DE3215396A1 - NICRO-MINIATURE COOLING DEVICE AND METHOD FOR THEIR PRODUCTION - Google Patents

Description

Dipl-Phy. Heinrich Seidi · Patent attorney ■ Biers tad ter Höhe 15 · P.O. Box 5105 · 6200 Wiesbaden 1 ■ ST (0 6121) 56 20

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The invention relates to micro-miniature cooling devices for cooling small objects, such as electrically superconducting devices and the like .. Also relates the invention relates to methods of making such micro-miniature cooling devices.

Certain materials, so-called superconductors, have the property of electrical current without electrical resistance to pass through. Since the superconductivity is only at If there is temperatures that are close to absolute zero, it is a major concern to be reliable, continuous to provide working cooling devices for such superconducting electrical devices. Electric superconductive devices such as super sensitive magnetometers, Voltmeters, ammeters, voltage standards, current comparators, etc. require a cryogenic to operate Surroundings. Conventionally, this is generated by a bath of liquid helium. The helium is liquefied somewhere and fed and inserted into a dewar. The difficult and complex way of working that this creates has severely restricted the use of such facilities. Many of the superconductive ones listed above Devices give off only a few microwatts of thermal energy when in operation, while the cryogenic Systems have a cooling capacity on the order of watts, so that these devices are poor at their

Dipl.-Phys, Heiniidt Seids. Patent Attorney · Bieretadter Höhe 15 · PO Box 5105 · 6200 Wiesbaden 1 · S? (0 6121) 562022

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Cooling devices are adapted.

In addition, many devices, such as optical microscope stages, Sample holder for X-ray diffraction, electron microscope quay tstuf s, devices for cryosurgery in the brain, for ECG, MCG and EKG measurements and amplifiers with low noise levels require operating temperatures that are or will be below ambient temperature at least influenced favorably by this.

In addition, there are a number of devices that operate at high speed or high power, such as VLSI (Very Large Scale Indication) disks and transmitters, which have dimensions on the order of a square centimeter and relatively large amounts of power dissipation output, on the order of 10 to 50 watts. Conventional Cooling devices such as blowers for convection cooling are not suitable for such amounts of heat without noticeable To distribute temperature rise in the area.

£ s are already miniature cooling devices with closed Cooling circuit, for example those based on a Gifford-Mc-Mahon circle, Vuilleumier circle, Stirling circle etc. has been developed. These cooling devices are available with cooling capacities in the range of 0.5 to 10 watts convenient to use and compact. Because of their movable

Dipl.-Phyf. Heinrieh Seids patents waft ".Bterstädter Höhe IS * Postfach 5105-6200 Wiesbaden 1 S ¹ (06121) 56 2022

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Parts, however, introduce a large amount of vibration and magnetic noise, which makes the operation of the cooler impossible Objects. Miniature Joule-Thomson system cooling devices have also been developed which have cooling capacity typically between 0.5 and 10 watts. These compact systems are generally in the form of helically lamellar tubes around a Core are wound. The gas under high pressure flows inside these tubes and flows under low pressure Pressure from these pipes. Such helically finned and wound heat exchangers are made by difficult welding or soldering together of the individual parts. Because of the difficulty of such Device could use micro-miniature coolers Capacities in the milliwatt range have not yet been established.

There is a need for a micro-miniature cooler in many devices available, which is about 1 to 10 cm in size and a cooling capacity in the milliwatt range having. There is also a need for manufacturing processes for such micro-miniature cooling devices that the conventional difficult welding and Avoid soldering and the formation of very small gas pipes for the operation of heat exchangers in the regime of the laminar flow and with still good heat exchange effect

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Dipl.-Phys. Heinrich Seids · Patent Attorney ■ Bierstadter Höhe 15 · P.O. Box 5105 · 6200 Wiesbaden 1 · ® (06121) 562022

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allow degree. The consistent lack of 'turbulence in the Gas flow eliminates vibration and noise, both important considerations for use in superconducting devices Devices. The miniature dimensions would be incorporating a unit of cryogenic system and superconducting »sensor as a hybrid component in electronic Enable circles. The micro-miniature cooling capacity would allow the cooling system to be adapted to the load to be cooled. The object of the invention is therefore to provide a micro-miniature cooling device that this Requirements are sufficient.

This object is achieved according to the invention in that at least two elements made of glass or similar material with the same low thermal conductivity and temperature expansion coefficient with the formation of at least one pressure-tight contact interface are connected to form a rigid laminate, on this intermediate surface or these intermediate surfaces a cooling chamber and flow channels connected to this for a coolant as parts of a according to the principle of Pressure release working cooling circuit is formed, namely a coolant supply channel leading to the cooling chamber, the at least one capillary section opening into the cooling chamber for partial relaxation of the lower part Having high pressure supplied coolant, and a return channel connected to the cooling chamber for the

Dlpl.-Phys. Heinrich Seid «■ Patent attorney " ■ Biers tad ter Höhe 15 ■ "Postfach 5105-6200 Wiesbaden 1. S? (0 6121) 56 20

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Coolant guided in the manner of a heat exchanger along at least a section of the coolant supply channel is.

In addition to solving the problem posed, the invention also addresses the need for micro-miniature cooling devices the same general dimensions as stated above, but which also draw off large amounts of heat can, for example, 10 to 50 W as required by certain small devices, these devices at or below ambient temperature Ambient temperature are kept at operating temperature. Such cooling devices can according to the invention can be easily produced, in training that is compatible with that of electronic devices.

As explained in detail below, the micro-miniature cooling device according to the invention contains in a unique form and Large a plurality of mutually sealed plate-like elements, which between them the cooling chamber, a heat exchanger, capillary passages and flow passages for guiding the inflowing and the outflowing Form coolant. The return or outflow channels from the cooling chamber are used as part of the heat exchanger used in countercurrent to the channels for the inflowing coolant and then led to the outside.

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Diploma Phys. Heinrich Seids. Patent attorney · Bierstadter Höhe 15 "Postfach 5105 · 6200 Wiesbaden 1 - Q? (061 21) 562022

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The micro-miniature cooling device according to the invention represents a reduction in size of conventional cooling devices by a factor of about 1000.

In summary, if d is the diameter of the Heat exchanger tube, 1 the length of the heat exchanger tube and t the cooling time are in comparison to the capacity, the Proportional to in, the flowing mass is as follows:

0.5
(m)

(m) ° ⁶
Vf * (m) ° ' ⁶

A micro-miniature cooling device that works with turbulent flow with a capacity of a few milliwatts would require: d = 25 µm and 1 a few centimeters. The smaller the devices, the smaller the flowing mass becomes, too small to be turbulent Flow of the coolant could occur. Laminar flow then becomes possible without any loss. Cooling efficiency and at the same time with an improved way of working.

For micro-miniature heat exchangers according to the invention that should work in the area of laminar flow over the same pressure regime and have the same efficiency, the Exchanger length (1) can be made proportional to the square of the diameter (d) of the exchanger channel. At-

Dipl.-Phy *. Heinrich Seids · Patent Attorney · Bierstadter ftone IS "Postfach 5105 · 6200 Wiesbaden 1 · SP (06121) 56 2022

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For example, a Joule-Thomson heat exchanger which works with N ₂ at 120 bar, with a 5 cm long capillary channel 110 μm wide and 6 μm deep, results in a cooling capacity of approximately 25 mW. Different cooling capacities can be achieved by varying the width of the duct without changing the efficiency. It is thus possible to work under flow conditions free of vibration and turbulence noise, an advantage in particular for superconducting devices that require a very low noise level.

In a Joule-Thomson cooler of this type it is usually convenient to use a capillary channel to throttle the compressed gas. But it is also in the Technique known, instead porous material, for example porous metal, sintered ceramic, etc. for throttling to use the gas.

To increase the efficiency of the cooling device for certain applications, one embodiment of the Invention two capillary sections, which are arranged in series or parallel to each other and passages to Discharging a considerable part of the gas directly to the exhaust passage of the heat exchanger after flowing therethrough only one of these capillary sections.

For the construction of micro-miniature cooling devices, new

Dipl.-Phy ». Heinrich Seids. Patent attorney · Bierstadter Höhe IS. P.O. Box SX05 · 6200 Wiesbaden 1 - 3? (06121) 562022

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Techniques needed to make heat exchangers and expansion nozzles to form, which are by a factor of 100 to 1000 smaller than the conventional cooling devices.

Conventional manufacturing techniques are unsuitable for this purpose because Channels on the order of 5 µm to 500 µm must be formed with accuracy and the device It must be sealed so that it has high pressure in the range of 10 bar to 210 bar for the achievement of the desired Must withstand cooling efficiency.

Accordingly, it is a particular advantage of the invention that a novel micro-miniature cooling device, in particular for cryogenic cooling, and a favorable manufacturing method can be created.

The new micro-miniature cooling device can with a cooling capacity within a range of milliwatts up to about 50 W and more.

The micro-miniature cooling device according to the invention can received a novel structure with a large number of layers.

The micro-miniature cooling device can be in a novel way with a single stage for cryogenic operation.

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Dlpl.-Phy ». Helntkh Selds. Patent attorney ■ BlerBtadtcr H'itVr is "· Postiath 510S ■ 6200 Wiesbaden 1 ■ <S1 '(06121) SblOl'l

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to be built.

However, a multi-stage or multi-stage design of the cryogenic micro-miniature cooling device is also possible.

In a further embodiment of the invention, a novel cooling device with small dimensions is created, which has two or more plates of a material with low thermal conductivity, for example glass plates, which are held in a pressure-tight surface connection, and gas supply channels on one or more intermediate plate surfaces and return ducts to a micron-sized cooling chamber, the apparatus being adapted to do so is to continuously cool a superconductor or similar device. The device is suitable for this Gas with a pressure in the range of IO bar to 210 bar, the passages having a width in 5 µm to 500 µm in size and 5 µm to 60 µm in depth.

In addition to this, the cooling chamber can be formed in the form of a recess in a surface area of a plate be, or it can be the channels at the interface or the intermediate surfaces are formed by attached walls.

Dipl.-Phys. Heinrich Seids · Patent Attorney - Bierstadter Höhe 15 · PO Box 5105 · 6200 Wiesbaden 1 ■ Q? (06121) 562022

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In the context of the invention, two-ply or multi-ply Cooling devices for cascade cooling to achieve lower cryogenic temperatures are formed.

For example, a micro-miniature cooling device according to the invention constructed from three or more similar sheets of glass or equivalent material in the form of a stack be, with flow channels for high pressure inlet and low pressure outlet and the associated cooling chamber formed in the micron order and arranged in separate layers at interfaces between the adjacent plates are. Here, heat exchanger channels and capillary expansion channels can be arranged in a row on one surface the inner plate and the outlet channel are formed on the other surface of the inner plate.

The novel cooling device can be provided with a holder surrounding it at one end, with which it can be held self-supporting in the interior of an evacuated housing.

According to the invention there is thus a micro-miniature cooling device and methods for their manufacture have been created with which it is possible to dimension the cooling device and adapt cooling capacity for the respective applications.

Diploma Phys. Heinrich Seids ■ Patent attorney · Bierstadter Höhe 15 " Postfach 5105 · 6200 Wiesbaden 1 · G? (06121) 56 2022

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The cooling device according to the invention offers excellent Suitable for a wide range of laboratory applications and the like. It comfortably generates very low temperatures. she is characterized by its economical operation. The dimensions of the device are small and its weight small, so that the device can be attached directly to instruments and microscope stages. The small dimensions also allow use for cooling very small devices and enable tools or optical instruments to work without interference with directly attached cooling device. Low gas consumption of the Device enables days of continuous use with operation from a standardized pressurized Gas cylinder. Temperature control is easy. The cooling device is simple in its construction and can create and operate easily and safely.

The invention also relates to novel manufacturing methods for micro-miniature flow circuits, in particular micro-miniature cooling devices. For this purpose channels and; 20 wells according to the pattern of a desired one Flow circle attached in at least one major flat surface of a plate and then with another plate covered with a flat main surface on the with grooves and depressions provided main surface of the first plate is bonded pressure-tight.

Dlpl.-Phys. Heinridi Seid »· Patent attorney. BIerstadter Höhe 15 * P.O. Box 5105. 6200 Wiesbaden 1 · 5? (06121) 562022

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With micro-miniature cooling devices, especially those for cryogenic cooling, plates with the same temperature expansion coefficient as possible will be chosen. the Channels and depressions can be made in the plate surface by etching. But one is preferred Use sandblasting technique with fine particles, because you get a much better resolution of the channel and Recess pattern achieved because the side edges of the channels and recesses are thereby substantially rectangular can be cut into the panel surface and because the depth of cut depends on the number of Sahdstrahlwege can be controlled very precisely. To apply this sandblasting technique, one will first on the surface to be provided with the grooves and depressions with a sandblasting treatment against this use resistant material. One is then using lithographic or photolithographic methods that Define the desired pattern in this support layer and the support layer according to this pattern in the area of the Remove grooves and depressions to be made.

A particularly favorable layer can be formed, for example, in the following ratio: 7 grams of gelatine,

3 1 gram of ammonium dichromate and 50 cm of hot water.

The appropriate methods and materials for pressure-sealing

: Dipl.-Phys. Heinrich Seids ■ Patent attorney · Bierstadter Γ-TöVe 15 "· Postfa" * 5105 · 6200 Wiesbaden 1 ■ Sf (06121) 56 20

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A sufficient selection of binding the laminate panels is available to those skilled in the art.

Overall, the manufacturing process is simple and safe. Above all, it leads to a very precise, well-reproducible training of the flow circuit forming Channels and chambers. In particular, the capillary channels that are important for the high efficiency of micro-miniature cooling devices and heat exchanger sections.

Embodiments of the invention are described below explained in more detail with reference to the drawing. Show it:

Fig. 1 is an exploded view of a micro-miniature cooling device in a Embodiment of the invention;

Figure 2 is a general plan view showing a micro-miniature cooler portion Arrangement or

Shows patterns of coolant passages according to a further embodiment; 3 is a generally perspective view showing a micro-miniature cooler portion shows in a further modification;

Figure 4 is a plan view of a module for a multiple unit implementation a micro-miniature cooling device;

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Dipl.-Phy ». Heinrich Seids · Patent attorney ■ BiersUdter Höhe 15 · P.O. Box 5105 ■ 6200 Wiesbaden 1 ■ ST (06121) 562022

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5 shows a section through another embodiment of a micro-miniature cooling device;

6 is a cross section through another embodiment of one of a plurality of Modular units constructed micro-miniature

Cooling device;

Figure 7a

to 7e sections, the procedural steps in the Reproduce manufacture of a micro-miniature cooling device;

Figure 8a

to 8d cuts, the procedural steps of another Reproducing the manufacturing method of a micro-miniature cooling device; Figure 9a

through 9c sections which reproduce process steps in a manufacturing process for a micro-miniature cooling device with channel walls attached;
Figure 10a

bis iod cuts, the process steps in one

another manufacturing method for a micro-miniature cooler reproduce;

11 is a section showing the manufacture of a built up from a plurality of modular units

Embodiment shows;

'Dipl.-Phys. Heinrich Seids. Patent attorney Biers tad (er Höhe 15 Postfach 5105 6200 Wiesbaden 1 ■ & (06121) 56 20

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Figure 12 is a top plan view showing an application and environment reproduces a cooling device according to the invention;

Fig. 13 is a schematic plan view showing the electrical circuit in the cooling device according to the invention

reproduces;
^; Fig. 14 is a section showing the laminate construction of the

Figure 9 shows cooling device and the multilayer flow paths for the coolant; Figure 15 is a top plan view, partially broken away, of a

Holder for a cooling device, as a detail of the device according to Figure 14; FIG. 16 shows a section essentially along the line 16-16 of FIG. 15;
17, 18 and 19 are plan views of three (upper, middle and lower) elements which make up the laminate or sandwich construction of a cooling device of a preferred embodiment of the invention, in which different flow paths and chambers for the coolant

are provided;
FIGS. 20 and 21 are sections essentially along the lines of FIG

Lines 20-20 and 21-21, respectively, in Figure 17;

Figure 22 is a section taken substantially along lines 22-22 of Figure 18;

23 and 24 sections substantially along the

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Dipl.-Phys. Heinrich Seids ■ Patent attorney ■ Biers tad ter Höhe 15 · P.O. Box 5105 · 6200 Wiesbaden 1 · 5? (06121) 5620 22

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lines 23-23 and 24-24, respectively, in Figure 19; Fig. 25 is an exploded view of an embodiment ungs form in which the flow channels are located differently; Figure 26 is an exploded view of an embodiment in which two low pressure flow paths are provided;

27 is a partial section showing a flow path of increased thermal conductivity at the cold Reproduces the end of the cooling device;

28 shows an exploded view of a multilayer cooling device in a further one Embodiment;

FIG. 29 is a plan view of the plate provided in FIG. 28 with a low-pressure gas passage; FIG. 30 is a top view of that provided in FIG

Plate with high pressure ports; Fig. 31 is a representation of the laminate construction of two to a unit of combined multilayer cooling devices for cascade cooling;

32 shows a section along the line 32-32 in FIG. 31; 33 is an exploded view of a further embodiment of the invention; and

34 is a plan view of a component of a

further embodiment of the invention.

'< Dipl.-Phys. Heinrich Seids · Patent attorney ■ Bieretadter Hishe 15 * · Postfach 5105 ■ 620Q Wiesbaden 1 · ST (06121) 56 20 22

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In the embodiment of a micro-miniature cooling device shown in an exploded perspective view in FIG a heat sink 12 is provided in sealed surface contact with a carrier 10. the heat sink 12 can be made of crystalline material (e.g. silicon), amorphous material (e.g. Glass) or metallic material (e.g. copper, stainless steel). The carrier 10 consists of a material with a temperature expansion coefficient that is compatible with the temperature expansion coefficient of the heat sink 12, for example made of borosilicate glass (known under the trade name "Pyrex"), soda glass (Soda glass) or kovar. The heat sink 12 and the carrier 10 are preferably thin glass plates which extend uniformly.

The heat sink 12 and the carrier 10 must be sufficiently thick and / or strong enough to withstand the pressure of the entering To withstand the gas, typically on the order of between 10 bar and 200 bar (150-3000 psi). For example A silicon heat sink can be approximately 300 µm (0.0118 ") thick A glass heat sink can be approximately 250 µm to 510 µm thick and a substrate made of glass can be approximately 250 µm to 510 µm.

On that surface of the heat sink 12 that is on the Carrier 10 is worn are parallel "serpentine"

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Dipl.-Phys. Heinrich Seids. Patent attorney ■ Bierstadter Hohe 15 · Poetfach 5105 · 6200 Wiesbaden 1 ■ S ¹ (0 6121) 562022

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Channels 14 and 16 are formed or etched in which are 5 µm to 300 µm wide and through 150 µm to 500 µm wide walls 15 are separated from each other. The channels 14 and 16 connect an outlet 18 (low pressure return) and one, respectively Inlet 20 (high pressure inlet) with a reservoir or cooling chamber 24. The dimensions of the reservoir 24 are determined by the desired reserve capacity, which is required for fluctuating requirements. The above named channels and the reservoir are formed in the bottom surface 13 of the heat sink 12, which lie flat is bonded to the carrier's flat top surface 17 which effectively closes it. The through the underside face 13 of the heat sink 12 and the upper side surface 17 of the carrier 10 formed intermediate surface is pressure-tight bound.

The channels 14 and 16 each define low-pressure cooling lines and high-pressure cooling lines over an initial length run in the vicinity and thereby form a heat exchanger section at 22. Between the inlet and A fine duct filter section 21 is provided in the heat exchanger section. Behind the heat exchanger section 22, the inlet port 16 becomes independently serpentine and narrower at 26 on the carrier 10 so that the coolant will drop in pressure and then expand. For example, the channel section 22 is approximately 250 µm wide and 50 µm deep while

Dipl.-Phy «. Heinrich Silk · Patent Attorney ■ Bierstadter Höhe 15 · P.O. Box 5105 · 6200 Wiesbaden 1 · & (0 6121) 56 20

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the channel 26 is approximately 125 µm wide and 10 µm deep. The end of the expansion line 26 opens directly into the reservoir 24, and exit channel 14 extends from reservoir 24 back through the heat exchanger to outlet 18. Das Reservoir 24 is preferably about 20 µm to 50 µm deep.

On the other or lower surface of the carrier 10 is a connection unit 30 made of a suitable metal alloy, for example Kovar (an alloy of iron, nickel and cobalt, the coefficient of thermal expansion of which is approximately the same as that of the material of the carrier 10). These connection units are provided with through holes 32 and 34 which are connected to the connections 18 and 20 in the heat sink via aligned bores in the carrier 10. With this connection unit 30, a pair of small tubes 36 and 38 are connected, which supply the coolant to the cooling device and remove it from it. These tubes 36 and 38 can be made of stainless steel, as used for hypodermic needles, or made of polytetrafluoroethylene. The connection unit 30 is attached to the carrier 10 by means of a suitable sealing compound, for example an epoxy seal. An object 40 to be cooled is attached to the top of the cooling body 12 in direct contact with the wall of the reservoir 24. The object 40 may be any of a large number of devices that are to operate at low temperatures (beispiels- ^w _. ^E ise super sensitive magnetometers, gradiometers, bolometer

Dipl.-Phys. Heinrich Seids · Patent attorney · Blerstadter riöVe is "· Postfach 5105 · 6200 Wiesbaden 1 · S? (00121) 56 20

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and the like devices that operate on the basis of the Josephson effect or other known devices). Devices for operation at higher temperatures are also possible (e.g. infrared detectors, solid-state lasers or samples whose physical Properties are to be determined). The entire device can be placed in a dewar vessel or a vacuum vessel be used to reduce the heat input to the parts.

The reproduced micro-miniature cooling device is a Joule-Thomson open circuit cooling system in which the tube 38 via a control valve 39 with a container 37 for highly compressed refrigerant gas, for example Nitrogen, hydrogen or helium.

The highly compressed gas enters the inlet at a pressure of approximately 10 bar to 200 bar and in an amount of flow from approximately 5 to 50 ml / sec through inlet 20 and flows through heat exchanger 22 where this gas 4, by low pressure, highly refrigerated Gas is cooled which leaves the device via the channel 14, the outlet 18 and the tube 36. That under high Pressurized gas leaves the heat exchanger 22 and passes through the expansion capillary 26, where the pressure drop is the Lowers temperature of the gas that supercooled as one

Dipl.-Phye. Heiniich Silk · Patent Attorney · Bierstadter Flöhe * 15 · * PostfaÄ 5105. 6200 Wiesbaden 1 ■ ® (06121) 56 20

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or cryogenic liquid enters reservoir 24. The low-temperature reservoir 24 in turn cools the object 40, which is mounted on the reservoir 24. The absorbed heat causes the liquid to evaporate and them flows through channel 14 to outlet 18.

For example, a micro-miniature cooler has a heat sink that is 500 µm thick, 1.3 cm wide, and 7.6 cm long glass plate, a cooling capacity of 100 mW at 122 K. The channel dimensions are in the size of 100 µm and the flow rate about 30 ml / sec (STP) nitrogen at an inlet pressure of 110 bar (1600 psi). The carrier is a glass plate of the same size.

In another example, a micro-miniature cooling device, the heat sink of which is made of silicon and has dimensions of 75: 12: 2 mm, has a 30 cm long heat exchanger section and operates from room temperature to 200 ° K using CO ₂ - the micro-miniature Cooling device can be approximately 1.3 to 10 cm long, 1.3 cm wide and 0.1 to 0.2 cm thick with typical channel dimensions between 5 and 500 µm and partitions 150 to 500 µm wide. This cooling device can have a cooling capacity between 1.0 and 50,000 mW at temperatures between 2 and 300 ° K. It can absorb inlet pressures between 10 bar and 200 bar. It should be noted, however, that the described

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Dipl.-Phys. Heinrich Seids. Patent attorney ■ Bicrstadter Höhe 15. Postfadi S105 ■ 6200 Wiesbaden 1. S? (0 6121) 56 2022

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Micro-miniature cooling device for certain purposes can also be enlarged or reduced in terms of dimensions and capacity.

In addition to an open cooling circuit described above, it should be noted that the cooling device using a Compressor for recompressing the gas can be designed as a closed circle system. Additionally It should be noted that the manufacturing process described here is also used for the construction of cooling device parts in which other circles, for example Servel system, Gifford-McMahon system, pulsating pipe system and Vuilleumier system are provided.

In some of the laminar flow devices, the shape of the channels may be in a straight line rather than a "serpentine" design can be modified as shown in FIG. Figure 2 shows the lower surface of one Heat sink. In this embodiment, gaseous coolant enters at inlet 42, flowing through the parallel ones Heat exchange channels 43 to the meandering capillary channel section 44, from there to the reservoir or the cooling chamber 45, through the negative pressure return 46 to the outlet 47. An advantage this shape consists in that the low pressure return 46, as shown, completely surrounds the high pressure channel lines, so that any small gas leakage from a high pressure

Dipl.-Phys. Heinrich Seid «■ Patent attorney · Bierstadter HJiVe IS * · PO Box 510S · 6200 Wiesbaden 1 · G? (0 6121) 56 2022

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channel is caught by the low pressure return and does not escape into the surrounding vacuum, which the cooling device isolated from the environment. A possible disadvantage of this shape is the long way for the heat to get to the heat exchanger section to migrate through the glass between the input channels 43 and the output channel 46. This difficulty can be avoided in that the heat sink made of glass is combined with a carrier 48 made of glass, as it is shown in Figure 3 on which highly thermally conductive transversely extending metal strips or wires 49 are printed or are tied up. These strips can be attached to that surface of the glass support that the Forms an intermediate surface with the heat sink 41. These transversely extending heat conductor pieces 49 create a highly thermally conductive Away laterally over the cooling device, while the thermal conductivity in the longitudinal direction of the cooling device remains at the low value determined by the glass.

The cryogenic micro-miniature device and cooling device is also suitable for multi-unit construction. For example For example, a plurality of cooling devices each operated with a different coolant may be one Cascade cooling of one gas through another, creating cooling to extremely low temperatures. There can be additional connections with these additional

Dipl.-Phy *. Heinrich Seid ». Patent attorney . Bierstadter FTötie is ". P.O. Box 5105. 6200 Wiesbaden 1 · ® (0 6121) S6 2022

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Connections connecting channels and additional reservoirs for further cooling of a cryogenic device included be.

FIG. 4 shows, in perspective, a heat sink made of glass for a multi-unit module 51 of a micro-miniature cooling device.

Two reservoir or coolant chambers 52 and 53 are provided there. The chamber 52 has an inlet conduit 54 which from inlet port 55 via a meandering heat exchanger section 56 and a fine capillary section 5 7 leads into the chamber, and an outlet conduit 58, which is a meandering Has heat exchanger section 59 along section 56 and leads to outlet connection 60. The chamber 53 has an inlet conduit 61 leading from the inlet port 62 through a tortuous heat exchanger section 63 and a capillary section 64 leads into the chamber; and an outlet conduit 65 which is a tortuous heat exchanger section 66 along the section 6 3 and leads into the outlet connection 67. A source of high pressure standing nitrogen is connected to port 55 and is a source of high pressure hydrogen is attached to connection 62. The two circles are thus partially effective on one another, which creates a chamber 53 flowing coolant before expansion

\ Dipl.-Phys. Heinrieh Seids · Patent attorney. Bierstadter-Riine \ S · Postfäcii 5105 ■ 6200 'Wiesbaden 1 · ® (0 6121) 56 20

is cooled. One circle uses Joule-Thomson expansion of nitrogen to bring the hydrogen to 77 ° K at the chamber 52 to cool. The other circle uses Joule-Thomson expansion of the precooled hydrogen to make the Kanuner 53 21 K to reach. The entire cooling device comprises - as shown - two heat exchangers, two expansion sections, two cold fluid reservoirs and the inlet and outlet ports. The dimensions of the device are approximately 5 cm by 13 cm. Similarly, a three-stage leaves System or use of nitrogen, hydrogen and helium achieve a cooling of up to 4.5 K.

Figure 5 is a sectional view of another embodiment for a multi-layer micro-miniature cooling device, in which the input channels 73 and output channels 74 at either side or on both sides of the heat sink 75 are formed from glass and in which on either side or two supports made of glass or cover plates 76 and 77 are bound on both sides. The refrigerant under high pressure flows along channels 73 and returns through the channels. The channels 73 and 74 can be etched or otherwise Way be formed in the surfaces of the heat sink 75, as indicated in full lines. But you can also etched or otherwise formed in the surfaces of one or both cover plates 76 and 77 made of glass be, as shown in dashed lines at 73 'and 74'.

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Dipl.-Phys. Heinrich Seids · Patent attorney · Bierstadter "iföh'e IS * · Postfach 5105 · 6200 Wiesbaden 1 ■ ίΕ? (0 6121) 56 2022

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The channels 73 and 74 can also be formed through attached channel walls on the heat sink 75 or on the carriers 76 and 77 be educated. In any case, the channels 73 and 74 consist of inlet sections, heat exchanger sections, capillary sections and cooling chambers, which can each be designed and arranged as shown in FIGS. 1 to 4 is shown. The difference between the device of Figure 5 and that of Figure 1 is that according to Figure 1, the input channel and the output channel can be formed in a single layer, i.e. in the same or an adjacent flat surface, while according to Figure 5 they in non-superimposed surfaces are formed '. It should be considered that according to Figure 1, the input channels and output channels in the opposite Areas 13 and 17 can be formed.

FIG. 6 is a section through another embodiment of a micro-miniature cooling device constructed from modular units . The channels 80, 81, 82 and 83 are in the surfaces of thin heat sinks 84, 85, 86, 87 and 88 formed from glass by etching, sandblasting or by forming attached channel walls. For example, nitrogen occurs under high pressure in the channel 80 and flows back via the low pressure channel 81, while hydrogen under high pressure enters the channel 82 and is cooled by nitrogen in the channel 81. The hydrogen comes under

Dipl.-Phys. Heinrich Silk. Patent attorney · Bierstadter "H8Ke is" · Postfaäi SlOS · 6200 Wiesbaden 1 · 5? (0 6121) 562022

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low pressure from channel 83. The inlets, heat exchanger sections, Expansion lines and reservoirs are included in the respective channels, as with the above Embodiments is explained.

Production method:

FIGS. 7a to 7e illustrate a manufacturing method for the cooling device by etching channels in glass or silicon plates. The technical measures to be described are known to some extent in the manufacture of semiconductor devices, such as integrated circuits, and may include the use of conventional photoresist masks and etching techniques. In one case, using a silicon plate material having a surface crystal orientation in the (1,0,0) plane, anisotropic etching can be used to etch V-shaped grooves in the surface of the silicon plate. Alternatively, vertical walls can be created using a silicon plate with a surface orientation of the (1,1,0) plane. In Figure 7a a part of a silicon plate 9 ¹ O is shown in cross-section, which is provided on a main surface with a silicon oxide layer 91st The plate is about 300 µm thick and the oxide layer 91 is approximately 9000 Å (0.9 µm). The oxide layer can be produced by heating the silicon plate in a wet oxygen atmosphere. A photoresist 92 is on the surface

Dipl.-Phys. Heinrich Seid «. Patent attorney Bieretadter'nöhe 15 * P.O. Box 5105. 6200 Wicibaden 1 ■ 5? (0 6121) 56 2022

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of silicon oxide 91 and is exposed under a photomask with the desired channel pattern. Of the Photoresist is removed and the exposed oxide is etched, forming it in pattern 93 as shown in Figure 7b. remains. The silicon oxide now acts as a mask and the exposed silicon is made using an anisotropic one Etchant, for example ethylene diamine, etched, resulting in V-grooves 94, as shown in Figure 7, result. After the V-grooves have been completely etched, the remaining oxide layer 93 is removed from the silicon plate and the Plate cleaned. A flat sheet of borrosilicate or equivalent glass plate 95 is then placed on the etched surface of silicon plate 90, as shown in Figure 7D. The bonding of the glass to the silicon surface is done using known field assisted or anodic bonding techniques. After that, will - As shown in Figure 7e - the silicon plate 90 is etched or removed in some other way on the rear side in order to achieve the Thickness of the entirety of the two plates and hence the thermal conductivity of the laminated cooler structure to improve.

There are then inlet lines and outlet lines in the Opposite side of the glass support 95 is drilled or etched, and the tubular gas lines are then attached to the rear side bonded to the glass plate by means of epoxy resin.

Dipl.-Phys. Heinrich Seids ■ Patent attorney ■ Biers tad ter Höhe 15 '· Postfach 5105 · 6200 Wiesbaden 1. & (061 21) 56 2022

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Using photolithographic pinning and chemical etching, the entire cooling device, including Heat exchanger, expansion line and liquid reservoir can be formed in one step. as well like chemical etching, electron beam or X-ray lithography and electrolytic and plasma etching can also be used to be used. The above photoresist method can be used wherever the heat sink and carrier are glass panels are using conventional materials and techniques.

Figures 8a to 8d illustrate another method of making incised canals in a hard, amorphous isotropic material like glass or crystalline material like silicon. The method allows good dimensional control, improved resolution compared to chemical etching, eliminates undercuts and allows the formation of vertical walls. This process is not limited to the manufacture of micro-miniature cooling devices limited. In Figure 8a is a part of a glass plate 100 with a thickness of about 0.5 mm in cross section shown, on one main surface of which a resist layer 101 is provided. The purpose of this resist layer is to protect the underlying surface and create a pattern for the duct placement. Of the Resist can be a photosensitive or non-photosensitive

Dipl.-Phys. Heinrich Selds · Patent Attorney · BlerstadterWöhe 15 · Postfach 5105 ■ 6200 Wiesbaden 1 · QS * (06121) 562022

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be more sensitive resist. But it must be elastic enough or tough to withstand fine particle "sandblasting" as discussed below. The resist can do the Cover surface of the entire plate or it can be screen printed on the plate in a desired pattern to be appropriate. When the resist is a photoresist, it is passed through a conventional photomask with ultraviolet light exposed to establish a pattern. A novel photoresist which satisfies the requirement that it is sufficient resistant to "sandblasting" with fine particles is composed of: 7 grams of gelatine (e.g. Knox) and 1 gram of ammonium dichromate dissolved in 50 ecm hot water. The resist forms a thick, spongy layer about twenty to thirty times the thickness of one conventional resists. The unexposed parts of the resist can be removed with hot water or by using the enzyme protease to digest the unexposed part, resulting in a in Figure 8b shown structure results. The remaining resist 102 is strong and elastic, suitable for the abrasive action of fine Particles resist during "sandblasting" while the exposed areas of the glass plate surface can be rubbed off. A miniature air abrasion device that emits a jet of fine particles of alumina Developed at about 5.5 bar (80 psi) acts as a fine particle sandblasting device. The "sandblast" -

Dipl.-Phys. Heinrich Silk · Patent Attorney · Bierstadter Höhe 15 ■ P.O.Box 5105 · 6200 Wiesbaden 1 · <£ '(06121) 56 2022

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The device is guided in a constant advance over the plate surface carrying the resist according to FIG. 8b, with a jet of abrasive powder with a particle size of about 17 µm can be used to add approximately 2 µm of material to be removed from each pass. Larger powder particles (for example 27 µm and 50 µm) wear faster, but give poorer resolution and definition of the Channel pattern. They can be used for making larger devices with corresponding accuracy.

The channels 103, which by this particle beam method, as in Figure 8c; have a precisely controlled depth (2 µm to 300 µm), vertical walls and Edge definition of approximately 5 µm roughness. After full Forming the incised channels, the remaining photoresist is removed and the plate loo cleaned. The entire system of cooling chamber and passages of the cooling device can thus be produced in one step will.

As shown in Figure 8d, a carrier 104, such as a soda glass cover plate, is on the etched surface of the Glass plate 100 bonded with a layer of adhesive that is less than 10 µm, but suitable for about 35 bar

withstand up to 207 bar (500-3000 psi). This is the same way of binding as it is in all embodiments

Dipl.-Phys. Heinddt Seid »■ Patent attorney · Bierstadter Höhe 15 · Poetfach 5105 · 6200 Wiegbaden 1 · S? (06121) 562022

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can be used to fasten two or more glass plates together to form a permanent, pressure-resistant unit. Such a bond can also be made with epoxy resin or
ultraviolet-curable cement. One
Gasket with a thickness in the micron range can be obtained by pulling in

of diluted adhesive into the space between the plate 100 and the carrier 104 by capillary action. The cooling device is then exposed to intense ultraviolet radiation until the adhesive polymerizes and the
Bond trains.

Alternatively, the cover plate or the carrier on the
etched radiator plate by means of a thin film of
Glass solder can be welded using conventional methods for the manufacture of liquid crystal displays
are to be applied. The inlet lines and outlet lines
are drilled or etched into the back of the glass support 104 and hypodermic tubes made of stainless steel or polytetrafluoroethylene are then used as gas lines

bonded to the back of the glass plate 104 by means of epoxy resin. When using the sandblasting technique with fine
Particulate matter, a hard amorphous isotropic material such as glass can be used for the heat sink plate 100 of the cooling device. The use of such material avoids dealing with the high thermal conductivity of

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'Dipl.-Phys. Heinrich Silk. Patent attorney Bierstadtor WSKe 15 * Postfcicn 5105. 6200 "Wiesbaden 1 · ®" (06121) 56 2022

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Silicon resulting problems, so that lower temperatures at the cooling chamber end of the cooling device can be achieved are.

Figs. 9a to 9c show a manufacturing method for a micro-miniature cooling device by forming attached Channel walls on a surface in contrast to the cutting of the channels in a surface again. the Plate 110, on whose flat surface 111 channels are to be formed, can be made of crystalline, amorphous or metallic Material. Material 112, for example sintered glass powder, epoxy resin, glass solder, by ultraviolet radiation hardenable cement, etc., is screen printed onto the surface 111 in a desired pattern, as shown in FIG Figure 9b is shown. The sintered glass powder melts when heated and forms the canal walls. The epoxy resin or the glass solder hardens in a corresponding manner Ultraviolet radiation curable cement is exposed to ultraviolet radiation to form the canal walls. In order to form the channels, distances of between 5 μm and 300 μm are provided. Figure 9b shows a carrier plate 113 made of glass that has been bonded to the heat sink plate in one of the above-mentioned ways to seal the gas exchange system. After then input lines and output lines in the back of the plate 113 have been drilled or etched, the

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Dlpl.-Phys. Helnrith Seid «· Patent attorney · Bicrstadter-FPhe 15- · Postfach 5103 · 620σ tViAtftden 1 · SP (06121) 562022

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Gas supply lines and discharges tied to the back of the plate 113.

Figures 10a to 10d show a method for the production according to Figure 5, in which the channels on one or both flat sides of a glass plate 120 are etched onto which the two glass plates 121 and 122 (figure iod) be attached. This simplifies the construction of multi-stage devices, especially for the laminar one Flow system.

To manufacture the device, the plate 120 is im Screen printing provided with a thin continuous layer of sintered glass or covered with glass solder 123 on each side. (The same can also be provided on only one side.) These layers are then melted, as in the process step according to Figure 10a. Then a resist 124 is printed on either the top and the bottom, or a photoresist is used and exposed and developed on each side at 124 (Figure lob) so that each Side of the plate 120 is given the desired pattern using one of the methods discussed above. The plate is now removed (by sandblasting or the like) and then the resist is removed. The remaining plate 120 is in Figure 10c shown. It should be noted that the channels and 126 appear in separate layers and the glass surfaces

Dipl.-Phys. Heinrich Silk · Patent Attorney ■ Bieretadter Höhe IS · PO Box 5105 ■ 6200 Wiesbaden 1 ■ §? (06121) 562022

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surfaces between these are covered with the melted layer 123.

There are then cover glass plates 121 and 122 in a program on the top and bottom attached, the first includes heating the entire assembly to the softening temperature of the glass solder or glass sinter. As a result, the inlet opening and the outlet opening for completing the cooling device (Fig iod) sealed. Extinguishers through the plate at the cold or cooling chamber end close with the capillary channels Reservoir connected to the high pressure channels 125 to the low pressure channels 126. High pressure gas passes through the Channels 125 to the cooling chamber and from there back through the channels. The channel layers can also be in one or both Carrier plates 121 and 122 are mounted in the heat sink plate 120 instead of in their entirety.

FIG. 11 depicts a method of making a "stacked" multi-stage cooling device 130, like them is shown in FIG. By doing this, multi-stage cooling devices can be constructed in a conventional manner in which different gases are bound together by spaced layers through passages in one Plate stacks occur as shown in FIG.

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Dipl.-Phys. Heiniich Seid »■ Patent attorney · Bieratadter Höhe 15 ■ Postfach 5105 ■ 6200 Wiesbaden 1 ■ β? (06121) 562022

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This cooling device has five surfaces bonded together Glass plates, preferably of the same size in a stack. The three inner plates 131, 132 and 133 are provided with surface recesses in one of the processes described above. For example be plates 131 and 132 with surface channels 134 and

135 in the method according to FIGS. 7a to 7e, FIGS. 8a to

8d or FIGS. 9a to 9c, while the plate is provided with surface channels 136 and 137, respectively, on both sides is, for example in a method according to Figure 10a to 10d. In any case, the "sandblasting process" is preferred, whereby the open edges of adjacent channels by melted layers of glass sinter or glass solder are separated from each other on the glass surface.

In the illustrated two-stage device, nitrogen under high pressure can enter via channel 134 and flow back via the vacuum channel 135. Hydrogen under high pressure can use the channel

136 enter and is through heat exchange with the sticks > toff pre-cooled in channel 135. The hydrogen under low pressure flows through the channels 13 7 to the outlet opening. As already explained, the entire arrangement is tied together with glass solder. Alternatively, plates can also be used with attached duct walls instead of the plates with incised ducts in two-stage or multi-stage cooling

Dipl.-Phyi. Heinrich Silk · Patent Attorney · Blerstedter Hölie 15 · PO Box 5105 ■ 6200 Wiesbaden 1 - S? (0 6121) 562022

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arrangements are used. The communicating inlets and passages between the various layers are appropriately formed.

While in the embodiments described above, the cooling device is a crystalline or amorphous heat sink in some cases the cooling device can also be photoetched in a copper film on the surface a circuit board or a thin plate made of stainless steel. While the described cooling device, As explained above, is designed with an open cooling circuit, can using the above-described Working methods also cooling devices with a closed cooling circuit can be produced. It's too Note that the channels are also attached to tubes, for example capillary tubes, in the manner described above with the outer surface of this tube in contact with the inner surface of another surrounding it Tube is to form a cylindrical heat exchanger cooler. The mutual sealing of the two coaxial Pipes can be made by shrinking on the outer pipe (this comes under the name "Betalloy" ((Raychem Corp.)).)

The channel dimensions, surface bonding techniques and other properties of the cooling device can be such as

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Dipl.-Phys. Heiniich Seid »· Patent attorney · Bierstadter Höhe 15 · Poitfach 5105 · 6200 Wiesbaden 1 · B" (06121) 562022

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they are described below in connection with the exemplary embodiments according to FIGS. 12 to 32.

FIG. 12 shows a typical structure in which the cooling device 211 is in a holder at one end 212 is attached, within which it is attached such that the cooling device and the holder usually form a uniform arrangement, as indicated at 213.

In the illustrated arrangement, the cooling device contains flow channels which pass through the holder to the Inlet and outlet devices for the coolant are connected.

FIG. 12 shows how the cooling arrangement in the inner space 214 a typical box-like housing 215 is attached, which is closed with an airtight lid indicated at 216 is. In the housing, the holder 212 is fastened in a suitable manner to the floor of the interior space, and the The cooling device extends through the interior in a self-supporting manner. Preferably, the interior space becomes a

217 vacuum source 218 leading line / held at negative pressure.

The object to be continuously cooled, for example a small superconducting chip or the like

Dlpl.-Phys. Heinrich Silk. Patent attorney. Bierstadter'Höhe IS. P.O. Box SlOS 6200 Wiesbaden 1. S? (0 6121) 56 2022

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is suitably mounted in the interior space 214, preferably in contact with the coldest area of the Cooling device, as indicated by dashed lines in the drawing, with lines (not shown) sealed by Step through passages in the housing. In the embodiment shown, the object to be cooled is preferably mounted in direct contact with the glass surface of the cover plate for the cooling chamber 224 of the cooling device.

In Figure 13, the flow path is shown at least schematically. The cooling device 211 has an inlet port 221 for supplying highly compressed gas through a Passage occurs, which is indicated at 222 heat exchanger section and a capillary section 223 with a smaller one Has diameter and opens into the cooling chamber 224. The object to be cooled 219 is as close as possible located at chamber 224 which is the coldest part of the cooling device. The coolant exiting chamber 224 flows back along a passage 225 which is adjacent and in a heat exchanging manner along the section 222 of the inlet passage and leads to an outlet opening 226. These passages have dimensions in the micron range for very low temperature cooling devices with capacity in the On the order of milliwatts.

Dipl.-Phys. Heinrich Selds patent attorney Bierstadter Höhe 15. Poftfach 5105 ■ 6200 Wiesbaden 1 · G? (06121) 562022

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The inlet port 221 and the outlet port 226 are in FIG Connection with holes 227 and 228 in the holder 212, and the holder is mounted in the housing that it is with the bores 227 and 228 in connection with a coolant inlet line 229 and a coolant outlet line 231 which extend away from the housing. if For example, if the system provides an open circuit, line 229 is with a source of pressurized gaseous Coolant connected and line 132 to a suitable gas outlet. In a system with closed The lines 229 and 231 are connected to one another via a loop, which has a condenser and a cooling circuit Includes pressure generator.

As can best be seen from FIG. 14, the cooling device 211 has a "sandwich composite" made up of three elements. which consists essentially of three similar precisely planes that are tied to one another on the surfaces Plates 232, 233 and 234 made of glass or other material with similarly low thermal conductivity inst, these plates being approximately equal in length and Width and thickness preferably on the order of 0.5 now. The middle plate can be thinner than the other two plates are to allow heat exchange between the inflow channels and the outflow channels to increase. The cooling device 211 can in total

Dipl.-Phys. Heinrich Seid »· Patent attorney. BiersladterHöhe IS ■ Postfach 5105 · 6200 Wiesbaden 1 · ί? (Ο 6121) 56 20

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including about 1.3 cm wide, 5.7 cm long and about 0.15 cm thick (total thickness). With these dimensions, the Cooling device 211 an operable embodiment that has been successfully tested. Another working embodiment provides as dimensions: 5 mm width, 25 mm length and 1.5 mm total thickness.

The cooling device has a multiple gas layer structure, which means: The supply channels 222 and 22 3 for the coolant and the cooling chamber are designed so that they a Form a flow passage layer for the coolant within the sandwich structure essentially in one plane, while the return flow passage is formed to have a separate flow passage location for the coolant forms within the sandwich structure essentially in a separate plane. As can be seen from the drawing, these layers are in flow connection through an opening made in the wall of the cooling chamber.

Figures 17 to 24 illustrate in detail another embodiment. The thin flat glass plates 232, 233 and 2 34 are of the same dimensions. The middle glass plate 233 is smooth with opposing planes, smooth coplanar surfaces 235 and 236 (Figure 22). As shown, the top plate 232 is transparent. As in the example of Figure 17, the plate 232 has cut

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Dipl.-Phys. Heinrich Seids · Patent attorney ■ Bierstadter Höhe 15 · PO Box 5105 · 6200 Wiesbaden 1 · S "(06121) 562022

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tene areas or channels in their lower surface 237 which the inlet port 221, the heat exchanger channel section 222, forming the capillary channel section 223 and the cooling chamber 224 arranged in series in the continuous flow path from inlet port 221 to chamber 224. The inlet opening 221 is in the form of a closed bottom shaft educated.

The intermediate plate 233 closes one side of the channels in the plate 2 32 and has one at one end through bore 238 which is aligned with inlet port 221 of plate 232 in the assembly. At the other At the end, the plate 2 33 has a passage 239 which is aligned with the cooling chamber 224.

The lower plate 2 34 is on its top or in its upper surface 240 with the low-pressure return path for the Formed coolant, namely with a generally rectangular wide surface incision 241. One Row of spaced apart ribs 242 and various rows of protrusions 243 are on the floor this incision is provided to make bearing contact with the lower surface 236 of the center panel in the assembly to hold, but without significantly hindering the flow of the coolant. The plate 234 is with a through hole 243 provided in the assembled

Dipl.-Phys. Heinrich SeJds · Patent Attorney ■ Bierstadler Höhe JS. P.O. Box S105 6200 Wiesbaden 1 - & (06121) 562022

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State of Figure 16 is aligned with the bores 238 and 221. A second hole 244 in plate 234 opens into the incision 241. The coolant emerging from the cooling chamber passes through the passage 239 into the incision 241 and then exits the assembly through the outlet port 244.

In the assembled state, the glass plates 232, 233 and 234 are at their intermediate surfaces to form a stack bound together pressure-tight and pressure-tight. This laminate is placed in the holder 212, where one end means Adhesive layers 2 49 and 250 are bound to the metal holder and the openings 243 and 244 with the bores 227 and 228 are aligned. In addition to a carrier for the cooling device, this also makes sealed leak-proof ones Inlet and outlet connections created for the flow channels of the cooling device. The dimensions the channels are selected according to the desired cooling capacities.

The passages 222, 223 and 225 have dimensions on the micron order. The passages 222 and in particular 223 are micron-sized, on the order of between 5 µm and 500 µm. In a typical Cooling devices, these passages can be flat, i.e. with a depth of 5 µm to 10 µm, and shallow, i.e. one

Dipl.-Phys. Heinrich Seids ■ Patent attorney · Bierstadter Höhe XS · PO Box 5105 ■ 6200 Wiesbaden 1 · ¹ S? (06121) 562022

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Width between 150 µm to 200 µm. In passage 222 the gas moves in a laminar flow, thereby reducing vibration, noise and other problems caused by turbulent flow. Of the Incision 241 is typically about 20 µm to 240 µm deep.

In a modification of the above example, the inlet channel and the outlet channel as grooves or in otherwise be formed in the opposite surfaces of the middle plate 233. It is also possible, to install one channel in the plate 2 33 and the other in one of the two outer plates.

During operation of a cooling device according to FIGS. 12 to 24, compressed gas, for example nitrogen or Ammonia, introduced through line 229 and inlet port 221 at ambient temperature (15 ° C to 32 °). the The gas pressures used are in the range from about 10 bar to 210 bar.

The gas flows through the heat exchanger section 222 of the micron sized channels and then through the still smaller cross-section of the capillary section 223, where the gas expands and its temperature decreases and enters the cooling chamber 224. The coolant in the

Dipl.-Phys. Heinrich Seids. Patent attorney ■ Bierstadter Höhe IS. P.O. Box SlOS · 6200 Wiesbaden 1 · ® "(0 6121) 56 20 22

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Cooling chamber 224 can be supercooled gas, liquid, or a mixture of both. In any case, this is the coldest Part of the cooling device.

The coolant leaves the cooling chamber 224 through the passage 239, flows at reduced pressure through the return channel 225 in heat exchange with inlet channel 222 and then through outlet port 226 and conduit 231. Es it should be noted that this heat exchange is essentially directly due to the small uniform thickness of the middle Glass plate 233 takes place and takes place effectively and precisely defined, with the cold flowing out under low pressure Gas pre-cools the incoming highly compressed gas.

The heat exchange between the heat exchanger sections of the high pressure gas channel and the low pressure return flow channel takes place through walls, which have the thickness dimensions of the respective plates, whereby an accurate relative arrangement is possible. The heat exchange is determined by the plate thickness.

One of the special advantages of using laminar flow in the low pressure return flow in a separate one Layer is that the cooler can operate at a lower temperature than coolers,

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Dipl.-Phys. Heinrich Seids · Patent Attorney. Biersfadter height 15. Poitfach 5105 ■ 6200 Wiesbaden 1 ■ δ "(06121) 562022

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which are designed for turbulent flow in the return duct. This is because the laminar flow in creates lower back pressures in the ducts and thus lower operating temperatures.

Experience has shown that multilayer cooling devices of the type discussed above can be used with up to a third less Volume of material can be manufactured as a single layer Cooling devices (single layer means that the inlet channels and the return channels are formed in only one intermediate surface are), where the same cooling capacity is assumed. The management of the coolant in two layers thus leads to higher efficiency, i.e. higher cooling efficiency in the cooling device.

The plates 232, 233 and 234 are preferably made of soda-lime glass, borrosilicate glass or similar material low thermal conductivity. You just have to, with less Thermal conductivity and be able to be machined to make the surface incisions for those described above Form passages and the cooling chambers. This is particularly desirable when cooling down to -50 C or underneath is required. However, if the required temperature is not so low, one is preferred upper plate made of a material with very high thermal conductivity, but with essentially the same temperature

Dipl.-Phys. Heinrich Silk. Patent attorney · ßlerstadtcr amount 15 ■ Postfach 5105 · 6200 Wiesbaden 1 · $? (0 6121) 5620

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Use expansion coefficients, for example from Beryllium oxide, silicon or a crystalline aluminum oxide in order to increase the efficiency for this way to achieve heat exchange.

In some embodiments, the high pressure inlet duct system and the low pressure duct system etched into, or in, opposite sides of the center plate be incorporated in another way, while the other two plates of the stack are formed with flat surfaces to close the open incision sides. One can also use one channel layer (high pressure channels or Low pressure ducts) in the middle plate and the other layer of ducts in the upper plate or the lower plate.

FIG. 25 shows an embodiment in which three similar plates 251, 252 and 253 approximately 0.5 mm thick form the passage channels in micron dimensions. The panels are tied together in a stack, but in eier drawing shown exploded to the To better show details of the cooler parts.

The high pressure gas is introduced into the inflow port 254 of the plate 251, which is a shallow one Glass plate with flat surfaces is, and flows through

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Dipl.-Phys. Heinrich Silk ■ Patent Attorney ■ Bierstadter Höhe 15 · P.O. Box 5105 · 6200 Wiesbaden I · 5? (06121) 562022

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the bore 255 in the plate 252 to a trough-like recess 256 with a closed bottom in the upper surface the lower plate 253, which can be the same as the plate 232 according to FIGS. 12 to 24. The flow circuit for higher pressure settles in plate 253 as a heat exchanger section 257 and a capillary expansion section 258, which opens into the cooling chamber recess 259.

The intermediate plate 252, which is the same as the plate 234 of the figures 12 to 24, is flat and level on its lower surface to accommodate the channels in plate 253 to complete. The top surface of plate 252 is recessed at 261 to provide the low pressure return flow passage to build. A through hole 262 in the bottom of the recess 251 connects the low-pressure channel 261 with the cooling chamber 259 and a bore 26 3 in the plate

251 connects the low-pressure channel 261 to an external coolant circuit.

Figure 26 shows an embodiment similar to that according to FIG. 25, but with two low-pressure return flow channels. Four plates of similar dimensions are in one Stacks bound to one another and shown exploded in FIG. 26 for clarity. The Plattm 251,

252 and 253 are the same as in the example of Figure 24, and a fourth plate 264 is to form a second

Dipl.-Phys. Heinrich Seids. Patent attorney · BiersUdter Höhe IS. P.O. Box SlOS 6200 Wiesbaden 1. SP (06121) 56 2022

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Negative pressure return channel added. The plate 264 can be a second piece of the plate 252 with the difference that that the recess for the low pressure return channel is formed in the upper surface. However connects a through hole 265 in the plate 263 in the bottom of the cooling chamber 259, this cooling chamber with the vacuum channel 266 in the top surface of plate 264. Furthermore, there is no hole corresponding to hole 262 in the recess 266 is provided, but the gas under low pressure flows from the recess 266 through a through hole 267 in plate 253 and a through hole 268 in plate 253 to connect with the To combine the gas flowing out of the recess 261 and to flow through the outlet opening 263. In this way two heat exchanger paths are provided in this embodiment, which precool the faster and deeper cause high pressure entering gas.

In the embodiment of Figure 2 7 the cold end of the cooling device 211 is modified to the extent that the Cooling chamber instead of a recess, as at 224 in FIG. 14, now has a through opening 271 in the covering glass plate 251 and that over this opening a thin, flat cushion 271 of a material with very high thermal conductivity placed and bound in a pressure-tight manner is. The object to be cooled 219 is directly on this

Dipl.-Phys. Heinrich Seids. Patent attorney ■ Bierstadter Höhe IS ■ Pottfadi 5106. 6200 Wiesbaden 1 SSf (06121) 562022

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Cushion 271 attached. In this way, the coolant will contact the lower surface at its lowest temperature this pillow 271.

Preferred materials for cushion 271 are silicon, beryllium, and sapphire. All have very high and very high low temperatures strongly increasing thermal conductivity and can be connected to a suitable plate material with about be adapted to the same temperature expansion coefficient. The preferred material is beryllium oxide. This material combines high hardness with one closer to the preferred Glass plate material lying temperature expansion coefficient.

Figures 28 to 30 show another form of a multilayer cooling device, which works on the same principle. As shown in Figure 28, the cooler laminate three similar thin planar plates 280, 281 and 282 of material that can be etched. Preferred panels 280 and 281 are glass panels. The plate 2 * β2 can be made of glass for many purposes, but for others Purposes it can consist of a glass-like material with higher thermal conductivity, for example crystalline aluminum oxide (sapphire), beryllium or silicon.

Dlpl.-Phys. Heinrich Seids. Patent attorney · Bierstadter "Höhe 15 · Poetfach 5105 · 6200 Wiesbaden 1 - $? (0 6121) 5620

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On top surface 283 of plate 280 is the high pressure gas inlet port etched or shaped in an equivalent manner, which here essentially consists of a capillary groove 284 consists of micron dimensions, which are incised from the inlet opening 285 in a labyrinth to the central Cooling chamber 286 runs.

The plate 281 has a continuous flat lower surface 287 which is pressure-tightly bonded to the plate 280, to complete the inlet duct and the cooling chamber.

In the top surface 288 of plate 281 is a wide groove 289 for low pressure gas recirculation from a passage 290 from attached. A series of protruding radial ribs 291 in the recess or groove 289 contact accordingly the plates 280 to improve the mechanical strength of the assembly. The escaping gas with reduced pressure flows in the groove 289 to an outlet opening 292 which extends through one of the plates 280 or 282 continues to the outside, as in the embodiments described above.

As indicated in FIG. 28, the plate 282 is pressure-tight

bound in on plate 281 to the / micron dimensions to cover or complete deep return channel 289.

Dipl.-Phys. Helnrldi Seids. Patent Attorney · Biersladtcr Höhe IS · Postfach 5105 ■ 6200 Wiesbaden 1. & (06121) 562022

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On the upper side 293 of the plate 282, the chip 294 to be cooled is attached directly, and a printed or Similar circuit 295 for this chip extends across board 282 to appropriate external electrical Connections. The chip is in this way the cooled coolant at what is essentially the coldest area of the Cooling device exposed. This type of attachment for the object to be cooled can in all embodiments to be used.

In this embodiment, the capillary channel fulfills a heat exchange function with the outlet channel 289 for the Coolant. This arrangement can preferably be used for higher temperature cooling, i.e. where a Cooling down to cryogenic temperatures is not necessary. For example, ammonia can be used as a coolant, to reach temperatures of -30 C and cooling capacities of up to 50 watts.

When the requirements for cryogenic cooling approach, a heat exchanger region for pre-cooling in front of the capillary section to be provided. For example, the coolant can be freon, which is introduced under high pressure and drops in pressure, expands and cools the capillary section 284 while it is in heat exchange with the returning Gas in groove 289 is available for further cooling.

Dipl.-Phys. Heinrich Seids. Patent attorney "· Blerstadtef" Höhe Ί5 ■ Posffacn T51D5 · 6200 Wiesbaden 1 · $ 8 "(0 61 21) 56 20

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When the cryogenic cooling gas is nitrogen, as in the example of Figures 12-24, there is a longer heat exchange region to be provided for pre-cooling.

The cooling device described above can be of particular value in cooling larger computer chips such as these for example as VLSI chips (very large scale indecration) are known and today with greater circuit density and increased energy capacity and thus large amounts of heat, i.e. 10 to 50 watts (power loss) spread. Cooling enables such chips to operate at low temperatures, which increases their operating efficiency, speed and reliability improved and their service life increased.

Figures 31 and 32 illustrate a cooling device unit, which consists of two multilayer cooling devices between consists of five laminated panels. This structure allows cascade cooling, that is, pre-cooling of a coolant by another to achieve either faster cooling or lower temperatures. For example can Ammonia in the first stage as a coolant in the first cascade stage with the layers 294 are used to nitrogen pre-cool in the second cascade stage with layers 295. This will cool down the nitrogen by a factor "3" or more enlarged. As another example, could

Dipl.-Phys. Heinrich Seids patent attorney Bierstadter Höhe 15. P.O. Box SlOS · 6200 Wiesbaden 1 · 5? (06121) 562022

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Nitrogen in the shorter stage with layers 294 can be used to pre-cool hydrogen, which is then up to 20 ° K cools. Coolants with a low boiling point, e.g. hydrogen and helium, do not cool in the Joule-Thomson cycle, unless they are precooled in such a way to a suitable temperature. Cooling devices with three or more stages can be constructed in a similar manner.

Other channel dimensions can be those as they are in connection with the embodiments according to FIGS have been explained. The formation of the channels and the joining of the plate are achieved by procedures and connecting materials as described in connection with these embodiments.

As was found according to another aspect of the invention, there is a relationship between the efficiency of the Heat exchanger and the minimum temperature that can be achieved in the cooling section of the cooling device. This minimum temperature is determined by the gas pressure at the point at which the gas exits the cooling chamber. The lower the pressure at this point, the lower the attainable minimum temperature. On the other hand is the heat exchanger efficiency a function of the pressure drop across the outflow channel. An increase in pressure drop

Dipl.-Phys. Heinrich Seids. Patent attorney ■ Bierstadter Höhe 15 ■ P.O. Box 5105 - 6200 Wiesbaden 1 ■ & (06121) 5620

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increases the efficiency of the heat exchanger. The pressure at which the gas leaves the cooling chamber would have to be relatively high in order to achieve an effective heat exchange, which leads to faster cooling and / or lower gas consumption. Conversely, in order to achieve a maximum temperature drop in the cooling chamber, the gas pressure at the same point would have to be relatively high.

The embodiments according to FIGS. 33 and 34 offer an effective solution to this problem. In each of these Embodiments are provided with two capillary sections, and part of the inflowing gas is directly into the The outflow channel of the heat exchanger is branched off after flowing through one of the capillary sections, so as to create the cooling chamber partially short-circuited.

The embodiment of Figure 33 includes a stack of four plates 300, 302, 304 and 406 made of the same materials can exist and are connected to one another in the same way as in the previously described embodiments. In this embodiment, two capillary sections 308 and 310 are provided in series.

A small passage 312 is provided between the two capillary sections, which into the upstream side End of the outflow channel 314 formed for the heat exchanger in the plate 300 leads. The downstream end

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Dipl.-Phys. Heinrich Seids. Patent attorney ■ Blerstadter Höhe 15 · P.O. Box 5105 · 6200 Wiesbaden 1 ■ & (06121) 562022

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of the second capillary section 310 is connected to the cooling chamber 516, which in turn via a passage 318 with a second outflow channel 320 connected to the recessed surface of the plate 304 is formed. Ribs 322 are provided in plate 304 to give the unit the required rigidity give and uniform spacing between plates 304 and 3O6 to ensure.

During operation, gas flows under high pressure through the inlet

324
tion section / of the heat exchanger and expands and drops in pressure as it flows through the first capillary section 308 to the passage 320. At this point the gas flow is split so that a substantial portion of the gas flows through passage 312 directly into exhaust and heat exchange duct 314.

The passage 312 and the outflow channel 314 are dimensioned so that a relatively high pressure is maintained at the passage 312 is obtained, typically 10 to 30 bar. Accordingly, there is a large pressure drop in the outflow section 314 of the heat exchanger and creates a high efficiency of the heat exchanger function.

The rest of the gas flows through the second capillary section 310 into the cooling chamber 316. Here the gas takes over

Dipl.-Phys. Heinrich Seids · Patent Attorney · Bl'erstadtcr Höhe 15 · Postfach 5X05 · 0200 Wiesbaden 1 ■ G? (06121) 56 2022

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Heat from the object to be cooled and then flows through the passage 318 and through the second outflow channel 320 at a relatively low pressure, typically 2 to 3 bar to the outside. This low pressure ensures that the desired low pressure in the cooling chamber is achieved.

It has been found that both, namely high efficiency of the heat exchanger and the desired cooling can be achieved, if one allows between 50% up to 95% of the gas through the passage 312 and the outflow channel 314 of the heat exchanger.

FIG. 34 illustrates a plate 325 which is used instead of the plate 302 in the embodiment according to FIG can be used to achieve similar results. In this embodiment the two are capillary sections 326 and 328 in contrast to the embodiment according to FIG 33 arranged in parallel rather than in series. The incoming

324 Gas passes through the inflow section / heat exchanger

through the first capillary section 326 and through the passage 312 to reach the first outflow channel 314 of the To reach the heat exchanger. The remainder of the gas enters the cooling chamber 316 through the second capillary section 328 and from there into the second outflow channel 320. As with the first option, good results are achieved here too.

Dipl.-Phys. Heinrich Seid »· Patent attorney · Blerctadter Höhe 15 ■ PO Box 5105 · 6Z0O Wicfbaden 1 · flp (06121) 56 2022

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aims when you get between 50% to 95% of the incoming Gas can flow through passage 312.

Other channel dimensions or other characteristics of the cooling device can, as described above, be provided be. The formation of the channels and the connection of the plates can be carried out in the same way in these embodiments and can be achieved with the same connecting material as described above.

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PATENT ADVOCATE DIPL-PHYS. HEINRICH SEIDS Wiesbaden 1 ■ Bierstadter Höhe 15 · Postfach 5105 'Telephone (o 6121) 56 20 Postscheck Frankfurt / Main ίδιο o8 - 602 · Bank Deutsche Bank 706 571 · Nass. Sparkasse 120 040

Wiesbaden, April 23, 1982 L 294 VNR: 107565 S / ha

William A. LITTLE
Crescent Drive
Palo Alto, California USA

Micro miniature cooling device and method for their manufacture

Priority: USA patent application

354,616 of March 4, 1982

U.S. Patent Application 259,688, dated May 1, 1981

U.S. Patent Application 259,687 dated May 1, 1981

List of reference symbols

10 carrier 12th Heat sink > 3 Floor area 14th channel 16 channel 17th Top surface 18th Outlet 20th Inlet 21 Channel filter section

Dipl.-Phys. Heinrich Silk ■ Palentanwalt · Bierstadter Höhe 15 ■ PO Box 5105 ■ 6200 Wiesbaden 1 ■ Q? (06121) 56 2022

22nd Heat exchanger section 24 Cooling chamber 26th channel 30th Connection unit 32 Holes 34 Holes 36 tube 37 container 38 tube 39 Control valve 40 object 42 Inlet 43 Heat exchange channels 44 Capillary channel section 45 Cooling chamber 46 Vacuum return 47 Outlet 48 carrier 49 Metal strips 51 Multi-unit module ". Coolant chamber 53 Coolant chamber 54 Inlet pipe 55 Inlet pipe 56 Heat exchanger section 57 Capillary section 5.8, Outlet pipe

^: Dipl.-Phys. Heinrich Seids · Patent Attorney ■ BlerstadterHöhe "15 ■ Postfach 5105 · 6200 Wiesbaden 1 ■ 3? (06121) 56 20 22

59 Heat exchanger section 60 Outlet connection 61 Inlet pipe 62 Inlet connection 63 Heat exchanger section 64 Capillary section 65 Outlet pipe 66 Heat exchanger section 67 Outlet connection 73 Input channels 73 « channel 74 Output channels 74 ' channels 75 Heat sink 76 Ceiling tiles 77 Ceiling tiles 80 channel 81 channel 82 channel 83 channel a4 Heat sink 85 Heat sink 86 Heat sink 87 Heat sink 88 Heat sink 90 Silicon plate 91 Silicon oxide layer

Dlpl.-Phys. Heinrich Seids · Patent Attorney · Bierstadter Höhe IS · Postfadi 5105 · 6200 Wiesbaden 1 ■ ί? (06121) 562022

- A -

92 Photoresist 93 Oxide layer 94 V-grooves 95 Glass plate 100 Glass plate 101 Resist layer 102 Resist 103 channels 104 carrier 110 plate 111 surface 112 material 113 Carrier plate 120 Glass plate 121 Glass plate 122 Glass plate 123 Glass solder 124 Resist 125 channel 126 channel 1.30 Cooling device 131 inner plate 132 inner plate 133 inner plate 134 Surface channel 135 Surface channel

Dlpl.-Phys. Heinrich Seids · Patent Attorney · Bierstadter Höhe 15 · PO Box 5105 · 6200 Wiesbaden 1 · S? (06121) 56 20 22

136 Surface channel 137 Surface channel 211 Cooling device 212 holder 213 arrangement 214 inner space '215 casing 216 lid 217 Vacuum line 218 Vacuum source 219 object 221 Inlet port 222 Heat exchanger section 223 Capillary section 224 Cooling chamber 225 Passage 226 Outlet opening 227 drilling 228 drilling 229 Coolant inlet pipe 231 Coolant outlet line 232 plates 233 Intermediate plate 234 Lower plate 235 coplanar surface 236 coplanar surface

r:. -A:> _f niÄ, _s #. '. t + ewmmmmmmeunmmimmmmwmm .... ä-

Dipl.-Phys. Heinrich Seid »· Patent attorney ■ Bieretadter Höhe 15 · PO Box 5105 · 6200 Wiesbaden 1. GP (0 6121) 56 2022

237 lower surface 238 drilling 239 Passage 240 upper surface 241 Surface incision 242 Ribs 243 Ledges 244 drilling 249 Adhesive layers 250 Adhesive layers 251 plates 252 plates 253 plates 254 Inflow opening 255 drilling 256 deepening 257 Heat exchanger section 258 Expansion section 259 Cooling chamber recess 261 Low pressure duct 262 drilling 263 drilling 264 plate 265 drilling 266 deepening 267 drilling 268 drilling

Dipl.-Phye. Heinrich Silk. Patent attorney · Blerstadter Höhe IS · Postfach SlOS ■ 6200 Wiesbaden 1 · <S? (06121) 56 20

_ Sf -

2 71 pillow 280 plates 281 plates 282 plates 283 area 284 Capillary groove 285 Inlet port 286 Cooling chamber 287
288
289 surface
surface
Groove 290 Passage 291 Ribs 292 Outlet opening 293 Top 294 chip 295 Circuit 300 plates 302 plates 304 plates 306 plates 308
* Capillary section 310 Capillary section 312 Passage 314 Outflow channel 316 Cooling chamber

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Dipl.-Phys. Heinrich Seids ■ Patent Attorney ■ Bicrstadlcr Höhe 15 · Postfach 5105 · 62CfO Wleibaden 1 ■ QP (061 21) 56 2022

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318 passage

320 outflow channel

322 ribs

324 inlet section

325 plate

326 capillary section 328 capillary section

Claims (16)

37TS39fi PATENT ADVERTISER DIPL-PHYS. HEINRICH SEIDS 6200 Wiesbaden ι ■ Bierstadter Höhe 15 · Postfach 5105 'Telephone (o 6121) 56 20 22 Postscheck Frankfurt / Main 1810 08 - 602 · Bank Deutsche Bank 306 571 · Nm *. Sparkaue 320 040 Wiesbaden, April 23, 1982 L 294 VNR: 107565 S / ha William A. LITTLE 15 Crescent Drive Palo Alto, Califormien USA Micro-miniature cooling device and process for its production Priority: USA patent application 354,616 of March 4, 1982 USA patent application 259,688 dated May 1, 1981 USA patent application 259,687 dated May 1, 1981 rüche patent applications 1) / micro miniature cooling device for cooling small items, For example, electrically superconducting devices such as chips, etc., characterized in that at least two elements Glass or the like Material with low thermal conductivity and substantially the same temperature expansion coefficient th with the formation of at least one pressure-tight contact Interfaces are connected to form a rigid laminate, V -:.:. - Γ:!.:. · F [\. ^: 321 5596 Dipl.-Phys. Heinrich Seids · Patent attorney "Bierstadter Höhe IS · PO Box 5105 · 6200 Wiesbaden 1 · ® (0 6121) 56 2022 wherein on this contact interface or these contact interfaces a cooling chamber and with this connected flow channels for a coolant as parts of a working on the principle of pressure release Cooling circuit are formed, namely a leading to the cooling chamber coolant supply channel, the at least a capillary section opening into the cooling chamber to partially relax the under high pressure having supplied coolant, and a return channel connected to the cooling chamber for the coolant, in the manner of a heat exchanger along at least a section of the coolant supply channel is led. 2) Cooling device according to claim 1, characterized in that for training for cryogenic cooling of the coolant supply channel upstream of the capillary section an additional one along the coolant return channel Has guided heat exchanger section. 3) cooling device according to claim 1 or 2, characterized in that that the coolant passages act as channel grooves in surfaces of one or more elements of the laminate are formed. Dipl.-Phys. Heinrich Seids ■ Patent attorney ■ Bierstadter Höhe 15 · P.O. Box 5105 · 6200 Wiesbaden 1. & (06121) 56 20 22 - 3 - 4) Cooling device according to claim 1 or 2, characterized in that that coolant passages in the form of channels with on surfaces of one or more of the elements of the laminate attached walls are formed. 5) Cooling device according to claim 1 or 2, characterized by the following features for forming a multiple cooling Fixture unit: a) Providing a plurality of sealed surface contacts located laminate elements; b) Providing an even number of flow paths at the interface interfaces, with parts these flow paths are arranged in the manner of heat exchangers to one another and c) Provision of devices for the passage of different coolants in countercurrent flow from one at a time Inlet port to an outlet port on the respective Flow paths and cascade-like mutual arrangement of these devices and flow paths. 6) Cooling device according to claim 1 or 2, characterized in that two separate coolant inlet channels are provided in micron dimensions to form a multiple cooling device unit with a cascade arrangement in a glass plate laminate, one coolant inlet channel extending from a first inlet opening through a Dipl.-Phys. Heinrich Seids. Patent attorney ■ Bierstadter Höhe 15 · Postfach 5105 · 6200 Wiesbaden 1 ■ <£? (06121) 56 2022 first heat exchanger section and a first capillary section in series with a first cooling chamber extends, while the other coolant inlet channel extends from a second inlet port through a second Heat exchanger section in a heat exchanging arrangement with respect to the first heat exchanger section and then in series through a third heat exchanger section and a second capillary portion extending to, and that separate from, a second cooling chamber separate outlet openings leading return channels from each cooling chamber for the under low pressure Coolant is provided, the return channel from the first cooling chamber acting as a heat exchanger channel extends to the first heat exchanger section and the second heat exchanger section, while the return duct from the second cooling chamber as a heat exchanger channel through the third heat exchanger section and second heat exchanger section. 7) Cooling device according to claim 1 or 2, characterized in that " distinguishes that for training as a multilayer micro-miniature cooling device, a laminate of at least three thin plates is formed by pressure-tight bonding to flat contact interfaces, in one Contact interface between two adjacent plates, a first uninterrupted passage channel Dipl.-Phys. Heinrich Seids · Patent Attorney ■ Bierstadter Höhe IS · Poetfach 5105 ■ 6200 Wiesbaden 1 - 5? (06121) 562022 formed by an inlet to a cooling chamber and this inlet to a source of high pressure Coolant gas is connected, further being in another contact interface between two adjacent plates another uninterrupted channel leads to an outlet and this channel to discharge of reducing pressure coolant is connected with a passage to the cooling chamber, further this outflow channel is guided in a counterflow arrangement in the manner of a heat exchanger along the inflow channel and finally these channels for the formation of a laminar coolant flow in their interior with their Dimensions in the micron range are formed. 8) cooling device according to claim 7, characterized in that that the plates are thin glass plates of uniform thickness. 9) Cooling device according to claim 7, characterized in that the inflow channels have a width of about 250 µm, a Depth of about 10 µm, while the channels in the capillary section have a width of about 200 µm and one Depth of about 10 µm and that the return flow channels have a width of about 15000 µm and a depth of about 25 µm. Dlpl.-Phys. Heinrich Seids. Patent attorney · Bierstadter Höhe IS. P.O. Box SlOS ■ 6200 Wiesbaden 1 · ® (06121) 562022 -β- 10) cooling device according to claim 7, characterized in that that the plates are made of glass and the cooling chamber is a through opening in one of these plates and that a pillow-like element is bonded pressure-tight via this through opening, this cushion-like element, with which the object to be cooled is to be brought into contact, made of material with higher There is thermal conductivity than the plate in which the opening is formed. 11) Cooling device according to claim 7, characterized in that the cooling chamber is essentially centrally in the laminate is arranged and an electrical device to be cooled, for example one with electrical connections provided chip directly on another plate substantially directly aligned with the cooling chamber is attached and that the electrical circuit parts and connections of the electrical equipment on the adjacent surface of this other plate are attached or formed. • m 12) cooling device according to claim 1 or 2, characterized in that that to form a micro-miniature cryogenic cooling device for cooling electrically superconductive Elements and the like a plurality of elements with essentially the same coefficient of thermal expansion. Dipl.-Phys. Heinrich Seids ■ Patent attorney · Blerstadter Höhe 15 · PO Box 5105 · 6200 Wiesbaden 1 ■ $? (06121) 56 2022 it is seen that these elements have parallel contact interfaces are bonded together to form a laminate that a cryogenic chamber in this laminate is formed that a coolant supply channel is formed, which leads from outside the cooling device to this cryogenic chamber and contains in series a heat exchanger section and a capillary section that is in the laminate Return channel for the coolant from the cryogenic chamber is formed to the outside of the cooling device, which is in the manner of a heat exchanger along the introduction channel is guided and that an additional passage for part of the coolant in the introduction channel below Bypassing the cryogenic chamber is formed and that a second Äuslaßkanal in Art a heat exchanger duct is guided along the inflow duct to the outside of the cooling device. 13) Cooling device according to claim 12, characterized in that the capillary section of the inflow channel has two - Has capillary passages in series and the additional passage to the capillary portion of the inlet channel is connected at a point between the two capillary passages. 'Dlpl.-Phy *. Heinrich Seids. Patentanwaiy-'fflerstadter HoKe XS * Postfach 5105 "6200 Wiesbaden 1 · §? (0 6121) 56 20 14) Cooling device according to claim 12, characterized in that that the capillary section of the inflow channel has two capillary passages which are arranged in parallel and the additional passage is arranged at the downstream end of one of these capillary passages is. 15) A method for producing a cooling device according to any one of claims 1 to 14, characterized in that that on at least one main surface of a thin glass plate grooves and depressions in the for the respective Cooling circuit attached to the desired pattern and by tying a second plate with it approximately the same temperature expansion coefficient can be covered, the following steps being provided are: a) Formation of a layer or layer against "sandblasting" with fine particles of resistant material on at least one surface of the glass plate . - b) determining a flow pattern in this resistant material by lithographic covering and selective etching and accordingly exposing the underlying surface of the glass plate in this pattern;
c) Formation of groove-shaped channels and indentations i ι · ■ ι, .-., * -a . ^ i ^ Dipl.-Phys. Heinrich Seids · Patent Attorney ■ Bicrstadter Höhe IS · PO Box 5105 · 6200 Wiesbaden 1 · ® (06121) 56 2022 The desired depth in this glass plate surface by sandblasting with fine particles to be guided over the glass plate surface by means of a Miniature sandblasting device, the number of these sandblasting passes being the desired in each case Groove depth corresponds to; and d) Tying the further plate onto the grooved surface of the glass plate. 16) Method according to claim 15, characterized in that the material that is resistant to sandblasting Gelatin, ammonium dichromate and hot water were formed in amounts approximately proportional to 7g, Ig and 50 cm will.