Superconducting Printed Circuit Board and Preparation Method

Abstract

The present disclosure provides a method for preparing a superconducting printed circuit board, including: preparing a circuit board substrate; preparing copper circuits on the front side and / or the back side of the circuit board substrate; and tinning the surface of the copper circuits to form a tin thin film layer, thereby obtaining a single-piece circuit board substrate; laminating a plurality of single-piece circuit board substrates to complete the preparation of the superconducting printed circuit board. The present disclosure further provides a superconducting printed circuit board, including: at least one single-piece circuit board substrate; each circuit board substrate including: a circuit board substrate; copper circuits prepared on the front side and / or the back side of the circuit board substrate; and a tin thin film layer prepared on the surface of the copper circuits.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic technologies, and particularly to a printed circuit board with superconducting characteristics and a preparation method thereof. Background Art

[0002] A PCB (Printed Circuit Board) is an important carrier for realizing current electronic devices. It is a carrier for electronic components such as chips, resistors, and capacitors when realizing circuit functions, and provides interconnected lines. The printed circuit board has developed in many aspects such as the number of circuit layers, signal bandwidth, and flexibility. In the special field of quantum computing, printed circuit boards are also used. A quantum chip is placed on the printed circuit board (soldered or wired), and the signal lines of the chip are led out to a connector through the lines on the circuit board. However, since most of the current printed circuit board circuit layers use copper as the material, the printed lines have a certain static resistance, which has an unwanted impact on the operation of the quantum chip. Moreover, even in the extremely low temperature environment where the quantum chip operates, the static resistance only decreases slightly and cannot completely disappear, so its impact still exists.

[0003] Therefore, how to provide a printed circuit board with low-temperature superconducting characteristics is an urgent technical problem to be solved. Summary of the Invention

[0004] (1) Technical Problems to be Solved

[0005] Based on the above problems, the present disclosure provides a superconducting printed circuit board and a preparation method thereof to alleviate technical problems such as the large static resistance of the existing PCB.

[0006] (2) Technical Solutions

[0007] One aspect of the present disclosure provides a preparation method of a superconducting printed circuit board, including: preparing a circuit board substrate; preparing copper lines on the front and / or back of the circuit board substrate; and tinning the surface of the copper lines to form a tin thin film layer to obtain a single-piece circuit board substrate; laminating a plurality of single-piece circuit board substrates to complete the preparation of the superconducting printed circuit board.

[0008] According to an embodiment of the present disclosure, the circuit board substrate includes a flexible substrate or a rigid substrate.

[0009] According to an embodiment of the present disclosure, the flexible substrate is prepared with a polyester film or a polyimide as the substrate.

[0010] According to an embodiment of the present disclosure, the preparation material of the rigid substrate is selected from: phenolic paper laminate, epoxy paper laminate, polyester glass mat laminate, or epoxy glass cloth laminate.

[0011] According to an embodiment of the present disclosure, preparing copper circuits on the front and / or back of the circuit board substrate includes: electroplating and depositing copper on the circuit board substrate to form copper circuits; or forming copper circuits by etching after copper cladding on the circuit board substrate.

[0012] According to an embodiment of the present disclosure, forming a tin thin film layer on the surface of the copper circuits to obtain a single-piece circuit board substrate includes: plating tin or spraying tin on the surface of the copper circuits so that tin materials adhere to the surface of the copper circuits.

[0013] According to an embodiment of the present disclosure, forming a tin thin film layer on the surface of the copper circuits to obtain a single-piece circuit board substrate further includes: preparing a tin alloy thin film layer on the surface of the copper circuits.

[0014] According to an embodiment of the present disclosure, the preparation materials of the tin alloy thin film layer are selected from leaded tin or lead-free tin.

[0015] According to an embodiment of the present disclosure, multiple single-piece circuit board substrates are interconnected by through holes, blind holes, and buried holes.

[0016] On the other hand, the present disclosure provides a superconducting printed circuit board prepared by the preparation method described in the above item. The superconducting printed circuit board includes: at least one single-piece circuit board substrate; each circuit board substrate includes: a circuit board substrate; copper circuits prepared on the front and / or back of the circuit board substrate; and a tin thin film layer prepared on the surface of the copper circuits.

[0017] (III) Beneficial effects

[0018] It can be seen from the above technical solutions that the superconducting printed circuit board and the preparation method of the present disclosure have at least one or some of the following beneficial effects:

[0019] (1) The modification to the existing PCB processing process is small, the process modification is small (process compatibility), and the cost is low;

[0020] (2) The low-temperature superconducting characteristics of the printed circuit board are realized. Description of the drawings

[0021] Figure 1 It is a schematic flow chart of the preparation method of the superconducting printed circuit board according to an embodiment of the present disclosure.

[0022] Figure 2 It is a schematic structural diagram of the superconducting printed circuit board according to an embodiment of the present disclosure.

[0023] Reference numerals

[0024] 1 Substrate; 2 Copper circuits; 3 Tin thin film layer. Detailed implementation manners

[0025] The present invention provides a superconducting printed circuit board and a preparation method, which can realize superconducting circuits under extremely low temperature conditions and realize circuits without static resistance. It meets the demand for superconducting circuits when quantum computing chip signals are led out, and eliminates the influence of line resistance on the performance of quantum chips. It can be applied to the signal lead-out circuit board of quantum chips, and can also be made into simple strip lines and microstrip lines for use as superconducting transmission lines.

[0026] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0027] In an embodiment of the present disclosure, a method for preparing a superconducting printed circuit board is provided, Figure 1 and Figure 2 As shown, the preparation method shown includes: including:

[0028] Preparing a circuit board substrate 1;

[0029] Preparing a copper circuit 2 on the front and / or back side of the circuit board substrate; and

[0030] Tin forms a tin film layer 3 on the surface of the copper circuit to obtain a single-chip circuit board substrate;

[0031] Depending on the specific needs, multiple single-piece circuit board substrates can be pressed together, such as Figure 2 As shown, it includes multiple (3 or 4, the specific number is not limited) single-piece circuit board substrates with copper circuits 2 and tin film layers 3 on both the front and back sides. After the above multiple single-piece circuit board substrates are pressed together, the preparation of a multi-layer superconducting printed circuit board is completed.

[0032] Inserting multiple / multiple tinning links (there are many tinning schemes, such as tin plating, tin spraying, etc.) in the process of circuit board processing changes the structure of each signal layer metal in the original circuit board process, so that a layer of tin material is attached to the surface of the original copper. Tin has superconducting properties at low temperatures (3.75K), which realizes the superconductivity of the circuit. Tin materials can be appropriately doped, or their alloys (such as lead tin Sn63Pb37, lead-free tin SnAg3Cu0.5, etc.) can be directly used to improve their low-temperature physical properties. Pure tin will become powder below low temperatures (-13.2 degrees), but in fact, the physical form of doped tin (alloy) is relatively stable at low temperatures. The present disclosure mainly utilizes the existing PCB process flow, and adds tinning (tin spraying) operations after the inner layer graphics are completed (the inner layer actually has different numbers of inner layers and different processing times due to different circuit board design layers) and the outer layer graphics are completed, which is equivalent to the surface treatment process. Then continue to complete the other links in the process.

[0033] The original PCB processing process is not limited. Only a soldering operation is added after the processing of each layer of circuits is completed. Other materials of the circuit board are not limited. For example, the materials between PCB layers can still be FR-4, Rogers, thin films, etc. The physical properties of the circuit board are not limited. For example, with the thin film solution and in combination with the present disclosure, a flexible superconducting FPC board can be achieved, etc. Making a transmission line can be a specific application case. There are no restrictions on the user's circuit design and size specifications. There are no special constraints on the composition of the tin, as long as it contains tin. After some actions of drilling and electroless copper plating in the circuit board process, the soldering process can also be added, but this is optional and not limited. In combination with the circuit board design and material selection, for example, when it belongs to PPC preparation, using the FPC processing technology and inserting the process of the present disclosure to fabricate a flexible superconducting FPC board, and combined with the circuit design, a flexible superconducting transmission line can be achieved, such as microstrip line, stripline and other solutions. Using the standard PCB processing technology and combined with the circuit design to achieve a quantum chip signal fan-out circuit board.

[0034] According to an embodiment of the present disclosure, the circuit board substrate includes a flexible substrate or a rigid substrate.

[0035] According to an embodiment of the present disclosure, the flexible substrate is prepared with a polyester film or a polyimide as the substrate.

[0036] According to an embodiment of the present disclosure, the preparation materials of the rigid substrate are selected from: phenolic paper laminated board, epoxy paper laminated board, polyester glass felt laminated board or epoxy glass cloth laminated board.

[0037] According to an embodiment of the present disclosure, preparing copper circuits on the front and / or back of the circuit board substrate includes: electroplating and electroless copper plating on the circuit board substrate to form copper circuits; or etching after copper cladding on the circuit board substrate to form copper circuits.

[0038] According to an embodiment of the present disclosure, soldering on the surface of the copper circuits to form a tin thin film layer to obtain a single-chip circuit board substrate includes: tin plating or spraying tin on the surface of the copper circuits so that the tin material adheres to the surface of the copper circuits.

[0039] According to an embodiment of the present disclosure, soldering on the surface of the copper circuits to form a tin thin film layer to obtain a single-chip circuit board substrate further includes: preparing a tin alloy thin film layer on the surface of the copper circuits.

[0040] According to an embodiment of the present disclosure, the preparation materials of the tin alloy thin film layer are selected from leaded tin or lead-free tin.

[0041] The present disclosure also provides a superconducting printed circuit board prepared by the preparation method described in any one of the above, as Figure 2 shown, the superconducting printed circuit board includes:

[0042] At least one single-chip circuit board substrate;

[0043] Each circuit board substrate includes:

[0044] A circuit board base material 1;

[0045] Copper circuits 2, prepared on the front and / or back of the circuit board base material; and

[0046] A tin thin film layer 3, prepared on the surface of the copper circuits.

[0047] According to an embodiment of the present disclosure, the multiple single circuit board substrates are interconnected by vias, blind vias, and buried vias.

[0048] So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It should be noted that, in the accompanying drawings or the text of the specification, the implementation manners that are not illustrated or described are all forms known to those of ordinary skill in the art, and no detailed description is given. In addition, the definitions of the above-mentioned various elements and methods are not limited to the specific structures, shapes, or manners mentioned in the embodiments, and those of ordinary skill in the art can make simple changes or substitutions thereto.

[0049] Based on the above description, those skilled in the art should have a clear understanding of the superconducting printed circuit board and its manufacturing method of the present disclosure.

[0050] In summary, the present disclosure provides a superconducting printed circuit board and its manufacturing method, which can realize superconducting circuits under extremely low temperature conditions and realize circuits without static resistance. It meets the requirements for superconducting circuits when the quantum computing chip signals are led out, and eliminates the influence of circuit resistance on the performance of the quantum chip. It can be applied to the signal lead-out circuit board of the quantum chip, or can be made into a simple strip line or microstrip line for use as a superconducting transmission line.

[0051] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "rear", "left", "right", etc., are only references to the directions in the accompanying drawings and are not used to limit the protection scope of the present disclosure. Throughout the accompanying drawings, the same elements are represented by the same or similar reference numerals. When it may cause confusion in the understanding of the present disclosure, the conventional structures or configurations will be omitted. And the shapes and sizes of the components in the figures do not reflect the actual sizes and proportions, but only illustrate the content of the embodiments of the present disclosure.

[0052] The ordinal numbers used in the specification and the claims, such as "first", "second", "third", etc., are used to modify the corresponding elements, and they do not mean that the elements have any ordinal numbers in themselves, nor do they represent the order of one element and another element or the order in the manufacturing method. The use of these ordinal numbers is only to clearly distinguish an element with a certain name from another element with the same name.

[0053] In addition, unless specifically described or steps that must occur in sequence, the order of the above steps is not limited to those listed above and can be varied or rearranged according to the required design. Also, based on considerations of design and reliability, the above embodiments can be used in combination with each other or in combination with other embodiments, that is, the technical features in different embodiments can be freely combined to form more embodiments.

[0054] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present disclosure. It should be understood that the above are only specific embodiments of the present disclosure and are not used to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure should be included within the protection scope of the present disclosure.

Claims

1. A preparation method of a cryogenic superconducting printed circuit board, comprising: Preparing a circuit board substrate, where the circuit board substrate includes a flexible substrate or a rigid substrate; Preparing copper circuits on the front and / or back of the circuit board substrate; And Tinning an alloy on the surface of the copper circuits to form a tin alloy thin film layer, obtaining a single-piece circuit board substrate; Pressing multiple single-piece circuit board substrates together to complete the preparation of the superconducting printed circuit board, realizing superconducting circuits without static resistance under extremely low temperature conditions.

2. The preparation method of the cryogenic superconducting printed circuit board according to claim 1, wherein the flexible substrate is prepared with a polyester film or a polyimide as the substrate.

3. The preparation method of the cryogenic superconducting printed circuit board according to claim 1, wherein the preparation material of the rigid substrate is selected from: phenolic paper laminated board, epoxy paper laminated board, polyester glass felt laminated board or epoxy glass cloth laminated board.

4. The method for preparing a cryogenic superconducting printed circuit board according to claim 1, wherein preparing copper circuits on the front and / or back of the circuit board substrate includes: Electroplating and depositing copper on the circuit board substrate to form copper circuits; Or Etching to form copper circuits after copper coating on the circuit board substrate.

5. The preparation method of the cryogenic superconducting printed circuit board according to claim 1, wherein the preparation material of the tin alloy thin film layer is selected from leaded tin or lead-free tin.

6. The preparation method of the cryogenic superconducting printed circuit board according to claim 1, wherein multiple single-piece circuit board substrates are interconnected by through holes, blind holes and buried holes.

7. A cryogenic superconducting printed circuit board prepared by the preparation method according to any one of claims 1 to 6, the superconducting printed circuit board comprising: At least one single-piece circuit board substrate; Each circuit board substrate includes: A circuit board substrate; Copper circuits prepared on the front and / or back of the circuit board substrate; and A tin alloy thin film layer prepared on the surface of the copper circuits.

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