# US 2017/0290194 A1 · Thermal modulation of an electronic device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0290194 A1 - Document ID: US20170290194A1 - Status: Published application - Kind: A1 - Application number: 15/087,864 - Filed: 2016-03-31 - Published: 2017-10-05 - Earliest claimed: 2016-03-31 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Rajat MITTAL; Mehdi SAEIDI; Vivek SAHU; Ryan COUTTS - Web page: https://patentgrep.com/patent/US20170290194A1 ## CPC - H05K 7/2039: {characterised by the heat transfer by conduction from the heat generating element to a dissipating body (arrangements for increasing/decreasing heat-transfer, e.g. fins details, F28F13/00)} - H05K 7/20445: {the coupling element being an additional piece, e.g. thermal standoff} - H05K 7/20472: {Sheet interfaces} - H10N 30/204: {using bending displacement, e.g. unimorph, bimorph or multimorph cantilever or membrane benders} - H10N 30/2047: {Membrane type} - H10N 30/802: {Circuitry or processes for operating piezoelectric or electrostrictive devices not otherwise provided for, e.g. drive circuits} - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract An electronic device includes an integrated circuit, a flexible heat spreader, an actuator, and a controller. The actuator is coupled to the flexible heat spreader and the controller is configured to control the actuator between a first actuation mode and a second actuation mode. When in the first actuation mode, the actuator positions the flexible heat spreader with an air gap between the flexible heat spreader and the integrated circuit such that the flexible heat spreader is thermally separated from the integrated circuit to increase a thermal impedance between the flexible heat spreader and the integrated circuit. When in the second actuation mode, the actuator positions the flexible heat spreader in thermal contact with the integrated circuit without the air gap there between to reduce the thermal impedance between the flexible heat spreader and the integrated circuit. ## Claims ### Claim 1 An electronic device, comprising: an integrated circuit; a flexible heat spreader; an actuator coupled to the flexible heat spreader; and a controller coupled to the actuator and configured to control the actuator between a first actuation mode and a second actuation mode, wherein: when in the first actuation mode, the actuator positions the flexible heat spreader with an air gap between the flexible heat spreader and the integrated circuit such that the flexible heat spreader is thermally separated from the integrated circuit to increase a thermal impedance between the flexible heat spreader and the integrated circuit, when in the second actuation mode, the actuator positions the flexible heat spreader in thermal contact with the integrated circuit without the air gap there between to reduce the thermal impedance between the flexible heat spreader and the integrated circuit, the controller is configured to switch the actuator from the first actuation mode to the second actuation mode during a benchmarking procedure performed by the electronic device, wherein the benchmarking procedure includes one or more operations to measure a performance of the integrated circuit, and the controller is configured to switch the actuator back to the first actuation mode upon completion of the benchmarking procedure. ### Claim 2 (depends on 1) The electronic device of claim 1, further comprising: thermal interface material (TIM) disposed on and in thermal contact with the integrated circuit, wherein: when in the first actuation mode, the actuator positions the flexible heat spreader with the air gap between the flexible heat spreader and the TIM such that the flexible heat spreader is physically separated from the TIM to increase the thermal impedance between the flexible heat spreader and the integrated circuit, and when in the second actuation mode, the actuator positions the flexible heat spreader in physical contact with the TIM without the air gap there between to reduce the thermal impedance between the flexible heat spreader and the integrated circuit. ### Claim 3 (depends on 1) The electronic device of claim 1, further comprising: a thermal interface material (TIM) disposed on and in thermal contact with the flexible heat spreader, wherein: when in the first actuation mode, the actuator positions the flexible heat spreader with the air gap between the TIM and the integrated circuit such that the TIM is physically separated from the integrated circuit to increase the thermal impedance between the flexible heat spreader and the integrated circuit, and when in the second actuation mode, the actuator positions the flexible heat spreader such that the TIM is in physical contact with the integrated circuit without the air gap there between to reduce the thermal impedance between the flexible heat spreader and the integrated circuit. ### Claim 4 (depends on 1) The electronic device of claim 1, wherein the actuator comprises a piezo electric layer coupled to the flexible heat spreader. ### Claim 5 (depends on 4) The electronic device of claim 4, wherein the controller is configured to switch the actuator to the second actuation mode by applying an actuation voltage to the piezo electric layer and to switch the actuator to the first actuation mode by removing the actuation voltage from the piezo electric layer. ### Claim 6 (depends on 5) The electronic device of claim 5, wherein the piezo electric layer is configured to have a curved shape in response to the actuation voltage and to have a planar non-curved shape in the absence of the actuation voltage. ### Claim 7 (depends on 1) The electronic device of claim 1, wherein the flexible heat spreader comprises a structure configured to disperse heat generated by the integrated circuit, the structure selected from the group consisting of a graphite sheet, a metal sheet, a copper sheet, and a mid-frame of the electronic device. ### Claim 8 (canceled) ### Claim 9 (depends on 1) The electronic device of claim 1, further comprising a thermal interface material (TIM) disposed between the flexible heat spreader and the integrated circuit, wherein when in the second actuation mode, the actuator applies a force against the flexible heat spreader to reduce a contact impedance between the TIM and the integrated circuit. ### Claim 10 (depends on 1) The electronic device of claim 1, further comprising an exterior housing of the electronic device, wherein: when in the first actuation mode, the actuator positions the flexible heat spreader to maintain a temperature of the exterior housing to less than a skin temperature limit of the exterior housing, and when in the second actuation mode, the actuator positions the flexible heat spreader to maintain a temperature of the integrated circuit to less than a junction temperature limit of the integrated circuit. ### Claim 11 (depends on 1) The electronic device of claim 1, wherein the controller is configured to receive a first temperature reading of the integrated circuit and a second temperature reading of a second component of the electronic device, and wherein the controller is configured to switch the actuator to the second actuation mode if both the first temperature reading is greater than or equal to a junction temperature limit of the integrated circuit and the second temperature reading of the second component is less than a second temperature limit associated with the second component. ### Claim 12 (depends on 11) The electronic device of claim 11, wherein the second component is an exterior housing of the electronic device. ### Claim 13 (depends on 1) The electronic device of claim 1, wherein the controller is configured to receive a first temperature reading of the integrated circuit and a second temperature reading of a second component of the electronic device, and wherein the controller is configured to switch the actuator to the first actuation mode if both the first temperature reading is less than a junction temperature limit of the integrated circuit and the second temperature reading of the second component is greater than or equal to a second temperature limit associated with the second component. ### Claim 14 (depends on 13) The electronic device of claim 13, wherein the second component is an exterior housing of the electronic device. ### Claim 15 (depends on 1) The electronic device of claim 1, wherein the integrated circuit comprises a mobile station modem (MSM) integrated circuit of the electronic device. ### Claim 16 A method of thermally modulating an electronic device that includes an integrated circuit, a flexible heat spreader, and an actuator, the method comprising: controlling the actuator between a first actuation mode and a second actuation mode, wherein: when in the first actuation mode, the actuator positions the flexible heat spreader with an air gap between the flexible heat spreader and the integrated circuit such that the flexible heat spreader is thermally separated from the integrated circuit to increase a thermal impedance between the flexible heat spreader and the integrated circuit, and when in the second actuation mode, the actuator positions the flexible heat spreader in thermal contact with the integrated circuit without the air gap there between to reduce the thermal impedance between the flexible heat spreader and the integrated circuit; switching the actuator from the first actuation mode to the second actuation mode during a benchmarking procedure performed by the electronic device, wherein the benchmarking procedure includes one or more operations to measure a performance of the integrated circuit; and switching the actuator back to the first actuation mode upon completion of the benchmarking procedure. ### Claim 17 (depends on 16) The method of claim 16, further comprising: receiving a first temperature reading of the integrated circuit; receiving a second temperature reading of a second component of the electronic device; and switching the actuator between the first actuation mode and the second actuation mode in response to the first temperature reading and the second temperature reading. ### Claim 18 (depends on 17) The method of claim 17, further comprising: switching the actuator to the first actuation mode in response to both the first temperature reading being less than a junction temperature limit of the integrated circuit and the second temperature reading of the second component being greater than or equal to a second temperature limit associated with the second component; and switching the actuator to the second actuation mode in response to both the first temperature reading being greater than or equal to a junction temperature limit of the integrated circuit and the second temperature reading of the second component being less than a second temperature limit associated with the second component. ### Claim 19 (canceled) ### Claim 20 (depends on 17) The method of claim 17, wherein the second component is an exterior housing of the electronic device. ### Claim 21 An electronic device, comprising: an integrated circuit; a heat spreading means for dispersing heat generated by the integrated circuit; an actuator means for positioning the heat spreading means in a first position while in a first actuation mode and in a second position while in a second actuation mode; and a means for controlling the actuator means between the first actuation mode and the second actuation mode, wherein when in the first actuation mode, the first position comprises the flexible heat spreader positioned with an air gap between the flexible heat spreader and the integrated circuit such that the flexible heat spreader is thermally separated from the integrated circuit to increase a thermal impedance between the flexible heat spreader and the integrated circuit, and when in the second actuation mode, the second position comprises the flexible heat spreader positioned in thermal contact with the integrated circuit without the air gap there between to reduce the thermal impedance between the flexible heat spreader and the integrated circuit; means for switching the actuator means from the first actuation mode to the second actuation mode during a benchmarking procedure performed by the electronic device, wherein the benchmarking procedure includes one or more operations to measure a performance of the integrated circuit; and means for switching the actuator means back to the first actuation mode upon completion of the benchmarking procedure. ### Claim 22 (depends on 21) The electronic device of claim 21, further comprising: a thermal interface material (TIM) disposed on and in thermal contact with the integrated circuit, wherein when in the first actuation mode, the actuator means positions the heat spreading means with the air gap between the heat spreading means and the TIM such that the heat spreading means is physically separated from the TIM to increase the thermal impedance between the heat spreading means and the integrated circuit, and when in the second actuation mode, the actuator means positions the heat spreading means in physical contact with the TIM without the air gap there between to reduce the thermal impedance between the heat spreading means and the integrated circuit. ### Claim 23 (depends on 21) The electronic device of claim 21, further comprising: a thermal interface material (TIM) disposed on and in thermal contact with the heat spreading means, wherein when in the first actuation mode, the actuator means positions the heat spreading means with the air gap between the TIM and the integrated circuit such that the TIM is physically separated from the integrated circuit to increase the thermal impedance between the heat spreading means and the integrated circuit, and when in the second actuation mode, the actuator means positions the heat spreading means such that the TIM is in physical contact with the integrated circuit without the air gap there between to reduce the thermal impedance between the heat spreading means and the integrated circuit. ### Claim 24 A wireless mobile station, comprising: an integrated circuit disposed within an exterior housing of the wireless mobile station; a flexible heat spreader comprising a structure configured to disperse heat generated by the integrated circuit to at least the exterior housing, the structure selected from the group consisting of a graphite sheet, a metal sheet, a copper sheet, and a mid-frame of the wireless mobile station; an actuator comprising a piezo electric layer coupled to the flexible heat spreader; and a controller coupled to the actuator and configured to control the actuator between a first actuation mode and a second actuation mode, wherein the controller is configured to switch the actuator to the second actuation mode by applying an actuation voltage to the piezo electric layer and to switch the actuator to the first actuation mode by removing the actuation voltage from the piezo electric layer, wherein: when in the first actuation mode, the actuator positions the flexible heat spreader with an air gap between the flexible heat spreader and the integrated circuit such that the flexible heat spreader is thermally separated from the integrated circuit to increase a thermal impedance between the flexible heat spreader and the integrated circuit, wherein the piezo electric layer is configured to have a planar non-curved shape when the actuator is in the first actuation mode, when in the second actuation mode, the actuator positions the flexible heat spreader in thermal contact with the integrated circuit without the air gap there between to reduce the thermal impedance between the flexible heat spreader and the integrated circuit, wherein the piezo electric layer is configured to have a curved shape when the actuator is in the second actuation mode, the controller is configured to switch the actuator from the first actuation mode to the second actuation mode during a benchmarking procedure performed by the electronic device, wherein the benchmarking procedure includes one or more operations to measure a performance of the integrated circuit, and the controller is configured to switch the actuator back to the first actuation mode upon completion of the benchmarking procedure. ### Claim 25 (canceled) ### Claim 26 (depends on 24) The wireless mobile station of claim 24, wherein the integrated circuit comprises a mobile station modem (MSM) integrated circuit of the wireless mobile station. ### Claim 27 (depends on 24) The wireless mobile station of claim 24, further comprising: a thermal interface material (TIM) disposed on and in thermal contact with the integrated circuit, wherein when in the first actuation mode, the actuator positions the flexible heat spreader with the air gap between the flexible heat spreader and the TIM such that the flexible heat spreader is physically separated from the TIM to increase the thermal impedance between the flexible heat spreader and the integrated circuit, and when in the second actuation mode, the actuator positions the flexible heat spreader in physical contact with the TIM without the air gap there between to reduce the thermal impedance between the flexible heat spreader and the integrated circuit. ### Claim 28 (depends on 24) The wireless mobile station of claim 24, further comprising: a thermal interface material (TIM) disposed on and in thermal contact with the flexible heat spreader, wherein when in the first actuation mode, the actuator positions the flexible heat spreader with the air gap between the TIM and the integrated circuit such that the TIM is physically separated from the integrated circuit to increase the thermal impedance between the flexible heat spreader and the integrated circuit, and when in the second actuation mode, the actuator positions the flexible heat spreader such that the TIM is in physical contact with the integrated circuit without the air gap there between to reduce the thermal impedance between the flexible heat spreader and the integrated circuit. ### Claim 29 (depends on 24) The wireless mobile station of claim 24, wherein the controller is configured to receive a first temperature reading of the integrated circuit and a second temperature reading of the exterior housing, and wherein the controller is configured to switch the actuator to the second actuation mode if both the first temperature reading is greater than or equal to a junction temperature limit of the integrated circuit and the second temperature reading of the exterior housing is less than a second temperature limit associated with the exterior housing. ### Claim 30 (depends on 24) The wireless mobile station of claim 24, wherein the controller is configured to receive a first temperature reading of the integrated circuit and a second temperature reading of the exterior housing, and wherein the controller is configured to switch the actuator to the first actuation mode if both the first temperature reading is less than a junction temperature limit of the integrated circuit and the second temperature reading of the exterior housing is greater than or equal to a second temperature limit associated with the exterior housing.