Quantum Computing Interconnects

Custom Interconnects manufactures cryogenic quantum computing interconnects and high-density interposers engineered for superconducting qubit, ion trap, and cryogenic RF systems. Built around our Fuzz Button® technology, with contacts down to .010 inch in diameter and pitch spacing down to 0.5mm, our solutions deliver the signal integrity and grounding performance required where standard pogo pins and spring probes are not sufficient. Every part is manufactured in the USA, and we inspect 100% of what we ship.

Built for the Cryogenic Environment

Quantum processors run at temperatures approaching absolute zero, staged from the 4 Kelvin plate down to the mixing chamber of a dilution refrigerator which reach base temperatures of 5mK to 10mK. Interconnects at these stages have to survive repeated thermal cycling, add minimal thermal load, and hold their mechanical and electrical properties across the full temperature range.

Our cryogenic interconnects and connectors are designed for exactly this environment: reliable mating from room temperature down to millikelvin operation, without the compliance loss and contact degradation that the coil-and-plunger architecture of pogo pins and spring probes can exhibit as it cools. From the 4 K plate to the coldest stage, they hold a consistent, low-resistance connection.

Engineered for Qubit Signal Integrity

Control and readout fidelity depend on a clean signal path, and loss or reflection anywhere in that path degrades it. Our Fuzz Button interconnects provide a short, low-inductance electrical path for the high-frequency control and readout lines running to and from the qubit plane, usable to 40 GHz in natural state and up to 100 GHz with design optimization.

For superconducting qubit and cryogenic RF interconnect applications, that translates into clean control and readout lines at the density that rising qubit counts demand. Because the connection is compliant in every axis, it also tolerates the mechanical and thermal movement of a cryostat without stressing the die or the board.

High-Density Cryogenic Interposers

Because a Fuzz Button is itself a complete connector, our interposers reach an interconnect density that pin-and-socket designs cannot match. We build custom cryogenic PCB interposers loaded with Fuzz Buttons in configurations up to 6,000+ positions, in a footprint that scales as qubit counts rise.

Each interposer is designed to your footprint, position count, and thermal budget rather than adapted from a catalog part. A wide array of high quality interconnect body/carrier materials are available to choose from, including Ultem®, PTFE, PEEK®, Torlon®, FR4, G10, Aluminum and Brass, as well as any other commercially available dielectric plastic or metal you may prefer. We are willing to try any material you bring to us, and have recently been experimenting with cutting edge materials such as Niobium, Diamond and Aluminum Nitride Ceramic.

Non-Magnetic by Design

Magnetic material near the qubit plane introduces flux noise and erodes coherence, and in ion trap systems stray fields disturb trapped ions directly. Our interconnects are built from non-magnetic, no-nickel materials, including gold-plated molybdenum (Au/Mo), so they can sit close to sensitive quantum hardware without adding magnetic interference.

Materials Engineered for Cryogenic Performance

Material choice is central to cryogenic and quantum performance. We work in gold-plated molybdenum (Au/Mo) and no-nickel gold-plated beryllium copper (Au/BeCu), selected for how they behave at cryogenic temperatures and for their non-magnetic, no-nickel construction. Just like our custom interposers, we are willing to try any material you bring to us, including materials such as Gold Plated Molybdenum Rhenium which we have recently been experimenting with.

Quantum Applications We Support

• Superconducting qubit systems: control and readout interconnect at the mixing-chamber stage.
• Ion trap systems: non-magnetic interconnect that keeps stray fields away from trapped ions using ultra-high vacuum (UHV).
• Cryogenic RF and microwave signal delivery through the refrigerator stages.
• Dilution refrigerator wiring and high-density interposers between stages.
• Closed-cycle (dry) cryostats, continuous-flow cryostats, bath cryostats, and medical/microtome cryostats.

Why Quantum Teams Choose Custom Interconnects

Request a Quote for Your Quantum Program

Tell us about your cryogenic or quantum interconnect requirement and our engineers will respond with a custom solution. We work on custom engineered programs rather than catalog parts, and our team will scope the design with you directly.

Request a Quote

Frequently Asked Questions

What temperature can your cryogenic interconnects operate at?

They are designed for the full cryogenic range used in quantum systems, from the 4 Kelvin plate down to the mixing chamber at 5mK to 10mK, surviving repeated thermal cycling without loss of contact.

Are your quantum interconnects non-magnetic?

Yes. They are built from non-magnetic, no-nickel materials such as gold-plated molybdenum so they can be placed near qubits and trapped ions without adding flux noise or magnetic interference.

What is a fuzz button interposer?

It is a board-to-board interposer loaded with Fuzz Buttons. Each Fuzz Button is a compressed strand of gold-plated wire that acts as a complete connector on its own, elastic in every axis, so the interposer reaches very high density in a small footprint while tolerating thermal contraction and mechanical movement.

Do you support superconducting qubit and ion trap systems?

Yes. We supply cryogenic RF interconnect for superconducting qubit control and readout, and non-magnetic interconnect for ion trap systems, in custom configurations.

What materials do you offer for cryogenic applications?

Gold-plated molybdenum (Au/Mo), non-magnetic gold-plated beryllium copper (Au/BeCu), and we are always pushing the limits on cutting edge materials such as Molybdenum Rhenium.