JP2015067471A - Manufacturing method of glass substrate of cover glass for electronic instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a glass substrate of a cover glass for an electronic instrument, capable of imparting designability to an end face shape and hence improving designability of the electronic instrument, while securing high mechanical strength.SOLUTION: A manufacturing method of a glass substrate of a cover glass for an electronic instrument typically includes: an etching-resistant layer forming step of forming etching-resistant layers 114a and 114b respectively on a first main surface 110a and a second main surface 110b of a glass blank 110; and an etching treatment step of dissolving the glass blank along a processing pattern by performing the etching treatment and separating a glass substrate 118 having a shape of a cover glass for an electronic instrument from the glass blank. By making a processing pattern on the first main surface side wider than a processing pattern on the second main surface side in the etching-resistant layer forming step, the end face of the glass substrate is formed asymmetrical in the etching treatment step, in the thickness direction when cross-sectionally viewed.

Description

  The present invention relates to a method for manufacturing a glass substrate of a cover glass for an electronic device including a cover glass for a portable device used as a cover member for a display screen of a portable device (portable electronic device).

  In order to protect display devices such as liquid crystals, mobile devices including smartphones, portable game machines, slate PCs (Personal Computers), PDAs (Personal Digital Assistants), digital still cameras, video cameras, etc. A cover glass is disposed outside the display device. Also in the touch sensor, a cover glass is disposed to protect the sensor substrate.

  In general, a cover glass is manufactured by separating a glass substrate having an arbitrary shape from a large glass sheet (outer shape processing), and further processing such as printing on the separated glass substrate. As a method for separating the glass substrate from the glass base plate, not only machining but also a method using an etching process is known.

  In patent document 1, the glass base plate which formed the resist pattern in the main surface is etched, and the glass substrate of a desired shape is isolate | separated from the glass base plate. By forming the outer shape by the etching process in this way, the end surface becomes a mirror surface and has very high smoothness, and microcracks that are inevitably generated in machining are not generated. For this reason, the high intensity | strength calculated | required by the cover glass for portable terminals can be obtained. Further, there is an advantage that even a complicated shape difficult to machine can be easily processed by an etching process.

JP 2009-167086 A

  In recent years, with the advancement of touch sensor technology, portable devices tend to have a configuration in which an operation unit (such as a numeric keypad) that is an independent set of buttons is eliminated and a cover glass is disposed almost on the front surface of the housing. is there. For this reason, the design of mobile devices has become uniform, and it is differentiated by enhancing the design with cover glass for mobile devices (cover glass for exterior) and cover glass for touch sensors (external protective cover glass). There is a request to plan.

  As one of the techniques for improving the design of the cover glass for electronic equipment, it is conceivable to impart design to the end face shape. Here, conventionally, the external shape processing of the glass substrate is performed by separating a glass substrate having a desired shape from the glass base plate by etching as in Patent Document 1.

  However, since the etching proceeds isotropically from both main surfaces of the glass base plate with the above method, the end surface of the glass substrate is symmetrical in the thickness direction when the main surface on the front side is the top surface. Can only be processed into a shape. For this reason, the shape (design) of the end face is still uniform. In addition, it is possible to form an asymmetric end face in the thickness direction by polishing the end face with mechanical processing means, but when processing with mechanical processing means, Microcracks are generated, causing a decrease in strength.

  In view of such a problem, the present invention can provide a design for an end face shape while ensuring high mechanical strength, and thus an electronic device cover capable of improving the design of an electronic device. It aims at providing the manufacturing method of the glass substrate of glass.

  In order to solve the above-mentioned problems, a typical configuration of a method for manufacturing a glass substrate of a cover glass for an electronic device according to the present invention is the electronic device on the first main surface and the second main surface of the glass base plate. An etching-resistant layer forming step for forming an etching-resistant layer in which a processing pattern in the shape of a cover glass is formed, and by etching both main surfaces of the glass base plate, the glass base plate along the processing pattern And an etching process step of separating the glass substrate in the shape of the cover glass for electronic equipment from the glass base plate, and the width of the processing pattern on the first main surface side in the etching resistant layer forming step is set to the second main pattern. By making it wider than the width of the processing pattern on the front surface side, the end surface of the glass substrate is formed so as to be asymmetric in the thickness direction in a sectional view in the etching process.

  According to the above configuration, by making the width of the processing pattern on the first main surface side wider than the width of the processing pattern on the second main surface side, the design that is asymmetric in the thickness direction in a cross-sectional view in the glass substrate An end face shape having the shape can be formed. Therefore, it is possible to impart design properties to the end face shape while ensuring high quality stability, and as a result, it is possible to improve the design properties of electronic devices.

  Moreover, since the degree of inclination of the end surface can be adjusted by appropriately adjusting the width of the processing pattern on the first main surface side and the width of the processing pattern on the second main surface side, the end surface shape can be changed to an arbitrary shape. Molding is also possible. Furthermore, if the width of the processing pattern on the first main surface side and the width of the processing pattern on the second main surface side are adjusted so that the end surface shape is a gently curved shape having R, cracks on the end surface In addition, it is possible to prevent catching when the end face is touched.

  On the end surface of the glass substrate, a top portion protruding outward in the surface direction is formed, and the shape of the end surface of the glass substrate is the distance between the first main surface and the top portion in the thickness direction, and the thickness direction. The distance between the second main surface and the top may be different from each other. Thereby, it is possible to prevent concentration of bending stress on the end portion on the first main surface side on the end surface of the glass substrate, and it is possible to improve the mechanical strength.

  The etching process is showering, and in the etching process, the showering conditions on the first main surface side and the second main surface side may be the same. According to such a configuration, since the showering conditions are the same as when manufacturing a glass substrate whose end face shape is symmetrical in the thickness direction as in the prior art, it is necessary to change the showering conditions according to the end face shape to be formed. Absent. Therefore, high quality stability can be ensured without incurring deterioration in quality stability that occurs when the showering conditions for the first main surface side and the second main surface side are made different.

  Moreover, it is possible to manufacture a glass substrate having a target end face shape in the thickness direction and a glass substrate having an end face shape that is asymmetric in the thickness direction, that is, having a design property, under the same manufacturing conditions (showering conditions). Therefore, glass base plates of different models can be mixed and flowed to the manufacturing apparatus, and production efficiency can be improved.

  The etching process may be dipping. According to the present invention, it is possible to arbitrarily shape the end face shape even in dipping in which the etching conditions cannot be changed with respect to the first main surface side and the second main surface side.

  ADVANTAGE OF THE INVENTION According to this invention, while ensuring high mechanical strength, it can give design property to an end surface shape, and by extension, the glass substrate of the cover glass for electronic devices which can aim at the improvement of the design property of electronic devices is attained. A manufacturing method can be provided.

It is a figure explaining the cover glass for electronic devices manufactured by the manufacturing method of the glass substrate of the cover glass for electronic devices concerning this embodiment. It is typical sectional drawing of the smart phone shown in FIG. It is a flowchart explaining the manufacturing method of the glass substrate of the cover glass for electronic devices concerning this embodiment. It is typical sectional drawing which shows the state of the cover glass for electronic devices in a manufacturing process. It is a figure which illustrates the etching process process in the conventional manufacturing method. It is a figure explaining control of the end face shape of a glass substrate by processing pattern width.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a diagram illustrating an electronic device cover glass manufactured by the method for manufacturing a glass substrate for an electronic device cover glass according to the present embodiment. In the embodiment, the smart phone 300 is illustrated as an electronic device, but the present invention is not limited to this, and other mobile phones, portable game machines, PDAs (Personal Digital Assistants), digital still cameras, video cameras, or slate. It may be a PC (Personal Computer) or the like.

  As shown in FIG. 1, a smartphone 300 that is an electronic device according to the present embodiment covers a touch panel display 302 (touch sensor) and the surface of the touch panel display 302 and is used as a cover member of the touch panel display 302. An electronic device exterior cover glass (hereinafter referred to as exterior cover glass 304), which is a cover glass. The exterior cover glass 304 is attached to the inside of the bezel of the housing 306 so as to form a part of the exterior of the smartphone 300. That is, the exterior cover glass 304 constitutes a part of the exterior of the smartphone 300.

  The protective cover glass 100 is an external cover glass for portable equipment (external protective cover glass for electronic equipment) that is detachably attached so as to cover the display screen in the exterior of the electronic equipment. The protective cover glass 100 includes the glass plate 102 and is attached so as to cover the outer main surface of the exterior cover glass 304, thereby protecting the exterior cover glass 304. In the present embodiment, both the exterior cover glass 304 and the protective cover glass 100, that is, the cover glass for an electronic device including both are simply referred to as a cover glass.

  FIG. 2 is a schematic cross-sectional view of the smartphone 300 shown in FIG. 1, FIG. 2 (a) is a cross-sectional view of a state in which the protective cover glass 100 is pasted on the smartphone 300, and FIG. FIG. 5 is a cross-sectional view of a state in which an exterior cover glass 304 is disposed on the entire surface on the side where the touch panel display 302 is disposed in the smartphone 300. In FIGS. 2A and 2B, components other than the cover glass 304 for the exterior of the smartphone 300 are schematically illustrated as the smartphone main body 300a.

  As shown in FIG. 2A, the protective cover glass 100 is provided on the back side of the glass plate 102 for protecting the smartphone 300 and the glass plate 102, and the glass plate 102 can be attached to and detached from the electronic device (smart phone 300). And a sticking layer 104 for sticking to the head. The glass plate 102 includes a first main surface 102b serving as a front surface, a second main surface 102c serving as a back surface, and an end surface 102a connecting the first main surface 102b and the second main surface 102c. Yes. As thickness of the glass plate 102, 0.2-0.5 mm can be illustrated, for example. As shown in FIG. 1, openings 102d and 102e are formed in the glass plate 102 so as to correspond to positions of a microphone, a speaker, a button, or the like of the electronic device.

  In FIG. 2A, the configuration in which the exterior cover glass 304 is incorporated into a part of the upper surface of the smartphone main body 300a is illustrated. However, as shown in FIG. A configuration in which the exterior cover glass 304 is disposed on the entire upper surface of the substrate is also possible. In such a case, in addition to the end surface of the exterior cover glass 304 having an R shape, the design of the end surface is also important.

  FIG. 3 is a flowchart illustrating a method for manufacturing the glass substrate of the cover glass for an electronic device according to the present embodiment. FIG. 4 is a schematic cross-sectional view showing the state of the cover glass for electronic equipment in the manufacturing process. In addition, although the case where the cover glass 304 for exterior is manufactured is illustrated in the following description, it is not limited to this, When manufacturing the glass plate 102 of the protective cover glass 100, it is for electronic devices of this embodiment. It is possible to apply the manufacturing method of the glass substrate of a cover glass.

  As shown in FIG. 3, in the manufacturing method of the glass substrate of the cover glass for an electronic device according to the present embodiment, first, in the etching resistant layer forming step (step S402), the first main surface 110a and the second main surface 110a of the glass base plate 110 are processed. Etching-resistant layers 114a and 114b each having a processing pattern in the shape of an electronic device cover glass (exterior cover glass 304) are formed on the main surface 110b (see FIG. 4). In the etching resistant layer forming step, first, as shown in FIG. 4A, by applying a resist material on the first main surface 110a and the second main surface 110b of the glass base plate 110 that is a glass plate, Resist films 112a and 112b are formed.

Examples of the glass base plate 110 include aluminosilicate glass, soda lime glass, and borosilicate glass. Aluminosilicate glass is more preferable from the viewpoint of forming a strong compressive stress. Among _them, is preferably aluminosilicate glass containing _{SiO 2, Al 2 O 3,} Li 2 O and / or Na ₂ O, more _preferably, SiO 2: 58-75 _wt%, Al _{2 O} 3: 4 20 _wt%, Li 2 O: _{3~10 wt%,} Na 2 O: _4~13 preferably used aluminosilicate glass containing by weight%.

Al ₂ O ₃ is useful because it improves ion exchange performance in chemical strengthening described later. Li ₂ O is a component for ion exchange with Na + ions in chemical strengthening. Na ₂ O is a component for ion exchange with K + ions in chemical strengthening. ZrO ₂ is useful for increasing the mechanical strength. Of Li2O and Na2O, any glass composition containing Na2O may be used, and Li2O can be omitted. In this case, a molten salt of potassium nitrate can be used for the chemical strengthening treatment liquid described later (sodium nitrate can be omitted). In the present embodiment, the configuration using aluminosilicate glass is exemplified, but the present invention is not limited to this, and soda lime glass or the like can also be used.

  Any resist material may be used as long as it is resistant to an etchant used in an etching process described later. In many cases, glass is etched by wet etching of an aqueous solution containing hydrofluoric acid or dry etching of a fluorine-based gas, so that, for example, a resist material having excellent resistance to hydrofluoric acid can be used.

  Next, as shown in FIG. 4A, a mask pattern corresponding to a processing pattern to be formed on the etching-resistant layers 114a and 114b, that is, a processing pattern in the shape of an electronic device cover glass (exterior cover glass 304) is provided. Photomasks 116a and 116b are arranged parallel to both main surfaces of glass base plate 110, and exposure is performed by irradiating light from both surfaces of resist films 112a and 112b. Then, when the resist films 112a and 112b after exposure are developed, as shown in FIG. 4B, an electronic device is formed in an area other than an area etched in an etching process described later (area that becomes the glass substrate 118). Etch-resistant layers 114a and 114b in which a processing pattern (resist pattern) in the shape of a cover glass is formed on the first main surface 110a and the second main surface 110b of the glass base plate 110, respectively.

  After the etching resistant layers 114a and 114b are formed on the first main surface 110a and the second main surface 110b of the glass base plate 110, an etching process is subsequently performed (step S404). In the etching process, the glass base plate 110 is melted along the processing pattern by etching both main surfaces of the glass base plate 110. The etching process includes a dry etching process and a wet etching process. In this embodiment, wet etching (wet etching) is employed as the etching process.

  In addition, there are a shower ring and a dip method in wet etching (etching process), and in this embodiment, a case where a shower method is employed is illustrated. When external processing of a glass substrate is performed by wet etching, the shower method can easily perform precipitate management and etching rate management compared to the dip method, so the cover for electronic equipment that requires dimensional accuracy is required. It is because it is suitable for the external shape processing of glass. Note that an etchant used for wet etching may be any material that can etch the glass base plate 110. For example, an acidic solution containing hydrofluoric acid as a main component or a mixed acid containing at least one of sulfuric acid, nitric acid, hydrochloric acid, and silicic hydrofluoric acid in hydrofluoric acid can be used.

  FIG. 5 is a diagram illustrating an etching process in a conventional manufacturing method. As shown in FIG. 5A, when an etchant is showered on the glass base plate 10 on which the etching resistant layers 14a and 14b are formed, the region along the processing pattern, that is, not masked by the etching resistant layers 14a and 14b. The etchant flows into. Then, the glass base plate 10 in that region is melted so that the groove is dug down from each of the first main surface 10a and the second main surface 10b. And as shown in FIG.5 (b), the glass substrate 18 of the shape of the cover glass for electronic devices is isolate | separated from the glass base plate 10 because the groove | channel continues in the approximate center part of plate | board thickness.

  That is, in the wet etching, the etching proceeds isotropically from both main surfaces of the glass base plate 10. For this reason, as shown in FIG. 5B, in the conventional manufacturing method, the end surface 18a of the glass substrate 18 separated from the glass base plate 10 has a symmetrical shape in the thickness direction, and the shape of the end surface 18a. (Design) will be standardized. Here, it is considered that the end surface 18a of the glass substrate 18 can be formed into an arbitrary shape asymmetric in the thickness direction by polishing or the like by mechanical processing means. Microcracks are generated on the processed surface, causing a decrease in strength.

  For this reason, the inventor has studied, and in the etching process, the shape of the end face 18a can be formed into an arbitrary shape by changing the showering conditions between the first main surface 10a and the second main surface 10b. I thought that. However, if the showering conditions on the first main surface 10a side (front side main surface) and the second main surface 10b side (back side main surface) are made different, the shape of the end face 18a can be arbitrarily changed. It has been found that the end face quality becomes unstable and the yield decreases. Therefore, the inventor studied a method capable of forming the shape of the end face 18a into an arbitrary shape without changing showering conditions. Then, paying attention to the processing pattern in the etching resistant layers 14a and 14b formed on both main surfaces, and further earnestly studying, the present invention has been conceived.

  That is, in the method for manufacturing a glass substrate for electronic equipment according to the present embodiment, as shown in FIG. 4B, in the etching resistant layer forming step, the width A of the processing pattern on the first main surface 110a side is set to the second. The etching-resistant layers 114a and 114b are formed so as to be wider than the width B of the processing pattern on the main surface 110b side. Accordingly, when the etchant is showered on the glass base plate 110 shown in FIG. 4B, the glass base plate 110 in the unmasked region is grooved from each of the first main surface 110a and the second main surface 110b. Dissolves so that it can be dug down.

  At this time, in this embodiment, since the width A of the processing pattern on the first main surface 110a side is wider than the width B of the processing pattern on the second main surface 110b side, the first main surface 110a side The area that dissolves is wider. As a result, the end surface 118a of the glass substrate 118 after the etching process is asymmetric in the thickness direction in a cross-sectional view, as shown in FIG. Therefore, the shape of the end surface 118a of the glass substrate 118 can be formed into an arbitrary shape without changing showering conditions. Thereby, it becomes possible to improve the yield without deteriorating the quality stability that occurs when the showering conditions for the first main surface 110a side and the second main surface 110b side are made different. .

  Further, it is not necessary to make the showering conditions on the first main surface 110a side and the second main surface 110b side different from each other, that is, the showering conditions on the first main surface 110a side and the second main surface 110b side are the same. Therefore, the showering conditions are the same as those in the case of manufacturing a glass substrate whose end face shape is symmetrical in the thickness direction as in the prior art. For this reason, it is not necessary to change showering conditions according to the shape of the end surface to be molded, and a glass substrate 118 having a target end surface shape in the thickness direction and an end surface shape having an asymmetric design in the thickness direction. Can be manufactured under the same manufacturing conditions (showering conditions). Therefore, the glass base plates 110 serving as the basis of the glass substrates of different models can be mixed and flowed to the manufacturing apparatus, and the production efficiency can be improved.

  Furthermore, in other words, the end face shape of the glass substrate 118 can be arbitrarily formed without depending on the showering conditions on the first main surface 110a side and the second main surface 110b side as in this embodiment. This means that the end face shape of the glass substrate 118 can be arbitrarily formed even in wet etching in which the etching conditions cannot be changed. Therefore, the end face shape of the glass substrate 118 can be arbitrarily formed even when dipping is employed in the wet etching.

  Further, as in this embodiment, the end face shape can be arbitrarily formed by the width A of the processing pattern on the first main surface 110a side and the width B of the processing pattern on the second main surface 110b side, instead of the showering condition. Therefore, the end face shape of the glass substrate 118 can be easily changed by appropriately setting the width A and the width B thereof. That is, the inclination degree of the end surface 118a can be adjusted by appropriately adjusting the width of the processing pattern on the first main surface 110a side and the width of the processing pattern on the second main surface 110b side.

  FIG. 6 is a diagram for explaining the control of the end face shape of the glass substrate 118 according to the processing pattern width. FIG. 6A is an enlarged view of the end face of the glass substrate 118 shown in FIG. FIG. 6B is a diagram for explaining the position of the apex 118b of the end face 118a according to the processing pattern width. 6A, in the end surface 118a of the glass substrate 118, the distance C from the end of the first main surface 110a to the vertex 118b of the end surface 118a is the distance C, and the top of the end surface 118a from the first main surface 110a. The thickness up to the vertex 118b is the thickness D.

  At this time, as shown in Examples 1 to 9 in FIG. 6B, a value obtained by subtracting the width B of the processing pattern on the second main surface 110b side from the width A of the processing pattern on the first main surface 110a side. That is, as the difference between the width A and the width B increases, both the distance C and the thickness D increase, and the apex of the end surface 118a of the glass substrate 118 is separated from the first main surface 110a in both the distance C and the thickness D. Position. From this, the end face shape of the glass substrate 118 can be arbitrarily controlled by changing the width A of the processing pattern on the first main surface 110a side and the width B of the processing pattern on the second main surface 110b side. I understand that. In other words, in the present embodiment, the shape of the end surface 118a of the glass substrate 118 is such that the first main surface in the thickness direction with respect to the vertex 118b that is the top formed so as to protrude outward in the surface direction on the end surface 118a. The distance between 110a and vertex 118b is different from the distance between second main surface 110b and vertex 118b in the thickness direction.

  Furthermore, in the present embodiment, as shown in FIG. 4C, the end surface 118a of the glass substrate 118 is etched so that the end on the first main surface 110a side is curved inward. Do. Thereby, concentration of bending stress on the end portion of the end surface of the glass substrate 118 on the first main surface 110a side can be prevented, and mechanical strength can be improved.

  Specifically, in the etching resistant layer 114a formed on the first main surface 110a, the resist material is polymerized in the thickness direction from the surface not in contact with the glass base plate 110 toward the surface in contact. A degree of polymerization gradient is provided so that the degree is low. As a method of giving a polymerization degree gradient, the resist thickness, the exposure amount during development, and post-baking conditions are adjusted by appropriately changing the type of resist used and the exposure light source (energy).

  As described above, the etching resistance layer 114a formed on the first main surface 110a has a polymerization degree gradient so that the first main surface 110a of the glass base plate 110 and the etching resistance layer formed thereon are formed. Adhesion with 114a is weakened, and an etchant easily enters between them in the etching process. Therefore, the etching of the end portion on the first main surface 110a side of the glass substrate 118 is promoted, and the end portion can be shaped to be curved inward. Thereby, the stress concentration on the end portion on the first main surface 110a side on the end surface of the glass substrate 118 is alleviated, and the three-point bending strength (three-point bending strength) can be improved.

  The thickness (resist film thickness) of the etching resistant layer 114a having a polymerization degree gradient in the thickness direction is preferably 20 μm to 150 μm. The exposure energy for forming the etching resistant layer 114a is preferably 200 mJ / cm2 to 500 mJ / cm2, and the post-baking temperature is preferably 110 ° C to 200 ° C. The polymerization degree gradient of the etching resistant layer 114a can be indirectly confirmed by measuring the transmittance at the sensitivity wavelength of the unexposed resist and the change with time of the transmittance. The polymerization degree gradient can also be confirmed by a Raman spectrometer.

  As described above, when the glass substrate 118 in the shape of the cover glass for electronic equipment is separated from the glass base plate 110 in the etching process, the etching resistant layer peeling step (step for peeling the etching resistant layers 114a and 114b from the glass substrate 118 is performed. S406) is performed. Thereby, as shown in FIG. 4D, the etching resistant layers 114a and 114b are peeled off from the first main surface 110a and the second main surface 110b of the glass substrate 118. As the stripping solution used in the etching-resistant layer stripping step, it is preferable to use an alkaline solution such as KOH or NaOH. Note that the types of the resist material, the etchant, and the stripping solution can be appropriately selected according to the material of the glass base plate 110 that is the material to be etched.

  After the etching resistant layers 114a and 114b are peeled off, a chemical strengthening step (step S408) is subsequently performed. In the chemical strengthening step, a chemical strengthening process is performed in which the glass substrate 118 is brought into contact with the molten chemical strengthened salt. In the chemical strengthening treatment, alkali metal ions having a relatively large atomic radius in the chemically strengthened salt are ion-exchanged with alkali metal ions having a relatively small atomic radius in the glass substrate 118, and ions are formed on the surface layer of the glass substrate 118. It penetrates alkali metal ions with a large radius. By this compressive stress being generated on the surface of the glass substrate 118 by this chemical strengthening treatment, the mechanical strength can be increased and the impact resistance can be improved.

  As the chemically strengthened salt, it is preferable to use an alkali metal nitrate such as potassium nitrate or sodium nitrate. Further, as a method of chemical strengthening treatment, a low temperature type ion exchange method in which ion exchange is performed in a temperature range not exceeding the temperature of the glass transition point, for example, a temperature of 300 to 500 degrees Celsius is preferable. Since the chemically strengthened glass substrate 118 has improved strength and excellent impact resistance, for example, the protective cover glass 100 or the exterior cover glass 304 can sufficiently function even when the thickness is about 0.3 mm.

  Subsequently, a cleaning process (step S410) for cleaning the glass substrate 118 is performed. Thereby, the deposit | attachment adhering to the 1st main surface 110a and the 2nd main surface 110b of the glass substrate 118 is removed. As a cleaning method, a method of rinsing with a cleaning solution such as water, a dipping method of immersing in the cleaning solution, a scrub cleaning method of bringing a rotating roll body into contact with the glass substrate 100 while flowing the cleaning solution, and the like can be used. The dipping method may be performed in a state where ultrasonic waves are applied to the cleaning liquid. Then, the exterior cover glass 304 is manufactured by decorating the glass substrate 100 as necessary.

  As described above, according to the method for manufacturing the glass substrate of the cover glass for an electronic device according to the present embodiment, the width A of the processing pattern on the first main surface 110a side is set to the processing pattern on the second main surface 110b side. By making it wider than the width B of the glass substrate 118, it is possible to form an end face shape having a design property that is asymmetric in the thickness direction in a cross-sectional view. Accordingly, the quality stability that has occurred when the design property is imparted to the end face of the glass substrate 118 by changing the showering condition does not occur. Therefore, it is possible to impart design properties to the end face shape while ensuring high quality stability, and as a result, it is possible to improve the design properties of the electronic device (smartphone 300). Further, if the end surface shape of the glass substrate 118 is a gently curved shape having R, it is possible to prevent the end surface 118a from being cracked or caught when the end surface 118a is touched.

  As mentioned above, although preferred embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention relates to a cover glass for an electronic device including a cover glass for a portable device used as a cover member for a display screen of a portable device (portable electronic device) and a cover glass for a touch sensor used as a cover member for the touch sensor. It can utilize for the manufacturing method of a glass substrate.

14a ... Etching-resistant layer, 14b ... Etching-resistant layer, 100 ... Protective cover glass, 102 ... Glass plate, 102a ... End face, 102b ... Main surface, 102c ... Main surface, 102d ... Opening, 102e ... Opening, 104 ... Adhesive layer, DESCRIPTION OF SYMBOLS 110 ... Glass base plate, 110a ... 1st main surface, 110b ... 2nd main surface, 112a ... Resist film, 112b ... Resist film, 114a ... Etch-resistant layer, 114b ... Etch-resistant layer, 116a ... Photomask, 116b DESCRIPTION OF SYMBOLS ... Photomask, 118 ... Glass substrate, 118a ... End face, 118b ... Apex, 300 ... Smartphone, 300a ... Smartphone main body, 302 ... Touch panel display, 304 ... Exterior cover glass, 306 ... Housing

Claims (4)

An etching resistant layer forming step for forming an etching resistant layer in which a processing pattern in the shape of a cover glass for an electronic device is formed on the first main surface and the second main surface of the glass base plate;
Both main surfaces of the glass base plate are etched to dissolve the glass base plate along the processing pattern and separate the glass substrate in the shape of the electronic device cover glass from the glass base plate. An etching process,
By making the width of the processing pattern on the first main surface side larger than the width of the processing pattern on the second main surface side in the etching resistant layer forming step, the end surface of the glass substrate is made in the etching processing step. A method for producing a glass substrate for a cover glass for electronic equipment, wherein the glass substrate is formed so as to be asymmetric in a thickness direction in a cross-sectional view. On the end surface of the glass substrate, a top portion protruding outward in the surface direction is formed,
The shape of the end surface of the glass substrate is a distance between the first main surface and the top in the thickness direction, and a distance between the second main surface and the top in the thickness direction. The manufacturing method of the glass substrate of the cover glass for electronic devices of Claim 1 characterized by the above-mentioned. The etching process is a shower ring,
3. The glass of the cover glass for an electronic device according to claim 1, wherein in the etching treatment step, the showering conditions on the first main surface side and the second main surface side are the same. 4. A method for manufacturing a substrate.   The method for manufacturing a glass substrate of a cover glass for electronic equipment according to claim 1, wherein the etching treatment is dipping.

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