U.S. patent application number 12/511167 was filed with the patent office on 2011-02-03 for glass substrate comprising an edge web portion.
Invention is credited to Sean M. Garner, Gary E. Merz.
Application Number | 20110023548 12/511167 |
Document ID | / |
Family ID | 43525708 |
Filed Date | 2011-02-03 |
United States Patent
Application |
20110023548 |
Kind Code |
A1 |
Garner; Sean M. ; et
al. |
February 3, 2011 |
GLASS SUBSTRATE COMPRISING AN EDGE WEB PORTION
Abstract
A glass ribbon coated with a flexible material, the flexible
coating forming a flexible web portion that extends from an edge of
the glass ribbon at least one millimeter. The flexible web portion
can be used to facilitate handling of the glass ribbon in a
manufacturing process, and may include registration markings, or
perforations, that further facilitate precise positioning of the
ribbon.
Inventors: |
Garner; Sean M.; (Elmira,
NY) ; Merz; Gary E.; (Rochester, NY) |
Correspondence
Address: |
CORNING INCORPORATED
SP-TI-3-1
CORNING
NY
14831
US
|
Family ID: |
43525708 |
Appl. No.: |
12/511167 |
Filed: |
July 29, 2009 |
Current U.S.
Class: |
65/106 ;
428/192 |
Current CPC
Class: |
Y10T 428/24777 20150115;
B32B 17/06 20130101; B32B 2405/00 20130101; B32B 3/08 20130101;
B32B 2307/546 20130101; B65H 20/20 20130101; B32B 7/12 20130101;
B32B 2255/10 20130101; B65H 18/28 20130101; B65H 18/145 20130101;
B32B 37/142 20130101; B32B 2250/02 20130101; B65H 20/06 20130101;
Y10T 156/10 20150115; B65H 20/02 20130101; B32B 2307/20 20130101;
B32B 2255/26 20130101; B65H 18/00 20130101; B32B 17/064 20130101;
B32B 2457/20 20130101 |
Class at
Publication: |
65/106 ;
428/192 |
International
Class: |
C03B 23/02 20060101
C03B023/02; B32B 3/02 20060101 B32B003/02 |
Claims
1. A glass substrate comprising: first and second major surfaces
and first and second edges, the first and second edges separated by
a width W; a flexible coating disposed over at least a portion of
the first and second major surfaces, the coating comprising web
portions extending from at least one of the first or second edge a
distance of at least 1 mm.
2. The glass substrate according to claim 1, wherein the glass
substrate is a glass ribbon.
3. The glass substrate according to claim 1, wherein the glass
substrate is a glass sheet.
4. The glass substrate according to claim 1, wherein the flexible
coating comprises a web portion extending from the first edge a
distance of at least 1 mm and a web portion extending from the
second edge a distance of at least 1 mm.
5. The glass substrate according to claim 1, wherein a thickness of
the glass substrate is equal to or less than 0.3 mm.
6. The glass substrate according to claim 1, wherein the flexible
coating coats the first and second major surfaces across the entire
width W of the glass substrate.
7. The glass substrate according to claim 1, wherein the web
portion extending from the at least one of the first or second edge
of the glass substrate comprises perforations.
8. The glass substrate according to claim 1, wherein a surface of
the flexible coating that coats at least a portion of the first
major surface of the glass substrate has a non-planar shape
complimentary to a non-planar shape of a surface of the flexible
coating that coats at least a portion of the second major
surface.
9. The glass substrate according to claim 1, wherein the flexible
coating is adhered to the first and second major surfaces with an
adhesive disposed between the coating and the glass substrate.
10. The glass substrate according to claim 1, wherein the flexible
coating comprises strengthening fibers.
11. The glass substrate according to claim 1, wherein the flexible
coating comprises registration markings.
12. The glass substrate according to claim 1, wherein one or both
of the first and second major surfaces include one or more layers
of a laminating or deposited material.
13. A glass ribbon comprising: first and second major surfaces and
first and second edges; a flexible polymer coating disposed over
the first and second major surfaces and extending beyond the first
and second edges a distance of at least 1 mm to form flexible web
portions.
14. The glass ribbon according to claim 13, wherein the flexible
web portions comprise perforations.
15. The glass ribbon according to claim 13, wherein the flexible
polymer coating comprises registration markings.
16. A method of conveying a glass ribbon comprising: dispensing a
length of a glass ribbon from a first spool, the glass ribbon
comprising a coating including a web portion extending from an edge
of the ribbon at least 1 mm; engaging the web portion with a roller
to convey the ribbon; and collecting the dispensed ribbon by
winding the dispensed ribbon onto a take-up spool.
17. The method according to claim 16, wherein the web portion
comprises perforations, and the roller comprises teeth that engage
with the perforations.
18. The method according to claim 16, wherein the coating comprises
registration indicia, and the method further comprising detecting
the indicia and positioning the ribbon in response to the detected
indicia.
19. The method according to claim 16, further comprising depositing
an electrically functional material on at least a portion of the
dispensed length prior to the collecting.
20. The method according to claim 19, further comprising removing
the web portion after the depositing.
Description
TECHNICAL FIELD
[0001] This invention is directed to a thin glass substrate
comprising a web portion extending beyond at least one of the edges
of the glass substrate to facilitate handling and/or conveying
and/or positioning the substrate.
BACKGROUND
[0002] Thin glass substrates can be used in a variety of
applications, including so-called "e-paper" and touch sensors. The
glass for such substrates can be quite thin, typically less than
about 0.3 mm. The processing of the substrates can be performed on
an individual glass sheet basis, or most efficiently by conveying
the substrate as a long glass ribbon wound on a roll. The method
includes dispensing the ribbon from one roll, processing the
dispensed portion, then winding the ribbon onto a take-up roll.
[0003] One drawback to a so-called "roll-to-roll" process is the
fragility of the thin glass ribbon--mechanical contact of the
ribbon during handling can lead to damage, including scratches,
chipping and in the worst case, fracture. What is needed is a glass
substrate, in either sheet or ribbon form, that can be safely
handled without damaging the glass.
SUMMARY
[0004] A glass substrate is described that includes a coating
material disposed thereon that extends from at least one edge of
the substrate as a web portion that facilitates handing and/or
conveying of the substrate without damage. The web portion of this
handling coating is preferably flexible, and can be used to hold
and/or convey and/or align the glass substrate for processing in a
manufacturing step without the need to directly contact interior
non-coated portions of the substrate. A method for holding,
conveying and/or aligning the glass ribbon is also described.
[0005] In one embodiment, a glass substrate is described comprising
first and second major surfaces and first and second edges, the
first and second edges separated by a width W. The first and second
edges are preferably substantially parallel with each other. The
glass substrate includes a flexible coating disposed over at least
a portion of the first and second major surfaces, and the coating
comprises web portions extending from at least one of the first or
second edge a distance of at least 1 mm.
[0006] The glass substrate may be in the form of a glass ribbon, or
an individual glass sheet and preferably has a thickness equal to
or less than 0.3 mm. The coating also comprises a web portion
extending from the first edge of the glass substrate a distance of
at least 1 mm and a web portion extending from the second edge a
distance of at least 1 mm. The flexible coating may coat only a
portion of either or both of the first and second major surfaces,
or the flexible coating may extend across the entire width W of the
glass substrate on either one or the other, or both of the major
surfaces of the substrate.
[0007] The web portion extending from the at least one of the first
or second edge of the glass substrate may comprise perforations for
engaging with a sprocket or other toothed member. The toothed
member may instead be a track that engages with the web
portion.
[0008] A surface of the flexible coating that coats at least a
portion of the first major surface of the glass substrate may
include a non-planar shape complimentary to a non-planar shape of a
surface of the flexible coating that coats at least a portion of
the second major surface. For example, an upper portion of the
coating on one side of a layer of glass may have a shape that is
complimentary to the lower portion of the coating on another,
adjacent layer of glass that aligns the glass layers, and
preferably prevents the glass of one layer from contacting the
glass of another adjacent layer.
[0009] The flexible coating may be adhered to the first and/or
second major surfaces with an adhesive disposed between the coating
and the glass substrate. The coating may further comprise
strengthening members, such as fibers.
[0010] The web and non-web portions of the coating may include
registration markings to aid in alignment or positioning of the
glass substrate. In some embodiments, one or both of the first and
second major surfaces of the glass substrate may include one or
more layers of a laminating or deposited material. For example, the
glass substrate may be coated with another material prior to the
application of the web coating material. The other material may be
a laminating material such as a barrier layer to prevent leaching
of the glass. Additionally, after the application of the web and
non-web portions of the handling coating, additional materials may
be formed on the substrate, such as, for example, electrically
functional materials that may comprise an electronic device (e.g. a
semiconductor device). As used herein, an electrically functional
device includes organic or inorganic semiconductor and/or conductor
materials.
[0011] In another embodiment, a glass ribbon is described
comprising first and second major surfaces and first and second
edges and a polymer coating disposed over the first and second
major surfaces and extending beyond the first and second edges a
distance of at least 1 mm to form flexible web portions. The
flexible web portions may comprise perforations that can be used to
engage with teeth in a roller (sprocket) or a track. The flexible
web portion(s) or non-web portions of the coating may comprise
registration markings such as lines or symbols for aligning the
glass ribbon.
[0012] In still another embodiment, a method of conveying a glass
ribbon is disclosed comprising dispensing a length of a glass
ribbon from a first spool, the glass ribbon comprising a coating
including a web portion extending from an edge of the ribbon at
least 1 mm, engaging the web portion with a feed apparatus to
convey the ribbon, the feed apparatus comprising a roller or track
for engaging with the web portion, and collecting the dispensed
ribbon by winding the dispensed ribbon onto a take-up spool. The
web portion may comprise perforations, for engaging with the feed
apparatus. For example, the feed apparatus may comprise sprockets,
wherein the teeth of the sprocket engage with the perforations to
transport the glass ribbon. However, the feed apparatus is not
limited to sprockets, but may further include rollers or tracks for
engaging with the web portion. In another example, pinch rollers
may be used to engage with the web and/or non-web portion of the
handling coating.
[0013] In some embodiments, the coating may include registration
indicia, and the method further comprises detecting the indicia and
positioning the ribbon in response to the detected indicia. The
detecting can be performed by any suitable machine vision system as
is known in the art for performing such tasks. If the glass ribbon
is to be used for the manufacturing of electronic devices, the
method may further comprise depositing an electrically functional
material on at least a portion of the dispensed length prior to the
collecting. For example, the glass ribbon is rolled off a first
spool, the desired components are deposited on ribbon, and then the
ribbon is collected by rolling the ribbon onto a second spool. The
web portions may be removed from the ribbon after the depositing,
leaving the interior portions of the ribbon undamaged.
[0014] The invention will be understood more easily and other
objects, characteristics, details and advantages thereof will
become more clearly apparent in the course of the following
explanatory description, which is given, without in any way
implying a limitation, with reference to the attached Figures. It
is intended that all such additional systems, methods, features and
advantages be included within this description, be within the scope
of the present invention, and be protected by the accompanying
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 a perspective view of a "roll-to-roll" process for
conveying a glass ribbon.
[0016] FIG. 2A-2B are cross sectional views of a glass substrate
(glass sheet or glass ribbon) comprising a coating that includes a
web portion along an edge of the substrate.
[0017] FIGS. 3A-3B are cross sectional views of a glass substrate
(glass sheet or glass ribbon) comprising a coatings that includes
web portions along two edges of the substrate.
[0018] FIG. 4 depicts a cross sectional view of a glass substrate
fully encapsulated by a coating that comprises two web portions
along two edges of the substrate.
[0019] FIG. 5 is a cross sectional view of a stack (or roll) of
glass sheets (or a rolled ribbon of glass) illustrating the
formation of a gap between the layers that prevents contact between
the glass layers.
[0020] FIG. 6 is a cross sectional view of a stack (or roll) of
glass sheets (or a rolled ribbon of glass) illustrating
complimentary features in the upper and lower surfaces of the
coating that facilitate mating and alignment of the layers.
[0021] FIG. 7 is a top view of a portion of a glass substrate
comprising a coating that includes web portions, wherein the web
portions comprise perforations and indicia markings.
[0022] FIG. 8 is a side view showing sprockets being used to convey
a glass substrate comprising a coating with web portions, wherein
teeth of the sprocket engage with perforations in the web
portions.
[0023] FIG. 9 is a cross sectional view of a glass substrate being
conveyed by pinch rollers that engage web portions of the
coating.
[0024] FIG. 10 is a side view of a glass ribbon being conveyed by
tractor assemblies that engage with the web portions of a coating
on the ribbon, including a payoff roll and a take up roll.
DETAILED DESCRIPTION
[0025] 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 the present invention. However, it will be apparent to one
having ordinary skill in the art, having had the benefit of the
present disclosure, that the present invention 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
the present invention. Finally, wherever applicable, like reference
numerals refer to like elements.
[0026] While glass is known as a brittle material, inflexible and
prone to scratching, chipping and fracture, in glass having a thin
cross section can in fact be quite flexible. One need only consider
the flexibility of hair-thin strands of optical fiber. Similarly,
in thin sheets or ribbons, glass can be wound and un-wound from
rolls, much like paper or plastic film. However, even though glass
can be made flexible, it retains its brittle characteristic, and
can be damaged by contact. For certain applications, particularly
those for which visual defects can be distracting (e.g. display
applications), even minor, seemingly cosmetic defects are
unacceptable. For other applications requiring high mechanical
strength, defects even less than 1 um can limit the mechanical
reliability of the glass article. Thus, handling of the sheets in a
manufacturing process, for example the depositing of thin film
devices on the sheet, can become a source of loss and high
cost.
[0027] Although glass can be processed on an individual sheet
basis, a method contemplated herein, a more efficient method
involves starting with a thin ribbon of glass wound on a roll as
illustrated in FIG. 1. As glass ribbon 10 is un-wound from the roll
12, the un-wound or dispensed portion 14 can be processed, and then
re-wound on a second "take-up" roll 16. In this context, the term
"processed" can include any step subsequent to the formation of the
glass, including but not limited to grinding, polishing, cleaning,
or the deposition of additional layers and/or components (e.g.
electrical/electronic components or portions thereof) on the glass.
However, in some instances, the transport of the glass ribbon
through the processing equipment can require precise positioning of
the ribbon. For example, the formation of thin film devices (e.g.
transistors, electroluminescent layers, etc.) on the glass
substrate may require the ribbon to position, or index, between
multiple stations or equipment placement, and require exacting
registration from position to position. Performing this form of
conveyance on a ribbon of glass less than 0.3 mm or less than 0.1
mm or less than 0.05 mm in thickness is difficult enough. Once the
devices are formed, there is the problem of stacking or re-winding
the ribbon for later use, perhaps in a subsequent manufacturing
process, without damage to glass ribbon or the devices formed on
one or both surfaces of the ribbon.
[0028] FIG. 2A illustrates an edge view of an embodiment of the
present invention comprising glass substrate 10 (e.g. glass sheet
or glass ribbon 10) shown extending into the figure) including a
first major surface 18 and a second opposing major surface 20. The
glass substrate is further bounded by first edge 22a and second
edge 22b. Also shown is coating 24 that includes a section 24a that
coats at least a portion of first major surface 18 and also a web
portion 24b that extends from first edge 22a a minimum of at least
1 mm, preferably at least 2 mm, and more preferably at least 3 mm.
In some embodiments the web portion or portions may extend up to 1
cm or more from the edge of the glass substrate. Web portion 24b
thus provides a handling surface that can be contacted by handing
equipment, such as rollers, without the need to physically contact
the glass itself, and may further be used as an alignment aid
should alignment with processing equipment be desired. Thus, in one
embodiment, a glass substrate includes a coating or film that
extends from an edge of the ribbon, and the extended portion of the
coating or film can be used to support or convey the glass
substrate without contact or damage to the substrate. For example,
the extended portion of the coating can be gripped by rollers,
engaged with sprockets, clamped or any other method of securing the
extended portion of the coating. The glass substrate edges 22a and
22b need not be planar features as shown in FIG. 2A but may have
out-of-plane features such as rounded edge bead features. Likewise,
the coating web portion 24b could also possess non-planar
features.
[0029] In another embodiment, depicted in FIG. 2B, a portion of
both major surfaces 18 and 20 of the glass substrate are coated
with coating 24. Conveying the glass substrate may include gripping
the extended portion of the coating 24b as well as the coating
portion 24a above the glass substrate.
[0030] In still another embodiment illustrated in FIG. 3A, glass
coating 24 may be applied to glass ribbon 10 so that a portion
(24a) of coating 24 is applied to at least one major surface of
glass ribbon 10 (e.g. surface 18), and another portion (24b) of
coating 24 extends from edges 22a, 22b, respectively, by at least 1
mm. Alternatively, as shown in FIG. 3B, coating 24 may be applied
to at least a portion of both major surfaces of ribbon 10 and the
two web portions 24b extend from each of the first and second edges
by at least 1 mm.
[0031] In some embodiments, it may be desirable that the coating
material extend completely over the entirety of a least one (first
or second) major surface. In this way, surfaces of adjacent glass
layers are prevented from having direct contact with each other,
and at least one extended portion (web) can be used to position or
convey the glass as previously described. Thus, the glass may be
encapsulated by a coating that extends from one or both edges, and
which coating may cover one or both major sides of the glass. As
depicted in FIG. 4, glass substrate 10 encapsulated by coating
material 24 that covers both major surfaces 18, 20 with a first
coating portion 24a. In this embodiment, the glass substrate is
flanked by two extended coating web portions 24b that may be
handled in a manner similar to the preceding embodiments.
[0032] As shown in FIG. 5, the thickness of the coatings can be
selected to form a gap 26 between successive layers to prevent one
layer of glass substrate to overlie another layer of glass
substrate without allowing any one layer of glass to physically
contact another layer of glass. In sheet form, thin glass panels
may then be stacked one on top of another, and the thickness of the
coating at the edges of the glass creates a gap between the glass
panels so that the glass from one panel does not contact the glass
of an adjacent panel. In ribbon form, the glass ribbon can be wound
with similar effect--the glass from one layer of the wind can be
prevented from contact the glass of a preceding layer of the wind.
The winding may impart a bend radius of less than about 10 cm on
the glass ribbon.
[0033] Where a ribbon is to be wound onto a spool or other take-up
device, or one sheet is to be stacked onto another sheet, surfaces
of the coating can be molded to include physically complementary
features, as depicted in FIG. 6. Not only can these complimentary
features function to prevent contact between layers of glass,
either in sheet or ribbon form, but these complimentary features
can be used to align one layer of the ribbon over a previous layer
during stacking or winding. Such complimentary features would
typically comprise protrusions and complimentary indentations
configured to receive the protrusions. For example, a protrusion 28
on the exposed surface on the upper surface of the substrate and a
complimentary indentation 30 on the exposed surface of coating
applied to a lower surface of the ribbon allow the substrate to be
stacked or wound such that the complimentary features engage and
help align the substrate during the stacking or winding
process.
[0034] To facilitate positioning of the substrate, a web portion
may include perforations 32 that allow engagement with a sprocket
wheel, as shown in FIGS. 7 and 8. FIG. 8 illustrates the teeth of
sprocket wheels 36 engaged with web portions 24b. A web portion may
also include registration indicia 34, such as printed or machined
markings (lines, circles or the like) that indicate specific
locations along the ribbon and preferably are readable by machine
vision systems. Furthermore, the perforations themselves may be
utilized as indicia. However, the use of indicia need not be
limited to a web portion, and may be placed on any portion of the
coating to indicate position not only in a length-wise fashion, but
across the width of the ribbon if so desired. That is, an indicia
line can run transverse or parallel with the ribbon. It should be
noted that the use of perforations and indicia is not limited to
the use of glass ribbons, but may be employed as well with
individual glass sheets or panels.
[0035] FIGS. 9 and 10 illustrate several alternative conveyance
methods. For example, FIG. 9 shows the substrate being conveyed by
pinch rollers 38, 40 wherein upper rollers 38 and lower rollers 40
pinch web portions 24b between the two roller sets.
[0036] FIG. 10 shows a side view of two tractor assemblies 42 that
comprise belts 44 that pinch the web portions of the substrate
between the belts. FIG. 10 depicts glass ribbon 10 that is
undergoing winding from first roll 12 to a second roll 16.
[0037] The coating can be applied as a liquid to the glass (ribbon
or sheet) or as a pre-formed film. Suitable pre-formed films can be
polymers, for example, silicone or polyimide. The choice of
material can be selected to be compatible with the contemplated
processing. Kapton.RTM. tape with an acrylic adhesive with a total
thickness preferably in the range between about 50 .mu.m and 100
.mu.m (e.g. 63.5 microns), for example, has been shown to be a
suitable pre-formed tape that can be applied to glass in a manner
as described above, and that allows vacuum processing of the ribbon
at temperatures as high as 300.degree. C. In some instances a metal
coating may also be used, either separately or in combination with
a polymer. For example, the coating may be a laminated coating.
Pre-formed films or coatings may be applied with an adhesive, such
as an acrylic adhesive.
[0038] To provide increased strength, the web portions may include
strengthening members. For example, a preformed tape may include
glass or polymer fibers (e.g. Kevlar.RTM. fibers to provide
additional strength to the coating material.
[0039] The glass substrate may be laminated or coated with a
laminating or deposited material prior to the application of the
web and non-web portions of the handling coating. For example, a
barrier or other protective layer may be applied to the substrate
prior to the application of the handling or conveyance coating 24.
The laminating or coated material may be an organic material or an
inorganic material, as needed.
[0040] Once the handling coating has been applied, additional
materials may be formed on the substrate, such as electrically
functional materials. For example, the substrate may be in the form
of a glass ribbon comprising handing coating 24 wound on a first
spool (see FIG. 1). The glass ribbon is unwound from the first
spool and conveyed in a manner as described above (see FIGS. 7-10
for example). The ribbon is then collected and wound onto a second
spool. The dispensed portion of the ribbon between the first and
second spools may be further processed, such as by the deposition
of one or more electrically functional materials onto the ribbon.
Such deposition may be accomplished by conventional methods (e.g. a
photolithography method). For example, FIG. 9 shows ribbon 10
having electrically functional material 46 deposited thereon.
[0041] It should be emphasized that the above-described embodiments
of the present invention, particularly any "preferred" embodiments,
are merely possible examples of implementations, merely set forth
for a clear understanding of the principles of the invention. Many
variations and modifications may be made to the above-described
embodiments of the invention without departing substantially from
the spirit and principles of the invention. All such modifications
and variations are intended to be included herein within the scope
of this disclosure and the present invention and protected by the
following claims.
* * * * *