Covers for electronic devices

Abstract

The present disclosure is drawn to covers for electronic devices. In one example, a substrate can include a metal alloy. An acid anodizing layer can be formed on the substrate. A dye application can be applied on the acid anodizing layer. A first nickel-free sealing layer can be formed on the dye application. An alkaline anodizing layer can be formed on the first sealing layer. A second nickel-free sealing layer can be formed on the alkaline anodizing layer.

What is claimed is: 
     
         1 . A cover for an electronic device comprising:
 a substrate including a metal alloy;   an acid anodizing layer on the substrate;   a dye application on the acid anodizing layer;   a first nickel-free sealing layer on the dye application;   an alkaline anodizing layer on the first sealing layer; and   a second nickel-free sealing layer on the alkaline anodizing layer.   
     
     
         2 . The cover of  claim 1 , wherein the metal alloy is an aluminum alloy, a magnesium alloy, or hybrid where a first portion of the substrate is composed of an aluminum alloy and a second portion is composed of a magnesium alloy. 
     
     
         3 . The cover of  claim 1 , further comprising a milled edge is formed along a corner of the substrate to expose a portion of the substrate after the first nickel-free sealing layer is formed and before the alkaline anodizing layer is formed, wherein the alkaline anodizing layer covers the milled edge. 
     
     
         4 . The cover of  claim 3 , wherein the milled edge is a chamfered edge formed by computer numeric control, diamond cutting, or laser engraving. 
     
     
         5 . The cover of  claim 1 , wherein the alkaline anodizing layer is formed using about 3 wt % to about 10 wt % of borax and about 2 vit % to about 8 wt % of sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, sodium carbonate, and/or a complexing agent. 
     
     
         6 . The cover of  claim 1 , wherein the first sealing layer and the second sealing layer includes aluminum fluoride, cerium fluoride, cerium acetate, chromium(III) hydroxide, and/or aluminum acetate. 
     
     
         7 . The cover of  claim 1 , wherein the dye application includes a dye selected from methylene blue, basic fuchsin, crystal violet, eosin, acid fuchsin, congo red, gentian violet, methyl violet, brilliant crystal glue, romanowsky dye, anthraquinone dyes; acridine orange, quinone-imine dyes, xanthene dyes, 2-amino-4-(azoyl)-azo-thiazole, or a combination thereof. 
     
     
         8 . The cover of  claim 1 , wherein the substrate is degreased before the acid anodizing layer is formed using a degreasing compound including sodium carbonate and NaOH, and a surfactant including sodium caseinate, sodium polyacrylate, sodium polyoxyethylene alkyl ether carboxylate, sodium lauryl sulphate, and/or sodium dodecyl sulfate. 
     
     
         9 . The cover of  claim 1 , wherein the substrate is neutralized before the acid anodizing layer is formed using a neutralization compound including sulfuric acid, nitric acid, hydrophilic acid, and/or phosphate acid. 
     
     
         10 . An electronic device comprising:
 an electronic component; and   a cover enclosing a portion or all of the electronic component, the cover comprising:
 a substrate including a metal alloy; 
 an acid anodizing layer on the substrate; 
 a dye application on the acid anodizing layer; 
 a first nickel-free sealing layer on the dye application; 
 an alkaline anodizing layer on the first sealing layer; and 
 a second nickel-free sealing layer on the alkaline anodizing layer. 
   
     
     
         11 . The electronic device of  claim 10 , wherein the electronic device is a laptop, a desktop computer, a keyboard, a mouse, a smart phone, a tablet, a monitor, a television, a speaker, a game console, a video player, an audio player, or a combination thereof, and wherein a milled edge is located at an edge of a touchpad, an edge of a fingerprint scanner, or an edge of a logo. 
     
     
         12 . A method of making a cover for an electronic device comprising:
 forming an enclosure with a substrate;   applying an acid anodizing layer on the substrate;   applying a dye application on the acid anodizing layer;   applying a first nickel-free sealing layer on the dye application;   applying an alkaline anodizing layer on the first sealing layer; and   applying a second nickel-free sealing layer on the alkaline anodizing layer.   
     
     
         13 . The method of  claim 12 , further comprising milling an edge along a corner of the substrate to expose a portion of the substrate after the first nickel-free sealing layer is applied and before the alkaline anodizing layer is applied, wherein the alkaline anodizing layer covers the milled edge. 
     
     
         14 . The method of  claim 12 , further comprising degreasing the substrate before the acid anodizing layer is formed using a degreasing compound including sodium carbonate and NaOH, and a surfactant including sodium caseinate, sodium polyacrylate, sodium polyoxyethylene alkyl ether carboxylate, sodium lauryl sulphate, and/or sodium dodecyl sulfate. 
     
     
         15 . The method of  claim 12 , further comprising neutralizing the substrate before the acid anodizing layer is formed using a neutralization compound including sulfuric acid, nitric acid, hydrophilic acid, and/or phosphate acid.