Method of manufacturing a window

Abstract

A method of manufacturing a window is provided. The method of manufacturing a window includes: irradiating a laser to a glass; immersing the glass irradiated by the laser into a KOH solution to form a groove in the glass irradiated by the laser and performing a primary strengthening on the glass irradiated by the laser; masking the groove of the glass which is primarily strengthened; and performing a secondary strengthening on the masked glass.

Description

[0001] This application claims priority to Korean Patent Application No. 10-2020-0177407 filed on December 17, 2020, as well as all derivative applications thereof, the contents of which are incorporated by reference in their entirety. TECHNICAL FIELD

[0002] The present application relates to a window manufacturing method, and more particularly, to a window manufacturing method for a cover window of a foldable display device. BACKGROUND

[0003] With recent developments in display-related technology, research and development are being conducted on display devices that are convertible during use, such as folding, rolling into a reel shape, or stretching. Since such a display is convertible into various forms, both the demand for a large-sized display in the use stage and the demand for a reduced-sized display for portability can be satisfied.

[0004] When a display device is folded, a large amount of stress is concentrated in the folding portion, and constituent elements of the display device in the folding portion can be lifted or damaged. In particular, in a foldable display device, at the folding portion, some regions can receive tensile stress, and some regions can receive compressive stress. Such stress imbalance of the display device can damage a cover window positioned in front of the display device. SUMMARY

[0005] Embodiments relate to a window manufacturing method for uniform chemical strengthening and stress distribution of a window having different thicknesses for each region.

[0006] Embodiments of a window manufacturing method according to the present application include: irradiating a laser to a glass; immersing the laser-irradiated glass in a KOH solution to form grooves in the laser-irradiated glass and performing a primary strengthening on the laser-irradiated glass; masking the grooves of the primary-strengthened glass; and performing a secondary strengthening on the masked glass.

[0007] In embodiments, in immersing the laser-irradiated glass in the KOH solution, the temperature of the KOH can be in a range of about 50°C to about 300°C.

[0008] In embodiments, in immersing the laser-irradiated glass in the KOH solution, the immersion time can be in a range of about 30 minutes to about 72 hours.

[0009] In embodiments, the grooves can be positioned along a predetermined direction of the primary-strengthened glass and can not penetrate the primary-strengthened glass.

[0010] In one embodiment, after the glass to be irradiated by the laser is immersed in a KOH solution, the thickness of the initially reinforced region of the initially reinforced glass can be in the range of about 1 nanometer (nm) to about 20 micrometer (μm).

[0011] In one implementation, the groove for masking the initially reinforced glass may include filling the entire interior of the groove with a masking pattern.

[0012] In one implementation, performing secondary reinforcement on the masked glass may include using KNO3.

[0013] In one implementation, the thickness of the area of ​​the window that has undergone secondary enhancement may be greater than the thickness of the area of ​​the window that has undergone primary enhancement.

[0014] In an implementation, a window may include a primary enhancement area, a secondary enhancement area, and a non-enhanced area.

[0015] In one embodiment, the window may be a cover window for the foldable display device, and the recess of the window may correspond to the area where the foldable display device is folded.

[0016] An embodiment of the window manufacturing method according to the present invention includes: irradiating glass with a laser; etching the glass irradiated by the laser to form grooves; immersing the glass including the grooves in a KOH solution to perform a primary strengthening of the glass including the grooves; masking the grooves of the primary strengthened glass; and performing a secondary strengthening of the masked glass.

[0017] In one embodiment, etching the laser-irradiated glass to form a groove may include using HF.

[0018] In one embodiment, the glass including the groove is immersed in a KOH solution, and the temperature of the KOH can be in the range of about 50°C to about 300°C.

[0019] In one embodiment, the glass including the groove is immersed in a KOH solution for a time ranging from about 30 minutes to about 72 hours.

[0020] In one embodiment, after immersing the glass including the groove into a KOH solution, the thickness of the initially reinforced region of the initially reinforced glass can be in the range of about 1 nm to about 20 μm.

[0021] In one embodiment, the groove may be positioned along a predetermined direction of the glass including the groove and may not penetrate the glass including the groove.

[0022] In one implementation, performing secondary enhancement may include using KNO3.

[0023] In this implementation, the thickness of the area of ​​the window that has undergone secondary enhancement may be greater than the thickness of the area of ​​the window that has undergone primary enhancement.

[0024] In an embodiment, the window can include a primary enhancement region, a secondary enhancement region, and a non-enhancement region.

[0025] In an embodiment, the window can be a cover window of a foldable display device, and the groove of the window can correspond to a region in which the foldable display device can be folded.

[0026] According to an embodiment of the present application, there is provided a manufacturing method of a window for uniform chemical enhancement and uniform stress distribution in a window having regions with different thicknesses from each other. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 FIG. 1 is a process flow diagram illustrating a manufacturing process of a window according to an embodiment.

[0028] Figure 2 FIG. 2 is a view illustrating a window on which laser is irradiated.

[0029] Figure 3 FIG. 3 is a view illustrating a window on which etching and a primary enhancement process are performed.

[0030] Figure 4 FIG. 4 is a view schematically illustrating a principle that a window is enhanced by KOH.

[0031] Figure 5 FIG. 5 is a view illustrating a window that is masked.

[0032] Figure 6 FIG. 6 is a view illustrating a window on which secondary enhancement occurs.

[0033] Figure 7 FIG. 7 is a process flow diagram illustrating a manufacturing process according to an embodiment.

[0034] Figure 8 FIG. 8 is a view illustrating a window on which laser is irradiated.

[0035] Figure 9 FIG. 9 is a view illustrating a window that is etched.

[0036] Figure 10 FIG. 10 is a view illustrating a window on which a primary enhancement process is performed.

[0037] Figure 11 FIG. 11 is a view illustrating a window that is masked.

[0038] Figure 12 FIG. 12 is a view illustrating a window on which secondary enhancement occurs. DETAILED DESCRIPTION

[0039] The present application will be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments of the application are shown. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0040] The drawings and description are to be read in conjunction with the accompanying drawings, wherein like reference numerals portray like elements, and in which:

[0041] Furthermore, the size and thickness of each configuration shown in the drawings are arbitrarily shown for understanding and easy description, but the present application is not limited thereto. In the drawings, the thickness of layers, films, panels, regions, and the like is exaggerated for clarity. In the drawings, the thickness of some layers and regions is exaggerated for clarity.

[0042] It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. In addition, in the description herein, the word "on" or "above" means positioned on or below the object, and does not necessarily mean positioned on the upper side of the object based on the direction of gravity.

[0043] It will be understood that, although the terms "first", "second", "third", and the like can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first "element", "component", "region", "layer", or "section" discussed below could be termed a second element, component, region, layer or section without departing from the teachings herein.

[0044] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the terms "a," "an," "the," and "at least one" are not intended to refer to a limitation on a number of embodiments and are intended to be used in the context with the other terms in this document to include one or at least one. For example, the term "element" shall mean either one or at least one of a number of elements. The use of "at least one" will not be construed as limiting the number of elements. The term "or" means "and / or" as used throughout this document. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "comprises" and / or "comprising," or "includes" and / or "including" when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0045] In addition, relative terms such as "lower" or "bottom" and "upper" or "top" can be used herein to describe one element's or feature's relationship to another element or feature as illustrated in the figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in one of the figures is turned over, elements described as being on the "lower" side of other elements would then be oriented on "upper" sides of the other elements. The term "lower" can encompass both an orientation of "lower" and "upper," depending on the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as "below" or "beneath" other elements would then be oriented "above" the other elements. The terms "below" or "beneath" can encompass both an orientation of above and below, depending on the particular orientation of the figure.

[0046] Furthermore, in the specification, the phrase "in plan view" means when the subject portion is viewed from above, and the phrase "in cross-sectional view" means when a cross-section taken by cutting the subject portion vertically is viewed from the side.

[0047] "About" or "approximately," as used in this document, includes the stated value and means within a reasonable deviation of the stated value as determined by one of ordinary skill in the art, considering the measurement and error associated with the particular measurement technique. For example, "about" can mean within one or more standard deviations, or within ±30%, ±20%, ±10%, or ±5% of the stated value.

[0048] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0049] The implementations described herein are not to be interpreted to be limited to the specific shapes of regions as shown herein, but rather are to include deviations in shape resulting from, for example, manufacturing. For example, regions shown or described as flat can generally have rough and / or nonlinear features. Also, shown corners can be rounded. Thus, the regions shown in the figures are schematic in nature and their shapes are not intended to show the precise shape of the regions and are not intended to limit the scope of the present claims.

[0050] Now, embodiments of a manufacturing method of a window according to the present application will be described in detail with reference to the accompanying drawings.

[0051] Figure 1 is a process flow diagram showing a manufacturing process of a window according to an embodiment.

[0052] Referring to Figure 1 Embodiments of a manufacturing process of a window include irradiating a laser to form a pattern (S10), etching and primary reinforcement (S20), and secondary reinforcement (S30).

[0053] In this embodiment, referring to Figure 1 A laser is irradiated to the window to form a pattern (S10). Figure 2 is a view showing a window to which a laser is irradiated. Figure 2 A laser irradiation region LA is shown. This laser irradiation region LA is a region to be removed later by etching, and as Figure 2As shown, this laser-irradiated area LA is formed on a portion of the center of window 100. The laser-irradiated area LA is subjected to thermal damage, and the damaged area can be removed by an etching process in a subsequent process. In this embodiment, the desired shape can be etched by using the difference in etching selectivity between the laser-treated (or irradiated) area and the laser-untreated (or unirradiated) area.

[0054] In the implementation method, such as Figure 1 As shown, the window irradiated by the laser is etched and subjected to initial enhancement (S20). In this embodiment, the etching and initial enhancement of the window can be performed using KOH. In another embodiment, the etching and initial enhancement of the window can be performed by immersing the window in a chemical solution containing KOH. In this embodiment, the enhancement time can be from about 30 minutes to about 72 hours. In this embodiment, the temperature of the KOH can be greater than or equal to about 50°C and less than or equal to about 300°C. If the temperature is below about 50°C, the enhancement of the window may not be possible, and if the temperature is above about 300°C, it may be difficult to ensure the process characteristics. Therefore, in this embodiment, about 50°C can be the minimum temperature at which the enhancement depth of the window can be checked, and about 300°C can be the maximum temperature at which the process characteristics can be ensured.

[0055] Figure 3 This is a view showing the window where etching and initial enhancement processes were performed. (Refer to...) Figure 3 Etching and Figure 2 The portion corresponding to the laser irradiation area LA is used to form a groove 110.

[0056] exist Figure 3 In this embodiment, the primary enhancement region is represented by FA1. Enhancement occurs in the edge or surface region of window 100 via KOH. The thickness of the primary enhancement region FA1 can range from about 1 nanometer (nm) to about 20 micrometer (μm).

[0057] Figure 4 This is a schematic view illustrating the principle of enhancement through the KOH generation window. (See reference) Figure 4 K ions (K+) in KOH chemical solution + ) and Na ions (Na+) inside the glass (i.e., window 100) + It undergoes a substitution reaction. Therefore, as... Figure 4 As shown, enhancement by ion substitution can occur in the edge or surface region of window 100.

[0058] Next, refer to Figure 5 The groove 110 of window 100 is filled to be concealed. Figure 5 The obscured window 100 is shown. (As shown) Figure 5As shown in FIG. 1, the masking can be performed by filling the inside of the recess 110 of the window 100 with the masking pattern 120. In an embodiment, as shown in FIG. 2, the masking can be performed by filling the inside of the recess 110 of the window 100 with the masking pattern 120. Figure 5 As shown in FIG. 1, the masking can be performed by filling the inside of the recess 110 of the window 100 with the masking pattern 120. In an embodiment, as shown in FIG. 2, the masking can be performed by filling the inside of the recess 110 of the window 100 with the masking pattern 120.

[0059] In an embodiment, as shown in FIG. 1, the window (S30) to which the masking is applied is reinforced. In this embodiment, the reinforcement can be performed by using KNO3. In this embodiment, the reinforcement is performed only in the non-masked area. Figure 1 As shown in FIG. 1, the window (S30) to which the masking is applied is reinforced. In this embodiment, the reinforcement can be performed by using KNO3. In this embodiment, the reinforcement is performed only in the non-masked area. Figure 6 As shown in FIG. 1, the window (S30) to which the masking is applied is reinforced. In this embodiment, the reinforcement can be performed by using KNO3. In this embodiment, the reinforcement is performed only in the non-masked area. Figure 6 As shown in FIG. 1, the window (S30) to which the masking is applied is reinforced. In this embodiment, the reinforcement can be performed by using KNO3. In this embodiment, the reinforcement is performed only in the non-masked area.

[0060] Referring to FIG. 1, Figure 6 , the window 100 can include a primary reinforcement area FA1, a secondary reinforcement area FA2, and a non-reinforcement area NA.

[0061] In this embodiment, the window 100 can be a window applied to a foldable display device. In this embodiment, the recess 110 of the window 100 can correspond to an area in which the foldable display device is folded (or overlap with an area in which the foldable display device is folded). In this embodiment, different stresses occur with respect to each area of the window 100. Specifically, a compressive stress occurs near the edge of the window 100, and a tensile stress occurs in the central area and the area adjacent to the recess 110.

[0062] According to an embodiment of the present application, a manufacturing method of a window is performed by dividing a primary reinforcement process and a secondary reinforcement process, and particularly, in this embodiment, the recess 110 is masked in the secondary reinforcement process to adjust the reinforcement area. In this embodiment, by differently controlling the degree of reinforcement in the area near the recess 110 and the degree of reinforcement in the area without the recess, uniform chemical reinforcement can occur in the entire area of the window having different thicknesses with respect to each area. That is, although the thickness of the window 100 is different with respect to each area due to the formation of the recess 110, this difference in thickness can be compensated for by performing the primary reinforcement and the secondary reinforcement after the masking. Accordingly, when the window is applied as a cover glass of a display device, high strength can be maintained.

[0063] In this embodiment, the manufacturing method of the window can maintain a uniform internal stress distribution in the window 100 formed with the recess 110. As shown in FIG. 1, Figure 6 As shown in FIG. 1, since the thickness of the reinforcement area in the area without the recess 110 is thicker than the thickness of the reinforcement area around the recess 110, the internal stress can be uniformly maintained.

[0064] Next, alternative embodiments of a manufacturing process of a window according to the present application will be described in detail. Figure 7 is a process flow diagram illustrating a manufacturing process of a window according to an embodiment. The embodiment of the manufacturing process of a window includes irradiating a laser to form a pattern (S10), etching (S11), a primary strengthening (S20), and a secondary strengthening (S30).

[0065] Referring to Figure 7 and Figure 8 A laser is irradiated to the window to form a pattern (S10). Figure 8 is a view illustrating a window 100 to which a laser is irradiated. In Figure 8 , a laser irradiation area LA is illustrated. The laser irradiation area LA is an area to be removed by etching, and as Figure 8 illustrated in , the laser irradiation area LA is formed in a partial area of the center of the window 100. The laser irradiation area LA is subjected to thermal damage, and a damage area is removed by an etching process in a subsequent process. In this embodiment, by using a difference in etching selectivity between a processed area and an unprocessed area, the window 100 can be etched into a desired shape.

[0066] Figure 7 Next, referring to Figure 9 , the window 100 is etched. Figure 9 is a view illustrating the window 100 that is etched. In this embodiment, etching can be performed using HF as an etchant. When the etching and the strengthening process are simultaneously performed with KOH as in the embodiment described above with reference to Figure 1 , the process takes a long time, and thus the productivity can be deteriorated. In the embodiment of the manufacturing method of a window, the etching process can be performed separately using HF, thereby improving the process productivity. The etching speed of HF is about 10 times or more of the etching speed of KOH. The etching is performed on a portion corresponding to the laser irradiation area LA of Figure 8 to form a groove 110.

[0067] Next, referring to Figure 10 , the window is primarily strengthened by using KOH. Figure 10 is a view illustrating the window 100 on which a primary strengthening process is performed. The primary strengthening can be performed by immersing the window 100 in a chemical solution containing KOH. In this embodiment, the strengthening time can be about 30 minutes to about 72 hours. In this embodiment, the KOH temperature can be greater than or equal to about 50°C and less than or equal to about 300°C. If the temperature is lower than about 50°C, it can be impossible to perform the strengthening of the window, and if the temperature is higher than about 300°C, it can be difficult to secure the process characteristics. Thus, in this embodiment, 50°C can be the lowest temperature at which the strengthening depth of the window can be checked, and 300°C can be the highest temperature at which the process characteristics can be secured.

[0068] In Figure 10 , a primary strengthening region FA1 in which primary strengthening occurs is shown. In an embodiment, the primary strengthening occurs in the edge or surface region of the window 100 by KOH. The thickness of the primary strengthening region FA1 can be in the range of about 1 nm to about 20 μm.

[0069] In an embodiment, referring to Figure 11 , the recess 110 of the window 100 is filled to be masked. Figure 11 is a view showing the window 100 that is masked. As shown in Figure 11 , the masking can be performed by filling the inside of the recess 110 of the window 100 with the masking pattern 120. As shown in Figure 11 , the masking pattern 120 can be positioned while filling the recess 110 of the window 100.

[0070] In an embodiment, as shown in Figure 7 and Figure 12 , the window that is masked is secondarily strengthened (S20). In this embodiment, the secondary strengthening can be performed using KNO3. In this embodiment, the secondary strengthening is performed only in the non-masked region. Figure 12 is a view showing the window 100 in which secondary strengthening occurs. The secondary strengthening region is denoted by FA2. As shown in Figure 12 , the edge or surface region of the window 100 except for the masked recess 110 is strengthened. In this embodiment, the secondary strengthening region FA2 can be wider than the primary strengthening region FA1.

[0071] Referring to Figure 12 , the window 100 can include the primary strengthening region FA1, the secondary strengthening region FA2, and the non-strengthening region NA. In this embodiment, as described above, the primary strengthening region FA1 and the secondary strengthening region FA2 are applied to perform uniform chemical strengthening across all regions of the window 100 having different thicknesses for each region. Accordingly, when the window 100 is used as a cover window such as for a foldable display device, stress is uniformly maintained in the recess 110 in which folding is performed and in other regions to prevent the window 100 from being damaged.

[0072] The present application should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0073] While the present application has been particularly shown and described with reference to embodiments thereof, it will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the spirit or scope of the application as defined by the appended claims.

Claims

1. A method for manufacturing a window, the method comprising: Irradiate the glass with a laser; The glass to be irradiated by the laser is immersed in a KOH solution to form grooves in the irradiated glass and simultaneously perform initial strengthening on the irradiated glass. The groove that conceals the initially reinforced glass; and The masked glass is subjected to secondary reinforcement.

2. The method for manufacturing a window according to claim 1, wherein, The laser-irradiated glass is then immersed in the KOH solution. The temperature of the KOH solution is in the range of 50°C to 300°C.

3. The method for manufacturing a window according to claim 1, wherein, The laser-irradiated glass is then immersed in the KOH solution. Immersion time ranges from 30 minutes to 72 hours.

4. The method for manufacturing a window according to claim 1, wherein, The groove is positioned along a predetermined direction of the initially reinforced glass and does not penetrate the initially reinforced glass.

5. The method for manufacturing a window according to claim 1, wherein, After immersing the laser-irradiated glass in the KOH solution... The thickness of the initially reinforced region of the initially reinforced glass is in the range of 1 nm to 20 μm.

6. The method for manufacturing a window according to claim 1, wherein, The groove that masks the initially reinforced glass includes filling the entire interior of the groove with a masking pattern.

7. The method for manufacturing a window according to claim 1, wherein, Performing the secondary reinforcement on the masked glass includes using KNO3.

8. The method for manufacturing a window according to claim 1, wherein, The thickness of the region of the window that underwent the secondary enhancement is greater than the thickness of the region of the window that underwent the primary enhancement.

9. The method for manufacturing a window according to claim 1, wherein, The window includes a primary enhancement area, a secondary enhancement area, and a non-enhanced area.

10. The method for manufacturing a window according to claim 1, wherein, The window is a cover window for a foldable display device, and The recess in the window corresponds to the area where the foldable display device is folded.

Images