Substrate and quantum chip flip-chip bonding structure

Abstract

The utility model discloses a substrate and a quantum chip flip-chip bonding structure, and belongs to integrated circuit packaging. The substrate comprises the coplanar waveguide signal line and the air band, the air band is arranged above the central band of the coplanar waveguide signal line in a striding mode through the first side part and the second side part and is connected with the grounding band of the coplanar waveguide signal line, signal shielding is carried out on the coplanar waveguide signal line, and crosstalk of the quantum chip can be reduced. In addition, the first air outlet holes located in the first side portion of the air belt and the second air outlet holes located in the second side portion of the air belt are staggered, the arrangement density and number of the overall air outlet holes of the air belt are reduced, the signal shielding strength of the coplanar waveguide signal line can be improved, and the success rate of technology glue discharging in the air belt machining process can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of integrated circuit packaging, in particular to a substrate and a quantum chip flip-chip welding structure. Background Art

[0002] As the number of qubits on a quantum chip increases, the number of control lines also increases. To accommodate more control lines within the layout, the spacing between control lines on the substrate is reduced. This reduction in spacing between control lines on the substrate can lead to severe ground splitting and introduce crosstalk. Furthermore, quantum chips are often fabricated using a flip-chip process, with the bit structure positioned on the upper substrate and the control lines on the lower substrate. Due to the relatively small spacing between the upper and lower substrates, signals from the lower control lines can be introduced into the upper bit structure, causing crosstalk to the qubits.

[0003] Therefore, how to reduce the crosstalk intensity on the substrate in the flip-chip quantum chip structure is an urgent problem to be solved. Utility Model Content

[0004] The purpose of the utility model is to provide a quantum chip packaging structure and a quantum computer to address the deficiencies in the prior art, and it is possible to reduce the crosstalk intensity on the substrate in a flip-chip quantum chip structure.

[0005] The solution of this application example is implemented through the following content.

[0006] In a first aspect, an example of the present application provides a substrate including a coplanar waveguide signal line and an air strip;

[0007] The coplanar waveguide signal line includes a central strip and ground strips located on both sides of the central strip;

[0008] The air belt comprises a first side portion and a second side portion connected to each other, the air belt is connected to the ground belt via the first side portion and the second side portion, and is arranged across the center belt;

[0009] The first side portion has a first air outlet hole, the second side portion has a second air outlet hole, and the first air outlet hole and the second air outlet hole are staggered.

[0010] According to some examples of the present application, there is a first preset distance between the first air outlet and the edge of the first side portion; and there is a second preset distance between the second air outlet and the edge of the second side portion.

[0011] According to some examples of the present application, there is a third preset distance between the first air outlet and the second air outlet.

[0012] According to some examples of the present application, along a direction perpendicular to the substrate, projections of the first air outlet and the second air outlet do not overlap with the central band.

[0013] According to some examples of the present application, the first air outlet and the second air outlet have the same shape and size.

[0014] According to some examples of the present application, the shapes of the first air outlet and the second air outlet include circular, semicircular, or rectangular.

[0015] According to some examples of the present application, the first side portion includes a plurality of the first air outlet holes, and distances between adjacent first air outlet holes are equal;

[0016] The second side portion includes a plurality of second air outlet holes, and distances between adjacent second air outlet holes are equal.

[0017] According to some examples of the present application, the first side portion includes a plurality of the first air outlet holes, and the second side portion includes a plurality of the second air outlet holes;

[0018] The first air outlet holes are distributed on the perpendicular bisector of two adjacent second air outlet holes.

[0019] According to some examples of the present application, a cross-sectional shape of the air belt is trapezoidal or arched.

[0020] In a second aspect, an example of the present application proposes a quantum chip flip-chip structure, comprising a quantum chip and the substrate described in the first aspect above, wherein the quantum chip is flip-chip soldered on the substrate.

[0021] In the aforementioned example substrate of this application, the air strip spans the center strip of coplanar waveguide signal lines via the first and second side portions and connects to the ground strip, shielding the coplanar waveguide signal lines and reducing crosstalk within the quantum chip. Furthermore, the first air outlet holes on the first side portion and the second air outlet holes on the second side portion are staggered, reducing the overall air outlet hole density and number in the air strip, thereby improving the success rate of debinding during the air strip fabrication process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] For a clearer explanation, the following briefly introduces the drawings required for the description.

[0023] Figure 1 A top view of the structure of a substrate in an example of this application;

[0024] Figure 2 A top view of the structure of a substrate in another example of the present application;

[0025] Figure 3A structural cross-sectional view of a substrate in an example of the present application;

[0026] Figure 4 This is a structural cross-sectional view of a substrate in another example of the present application. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of this application. The embodiments described below with reference to the drawings are exemplary and are only used to explain this application, and cannot be interpreted as limiting this application.

[0028] In the description of the present invention, it should be understood that the terms "center", "up", "down", "left", "right", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0030] As the number of qubits on a quantum chip increases, the number of control lines also increases. When the substrate size is fixed, as the number of control lines increases, the spacing between the control lines decreases. However, this reduction in spacing between control lines on the substrate leads to more severe ground splitting, which increases the crosstalk intensity between control lines on the substrate. Furthermore, quantum chips are often fabricated using a flip-chip process, with the bit structure positioned on the upper substrate and the control lines on the lower substrate. Due to the relatively small spacing between the upper and lower substrates, signals from the control lines on the lower substrate can be introduced into the bit structure on the upper substrate, causing crosstalk between the qubits.

[0031] Based on this, Figures 1 to 2 As shown, an embodiment of the present invention provides a substrate, which includes a coplanar waveguide signal line 110 and an air strip 120.

[0032] The coplanar waveguide signal line 110 includes a center strip 111 and ground strips 112 located on both sides of the center strip 111;

[0033] The air belt 120 includes a first side portion 121 and a second side portion 122 connected to each other. The air belt 120 is connected to the ground belt 112 through the first side portion 121 and the second side portion 122 and is arranged above the center belt 111.

[0034] The first side portion 121 has a first air outlet 131 , and the second side portion 122 has a second air outlet 132 . The first air outlet 131 and the second air outlet 132 are staggered.

[0035] The coplanar waveguide signal line 110 is an axisymmetric structure, and the air strip 120 spanning the coplanar waveguide signal line 110 can be divided into a first side portion 121 and a second side portion 122 along the axis of symmetry.

[0036] Specifically, both the first side portion 121 and the second side portion 122 have vents (i.e., release holes) for discharging the photoresist between the air strip 120 and the coplanar waveguide signal line 110 during the preparation of the air strip 120. Furthermore, the first vents 131 on the first side portion 121 and the second vents 132 on the second side portion 122 are staggered. This staggered distribution indicates that along a direction parallel to the substrate plane and perpendicular to the axis of symmetry of the coplanar waveguide signal line 110, the first vents 131 and the second vents 132 partially overlap or do not overlap.

[0037] It should be noted that the present application does not impose any specific restrictions on the shapes and sizes of the first air outlet 131 and the second air outlet 132 , as long as they meet the staggered distribution requirements.

[0038] The aforementioned substrate includes a coplanar waveguide signal line 110 and an air strip 120 extending across the coplanar waveguide signal line 110. The first air outlet holes 131 on the first side 121 of the air strip 120 and the second air outlet holes 132 on the second side 122 of the air strip 120 are staggered. Based on this, the substrate provided herein shields the coplanar waveguide signal line 110 by extending the air strip 120 across the coplanar waveguide signal line 110, thereby reducing crosstalk between signal lines on the substrate.

[0039] Furthermore, the staggered distribution of the first air outlet holes 131 on the first side 121 of the air strip 120 and the second air outlet holes 132 on the second side 122 can reduce the density and number of air outlet holes in the air strip 120 as a whole, thereby further improving the shielding strength of the air strip 120 against the coplanar waveguide signal line 110. When discharging the photoresist located between the air strip 120 and the coplanar waveguide signal line 110, the staggered distribution of the first air outlet holes 131 on the first side 121 of the air strip 120 and the second air outlet holes 132 on the second side 122 of the air strip 120 subjects the photoresist to an asymmetric force (e.g., suction), thereby increasing the success rate of discharging all the photoresist and improving the yield rate of substrate preparation.

[0040] In one embodiment of the present application, a first preset distance is defined between the first air outlet 131 and the edge of the first side portion 121 ; a second preset distance is defined between the second air outlet 132 and the edge of the second side portion 122 .

[0041] The edge of the first side portion 121 and the edge of the second side portion 122 both refer to the sides of the air strip 120 corresponding to the first side portion 121 and the second side portion 122 .

[0042] Specifically, the first preset spacing and the second spacing are both greater than zero, and the specific values can be set according to actual needs.

[0043] Since impedance requires a continuous wave surface, and there is a distance between the first air outlet 131 and the second air outlet 132 in the substrate provided by the present application and the side of the air belt 120, the structure in which the air outlets provided by the present application are not on the side of the air belt 120 can reduce the impact on the impedance of the substrate.

[0044] In one embodiment of the present application, a third preset distance is defined between the first air outlet 131 and the second air outlet 132 .

[0045] Specifically, the third preset distance is greater than zero, and the specific value can be set according to actual needs. The presence of a distance between the first air outlet 131 and the second air outlet 132 also indicates that the first air outlet 131 and the second air outlet 132 are not connected.

[0046] In one embodiment of the present application, along a direction perpendicular to the substrate, projections of the first air outlet hole 131 and the second air outlet hole 132 do not overlap with the central band 111 .

[0047] Furthermore, along a direction perpendicular to the substrate, projections of the first air outlet 131 and the second air outlet 132 on the substrate are both located in the area where the grounding strip 112 is located.

[0048] By controlling the positional relationship between the projections of the first and second air outlet holes 131 and 132 and the center strip 111 and the ground strip 112 , the risk of damaging the coplanar waveguide signal line 110 during the debonding process through the first and second air outlet holes 131 and 132 can be reduced.

[0049] In one embodiment of the present application, the first air outlet hole 131 and the second air outlet hole 132 have the same shape and size.

[0050] In one embodiment of the present application, the shapes of the first air outlet 131 and the second air outlet 132 include circular, semicircular or rectangular.

[0051] Specifically, to improve processing efficiency, the first and second air outlet holes 131, 132 on the air belt 120 may be of the same size and shape. It should be noted that the first and second air outlet holes 131, 132 may be of different sizes and shapes, and may be one or more of rectangular, circular, semicircular, or elliptical shapes.

[0052] In one embodiment of the present application, the first side portion 121 includes a plurality of first air outlet holes 131 , and the distances between adjacent first air outlet holes 131 are equal;

[0053] The second side portion 122 includes a plurality of second air outlet holes 132 , and the distances between adjacent second air outlet holes 132 are equal.

[0054] Specifically, along a direction parallel to the symmetry axis of the coplanar waveguide signal line 110 , the spacing between adjacent first air outlet holes 131 may be equal to the spacing between adjacent second air outlet holes 132 .

[0055] In one embodiment of the present application, the first side portion 121 includes a plurality of first air outlet holes 131 , and the second side portion 122 includes a plurality of second air outlet holes 132 ;

[0056] The first air outlet holes 131 are distributed on the perpendicular bisector of two adjacent second air outlet holes 132 .

[0057] like Figures 3 and 4 As shown, in one embodiment of the present application, the cross-sectional shape of the air belt 120 is trapezoidal or arched.

[0058] It should be noted that in this application, the first air outlet 131 and the second air outlet 132 only need to meet the following requirements: 1) after the first air outlet 131 moves in a direction parallel to the plane of the substrate and perpendicular to the symmetry axis of the coplanar waveguide signal line 110, the first air outlet 131 and the second air outlet 132 have a partial overlap or no overlap; and 2) the first air outlet 131 and the second air outlet 132 are both spaced apart from the side of the air strip 120. This application does not impose specific restrictions on the shape and size of the first air outlet 131 and the second air outlet 132, or the spacing between them, and they can be set according to actual needs.

[0059] An embodiment of the present invention further provides a quantum chip flip-chip structure, comprising a quantum chip and the above-mentioned substrate, wherein the quantum chip is flip-chip soldered on the substrate.

[0060] Specifically, the quantum chip flip-chip structure utilizes the aforementioned substrate. An air strip 120, positioned across the coplanar waveguide signal line 110, shields all signal lines within the quantum chip flip-chip structure. This reduces crosstalk between adjacent signal lines and between signal lines on the upper and lower substrates. The staggered placement of the first and second air holes 131, 132 on the air strip 120 facilitates thorough debinding and improves the success rate of substrate fabrication. Furthermore, the staggered placement of the first and second air holes 131, 132 on the air strip 120 reduces the exposed area of the signal lines, enhancing the strength of signal shielding between the signal lines.

[0061] Throughout this specification, references to terms such as "some embodiments" or "examples" indicate that the specific features, structures, materials, or characteristics described in conjunction with such embodiments or examples are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments. Furthermore, those skilled in the art may combine and reconcile the different embodiments or examples described in this specification.

[0062] The above description is merely a preferred embodiment of the present invention and does not limit the present invention in any way. Any person skilled in the art who, without departing from the scope of the present invention, makes any equivalent substitution, modification, or other variation to the technical solution and technical content disclosed herein shall be deemed to fall within the scope of the present invention and remain within the scope of protection of the present invention.

Claims

1. A substrate, characterized in that including a coplanar waveguide signal line and an air strip; The coplanar waveguide signal line includes a central strip and ground strips located on both sides of the central strip; The air belt comprises a first side portion and a second side portion connected to each other, the air belt is connected to the ground belt via the first side portion and the second side portion, and is arranged across the center belt; The first side portion has a first air outlet hole, the second side portion has a second air outlet hole, and the first air outlet hole and the second air outlet hole are staggered.

2. The substrate according to claim 1, wherein There is a first preset distance between the first air outlet and the edge of the first side portion; there is a second preset distance between the second air outlet and the edge of the second side portion.

3. The substrate according to claim 1, wherein There is a third preset distance between the first air outlet hole and the second air outlet hole.

4. The substrate according to claim 1, wherein Along a direction perpendicular to the substrate, projections of the first air outlet and the second air outlet do not overlap with the central zone.

5. The substrate according to claim 1, wherein The first air outlet hole and the second air outlet hole have the same shape and size.

6. The substrate according to claim 5, wherein The shapes of the first air outlet and the second air outlet include circular, semicircular or rectangular.

7. The substrate according to claim 1, wherein The first side portion includes a plurality of the first air outlet holes, and the distances between adjacent first air outlet holes are equal; The second side portion includes a plurality of second air outlet holes, and distances between adjacent second air outlet holes are equal.

8. The substrate according to claim 1, wherein The first side portion includes a plurality of the first air outlet holes, and the second side portion includes a plurality of the second air outlet holes; The first air outlet holes are distributed on the perpendicular bisector of two adjacent second air outlet holes.

9. The substrate according to claim 1, wherein The cross-section of the air belt is trapezoidal or arched.

10. A quantum chip flip-chip structure, characterized in that: The invention comprises a quantum chip and the substrate according to any one of claims 1 to 9, wherein the quantum chip is flip-chip soldered on the substrate.

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