CN113203219A

CN113203219A - Micro refrigerator and machining method thereof

Info

Publication number: CN113203219A
Application number: CN202110502529.3A
Authority: CN
Inventors: 刘大川; 胡小燕; 赵少宇
Original assignee: Information Science Research Institute of CETC
Current assignee: Information Science Research Institute of CETC
Priority date: 2021-05-08
Filing date: 2021-05-08
Publication date: 2021-08-03

Abstract

The invention provides a micro refrigerator and a processing method thereof, wherein the micro refrigerator comprises: the second base body is connected with the first base body, and a first concave part and a second concave part are arranged between the first base body and the second base body; a compression device; the chip to be refrigerated is arranged on the surface of the second base body, which is far away from the first base body, and corresponds to the second concave part; a first channel and a second channel are also arranged between the first base body and the second base body, the first channel comprises a first section and a second section which are communicated with each other, the first section is communicated with the first concave part, the second section is communicated with the second concave part, and the cross section area of the second section is smaller than that of the first section; the second passage communicates the first recess and the second recess and is provided independently of the first passage. The technical scheme of the application effectively solves the problems that the refrigerating device of the chip in the related technology is complex in structure and cannot realize on-chip integration.

Description

Micro refrigerator and machining method thereof

Technical Field

The invention relates to the technical field of semiconductor micro refrigerators, in particular to a micro refrigerator and a processing method thereof.

Background

The refrigerator is one of important parts of a low-temperature working device or system, and mainly has the following applications:

(1) low power electronic components are cooled to reduce thermal noise, enhance bandwidth, and achieve superconductivity in the sensor. The reduction in thermal noise may improve the signal-to-noise ratio of the preamplifier. The parasitic resistance of the inductor in an LRC filter is usually the limiting quality factor of the filter, so the use of superconducting materials operating at low temperatures can significantly improve the quality factor. New commercial applications use high temperature superconductors as microwave filters, particularly in base stations of wireless communication systems.

(2) Military infrared photodetectors are a typical application of refrigerators (devices), and the operating temperature of the military infrared photodetectors needs to be reduced to 150K or even below 100K to ensure the operating performance of the devices. In laser radars, for example, InGaAs APDs (Avalanche photodiodes) require a low temperature of about 200K, and currently, most of them use TEC (Thermo Electric Cooler) for cooling.

(3) Terahertz sensor. The terahertz sensor can be used for imaging of hidden non-metal weapons and spectral identification of chemical and biological materials; mixers in terahertz imaging systems are based on superconducting thermionic bolometers (HTS HEBs) operating at around 70K.

On the other hand, electronic devices (e.g., low noise amplifiers) and sensors (e.g., infrared detectors) are becoming smaller due to the compactness of the arrangement, and there is a need to provide on-chip cooling that is close to the size of the device to reduce the overall system size, while improving thermal performance and reducing cooler input power. On the other hand, the small size, low power consumption, low parasitic and device loading of these devices and equipment themselves also reduce the need for refrigeration, making it possible to equip small near-end or on-chip cryocoolers.

The size, the weight and the power consumption of the conventional refrigerating machine are large, the level of on-chip integration cannot be achieved far away, and the high integration and the miniaturization of an infrared detection system are seriously limited, so that the application requirements of miniaturized platforms such as unmanned aerial vehicles and micro-nano satellites in the future are difficult to meet.

Disclosure of Invention

The invention mainly aims to provide a micro refrigerator and a processing method thereof, and aims to solve the problems that a chip refrigerating device in the related art is complex in structure and cannot realize on-chip integration.

In order to achieve the above object, according to one aspect of the present invention, there is provided a micro refrigerator including: the surface of the first substrate is connected with the surface of the second substrate, and a first concave part and a second concave part are arranged between the first substrate and the second substrate; the compression device is arranged on one side of the first base body, which is far away from the second base body, or the compression device is arranged on one side of the second base body, which is far away from the first base body; the chip to be refrigerated is arranged on the surface, away from the first base body, of the second base body and corresponds to the second concave part; the first channel comprises a first section and a second section which are communicated with each other, the first section is communicated with the first concave part, the second section is communicated with the second concave part, and the cross-sectional area of the second section is smaller than that of the first section; the second passage communicates the first recess and the second recess, and the second passage is provided independently of the first passage.

Furthermore, the micro refrigerator also comprises an installation plate and a shell, the shell is installed on the installation plate, a vacuum space is formed between the installation plate and the shell, and the first base body, the second base body and the chip to be refrigerated are all located in the vacuum space.

Further, the compression device comprises lead zirconate titanate piezoelectric ceramics which are positioned in the vertical space of the first concave part.

Furthermore, the first channel and the second channel are bent, and the length of the second section is greater than that of the first section in a preset area.

Furthermore, the micro refrigerator also comprises a first micro valve and a second micro valve, wherein the first micro valve is arranged on the second section, and the second micro valve is arranged on the second channel.

Further, the first and second micro valves are formed by etching.

Furthermore, the first substrate and the second substrate are both made of materials compatible with the semiconductor process.

Further, the ratio of the cross section of the first section to the cross section of the second section is 0.5-0.1, and the chip to be refrigerated is located in the vertical space where the second concave part is located.

Further, the micro refrigerator also comprises a lead wire, and the lead wire is electrically connected with the compression device.

According to another aspect of the present invention, there is provided a method for processing a micro refrigerator, the method comprising the steps of: step S10: etching and forming a first channel, a second channel and a first concave part on the surface of the first substrate; step S20: etching and forming a second concave part on the surface of the second substrate facing the first substrate; step S30: bonding the first substrate and the second substrate to form a closed cavity, and sealing the working medium in the cavity; step S40: thinning the second substrate; step S50: mounting a compression device on a surface of the second substrate facing the first substrate; step S60: arranging a chip to be refrigerated on the surface of the second substrate, which is far away from the first substrate; s70: and packaging the first base body and the second base body in an installation space formed by the installation plate and the shell, and vacuumizing the installation space.

By applying the technical scheme of the invention, the surface of the first base body is provided with the first concave part, the second base body is arranged on one side of the first base body, the second base body is provided with the second concave part and the compression device, the second concave part and the compression device are respectively positioned on two corresponding surfaces of the second base body, and the second concave part and the compression device are arranged in a staggered manner. The compression device is arranged on one side of the first base body far away from the second base body, or is arranged on one side surface of the second base body far away from the first base body and corresponds to the first concave part. The chip to be refrigerated is arranged on the surface, deviating from the first base body, of the second base body, and corresponds to the second concave portion. The first channel is arranged between the first base body and the second base body, the first channel comprises a first section and a second section which are communicated with each other, the first section is communicated with the first concave part, the second section is communicated with the second concave part, and the cross-sectional area of the second section is smaller than that of the first section. The compression device is started, and the gas in the first concave part is compressed to form high-pressure medium; high-pressure medium flows to the second concave part through the first channel, because the first channel includes first section and second section, the cross sectional area of second section is less than the cross sectional area of first section, the medium flows to little section department by big section, the velocity of flow reduces, then the medium gets into in the second concave part, expand rapidly, the temperature reduces, and then can treat the refrigeration chip and cool down, first base member and second base member are connected as an organic whole simultaneously, and then realize treating the integration on the integration piece of refrigeration chip and refrigerator, simultaneously the medium in the second concave part flows back to first concave part through the second channel again. The structure effectively realizes the cooling of the chip to be refrigerated, and the structure is simple and convenient to process, and can effectively realize the miniaturization of the refrigerating device of the miniature refrigerator.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic perspective view of an embodiment of a micro refrigerator according to the present invention;

FIG. 2 is a perspective view of the micro-refrigerator of FIG. 1 from a second perspective;

FIG. 3 is a perspective view of the micro-refrigerator of FIG. 1 from a third perspective;

FIG. 4 shows a schematic perspective view of the first substrate of FIG. 1;

FIG. 5 shows a schematic top view of a first base of the micro-refrigerator of FIG. 4;

FIG. 6 shows a schematic partial cross-sectional view of the first substrate of FIG. 5;

FIG. 7 shows a perspective view of the second substrate of FIG. 1;

FIG. 8 shows a schematic perspective view of the second substrate of FIG. 7; and

fig. 9 shows a schematic flow diagram of an embodiment of a method for processing a micro refrigerator according to the present invention.

Wherein the figures include the following reference numerals:

10. a first substrate; 11. a first recess; 20. a second substrate; 21. a second recess; 22. a compression device; 30. a chip to be refrigerated; 40. a first channel; 41. a first stage; 42. a second stage; 50. a second channel; 61. mounting a plate; 62. a housing; 71. a first microvalve; 72. a second microvalve; 80. and (7) leading wires.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the related art, a to-be-refrigerated chip is cooled by using an external compressor and an MEMS (micro electro mechanical system) heat exchange tube and a cold end, and the MEMS cold end and a heat exchanger are developed based on quartz glass by the method, so that the refrigerating capacity of 10mW at 96K is realized. As shown in the following figures, formed by stacking 3 layers of glass, the gap between each two layers of glass is a high pressure channel and a low pressure channel, respectively, and an evaporation cavity is formed at one end of the structure. The refrigerator uses nitrogen as working medium, the flow rate is 1mg/s, the high-pressure end is 80bar, and the low-pressure end is 6 bar. The test results achieved a net refrigeration power of 5mW at a temperature of 105K. The dimensions of the heat exchanger and cold end were 28mm x 2.2mm x 0.8 mm. However, the system uses an external activated carbon adsorption type compressor, and needs heating to release high-pressure gas, and the method can generate high-pressure gas, but has high power consumption and volume, is incompatible with a semiconductor process, and is not beneficial to monolithic integration. The scheme also realizes the chip formation of part of the components (the heat exchange tube and the cold end) of the J-T refrigerator, but high-pressure gas is obtained by an external compressor, so that the power consumption and the volume are large, the semiconductor process is incompatible, and the monolithic integration cannot be realized. In addition, the refrigeration time is long and some applications are limited.

To solve the above-mentioned technical problems and to reduce the complexity of the structure. As shown in fig. 1 to 8, in the present embodiment, the micro refrigerator includes: the cooling structure comprises a first base body 10, a second base body 20, a chip 30 to be cooled, a first channel 40 and a second channel 50, wherein a first concave part 11 is arranged on the surface a of the first base body 10. The second base 20 is arranged on one side of the first base 10, the second base 20 is provided with a second concave portion 21 and a compression device 22, the second concave portion 21 and the compression device 22 are respectively located on two corresponding surfaces of the second base 20, the second concave portion 21 and the compression device 22 are arranged in a staggered mode, and the compression device 22 is arranged on one side, far away from the first base 10, of the second base 20. The chip 30 to be cooled is arranged on the surface b of the second substrate 20 facing away from the first substrate 10 and corresponds to the second recess 21. Wherein, a first channel 40 and a second channel 50 are further arranged between the first base body 10 and the second base body 20, the first channel 40 comprises a first section 41 and a second section 42 which are communicated with each other, the first section 41 is communicated with the first recess 11, the second section 42 is communicated with the second recess 21, and the cross-sectional area of the second section 42 is smaller than that of the first section 41. The second passage 50 communicates the first recess 11 and the second recess 21, and the second passage 50 is provided independently of the first passage 40.

By applying the technical solution of the present embodiment, the first concave portion 11 is disposed on the surface of the first substrate 10, the second substrate 20 is disposed on one side of the first substrate 10, the second concave portion 21 and the compressing device 22 are disposed on the second substrate 20, the second concave portion 21 and the compressing device 22 are respectively located on two corresponding surfaces of the second substrate 20, and the second concave portion 21 and the compressing device 22 are disposed above the first concave portion 11 in a staggered manner. The chip 30 to be cooled is arranged on the surface of the second substrate 20 facing away from the first substrate 10, and the chip 30 to be cooled corresponds to the second recess 21. The first channel 40 is disposed between the first base body 10 and the second base body 20, the first channel 40 includes a first section 41 and a second section 42 communicating with each other, the first section 41 communicates with the first recess 11, the second section 42 communicates with the second recess 21, and a cross-sectional area of the second section 42 is smaller than a cross-sectional area of the first section 41. The compression device 22 is started, the gas in the first concave part 11 is compressed, and high-pressure medium is formed; high-pressure medium flows into the second concave part 21 through the first channel 40, because the first channel 40 comprises a first section 41 and a second section 42, the cross sectional area of the second section 42 is smaller than that of the first section 41, the medium flows from a large section to a small section, the flow speed is reduced, then the medium enters the second concave part 21, the medium expands rapidly, the temperature is reduced, the chip 30 to be refrigerated can be cooled, meanwhile, the first base body 10 and the second base body 20 are connected into a whole, integration on the integrated chip of the chip 30 to be refrigerated and a refrigerator is further realized, and meanwhile, the medium in the second concave part 21 flows back to the first concave part 11 through the second channel 50. The cooling of the chip to be cooled is effectively realized through the structure, the structure is simple, the processing is convenient, and the on-chip integration of the chip cooling device can be effectively realized.

It should be noted that the cross-sectional area refers to an area of the first passage 40 in a plane perpendicular to a center line of the first passage 40, and specifically, as shown in fig. 6, fig. 6 is a schematic sectional view taken along a length direction of fig. 5.

In the present embodiment, a first channel 40 and a second channel 50 are further disposed between the first substrate 10 and the second substrate 20, which may be specifically explained as disposing the first channel 40 and the second channel 50 on the first substrate 10, or disposing the first channel 40 and the second channel 50 on the second substrate 20, or forming the first channel 40 and the second channel 50 together after grooving the corresponding positions of the first substrate 10 and the second substrate 20, or disposing one of the first channel 40 and the second channel 50 on the first substrate 10 and disposing the other one on the second substrate 20.

In an embodiment not shown in the figures, the compression means are arranged on said first base, while the second base is located below the first base. The compression device 22 corresponds to the first recess 11, specifically: the compression means 22 are located within the range defined by the projection of the first recess 11 on the surface b.

The correspondence between the chip 30 to be cooled and the second concave portion 21 specifically means: the chip 30 to be cooled is located within a range defined by a projection of the second concave portion 21 on the surface b, or the chip 30 to be cooled and the projection of the second concave portion 21 on the surface b are coincident.

In the present embodiment, the compressing device 22 is disposed on the side of the first substrate 10 away from the second substrate 20, or the compressing device is disposed on the side of the second substrate 20 away from the first substrate 10, which can be specifically interpreted as that the compressing device 22 is disposed on the lower surface of the first substrate 10, i.e. the first substrate 10 is located between the compressing device 22 and the second substrate 20; alternatively, the compression means 22 is arranged on the upper surface of the second substrate 20, i.e. the second substrate 20 is located between the first substrate 10 and the compression means 22.

The specific working principle of the technical scheme of the embodiment is as follows: the high pressure gas generated by the compression device 22 enters the high pressure conduit (first section 41 of the first channel 40) in the heat exchange tube, exchanges heat with the low temperature gas in the adjacent low pressure conduit (second channel 50), and then enters the throttling element (second section 42 of the first channel 40), the flow is impeded due to the reduced cross-sectional area, the pressure behind the throttling element is much lower than before, the gas pressure decreases rapidly, the gas expands thermally and cools, which is the joule-thomson (throttling) effect. The fluid is then vaporized, and the heat of the cold end and the environment is absorbed in the evaporation cavity (the second concave portion 21) in a large quantity, so that the refrigeration of the chip 30 to be refrigerated is realized.

According to the technical scheme of the embodiment, the refrigeration system can be integrated on a chip, so that the size, weight and power consumption of an infrared detection system and other applications are greatly reduced; the arrangement mode enables the cold end (the second concave part 21) of the refrigerator to be closer to the chip to be refrigerated, the required refrigerating capacity is less, the refrigerating efficiency is high, and unnecessary waste is reduced; the technical scheme of the embodiment has the advantages of simple processing technology, one-step processing and forming by adopting the MEMS technology, and no need of assembly.

In order to further ensure the cooling effect, as shown in fig. 1 and fig. 2, in the present embodiment, the micro refrigerator further includes a mounting plate 61 and a housing 62, the housing 62 is mounted on the mounting plate 61, a vacuum space is formed between the mounting plate 61 and the housing 62, and the first substrate 10, the second substrate 20 and the chip 30 to be cooled are located in the vacuum space. The vacuum space can effectively insulate heat, and further can further ensure that the chip 30 to be refrigerated is in a state of low temperature, so that the performance of the micro refrigerator can be improved. After the housing 62 is mounted on the mounting plate 61, air between the housing 62 and the mounting plate 61 is evacuated by vacuuming, thereby forming a vacuum space.

Considering the compression performance, volume and other factors, the piezoelectric ceramic is selected, and as shown in fig. 1, 2 and 5 to 8, in the present embodiment, the compression device 22 includes a lead zirconate titanate piezoelectric ceramic located in the vertical space of the first recess 11. The compression device 22 of the present embodiment is designed based on MEMS technology for easy integration, but this also places major limitations on the design of the compression device 22 and the microvalve. The technical scheme of this embodiment adopts the piston refrigerator, realizes the function of piston reciprocating motion by the vibrating diaphragm (the surface of first concave part) of MEMS processing, and simultaneously, the gas tightness of chip level encapsulation is also good enough for the realization of MEMS refrigerator becomes possible. The driving mode of the MEMS vibration structure mainly comprises piezoelectric driving and electrostatic driving. The piezoelectric driving utilizes piezoelectric materials, and the electrostatic driving realizes electrostatic force through a plate capacitor or a comb capacitor. Since the number of piezoelectric driving structures is small, the piezoelectric driving method based on PZT (lead zirconate titanate piezoelectric ceramic) material is selected in the present embodiment, PZT (lead zirconate titanate piezoelectric ceramic) is grown on the surface of the silicon vibration film (the compression device 22), and the film can be vibrated up and down by applying ac driving voltage to both surfaces of PZT.

As shown in fig. 7, in this embodiment, after being energized, PZT (compression device 22) swings, so as to compress the medium in the first recess 11, and further, the high-pressure medium flows into the second recess 21 through the first channel 40, thereby effectively cooling the chip to be cooled.

The MEMS process is a generic term for a microstructure processing process down to the nanometer scale and up to the millimeter scale.

Likewise, in order to increase the cooling effect of the medium. As shown in fig. 3 and 4, in the present embodiment, the first channel 40 and the second channel 50 are bent and closely attached, and the length of the second section 42 is greater than that of the first section 41 within a preset area, so that the medium with lower temperature flowing back from the cold end (the second recess 21) pre-cools the high-pressure medium flowing out of the first recess 11 under the driving of the compressor, and the temperature after the throttling effect is further reduced. The length of the second section 42 is greater than that of the first section 41 within a predetermined area, which can effectively improve the cooling effect. It should be noted that the predetermined area is a fixed area on the surface a of the first substrate 10, the first segment 41 is completely disposed in the predetermined area, the length of the first segment 41 is calculated, the second segment 42 is completely disposed in the predetermined area, the length of the second segment 42 is calculated, and finally the lengths of the first segment 41 and the second segment 42 are compared. In order to ensure that the flow direction of the medium is fixed, as shown in fig. 3 and 4, in the present embodiment, the micro refrigerator further includes a first micro valve 71 and a second micro valve 72, the first micro valve 71 is disposed on the second section 42, and the second micro valve 72 is disposed on the second channel 50. The first micro valve 71 and the second micro valve 72 are both one-way valves, the first micro valve 71 enables the medium to flow from the first concave portion 11 to the second concave portion 21 only through the first passage 40, and the second micro valve 72 enables the medium to flow from the second concave portion 21 to the first concave portion 11 only through the second passage 50, so that the flowing direction of the medium is easier to control, and the overall cooling effect of the micro refrigerator is more stable.

Specifically, the first and second microvalves 71 and 72 allow flow in one direction while preventing flow in the other direction. When the air flow is driven by the compressing device 22 to flow in the first direction, the pressure of the air flow acts on the opening surface inclined downwards inside the first micro valve 71, so as to push open the right first micro valve 71, and the opening degree is in a direct function relationship with the pressure of the air flow; and with the first microvalve 71 on the left, the pressure of the air flow acts on the opening surface that is inclined inward and upward, thereby closing the valve. If the gas flow is reversed, i.e. in a second direction, the first and second microvalves 71 and 72 operate in reverse.

As shown in fig. 3 and 4, in the present embodiment, the first and second

micro valves

71 and 72 are formed by etching. The processing mode of the etching is simple, and the method can be suitable for processing of the micro refrigerator.

As shown in fig. 1 to 8, in the present embodiment, the first substrate 10 and the second substrate 20 are both made of a material compatible with a semiconductor process. Semiconductor process compatible materials including, but not limited to, silicon, glass, organic polymers, and the like. Specifically, in this embodiment, the first substrate 10 is made of glass, the second substrate 20 is made of silicon, and the thermal conductivity of glass is much lower than that of silicon, so that heat leakage from the hot end to the cold end can be reduced, but heat exchange between the first channel 40 and the second channel 50 is not facilitated. In the technical scheme of the embodiment, the substrates of the first channel 40 and the second channel 50 are glass, so that heat can be effectively insulated; the packaging cover plate is made of silicon, and can effectively exchange heat. The top of the silicon package may be coated with a low thermal conductivity material to enhance thermal isolation of the system.

As shown in fig. 4 to 6, in the present embodiment, the ratio of the cross section of the first section 41 to the cross section of the second section 42 is between 0.5 and 0.1, and the chip 30 to be cooled is located in the vertical space in which the second recess 21 is located. The overall size of the micro-refrigerator is small, making the micro-refrigerator more applicable. The ratio of the cross-sections of the first section 41 and the second section 42 described above is effective in cooling the medium, and specifically, in the present embodiment, the ratio of the cross-section of the first section 41 to the cross-section of the second section 42 is 0.25. The chip to be cooled is located right above the second concave portion 21, the second concave portion 21 is an evaporation cavity, the cooling effect of the chip to be cooled 30 is good due to the arrangement, and the cooling efficiency can be improved.

As shown in fig. 1 to 8, in the present embodiment, the micro refrigerator further includes a lead wire 80, and the lead wire 80 is electrically connected to the compression device 22. The lead wire 80 is energized to the compression device.

The technical solution of the present embodiment is based on joule-thomson effect, and mainly includes a first substrate 10, a second substrate 20, a compressing device 22, a first channel 40, a second channel 50, and the like. The compression device 22 adopts a piezoelectric driving mode based on piezoelectric ceramics (PZT); the processing technology is to adopt an MEMS technology to process the core component compression device 22, the first micro valve 71, the second micro valve 72, the first channel 40, the second channel 50, the first concave part 11, the second concave part 21 and the chip 30 to be refrigerated of the micro refrigerator grade refrigerator, and the main materials are based on silicon and glass; the on-chip ultra-micro refrigerator is realized by forming a closed sealing cavity after inflation and packaging, and working medium gas in the sealing cavity circulates to finish heat exchange and throttling processes without adding a high-pressure gas cylinder.

The gas includes nitrogen, hydrogen or a hydrocarbon mixed gas.

As shown in fig. 9, in an embodiment of a method for processing a micro refrigerator, the method for processing a micro refrigerator is used for processing the micro refrigerator, and the method comprises the following steps:

step S10: etching and forming a first channel 40, a second channel 50 and a first concave part 11 on the surface of the first substrate 10;

step S20: etching a second concave part 21 on the surface of the second substrate 20 facing the first substrate 10;

step S30: bonding the first matrix 10 and the second matrix 20 in a pure nitrogen environment to form a closed cavity, and sealing the working medium in the cavity;

step S40: thinning the second substrate 20;

step S50: mounting a compression device 22 on a surface of the second substrate 20 facing the first substrate 10;

step S60: arranging a chip 30 to be cooled on the surface of the second substrate 20, which is far away from the first substrate 10;

step S70: the first substrate 10 and the second substrate 20 are enclosed in the installation space formed by the installation plate 61 and the housing 62, and the installation space is vacuumized.

In the processing method, the first channel 40, the second channel 50, the first concave part 11 and the second concave part 21 are respectively processed on the first substrate 10 and the second substrate 20 by an etching processing mode, and the processing method is simple in process and easy to implement. The compression device 22 is arranged on the second base body 20, the compression device 22 corresponds to the first concave part 11, the first base body 10 and the second base body 20 are packaged and filled with media, the first base body 10 and the second base body 20 can be effectively connected together in a bonding mode, the sealing effect is guaranteed, and the media are prevented from flowing out. The second base body 20 is thinned, so that the chip 30 to be cooled can be easily contacted with low-temperature gas, and cooling is further realized. The chip 30 to be cooled is mounted to a position corresponding to the second concave portion 21, and the cooling effect is sufficiently ensured. And finally, vacuumizing the space formed by the casing 62 and the mounting plate 61 of the bonded first substrate 10 and second substrate 20, so as to further ensure the cooling effect and avoid the heat of the external environment from being transferred to the chip to be cooled.

In the present embodiment, the first recess 11 and the corresponding first substrate 10 constitute a MEMS refrigerator, generating a high-pressure working medium gas. The first section 41 of the first channel 40 and the first half section of the second channel 50 are heat exchange tubes, wherein the first section 41 of the first channel 40 is a high-pressure tube, and the first half section of the second channel 50 is a low-pressure channel; the second section 42 of the first passage 40 and the second half of the second passage 50 are throttling elements. The second recess 21 is an evaporation chamber of the refrigerator.

After the refrigerator generates high-pressure gas, the high-pressure gas passes through the high-pressure heat exchange tube, the throttling element, the evaporation cavity and the low-pressure heat exchange tube in sequence and returns to the refrigerator to form a closed-loop system.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A micro-refrigerator, comprising:

a first base body (10) having a first base surface,

a second base (20), the second base (20) being connected to a surface (a) of the first base (10), a first recess (11) and a second recess (21) being provided between the first base (10) and the second base (20);

a compression device (22) arranged on the side of the first base body (10) far away from the second base body (20), or the compression device (22) is arranged on the side of the second base body (20) far away from the first base body (10);

a chip (30) to be cooled, arranged on a surface (b) of the second substrate (20) facing away from the first substrate (10) and corresponding to the second recess (21);

wherein a first channel (40) and a second channel (50) are further arranged between the first base body (10) and the second base body (20), the first channel (40) comprises a first section (41) and a second section (42) which are communicated with each other, the first section (41) is communicated with the first recess (11), the second section (42) is communicated with the second recess (21), and the cross-sectional area of the second section (42) is smaller than that of the first section (41); the second passage (50) communicates the first recess (11) and the second recess (21), and the second passage (50) is provided independently of the first passage (40).

2. The micro refrigerator according to claim 1, further comprising a mounting plate (61) and a housing (62), wherein the housing (62) is mounted on the mounting plate (61), and a vacuum space is formed between the mounting plate (61) and the housing (62), and the first substrate (10), the second substrate (20), and the chip (30) to be cooled are located in the vacuum space.

3. A micro-refrigerator according to claim 1, characterized in that the compression means (22) comprises a lead zirconate titanate piezoelectric ceramic.

4. A micro-refrigerator according to claim 1, characterized in that the first (40) and second (50) channels are bent, the length of the second section (42) being greater than the length of the first section (41) within a predetermined area.

5. The micro-refrigerator according to claim 1, further comprising a first micro-valve (71) and a second micro-valve (72), the first micro-valve (71) being disposed on the second section (42), the second micro-valve (72) being disposed on the second channel (50).

6. The micro-refrigerator according to claim 5, wherein the first micro-valve (71) and the second micro-valve (72) are formed by etching.

7. The micro refrigerator according to claim 1, wherein the first substrate (10) and the second substrate (20) are made of materials compatible with semiconductor process.

8. A micro-refrigerator according to claim 1, characterized in that the ratio of the cross-section of the first section (41) to the cross-section of the second section (42) is between 0.5 and 0.1, the chip (30) to be cooled being located in the vertical space in which the second recess (21) is located.

9. The micro-refrigerator according to claim 1, further comprising a lead wire (80), the lead wire (80) being electrically connected to the compression device (22).

10. A method of manufacturing a micro refrigerator according to any one of claims 1 to 9, wherein the method comprises the steps of:

step S10: etching and forming a first channel (40), a second channel (50) and a first concave part (11) on the surface of the first substrate (10);

step S20: etching a second concave part (21) on the surface of a second substrate (20) facing the first substrate (10);

step S30: bonding the first substrate (10) and the second substrate (20) to form a closed cavity, and sealing the working medium in the cavity;

step S40: thinning the second substrate (20);

step S50: -mounting a compression means (22) on the surface of the second substrate (20) facing the first substrate (10);

step S60: arranging a chip (30) to be cooled on the surface of the second substrate (20) facing away from the first substrate (10);

step S70: the first base body (10) and the second base body (20) are packaged in a mounting space formed by a mounting plate (61) and a shell (62), and the mounting space is vacuumized.