JP7095136B2 - Flexible wiring for low temperature applications - Google Patents

Description

The present disclosure relates to flexible wiring for low temperature applications such as quantum processors using superconducting qubits.

Quantum computing is a relatively new computing method that utilizes quantum effects such as ground state superposition and entanglement to perform specific calculations more efficiently than traditional digital computers. In contrast to digital computers, which store and manipulate information in the form of bits (eg, "1" or "0"), qubits can be used to manipulate information. A qubit can refer to a quantum device that allows superposition of multiple states (eg, data in both "0" and "1" states) and / or superposition of the data in multiple states themselves. can. According to conventional terms, the superposition of "0" and "1" states in a quantum system can be represented, for example, as α | 0> + β | 1>. The "0" and "1" states of a digital computer are similar to the | 0> and | 1> ground states of a qubit, respectively. The value | α | ² represents the probability that the qubit is in the | 0> state, and the value | β | ² represents the probability that the qubit is in the | 1> ground state.

In general, in some embodiments, the subject matter of the present disclosure is an elongated flexible substrate, a plurality of conductive traces arranged in an array on the first side of the elongated flexible substrate, and a second side of the elongated flexible substrate. It can be embodied in devices such as flexible wiring that include an electromagnetic shielding layer, the second side is on the opposite side of the first side, and the elongated flexible substrate has the electromagnetic shielding layer with the first conductive trace and the first. A folding region is included between the first conductive trace and the second conductive trace so as to provide electromagnetic shielding between the two conductive traces.

The device implementation may include one or more of the following functions: For example, in some implementations, the folding region contains a raised band in the flexible substrate, and the length of the elongated raised band extends parallel to the length of the first conductive trace and the second conductive trace. ..

In some implementations, the flexible wiring includes a first elongated groove in the folding region, where the length of the first elongated groove is the length of the first conductive trace and the length of the second conductive trace. It is parallel.

The first elongated groove may extend to the first side or the second side of the elongated flexible substrate. The flexible wiring may include a second elongated groove in the folding region, the length of the second elongated groove being parallel to the length of the first conductive trace and the length of the second conductive trace, the first. The elongated groove is on the first side of the substrate and the second elongated groove is on the second side of the substrate. The first elongated groove may extend to the electromagnetic shielding layer. The first elongated groove may extend into an elongated flexible substrate.

In some implementations, the conductive trace of at least one of the plurality of conductive traces comprises a double layer, the double layer having a superconductor layer and a metal layer on the superconductor layer. The superconductor layer may contain niobium or NbTi. The metal layer may include copper or a copper alloy.

In some implementations, the electromagnetic shielding layer comprises a bilayer, which comprises a superconductor layer and a metal layer on the superconductor layer. The superconductor layer may contain niobium or NbTi. The metal layer may include copper or a copper alloy.

In some embodiments, the electromagnetic shielding layer comprises a plurality of microstrips having lengths oriented orthogonal to the length of the plurality of conductive traces.

In general, in some other aspects, the subject matter of the present disclosure is a first elongated flexible layer, a second elongated flexible layer joined to the first elongated flexible layer, a first elongated flexible layer and a first. A plurality of conductive traces arranged at a bond interface between two elongated flexible layers, a first electromagnetic shielding layer on the main surface of the first elongated flexible layer, and a second elongated flexible layer. Vias extending through a second electromagnetic shielding layer on the main surface of the layer and a first elongated flexible layer, embodied in devices such as flexible wiring, including vias including superconductor via contacts. Can be done.

Flexible wiring implementations may include one or more of the following functions: For example, in some implementations, vias include an adhesive layer and superconductor via contacts are formed on the adhesive layer.

In some embodiments, the via extends from the first electromagnetic shielding layer to at least one of the plurality of conductive traces, and the superconductor via contact is with the first electromagnetic shielding layer and at least one. Connected to two conductive traces.

In some implementations, vias extend from the first electromagnetic shielding layer to the second electromagnetic shielding layer, and superconductor via contacts are connected to the first electromagnetic shielding layer and at least one conductive trace. Beer.

In general, in other aspects, the subject matter of the present disclosure is a first elongated flexible substrate and a first plurality of conductive traces arranged in an array on the first side of the first elongated flexible substrate. A first electromagnetic shielding layer on the second side of one elongated flexible substrate, wherein the second side of the first elongated flexible substrate is on the opposite side of the first side of the first elongated flexible substrate. A first flexible wiring provided with a first electromagnetic shielding layer, a second elongated flexible substrate, and a second plurality of conductive pieces arranged in an array on the first side of the second elongated flexible substrate. The trace and the second electromagnetic shielding layer on the second side of the second elongated flexible substrate, the second side of the second elongated flexible substrate is opposite to the first side of the second elongated flexible substrate. It can be embodied in a device comprising a second flexible wiring, including a second electromagnetic shielding layer on the side, the first flexible wiring being coupled to the second flexible wiring through butt junction.

The device implementation may include one or more of the following functions: For example, in some implementations, the butt joint is a wire that connects the first conductive trace from the first plurality of conductive traces to the first conductive trace from the second plurality of conductive traces. Including bond.

In some implementations, the butt joint provides a solder bridge that connects the first conductive trace from the first plurality of conductive traces to the first conductive trace from the second plurality of conductive traces. include.

In some embodiments, the device comprises a first electromagnetically shielded layer and a metal block that is fixed and in thermal contact with the second electromagnetically shielded layer.

In general, in other aspects, the subject matter of the present disclosure is a first elongated flexible substrate, a first plurality of conductive traces located at a junction interface within the first elongated flexible substrate, and a first elongated flexible substrate. A first flexible wiring comprising a first electromagnetic shielding layer on a first main surface of a substrate and a second electromagnetic shielding layer on a second main surface of a first elongated flexible substrate. Two elongated flexible substrates, a second plurality of conductive traces located at the junction interface within the second elongated flexible substrate, and a third electromagnetic shield on the first main surface of the second elongated flexible substrate. It can be embodied in a second flexible wiring device, including a layer and a fourth electromagnetic shielding layer on the second main surface of the second elongated flexible substrate, the first flexible wiring through butt junction. It is electrically connected to the second flexible wiring.

The device implementation may include one or more of the following functions: For example, in some implementations, the first elongated flexible substrate comprises a first cavity in which the first conductive traces of the first plurality of conductive traces are exposed, and the second elongated flexible substrate. , A second cavity to which the first conductive trace of the second plurality of conductive traces is exposed. The butt joint may include a wire bond connecting the exposed first conductive trace of the first plurality of conductive traces to the exposed first conductive trace of the second plurality of conductive traces.

In some implementations, the butt joint is a solder that connects the exposed first conductive trace of the first plurality of conductive traces to the exposed first conductive trace of the second plurality of conductive traces. May include bridges.

In some embodiments, the device further comprises a first electromagnetic shielding layer and a first metal block that is fixed and in thermal contact with the third electromagnetic shielding layer. The device may further include a second electromagnetic shielding layer and a second metal block that is fixed and in thermal contact with the fourth electromagnetic shielding layer.

In general, in other aspects, the subject matter of the present disclosure is a cryostat comprising a first stage configured to be kept within a first temperature range, a quantum information processing system within the first stage, and a first. Within step 1 and can be embodied in a system that includes flexible wiring coupled to a quantum information processing system, the flexible wiring is arranged in an array on the elongated flexible substrate and the first side of the elongated flexible substrate. Can be embodied in devices such as flexible wiring, including multiple conductive traces and an electromagnetic shielding layer on the second side of an elongated flexible substrate, the second side being opposite to the first side and elongated. The flexible substrate is provided between the first conductive trace and the second conductive trace so that the electromagnetic shielding layer provides electromagnetic shielding between the first conductive trace and the second conductive trace. Includes folding area.

In general, in other aspects, the subject matter of the present disclosure is a cryostat comprising a first stage configured to be kept within a first temperature range, a quantum information processing system within the first stage, and a first. Within step 1, it can be embodied in a system that includes flexible wiring coupled to a quantum information processing system, the flexible wiring being joined to a first elongated flexible layer and a first elongated flexible layer. A plurality of conductive traces arranged at the junction interface between the two elongated flexible layers and the first elongated flexible layer and the second elongated flexible layer, and the first on the main surface of the first elongated flexible layer. And vias that extend through the electromagnetic shielding layer, the second electromagnetic shielding layer on the main surface of the second elongated flexible layer, and the first elongated flexible layer, including the superconductor via contact. including.

Certain embodiments of the subject matter described herein can realize one or more of the following advantages: For example, in some implementations, the folded area of the flexible wiring provides electromagnetic shielding between signal traces. Shielding can reduce crosstalk without the need to form via holes in the substrate. In some implementations, once the vias are provided in the substrate, the vias can be filled with a superconducting material (eg, niobium) that allows for improved signal integrity and reduced crosstalk. Furthermore, since superconducting materials do not exhibit DC resistance, via metals do not lead to resistance heating. In some embodiments, flexible wiring significantly increases the number and density of wires that can be connected to devices contained within the cryostat (eg, quantum information processing systems) compared to devices that use coaxial cables. Will be possible. Moreover, by using flexible wiring instead of coaxial cable, the space required by coaxial cable can be freed for purposes other than providing electrical connectivity. In some implementations, flexible wiring utilizes materials such as copper, copper alloys (eg brass), or superconductors (eg NbTi) that provide relatively low thermal conductivity and thus low thermal load. do. Moreover, in some implementations, the manufacturing costs associated with flexible wiring may be lower per wire than equipment that relies on coaxial cable. In some implementations, butt joints can be used instead of coaxial cable connectors to join flexible wiring to other flexible wiring. By using butt joints instead of coaxial cable connectors, multiple connections can be established. Also, butt joints can free up space in cryostats that would otherwise be used by coaxial cable connectors. Moreover, in some implementations, butt joints provide a lower cost manufacturing technique than soldering circuit boards, especially when a large number of connections need to be made.

Details of one or more implementations are given in the accompanying drawings and the following description. Other features and advantages will become apparent from the description, drawings, and claims.

It is a schematic diagram which shows an example of the cooling system for cooling a quantum information processing system. It is a schematic diagram which shows an example of flexible wiring. It is a schematic diagram which shows an example of flexible wiring. It is a schematic diagram which shows an example of flexible wiring. It is a schematic diagram which shows an example of flexible wiring. It is a schematic diagram which shows an example of the modified butt-joining bond for flexible wiring. It is a schematic diagram which shows an example of the modified butt-joining bond for flexible wiring. It is a side view of the flexible wiring shown in FIG. 7A.

In quantum computing, it is necessary to coherently process quantum information stored in a qubit of a quantum computer. Superconducting quantum computing is a promising implementation of solid-state quantum computing technology in which quantum information processing systems are partially formed from superconducting materials. In order to operate a quantum information processing system that employs solid-state quantum computing technology such as superconducting qubits, the system is maintained at a very low temperature, for example, several tens of mK. Extreme cooling of the system helps keep the superconducting material below the critical temperature and avoids unwanted state transitions. To maintain such a low temperature, the quantum information processing system may be operated in a cryostat such as a dilution refrigerator. In some embodiments, the limited cooling capacity of such cryostats is available at much higher cooling capacity, and the higher temperatures are less likely to cause the dissipative circuit to disturb the qubits in the quantum information processing system. It is necessary that the control signal is generated in the environment of. The control signal can be transmitted to the quantum information processing system using a shielded impedance controlled GHz capable transmit line such as a coaxial cable.

The number of qubits used in quantum information processing systems is expected to increase significantly in the near future (eg, tens of thousands, hundreds of thousands, millions or more). As the number of qubits increases, so does the number of transmission lines (eg, control lines and data lines) needed to drive the qubits and to read the output from the operations performed by the quantum information processing system. May increase.

The present disclosure is intended for wiring for low temperature applications such as superconducting quantum information processing systems, and in certain implementations, wiring results in significant transmission line density while maintaining low crosstalk and low thermal load between transmission lines. It will be possible to increase to. Moreover, the devices and methods disclosed herein may provide a low cost alternative to bulky transmission lines such as coaxial cables in certain implementations.

FIG. 1 is a schematic diagram showing an example of a cooling system 100 for cooling a quantum information processing system. An exemplary cooling system 100 includes a cryostat 102 that may include a quantum information processing system 110. The cryostat 102 cools the ambient environment surrounding the quantum information processing system 110 to a temperature suitable for performing operations in the system 110. For example, in an embodiment in which the quantum information processing system 110 includes a quantum processor having superconducting qubits, the cryostat 102 sets the ambient environment surrounding the quantum processor to a temperature below the critical temperature of the superconducting material, for example, about 20 mK. , Or can be cooled to about 10 mK. Examples of superconducting materials that can be used in superconducting quantum information processing systems include Al (Tc = 1.2K), In (Tc = 3.4K), and Nb (Tc = 9.3K). The cryostat 102 may be cooled with a liquid or gaseous cryogen such as helium and nitrogen, or with a closed cycle cryocooler using helium gas. In some cases, the circuit elements of the quantum information processing system 110 operate at microwave frequencies (for example, frequencies in the range of about 300 MHz to about 100 GHz, such as between about 300 MHz and 10 GHz). Therefore, the cryostat 102 may include external and internal electromagnetic shielding to block interference with the quantum information processing system 110.

In some embodiments, the cryostat comprises multiple thermally separated stages over large temperature differences (eg, different stages of the dilution refrigerator). For example, the exemplary cryostat 102 includes a plurality of stages 101, 103, and 105. The first step 101 can be maintained in the first temperature range T1, the second step 103 can be maintained in the second temperature range T2 lower than the first temperature T1, and the third step 105 can be maintained in the second temperature range T2. It can be maintained in a third temperature range T3, which is lower than the temperature T2. For example, the third temperature range T3 may be less than or equal to the critical temperature Tc of the superconducting material used in the quantum information processing system 110, for example, T2 ≈ 10 to 20 mK. In contrast, the second step 103 can be maintained at a higher temperature than the third step 105. For example, the second step 103 may be maintained within the temperature range T2 below 3K and above 20mK. The first step 101 can be maintained within a higher temperature range than the second step 103. For example, the first step 101 may be maintained within the temperature range T1 below 300K and above 3K. Although only three stages are shown in the example of FIG. 1, the cryostat can include additional stages at different temperature levels. For example, in some cases, the cryostat may include fourth and fifth steps held within a fourth temperature range T4 and a fifth temperature range T5, respectively. Each temperature step of the cryostat usually spans several centimeters, for example, to the next temperature step.

Each stage within the cryostat 102 can be separated by boundaries 104, 106. Boundaries 104, 106 may include a thermal sink held at a constant temperature. The stage of cryostat 102 is operated in a vacuum environment. For example, the first step 101, the second step 103, and the third step 105 can be operated under a vacuum base pressure of about 1 × ^10-7 Torr or less. The quantum information processing system 110 may include a substrate on which a quantum information processing device such as a qubit is formed (for example, a dielectric substrate such as silicon or sapphire). The qubits may be coupled to each other during the operation of the system 110 so that the qubits perform useful calculations. In addition to the qubit, the quantum information processing system 110 may include other components such as a measurement and readout device, a coupler device for coupling the qubit, and a control device for driving and adjusting the qubit. The quantum information processing system 110 may be arranged and / or fixed to the sample mount 112 in the third stage 105.

In order to control the quantum information processing system 110 and read data from it, the quantum information processing system 110 may be coupled to a control electronic device 150 located outside the cryostat 102. In the example shown in FIG. 1, the control electronic device 150 is coupled to the quantum information processing system 110 in the cryostat 102 using flexible wiring 114, 116. The signal generated by the control electronic device 150 or the quantum information processing system 110 is transmitted via the flexible wirings 114 and 116. Flexible wiring 114, 116 includes, for example, a plurality of conductive wires on or inside an elongated flexible substrate. Flexible wiring 114, 116 may include electromagnetic shielding to protect the wire from signal interference. Further, the wires in the wirings 114, 116 may be impedance matched to the quantum information processing system 110 and the control electronics 150 in order to reduce signal reflection from the load.

Each flexible wiring 114, 116 may include a plurality of individual wires. The individual wires may extend along the length (long dimension) of the flexible wiring 114, 116 and may be arranged in an array (eg, the wires extend parallel along the length of the flexible wiring 114, 116). You can). The total number of wires in or on flexible wiring may vary. For example, each flexible wiring 114, 116 may include 10 or more wires, 20 or more wires, 30 or more wires, 50 or more wires, 100 or more wires, or 200 or more wires. Similarly, other numbers of wires may be used within each flexible wiring 114, 116. Each flexible wiring can be coupled to another flexible wiring so that data and control signals can be transmitted from one flexible wiring to another. For example, the flexible wiring 114 may be coupled to the flexible wiring 116. In some implementations, the first set of at least two flexible wirings is coupled to the second set of at least two flexible wirings, respectively. For example, a first set of 5, 10, 15, 20 or more flexible wiring may be coupled to a second set of 5, 10, 15, 20 or more flexible wiring, respectively. Other numbers of flexible wires may be coupled together. In the first and / or second set, the flexible wires in the set may be stacked directly on each other, or the individual flexible wires in the stack may be separated from each other using spacers (eg, spacers of 2-10 mm). You may. The advantage of forming multiple wires within a flexible wiring and / or using multiple flexible wirings is that in some implementations, the flexible wiring footprint is smaller and the wire density is higher, resulting in quantum information processing. It is possible that the total number of connections between the system and the control electronics can be significantly increased compared to devices that rely on coaxial cables. In some implementations, the short portion of the flexible wiring 114, 116 is fixed somewhere within the boundaries 104, 106 or cryostat 102 to heat sink the flexible wiring 114, 116. For example, wiring 116 may be secured to a thermal sink held at a temperature of 3K at boundary 104. Similarly, the wiring 114 may be secured to a thermal sink maintained at a temperature of 20 mK at the boundary 106. In contrast, the distance between the boundaries of the wires 114, 116 is much longer than the clamp length to reduce the flow of thermal energy.

FIG. 2 is a schematic diagram illustrating an example of flexible wiring that can be used in low temperature applications, including, for example, coupling to a quantum information processing system in a cryostat such as the cryostat 102. A plan view of the upper surface of the flexible wiring 200 and a cross-sectional view of the flexible wiring 200 along the lines AA are shown in FIG. As shown in the plan view, the flexible wiring 200 includes an elongated flexible substrate 202. The flexible wiring 200 also includes a plurality of conductive traces 204 arranged on the main surface (eg, top or top) of the elongated flexible substrate 202. Each conductive trace 204 corresponds to an individual wire, and a plurality of traces 204 may be arranged in an array. For example, the conductive traces 204 may be arranged in parallel such that their length dimensions (eg, their length) extend along the length dimension (length) of the elongated flexible substrate 202. The spacing between adjacent traces 204 can be the same for each pair of adjacent traces 204.

The elongated flexible substrate 202 can be formed from a flexible plastic ribbon such as a polyimide ribbon. Examples of materials that can be used for the elongated flexible substrate 202 include, for example, poly (4,4'-oxydiphenylene-pyromellisimide) (also referred to as Kapton®). The thickness of the elongated flexible substrate 202 can be, for example, between about 10 μm and about 500 μm, including, among other things, thicknesses such as about 20 μm, 50 μm, 75 μm, and 100 μm. The width of the elongated flexible substrate 202 can be, for example, between about 1 mm and about 30 mm, including, for example, widths such as, among other things, 10 mm, 15 mm, and 20 mm. The length of the elongated flexible substrate 202 can be at least the length required to provide coupling between devices, systems, and / or other wiring.

The conductive trace 204 contains a thin film material that can be patterned on an elongated flexible substrate 202. The conductive trace 204 may include, for example, a single layer of material or two layers of material. Materials that can be used to form the conductive trace 204 may include superconducting materials and / or non-superconducting metals. Examples of materials that can be used to form the conductive trace 204 include, for example, copper, copper alloys (cupronickel, brass, bronze), aluminum, indium, NbTi, NbTi alloys, and / or niobium. In some cases, it may be advantageous to use a copper alloy with low thermal conductivity, as copper may have too high a thermal conductivity, otherwise heat transport may be higher. .. This helps reduce the lower thermal power load so that the cryostat maintains the low temperatures required for the operation of the quantum information processing system 110. In the case of a two-layer trace, the trace 204 is formed on the elongated flexible substrate 202 and on the first layer formed in contact with the first layer, and on the first layer and in contact with the first layer. May include layers of. The first layer of the two-layer trace may contain a superconducting material such as niobium and the second layer of the two-layer trace may contain a non-superconducting material such as copper or a copper alloy. To improve the adhesion of the metal or superconductor to the surface of the substrate 202, for example, in the case of a polyimide substrate, the substrate 202 can be ion-milled. Alternatively, the first layer of the two-layer trace may contain a non-superconducting material such as copper and the second layer of the two-layer trace may contain a superconducting material such as niobium or aluminum. In some implementations, the material used to form the conductive traces may depend on where the flexible wiring is used in the cryostat. In the lowest temperature regions, such as between 3K and 10mK (eg, where quantum information processing systems can be located), flexible wiring can be formed using materials with low loss tangents and low thermal transport. In such cases, the conductive trace can be formed from a superconductor such as niobium. In the high temperature regions of the cryostat (eg, where the wiring transitions from low temperature to room temperature), such as temperatures above 3K, flexible wiring can be formed of materials that are not superconducting but have lower heat transfer, such as copper alloys. However, high temperature superconductors (eg, Nb) can also be used. In addition, in some implementations, the material forming the trace may be selected for its role in providing the solder connection. For example, copper may be used in areas where wire bonds or other solder bonds are required.

The length of the conductive trace 204 can be the same as the length of the elongated flexible substrate 202. The width of each conductive trace 204 can be, for example, between about 1 μm and about 250 μm, including widths such as 5 μm, 10 μm, 20 μm, 30 μm, 50 μm, or 100 μm, among others. In some implementations, the width of the conductive trace is selected to provide a predetermined impedance, such as an impedance of 50 ohms, or an impedance of 75 ohms to reduce signal reflection from the load. .. The thickness of each conductive trace 204 can be, for example, between about 10 μm and about 100 μm, including, among other things, thicknesses such as 50 nm, 100 nm, 250 nm, 500 nm, 750 nm, 1 μm, 5 μm, 10 μm, 20 μm, 50 μm. In the case of two layers of conductive traces, the thickness of each layer may be the same or different. For example, in some implementations, the thickness of the first layer is 2 μm, whereas the thickness of the second layer is 5 μm. Alternatively, in some cases, the thickness of the first layer is 20 μm, while the thickness of the second layer is 5 μm. The conductive trace 204 may be separated at a constant or variable pitch. For example, in some implementations, the pitch between adjacent conductive traces 204 is between about 1 μm and about 1 mm, including pitches such as 5 μm, 10 μm, 50 μm, 100 μm, 250 μm, 500 μm, or 750 μm, among others. .. The conductive trace 204 may be formed on an elongated flexible substrate 202 using integrated chip (IC) manufacturing techniques such as deposition (eg, sputtering and deposition), etching, and / or lift-off techniques.

As shown in sectional views AA of FIG. 2, the flexible wiring 200 includes a conductive layer 208 on the second main surface / bottom surface of the elongated flexible substrate 202, and the second main surface is the first main surface. / The opposite side of the top surface. The conductive layer 208 can be an electromagnetic shielding layer for shielding the conductive trace 204 from crosstalk. The flexible substrate 202 includes a folding region 206 so that the electromagnetic shielding layer 208 can provide shielding between the traces 204. The folding region 206 includes an region of the flexible substrate 202 in which the substrate 202 is folded so that an elongated raised band is provided. The elongated raised band of the folding region 206 may have a length extending between and along the conductive traces 204. For example, the elongated ridge band of the folding region 206 may extend parallel to the conductive trace 204 in the space between adjacent conductive traces 204. The raised band can be formed by folding the flexible substrate onto itself in a manner similar to pleats. In some implementations, the peak or apex of the raised band extends over the top surface of the conductive trace 204 (eg, the surface of the trace 204 facing away from the substrate 202). With the substrate 202 thus folded, the electromagnetic shielding layer 208 of the folding region 206 creates an elongated arc that acts as a wall extending between adjacent traces 204. The span of the arc of each folding region 206 is shown by two parallel dashed lines in the plan view of FIG. Further, the peak or apex of the elongated arc in the folding region 206 may extend over the top surface of the conductive trace 204. As a result, the electromagnetic shielding layer 208 within the folding region 206 provides an electromagnetic barrier between adjacent traces to shield crosstalk between traces. As shown in the cross-sectional view of FIG. 2, the folding region 206 appears as raised fins, giving the flexible wiring an accordion-like shape. The folding region 206 shown in FIG. 2 includes a portion of the first main surface of the flexible substrate on which the conductive trace 204 is not formed. In other mounting embodiments, the folding region 206 may include a portion of the first main surface of the substrate 202 on which the conductive trace 204 is formed. The advantage of introducing folding area 206 is that it provides shielding between traces without providing external shielding for the wires or forming shielding within substrate 202, as may be required for stripline design. It is possible to provide. In some implementations, the folding region 206 has a crosstalk between adjacent conductive traces of 20 to 20-as compared to a flexible wiring having a conductive trace formed on a first main surface without a folding region. Reduce by 60 dB or more.

To hold the folded area in place so that the board does not return to its initial flat state, to introduce the mechanical stress that helps to keep the folded shape, the board and / or the electromagnetic shielding layer 208. It can be fixed. FIG. 3 is a schematic diagram showing an example of a flexible wiring 250 including a groove region for introducing mechanical stress to hold a folded region in place. Like the wiring 200, the flexible wiring 250 includes an elongated flexible substrate 202, a conductive trace 204 on the first main surface of the substrate 202, and an electromagnetic shielding layer 208 on the second main surface of the substrate 202. .. The various material and dimensional parameters described herein for wiring 200 may also apply to wiring 250. The difference between the wiring 250 (shown in the plan view and the sectional view along the line AA in FIG. 3) and the wiring 200 in FIG. 2 is that the wiring 250 is provided to help illustrate the grooves formed in the folding region. It is shown in a flat state. When the substrate 202 is folded to provide a folding area, the grooves may provide mechanical stress to hold the folding area in place.

In some mounting embodiments, the groove, eg, the groove 210, is formed in the first main surface of the substrate 202. The length of the groove 210 extends parallel to the length of one or more adjacent conductive traces 204 (eg, along the X direction in FIG. 3). The groove 210 may have various different depths to the substrate 202. For example, the groove depth can range from about 1 μm to about 500 μm, such as 10 μm, 20 μm, 50 μm, 70 μm, 100 μm, 200 μm, 250 μm, 300 μm, or 400 μm, among other depths. The groove 210 can have a variety of different widths. For example, the width of the groove can range from about 10 μm to about 1 mm, such as 20 μm, 50 μm, 100 μm, 250 μm, 500 μm, or 750 μm, among other widths. The groove 210 may extend over the entire length of the elongated flexible substrate 202, or may extend to a length shorter than the overall length of the elongated flexible substrate. In the example of FIG. 3, each groove 210 is shown as a single continuum extending between adjacent conductive traces 204. In other embodiments, multiple separate individual grooves may be formed between the conductive traces 204, whether arranged in a single line or a series of lines (eg, a two-dimensional array).

In some mounting embodiments, the groove, eg, the groove 212, is formed in the second main surface of the substrate 202. The same changes in groove depth, width length, and arrangement described herein with respect to the groove 210 may apply to the groove 212. The electromagnetic shielding layer 208 may cover the groove formed in the second main surface of the flexible substrate 202. As shown in the cross-sectional view along line AA of FIG. 3, the groove 212 may be located between adjacent conductive traces 204, for example along the Y axis. In some implementations, the groove 212 is formed in the electromagnetic shielding layer 208 instead of the second main surface of the substrate 202, as shown in FIG. That is, the electromagnetic shielding layer 208 can be patterned (eg, through photolithography and etching or lift-off processes) such that the openings are formed only within the electromagnetic shielding layer, not within the substrate 202. The groove depth may completely penetrate the electromagnetic shielding layer 208, or may partially penetrate the electromagnetic shielding layer 208. In some implementations, the grooves extend through the electromagnetic shielding layer 208 to the second main surface of the flexible substrate 202, as indicated by the grooves 214 separated by dashed lines in the cross-sectional view of FIG.

Grooves are made into the flexible substrate 202 using photographic processing techniques (eg, spin-coated resist on substrate 202, exposure and development of patterns in the resist, and etching of exposed areas of substrate 202 to form grooves). Can be formed. In other embodiments, the grooves may be formed by user laser machining (eg, polyimide laser drilling techniques).

In some implementations, the folded area of the flexible wiring may be held in place by placing the electromagnetic shielding layer on a plurality of strips extending across the second main surface of the elongated flexible substrate. Strips may be used in place of or in addition to the grooves described herein. For example, it is a schematic diagram which shows an example of a flexible wiring 300. Specifically, FIG. 4 includes a plan view of a second main surface of the flexible wiring board 302 on which the electromagnetic shielding layer 308 is formed, and a cross-sectional view taken along the line AA through the board 302. In the plan view of FIG. 4, the positions, boundaries, and arrangements of the conductive traces 304 formed on the first main surface of the substrate 302 are shown using dashed lines. The flexible wiring 300 is shown in a flat state, that is, in a state in which a folding region has not yet been formed.

As shown in FIG. 4, the electromagnetic shielding layer 308 is arranged on a plurality of separate strips having a length extending along the Y direction. When the substrate 302 is folded to provide a folding area, the shielding layer strip 308 may provide mechanical stress to hold the folding area in place. As further shown in the plan view of FIG. 4, the length of the strip 308 extends along a direction (Y direction) orthogonal to the direction (X direction) in which the length of the conductive trace 304 extends. The advantage of using separate strips to form the electromagnetic shielding layer 308 is that overall heat transport can be reduced due to the use of materials with low thermal conductivity to provide the shielding layer.

Alternatively, in some embodiments, the strip may be formed in addition to the ground layer rather than as a ground layer. For example, a tread layer such as layer 208 may be provided on a second main surface of an elongated flexible substrate to provide a tread, and multiple strips such as strip 308 may provide mechanical stability. Can be formed on the surface of the ground plane layer. For example, the tread layer may be formed from niobium, while the strips formed on the surface of the tread layer may be made from copper. The dimensions described herein with respect to layer 208 may also apply to the ground plane layer. Similarly, the dimensions and spacing described herein for strip 308 may also apply to strips formed in the tread layer.

In some implementations, the number of wires contained within the flexible wiring can be increased by stacking the flexible wiring. For example, to provide laminated flexible wiring, any of the flexible wiring 200, 250, or 300 can be stacked together. In some cases, flexible wiring can be stacked together using an adhesive-based or adhesive-free laminate bonding technique (eg, application of heat and / or pressure to join the polyimide layers). In certain implementations, the use of adhesiveless polyimide bonds may be advantageous in order to eliminate adhesives that may cause degassing in a vacuum environment. In addition, adhesive-free laminates can have a CTE that closely matches the coefficient of thermal expansion (CTE) of copper, thus significantly increasing the temperature when cooling to extremely low temperatures, such as those used in cryostats. Reduces the stress between the substrate and the shield / trace caused by the changes. In some cases, a polymer capsule material sprayed or painted on the first elongated polymer substrate containing a conductive trace / shielding layer can be used to form laminated flexible wiring. For example, in some cases, flexible wiring such as wiring 200, 250, 300 may be sprayed or painted with an epoxy capsule material (eg, Stycast2850FT), then cured to provide an additional polymer layer, and further conductive on it. Sexual materials can be deposited and patterned.

In contrast to the flexible wiring shown in FIGS. 2-4, in some implementations the flexible wiring can be formed as striplines. FIG. 5 is a schematic view showing an example of the flexible wiring 500 formed in the stripline configuration. The flexible wiring 500 includes a signal trace 506 disposed between the first elongated flexible substrate portion 502 and the second elongated flexible substrate portion 504. The signal trace 506 may include a conductive thin film material for transmitting control and / or data signals. The upper surface of the first elongated flexible substrate portion 502 (eg, the first main surface) may include the first conductive layer 508, while the bottom surface of the second elongated flexible substrate portion 504 (eg, the second main surface). The main surface) may include a second conductive layer 510. The first conductive layer 508, the second conductive layer 510, and the signal trace 506 may include a thin film material such as, for example, a metal or superconductor thin film. For example, a thin film of metal or superconductor may include a thin film layer of copper, copper alloy, aluminum, niobium, or indium. Although only a single signal trace 506 is shown in FIG. 5, a plurality of signal traces 506 are located between the first elongated flexible substrate portion 502 and the second elongated flexible substrate portion 504 (eg, FIG. Can be included (along the Y-axis entering and exiting page 5). For example, such signal traces 506 can be aligned in parallel in a manner similar to the conductive traces 204 shown in FIG.

In some cases, the first conductive layer 508, the second conductive layer 510, and / or the signal trace 506 may include a two-layer film as described herein with respect to the flexible wiring 200. For example, as shown in FIG. 5, the second conductive layer 510 has a first thin film layer 518 formed on and / or in contact with the bottom surface of the second elongated flexible substrate portion 504. It may include a layered membrane. The two-layer film may further include a second thin film layer 516 formed on and in contact with the first thin film layer 518. The two-layer film can also be formed on the upper surface of the first elongated flexible substrate portion 502. In some embodiments, a portion of the second layer 516 is removed to reveal the underlying first layer 518.

The length of the signal trace 506 can be the same as the length of the elongated flexible substrate portions 502, 504. The width of each signal trace 506 can be, for example, between about 1 μm and about 250 μm, including widths such as 5 μm, 10 μm, 20 μm, 30 μm, 50 μm, or 100 μm, among others. The thickness of each signal trace 506 can be, for example, between about 10 μm and about 100 μm, including, among other things, thicknesses such as 50 nm, 100 nm, 250 nm, 500 nm, 750 nm, 1 μm, 5 μm, 10 μm, 20 μm, 50 μm. In the case of two layers of conductive traces, the thickness of each layer may be the same or different. For example, in some implementations, the thickness of the first layer is 2 μm, whereas the thickness of the second layer is 5 μm. Alternatively, in some cases, the thickness of the first layer is 20 μm, while the thickness of the second layer is 5 μm. The conductive trace 204 may be separated at a constant or variable pitch. For example, in some implementations, the pitch between adjacent signal traces 506 is between about 1 μm and about 1 mm, including pitches such as 5 μm, 10 μm, 50 μm, 100 μm, 250 μm, 500 μm, or 750 μm, among others. The signal trace 506 can be formed on an elongated flexible substrate portion 502 or 504 using integrated chip (IC) manufacturing techniques such as deposition (eg, sputtering and deposition), etching, and / or lift-off techniques.

Each of the first elongated flexible substrate portion 502 and the second elongated flexible substrate portion 504 is made from a flexible plastic ribbon such as, for example, a polyimide ribbon (for example, poly (for example, poly (4, 4'-oxydiphenylene-pyromellisimide))). Can be formed. The first elongated flexible substrate portion 502 can be joined to the second elongated flexible substrate portion 504. The thickness of the substrate portions 502 and 504 can be, for example, between about 10 μm and about 500 μm, including, among other things, thicknesses such as about 20 μm, 50 μm, 75 μm, and 100 μm. The width of the elongated flexible substrate 502 can be, for example, between about 1 mm and about 30 mm, including, for example, widths such as, among other things, 10 mm, 15 mm, and 20 mm. The length of the elongated flexible substrate portions 502 and 504 can be at least the length required to provide coupling between devices, systems, and / or other wiring.

The first conductive layer 508 and the second conductive layer 510 can each correspond to an electromagnetic shielding layer that shields the signal trace 506 from external signal noise. In some implementations, the flexible wiring 500 is combined with one or more flexible wiring 500 to provide a laminated flexible wiring with an increased number of signal lines for transmitting control signals and / or data signals. Can be stacked. As described herein, flexible wiring can be stacked together using an adhesive-based or adhesive-free laminate bonding technique. In some cases, a polymer capsule material sprayed or painted on the first elongated polymer substrate containing a conductive trace / shielding layer can be used to form laminated flexible wiring. For example, in some cases, flexible wiring such as wiring 500 may be sprayed or painted with an epoxy capsule material (eg, Stycast2850FT), then cured to provide an additional polymer layer, on which additional conductive material is deposited. It can be made to be patterned.

In some implementations, the flexible wiring 500 includes one or more vias 512 extending through the first elongated flexible substrate portion 502. The via 512 may include a conductive material (via contact 514) formed within the via 512. The via contact 514 may include superconducting and / or non-superconducting metals such as, for example, copper, aluminum, niobium, indium, or copper alloys. In some cases, the via contact 514 is formed on the side wall of the via 512, but does not completely fill the via 512. In other cases, the via contact 514 completely fills the via 512, so that there is no continuous opening extending through the via 512. In some embodiments, the via contact 514 includes an adhesive layer formed to help the via contact 514 adhere to the sides of the via 512. For example, the adhesive layer may include a film of copper or niobium (eg, a thickness between about 1 nm and about 1 micron as defined for the via sidewall). In some implementations, the material of the via contact 514 formed on the adhesive layer is a copper or niobium film (eg, a thickness between about 500 nm and about 20 microns defined for the via sidewall). Can include.

The adhesive layer uses, for example, electroless plating of the adhesive layer material (eg Cu) to establish a thin first adhesive layer, then establishes a second adhesive layer on top of the first adhesive layer. It can be formed by performing electroplating of the adhesive layer material (eg Cu) to do so. The remaining material of the via contact 514 (eg, Al, Cu, or Nb) can then also be formed on the adhesive layer using, for example, electroplating. For example, aluminum can be plated (eg, electroplated) on the adhesive layer. Other plating techniques may also be used to plate the via contact 514. For example, solvent-based plating may be used to form niobium via contacts.

In some implementations, the via 512 extends from the first conductive layer 508 to the signal trace 506, just as the via contact 514 connects the first conductive layer 508 to the signal trace 506. In some implementations, the via 512 connects the first conductive layer 508 to the second conductive layer 510 so that the via contact 514 connects the first conductive layer 508 to the second conductive layer 510. Extends to. In some implementations, the via 512 extends from the second conductive layer 510 to the signal trace 506, just as the via contact 514 connects the second conductive layer 510 to the signal trace 506. The via 512 can be formed using laser drilling techniques.

In some implementations, the flexible wiring 500 has an exposed area of the signal trace 506 so that electrical connections such as wire bonds or bump bonds can be made to the signal trace. Exposing the signal trace 506 involves removing a portion of the first elongated flexible substrate portion 502 and / or removing a portion of the second elongated flexible substrate portion 504 covering the signal trace 506. obtain. In some cases, the length of the first elongated flexible substrate portion 502 and / or the second elongated flexible substrate portion 504 is long enough to cover the entire signal trace 506 so that a portion of the signal trace 506 is exposed. Not really.

An example of a technique for connecting flexible wiring to each other, to a quantum information processing system, and / or to a circuit component is to use a coaxial connector such as an SMA connector. However, coaxial connections can be bulky and therefore occupy a lot of the limited available space within the cryostat. In addition, the bulk of the coaxial connector can make it difficult to connect high density flexible wiring to contacts. An alternative to coaxial connectors is the use of modified butt-bonding bonds that employ wire bonding between the contacts of flexible wiring. FIG. 6 is a schematic diagram showing an example of a modified butt-bonding bond that employs wire bonding. Specifically, FIG. 6 shows a cross-sectional view of the first flexible wiring 602 coupled to the second flexible wiring 604 using a modified butt joint bond. Each of the first flexible wiring 602 and the second flexible wiring 604 may have the same configuration as the flexible wiring 200 shown in FIG. For example, the flexible wiring 602 includes an elongated flexible substrate 606, a plurality of conductive traces 608 arranged on the main surface of the elongated flexible substrate 606 (one trace 608 is shown in FIG. 6), and an elongated flexible substrate 606. Can include a conductive layer 610 on the second main surface of the. Similarly, the flexible wiring 604 includes an elongated flexible substrate 612, a plurality of conductive traces 614 arranged on the main surface of the elongated flexible substrate 612 (one trace 614 is shown in FIG. 6), and an elongated flexible substrate. It may include a conductive layer 616 on the second main surface of the 612. Like the flexible wiring 200 shown in FIG. 2, each conductive trace 608, 614 corresponds to an individual wire, and the plurality of traces can be arranged in an array (eg, in the Y direction entering and exiting the page of FIG. 6). Along). Further, the conductive layers 610 and 616 can be electromagnetic shielding layers for shielding the conductive traces 608 and 614 from crosstalk, respectively. Although both flexible wiring 602 and 604 are shown flat in FIG. 6, they can include a folding area such as flexible wiring 200, so that layers 610, 616 are shielded by traces 608, 614. Can be provided.

The first flexible wiring 602 is arranged at the edge 601 facing the edge 603 of the second flexible wiring 604. The edges 601 may be separated from the edge 603 by a relatively short distance of 622 or may contact each other. For example, the distance 622 can be between about 25 microns and about a few millimeters, such as 100 μm or 250 μm, among other distances. A wire bond 618 that can be used to electrically connect the trace 608 of the first flexible wiring 602 to the trace 614 of the second flexible wiring 604 is provided.

In some implementations, a solder bridge may be used instead of a wire bond to electrically connect the trace 608 of the first flexible wiring 602 to the trace 614 of the second flexible wiring 604. The distance 622 needs to be kept as small as possible to allow the solder bridge to form. The solder used to form the wire bond 618 or solder bridge can be formed from superconducting or non-superconducting materials.

Both the edge 601 of the first flexible wiring 602 and the edge 603 of the second flexible wiring 604 can be cut using laser machining to provide a more accurate and relatively smooth edge. The edges 601 and 603 can then be placed close to each other to reduce the bridge length of the solder bridge, which improves connection integrity and facilitates the bonding process.

In some embodiments, the junction between the first flexible wiring 602 and the second flexible wiring 604 provides an electrical connection between the first flexible wiring 602 and the second flexible wiring 604. For and / or to the metal block to provide mechanical connectivity to the first flexible wiring 602 and the second flexible wiring 604 to maintain the wiring at the temperature of the cryostat stage where the wiring is located. Is fixed. For example, as shown in FIG. 6, the metal block 620 may be fixed to the electromagnetic shielding layers 610 and 616 and may be in thermal contact. In some implementations, the metal block 620 is fixed in place with respect to the flexible wires 602 and 604. Alternatively or additionally, the metal block 620 is fixed to the shielding layers 610, 616 through an adhesive such as solder. The metal block 620 can be formed from a material suitable for providing sufficient heat transfer within the cryostat, such as copper. In some implementations, the shielding layers 610, 616 also serve as a grounding surface, and the metal block 620 provides a common grounding.

FIG. 6 shows a modified butt joint for flexible wiring with the provided configuration shown in FIG. In some implementations, the modified butt joint can also be used for flexible wiring with the configuration shown in FIG. For example, FIG. 7A is a schematic diagram showing a cross section of a first flexible wiring 702 coupled to a second flexible wiring 704 using a modified butt joint. Each of the first flexible wiring 702 and the second flexible wiring 704 has the same stripline configuration as the flexible wiring 500 shown in FIG. For example, the flexible wiring 702 includes a first elongated flexible substrate portion 706, a second elongated flexible substrate portion 708, a signal trace 714 disposed between the portions 706 and 708, and a first surface of the substrate portion 706. The conductive layer 710 of 1 and the second conductive layer 712 on the bottom surface of the substrate portion 708 may be included. Similarly, the flexible wiring 704 is a signal trace 724 arranged between the first elongated flexible substrate portion 716, the second elongated flexible substrate portion 718, the portions 716 and 718, and the upper surface of the substrate portion 716. It may include a first conductive layer 720 and a second conductive layer 722 on the bottom surface of the substrate portion 718. Like the flexible wiring 500 shown in FIG. 5, each signal trace 714, 724 corresponds to an individual wire, and the plurality of traces can be arranged in an array (eg, along the Y direction entering and exiting the page of FIG. 7A). hand). Further, the conductive layers 710, 712, 720, 722 may be electromagnetic shielding layers for shielding signal traces 714, 724 from crosstalk.

The first flexible wiring 702 is arranged at the edge 701 facing the edge 703 of the second flexible wiring 704. The edges 701 may be separated from the edge 703 by a relatively short distance or may be in contact with each other. For example, the edge 701 may be separated from the edge 703 by a distance between about 25 microns and about a few millimeters, such as 100 μm or 250 μm, among other distances. A wire bond 730 that can be used to electrically connect the trace 714 of the first flexible wiring 702 to the trace 724 of the second flexible wiring 704 is provided. In some implementations, a solder bridge may be used instead of a wire bond to connect the trace 714 of the first flexible wiring 702 to the trace 724 of the second flexible wiring 704. The distance between the first edge 701 and the second edge 703 needs to be kept as small as possible to allow the solder bridge to form. Both the edge 701 of the first flexible wiring 702 and the edge 703 of the second flexible wiring 704 can be cut using laser machining to provide a more accurate and relatively smooth edge. The edges 701 and 703 can then be placed close to each other to reduce the bridge length of the solder bridge, which improves connection integrity and facilitates the bonding process. The solder used to form the wire bond 730 or solder bridge can be formed from superconducting or non-superconducting materials.

In some implementations, the first flexible wiring 702 may include a region 726 where the substrate portion 706 is removed or part of the signal trace 714 is not exposed. Similarly, the second flexible wiring 704 may include a region 728 in which the substrate portion 716 is removed or part of the signal trace 724 is not exposed. By exposing the signal traces in regions 726, 728, the signal traces 726, 728 can be accessed to form wire bonds or solder bridge bonds. FIG. 7B is a schematic view showing a side view of the edge 703 and the region 728 of the second flexible wiring 704 of FIG. 7A. As shown in FIG. 7B, only a portion of the substrate portion 716 directly above the signal trace needs to be removed or absent in order to form the region 728 and expose the signal trace 724. The left and right substrate portions 716 of the region 728 may be joined to the substrate portion 718 and left in place to provide a support surface for the conductive layer 720. In some implementations, regions 726, 728 include solder forming an electrical connection between the first flexible wiring 702 and the second flexible wiring 704.

In some embodiments, the junction between the first flexible wiring 702 and the second flexible wiring 704 provides an electrical connection between the first flexible wiring 702 and the second flexible wiring 704. Metal to provide a mechanical connection between the first flexible wire 702 and the second flexible wire 704 for and / or to maintain the wire at the cryostat stage temperature at which the wire is placed. It is fixed to the block and is in thermal contact. For example, as shown in FIG. 7A, the metal block 732 may be disposed with respect to the electromagnetic shielding layers 712,722. In some implementations, the metal block 732 is fixed in place with respect to the flexible wires 702 and 704. Alternatively or additionally, the metal block 732 is fixed to the shielding layers 712,722 through an adhesive such as solder. Alternatively or additionally, additional metal blocks are secured to the shielding layers 710, 720 and are in thermal contact. Additional metal blocks may also be secured to the shielding layers 710, 720 through an adhesive such as solder. The metal block can be formed from a material suitable for providing sufficient heat transfer within the cryostat, such as copper. In some implementations, the shielding layers 712, 722 also serve as a ground plane and the metal block 732 provides a common ground. Similarly, the shielding layers 710, 720 may also serve as a grounding surface on which additional metal blocks provide a common grounding.

In some implementations, the junction between the first flexible wire and the second flexible wire is different from one temperature step of the cryostat held at the first temperature and the first step. It may be provided at the boundary within the cryostat that separates it from the second temperature stage of the cryostat held at a temperature of 2. For example, the junction may have a first flexible wire, such as a first flexible wire 602 or 702, in a temperature step held at a temperature below 3K (eg, step 103 in FIG. 1), which is higher than 3K but above room temperature. It may be connected to a second flexible wire such as a second flexible wire 604 or 704 in a temperature step kept at a lower temperature (eg, step 101 in FIG. 1). In some embodiments, flexible wiring in transitions between different temperature stages within a cryostat, or transitions from a vacuum environment to another vacuum or non-vacuum environment, is a flexible wiring and clamp device (eg, a metal such as a copper ring). It can be sealed at the transition using an epoxy adhesive fixed to the ring).

As disclosed herein, various techniques can be used to manufacture flexible wiring. For example, in some implementations, flexible wiring can be constructed by providing a large substrate on which the metal and / or superconducting film is formed (eg, a flexible plastic substrate such as polyimide). The substrate may include, for example, a large sheet larger than 8 inches on a side, for example 12 inches x 14 inches. The substrate may be placed in a vacuum chamber to deposit the metal / superconducting membrane. The substrate surface may be cleaned, for example, by performing ion cleaning (eg, Ar ion cleaning) prior to depositing the membrane. When a two-layer film is formed on the substrate, a first layer of material is blanket deposited on the substrate. The first layer may include, for example, a superconductor membrane such as niobium deposited using sputtering. Alternatively, the first layer may include a non-superconducting film such as copper. The first layer can be deposited to have a thickness of up to about 5 μm. For example, the first layer can be deposited to have a thickness of 100 nm, 250 nm, 500 nm, 750 nm, 1 μm, or 2 μm, among other thicknesses. The second layer is then blanket deposited (eg, sputtering or electroless plating) on the first layer. The second layer may include a non-superconducting membrane such as copper or a superconducting membrane such as niobium or aluminum. The second layer can be deposited to have a thickness of up to about 20 μm. For example, the second layer can be deposited to have a thickness of 100 nm, 250 nm, 500 nm, 750 nm, or 1 μm. In some cases, the first deposited portion of the second layer serves as the base layer for later electroplating steps. For example, a thin 100 nm film of copper can be deposited after a thicker layer of copper is electroplated. In some implementations, the membrane is deposited on both the top and bottom of the substrate. The deposited membrane can then be patterned (eg, using an etching or lift-off process) to form the desired circuit pattern. In some cases, in the case of a two-layer film, the same pattern is transferred to both the first layer and the second layer during the patterning step. In other cases, in the patterning step, different patterns are formed in the first layer and then in the second layer. In some implementations, a laser etching process is used to form via holes in the substrate. Via holes can then be filled with via contact material (eg, copper and / or superconducting material) to form via contacts. Once patterned, the substrate sheet can be divided into individual flexible wiring. To split the substrate sheet, it may be necessary to perform laser cutting on the substrate sheet or use a blade to mechanically cut the substrate sheet. In some implementations, the board sheet is split to give the final flexible wiring. Alternatively, in some implementations, to form laminated flexible wiring (eg, a stack of multiple flexible wiring 200), to form a stripline configuration (eg, flexible wiring 500), or to form laminated stripline flexible. The divided substrate sheets can be stacked together to form the wiring. Stacking the divided substrate sheets may involve introducing an adhesive between the cured substrates so that the laminated substrates are joined together. Alternatively, the divided substrate sheets can be joined together using a non-adherens junction technique. After obtaining the laminated flexible wiring, further processing may be performed as needed. For example, additional via contacts may be formed within one or more of the laminated substrates to provide a connection to the conductive traces on the laminated flexible wiring.

In some implementations, flexible wiring can be constructed using extrusion and roll processes. For example, a first elongated sheet of superconducting or non-superconducting material (eg, a 0.25 inch thick niobium, aluminum, or copper sheet) may be provided. In some cases, a second elongated sheet of superconducting or non-superconducting material (eg, a 0.25 inch thick niobium, aluminum, or copper sheet) may be provided on top of the first elongated sheet. If only a single sheet is provided, a single sheet of material is passed through an extruder that thins the sheet (eg, to a thickness between about 20 microns and about 10 mm). If two layers are provided, the first and second elongated sheets may be pressed together under vacuum and / or heat and passed through an extruder that thins the two layers (eg, about 20). The materials in the two-layer sheet adhere to each other (to a thickness between micron and about 10 mm). The thinned single-layer or two-layer sheet can then be laminated with the polyimide substrate. In some mounting embodiments, thinned single-layer or two-layer sheets are laminated on both sides of the polyimide substrate. As described herein, superconducting and / or non-superconducting films on a polyimide substrate can be patterned (eg, using an etching process) to form the desired circuit pattern. In some cases, in the case of a two-layer film, the same pattern is transferred to both the first layer and the second layer during the patterning step. In other cases, in the patterning step, different patterns are formed in the first layer and then in the second layer. In some implementations, a laser etching process is used to form via holes in the substrate. Via holes can then be filled with via contact material (eg, copper and / or superconducting material) to form via contacts. Once patterned, the substrate sheet containing the patterned membrane can be divided into individual flexible wiring. To split the substrate sheet, it may be necessary to perform laser cutting on the substrate sheet or use a blade to mechanically cut the substrate sheet. In some implementations, the board sheet is split to give the final flexible wiring. Alternatively, in some implementations, to form laminated flexible wiring (eg, a stack of multiple flexible wiring 200), to form a stripline configuration (eg, flexible wiring 500), or to form laminated stripline flexible. The divided substrate sheets can be stacked together to form the wiring. Stacking the divided substrate sheets may involve introducing an adhesive between the cured substrates so that the laminated substrates are joined together. Alternatively, the divided substrate sheets can be joined together using a non-adherens junction technique. After obtaining the laminated flexible wiring, further processing may be performed as needed. For example, additional via contacts may be formed within one or more of the laminated substrates to provide a connection to the conductive traces on the laminated flexible wiring.

The quantum themes and implementations of quantum operation described herein include suitable quantum circuits, or more generally, the structures disclosed herein and their structural equivalents. It can be implemented in quantum computing systems, also called systems, or in one or more combinations thereof. The terms "quantum computing system" and "quantum information processing system" may include, but are not limited to, a quantum computer, a quantum cryptography system, a topology quantum computer, or a quantum simulator.

The terms quantum information and quantum data refer to information or data carried by a quantum system and held or stored in the quantum system, the smallest important system being a qubit, for example defining a unit of quantum information. It is a system to do. It is understood that the term "qubit" includes all quantum systems that can be adequately approximated as a two-level system in the corresponding context. Such a quantum system may include, for example, a multi-level system with two or more levels. As an example, such a system can include atoms, electrons, photons, ions, or superconducting qubits. It is understood that in some implementations, the calculated ground state is identified by the ground and the first excited state, but other setups are possible in which the calculated state is identified by a higher level excited state. Quantum memory is a device that can store quantum data over a long period of time with high fidelity and efficiency, such as the optical material interface in which light is used for transmission, and the quantum of quantum data such as superposition or quantum coherence. It is understood that it is for storing and preserving features.

Quantum circuit elements (also called quantum computing circuit elements) include circuit elements for performing quantum processing operations. That is, quantum circuit elements are configured to utilize quantum mechanical phenomena such as superposition and entanglement in order to perform operations on data in a non-deterministic way. Certain quantum circuit elements, such as qubits, can be configured to simultaneously represent and operate information in multiple states. Examples of superconducting quantum circuit elements are, among other things, quantum LC oscillators, quantum bits (eg, flux qubits, phase qubits, or charge qubits), and superconducting quantum interference devices (SQUIDs) (eg, RF-SQUIDs or Includes circuit elements such as DC-SQUID).

In contrast, classical circuit elements generally process data in a deterministic way. Classic circuit elements can be configured to execute the instructions of a computer program together by performing basic arithmetic, logic, and / or input / output operations on the data. Represented in analog or digital format. In some implementations, classical circuit devices can be used to send data to and / or receive data from quantum circuit devices via electrical or electromagnetic connections. Examples of classical circuit elements include CMOS circuits, fast single flux quantum (RSFQ) devices, mutual quantum logic (RQL) devices, and circuit elements based on ERSFQ devices, which are RSFQs that do not use bias resistors. It is an energy efficient version.

The manufacture of quantum circuit elements and classical circuit elements described herein can involve the deposition of one or more materials such as superconductors, dielectrics, and / or metals. Depending on the material selected, these materials may be deposited using a deposition process such as chemical vapor deposition, physical vapor deposition (eg, vapor deposition or sputtering), or epitaxial techniques, among other deposition processes. Can be done. The process for manufacturing the circuit elements described herein may involve removing one or more materials from the device during manufacturing. Depending on the material to be removed, the removal process can include, for example, a wet etching technique, a dry etching technique, or a lift-off process. The materials forming the circuit elements described herein can be patterned using known lithography techniques (eg, photolithography or electron beam lithography).

During the operation of a superconducting quantum circuit element such as the circuit element described herein and / or a quantum computing system using a superconducting classical circuit element, the superconducting circuit element is a superconducting material exhibiting superconducting properties. Cooled in the cryostat to a temperature that allows. A superconducting (or superconducting) material can be understood as a material that exhibits superconducting properties below the superconducting critical temperature. Examples of superconducting materials are aluminum (superconducting critical temperature of about 1.2 Kelvin), indium (superconducting critical temperature of about 3.4 Kelvin), NbTi (superconducting critical temperature of about 10 Kelvin), and niobium (superconducting critical temperature of about 10 Kelvin). Approximately 9.3 Kelvin superconducting critical temperature) is included. Therefore, superconducting structures such as superconducting traces and superconducting ground planes are formed from materials that exhibit superconducting properties below the superconducting critical temperature.

Although this specification contains many specific implementation details, these should be construed as a description of features that may be specific to a particular implementation, rather than as a limitation to the extent that can be claimed. In the context of the individual implementations, the particular features described herein can also be implemented in combination in a single implementation. Conversely, the various features described in the context of a single implementation can also be implemented individually in multiple implementations or in the appropriate subcombination. Further, a function is described above as functioning in a particular combination and may be initially claimed as such, but in some cases one or more functions from the claimed combination may be removed from the combination. The claimed combination can be a sub-combination or a variation of the sub-combination.

Similarly, the movements are depicted in a particular order in the drawings, but this means that such movements are performed in a particular order or order shown, or all, in order to achieve the desired result. It should not be understood as requiring the described actions to be performed. For example, the actions described in the claims can be performed in a different order and still achieve the desired result. In certain situations, multitasking and parallelism may be advantageous. Moreover, the separation of the various components in the implementations described above should not be understood as requiring such separation in all implementations.

Many implementations have been described. Nevertheless, it will be appreciated that various modifications may be made without departing from the spirit and scope of the invention. Therefore, other implementations are within the scope of the following claims.

100 Cooling system 102 Cryostat 101 First stage 103 Second stage 104 Boundary 105 Third stage 106 Boundary 110 Quantum information processing system 112 Sample mount 114 Flexible wiring 116 Flexible wiring 150 Control electronics 200 Flexible wiring 202 Elongated flexible board 204 Conductive trace 206 Folding area 208 Conductive layer 208 Electromagnetic shielding layer 210 Groove 212 Groove 214 Groove 250 Flexible wiring 300 Flexible wiring 302 Flexible wiring board 304 Conductive trace 308 Electromagnetic shielding layer 308 Shielding layer strip 500 Flexible wiring 502 First elongated Flexible substrate part 504 Second elongated flexible substrate part 506 Signal trace 508 First conductive layer 510 Second conductive layer 512 Via 514 Via contact 516 Second thin film layer 518 First thin film layer 601 Edge 602 First Flexible wiring 603 Edge 604 Second flexible wiring 606 Elongated flexible wiring 608 Conductive trace 610 Conductive layer 610 Electromagnetic shielding layer 612 Elongated flexible substrate 614 Conductive trace 616 Conductive layer 616 Electromagnetic shielding layer 618 Wire bond 620 Metal block 622 Distance 701 Edge 702 First flexible wiring 703 Edge 704 Second flexible wiring 706 First elongated flexible substrate portion 708 Second elongated flexible substrate portion 710 Shielding layer 710 First conductive layer 712 Shielding layer 712 Second Conductive layer 712 Electromagnetic shielding layer 714 Signal trace 716 First elongated flexible substrate part 718 Second elongated flexible substrate portion 720 First conductive layer 720 Shielding layer 722 Second conductive layer 722 Shielding layer 722 Electromagnetic shielding layer 724 Signal Trace 726 Area 728 Area 730 Wire Bond 732 Metal Block

Claims (15)

The first elongated flexible layer and
A second elongated flexible layer joined to the first elongated flexible layer,
A plurality of conductive traces arranged at the junction interface between the first elongated flexible layer and the second elongated flexible layer.
A first electromagnetic shielding layer on the main surface of the first elongated flexible layer,
A second electromagnetic shielding layer on the main surface of the second elongated flexible layer,
Flexible wiring comprising vias extending through the first elongated flexible layer, including superconductor via contacts. The flexible wiring according to claim 1 , wherein the via comprises an adhesive layer and the superconductor via contact is formed on the adhesive layer. The via extends from the first electromagnetic shielding layer to at least one of the plurality of conductive traces, and the superconductor via contact is the first electromagnetic shielding layer and the at least one. The flexible wiring according to claim 1 , which is connected to a conductive trace. The via extends from the first electromagnetic shielding layer to the second electromagnetic shielding layer, and the superconductor via contact is connected to the first electromagnetic shielding layer and at least one conductive trace. , The flexible wiring according to claim 1 . A first elongated flexible substrate, a plurality of conductive traces arranged in an array on the first side of the first elongated flexible substrate, and a second side of the first elongated flexible substrate. A first electromagnetic shielding layer, wherein the second side of the first elongated flexible substrate is opposite to the first side of the first elongated flexible substrate. With the first flexible wiring,
A second elongated flexible substrate, a second plurality of conductive traces arranged in an array on the first side of the second elongated flexible substrate, and a second side of the second elongated flexible substrate. A second electromagnetic shielding layer in which the second side of the second elongated flexible substrate is opposite to the first side of the second elongated flexible substrate. A device comprising, with a second flexible wiring.
A device in which the first flexible wiring is coupled to the second flexible wiring through a butt joint. The butt joint comprises a wire bond connecting a first conductive trace from the first plurality of conductive traces to a first conductive trace from the second plurality of conductive traces. The device according to 5 . The butt joint comprises a solder bridge connecting a first conductive trace from the first plurality of conductive traces to a first conductive trace from the second plurality of conductive traces. The device according to 5 . The device according to claim 5 , further comprising a metal block fixed to and thermally contacted with the first electromagnetic shielding layer and the second electromagnetic shielding layer. A first elongated flexible substrate, a first plurality of conductive traces arranged at a bonding interface in the first elongated flexible substrate, and a first on a first main surface of the first elongated flexible substrate. A first flexible wiring comprising the electromagnetic shielding layer of the first elongated flexible substrate and a second electromagnetic shielding layer on the second main surface of the first elongated flexible substrate.
A second elongated flexible substrate, a second plurality of conductive traces arranged at the joining interface in the second elongated flexible substrate, and a third on the first main surface of the second elongated flexible substrate. A device comprising a second flexible wiring comprising the electromagnetic shielding layer of the above and a fourth electromagnetic shielding layer on the second main surface of the second elongated flexible substrate.
A device in which the first flexible wiring is electrically connected to the second flexible wiring through a butt joint. The first elongated flexible substrate comprises a first cavity from which the first conductive trace of the first plurality of conductive traces is exposed, and the second elongated flexible substrate comprises the second plurality. 9. The device of claim 9 , comprising a second cavity in which the first conductive trace of the conductive trace is exposed. The butt joint provides a wire bond that connects the exposed first conductive trace of the first plurality of conductive traces to the exposed first conductive trace of the second plurality of conductive traces. The device according to claim 10 . The butt joint provides a solder bridge that connects the exposed first conductive trace of the first plurality of conductive traces to the exposed first conductive trace of the second plurality of conductive traces. The device according to claim 10 . The device according to claim 10 , further comprising a first metal block fixed to and thermally contacted with the first electromagnetic shielding layer and the third electromagnetic shielding layer. 13. The device of claim 13 , further comprising a second electromagnetic shielding layer and a second metal block that is fixed and in thermal contact with the fourth electromagnetic shielding layer. A cryostat with a first stage configured to be kept within a first temperature range,
The quantum information system in the first stage and
A system that is in the first stage and includes flexible wiring coupled to the quantum information processing system, wherein the flexible wiring is:
The first elongated flexible layer and
A second elongated flexible layer joined to the first elongated flexible layer,
A plurality of conductive traces arranged at the junction interface between the first elongated flexible layer and the second elongated flexible layer.
A first electromagnetic shielding layer on the main surface of the first elongated flexible layer,
A second electromagnetic shielding layer on the main surface of the second elongated flexible layer,
A system comprising vias extending through the first elongated flexible layer, comprising superconductor via contacts.

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