JPS5910248A - Ebullition type cooling apparatus for semiconductor - Google Patents

Abstract

PURPOSE:To reduce the length of a wiring and thereby to improve the effect of surge voltage absorption by a constitution wherein airtight housings connected to a semiconductor are provided in the wall part of a hermetically-sealed vessel near the semiconductor and are connected directly to a capacitor located outside the vessel so as to constitute a snubber circuit. CONSTITUTION:Airtight bushings 21a and 21b are provided in the wall part of a hermetically-sealed vessel 10 near the terminals A and B of a semiconductor 1 and are connected to the terminals of the semiconductor 1 respectively. A snubber capacitor 2 is provided on the wall part of the vessel 10, and terminal conductors 2D and 2E are connected directly to the airtight bushings 21a and 21b. A heat insulator 23 is provided to prevent the temperature of a liquid-phase refrigerant 18 from being conducted to the capacitor 2 through the wall part. A snubber resistor 4 is provided outside the vessel 10 and connected between airtight bushings 11 and 21a. By this constitution, the length of a wiring from the semiconductor 1 and a diode 3 to the capacitor 2 is made very small, and the inductance of wiring is reduced, whereby the effect of surge voltage absorption in a snubber circuit is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor evaporative cooling device, and more particularly, to a semiconductor evaporative cooling device, which cools a semiconductor by utilizing a phase change between a liquid phase and a gas phase of a condensable cooling medium, and which includes a snubber circuit. The present invention relates to a semiconductor evaporative cooling device.

Generally, in a semiconductor boiling cooling device, a semiconductor is stored in a sealed container, and the semiconductor is immersed in a fluorocarbon R//
It is constructed by enclosing a condensable refrigerant such as No. 3. Therefore,
When a semiconductor generates heat due to energization, the condensable refrigerant boils and changes its phase from the liquid phase to the gas phase.At this time, the latent heat is taken away from the semiconductor that is generating heat, and the semiconductor is cooled. A condenser is installed at the top of the container, and the gaseous refrigerant that has undergone a phase change and vaporized within the sealed container flows into the condenser and is converted into a gaseous phase by releasing latent heat to the air outside the condenser. The refrigerant is condensed and liquefied to become a liquid phase refrigerant, which returns to the sealed container again. In this way, the condensable refrigerant circulates between the sealed container and the condenser due to the phase change between the liquid phase and the gas phase. Heat generated in a semiconductor housed in a sealed container is efficiently transferred to a condenser 12 to cool the semiconductor.

On the other hand, semiconductors are used for purposes such as suppressing surge voltage.
A snubber circuit is provided in parallel to the semiconductor.

A conventional semiconductor evaporative cooling device has such a structure, and an example of this structure, particularly its snubber circuit, is shown in FIG. 1 of the attached drawings.

In the figure, the symbol / indicates a semiconductor such as a thyristor, gate turn-off thyristor (GTO thyristor), or diode. The symbol ``H'' indicates the components that make up the entire snubber circuit, and the symbol ``ko'' indicates a capacitor, ``3'' indicates a diode, and ``S'' indicates a resistor.

Now, if the semiconductor / is a semiconductor that controls a DC high voltage and large current circuit ON-OFF, for example, a GTO thyristor, when a high-speed switching operation is performed, an abnormal voltage will be generated across the semiconductor /, and this abnormality will occur. If the voltage exceeds the permissible voltage of the semiconductor 1, the semiconductor 1 will be destroyed. Therefore, in order to absorb the abnormal voltage generated across the semiconductor, the first
As shown in the figure, a snubber circuit is connected in parallel to the semiconductor, and in this snubber circuit, especially the wiring that constitutes the closed circuit formed by the capacitor, the diode 3, and the semiconductor 1 is It is preferable to keep it as short as possible.

If the snubber circuit wiring is long, the wiring inductance increases, the surge voltage absorption effect decreases, and there is a risk that the semiconductor will be destroyed.

However, in the conventional semiconductor evaporative cooling device, as shown in FIG. Both the resistor and the semiconductor are connected to the conductor ( Wiring) l, t,? a, /,? b,
/,? Therefore, there is a limit to the shortening of the wiring length, and as a result, there is a drawback that a sufficient surge voltage absorption effect of the semiconductor cannot be obtained.

Kneading will now be described in detail based on FIG. 2, which shows the configuration of a conventional device.

In the figure, io is a sealed container, /l is an airtight bushing, /3a, /3b, /3c are wiring conductors, /
is the condenser, /41a is the condenser /4! The fin tube 15 constituting the 1. generated inside the sealed container IO. A vapor pipe /7 is a vapor pipe for guiding the vapor phase refrigerant 16 to the condenser /4', and a liquid pipe /7 is a liquid pipe for returning the liquid phase refrigerant /l condensed in the condenser /41 to the sealed container 10. In addition, a semiconductor l and a liquid phase condensable refrigerant/g are sealed in the sealed container lO, and a predetermined amount of liquid phase refrigerant 1g is sealed so that the semiconductor l is sufficiently immersed in the liquid phase refrigerant l. Sleeping. Further, the upper space of the sealed container /θ and the inside of the condenser /g are configured to be filled with the gas phase refrigerant 16 without mixing with non-condensable gas such as air.

O, an airtight bushing l/ is disposed on the wall of the sealed container /θ, and is electrically connected to the semiconductor stored in the sealed container 10 by a conductor /U, and furthermore, Conductors IJa, /3b are connected between the capacitor 3, the diode resistor 3, and the airtight bushing 11, which constitute the snubber circuit.
, /3c.

The conventional semiconductor evaporative cooling device is constructed in this manner, and its operation will be described next.

First, when the semiconductor / generates heat, it contacts the semiconductor / (the liquid phase refrigerant ig boils) -1 and undergoes a phase transformation from the liquid phase to the gas phase.At this time, the latent heat is taken away from the semiconductor /, so the semiconductor l is cooled. On the other hand, the phase-changed gas phase refrigerant /6 rises upward due to the density difference and cannot be led to the condenser/S through the steam pipe/left. Since the outside of the large number of fin tubes/fa is cooled by air, latent heat is released inside the condenser, condensing and liquefying (-1 liquid phase refrigerant). The coolant π returns to the sealed container 10 through the liquid pipe 17 due to the action of gravity, and cools the semiconductor 1 again.

As described above, the refrigerant circulates between the sealed container 10 and the condenser 6/l/ while undergoing a phase change, and the heat generated in the semiconductor 1 is efficiently transferred to the condenser/g. Dissipates into the air from the surface.

In this way, in the conventional device, the semiconductor 1 is built in the sealed container/θ, and the snubber circuit consisting of the capacitor, the diode 3, and the resistor is placed outside the sealed container/θ. As shown in the figure, conductors /3a, /, ? It had to be connected by long wires of b and /3c.

However, in the snubber circuit, it is particularly necessary to reduce the inductance of the closed circuit formed by the diode 3, the capacitor, and the semiconductor/conductor. 7.2-Hermetic pushing/l-conductor/? Since a snubber circuit is not formed by the wiring route of a me diode 3 conductor / 3 b - capacitor conductor / 3 (cor hermetic bushing / / - conductor 7.2 - semiconductor /), no matter how short the wiring is, There is a limit to how much inductance can be reduced, so the drawback is that the surge voltage absorption effect cannot be sufficiently absorbed.

In order to improve the shortcomings of such conventional devices,
As shown in FIG. 3 of the accompanying drawings, a diode 3 and a capacitor are housed together with a semiconductor l in a sealed container IO, and a conductor /3a' is connected between these parts.

/ ,? I can't think of a way to wire b', /3c'. Note that the resistor is placed outside the container 10 and wired as shown in the figure via an airtight bushing. According to such a method, it is possible to wire the diode 3 and the capacitor λ close to the semiconductor, so that the wiring inductance is reduced and the surge voltage absorption effect is certainly increased. However, on the other hand, this method has the following drawbacks. In other words, (/l) The material constituting the capacitor element is a plastic film or paper as a dielectric, and the electrode is made of a dielectric button made of vapor-deposited metal such as zinc or an ultra-thin aluminum material. Foil is used.

The material corrodes when it comes into contact with a refrigerant, such as Freon R//3, and its electrical properties as a capacitor are significantly reduced.

Therefore, store the capacitor in a sealed container! The capacitor element is stored in a metal case on the platform; 7.
Insulating oil is sealed as a coolant, but an oil-filled capacitor must be used. Such oil-filled capacitors are usually open at one end. The capacitor element is placed inside a metal case, the open part of the metal case is closed by soldering with a metal plate called a top plate with a bushing, and insulating oil is applied.

17f+・1. However, if the insulating oil inside the capacitor leaks and mixes with the refrigerant, the boiling cooling effect will be affected.
On the other hand, if refrigerant vapor is inside the condenser, there is a risk that the refrigerant, such as fluorocarbon, will corrode and deteriorate. First, the capacitor case needs to have a completely airtight structure.For this purpose, it is necessary to weld the capacitor case because even if the capacitor case is sealed by soldering as in the past, sufficient airtightness cannot be ensured. However, in the case of relatively small capacitors such as snubber capacitors (normally a parallelepiped with a size of 15θ x lθOXkOm), welding the metal case and the top plate requires high temperatures generated during welding. There is a risk of thermal deterioration of the internal capacitor element due to heat.In order to prevent this thermal deterioration, it is necessary to make the case larger and insert insulation material with sufficient distance between the welding point and the element. Although it is possible, the capacitor would be large and the design would be very uneconomical.

(, 2) Since capacitor elements are usually made of dielectric material such as paper or glass, the maximum allowable temperature of the element is 7 s-gk'C, which is relatively low. On the other hand, the allowable temperature for semiconductors is /2 to /0
℃, cold #deterioration in boiling cooling equipment is generally,
The temperature is set at 7θ to ts°C. Therefore, when a capacitor is stored in a sealed container, the wall temperature of the capacitor case will be 7θ to 75°C of the refrigerant temperature, and furthermore, due to the heat generated by the capacitor itself, the element center temperature will be higher than the refrigerant temperature of the case, which will limit the allowable temperature of the capacitor. I will cross it. Therefore, if the center temperature of the condenser element is to be lower than the allowable temperature, the refrigerant temperature must be set low, which necessitates making the condenser larger.
The semiconductor evaporative cooling device itself becomes larger in size and therefore heavier, making it extremely uneconomical.

(3) When a condenser is placed in a sealed container, the sealed container becomes larger, and this, along with the larger condenser described in item 2 above, causes the semiconductor boiling cooling device to become even larger. Furthermore, the boiling cooling device uses Freon R-// as a refrigerant. When the refrigerant temperature exceeds 7°C, the pressure inside the sealed container becomes higher than the outside pressure. Therefore, boiling cooling equipment is subject to the pressure vessel regulations stipulated in the Industrial Safety and Health Act, but if the condenser is not housed in a sealed container, the internal volume of the container is small and regulations as a pressure vessel do not apply, so-called simple containers. However, by housing a capacitor or the like in a sealed container, the internal volume of the sealed container increases and is subject to regulations as a pressure vessel. When pressure vessels are regulated in this way, inspection duties become mandatory, which results in a longer manufacturing period and an increase in manufacturing cost as well as an increase in manufacturing man-hours.

As shown in Fig. 3, the method of storing the capacitor and diode 3 in the sealed container /θ is suitable as a method for shortening the wiring of the closed circuit consisting of the semiconductor 1, the capacitor, and the diode 3. However, on the other hand, it has the above-mentioned drawbacks, and therefore, this method can be said to be impractical.

The present invention provides a suitable semiconductor boiling cooling device that improves the drawbacks of the conventional device described above, and further reduces the wiring inductance by shortening the wiring length of the semiconductor/snubber circuit, thereby improving the surge voltage absorption effect. Its purpose is to provide.

In order to achieve this object, the present invention provides an airtight bushing that is connected to the semiconductor on a wall of the sealed container close to the semiconductor, and a snubber that is provided close to the outside of the wall where the airtight bushing is installed in the sealed container. - Install circuit capacitors,
Direct connection between the terminals of the capacitor and the hermetic bushing] 7. The semiconductor in the sealed container and the capacitor outside the sealed container are connected by wire to form a snubber circuit. It's something.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

In the figure, a semiconductor l and a snubber diode 3 are housed in a sealed container /θ, and a liquid phase refrigerant /g is filled therein. An airtight bushing// is provided on the wall of the sealed container 10, and the airtight bushing//l and the terminal of the semiconductor// are connected by a conductor//.

On the other hand, airtight bushings 2/a and 2/b connected to the semiconductor 1 are provided on the wall of the sealed container 10 near the terminals A and B of the semiconductor 1, and the airtight bushing 21b and the B terminal of the semiconductor 1 are connected to each other by a conductor. 22b also connects the A terminal of the semiconductor / and the hermetic bushing 2/a through the diode 3 as a conductor! , 2a. Also, the airtight bushing 2/a.

A snubber capacitor is provided adjacent to 21bK on the wall of the sealed container 10 via a heat insulating material 3, and the terminal conductors jD and 2E of this capacitor are connected to the airtight bushings 2/a, -/b. A direct connection is made, and this connection is made by soldering or by screwing. Note that, depending on the structure of the electrodes, this capacitor can be classified into a foil electrode type and a metal vapor deposition type as shown in FIG. 5 of the accompanying drawings.

O, the reason why the insulation material 3 is interposed between the wall of the sealed container/θ and the capacitor λ is that the capacitor is placed in the sealed container 1.
0, the sealed container i.

Since the temperature of the liquid phase refrigerant is conducted to the condenser through the wall of the sealed container/θ
A heat insulating material 23 is installed between the capacitor and the condenser (7).

Note that the snubber resistor G is installed outside the sealed container 10, and wired between the airtight bushings // and C and /A using a conductor 2D.

Since the semiconductor evaporative cooling device of the present invention, particularly its snubber circuit, is configured as described above, the following characteristics or effects are lost.

(1) Airtight bushings 2/a, 21b are provided near the terminals A and B of the semiconductor 1, and outside the sealed container IO, the airtight bushings 2/a, 21bK, the terminal conductor of the capacitor D, A semiconductor placed inside a sealed container io to connect and configure the core! Also, the wiring length between the diode 3 and the capacitor provided outside the sealed container 10 becomes extremely short, so that the surge voltage absorption effect in the snubber circuit is greatly increased by reducing the wiring inductance.

(k) The capacitor has insulation material on the outer wall of the sealed container lθ, and the ear through 23! Since the refrigerant inside the sealed container 10 has little heat influence, the heat generated in the condenser 1 is dissipated to the outside air from the exposed surface other than the surface where the condenser is added, resulting in lower temperature and reliability. Improves sex.

(3) Since the capacitor does not connect the terminal conductor directly to the end surface of the electrode by a method such as soldering, it is possible to manufacture a capacitor with a small inductance. In conventional capacitor elements, the capacitor element is housed in a metal case, and the bushing provided in the metal case and the capacitor element are connected using flexible lead wires, so the cross-sectional area of the lead wires is relatively thin. Also,
Since the lead wire is point-connected to a part of the electrode end surface by a method such as soldering, the inductance between the bushing and the element is relatively large. In this case, a metal case is not used, and therefore a bushing is not required, and a plate-shaped terminal conductor can be simply connected directly from a capacitor element to an electrode end surface of the capacitor element. The large connection area between the terminal conductor and the end face of the electrode means that since the electrode is wound, power is supplied directly from the terminal conductor to each part of the electrode, which reduces inductance. become.

(S) Since the capacitor is not built into the sealed container, the sealed container is small and can be made into a simple container that is not subject to the regulations for pressure vessels stipulated in the Industrial Safety and Health Act. Therefore, the manufacturing period is short and Economical production becomes possible.

t51 In the unlikely event that a condenser malfunctions, the method shown in Figure 3 requires opening the sealed container, replacing or repairing the capacitor stored inside, resealing it, and injecting refrigerant under vacuum. In the packaging of the present invention, it is not necessary to open the sealed container, and the capacitor terminal conductors ul), 2E and airtight bushings u/a, 21 can be connected as they are.
By cutting off the connection to 'O', the capacitor can be easily replaced, thereby shortening the repair period and significantly reducing the repair cost.

As described above, the semiconductor evaporative cooling device of the present invention has a number of features and has the effect of being extremely practical and effective.

In the embodiment shown in Figure 2, the capacitor is placed below the sealed container lθ, but if the wiring of the snubber circuit can be shortened, it can be placed in any direction of the sealed container IO. Also, diode 3
Sealed! /θ is shown, but kneading does not have to be limited to being inside the sealed container, and may be placed outside the sealed container. Furthermore, the resistor DA may be housed in a sealed container io.

[Brief explanation of drawings]

Fig. 1 is a circuit configuration diagram showing an example of a semiconductor and snubber circuit, Fig. 2 is a vertical cross-sectional explanatory diagram showing the structure of a conventional semiconductor evaporative cooling device, and Fig. 3 is a diagram showing a configuration of a conventional semiconductor evaporative cooling device. FIG.
The figure is a longitudinal cross-sectional view of a foil electrode type capacitor. l...Semiconductor, λ...Capacitor, 3...Diode,
V...Resistor, 10...Sealed container, / /. j/a, J/b=airtight bushing, lyu, t3a. t 3 b, / J c, / 3 a
' , i 3 b', i J c',
/ 7゜Co2a, Co2b...Conductor, ll...Condenser, 1
6. Gas phase refrigerant, 7 g. Liquid phase refrigerant, 23. Insulation material. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Makoto Kuzuno - Asahi 1 figure 1゜Homura 2 figure 4 Hei 4 figure

Claims (1)

[Claims] T/l A semiconductor housed immersed in a cooling medium sealed in a sealed container is heated by utilizing the phase change between the liquid phase and the gas phase of the cooling medium. In a semiconductor boiling cooling device which cools by transferring heat to a condenser and is equipped with a snubber circuit, an airtight bushing connected to the semiconductor is provided on a wall portion of the sealed container close to the semiconductor, and the airtight bushing is connected to the semiconductor. A snubber circuit capacitor is installed close to the outside of the wall where the airtight bushing is installed in the container.
A semiconductor boiling device characterized in that the terminal of the capacitor is directly connected to the airtight bushing, and the semiconductor inside the sealed container and the capacitor outside the sealed container are connected by wiring to constitute a snubber circuit. Cooling system. (,2) A snubber circuit capacitor installed close to the outside of the wall where the airtight bushing of the sealed container is installed is installed with a heat insulating material interposed between the snubber circuit capacitor and the wall. Semiconductor boiling cooling device as described in Section 1.