Motorola Corporation

Motorola Solutions, Inc.

Kin P Tsui

Daniel Roman Gamota

John Szczech

Jie Zhang

Jerzy Wielgus

Tomasz L Klosowiak

Paul W Brazis, Jr

A method and apparatus for forming controlled stress fractures in metal produces electrically isolated, closely spaced circuit sub-entities for use on a metallized printed wiring board. A polymeric substrate has a layer of metal adhered to the surface, and the metal layer is formed into entities. Each entity has a fracture initiating feature formed into it, which serves to initiate and/or direct a stress crack that is induced in the metal. The entities are fractured in a controlled manner by subjecting the substrate and the entities to mechanical stress by a rapid thermal excursion, creating a stress fracture in the entity extending from the fracture initiating feature. The stress fracture divides each entity into two or more sub-entities that are electrically isolated from each other by the stress fracture. The resulting structure can be used to form circuitry requiring very fine spaces for high density printed circuit boards. The rapid thermal stress may be induced by a high intensity, strobed xenon arc lamp.

Method and apparatus for providing electrically isolated closely spaced features on a printed circuit board

A method and apparatus for an irreversible temperature sensor for measuring a peak exposure temperature. The apparatus is fabricated by printing an admixture of conductive nanoparticles on a dielectric substrate to form a film. The film has an electrical resistance that is inversely proportional to the exposure temperature. The electrical resistance also irreversibly decreases as the exposure temperature of the film increases. A portion of the film is exposed to a pulse of electromagnetic energy sufficient to render it substantially more electrically conductive than the portion that was not exposed. In use, the peak exposure temperature is determined by measuring the electrical resistance of the non-altered portion of the film and the electrical resistance of the portion that was exposed to the pulse of electromagnetic energy, and subtracting the electrical resistance of the altered portion from the electrical resistance of the portion that was not altered, to provide a difference value. The peak exposure temperature is then be calculated as a function of the difference value.

Method and apparatus for a temperature sensor for measuring peak temperatures

An inverter circuit () having a drive transistor () that operably couples to a voltage bias input () (and where that drive transistor controls the inverter circuit output by opening and closing a connection between the output () and ground ()) is further operably coupled to a feedback switch (). In a preferred approach the feedback switch is itself also operably coupled to the voltage bias input and the output and preferably serves, when the drive transistor is switched 'off,' to responsively couple the voltage bias input to the drive transistor in such a way as to cause a gate terminal of the drive transistor to have its polarity relative to a source terminal of the drive transistor reversed and hence permit the inverter circuit to operate across a substantially full potential operating range of the drive transistor.

Inverter circuit having a feedback switch and methods corresponding thereto

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Morton Grove, IL, United States of America

Kin P Tsui