipe type cooler 6. Since the structure allows the semiconductor elements to be attached to each other, it is possible to attach these semiconductor elements with different pressure contact forces, and from the viewpoint of strength, there is a large degree of freedom in selecting semiconductor elements.

Furthermore, since the length of the semiconductor stack can be shortened, displacement of the axis of the semiconductor stack due to vibration is suppressed even under harsh vibration conditions, and the load is always applied evenly to the contact surface of the semiconductor element. It becomes easier to maintain
It is possible to conduct electricity satisfactorily inside the semiconductor element.

Furthermore, since the semiconductor stack is small and lightweight, it is easy to assemble, transport, attach to equipment, remove, and
In addition, since the semiconductor stack is the main part of the power conversion device and accounts for a large proportion of the overall size and weight of the device, the overall device size can be significantly reduced.
This will result in weight reduction.

Next, a second embodiment of the present invention will be explained based on FIGS. 3 and 4.

In this second embodiment, the snubber diodes 3 and 3' are connected to the boiling block 7 of the heat pipe type cooler 6.
It is attached directly to the In other words, the boiling block 7 is made large enough to accommodate the snubber diodes 3 and 3', and the snubber diodes 3 are arranged on the pressed surfaces of the GTOs 1 and 1', and the snubber diodes 3 are arranged on the pressed surfaces of the GTOs 1 and 1'. The snubber diodes 3' are lined up and attached so as to be in pressure contact with the boiling part block 7, and the connecting conductor 9 is also connected to GTO1.
, 1' are further extended.

[0043] With such a structure, the GTO
The wiring length between the snubber diodes 1 and 1' and the snubber diodes 3 and 3' becomes shorter, making it possible to further reduce the inductance of the snubber circuit.

FIGS. 5 to 7 show a third embodiment of the invention.

In this third embodiment, the boiling part block 7 of the heat pipe type cooler 6 is made horizontally long, and the GTO 1 and the flywheel diode 2 are arranged side by side on one side, and the GTO 1 and the flywheel diode 2 are arranged side by side on one side, and In the same way, the GTO 1' and the flywheel diode 2' are arranged and attached so as to be pressed against the boiling part block 7.

According to this third embodiment, the number of heat pipes 12 used in the heat pipe type cooler 6 can be increased, and the boiling part block 7 and the heat radiation part 10 are
The heat pipe 12a attached to the pressed part of the GTO 1, 1' of the boiling section block 7 mainly contributes to the cooling of the O1, 1' and the flywheel diodes 2, 2'. The heat pipe 12b attached to the pressed portion of the flywheel diodes 2, 2' mainly transports the heat of the flywheel diodes 2, 2'. Therefore, as shown in the figure, if there is a difference in the amount of heat generated between GTOs 1 and 1' and flywheel diodes 2 and 2', the optimal arrangement and number of heat pipes for cooling can be achieved by varying the number of heat pipes. By setting the heat pipe to , you will be able to perform heat pipe cooling efficiently.

[0047]

As described above, according to the present invention, a self-extinguishing semiconductor element and a flywheel diode, which constitute a power conversion device such as an inverter, are mounted in pressure contact with one side of one boiling section block. On the other side of the boiling section block, another self-arc-extinguishing semiconductor element and a flywheel diode are attached in pressure contact, and the average heat generation amount of the self-arc-extinguishing element and the flywheel diode, which generate heat alternately, is Since the structure is one in which one heat dissipation part of a size commensurate with the size of the boiling part is connected to the boiling part block, the structure is simpler than the conventional structure in which the boiling part block for cooling each semiconductor element is assembled in a stacked structure. It is possible to simplify and downsize the arm circuit, and also to shorten the connecting conductor of the arm circuit, thereby reducing inductance.

Furthermore, since the overall length of the semiconductor stack can be shortened, vibration resistance can be improved, and at the same time, the entire power conversion device incorporating such a semiconductor stack can be made smaller and lighter. become.

Furthermore, if the snubber diode of the snubber circuit is installed in pressure contact with the boiling part block together with the self-extinguishing semiconductor element and the flywheel diode, the connecting conductor to the snubber diode can be shortened, and the inductance of the snubber circuit can be reduced. It will also be possible to improve the

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of the present invention.

FIG. 2 is a side view of the above embodiment.

FIG. 3 is a front view of another embodiment of the invention.

FIG. 4 is a side view of the above embodiment.

FIG. 5 is a front view of still another embodiment of the invention.

FIG. 6 is a side view of the above embodiment.

FIG. 7 is a view along arrow VII in FIG. 6;

FIG. 8 is a circuit diagram showing a configuration for one phase of an arm circuit of an inverter as a general power converter.

FIG. 9 is a front view of a conventional example.

FIG. 10 is a side view of a conventional example.

FIG. 11 is a front view of another conventional example.

[Explanation of symbols]

1,1' Gate turn-off thyristor (GTO) 2
, 2' Flywheel diode 3, 3' Snubber diode 4, 4' Snubber capacitor 5, 5' Snubber resistor 6 Heat pipe type cooler 7 Boiling part block 8 Conductor 9 Connection conductor 10 Heat radiation part 12 Heat pipe

Claims (2)

[Claims] [Claim 1] An arm circuit consisting of a self-extinguishing element as a power conversion semiconductor element, a flywheel diode connected antiparallel to the element, and a snubber circuit including a snubber diode is connected in series. In a heat pipe type semiconductor stack assembled to cool a power conversion device constituted by a heat pipe type cooler using a heat pipe type cooler, a self-arc extinguishing circuit forming an arm circuit is provided on one side of a boiling part block of one heat pipe type cooler. A self-extinguishing element and a flywheel diode are attached to the other side of the boiling part block, and a self-extinguishing element and a flywheel diode constituting another arm circuit connected in series with the arm circuit are attached to the other side of the boiling section block, and the flywheel diode is alternately connected to the arm circuit. A heat pipe type semiconductor stack comprising a heat dissipating section having a size commensurate with the average amount of heat generated by the self-extinguishing element and the flywheel diode, which generate heat, and connected to the boiling section block. 2. The heat pipe type semiconductor stack according to claim 1, wherein a snubber diode included in a snubber circuit belonging to an arm circuit attached to each side is provided on one side and the other side of the boiling section block. What was installed.