Methods and apparatus for forming shaped articles, shaped articles, methods for manufacturing liquid lenses, and liquid lenses

A method includes depositing a surface modification layer on sidewalls of a plurality of cavities of a shaped article. The surface modification layer is formed from a glass material including a mobile component. The shaped article is formed from a glass material, a glass ceramic material, or a combination thereof. At least a portion of the mobile component is migrated from the surface modification layer into surface regions of the sidewalls of the shaped article, whereby subsequent to the migration, the surface regions have a reduced annealing point compared to a bulk of the shaped article. The surface modification layer and the surface regions of the sidewalls are reflowed. A surface roughness of the surface modification layer disposed on the sidewalls following the reflowing is less than a surface roughness of the sidewalls prior to the depositing.

BACKGROUND

Field

This disclosure relates to methods and apparatus for forming shaped articles, which can be used to manufacture liquid lenses.

Technical Background

Isothermal glass pressing generally includes pressing a glass plate at a relatively low temperature (e.g., a temperature at which the glass has a relatively high viscosity of 1010poise to 1012poise) using a polished ceramic or metallic mold. Such high viscosity of the glass helps to prevent the glass from sticking to the mold and to maintain the surface quality of the finished article. The mold complexity and relatively high pressing force generally limits isothermal glass pressing to small glass articles with simple geometries (e.g., ophthalmic lenses).

SUMMARY

Disclosed herein are methods and apparatus for forming shaped articles, shaped articles, methods of manufacturing liquid lenses, and liquid lenses.

Disclosed herein is a method comprising depositing a surface modification layer on sidewalls of a plurality of cavities of a shaped article. The surface modification layer is formed from a glass material comprising a mobile component. The shaped article is formed from a glass material, a glass-ceramic material, or a combination thereof. At least a portion of the mobile component is migrated from the surface modification layer into surface regions of the sidewalls of the shaped article, whereby subsequent to the migration, the surface regions have a reduced annealing point compared to a bulk of the shaped article. The surface modification layer and the surface regions of the sidewalls are reflowed. A surface roughness of the surface modification layer disposed on the sidewalls following the reflowing is less than a surface roughness of the sidewalls prior to the depositing.

Disclosed herein is a shaped article comprising a plate formed from a glass material, a glass-ceramic material, or a combination thereof. A plurality of cavities is formed in the plate. A surface modification layer is disposed on sidewalls of the plurality of cavities. The surface modification layer is formed from a glass material comprising a mobile component. Doped regions of the plurality of cavities adjacent the surface modification layer comprise a gradient in a concentration of the mobile component.

Disclosed herein is a liquid lens comprising a lens body comprising a first window, a second window, a cavity disposed between the first window and the second window, and a surface modification layer disposed on a sidewall of the cavity. The lens body comprises a glass material, a glass-ceramic material, or a combination thereof. The surface modification layer comprises a glass material comprising a mobile component. A doped region of the cavity adjacent the surface modification layer comprises a gradient in a concentration of the mobile component. A first liquid and a second liquid are disposed within the cavity of the lens body. The first liquid and the second liquid are substantially immiscible with each other and have different refractive indices such that an interface between the first liquid and the second liquid forms a lens.

Disclosed herein is a method of manufacturing a liquid lens, the method comprising depositing a surface modification layer on sidewalls of a plurality of cavities of a shaped article. The surface modification layer is formed from a glass material comprising a mobile component. The shaped article is formed from a glass material, a glass-ceramic material, or a combination thereof. The surface modification layer is heated to a heating temperature for a heating time sufficient to migrate at least a portion of the mobile component from the surface modification layer into surface regions of the sidewalls of the shaped article such that, subsequent to the migration, the surface regions have a reduced annealing point compared to a bulk of the shaped article. A first liquid and a second liquid are deposited in each of the plurality of cavities of the shaped article. The first liquid and the second liquid are substantially immiscible with each other and have different refractive indices such that an interface between the first liquid and the second liquid forms a lens. A cap is bonded to a surface of the shaped article to seal the first liquid and the second liquid within the plurality of cavities of the shaped article and form a liquid lens array.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary embodiments which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. The components in the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the exemplary embodiments.

Numerical values, including endpoints of ranges, can be expressed herein as approximations preceded by the term “about,” “approximately,” or the like. In such cases, other embodiments include the particular numerical values. Regardless of whether a numerical value is expressed as an approximation, two embodiments are included in this disclosure: one expressed as an approximation, and another not expressed as an approximation. It will be further understood that an endpoint of each range is significant both in relation to another endpoint, and independently of another endpoint.

As used herein, the term “average coefficient of thermal expansion,” or “average CTE,” refers to the average coefficient of linear thermal expansion of a given material between 0° C. and 300° C. As used herein, the term “coefficient of thermal expansion,” or “CTE,” refers to the average coefficient of thermal expansion unless otherwise indicated. The CTE can be determined, for example, using the procedure described in ASTM E228 “Standard Test Method for Linear Thermal Expansion of Solid Materials With a Push-Rod Dilatometer” or ISO 7991:1987 “Glass—Determination of coefficient of mean linear thermal expansion.”

As used herein, the term “surface roughness” means Ra surface roughness determined as described in ISO 25178, Geometric Product Specifications (GPS)—Surface texture: areal, filtered at 25 μm unless otherwise indicated. The surface roughness values reported herein were obtained using a Keyence confocal microscope.

As used herein, the term “formed from” can mean one or more of comprises, consists essentially of, or consists of. For example, a component that is formed from a particular material can comprise the particular material, consist essentially of the particular material, or consist of the particular material.

In various embodiments, a method comprises depositing a surface modification layer on sidewalls of a plurality of cavities of a shaped article. The surface modification layer is formed from a glass material comprising a mobile component. The shaped article is formed from a glass material, a glass-ceramic material, or a combination thereof. In some embodiments, at least a portion of the mobile component is migrated from the surface modification layer into surface regions of the sidewalls of the shaped article, whereby subsequent to the migration, the surface regions have a reduced annealing point compared to a bulk of the shaped article. In some embodiments, the surface modification layer and the surface regions of the sidewalls are reflowed. A surface roughness of the surface modification layer disposed on the sidewalls following the reflowing is less than a surface roughness of the sidewalls prior to the depositing.

The methods described herein can enable production of relatively large shaped articles having cavities with reduced sidewall roughness compared to conventional pressing, laser cutting, and/or etching methods.

The methods described herein can be used to manufacture shaped articles with smooth cavities formed therein. For example, in various embodiments, a shaped article comprises a plate formed from a glass material, a glass-ceramic material, or a combination thereof and a plurality of cavities formed in the plate. In some embodiments, a surface modification layer is disposed on sidewalls of the plurality of cavities. The surface modification layer is formed from a glass material comprising a mobile component. In some embodiments, doped regions of the plurality of cavities adjacent the surface modification layer comprise a gradient in a concentration of the mobile component.

The methods described herein can be used to manufacture liquid lenses. For example, in various embodiments, a liquid lens comprises a lens body comprising a first window, a second window, a cavity disposed between the first window and the second window, and a surface modification layer disposed on a sidewall of the cavity. The lens body comprises a glass material, a glass-ceramic material, or a combination thereof. The surface modification layer is formed from a glass material comprising a mobile component. In some embodiments, a doped region of the cavity adjacent the surface modification layer comprises a gradient in a concentration of the mobile component. A first liquid and a second liquid are disposed within the cavity of the lens body. The first liquid and the second liquid are substantially immiscible with each other and have different refractive indices such that an interface between the first liquid and the second liquid forms a lens.

In various embodiments, a method of manufacturing a liquid lens comprises depositing a surface modification layer on sidewalls of a plurality of cavities of a shaped article. The surface modification layer is formed from a glass material comprising a mobile component. The shaped article is formed from a glass material, a glass-ceramic material, or a combination thereof. In some embodiments, the surface modification layer is heated to a heating temperature for a heating time sufficient to migrate at least a portion of the mobile component from the surface modification layer into surface regions of the sidewalls of the shaped article such that, subsequent to the migration, the surface regions have a reduced annealing point compared to a bulk of the shaped article. A first liquid and a second liquid are deposited in each of the plurality of cavities of the shaped article. The first liquid and the second liquid are substantially immiscible with each other and have different refractive indices such that an interface between the first liquid and the second liquid forms a lens. In some embodiments, a cap is bonded to a surface of the shaped article to seal the first liquid and the second liquid within the plurality of cavities of the shaped article and form a liquid lens array.

FIG.1is a flowchart representing some embodiments of a method100for forming a shaped article. In some embodiments, method100comprises forming a plurality of cavities in a preform at step102.

FIG.2is a perspective view of some embodiments of a preform200, andFIG.3is a cross-sectional view of the preform. In some embodiments, preform200is configured as a sheet or plate. For example, preform200comprises a first surface202and a second surface204substantially parallel to the first surface. A thickness of preform200is a distance between first surface202and second surface204. In some embodiments, preform200has a rectangular circumferential or perimetrical shape as shown inFIG.2. In other embodiments, the preform can have a triangular, circular, elliptical, or other polygonal or non-polygonal circumferential or perimetrical shape. For example, the preform can be a wafer having a substantially circular circumferential shape and with or without a reference flat disposed on an outer circumference or perimeter of the preform. In some embodiments, first surface202of preform200has a surface area of at least about 100 cm2, at least about 200 cm2, at least about 300 cm2, at least about 400 cm2, at least about 500 cm2, at least about 600 cm2, at least about 700 cm2, at least about 800 cm2, at least about 900 cm2, at least about 1000 cm2, at least about 1100 cm2, at least about 1200 cm2, at least about 1300 cm2, at least about 1400 cm2, or at least about 1500 cm2. For example, preform200can be a 6 inch wafer with a surface area of about 121.55 cm2, an A6 plate with a surface area of about 155.4 cm2, an 8 inch wafer with a surface area of about 162.15 cm2, an A5 plate with a surface area of about 310.8 cm2, an A4 plate with a surface area of about 623.7 cm2, an A3 plate with a surface area of about 1247.4 cm2, or another suitably sized preform with a suitable surface area. In some embodiments, preform200is formed from a glass material, a glass-ceramic material, or a combination thereof. For example, preform200is a glass sheet or plate.

In some embodiments, the forming the plurality of cavities comprises pressing the plurality of cavities in the preform using a mold. Additionally, or alternatively, the forming the plurality of cavities comprises cutting the plurality of cavities in the preform using a laser. Additionally, or alternatively, the forming the plurality of cavities comprises etching the plurality of cavities in the preform using an etchant. The ability to use glass pressing, laser cutting, and/or etching techniques to form the plurality of cavities can be enabled by the methods described herein. For example, depositing a surface modification layer onto sidewalls of the cavities can enable use of cavities formed by glass pressing, laser cutting, and/or etching processes that produce sidewalls with relatively rough surfaces that may be unsuitable for use in electrowetting applications.

FIG.4is a partial cross-sectional schematic view of some embodiments of a shaped article300following the forming the plurality of cavities. Shaped article300comprises a first surface302corresponding to first surface202of preform200and a second surface304opposite the first surface and corresponding to second surface204of the preform. In some embodiments, shaped article300comprises a plurality of cavities306formed in first surface302(e.g., formed by mold features during pressing and/or by laser cutting). In some embodiments, cavities306are blind holes that do not extend entirely through shaped article300as shown inFIG.4. Thus, cavities306comprise an open end at first surface302of shaped article300and a closed end near second surface304of the shaped article. In other embodiments, the cavities are through-holes extending entirely through the shaped article.

In some embodiments, following the forming the plurality of cavities, shaped article300comprises one or more raised portions308disposed on one or more surfaces of the shaped article as shown inFIG.4. For example, such raised portions308can result from flow of material of preform200during pressing. Thus, in various embodiments, first surface302and/or second surface304are non-planar following the forming the cavities.

In some embodiments, method100comprises polishing the shaped article at step104as shown inFIG.1. For example, polishing shaped article300comprises polishing at least one of first surface302of the shaped article or second surface304of the shaped article following the forming the cavities.FIG.5is a cross-sectional schematic view of some embodiments of shaped article300following the polishing. In some embodiments, the polishing comprises removing material from first surface302of shaped article300. For example, the polishing comprises removing material from first surface302down to dashed line310shown inFIG.4. Such polishing can remove raised portions308on first surface302, resulting in a substantially planar surface, excluding cavities306, as shown inFIG.5. In some embodiments, the polishing comprises removing material from second surface304of shaped article300. For example, the polishing comprises removing material from second surface304down to dashed line312shown inFIG.4. Such polishing can remove raised portions308on second surface304, resulting in a substantially planar surface, excluding cavities306, as shown inFIG.5. The polishing can be achieved by mechanical grinding, chemical etching, thermal treatment, or another suitable polishing process. Mechanical grinding can be beneficial in enabling removal of material from the surfaces of the shaped article without altering the sidewalls of the cavities, which can help to preserve the shape and/or surface quality of the sidewalls as described herein.

In some embodiments, after the forming cavities306and prior to the polishing, the cavities of shaped article300comprise blind holes as shown inFIG.4and described herein. In some of such embodiments, the polishing opens the blind holes to transform the plurality of cavities306into a plurality of through-holes as shown inFIG.5. For example, the polishing removes the closed end of the blind holes to open the blind holes and form the through-holes.

In some embodiments, a thickness of shaped article300(e.g., a distance between first surface302and second surface304), before or after polishing, can be at most about 5 mm, at most about 4 mm, at most about 3 mm, at most about 2 mm, at most about 1 mm, at most about 0.9 mm, at most about 0.8 mm, at most about 0.7 mm, at most about 0.6 mm, or at most about 0.5 mm. Additionally, or alternatively, the thickness of shaped article300, before or after polishing, can be at least about 0.1 mm, at least about 0.2 mm, at least about 0.3 mm, at least about 0.4 mm, at least about 0.5 mm, at least about 0.7 mm, at least about 0.7 mm, at least about 0.8 mm, at least about 0.9 mm, or at least about 1 mm.

In some embodiments, method100comprises depositing a surface modification layer (SML) on sidewalls of the plurality of cavities of the shaped article at step106as shown inFIG.1. For example, method100comprises depositing a surface modification layer on a sidewall of each of the plurality of cavities306of shaped article300.FIG.6is a cross-sectional schematic view of some embodiments of shaped article300comprising surface modification layer307deposited on the sidewalls of the plurality of cavities306, andFIG.7is a perspective view of the shaped article. In some embodiments, surface modification layer307is formed from a glass material comprising a mobile component. For example, in some embodiments, surface modification layer307is formed from a fluorosilicate glass, a borosilicate glass, or a combination thereof. In some embodiments, the mobile component comprises fluorine, boron, phosphorous, or a combination thereof. For example, in some embodiments in which surface modification layer307is formed from a fluorosilicate glass, the mobile component comprises, consists essentially of, or consists of fluorine. In some embodiments in which surface modification layer307is formed from a borosilicate glass, the mobile component comprises, consists essentially of, or consists of boron. In some embodiments, a fluorosilicate glass and/or a borosilicate glass can be doped with phosphorous. Such glass materials can have a relatively low softening point suitable for use in the methods and apparatus described herein. Additionally, or alternatively, the mobile component of such glass materials can migrate into the shaped article to form a doped surface region with a reduced strain point, annealing point, and/or softening point as described herein.

In some embodiments, the depositing surface modification layer307comprises depositing the surface modification layer using flame hydrolysis deposition (FHD), sputtering, sol gel deposition, chemical vapor deposition (CVD), or another suitable deposition technique. In some embodiments, the depositing surface modification layer307comprises depositing the surface modification layer using chemical vapor deposition (CVD). For example, the depositing comprises depositing surface modification layer307using low pressure chemical vapor deposition (LPCVD), sub-atmospheric chemical vapor deposition (SACVD), or plasma enhanced chemical vapor deposition (PECVD). In some embodiments, the depositing comprises depositing a fluorosilicate glass from SiF4and SiH4by CVD. Depositing the surface modification layer by CVD can enable the incorporation of the mobile component in the glass material of the surface modification layer at a sufficiently high concentration for migration of the mobile component into the surface layer of the shaped article as described herein.

In some embodiments, a concentration of the mobile component in the glass material of surface modification layer307is at least about 5 wt %, at least about 6 wt %, at least about 7 wt %, at least about 8 wt %, at least about 9 wt %, at least about 10 wt %, or at least about 11 wt %. Additionally, or alternatively, a concentration of the mobile component in the glass material of surface modification layer307is at most about 25 wt %. In some embodiments, a concentration of SiO2in the glass material of surface modification layer307is at least about 75 wt %, at least about 80 wt %, at least about 85 wt %, at least about 89 wt %, at least about 90 wt %, at least about 91 wt %, or at least about 92 wt %.

In some embodiments, method100comprises migrating at least a portion of the mobile component from the surface modification layer into surface regions of the sidewalls of the shaped article at step108as shown inFIG.1. For example, migrating the mobile component from surface modification layer307comprises migrating ions of the mobile component across an interface between the surface modification layer and shaped article300such that the surface regions (e.g., regions extending from the interface inward into the shaped article) become doped with the mobile component. Thus, the migrating the mobile component comprises doping the surface regions of shaped article300with the mobile component such that the doped surface regions have a higher concentration of the mobile component than a bulk of the shaped article (e.g., undoped regions of the shaped article). In some embodiments, the doped surface regions of shaped article300extend from the interface into the shaped article to a depth of at least about 1 μm, at least about 2 μm, at least about 3 μm, at least about 4 μm, at least about 5 μm, at least about 6 μm, at least about 7 μm, at least about 8 μm, at least about 9 μm, at least about 10 μm, at least about 15 μm, at least about 20 μm, at least about 25 μm, at least about 30 μm, at least about 35 μm, at least about 40 μm, at least about 45 μm, or at least about 50 μm. Additionally, or alternatively, the doped surface regions of shaped article300extend from the interface into the shaped article to a depth of at most about 100 μm, at most about 90 μm, at most about 80 μm, at most about 70 μm, at most about 60 μm, at most about 50 μm, at most about 40 μm, at most about 30 μm, at most about 20 μm, at most about 10 μm, or at most about 5 μm.

In some embodiments, the doped surface regions comprise a gradient in a concentration of the mobile component. For example, the concentration of the mobile component in the surface regions decreases gradually from the interface with surface modification layer307into shaped article300(e.g., as a result of the migration). In some embodiments, subsequent to the migrating, the doped surface regions have a reduced strain point, annealing point, and/or softening point compared to the bulk of the shaped article. For example, doping the surface regions with the mobile component can reduce the strain point, annealing point, and/or softening point of the surface regions without substantially changing the strain point, annealing point, and/or softening point of the undoped regions (e.g., the bulk) of the shaped article. For example, it has been found that doping silicate glass (e.g., SiO2, or fused silica) with fluorine can decrease the annealing point of the silicate glass by 113° C./wt % F. Also for example, it has been found that doping silicate glass with boron can decrease the annealing point of the silicate glass by 26° C./wt % B2O3.

In some embodiments, method100comprises reflowing the surface modification layer and the surface regions of the sidewalls at step110as shown inFIG.1. For example, the reflowing comprises causing the glass material of surface modification layer307and the glass material, the glass-ceramic material, or the combination thereof of the surface regions (e.g., the doped regions) of shaped article300to flow. In some embodiments, the reflowing comprises heating the glass material of the surface modification layer307and the glass material, the glass-ceramic material, or the combination thereof of the surface regions (e.g., the doped regions) of shaped article300above the softening points of the respective materials such that the materials flow. Such flowing can smooth surface modification layer307and/or the interface between the surface modification layer and the sidewalls of shaped article300, which can enable a reduction in the roughness of the surface modification layer. In some embodiments, a surface roughness of surface modification layer108disposed on the sidewalls following the reflowing is less than a surface roughness of the sidewalls prior to the depositing. For example, the surface roughness of the sidewalls prior to the depositing can be at least about 0.5 μm, at least about 1 μm, at least about 2 μm, at least about 3 μm, at least about 4 μm, at least about 5 μm, or at least about 10 μm. Additionally, or alternatively, the surface roughness of surface modification layer108disposed on the sidewalls following the reflowing can be at most about 1000 nm, at most about 900 nm, at most about 800 nm, at most about 700 nm, at most about 600 nm, at most about 500 nm, at most about 400 nm, at most about 300 nm, at most about 200 nm, at most about 100 nm, or at most about 50 nm.

The methods described herein comprising doping the surface regions of the shaped article and then reflowing both the surface modification layer and the doped surface regions can enable reduced surface roughness compared to methods comprising depositing a coating (e.g., a glass coating) on the shaped article and reflowing the coating without the doping and the reflowing the surface regions. For example, during the reflowing described herein, smoothing can occur both at the surface of the surface modification layer and at the interface between the surface modification layer and the shaped article. The relatively low strain point, annealing point, and/or softening point of the doped surface regions and the relatively high strain point, annealing point, and/or softening point of the bulk of the shaped article can enable such smoothing without substantial alterations of the size and/or shape of the coated sidewalls. Thus, the geometry of the shaped article can be maintained during the smoothing of the surfaces.

In some embodiments, method100comprises heating the surface modification layer to a heating temperature. For example, method100comprises heating surface modification layer307disposed on the sidewalls of the plurality of cavities306and/or the doped surface region of shaped article300to the heating temperature for a heating time sufficient to cause the migrating and/or the reflowing as described herein. In some embodiments, the heating comprises heating glass article300with surface modification layer307disposed thereon (e.g., in an oven or a lehr). In some embodiments, the migrating and the reflowing are caused by a single heating step (e.g., ramping from room temperature to the heating temperature, holding at the heating temperature for the heating time, and ramping from the heating temperature to room temperature). In other embodiments, the migrating is caused by a first heating step, and the reflowing is caused by a second heating step.

FIGS.8-11are close-up cross-sectional schematic views depicting a portion of some embodiments of shaped article300during some embodiments of the depositing and the heating.FIG.8shows shaped article300prior to the depositing. In some embodiments, prior to the depositing, shaped article300has a relatively rough surface as described herein.FIG.9shows shaped article300after the depositing. In some embodiments, after the depositing, surface modification layer307is disposed on sidewalls of cavities306of shaped article300. Immediately following the depositing (e.g., prior to the migrating and the reflowing), the surface roughness of surface modification layer307can be similar to the surface roughness of the underlying glass article300prior to the depositing.FIG.10shows shaped article300after the migrating. For example, during an initial stage of the heating, ions of the mobile component migrate from surface modification layer307into a surface region301B to dope the surface region as described herein, thereby lowering the strain point, the annealing point, and/or the softening point of the surface region. Subsequent to the migrating, the strain point, the annealing point, and/or the softening point of the surface region is lower than the strain point, the annealing point, and/or the softening point, respectively, of a bulk301A of shaped article300. In some embodiments, the reflowing surface modification layer307begins during the migrating. For example, the heating temperature during the migrating can be greater than the softening temperature of surface modification layer307such that the surface modification layer is able to flow during the migrating.FIG.11shows shaped article300after the reflowing. For example, during a subsequent stage of the heating (e.g., following the initial stage or during a separate heating step), surface modification layer307and the doped surface region301B can reflow, thereby lowering the surface roughness of the surface modification layer and the interface between the surface modification layer and shaped article300as shown inFIG.11. In some embodiments, bulk301A of shaped article300does not substantially reflow during the reflowing step (e.g., as a result of the higher strain point, annealing point, and/or softening point of the bulk of the shaped article compared to the doped surface region301B).

The heating temperature between the softening point of the surface modification layer and the softening point of the bulk of the shaped article can enable migration of the mobile component of the glass material of the surface modification layer, reflowing of the surface modification layer, and/or reflowing of the doped surface region of the shaped article without substantially altering the size and/or shape of the underlying bulk of the shaped article, which can enable smoothing of the cavity surfaces without substantially deforming the cavities. In some embodiments, the heating time is at least about 5 minutes, at least about 6 minutes, at least about 7 minutes, at least about 8 minutes, at least about 9 minutes, at least about 10 minutes, at least about 15 minutes, at least about 20 minutes, at least about 25 minutes, or at least about 30 minutes. Additionally, or alternatively, the heating time is at most about 1 hour.

In some embodiments, a thickness of surface modification layer307, before or after the migrating and/or the reflowing, is at least about 500 nm, at least about 600 nm, at least about 700 nm, at least about 800 nm, at least about 900 nm, at least about 1000 nm, at least about 1100 nm, at least about 1200 nm, at least about 1300 nm, at least about 1400 nm, at least about 1500 nm, at least about 1600 nm, at least about 1700 nm, at least about 1800 nm, at least about 1900 nm, at least about 2000 nm, at least about 2500 nm, or at least about 3000 nm. Additionally, or alternatively, the thickness of surface modification layer307, before or after the migrating and/or the reflowing, is at most about 10 μm, at most about 9 μm, at most about 8 μm, at most about 7 μm, at most about 6 μm, or at most about 5 μm. It has been observed that a thicker surface modification layer can reflow at a lower temperature.

In some embodiments, method100comprises etching the surface modification layer. For example, method100comprises contacting surface modification layer307with an etchant subsequent to the migrating and/or the reflowing. In some embodiments, the etchant comprises an aluminum etchant. For example, the etchant comprises a Type A aluminum etchant. During the migrating and/or the reflowing, mobile components present in the glass material, the glass-ceramic material, or the combination thereof of shaped article300can migrate into surface modification layer307. For example, in embodiments in which shaped article300is formed from an alkali aluminosilicate glass composition, mobile components, such as alkali components, present in the shaped article can migrate into surface modification layer307during the heating as described herein. Such migration can result in formation of salts (e.g., alkali fluoride salts) in surface modification layer307, including at the surface of the surface modification layer. In some embodiments, the etching dissolves the salts present on the surface of surface modification layer307without substantially dissolving the glass material of the surface modification layer and/or the glass material, the glass-ceramic material, or the combination thereof of shaped article300. Such etching can help to preserve the smoothness of the surface modification layer (e.g., by removing salts that can increase the roughness of the surface).

In some embodiments, cavities306have a diameter or width, before or after the deposition, the migrating, the reflowing, and/or the etching, of at most about 5 mm, at most about 4 mm, at most about 3 mm, at most about 2 mm, or at most about 1 mm. Additionally, or alternatively, cavities306have a diameter or width, before or after the deposition, the migrating, the reflowing, and/or the etching, of at least about 0.5 mm or at least about 1 mm. The diameter or width of cavities306can refer to the diameter or width at first surface302of shaped article300and/or second surface304of the shaped article. Such small cavities with smooth and/or straight sidewalls can be enabled by the methods described herein. In some embodiments, the number of cavities406in the plurality of cavities can be at least 100, at least 200, at least 300, at least 400, at least 500, at least 600, at least 700, at least 800, at least 900, at least 1000, at least 1100, at least 1200, at least 1300, at least 1400, or at least 1500. Such a large number of cavities on a single shaped article can enable large-scale production of devices, such as liquid lenses, using wafer manufacturing techniques. In some embodiments, the sidewalls of cavities306of shaped article300, before or after the deposition, the migrating, the reflowing, and/or the etching, are substantially straight. For example, the deviation of the sidewalls of cavities306from linear is within +/−0.25 μm/mm along the sidewall through a thickness of shaped article300. In some embodiments, cavities306have a truncated conical shape with smooth and substantially straight sidewalls.

In some embodiments, method100comprises singulating the shaped article at step112as shown inFIG.1. For example, singulating shaped article300comprises separating the shaped article into two or more shaped sub-articles following the forming, the polishing, the depositing, the migrating, the reflowing, and/or the etching. In some embodiments, singluating shaped article300comprises cutting or breaking the shaped article along one or more cutting paths. In some embodiments, singulating shaped article300comprises dicing the shaped article (e.g., with a mechanical dicing saw, a laser, or another suitable cutting device). For example, the singulating comprises dicing shaped article300to form a plurality of shaped sub-articles, and each sub-article comprises a single cavity406. Such shaped sub-articles can be used to form liquid lenses as described herein.

In some embodiments, the methods described herein can be used to manufacture liquid lenses.FIG.12is a cross-sectional schematic view of some embodiments of a liquid lens400incorporating shaped article300. In some embodiments, liquid lens400comprises a lens body435and a cavity406formed in the lens body. In some embodiments, a surface modification layer408is disposed on a sidewall of cavity406. Thus, the sidewall of cavity406is a coated sidewall. A first liquid438and a second liquid439are disposed within cavity406. In some embodiments, first liquid438is a polar liquid or a conducting liquid. Additionally, or alternatively, second liquid439is a non-polar liquid or an insulating liquid. In some embodiments, first liquid438and second liquid439are immiscible with each other and have different refractive indices such that an interface440between the first liquid and the second liquid forms a lens. Interface440can be adjusted via electrowetting. For example, a voltage can be applied between first liquid438and a surface of cavity406(e.g., an electrode positioned near the surface of the cavity and insulated from the first liquid) to increase or decrease the wettability of the surface of the cavity with respect to the first liquid and change the shape of interface440. In some embodiments, adjusting interface440changes the shape of the interface, which changes the focal length or focus of liquid lens400. For example, such a change of focal length can enable liquid lens400to perform an autofocus (AF) function. Additionally, or alternatively, adjusting interface440tilts the interface relative to an optical axis476. For example, such tilting can enable liquid lens400to perform an optical image stabilization (OIS) function. Such adjustment of interface440via electrowetting can be sensitive to surface roughness and/or non-linearity of the sidewalls of cavity406. Thus, the methods described herein for forming shaped article300having cavities306with smooth and/or substantially straight sidewalls may be beneficial for forming cavity406for liquid lens400. In some embodiments, first liquid438and second liquid439have substantially the same density, which can help to avoid changes in the shape of interface440as a result of changing the physical orientation of liquid lens400(e.g., as a result of gravitational forces).

In some embodiments, lens body435of liquid lens400comprises a first window441and a second window442. In some of such embodiments, cavity406is disposed between first window441and second window442. In some embodiments, lens body435comprises a plurality of layers that cooperatively form the lens body. For example, in the embodiments shown inFIG.12, lens body435comprises a cap443, a shaped plate444, and a base445. In some embodiments, shaped plate444with cavity406comprises or is formed from shaped article300with cavity306. For example, shaped plate444with cavity406is formed as described herein with reference to shaped article300with cavity306, cap443is bonded to one side (e.g., an object side) of the shaped plate, and base445is bonded to the other side (e.g., an image side) of the shaped plate such that the cavity is covered on opposing sides by the cap and the base. Thus, a portion of cap443covering cavity406serves as first window441, and a portion of base445covering the cavity serves as second window442. In other embodiments, the cavity is a blind hole that does not extend entirely though the shaped plate. In such embodiments, the base can be omitted, and the closed end of the cavity can serve as the second window.

In some embodiments, cavity406has a truncated conical shape as shown inFIG.12such that a cross-sectional area of the cavity decreases along optical axis476in a direction from the object side to the image side. Such a tapered cavity can help to maintain alignment of interface440between first liquid438and second liquid439along optical axis476. In other embodiments, the cavity is tapered such that the cross-sectional area of the cavity increases along the optical axis in the direction from the object side to the image side or non-tapered such that the cross-sectional area of the cavity remains substantially constant along the optical axis.

In some embodiments, image light enters liquid lens400through first window441, is refracted at interface440between first liquid438and second liquid439, and exits the liquid lens through second window442. In some embodiments, cap443and/or base445comprise a sufficient transparency to enable passage of image light. For example, cap443and/or base445comprise a polymeric material, a glass material, a ceramic material, a glass-ceramic material, or a combination thereof. In some embodiments, outer surfaces of cap443and/or base445are substantially planar. Thus, even though liquid lens400can function as a lens (e.g., by refracting image light passing through interface440), outer surfaces of the liquid lens can be flat as opposed to being curved like the outer surfaces of a fixed lens. In other embodiments, outer surfaces of the cap and/or the base are curved. Thus, the liquid lens comprises an integrated fixed lens. In some embodiments, shaped plate444comprises a glass material, a glass-ceramic material, or a combination thereof as described herein. Because image light can pass through the cavity through shaped plate444, the shaped plate may or may not be transparent.

AlthoughFIG.12illustrates a single liquid lens400, liquid lenses can be manufactured in arrays using a wafer manufacturing process as described herein. For example, a liquid lens array comprises a plurality of liquid lenses400attached in a plate or wafer. Thus, prior to singulation to form single liquid lens400, shaped plate444comprises a plurality of cavities406. Additionally, or alternatively, prior to singulation, cap443comprises a plate with a plurality of first windows441corresponding to the plurality of cavities406. Additionally, or alternatively, prior to singulation, base445comprises a plate with a plurality of second windows442corresponding to the plurality of cavities406. After formation, the liquid lens array can be singulated to form the individual liquid lenses400.

FIG.13is a flowchart representing some embodiments of a method500for manufacturing a liquid lens. In some embodiments, method500comprises forming a shaped plate comprising a plurality of cavities. For example, method500comprises forming shaped plate444comprising the plurality of cavities406at step502(e.g., as described herein with reference to forming shaped article300comprising the plurality of cavities306).

In some embodiments, method500comprises bonding a base to a surface of the shaped plate. For example, method500comprises bonding base445to shaped plate444at step504. The bonding comprises, for example, laser bonding, adhesive bonding, or another suitable bonding technique.

In some embodiments, method500comprises depositing first and second liquids into the plurality of cavities of the shaped plate. For example, method500comprises depositing first liquid438and second liquid439in each of the plurality of cavities406of shaped plate444at step506.

In some embodiments, method500comprises bonding a cap to a surface of the shaped plate to seal the first liquid and the second liquid within the plurality of cavities and form a liquid lens array. For example, method500comprises bonding cap443to shaped plate444to seal first liquid438and second liquid439within the plurality of cavities406of the shaped plate at step508. The bonding comprises, for example, laser bonding, adhesive bonding, or another suitable bonding technique.

In some embodiments, method500comprises singulating the liquid lens array to form a plurality of individual liquid lenses. For example, method500comprises singulating the liquid lens array comprising cap443, shaped plate444, and optionally, base445to form the plurality of individual liquid lenses400at step510. The singulating comprises, for example, mechanical dicing, laser dicing, or another suitable dicing technique.

The methods described herein for forming shaped articles with a plurality of cavities formed therein can enable large-scale production of shaped plates having cavities with sufficiently smooth surfaces to be used in electrowetting applications, which in turn, can enable efficient manufacturing of liquid lens arrays and/or singulated liquid lenses.

AlthoughFIG.13illustrates using the methods described herein to manufacture liquid lenses, other embodiments are included in this disclosure. For example, in other embodiments, the methods and apparatus described herein can be used to make shaped articles for use in optics, biological, microfluidic, or any other suitable applications.

EXAMPLES

Various embodiments will be further clarified by the following examples.

Throughout the examples, a fluorosilicate glass (FSG) film having the thickness described below was deposited onto a sidewall of a conical cavity formed in a glass substrate. The cavity had a 30° sidewall formed by a laser damage and etch process, resulting in a surface roughness of about 5 μm as formed. The glass substrate was formed from an alkali-aluminosilicate glass commercially available as Corning® Gorilla® Glass from Corning Incorporated (Corning, N.Y.) and had a strain point of 563° C., an annealing point of 613° C., and a softening point of 852° C. The FSG film was deposited from a mixture of SiF4and SiH4using high density plasma chemical vapor deposition (HDPCVD) in equipment from Plasma-Therm (Saint Petersburg, Fla.) using 28 sccm SiH4—SiF4mixture, 56 sccm 02, and 20 sccm Ar at 5 mT with 600 W 2 MHz RF applied to the coil and 25 W 13.56 MHz RF bias applied to the platen. The substrate temperature during the deposition was 150° C.

A 2000 nm FSG film with an estimated 11 wt % F was deposited as described above. After deposition, the coated substrate was heated to a heating temperature of 650° C. in flowing N2and held at 650° C. for a heating time of 30 minutes in flowing N2.

A 2000 nm FSG film with an estimated 11 wt % F was deposited as described above. After deposition, the coated substrate was heated to a heating temperature of 700° C. in flowing N2and held at 700° C. for a heating time of 30 minutes in flowing N2.

A 2000 nm FSG film with an estimated 11 wt % F was deposited as described above. After deposition, the coated substrate was heated to a heating temperature of 725° C. in flowing N2and held at 725° C. for a heating time of 30 minutes in flowing N2.

A 2000 nm FSG film with an estimated 11 wt % F was deposited as described above. After deposition, the coated substrate was heated to a heating temperature of 750° C. in flowing N2and held at 750° C. for a heating time of 30 minutes in flowing N2.

A 2000 nm FSG film with an estimated 11 wt % F was deposited as described above. After deposition, the coated substrate was heated to a heating temperature of 800° C. in flowing N2and held at 800° C. for a heating time of 10 minutes in flowing N2.

A 2000 nm FSG film with an estimated 11 wt % F was deposited as described above. After deposition, the coated substrate was heated to a heating temperature of 850° C. in flowing N2and held at 850° C. for a heating time of 8 minutes in flowing N2.

Following the heating, salts were observed in and on the FSG film, and bubbles were observed within the FSG film.

A 5000 nm FSG film with an estimated 11 wt % F was deposited as described above. After deposition, the coated substrate was heated to a heating temperature of 700° C. in flowing N2and held at 700° C. for a heating time of 30 minutes in flowing N2.

A 5000 nm FSG film with an estimated 11 wt % F was deposited as described above. After deposition, the coated substrate was heated to a heating temperature of 750° C. in flowing N2and held at 750° C. for a heating time of 30 minutes in flowing N2.

Following the heating, salts were observed in and on the FSG film, and bubbles were observed within the FSG film.

A 5000 nm FSG film with an estimated 11 wt % F was deposited as described above. After deposition, the coated substrate was heated to a heating temperature of 800° C. in flowing N2and held at 800° C. for a heating time of 30 minutes in flowing N2.

Following the heating, salts were observed in and on the FSG film, and bubbles were observed within the FSG film.

As the heating temperature was increased in Examples 1-6, the surface roughness of the resulting coated cavity sidewall was found to decrease. Thus, Examples 1-6 illustrate that increasing the heating temperature can reduce the surface roughness of the coated cavity sidewall. However, salts were observed to form in and on the FSG layer, and bubbles were observed within the FSG layer at a heating temperature of 850° C. (Example 6). The salts are believed to have been formed by the reaction of fluorine from the FSG layer with alkali components from the glass substrate. The bubbles are believed to be blisters formed by the reaction of fluorine from the FSG layer with water, carbon, or other constituents in the glass substrate and/or at the interface between the FSG layer and the glass substrate to form volatile species.

As the heating temperature was increased in Examples 7-9, the surface roughness of the resulting coated cavity sidewall was found to decrease. Thus, Examples 7-9 again illustrate that increasing the heating temperature can reduce the surface roughness of the coated cavity sidewall. However, salts were observed to form in and on the FSG layer, and bubbles were observed within the FSG layer at a heating temperature of 750° C. (Examples 8 and 9).

Comparing Examples 7-9 to Examples 1-6, salts and bubbles were observed in and on the thicker FSG layer of Examples 7-9 at a lower temperature than the thinner FSG layer of Examples 1-6. In both cases, the salts were removed with a 5 minute etch in room temperature Type A aluminum etchant.

It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the claimed subject matter. Accordingly, the claimed subject matter is not to be restricted except in light of the attached claims and their equivalents.