The present disclosure relates to glass articles with protective films and methods of forming glass articles with protective films, and in particular glass articles with protective films used for processing hard disk drive substrates and methods of forming glass articles with protective films used for processing hard disk drive substrates.
Ready to sputter (RTS) substrates that can be coated with magnetic films to form magnetic recording media (such as hard disk drives) may be formed from processed glass blanks. The glass blanks may undergo processing steps such as packing, shipping, edge grinding, edge chamfering, and edge polishing. During the processing steps listed above, the glass surface may come into contact with other surfaces that can cause damage (e.g. scratches, digs, chips). To address defects in the glass blank produced during the glass blank formation process, the surfaces of the glass blank are polished resulting in material removal from the glass blank. If the depth (including subsurface damage) of such damage exceeds the material removal during the surface polishing the RTS substrate produced may suffer from low strength or defectivity that exceeds the specification for proceeding to the magnetic thin film coating process step.
Accordingly, the inventors have developed improved glass articles with protective films used for forming ready to sputter substrates and methods of forming glass articles with protective films used for forming ready to sputter substrates.
SUMMARY
Additional features and advantages are set forth in the Detailed Description that follows, and in part will be readily apparent to those skilled in the art from the description or recognized by practicing the embodiments as described in the written description and claims hereof, as well as the appended drawings. It is to be understood that both the foregoing general description and the following Detailed Description are merely exemplary, and are intended to provide an overview or framework to understand the nature and character of the claims.
A first embodiment of the present disclosure includes a glass sheet, comprising a first surface, a second surface opposing the first surface, and an edge surface connecting the first surface and the second surface; a first coating forming a plurality of first coated regions disposed atop the first surface, each first coated region separated from an adjacent first coated region by an uncoated region; a second coating forming a plurality of second coated regions disposed atop the second surface, each second coated region separated from an adjacent second coated region by an uncoated region, wherein each of the second coated regions is positioned on the second surface opposite a corresponding first coated region on the first surface.
A second embodiment of the present disclosure may include the first embodiment, wherein the first coating has a thickness of about 10 nm to about 1 mm.
A third embodiment of the present disclosure may include the first and second embodiment, wherein the second coating has a thickness of about 10 nm to about 1 mm.
A fourth embodiment of the present disclosure may include the first to third embodiment, wherein each first coated region comprises an inner radius and an outer radius, wherein the inner radius defines an inner uncoated region.
A fifth embodiment of the present disclosure may include the fourth embodiment, wherein the inner radius of the first coated region is about 15 mm to about 30 mm.
A sixth embodiment of the present disclosure may include the fourth embodiment, wherein the outer radius of the first coated region is about 50 mm to about 100 mm.
A seventh embodiment of the present disclosure may include the first to sixth embodiment, wherein each second coated region comprises an inner radius and an outer radius, wherein the inner radius defines an inner uncoated region.
A eighth embodiment of the present disclosure may include the seventh embodiment, wherein the inner radius of the second coated region is about 15 mm to about 30 mm.
A ninth embodiment of the present disclosure may include the eighth embodiment, wherein the outer radius of the second coated region is about 50 mm to about 100 mm.
A tenth embodiment of the present disclosure includes a glass blank, comprising: a first surface, a second surface opposing the first surface, and an edge surface connecting the first surface and the second surface; wherein the first surface comprises a first coated portion and a first uncoated portion surrounding the first coated portion, wherein the first uncoated portion extends a first distance radially inward from the edge toward a center of the first surface, wherein the second surface comprises a second coated portion and a second uncoated portion surrounding the second coated portion, wherein the second uncoated portion extends a second distance radially inward from the edge toward a center of the second surface.
A eleventh embodiment of the present disclosure may include the tenth embodiment, wherein the first distance is about 100 microns to about 300 microns.
A twelfth embodiment of the present disclosure may include the tenth to eleventh embodiment, wherein second distance is about is about 100 microns to about 300 microns.
A thirteenth embodiment of the present disclosure may include the tenth to twelfth embodiment, wherein a portion of the uncoated portion comprises a chamfered surface.
A fourteenth embodiment of the present disclosure may include the tenth to thirteenth embodiment, wherein a portion of the uncoated portion comprises a polished surface.
A fifteenth embodiment of the present disclosure may include the tenth to fourteenth embodiment, wherein the first coated portion comprises an inner radius and an outer radius, wherein the inner radius defines an inner uncoated region.
A sixteenth embodiment of the present disclosure may include the fifteenth embodiment, wherein the inner radius of the first coated region is about 15 mm to about 30 mm.
A seventeenth embodiment of the present disclosure may include the fifteenth embodiment, wherein the outer radius of the first coated region is about 50 mm to about 100 mm.
A eighteenth embodiment of the present disclosure may include the tenth to seventeenth embodiment, wherein the second coated portion comprises an inner radius and an outer radius, wherein the inner radius defines an inner uncoated region.
A nineteenth embodiment of the present disclosure may include the eighteenth embodiment, wherein the inner radius of the first coated region is about 15 mm to about 30 mm.
A twentieth embodiment of the present disclosure may include the eighteenth embodiment, wherein the outer radius of the first coated region is about 50 mm to about 100 mm.
A twenty-first embodiment of the present disclosure includes a method of producing a glass blank, comprising: cutting a glass sheet via a pulsed laser beam focused into a quasi-non-diffracting beam, wherein the glass sheet comprises a first surface, a second surface opposing the first surface, an edge surface connecting the first surface and the second surface, a first coating disposed on the first surface of the glass sheet, and a second coating disposed on the second surface of the glass sheet, wherein the laser beam is directed into a stack comprising the first coating, the glass sheet, and the second coating, wherein the quasi-non-diffracting beam enters the stack and generates an induced absorption within the stack, wherein the induced absorption produces a damage track defining the glass blank within the first coating at the first surface, the glass sheet, and the second coating at the second surface, wherein the first coating and the second coating is transparent to at least one wavelength of the pulsed laser beam; removing a portion of the first coating from the glass sheet; removing a portion of the second coating from the glass sheet; and separating the coated portion of the glass sheet to form the glass blank from the uncoated portion of the glass sheet.
A twenty-second embodiment of the present disclosure includes a method of producing a glass blank, comprising: directing a pulsed laser beam, focused into a quasi-non-diffracting beam, into a glass sheet, wherein the glass sheet comprises a first surface, a second surface opposing the first surface, an edge surface connecting the first surface and the second surface, a first coating disposed on the first surface of the glass sheet, and a second coating disposed on the second surface of the glass sheet, wherein the quasi-non-diffracting beam generates an induced absorption to produce a first damage track within the first coating; removing a portion of the first coating defined by the first damage track from the first surface; directing the pulsed laser beam, focused into the quasi-non-diffracting beam, into the second coating, wherein the quasi-non-diffracting beam generates an induced absorption to produce a second damage track within the second coating at the second surface; removing a portion of the second coating defined by the second damage track from the second surface; directing the pulsed laser beam, focused into the quasi-non-diffracting beam, into the portion of the glass sheet without the first coating and the second coating, wherein the quasi-non-diffracting beam generates an induced absorption within the glass sheet to produce a third damage track within the glass sheet; and separating the glass blank from the glass sheet.
A twenty-third embodiment of the present disclosure includes a method of producing a glass article, comprising: directing a pulsed laser beam, focused into a quasi-non-diffracting beam, into a glass sheet, wherein the glass sheet comprises a first surface, a second surface opposing the first surface, an edge surface connecting the first surface and the second surface, a first coating disposed on the first surface of the glass sheet, and a second coating disposed on the second surface of the glass sheet , wherein the quasi-non-diffracting beam generates an induced absorption to produce a first damage track within the first coating at the first surface; removing a portion of the first coating defined by the first damage track from the first surface; directing the pulsed laser beam, focused into the quasi-non-diffracting beam, into the portion of the glass sheet without the first coating, wherein the quasi-non-diffracting beam generates an induced absorption within the glass sheet to produce a second damage track within the glass sheet; directing the pulsed laser beam, focused into the quasi-non-diffracting beam, into the second coating, wherein the quasi-non-diffracting beam generates an induced absorption to produce a third damage track within the second coating at the second surface; removing a portion of the second coating defined by the second damage track from the second surface; and separating the glass blank from the glass sheet.
A twenty-fourth embodiment of the present disclosure includes a method of producing a glass article, comprising: directing a pulsed laser beam, focused into a quasi-non-diffracting beam, into a glass sheet, wherein the glass sheet comprises a first surface, a second surface opposing the first surface, an edge surface connecting the first surface and the second surface, a first coating disposed on the first surface of the glass sheet, and a second coating disposed on the second surface of the glass sheet, wherein the quasi-non-diffracting beam generates an induced absorption to produce a first damage track within the first coating at the first surface; removing a portion of the first coating defined by the first damage track from the first surface; directing a pulsed laser beam focused into a quasi-non-diffracting beam into glass sheet, wherein the quasi-non-diffracting beam generates an induced absorption to produce a second damage track within the glass sheet and the second coating; removing a portion of the second coating defined by the second damage track from the second surface; and separating the glass blank from the glass sheet.
A twenty-fourth embodiment of the present disclosure includes a method of cutting a glass article, comprising: directing a laser beam into a first surface of a glass sheet to produce a damage track within the glass sheet, wherein the first surface is a flat surface and wherein the glass sheet further comprises: a second surface opposing the first surface, wherein the second surface is a structured surface, a protective coating disposed on the second surface, the protective coating having a refractive index greater than or equal to a refractive index of the glass sheet; guiding the laser beam over the glass sheet to define the glass article; and separating the glass article from the glass sheet.
The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the Detailed Description serve to explain principles and operation of the various embodiments. As such, the disclosure will become more fully understood from the following Detailed Description, taken in conjunction with the accompanying Figures, in which:
Reference is now made in detail to various embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Whenever possible, the same or like reference numbers and symbols are used throughout the drawings to refer to the same or like parts. The drawings are not necessarily to scale, and one skilled in the art will recognize where the drawings have been simplified to illustrate the key aspects of the disclosure.
The claims as set forth below are incorporated into and constitute part of this detailed description.
In this document, relational terms, such as first and second, top and bottom, and the like, are used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions.
It will be understood by one having ordinary skill in the art that construction of the described disclosure, and other components, is not limited to any specific material. Other exemplary embodiments of the disclosure disclosed herein may be formed from a wide variety of materials, unless described otherwise herein.
The glass sheet 100 includes a first coating 108 and a second coating 110. The first coating 108 forms a plurality of first coated regions 112 atop the first surface 102 of the glass sheet 100. The second coating 110 forms a plurality of second coated regions 114 disposed atop the second surface 104. In some embodiments, the first coated region 112 covers the entirety of the first surface 102 and the second coated region 114 covers the entirety of the second surface 104.
In some embodiments, as shown in
In some embodiments, the first coating 108 may have a coating thickness of less than about 1 mm. In some embodiments, the first coating 108 may have a coating thickness of about 10 nm to about 1 mm, or in some embodiments about 10 nm to about 0.5 mm, or in some embodiments about 10 nm to about 0.1 mm, or in some embodiments about 10 nm to about 0.01 mm, or in some embodiments about 10 nm to about 0.001 mm, or in some embodiments about 10 nm to about 0.0001 mm.
In some embodiments, the second coating 110 may have a coating thickness of less than about 1 mm. In some embodiments, the second coating 110 may have a coating thickness of about 10 nm to about 1 mm, or in some embodiments about 10 nm to about 0.5 mm, or in some embodiments about 10 nm to about 0.1 mm, or in some embodiments about 10 nm to about 0.01 mm, or in some embodiments about 10 nm to about 0.001 mm, or in some embodiments about 10 nm to about 0.0001 mm. In some embodiments, the first coating 108 and the second coating 110 may have the same coating thickness. In some embodiments, the first coating 108 and the second coating 110 may have different coating thicknesses.
In some embodiments, the first coating and the second coating may be a polyethylene plastic sheeting (e.g., Visqueen). In some embodiments, the first coating and the second coating may be a dry photoresist material (e.g. DuPont MX500). In some embodiments, the coating may be applied to the surface of the glass sheet by a screen printing. An exemplary screen printing process and apparatus is described in U.S. Patent Publication 20170217151 published Aug. 3, 2017 to Cutcher et. al. The embodiments of the present disclosure are not limited to coatings deposited via a screen printing process, as embodiments described herein are equally applicable to other deposition processes such as, but not limited to, spray coating, dip coating, fog coating, chemical vapor deposition, and other deposition processes known to those skilled in the art.
In some embodiments, a portion of the exemplary glass sheet, as described above with respect to any of
The glass blank 200 includes a first coating 208 and a second coating 210. The first coating 208 forms a first coated region 212 atop the first surface 202 of the glass blank 200. The second coating 210 forms a second coated region 214 disposed atop the second surface 204. The second coated region 214 is positioned on the second surface 204 opposite the first coated region 212 on the first surface 202. A first uncoated portion 216 surrounds the first coated region 212 and extends a first distance 218 radially inward from the edge 206 toward a center 220 of the first surface 202. A second uncoated portion 222 surrounds the second coated region 214 and extends a second distance 224 radially inward from the edge 206 toward a center 220 of the second surface 204.
In some embodiments, the first distance 218 is about 100 microns to about 300 microns, or in some embodiments about 125 microns to about 300 microns, or in some embodiments about 150 microns to about 300 microns, or in some embodiments about 175 microns to about 300 microns, or in some embodiments about 200 microns to about 300 microns, or in some embodiments about 225 microns to about 300 microns, or in some embodiments about 250 microns to about 300 microns.
In some embodiments, the second distance 222 is about 100 microns to about 300 microns, or in some embodiments about 125 microns to about 300 microns, or in some embodiments about 150 microns to about 300 microns, or in some embodiments about 175 microns to about 300 microns, or in some embodiments about 200 microns to about 300 microns, or in some embodiments about 225 microns to about 300 microns, or in some embodiments about 250 microns to about 300 microns.
In some embodiments, a portion of the first uncoated region 216 comprises a processed surface. In some embodiments, a portion of the second uncoated region 222 comprises a processed surface. For example, the processed surface can be a chamfered surface or a polished surface. In some embodiments, the uncoated regions 216, 222 may have a chamfer that begins at the edge and extends about 50 microns radially inwards toward the center of the surface, or in some embodiments about 100 microns, or in some embodiments, about 150 microns, or in some embodiments about 200 microns.
In some embodiments, the glass blank 200 comprises an central opening 232. As shown in
In some embodiments, the distance 218, 224 is about 0 mm to about 5 mm. In some embodiments, as depicted in
The glass blank 200 may be subjected to further processing, including packing, shipping, edge grinding, edge chamfering, and edge polishing, to convert the glass blank into a ready to sputter (RTS) glass substrate suitable for coating with magnetic films for use in magnetic recording media (e.g. hard disk drives). During the processing steps listed above, the glass surface may come into contact with other surfaces that can cause damage (e.g. scratches, digs, chips). To address defects in the glass blank produced during the glass blank formation process, the surfaces of the glass blank are polished resulting in material removal from the glass blank. If the depth (including subsurface damage) of such damage exceeds the material removal during the surface polishing the RTS substrate produced may suffer from low strength or defectivity that exceeds the specification for proceeding to the magnetic thin film coating process step. Embodiments of the glass blanks disclosed herein may advantageously be processed with less surface damage compared to glass blanks produced without a surface coating. Minimizing the surface damage to the glass blank during the processes listed above enables reduced surface removal during subsequent surface polishing steps, thereby reducing costs and improving surface quality.
At 302, a pulsed laser beam is focused into a quasi-non-diffracting beam and directed into a stack comprising the first coating 108, the glass sheet 100, and the second coating 110. The quasi-non-diffracting beam enters the stack and generates an induced absorption within the stack producing a damage track 124 defining the glass blank within the first coating, the glass sheet, and the second coating. The first coating 108 and the second coating 110 are transparent to at least one wavelength of the pulsed laser beam. For example, in some embodiments, the first coating 108 and the second coating 110 are transparent to a wavelength of 1064 nm. Alternatively, in some embodiments, the first coating 108 and the second coating 110 are transparent to a wavelength of 532 nm. The damage track 124 may define a glass blank having a circular shape. The embodiments of the present disclosure are not limited to glass blanks having a circular shape, as embodiments described herein are equally applicable to other shapes such as, but not limited to, oval, rectangular, square, or irregular (free form) shapes. Next, at 304 and as depicted in
In some embodiments, the coatings 108, 110 can be removed from the glass sheet via a chemical etching process. In some embodiments, the glass blank 200 can be mechanically separated from the glass sheet 100.
At 402, a pulsed laser beam is focused into a quasi-non-diffracting beam and directed into the first coating 108. The quasi-non-diffracting beam generates an induced absorption to produce a first damage track 124 within the first coating 108. The embodiments of the present disclosure are not limited to quasi-non-diffracting beam to produce a damage track within the coating, other laser beams such as a gaussian beam may be used. At 404, the scrap coating portion of the first coating 108 is removed from the first surface 102. At 406, and as depicted in
At 502, a pulsed laser beam is focused into a quasi-non-diffracting beam and directed into the first coating 108. The quasi-non-diffracting beam generates an induced absorption to produce a first damage track 124 within the first coating 108. At 504, the scrap coating portion of the first coating 108 is removed from the first surface 102.
At 506, and as depicted in
At 508, and as depicted in
At 602, a pulsed laser beam is focused into a quasi-non-diffracting beam and directed into the first coating 108. The quasi-non-diffracting beam generates an induced absorption to produce a first damage track 124 within the first coating 108. At 604, the scrap coating portion of the first coating 108 is removed from the first surface 102.
At 606, and as depicted in
At 704, the laser beam is guided over the glass sheet to define the glass article. In some embodiments, the laser beam is held stationary and the glass sheet is rotated to define the glass article. At 706, the glass article is separated from the glass sheet. In some embodiments, the glass article can be mechanically separated from the glass sheet. In some embodiments, the glass sheet can be subjected to a further laser process (e.g. using a CO2 laser) to crack and separate the glass article from the glass sheet.
It will be apparent to those skilled in the art that various modifications to the preferred embodiments of the disclosure as described herein can be made without departing from the spirit or scope of the disclosure as defined in the appended claims. Thus, the disclosure covers the modifications and variations provided they come within the scope of the appended claims and the equivalents thereto.
This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Ser. No. 63/071,117 filed on Aug. 27, 2020, the content of which is relied upon and incorporated herein by reference in its entirety.
Number | Date | Country | |
---|---|---|---|
63071117 | Aug 2020 | US |