Fuzz Buttons

Fuzz Buttons® are high performance proprietary trademarked contact pins available ONLY from Custom Interconnects and manufactured ONLY in the USA.

Fuzz Buttons® offer superior value to other contact technologies such as Pogo Pins, Spring Probes, Hyberboloid contacts or even soldering.  This becomes especially evident when requirements such as low signal distortion, high frequency, low insertion force, planarity, shock/vibration resistance, weight and/or extended life come into play.

Fuzz Buttons® are available in a wide variety of diameters and lengths, with diameters ranging from .010" to .500" and lengths ranging from .030" to as long as .500".

Most Fuzz Buttons® we manufacture are intended to address fine pitch contact requirements primarily at the 1mm pitch level, but also can serve applications with as small as a .4mm pitch.   Fuzz Buttons® can mate to virtually any packaging type used in the market today - including PGA, BGA, LGA, CGA, QFN and MCM, as well as any custom packaging that a customer may be employing.  This makes them ideal for use in PCB/PWB interposers, connectors, Test Sockets and chip packaging.

We also manufacture many large format Fuzz Buttons® that can resemble cylinders, slugs, discs, doughnuts and washers.  These are typically utilized for specialized EMI Shielding and/or for compliant high current capable ground pads.  It is also possible to lay small or large Fuzz Buttons® on their sides individually or in an end-to-end configuration to emulate a compliant EMI "bead" or to make a long X-axis or Y-axis connection.

History 

Fuzz Buttons® were first introduced to the electronics marketplace in 1959 and were mainly used in grounding applications.  A later example includes their use as static dissipation pads for IBM computer chassis in the 1980s.  Additional customers and applications began to emerge as Fuzz Buttons® gained popularity in the marketas a highly flexible interconnect design solution.  Soon the military sector took notice and began to utilize them in shock- resistant PCB connectors for missile and satellites.  In the early 1990s, Fuzz Buttons® were miniaturized to address the growing semiconductor test market.  Fuzz Button® test sockets were highly regarded by customers such as Qualcomm, AMD and Texas Instruments, when low signal distortion was especially important during development testing, but also for the high mating cycles required for production testing.

Today Fuzz Buttons® still serve the military and commercial markets in many surprising applications.  You will find them in missiles, satellites, space probes, aircraft, test floors, laboratories, radar arrays, antennas, supercomputers, crash test dummies, automotive production, communications and even packaged inside high-end RF products such as attenuators and amplifiers.  Because they are so versatile, Fuzz Buttons® can be used for DC, VHF, UHF, L, S, C, X, Ku, Ka and Q Bands.

Making a Fuzz Button®

 Fuzz Buttons® are a simple, yet elegant structure - whereby, the signal element and the spring are one and the same.  There are no other moving parts that can cause failure or degrade signal integrity, the Fuzz Button® is the direct mating point.

They are manufactured from a long strand of Gold-plated highly specialized very fine wire (often as fine as human hair) that offers high levels of conductivity, strength and oxidation resistance.   The standard wire material used is a Gold-plated Beryllium Copper alloy (Au/BeCu)- which offers the lowest signal distortion levels, high mating cycle repeatability and excellent stability under shock/vibration..

Fuzz Buttons® are also available in specialty materials, such as Gold-plated Molybdenum (Au/Mo) or non-magnetic Au/BeCu).  These are used in special cases - such as operating states at extremely high current or temperature - or when magnetic properties are of special concern.

Fuzz Buttons® are fashioned from these wires using a highly-guarded process that forms them into individual units of certain diameter and length specs.  The manufacturing process causes the wire to be randomized throughout the Fuzz Button® structure.

This randomization results in some very desirable effects, such as

• Breaking up of internal induction fields that otherwise would form from a coiled spring
• configuration
• Reduced signal path length and skin effect levels
• Increasing the overall structural integrity and strength of the Fuzz Button®
• Creating multiple points of contact within the Fuzz Button® itself, an internal "redundancy"

Fuzz Button® Specs

• Applications: LGA, BGA, PGA, CGA, QFN and more
• Pitch Capability: .4mm and above
• Compliance/Travel: 15 - 30% of length / 20% nominal
• Compression Force: 34 grams
• Current Capability: 5 Amps Continuous
• Operating Temp: -60°C to 150°C (customer testing has proven this range very conservative)
• Typical Mating Cycles: Fuzz Buttons alone up to 5000 cycles/ with Hardhats up to 500,000 cycles
• Frequency Capability: to 40 GHz in natural state, to 100 GHz with design optimization
• Cross Talk/Bandwidth: -20dB@10Ghz
• Insertion Loss S21: -1dB@26GHz
• Return Loss S11: -20dB@10GHz
• Inductance: 0.19nH Self / 0.03nH Mutual
• Capacitance: 0.16pF Ground / 0.008pF Mutual
• Resistance: <10mΩ
• Rise/Fall TIme: 50ps / 50ps

Note: Representative values above are for .020" diameter/1mm Pitch, see Technical Data page for more information on other configurations.

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