JP2015068909A - Method of manufacturing cover glass for electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cover glass for an electronic apparatus that can prevent an air gap and reduction in visibility of a display area due to the air gap while preventing increase in total thickness, and achieve reduction in costs, and to provide a method of manufacturing the same.SOLUTION: A method of manufacturing a cover glass for an electronic apparatus (outer package cover glass 304) includes: forming a frame-like decorative layer 122 on a periphery of a main surface of a plate-like glass substrate 120 so as to protrude from the main surface; filling the inside of a frame of the frame-like decorative layer 122 with a liquid transparent resin 126 so as to have the same thickness as the decorative layer 122; and curing the transparent resin 126.

Description

  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 relates to a manufacturing method.

  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 recent years, in electronic devices such as those described above, most of the surface on which the display device is provided (hereinafter referred to as a display surface) is a display region, and a frame-like non-display region (display) is displayed around the display region. An area other than the area) is provided. In order to form this non-display area, a decorative layer (also referred to as a shielding layer) is formed on the cover glass in an area corresponding to the non-display area. Hereinafter, in the cover glass, an area where the decorative layer is formed (area corresponding to the non-display area on the display surface) is referred to as a decorative area, and an area where the decorative layer is not formed (area corresponding to the display area on the display surface) ) Is referred to as a non-decorated region.

  As a method for forming a decorative layer on a cover glass, conventionally, a method of attaching the decorative layer to the cover glass with a double-sided tape has been used. However, with this method, a gap in the thickness direction is generated between the display device and the cover glass depending on the thickness of the base material of the decorative layer (ink) or the double-sided tape. In other words, the visibility of the display area is reduced due to this.

  Therefore, for example, in Patent Document 1, a transparent adhesive filling layer that fills the gap is provided. Specifically, in the protective plate that protects the surface of the display device, a transparent adhesive filling layer is formed on the first transparent film on which the printing layer is formed so as to cover the printed layer, and the first transparent of the transparent adhesive filling layer is formed. The 2nd transparent film is arrange | positioned on the surface on the opposite side to the film side. And the transparent adhesive layer is formed in the surface on the opposite side to the transparent adhesive filling layer of a 2nd transparent film, and the said protection board is stuck to the display apparatus by this transparent adhesive layer.

  If a transparent adhesive filling layer is provided as in Patent Document 1, it is considered that gaps in the thickness direction generated by the printing layer can be suitably filled, and visibility degradation due to an air gap can be suppressed. Also, by sandwiching the transparent adhesive filling layer between the first film and the second film, the surface of the protective plate can be flattened, and the occurrence of a step that tends to occur when the transparent adhesive filling layer is provided can be suppressed. It is thought that.

JP2013-11699A

  However, with the configuration of Patent Document 1, although it is possible to suppress a reduction in visibility of the display area due to the air gap, the thickness of the second transparent film is added in addition to the first transparent film, Furthermore, since the transparent adhesive filling layer is also formed on the printing layer, the total thickness of the protective plate is remarkably increased. For this reason, it is difficult to achieve this in a protective cover panel that has recently been required to be further reduced in weight and thickness.

  In addition, when the protective plate includes a transparent film as in Patent Document 1, optical requirements are restricted in the material used for the transparent film. For this reason, it is essential for the transparent film to employ an optical film having a high total light transmittance and a low haze value, resulting in an increase in cost.

  In view of such a problem, the present invention is an electronic device capable of preventing a reduction in visibility of a display area caused by the air gap and thus preventing an increase in total thickness and reducing costs. An object of the present invention is to provide a method for producing a cover glass.

  In order to solve the above problems, a typical configuration of the method for manufacturing a cover glass for an electronic device according to the present invention is to add a frame-shaped additive so as to protrude from the main surface to the outer peripheral portion of the main surface of the plate-shaped glass substrate. A decorative layer is formed, a liquid transparent resin is filled in the frame of the frame-shaped decorative layer so as to have the same thickness as the decorative layer, and the transparent resin is cured.

  According to the said structure, the liquid transparent resin is filled in the space in the frame of a decoration layer, The space in the frame of the decoration layer used as the air gap conventionally is filled with transparent resin. Thereby, the fall of the visibility of the display area resulting from an air gap can be suppressed. Conventionally, the resin layer is formed even on the decorative layer (printing layer), whereas in the above configuration, the transparent resin is filled only in the space in the frame of the decorative layer, and they have the same thickness. . Therefore, an increase in thickness due to the resin used for filling is suppressed, and the cover glass can be reduced in weight and thickness.

  In addition, since the cover glass is thinned as described above, the space (volume) occupied by the cover glass in the housing of the electronic device can be narrowed, and the narrowed space can be used for mounting a large-capacity battery. It becomes possible. In addition, by filling only the space in the frame of the decorative layer with transparent resin, the amount of resin used is reduced compared to the conventional method, minimizing the cost of the resin and reducing manufacturing costs. It becomes.

  Prior to curing the transparent resin, a release film is applied to the transparent resin, the transparent resin is pressed through the release film to flatten the transparent resin, and after the transparent resin is cured, the release film is peeled off. Good. By flattening the transparent resin before curing the transparent resin as in this configuration, the flatness of the surface of the transparent resin after curing is increased, and the thickness of the decorative layer and the thickness of the transparent resin after curing are further increased. It is possible to align. Moreover, the release film can be peeled after planarization by making the film affixed on transparent resin in planarization into a release film. Therefore, it is possible to suitably prevent an increase in the total thickness due to the film.

  In order to solve the above problems, another configuration of the method for manufacturing a cover glass for an electronic device according to the present invention is to add a frame-like shape so as to protrude from the main surface to the outer peripheral portion of the main surface of the plate-like glass substrate. A decorative layer is formed, and a liquid transparent resin is filled in the frame of the frame-shaped decorative layer, and a liquid transparent resin is applied so as to cover the surface of the decorative layer on the side opposite to the glass substrate. Before curing, a release film is attached to the transparent resin, the transparent resin is pressed from above the release film to flatten the transparent resin, and after the transparent resin is cured, the release film is peeled off. . According to such a configuration, in addition to the effects described above, it is possible to suitably prevent peeling of the decorative layer when the electronic device cover glass is assembled to the electronic device body.

  A printed layer is formed on the main surface of the base film through a release layer, and the printed layer is cut along an edge of a non-decorated area that is an area other than the decorated area in the cover glass for electronic equipment, The printed layer of the cut non-decorative area is peeled off from the release layer and removed from the base film, and the printed layer of the decorative area remaining on the base film is transferred to the glass substrate. The decorative layer may be formed by peeling the film.

  According to such a configuration, since only the printed layer is transferred to the glass substrate, an increase in the total thickness of the cover glass due to the base film can be prevented. Therefore, it is possible to further reduce the weight and thickness of the cover glass as compared with the conventional method in which the base film on which the printed layer is formed is attached to the glass substrate. Further, since the base film is peeled off, the base film is excluded from the constituent elements of the cover glass. Therefore, since it is not necessary to employ an optical film as the base film, an inexpensive material can be selected, and the cost can be further reduced.

  ADVANTAGE OF THE INVENTION According to this invention, manufacture of the cover glass for electronic devices which can suppress the fall of the visibility of the display gap resulting from an air gap by extension, preventing the increase in total thickness, and can aim at reduction of cost. A method can be provided.

It is a figure explaining the cover glass for electronic devices manufactured by the manufacturing method concerning this embodiment. It is a flowchart explaining the manufacturing method of the cover glass for electronic devices concerning this embodiment. It is a flowchart explaining a decoration layer formation process. It is typical sectional drawing which shows the state of the cover glass for electronic devices in a decoration layer formation process. It is typical sectional drawing which shows the state of the cover glass for electronic devices in a decoration layer formation process. It is a schematic diagram which shows the state of the cover glass for electronic devices in the manufacturing process after a decoration layer formation process.

  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 manufacturing method according to the present embodiment. FIG. 1A is an external perspective view of a smartphone 300 exemplified as an electronic device and a protective cover glass 200 affixed thereto, and FIG. 1B is a schematic diagram of the smartphone 300 shown in FIG. FIG. In the present embodiment, the smart phone 300 is exemplified as the electronic device. However, the present invention is not limited to this, but other mobile phones, portable game machines, PDAs (Personal Digital Assistants), digital still cameras, video cameras Alternatively, a slate PC (Personal Computer) or the like may be used.

  As illustrated in FIG. 1A, a smartphone 300 that is an electronic device according to the present embodiment covers a touch panel display 302 (touch sensor) that is a display device and a surface of the touch panel display 302, and covers the touch panel display 302. An electronic device exterior cover glass (hereinafter referred to as exterior cover glass 304), which is a touch sensor cover glass used as a member. 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 200 is an external cover glass for portable devices (an external protective cover glass for electronic devices) that is detachably attached so as to cover the display screen in the exterior of the electronic device. The protective cover glass 200 is configured to include a glass plate 202 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 200, that is, the cover glass for an electronic device including both are simply referred to as a cover glass.

  As shown in FIG. 1A, in the smartphone 300, most of the surface (display surface) on which the touch panel display 302, which is a display device, is provided is a display area that is displayed on the touch panel display 302. In addition, as shown in FIG. 1B, the area (outer periphery) around the display area is a non-display area. In order to form this non-display area, a decorative layer is formed on the exterior cover glass 304 in an area corresponding to the non-display area.

  FIG. 2 is a flowchart illustrating a method for manufacturing the cover glass for an electronic device according to the present embodiment. In the following description, the case where the exterior cover glass 304 is manufactured will be described as an example. However, the present invention is not limited to this, and the present invention is preferably applied also when the protective cover glass 200 is manufactured. Can do. In addition, for convenience of explanation, in the present embodiment, in the exterior cover glass 304, an area corresponding to a non-display area on the display surface of the smartphone 300, that is, an area corresponding to the outer periphery is defined as a decoration area 304a to be decorated. An area corresponding to the display area on the display surface is referred to as a non-decorated area 304b that is not decorated.

  As shown in FIG. 2, in the manufacturing method of the cover glass for electronic devices of this embodiment, first, in the decorative layer forming step (step S400), the outer peripheral portion of the main surface of the plate-like glass substrate 120 (see FIG. 5). In addition, the frame-shaped decorative layer 122 is formed so as to protrude from the main surface. FIG. 3 is a flowchart for explaining the decorative layer forming step. 4 and 5 are schematic cross-sectional views showing the state of the cover glass for electronic equipment in the decorative layer forming step.

  As shown in FIG. 3, in the decorative layer forming step (step S400), first, in the release layer forming step (step S402), a release agent having water repellency is applied to the base film 102, so that FIG. A release layer 104 is formed on the base film 102 as shown in FIG. The base film 102 is preferably a material having appropriate heat resistance and capable of continuous printing such as a roll material, and examples thereof include a polyethylene terephthalate film (PET film). Further, as will be described later, since the print layer 106 is formed on the release layer 104, from the viewpoint of preventing repelling and unevenness of the print layer 106, the release agent constituting the release layer 104 is a non-silicone type. It is preferable to use a mold release agent.

  Here, in this embodiment, although the structure which forms the mold release layer 104 was illustrated, it is not limited to this. For example, it is possible to prepare the base film 102 in which the release layer 104 is provided on the main surface in advance, and to eliminate the release layer forming step (step S402).

  Next, in the printing layer forming step (step S404), by applying ink onto the release layer 104, the print layer 106 is formed on the release layer 104 as shown in FIG. As a printing method at this time, for example, gravure printing or the like can be suitably employed. Through these steps, the release layer 104 and the print layer 106 are sequentially formed on the base film 102.

  When the print layer 106 is sufficiently dried, the pressure-sensitive adhesive layer 108 is formed on the print layer 106 in the pressure-sensitive adhesive layer forming step (step S406) as shown in FIG. The pressure-sensitive adhesive layer 108 may be formed by applying a pressure-sensitive adhesive (adhesive) on the printing layer 106, or a film-like pressure-sensitive adhesive sheet, for example, OCA (Optical Clear Adhesive) is stuck on the printing layer 106. May be formed. Thus, by providing the adhesive layer 108 on the print layer 106, the adhesion strength of the print layer 106 to the glass substrate 120 can be increased.

  In the present embodiment, the configuration in which the adhesive layer 108 is formed on the print layer 106 is illustrated, but the present invention is not limited to this. In the case where the ink constituting the printing layer 106 is capable of obtaining adhesiveness or adhesiveness that can sufficiently secure the adhesion strength with the glass substrate 120, the adhesive layer 108 and the adhesive layer forming step can be omitted. is there.

  When the adhesive layer 108 is formed, the separator 110 is attached on the adhesive layer 108 as shown in FIG. 4D in the separator attaching step (step S408). In addition, when not forming the adhesion layer 108, you may abbreviate | omit a separator sticking process. Further, even when the adhesive layer 108 is formed by OCA and the OCA is provided with a separator, the separator attaching step can be omitted by using the separator.

  In addition, as thickness of the base film 102 and the mold release layer 104 formed on it, 38-50 micrometers can be illustrated, and since the thickness of the mold release layer 104 will be 0.1 micrometer or less, The thickness of the base film 102 and the release layer 104 formed thereon is approximately the thickness of the base film 102 itself. Further, the thickness of the printing layer 106 can be exemplified by 10 μm, the thickness of the adhesive layer 108 can be exemplified by 15-20 μm, and the thickness of the separator 110 can be exemplified by 20 μm. However, these thicknesses are merely examples, and are not limited thereto.

  When the separator 110 is pasted, in the cutting process (step S410), as shown in FIG. 4E, the separator 110 to the base film 102 are cut along the outer shape of the outer cover glass 304, and the outer cover is covered. Cutting is performed from the separator 110 to the printing layer 106 along the edge of the non-decorative region 304b, which is a region other than the decorative region 304a in the glass 304. As a cutting method at this time, die cutting, laser cutting, or the like can be suitably employed.

  Then, in the printing layer sampling step (step S412), as shown in FIG. 4 (f), the printing layer 106 in the region corresponding to the cut non-decorative region 304b is peeled from the release layer 104 together with the separator 110. The printed layer 106 in a region corresponding to the non-decorated region 304b is removed from the base film. Thereby, the transfer sheet 112 from which the printing layer 106 in the area corresponding to the non-decorative area 304b is removed is manufactured.

  As described above, since the release layer 104 is formed between the base film 102 and the print layer 106, the adhesion strength between the base film 102 and the print layer 106 is reduced. On the other hand, since the adhesive layer 108 is formed between the separator 110 and the printing layer 106, high adhesion strength can be obtained between the separator 110 and the printing layer 106. For this reason, the printed layer 106 in a desired region is peeled off together with the separator 110, so that the printed layer 106 is peeled off from the base film 102 while adhering to the separator 110, and the printed layer 106 in that region is removed from the base film 102. Is done. Therefore, according to the manufacturing method according to the present embodiment, it is possible to easily manufacture the printing layer 106 having a shape corresponding to the shape of the decoration region 304a, that is, the transfer sheet 112 on which the print pattern of the decoration region 304a is formed. Is possible.

  In the present embodiment, in the cutting step (step S410), cutting along the outer shape of the exterior cover glass 304 and cutting along the edge of the region corresponding to the non-decorated region 304b of the exterior cover glass 304 are performed. However, this configuration is merely an example, and the present invention is not limited to this. Such cutting may be performed in separate cutting steps, and in that case, the order of cutting can be arbitrarily set.

  When performing the separator pasting process from the release layer forming process to the base film 102 individually cut into the shape of the exterior cover glass 304 in advance, cutting along the outer shape of the exterior cover glass 304 is performed. Naturally it is unnecessary. Furthermore, the separator pasting process is performed from the release layer forming process only on the area corresponding to the decoration area of the exterior cover glass 304 with respect to the base film 102 previously cut into the shape of the exterior cover glass 304. In some cases, it is possible to eliminate the cutting process itself.

  When the transfer sheet 112 shown in FIG. 4 (f) is manufactured, in the separator peeling step (step S414), as shown in FIG. 5 (a), the surface on the separator 110 side of the transfer sheet 112 is opposed to the glass substrate 120. The separator 110 is peeled off as shown in FIG. Then, by sticking the transfer sheet 112 to the glass substrate 120 in the printing layer attaching step (step S416), the adhesive layer 108 is attached to the glass substrate 120 as shown in FIG. The printed layer 106 is affixed to the glass substrate 120, and the printed layer 106 in a region corresponding to the decorative region 304 a remaining on the base film 102 is transferred to the glass substrate 120.

Examples of the glass substrate 120 include aluminosilicate glass, soda lime glass, borosilicate glass, and the like. 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 for improving ion exchange performance in chemical strengthening. 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 (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.

  After affixing the printing layer 106, a deaeration process (defoaming process) using an autoclave or the like may be performed according to the adhesion strength with the glass substrate 120. When sufficient adhesion strength with the glass substrate 120 is obtained, in the base film peeling step (step S418), as shown in FIG. Peel from.

  At this time, since the release layer 104 is formed between the base film 102 and the printing layer 106, the adhesion strength is low, and between the glass substrate 120 and the printing layer 106, a high adhesion strength is obtained by the adhesive layer 108. . Therefore, the print layer 106 is peeled from the base film 102 at the interface with the release layer 104, and the print layer 106 is attached onto the glass substrate 120 through the adhesive layer 108. Thereby, in the main surface of the plate-shaped glass substrate 120, the frame-shaped decorative layer 122 including the printed layer 106 is formed in the decorative region 304a (see FIG. 1B) which is the outer peripheral portion (see FIG. 5 (d)).

  As described above, in this embodiment, since the release layer 104 is formed on the base film 102, the base film 102 is removed from the print layer 106 after the print layer 106 is pasted on the glass substrate 120. Can be peeled off. Accordingly, in the configuration in which the print layer 106, the adhesive layer 108, and the adhesive layer 108 are not formed, only the print layer 106 can be transferred onto the glass substrate 120, and the base film 102 remains in the decorative region as in the past. Does not occur. Thereby, the film thickness at the time of decoration can be thinned about 30 to 50% compared with the past, and the increase in the total thickness of the cover glass by the base film 102 can be prevented.

  Moreover, according to the structure of this embodiment, compared with the case where the base film 102 is a component of a decoration layer like the past, the thickness of a decoration layer is reduced significantly. Therefore, since the thickness of the air gap formed by the decoration layer is reduced, it is possible to suppress a decrease in the visibility of the display area due to the air gap. Furthermore, since the base film 102 is removed from the constituent elements of the decorative layer by peeling the base film 102, the cover glass can be reduced in weight and thickness, and the optical film can be used as the base film 102. Therefore, it is possible to select an inexpensive material for the base film 102 and to reduce the cost.

  FIG. 6 is a schematic diagram showing the state of the cover glass for electronic equipment in the manufacturing process after the decorative layer forming process, and FIG. 6A is a plan view of the glass substrate 120 in the resin filling process. (B)-(g) is typical sectional drawing which shows the state of the cover glass for electronic devices in the manufacturing process after a decoration layer formation process. As described above, after the decorative layer 122 is formed on the glass substrate 120 in the decorative layer forming step (step S400), subsequently, in the resin filling step (step S422), the space inside the frame-shaped decorative layer 122. Is filled with a liquid transparent resin 126 as shown in FIG. 6B.

  At this time, in this embodiment, as shown in FIG. 6B, the transparent resin 126 is dropped into the stepped portion 124 instead of pouring the transparent resin into the entire stepped portion 124. As shown in FIG. 6A, in this embodiment, the transparent resin 126 is dropped in the stepped portion 124 so as to have a fishbone shape. The filling amount (dropping amount) of the transparent resin 126 may be appropriately set according to the volume of the stepped portion 124, the shrinkage amount of the transparent resin 126 in the resin curing step described later, and the like.

  As the above-described transparent resin 126, it has high adhesion, high transparency, high transmittance, low haze, chemical resistance, heat resistance and weather resistance, and has good followability to the four corners of the stepped portion 124, and after curing. A resin that loses its adhesiveness is preferred. Specifically, silicon-based, urethane-based, acrylic-based, melamine-based, epoxy-based, polyester-based, urea-based and phenol-based resins can be suitably used. In the present embodiment, since UV curing is performed in a resin curing step to be described later, a case where a UV curable resin is used as the transparent resin 126 is illustrated, but the present invention is not limited to this. When other curing methods such as heat curing and moisture curing are employed, a resin may be appropriately selected according to the curing method.

  After filling (dropping) the transparent resin 126 into the stepped portion 124, the release film 128 is attached to the transparent resin 126 and the decorative layer 122 in the release film attaching step (step S424) before the transparent resin 126 is cured. In the pressure flattening step (step S426), the transparent resin 126 is flattened by pressing the transparent resin 126 from above the release film 128 with the roller 130. In this embodiment, as shown in FIG. 6B, the transparent resin 126 is applied from above the release film 128 by the roller 130 while the release film 128 is applied to the transparent resin 126 and the decorative layer 122 by the roller 130. Pressurize. That is, in this embodiment, the release film sticking step and the pressure flattening step are performed simultaneously.

  By performing the above-described pressure flattening step, as shown in FIG. 6C, the transparent resin 126 is coated on the entire surface of the step portion 124, and the flat surface of the transparent resin 126 is flattened. And the decorative layer 122 have the same thickness. Thus, by flattening the transparent resin 126 before performing the resin curing step, the thickness of the transparent resin 126 and the thickness of the decorative layer 122 are preferably increased while increasing the flatness of the surface of the transparent resin 126. Can be aligned. Therefore, it is possible to further improve the flatness and thickness coincidence of the transparent resin 126 after curing.

  In addition, in this embodiment, although the structure filled with the liquid transparent resin 126 in the frame of the frame-shaped decoration layer 122 was illustrated, it is not limited to this, In the frame of the frame-shaped decoration layer 122 In addition, the liquid transparent resin 126 may be filled and the liquid transparent resin 126 may be applied so as to cover the surface of the decorative layer 122 on the side opposite to the glass substrate. Thereby, peeling of the decoration layer 122 at the time of assembling the said cover glass for electronic devices to an electronic device main body can be prevented suitably.

  After the transparent resin 126 has been flattened, in the resin curing step (step S428), as shown in FIG. 6D, the UV resin is irradiated from the release film 128 with ultraviolet rays as shown in FIG. 126 is cured, and a transparent resin layer 134 made of the cured transparent resin 126 is formed. As a result, the stepped portion 124 (see FIG. 6B), which is the space in the frame of the decorative layer 122, is filled with the transparent resin layer 134 (transparent resin 126), so that the air gap caused by the stepped portion 124 is eliminated. It is possible to suppress a reduction in the visibility of the display area due to the air gap.

  In this embodiment, the transparent resin 126 is filled only in the stepped portion 124, and the thickness of the transparent resin layer 134 and the thickness of the decorative layer 122 are made uniform. Thereby, compared with the case where the resin layer was formed even on the decoration layer (printing layer) like the past, the increase in the thickness of the cover glass 304 for exterior by the resin used for filling is suppressed, It becomes possible to promote weight reduction and thinning. Further, according to the configuration in which the transparent resin 126 is filled only in the stepped portion 124 that is the space in the frame of the decorative layer 122, the amount of the transparent resin 126 used can be reduced as compared with the conventional case. It is possible to reduce the manufacturing cost.

  After the transparent resin 126 is cured, in the release film peeling step (step S430), as shown in FIG. 6E, the release film stuck on the transparent resin layer 134 (transparent resin 126) and the print layer 106. 128 is peeled off. Since the release film 128 can be peeled after the pressure flattening step, the film to be attached to the transparent resin 126 when performing the pressure flattening step described above can be peeled off after the pressure flattening step. It is possible to prevent an increase in the total thickness of the exterior cover glass 304 due to the film applied during the process.

  After the transparent resin 126 is cured, when the release film 128 is peeled off as shown in FIG. 6 (f), a degassing step (step S432) is provided as necessary, and a degassing process such as an autoclave is performed. Thereby, as shown in FIG. 6G, the bubbles 126a included in the transparent resin layer 134 (transparent resin 126) are degassed, and the exterior cover glass 304 is manufactured. By performing the deaeration treatment as in this embodiment, it is possible to reduce product defects caused by bubbles and improve the quality and yield of the exterior cover glass 304 (electronic device cover glass). In addition, although the case where the deaeration process is performed after the release film peeling process is illustrated in the present embodiment, the present invention is not limited to this, and before the transparent resin 126 is cured in the resin curing process, the process illustrated in FIG. The transparent resin 126 may be cured by performing a deaeration process in the state and then performing a pressure flattening process again.

  As described above, according to the method for manufacturing the cover glass for an electronic device of the present embodiment, as shown in FIG. 6G, the frame-shaped decoration formed on the outer peripheral portion of the main surface of the glass substrate 120. The transparent resin layer 134 provided in the space in the frame of the layer 122 and the frame-like decorative layer 122 on the main surface of the glass substrate 120, and the thickness of the decorative layer 122 and the transparent resin layer 134 is equal. An exterior cover glass 304 can be manufactured. In the exterior cover glass 304, the space in the frame of the decorative layer 122 that has become the air gap is filled with the transparent resin layer 134 (transparent resin 126), and thus the visibility of the display area caused by the air gap is improved. Is prevented from decreasing.

  Further, since the transparent resin layer 134 is not formed on the decorative layer 122 and the decorative layer 122 and the transparent resin layer 134 have the same thickness, an increase in thickness due to the transparent resin layer 134 can be prevented, and the exterior It is possible to reduce the weight and thickness of the cover glass 304 for use. The space (volume) occupied by the exterior cover glass 304 in the housing 306 of the electronic device (smart phone 300) is reduced by being thin like the exterior cover glass 304 of the present embodiment. can do. Therefore, the space vacated by the narrowing can be used for mounting a large-capacity battery.

  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 be used for manufacturing methods.

DESCRIPTION OF SYMBOLS 102 ... Base film, 104 ... Release layer, 106 ... Print layer, 108 ... Adhesive layer, 110 ... Separator, 120 ... Glass substrate, 122 ... Decoration layer, 124 ... Step part, 126 ... Transparent resin, 128 ... Release Mold film, 130 ... roller, 132 ... UV lamp, 134 ... transparent resin layer, 200 ... protective cover glass, 202 ... glass plate, 300 ... smartphone, 302 ... touch panel display, 304 ... cover glass for exterior, 304a ... decoration area , 304b ... non-decorative region, 306 ... casing

Claims (4)

A frame-shaped decorative layer is formed so as to protrude from the main surface on the outer peripheral portion of the main surface of the plate-like glass substrate,
Fill the frame of the frame-shaped decorative layer with a liquid transparent resin so as to have the same thickness as the decorative layer,
The manufacturing method of the cover glass for electronic devices characterized by hardening the said transparent resin. Before curing the transparent resin, a release film is attached to the transparent resin,
Pressurizing the transparent resin through the release film to flatten the transparent resin,
The method for producing a cover glass for an electronic device according to claim 1, wherein the release film is peeled after the transparent resin is cured. A frame-shaped decorative layer is formed so as to protrude from the main surface on the outer peripheral portion of the main surface of the plate-like glass substrate,
While filling the liquid transparent resin in the frame of the frame-shaped decorative layer, and applying the liquid transparent resin so as to cover the surface of the decorative layer on the side opposite to the glass substrate,
Before curing the transparent resin, a release film is attached to the transparent resin,
Pressurizing the transparent resin from above the release film to flatten the transparent resin,
A method for producing a cover glass for electronic equipment, comprising: releasing the release film after curing the transparent resin. Form a print layer on the main surface of the base film through a release layer,
Cutting the printed layer along the edge of the non-decorative region which is a region other than the decorative region in the cover glass for the electronic device,
The cut print layer of the non-decorative region is removed from the base film by peeling off the release layer and removing it,
Transfer the decorative layer printed layer remaining on the base film to the glass substrate,
The method for producing a cover glass for an electronic device according to any one of claims 1 to 3, wherein the decorative layer is formed by peeling the base film.

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