Littelfuse, Inc.

Littlefuse, Inc.

Louis Rector

Hugh M Hyatt

Anthony D Minervini

Stephen J Whitney

Honorio S Luciano

Andrew J Neuhalfen

Robert G Swensen

Andrew W S Elliott

The present invention provides a multifunction resistor having an improved voltage variable material ('VVM'). More specifically, the present invention provides a polymer VVM that has been formulated with a high percentage loading of conductive and/or semiconductive particles. A known length of the relatively conductive VVM is placed between adjacent electrodes to produce a desired Ohmic normal state resistance. When an electrostatic discharge event occurs, the VVM of the multifunctional resistor becomes highly conductive and dissipates the ESD threat. One application for this 'resistor' is the termination of a transmission line, which prevents unwanted reflections and distortion of high frequency signals.

Electrostatic discharge multifunction resistor

An arrangement of voltage variable materials for the protection of electrical components from electrical overstress (EOS) transients. A device having a plurality of electrical leads, a ground plane and a layer of voltage variable material. The voltage variable material physically bonds the plurality of electrical leads to one another as well as provides an electrical connection between the plurality of electrical leads and the ground plane. A die having a circuit integrated therein is attached to the ground plane. Conductive members electrically connect the plurality of electrical leads to the integrated circuit. At normal operating voltages, the voltage variable material has a high resistance, thus channeling current from the electrical leads to the integrated circuit via the conductive members. In response to a high voltage EOS transient, the voltage variable material essentially instantaneously switches to a low resistance state, channeling the potentially harmful EOS transient to the ground plane and away from the integrated circuit.

Protection of electrical devices with voltage variable materials

A composition for providing protection against electrical overstress (EOS) comprising an insulating binder, doped semiconductive particles, and semiconductive particles. The composite materials exhibit a high electrical resistance to normal operating voltage values, but in response to an EOS transient switch to a low electrical resistance and clamp the EOS transient voltage to a low level for the duration of the EOS transient.

Polymer composite materials for electrostatic discharge protection

A composition and devices utilizing these compositions for providing protection against electrical overstress including a matrix formed of a mixture of an insulating binder, conductive particles having an average particle size of less than 10 microns, and semiconductive particles having an average particle size of less than 10 microns. The compositions exhibit improved clamping voltages in a range of about 30 volts to greater than 2,000 volts.

Polymer composites for overvoltage protection

The thin film, electrical device is an subminiature overvoltage circuit protection device in a surface mountable configuration for use in printed circuit board or thick film hybrid circuit technology. The surface mountable device (SMD) is designed to protect against electrostatic discharge (ESD) damage to electronic components. The circuit protection device comprises three material subassemblies. The first subassembly generally includes a substrate carrier, electrodes, and terminal pads for connecting the protection device,to a PC board. The second subassembly includes a voltage variable polymer material with nonlinear resistance characteristics, and the third subassembly includes a cover coat for protecting other elements of the circuit protection device. The devices of the present invention employ various electrode configurations and profiles to control the electrical field created between the electrodes and increase the active area of the electrodes in contact with the voltage variable material to enhance the electrical characteristics of the device.

Growing community of inventors

Allegany, NY, United States of America

Louis Rector