# US 2013/0153429 A1 · Dual anodization surface treatment > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153429 A1 - Document ID: US20130153429A1 - Status: Published application - Kind: A1 - Application number: 13/766,410 - Filed: 2013-02-13 - Published: 2013-06-20 - Earliest claimed: 2009-07-24 - Assignees: Apple Inc. - Inventors: Jivan K. KHOSLA - Web page: https://patentgrep.com/patent/US20130153429A1 ## CPC - C25D 5/02: Electroplating of selected surface areas - C25D 11/022: {Anodisation on selected surface areas} - C25D 11/12: Anodising more than once, e.g. in different baths - H05K 5/0243: {for decorative purposes} - H05K 5/04: Metal casings - C25D 7/10: Bearings - C25D 11/22: for colouring layers - C25D 11/243: {using organic dyestuffs} - C25D 11/246: {for sealing layers} - Y10T 428/257: Iron oxide or aluminum oxide - C25D: PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A metal surface treated to have two anodized layers or regions may be used in electronic devices. The surface treatment may include performing a first anodization process to create a first anodized layer, removing the first anodized layer at select locations, and performing a second anodization process to create a second anodized layer at the select locations. The first and second anodized regions may have different decorative properties, such as color, and different structural properties, such as degree of abrasion resistance. One of the anodization processes may be hard anodization and the other may be standard anodization. ## Claims ### Claim 1 A metal part, comprising: a metal substrate having a first surface and a second surface, wherein the second surface is laterally displaced within metal substrate a distance below the first surface; a first anodized layer disposed on at least a portion of the first surface, the first anodized layer having a first top surface and first hardness; and a second anodized layer disposed on at least a portion the second surface and in contact with the first anodized layer, the second anodized layer having a second top surface that extends above the first top surface, the second anodized layer having a second hardness which is greater than the first hardness, wherein the second anodized protects the first anodized layer from scratching or abrasion. ### Claim 2 (depends on 1) The metal part of claim 1, wherein the second surface is a plurality of holes arranged in a pattern in the metal substrate. ### Claim 3 (depends on 2) The metal part of claim 2, wherein a pitch between the plurality of holes is between about 10 to 200 microns. ### Claim 4 (depends on 2) The metal part of claim 2, wherein the diameter of each of the plurality of holes is about 5 to 1000 microns. ### Claim 5 (depends on 2) The metal part of claim 2, where each of the plurality of holes has a shape selected from the group consisting of a square, an oval, an ellipse, a rectangle, a hexagon and a triangle. ### Claim 6 (depends on 1) The metal part of claim 1, wherein the second top surface extends above the first top surface up to about 50 microns. ### Claim 7 (depends on 1) The metal part of claim 1, wherein the second anodized layer provides structural support for the first anodized layer. ### Claim 8 (depends on 1) The metal part of claim 1, wherein the first and second anodized layers have different colors. ### Claim 9 (depends on 1) The metal part of claim 1, wherein the second anodized layer protects the first anodized layer and the first anodized layer provides a cosmetically appealing quality to the metal part. ### Claim 10 (depends on 8) The metal part of claim 8, wherein the first anodized layer has a dye embedded therein and the first anodized layer has a more vibrant color than the second anodized layer. ### Claim 11 (depends on 1) The method of claim 1, wherein the second surfaces are formed by removing the first anodized layer at select locations. ### Claim 12 An enclosure of an electronic device, comprising: a metal base having a shape and size to house a plurality of electronic components, the metal base having a first surface and a second surface, wherein the second surface extends farther within the metal base than the first surface; a first anodized layer disposed on at least a portion the first surface, the first anodized layer having a first top surface and first hardness; and a second anodized layer disposed on at least a portion the second surface and in contact with the first anodized layer, the second anodized layer having a second top surface that extends above the first top surface, the first and second top surfaces corresponding to the exterior of the enclosure, the second anodized layer having a second hardness which is greater than the first hardness, wherein the second anodized layer provides structural support for and protects the first anodized layer from scratching or abrasion. ### Claim 13 (depends on 12) The enclosure of claim 12, wherein the second surface is a plurality of holes arranged in a pattern in the metal base. ### Claim 14 (depends on 13) The enclosure of claim 13, wherein a pitch between the plurality of holes is between about 10 to 200 microns. ### Claim 15 (depends on 13) The enclosure of claim 13, wherein the diameter of each of the plurality of holes is about 5 to 1000 microns. ### Claim 16 (depends on 12) The enclosure of claim 12, wherein the each of the plurality of holes has a shape selected from the group consisting of a square, an oval, an ellipse, a rectangle, a hexagon and a triangle. ### Claim 17 A metal part, comprising: a metal base having a first surface and a second surface, wherein the second surface extends farther within the metal base than the first surface; a first anodized layer disposed on at least a portion the first surface, the first anodized layer having a first top surface and first hardness; a second anodized layer disposed on at least a portion the second surface and in contact with the first anodized layer, the second anodized layer having a second top surface that is flush with or extends above the first top surface, the first and second top surfaces corresponding to the exterior of the enclosure, the second anodized layer having a second hardness which is greater than the first hardness, wherein the second anodized layer provides structural support for and protects the first anodized layer from scratching or abrasion; and a sealant disposed over at least a portion the first and second top surfaces to seal pores within the first and second anodized layers. ### Claim 18 (depends on 17) The metal part of claim 17, wherein the second surface is a plurality of holes having a pitch between the plurality of holes that is between about 10 to 200 microns. ### Claim 19 (depends on 17) The metal part of claim 17, wherein the second surface is a plurality of holes with each hole having a diameter about 5 to 1000 microns. ### Claim 20 (depends on 17) The metal part of claim 17, wherein the first and second anodized layers each have dyes having different colors embedded therein.