JP6324599B1 - Manufacturing method of cover glass - Google Patents

Abstract

A method of manufacturing a cover glass that receives a touch operation from a user, the cover glass having a region including a curved shape at a peripheral edge. A cover glass manufacturing method includes a protection step, a first patterning step, a first etching step, a cutting step, and an end face forming step. The protection step is a process in which both main surfaces of the glass substrate 30 for multi-faces are covered with the protection film 32. The first patterning step is a step of removing a part of the protective film 32. The first etching step is a step of forming the recess 38 in the region where the protective film 32 has been removed by an etching process. The dividing step is a step of dividing the glass base material 30 along the planned cutting line 40. The end surface forming step is a step of polishing so that the divided section 42 formed in the dividing step is substantially parallel to the side surface portion of the recess 38. [Selection] Figure 5

Description

  The present invention relates to a method for manufacturing a cover glass that accepts a touch operation from a user, and more particularly, to a method for manufacturing a cover glass having a curved region at a peripheral edge.

  In recent years, a touch panel has been adopted in a wide range of fields as an interface when a user operates a device because of an advantage that an intuitive operation is possible. The cover glass for the touch panel is arranged on the side where the touch panel is exposed to the user, and is configured to accept a touch operation performed while the user visually recognizes a touch operation area where icons and the like are displayed. Due to the improved design due to the flatness of the cover glass and high transparency, the movement to replace with a touch panel has spread to devices that conventionally used physical buttons and keyboards. For example, in a portable electronic terminal such as a smartphone, most operations can be performed with a touch panel.

  Usually, the cover glass is manufactured by dividing into a desired individual glass substrate from a large glass base material, and the dividing process is generally performed by machining such as a scribe break process. is there. In recent years, there has been a demand for a cover glass that includes a curved region or a notch region in the contour portion for differentiation in terms of design, but the curved region or the notch region is divided using a scribing device. It was difficult to do.

  Therefore, among the prior arts, there has been a technique for manufacturing a cover glass including a curved region or the like by dividing a glass substrate by an etching process (see, for example, Patent Document 1). Furthermore, since it is possible to remove fine scratches on the end face by dividing by etching without performing machining such as scribe break, it is said that the strength of the cover glass is improved.

Japanese Patent No. 5654072

  The etching process can easily control the shape of the cover glass, but a convex protrusion is formed at the center in the thickness direction on the end surface of the cover glass. The protruding portion has a tapered shape, has low strength even in the end face, and may be damaged or chipped even with a slight impact. For this reason, it may be necessary to additionally perform an etching process or end face polishing after the dividing process to shorten the protruding distance of the protruding portion.

  Furthermore, some recent portable information terminals such as smartphones and tablets have a curved region at the peripheral edge for the purpose of design differentiation. For this reason, the cover glass must also be formed in a shape that follows the curved area, but it is very difficult to curve only the peripheral edge of the cover glass. Examples of the peripheral edge bending process include a heat treatment step and end face polishing. In the heat treatment, the peripheral edge of the cover glass must be heated to the softening point and then processed with a mold or the like, and the productivity is low. In the end surface polishing step, a polishing device such as a spindle is used. However, there are problems that the end surface is finely scratched, and that the productivity decreases when the polishing amount increases. Further, since the etching process isotropically progressed, it has been difficult to form a desired shape.

  The objective of this invention is providing the manufacturing method of a cover glass provided with the area | region containing a curved shape in a peripheral part in the cover glass which receives the touch operation from a user.

  The cover glass manufacturing method according to the present invention includes a protection step, a first patterning step, a first etching step, a cutting step, and an end face forming step. The protection step is a step of covering both main surfaces of the glass substrate for multi-faceting the cover glass with a protective layer having at least etching resistance. The first patterning step is a step of removing the protective layer in the region corresponding to the central portion on the second main surface of the glass substrate. The first etching step is a step of forming a recess in the region where the protective layer has been removed by bringing the glass substrate into contact with an etching solution. The dividing step is a step of dividing the outer edge of the recess along the planned cutting line of the cover glass. The end surface forming step is a step of polishing so that the divided cross section formed in the dividing step is substantially parallel to the side surface portion of the recess. The cover glass manufactured by this invention is comprised with the single glass member, and is provided with the peripheral part arrange | positioned around the flat center part and the center part. The peripheral portion is a region having a curved portion that is curved from the first main surface to the second main surface.

  In the present invention, it is possible to form a curved region in the peripheral portion of the glass substrate by combining etching and machining. By including an etching process in the process of forming the peripheral edge, a cover glass can be efficiently manufactured from a glass substrate for multi-face production. Furthermore, by combining the etching process, the amount of polishing of the glass substrate can be reduced by machining, so that fine scratches on the peripheral edge can be suppressed and production can be performed without reducing the strength of the cover glass. Can do.

  The dividing step preferably includes a second patterning step and a second etching step. The second patterning step is a step of removing a part of the protective layer coated on both main surfaces of the glass substrate along the planned cutting line. Further, in the second patterning step, the protective layer is removed so that the width of the planned cutting line formed on the first main surface is smaller than the width of the planned cutting line formed on the second main surface. Is called. The second etching step is a step of dividing the glass substrate along the planned cutting line by bringing the glass substrate into contact with the etching solution. By adjusting the width of the planned cutting line in the second patterning and then dividing by the etching process, the inclination angle of the side surface of the recess and the inclination angle of the dividing surface become approximately the same, so the amount of end face polishing in the end face forming step is suppressed. Production efficiency can be improved.

  In the second etching step, it is preferable that the etchant is simultaneously brought into contact with the first main surface and the second main surface. Since the etching process isotropically progressed, adjustment of the angle of the sectional surface requires multi-stage etching, which may reduce the production efficiency. However, since the width of the planned cutting line is adjusted in the second patterning step, it is possible to form a sectional surface having a desired inclination angle by one etching.

  According to the present invention, it is possible to easily manufacture a cover glass having a curved region at the peripheral edge.

It is a figure which shows the cover glass which concerns on one Embodiment of this invention. It is a figure which shows the cover glass mounted on the portable information terminal. It is a figure shown about patterning of a glass base material. It is a figure shown about formation of the recessed part to a glass base material. It is a figure shown about the process of the end surface shape of a cover glass. It is a figure shown about patterning of a glass base material. It is a figure which shows the mode of the division | segmentation by the etching of a glass base material. It is a figure shown about the process of the end surface shape of a cover glass.

  From here, one Embodiment of this invention is described using drawing. FIG. 1 is a view showing a cover glass 10 manufactured according to an embodiment of the present invention. Cover glass 10 is a glass substrate having a first main surface 12 and a second main surface 14. Further, the cover glass 10 includes a flat portion 16 disposed at the center of the cover glass 10 and a curved portion 18 disposed around the flat portion 16.

  The glass substrate used for the cover glass 10 is preferably aluminosilicate glass, but is not particularly limited, and soda glass or non-alkali glass may be used. The cover glass 10 preferably has a thickness of about 0.1 to 1.5 mm. Further, if necessary, a compressive stress layer may be formed. The compressive stress layer can be formed by a known ion exchange method, and the thickness of the formed compressive stress layer is adjusted in the range of 5 to 100 μm. The

  The flat portion 16 is a flat region existing in the central portion of the cover glass 10. The plate thickness of the flat portion 16 is preferably about 0.1 to 0.5 mm, but is not limited thereto. The curved portion 18 is a region formed at the peripheral edge of the cover glass 10. The curved portion 18 has a shape that inclines from the first main surface 12 side toward the second main surface 14 side at the peripheral edge of the cover glass 10. Further, the main surface area of the bending portion 18 is configured to bend in a convex shape toward the outside. The boundary between the flat portion 16 and the curved portion 18 is configured to have a rounded shape. The inclination angle of the bending portion 18 is appropriately adjusted according to the device to which the cover glass 10 is attached. In addition, the bending part 18 does not need to be arrange | positioned over the peripheral part whole region of the cover glass 10, and may be arrange | positioned only on one desired side.

  Cover glass 10 can be used for portable information terminal 50 shown in Drawing 2 (A), for example. The portable information terminal 50 has an information display area 52 in the center. The information display area 52 is an area for displaying information such as icons on a flat panel display such as a liquid crystal display. Moreover, the peripheral part of the information display area 52 has a curved shape in a cross-sectional view.

  The cover glass 10 is disposed so as to cover the main surface on which the information display area 52 is disposed. Since the curved portion 18 is curved so as to correspond to the end portion of the portable information terminal 50, the end portion of the portable information terminal 50 can also be reliably protected. In the cover glass 101 having a flat shape, the end of the portable information terminal 50 is exposed as shown in FIG.

  From here, the manufacturing method of the cover glass 10 is demonstrated using FIGS. When manufacturing the cover glass 10, the large sized glass base material 30 by which the several cover glass 10 was chamfered is normally used. The cover glass 10 is formed into a desired shape by being divided into individual pieces from the glass base material 30. In the present embodiment, a method for manufacturing a rectangular cover glass will be described, but the cover glass can be formed into a desired shape by an etching process.

  First, the protective film 32 having etching resistance is covered on the first main surface 34 and the second main surface 36 of the glass base material 30. In the present embodiment, a self-adhesive film having at least resistance to hydrofluoric acid is used as the protective film 32. In addition to the film, a resin agent or a resist agent may be used as long as it has resistance to hydrofluoric acid.

  After covering both main surfaces of the glass base material 30 with the protective film 32, as shown in FIG. 3 (A) and FIG. 3 (B), the protective film from the region corresponding to the flat portion 16 in the second main surface 34. A patterning process for removing 32 is performed. An example of the patterning process includes a method of removing the protective film 32 using a laser device. The laser device used for the patterning process is not particularly limited as long as the glass base material 30 is not excessively damaged. When the glass base material 30 is coated using a photosensitive resist material, patterning can also be performed using photolithography.

  Subsequently, the glass base material 30 is brought into contact with the etching solution to perform an etching process for forming a recess 38 in the patterned region. Examples of the etching treatment include a dip type etching method in which the glass base material 30 is immersed in the etching liquid and a spray type etching method in which the etching liquid is sprayed onto the glass base material 30. The etching solution contains at least hydrofluoric acid, and it is possible to add an inorganic acid such as hydrochloric acid or an etching aid such as a surfactant as necessary.

  The recess 38 formed by the etching process is formed so that the bottom surface is substantially horizontal to the first main surface 34 as shown in FIG. Moreover, the side part of the recessed part 38 is exhibiting the inclined surface which spreads toward an open side. Furthermore, the side surface of the recess 38 is curved by the etching process. The curved shape of the side surface of the recess 38 and the inclination of the taper can be appropriately adjusted depending on the composition of the etching solution and the etching method, and are changed according to the shape of the article on which the cover glass 10 is disposed.

  The glass base material 30 on which the plurality of recesses 38 are formed is cut along the planned cutting line 40 after the protective film 32 is peeled off. The planned cutting line 40 is a broken line shown in FIG. 4A and is a line corresponding to the contour portion of the cover glass 10 in the outer peripheral region of the recess 38. A known scribing break device or a laser device can be used for the cutting process. In the present embodiment, the glass base material 30 is divided by a scribe break, and the dividing surface 42 is formed so as to be substantially perpendicular to the main surface of the glass base material 30 as shown in FIG. . When the planned cutting line is composed only of straight lines, it is effective to divide by a scribing device. However, when the contour portion of the cover glass 10 includes a curved region, it is preferable to use a laser device or the like.

  Subsequently, the divided section 42 of the cover glass 10 divided into pieces from the glass base material 30 is polished until it becomes substantially parallel to the side surface of the recess 38. By polishing the dividing surface 42 until it is substantially parallel to the side surface of the recess 38, the peripheral edge of the cover glass 10 is shaped to curve downward as shown in FIG. 5C. At this time, the end surface 44 of the cover glass 10 is configured to be substantially parallel to the main surface. A known end face polishing apparatus such as a spindle can be used for the polishing process. The spindle is subjected to the polishing process until the desired end face shape is obtained while changing the count and repeating the polishing process a plurality of times. Further, it is preferable to remove fine scratches by slightly etching the dividing surface 42 after end face polishing.

  In the present embodiment, the curved portion 18 can be formed on the peripheral edge of the cover glass 10 by combining the etching process and the machining. Since the etching process can simultaneously form a plurality of recesses 38 in the glass base material 30, the production efficiency is high. In addition, by forming the end surface of the cover glass 10 after forming the concave portion 30, the amount of polishing of the end surface by machining can be suppressed. In the case where the concave portion 38 is formed by machining, the total volume for performing the polishing process is increased, which results in an inefficient process. Further, in machining, fine scratches are generated on the glass substrate, and the strength of the cover glass 10 is likely to be reduced. In this embodiment, since the recessed part 38 is formed by an etching process, the fall of the intensity | strength of the cover glass 10 can be suppressed.

  From here, the other manufacturing method of the cover glass 10 is demonstrated using FIGS. In the present embodiment, a method for performing the cutting process of the glass base material 30 after forming the recess 38 by etching will be described. First, the protective film 32 is again coated on both main surfaces of the glass base material 30 in which the recesses 38 are formed. At this time, it is preferable that the protective film 32 used at the time of forming the concave portion 38 is re-coated with a new protective film 32 after being once peeled off.

  Subsequently, a patterning process is performed on the protective film 32 along the planned cutting line. At this time, the width of the planned cutting line 401 formed on the first main surface 34 is formed to be narrower than the planned cutting line 402 formed on the second main surface 36 side where the recess 38 is formed. Is done. The width difference between the planned cutting line 401 and the planned cutting line 402 is preferably adjusted to be narrow within a range of 5 to 60% with respect to the plate thickness of the glass base material 30. When the glass substrate is divided by the etching process, it becomes an end face that has a convex protrusion formed on a substantially vertical end face, but by adjusting the patterning width, the inclination angle of the end face and the position of the protrusion can be adjusted. It becomes possible to shift. The patterning process can be performed by a laser device or photolithography in the same manner as described above.

  The glass base material 30 on which the patterning process has been performed is divided by an etching process. The etching process is performed by bringing the glass base material 30 into contact with an etching solution containing at least hydrofluoric acid as in the above-described etching process. By performing the etching process, the cutting of the glass base material 30 proceeds while the cross-sectional shape changes as shown in FIGS. 7 (A) to 7 (C). FIG. 7A is a drawing showing a state of a divided section of the glass base material 30 immediately after the start of the etching process. The first main surface 34 having a wider patterning width of the protective film 32 is more etched in the plate thickness direction than the second main surface 36. The etching process proceeds simultaneously on the first main surface 34 and the second main surface 36, but the first main surface 34 having a wider width of the planned cutting line has a faster etching progress.

  FIG. 7B is a view showing a state immediately after the etching proceeds further than in FIG. 7A and the glass base material 30 is divided. The dividing surface 42 is formed with a protrusion 46 on the second main surface 36 side in the thickness direction. Further, the inclination angle of the dividing surface 42 is close to the inclination angle of the recess 38 because it is formed by etching. FIG. 7C is a diagram illustrating a state in which etching has progressed more than FIG. 7B and is completely divided. The top of the protrusion 46 has a rounded shape.

  The cover glass 10 that has been divided into individual pieces from the glass base material 30 by etching is subjected to a polishing process on the dividing surface 42 by mechanical polishing after the protective film 32 is peeled off. The mechanical polishing is performed by a known polishing apparatus such as a spindle similarly to the above-described end surface polishing process. The dividing surface 42 including the protrusion 46 is polished by mechanical polishing (see FIG. 8B), and the cover glass 10 is finally configured so that the side surface of the recess 38 and the dividing surface 42 are substantially horizontal. By dividing the glass base material 30 by etching, the shape of the dividing surface 42 is close to the shape of the side surface of the recess 38, so that the polishing amount of the end surface processing is suppressed more than the end surface formed by the scribe break. It becomes possible to perform more efficient production.

  The above description of the embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

10-cover glass 12-first main surface 14-second main surface 16-planar portion 18-curved portion 30-glass base material 32-protective film 38-recess 40-planned cutting line 42-section

Claims (4)

A cover glass composed of a single glass member, which is a flat central portion and a peripheral portion disposed around the central portion, and is curved from the first main surface to the second main surface side. A cover glass manufacturing method comprising a peripheral portion having a curved portion,
A protective step of covering both main surfaces of the glass substrate for multi-chatting the cover glass with a protective layer having at least etching resistance;
A first patterning step of removing the protective layer in a region corresponding to the planar portion on the second main surface of the glass substrate;
A first etching step of forming a recess in a region where the protective layer has been removed by bringing the glass substrate into contact with an etching solution;
A cutting step of cutting the glass substrate along a planned cutting line corresponding to a contour portion of the cover glass;
An end face forming step for polishing so that the divided cross section formed in the dividing step is substantially parallel to the side surface of the recess;
The manufacturing method of the cover glass characterized by including.   The method for manufacturing a cover glass according to claim 1, wherein in the dividing step, the dividing surface is divided so as to be substantially perpendicular to a main surface of the glass substrate. The dividing step includes a second patterning step of removing a part of the protective layer covered on both main surfaces of the glass substrate along a planned cutting line;
A second etching step of dividing the glass substrate along a planned cutting line by contacting the glass substrate with an etching solution;
Contains
The cover glass manufacturing method according to claim 1, wherein a width of the planned cutting line formed on the first main surface is larger than a width of the planned cutting line formed on the second main surface. .   The method for manufacturing a cover glass according to claim 3, wherein in the second etching step, an etching solution is simultaneously brought into contact with the first main surface and the second main surface.

Images