# US 8,787,600 B2 · Assembly of a capacitive acoustic transducer of the microelectromechanical type and package thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,600 B2 - Document ID: US8787600B2 - Status: Granted - Kind: B2 - Application number: 13/861,324 - Filed: 2013-04-11 - Published: 2013-08-29 - Granted: 2014-07-22 - Earliest claimed: 2009-05-11 - Assignees: STMicroelectronics S.r.l. - Applicants: STMicroelectronics S.r.l. - Inventors: Sebastiano Conti; Benedetto Vigna; Mario Francesco Cortese - Web page: https://patentgrep.com/patent/US8787600B2 ## CPC - B81C 1/00158: {Diaphragms, membranes (manufacture process for semi-permeable inorganic membranes B01D67/0039)} - B81B 3/0018: {Structures acting upon the moving or flexible element for transforming energy into mechanical movement or vice versa, i.e. actuators, sensors, generators} - B81B 7/0061: {suitable for fluid transfer from the MEMS out of the package or vice versa, e.g. transfer of liquid, gas, sound} - H04R 1/2838: {of the bandpass type} - H04R 19/005: {using semiconductor materials} - H04R 19/04: Microphones (H04R19/01 takes precedence) - B81B 2201/0257: Microphones or microspeakers - H04R 1/04: Structural association of microphone with electric circuitry therefor (in electric hearing aids H04R25/00) - H04R 1/06: Arranging circuit leads; Relieving strain on circuit leads - H04R 1/086: {Protective screens, e.g. all weather or wind screens} - H04R 2201/003: Mems transducers or their use - H10W 72/5434: {the connected ends being on auxiliary connecting means on bond pads, e.g. on other bond wires} - H10W 90/752: {between stacked chips} - H10W 90/753: {between laterally-adjacent chips} - 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) - B81B: MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES (piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/00, H10N35/00) - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract A microelectromechanical-acoustic-transducer assembly has: a first die integrating a MEMS sensing structure having a membrane, which has a first surface in fluid communication with a front chamber and a second surface, opposite to the first surface, in fluid communication with a back chamber of the microelectromechanical acoustic transducer, is able to undergo deformation as a function of incident acoustic-pressure waves, and faces a rigid electrode so as to form a variable-capacitance capacitor; a second die, integrating an electronic reading circuit operatively coupled to the MEMS sensing structure and supplying an electrical output signal as a function of the capacitive variation; and a package, housing the first die and the second die and having a base substrate with external electrical contacts. The first and second dice are stacked in the package and directly connected together mechanically and electrically; the package delimits at least one of the front and back chambers. ## Claims ### Claim 1 An assembly comprising: a microelectromechanical (MEMS) sensor integrated in a first die of semiconductor material that includes upper and lower surfaces and having active surfaces at the upper surface that are configured to sense a change in capacitance; an electronic circuit integrated in a second die of semiconductor material, the electronic circuit operatively coupled to said MEMS sensor, the first die being stacked on the second die, the second die having a plurality of through holes that place the active surfaces of the MEMS sensor in fluid communication with an environment external to the assembly; and a cap located above the first die and second die, the cap, the first die, and the second die forming a cavity therebetween. ### Claim 2 (depends on 1) The assembly of claim 1, wherein the plurality of through holes act as a filter. ### Claim 3 (depends on 1) The assembly of claim 1, wherein one of the active surfaces of the MEMS sensor is a membrane. ### Claim 4 (depends on 3) The assembly of claim 3, wherein the MEMS sensor is a microphone. ### Claim 5 (depends on 1) The assembly of claim 1, further comprising a substrate, the electronic circuit being secured to an upper surface of the substrate and the cap being secured to an upper surface of the substrate. ### Claim 6 (depends on 5) The assembly of claim 5, wherein the substrate has a through hole that is substantially concentric with one of the plurality of through holes of the second die. ### Claim 7 (depends on 1) The assembly of claim 1, wherein the first die is coupled to the second die by wire bonds. ### Claim 8 An electronic device comprising: a central processing unit; an assembly electrically coupled to the central processing unit, the assembly including: a substrate having first and second surfaces and a through hole extending from the first surface to the second surface; a microelectromechanical (MEMS) sensor integrated in a first die of semiconductor material and configured to sense a change in capacitance; an electronic circuit integrated in a second die of semiconductor material, the electronic circuit operatively coupled to said MEMS sensor, the first die being stacked on the second die and the second die located on the first surface of the substrate, the second die having a plurality of through holes that are located above with the through hole of the substrate and places a portion of the MEMS sensor in fluid communication with an external environment; and a cap coupled to the first surface of the substrate and covering the first die and the second die and forming a cavity therebetween. ### Claim 9 (depends on 8) The electronic device of claim 8, wherein the second die includes a plurality of through holes that place the portion of the MEMS sensor in fluid communication with the external environment. ### Claim 10 (depends on 8) The electronic device of claim 8, wherein the plurality of through holes act as a filter. ### Claim 11 A method comprising: stacking a first die of semiconductor material that integrates an electronic circuit and has a plurality of through holes onto a first surface of a substrate, the substrate having a through hole, the stacking including aligning the plurality of through holes of the first die with the through hole of the substrate; stacking a microelectromechanical (MEMS) sensor integrated in a second die of semiconductor material and configured to sense a change in capacitance on to the first die of semiconductor material, the stacking including aligning a membrane of the second die with the plurality of through holes of the first die and with the through hole of the substrate, wherein the plurality of through holes of the first die and the through of the substrate place the membrane in fluid communication with an environment outside of the stack; electrically coupling the MEMS of the second die to the electronic circuit of the first die; and covering the second die and at least a portion of the first die by coupling a cap to the first surface of the substrate. ### Claim 12 (depends on 11) The method of claim 11, wherein the plurality of through holes act as a filter. ### Claim 13 (depends on 11) The method of claim 11, wherein stacking said MEMS sensor includes aligning a membrane of the second die with the plurality of through holes of the first die.