# US 10,312,185 B2 · Inductively coupled microelectromechanical system resonator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,312,185 B2 - Document ID: US10312185B2 - Status: Granted - Kind: B2 - Application number: 15/726,284 - Filed: 2017-10-05 - Published: 2019-04-11 - Granted: 2019-06-04 - Earliest claimed: 2017-10-05 - Assignees: Texas Instrument Incorporated - Applicants: Texas Instruments Incorporated - Inventors: Bichoy Bahr; Baher Haroun; Ali Kiaei - Web page: https://patentgrep.com/patent/US10312185B2 ## CPC - H10W 70/421: {Shapes or dispositions} - B81B 7/0048: {between the MEMS die and the substrate} - B81B 7/02: containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS] (B81B7/04 takes precedence) - B81C 1/0023: {Packaging together an electronic processing unit die and a micromechanical structure die (MEMS packages B81B7/0032; MEMS packaging processes B81C1/00261)} - G01C 19/56: Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces - H10W 20/497: {Inductive arrangements or effects of, or between, wiring layers} - H10W 70/411: {Chip-supporting parts, e.g. die pads} - H10W 70/424: {Cross-sectional shapes (H10W70/481 takes precedence)} - H10W 72/50: Bond wires - H10W 90/811: {Multiple chips on leadframes} - B81B 2201/0271: Resonators; ultrasonic resonators - B81B 2207/012: the micromechanical device and the control or processing electronics being separate parts in the same package - B81C 2203/0154: Moulding a cap over the MEMS device - B81C 2203/0792: Forming interconnections between the electronic processing unit and the micromechanical structure - H10W 72/252: {comprising solid metals or solid metalloids, e.g. PbSn, Ag or Cu} - H10W 72/865: {Die-attach connectors and bond wires} - H10W 72/884: {Die-attach connectors and bond wires} - H10W 90/724: {between a chip and a stacked insulating package substrate, interposer or RDL} - H10W 90/732: {between stacked chips} - H10W 90/752: {between stacked chips} - H10W 90/753: {between laterally-adjacent chips} - H10W 90/756: {between a chip and a stacked lead frame, conducting package substrate or heat sink} - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - B81B: MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES (piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/00, H10N35/00) - B81C: PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS (making microcapsules or microballoons B01J13/02; processes or apparatus specially adapted for the manufacture or treatment of piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/01) - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) ## Abstract An integrated circuit package includes a first die that has a microelectromechanical system (MEMS) resonator coupled to a coil. A second die includes a coil fabricated on a top surface of the second die, and an electronic circuit with tank circuit terminals fabricated on the second die and coupled to the second coil. The second die is positioned adjacent the first die such that the first coil is operable to electromagnetically couple to the second coil. ## Claims ### Claim 1 An integrated circuit (IC) comprising: a first die having a first coil fabricated on a top surface of the first die, and a microelectromechanical (MEMS) resonator fabricated on the first die and coupled to the first coil; a second die having a second coil fabricated on a top surface of the second die, and an electronic circuit with tank circuit terminals fabricated on the second die and coupled to the second coil; and wherein the second die is positioned adjacent the first die such that the first coil is operable to electromagnetically couple to the second coil. ### Claim 2 (depends on 1) The IC of claim 1, wherein the first coil has m turns, the second coil has n turns, and n is greater than m. ### Claim 3 (depends on 1) The IC of claim 1, wherein the first coil is a planer coil formed by one or more metal layers on the top surface of the first die, and the second coil is a planer coil formed by one or more metal layers on the top surface of the second die. ### Claim 4 (depends on 1) The IC of claim 1, wherein the first coil is a planer coil formed by one or more metal layers on the top surface of the first die, wherein the MEMS resonator is surrounded by the first coil. ### Claim 5 (depends on 1) The IC of claim 1, wherein the first die and the second die together are surrounded by an encapsulation material. ### Claim 6 (depends on 5) The IC of claim 5, further including: a die attach pad and lead frame contacts, wherein the second die is attached to the die attach pad; and a blob of protective material surrounds the first die separating the encapsulation material from the first die. ### Claim 7 (depends on 5) The IC of claim 5, further including: a die attach pad and lead frame contacts, wherein the second die is attached to the die attach pad; and wherein the first die is positioned in a cavity in the die attach pad such that the first die is positioned between the second die and the die attach pad. ### Claim 8 (depends on 1) The IC of claim 1, wherein the first die is flipped and mounted on the second die such that the top surface of the first die is adjacent to the top surface of the second die. ### Claim 9 (depends on 8) The IC of claim 8, further comprising a soft die attach material located between the top surface of the first die and the top surface of the second die. ### Claim 10 (depends on 9) The IC of claim 9, wherein the soft die attach material has a thickness of approximately 20 μm. ### Claim 11 (depends on 1) The IC of claim 1, further comprising solder bumps placed on the second die to form a flip-chip die. ### Claim 12 (depends on 11) The IC of claim 11, further comprising a substrate, wherein the first die is attached to the substrate and the solder bumps of the second die are attached to the substrate such the second die is positioned above the first die. ### Claim 13 (depends on 12) The IC of claim 12, further comprising encapsulation material placed on the substrate to surround the first die and the second die. ### Claim 14 (depends on 1) The IC of claim 1, wherein the electronic circuit is an oscillator circuit or a filter circuit. ### Claim 15 A method for operating an oscillator, the method comprising: using a microelectromechanical (MEMS) resonator as a tank circuit of the oscillator to produce a resonant frequency of operation, wherein the MEMS resonator is on a first substrate and the oscillator is on a second substrate separated from the first substrate; and inductively coupling the MEMS resonator to the oscillator using a first coil on the first substrate positioned in proximity to a second coil on the second substrate. ### Claim 16 (depends on 15) The method of claim 15, wherein the first coil has m turns, the second coil has n turns, and n is greater than m. ### Claim 17 (depends on 15) The method of claim 15, further comprising: fabricating the oscillator circuit on the first substrate; and fabricating the second coil as a planar inductor in one or more metallic layers on a surface of the first substrate. ### Claim 18 (depends on 15) The method of claim 15, further comprising: fabricating the. MEMS resonator on the second substrate; and fabricating the transformer as a planar inductor in one or more metallic layers on a surface of the second substrate. ### Claim 19 A method for operating an oscillator, the method comprising: placing a first device adjacent to a second device, wherein the first device includes a microelectromechanical (MEMS) resonator connected to a first coil, and the second device includes an oscillator circuit coupled to a second coil; inductively coupling the MEMS resonator to the oscillator using the first coil on the first device positioned in proximity to the second coil on the second device; and using MEMS resonator as a tank circuit of the oscillator to produce a resonant frequency of operation. ### Claim 20 (depends on 19) The method of claim 19, further comprising removing the first device from adjacent the second device to cause the oscillator to cease oscillation.