Chip test low-temperature system for helium liquefaction and recondensation
The low-temperature system for helium liquefaction and recondensation addresses electromagnetic interference and helium consumption issues by using a pulse tube refrigerator and magnetic shielding, enabling efficient, cost-effective, and zero-evaporation chip testing for large-scale superconducting chips.
Patent Information
- Application Number
- CN202420544827.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-20
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2034-03-20
AI Technical Summary
Existing chip testing methods for large-scale superconducting chips face issues with electromagnetic interference when using refrigerators and excessive liquid helium consumption when immersed in liquid helium environments, making them costly and unsuitable for long-term testing.
A low-temperature system utilizing a pulse tube refrigerator with a condensing heat exchanger and magnetic shielding, combined with a liquid helium test chamber, enables helium liquefaction and recondensation, creating a stable, non-magnetic environment for chip testing with zero evaporation and reduced helium consumption.
The system provides a compact, low-interference, cost-effective solution for long-term chip testing by recycling helium and maintaining a stable low-temperature, low-magnetic environment, ensuring efficient and economical testing without helium loss.
Smart Images
Figure CN222167171U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of cryogenic system integration, in particular to a chip testing cryogenic system for helium liquefaction and recondensation, which can be used for performing cryogenic testing on relatively large-scale complex superconducting chips. Background Art
[0002] The testing process of large-scale complex superconducting chips requires a long-term, stable and non-magnetic 4.2K low-temperature environment. In order to meet the testing environment of large-scale complex superconducting chips, it is usually necessary to use a refrigerator to directly cool the chip or immerse the chip in a liquid helium environment for testing.
[0003] When using a refrigerator to directly cool the chip for testing, the refrigerator and the external environment will cause electromagnetic interference, which makes the chip testing have the problem of excessive electromagnetic interference; the method of immersing the chip in a liquid helium environment for testing can avoid the electromagnetic interference problem, but liquid helium evaporates too quickly at room temperature, so there is a problem of excessive liquid helium consumption. For future large-scale superconducting computer chip testing, the cost of using liquid helium is too high. Utility Model Content
[0004] The utility model provides a chip testing low temperature system for helium liquefaction and recondensation, which is used to solve the defects in the prior art that directly cooling the chip with a refrigerator or immersing the chip in a liquid helium environment for testing cannot meet the long-term testing requirements of large-scale superconducting chips.
[0005] The utility model provides a low temperature system for chip testing by helium liquefaction and recondensation, comprising:
[0006] Liquid helium test chamber, used to contain liquid helium to provide an immersion test environment;
[0007] A pulse tube refrigerator, comprising a refrigerator compressor, a refrigerator cold head and a refrigerator cold shield, wherein the refrigerator cold head is connected to a condensing heat exchanger, the liquid helium test cavity and the condensing heat exchanger are located in the refrigerator cold shield, the refrigerator cold head is connected to the liquid helium test cavity through a cold helium gas return pipeline, and the condensing heat exchanger is connected to the liquid helium test cavity through a liquid helium reflux pipeline;
[0008] A helium tank is connected to the cold head of the refrigerator through a pipeline.
[0009] According to a chip testing cryogenic system for helium liquefaction and recondensation provided by the utility model, a precooling heat exchanger is wound around the outside of the cold head of the refrigerator.
[0010] According to a helium liquefaction and recondensation chip testing cryogenic system provided by the utility model, the helium liquefaction and recondensation chip testing cryogenic system also includes a magnetic shielding device, and the magnetic shielding device is used to form a low magnetic field environment inside the liquid helium test chamber.
[0011] According to a low-temperature system for chip testing of helium liquefaction and recondensation provided by the utility model, the magnetic shielding device includes a low-temperature magnetic shielding cover and a normal-temperature magnetic shielding cover, the low-temperature magnetic shielding cover is located in the liquid helium test chamber, and the normal-temperature magnetic shielding cover is outside the refrigerator cold screen.
[0012] According to a chip testing cryogenic system for helium liquefaction and recondensation provided by the utility model, the liquid helium testing chamber is provided with a superconducting chip testing insertion interface for plugging in a superconducting chip interconnection module, and the superconducting chip interconnection module is provided with a long strip connector, and the long strip connector is used to connect a superconducting chip so as to extend into the liquid helium testing chamber to test the superconducting chip.
[0013] According to a chip testing cryogenic system for helium liquefaction and recondensation provided by the utility model, the liquid helium testing chamber comprises a liquid holding chamber and a plug-in chamber connected to the liquid holding chamber, the liquid holding chamber holds liquid helium, the end of the plug-in chamber is provided with the superconducting chip testing insertion interface, and a reverse check device is provided at the superconducting chip testing insertion interface to prevent gaseous helium from flowing out of the superconducting chip testing insertion interface.
[0014] According to a chip testing cryogenic system for helium liquefaction and recondensation provided by the utility model, the liquid storage cavity is connected to an exhaust pipeline, and an exhaust valve and a pressure sensor are arranged on the exhaust pipeline.
[0015] According to the helium liquefaction and recondensation chip testing cryogenic system provided by the utility model, the liquid storage cavity is also connected to a liquid infusion pipeline for adding liquid helium into the liquid storage cavity from the outside.
[0016] According to a low-temperature system for chip testing for helium liquefaction and recondensation provided by the utility model, a liquid helium electronic level gauge is arranged inside the liquid storage cavity.
[0017] According to a chip testing cryogenic system for helium liquefaction and recondensation provided by the utility model, a helium pressure reducing valve and a flow controller are arranged on the pipeline connecting the helium tank to the cold head of the refrigerator.
[0018] The utility model provides a low-temperature system for chip testing with helium liquefaction and recondensation. The helium provided by the helium tank is precooled step by step through the cold head of the refrigerator, and finally liquefied in the condensing heat exchanger. The liquefied liquid helium enters the liquid helium test chamber through the liquid helium return pipeline to provide a liquid helium immersion environment. The cold head of the pulse tube refrigerator can also precool the refrigerator cold screen to ensure the thermal insulation performance of the system. The superconducting chip is immersed in the liquid helium environment in the liquid helium test chamber, and the evaporated cold helium is recondensed by the pulse tube refrigerator. The liquid helium environment can effectively avoid electromagnetic interference in the test process. The evaporated cold helium in the liquid helium test chamber reaches the condensing heat exchanger through the cold helium return pipeline, and after recondensation, it flows back into the liquid helium test chamber from the liquid helium return pipeline, thereby achieving zero evaporation of liquid helium during the superconducting chip test process. The low-temperature system for chip testing with helium liquefaction and recondensation has a compact structure and has the advantages of zero evaporation of liquid helium, low electromagnetic interference, and convenient use. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0020] Figure 1 It is a structural schematic diagram of a chip testing cryogenic system for helium liquefaction and recondensation provided by the utility model;
[0021] Figure 2 It is a structural schematic diagram of the liquid helium test chamber provided by the utility model.
[0022] Reference numerals:
[0023] 1. Liquid helium test chamber; 101. Superconducting chip test insertion interface; 102. Superconducting chip interconnection module; 103. Long strip connector; 104. Superconducting chip; 105. Liquid holding chamber; 106. Plug-in chamber; 107. Exhaust pipeline; 108. Infusion pipeline; 109. Liquid helium electronic level gauge; 2. Pulse tube refrigerator; 201. Refrigerator compressor; 202. Refrigerator cold head; 203. Refrigerator cold screen; 3. Condensation heat exchanger; 4. Cold helium return pipeline; 5. Liquid helium reflux pipeline; 6. Helium tank; 601. Helium pressure reducing valve; 602. Flow controller; 7. Precooling heat exchanger; 8. Magnetic shielding device; 801. Low-temperature magnetic shielding cover; 802. Normal temperature magnetic shielding cover. DETAILED DESCRIPTION
[0024] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0025] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.
[0026] In the description of the embodiments of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present utility model can be understood in specific circumstances.
[0027] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.
[0028] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model embodiment. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0029] Combine the following Figure 1 and Figure 2 The specific structure and working principle of the helium liquefaction and recondensation chip testing cryogenic system of the utility model are described.
[0030] One embodiment of the utility model provides a low temperature system for chip testing by helium liquefaction and recondensation, see Figure 1 As shown, it includes a liquid helium test chamber 1, a pulse tube refrigerator 2 and a helium tank 6, wherein the liquid helium test chamber 1 is used to contain liquid helium to provide an immersion test environment; the pulse tube refrigerator 2 includes a refrigerator compressor 201, a refrigerator cold head 202 and a refrigerator cold shield 203, the refrigerator cold head 202 is connected to a condensing heat exchanger 3, the liquid helium test chamber 1 and the condensing heat exchanger 3 are located in the refrigerator cold shield 203, the refrigerator cold head 202 is connected to the liquid helium test chamber 1 through a cold helium return gas pipeline 4, and the condensing heat exchanger 3 is connected to the liquid helium test chamber 1 through a liquid helium reflux pipeline 5; the helium tank 6 is connected to the refrigerator cold head 202 through a pipeline.
[0031] It can be understood that the chip testing low temperature system for helium liquefaction and recondensation provided in this embodiment is a superconducting chip low temperature testing system based on refrigerator + liquid helium. When testing, firstly, vacuum treatment is carried out by an external vacuum pump, and high vacuum is maintained by a static sealing structure. The helium tank 6 and the pulse tube refrigerator 2 are turned on, and the helium in the helium tank 6 is precooled step by step under the action of the refrigerator cold head 202, and finally liquefied in the condensing heat exchanger 3. The liquefied liquid helium enters the liquid helium test chamber 1 through the liquid helium reflux pipeline 5 to provide a liquid helium immersion environment. The refrigerator cold head 202 of the pulse tube refrigerator 2 can also precool the refrigerator cold screen 203, thereby ensuring the thermal insulation performance of the system. The superconducting chip is immersed in the liquid helium environment in the liquid helium test chamber 1, and the evaporated cold helium is recondensed by the pulse tube refrigerator 2. The liquid helium environment can effectively avoid electromagnetic interference during the test process. The cold helium gas evaporated in the liquid helium test chamber 1 reaches the condensation heat exchanger 3 through the cold helium gas return pipeline 4, and after recondensation, it flows back into the liquid helium test chamber 1 through the liquid helium return pipeline 5, thereby achieving zero evaporation of liquid helium during the superconducting chip test process.
[0032] In some embodiments, in a low temperature system for chip testing with helium liquefaction and recondensation of the utility model, a precooling heat exchanger 7 is wound around the outside of the refrigerator cold head 202. Specifically, a GM pulse tube refrigerator can be used, and its refrigerator cold head 202 has a primary cold head and a secondary cold head. The precooling heat exchanger 7 is wound around the primary cold head, the secondary cold head and the refrigerator cylinder wall. The condensing heat exchanger 3 is connected to the secondary cold head. After being fully precooled by the multi-stage precooling heat exchanger 7, the normal temperature helium enters the condensing heat exchanger 3 connected to the secondary cold head to achieve liquefaction.
[0033] In some other embodiments, a low temperature system for chip testing of helium liquefaction and recondensation of the utility model further includes a magnetic shielding device 8, which is used to form a low magnetic field environment inside the liquid helium test chamber 1. Specifically, the magnetic shielding device 8 includes a low temperature magnetic shielding cover 801 and a normal temperature magnetic shielding cover 802, the low temperature magnetic shielding cover 801 is located in the liquid helium test chamber 1, and the normal temperature magnetic shielding cover 802 is covered outside the refrigerator cold shield 203, and an efficient magnetic shielding structure is formed by the combined magnetic shielding structure of the normal temperature magnetic shielding cover 802 and the low temperature magnetic shielding cover 801 to ensure a low magnetic field environment for chip testing.
[0034] In some other embodiments, a liquid helium test chamber 1 of a low temperature system for chip testing for helium liquefaction and recondensation of the utility model is provided with a superconducting chip test insertion interface 101 for plugging in a superconducting chip interconnection module 102. The superconducting chip interconnection module 102 is provided with a long strip connector 103. The long strip connector 103 is used to connect a superconducting chip 104 so as to extend into the liquid helium test chamber 1 for testing the superconducting chip. The superconducting chip test insertion interface 101 is provided, and through an external control program, the superconducting chip 104 can be hot-swapped through the superconducting chip interconnection module 102, so as to ensure that the superconducting chip 104 can be replaced without stopping the system.
[0035] Specifically, for some examples, see Figure 2 As shown, the liquid helium test chamber 1 includes a liquid holding chamber 105 and a plug-in chamber 106 connected to the liquid holding chamber 105. The liquid holding chamber 105 holds liquid helium. A superconducting chip test insertion interface 101 is provided at the end of the plug-in chamber 106. A reverse check device is provided at the superconducting chip test insertion interface 101 to prevent gaseous helium from flowing out of the superconducting chip test insertion interface 101. When performing chip testing, the superconducting chip interconnection module 102 is connected to the superconducting chip 104 through the long strip connector 103, and the superconducting chip 104 is inserted from the superconducting chip test insertion interface 101. The superconducting chip 104 finally reaches the low-temperature magnetic shielding cover 801. The superconducting chip interconnection module 102 is located at the superconducting chip test insertion interface 101. The low-temperature magnetic shielding cover 801 cooperates with the liquid helium in the liquid holding cavity 105 to provide an extremely low magnetic liquid helium immersion environment. The superconducting chip interconnection module 102 can perform the hot-swap function of the superconducting chip 104 test through an external control program. When the superconducting chip 104 needs to be replaced, it can be directly replaced at the superconducting chip test insertion interface 101 through the superconducting chip interconnection module 102, thereby realizing the online replacement function of the superconducting chip.
[0036] On the basis of the above examples, in other examples, the liquid holding cavity 105 is connected to an exhaust pipeline 107, and an exhaust valve and a pressure sensor are provided on the exhaust pipeline 107. The exhaust pipeline 107 can ensure the safety of the pressure in the liquid helium test cavity 1. When the pressure inside the liquid helium test cavity 1 is too high, the exhaust valve can be opened to release the pressure through the exhaust pipeline 107. The pressure sensor can detect the pressure to ensure that the pressure inside the liquid helium test cavity 1 is normal. In other examples, the liquid holding cavity 105 is also connected to a liquid infusion pipeline 108 for adding liquid helium to the liquid holding cavity 105 from the outside, and a liquid helium electronic level meter 109 is provided inside the liquid holding cavity 105. In addition to providing helium from the helium tank 6 to the system to form liquid helium, liquid helium can also be directly filled into the liquid helium test chamber 1 through the infusion pipeline 108, and the liquid level of the liquid helium in the liquid helium test chamber 1 is observed by the liquid helium electronic level meter 109 to ensure that the low-temperature magnetic shielding cover 801 can be immersed, providing an extremely low magnetic liquid helium immersion test environment.
[0037] The above-mentioned various embodiments of the utility model can be used in combination. In some specific examples, a helium pressure reducing valve 601 and a flow controller 602 are provided on the pipeline connecting the helium tank 6 to the cold head 202 of the refrigerator. When testing the superconducting chip, the system first performs a vacuum treatment through an external vacuum pump, maintains a high vacuum through a static sealing structure, and at the same time fills the system liquid helium test chamber 1 with high-purity helium at a certain pressure. Then, the pulse tube refrigerator 2 is turned on. At this time, the helium can be liquefied by turning on the high-purity helium tank 6 and the flow controller 602, or the liquid helium infusion operation can be directly performed through the infusion pipeline 108. When the liquid helium infusion volume reaches the requirement of the liquid helium electronic level meter 109, the exhaust valve of the infusion pipeline 108 is closed, and the refrigerator is waited for to reach the temperature. After the refrigerator reaches the temperature, the superconducting chip test insertion interface 101 is opened, and the superconducting chip 104 connected to the superconducting chip interconnection module 102 is inserted from the superconducting chip test insertion interface 101, and the system test is started. During the test, if the superconducting chip 104 needs to be replaced, the superconducting chip test insertion interface 101 can be opened again to replace the chip.
[0038] A multi-stage pre-cooling heat exchanger 7 is designed on the two-stage cold head and the outer wall of the cylinder of the pulse tube refrigerator 2, which can pre-cool the helium at room temperature step by step, and finally liquefy it in the condensing heat exchanger 3 connected to the second-stage cold head. The liquefied liquid helium can enter the liquid helium test chamber 1 through the liquid helium return pipe 5, thereby realizing the liquefaction function of helium. The helium evaporated in the liquid helium test chamber 1 reaches the condensing heat exchanger 3 through the cold helium return pipe 4, and after re-condensation, it flows back into the liquid helium test chamber 1 from the liquid helium return pipe 5, thereby realizing zero evaporation of liquid helium during the superconducting chip test process. In addition, a combined magnetic shielding structure of a low-temperature magnetic shielding cover 801 and a normal temperature magnetic shielding cover 802 is designed in the system, which can ensure that the inside of the liquid helium test chamber 1 is in an extremely low magnetic field environment. The chip testing cryogenic system for helium liquefaction and recondensation in this example has a compact structure, and utilizes the pulse tube refrigerator 2 to realize the liquid helium closed circulation function, thereby ensuring that liquid helium is not consumed during the chip testing process, and effectively reducing the use cost. In addition, room temperature helium can be used for liquefaction, thereby ensuring that the system can be filled with liquid helium without external means. In addition, the system's efficient magnetic shielding structure eliminates the electromagnetic interference problem caused by the refrigerator and the external environment. The system has the advantages of compact structure, zero evaporation of liquid helium, low electromagnetic interference, and easy use.
[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.
Claims
1. A chip testing cryogenic system for helium liquefaction and recondensation, characterized in that: include: A liquid helium test chamber (1), used for containing liquid helium to provide an immersion test environment; A pulse tube refrigerator (2), comprising a refrigerator compressor (201), a refrigerator cold head (202) and a refrigerator cold shield (203), wherein the refrigerator cold head (202) is connected to a condensing heat exchanger (3), the liquid helium test chamber (1) and the condensing heat exchanger (3) are located in the refrigerator cold shield (203), the refrigerator cold head (202) is connected to the liquid helium test chamber (1) via a cold helium gas return pipeline (4), and the condensing heat exchanger (3) is connected to the liquid helium test chamber (1) via a liquid helium return pipeline (5); A helium tank (6) is connected to the refrigerator cold head (202) via a pipeline.
2. The chip testing cryogenic system for helium liquefaction and recondensation according to claim 1, characterized in that: A pre-cooling heat exchanger (7) is wound around the outside of the refrigerator cold head (202).
3. The chip testing cryogenic system for helium liquefaction and recondensation according to claim 1, characterized in that: The helium liquefaction and recondensation chip testing cryogenic system further comprises a magnetic shielding device (8), wherein the magnetic shielding device (8) is used to form a low magnetic field environment inside the liquid helium testing chamber (1).
4. The chip testing cryogenic system for helium liquefaction and recondensation according to claim 3, characterized in that: The magnetic shielding device (8) comprises a low-temperature magnetic shielding cover (801) and a normal-temperature magnetic shielding cover (802), wherein the low-temperature magnetic shielding cover (801) is located in the liquid helium test chamber (1), and the normal-temperature magnetic shielding cover (802) covers the outside of the refrigerator cold shield (203).
5. The chip testing cryogenic system for helium liquefaction and recondensation according to any one of claims 1 to 4, characterized in that: The liquid helium test chamber (1) is provided with a superconducting chip test insertion interface (101) for plugging in a superconducting chip interconnection module (102); the superconducting chip interconnection module (102) is provided with a long strip connector (103); the long strip connector (103) is used to connect a superconducting chip (104) so as to extend into the liquid helium test chamber (1) to test the superconducting chip.
6. The chip testing cryogenic system for helium liquefaction and recondensation according to claim 5, characterized in that: The liquid helium test chamber (1) comprises a liquid holding chamber (105) and a plug-in chamber (106) connected to the liquid holding chamber (105); the liquid holding chamber (105) holds liquid helium; the end of the plug-in chamber (106) is provided with the superconducting chip test insertion interface (101); a reverse check device is provided at the superconducting chip test insertion interface (101) to prevent gaseous helium from flowing out of the superconducting chip test insertion interface (101).
7. The chip testing cryogenic system for helium liquefaction and recondensation according to claim 6, characterized in that: The liquid storage cavity (105) is connected to an exhaust pipeline (107), and an exhaust valve and a pressure sensor are provided on the exhaust pipeline (107).
8. The chip testing cryogenic system for helium liquefaction and recondensation according to claim 7, characterized in that: The liquid holding cavity (105) is also connected to a liquid infusion pipeline (108) for adding liquid helium into the liquid holding cavity (105) from the outside.
9. The chip testing cryogenic system for helium liquefaction and recondensation according to claim 8, characterized in that: A liquid helium electronic liquid level gauge (109) is arranged inside the liquid holding cavity (105).
10. The chip testing cryogenic system for helium liquefaction and recondensation according to any one of claims 1 to 4, characterized in that: A helium pressure reducing valve (601) and a flow controller (602) are provided on the pipeline connecting the helium tank (6) to the refrigerator cold head (202).