DEVICE FOR MONITORING THE TEMPERATURE OF AN ELEMENT

• US 20100158072A1
• Filed: 12/21/2009
• Published: 06/24/2010
• Est. Priority Date: 12/24/2008
• Status: Active Grant

• Current Assignee: STMicroelectronics SAS (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SAS (STMicroelectronics NV)
• Inventors: Fornara, Pascal, Rivero, Christian
• Granted Patent: US 8,672,540 B2
• Time in Patent Office: Days
• US Class Current: 374/152
• CPC Class Codes: G01K 13/00 Thermometers specially adapted for specific purposes
• CPC Class Codes: H01H 1/0036 Switches making use of microelectromechanical systems [MEMS] for electromagnetic relays H01H50/005; for electrostatic relays H01H59/0009
• CPC Class Codes: H01H 2037/008 Micromechanical switches operated thermally
• CPC Class Codes: H01H 37/46 actuated due to expansion or contraction of a solid deflection of a bimetallic element H01H37/52

Abstract

A device for monitoring the temperature surrounding a circuit, including: a charge storage element; a charge evacuation device; and a thermo-mechanical switch connecting the storage element to the evacuation element, the switch being capable of closing without the circuit being electrically powered, when the temperature exceeds a threshold.

Claims

1. A circuit for monitoring the temperature surrounding the circuit, comprising:

a charge storage element;

a charge evacuation device;

a thermo-mechanical switch connecting the storage element to the evacuation element, said switch being capable of closing without for the circuit being electrically powered, when the temperature exceeds a threshold; and

a device for reading the amount of charge in the storage element.

2. The circuit of claim 1, wherein the thermo-mechanical switch is formed of two metal strips having opposite ends separated by a distance (d) adapted to decreasing as the temperature increases and to come down to zero when the temperature exceeds the threshold.

3. The circuit of claim 2, comprising an interconnect stack in which the metal strips are formed, the ends of the strips being separated by a region filled with air formed in the interconnect stack.

4. The circuit of claim 2, wherein the metal strips are made of copper or aluminum.

5. The circuit of claim 1, wherein the storage element is formed of a dual-gate MOS transistor comprising a control gate and a floating gate, the floating gate being connected to the thermo-mechanical switch.

6. The circuit of claim 1, wherein the charge evacuation element is formed of a contact between the thermo-mechanical switch and the substrate in and on which the circuit is formed.

7. The circuit of claim 1, formed using CMOS technology.

8. An integrated circuit comprising CMOS components implementing the circuit according to claim 1.

9. A method for monitoring the temperature of an element comprising the steps of:

powering a circuit attached to the element to inject charges into a charge storage element of this circuit;

removing the power;

causing an evacuation of the charges if the temperature exceeds a temperature threshold;

powering the circuit; and

reading the amount of charge present in the storage element.