# US 10,373,996 B2 · Optical modules including focal length adjustment and fabrication of the optical modules > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,373,996 B2 - Document ID: US10373996B2 - Status: Granted - Kind: B2 - Application number: 15/651,510 - Filed: 2017-07-17 - Published: 2017-11-02 - Granted: 2019-08-06 - Earliest claimed: 2012-11-02 - Assignees: ams Sensors Singapore Pte. Ltd. - Applicants: ams Sensors Singapore Pte. Ltd. - Inventors: Stephan Heimgartner; Ville Kettunen; Nicola Spring; Alexander Bietsch; Mario Cesana; Hartmut Rudmann; Jukka Alasirnio; Robert Lenart - Web page: https://patentgrep.com/patent/US10373996B2 ## CPC - H10F 39/806: {Optical elements or arrangements associated with the image sensors} - B29D 11/00307: {Producing lens wafers} - B29D 11/00403: {Producing compound lenses} - G02B 27/0025: {for optical correction, e.g. distorsion, aberration} - H04N 23/55: Optical parts specially adapted for electronic image sensors; Mounting thereof - H10F 39/024: {of coatings or optical elements} - H10F 39/026: {Wafer-level processing} - H10F 39/8053: {Colour filters} - H10F 39/8063: {Microlenses} - H10F 77/331: {for filtering or shielding light, e.g. multicolour filters for photodetectors} - H10F 77/334: {for shielding light, e.g. light blocking layers or cold shields for infrared detectors} - H10F 77/407: {indirectly associated with the devices} - Y10T 29/49826: Assembling or joining - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Fabricating optical devices can include mounting a plurality of singulated lens systems over a substrate, adjusting a thickness of the substrate below at least some of the lens systems to provide respective focal length corrections for the lens systems, and subsequently separating the substrate into a plurality of optical modules, each of which includes one of the lens systems mounted over a portion of the substrate. Adjusting a thickness of the substrate can include, for example, micro-machining the substrate to form respective holes below at least some of the lens systems or adding one or more layers below at least some of the lens systems so as to correct for variations in the focal lengths of the lens systems. ## Claims ### Claim 1 A method of fabricating optical devices, the method comprising: attaching, over a substrate that is transparent to light of a particular wavelength or range of wavelengths, a wafer stack that includes a plurality of lens systems adjacent one another, the wafer stack including a plurality of wafers separated from one another by a first spacer, the wafer stack including a surface of one of the plurality of wafers farthest from the substrate; forming openings in portions of the wafer stack that separate the lens systems from one another, the openings being formed in a direction perpendicular to a plane of the substrate, each particular one of the openings extending from a plane that is flush with the surface of the wafer farthest from the substrate, the openings extending at least partially into a second spacer that separates the substrate from the plurality of wafers; injecting a material into the openings, wherein the material is non-transparent to light of the particular wavelength or range of wavelengths, wherein the non-transparent material injected into the openings substantially fills the openings at least up to the surface of the wafer farthest from the substrate; adjusting a thickness of one or more regions of the substrate to provide focal length correction for a respective one or more of the lens systems; and separating the substrate into a plurality of optical modules, each of which includes one or more of the lens systems mounted over a respective portion of the substrate. ### Claim 2 (depends on 1) The method of claim 1 wherein at least one of the first spacer or the second spacer is non-transparent to light of the particular wavelength or range of wavelengths, optical elements being disposed on the plurality of wafers to form the lens systems, wherein each optical module of the plurality of optical modules includes lateral sides of sections of wafers, on which the lenses are disposed, covered by the material that is non-transparent to light of the particular wavelength or range of wavelengths. ### Claim 3 (depends on 1) The method of claim 1 wherein the openings are trenches. ### Claim 4 (depends on 3) The method of claim 3 including forming the trenches so as to extend through an entire thickness of the plurality of wafers. ### Claim 5 (depends on 3) The method of claim 3 including forming the trenches so as to extend to an upper surface of the substrate. ### Claim 6 (depends on 1) The method of claim 1 wherein the non-transparent material is injected into the openings in the wafer stack by vacuum injection. ### Claim 7 (depends on 1) The method of claim 1 wherein the non-transparent material is injected into the openings in the wafer stack using a vacuum injection PDMS tool. ### Claim 8 (depends on 1) The method of claim 1 wherein the non-transparent material injected into the openings comprises a UV-curing polymer. ### Claim 9 (depends on 1) The method of claim 1 wherein the non-transparent material injected into the openings comprises a thermally-curing polymer. ### Claim 10 (depends on 1) The method of claim 1 wherein the non-transparent material injected into the openings comprises a polymer containing a dark pigment, an inorganic filler or a dye. ### Claim 11 (depends on 1) The method of claim 1 wherein the non-transparent material injected into the openings provides a surface that is substantially flush with the surface of the wafer farthest from the substrate. ### Claim 12 (depends on 1) The method of claim 1 wherein the non-transparent material injected into the openings is composed of a same material as at least one of the first spacer or the second spacer. ### Claim 13 (depends on 1) The method of claim 1 wherein adjusting a thickness of one or more regions of the substrate to provide focal length correction includes removing selected portions of the substrate. ### Claim 14 (depends on 1) The method of claim 1 wherein adjusting a thickness of one or more regions of the substrate to provide focal length correction includes adding one or more layers on the substrate. ### Claim 15 A method of fabricating optical modules, the method comprising: providing a wafer/spacer stack attached to a flange focal length correction substrate, wherein the wafer/spacer stack includes a plurality of wafers separated from one another by a first spacer, the wafer/spacer stack being separated from the flange focal length correction substrate by a second spacer, the first and second spacers being composed of a material that is non-transparent to light of a particular wavelength or range of wavelengths, optical elements being disposed on the plurality of wafers to form lens systems, and the wafer/spacer stack including a surface of one of the plurality of wafers farthest from the flange focal length correction substrate; forming trenches in respective portions of the wafer/spacer stack, the trenches separating the lens systems from one another, each particular one of the trenches extending from a plane that is flush with the surface of the wafer farthest from the substrate, the trenches extending at least partially into the second spacer that separates the substrate from the wafer/spacer stack; injecting a material into the trenches, wherein the injected material is non-transparent to light of the particular wavelength or range of wavelengths, wherein the non-transparent material injected into the trenches substantially fills the trenches at least up to the surface of the wafer farthest from the flange focal length correction substrate; and adjusting a thickness of one or more regions of the flange focal length correction substrate to provide focal length correction for a respective one or more of the lens systems. ### Claim 16 (depends on 15) The method of claim 15 including forming the trenches so as to extend through an entire thickness of the plurality of wafers. ### Claim 17 (depends on 15) The method of claim 15 wherein the non-transparent material injected into the trenches is injected by a vacuum injection technique. ### Claim 18 (depends on 15) The method of claim 15 wherein the non-transparent material injected into the trenches comprises at least one of a UV-curing polymer or a thermally-curing polymer.