# US 10,370,244 B2 · Deposition of protective material at wafer level in front end for early stage particle and moisture protection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,370,244 B2 - Document ID: US10370244B2 - Status: Granted - Kind: B2 - Application number: 15/827,057 - Filed: 2017-11-30 - Published: 2019-05-30 - Granted: 2019-08-06 - Earliest claimed: 2017-11-30 - Assignees: Infineon Technologies AG - Applicants: Infineon Technologies AG - Inventors: Florian Brandl; Manfred Fries; Franz-Peter Kalz - Web page: https://patentgrep.com/patent/US10370244B2 ## CPC - B81C 1/00285: {using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters} - B81B 7/0025: {Protection against chemical alteration} - B81B 7/0029: {Protection against environmental influences not provided for in groups B81B7/0012 - B81B7/0025} - B81B 7/0038: {using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters} - B81B 7/0045: {for reducing stress inside of the package structure} - B81B 7/0048: {between the MEMS die and the substrate} - B81B 7/0051: {between the package lid and the substrate} - B81C 1/00063: {Trenches} - B81C 1/0019: {Flexible or deformable structures not provided for in groups B81C1/00142 - B81C1/00182} - B81C 1/00301: {Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias} - B81C 1/0038: {Processes for creating layers of materials not provided for in groups B81C1/00357 - B81C1/00373} - B81C 1/00904: {Multistep processes for the separation of wafers into individual elements not provided for in groups B81C1/00873 - B81C1/00896} - H10W 76/12: characterised by their shape - H10W 76/60: Seals - H10W 95/00: Packaging processes not covered by the other groups of this subclass - B29C 35/02: Heating or curing, e.g. crosslinking or vulcanizing {during moulding, e.g. in a mould}(cold vulcanisation B29C35/18 {; vulcanising tyres, presses therefor B29D30/0601}) - 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) - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) ## Abstract A semiconductor device and a method of manufacturing the same are provided such that a microelectromechanical systems (MEMS) element is protected at an early manufacturing stage. A method for protecting a MEMS element includes: providing at least one MEMS element, having a sensitive area, on a substrate; and depositing, prior to a package assembly process, a protective material over the sensitive area of the at least one MEMS element such that the sensitive area of at least one MEMS element is sealed from an external environment, where the protective material permits a sensor functionality of the at least one MEMS element. ## Claims ### Claim 1 A method of protecting a microelectromechanical systems (MEMS) element, comprising: providing at least one MEMS element, comprising a sensitive area, on a substrate; depositing, prior to a package assembly process, a protective material over the sensitive area of the at least one MEMS element such that the sensitive area of at least one MEMS element is sealed from an external environment, wherein the protective material permits a sensor functionality of the at least one MEMS element; forming at least one stop frame on the substrate at a region that surrounds the at least one MEMS element, wherein the at least one stop frame is configured to confine the protective material inside the region curing the protective material; and removing the at least one stop frame subsequent to curing the protective material. ### Claim 2 (depends on 1) The method of claim 1, further comprising: separating a portion of the substrate that includes the at least one MEMS element to form a chip, wherein the chip includes at least one stress-decoupling trench laterally spaced from the at least one MEMS element and extending into the substrate, and the protective material is confined to an area within a region defined by the at least one stress-decoupling trench. ### Claim 3 (depends on 1) The method of claim 1, wherein the at least one stop frame comprises imide, SU-8, or silicone, each having a higher degree of elastic modulus than the protective material. ### Claim 4 (depends on 1) The method of claim 1, further comprising: separating a portion of the substrate that includes the at least one MEMS element to form a chip, wherein the chip includes at least one stress-decoupling trench at an edge of the region such that the at least one stop frame is formed proximate to the at least one stress-decoupling trench and is configured to prevent the protective material from entering the at least one stress-decoupling trench. ### Claim 5 (depends on 1) The method of claim 1, further comprising: depositing a coating on the substrate at a region that surrounds the at least one MEMS element, wherein the coating is configured to confine the protective material inside the region. ### Claim 6 (depends on 1) The method of claim 1, further comprising: performing the package assembly process, including mounting a chip to a package, wherein the chip includes a portion of the substrate that includes the at least one MEMS element and that further includes the protective material disposed over the sensitive area of the at least one MEMS element. ### Claim 7 (depends on 1) The method of claim 1, wherein depositing the protective material comprises: depositing the protective material as a locally defined droplet confined to a local region of the substrate that surrounds the at least one MEMS element. ### Claim 8 (depends on 7) The method of claim 7, wherein the protective material is deposited using inkjet printing or micro dispensing. ### Claim 9 (depends on 1) The method of claim 1, wherein each of the at least one MEMS element is a pressure sensor. ### Claim 10 (depends on 1) The method of claim 1, wherein the protective material is a temperature hardening gel or a ultraviolet (UV) hardening gel. ### Claim 11 (depends on 1) The method of claim 1, wherein protective material permits full sensor functionality of the MEMS element, including mechanical functionality and electrical functionality, while sealing an entire surface of the at least one MEMS element. ### Claim 12 (depends on 1) The method of claim 1, wherein the protective material is a permanent protective material deposited in between a front end process and a preassembly process or between the preassembly process and the package assembly process. ### Claim 13 A semiconductor device comprising: a semiconductor chip comprising: a substrate; at least one microelectromechanical systems (MEMS) element, comprising a sensitive area, disposed at a surface of the substrate; and a protective material disposed over the sensitive area of the at least one MEMS element such that the sensitive area of at least one MEMS element is sealed from an external environment, wherein the protective material is configured to permit a sensor functionality of the at least one MEMS element; a package to which the semiconductor chip is mounted, wherein the package includes encapsulation material that is excluded from a first region, the first region extending over the sensitive area of the at least one MEMS element; at least one stress-decoupling trench laterally spaced from the at least one MEMS element and extending into the substrate, and the protective material is confined to an area within a region defined by the at least one stress-decoupling trench, wherein the at least one stress-decoupling trench defines an inside region of the surface of the substrate and a peripheral region of the surface of the substrate, and the encapsulation material is attached to the surface of the substrate at the peripheral region, and the first region is defined at least by the inside region. ### Claim 14 (depends on 13) The semiconductor device of claim 13, wherein the semiconductor chip further comprises: at least one stop frame disposed on the surface of the substrate at a second region, the second region surrounding the at least one MEMS element, wherein the at least one stop frame is configured to confine the protective material inside the second region. ### Claim 15 (depends on 14) The semiconductor device of claim 14, wherein the at least one stop frame comprises imide, SU-8, or silicone, each having a higher degree of elastic modulus than the protective material. ### Claim 16 (depends on 14) The semiconductor device of claim 14, wherein the at least one stress-decoupling trench is at an edge of the second region such that the at least one stop frame is formed proximate to the at least one stress-decoupling trench and is configured to prevent the protective material from entering the at least one stress-decoupling trench. ### Claim 17 (depends on 13) The semiconductor device of claim 13, wherein: each of the at least one MEMS element is a pressure sensor, the protective material is a locally defined droplet confined to a local region of the substrate that surrounds the at least one MEMS element, and the protective material permits full sensor functionality of the MEMS element, including mechanical functionality and electrical functionality, while sealing an entire surface of the at least one MEMS element. ### Claim 18 A semiconductor device comprising: a semiconductor chip comprising: a substrate; at least one microelectromechanical systems (MEMS) element, comprising a sensitive area, disposed at a surface of the substrate; and a protective material disposed over the sensitive area of the at least one MEMS element such that the sensitive area of at least one MEMS element is sealed from an external environment, wherein the protective material is configured to permit a sensor functionality of the at least one MEMS element; a package to which the semiconductor chip is mounted, wherein the package includes encapsulation material that is excluded from a first region, the first region extending over the sensitive area of the at least one MEMS element; at least one stop frame disposed on the surface of the substrate at a second region, the second region surrounding the at least one MEMS element, wherein the at least one stop frame is configured to confine the protective material inside the second region; and a seal ring disposed on the surface of the substrate at a third region, the third region spaced apart from and surrounding the at least one stop frame, wherein the encapsulation material is attached to the surface of the substrate peripheral to the third region and is excluded from the surface of the substrate internal to the third region. ### Claim 19 (depends on 18) The semiconductor device of claim 18, wherein the encapsulation material is disposed onto the seal ring.