# US 9,040,355 B2 · Sensor package and method of forming same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,040,355 B2 - Document ID: US9040355B2 - Status: Granted - Kind: B2 - Application number: 13/546,902 - Filed: 2012-07-11 - Published: 2014-01-16 - Granted: 2015-05-26 - Earliest claimed: 2012-07-11 - Assignees: Freescale Semiconductor, Inc. - Applicants: Philip H. Bowles; Paige M. Holm; Stephen R. Hooper; Raymond M. Roop - Inventors: Philip H. Bowles; Paige M. Holm; Stephen R. Hooper; Raymond M. Roop - Web page: https://patentgrep.com/patent/US9040355B2 ## CPC - B81B 7/0006: {Interconnects} - B81B 7/0077: {Other packages not provided for in groups B81B7/0035 - B81B7/0074} - B81C 1/0023: {Packaging together an electronic processing unit die and a micromechanical structure die (MEMS packages B81B7/0032; MEMS packaging processes B81C1/00261)} - B81B 2201/02: Sensors - B81B 2203/0127: Diaphragms, i.e. structures separating two media that can control the passage from one medium to another; Membranes, i.e. diaphragms with filtering function - H10W 72/536: {the connected ends being ball-shaped} - 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) - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract A method (70) of forming sensor packages (20) entails providing a sensor wafer (74) having sensors (30) formed on a side (26) positioned within areas (34) delineated by bonding perimeters (36), and providing a controller wafer (82) having control circuitry (42) at one side (38) and bonding perimeters (46) on an opposing side (40). The bonding perimeters (46) of the controller wafer (82) are bonded to corresponding bonding perimeters (36) of the sensor wafer (74) to form a stacked wafer structure (48) in which the control circuitry (42) faces outwardly. The controller wafer (82) is sawn to reveal bond pads (32) on the sensor wafer (74) which are wire bonded to corresponding bond pads (44) formed on the same side (38) of the wafer (82) as the control circuitry (42). The structure (48) is encapsulated in packaging material (62) and is singulated to produce the sensor packages (20). ## Claims ### Claim 1 A method of forming sensor packages comprising: providing a sensor wafer having a first side and a second side opposite said first side, said first side including sensors positioned within areas on said first side delineated by first bonding perimeters, and said sensor wafer including first bond pads formed on said first side outside of said areas delineated by said first bonding perimeters; providing a controller wafer having a third side and a fourth side opposite said third side, said third side including control circuitry and second bond pads, and said fourth side including second bonding perimeters; bonding said second bonding perimeters of said controller wafer to said first bonding perimeters of said sensor wafer to form a stacked wafer structure that includes multiple sensor packages; removing portions of said controller wafer to reveal said first bond pads formed on said first side of said sensor wafer; attaching bond wires between corresponding ones of said first and second bond pads; and singulating said stacked wafer structure to produce said sensor packages. ### Claim 2 (depends on 1) A method as claimed in claim 1 wherein said controller wafer exhibits an initial thickness, and said method further comprises prior to said bonding operation, backgrinding said fourth side of said controller wafer to a final thickness that is less than said initial thickness. ### Claim 3 (depends on 1) A method as claimed in claim 1 further comprising applying bonding material to said fourth side of said controller wafer at said second bonding perimeters. ### Claim 4 (depends on 1) A method as claimed in claim 1 further comprising forming features at said fourth side of said controller wafer prior to said bonding operation, said features being functional components of said sensors located at said first side of said sensor wafer. ### Claim 5 (depends on 4) A method as claimed in claim 4 wherein said features include cavities, and said forming operation comprises forming said cavities extending into said controller wafer from said fourth side such that said cavities are aligned with said sensors following said bonding operation. ### Claim 6 (depends on 4) A method as claimed in claim 4 wherein said features include electrodes, and said forming operation comprises forming said electrodes on said fourth side such that said electrodes are aligned with said sensors following said bonding operation. ### Claim 7 (depends on 1) A method as claimed in claim 1 wherein said sensor wafer exhibits an initial thickness, and said method further comprises backgrinding said second side of said sensor wafer following said bonding operation to a final thickness that is less than said initial thickness. ### Claim 8 (depends on 1) A method as claimed in claim 1 wherein said removing and attaching operations are performed prior to said singulating operation. ### Claim 9 (depends on 1) A method as claimed in claim 1 wherein said controller wafer includes bump pads formed on said third side, and said method further comprises forming conductive elements on said bump pads following said bonding operation. ### Claim 10 (depends on 9) A method as claimed in claim 9 further comprising applying a packaging material over said third side of said controller wafer to encapsulate said control circuitry and to at least partially encapsulate said conductive elements. ### Claim 11 (depends on 1) A method as claimed in claim 1 further comprising mounting sensor dies on said third side of said controller wafer following said bonding operation. ### Claim 12 A method of forming sensor packages comprising: providing a sensor wafer having a first side and a second side opposite said first side, said first side including sensors positioned within areas on said first side delineated by first bonding perimeters; providing a controller wafer having a third side and a fourth side opposite said third side, said third side including control circuitry and said fourth side including second bonding perimeters; bonding said second bonding perimeters of said controller wafer to said first bonding perimeters of said sensor wafer to form a stacked wafer structure that includes multiple sensor packages; applying a packaging material over said third side of said controller wafer to encapsulate said control circuitry; and singulating said stacked wafer structure to produce said sensor packages, said singulating operation being performed following said applying operation. ### Claim 13 A method of forming sensor packages comprising: providing a sensor wafer having a first side and a second side opposite said first side, said first side including sensors positioned within areas on said first side delineated by first bonding perimeters, and said first side further including first bond pads positioned outside of said areas; providing a controller wafer having a third side and a fourth side opposite said third side, said third side including control circuitry and second bond pads, and said fourth side including second bonding perimeters; bonding said second bonding perimeters of said controller wafer to said first bonding perimeters of said sensor wafer to form a stacked wafer structure that includes multiple sensor packages; removing portions of said controller wafer to reveal said first bond pads formed on said first side of said sensor wafer; attaching bond wires between corresponding ones of said first and second bond pads; applying a packaging material over said third side of said controller wafer to encapsulate said control circuitry and said bond wires; and following said applying operation, singulating said stacked wafer structure to produce said sensor packages. ### Claim 14 (depends on 13) A method as claimed in claim 13 wherein said controller wafer exhibits an initial thickness, and said method further comprises prior to said bonding operation, backgrinding said fourth side of said controller wafer to a final thickness that is less than said initial thickness. ### Claim 15 (depends on 13) A method as claimed in claim 13 further comprising forming features at said fourth side of said controller wafer prior to said bonding operation, said features being functional components of said sensors located at said first side of said sensor wafer.