Printed circuit board to dielectric layer transition with controlled impedance and reduced and / or mitigated crosstalk for quantum applications

Abstract

Transitions between printed circuit boards and dielectric layers with controlled impedance and reduced and / or mitigated crosstalk for quantum applications are provided. A quantum device can include a microwave quantum circuit on a dielectric substrate and a printed circuit board including a via including a transmission line. Wire bonds between the transmission line of the printed circuit board and the transmission line of the microwave quantum circuit operably couple the microwave quantum circuit to the printed circuit board. The via includes a defined characteristic impedance. The wire bonds provide a microwave signal connection between the printed circuit board and the microwave quantum circuit.

Description

[0001] BACKGROUND

[0002] Crosstalk in electronic devices can occur when a signal transmitted on a first circuit or first channel of a transmission line (or system) produces an unintended material impact in a second circuit or second channel. Crosstalk can be caused by an electric or magnetic field of a first communication signal affecting a second communication signal in one or more adjacent circuits. For supercomputing technology devices (e.g., where crosstalk tolerance is highly sensitive), the effects of crosstalk can significantly increase the risk of damaging signals and can lead to unpredictable and / or erroneous circuit behavior.

[0003] Several specific areas of potential crosstalk impact can be observed when using supercomputing technology devices. These areas can include device packaging, such as printed circuit boards (PCBs), quantum chip dielectric layers on a dielectric substrate (DIE), and / or wirebonds connecting the packaging to the quantum chip dielectric layer. Wirebonds can be physically very close to adjacent wirebonds and, as a result, can increase distortion and / or crosstalk of adjacent wirebond signals due to electromagnetic interference and / or voltage leakage.

[0004] A problem associated with quantum (e.g., superconducting) applications is the use of wirebonds to connect printed circuit board lines to chip components on a dielectric layer, transmission lines on a dielectric substrate, and / or transmission lines on different dielectric substrates. In addition, the increase in the number of qubits has a corresponding increase in the number of required connections (e.g., wirebonds) in close proximity to each other. This can introduce unwanted cross-communication (e.g., crosstalk or xtalk) between nearby wirebonds. Additionally, the transition from a printed circuit board to a component and / or transmission line on a dielectric layer cannot maintain characteristic impedance continuity. SUMMARY

[0005] The following presents a summary to provide a basic understanding of one or more embodiments of the application. This summary is not intended to identify key or critical elements, or delineate any scope of particular embodiments or any scope of the claims. Its sole purpose is to present concepts in a simplified form as a prelude to the more detailed description that is presented later. One or more embodiments described herein are devices, systems, methods, computer-implemented methods, apparatuses, and / or computer program products that facilitate a printed circuit board to dielectric layer transition with controlled impedance and reduced and / or mitigated crosstalk for quantum applications.

[0006] According to one embodiment, a quantum device can include a microwave quantum circuit on a dielectric substrate and a printed circuit board including a via including a transmission line. Wire bonds between the transmission line of the printed circuit board and a transmission line of the microwave quantum circuit can operatively couple the microwave quantum circuit to the printed circuit board. Further, the via can include a defined characteristic impedance. Such a quantum device is advantageous in that the via can be designed to a defined impedance, whereby characteristic impedance continuity can be maintained.

[0007] In some examples, a dielectric substrate can be formed on the printed circuit board. In other examples, the dielectric substrate can be at least partially formed inside the printed circuit board. In other examples, the device can include a lid supporting the printed circuit board and the dielectric substrate. Such a quantum device is advantageous in that the length of the wire bonds is based on the distance between the via and the dielectric substrate, which provides for shorter wire bonds, and thus, can reduce and / or mitigate crosstalk, as crosstalk is directly proportional to the length of the wire bonds.

[0008] According to one embodiment, a method can include filling a via in a printed circuit board with a transmission line. The via can include a defined characteristic impedance. Further, the method can include operatively coupling the printed circuit board to a microwave quantum circuit on a dielectric substrate via wire bonds between the transmission line of the printed circuit board and a transmission line of the microwave quantum circuit. Such a method is advantageous in that the via can be designed to a defined characteristic impedance, which can maintain characteristic impedance continuity.

[0009] In some examples, operatively coupling the printed circuit board to the microwave quantum circuit can include attaching a length of wire bonds to the printed circuit board and the microwave quantum circuit. The length can be determined according to a first location of the via and a second location of the microwave quantum circuit. Such a method is advantageous in that signal crosstalk is directly related to the length of the wire bonds. Thus, controlling the placement of the first location and the second location can reduce the length of the wire bonds, and thus, can reduce and / or mitigate crosstalk.

[0010] According to one embodiment, an integrated circuit can include a microwave quantum circuit on a dielectric substrate and a printed circuit board including a via including a transmission line, the printed circuit board can be operatively coupled to the microwave quantum circuit via wire bonds between the transmission line of the printed circuit board and a transmission line of the microwave quantum circuit. Further, the via can include a defined characteristic impedance. Such an integrated circuit is advantageous in that the via can be designed to a defined characteristic impedance, which can maintain characteristic impedance continuity.

[0011] According to another embodiment, a device package is provided that can include a printed circuit board including a first via including a first transmission line and a second via including a second transmission line. The first via can include a first defined characteristic impedance, and the second via can include a second defined characteristic impedance. The device package can further include a microwave quantum circuit on a dielectric substrate formed at least partially inside the printed circuit board. The microwave quantum circuit can be operatively coupled to the printed circuit board via a first wire bond between the first transmission line of the printed circuit board and a first transmission line of the microwave quantum circuit and a second wire bond between the second transmission line of the printed circuit board and the microwave quantum circuit. An advantage of such a device package is that vias can be designed to a defined impedance, which can maintain characteristic impedance continuity. Another advantage of such a device package is that the length of the wire bonds is based on the distance between the vias and the dielectric substrate, which provides shorter wire bonds, and thus, can reduce and / or mitigate crosstalk, as crosstalk is directly proportional to the length of the wire bonds.

[0012] According to another embodiment, a device package is provided that can include a printed circuit board including a first via including a first transmission line and a second via including a second transmission line. The first via can include a first defined characteristic impedance, and the second via can include a second defined characteristic impedance. The device package can further include a microwave quantum circuit on a dielectric substrate formed at least partially inside the printed circuit board. The microwave quantum circuit can be operatively coupled to the printed circuit board via a first wire bond between the first transmission line of the printed circuit board and a first transmission line of the microwave quantum circuit and a second wire bond between the second transmission line of the printed circuit board and the microwave quantum circuit. An advantage of such a device package is that vias can be designed to a defined impedance, which can maintain characteristic impedance continuity. Another advantage of such a device package is that the length of the wire bonds is based on the distance between the vias and the dielectric substrate, which provides shorter wire bonds, and thus, can reduce and / or mitigate crosstalk, as crosstalk is directly proportional to the length of the wire bonds. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1A A quantum chip circuit including wire bonds is shown in accordance with one or more embodiments described herein.

[0014] Figure 1B A detailed example of a portion of a quantum chip circuit is shown in accordance with one or more embodiments described herein.

[0015] Figure 1C A transition from a printed circuit board line to a transmission line on a dielectric layer that does not maintain characteristic impedance continuity is shown in accordance with one or more embodiments described herein.

[0016] Figure 2An example, non-limiting side view of a portion of a quantum device is shown in accordance with one or more embodiments described herein.

[0017] Figure 3 An example, non-limiting side view of a portion of a quantum computing device is shown in accordance with one or more embodiments described herein.

[0018] Figure 4 An example, non-limiting side view of a portion of another quantum computing device is shown in accordance with one or more embodiments described herein.

[0019] Figure 5 An example, non-limiting side view of a portion of yet another quantum computing device is shown in accordance with one or more embodiments described herein.

[0020] Figure 6 An example, non-limiting side view of a portion of another quantum computing device is shown in accordance with one or more embodiments described herein.

[0021] Figure 7 An example, non-limiting printed circuit board used in simulations in accordance with one or more embodiments described herein is shown.

[0022] Figure 8 An example, non-limiting plot of time domain reflectometry results of a simulation of the printed circuit board of Figure 7

[0023] Figure 9 An example, non-limiting plot of scattering parameter results of a simulation of the printed circuit board of Figure 8

[0024] Figure 10 A portion of a quantum device utilizing magnetic shielding walls in accordance with one or more embodiments described herein is shown.

[0025] Figure 11A and Figure 11B Alternative embodiments of shielding walls in accordance with one or more embodiments described herein are shown.

[0026] Figure 12 An example, non-limiting implementation of a multi-layer printed circuit board in accordance with one or more embodiments described herein is shown.

[0027] Figure 13 An example, non-limiting via size in accordance with one or more embodiments described herein is shown.

[0028] Figure 14 ​​A flow diagram illustrating an example non-limiting method for fabricating an integrated circuit in accordance with one or more embodiments described herein is shown.

[0029] Figure 15 A block diagram illustrating an example non-limiting operating environment that can facilitate one or more embodiments described herein is shown. DETAILED DESCRIPTION

[0030] The following detailed description is merely illustrative and is not intended to limit embodiments and / or the application or uses of embodiments. Furthermore, there is no intention to be bound by any expressed or implied information presented in the preceding “BACKGROUND” or “SUMMARY” sections, or the “DETAILED DESCRIPTION” section.

[0031] One or more embodiments will now be described, by way of example only, with reference to the attached figures, wherein like references are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a more thorough understanding. It will be apparent, however, to one skilled in the art that one or more embodiments can be practiced without these specific details.

[0032] Because of the involvement of circuitry, and more specifically quantum circuitry, wirebonds are used to connect printed circuit board (PCB) transmission lines to dielectric substrate (DIE) components. For illustrative purposes, Figure 1A A quantum chip circuit (denoted as [1]) is shown in circle 102 in accordance with one or more embodiments described herein. The wirebonds are transitional connecting lines between the dielectric layer lines and the printed circuit board lines. For example, when there is a quantum processor or quantum device, the processor or device can be connected by a thin wirebond (e.g., a thin wire made of aluminum or other material) that connects the ground layer of the printed circuit board (around the quantum processor) and the components on the dielectric layer. Additionally or alternatively, the wirebonds can be used to connect the transmission lines of the printed circuit board to the transmission lines on the quantum processor itself, as shown. Figure 1B A detailed example of a portion of a quantum chip circuit in accordance with one or more embodiments described herein is shown.

[0033] A challenge that can arise with quantum devices is that the wirebonds are very close to each other between the transmission lines, and as the number of qubits or other components on the quantum processor increases, the number of wirebonds can increase and become closer to each other. The closer the wirebonds are; the more crosstalk or coupling between the wirebonds occurs. This means that when a signal is sent through a first wirebond 104, some portion of the signal can leak to other wirebonds (e.g., second wirebond 106) near the first wirebond 104 based on their magnetic coupling. As Figure 1BAs shown, the first wire bond 104 and the second wire bond 106 are separated by a distance of approximately 1.5 millimeters (mm), however, other distances can be used to separate the wire bonds. Increasing the number of qubits leads to an increase in the number of qubits that are close to each other (e.g., wire bonds). This close proximity can introduce unwanted crosstalk (e.g., crosstalk or xtalk) between nearby wire bonds (e.g., the first wire bond 104 and the second wire bond 106). Crosstalk should be avoided because when controlling the first qubit via signaling, the state of the second qubit (or the state of other qubits) should not be inadvertently changed based on crosstalk received from the signal controlling the first qubit.

[0034] Furthermore, such as Figure 1C As shown, the transition from a printed circuit board (PCB) line to a transmission line on a dielectric layer (e.g., via one or more wire bonds as shown in 108) does not maintain characteristic impedance continuity. For example, in conventional devices, the transmission from the PCB to the dielectric layer is mismatched in terms of characteristic impedance. As shown, the PCB and dielectric layer can be designed with a first impedance (e.g., 50 ohms), while the transition (at 108) can be at a second impedance (e.g., approximately 70 ohms). This means that a portion of the signal may be reflected back as it passes through the wire bond. Input lines are typically 50 ohms (this is likely standard for microwave components), and the same input lines are designed for quantum devices with transmission lines, but unfortunately, the wire bond itself cannot be perfectly controlled to be 50 ohms. As shown, the transition is approximately 70 ohms in most cases, which can introduce some noise or problems in the design.

[0035] The problem addressed by the disclosed aspect is to reduce and / or mitigate the negative impact of "crosstalk" in superconducting devices. Superconducting qubits can operate within a relatively small bandwidth (e.g., 100 MHz) in the vicinity of 5 GHz, and other components used to control the qubits can operate between approximately 6 GHz and approximately 10 GHz. Simulations discussed in the upcoming figures plot crosstalk results in the range between 1 GHz and 20 GHz (e.g., Figure 7 , Figure 8 and Figure 9 (As shown). Crosstalk has become a critical source of performance degradation and signal integrity issues in high-speed printed circuit board designs, and it worsens with increasing frequency. Due to the high interconnect density in superconducting devices, transmission lines often need to be very close together, making it highly likely that signals from adjacent lines will be disrupted. A common symptom of crosstalk is retransmission, which can lead to a significant reduction in randomness, resulting in unpredictable outcomes and potential circuit failures.

[0036] Some attempts have been made to mitigate crosstalk. Concepts such as proposed various signal routing topologies have been applied to reduce and / or mitigate crosstalk between adjacent lines, however, this increases the footprint area required on the printed circuit board. In addition, other attempts have been made, such as reducing driver size, wiring spacing, defined wire bond placement, optical specific techniques, and simultaneous buffering and wiring, to reduce and / or mitigate crosstalk noise. However, such attempts do not address the problem of reducing and / or mitigating crosstalk while maintaining continuity of characteristic impedance, which will be discussed in further detail below.

[0037] Additionally, these existing solutions are unable to achieve crosstalk reduction and / or mitigation near negative 50 dB (-50 dB) because -30 dB is considered sufficient for a quality signal for classical applications in the semiconductor industry. Certain of these potential solutions can be implemented after the circuit design. However, the purpose of the disclosed aspects is to design the circuit to mitigate features prior to manufacturing.

[0038] Figure 2 An exemplary, non-limiting side view of a portion of a quantum device 200 is shown in accordance with one or more embodiments described herein. As shown, the quantum device 200 includes a bottom cap 202, which can be formed of copper or another material. Also included in the quantum device 200 can be a dielectric layer (e.g., a dielectric substrate 204) and a printed circuit board 206, which is shown as including a first layer 2061 and a second layer 2062 over the first layer 2061. The device 200 also includes a top cap 208, which can be formed of copper or another material.

[0039] To form a transition from the printed circuit board 206 to the microwave quantum circuit 210 on the dielectric substrate 204, one or more portions of the printed circuit board 206 can be cut away. For example, portions of the second layer 2062 can be cut, as shown at 212 and 214. Thus, instead of the first layer 2061 and the second layer 2062 having substantially the same length, the second layer 2062 is cut to accommodate one or more wire bonds. A first wire bond 216 can extend from the first cut portion 212 (e.g., the second layer 2062) of the printed circuit board 206 to one or more components (e.g., the microwave quantum circuit 210) on the dielectric substrate 204. A wire bond 218 can extend from the second cut portion 214 (e.g., the second layer 2062) of the printed circuit board 206 to one or more components (e.g., the microwave quantum circuit 210, one or more transmission lines) on the dielectric substrate 204.

[0040] As shown at 212 and 214, the cutout portion of the printed circuit board 206 (e.g., second layer 2062) is the cause of the transition not matching 50 ohms, which is another issue associated with traditional quantum devices. The transition does not match 50 ohms because the characteristic impedance cannot be accurately controlled when creating the cutout. Additionally, the length from the top of the printed circuit board (e.g., at 212 and 214) to the wire bonds (e.g., first wire bond 216, second wire bond 218) of the dielectric substrate 204 increases the inaccuracy of the characteristic impedance of the transition. To overcome these issues, the disclosed aspects provide a quantum device that includes one or more vias designed to define an impedance that can maintain characteristic impedance continuity.

[0041] Additionally, Figure 2 The quantum device of Figure 2 does not provide the level of isolation between the wire bonds required for quantum applications. The reason is that in order to decouple two qubits from each other, they must be isolated below -50 dB. While Figure 1C the device of Figure 2 can reduce and / or mitigate crosstalk, as provided by the disclosed aspects, crosstalk still does not improve the 50 ohm condition.

[0042] Figure 3 An exemplary, non-limiting side view of a portion of a quantum computing device 300 is shown in accordance with one or more embodiments described herein. Repetitive description of like elements employed in other embodiments described herein is omitted for sake of brevity. The quantum computing device 300 (as well as other quantum devices discussed herein) can be a superconducting device, can be implemented on a printed circuit board, in an integrated circuit, and / or in a superconductor package.

[0043] As shown, the quantum computing device 300 can include a printed circuit board 302, which can be a single layer printed circuit board. As discussed with respect to Figure 2 As shown in 212 and 214 in Figure 2 , an issue associated with traditional quantum devices (e.g., quantum device 200) is that the printed circuit board (e.g., printed circuit board 206, second layer 2062) must be cut to create a connection or contact point for the wire bonds. One solution provided by the quantum devices discussed herein is that one or more vias can be formed within the printed circuit board 302 without having to cut a portion of the printed circuit board. The one or more vias can be formed using a via formation process. The vias of the quantum computing device 300 are shown as a first via 304 and a second via 306.

[0044] The transmission lines can be formed in one or more vias (e.g., first via 304, second via 306). For example, the first via 304 can include a first transmission line and the second via 306 can include a second transmission line. The first wire bond 308 can connect the first via 304 to a dielectric layer (e.g., dielectric substrate 310) and / or to one or more components (e.g., microwave quantum circuit 312, one or more transmission lines, second transmission line) located on the dielectric substrate 310. The second wire bond 314 can connect the second via 306 to the dielectric substrate 310 and / or one or more components (e.g., microwave quantum circuit 312, one or more transmission lines, such as the second transmission line) located on the dielectric substrate 310.

[0045] The first wire bond 308 and the second wire bond 314 can provide microwave signal connections between the printed circuit board 302 and the microwave quantum circuit 312. According to some embodiments, the first wire bond 308 and the second wire bond 314 can provide microwave signal connections between printed circuit board 302 chip components on a dielectric layer (DIE), wires on a dielectric layer (DIE), and / or between different dielectric substrates (DIE).

[0046] A first length of the first wire bond 308 can be based on a first distance between a first location 316 of the first via 304 and a second location 318 of the dielectric substrate 310 and / or a first distance to the microwave quantum circuit 312 located on the dielectric substrate 310. A second length of the second wire bond 314 can be based on a second distance between a third location 320 of the second via 306 and a fourth location 322 of the dielectric substrate 310 and / or a second distance to the microwave quantum circuit 312 located on the dielectric substrate 310. Further, according to some embodiments, the first length of the first wire bond 308 and the second length of the second wire bond 314 can be less than 2 millimeters (mm).

[0047] The wire bonds (e.g., first wire bond 308, second wire bond 314) can include, for example, aluminum and / or niobium. Further, the wire bonds (e.g., first wire bond 308, second wire bond 314) can include diameters in a range of approximately 15 micrometers (pm) to a few hundred micrometers, where the upper end of the range can be used for high power applications. Further, a lid 324 can be placed on the printed circuit board 302, the dielectric substrate 310, the microwave quantum circuit 312, the first wire bond 308, and the second wire bond 314.

[0048] Another issue associated with conventional quantum devices (e.g., quantum device 200) is that by cutting off a portion of the printed circuit board (e.g., as in Figure 2impedance of the transmission lines in the printed circuit board cannot be controlled. The solution provided by the disclosed aspects is that the transmission lines (e.g., first transmission line, second transmission line) are located inside the printed circuit board 302, thus, there is no need to cut the printed circuit board 302 in order to facilitate establishing a connection with wirebonds. Further, the vias and / or transmission lines can be designed to be approximately 50 ohms, or another desired impedance. For example, the first via 304 can include a first defined characteristic impedance, while the second via 306 can include a second defined characteristic impedance. According to some embodiments, the first defined characteristic impedance and the second defined characteristic impedance can be different characteristic impedances. In some embodiments, the first defined characteristic impedance and the second defined characteristic impedance can be the same characteristic impedance or a similar characteristic impedance.

[0049] The quantum computing device 300 can include one or more small copper vias underneath the printed circuit board 302. For example, the one or more small copper vias are shown as a first small via 324, a second small via 326, a third small via 328, and a fourth small via 330. The small vias (e.g., first small via 324, second small via 326, third small via 328, and fourth small via 330) can be connected to another piece of copper 332 placed underneath the dielectric substrate 310. Since there is no bottom lid contacting the dielectric substrate 310 for the quantum computing device 300, the piece of copper 332 can be utilized to improve the thermalization of the chip. It should be noted that copper is used since copper is a good thermal conductor while the printed circuit board 302 and the dielectric substrate 310 are not good thermal conductors. Thus, the small copper vias (e.g., first small via 324, second small via 326, third small via 328, and fourth small via 330) can thermallyize the dielectric substrate 310. Further, as discussed herein, by having shorter wirebonds (e.g., reduced length by via and / or dielectric layer location), since crosstalk can be proportional to the length of the wirebonds, crosstalk can be reduced and / or mitigated accordingly.

[0050] In view of the above-described problems of prior art superconducting devices, various aspects provided herein can be implemented to produce a solution to one or more of these problems in the form of superconducting devices, superconducting circuits, and methods of manufacturing the same. Implementing such systems, devices, circuits, methods, computer-implemented methods, and / or computer program products that embody such superconducting devices can have the advantage of reducing and / or mitigating crosstalk, and / or maintaining characteristic impedance continuity, as compared to conventional techniques.

[0051] Figure 3 The quantum computing device 300 of FIG. 3 shows that the dielectric substrate is on top of the printed circuit board 302. For example, in Figure 3In this circuit, the dielectric substrate 310 may be formed above the printed circuit board 302 and may be operatively attached to the printed circuit board 302 via a first wire bond 308 between the dielectric substrate 310 and a first transmission line (e.g., a first via 304) and a second wire bond 314 between the dielectric substrate 310 and a second transmission line (e.g., a second via 306).

[0052] Figure 4 An exemplary non-limiting side view of a portion of another quantum computing device 400 according to one or more embodiments described herein is shown. For brevity, repeated descriptions of similar components used in other embodiments described herein are omitted. As shown, the dielectric substrate 310 of the quantum computing device 400 can be at least partially inserted into a printed circuit board 302. In this embodiment, the top of the dielectric substrate 310 is closer to the printed circuit board 302. The first length of the first wire bond 308 and the second length of the second wire bond 314 may be compared to those used for... Figure 3 The wire bonding length of the quantum computing device 300 is slightly shorter.

[0053] Figure 5 An exemplary non-limiting side view of a portion of yet another quantum computing device 500 according to one or more embodiments described herein is shown. For brevity, repeated descriptions of similar components used in other embodiments described herein are omitted. As shown, the top of the dielectric substrate 310 of the quantum computing device 500 may be substantially the same height as the top of the printed circuit board 302.

[0054] exist Figure 5 In some embodiments, the bottom cover 502 can be used to support the dielectric substrate 310 and the printed circuit board 302. For example, the bottom of the printed circuit board 302 and the bottom of the dielectric substrate 310 can be supported on the bottom cover 502.

[0055] Figure 6 An exemplary non-limiting side view of a portion of another quantum computing device 600 according to one or more embodiments described herein is shown. For the sake of brevity, repeated descriptions of similar components employed in other embodiments described herein are omitted.

[0056] As shown, the height of the dielectric substrate 310 and the printed circuit board 302 can be different. Due to the height difference between the dielectric substrate 310 and the printed circuit board 302, one or more pillars or other support structures can be utilized to support the dielectric substrate on the bottom cover 502. For example, as shown, a first pillar 602 and a second pillar 604 can support the dielectric substrate 310. However, it should be noted that in some cases, a single pillar can be utilized to support the dielectric substrate 310 and / or more than two pillars can be used to support the dielectric substrate 310.

[0057] In comparison to conventional quantum devices including Figure 2 quantum computing device 300, the quantum computing device 400, the quantum computing device 500, and / or the quantum computing device 600 have some advantages. First, one or more vias (e.g., the first via 304, the second via 306) within the printed circuit board 302 can be designed to be approximately 50 ohms. For example, the diameter of the via can be selected such that the via is 50 ohms. Thus, with the disclosed aspects, the 50 ohm transition from the printed circuit board 302 to the dielectric substrate 310 can be improved.

[0058] Another advantage is that the dielectric substrate 310 and the wirebonds (e.g., the first wirebond 308, the second wirebond 314) in close proximity to the vias (e.g., the first via 304, the second via 306) are shorter in comparison to the first wirebond 216 and the second wirebond 218 of the conventional quantum device 200. Since the length of the wirebond is linearly related to the inductance of the transition, the wirebond can be in the 50 ohm transition when the wirebond is shorter. Thus, the shorter the wire, the better the 50 ohm approximation. Figure 2

[0059] Another advantage is that the shorter the wirebond, the less mutual inductance between the wirebonds in close proximity, which can reduce and / or mitigate crosstalk below the 50 dB (-50 dB) threshold (in the case of quantum applications).

[0060] ​Various aspects provide a transition of a printed circuit board (e.g., printed circuit board 302) to a dielectric substrate (e.g., dielectric substrate 310 and / or microwave quantum circuit 312) with controlled impedance and reduced and / or mitigated crosstalk without difficultly fabricating vias (e.g., first via 304, second via 306). Moreover, the disclosed aspects can utilize a non-superconducting printed circuit board (e.g., printed circuit board 302) to improve thermalization (as superconductors are poor thermal conductors). For example, a superconductor is a material that exhibits certain properties when cooled to a certain temperature. When such a material reaches a certain temperature, the material will become a near perfect conductor with a resistance of approximately zero ohms. Thus, current in a superconductor can flow through without much loss. Moreover, superconductors are highly sensitive to noise and possible damage to transmitted signals (e.g., crosstalk), which can be critical to perform applications.

[0061] For the disclosed aspects, intrusions in the form of potentially disruptive interference are disclosed within the circuit that can affect the integrity of superconductor data and compromise its functionality as well as the disclosed aspects to mitigate such negative effects. Additionally, the various aspects provided herein are easier to implement than traditional devices and only utilize non-superconducting materials for packaging to improve thermal conductivity.

[0062] Figure 7 An exemplary non-limiting printed circuit board 700 used in simulations in accordance with one or more embodiments described herein is shown. Repetitive description of like elements employed in other embodiments described herein is omitted for sake of brevity.

[0063] For example, there can be two transmission lines (e.g., first transmission line 702 and second transmission line 704) embedded in the printed circuit board 700. Moreover, there can be four vias (e.g., first via 706, second via 708, third via 710, and fourth via 712) available to implement a transition using wirebonds (e.g., first wirebond 714, second wirebond 716, third wirebond 718, and fourth wirebond 720). The first transmission line 702 can be between a first port 722 (P1) and a second port 724 (P2). The second transmission line 704 can be between a third port 726 (P3) and a fourth port 728 (P4). In an example, a wirebond can connect the first transmission line 702 to an attenuator, while another wirebond can connect the attenuator to the second transmission line 704.

[0064] As shown in the figure, the transmission lines in the printed circuit board 700 (e.g., first transmission line 702, second transmission line 704) are intentionally designed to be approximately 47 ohms so that, if there is an offset from 47 ohms, the impact of wire bonding and vias on the 50-ohm transition quality of the overall design can be determined. The distance between the two components, namely the first component 730 and the second component 732 (e.g., one or more components), is approximately 1.5 mm, which is very close to or similar to the dimensions used in practical applications.

[0065] Figure 8 One or more embodiments according to the description herein are shown. Figure 7 An exemplary non-limiting graph 800 shows the simulated time-domain reflectometry results of the printed circuit board 700. Time, in nanoseconds (ns), is displayed on the horizontal axis 802, and ohms are displayed on the vertical axis 804.

[0066] The time domain reflectometer (TDR) provides the value of the characteristic impedance along the lines (e.g., the first transmission line 702 and the second transmission line 704). The impedance of the first line (e.g., TDRZ(1)) is represented by the first line 806, and the impedance of the second line (e.g., TDRZ(2)) is represented by the second line 808.

[0067] The first transmission line 702 of the printed circuit board 700 (e.g., a 47-ohm line) is intentionally used, along with a 50-ohm stripline on the silicon (Si) dielectric substrate. As shown, at 810 of Figure 800, the resulting spike is almost three ohms higher than 50 ohms. This spike, called inductive overshoot, is caused by the wire bonding. Shortening the wire bonding may improve the inductive overshoot. However, the disclosed aspect has improved this overshoot compared to a spike of 70 ohms or higher in a conventional design. After the overshoot at 802, the result returns to 47 ohms, which is... Figure 7 The values ​​used in the associated simulations.

[0068] Figure 9 One or more embodiments according to the description herein are shown. Figure 7 An exemplary non-limiting graph 900 shows the simulated scattering parameter results of the printed circuit board 700. The horizontal axis 902 shows the frequency in gigahertz (GHz), and the vertical axis 904 shows the decibel (dB). Although the frequencies shown are between 0 GHz and 20 GHz, it should be noted that 20 GHz may exceed what is necessary for quantum applications.

[0069] The first line 906 represents dB(S(l, l)) and is a reflection portion and indicates that if energy is put into the first port 722, only a small amount of energy returns to the power source. For example, the reflection is below negative 10 dB (< -10 dB). The second line 908 represents dB(S(l, 2)) which shows the energy that flows from port 1 (e.g., the first port 722) to port 2 (e.g., the second port 724) without attenuation.

[0070] The third line 910 represents dB(S(l, 4)) which represents crosstalk between the first port 722 and the third port 726 (e.g., energy leaking from the first port 722 to the third port 726). The fourth line 912 represents dB(S(l, 3)) which represents crosstalk between the first port 722 and the fourth port 728 (e.g., energy leaking from the first port 722 to the fourth port 728).

[0071] As shown, before 20 GHz, the crosstalk is below negative 50 dB (< -50 db). This is more than sufficient given quantum applications, as typically superconducting qubits operate at 5 GHz or below. Thus, the plot 900 shows that the disclosed aspects are effective at higher frequencies. Likewise, the simulation demonstrates that having a printed circuit board with one or more vias and one or more wire bond transitions, as discussed herein, can improve the characteristic impedance and the crosstalk of the design.

[0072] According to some embodiments, the crosstalk can be further reduced and / or mitigated using copper (Cu) walls. For example, Figure 10 A portion of a quantum device 1000 utilizing magnetic shielding walls according to one or more embodiments described herein is shown.

[0073] The first shielding wall 1002 and the second shielding wall 1004 can be on opposite sides of the wire bond 1006. Thus, the first shielding wall 1002 and the second shielding wall 1004 can isolate the wire bond 1006. As shown, the shielding walls shown with respect to the second shielding wall 1004 can have dimensions (A (width), B (height), and C (length)) to isolate the wire bond.

[0074] The thickness (A) of the shielding walls (e.g., the first shielding wall 1002, the second shielding wall 1004) using a non-superconducting material such as copper can be greater than the skin depth. If the shielding walls (e.g., the first shielding wall 1002, the second shielding wall 1004) are made of a type-I superconductor material (e.g., aluminum), the thickness can be limited by the London penetration (the London penetration depth defines the thickness in which a supercurrent flows to cancel out an external magnetic field).

[0075] In at least one non-limiting embodiment, the length (C) of the shield wall (e.g., first shield wall 1002, second shield wall 1004) can be at least 5 times the length of the extension portion of the wire bond 1006. Further, the height (B) of the shield wall (e.g., first shield wall 1002, second shield wall 1004) can be at least 2 times the height of the wire bond 1006.

[0076] According to some embodiments, the shield wall (e.g., first shield wall 1002, second shield wall 1004) can be configured as part of the circuit fabrication. In alternative embodiments, the shield wall (e.g., first shield wall 1002, second shield wall 1004) can be soldered in place after the circuit is fabricated. It should be appreciated that the dimensional ratios can vary according to various parameters and conditions in embodiments.

[0077] Figure 11A and 11B Alternative embodiments of shield walls according to one or more embodiments described herein are shown. Repetitive description of like elements employed in other embodiments described herein is omitted for sake of brevity.

[0078] As shown, the magnetic shield wall (e.g., first shield wall 1002, second shield wall 1004) can include a top plate and / or enclosed portion 1102, 1104. The top plate or enclosed portion 1102, 1104 can be flat (as shown), curved (as shown), solid or non-solid to facilitate mitigation of cross-talk at the respective wire bonds. It should be appreciated that any suitable magnetic shielding material and wall thickness, height, and depth can be used in combination to reduce cross-talk levels to below -50 dB depending on the desired range of superconducting quantum circuit applications. Figure 11A Figure 11B As shown, the magnetic shield wall (e.g., first shield wall 1002, second shield wall 1004) can include a top plate and / or enclosed portion 1102, 1104. The top plate or enclosed portion 1102, 1104 can be flat (as shown), curved (as shown), solid or non-solid to facilitate mitigation of cross-talk at the respective wire bonds. It should be appreciated that any suitable magnetic shielding material and wall thickness, height, and depth can be used in combination to reduce cross-talk levels to below -50 dB depending on the desired range of superconducting quantum circuit applications.

[0079] Figure 12 An exemplary non-limiting implementation 1200 for a multi-layer printed circuit board according to one or more embodiments described herein is shown. The multi-layer printed circuit board can be a stacked printed circuit board. Possible dimensions for different layers (e.g., substrate, dielectric layers, metal thickness of transmission lines, etc.) are shown. Note that these values and / or materials are for example purposes only and the disclosed aspects are not meant to be limited to Figure 12 the implementation 1200 shown.

[0080] Figure 13 An exemplary non-limiting via size 1300 according to one or more embodiments described herein is shown. The via size 1300 can be selected to achieve a 50 ohm transition. Note that these values are for example purposes only and the disclosed aspects are not meant to be limited to the via size 1300 shown. The via size 1300 is provided Figure 12 and Figure 13 ​To demonstrate that, in accordance with the various aspects provided herein, various software programs can be utilized to determine whether a particular design can achieve a 50 ohm result.

[0081] Figure 14 A flow diagram illustrating an example, non-limiting method 1400 for fabricating an integrated circuit, in accordance with one or more embodiments described herein is shown. Repetitive description of like elements employed in other embodiments described herein is omitted for sake of brevity.

[0082] When a via (e.g., first via 304, second via 306) in a printed circuit board (e.g., printed circuit board 302) is filled with a transmission line, the method 1400 begins at 1402. The via can include a defined characteristic impedance. Further, at 1404, the printed circuit board is operatively coupled to a microwave quantum circuit (e.g., microwave quantum circuit 312, one or more transmission lines) via wirebonds (e.g., first wirebond 308, second wirebond 314) between a transmission line of the printed circuit board and a transmission line of the microwave quantum circuit. The wirebonds can be configured to convey microwave signals between the printed circuit board and the microwave quantum circuit.

[0083] According to some embodiments, the method 1400 can include, at 1406, attaching a length of the wirebond is determined as a function of a first location (e.g., first location 316, third location 320) of the via and a second location (e.g., second location 318, fourth location 322) of the dielectric substrate.

[0084] In some embodiments, the dielectric substrate can be formed on the printed circuit board. In other embodiments, the dielectric substrate can be at least partially formed inside the printed circuit board.

[0085] In some embodiments, the method 1400 can further include, at 1408, forming a shielding wall (e.g., first shielding wall 1002, second shielding wall 1004) between the wirebond and another wirebond. For example, a first shielding wall can be placed on a first side of the wirebond and a second shielding wall can be placed on a second side of the wirebond. The first shielding wall and the second shielding wall can isolate the wirebond from other adjacent wirebonds.

[0086] As discussed herein, a method for a printed circuit board to dielectric substrate transition is provided with controlled impedance and reduced and / or mitigated crosstalk. The printed circuit board can be designed to reduce and / or mitigate crosstalk between adjacent lines (e.g., wirebonds). One or more vias with a desired characteristic impedance can be inserted inside the printed circuit board. Additionally, short wirebonds (e.g., < 2mm) can provide microwave signal connections from the printed circuit board via to transmission lines on a dielectric substrate (DIE). Furthermore, in alternative embodiments, metal walls can be used to further reduce and / or mitigate crosstalk between wirebonds. In alternative or additional embodiments, additional ground vias can be used to reduce and / or mitigate crosstalk between vias. The method can be used for interconnections of quantum devices and integrated components (e.g., superconductor packages) for cryogenic applications (e.g., attenuators, high electron mobility transistors (HEMTs), low noise amplifiers (LNAs), etc.), without limitation.

[0087] For simplicity of explanation, methods and / or computer-implemented methods are depicted and described as a series of acts. It is to be understood and appreciated that the inventive subject matter is not limited by the acts illustrated and / or by the order of acts, for example acts can occur in various orders and / or concurrently, and with other acts not presented and described herein. Furthermore, not all illustrated acts can be required to implement the computer-implemented methods in accordance with the disclosed subject matter. In addition, those skilled in the art will understand and appreciate the contexts of the computer-implemented methods disclosed and described herein, and it will be understood and appreciated that the computer- implemented methods could be carried out via state machines that change

[0088] To provide context for the various aspects of the disclosed subject matter, Figure 15 and the following discussion is intended to provide a general description of a suitable environment in which the various aspects of the disclosed subject matter can be implemented. Figure 15 A block diagram illustrating an example, non-limiting operating environment in which one or more embodiments described herein can be facilitated is shown. Repetitive description of like elements employed in other embodiments described herein is omitted for sake of brevity. See Figure 15A suitable operating environment 1500 for implementing various aspects of this disclosure can also include the computer 1512. The computer 1512 can also include a processing unit 1514, a system memory 1516, and a system bus 1518. The system bus 1518 couples system components including, but not limited to, the system memory 1516 to the processing unit 1514. The processing unit 1514 can be any of various available processors. Dual microprocessors and other multiprocessor architectures can also be employed as the processing unit 1514. The system bus 1518 can be any of several types of bus structures including a memory bus or memory controller, a peripheral bus or external bus, and / or a local bus using any of a variety of bus architectures such as Industrial Standard Architecture (ISA), Micro Channel Architecture (MSA), Extended ISA (EISA), Intelligent Drive Electronics (IDE), VESA Local Bus (VLB), Peripheral Component Interconnect (PCI), Card Bus, Universal Serial Bus (USB), Advanced Graphics Port (AGP), Firewire (IEEE 1394), and Small Computer Systems Interface (SCSI), among others. The system memory 1516 can also include volatile memory 1520 and nonvolatile memory 1522. The nonvolatile memory 1522 can also include basic input / output system (BIOS), containing the basic routines that help to transfer information between elements within the computer 1512, such as during start-up. By way of illustration, and not limitation, nonvolatile memory 1522 can include read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, or nonvolatile random access memory (RAM) (e.g., ferroelectric RAM (FeRAM)). Volatile memory 1520 can also include random access memory (RAM), which acts as external cache memory. By way of illustration and not limitation, RAM is available in many forms such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), direct Rambus RAM (DRRAM), and Rambus dynamic RAM (RDRAM).

[0089] The computer 1512 can also include removable / non-removable, volatile / non-volatile computer storage media. Figure 15A disk storage 1524 is also depicted. Disk storage 1524 can also include, but is not limited to, devices like a magnetic disk drive, a soft disk drive, a tape drive, a Jaz drive, a Zip drive, an LS-100 drive, a flash memory card, or a Figure 15 Software is also depicted as being used in the described operating environment 1500, which serves to mediate between the user and the basic computer resources described. Such software can also include, for example, an operating system 1528. Operating system 1528, which can be stored on disk storage 1524, acts to control and allocate resources of the computer 1512. System applications 1530 take advantage of the management of the resources by operating system 1528 through program modules 1532 and program data 1534, e.g., stored both on the system memory 1516 and on the disk storage 1524. It is to be appreciated that this disclosure can be implemented with both different operating systems or combinations of operating systems. A user enters commands or information into the computer 1512 through input device(s) 1536. Input devices 1536 include, but are not limited to, a pointing device such as a mouse, trackball, stylus, touchpad, keyboard, microphone, joystick, game pad, satellite dish, scanner, TV tuner card, digital camera, digital video camera, web camera, and the like. These and other input devices connect to the processing unit 1514 through the system bus 1518 via interface port(s) 1538. Interface port(s) 1538 include, for example, a serial port, a parallel port, a game port, and a universal serial bus (USB). Output device(s) 1540 use some of the same type of ports as input device(s) 1536. Thus, for example, a USB port can be used to provide input to computer 1512, and to output information from computer 1512 to an output device 1540. Output adapter 1542 is provided to illustrate that there are some output devices 1540 like monitors, speakers, and printers, among other output devices 1540, that require special adapters. The output adapters 1542 include, by way of illustration and not limitation, video and sound cards that provide a method of connection between the output device 1540 and the system bus 1518. It should be noted that other devices and / or systems of devices provide both input and output capabilities such as remote computer(s) 1544.

[0090] The computer 1512 can operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 1544. The remote computer 1544 can be a computer, a server, a router, a network PC, a workstation, a microprocessor-based appliance, a peer device, or other common network node, and typically includes many or all of the elements described relative to the computer 1512. For purposes of brevity, only a memory storage device 1546 is illustrated with the remote computer 1544. The remote computer 1544 is logically connected to the computer 1512 through a network interface 1548 and then physically connected via a communication connection 1550. The network interface 1548 encompasses wire and / or wireless communication networks such as local-area networks (LAN), wide-area networks (WAN), cellular networks, etc. LAN technologies include Fiber Distributed Data Interface (FDDI), Copper Distributed Data Interface (CDDI), Ethernet, Token Ring and others. WAN technologies include, but are not limited to, point-to-point links, circuit-switching networks like the

[0091] The present application can be a system, a method, an apparatus, and / or a computer program product at any possible technical detail level of integration. The computer program product can include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present application. The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium can be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium include the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.

[0092] The computer readable program instructions described herein can be downloaded to respective computing / processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and / or a wireless network. The network can comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and / or edge servers. A network adapter card or network interface in each computing / processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing / processing device. Computer readable program instructions for carrying out operations of the present application can be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, configuration data for integrated circuitry, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The computer readable program instructions can execute entirely on the user's computing / processing device, partly on the user's computing / processing device, as a stand-alone software package, partly on the user's computing / processing device and partly on a remote computing / processing device or entirely on the remote computing / processing device or server. In the latter scenario, the remote computing / processing device can be connected to the user's computing / processing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate array (FPGA), or programmable logic array (PLA) can execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present application.

[0093] The computer readable program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0094] The flow diagrams and block diagrams in the drawings are described as follows. Each block in the flow diagrams and / or block diagrams can represent a module, a segment, or a portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks can occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and / or flowchart illustrations, and combinations of blocks in the block diagrams and / or flowchart illustrations, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

[0095] While the subject matter has been described above in the general context of computer-executable instructions of a computer program product that runs on a computer and / or computers, those skilled in the art will recognize that the disclosure also can or can not be implemented in combination with other program modules. Generally, program modules include routines, programs, components, data structures, etc. that perform particular tasks and / or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the inventive computer-implemented methods can be practiced with other computer system configurations, including single-processor or multiprocessor computer systems, minicomputers, mainframe computers, as well as computers, hand-held computing devices (e.g., PDA, phone), microprocessor-based or programmable consumer or industrial electronics, etc. The illustrated aspects can also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. However, some, if not all, aspects of this disclosure can be practiced on stand-alone computers. In a distributed computing environment, program modules can be located in both local and remote memory storage devices.

[0096] As used in this application, the terms "component," "system," "platform," "interface," and the like can refer to and / or can include a computer-related entity or an entity that is related to an operational machine with one or more specific functionalities. The entities disclosed herein can be either hardware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and / or a computer. By way of illustration, both an application running on a server and the server can be a component. One or more components can reside within a process and / or thread of execution and a component can be localized, co-resident, and / or distributed amongst one computer and / or across multiple computers. In another example, a component can execute from various computer readable media having various data structures stored thereon. The components can communicate via local and / or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and / or across a network such as the Internet with other systems via the signal). As another example, a component can be an apparatus with specific functionality provided by mechanical parts operated by electric or electronic circuitry, which is operated by a software or firmware application executed by a processor. In such a case, the processor can be internal or external to the apparatus and can execute at least a part of the software or firmware application. As yet another example, a component can be an apparatus that provides specific functionality through electronic components without mechanical parts, wherein the electronic components can include a processor or other means for executing software or firmware that confers at least in part the functionality of the electronic components. In an aspect, a component can emulate an electronic component via a virtual machine, for example, within a cloud computing system.

[0097] Furthermore, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise, or clear from context, "X employs A or B" is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then "X employs A or B" is satisfied under any of the foregoing instances. Moreover, articles "a" and "an" as used in the subject specification and annexed drawings should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. As used herein, the terms "example" and / or "exemplary" are utilized to mean serving as an example, instance, or illustration. For the avoidance of doubt, the subject matter disclosed herein is not limited by such examples. In addition, any aspect or design described herein as an "example" and / or "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs, nor is it meant to preclude equivalent exemplary structures and techniques known to those of ordinary skill in the art.

[0098] As employed in the subject specification, the term "processor" can refer to substantially any computing processing unit or device comprising single-core processors; single-processors with software multithread execution capability; multi-core processors; multi-core processors with software multithread execution capability; multi-core processors with hardware multithread technology; parallel platforms; and parallel platforms with distributed shared memory. Additionally, a processor can refer to an integrated circuit, an application specific integrated circuit (ASIC), a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic controller (PLC), a complex programmable logic device (CPLD), a discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. Further, processors can utilize nano- scale architectures such as, but not limited to, molecular and quantum-dot based transistors, switches and gates, in order to optimize space usage or enhance performance of user equipment. A processor can also be implemented as a combination of computing processing units. In the present disclosure, terms such as "store," "storage," "data store," data storage," "database," and substantially any other information storage component relevant to operation and functionality of a component are utilized to refer to "memory components," entities embodied in a "memory," or components comprising a memory. It is appreciated that memory and / or memory components described herein can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. By way of illustration, and not limitation, nonvolatile memory can include read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable ROM (EEPROM), flash memory, or nonvolatile random access memory (RAM) (e.g., ferroelectric RAM (FeRAM)). Volatile memory can include RAM, which, as

[0099] The foregoing description of implementations has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to be limited to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the embodiments described herein be limited not by this detailed description, but rather by the claims of this document.

Claims

1. A quantum device, comprising: a microwave quantum circuit on a dielectric substrate; and a printed circuit board comprising a via, the via comprising a first transmission line; a shield wall between a wire bond and another wire bond, wherein the wire bond is a wire bond between the first transmission line of the printed circuit board and a second transmission line of the microwave quantum circuit and one end of the wire bond is connected to the via at a location of the via, the wire bond operably coupling the microwave quantum circuit to the printed circuit board, and wherein the via comprises a characteristic impedance defined by dimensions of the via such that continuity of the characteristic impedance is maintained via a transition between the first transmission line and the second transmission line of the wire bond, the shield wall is a type-I superconductor material.

2. The quantum device of claim 1, wherein a length of the wire bond is based on the location of the via and a second location of the dielectric substrate.

3. The quantum device of claim 1, wherein the dielectric substrate is formed on the printed circuit board.

4. The quantum device of claim 1, wherein the dielectric substrate is at least partially formed inside the printed circuit board.

5. The quantum device of claim 1, further comprising: a lid supporting the printed circuit board and the dielectric substrate.

6. The quantum device of claim 1, further comprising a lid on the printed circuit board and the dielectric substrate.

7. The quantum device of claim 1, a length of the shield wall is at least 5 times a length of an extension of the wire bond.

8. The quantum device of claim 1, a height of the shield wall is at least 2 times a height of the wire bond.

9. The quantum device of claim 1, wherein the printed circuit board comprises a ground via that reduces crosstalk between the via and another via.

10. The quantum device of claim 1, the quantum device is a superconductor quantum computing device.

11. A method for fabricating an integrated circuit, comprising: filling a via in a printed circuit board with a first transmission line, wherein the via comprises a characteristic impedance defined by dimensions of the via; operably coupling the printed circuit board to a microwave quantum circuit on a dielectric substrate via a wire bond between the first transmission line of the printed circuit board and a second transmission line of the microwave quantum circuit, one end of the wire bond being connected to the via at a location of the via, and wherein with the defined characteristic impedance, continuity of the characteristic impedance is maintained via a transition between the first transmission line and the second transmission line of the wire bond; and forming a shield wall between the wire bond and another wire bond, the shield wall is a type-I superconductor material.

12. The method of claim 11, wherein operably coupling the printed circuit board to the microwave quantum circuit comprises: attaching a length of the wire bond to the printed circuit board and the microwave quantum circuit, wherein the length is determined as a function of a first location of the via and a second location of the microwave quantum circuit.

13. The method of claim 11, further comprising: forming the dielectric substrate on the printed circuit board.

14. The method of claim 11, further comprising: forming the dielectric substrate at least partially inside the printed circuit board.

15. The method of claim 11, further comprising: placing the printed circuit board and the dielectric substrate on a lid, wherein the lid supports the printed circuit board and the dielectric substrate.

16. The method of claim 11, wherein the wire bonds are configured to transmit microwave signals from the via to the dielectric substrate.

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