# US 11,299,421 B2 · Electronic device enclosure with a glass member having an internal encoded marking > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,299,421 B2 - Document ID: US11299421B2 - Status: Granted - Kind: B2 - Application number: 16/540,024 - Filed: 2019-08-13 - Published: 2020-11-19 - Granted: 2022-04-12 - Earliest claimed: 2019-05-13 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Michael M. Li; Dale N. Memering; Matthew N. Van Dyke - Web page: https://patentgrep.com/patent/US11299421B2 ## CPC - C03C 23/0025: {by a laser beam} - C03C 21/002: {to perform ion-exchange between alkali ions (C03C21/005 takes precedence)} - H05K 5/03: Covers - C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract An electronic device may include a housing, a display positioned at least partially within the housing, a cover assembly coupled to the housing and comprising a chemically strengthened glass member, and an encoded marking formed within the chemically strengthened glass member between an upper surface and a lower surface of the chemically strengthened glass member. The encoded marking may include an array of marks, each mark of the array of marks having a dimension between about 3 microns and about 10 microns and set apart from an adjacent mark by an unmarked area of the chemically strengthened glass member. Each mark may represent a bit of information in a binary number system. The encoded marking may be readable, by an optical magnification apparatus, through the upper surface. ## Claims ### Claim 1 An electronic device, comprising: a housing; a display positioned at least partially within the housing; a cover assembly coupled to the housing and comprising a chemically strengthened glass member; and an encoded marking formed within the chemically strengthened glass member and comprising an array of marks, each mark of at least a subset of the array of marks: having a dimension between about 3 microns and about 10 microns; set apart from an adjacent mark by an unmarked area of the chemically strengthened glass member; and positioned entirely between an upper surface of the chemically strengthened glass member and a lower surface of the chemically strengthened glass member. ### Claim 2 (depends on 1) The electronic device of claim 1, wherein: the cover assembly defines: a transparent region positioned over the display and configured to allow graphical outputs of the display to be viewed through the cover assembly; and an opaque region at least partially surrounding the transparent region; and the encoded marking is in the opaque region. ### Claim 3 (depends on 1) The electronic device of claim 1, wherein each mark represents a bit of information in a binary number system. ### Claim 4 (depends on 1) The electronic device of claim 1, wherein: the chemically strengthened glass member defines: a first compressive stress region extending to a first depth into the chemically strengthened glass member from the upper surface; a second compressive stress region extending to a second depth into the chemically strengthened glass member from the lower surface; and a tensile stress region between the first and second compressive stress regions; and the encoded marking is in the tensile stress region. ### Claim 5 (depends on 1) The electronic device of claim 1, wherein the encoded marking is readable, by an optical magnification apparatus, through the upper surface. ### Claim 6 (depends on 1) The electronic device of claim 1, wherein the encoded marking is readable, by an optical magnification apparatus, through a side surface of the chemically strengthened glass member, the side surface extending from the upper surface to the lower surface and defining an exterior surface of the electronic device. ### Claim 7 (depends on 1) The electronic device of claim 1, wherein the encoded marking is formed before the chemically strengthened glass member is subjected to a chemical strengthening operation. ### Claim 8 An electronic device, comprising: a housing; a display positioned at least partially within the housing; and a chemically strengthened glass member at least partially covering the display and defining: a first surface defining an exterior surface of the device and configured to receive touch inputs from a user; a second surface opposite the first surface; and an encoded marking within the chemically strengthened glass member and comprising: a group of marks, at least a subset of the marks in the group of marks positioned a first distance below the first surface of the chemically strengthened glass member and a second distance above the second surface of the chemically strengthened glass member and having a dimension between about 3 microns and about 10 microns. ### Claim 9 (depends on 8) The electronic device of claim 8, wherein: the group of marks is a first group of marks; the first group of marks is a first portion of an array representing encoded information; and the encoded marking further comprises a second group of marks set apart from the first group of marks, each mark in the second group of marks having a dimension between about 3 microns and about 10 microns; and the second group of marks is a second portion of the array representing the encoded information. ### Claim 10 (depends on 9) The electronic device of claim 9, wherein the encoded marking further comprises: a third group of marks set apart from the first and second group of marks, each mark in the third group of marks having a dimension between about 3 microns and about 10; a fourth group of marks set apart from the first, second, and third groups of marks, each mark in the fourth group of marks having a dimension between about 3 microns and about 10; the chemically strengthened glass member defines a shape with four corners; and each of the first, second, third, and fourth groups of marks is positioned proximate a respective corner of the four corners. ### Claim 11 (depends on 9) The electronic device of claim 9, wherein the first group of marks and the second group of marks are not visible to an unaided eye. ### Claim 12 (depends on 9) The electronic device of claim 9, wherein a distance between the first group of marks and the second group of marks is greater than a distance between any two marks in the first group of marks. ### Claim 13 (depends on 9) The electronic device of claim 9, wherein the marks of the first and second groups of marks have a different index of refraction than an unmarked region of the chemically strengthened glass member. ### Claim 14 A method of marking a glass member for an electronic device, comprising: laser forming, along an interior of the glass member, an encoded marking comprising a group of discrete marks each having a dimension between about 3 microns and about 10 microns; and after laser forming the encoded marking, chemically strengthening the glass member, comprising: placing the glass member in an ion exchange bath; and while the glass member is in the ion exchange bath, heating the glass member as a result of contact between the glass member and the ion exchange bath. ### Claim 15 (depends on 14) The method of claim 14, wherein: the method further comprises encoding a unique identifier into a two-dimensional array; and the discrete marks are arranged in a pattern that corresponds to the two-dimensional array. ### Claim 16 (depends on 15) The method of claim 15, further comprising: removing the glass member from the ion exchange bath; and after removing the glass member from the ion exchange bath, optically analyzing the glass member to optically detect the encoded marking. ### Claim 17 (depends on 16) The method of claim 16, wherein: optically analyzing the glass member comprises: placing the glass member in a fixture configured to position the encoded marking in a fixed position relative to an optical magnification apparatus; and capturing an image of the encoded marking with the optical magnification apparatus; decoding the encoded marking to extract the unique identifier from the encoded marking; and the method further comprises associating data relating to the glass member with the unique identifier. ### Claim 18 (depends on 14) The method of claim 14, wherein: the glass member defines: an upper surface; and a lower surface; the encoded marking is positioned between a first area of the upper surface and a second area of the lower surface; and the method further comprises after chemically strengthening the glass member, applying an opaque coating to at least the second area of the lower surface. ### Claim 19 (depends on 14) The method of claim 14, wherein laser forming the encoded marking comprises: laser forming a first partial marking in a first region of the glass member; and laser forming a second partial marking in a second region of the glass member, the second region set apart from the first region. ### Claim 20 (depends on 14) The method of claim 14, wherein laser forming the encoded marking comprises: applying an index-matching material to a surface of the glass member; and directing a laser beam through the index-matching material and through the surface to form the group of discrete marks.