WO2019226627A1

WO2019226627A1 - Glazed ceramic substrate for liquid lenses and methods for making same

Info

Publication number: WO2019226627A1
Application number: PCT/US2019/033274
Authority: WO
Inventors: Thomas Mark Leslie
Original assignee: Corning Inc
Current assignee: Corning Inc
Priority date: 2018-05-22
Filing date: 2019-05-21
Publication date: 2019-11-28
Anticipated expiration: 2020-11-22
Also published as: TW202005935A

Abstract

A liquid lens can have a ceramic body. A ceramic slurry can be tape cast to form a sheet. Holes can be punched in the sheet and the holes can be reshaped, such as to have the shape of a truncated cone. A glaze can be used, which can increase the smoothness of the ceramic material. The ceramic and/or glaze can be heated. The ceramic body can form at least a portion of the cavity of the liquid lens. One or more electrodes can be applied over the ceramic body. One or more insulating and/or hydrophobic materials can be applied over the ceramic body and/or over the one or more electrodes. First and second fluids can be positioned inside the cavity, and an interface can be between the first and second fluids.

Description

GLAZED CERAMIC SUBSTRATE FOR LIQUID LENSES AND METHODS FOR

MAKING SAME

REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent App. No. 62/675,051, titled “GLAZED CERAMIC SUBSTRATE FOR LIQUID LENSES AND METHODS FOR MAKING SAME,” and filed on May 22, 2018. The entire disclosure of that application is hereby made part of this specification as if set forth fully herein and incorporated by reference for all purposes for all that it contains.

BACKGROUND

Field of the Disclosure

[0002] Some embodiments of this disclosure relate to the design of liquid lenses, manufacturing liquid lenses, and materials in liquid lenses. Some examples specifically discuss ceramic materials and ceramic manufacturing techniques.

Description of the Related Art

[0003] Although some liquid lenses are known, there remains a need for improved liquid lenses and associated manufacturing processes and techniques.

SUMMARY OF CERTAIN EMBODIMENTS

[0004] Certain example embodiments are summarized below for illustrative purposes. The embodiments are not limited to the specific implementations recited herein. Embodiments may include several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to the embodiments.

[0005] Some aspects of this disclosure relate to a method for making a liquid lens with a ceramic body. The method can include forming a tape from a slurry (e.g., comprising ceramic particles). The method can include punching a hole through the tape and/or reshaping the hole into a truncated cone. The method can include heating the slurry with a first temperature to turn the slurry into ceramic, glazing the ceramic with a glaze, and heating the glaze at a second temperature to form glass. In some cases, the method can include coating the glass with a conductive material to form an electrode and/or coating the electrode with an insulating material.

[0006] Punching the hole through the tape can include punching a cylindrical portion of the slurry out of the slurry and through a carrier surface. Reshaping the hole into a truncated cone can include punching the hole with a punching tool that has a reshaping portion that is shaped as a truncated cone. Reshaping the hole can be performed using a reshaping tool that has a widest radius greater than a radius of the hole and a smallest radius that is smaller than the radius of the hole. In some cases one punching tool can be used for both punching the hole and reshaping the hole in a single punching motion. Punching the hole can be performed using a cylindrical punching tool. Reshaping the hole can be performed using a separate reshaping tool shaped as a truncated cone. The first temperature can be at least 1000 ° Celsius, although other temperatures can be used, as discussed herein. The method can further include heating the ceramic to a second temperature that is lower than the first temperature. The second temperature can still be high enough to melt the glass.

[0007] A radius of the hole after punching can be less than 5 mm, for example. The glass can have a surface roughness of not more than 0.07 pm, for example. The insulating material can be parylene, for example. The method can include positioning, in the hole, at least two liquids, which in some cases can be immiscible with each other to form a fluid interface. The method can include reflowing the glass. The glass can have reduced surface roughness after reflowing the glass.

[0008] A liquid lens can be made by the method. The resulting liquid lens can include a chamber shaped as the truncated cone, a first fluid in the chamber, and a second fluid contained in the chamber. An interface can be between the first fluid and the second fluid. One or more electrodes can be configured to receive voltages for shaping the interface. The chamber can include a ceramic layer comprising the ceramic, a glass layer over the ceramic layer, the glass layer comprising the glass, and an insulating layer over the glass layer, the insulating layer comprising the insulating material.

[0009] Some aspects of this disclosure relate to a method for making a liquid lens with a ceramic body. The method can include forming a tape from a slurry, which can include ceramic particles. The method can include punching a hole through the tape and/or reshaping the hole into a truncated cone. The method can include glazing the tape with a glaze. The method can include heating the slurry and the glaze at a first temperature to form a glazed ceramic (e.g., coated with glass). A hydrophobic coating can be formed over the glazed ceramic.

[0010] Punching the hole through the tape can include punching a cylindrical portion of the slurry out of the slurry and through a carrier surface. Reshaping the hole into a truncated cone can include punching the hole with a punching tool that has a reshaping portion that is shaped as a truncated cone. Reshaping the hole can be performed by a tool that has a widest radius greater than a radius of the hole and a smallest radius that is smaller than the radius of the hole. In some embodiments, the punching tool has a reshaping portion with a smallest radius that is at least as large as the radius of the cylindrical portion punched out of the slurry. One punching tool can be used for both punching the hole and reshaping the hole in a single punching motion. Punching the hole can be performed using a cylindrical punching tool, and reshaping the hole can be performed using a separate reshaping tool that can be shaped as a truncated cone.

[0011] The first temperature can be at less than 1000 ° Celsius, although other suitable temperatures could be used in other implementations. The glaze can include low temperature melting glass. A radius of the hole after punching can be less than 5 mm, for example. The glass can have a surface roughness of not more than 0.07 pm, for example. The hydrophobic coating can be parylene, for example. The method can include positioning, in the hole, at least two liquids, which can be immiscible with each other and form a fluid interface in some cases. The method can include providing a plurality of electrodes at positions to control a position of the fluid interface. The method can include reflowing the glaze. The glaze can have reduced surface roughness after reflowing the glaze.

[0012] A liquid lens made by the method. The resulting liquid lens can include a chamber, which can be shaped as a truncated cone, a first fluid in the chamber, and a second fluid contained in the chamber. An interface can be between the first fluid and the second fluid, which can be immiscible in some implementations. One or more electrodes can be configured to receive voltages for shaping the interface. The chamber can include a ceramic layer including the ceramic, a glass layer over the ceramic layer, the glass layer including the glass, and a hydrophobic layer over the glass layer, the hydrophobic layer including the hydrophobic coating.

[0013] Some aspects of this disclosure can relate to a liquid lens system, which can include a chamber shaped as a truncated cone, a first fluid in the chamber, and a second fluid contained in the chamber. The first fluid and the second fluid can be immiscible. An interface can be between the first fluid and the second fluid. The liquid lens system can include one or more of electrodes, which can be configured to receive voltages for shaping the fluid interface. The chamber can include a ceramic layer, a glaze (e.g., glass) layer over the ceramic layer, and an insulating layer over the glaze layer. [0014] The one or more electrodes can include a first electrode insulated from the first and second fluid. The first electrode can be configured to receive a first voltage signal for shaping the interface. A second electrode can be in electrical communication with the first fluid. The glaze layer can have a surface roughness of not more than 0.09 pm, for example. The glaze layer can have a surface roughness of not more than 0.01 pm, for example. The glaze layer can have a thickness of more than 0.3 mm, for example. The insulating layer can be a parylene layer, and in some cases can have a surface roughness of not more than 0.09 pm, for example. The parylene layer can have a surface roughness of not more than 0.01 pm, for example. The truncated cone can include sloped side walls, and a smaller end of the truncated cone is less than 10 mm in radius, for example. The truncated cone can include sloped side walls, and a smaller end of the truncated code can be less than 5 mm in radius, for example. The truncated cone can include sloped side walls, and a smaller end of the truncated code can be less than 1 mm in radius, for example. The truncated cone can include sloped side walls with an incline of at least 15 degrees, for example. The truncated cone can include sloped side walls with an incline of at least 45 degrees, for example. The truncated cone can include sloped side walls with an incline of at least 75 degrees, for example.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Certain embodiments will be discussed in detail with reference to the following figures, wherein like reference numerals refer to similar features throughout. These figures are provided for illustrative purposes and the embodiments are not limited to the specific implementations illustrated in the figures.

[0016] Figure 1 is a cross-sectional view of an example embodiment of a liquid lens.

[0017] Figure 2 shows the liquid lens in a second state where a voltage is applied.

[0018] Figure 3 shows a plan view of an example embodiment of a liquid lens.

[0019] Figure 4 shows a cross-sectional view taken through opposing electrodes.

[0020] Figure 5 shows a cross sectional view of a system for tape casting a ceramic slurry.

[0021] Figure 6A through Figure 6F shows a two punching tool process for punching an angled hole through the tape.

[0022] Figure 7A through Figure 7D shows a one punching tool process for punching an angled hole through the tape. [0023] Figure 8A through Figure 8E show examples of punching tools.

[0024] Figure 9 A shows a side view of a cylindrical hole punched in a tape.

[0025] Figure 9B shows a side view of a hole with sloped side walls in a tape.

[0026] Figure 10 shows a plurality of holes in a tape.

[0027] Figure 11 shows an example system for making glazed ceramic substrates with sloped side walls for liquid lenses.

[0028] Figure 12 shows a zoomed-in example cross section of a fluid chamber of a liquid lens.

[0029] Figure 13 shows a flowchart of a method for coating a glass layer.

[0030] Figure 14 shows a flowchart of a first method for making a glazed ceramic body for a liquid lens.

[0031] Figure 15 shows a flowchart of a second method for making a glazed ceramic body for a liquid lens.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

Introduction

[0032] Figure 1 is a cross-sectional view of an example embodiment of a liquid lens 10. The liquid lens 10 can have a cavity 12 that contains at least two fluids (e.g., liquids), such as a first fluid 14 and a second fluid 16. The two fluids can be substantially immiscible so that a fluid interface 15 is formed between the first fluid 14 and the second fluid 16. Although some embodiments disclosed herein have a fluid interface between two fluids that directly contact each other, the interface can be formed by a membrane or other intermediate structure or material between two fluids. Thus, various embodiments disclosed herein can be modified to use various different fluids, such as those that could mix if in direct contact. In some embodiments the two fluids 14 and 16 can be sufficiently immiscible to form the fluid interface 15. The interface 15, when curved for example, can refract light with optical power as a lens. The first fluid 14 can be electrically conductive, and the second fluid 16 can be electrically insulating. In some embodiments, the first fluid 14 can be a polar fluid, such as an aqueous solution. In some embodiments, the second fluid 16 can be an oil. The first fluid 14 can have a higher dielectric constant than the second fluid 16. The first fluid 14 and the second fluid 16 can have different indices of refraction, for example, so that light can be refracted as it passes through the fluid interface 15. The first fluid 14 and the second fluid 16 can have substantially similar densities, which can impede either of the fluids 14 and 16 from floating relative to the other. [0033] The cavity 12 can include a portion having a shape of a frustum or truncated cone. The cavity 12 can have angled side walls. The cavity 12 can have a narrow portion where the side walls are closer together and a wide portion where the side walls are further apart. The narrow portion can be at the bottom end of the cavity 12 and the wide portion can be at the top end of the cavity 12 in the orientation shown, although the liquid lenses 10 disclosed herein can be positioned at various other orientations. The edge of the fluid interface 15 can contact the angled side walls of the cavity 12 The edge of the fluid interface 15 can contact the portion of the cavity 12 having the frustum or truncated cone shape. Various other cavity shapes can be used. For example, the cavity can have curved side walls (e.g., curved in the cross-sectional view of Figures 1 2 The side walls can conform to the shape of a portion of a sphere, toroid, or other geometric shape. In some embodiments, the cavity 12 can have a cylindrical shape. In some embodiments, the cavity can have a flat surface and the fluid interface can contact the flat surface (e.g., as a drop of the second fluid 16 sitting on the base of the cavity 12).

[0034] A lower window 18, which can include a transparent plate, can be below the cavity 12 An upper window 20 which can include a transparent plate, can be above the cavity 12 The lower window 18 can be located at or near the narrow portion of the cavity 12 and/or the upper window 20 can be located at or near the wide portion of the cavity 12 The lower window 18 and/or the upper window 20 can be configured to transmit light therethrough. The lower window 18 and/or the upper window 20 can transmit sufficient light to form an image, such as to an imaging sensor of a camera. In some cases, the lower window 18 and/or the upper window 20 can absorb and/or reflect a portion of the light that impinges thereon.

[0035] A first one or more electrodes 22 (e.g., insulated electrodes) can be insulated from the fluids 14 and 16 in the cavity 12 such as by one or more insulation materials 24 One or more second electrodes 26 can be in electrical communication with the first fluid 14 The second one or more electrodes 26 can be in contact with the first fluid 14 In some embodiments, the second one or more electrodes 26 can be capacitively coupled to the first fluid 14 Voltages can be applied between the electrodes 22 and 26 to control the shape of the fluid interface 15 between the fluids 14 and 16 such as to vary the focal length of the liquid lens 10. Direct current (DC) voltage signals can be provided to one or both of the electrodes 22 and 26 Alternating current (AC) voltage signals can be provided to one or both of the electrodes 22 and 26 The liquid lens 10 can respond to the root mean square (RMS) voltage signal resulting from the AC voltage(s) applied. In some embodiments, AC voltage signals can impede charge from building up in the liquid lens 10, which can occur in some instances with DC voltages. In some embodiments, the first fluid 14 and/or the second one or more electrodes 26 can be grounded. In some embodiments, the first one or more electrodes 22 can be grounded. In some embodiments, voltage can be applied to either the first electrode(s) 22 or the second electrode(s) 26, but not both, to produce voltage differentials. In some embodiments, voltage signals can be applied to both the first electrode(s) 22 and the second electrode(s) 26 to produce voltage differentials.

[0036] The chamber 12 can have one or more side walls made of a hydrophobic material. For example, the insulating materials 24 can include parylene, which can be insulating and hydrophobic, although various other suitable materials can be used. In some embodiments, cone-shaped substrate 21 can be formed. The electrode 22 can be deposited, or otherwise formed, over (e.g., onto) the cone-shaped substrate 21. The electrode 22 can include a metallization layer. The insulating material 24 can be deposited, or otherwise formed, over (e.g., onto) the electrode 22. In some embodiments, the cone-shaped substrate 21 can include a ceramic material and a glaze coating on the ceramic. In some embodiments, the glaze coating can be formed over the electrode 22. The sidewalls of the ceramic material can form a truncated cone shape, a cross-section of which is shown in Figure 1.

[0037] Figure 1 shows the liquid lens 10 in a first state where no voltage is applied between the electrodes 22 and 26, and Figure 2 shows the liquid lens 10 in a second state where a voltage is applied between the electrodes 22 and 26.

[0038] When no voltage is applied, the hydrophobic material on the side walls can repel the first fluid 14 (e.g., an aqueous solution) so that the second fluid 16 (e.g., an oil) can cover a relatively large area of the side walls to produce the fluid interface 15 shape shown in Figure 1. When a voltage is applied between the first electrode 22 and the first fluid 14 (e.g., via the second electrode 26), the first fluid 14 can be attracted to the first electrode 22, which can drive the location of the fluid interface 15 down the side wall so that more of the side walls are is in contact with the first fluid 14. Changing the applied voltage differential can change the contact angle between the edge of the fluid interface 15 and the surface of the cavity 12 (e.g., the angled side wall of the truncated cone portion of the cavity 12) based on the principle of electrowetting. The fluid interface 15 can be driven to various different positions by applying different amounts of voltage between the electrodes 22 and 26, which can produce different focal lengths or different amounts of optical power for the liquid lens 10

[0039] Figure 3 shows a plan view of an example embodiment of a liquid lens 10. In some embodiments, the first one or more electrodes 22 (e.g., insulated electrodes) can include multiple electrodes 22 positioned at multiple locations on the liquid lens 10. The liquid lens 10 can have four electrodes 22a, 22b, 22c, and 22d, which can be positioned in four quadrants of the liquid lens 10. In other embodiments, the first one or more electrodes 22 can include various numbers of electrodes (e.g., 1 electrode, 2 electrodes, 4 electrodes, 6 electrodes, 8 electrodes, 12 electrodes, 16 electrodes, 32 electrodes, or more, or any values therebetween) in any number of sections (e.g., 1 section, 2 sections, 4 sections, 6 sections, 8 sections, 12 sections, 16 sections, 32 sections, or more, or any values therebetween) comprising any combination of shapes (e.g., pie wedges, conic sections, grid, doughnut sections, and the like). Although various examples are provided herein with even numbers of insulated electrodes 22, odd numbers of insulated electrodes 22 can also be used. The electrodes 22a-d can be driven independently (e.g., having the same or different voltages applied thereto), which can be used to position the fluid interface 15 at different locations on the different portions (e.g., quadrants) of the liquid lens 10. In the top-down plan view, the insulation materials 24 are seen as a circular slice of a truncated cone.

[0040] Figure 4 shows a cross-sectional view taken through opposing electrodes 22a and 22c. If more voltage is applied to the electrode 22c than to the electrode 22a, as shown in Figure 4, the fluid interface 15 can be pulled further down the sidewall at the quadrant of the electrode 22c than at the quadrant of the electrode 22a.

[0041] The tilted fluid interface 15 can turn light that is transmitted through the liquid lens 10. The liquid lens 10 can have an axis 28. The axis 28 can be an axis of symmetry for at least a portion of the liquid lens 10. For example, the cavity 12 can be substantially rotationally symmetrical about the axis 28. The truncated cone portion of the cavity 12 can be substantially rotationally symmetrical about the axis 28. The axis 28 can be an optical axis of the liquid lens 10. For example, the curved and untilted fluid interface 15 can converge light towards, or diverge light away from, the axis 28. The axis 28 can be a longitudinal axis of the liquid lens 10, in some embodiments. Tilting the fluid interface 15 can turn the light 30 passing through the tilted fluid interface relative to the axis 28 by an optical tilt angle 32. The light 30 that passed through the tilted fluid interface 15 can converge towards, or diverge away from, a direction that is angled by the optical tilt angle 32 relative to the direction along which the light entered the liquid lens 10. The fluid interface 15 can be tilted by physical tilt angle 34 that produces the optical tilt angle 32. The relationship between the optical tilt angle 32 and the physical tilt angle 34 depends at least in part on the indices of refraction of the fluids 14 and 16.

[0042] The optical tilt angle 32 produced by tilting the fluid interface 15 can be used by a camera system to provide optical image stabilization, off-axis focusing, etc. In some cases different voltages can be applied to the electrodes 22a-d to compensate for forces applied to the liquid lens 10 so that the liquid lens 10 maintains on-axis focusing. Voltages can be applied to control the curvature of the fluid interface 15, to produce a desired optical power or focal length, and the tilt of the fluid interface 15, to produce a desired optical tilt (e.g., an optical tilt direction and an amount of optical tilt). Accordingly, the liquid lens 10 can be used in a camera system to produce a variable focal length while simultaneously producing optical image stabilization.

Advantages

[0043] It can be desirable to produce the liquid lens shown in Figures 1-4 in high volume and/or at low cost. The various embodiments and technology disclosed herein can achieve one, some, or any combination of the advantages disclosed herein. Mass production techniques can be used to produce multiple devices at a time. Low cost materials can be used. The materials can allow for precise fabrication and shaping. The materials can be resistant to thermal variations. The materials can be structurally strong. The materials can be thin enough for electrical fields of nearby electrodes to affect a fluid interface. In some embodiments, the method for shaping the materials should not damage or crack the materials, which may be brittle. Additionally, the body can be shaped (such as into a truncated cone) and have a smooth surface roughness. The shape of the body, which affects the shape of the fluid interface, can be precisely controlled so that the fluid interface can have a proper shape. Additionally, the body can have a low surface roughness in the range of single digit nanometers to tens of nanometers. The low surface roughness can cause the fluid interface 15 to move up and down (e.g., as shown in Figure 1 and Figure 2) along the sidewalls of the insulation materials 24 with reduced hysteresis. With reduced hysteresis, known voltages can be applied to cause the fluid interface to achieve desired focuses. Hysteresis can cause the fluid interface to resist moving up or down the sidewall of the insulation materials 24 to the intended position. The resulting materials can be wet and in contact with liquids for extended times without degrading. Continuous manufacturing methods can be used to tape cast, calendar, or otherwise produce continuous thin sheets of ceramic substrates with cavities (e.g., having a truncated cone shape) and provide economy of scale and consistent quality.

[0044] The processes can be used to make small lenses from single digit millimeters to the tens of millimeters in size, or any other suitable size, and the process can be used to make precisely shaped, small-diameter holes in ceramic with sloped side walls that can be coated with layers of materials such as glass, metal, and/or insulating materials (e.g., parylene). The coating techniques can provide smooth coating on sloping side walls that may be fractions of a millimeter or several millimeters across. The process can be used for smaller size liquid lenses. The slopes of the sides can be made shallower or steeper, and layers of materials can be deposited across a range of angles for the sides.

[0045] Furthermore, there can be synergy between a smooth ceramic body, a smooth glaze coating on the ceramic, and a smooth insulating layer. Techniques may be used to smooth a glaze or insulating layer. However, the smoothness of these layers can be affected by the layer below them, as they may copy a surface roughness of the layer below. Accordingly, a smooth ceramic layer may allow for smoother glaze layers, which may allow for a smoother insulating layer than could be individually achieved.

Manufacture

[0046] Figure 5 shows a cross sectional view of a system 500 for tape casting using a ceramic slurry. A container 501 holds a slurry mixture 503 against a carrier 505. At least one of the container 501 or the carrier 505 is moved relative to the other, forming a trail of tape 509. As the slurry 503 exits the container 501, a knife 507, blade, or other similar device controls a height of an opening or slot in the container 501 through which the slurry 503 is deposited onto the carrier 505.

[0047] The ceramic slurry 503 can include ceramic particles. The term ceramic slurry can refer to a slurry that is used to create a ceramic material, even though the slurry itself may not be a finalized ceramic product. Similarly, the term ceramic particles can refer to particles that can be used to create a ceramic material (e.g., as ingredients of the ceramic slurry), even though the ceramic particles may not themselves be finalized ceramic products. Ceramic particles can include various clay, or oxides, or any suitable raw materials can be used to produce finalized ceramic materials. The ceramic particles can be mixed with a solvent, binder, and/or other additives. The slurry 503 is transported in the container 501 and can be released through a thin opening in the container 501 below a knife 507. The slurry 507 forms a tape 509 as it is released through the thin opening. The slurry 503 can include fine particles of ceramic material, binders, and other materials. The mixture and system can be configured to lay out a tape 509 with a smooth surface (low surface roughness). The slurry can be flat and very thin. The thickness of the slurry can be several millimeters or less than 1 millimeter, such as in the hundreds of micrometer range, tens of micrometers, or single digit micrometers, such as about 1 micron, about 2 microns, about 5 microns, about 10 microns, about 15 microns, about 25 microns, about 50 microns, about 100 microns, about 250 microns, about 500 microns, about 750 microns, about 1 mm, about 1.5 mm, about 2 mm, about 3 mm, about 5 mm, about 10 mm, about 20 mm, about 30 mm, about 50 mm, or any values therebetween, or any ranges bounded therein, although other embodiments are possible.

[0048] The carrier 505 can be pressed against the container and moved to cause a thin tape to form on the carrier 505. The carrier can be a hard or soft material. In some embodiments, a film or foil can be used for the carrier. A supply roll 513 of film or foil can be unraveled and passed below the container 501. The carrier can be moved by one or more rollers 515 (e.g., to the right in Figure 5). In some embodiments, the carrier 505 can be a belt that loops continuously.

[0049] As an additional or alternative movement system, the container 501 can be pressed against and moved (e.g., to the left in Figure 5) relative to a (stationary) carrier 505. The container 501 can be moved along a rail 511 across the carrier 505. In some cases, the carrier 505 can move in a first direction (e.g., to the right in Figure 5), and the container 501 (or a portion thereof, such as the blade 507) can move in a second direction (e.g., up and down in Figure 5).

[0050] Although Figure 5 shows some types of casting systems, other tape casting systems can be used to lay out a tape 509 that includes ceramic material. The tape 509 can optionally be left to lightly dry for a period of time, such as several minutes or hours. Afterward, the tape 509 can be hole punched (or otherwise formed), for example as described with respect to Figure 6. The holes can be punched while the tape 509 of ceramic material is still malleable, before it has dried. In some cases, the tape 509 can partially dry before the holes are punched and can complete the drying afterward. This can help the formed holes to hold their shape.

[0051] Figure 6A through Figure 6F shows a two punching tool process 600 for forming (e.g., punching) an angled hole through the tape 509. In Figure 6A, a plurality of cylindrical punches 601 are arranged on an upper pressing panel 603. A close up of an example cylindrical punch 601 is shown in Figure 8A. The tape 509 can be positioned on (e.g., laid over or moved over) a lower panel 605 that can include a plurality of cylindrical holes 607 (although other shapes can be used) that are aligned with the punches 601 and sized such that the cylindrical punches 601 can pass through. In some embodiments, the lower panel 605 can be the carrier 505 that the tape 509 was formed onto. The carrier 505 can have holes 607.

[0052] Figure 6B shows that the upper pressing panel 603 is pressed towards the lower panel 605 (e.g., downward), and the cylindrical punches 601 punch pieces 609 of the tape 509 through the cylindrical holes 607. A stripper can remove the punched out pieces 609 off of the punches, and the pieces 609 can be discarded or re-mixed and re-cast as another tape.

[0053] Figure 6C shows that the upper pressing panel 603 is moved away from the lower panel 605 (e.g., raised), and the tape 509 is left with cylindrical holes 611 where the cylindrical punches 601 had punched through the tape 509. The cylindrical holes 611 can have a first radius Rl determined by the size of the cylindrical punches 601.

[0054] Figure 6D shows that the tape has been moved between a second pressing panel 623 and lower pressing panel 625. In some cases, the carrier 505 can move the tape 509 to the second pressing panel 623. The carrier 505 can be the lower pressing panel 625. Although not shown, the carrier can have holes 607, as discussed herein. A plurality of punches or reshaping tools 621 having tips shaped as truncated conical sections is arranged on the upper pressing panel 623. A close up of an example punch 612 in the shape of a truncated conical section is shown in Figure 8B. A larger radius R2 of the punch 612 can be larger than the first radius Rl, and a smaller radius of the punch R3 can be smaller than the first radius Rl. The lower pressing panel 625 can be without holes, in some embodiments. In some embodiments, after Figure 6C and before Figure 6D, the temperature of the slurry or green sheet can be raised until plasticized so that the slurry or green sheet can be more easily molded. In some cases, the steps of Figures 6A to 6F can be performed before the tape 509 has dried or cooled. Accordingly, the tape 509 can be malleable.

[0055] Figure 6E shows the upper panel 623 pressing towards the lower panel 625 (e.g., downward), and the punches or reshaping tools 621 can press into the tape 509, causing the cylindrical holes to be reshaped into truncated-cone holes. Portions of the cylindrical sidewalls of the tape 509 can be pressed inward while other portions are forced outward by the tool 621, reshaping the cylindrical hole to have sloping side walls in the shape of a truncated cone. In some embodiments, the punches or reshaping tools 621 can have a cone shape. A tip or narrow portion of the cone or truncated-cone shaped punches or tools 621 can extend through the tape 509 and into the holes 607 (not shown in Figure 6E).

[0056] Figure 6F shows that the upper panel 623 is moved away from the lower panel 625 (e.g., upward) and separated from the tape 509, leaving the tape 509 with holes in the shapes of truncated conical sections.

[0057] Figure 7A through Figure 7D shows a one example punching tool process 700 for punching an angled hole through the tape 509. The punch can be also pressed in one downward motion to create the angled hole.

[0058] In Figure 7A, a plurality of punches 701 are arranged on an upper pressing panel 703. Each of the punches can include at least a first, cylindrical portion and a second, truncated conical portion. Close up of examples of punches 701 are shown in Figure 8C and Figure 8D. The tape 509 is laid over or moved over a lower panel 705 that includes a plurality of cylindrical holes 707 (although other shapes could also be used) that are aligned with the punches 701 and sized such that a cylindrical portion of the punches 701 can pass through the holes 707. The carrier 505 can be the lower panel 705. The carrier 505 can have holes 707.

[0059] Figure 7B shows that the upper pressing panel 703 is pressed towards the lower panel 705 (e.g., downward), and the first cylindrical portion of the punches 701 punch pieces 709 of the tape 509 through the cylindrical holes. A stripper can clean the punched out pieces 709 off of the punches, and the pieces 709 can be discarded or re-mixed and re cast as another tape.

[0060] Figure 7C shows that the upper pressing panel 703 continues to be pressed towards the lower panel 705 (e.g., downward), and the second, truncated conical portion of the punches 701 are pressed into the tape 509. Portions of the cylindrical sidewalls of the tape 509 can be pressed outward by the tool 701, reshaping the cylindrical hole to have sloping side walls in the shape of a truncated cone.

[0061] In some embodiments, the height of the truncated conical portion of the punches 701 can be approximately similar to or greater than the height of the tape 509. If the height of the truncated conical portion of the punches 701 is greater than the height of the tape, then any parts of the tape 509 forced to flair upward like a crater wall during the pressing process will still have an inner surface following the shape of a truncated cone. If any parts flared upward above the height of the tape are not desired, they can be later cut off or otherwise removed.

[0062] In some embodiments, the truncated conical portion of the punches 701 can be positioned against the upper pressing panel 703, such as shown in Figure 6D. Accordingly, the upper pressing panel 703 can function as a flat surface at the top of the punches 701 that prevents portions of the tape from being moved upward above the height of the truncated conical portion of the punches 701. Crater rims can similarly be prevented by using a larger radius collar above the truncated conical portion of the punches 701, such as shown in Figure 8D.

[0063] Figure 7D shows that the upper panel 703 is moved away from the lower panel 705 (e.g., upward) and separated from the tape 509, leaving the tape 509 with holes in the shapes of truncated conical sections. Although various embodiments disclose an upper panel that moves down and then up to punch and/or shape a hole, any other suitable approach can be used. For example, the lower panel can be moved up and down, while the upper panel is stationary. In some implementations, both the upper panel and the lower panel can move (e.g. towards each other and then away from each other). Any suitable orientation can be used. For example, a substantially horizontal orientation can be used, such as with upper and lower panels with substantially vertical movement. However, first and second panels could be used in any suitable orientation.

[0064] As shown in Figure 6A through Figure 6E and Figure 7A through Figure 7D, a first punch or punch section can be used to remove an excess portion of the tape and to form a first punched hole (e.g., a cylindrical hole). The hole can have vertical sidewalls. The hole can be similar to a desired shape that includes angled side walls. Angled side walls or tapered cones can be difficult to directly punch out of a material. The second punch or punch section can be used to reshape the punched hole into the desired shape with sloped side walls. It will be understood that some examples discussed herein discuss a truncated cone as an example of a shape with sloped side walls, but the examples can extend to any shape with sloped side walls, tapered side walls, or conic sections. The second punch or punch section can have a smooth surface, and reshaping the punched hole can help the side walls have a similarly smooth surface.

[0065] Figure 8A shows an example of a solid cylindrical punch 800. The cylindrical punch 800 can have a first radius Rl. [0066] Figure 8B shows an example of a punch or reshaping tool 810 having a portion in the shape of a truncated cone. The truncated cone has a smaller end with a radius R3 that can be smaller than, similar to, substantially the same as, or larger than the first radius Rl . The truncated cone has a larger end with a radius R2 that can be larger than the radius R3 and/or larger than the first radius Rl .

[0067] In Figure 8B, dotted lines show optional extension portions 811 (e.g. a driver) of various diameters. The optional extension portions can be used to separate the truncated cone punch 810 from a pressing surface so that when the truncated cone punch is pressed into the tape, the pressing surface can avoid contacting the surface of the tape. Additionally, the optional extension portion 811 can have a radius that is larger than radius R2 to prevent crater walls from rising up above the tape around the truncated cone punch 810 when pressing while still allowing the pressing surface to avoid contact with the surface of the tape. In some embodiments, the radius of the optional extension portion 811 can have a radius sufficiently larger than R2 such that any crater walls or other surface protrusions forming around the optional extension portion 811 are distant enough from the punched hole to be cut off or cut away without affecting the structure of the punched hole or surrounding ceramic. The optional extension portion 811 can have a radius that is similar to or substantially the same as the radius R2. The optional extension portion 811 can also have a radius that is less than the radius R2. The extension portion 811 can be omitted in some embodiments.

[0068] As another alternative, the truncated cone portion can have a greater height (and corresponding larger radius R2) than a height of the tape. In some embodiments, the pressing surface can be pressed up to the tape when the tape is punched with the truncated cone portion to avoid bulges in the surface of the tape. In some cases, the punch or reshaping tool 810 can have a cone tip 813 that extends through the tape and into a hole when pressed into the tape. In some cases, the height of tapered side wall of the punch or reshaping tool 810 can be taller than the thickness of the tape. For example, when the punch or reshaping tool 810 is pressed to the position that forms the desired truncated cone shape in the tape, the narrow end of the punch or tool 810 can extend past the bottom of the tape and/or the wide end of the punch or tool 810 can be positioned higher than the top of the tape. The narrow end of the punch or tool 810 can have a smaller radius than the truncated cone shape that is pressed into the tape. The wide end of the punch or tool 810 can have a larger radius than the truncated cone shape that is pressed into the tape. [0069] Figure 8C shows an example of a punch 820 including a first cylindrical portion 821 directly connected to a second portion 822 in the shape of a truncated cone. The labeled radiuses can be sized such that R2 > R3 > Rl . The punch 820 can optionally include a thin, initial leading portion 823 with a radius smaller than Rl to pre-punch a hole with a smaller radius than Rl. A driver portion 824 can be positioned above the second portion. As shown the driver portion can have a radius smaller than R2, but any suitable configuration is possible, similar to the discussion of Figure 8B. The optional driver portion 824 can have a radius that is smaller than, substantially the same as, or larger than the radius R2.

[0070] Figure 8D shows an example of a punch 830 including a first cylindrical portion 821 coupled to a second portion 822 in the shape of a truncated cone. A driver 824 can have a radius greater than, less than, or substantially equal to the radius R2. In some embodiments, the driver portion 824 can be omitted. The labeled radiuses can be sized such that R2 > R3 > Rl. An extension region can be used to space the first cylindrical portion from the second portion. Various sizes are possible. In various embodiments any of the radii Rl, R2, and R3 can be about 50 mm, about 25 mm, about 10 mm, about 7 mm, about 5 mm, about 3 mm, about 2 mm, about 1 mm, about 0.7 mm, about 0.5 mm, about 0.3 mm, about 1 mm, about 0.75 mm, about 0.5 mm, about 0.25 mm, or any values therebetween, or any ranges bounded by these values, although other sizes are possible.

[0071] Figure 8E shows an example of a cylindrical punch 840 with sharp cutting blades for the wall of the cylinder (outlined by dotted lines). As the cylindrical punch 840 is pressed into a tape, the cutting blades cut a cylindrical portion of the tape to be punched out. It will be understood that any of the punch designs discussed herein, such as Figures 8A through 8D, could include cutting blades as shown in Figure 8E. As another possibility, any of the punch designs can have sharp exterior walls, at least on the bottom of the punch, with at least a partially hollow body. As another possibility, the holes can be drilled instead of punched. Any of the punches or tools disclosed herein can be rotated when pressed into or punched through the tape.

[0072] Although various embodiments discussed and illustrated herein have a cavity that includes a truncated cone shape, and has a cross-sectional shape with straight side walls, other cavity shapes are possible. For example, the cavity can have a cross-sectional shape with curved side walls. The cavity can have the shape of a portion of a sphere for example. In some embodiments, the cavity can have an upper truncated cone shape with side walls at a first angle, and lower truncated cone shape with side walls at a second angle (which can be greater or lower than the first angle). Accordingly, the steepness of the side walls can be different at different heights of the cavity. In some cases, some or all of the cavity can be cylindrical. The punches or shaping tools discussed herein can be modified to produce the other cavity shapes disclosed herein.

[0073] Figure 9A shows a side view of a cylindrical hole punched in a tape 509. The hole has a radius of Rl as a result of being punched by a cylindrical punch, such as in Figure 6C, or by the first punch section as in Figure 7B.

[0074] Figure 9B shows a side view of a hole with sloped side walls in a tape 509, such as shown in Figure 6F. The second punch or reshaping tool 621 can reshape the hole to have the tapered side walls. The hole has a larger radius of R2 at the top and a smaller radius of R3 at the bottom. When pressed with a second punch, portions of the tape may move in the direction indicated by the arrows, reshaping the vertical side walls into angled side walls. The radius R2 and the radius R3 can be sized such that approximately equal amounts of slurry can be moved toward and away from the center of the of the hole to avoid disturbing other parts of the tape and to avoid forming surface protrusions. In some embodiments, the radius R3 can be the same as or larger than Rl, and material can be driven outward to form the truncated cone shape.

[0075] Figure 10 shows a plurality of holes in a tape. Each hole can have a larger radius at the top and a smaller interior radius at the bottom of the hole. In between the top and bottom of each hole, the side walls can be sloping at an angle that can range from a shallow angle of about 5 degrees a steep angle of up to about 85 degrees. The slope can be about 5 degrees, about 10 degrees, about 15 degrees, about 20 degrees, about 30 degrees, about 40 degrees, about 50 degrees, about 60 degrees, about 70 degrees, about 75 degrees, about 80 degrees, or about 85 degrees, or any values or ranges bounded therein. The ring- shaped area of side wall, as seen from the top-down view of Figure 10, can be very small, and the target area for coating can just a few millimeters or even smaller than a millimeter across. For mass production, a plurality of holes, such as in a line or grid, can be punched together.

[0076] The distance between the holes can be very small. In some embodiments, holes can be punched with less than 1 millimeter pitch between holes, such as tens of pm or hundreds of pm. In some embodiments, the distance between holes can be larger to accommodate lanes for singulation and/or areas for the inclusion of other components to be mounted on the ceramic chip such as electrical traces, electrical components, and/or mechanical components. To reduce the likelihood of causing cracks or stress fractures to develop between the holes, a first set of holes can be punched with spaces therebetween, and a second set of holes can be punched in the spaces. As an example, to punch 10 holes in a line, holes 1, 3, 5, 7, and 9 can first be punched as a first set, and then holes 2, 4, 6, 8, and 10 can be subsequently punched as a second set. By doing so, the distance between holes being punched in one set can be doubled. The spacing can be increased to every 3^rd hole, every 4^th hole, etc.

[0077] The size of the holes, as shown in Figure 10, may not necessarily be the final size of the holes after heating. Ceramic and glaze may shrink during one or more heating processes. Accordingly, based on the rate that selected materials shrink, the size of the holes may be adjusted to compensate for shrinkage. For example, the holes can be formed initially smaller than the target size. The shrinkage of the material can cause the size of the holes to increase. The size of the holes can additionally or alternatively be adjusted for the thickness of additional layers that will be added during production, such as one or more layers of glaze, electrodes, dielectric, etc.

[0078] Figure 11 shows an example system 1100 for making glazed ceramic substrates with sloped side walls, such as for liquid lenses. A container 501 holds a slurry mixture 503 that is tape casted with a knife 507 through a slot. A dryer 1101 can optionally be used to lightly or partially dry the slurry. The slurry can optionally be flipped over a roller 1103. In some cases the roller 1103 can be omitted. A hole punching system 1105 can be used to punch a hole and reshape a hole in the slurry into a tapered, truncated cone with sloping side walls. The slurry can be heated by a heater 1107 or oven into a green sheet. A glazing system 1109 can be used to glaze the green sheet with a first material such as glass. A metal application system 1111 can be used to form metals for electrodes. A coating depositing system 1113 can be used to coat the glass, such as with parylene or other insulating and/or hydrophobic material. In various embodiments, the heating 1107 can be performed in a different order, such as after glazing system 1109, after the application system 1111, or after the coat deposition system 1113. The heating 1107 can be a firing step where the green sheet is heated to“ceram” or create the final ceramic material. The firing can be performed before the glaze. In some cases, a glaze precursor can be applied before the firing, and the green sheet and glaze can be fired together.

[0079] The container 501 and knife 507 can be used to tape cast the slurry 503 as discussed with respect to Figure 5. In various embodiments, the slurry can be otherwise casted, extruded, calendared, or pressed into a tape having a height from fractions of one millimeter to several tens of millimeters. The slurry can include a thermoplastic binder such as methylcellulose. The slurry can also include ceramic particles. For example, the slurry can be a mixture for porcelain.

[0080] An optional dryer can be used to partially dry the slurry 509 into a consistency appropriate for hole punching and reshaping. In some embodiments, the partially dried slurry can be brittle. In some embodiments, the partially dried slurry can still be malleable. Drying can include heating the slurry at lower temperatures, briefly firing/heating the slurry at higher temperatures, blowing air, and/or letting the slurry rest for a set amount of time while liquids evaporate from the slurry.

[0081] The hole punching system 1105 can include the systems shown in Figure 6A through Figure 6F and Figure 7A through Figure 7D. In Figure 11, a one punching tool system is shown, but a multiple punching tool system can also be used. The hole punching system can punch a portion of the slurry out through a corresponding support surface, and then the hole can be reshaped to have sloping or tapered side walls, such as in the shape of a truncated cone or other conic section. The inclined slope of the side walls can be at various angles, such as from about 15 degrees to about 75 degrees. In some embodiments, after a cylindrical hole punching, the slurry or green sheet can be heated until plasticized, and then the green sheet or slurry can be reshaped with the conic shaped punch. The temperature for plasticizing the slurry or green sheet can depend on the thermoplastic binder mixed with the ceramic in the slurry.

[0082] After hole punching, the slurry can be dried into a more brittle green sheet and optionally cooled to harden the green sheet. In other embodiments, the hole punching can be performed at a later stage, such as after firing the slurry in the heater 1107 and heating the green sheet until malleable. Accordingly, a green sheet can be hole punched instead of punching the slurry.

[0083] A heater 1107 can be used to fire the green sheet, turning the green sheet into a ceramic sheet. The heater can use fire, heat coils, or other radiation, or any suitable heat source. The green sheet can be heated to temperatures over 1000° Celsius for a period of time. Any suitable temperature can be used, such as depending on the materials that are used to form the slurry and/or the ceramic material being formed.

[0084] The ceramic sheet can proceed to a glazing system 1109 to be glazed with a smooth and/or insulating material such as glass or certain insulating crystals. For example, the ceramic sheet can be glazed with low temperature melting glass. The layer of glass can have a low surface roughness Ra of less than about 10 mth, less than about 9 mth, less than about 8 pm, less than about 7 pm, less than about 5 pm, less than about 3 mth, less than about 1000 nm, less than about 750 nm, less than about 500 nm, less than about 250 nm, less than about 100 nm, less than about 75 nm, less than about 50 nm, less than about 40 nm, less than about 30 nm, less than about 20 nm, less than about 15 nm, less than about 10 nm, less than about 7 nm, less than about 5 nm, less than about 4 nm, less than about 3 nm, less than about 2 nm, or any values therebetween, or any ranges bounded thereby, although other values can be used. In some embodiments, the glaze can be reflowed one or more times in order to increase the smoothness (e.g., lower the Ra), such as to the single digit nanometer range. For example, Ra can be reduced to about 4 nm.

[0085] The glass can be prepared as a glaze slurry and deposited onto the ceramic sheet. The glaze slurry can be drip coated, spray coated, or otherwise deposited. In some embodiments, the glass can be deposited as small particles with particle radiuses of about 5 pm or less or 2.5 pm or less. The glass can cover at least the sloped sidewalls.

[0086] After being deposited, the glaze slurry and the ceramic sheet can then be heated (e.g., to a lower temperature than used for firing), such as less than l000°C. In some embodiments, the temperature can be about 500-600°C. After heating, the glaze slurry can be cooled at a controlled rate e.g., to solidify into glass or other glaze material.

[0087] In some embodiments, the glaze slurry can be deposited onto the green sheet before the green sheet is fired, and higher temperature melting glass can be used. When firing the glaze slurry and the green sheet together, the temperature can be sufficiently high to sinter the ceramic, and at least some portions of the unfired ceramic can remain uncovered by glaze to allow vapors to escape.

[0088] In some embodiments, glaze slurry can be deposited onto the ceramic after the ceramic is fired and while the ceramic is cooling. Accordingly, lower melting temperature glass particles can be melted at temperatures below l000°C while the ceramic is cooling. In some embodiments, after the ceramic is fired, the ceramic can be cooled before depositing a glaze slurry, such as a low temperature melting glass, onto the ceramic.

[0089] A metal application system 1111 can be used to form electrodes for controlling the fluid in the liquid lens. The metals can be formed in positions such as the electrodes shown in Figure 1. Additionally, conductive vias, traces, wires, pads, pins, metal routing layers, and other metals can be formed for electrical connectivity. The metals are not necessarily placed above or below the sloped side walls. Although shown as one metal application system 1111, it should be realized that the metals can be deposited between any layers (e.g., ceramic and glass, glass and more glass, glass and parylene). In some embodiments, the glazing system can be repeatedly used to provide multiple layers of glass or other glaze material. One or more layers of metals can be deposited between the layers of glaze.

[0090] A coating depositing system 1113 can be used to coat the piece (e.g., the glass or other glaze material), such as with parylene or any other suitable coating, which can be hydrophobic and/or insulating. The parylene can cover at least the sloped side walls.

[0091] Figure 12 shows a zoomed-in example cross-section 1200 of a fluid chamber of a liquid lens, which can be similar to the embodiment of Figure 1. In Figure 12, the multiple layers of the side wall can be seen. The fluid chamber can be formed by a structure comprising a ceramic body 1201. The ceramic body or substrate 1201 can have a recess in the shape of a truncated cone, as discussed herein. A glaze 1202 layer (or multiple glaze layers) can be formed over (e.g., onto) the ceramic material or substrate 1201. An electrode (e.g., a metal layer) 1203 can be formed over (e.g., onto) the glaze 1202. An insulating and/or hydrophobic layer 1205 (e.g., parylene) can be formed over (e.g., onto) the electrode 1203. A plurality of electrodes is also shown, for example.

[0092] In the illustrated example, the body includes sloped side walls comprising four layers: the ceramic layer 1201, the glaze (e.g., glass) layer 1201, the electrode (e.g., metal layer) 1203, and the insulating (e.g., parylene) layer 1205. The side walls are shown at about a 70 degree incline, but other embodiments can have side walls at greater or smaller inclines, as discussed herein. The techniques disclosed herein can be used to make side walls at a desired incline as well as coat the side walls with glass and/or parylene, or other suitable materials. The ceramic body can rest on any appropriate support (not shown), such as another ceramic layer, a glass layer a parylene layer, a semiconductor layer, a printed circuit board, an insulator, etc.

[0093] The thickness of the layers can vary. The figures are not necessarily drawn to scale, although the dimensions and proportions illustrated are intended to form part of the present disclosure. For example, in some embodiments, the ceramic, glass, or parylene layer can range anywhere between about 0.001 mm to about 5 mm thick, although other sizes can be used as well.

[0094] The smoothness of each layer can vary. For some materials, the smoothness of the layer can copy or be affected by the smoothness of a layer below it. Accordingly, forming smooth ceramic side walls using the tools and techniques disclosed herein can allow for a smoother glaze layer. The smoothness of the glaze layer 1202 can be copied by or otherwise affect the smoothness of the electrode 1203 and/or the insulating (e.g., parylene) layer 1205. Accordingly, an insulating (e.g., parylene) layer with a surface roughness Ra of less than about 10 pm, less than about 9 pm , less than about 8 pm, less than about 7 pm, and the like can be achieved over the sloped side walls. In some embodiments, the Ra of the insulating (e.g., parylene) over the side walls can be reduced to the nanometer range, such as about 10 nm, about 5 nm, about 4 nm, and the like. Accordingly, various embodiments can feature an insulating (e.g., parylene) surface roughness Ra over the side walls of about less than about 2 nm, less than about 4 nm, about 4-10 nm, about 10-100 nm, about 100-500 nm, about 500 nm to about 1 pm, about 1 pm to about 4 pm, about about 4 pm to about 7 pm, about 7 pm to about 10 pm, about 10 pm to about 50 pm, and other ranges or values bounded by any combination of these values.

Example Flowcharts

[0095] Figure 13 shows a flowchart 1300 of a method for coating a glass layer (e.g., glazing). The method or parts thereof can be used, for example, at block 1109 of Figure 11. Additionally or alternatively, parts of the method can be performed before, combined with, and/or after with the heating by the heater 1107 of Figure 11.

[0096] At block 1301, glass materials can be assembled. The glass can be, for example, a glass frit. The materials can also include a mix of particles for making glass, such as SiCh, AI2O3, CaO, ZnO, and other particles. The glaze can also include additional additives for optical or material properties. The composition of the glaze can be varied to change the melting temperature and to change water contact angle with the glaze. For example, different glazes can have different water contact angles between 15-50 degrees.

[0097] At block 1303, the materials can be milled or ground or otherwise converted into small particle sizes. The quartz particles can be ground or milled into particle sizes that are, for example, less than about 5 pm in radius, less than 3 pm in radius, less than 2.5 pm in radius, or smaller. Milling can be performed dry or with a liquid additive such as water.

[0098] At block 1305, the materials can be vitrified into a glaze slurry. Vitrifying the materials can include heating the materials to high temperatures such as l000°C or above, l300°C or above, l500°C or above, or any higher temperature or temperature therebetween. In some cases, lower temperature melting glass can be used as a starting material. The lower temperature melting glass can be milled or ground into smaller particles and, at block 1305, heated to lower temperatures than l000°C, such as the 250°C to 900°C range or other range depending on the specific type of materials used.

[0099] At block 1307, the glaze slurry can be deposited onto a ceramic body. The glaze can be drip coated, spray coated, or otherwise deposited. The glaze slurry can be deposited onto the sloped side walls of the ceramic body of a small liquid lens. The glaze slurry can be deposited onto a green sheet before the green sheet is fired or deposited on a ceramic sheet after firing.

[0100] At block 1309, the glaze slurry can be baked on the green sheet or ceramic sheet. In some embodiments, the baking temperature can be high enough to solidify a green sheet into a ceramic sheet. The baking temperature can be high enough to soften and/or sinter the glaze slurry. In some embodiments, the baking temperature can be low enough such that the glaze slurry does not run down and off of the sloping side walls, and such a temperature can vary with the composition of the glaze slurry. In some embodiments, baking can occur at a temperature range of at least l000°C, but lower than the vitrification temperature. In some embodiments, for lower temperature melting glass, the baking can occur at about 250°C to 900°C but at a lower temperature than the vitrifiation temperature.

[0101] At block 1311, the glaze slurry can be cooled into glass. The cooling can happen at a controlled rate, such as cooling by less than about 400°C per hour, less than about 300°C per hour, less than about 200°C per hour, or less than about l00°C per hour. The resulting glass coat on the ceramic can have a surface roughness Ra of less than about 10 pm, less than about 9 pm , less than about 8 pm, less than about 7 pm, and the like, as discussed herein. The resulting glass can also be a single layer of phase -separated glass.

[0102] At block 1313, the glass can be reflowed a number of times for a smoother surface. After one or more reflows, the surface roughness Ra can be about less than 5 nm, less than 4 nm, etc. as discussed herein.

[0103] Figure 14 shows a flowchart 1400 of a first method for making a glazed ceramic body for a liquid lens. At block 1401, a slurry comprising ceramic can be mixed. The slurry can also include a thermoplastic binder.

[0104] At block 1403, the slurry can be formed into a tape. Block 1403 can be performed using tape casting, pressing, calendaring, or other technique. The tape can be thin, such as a few millimeter thick, less than a millimeter thick, a few micrometers thick, or smaller. [0105] At block 1405, the tape can optionally be partially dried. The slurry can be left to dry or actively heated or cooled to form a more brittle tape for hole punching.

[0106] At block 1407, a first cylindrical hole can be punched in the tape, such as described with respect to Figure 6A through Figure 6C and Figure 7A through Figure 7C.

[0107] At block 1409, the first cylindrical hole can be reshaped into a conical hole, such as described with respect to Figure 6D through Figure 6F and Figure 7D. In some embodiments, before block 1409, the slurry can be heated until plasticized so that the reshaping can be more easily performed. The plasticizing temperature can depend on the type of thermoplastic binder mixed in the slurry.

[0108] At block 1411, the slurry can optionally be dried or cooled to solidify the tape.

[0109] At block 1413, glaze can be deposited on the tape. The glaze can be, for example, a glass glaze. The glaze can be drip coated, spray coated, dipped, roller coated, or otherwise deposited.

[0110] At block 1415, the tape and glaze can be heated or fired together. The temperature can be at least l000°C, in some embodiments, although any suitable temperature can be used, e.g., depending on the materials. The tape can turn into ceramic. The glaze can turn into glass.

[0111] At block 1417, the ceramic and glass can be cooled. The rate of cooling can be controlled, such as cooling by less than about 400°C per hour, less than about 300°C per hour, less than about 200°C per hour, or less than about l00°C per hour.

[0112] At block 1419, the glass can optionally be reflowed one or more times. This can reduce the surface roughness Ra.

[0113] At block 1421, metals for electrodes can be deposited. The metals can be deposited on the glaze and before the parylene.

[0114] At block 1423, an insulator such as parylene can be applied as an additional layer over glass. The parylene can have a surface roughness that mimics the surface roughness of the glass.

[0115] Figure 15 shows a flowchart 1500 of a second method for making a glazed ceramic body for a liquid lens. At block 1501, a slurry comprising ceramic can be mixed. The slurry can also include a thermoplastic binder.

[0116] At block 1503, the slurry can be formed into a tape. Block 1503 can be performed using tape casting, pressing, calendaring, or other technique. The tape can be thin, such as a few millimeter thick, less than a millimeter thick, a few micrometers thick, or smaller.

[0117] At block 1505, the tape can optionally be partially dried. The slurry can be left to dry or actively cooled to form a more brittle tape for hole punching.

[0118] At block 1507, a first cylindrical hole can be punched in the tape, such as described with respect to Figure 6A through Figure 6C and Figure 7A through Figure 7C.

[0119] At block 1509, the first cylindrical hole can be reshaped into a conical hole, such as described with respect to Figure 6D through Figure 6F and Figure 7D. In some embodiments, before block 1509, the slurry can be heated until plasticized so that the reshaping can be more easily performed. The plasticizing temperature can depend on the type of thermoplastic binder mixed in the slurry.

[0120] At block 1511, the slurry can optionally be dried or cooled to solidify the tape.

[0121] At block 1513, the tape can be fired into a ceramic. This can occur at temperatures over l000°C, in some embodiments.

[0122] At block 1515, the ceramic can optionally be cooled.

[0123] At block 1517, glaze can be deposited onto the ceramic. The glaze can be, for example, a glass glaze. The glaze can be drip coated, spray coated, or otherwise deposited.

[0124] At block 1519, the glaze can be heated until the glaze is turns into glass. The temperature to vitrify the glaze can depend on the composition of the glaze. Although various embodiments disclosed herein use glass glaze, any suitable type of glaze can be used.

[0125] At block 1521, the ceramic and glass can be cooled. The rate of cooling can be controlled, such as cooling by less than about 400°C per hour, less than about 300°C per hour, less than about 200°C per hour, or less than about l00°C per hour

[0126] At block 1523, the glass can be reflowed one or more times. The glass can be reflowed a number of times for a smoother surface. After one or more reflows, the surface roughness Ra can be about less than 5 nm, less than 4 nm, etc.

[0127] At block 1525, metals for electrodes can be deposited. The metals can be deposited on the glaze and before the parylene. In the various embodiments disclosed herein, the metal can be divided by insulating material to produce separate electrode elements (e.g., for forming the driving electrodes 22a-c and/or the common electrode 26). [0128] At block 1527, an insulator such as parylene can be applied as an additional layer over glass. The parylene can have a surface roughness that copies or mimics the surface roughness of the glass.

[0129] After the methods described with respect to either Figure 14 or Figure 15, additional processing steps can be performed to produce the liquid lens. Upper and lower windows can be applied. A second one or more electrodes can be formed (e.g., electrode 26). Two immiscible fluids can be used to fill the chambers, which can then be sealed to provide a liquid lens.

Additional Details

[0130] In the disclosure provided above, apparatus, systems, and methods for making a liquid lens are described in connection with particular example embodiments. It will be understood, however, that the principles and advantages of the embodiments can be used for any other applicable systems, apparatus, or methods. Analog, digital, or mixed circuitry can be used to perform steps (e.g., automation). The principles and advantages discussed herein can be implemented for different parts as analog, digital, or mixed circuitry. In some figures, four electrodes (e.g., insulated electrodes) are shown. The principles and advantages discussed herein can be applied to embodiments with more than four electrodes or fewer than four electrodes.

[0131] The principles and advantages described herein can be implemented in various apparatuses. Examples of such apparatuses can include, but are not limited to, consumer electronic products, parts of the consumer electronic products, electronic test equipment, etc. The principles and advantages described herein relate to lenses. Examples products with lenses can include a mobile phone (for example, a smart phone), healthcare monitoring devices, vehicular electronics systems such as automotive electronics systems, webcams, a television, a computer monitor, a computer, a hand-held computer, a tablet computer, a laptop computer, a personal digital assistant (PDA), a refrigerator, a DVD player, a CD player, a digital video recorder (DVR), a camcorder, a camera, a digital camera, a copier, a facsimile machine, a scanner, a multi-functional peripheral device, a wrist watch, a clock, etc. Further, apparatuses can include unfinished products.

[0132] In some embodiments, the methods, techniques, microprocessors, and/or controllers described herein are implemented by one or more special-purpose computing devices. The special-purpose computing devices may be hard-wired to perform the techniques, or may include digital electronic devices such as one or more application-specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs) that are persistently programmed to perform the techniques, or may include one or more general purpose hardware processors programmed to perform the techniques pursuant to program instructions in firmware, memory, other storage, or a combination. The instructions can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of a non-transitory computer-readable storage medium. Such special-purpose computing devices may also combine custom hard wired logic, ASICs, or FPGAs with custom programming to accomplish the techniques. The special-purpose computing devices may be desktop computer systems, server computer systems, portable computer systems, handheld devices, networking devices or any other device or combination of devices that incorporate hard-wired and/or program logic to implement the techniques.

[0133] The processor(s) and/or controller(s) described herein can be coordinated by operating system software, such as iOS, Android, Chrome OS, Windows XP, Windows Vista, Windows 7, Windows 8, Windows Server, Windows CE, Unix, Linux, SunOS, Solaris, iOS, Blackberry OS, VxWorks, or other compatible operating systems. In other embodiments, the computing device may be controlled by a proprietary operating system. Conventional operating systems control and schedule computer processes for execution, perform memory management, provide file system, networking, I/O services, and provide a user interface functionality, such as a graphical user interface (“GUI”), among other things.

[0134] The processor(s) and/or controller(s) described herein may implement the techniques described herein using customized hard-wired logic, one or more ASICs or FPGAs, firmware and/or program logic which causes microprocessors and/or controllers to be a special-purpose machine. According to one embodiment, parts of the techniques disclosed herein are performed by a processor (e.g., a microprocessor) and/or other controller elements in response to executing one or more sequences instructions contained in a memory. Such instructions may be read into the memory from another storage medium, such as storage device. Execution of the sequences of instructions contained in the memory causes the processor or controller to perform the process steps described herein. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions.

[0135] Moreover, the various illustrative logical blocks and modules described in connection with the embodiments disclosed herein can be implemented or performed by a machine, such as a processor device, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A processor device can be a microprocessor, but in the alternative, the processor device can be a controller, microcontroller, or state machine, combinations of the same, or the like. A processor device can include electrical circuitry configured to process computer-executable instructions. In another embodiment, a processor device includes an FPGA or other programmable device that performs logic operations without processing computer-executable instructions. A processor device can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Although described herein primarily with respect to digital technology, a processor device may also include primarily analog components. For example, some or all of the rendering techniques described herein may be implemented in analog circuitry or mixed analog and digital circuitry.

[0136] Unless the context clearly requires otherwise, throughout the description and the claims, the words“comprise,”“comprising,”“include,”“including,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” The words“coupled” or connected,” as generally used herein, refer to two or more elements that can be either directly connected, or connected by way of one or more intermediate elements. Additionally, the words“herein,” “above,”“below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the Detailed Description using the singular or plural number can also include the plural or singular number, respectively. The words“or” in reference to a list of two or more items, is intended to cover all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. All numerical values provided herein are intended to include similar values (e.g., within a range of measurement error).

[0137] Although this disclosure contains certain embodiments and examples, it will be understood by those skilled in the art that the scope extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses and obvious modifications and equivalents thereof. In addition, while several variations of the embodiments have been shown and described in detail, other modifications will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of this disclosure. It should be understood that various features and aspects of the disclosed embodiments can be combined with, or substituted for, one another in order to form varying modes of the embodiments. Any methods disclosed herein need not be performed in the order recited. Thus, it is intended that the scope should not be limited by the particular embodiments described above.

[0138] Conditional language, such as, among others,“can,”“could,”“might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment. Any headings used herein are for the convenience of the reader only and are not meant to limit the scope.

[0139] Further, while the devices, systems, and methods described herein may be susceptible to various modifications and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular forms or methods disclosed, but, to the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the various implementations described. Although some features are indicated with dotted lines or stated as optional, it will be understood that other features can also be optional. Further, the disclosure herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element, or the like in connection with an implementation or embodiment can be used in all other implementations or embodiments set forth herein. Any methods disclosed herein need not be performed in the order recited. The methods disclosed herein may include certain actions taken by a practitioner; however, the methods can also include any third-party instruction of those actions, either expressly or by implication. [0140] The ranges disclosed herein also encompass any and all overlap, sub ranges, and combinations thereof. Language such as“up to,”“at least,”“greater than,”“less than,”“between,” and the like includes the number recited. Numbers preceded by a term such as“about” or“approximately” include the recited numbers and should be interpreted based on the circumstances (e.g., as accurate as reasonably possible under the circumstances, for example, ±1%, ±3%, ±5%, ±10%, ±15%, etc.). For example,“about 3.5 mm” includes“3.5 mm.” Recitation of numbers and/or values herein should be understood to disclose both the values or numbers as well as“about” or“approximately” those values or numbers, even where the terms“about” or“approximately” are not recited. For example, recitation of“3.5 mm” includes“about 3.5 mm.” Phrases preceded by a term such as“substantially” include the recited phrase and should be interpreted based on the circumstances (e.g., as much as reasonably possible under the circumstances). For example,“substantially constant” includes “constant.” Unless stated otherwise, all measurements are at standard conditions including ambient temperature and pressure.

Claims

WHAT IS CLAIMED IS:

1. A method for making a liquid lens with a ceramic body, the method comprising: forming a tape from a slurry;

punching a hole through the tape;

reshaping the hole into a truncated cone;

heating the slurry with a first temperature to turn the slurry into ceramic; glazing the ceramic with a glaze;

heating the glaze at a second temperature to form glass;

coating the glass with a conductive material to form an electrode; and coating the electrode with an insulating material.

2. The method of Claim 1, wherein:

punching the hole through the tape includes punching a cylindrical portion of the slurry out of the slurry and through a carrier surface.

3. The method of Claim 1, wherein:

reshaping the hole into a truncated cone comprises punching the hole with a punching tool that has a reshaping portion that is shaped as a truncated cone.

4. The method of Claim 1, wherein:

reshaping the hole is performed using a reshaping tool that has a widest radius greater than a radius of the hole and a smallest radius that is smaller than the radius of the hole.

5. The method of Claim 1, wherein:

one punching tool is used for both punching the hole and reshaping the hole in a single punching motion.

6. The method of Claim 1, wherein:

punching the hole is performed using a cylindrical punching tool; and reshaping the hole is performed using a separate reshaping tool shaped as a truncated cone.

7. The method of Claim 1, wherein:

the first temperature is at least 1000 ° Celsius.

8. The method of Claim 1, further comprising:

heating the ceramic to a second temperature that is lower than the first temperature, wherein the second temperature is still high enough to melt the glass.

9. The method of Claim 1, wherein: a radius of the hole after punching is less than 5 mm;

the glass has a surface roughness of not more than 0.07 pm; and

the insulating material is parylene.

10. The method of Claim 1, further comprising:

positioning, in the hole, at least two liquids that are immiscible with each other and form a fluid interface.

11. The method of Claim 1, further comprising:

reflowing the glass, wherein the glass has reduced surface roughness after reflowing the glass.

12. A liquid lens made by the method of Claim 1, the liquid lens comprising:

a chamber shaped as the truncated cone, the chamber comprising:

a ceramic layer comprising the ceramic;

a glass layer over the ceramic layer, the glass layer comprising the glass; and

an insulating layer over the glass layer, the insulating layer comprising the insulating material;

a first fluid in the chamber;

a second fluid in the chamber, wherein an interface is between the first fluid and the second fluid; and

one or more electrodes configured to receive voltages for shaping the interface.

13. A method for making a liquid lens with a ceramic body, the method comprising: forming a tape from a slurry;

forming a hole through the tape;

reshaping the hole into a truncated cone;

glazing the tape with a glaze;

heating the slurry and the glaze at a first temperature to form a glazed ceramic; and

forming a hydrophobic coating over the glazed ceramic.

14. The method of Claim 13, wherein:

punching the hole through the tape includes punching a cylindrical portion of the slurry out of the tape and through a carrier surface.

15. The method of Claim 13, wherein: reshaping the hole into a truncated cone comprises punching the hole with a punching tool that has a reshaping portion that is shaped as a truncated cone.

16. The method of Claim 13, wherein:

reshaping the hole is performed by a tool that has a widest radius greater than a radius of the hole and a smallest radius that is smaller than the radius of the hole.

17. The method of Claim 13, wherein:

18. The method of Claim 13, wherein:

punching the hole is performed using a cylindrical punching tool; and reshaping the hole is performed using a separate reshaping tool that is shaped as a truncated cone.

19. The method of Claim 13, wherein:

the first temperature is at less than 1000 ° Celsius; and

the glaze includes low temperature melting glass.

20. The method of Claim 13, wherein:

a radius of the hole after punching is less than 5 mm;

the glazed ceramic has a surface roughness of not more than 0.07 pm; and the hydrophobic coating is parylene.

21. The method of Claim 13, further comprising:

positioning, in the hole, at least two liquids that are immiscible with each other and form a fluid interface; and

providing a plurality of electrodes at positions to control a position of the fluid interface.

22. The method of Claim 13, further comprising:

reflowing the glaze, wherein the glazed ceramic has reduced surface roughness after reflowing the glaze.

23. A liquid lens made by the method of Claim 13, the liquid lens comprising:

a chamber shaped as a truncated cone, the chamber comprising:

a ceramic body including the glazed ceramic; and

a hydrophobic layer over the ceramic body, the insulating layer including the hydrophobic coating;

a first fluid in the chamber; a second fluid contained in the chamber, wherein an interface is between the first fluid and the second fluid; and

one or more electrodes configured to receive voltages for shaping the fluid interface.

24. A liquid lens system comprising:

a chamber shaped as a truncated cone, the chamber comprising:

a ceramic layer;

a glaze layer over the ceramic layer; and

an insulating layer over the glaze layer;

a first fluid in the chamber;

25. The liquid lens system of Claim 24, wherein the one or more electrodes include: a first electrode insulated from the first and second fluids, the first electrode configured to receive a first voltage signal for shaping the interface; and

a second electrode in electrical communication with the first fluid.

26. The liquid lens system of Claim 24, wherein:

the glaze layer has a surface roughness of not more than 0.09 pm.

27. The liquid lens system of Claim 24, wherein:

the glaze layer has a thickness of more than 0.3 mm.

28. The liquid lens system of Claim 24, wherein:

the insulating layer is a parylene layer having a surface roughness of not more than 0.09 pm.

29. The liquid lens system of Claim 24, wherein:

the truncated cone includes sloped side walls, and a smaller end of the truncated cone is less than 10 mm in radius.

30. The liquid lens system of Claim 24, wherein:

the truncated cone includes sloped side walls with an incline of at least 15 degrees.