Techniques for matte white metallic finish of electronic devices

Abstract

An enclosure for an electronic device includes an aluminum alloy substrate and an anodic oxide coating disposed on the aluminum alloy substrate, the anodic oxide coating having a nano-scale etched pattern. The enclosure includes a matte-white finish having a flop index between about 2 and about 10. The anodic oxide coating has a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2. The enclosure includes a sealant disposed on the anodic oxide coating, the sealant including a sol-gel coating, a hard-coat, an anodic electrophoretic deposition coating, or a combination thereof.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 684,841, filed 19 Aug. 2024, and entitled “TECHNIQUES FOR MATTE WHITE METALLIC FINISH OF ELECTRONIC DEVICES,” the entire disclosure of which is hereby incorporated by reference.FIELD

[0002] The described embodiments relate generally to surface finishes of electronic devices. More particularly, the present embodiments relate to techniques for forming and sealing metal oxide layers to improve the cosmetics of a metal substrate, enhance physical characteristics of the metal substrate, or both.BACKGROUND

[0003] The surfaces of many products in the commercial and consumer industries can be treated by any number of processes to alter the surface and create a desired effect, either functional, cosmetic, or both. One example of such a surface treatment is the anodizing of a metal substrate. Anodizing converts a portion of the metal substrate into a metal oxide, thereby creating a metal oxide layer, which is generally harder than the underlying metal substrate and can act as a protective layer. Metal oxide layers can have good corrosion and wear resistance for many consumer products. Further, dyes and other methods can be used to apply various cosmetic colorings to metal oxide materials. For example, dye molecules can be adsorbed into the metal oxide layer. The dye molecules can absorb various wavelengths of light and can allow the surface to reflect a different, darker color. Such methods can be referred to as subtractive coloring methods.

[0004] It can be desirable to achieve a white appearance (e.g., a matte white appearance) for metal oxide layers. However, a surface of a metal oxide layer can have a default silver appearance due to the properties of the underlying metal, and as a result, subtractive coloring methods can be unable to achieve a white appearance for the metal oxide layer. Consequently, techniques are needed for implementing a white (e.g., matte-white) appearance for metal oxide layers on metal substrates.SUMMARY

[0005] In some examples, an enclosure for an electronic device can include an aluminum alloy substrate and an anodic oxide coating disposed on the aluminum alloy substrate having a nano-scale etched pattern. The enclosure can include a matte-white finish having a flop index between about 2 and about 10. In some examples, the enclosure can include a sealant disposed on the anodic oxide coating. The sealant can include a sol-gel coating, a hard-coat, an anodic electrophoretic deposition coating, or a combination thereof. In some examples, the sealant can include a thickness of less than about 5 microns.

[0006] In some examples, the anodic layer can include a thickness between about 10 microns and about 20 microns. In some examples, a thickness of the sealant is proportional to a gloss value of the enclosure. In some examples, the anodic oxide coating has a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2. In some examples, the anodic oxide coating has a 60-degree gloss measurement of less than 30 gloss units. In some examples, the enclosure can include a surface hardness of about 300 HV0.05 or greater.

[0007] According to some examples, a housing can include a substrate including aluminum and an anodic layer disposed on and formed from at least a portion of the substrate and configured to diffuse ambient light. The housing can include a matte-white finish having a L* value greater than about 90. In some examples, the anodic layer can include an etched pattern having fissures that are configured to diffuse the ambient light.

[0008] In some examples, the housing can include a sealant disposed on the anodic layer. The sealant can include a sol-gel coating, a hard-coat, an anodic electrophoretic deposition layer, or a combination thereof. In some examples, the sealant can include a thickness of less than about 5 microns and the anodic layer can include a thickness between about 10 microns and about 20 microns. In some examples, the anodic layer has a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2. In some examples, the anodic layer has a 60-degree gloss measurement between about 5 and about 10 gloss units. In some examples, the enclosure can include a hardness of about 300 HV0.05 or greater.

[0009] According to some examples, a method for forming a surface on a substrate having a flop index between about 2 and about 10 includes forming an aluminum alloy substrate, anodizing a porous oxide layer on the aluminum alloy substrate, etching the porous oxide layer to form a nano-scale etched pattern, and sealing the porous oxide layer. In some examples, etching the porous oxide layer can include etching the porous oxide layer in 0.1M aluminum sulfate at between about 30-80° C.

[0010] In some examples, anodizing the porous oxide layer can include immersing the aluminum alloy substrate in an electrolyte including between about 150 and 250 g / L of sulfuric acid and applying a current having a current density between about 0.5 A / dm2 and 2.5 A / dm2 at about 20° C. In some examples, a flop index value of the surface is inversely proportional to a duration of time etching the porous oxide layer.

[0011] In some examples, sealing the porous oxide layer can include performing an anodic electrophoretic deposition on the etched porous oxide layer or applying a sol-gel coating or a clear-coat to the etched porous oxide layer. In some examples, the sealed porous oxide layer has a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:

[0013] FIG. 1 shows example electronic devices that can include the housings and enclosures with anodic oxide coatings described herein.

[0014] FIG. 2 shows a cross section view of an anodic oxide disposed on a substrate.

[0015] FIG. 3 shows cross section view of an etched anodic oxide disposed on a substrate.

[0016] FIG. 4 shows an example of a cross section view of a sealant disposed on an etched anodic oxide disposed on a substrate.

[0017] FIG. 5 shows an example of another cross section view of a sealant disposed on an etched anodic oxide disposed on a substrate.

[0018] FIG. 6 shows a flowchart indicating a method for forming an oxide layer on a substrate, according to some examples.DETAILED DESCRIPTION

[0019] Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims.

[0020] The following disclosure relates to techniques for anodizing processes that result in cosmetically appealing and durable anodic oxide films. Conventional anodizing processes can be unable to achieve a white finish on metal surfaces. As an example, subtractive coloring methods can provide colored finishes to a surface. In such examples, a porous oxide layer can be “dyed” using dye molecules adsorbed into the metal oxide layer. These dye molecules can absorb some wavelengths of light to allow the surface to reflect a different, darker color. However, the underlying metal (e.g., aluminum alloy substrate) can have material properties that result in a silver appearance of the metal surface. Therefore, a clear oxide layer can have a silver appearance, and while adding dye molecules can give darker colors, conventional techniques for anodizing are unable to give the metal surface a “white” appearance due to the persistent silver appearance of the metal surface and the lack of darker dye molecules to block the silver appearance.

[0021] Accordingly, the techniques described herein can provide for adding a white (e.g., matte-white) finish to metal surfaces. As an illustrative example, a surface can include an aluminum alloy substrate with a porous oxide layer and a sealant deposited on the porous oxide layer. The porous oxide layer can include an etched nano-scale pattern that is configured to diffuse light such that the surface has a white appearance as described herein. In some examples, a white appearance can correspond to one or more color metrics. For example, a surface with a white appearance can be a surface having an L* value of greater than about 90, an a* value of less than about 1, and / or a b* value of less than about 2. Additionally or alternatively, the surface can have a flop index value between about 2 and about 10. In some examples, the surface can have a 60-degree gloss measurement of less than 30 gloss units.

[0022] Further, the techniques described herein can provide for a white surface that satisfies one or more reliability thresholds. For example, the porous oxide layer can be sealed with a sealant in accordance with the techniques described herein (e.g., a sol-gel sealant, a hard coat sealant, etc.). Such sealant techniques can preserve the white appearance of the porous oxide layer while providing a stain and corrosion resistant finish to the surface, among other examples of reliability metrics.

[0023] These and other embodiments are discussed below with reference to FIGS. 1-6. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. Furthermore, as used herein, a system, a method, an article, a component, a feature, or a sub-feature comprising at least one of a first option, a second option, or a third option should be understood as referring to a system, a method, an article, a component, a feature, or a sub-feature that can include one of each listed option (e.g., only one of the first option, only one of the second option, or only one of the third option), multiple of a single listed option (e.g., two or more of the first option), two options simultaneously (e.g., one of the first option and one of the second option), or combination thereof (e.g., two of the first option and one of the second option).

[0024] Methods described herein can be used to form metal surface finishes that are reliable as well as cosmetically appealing for surfaces of enclosures and / or housings for consumer devices. FIG. 1 shows consumer products than can be manufactured using methods described herein. FIG. 1 includes portable phone 102, tablet computer 104, an electronic watch 106, and portable computer 106, which can each include enclosures and / or housings. The devices 102, 104, 106, and 108 can implement one or more techniques in accordance with the techniques described herein. For example, one or more of the devices 102, 104, 106, and 108 can have white appearing surfaces (e.g., enclosures or housings of the devices) that have a metal substrate, an anodic oxide layer, a sealant layer, or a combination thereof as discussed with reference to FIGS. 2-6. However, while described in the context of consumer devices for illustrative clarity, it is to be understood that the techniques described herein can additionally or alternatively be used for other types of devices or surfaces. Further, a surface of a device as described herein can additionally or alternatively be referred to as or be an example of a housing, an enclosure, an internal surface, an external surface, or a combination thereof.

[0025] The devices 102, 104, 106, and 108 can have metal surfaces. For instance, the surface of the devices 102, 104, 106, and 108 can include a metal substrate. The metal substrate can be referred to as or be an example of a metal, a metal layer, a metal surface, and the like. While described herein as a “metal” surface or substrate for illustrative clarity, any suitable anodizable material can implement one or more of the techniques described herein. In some examples, the metal substrate can include aluminum (e.g., an aluminum substrate, a substrate with an aluminum alloy, etc.), titanium, zinc, or a combination thereof, among other examples of anodizable materials. Although particular reference is made to 6000 and 7000-series aluminum alloys, and substrates that can include aluminum and / or aluminum alloys, the techniques described herein could be applied to other aluminum alloys or anodizable materials.

[0026] The metal substrate can be anodized to form an anodic oxide layer. For example, an anodizing process (e.g., an electrolytic passivation process) can be performed on the metal substrate to create or increase the thickness of a natural oxide layer on the surface of the metal substrate. That is, anodizing can convert a portion of a metal substrate into a metal oxide, thereby creating a metal oxide layer, which is generally harder than the underlying metal substrate and can act as a protective layer. As described herein, the terms “anodic film,”“anodic oxide,”“anodic layer,”“anodic oxide,”“anodic oxide film,”“anodic oxide layer,”“anodic oxide coating”“metal oxide,”“metal oxide film,”“metal oxide layer,” and “anodic coating” can be used interchangeably.

[0027] In some examples, the metal substrate and / or the anodic oxide layer of the devices 102, 104, 106, and 108 can be sealed. For example, a post-processing procedure can include sealing the substrate and / or anodic oxide layer. Such a procedure can enhance the physical characteristics of the surface, improve the cosmetic value of the surface, or both. Sealing the anodic oxide layer can improve a reliability of the surface by improving its resistance to corrosion and wear, among other examples of reliability metrics.

[0028] In some examples, an anodizing process (e.g., the formation of the metal substrate, the metal oxide layer, the sealing layer, or a combination thereof) can result in one or more cosmetic features of the surfaces of the devices 102, 104, 106, and 108. For example, cosmetic anodizing can be relatively clear, which gives a surface a silver appearance due to the material properties of the underlying metal (e.g., aluminum or aluminum alloy can have a silver hue, though other metals and hues can have non-white or off-white hues). As another example, the surfaces can be “dyed” to impart a color to the surfaces. In some cases, the dying process can be an example of a subtractive coloring method.

[0029] In some examples, the surfaces can be dyed by including dye molecules (e.g., organic chromophores) that absorb some wavelengths of light to allow the surface to reflect a different, darker color. The color of an anodized finish can be adjusted by adsorbing dye molecules (e.g., organic dye molecules) into the pores of the metal oxide prior to sealing, which will impart color to the surface. The dye molecules can include chromophores which absorb certain wavelengths of visible light such that the light reflected off the surface has a complimentary color. One or more hues can be achieved for a surface by dying (e.g., reds, pinks, blues, greens, yellows, oranges, etc.). In some examples, the color or hue of a surface can be described herein with reference to the Commission on Illumination LAB (CIELAB) color space. The term “CIELAB color space” can be used interchangeably with the term “CIE 1976 L*a*b* color space.”

[0030] However, such subtractive coloring methods can be unable to achieve a white finish for the surfaces of the devices. For example, due to the silver hue of the underlying metal, absorbing light with dye molecules can give a range from a silver hue (e.g., a L* of about 90 with relatively low absorption across the visible spectrum) to a black hue (e.g., a L* of about 25 with relatively high absorption across the visible spectrum), but not a white hue, based on the neutral, non-dyed finish having a metallic silver color. In some examples, a white hue can be a hue of a surface that has a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2, in accordance with the CIE 1976 L*a*b* color space.

[0031] Thus, techniques for obtaining a white hue on one or more surfaces of the devices can be desired. In some cases, the device surfaces can be painted white. Painting can impart a plastic look, touch, or feel to the surface based on a relatively low thermal conductivity of a polymeric coating compared to anodic oxides and underlying metal substrates that are not painted. In some cases, an anodizing process can incorporate white pigments into the surface of the devices, such as Titania, the anodizing process can use high voltage micro-arc oxidation, or a combination thereof. However, such techniques can fail to achieve white finishes that satisfy one or more thresholds. For example, these methods can result in an off-white appearance due to some intrinsic hue of the surfaces (e.g., an a* greater than about 2, a b* greater than about 2, or both). Additionally or alternatively, these techniques can result in an opaque appearance for the surface. Stated alternatively, the surface may not have a metallic character due to a relatively low flop value.

[0032] Accordingly, the techniques described herein can enable a white appearance for one or more surfaces of the devices 102, 104, 106, and / or 108. The surfaces of the devices can have metrics that satisfy one or more cosmetic thresholds, reliability thresholds, or both. For example, the surfaces can be referred to as “white” or “white appearing” surfaces based on having a L* value of greater than about 90, an a* value of less than about 1, a b* value of less than about 2, or a combination thereof. In some cases, such metrics can be measured by a spectrophotometer (e.g., a d / 8 spectrophotometer), though other values, instruments, or metrics can be used.

[0033] The surfaces of the devices can satisfy a flop threshold. For example, a surface can have a flop index value between about 2 and about 10. A flop index value can be referred to as or be an example of a “luster” metric of the surface (e.g., a metallic luster). Luster can be a visual characteristic of metal surfaces. “Flop” can be an example of a measure of how shiny or reflective a surface is as it is rotated through a series of viewing angles. In other words, flop can be quantified by the change of lightness values across different observation angles. As an illustrative example, the flop can be calculated in accordance with Equation 1:F=2.6⁢9⁢(L1-L3)1.1⁢1L20.8⁢6(1)

[0034] In Equation 1, F can represent the flop (i.e., flop index value, flop measurement, flop value, flop metric, etc.). L1 can represent the lightness (e.g., L* in the CIELAB color space, although other metrics can be used) at a first observation angle, L2 can represent the lightness at a second observation angle, and L3 can represent the lightness at a third observation angle. It is to be understood that Equation I is an illustrative example of a flop metric and different formulations or metrics can be used to quantify the flop (i.e., the measure of how the shine of a surface changes as the viewing angle changes) or luster. A flop value of 0 can indicate that there is no change in lightness based on the viewing angle. In some examples, a flop of a matte anodized metallic surface can be around 10 to around 18 (e.g., the matte anodized metallic surface can be associated with a luster of around 4 to around 7). The lower end of such a range can correspond to a relatively finer scale roughness for a surface of a device and the higher end of the range can correspond to a relatively coarser blast texture for a device (e.g., a display of a device). As one example, a flop value of a mirror-lapped anodized surface can be as high as around 20 to around 22 (e.g., the surface can be associated with a luster of around 10 to around 11).

[0035] Additionally or alternatively, the surfaces of a device can satisfy a gloss threshold. For example, a surface can have a 60-degree gloss measurement of less than around 30. A 60-degree gloss measurement can be referred to as or be an example of a measurement by a gloss meter that reflects a known quantity of light off a surface at a 60-degree angle and measures the reflectance, or an amount of the known quantity of light that is reflected of the surface. A relatively high 60-degree gloss measurement correspond to a high gloss of the surface while a relatively low 60-degree gloss measurement corresponds to a relatively low gloss of the surface. The gloss measurement can have units of Gloss Units (GUs), which is a scaling based on a highly polished reference black glass standard with a defined refractive index having a specular reflectance of 100 GUs at the 60-degree angle. Thus, a measurement of 0 GUs can correspond to a completely matte surface (e.g., no specular reflectance), a measurement of 50 GUs can have half the specular reflection of the reference standard (e.g., a medium gloss), and the like. As one illustrative example, a non-dyed aluminum finish (e.g., a Zirconium Oxide (ZrO2) blasted matte finish) can correspond to a flop of around 13 to around 15 and a 60-degree gloss measurement of around 9 to around 13. In some examples, a 60-degree gloss measurement of less than around 30 (e.g., around 5 to around 10) can correspond to a relatively “matte” finish, or a finish with a relatively low gloss.

[0036] Accordingly, in some examples one or more surfaces of the device 102, the device 104, the device 106, and / or the device 108 can have material properties that satisfy one or more cosmetic thresholds associated with a white appearance, a matte appearance, or both. For instance, a surface can have a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2, the surface can have a flop measurement between about 2 and about 10 (e.g., a flop measurement of about 5), the surface can have a 60-degree gloss measurement of less than about 30 gloss units (e.g., about 5 to about 10 gloss units), or a combination thereof. In some examples, the combination of a L* threshold (e.g., a L* of greater than 90 or 91) and a flop between about 2 and about 10 (e.g., about 5) can give the surface a white hue whilst retaining at least a portion of a metallic “shiny” character, which can be a desirable cosmetic appearance, although variations and other cosmetic appearances are possible. Additionally or alternatively, the one or more surfaces can satisfy one or more reliability thresholds as described in further detail with reference to FIG. 4.

[0037] FIG. 2 illustrates a cross section view of an enclosure 200 that includes an anodic oxide 205 disposed on a substrate 210. In some examples, the substrate 210 can include aluminum. In some examples, the enclosure 200 can be a housing for an electronic device or one or more surfaces of an electronic device. The anodic oxide 205 forms a coating over the substrate 210 to provide corrosion protection and cosmetic benefits.

[0038] The substrate 210 can include a metal or other anodizable material as described herein with reference to FIG. 1. For example, the substrate 210 can be an example of aluminum or an aluminum alloy. The anodic oxide 205 can be formed on the substrate 210 by anodizing the substrate 210 in an electrolyte. That is, the anodizing process can include immersing substrate 210 in the electrolyte at an anodizing temperature and applying a current for a duration of time to “grow” a thickness of the anodic oxide 205. In some examples, the anodizing process for the anodic oxide 205 can be referred to as a “Type II” anodizing process.

[0039] As an illustrative example, the substrate 210 can be immersed in 200 grams (g) per liter (L) of sulfuric acid at 20 degrees Celsius (C). A current with a current density of about 1 to about 1.5 amperes per square decimeter (ASD) can be applied to the immersed substrate 210 for the duration of time (e.g., a duration of time that corresponds to a target thickness of the layer of anodic oxide 205). The thickness of the oxide layer 305 can be controlled in part by the duration of the anodization process (e.g., the duration can be proportional to the thickness of the oxide layer 305 such that a relatively high duration of the anodization process corresponds to a relatively high thickness). In some such examples, the anodizing process can form the anodic oxide layer to a thickness of about 10 to about 20 microns, although other thicknesses can be implemented in accordance with the techniques described herein.

[0040] In some examples, the anodic oxide 205 can be relatively neutral in color and relatively bright. In some cases, the anodic oxide 205 being relatively clear or neutral can give the enclosure 200 a silver appearance due to the underlying properties of the substrate 200. For example, the cosmetic metrics (e.g., color metrics) of the anodic oxide 205 can be a L* of greater than about 90, an a* of less than about 1, and a b* of less than about 2 in the CIELAB color space. In some examples, some cosmetic metrics can be measured or obtained using a spectrophotometer with d / 8 geometry, a 10-degree observer, and a F2 or D65 illuminant. Additionally or alternatively, the flop of the anodic oxide 205 can be in the range of about 10 to about 22, for example, based on the texture that is applied to the substrate 210.

[0041] FIG. 3 illustrates a cross section view of an enclosure 300 having an etched anodic oxide 305 disposed on a substrate 310. The anodic oxide 305 can be an example of an anodic oxide as described herein, such as the anodic oxide 205. The substrate 210 can be an example of a substrate as described herein, such as the substrate 205. After formation of the anodic oxide 305, an etching process can configure the anodic oxide 305 with an etched section 315, a base section 320, or both. For example, the etched section 315 can include fissures between pillars 335 of anodic oxide 305. Fissures can be an example of, or can include, gaps between pillars 335 of the anodic oxide 305, fissures can be examples of relatively lower density areas in the anodic oxide 305 (e.g., areas with a reduced density of the anodic oxide 305 from etching can be referred to as “fissures” while areas with a relatively higher density of the anodic oxide 305 can be referred to as pillars 335), or a combination thereof.

[0042] The etching process can include etching the anodic oxide 305 in an etching solution. As an example, the anodic oxide 305 can be immersed in an etching solution of aluminum sulfate (e.g., between about 10 and 40 g / L of aluminum sulfate, between about 15 and 75 g / L of aluminum sulfate, about 10 g / L of aluminum sulfate, about 20 g / L of aluminum sulfate, about 30 g / L of aluminum sulfate, or any other effective concentration) at an etching temperature (e.g., between about 30-80 degrees C., between about 45 and 60 degrees C., at about 50 degrees C., at about 100 degrees C., and the like). In some examples, the etching process can include one or more other steps which can be performed in any order, such as cleaning, leveling, rinsing, neutralizing, drying, and the like.

[0043] The etching process can etch a nano-scale pattern into the anodic oxide 305. For example, the etched section 315 can have fissures and pillars 335 of anodic oxide 305 based on the etching process. The fissures and pillars 335 have roughly rectangular and triangular shapes for illustrative clarity, but it is to be understood that the form and pattern of the pillars 335 and / or the associated fissures can be of various shapes, depths, and densities. The term “nano-scale pattern” can additionally or alternatively be referred to as an “etched pattern,” a “nano-meter pattern,” an “etched surface structure,” and the like. Further, while described as a nano-scale pattern, other patterns having additional or alternative features at other scales can be used.

[0044] In the example of the enclosure 300, the fissures and pillars 335 can have a relatively higher diffusion of light at the surface of the enclosure 300 compared to a surface without the etched pattern. The diffusion of light can change the character of the color of the surface from a silver towards a white. In some examples, the nano scale pattern (e.g., nano-meter scale pillars 335 and fissures in the etched section 315) can have a relatively small impact on the hue of the surface. For instance, the surface of the enclosure 300 can have retain an a* of less than about 1, a b* of less than about 2, and an L* of about 90 (or greater than about 90), which can be similar to the metrics of the enclosure 200 without an etched pattern. The change of color from a metallic silver to a “white” appearance can be based on a reduction in flop of the enclosure 300 from an initial value (e.g., a value prior to the etching process) to a post-etch value. As an illustrative example, the nano-scale pattern can reduce the flop from a value of about 13 to about 15 to value in the range of about 2 to about 10.

[0045] In some examples, a duration of the etching process can be proportional to the reduction in the flop of the enclosure 300. For example, a relatively long etch duration can correspond to a relatively high reduction in flop. As an illustrative example, a longer duration for the etch can result in relatively more pillars 335 and fissures, deeper fissures (e.g., taller pillars 335), or a combination thereof, which can increase the light diffusing effect of the nano scale pattern and thus decrease the flop.

[0046] In some examples, the anodic oxide 305 can have an opaque appearance (e.g., white at a relatively large range of observer angles and illuminant values) at a flop index value of about 3 and thus have relatively small amount of a metallic character. In some other examples, the anodic oxide 305 can have both a white appearing finish as well as a metallic character based on the light diffusing nano-scale pattern, such as at flop values at about 5 or other intermediate values between about 3 and about 10. Thus, the enclosure 300 can have an appearance of an opaque white and / or a metallic white based on a duration of the etching process.

[0047] As an illustrative example of surface etching increasing the diffuse reflection of light for the anodic oxide 305, without etching the flop of the anodic oxide 305 can be about 14 (e.g., a silver appearing surface with a metallic character), with two minutes of etching the flop of the anodic oxide 305 can be about 8, with 4 minutes of etching the flop of the anodic oxide 305 can be about 7 (e.g., a whiter appearing surface with a metallic character), with 6 minutes of etching the flop of the anodic oxide 305 can be about 6, and with 8 minutes of etching the flop of the anodic oxide 305 can be about 5 (e.g., a white appearing surface with a metallic character). In some such examples, etching for a longer duration can result in a flop of lower than about 3, which can result in an opaque white appearing surface (e.g., white appearing without a metallic character). Thus, the flop of the surface (e.g., the metallic or opaque character and degree of how white appearing the surface is) can be controllable by a duration of the surface etching.

[0048] FIG. 4 illustrates a cross section view of an enclosure 400 having an etched anodic oxide 405 disposed on a substrate 410 and a sealant 415 disposed on the etched anodic oxide 405. The substrate can be an example of a substrate as described herein, such as the substrate 210 or the substrate 310. The etched anodic oxide 405 can be an example of an anodic oxide as described herein, such as the anodic oxide 205 or the anodic oxide 305.

[0049] The enclosure 400 can include a sealant 415. The sealant 415 can be formed on the anodic oxide 405. For example, a sealing process can deposit or form the sealant 415 over the anodic oxide 405 after an etching process is performed on the anodic oxide 405 as described herein with reference to FIG. 3. As described herein, the terms “sealant,” a “sealant layer,” a “sealing layer,” a “seal material,” a “seal film,” a “seal coating,” and a “sealant coating,” can be used interchangeably.

[0050] The sealant 415 can improve the reliability of the enclosure 400. For example, the sealant 415 can inhibit contamination or wear of the enclosure 400 by providing a protective layer of material at the surface (e.g., above the anodic oxide 405). Stated alternatively, the sealant 415 can keep out contaminants, protect the finish of the enclosure 400 from stains, corrosion, or environmental degradation, or a combination thereof, among other benefits.

[0051] In some examples, the sealing process can include a hydrothermal sealing process. In such examples, the anodic oxide 405 is immersed in a relatively hot aqueous solution and the pore walls of the anodic oxide 405 are hydrated as a result (e.g., the pore walls can swell to close off the pores and reduce a porosity of the oxide). If dye molecules are used, such a sealing process can seal in organic dies. However, in some cases, a hydrothermal sealing process can raise the flop of the etched pattern anodic oxide 405 (e.g., the appearance of the enclosure 400 can revert from a white appearance associated with the etched anodic oxide 405 to a silver appearance associated with the anodic oxide 405 prior to etching the pattern).

[0052] Thus, in addition or alternative to a hydrothermal sealing process, the sealing process can include other techniques for forming the sealant 415 that maintain a white appearance of the enclosure 400 and provide reliability and protection to the enclosure 400.

[0053] In some examples, the sealing process can include forming (e.g., depositing) the sealant 415 on the anodic oxide 405 via an anodic electrophoretic deposition process (i.e., an “e-coating”). As an example, anodic electrophoretic deposition can include applying an electric field to a material such that particles migrate (e.g., electrophoresis) to be deposited on an electrode. For instance, the sealant 415 can be deposited on the anodic oxide 405 by applying an electric field to a liquid containing the sealant 415 such that the sealant 415 moves to the surface of the anodic oxide 405.

[0054] In some examples, the sealing process can include forming the sealant 415 as a sol-gel (e.g., a matte sol-gel). That is, the sealant 415 can be an example of a sol-gel sealant. A sol-gel process can be an example of a wet-chemical technique to produce solid materials from relatively small molecules. As an example, a sol (e.g., a colloidal solution) is formed that has liquid removed until a gel or gel-like material forms. In some examples, the sol can undergo steps to develop target mechanical or material properties, such as firing, sintering, densification, and grain growth. The sol can be used as the sealant 415 for sealing the enclosure 400. In some examples, the sealant 415 can be an example of a sol-gel silicone with a carbon backbone.

[0055] In some examples, the sealing process can include forming the sealant 415 as a clear coat. That is, the sealant 415 can be an example of a clear coat or a hard-coat sealant. In some examples, a clear coat can include a thin application of coating similar to that used in typical automotive paint finishes. For example, the sealant 415 can be an example of a clear coat sealant comprising a blend of acrylic and polyurethane. The clear coat can be applied by spraying in some examples. In an example, the clear coat can by applied to a thickness of between about 25 and about 50 microns. The sealant 415 can offer scratch and environmental resistance.

[0056] In some examples, the sealant 415 can be deposited as a polymer (e.g., the sealant 415 can be a relatively thin layer of parylene, polysiloxanes, or other examples of polymers). In some examples, the sealant 415 can be an example of a fluorinated sealing material or can be deposited by applying a product with volatile compounds that evaporate to form the sealant 415 on the surface of the enclosure 400.

[0057] In some examples, the sealant 415 can be an example of any of the materials or similar materials described herein and can be applied through e-coating, spraying, or ink-jet printing onto the etched anodic oxide 405. In some examples, the sealant 415 can penetrate some depth into the columnar porosity of the anodic oxide coatings (e.g., the anodic oxide 405) and form a seal to protect against corrosion, staining, wear, and the like.

[0058] The various sealing techniques described herein can be used by themselves or in combination to form the sealant 415. While the sealant 415 is depicted as a single material and layer for illustrative clarity, it is to be understood that the sealant 415 can have any quantity or configuration of materials (e.g., sealants) or layers. Further, it is to be understood that one or more of the sealing techniques can be used independently or in combination and portions of the techniques can be removed or other techniques or steps can be added (e.g., cleaning steps, levelling steps, among other examples of techniques for sealing the enclosure 400).

[0059] The enclosure 400 can satisfy one or more cosmetic thresholds and / or one or more reliability thresholds based on the sealing process. In other words, the layer of sealant 415 can improve the reliability and / or provide protection to the enclosure 400 while retaining a desired cosmetic appearance of the enclosure 400. As an illustrative example, after sealing with the sealant 415 in accordance with the techniques described herein the enclosure 400 can have an a* of less than about 1 and a b* of less than about 2, a L* greater than about 90, a flop index value in a target range such as about 2 to about 10, or a combination thereof. In some examples, a gloss of the enclosure 400 can be proportional to a thickness of the sealant 415. For example, a relatively high thickness of the sealant 415 can give a higher gloss measurement for the surface of the enclosure 400. In some examples, the enclosure 400 can have a “matte” appearance represented by a cosmetic threshold of a 60-degree gloss measurement of less than around 30. As an example, this threshold can correspond to a thickness of the sealant 415 of less than around 5 microns, which can provide a matte-white appearance to the enclosure 400 while providing relatively high reliability for electronic devices.

[0060] Additionally or alternatively, the enclosure 400 can satisfy one or more reliability thresholds. For example, the enclosure can have a surface hardness of about 300 HV0.05 or greater. As known in the art, HV0.05 can refer to a Vickers hardness testing scale, specifically at a load of 50 g. Additionally or alternatively, the enclosure 400 can have a relatively low chemical sensitivity (e.g., a resistance to stains from the environment such as black coffee, lip polish, mustard, ketchup, sunscreen, and the like), a relatively high resistance to abrasions (e.g., rubbing against denim or steel wool), tumble and solar exposure testing (e.g., polymers can discolor in the sun and the enclosure 400 can have a resistance that satisfies a sensitivity threshold), and the like. Stated alternatively, the enclosure 400 can have reliability metrics (e.g., a sensitivity to staining, abrasions, etc.) that satisfy reliability thresholds for electronic consumer devices while retaining a white appearance as described herein.

[0061] FIG. 5 illustrates a cross section view of an enclosure 500 having an etched anodic oxide 505 disposed on a substrate 510 and a sealant 515 disposed on the etched anodic oxide 505. The components 500 can be examples of or include aspects of the corresponding components described herein with reference to FIGS. 1-4.

[0062] The enclosure 500 can be an example of a surface of an electronic device that has a white appearance. For example, the enclosure 500 can have a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2. Additionally or alternatively, the enclosure 500 can have a flop index value between about 2 and about 10. In some examples, the enclosure 500 can have a 60-degree gloss measurement of less than 30 gloss units.

[0063] In the example of the enclosure 500, length 520-a can represent a depth of the layer of sealant 515, which can be referred to as a “top coat.” Length 520-b can represent a depth of the layer of anodic oxide 505. Length 520-c can represent a depth of a coating infiltration. For example, the length 520-c can show that the sealant 515 has infiltrated past a top surface of the etched layer of anodic oxide 505. Length 520-d can represent an etching depth. For example, length 520-d can show how deep (e.g., on average) into the layer of anodic oxide 505 that the etching process has gone (e.g., a depth of the fissures as described herein with reference to FIG. 3). In some examples, the length 520-a can be less than or equal to about 5 microns in thickness of the sealant 515, which can correspond to a feel and character of a metallic surface (e.g., a higher thickness of the sealant 515 can result in a plastic feel and character).

[0064] FIG. 6 illustrates a flowchart indicating a method 600 for forming an oxide layer on a substrate, according to some examples. The method 600 can implement aspects of, or be implemented by, the enclosures and devices of FIGS. 1-5. For example, the substrates, anodic oxide, and sealants described herein can be examples of the corresponding substrates, anodic oxides, and sealants described herein with reference to FIGS. 1-5.

[0065] The method 600 can include the act 605 of forming an aluminum alloy substrate. The method 600 can include act 610 of anodizing a porous oxide layer. For example, the substrate can be anodized as described herein with reference to FIG. 2 to form the porous oxide layer disposed on the aluminum alloy substrate. In some examples, anodizing the porous oxide layer can include immersing the aluminum alloy substrate in an electrolyte comprising between about 150 and 250 g / L of sulfuric acid and applying a current having a current density between about 0.5 A / dm2 and 1.5 A / dm2, between about 0.75 A / dm2 and 2.0 A / dm2, or between 1.0 A / dm2 and 1.5 A / dm2 at between 15 and 25° C. In some examples, the anodized porous oxide layer can have a silver appearance due to the underlying properties (e.g., material properties such as hue or color, flop, and the like) of the formed aluminum alloy substrate. For example, the anodic oxide layer can have a L* of greater than about 90, an a* of less than about 1, and a b* of less than about 2 in the CIELAB color space, and a flop in the range of about 10 to about 22, depending on the texture applied to the aluminum alloy substrate.

[0066] The method 600 can include act 615 of etching the porous oxide layer. In some examples, the porous oxide layer can be etched to form a nano-scale etched pattern on the porous oxide layer as described herein with reference to FIG. 3. For example, etching the porous oxide layer can include etching the porous oxide layer in aluminum sulfate (e.g., between about 10 and 40 g / L of aluminum sulfate, between about 15 and 75 g / L of aluminum sulfate, about 10 g / L of aluminum sulfate, about 20 g / L of aluminum sulfate, about 30 g / L of aluminum sulfate, or any other effective concentration) at an etching temperature (e.g., between about 30-80 degrees C., between about 45 and 60 degrees C., at about 50 degrees C., at about 100 degrees C., and the like). In some examples, etching can be an example of a process to remove at least a portion of the porous oxide layer. In some examples, the etched porous oxide layer having the nano-scale etched pattern can have an a* of less than about 1, a b* of less than about 2, and a L* of about 90 or greater than about 90. Additionally or alternatively, the etched porous oxide layer having the nano-scale etched pattern can have a flop value between about 3 and about 10.

[0067] In some examples, a flop index value of the surface is inversely proportional to a duration of time associated with etching the porous oxide layer. For example, a longer etching duration can form a relatively higher quantity of fissures in the porous oxide layer, relatively deeper fissures in the porous oxide layer, or a combination thereof. The relatively higher quantity, density, and / or depth of the fissures can diffuse relatively more light and thus reduce the flop of the porous oxide layer. In contrast, a relatively lower etching duration can form a relatively lower quantity, density, and / or depth of the fissures. In such examples, the etched pattern at the porous oxide layer can have relatively less light diffusion and the flop of the porous oxide layer can be relatively higher. Fissures can be examples of gaps between pillars of the porous oxide material (e.g., space that can be at least partially filled with a sealant), fissures can be examples of areas in the porous oxide material (e.g., areas with a reduced density of porous oxide material can be referred to as “fissures” while areas with a relatively higher density of porous oxide material can be referred to as “pillars”), or a combination thereof.

[0068] The method 600 can include the act 620 of sealing the porous oxide layer. In some examples, sealing the porous oxide layer can include performing an anodic electrophoretic deposition on the etched porous oxide layer, applying a sol-gel coating or a hard-coat to the etched porous oxide layer, or a combination thereof, as described herein with reference to FIG. 4. For example, a sealant can be formed on the porous oxide layer and / or the aluminum substrate (e.g., the sealant can be deposited, sprayed, and / or ink-jet printed onto the porous oxide layer).

[0069] In some examples, the sealed porous oxide layer can satisfy one or more cosmetic thresholds. For example, the sealed porous oxide layer can have a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2, a flop index value between about 2 to about 10 (e.g., about 5), and a 60-degree gloss measurement of less than around 30 GUs (e.g., between about 5 and about 10 GUs), or a combination thereof, as described herein with reference to FIG. 4. Additionally or alternatively, the sealed porous oxide layer can satisfy one or more reliability thresholds. For example, the sealed porous oxide layer can have a hardness of about 300 HV0.05 or greater, the sealed porous oxide layer can satisfy a chemical sensitivity threshold for one or more chemicals, a tumble threshold, a solar exposure threshold, a physical abrasion threshold, or any combination thereof, as described herein with reference to FIG. 4.

[0070] Additionally, any of the above methods can further include one or more further treatments on surface. For example, rinsing, degreasing, de-smutting, dyeing, sealing, polishing, texturizing, brightening, or further anodization can also be conducted.

[0071] To the extent applicable to the present technology, gathering and use of data available from various sources can be used to improve the delivery to users of invitational content or any other content that can be of interest to them. The present disclosure contemplates that in some instances, this gathered data can include personal information data that uniquely identifies or can be used to contact or locate a specific person. Such personal information data can include demographic data, location-based data, telephone numbers, email addresses, X® (formerly TWITTER®) ID's, home addresses, data or records relating to a user's health or level of fitness (e.g., vital signs measurements, medication information, exercise information), date of birth, or any other identifying or personal information.

[0072] The present disclosure recognizes that the use of such personal information data, in the present technology, can be used to the benefit of users. For example, the personal information data can be used to deliver targeted content that is of greater interest to the user. Accordingly, use of such personal information data enables users to calculated control of the delivered content. Further, other uses for personal information data that benefit the user are also contemplated by the present disclosure. For instance, health and fitness data can be used to provide insights into a user's general wellness, or can be used as positive feedback to individuals using technology to pursue wellness goals.

[0073] The present disclosure contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and / or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. Such policies should be easily accessible by users, and should be updated as the collection and / or use of data changes. Personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection / sharing should occur after receiving the informed consent of the users. Additionally, such entities should consider taking any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. In addition, policies and practices should be adapted for the particular types of personal information data being collected and / or accessed and adapted to applicable laws and standards, including jurisdiction-specific considerations. For instance, in the US, collection of or access to certain health data can be governed by federal and / or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA); whereas health data in other countries can be subject to other regulations and policies and should be handled accordingly. Hence different privacy practices should be maintained for different personal data types in each country.

[0074] Despite the foregoing, the present disclosure also contemplates embodiments in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and / or software elements can be provided to prevent or block access to such personal information data. For example, in the case of advertisement delivery services, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services or anytime thereafter. In another example, users can select not to provide mood-associated data for targeted content delivery services. In yet another example, users can select to limit the length of time mood-associated data is maintained or entirely prohibit the development of a baseline mood profile. In addition to providing “opt in” and “opt out” options, the present disclosure contemplates providing notifications relating to the access or use of personal information. For instance, a user can be notified upon downloading an app that their personal information data will be accessed and then reminded again just before personal information data is accessed by the app.

[0075] Moreover, it is the intent of the present disclosure that personal information data should be managed and handled in a way to minimize risks of unintentional or unauthorized access or use. Risk can be minimized by limiting the collection of data and deleting data once it is no longer needed. In addition, and when applicable, including in certain health related applications, data de-identification can be used to protect a user's privacy. De-identification can be facilitated, when appropriate, by removing specific identifiers (e.g., date of birth, etc.), controlling the amount or specificity of data stored (e.g., collecting location data a city level rather than at an address level), controlling how data is stored (e.g., aggregating data across users), and / or other methods.

[0076] Therefore, although the present disclosure broadly covers use of personal information data to implement one or more various disclosed embodiments, the present disclosure also contemplates that the various embodiments can also be implemented without the need for accessing such personal information data. That is, the various embodiments of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data. For example, content can be selected and delivered to users by inferring preferences based on non-personal information data or a bare minimum amount of personal information, such as the content being requested by the device associated with a user, other non-personal information available to the content delivery services, or publicly available information.

[0077] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not meant to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Examples

Embodiment Construction

[0019]Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims.

[0020]The following disclosure relates to techniques for anodizing processes that result in cosmetically appealing and durable anodic oxide films. Conventional anodizing processes can be unable to achieve a white finish on metal surfaces. As an example, subtractive coloring methods can provide colored finishes to a surface. In such examples, a porous oxide layer can be “dyed” using dye molecules adsorbed into the metal oxide layer. These dye molecules can absorb some wavelengths of light to allow the surface to reflect a different, darker color. However...

CROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 684,841, filed 19 Aug. 2024, and entitled “TECHNIQUES FOR MATTE WHITE METALLIC FINISH OF ELECTRONIC DEVICES,” the entire disclosure of which is hereby incorporated by reference.FIELD

[0002] The described embodiments relate generally to surface finishes of electronic devices. More particularly, the present embodiments relate to techniques for forming and sealing metal oxide layers to improve the cosmetics of a metal substrate, enhance physical characteristics of the metal substrate, or both.BACKGROUND

[0003] The surfaces of many products in the commercial and consumer industries can be treated by any number of processes to alter the surface and create a desired effect, either functional, cosmetic, or both. One example of such a surface treatment is the anodizing of a metal substrate. Anodizing converts a portion of the metal substrate into a metal oxide, thereby creating a metal oxide layer, which is generally harder than the underlying metal substrate and can act as a protective layer. Metal oxide layers can have good corrosion and wear resistance for many consumer products. Further, dyes and other methods can be used to apply various cosmetic colorings to metal oxide materials. For example, dye molecules can be adsorbed into the metal oxide layer. The dye molecules can absorb various wavelengths of light and can allow the surface to reflect a different, darker color. Such methods can be referred to as subtractive coloring methods.

[0004] It can be desirable to achieve a white appearance (e.g., a matte white appearance) for metal oxide layers. However, a surface of a metal oxide layer can have a default silver appearance due to the properties of the underlying metal, and as a result, subtractive coloring methods can be unable to achieve a white appearance for the metal oxide layer. Consequently, techniques are needed for implementing a white (e.g., matte-white) appearance for metal oxide layers on metal substrates.SUMMARY

[0005] In some examples, an enclosure for an electronic device can include an aluminum alloy substrate and an anodic oxide coating disposed on the aluminum alloy substrate having a nano-scale etched pattern. The enclosure can include a matte-white finish having a flop index between about 2 and about 10. In some examples, the enclosure can include a sealant disposed on the anodic oxide coating. The sealant can include a sol-gel coating, a hard-coat, an anodic electrophoretic deposition coating, or a combination thereof. In some examples, the sealant can include a thickness of less than about 5 microns.

[0006] In some examples, the anodic layer can include a thickness between about 10 microns and about 20 microns. In some examples, a thickness of the sealant is proportional to a gloss value of the enclosure. In some examples, the anodic oxide coating has a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2. In some examples, the anodic oxide coating has a 60-degree gloss measurement of less than 30 gloss units. In some examples, the enclosure can include a surface hardness of about 300 HV0.05 or greater.

[0007] According to some examples, a housing can include a substrate including aluminum and an anodic layer disposed on and formed from at least a portion of the substrate and configured to diffuse ambient light. The housing can include a matte-white finish having a L* value greater than about 90. In some examples, the anodic layer can include an etched pattern having fissures that are configured to diffuse the ambient light.

[0008] In some examples, the housing can include a sealant disposed on the anodic layer. The sealant can include a sol-gel coating, a hard-coat, an anodic electrophoretic deposition layer, or a combination thereof. In some examples, the sealant can include a thickness of less than about 5 microns and the anodic layer can include a thickness between about 10 microns and about 20 microns. In some examples, the anodic layer has a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2. In some examples, the anodic layer has a 60-degree gloss measurement between about 5 and about 10 gloss units. In some examples, the enclosure can include a hardness of about 300 HV0.05 or greater.

[0009] According to some examples, a method for forming a surface on a substrate having a flop index between about 2 and about 10 includes forming an aluminum alloy substrate, anodizing a porous oxide layer on the aluminum alloy substrate, etching the porous oxide layer to form a nano-scale etched pattern, and sealing the porous oxide layer. In some examples, etching the porous oxide layer can include etching the porous oxide layer in 0.1M aluminum sulfate at between about 30-80° C.

[0010] In some examples, anodizing the porous oxide layer can include immersing the aluminum alloy substrate in an electrolyte including between about 150 and 250 g / L of sulfuric acid and applying a current having a current density between about 0.5 A / dm2 and 2.5 A / dm2 at about 20° C. In some examples, a flop index value of the surface is inversely proportional to a duration of time etching the porous oxide layer.

[0011] In some examples, sealing the porous oxide layer can include performing an anodic electrophoretic deposition on the etched porous oxide layer or applying a sol-gel coating or a clear-coat to the etched porous oxide layer. In some examples, the sealed porous oxide layer has a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:

[0013] FIG. 1 shows example electronic devices that can include the housings and enclosures with anodic oxide coatings described herein.

[0014] FIG. 2 shows a cross section view of an anodic oxide disposed on a substrate.

[0015] FIG. 3 shows cross section view of an etched anodic oxide disposed on a substrate.

[0016] FIG. 4 shows an example of a cross section view of a sealant disposed on an etched anodic oxide disposed on a substrate.

[0017] FIG. 5 shows an example of another cross section view of a sealant disposed on an etched anodic oxide disposed on a substrate.

[0018] FIG. 6 shows a flowchart indicating a method for forming an oxide layer on a substrate, according to some examples.DETAILED DESCRIPTION

[0019] Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims.

[0020] The following disclosure relates to techniques for anodizing processes that result in cosmetically appealing and durable anodic oxide films. Conventional anodizing processes can be unable to achieve a white finish on metal surfaces. As an example, subtractive coloring methods can provide colored finishes to a surface. In such examples, a porous oxide layer can be “dyed” using dye molecules adsorbed into the metal oxide layer. These dye molecules can absorb some wavelengths of light to allow the surface to reflect a different, darker color. However, the underlying metal (e.g., aluminum alloy substrate) can have material properties that result in a silver appearance of the metal surface. Therefore, a clear oxide layer can have a silver appearance, and while adding dye molecules can give darker colors, conventional techniques for anodizing are unable to give the metal surface a “white” appearance due to the persistent silver appearance of the metal surface and the lack of darker dye molecules to block the silver appearance.

[0021] Accordingly, the techniques described herein can provide for adding a white (e.g., matte-white) finish to metal surfaces. As an illustrative example, a surface can include an aluminum alloy substrate with a porous oxide layer and a sealant deposited on the porous oxide layer. The porous oxide layer can include an etched nano-scale pattern that is configured to diffuse light such that the surface has a white appearance as described herein. In some examples, a white appearance can correspond to one or more color metrics. For example, a surface with a white appearance can be a surface having an L* value of greater than about 90, an a* value of less than about 1, and / or a b* value of less than about 2. Additionally or alternatively, the surface can have a flop index value between about 2 and about 10. In some examples, the surface can have a 60-degree gloss measurement of less than 30 gloss units.

[0022] Further, the techniques described herein can provide for a white surface that satisfies one or more reliability thresholds. For example, the porous oxide layer can be sealed with a sealant in accordance with the techniques described herein (e.g., a sol-gel sealant, a hard coat sealant, etc.). Such sealant techniques can preserve the white appearance of the porous oxide layer while providing a stain and corrosion resistant finish to the surface, among other examples of reliability metrics.

[0023] These and other embodiments are discussed below with reference to FIGS. 1-6. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. Furthermore, as used herein, a system, a method, an article, a component, a feature, or a sub-feature comprising at least one of a first option, a second option, or a third option should be understood as referring to a system, a method, an article, a component, a feature, or a sub-feature that can include one of each listed option (e.g., only one of the first option, only one of the second option, or only one of the third option), multiple of a single listed option (e.g., two or more of the first option), two options simultaneously (e.g., one of the first option and one of the second option), or combination thereof (e.g., two of the first option and one of the second option).

[0024] Methods described herein can be used to form metal surface finishes that are reliable as well as cosmetically appealing for surfaces of enclosures and / or housings for consumer devices. FIG. 1 shows consumer products than can be manufactured using methods described herein. FIG. 1 includes portable phone 102, tablet computer 104, an electronic watch 106, and portable computer 106, which can each include enclosures and / or housings. The devices 102, 104, 106, and 108 can implement one or more techniques in accordance with the techniques described herein. For example, one or more of the devices 102, 104, 106, and 108 can have white appearing surfaces (e.g., enclosures or housings of the devices) that have a metal substrate, an anodic oxide layer, a sealant layer, or a combination thereof as discussed with reference to FIGS. 2-6. However, while described in the context of consumer devices for illustrative clarity, it is to be understood that the techniques described herein can additionally or alternatively be used for other types of devices or surfaces. Further, a surface of a device as described herein can additionally or alternatively be referred to as or be an example of a housing, an enclosure, an internal surface, an external surface, or a combination thereof.

[0025] The devices 102, 104, 106, and 108 can have metal surfaces. For instance, the surface of the devices 102, 104, 106, and 108 can include a metal substrate. The metal substrate can be referred to as or be an example of a metal, a metal layer, a metal surface, and the like. While described herein as a “metal” surface or substrate for illustrative clarity, any suitable anodizable material can implement one or more of the techniques described herein. In some examples, the metal substrate can include aluminum (e.g., an aluminum substrate, a substrate with an aluminum alloy, etc.), titanium, zinc, or a combination thereof, among other examples of anodizable materials. Although particular reference is made to 6000 and 7000-series aluminum alloys, and substrates that can include aluminum and / or aluminum alloys, the techniques described herein could be applied to other aluminum alloys or anodizable materials.

[0026] The metal substrate can be anodized to form an anodic oxide layer. For example, an anodizing process (e.g., an electrolytic passivation process) can be performed on the metal substrate to create or increase the thickness of a natural oxide layer on the surface of the metal substrate. That is, anodizing can convert a portion of a metal substrate into a metal oxide, thereby creating a metal oxide layer, which is generally harder than the underlying metal substrate and can act as a protective layer. As described herein, the terms “anodic film,”“anodic oxide,”“anodic layer,”“anodic oxide,”“anodic oxide film,”“anodic oxide layer,”“anodic oxide coating”“metal oxide,”“metal oxide film,”“metal oxide layer,” and “anodic coating” can be used interchangeably.

[0027] In some examples, the metal substrate and / or the anodic oxide layer of the devices 102, 104, 106, and 108 can be sealed. For example, a post-processing procedure can include sealing the substrate and / or anodic oxide layer. Such a procedure can enhance the physical characteristics of the surface, improve the cosmetic value of the surface, or both. Sealing the anodic oxide layer can improve a reliability of the surface by improving its resistance to corrosion and wear, among other examples of reliability metrics.

[0028] In some examples, an anodizing process (e.g., the formation of the metal substrate, the metal oxide layer, the sealing layer, or a combination thereof) can result in one or more cosmetic features of the surfaces of the devices 102, 104, 106, and 108. For example, cosmetic anodizing can be relatively clear, which gives a surface a silver appearance due to the material properties of the underlying metal (e.g., aluminum or aluminum alloy can have a silver hue, though other metals and hues can have non-white or off-white hues). As another example, the surfaces can be “dyed” to impart a color to the surfaces. In some cases, the dying process can be an example of a subtractive coloring method.

[0029] In some examples, the surfaces can be dyed by including dye molecules (e.g., organic chromophores) that absorb some wavelengths of light to allow the surface to reflect a different, darker color. The color of an anodized finish can be adjusted by adsorbing dye molecules (e.g., organic dye molecules) into the pores of the metal oxide prior to sealing, which will impart color to the surface. The dye molecules can include chromophores which absorb certain wavelengths of visible light such that the light reflected off the surface has a complimentary color. One or more hues can be achieved for a surface by dying (e.g., reds, pinks, blues, greens, yellows, oranges, etc.). In some examples, the color or hue of a surface can be described herein with reference to the Commission on Illumination LAB (CIELAB) color space. The term “CIELAB color space” can be used interchangeably with the term “CIE 1976 L*a*b* color space.”

[0030] However, such subtractive coloring methods can be unable to achieve a white finish for the surfaces of the devices. For example, due to the silver hue of the underlying metal, absorbing light with dye molecules can give a range from a silver hue (e.g., a L* of about 90 with relatively low absorption across the visible spectrum) to a black hue (e.g., a L* of about 25 with relatively high absorption across the visible spectrum), but not a white hue, based on the neutral, non-dyed finish having a metallic silver color. In some examples, a white hue can be a hue of a surface that has a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2, in accordance with the CIE 1976 L*a*b* color space.

[0031] Thus, techniques for obtaining a white hue on one or more surfaces of the devices can be desired. In some cases, the device surfaces can be painted white. Painting can impart a plastic look, touch, or feel to the surface based on a relatively low thermal conductivity of a polymeric coating compared to anodic oxides and underlying metal substrates that are not painted. In some cases, an anodizing process can incorporate white pigments into the surface of the devices, such as Titania, the anodizing process can use high voltage micro-arc oxidation, or a combination thereof. However, such techniques can fail to achieve white finishes that satisfy one or more thresholds. For example, these methods can result in an off-white appearance due to some intrinsic hue of the surfaces (e.g., an a* greater than about 2, a b* greater than about 2, or both). Additionally or alternatively, these techniques can result in an opaque appearance for the surface. Stated alternatively, the surface may not have a metallic character due to a relatively low flop value.

[0032] Accordingly, the techniques described herein can enable a white appearance for one or more surfaces of the devices 102, 104, 106, and / or 108. The surfaces of the devices can have metrics that satisfy one or more cosmetic thresholds, reliability thresholds, or both. For example, the surfaces can be referred to as “white” or “white appearing” surfaces based on having a L* value of greater than about 90, an a* value of less than about 1, a b* value of less than about 2, or a combination thereof. In some cases, such metrics can be measured by a spectrophotometer (e.g., a d / 8 spectrophotometer), though other values, instruments, or metrics can be used.

[0033] The surfaces of the devices can satisfy a flop threshold. For example, a surface can have a flop index value between about 2 and about 10. A flop index value can be referred to as or be an example of a “luster” metric of the surface (e.g., a metallic luster). Luster can be a visual characteristic of metal surfaces. “Flop” can be an example of a measure of how shiny or reflective a surface is as it is rotated through a series of viewing angles. In other words, flop can be quantified by the change of lightness values across different observation angles. As an illustrative example, the flop can be calculated in accordance with Equation 1:F=2.6⁢9⁢(L1-L3)1.1⁢1L20.8⁢6(1)

[0034] In Equation 1, F can represent the flop (i.e., flop index value, flop measurement, flop value, flop metric, etc.). L1 can represent the lightness (e.g., L* in the CIELAB color space, although other metrics can be used) at a first observation angle, L2 can represent the lightness at a second observation angle, and L3 can represent the lightness at a third observation angle. It is to be understood that Equation I is an illustrative example of a flop metric and different formulations or metrics can be used to quantify the flop (i.e., the measure of how the shine of a surface changes as the viewing angle changes) or luster. A flop value of 0 can indicate that there is no change in lightness based on the viewing angle. In some examples, a flop of a matte anodized metallic surface can be around 10 to around 18 (e.g., the matte anodized metallic surface can be associated with a luster of around 4 to around 7). The lower end of such a range can correspond to a relatively finer scale roughness for a surface of a device and the higher end of the range can correspond to a relatively coarser blast texture for a device (e.g., a display of a device). As one example, a flop value of a mirror-lapped anodized surface can be as high as around 20 to around 22 (e.g., the surface can be associated with a luster of around 10 to around 11).

[0035] Additionally or alternatively, the surfaces of a device can satisfy a gloss threshold. For example, a surface can have a 60-degree gloss measurement of less than around 30. A 60-degree gloss measurement can be referred to as or be an example of a measurement by a gloss meter that reflects a known quantity of light off a surface at a 60-degree angle and measures the reflectance, or an amount of the known quantity of light that is reflected of the surface. A relatively high 60-degree gloss measurement correspond to a high gloss of the surface while a relatively low 60-degree gloss measurement corresponds to a relatively low gloss of the surface. The gloss measurement can have units of Gloss Units (GUs), which is a scaling based on a highly polished reference black glass standard with a defined refractive index having a specular reflectance of 100 GUs at the 60-degree angle. Thus, a measurement of 0 GUs can correspond to a completely matte surface (e.g., no specular reflectance), a measurement of 50 GUs can have half the specular reflection of the reference standard (e.g., a medium gloss), and the like. As one illustrative example, a non-dyed aluminum finish (e.g., a Zirconium Oxide (ZrO2) blasted matte finish) can correspond to a flop of around 13 to around 15 and a 60-degree gloss measurement of around 9 to around 13. In some examples, a 60-degree gloss measurement of less than around 30 (e.g., around 5 to around 10) can correspond to a relatively “matte” finish, or a finish with a relatively low gloss.

[0036] Accordingly, in some examples one or more surfaces of the device 102, the device 104, the device 106, and / or the device 108 can have material properties that satisfy one or more cosmetic thresholds associated with a white appearance, a matte appearance, or both. For instance, a surface can have a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2, the surface can have a flop measurement between about 2 and about 10 (e.g., a flop measurement of about 5), the surface can have a 60-degree gloss measurement of less than about 30 gloss units (e.g., about 5 to about 10 gloss units), or a combination thereof. In some examples, the combination of a L* threshold (e.g., a L* of greater than 90 or 91) and a flop between about 2 and about 10 (e.g., about 5) can give the surface a white hue whilst retaining at least a portion of a metallic “shiny” character, which can be a desirable cosmetic appearance, although variations and other cosmetic appearances are possible. Additionally or alternatively, the one or more surfaces can satisfy one or more reliability thresholds as described in further detail with reference to FIG. 4.

[0037] FIG. 2 illustrates a cross section view of an enclosure 200 that includes an anodic oxide 205 disposed on a substrate 210. In some examples, the substrate 210 can include aluminum. In some examples, the enclosure 200 can be a housing for an electronic device or one or more surfaces of an electronic device. The anodic oxide 205 forms a coating over the substrate 210 to provide corrosion protection and cosmetic benefits.

[0038] The substrate 210 can include a metal or other anodizable material as described herein with reference to FIG. 1. For example, the substrate 210 can be an example of aluminum or an aluminum alloy. The anodic oxide 205 can be formed on the substrate 210 by anodizing the substrate 210 in an electrolyte. That is, the anodizing process can include immersing substrate 210 in the electrolyte at an anodizing temperature and applying a current for a duration of time to “grow” a thickness of the anodic oxide 205. In some examples, the anodizing process for the anodic oxide 205 can be referred to as a “Type II” anodizing process.

[0039] As an illustrative example, the substrate 210 can be immersed in 200 grams (g) per liter (L) of sulfuric acid at 20 degrees Celsius (C). A current with a current density of about 1 to about 1.5 amperes per square decimeter (ASD) can be applied to the immersed substrate 210 for the duration of time (e.g., a duration of time that corresponds to a target thickness of the layer of anodic oxide 205). The thickness of the oxide layer 305 can be controlled in part by the duration of the anodization process (e.g., the duration can be proportional to the thickness of the oxide layer 305 such that a relatively high duration of the anodization process corresponds to a relatively high thickness). In some such examples, the anodizing process can form the anodic oxide layer to a thickness of about 10 to about 20 microns, although other thicknesses can be implemented in accordance with the techniques described herein.

[0040] In some examples, the anodic oxide 205 can be relatively neutral in color and relatively bright. In some cases, the anodic oxide 205 being relatively clear or neutral can give the enclosure 200 a silver appearance due to the underlying properties of the substrate 200. For example, the cosmetic metrics (e.g., color metrics) of the anodic oxide 205 can be a L* of greater than about 90, an a* of less than about 1, and a b* of less than about 2 in the CIELAB color space. In some examples, some cosmetic metrics can be measured or obtained using a spectrophotometer with d / 8 geometry, a 10-degree observer, and a F2 or D65 illuminant. Additionally or alternatively, the flop of the anodic oxide 205 can be in the range of about 10 to about 22, for example, based on the texture that is applied to the substrate 210.

[0041] FIG. 3 illustrates a cross section view of an enclosure 300 having an etched anodic oxide 305 disposed on a substrate 310. The anodic oxide 305 can be an example of an anodic oxide as described herein, such as the anodic oxide 205. The substrate 210 can be an example of a substrate as described herein, such as the substrate 205. After formation of the anodic oxide 305, an etching process can configure the anodic oxide 305 with an etched section 315, a base section 320, or both. For example, the etched section 315 can include fissures between pillars 335 of anodic oxide 305. Fissures can be an example of, or can include, gaps between pillars 335 of the anodic oxide 305, fissures can be examples of relatively lower density areas in the anodic oxide 305 (e.g., areas with a reduced density of the anodic oxide 305 from etching can be referred to as “fissures” while areas with a relatively higher density of the anodic oxide 305 can be referred to as pillars 335), or a combination thereof.

[0042] The etching process can include etching the anodic oxide 305 in an etching solution. As an example, the anodic oxide 305 can be immersed in an etching solution of aluminum sulfate (e.g., between about 10 and 40 g / L of aluminum sulfate, between about 15 and 75 g / L of aluminum sulfate, about 10 g / L of aluminum sulfate, about 20 g / L of aluminum sulfate, about 30 g / L of aluminum sulfate, or any other effective concentration) at an etching temperature (e.g., between about 30-80 degrees C., between about 45 and 60 degrees C., at about 50 degrees C., at about 100 degrees C., and the like). In some examples, the etching process can include one or more other steps which can be performed in any order, such as cleaning, leveling, rinsing, neutralizing, drying, and the like.

[0043] The etching process can etch a nano-scale pattern into the anodic oxide 305. For example, the etched section 315 can have fissures and pillars 335 of anodic oxide 305 based on the etching process. The fissures and pillars 335 have roughly rectangular and triangular shapes for illustrative clarity, but it is to be understood that the form and pattern of the pillars 335 and / or the associated fissures can be of various shapes, depths, and densities. The term “nano-scale pattern” can additionally or alternatively be referred to as an “etched pattern,” a “nano-meter pattern,” an “etched surface structure,” and the like. Further, while described as a nano-scale pattern, other patterns having additional or alternative features at other scales can be used.

[0044] In the example of the enclosure 300, the fissures and pillars 335 can have a relatively higher diffusion of light at the surface of the enclosure 300 compared to a surface without the etched pattern. The diffusion of light can change the character of the color of the surface from a silver towards a white. In some examples, the nano scale pattern (e.g., nano-meter scale pillars 335 and fissures in the etched section 315) can have a relatively small impact on the hue of the surface. For instance, the surface of the enclosure 300 can have retain an a* of less than about 1, a b* of less than about 2, and an L* of about 90 (or greater than about 90), which can be similar to the metrics of the enclosure 200 without an etched pattern. The change of color from a metallic silver to a “white” appearance can be based on a reduction in flop of the enclosure 300 from an initial value (e.g., a value prior to the etching process) to a post-etch value. As an illustrative example, the nano-scale pattern can reduce the flop from a value of about 13 to about 15 to value in the range of about 2 to about 10.

[0045] In some examples, a duration of the etching process can be proportional to the reduction in the flop of the enclosure 300. For example, a relatively long etch duration can correspond to a relatively high reduction in flop. As an illustrative example, a longer duration for the etch can result in relatively more pillars 335 and fissures, deeper fissures (e.g., taller pillars 335), or a combination thereof, which can increase the light diffusing effect of the nano scale pattern and thus decrease the flop.

[0046] In some examples, the anodic oxide 305 can have an opaque appearance (e.g., white at a relatively large range of observer angles and illuminant values) at a flop index value of about 3 and thus have relatively small amount of a metallic character. In some other examples, the anodic oxide 305 can have both a white appearing finish as well as a metallic character based on the light diffusing nano-scale pattern, such as at flop values at about 5 or other intermediate values between about 3 and about 10. Thus, the enclosure 300 can have an appearance of an opaque white and / or a metallic white based on a duration of the etching process.

[0047] As an illustrative example of surface etching increasing the diffuse reflection of light for the anodic oxide 305, without etching the flop of the anodic oxide 305 can be about 14 (e.g., a silver appearing surface with a metallic character), with two minutes of etching the flop of the anodic oxide 305 can be about 8, with 4 minutes of etching the flop of the anodic oxide 305 can be about 7 (e.g., a whiter appearing surface with a metallic character), with 6 minutes of etching the flop of the anodic oxide 305 can be about 6, and with 8 minutes of etching the flop of the anodic oxide 305 can be about 5 (e.g., a white appearing surface with a metallic character). In some such examples, etching for a longer duration can result in a flop of lower than about 3, which can result in an opaque white appearing surface (e.g., white appearing without a metallic character). Thus, the flop of the surface (e.g., the metallic or opaque character and degree of how white appearing the surface is) can be controllable by a duration of the surface etching.

[0048] FIG. 4 illustrates a cross section view of an enclosure 400 having an etched anodic oxide 405 disposed on a substrate 410 and a sealant 415 disposed on the etched anodic oxide 405. The substrate can be an example of a substrate as described herein, such as the substrate 210 or the substrate 310. The etched anodic oxide 405 can be an example of an anodic oxide as described herein, such as the anodic oxide 205 or the anodic oxide 305.

[0049] The enclosure 400 can include a sealant 415. The sealant 415 can be formed on the anodic oxide 405. For example, a sealing process can deposit or form the sealant 415 over the anodic oxide 405 after an etching process is performed on the anodic oxide 405 as described herein with reference to FIG. 3. As described herein, the terms “sealant,” a “sealant layer,” a “sealing layer,” a “seal material,” a “seal film,” a “seal coating,” and a “sealant coating,” can be used interchangeably.

[0050] The sealant 415 can improve the reliability of the enclosure 400. For example, the sealant 415 can inhibit contamination or wear of the enclosure 400 by providing a protective layer of material at the surface (e.g., above the anodic oxide 405). Stated alternatively, the sealant 415 can keep out contaminants, protect the finish of the enclosure 400 from stains, corrosion, or environmental degradation, or a combination thereof, among other benefits.

[0051] In some examples, the sealing process can include a hydrothermal sealing process. In such examples, the anodic oxide 405 is immersed in a relatively hot aqueous solution and the pore walls of the anodic oxide 405 are hydrated as a result (e.g., the pore walls can swell to close off the pores and reduce a porosity of the oxide). If dye molecules are used, such a sealing process can seal in organic dies. However, in some cases, a hydrothermal sealing process can raise the flop of the etched pattern anodic oxide 405 (e.g., the appearance of the enclosure 400 can revert from a white appearance associated with the etched anodic oxide 405 to a silver appearance associated with the anodic oxide 405 prior to etching the pattern).

[0052] Thus, in addition or alternative to a hydrothermal sealing process, the sealing process can include other techniques for forming the sealant 415 that maintain a white appearance of the enclosure 400 and provide reliability and protection to the enclosure 400.

[0053] In some examples, the sealing process can include forming (e.g., depositing) the sealant 415 on the anodic oxide 405 via an anodic electrophoretic deposition process (i.e., an “e-coating”). As an example, anodic electrophoretic deposition can include applying an electric field to a material such that particles migrate (e.g., electrophoresis) to be deposited on an electrode. For instance, the sealant 415 can be deposited on the anodic oxide 405 by applying an electric field to a liquid containing the sealant 415 such that the sealant 415 moves to the surface of the anodic oxide 405.

[0054] In some examples, the sealing process can include forming the sealant 415 as a sol-gel (e.g., a matte sol-gel). That is, the sealant 415 can be an example of a sol-gel sealant. A sol-gel process can be an example of a wet-chemical technique to produce solid materials from relatively small molecules. As an example, a sol (e.g., a colloidal solution) is formed that has liquid removed until a gel or gel-like material forms. In some examples, the sol can undergo steps to develop target mechanical or material properties, such as firing, sintering, densification, and grain growth. The sol can be used as the sealant 415 for sealing the enclosure 400. In some examples, the sealant 415 can be an example of a sol-gel silicone with a carbon backbone.

[0055] In some examples, the sealing process can include forming the sealant 415 as a clear coat. That is, the sealant 415 can be an example of a clear coat or a hard-coat sealant. In some examples, a clear coat can include a thin application of coating similar to that used in typical automotive paint finishes. For example, the sealant 415 can be an example of a clear coat sealant comprising a blend of acrylic and polyurethane. The clear coat can be applied by spraying in some examples. In an example, the clear coat can by applied to a thickness of between about 25 and about 50 microns. The sealant 415 can offer scratch and environmental resistance.

[0056] In some examples, the sealant 415 can be deposited as a polymer (e.g., the sealant 415 can be a relatively thin layer of parylene, polysiloxanes, or other examples of polymers). In some examples, the sealant 415 can be an example of a fluorinated sealing material or can be deposited by applying a product with volatile compounds that evaporate to form the sealant 415 on the surface of the enclosure 400.

[0057] In some examples, the sealant 415 can be an example of any of the materials or similar materials described herein and can be applied through e-coating, spraying, or ink-jet printing onto the etched anodic oxide 405. In some examples, the sealant 415 can penetrate some depth into the columnar porosity of the anodic oxide coatings (e.g., the anodic oxide 405) and form a seal to protect against corrosion, staining, wear, and the like.

[0058] The various sealing techniques described herein can be used by themselves or in combination to form the sealant 415. While the sealant 415 is depicted as a single material and layer for illustrative clarity, it is to be understood that the sealant 415 can have any quantity or configuration of materials (e.g., sealants) or layers. Further, it is to be understood that one or more of the sealing techniques can be used independently or in combination and portions of the techniques can be removed or other techniques or steps can be added (e.g., cleaning steps, levelling steps, among other examples of techniques for sealing the enclosure 400).

[0059] The enclosure 400 can satisfy one or more cosmetic thresholds and / or one or more reliability thresholds based on the sealing process. In other words, the layer of sealant 415 can improve the reliability and / or provide protection to the enclosure 400 while retaining a desired cosmetic appearance of the enclosure 400. As an illustrative example, after sealing with the sealant 415 in accordance with the techniques described herein the enclosure 400 can have an a* of less than about 1 and a b* of less than about 2, a L* greater than about 90, a flop index value in a target range such as about 2 to about 10, or a combination thereof. In some examples, a gloss of the enclosure 400 can be proportional to a thickness of the sealant 415. For example, a relatively high thickness of the sealant 415 can give a higher gloss measurement for the surface of the enclosure 400. In some examples, the enclosure 400 can have a “matte” appearance represented by a cosmetic threshold of a 60-degree gloss measurement of less than around 30. As an example, this threshold can correspond to a thickness of the sealant 415 of less than around 5 microns, which can provide a matte-white appearance to the enclosure 400 while providing relatively high reliability for electronic devices.

[0060] Additionally or alternatively, the enclosure 400 can satisfy one or more reliability thresholds. For example, the enclosure can have a surface hardness of about 300 HV0.05 or greater. As known in the art, HV0.05 can refer to a Vickers hardness testing scale, specifically at a load of 50 g. Additionally or alternatively, the enclosure 400 can have a relatively low chemical sensitivity (e.g., a resistance to stains from the environment such as black coffee, lip polish, mustard, ketchup, sunscreen, and the like), a relatively high resistance to abrasions (e.g., rubbing against denim or steel wool), tumble and solar exposure testing (e.g., polymers can discolor in the sun and the enclosure 400 can have a resistance that satisfies a sensitivity threshold), and the like. Stated alternatively, the enclosure 400 can have reliability metrics (e.g., a sensitivity to staining, abrasions, etc.) that satisfy reliability thresholds for electronic consumer devices while retaining a white appearance as described herein.

[0061] FIG. 5 illustrates a cross section view of an enclosure 500 having an etched anodic oxide 505 disposed on a substrate 510 and a sealant 515 disposed on the etched anodic oxide 505. The components 500 can be examples of or include aspects of the corresponding components described herein with reference to FIGS. 1-4.

[0062] The enclosure 500 can be an example of a surface of an electronic device that has a white appearance. For example, the enclosure 500 can have a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2. Additionally or alternatively, the enclosure 500 can have a flop index value between about 2 and about 10. In some examples, the enclosure 500 can have a 60-degree gloss measurement of less than 30 gloss units.

[0063] In the example of the enclosure 500, length 520-a can represent a depth of the layer of sealant 515, which can be referred to as a “top coat.” Length 520-b can represent a depth of the layer of anodic oxide 505. Length 520-c can represent a depth of a coating infiltration. For example, the length 520-c can show that the sealant 515 has infiltrated past a top surface of the etched layer of anodic oxide 505. Length 520-d can represent an etching depth. For example, length 520-d can show how deep (e.g., on average) into the layer of anodic oxide 505 that the etching process has gone (e.g., a depth of the fissures as described herein with reference to FIG. 3). In some examples, the length 520-a can be less than or equal to about 5 microns in thickness of the sealant 515, which can correspond to a feel and character of a metallic surface (e.g., a higher thickness of the sealant 515 can result in a plastic feel and character).

[0064] FIG. 6 illustrates a flowchart indicating a method 600 for forming an oxide layer on a substrate, according to some examples. The method 600 can implement aspects of, or be implemented by, the enclosures and devices of FIGS. 1-5. For example, the substrates, anodic oxide, and sealants described herein can be examples of the corresponding substrates, anodic oxides, and sealants described herein with reference to FIGS. 1-5.

[0065] The method 600 can include the act 605 of forming an aluminum alloy substrate. The method 600 can include act 610 of anodizing a porous oxide layer. For example, the substrate can be anodized as described herein with reference to FIG. 2 to form the porous oxide layer disposed on the aluminum alloy substrate. In some examples, anodizing the porous oxide layer can include immersing the aluminum alloy substrate in an electrolyte comprising between about 150 and 250 g / L of sulfuric acid and applying a current having a current density between about 0.5 A / dm2 and 1.5 A / dm2, between about 0.75 A / dm2 and 2.0 A / dm2, or between 1.0 A / dm2 and 1.5 A / dm2 at between 15 and 25° C. In some examples, the anodized porous oxide layer can have a silver appearance due to the underlying properties (e.g., material properties such as hue or color, flop, and the like) of the formed aluminum alloy substrate. For example, the anodic oxide layer can have a L* of greater than about 90, an a* of less than about 1, and a b* of less than about 2 in the CIELAB color space, and a flop in the range of about 10 to about 22, depending on the texture applied to the aluminum alloy substrate.

[0066] The method 600 can include act 615 of etching the porous oxide layer. In some examples, the porous oxide layer can be etched to form a nano-scale etched pattern on the porous oxide layer as described herein with reference to FIG. 3. For example, etching the porous oxide layer can include etching the porous oxide layer in aluminum sulfate (e.g., between about 10 and 40 g / L of aluminum sulfate, between about 15 and 75 g / L of aluminum sulfate, about 10 g / L of aluminum sulfate, about 20 g / L of aluminum sulfate, about 30 g / L of aluminum sulfate, or any other effective concentration) at an etching temperature (e.g., between about 30-80 degrees C., between about 45 and 60 degrees C., at about 50 degrees C., at about 100 degrees C., and the like). In some examples, etching can be an example of a process to remove at least a portion of the porous oxide layer. In some examples, the etched porous oxide layer having the nano-scale etched pattern can have an a* of less than about 1, a b* of less than about 2, and a L* of about 90 or greater than about 90. Additionally or alternatively, the etched porous oxide layer having the nano-scale etched pattern can have a flop value between about 3 and about 10.

[0067] In some examples, a flop index value of the surface is inversely proportional to a duration of time associated with etching the porous oxide layer. For example, a longer etching duration can form a relatively higher quantity of fissures in the porous oxide layer, relatively deeper fissures in the porous oxide layer, or a combination thereof. The relatively higher quantity, density, and / or depth of the fissures can diffuse relatively more light and thus reduce the flop of the porous oxide layer. In contrast, a relatively lower etching duration can form a relatively lower quantity, density, and / or depth of the fissures. In such examples, the etched pattern at the porous oxide layer can have relatively less light diffusion and the flop of the porous oxide layer can be relatively higher. Fissures can be examples of gaps between pillars of the porous oxide material (e.g., space that can be at least partially filled with a sealant), fissures can be examples of areas in the porous oxide material (e.g., areas with a reduced density of porous oxide material can be referred to as “fissures” while areas with a relatively higher density of porous oxide material can be referred to as “pillars”), or a combination thereof.

[0068] The method 600 can include the act 620 of sealing the porous oxide layer. In some examples, sealing the porous oxide layer can include performing an anodic electrophoretic deposition on the etched porous oxide layer, applying a sol-gel coating or a hard-coat to the etched porous oxide layer, or a combination thereof, as described herein with reference to FIG. 4. For example, a sealant can be formed on the porous oxide layer and / or the aluminum substrate (e.g., the sealant can be deposited, sprayed, and / or ink-jet printed onto the porous oxide layer).

[0069] In some examples, the sealed porous oxide layer can satisfy one or more cosmetic thresholds. For example, the sealed porous oxide layer can have a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2, a flop index value between about 2 to about 10 (e.g., about 5), and a 60-degree gloss measurement of less than around 30 GUs (e.g., between about 5 and about 10 GUs), or a combination thereof, as described herein with reference to FIG. 4. Additionally or alternatively, the sealed porous oxide layer can satisfy one or more reliability thresholds. For example, the sealed porous oxide layer can have a hardness of about 300 HV0.05 or greater, the sealed porous oxide layer can satisfy a chemical sensitivity threshold for one or more chemicals, a tumble threshold, a solar exposure threshold, a physical abrasion threshold, or any combination thereof, as described herein with reference to FIG. 4.

[0070] Additionally, any of the above methods can further include one or more further treatments on surface. For example, rinsing, degreasing, de-smutting, dyeing, sealing, polishing, texturizing, brightening, or further anodization can also be conducted.

[0071] To the extent applicable to the present technology, gathering and use of data available from various sources can be used to improve the delivery to users of invitational content or any other content that can be of interest to them. The present disclosure contemplates that in some instances, this gathered data can include personal information data that uniquely identifies or can be used to contact or locate a specific person. Such personal information data can include demographic data, location-based data, telephone numbers, email addresses, X® (formerly TWITTER®) ID's, home addresses, data or records relating to a user's health or level of fitness (e.g., vital signs measurements, medication information, exercise information), date of birth, or any other identifying or personal information.

[0072] The present disclosure recognizes that the use of such personal information data, in the present technology, can be used to the benefit of users. For example, the personal information data can be used to deliver targeted content that is of greater interest to the user. Accordingly, use of such personal information data enables users to calculated control of the delivered content. Further, other uses for personal information data that benefit the user are also contemplated by the present disclosure. For instance, health and fitness data can be used to provide insights into a user's general wellness, or can be used as positive feedback to individuals using technology to pursue wellness goals.

[0073] The present disclosure contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and / or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. Such policies should be easily accessible by users, and should be updated as the collection and / or use of data changes. Personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection / sharing should occur after receiving the informed consent of the users. Additionally, such entities should consider taking any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. In addition, policies and practices should be adapted for the particular types of personal information data being collected and / or accessed and adapted to applicable laws and standards, including jurisdiction-specific considerations. For instance, in the US, collection of or access to certain health data can be governed by federal and / or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA); whereas health data in other countries can be subject to other regulations and policies and should be handled accordingly. Hence different privacy practices should be maintained for different personal data types in each country.

[0074] Despite the foregoing, the present disclosure also contemplates embodiments in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and / or software elements can be provided to prevent or block access to such personal information data. For example, in the case of advertisement delivery services, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services or anytime thereafter. In another example, users can select not to provide mood-associated data for targeted content delivery services. In yet another example, users can select to limit the length of time mood-associated data is maintained or entirely prohibit the development of a baseline mood profile. In addition to providing “opt in” and “opt out” options, the present disclosure contemplates providing notifications relating to the access or use of personal information. For instance, a user can be notified upon downloading an app that their personal information data will be accessed and then reminded again just before personal information data is accessed by the app.

[0075] Moreover, it is the intent of the present disclosure that personal information data should be managed and handled in a way to minimize risks of unintentional or unauthorized access or use. Risk can be minimized by limiting the collection of data and deleting data once it is no longer needed. In addition, and when applicable, including in certain health related applications, data de-identification can be used to protect a user's privacy. De-identification can be facilitated, when appropriate, by removing specific identifiers (e.g., date of birth, etc.), controlling the amount or specificity of data stored (e.g., collecting location data a city level rather than at an address level), controlling how data is stored (e.g., aggregating data across users), and / or other methods.

[0076] Therefore, although the present disclosure broadly covers use of personal information data to implement one or more various disclosed embodiments, the present disclosure also contemplates that the various embodiments can also be implemented without the need for accessing such personal information data. That is, the various embodiments of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data. For example, content can be selected and delivered to users by inferring preferences based on non-personal information data or a bare minimum amount of personal information, such as the content being requested by the device associated with a user, other non-personal information available to the content delivery services, or publicly available information.

[0077] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not meant to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Examples

Embodiment Construction

[0019]Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims.

[0020]The following disclosure relates to techniques for anodizing processes that result in cosmetically appealing and durable anodic oxide films. Conventional anodizing processes can be unable to achieve a white finish on metal surfaces. As an example, subtractive coloring methods can provide colored finishes to a surface. In such examples, a porous oxide layer can be “dyed” using dye molecules adsorbed into the metal oxide layer. These dye molecules can absorb some wavelengths of light to allow the surface to reflect a different, darker color. However...

Claims

1. An enclosure for an electronic device, comprising:an aluminum alloy substrate; andan anodic oxide coating disposed on the aluminum alloy substrate, the anodic oxide coating having a nano-scale etched pattern;wherein the enclosure comprises a matte-white finish having a flop index between about 2 and about 10.

2. The enclosure of claim 1, wherein the enclosure comprises a sealant disposed on the anodic oxide coating, the sealant comprising a sol-gel coating, a clear coat, an anodic electrophoretic deposition coating, or a combination thereof.

3. The enclosure of claim 2, wherein the sealant comprises a thickness less than about 5 microns.

4. The enclosure of claim 2, wherein the anodic layer comprises a thickness between about 10 microns and about 20 microns.

5. The enclosure of claim 2, wherein a thickness of the sealant is proportional to a gloss value of the enclosure.

6. The enclosure of claim 1, wherein the anodic oxide coating has a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2.

7. The enclosure of claim 1, wherein the anodic oxide coating has a 60-degree gloss measurement less than 30 gloss units.

8. The enclosure of claim 1, wherein the enclosure comprises a surface hardness of about 300 HV0.05 or greater.

9. A housing, comprising:an aluminum substrate; andan anodic layer disposed on at least a portion of the substrate and configured to diffuse ambient light, wherein the housing comprises a matte-white finish having a L* value greater than about 90.

10. The enclosure of claim 9, wherein the anodic layer comprises an etched pattern having fissures configured to diffuse the ambient light.

11. The enclosure of claim 9, wherein the housing comprises a sealant disposed on the anodic layer, wherein the sealant comprises a sol-gel coating, a hard-coat, an anodic electrophoretic deposition layer, or a combination thereof.

12. The enclosure of claim 11, wherein the sealant comprises a thickness less than about 5 microns and the anodic layer comprises a thickness between about 10 microns and about 20 microns.

13. The enclosure of claim 9, wherein the anodic layer exhibits a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2.

14. The enclosure of claim 9, wherein the anodic layer exhibits a 60-degree gloss measurement between about 5 and about 10 gloss units.

15. A method for forming a surface on a substrate having a flop index between about 2 and about 10, comprising:forming an aluminum alloy substrate;anodizing a porous oxide layer on the aluminum alloy substrate;etching the porous oxide layer to form a nano-scale etched pattern; andsealing the porous oxide layer.

16. The method of claim 15, wherein etching the porous oxide layer comprises etching the porous oxide layer in aluminum sulfate at between about 30 and 80° C.

17. The method of claim 15, wherein anodizing the porous oxide layer comprises:immersing the aluminum alloy substrate in an electrolyte comprising between about 150 and 250 g / L of sulfuric acid; andapplying a current having a current density between about 0.5 A / dm2 and 2.5 A / dm2 at about 20° C.

18. The method of claim 15, wherein a flop index value of the surface is inversely proportional to a duration of time etching the porous oxide layer.

19. The method of claim 15, wherein sealing the porous oxide layer comprises:performing an anodic electrophoretic deposition on the etched porous oxide layer or applying a sol-gel coating or a hard-coat to the etched porous oxide layer.

20. The method of claim 15, wherein the sealed porous oxide layer exhibits a L* value of greater than about 90, an a* value of less than about 1, and a b* value of less than about 2.

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