A plate-type superconducting thermal switch

Abstract

The present invention provides a plate-type superconducting thermal switch and a manufacturing method thereof; the plate-type superconducting thermal switch comprises a substrate, a first lead layer, a first insulating layer, a conductive layer, a second insulating layer, a second lead layer, a third insulating layer and a superconducting wire layer which are arranged layer by layer on the substrate, the conductive layer is a grid-shaped circuit composed of a plurality of patch resistors and a strip-shaped conductive circuit, each patch resistor is located at the intersection of the grid, the patch resistor is higher than the strip-shaped conductive circuit, the superconducting wire layer comprises a plurality of superconducting wires, and each superconducting wire is fixed at a position corresponding to the patch resistor by a low-temperature glue. The conductive layer of the plate-type superconducting thermal switch of the present application is a grid-shaped circuit composed of a plurality of patch resistors and a strip-shaped circuit, the structure is compact, and the deployment orderliness is also improved.

Description

Technical Field

[0001] The present application relates to the technical field of superconducting coils, and in particular to a plate-type superconducting thermal switch. Background Art

[0002] Superconducting coils are an important structure in superconducting physics. Superconducting coils include active superconducting coils and passive superconducting coils. Active superconducting coils receive continuous external input when working; passive superconducting coils form superconducting coil loops. After charging, the current stored inside the superconducting coils flows losslessly inside the superconducting coils. For passive superconducting coil loops, when charging current, releasing current, and adjusting the current size, the coil loop needs to be "opened" to cause the coil to partially quench. An important way to "open" is to heat the superconducting coil locally, which is called a thermal switch. The basic requirements for thermal switches include small size, large heat flux density, and good thermal contact with the superconducting coil.

[0003] For a large superconducting coil structure, the number of superconducting coils is very large, and the corresponding superconducting thermal switches are also very large. Multiple superconducting thermal switches cannot affect each other, which requires maintaining a sufficient distance between the thermal switches, which increases the layout space of the thermal switches. Summary of the invention

[0004] In view of this, it is necessary to provide a plate-type superconducting thermal switch with a compact structure and improved orderliness.

[0005] In order to solve the above technical problems, the present application provides a plate-type superconducting thermal switch, which includes a substrate, a first lead layer, a first insulating layer, a conductive layer, a second insulating layer, a second lead layer, a third insulating layer and a superconducting wire layer which are arranged layer by layer on the substrate, wherein the conductive layer is a grid circuit composed of a plurality of chip resistors and strip-shaped conductive circuits, each chip resistor is located at the intersection of the grid, and the chip resistor is higher than the strip-shaped conductive circuit, and the superconducting wire layer includes a plurality of superconducting wires, and each superconducting wire is fixed at a position corresponding to the chip resistor by low-temperature glue.

[0006] The chip resistor is connected to the strip-shaped conductive circuit by welding, and a soldering point is formed at the welding point, and the soldering point is not higher than the chip resistor.

[0007] The chip resistor exposes the second insulating layer, and the chip resistor is in direct contact with the second lead layer.

[0008] The third insulating layer is exposed at a position of the second lead layer corresponding to the chip resistor, and the superconducting wire is directly fixed to the second lead layer by low-temperature glue.

[0009] Wherein, the remaining positions of the superconducting wire are fixed to the third insulating layer by means of fixing glue.

[0010] Wherein, the plurality of chip resistors of the conductive layer are connected via a strip-shaped conductive circuit to form a rectangular or square structure.

[0011] The plurality of superconducting wires are arranged in parallel; or the plurality of superconducting wires include a first parallel superconducting wire group and a second parallel superconducting wire group, the first parallel superconducting wire group and the second parallel superconducting wire group are perpendicular to each other and the intersection thereof corresponds to the patch resistor.

[0012] The outer edges of the third insulating layer, the second lead layer and the second insulating layer overlap, and the outer edge of the second insulating layer is inwardly arranged relative to the first insulating layer.

[0013] In order to solve the above technical problems, the present application also provides a method for manufacturing a plate-type superconducting thermal switch, which comprises:

[0014] forming a first lead layer and a first insulating layer in sequence on a substrate, wherein the first lead layer covers a surface of the substrate, and the first insulating layer covers an upper surface of the first lead layer;

[0015] Forming a conductive layer on the first insulating layer, wherein the conductive layer is a grid-shaped circuit composed of a plurality of chip resistors and strip-shaped conductive circuits, each chip resistor is located at an intersection of the grid, and the chip resistor is higher than the strip-shaped conductive circuit;

[0016] forming a second insulating layer on the conductive layer, wherein the second insulating layer covers the strip-shaped conductive circuit and is retracted relative to the outer edge of the substrate;

[0017] forming a second lead layer on the second insulating layer, wherein the second lead layer is in direct contact with the chip resistor;

[0018] forming a third insulating layer on the second lead layer, wherein the third insulating layer covers other positions of the second lead layer that do not correspond to the chip resistor;

[0019] At least one group of multiple superconducting wires parallel to each other are fixed to the second lead layer at positions corresponding to the patch resistors by low-temperature glue;

[0020] The remaining positions of at least one group of multiple superconducting wires parallel to each other are fixed to the third insulating layer by means of fixing glue.

[0021] Wherein, the step of forming a conductive layer on the first lead layer specifically includes:

[0022] Making a plurality of strip-shaped conductive circuits on the first insulating layer, wherein the strip-shaped conductive circuits are insulated from each other;

[0023] Soldering a plurality of chip resistors one by one to two adjacent strip-shaped conductive circuits to form a grid-shaped circuit;

[0024] Clean the solder joints at the soldering locations so that the height of the solder joints does not exceed the height of the chip resistor.

[0025] The step of making a plurality of strip-shaped conductive circuits on the first insulating layer specifically includes:

[0026] A metal film is formed on the first insulating layer by coating, and a plurality of strip-shaped conductive circuits are obtained by etching the metal film;

[0027] Alternatively, a plurality of conductive circuits are made on the first insulating layer by printing;

[0028] Alternatively, conductive wires are adhered to the first insulating layer to form a plurality of strip-shaped conductive circuits.

[0029] Compared with the prior art, the conductive layer of the plate-type superconducting thermal switch of the present application is composed of a plurality of chip resistors and strip circuits to form a grid-like circuit, which has a compact structure and improved deployment orderliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0031] Figure 1 It is a cross-sectional structural diagram of a sub-switch position of a preferred embodiment of a plate-type superconducting thermal switch of the present invention;

[0032] Figure 2a to Figure 2f To obtain Figure 1 The structure diagram of the manufacturing process of the plate-type superconducting thermal switch shown;

[0033] Figure 3 This is a schematic diagram of a second implementation mode of superconducting wire deployment in another preferred embodiment of a plate-type superconducting thermal switch of the present invention;

[0034] Figure 4 for Figure 3 The schematic diagram of the structure of the plate-type superconducting thermal switch is shown after the superconducting wire is fixed by the adhesive layer.

[0035] Figure 5 For the general Figure 2d A schematic diagram showing numbering of connection points of a chip resistor and a strip-shaped conductive circuit of a plate-type superconducting thermal switch;

[0036] Figure 6 For the general Figure 4 A schematic diagram showing numbering of superconducting wire connection points of a superconducting layer of a plate-type superconducting thermal switch. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of this application clearer, the technical solution of this application will be clearly and completely described below in combination with the specific embodiments of this application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this application, not all of them.

[0038] Please combine Figure 1 and Figure 2a~2f A preferred embodiment of the present application of a plate-type superconducting thermal switch includes a substrate 10, a first lead layer 20, a first insulating layer 30, a conductive layer 40, a second insulating layer 50, a second lead layer 60, a third insulating layer 70 and a superconducting wire layer 80 arranged layer by layer on the substrate 10, wherein the conductive layer 40 is a grid-shaped circuit composed of a plurality of chip resistors 402 and a strip-shaped conductive circuit 401, each chip resistor 402 is located at the intersection of the grid, and the chip resistor 402 is higher than the strip-shaped conductive circuit 401, and the superconducting wire layer 80 includes a plurality of superconducting wires, and each superconducting wire is fixed to the corresponding position of the chip resistor 402 by low-temperature glue.

[0039] In a preferred embodiment, the chip resistor 402 is connected to the strip-shaped conductive circuit 401 by welding, and a soldering point is formed at the welding point, and the soldering point is not higher than the chip resistor 402 .

[0040] In a preferred embodiment, the chip resistor 402 is exposed from the second insulating layer 50 , and the chip resistor 402 is in direct contact with the second lead layer 60 .

[0041] In a preferred embodiment, the third insulating layer 70 is exposed at the position of the second lead layer 60 corresponding to the patch resistor 402, and the superconducting wire is directly fixed to the second lead layer 60 by low-temperature glue. The remaining positions of the superconducting wire are fixed to the third insulating layer 70 by fixing glue. The low-temperature glue and the fixing glue together constitute a glue layer 90 covering the superconducting wire layer 80 and the third insulating layer 70.

[0042] In a preferred embodiment, the plurality of chip resistors 402 of the conductive layer 40 are connected via strip-shaped conductive circuits 401 to form a rectangular or square structure.

[0043] exist Figure 2a to Figure 2f In the embodiment shown, the multiple superconducting wires are arranged in parallel. In this embodiment, the multiple superconducting wires are mostly suitable for the application scenario of a single superconducting wire. Figure 3-4 In the illustrated embodiment, the plurality of superconducting wires include a first parallel superconducting wire group and a second parallel superconducting wire group. The first parallel superconducting wire group and the second parallel superconducting wire group are perpendicular to each other and the intersection thereof corresponds to the patch resistor. The plurality of superconducting wires in this embodiment are mostly suitable for application scenarios with two strands of superconducting wires.

[0044] In a preferred embodiment, outer edges of the third insulating layer 70 , the second lead layer 60 and the second insulating layer 50 overlap, and the outer edge of the second insulating layer 50 is retracted relative to the first insulating layer 30 .

[0045] The present application also discloses a method for manufacturing the plate-type superconducting thermal switch shown in the above embodiment. The structures or processes not detailed in the above embodiment can be further improved or supplemented by the manufacturing method of this embodiment.

[0046] The production method includes:

[0047] S01, in Figure 2a The first lead layer 20 and the first insulating layer 30 are sequentially formed on the substrate 10 (see Figure 2b ), the first lead layer 20 covers the surface of the substrate 10, and the first insulating layer 30 covers the upper surface of the first lead layer 20;

[0048] The substrate 10 is a low thermal conductivity, insulating substrate. The first lead layer 20 and the first insulating layer 30 can be made by coating. The main plane areas of the first lead layer 20, the first insulating layer 30 and the substrate 10 are equal (or the same size).

[0049] S02, forming a conductive layer 40 on the first insulating layer 30, wherein the conductive layer 40 is a grid-shaped circuit composed of a plurality of chip resistors 402 and strip-shaped conductive circuits 401, wherein each chip resistor 402 is located at an intersection of the grid, and the chip resistor 402 is higher than the strip-shaped conductive circuit 401;

[0050] The formation process of the conductive layer 40 at least includes:

[0051] S021, a plurality of strip-shaped conductive circuits 401 are formed on the first insulating layer 30, and the strip-shaped conductive circuits 401 are insulated from each other (see Figure 2c );

[0052] Preferably, two adjacent strip-shaped conductive circuits 401 are arranged in parallel at positions close to each other so as to provide an effective electrical connection for the chip resistor 402 to be soldered and connected in the next step; in this embodiment, the substrate 10 is a square structure, and the strip-shaped conductive circuits 401 are deployed on the four sides of the square substrate; in other embodiments, in addition to the four sides of the square substrate, the strip-shaped conductive circuits can also be deployed inside the square substrate; or, the square structure substrate can also be replaced by a rectangular structure substrate.

[0053] S022, solder multiple chip resistors 402 one by one to two adjacent strip-shaped conductive circuits 401 to form a grid-shaped circuit (see Figure 2d );

[0054] Consistent with the strip-shaped conductive circuits being arranged on the four sides of the square substrate, after welding, the multiple chip resistors of the conductive layer 40 are connected one by one through the strip-shaped conductive circuits 401 to form a closed ring structure. In this embodiment, the ring structure is square, and when the substrate is a rectangular substrate, the ring structure is rectangular. When the strip-shaped conductive circuits are not only arranged on the four sides of the square substrate, but also arranged inside the substrate, the multiple chip resistors of the conductive layer can be arranged in a matrix through the strip-shaped conductive circuits 401.

[0055] S023 , cleaning the solder joints at the soldering positions so that the height of the solder joints does not exceed the height of the chip resistor 402 .

[0056] Furthermore, manufacturing a plurality of strip-shaped conductive circuits 401 on the first insulating layer 30 includes at least the following three situations:

[0057] First, a metal film is formed on the first insulating layer 30 by coating, and the metal film is etched to obtain a plurality of strip-shaped conductive circuits 401;

[0058] Second, a plurality of conductive circuits 401 are made on the first insulating layer 30 by printing;

[0059] Third, the conductive wires are pasted onto the first insulating layer 30 to form a plurality of strip-shaped conductive circuits 401 .

[0060] S03, forming a second insulating layer 50 on the conductive layer 40, wherein the second insulating layer 50 covers the strip-shaped conductive circuit 401 and is retracted relative to the outer edge of the substrate 10;

[0061] The thickness of the second insulating layer 50 can completely cover the strip-shaped conductive circuit 401 and the solder joint, and the height of the second insulating layer 40 is still lower than the height of the chip resistor 402. Preferably, the second insulating layer on the chip resistor 402 can be removed without damaging the insulation, so that the chip resistor 402 is exposed from the second insulating layer.

[0062] The second insulating layer 40 is retracted relative to the outer edge of the substrate 10, which means that each side of the second insulating layer 40 does not cover the corresponding outer edge of the substrate, so as to leave space for welding with external wires. In practical applications, when the strip-shaped conductive circuit 401 is directly made by pasting metal wires, the outer edge of the strip-shaped conductive circuit 401 can exceed the outer edge of the substrate, and the second insulating layer 40 does not need to be retracted relative to the substrate.

[0063] S04, forming a second lead layer 60 on the second insulating layer 50, wherein the second lead layer 60 is in direct contact with the chip resistor 402;

[0064] Since in the preferred embodiment, the second insulating layer 50 on the chip resistor 402 is removed and the height of the second insulating layer is lower than the height of the chip resistor 402, the chip resistor 402 is in direct contact with the second lead layer to achieve better heat transfer when the chip resistor is powered on.

[0065] The first lead layer 20 and the second lead layer 60 are used to achieve the effect of superconducting magnetic shielding at low temperature.

[0066] S05, forming a third insulating layer 70 on the second lead layer 60, wherein the third insulating layer 70 covers other positions of the second lead layer 60 that do not correspond to the chip resistor 402;

[0067] Preferably, the third insulating layer 70 is exposed at the position of the second lead layer 60 corresponding to the chip resistor, so that the superconducting wire is in direct contact with the second lead layer 60 .

[0068] The outer edges of the third insulating layer 70 , the second lead layer 60 and the second insulating layer 50 overlap and are all retracted relative to the outer edge of the substrate 10 to leave space for welding the strip-shaped conductive circuit 401 with external wires.

[0069] S06, at least one group of multiple mutually parallel superconducting wires are fixed to the second lead layer 60 at a position corresponding to the chip resistor 402 by low-temperature glue;

[0070] exist Figure 2a to Figure 2f The embodiment shown is an application demonstration of a group of multiple superconducting wires parallel to each other. In this embodiment, multiple superconducting wires are mostly suitable for application scenarios of single-strand superconducting wires. Figure 3-4 The embodiment shown is an application demonstration of two groups of multiple parallel superconducting wires. The two groups of superconducting wires are arranged perpendicular to each other and the intersections between them correspond to the patch resistors. The multiple superconducting wires in this embodiment are mostly suitable for application scenarios with two superconducting wires.

[0071] S07, fixing the remaining positions of at least one group of multiple mutually parallel superconducting wires to the third insulating layer 70 by means of fixing glue.

[0072] In a preferred embodiment, the superconducting wire is directly fixed to the second lead layer 60 by low temperature glue, and the rest of the superconducting wire is fixed to the third insulating layer 70 by fixing glue. The fixing glue and the low temperature glue together form a glue layer 90 covering the superconducting layer 80.

[0073] The above two preferred embodiments do not constitute a limitation on the shape of the superconducting thermal switch and the number of sub-switches; and can be applied to any occasion requiring a superconducting thermal switch.

[0074] The usage of the plate-type superconducting thermal switch is exemplified as follows:

[0075] Please combine Figure 5 and Figure 6The chip resistors are numbered 11, 12, 13, 14, 21, 24, 31, 34, 41, 42, 43, 44, the connection points of the strip conductive circuit 401 are numbered a1, a2, a3, a4, a5, a6, a7, a8, b1, b2, b3, b4, b5, b6, b7, b8, and the connection points of the superconducting wires of the superconducting wire layer are numbered A1, A2, A3, A4, A5, A6, A7, A8, B1, B2, B3, B4, B5, B6, B7, B8. The superconducting wires of the superconducting wire layer are connected to the external superconducting wires through the superconducting wire connection points, and the strip conductive circuit 401 is connected to the external circuit by welding or the like.

[0076] The resistance of the strip conductive circuit is very small compared to the chip resistor 402 and can be approximately ignored. It can be found that two joints such as a2-b7, a4-b5, b4-a5, b2-a7 are equivalent, because the two joints can be connected through the conductive circuit, and the combination of the above two joints should be avoided.

[0077] Superconducting wires can be used in situations where complex control logic is required. Here are some examples of how superconducting thermal switches can be used:

[0078] 1. Superconducting wire only Figure 2f When the single-layer coil is shown,

[0079] The first case: only a single point of the superconducting wire needs to quench, and it is not necessary to quench at the same time as other superconducting wires;

[0080] For example, when the external circuit is connected to the connection points a1 and a5 of the strip conductive circuit 401, the patch resistor 12 generates heat, and the superconducting wire loses superconductivity at a single point between the connection points B1-B2 of the superconducting wire; when the external circuit is connected to the connection points b5 and b1 of the strip conductive circuit 401, the patch resistor 21 generates heat, and the superconducting wire loses superconductivity at a single point between the connection points B3-B4 of the superconducting wire.

[0081] The second situation: only a single superconducting wire needs to quench at multiple points, and it does not need to quench at the same time as other superconducting wires;

[0082] For example, the external circuit is connected to the connection points b1 and b2 of the strip-shaped conductive circuit 401, and the chip resistors 11, 12, and 13 generate heat, causing the superconducting wire to lose superconductivity at multiple points between the connection points B1-B2 of the superconducting wire.

[0083] The third situation: multiple superconducting wires quench at the same time;

[0084] For example, the external circuit is connected to the connection points a1 and b3 of the strip conductive circuit 401, and the chip resistors 11 and 21 are heated, causing the superconducting wire between the connection points B1-B2 and the superconducting wire between the connection points B3-B4 of the superconducting wire to lose superconductivity at multiple points; the external circuit is connected to the connection points a1 and b4 of the strip conductive circuit 401, and the chip resistors 11, 21, and 31 are heated, causing the superconducting wire between the connection points B1-B2, the superconducting wire between the connection points B3-B4, and the superconducting wire between the connection points B5-B6 to lose superconductivity at multiple points; the external circuit is connected to the connection points a1 and a2 of the strip conductive circuit 401, and the chip resistors 11, 21, 31, and 41 are heated, causing the superconducting wire between the connection points B1-B2, the superconducting wire between the connection points B3-B4, the superconducting wire between the connection points B5-B6, and the superconducting wire between the connection points B7-B8 to lose superconductivity at multiple points.

[0085] 2. Superconducting wires Figure 3 In the double-layer coil shown, each thermal switch controls at least two superconducting wires, which can adapt to more complex control strategies so that any two crossed superconducting wires can be quenched simultaneously.

[0086] 3. When there are two superconducting wires with exactly the same control strategy, they can be superimposed on the board. For example, there are multiple superconducting wires with exactly the same layout between the connection points B1-B2.

[0087] 4. When the superconducting wire does not need to be controlled by a certain thermal switch node, the low-temperature glue can be removed to move the superconducting wire out of the influence range of the thermal switch patch resistor, thereby helping to achieve more complex control strategies.

[0088] Compared with the prior art, the conductive layer of the plate-type superconducting thermal switch of the present application is composed of a grid-like circuit consisting of multiple chip resistors and strip circuits, which has a compact structure and improved deployment orderliness; further, the control level of the thermal switch can be improved and the heat loss of the low-temperature system caused by the thermal switch leads can be reduced.

[0089] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A plate-type superconducting thermal switch, It is characterized in that The plate-type superconducting thermal switch comprises a substrate, a first lead layer, a first insulating layer, a conductive layer, a second insulating layer, a second lead layer, a third insulating layer, a superconducting wire layer, and a glue layer, which are arranged layer by layer on the substrate. The conductive layer is a grid-shaped circuit composed of a plurality of patch resistors and a strip-shaped conductive circuit. Each patch resistor is located at an intersection of the grid, and the patch resistor is higher than the strip-shaped conductive circuit. The superconducting wire layer comprises a plurality of superconducting wires, and each superconducting wire is fixed at a position corresponding to the patch resistor by a low-temperature glue. The chip resistor is connected to the strip-shaped conductive circuit by welding, and a solder joint is formed at the welding point, and the solder joint is not higher than the chip resistor; The chip resistor is exposed from the second insulating layer, and the chip resistor is in direct contact with the second lead layer; The third insulating layer is exposed at a position of the second lead layer corresponding to the chip resistor, and the superconducting wire is directly fixed to the second lead layer by low-temperature glue; The remaining positions of the superconducting wire are fixed to the third insulating layer by means of fixing glue; The low-temperature glue and the fixing glue together form a glue layer covering the superconducting wire layer and the third insulating layer.

2. The plate-type superconducting thermal switch according to claim 1, It is characterized in that The plurality of chip resistors in the conductive layer are connected via a strip-shaped conductive circuit to form a rectangular or square structure.

3. The plate-type superconducting thermal switch according to claim 2, It is characterized in that The plurality of superconducting wires are arranged in parallel; or the plurality of superconducting wires include a first parallel superconducting wire group and a second parallel superconducting wire group, the first parallel superconducting wire group and the second parallel superconducting wire group are perpendicular to each other and the intersection thereof corresponds to the patch resistor.

4. The plate-type superconducting thermal switch according to claim 1, It is characterized in that The outer edges of the third insulating layer, the second lead layer and the second insulating layer overlap, and the outer edge of the second insulating layer is retracted relative to the first insulating layer.

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