JPH08200864A - Small-sized low-temperature device apparatus - Google Patents

Abstract

PURPOSE: To improve the maintainability by providing an outer frame having an engaging part to be engaged with a closed cycle refrigerator, and a connector for thermally connecting a low-temperature device such as an information unit etc., to the refrigerator, and holding vacuum at the periphery of the device corresponding to a heat insulation chamber formed of the frame and the connector. CONSTITUTION: A small-sized low-temperature device apparatus sole unit is formed at an outer frame 1 made of a material having excellent heat insulation by providing an engaging part 6 at the center, a material having excellent thermal conductivity (preferably a material having thermal conductivity of 100kcal/mhr deg.C or more) is disposed at the part 6, and a low-temperature device 3 is disposed at the connector 2. The frame 1 in which the connector 2 is assembled together with the device 3 is introduced into a vacuum chamber, which is evacuated in vacuum, the frame 1 and the connector 2 are welded or integrated by adhering, and evacuated in vacuum. Such a low temperature device apparatus is detachably set to a closed cycle refrigerator, and easily replaced.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadcasting antenna (BS, etc.) using a cooling device, communication equipment utilizing millimeter waves, microwaves, and ultrashort waves, and infrared spectroscopy. The present invention relates to scientific equipment such as an analyzer (IR analysis) and a microwave spectrum analyzer, and information equipment such as a computer device and a recording device. 2. Description of the Related Art Recently, as communication equipment, scientific equipment, information equipment, and the like have become higher in performance, it has been considered to use a device that plays an important role in improving the performance in a low temperature environment. This is because, as is well known, not only can a superconducting device having extremely excellent performance be used, but also a semiconductor device can be made to have low noise, high speed, and high integration by making a low temperature environment. Cooling devices for maintaining a low temperature environment can be roughly classified into two types, an open cycle type and a closed cycle type. The open cycle type functions as a so-called cryogen cooling, liquid refrigerant cooling using liquid nitrogen or liquid helium, solid refrigerant cooling using latent heat of sublimation such as solid argon or methane, and a low temperature sink such as outer space to function passively. There is radiant cooling. These are mainly used for cooling large devices such as supercomputers, linear motor cars, and electric energy storage devices. The closed cycle type includes a Stirling cycle (ST) and a Gifford McMahon cycle (G
M), Bilmeier cycle (VM), Joule-Thomson cycle (JT), Brayton cycle (BR), pulse tube cycle and the like. These are mainly used in relatively small industrial and scientific equipment such as vacuum pumps (cryopumps) used in vapor deposition machines and sputtering equipment, cold traps, infrared image sensor cooling, and laser cooling. In recent years, the latter closed cycle type, which has few restrictions on the place of use and can easily change the cooling temperature, has been receiving attention. As shown in FIG. 13, the structure of the cooling device device using the closed cycle type is such that the low temperature device 3 is fixedly cooled on the cooling stage 9 cooled by the refrigerant of the cooling device, and the periphery thereof is vacuum cavity (insulation chamber). ) 5
The structure is covered with. The vacuum cavity (insulation chamber) 5 has a diffusion pump (DP) 21 for drawing a vacuum.
An exhaust system such as a rotary pump (RP) 22 is also provided. In addition, a cryopump, a turbo molecular pump, etc. are used for the exhaust system. [0006] However, the conventional low temperature device apparatus using the closed cycle cooling device has the following problems. (1) Since a diffusion pump, a rotary pump, a cryopump, a turbo molecular pump, etc. are provided side by side, downsizing is difficult, and if the structure becomes complicated, specialist maintenance is required. In FIG. 10, these systems are indicated by simplified symbols, but the size is several tens to several hundreds times larger than the vacuum cavity. This point was a major impediment to the spread of low-temperature device equipment to consumer equipment. (2) If the main body of the closed-cycle cooling device is downsized, the amount of the refrigerant is reduced, so that the cooling capacity is lowered, and there is a waste of heat insulation efficiency around the low temperature device and heat conduction efficiency between the cooling stage and the low temperature device. The low temperature device could not be cooled uniformly, resulting in deterioration of device characteristics. That is, there is a conflict between the miniaturization and the cooling capacity, and it can be said that how to increase the adiabatic efficiency and the heat conduction efficiency is the key to the miniaturization. (3) When the low-temperature device or the closed-cycle refrigerator is out of order, the low-temperature device device and the closed-cycle refrigerator are integrated, so that it is difficult to repair only necessary parts. Therefore, maintenance costs are high when repairing both the low temperature device and the closed cycle refrigerator. Moreover, even if the necessary parts can be repaired, it is possible at the manufacturer and not at the user, especially at home.
There was still no device that could be easily replaced at home. This point was also a major impediment to the spread of low-temperature device equipment to consumer equipment. (4) To transmit a high frequency signal of GHz or higher such as a microwave or a millimeter wave, it is necessary to make the lead wire thick to reduce loss. However, if the lead wire is made thick, the temperature of the low temperature device cannot be kept constant due to the penetration of thermal energy due to heat conduction from the lead wire. Such a problem also exists in the lead wire of the power supply. The present invention solves the above-mentioned problems and provides a small-sized low-temperature device device which can be miniaturized, easy to maintain, applicable to consumer equipment, and applicable to various fields. It is intended. In order to achieve the above object, a small-sized low-temperature device device of the present invention includes an outer frame having an engaging portion for engaging with a closed-cycle refrigerator, and a low-temperature device. A low temperature device and a closed-cycle refrigerator are thermally connected to each other, and a heat insulating chamber formed by the outer frame and the bonded body, that is, the peripheral portion of the low temperature device is held in a vacuum state, The outer frame is amber, the thermal conductivity of the insulator is 10k
cal / mhr ° C or lower, preferably 1 kcal / mhr ° C
It is made of the following so-called heat insulating material, and the bonded body is 100 k
It is characterized by being formed of a so-called good heat conductive material having a cal / mhr ° C. or higher. The degree of vacuum in this insulation room is 10
^-3 Torr or more, preferably 10 ^-5 torr or more. Further, the small-sized low-temperature device device according to the present invention is such that the small-sized low-temperature device device and the closed-cycle refrigerator are separate units, provided with a mounting mechanism such as a screw part for attaching and detaching, an anchor part, and a closed-cycle. A on the surface of the bonded body that is thermally connected to the low temperature stage of the refrigerator
A film or foil made of u, Pb, In, Ga metal or an alloy containing the metal as a main component is formed, packing is provided around the engaging portion, and a small low temperature device device and a closed cycle refrigerator are used. The void is isolated from the outside air, and the void is in a depressurized state or dry gas, preferably C ₆ H ₆ , CO ₂
It is characterized by being replaced by gas. Furthermore, in a small-sized low-temperature device device in which the peripheral part of the low-temperature device is held in a vacuum state, the peripheral part of the low-temperature device is provided with an oscillation circuit and a receiving circuit for communicating signals with the low-temperature device device and an external device. In addition, a small low temperature device device, which is provided with an element for converting electromagnetic waves such as a solar cell into electric energy and a capacitor around the periphery of the low temperature device device. EXAMPLES The present invention will be described in detail below with reference to examples. (Embodiment 1) The structure of a small-sized low-temperature device device of this embodiment is shown in FIGS. 1 and 2. FIG. 1 is a sectional view of a small-sized low-temperature device device alone, and FIG. 2 is a sectional view of a refrigerator-integrated device device in which the small-sized low-temperature device device is incorporated in a closed-cycle refrigerator. In the invention, the Stirling cycle, which has the highest efficiency among the closed cycle refrigerators and can be downsized, was used. First, referring to FIG. 1, a small low-temperature device unit alone will be described. The outer frame 1 is made of the material shown in Table 1 (heat conductivity is a value in the vicinity of 0 ° C.) having a good heat insulating property, and has an engaging portion 6 in the central portion. [Table 1] [Table 2] The thickness of the outer frame 1 is 1 to 2 mm in the present embodiment, but it is preferably as thin as possible in order to suppress heat intrusion due to heat conduction from the outside as long as the strength required for commercialization is obtained. When using a material such as inorganic glass that easily transmits electromagnetic waves such as sunlight that generate thermal energy, a metal film such as Al is deposited on the surface of the outer frame 1. This metal film not only prevents the intrusion of sunlight but also has the effect of preventing radiation. The joint body 2 is made of the material shown in Table 2 having good thermal conductivity. A material having a thermal conductivity of 100 kcal / mhr ° C. or higher is preferable. Further, the low temperature device 3 is tightly fixed to the bonded body 2. Next, the joined body 2 on which the low temperature device 3 and others (lead wires, etc.) are mounted is incorporated into the outer frame 1, and later placed in a vacuum chamber to evacuate and the outer frame 1 and the joined body 2 are welded or bonded to be integrated. . The heat insulation chamber 5 is maintained in a vacuum state by the integration. Vacuum degree is 10 ^-3
Torr or more is preferable, and 10 ⁻⁵ Tor is more preferable.
r or more. If the degree of vacuum is poor, the heat insulation is poor and the ability to cool the low temperature device 3 is reduced. Therefore, when the degree of vacuum cannot be maintained for a long period of time due to the gas released from the material, the outer frame 1 is baked and then joined to the joined body 2, Ti, Zr, Hf, which adsorbs the released gas on the inner surface of the outer frame 1, Take measures such as vapor deposition of active metals such as rare earths. Zn or S is used for joining materials with poor compatibility such as inorganic glass and metal.
When the bonding material 4 containing a metal that easily reacts with the inorganic glass such as Pb-Sn alloy containing b is added, strong and excellent sealing can be achieved. Further, when ultrasonic waves are applied at the time of joining, the effect becomes larger. The small-sized low-temperature device device (single unit) obtained as described above is set in the refrigerator 11 as shown in FIG. 2 to obtain a refrigerator-integrated device device. The refrigerator used here is the smallest refrigerator currently available. In FIG. 2, 8 and 9 and 10 are a cylinder, a cooling stage and a flange of the refrigerator 11, respectively. By setting the small-sized low-temperature device device in the refrigerator 11, the cooling stage 9 and the joined body 2, and further the low-temperature device 3 are thermally joined to cool the low-temperature device to a predetermined temperature. Let us analyze this thermal bonding in more detail. The heat transfer coefficient κ (WK ⁻¹ m ⁻² ) through the cooling stage 9 and the bonded body 2, that is, the contact between solid and solid is R.I. Berma
According to the study of n, it is shown by κ = αP (α is a proportional constant). That is, the heat transfer coefficient κ is the pressure P applied to the contacts.
Is proportional to. Therefore, in order to stably cool the low temperature device 3, it is necessary to bring the cooling stage 9 and the bonded body 2 into contact with each other at a predetermined stable pressure. [Table 3] Therefore, in the present invention, as shown in FIG. 3 or FIG. 4 or FIG. 5, a small low temperature device device is formed by forming a threaded portion on the joined body 2, the engaging portion 6 of the outer frame 1, or the outer peripheral portion of the outer frame 1. Is fixed to the refrigerator 11. In addition to the screw fixing, the fixing by the anchor 14 or the claw 15 as shown in FIG. 7 or 8 does not matter. The above-obtained refrigerator-integrated device device has an arrival time up to 77K and temperature stability at a low temperature of 77K, and a device using another material for the outer frame 1 or the bonded body 2 and a device having a conventional exhaust system. Compared with. The measurement was performed after operating for 1 hour in a thermo-hygrostat having a humidity of 60% and a temperature of 25 ° C. The results are shown in Table 3 (comparison by material) and Table 4 (comparison with conventional example: apparatus in FIG. 11). In addition, the shapes of the outer frame 1 and the bonded body 2 are almost the same in the example and the comparative example except that the materials are different. It can be seen from Table 3 that the cooling characteristics are greatly affected by the materials of the outer frame 1 and the bonded body 2, and that it is necessary to select an appropriate material. The significant difference was due to the use of the smallest small refrigerators currently available in consideration of the spread to consumer equipment.
Usually, when the size is reduced, the amount of the refrigerant is reduced and the cooling capacity is lowered. However, in consideration of its widespread use in consumer equipment, a decrease is inevitable, so it can be said that the point is how to suppress the intrusion of thermal energy from the outside and how to improve the cooling efficiency from the cooling stage 9 to the low temperature device. [Table 4] A device for exhausting the conventional heat insulating chamber by DP or RP by selecting an appropriate material, improving the heat transfer efficiency of the cooling path, and achieving a stable high vacuum of the heat insulating chamber 6 as in this embodiment Almost the same performance was obtained, although slightly lower than that shown in Table 4). The outer frame 1 and the bonded body 2 have a thermal conductivity of 10 kcal / mhr ° C or less and 100 kc, respectively.
It is understood that it is necessary to combine materials having al / mhr ° C. or higher. (Example 2) Borosilicate glass (Al vapor deposition on the inner surface) was used for the outer frame 1 and Cu was used for the bonded body 2 in the same process and structure as in Example 1, but FIG. As shown in the figure, the adhesive layer 1 is formed on the surface of the bonded body 2 that contacts the low temperature stage 9.
The point where 3 is formed is different. The surface of the adhesion layer 13 is A
It is formed by vapor deposition using a metal of u, Pb, In, Ga or an alloy containing them as a main component and adhering a foil. Adhesion layer 1
The thickness of No. 3 when assembled in the refrigerator 11 is 0.5 mm or less. Further, a material having a melting point near room temperature, such as a Ga-In alloy, is formed by melting in a state of being heated and melted, or incorporated in a refrigerator. The refrigerator-integrated device apparatus thus obtained was evaluated in the same manner as in Example 1. The results are shown in Table 5. [Table 5] As shown in Table 5, it can be seen that when the adhesion layer 13 is formed, the performance is further improved as compared with the first embodiment. This is improved by forming an adhesion layer 13 having excellent softness and stretchability in the intermediate portion between the bonded body 2 and the low temperature stage 9 so that the actual contact area is small due to dimensional variation of parts and surface irregularities of parts. It is due to the fact. Further, when the material is heated and melted as in the case of using In-Ga, the contact area is further increased and the bonding is surely performed, so that the cooling performance is further improved. In-Ga
Since the melting point of the alloy can be brought to near room temperature by adjusting the composition ratio, slight heating is sufficient and it can be easily performed at home. However, except for Au, the thermal conductivity is lower than that of the material of the bonded body 2 and if the thickness is too thick, the opposite effect occurs. Therefore, 0.5 mm or less is preferable. Thus, the formation of the adhesion layer 13 is effective when further cooling performance is required. When the adhesive layer 13 spreads to consumers who have a large individual difference, the adhesion layer 13 absorbs the set variation due to the individual difference. (Embodiment 3) In the apparatus of Embodiment 1, as shown in FIG. 9, packings 17 and 18 were formed on the flange portion and / or the cylinder portion. [Table 6] Further, the gap 19 formed when the small-sized low temperature device unit and the refrigerator are assembled is replaced with a reduced pressure state or a dry gas such as CO ₂ or N ₂ . The obtained device is assumed to be 90 degrees in humidity, assuming rain.
The arrival time up to 77K and the temperature stability were examined in a constant temperature and humidity chamber of not less than%. The arrival time is measured after 1H is put in the constant temperature and humidity chamber and the temperature of the refrigerator is raised and lowered once, and the temperature stability is a value measured after operating the 200H refrigerator after measuring the arrival time. As can be seen from Table 6, the apparatus in which packing is formed and replaced with dry gas or reduced pressure exhibits excellent long-term stability, while the apparatus without packing exhibits arrival time and temperature stability. , Both are getting worse. This is because in a device without packing, water vapor enters the gap 19 and condenses, and further solidifies in the vicinity of the bonded body 2 to increase the thermal conductivity in the gap 19 and reduce the heat insulating effect. For solidification, pressure was applied to the outer frame 1 and the engaging portion 6 of the outer frame 1 broke after 250 hours. In this example, CO ₂ has good characteristics during depressurization and CO ₂ because CO ₂ has the lowest thermal conductivity in the above-mentioned gas, and during depressurization, the free path of gas molecules becomes long and the thermal conductivity is further improved. This is because it is decreasing. (Example 4) Microwave, millimeter wave, etc. GH
It is suitable for low-temperature device devices that require thick lead wires for transmission of high-frequency signals of z or higher. 10 and 11 are schematic views of the circuit of the small-sized low-temperature device device according to this embodiment, and FIG. 12 is a sectional structural view thereof. Superconducting antenna, superconducting mixer (frequency mixing)
IF from the mixer near the low temperature device 2
A transmitter / receiver 20 is provided which includes a transmitter circuit for transmitting a signal to an external device outside the heat insulation chamber 5 and a receiver circuit for receiving a transmission signal for transmitting from a superconducting antenna from the external device. In this embodiment, a semiconductor laser is used as the transmitting element of the transmitting circuit and a photodiode is used as the receiving element of the receiving circuit. Further, an energy storage device 21 including a conversion element (for example, a solar cell) that converts an electromagnetic wave into electric energy and a capacitor that stores the electric energy is provided adjacent to the transmission / reception circuit 20. A pn junction element having a photoelectric phenomenon was used as the conversion element. The transmitter / receiver 20 and the low-temperature device 2 mainly receive electric energy from the energy storage device 21 to operate. The arrival time from room temperature to 77K and the thermal stability at 77K of the obtained refrigerator-integrated device were examined. The results are shown in Table 7 together with the comparative example using the lead wire. The lead wire of the comparative example used here is high frequency (GH
It is as thin as possible in order to suppress the propagation loss in the z region), but it is thick. [Table 7] As described above, in the present embodiment, since it is not necessary to draw the thick lead wire serving as the heat conduction path into the heat insulating chamber 5 which is vacuum-insulated, the arrival time up to 77K and the thermal stability are greatly improved. If an electromagnetic wave having a wavelength of millimeter wave or less is used for communication with an external device, signal transmission can be performed by an optical fiber made of quartz glass or an organic material with less heat intrusion, and the same effect can be obtained. In the above embodiment, the Stirling cycle type was used as the closed cycle refrigerator, but other closed cycle refrigerators such as the GM (Gifford McMahon Cycle) type, the Bilmeier cycle type and the pulse tube type may be used. Since the present invention is constructed as described above, it has the following effects. The low temperature device and its surroundings are hermetically held in a high vacuum with an appropriate material and an appropriate structure, a low temperature device side (small low temperature device device) and a refrigerator are provided as separate units, and a desorption mechanism is provided. And the low-temperature device side or the refrigerator side failed by forming a soft stretchable material film or foil on the engaging contact surface of the refrigerator and increasing the contact area so that heat conduction is not affected even if there is engagement variation. It became possible to easily replace the unit that needs to be replaced. Such ease of maintenance enables the popularization of high-performance low-temperature device devices into homes. By providing a device for receiving and transmitting signals and a device for converting electromagnetic waves into electric energy and storing it in the small-sized low-temperature device, lead wires can be eliminated and heat intrusion can be suppressed, so that cooling efficiency is improved. It has become possible to cool the low temperature device stably. The elimination of the lead wire does not require connection of the lead wire at the time of replacement, which leads to easier maintenance.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial vertical cross-sectional view showing an embodiment of a small-sized low-temperature device device of the present invention. FIG. 2 is a vertical cross-sectional view showing an engaged state of the small-sized low-temperature device device of the present invention with a refrigerator. FIG. 3 is a partial sectional view of an engaging portion of the small-sized low-temperature device device of the present invention. FIG. 4 is a partial sectional view of another engaging portion of the small-sized low-temperature device device of the present invention. FIG. 5 is a partial cross-sectional view showing another engaging portion of the compact low temperature device device of the present invention. FIG. 6 is a partial cross-sectional view showing another engaging portion of the small-sized low-temperature device device of the present invention. FIG. 7 is a partial cross-sectional view showing the attachment / detachment mechanism of the small-sized low-temperature device device of the present invention. FIG. 8 is a partial cross-sectional view showing another attachment / detachment mechanism of the small-sized low-temperature device device of the present invention. FIG. 9 is a partial cross-sectional view showing another embodiment of the small-sized low-temperature device device of the present invention. FIG. 10 is a circuit diagram of another embodiment of the small-sized low-temperature device device of the present invention. FIG. 11 is a circuit diagram of another embodiment of the small-sized low-temperature device device of the present invention. FIG. 12 is a partial vertical sectional view showing another embodiment of the small-sized low-temperature device device of the present invention. FIG. 13 is a partial vertical cross-sectional view of a conventional low temperature device device. [Description of Reference Signs] 1 outer frame 2 bonded body 3 low temperature device 4 bonding material 5 heat insulating chamber 6 engaging part 7 engaging part screw part 8 refrigerator cylinder 10 refrigerator flange 11 refrigerator body 12 outer frame screw portion 13 adhesion layer 14 Desorption Mechanism Anchor 15 Desorption Mechanism Claw 16 Desorption Mechanism Spring 17 External Packing 18 Inner Packing 19 Engagement Gap 20 Receiving / Transmitting Device 21 Energy Saving Device

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tatsuya Shimoda             Seiko, 3-3-3 Yamato, Suwa City, Nagano Prefecture             -In Epson Corporation

Claims (1)

Claim: What is claimed is: 1. An outer frame having an engaging portion for engaging with a closed cycle refrigerator, and a joint for mounting a low temperature device and thermally connecting the low temperature device and the closed cycle refrigerator. With a body,
Further, a small-sized low-temperature device device characterized in that the peripheral portion of the low-temperature device corresponding to the heat insulation chamber formed by the outer frame and the bonded body is held in a vacuum state. 2. The outer frame is formed of a heat insulating material having a thermal conductivity of 10 kcal / mhr ° C. or less such as an amber or an insulator,
The small-sized low-temperature device apparatus according to claim 1, wherein the bonded body is formed of a material having a good thermal conductivity of 100 kcal / mhr ° C. or higher. 3. A small-sized low-temperature device device characterized in that the small-sized low-temperature device device and the closed-cycle refrigerator are separate units, and a mounting mechanism such as a screw part and an anchor part for mounting and dismounting is provided. 4. A film or foil made of Au, Pb, In, Ga metal or an alloy containing the metal as a main component is formed on the surface of a bonded body that is thermally connected to a low temperature stage of a closed cycle refrigerator. The small-sized low-temperature device device according to claim 3, wherein 6. The small-sized low-temperature device apparatus according to claim 3, wherein packing is provided around the engagement portion, and a space formed by the small-sized low-temperature device apparatus and the closed-cycle refrigerator is isolated from outside air. 7. The small-sized low-temperature device device according to claim ₆ , wherein the voids are depressurized or replaced by a dry gas, preferably C ₆ H ₆ or CO ₂ gas. 8. A small-sized low-temperature device device in which a peripheral part of a low-temperature device is kept in a vacuum state, wherein a peripheral part of the low-temperature device is provided with a transmitting circuit and a receiving circuit for communicating signals with the low-temperature device device and an external device. Small-sized low-temperature device device. 9. A small-sized low-temperature device device in which a peripheral portion of the low-temperature device is kept in a vacuum state, which is provided with an element for converting electromagnetic waves into electric energy and a capacitor.