METHODS AND APPARATUS FOR POSITIONING AND SECURING GLASS, GLASS-CERAMIC AND CERAMIC SUBSTRATES FOR COATING
20190270669 ยท 2019-09-05
Inventors
- Daniel Robert Boughton (Naples, NY)
- James Gerard Fagan (Painted Post, NY, US)
- Valerie Elise Mebert (Corning, NY, US)
- Kenneth Spencer Morgan (Painted Post, NY, US)
Cpc classification
C03C27/10
CHEMISTRY; METALLURGY
C04B41/89
CHEMISTRY; METALLURGY
C03C2217/78
CHEMISTRY; METALLURGY
C03C17/007
CHEMISTRY; METALLURGY
C03C21/002
CHEMISTRY; METALLURGY
International classification
C03C17/00
CHEMISTRY; METALLURGY
C04B41/89
CHEMISTRY; METALLURGY
Abstract
A method of preparing a glass, glass-ceramic or ceramic substrate for coating that includes: treating a primary surface of a carrier to form a carrier bonding surface, the carrier having a thickness of at least 2 mm; disposing a carrier surface modification layer on the carrier bonding surface; bonding the carrier to at least one substrate having a substrate bonding surface and a thickness from about 0.1 mm to about 3.5 mm, the bonding conducted by temporarily joining the carrier at the carrier surface modification layer to the substrate at the substrate bonding surface. Further, the treating and disposing steps are conducted such that an adhesion energy between the carrier surface modification layer and the substrate bonding surface is from 50 to 1000 mJ/m.sup.2 after the bonding step.
Claims
1. A method of preparing an article for coating, comprising: treating a primary surface of a carrier to form a carrier bonding surface; disposing a carrier surface modification layer on the carrier bonding surface; bonding the carrier to at least one substrate, the at least one substrate comprising a substrate bonding surface, the bonding conducted by temporarily joining the carrier at the carrier surface modification layer to the at least one substrate at the substrate bonding surface of the at least one substrate, wherein the treating and disposing steps are conducted such that an adhesion energy between the carrier surface modification layer and each of the substrate bonding surfaces is from 50 to 1000 mJ/m.sup.2 after the bonding step.
2. The method according to claim 1, the carrier comprising a thickness of at least 2 mm, and the at least one substrate comprising a thickness from about 0.1 mm to about 3.5 mm.
3. The method according to claim 1, wherein the adhesion energy is from 50 to 1000 mJ/m.sup.2 after a coating is disposed on the at least one substrate at a coating temperature of 300 C. or less and a coating pressure from 10.sup.6 Torr to 760 Torr.
4. The method according to claim 1, wherein the surface area of the carrier surface modification layer is about 60% of the surface area of the substrate bonding surfaces, and the adhesion energy is from 180 to 1000 mJ/m.sup.2 after the bonding step.
5. The method according to claim 3, wherein the at least one substrate is a strengthened substrate suitable for display glass applications.
6. The method according to claim 3, wherein the coating is a scratch-resistant layer deposited on at least one primary surface of the at least one substrate with a physical vapor deposition or plasma-enhanced vapor deposition process.
7. The method according to claim 3, wherein the coating is disposed on the at least one substrate with a drum coating process that subjects the at least one substrate to a centrifugal force from about 1 N to 20 N.
8. The method according to claim 3, wherein the treating step comprises cleaning the primary surface of the carrier with a cleaning composition comprising deionized water and hydrogen peroxide at a temperature from ambient temperature to 70 C.
9. The method according to claim 3, wherein the carrier surface modification layer comprises a hydrocarbon-based material.
10. The method according to claim 3, further comprising the step: de-bonding the carrier from the at least one substrate after the coating is disposed on the at least one substrate, the de-bonding conducted by mechanically separating the carrier surface modification layer from the substrate bonding surface of the at least one substrate without breakage to the carrier and the at least one substrate.
11. The method according to claim 10, wherein the substrate bonding surface of the at least one substrate comprises no more than trace amounts of the carrier surface modification layer after the de-bonding step.
12. The method according to claim 1, wherein the at least one substrate is substantially non-planar in shape.
13. The method according to claim 1, wherein the at least one substrate is substantially non-planar in shape and the substrate bonding surface of the at least one substrate is located on a substantially planar portion of the at least one substrate.
14. The method according to claim 1, wherein the carrier surface modification layer has a smaller surface area than the primary surface of the carrier.
15. The method according to claim 1, wherein the surface modification layer has a smaller surface area than the substrate bonding surface of the at least one substrate.
16. An article for coating, comprising: a carrier comprising a carrier bonding surface; a carrier surface modification layer disposed on the carrier bonding surface; and at least one substrate, the at least one substrate comprising a substrate bonding surface, wherein the carrier surface modification layer and the substrate bonding surface of the at least one substrate are joined such that such that an adhesion energy from 50 to 1000 mJ/m.sup.2 exists between the carrier surface modification layer and the substrate bonding surface of the at least one substrate, and further wherein the carrier is mechanically removable from the at least one substrate without breakage to the at least one substrate and the carrier.
17. The article according to claim 16, the carrier comprising a thickness of at least 2 mm, the at least one substrate comprising a thickness from about 0.1 mm to about 3.5 mm.
18. The article according to claim 16, wherein the adhesion energy is from 50 to 1000 mJ/m.sup.2 after a coating is disposed on the at least one substrate at a coating temperature of 300 C. or less and a coating pressure from 10.sup.6 Torr to 760 Torr.
19. The article according to claim 16, wherein the surface area of the carrier surface modification layer is about 60% of the surface area of the substrate bonding surface of the at least one substrate, and the adhesion energy is from 180 to 1000 mJ/m.sup.2 after a coating is disposed on the at least one substrate at a coating temperature of 300 C. or less and a coating pressure from 10.sup.6 Torr to 760 Torr.
20. The article according to claim 16, wherein the carrier surface modification layer comprises a hydrocarbon-based material.
21. The article according to claim 16, wherein the carrier is mechanically removable from the at least one substrate such that the substrate bonding surface of the at least one substrate comprises no more than trace amounts of the carrier surface modification layer.
22. A fixture assembly for coating a substrate, comprising at least one carrier comprising a carrier bonding surface, and a mounting surface; a carrier surface modification layer disposed on the carrier bonding surface; and a cam assembly comprising at least one clamp that is removably coupled to the mounting surface of the at least one carrier, and a plate removably coupled to the at least one clamp, wherein the carrier surface modification layer temporarily couples to a substrate bonding surface of a substrate with an adhesion energy from 50 to 1000 mJ/m.sup.2.
23. The fixture assembly according to claim 22, wherein the at least one carrier and the at least one clamp are a plurality of corresponding carriers and clamps, and further wherein the carrier surface modification layer of each carrier temporarily couples to a substrate bonding surface of a substrate with an adhesion energy from 50 to 1000 mJ/m.sup.2.
24. The fixture assembly according to claim 22, wherein the carrier surface modification layer temporarily couples to a substrate bonding surface of a substrate with an adhesion energy from 50 to 1000 mJ/m.sup.2 after the coupling and the deposition.
25. The fixture assembly according to claim 22, wherein the fixture is adapted for coating a plurality of substrates in a drum coating process that subjects each substrate to a centrifugal force from about 1 N to 20 N.
26. The fixture assembly according to claim 22, wherein the carrier surface modification layer temporarily couples with a substrate bonding surface of a substrate that is substantially non-planar in shape such that an adhesion energy from 50 to 1000 mJ/m.sup.2 exists between the carrier surface modification layer and the substrate bonding surface.
27. The fixture assembly according to claim 22, the at least one carrier comprising a thickness of at least 2 mm.
28. The article according to claim 16, wherein the at least one substrate comprises a plurality of substrates.
29. The method according to claim 1, wherein the at least one substrate comprises a plurality of substrates.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0061] In the following detailed description, for purposes of explanation and not limitation, example embodiments disclosing specific details are set forth to provide a thorough understanding of various principles of the present disclosure. However, it will be apparent to one having ordinary skill in the art, having had the benefit of the present disclosure, that the present disclosure may be practiced in other embodiments that depart from the specific details disclosed herein. Moreover, descriptions of well-known devices, methods and materials may be omitted so as not to obscure the description of various principles of the present disclosure. Finally, wherever applicable, like reference numerals refer to like elements.
[0062] As used herein, the term about means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. When the term about is used in describing a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to. Whether or not a numerical value or end-point of a range in the specification recites about, the numerical value or end-point of a range is intended to include two embodiments: one modified by about, and one not modified by about. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.
[0063] Directional terms as used hereinfor example up, down, right, left, front, back, top, bottomare made only with reference to the figures as drawn and are not intended to imply absolute orientation.
[0064] As used herein, the singular forms a, an and the include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a component includes embodiments having two or more such components, unless the context clearly indicates otherwise.
[0065] In general, the energy of adhesion (i.e., bond energy or adhesion energy as used herein) between two surfaces is measured by a double cantilever beam method or wedge test. The tests simulate in a qualitative manner the forces and effects on an adhesive bond joint at interface between two surfaces. Wedge tests are commonly used for measuring bonding energy. For example, ASTM D5041, Standard Test Method for Fracture Strength in Cleavage of Adhesives in Bonded Joints, and ASTM D3762, Standard Test Method for Adhesive-Bonded Surface Durability of Aluminum, are standard test methods for measuring bonding of substrates with a wedge.
[0066] The test method for determining adhesion energies as disclosed herein, which test method is based on but not identical to the above-noted ASTM methods, is as follows. The first sheet is gently pre-cracked or separated at a corner of the glass article locally to break the bond between the first surface and the second surface. A razor blade is used to pre-crack the first surface from the second surface, for example, a GEM brand razor with a thickness of 22820 microns. In forming the pre-crack, momentary sustained pressure may be needed to fatigue the bond. A flat razor having the aluminum tab removed is slowly inserted until the crack front can be observed to propagate such that the crack separation increases. The flat razor does not need to be inserted significantly to induce a crack. Once a crack is formed, the glass article is permitted to rest for at least 5 minutes to allow the crack to stabilize. Longer rest times may be needed for high humidity environments, for example, above 50% relative humidity.
[0067] The glass article with the developed crack is evaluated with a microscope to record the crack length. The crack length is measured from the end separation point of the first surface from the second surface (i.e. furthest separation point from the tip of razor) and the closest non-tapered portion of the razor. The crack length is recorded and used in the following equation to calculate adhesion energy.
=3.sub.t.sub.
wherein is the adhesion energy, t.sub.b is the thickness of the blade, razor or wedge, E.sub.1 is the Young's modulus of the sheet having the first surface (e.g., a glass carrier), t.sub.w1 is the thickness of the sheet having the first surface, E.sub.2 is the Young's modulus of the sheet having the second surface (e.g., a thin glass sheet), t.sub.w2 is the thickness of the sheet having the second surface and L is the crack length between the first surface and second surface upon insertion of the razor blade as described above. The Young's modulus of thin glass sheets as disclosed herein was measured by Resonant Ultrasound Spectroscopy.
[0068] The adhesion energy is understood to behave as in silicon wafer bonding, where an initially hydrogen bonded pair of wafers are heated to convert much or all the silanol-silanol hydrogen bonds to SiOSi covalent bonds. While the initial, room temperature, hydrogen bonding produces bond energies of the order of about 100-200 mJ/m.sup.2 which allows separation of the bonded surfaces, a fully covalently bonded wafer pair as achieved during processing at elevated temperatures (on the order of 400 to 800 C.) has adhesion energy of about 2000-3000 mJ/m.sup.2 which does not allow separation of the bonded surfaces; instead, the two wafers act as a monolith. On the other hand, if both the surfaces are perfectly coated with a low surface energy material, for example a fluoropolymer, with thickness large enough to shield the effect of the underlying substrate, the adhesion energy would be that of the coating material, and would be very low leading to low or no adhesion between the bonding surfaces. Accordingly, the sheet with the second surface would not be able to be processed on the sheet with the first surface. Consider two extreme cases: (a) two standard clean 1 (SC1, as known in the art) cleaned glass surfaces saturated with silanol groups bonded together at room temperature via hydrogen bonding (whereby the adhesion energy is about 100-200 mJ/m.sup.2) followed by heating to a temperature that converts the silanol groups to covalent Si-O-Si bonds (whereby the adhesion energy becomes 2000-3000 mJ/m.sup.2). This latter adhesion energy is too high for the pair of surfaces to be detachable; and (b) two surfaces perfectly coated with a fluoropolymer with low surface adhesion energy (about 12-20 mJ/m.sup.2 per surface) bonded at room temperature and heated at a desired processing temperature. In this latter case (b), not only do the surfaces not bond at low temperature (because the total adhesion energy of about 24-40 mJ/m.sup.2, when the surfaces are put together, is too low), they do not bond at high temperature either as there are too few polar reacting groups. Between these two extremes, a range of adhesion energies exist, for example between 50-1000 mJ/m.sup.2, which can produce the desired degree of temporary bonding. Accordingly, the inventors have found various methods of providing a modification layer leading to an adhesion energy that is between these two extremes, and such that there can be produced temporary bonding. As used herein temporary bonding or temporarily bonding means bonding sufficient to maintain a pair of surfaces (for example substrate bonding surface 24a and the upper primary surface of the carrier 10) bonded to one another through processing but also of a degree that (even after processing at desired temperature, for example a temperature of about 300 C., allows the detachment of the first surface from the second surface after processing is complete. Moreover, the detachment of the first surface from the second surface can be performed by mechanical forces, and in such a manner that there is no significant damage to at least the sheet having the second surface, and preferably also so that there is no significant damage to the sheet having the first surface.
[0069] Embodiments of the disclosure generally pertain to methods and apparatus for positioning and securing articles containing substrates and carriers for coating. The disclosure also pertains to methods and apparatus for coating cover glass substrates (e.g., Gen 4.5 through Gen 10 size display glass substrates, for example, about 730 mm920 mm through about 3000 mm3000 mm) with scratch-resistant coatings (e.g., a layer comprising a silane, alumina, silicon nitride, aluminum nitride, aluminum oxynitride) and other functional coatings. Further, these methods and apparatus for positioning and securing substrates for coating advantageously do so with high reliability, low manufacturing cost and high manufacturing flexibility.
[0070] Referring to
[0071] Turning again to the article for coating 100 depicted in
[0072] Accordingly, the carrier 10 is mechanically removable from the substrates 20 (or vice versa) such that the risk of breakage of the substrates 20 is eliminated or otherwise significantly reduced, upon completion of the processing steps to develop the coating 50 on the substrates 20. In certain embodiments, the carrier 10 is mechanically removable from the substrates 20 (or vice versa) such that the substrate bonding surface 24a has no more than trace amounts of the carrier surface modification layer 30 on it upon removal of the carrier 10. In certain implementations of the article for coating 100, for example, the adhesion energy that exists between the carrier surface modification layer 30 and the substrate bonding surface 24a can be 50 mJ/m.sup.2, 100 mJ/m.sup.2, 150 mJ/m.sup.2, 200 mJ/m.sup.2, 250 mJ/m.sup.2, 300 mJ/m.sup.2, 350 mJ/m.sup.2, 400 mJ/m.sup.2, 450 mJ/m.sup.2, 500 mJ/m.sup.2, 550 mJ/m.sup.2, 600 mJ/m.sup.2, 650 mJ/m.sup.2, 700 mJ/m.sup.2, 750 mJ/m.sup.2, 800 mJ/m.sup.2, 850 mJ/m.sup.2, 900 mJ/m.sup.2, 950 mJ/m.sup.2, 1000 mJ/m.sup.2, and all adhesion energy values between these levels.
[0073] In certain embodiments of the article for coating 100, the carrier 10 has a thickness 18 of at least 2 mm. While there is no upper limit to the thickness 18 based on the concepts of this disclosure, practical upper limits for the thickness 18 can be based on a desire to minimize the cost of the carrier 10, size limitations of the apparatus employed to coat the substrates 20 temporarily bonded to the carrier 10, an understanding that strength of glass materials can decrease as a function of increasing size, and other factors. In many implementations, the upper limit of the thickness 18 of the carrier 10 is approximately 51 mm (i.e., about 2 inches). Further the size of the carrier 10 can accommodate one or more substrates 20 of a Gen 1 size or larger, for example, Gen 2 through Gen 10 (e.g., sheet sizes from 100 mm100 mm to 3 m3 m or greater).
[0074] Referring again to
[0075] Referring again to the article for coating 100 depicted in
[0076] In certain embodiments, a higher lower bound for the adhesion energy (e.g., >150 mJ/m.sup.2) between the carrier surface modification layer 30 and the substrate bonding surface 24a may be desirable when the surface area of the carrier surface modification layer 30 is less than 100% (e.g., from about 60% to 100%) of the surface area of the substrate bonding surface 24a (see also
[0077] Referring again to
[0078] Referring again to
[0079] Still referring to
[0080] Referring again to the article for coating 100 depicted in
[0081] Still referring to the article for coating 100 depicted in
[0082] According to other embodiments of the article for coating 100, the carrier surface modification layer 30 can have a smaller surface area than the primary surface of the carrier 14 and/or carrier bonding surface 14a. In such a configuration, manufacturing costs can be saved by limiting the extent of the surface modification layer 30 on the carrier 10 to conform to the relative size of the substrate(s) 20 temporarily bonded to the carrier. That is, the processes used to develop the surface modification layer 30 can be tailored to selectively deposit the surface modification layer 30 in particular regions of the carrier 10 that correspond to the temporary bonding location(s) of the substrate(s) 20. Besides reducing the material costs associated with the layer 30, the selective deposition of the surface modification layer 30 in this configuration can advantageously reduce the risk of residual amounts of surface modification layer 30 being left on the carrier 10 and/or substrate(s) 20.
[0083] According to some embodiments of the article for coating 100, the substrate(s) 20 are fabricated from a glass composition and subjected to a strength-enhancing process, e.g., for a display glass application. In certain embodiments, the strengthening can be achieved by thermal treatment, for example thermal tempering. In some embodiments, the strengthening can be achieved by thermally treating a substrate having a core portion and a clad portion. In some embodiments of a strength-enhanced substrate 20, one or more compressive stress regions are developed within the substrate that extend from a primary surface or surfaces to a selected depth or depths. In other embodiments, these compressive stress regions are developed through an ion-exchange (IOX) process. In such substrates with compressive stress regions developed through an IOX process, the compressive stress region(s) can include a plurality of ion-exchangeable metal ions and a plurality of ion-exchanged metal ions, the ion-exchanged metal ions selected so as to produce compressive stress in the compressive stress region(s) within the substrate 20. In certain embodiments of the article for coating 100, compressive stress regions are developed with the substrates with a maximum compressive stress (typically at the primary surface(s)) that can range from 50 MPa to 2000 MPa.
[0084] As shown in
[0085] Referring now to
[0086] Advantageously, this configuration of the article for coating 100 depicted in
[0087] Referring now to
[0088] In other implementations of the article for coating 100 depicted in
[0089] According to other embodiments of the disclosure, a method of preparing an article for coating (e.g., an article of coating 100 shown in
[0090] With further regard to the method of preparing an article for coating, the step of treating a primary surface of the carrier (e.g., carrier 10) can include a cleaning process. Cleaning removes particles from the bonding surface of the carrier and allows for the development of a base-line surface energy for the carrier bonding surface. With a stable surface energy associated with the cleaned, carrier bonding surface (e.g., carrier bonding surface 14a), it is easier to control the adhesion energy between the substrate(s) and the carrier through the subsequent development of the carrier surface modification layer over the bonding surface. In some embodiments of the method, the treating step is conducted with a dilute hydrogen peroxide and base (e.g., an SC1 process) or a dilute hydrogen peroxide and deionized water solution at a temperature from ambient temperature to about 70 C. In the former approach, deionized water and hydrogen peroxide can be prepared at a ratio of 40:2, with the cleaning conducted with this solution at about 55 C. It should also be understood that the same steps employed in the method for treating the carrier can also be employed to treat the surfaces of the substrates to be coated and/or temporarily bonded to the carrier. Further, those with ordinary skill in the art will also understand that various permutations to the treating step can be made, including the use of deionized water alone, brushes, ultrasonic cleaning devices, and other devices for cleaning the surface of the carrier prior to development of a surface modification layer.
[0091] Referring again to the method of preparing an article for coating, the step of disposing the carrier surface modification layer (e.g., surface modification layer 30) can be conducted with various methods to produce a layer that results in an adhesion energy that ranges from about 50 mJ/m.sup.2 to about 1000 mJ/m.sup.2 between the carrier and the substrate(s). For example, a surface modification layer comprising a hydrocarbon-based material can be developed on the carrier using an inductively coupled plasma (ICP) process that employs a precursor gas comprising a mixture of C.sub.2H.sub.4-H.sub.2 and N.sub.2-O.sub.2 gases. As another example, a surface modification layer comprising a hydrocarbon-based material can be developed on the carrier using a reactive ion etching (RIE) process that employs a precursor gas comprising a mixture of CH.sub.4, H.sub.2N.sub.2 and O.sub.2 gases. In certain implementations of the method, the step of disposing the coating onto the substrate 20 is conducted at a temperature of less than 300 C. at a pressure from 10.sup.6 Torr (1.3210.sup.9 atm) to 760 Torr (1 atm). In the foregoing RIE and ICP approaches, the surface modification layer can be developed on the carrier at an ambient temperature. Further, in preferred implementations of the method, the surface modification layer is developed on the carrier and includes an adhesion energy that ranges from about 50 mJ/m.sup.2 to 1000 mJ/m.sup.2 between the carrier surface modification layer and the substrate(s) and remains stable while the article comprising the carrier and substrate(s) is subjected to additional process steps for coating the substrate(s) at temperatures up to 300 C.
[0092] Still referring to the method of preparing an article for coating, the step of bonding the carrier to at least one substrate (e.g., substrate 20 as shown in
[0093] The method of preparing an article for coating can also include a step of coating the substrate(s) with a functional coating (e.g., coating 50 as shown in
[0094] Referring again to the method of preparing an article for coating, the method can also include a step of de-bonding the carrier from the at least one substrate after the coating is disposed on the at least one substrate, the de-bonding conducted by mechanically separating the carrier surface modification layer from the substrate bonding surface without breakage to the carrier and the substrate. In certain embodiments, the de-bonding is conducted with a manual operation to physically remove or peel the carrier from the substrate(s) or vice versa. In other embodiments, mechanical fixtures can be employed to grip the carrier and a manual operation can be conducted to de-bond the substrate(s) from the carrier. In further embodiments, mechanical fixtures can be employed to grip both the carrier and the substrate(s), and these fixtures can be controlled to de-bond the carrier from the substrate(s) or vice versa. Preferably, the de-bonding (and prior steps of the method) is conducted such that the substrate bonding surface has no more than trace amounts of the carrier surface modification layer after the de-bonding. Accordingly, in certain embodiments the adhesion energy between the carrier surface modification layer and the carrier is higher than the adhesion energy between the carrier surface modification layer and the substrate bonding surface, all within the range of from 50 to 1000 mJ/m.sup.2. The step of treating the carrier in the method can be adjusted, in some implementations, for this purpose of achieving a desired adhesion energy.
[0095] Turning now to
[0096] Referring again to
[0097] Referring again to the fixture assembly 300 depicted in
[0098] Referring now to
[0099] It should be emphasized that the above-described embodiments of the present disclosure, including any embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of various principles of the disclosure. Many variations and modifications may be made to the above-described embodiments of the disclosure without departing substantially from the spirit and various principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.
[0100] The terms substantial, substantially, and variations thereof as used herein are intended to note that a described feature is equal or approximately equal to a value or description. For example, a substantially planar surface is intended to denote a surface that is planar or approximately planar.