Self-limiting electrical triggering for initiating fracture of frangible glass
First Claim
1. A transient electronic device, comprising:
- a frangible glass substrate; and
a trigger mechanism comprising;
a self-limiting resistive element comprising a material disposed over a localized region of the frangible glass substrate, the self-limiting resistive element configured such that;
during a time period when a current from a power source flows through the self-limiting resistive element, heat generated by the self-limiting resistive element increases a localized temperature of the localized region from an initial temperature toward a first temperature level; and
a current-limiting portion of the self-limiting resistive element is configured to control the flow of a trigger current such that the trigger current flow is terminated when the localized temperature of the localized region increases to the first temperature level, thereby causing the localized temperature to decrease from the first temperature level to a second temperature level;
wherein the frangible glass substrate is configured such that the localized temperature increase and the localized temperature decrease causes the frangible glass substrate to fracture.
1 Assignment
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Accused Products
Abstract
A transient electronic device includes electronic elements (e.g., an SOI- or chip-based IC) and a trigger mechanism disposed on a frangible glass substrate. The trigger mechanism includes a switch that initiates a large trigger current through a self-limiting resistive element in response to a received trigger signal. The self-limiting resistive element includes a resistor portion that generates heat in response to the trigger current, thereby rapidly increasing the temperature of a localized (small) region of the frangible glass substrate, and a current limiting portion (e.g., a fuse) that self-limits (terminates) the trigger current after a predetermined amount of time, causing the localized region to rapidly cool down. The frangible glass substrate is engineered such that a stress profile produced by the rapid heating/cooling of the localized region generates an initial fracture force that subsequently propagates throughout the glass substrate, whereby sufficient potential energy is released to powderize the electronic elements.
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Citations
22 Claims
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1. A transient electronic device, comprising:
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a frangible glass substrate; and a trigger mechanism comprising; a self-limiting resistive element comprising a material disposed over a localized region of the frangible glass substrate, the self-limiting resistive element configured such that; during a time period when a current from a power source flows through the self-limiting resistive element, heat generated by the self-limiting resistive element increases a localized temperature of the localized region from an initial temperature toward a first temperature level; and a current-limiting portion of the self-limiting resistive element is configured to control the flow of a trigger current such that the trigger current flow is terminated when the localized temperature of the localized region increases to the first temperature level, thereby causing the localized temperature to decrease from the first temperature level to a second temperature level; wherein the frangible glass substrate is configured such that the localized temperature increase and the localized temperature decrease causes the frangible glass substrate to fracture. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of fracturing a transient electronic device, comprising:
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during a time period when a current from a power source flows through a self-limiting resistive element disposed over a localized region of a frangible glass substrate, generating heat by the self-limiting resistive element to increase a localized temperature of the localized region from an initial temperature toward a first temperature level; controlling the flow of a trigger current by a current-limiting portion of the self-limiting resistive element such that the trigger current flow is terminated when the localized temperature of the localized region increases to the first temperature level, thereby causing the localized temperature to decrease from the first temperature level to a second temperature level; and fracturing the frangible glass substrate in response to the increase and decrease in the localized temperature. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A transient electronic device, comprising:
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a frangible glass substrate; one or more electronic elements disposed on the frangible glass substrate; and a trigger mechanism comprising; a self-limiting resistive element comprising a material disposed over a localized region of the frangible glass substrate, the self-limiting resistive element configured such that; during a time period when a current from a power source flows through the self-limiting resistive element, heat generated by the self-limiting resistive element increases a localized temperature of the localized region from an initial temperature toward a first temperature level; and a current-limiting portion of the self-limiting resistive element is configured to control the flow of a trigger current such that the trigger current flow is terminated when the localized temperature of the localized region increases to the first temperature level, thereby causing the localized temperature to decrease from the first temperature level to a second temperature level; wherein the frangible glass substrate is configured such that the localized temperature increase and the localized temperature decrease causes the frangible glass substrate to fracture. - View Dependent Claims (18, 19, 20, 21, 22)
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Specification