TOUCH PANEL INTEGRATED WITH COVER GLASS AND MANUFACTURING METHOD THEREOF

Disclosed herein are a touch panel integrated with a cover glass and a manufacturing method thereof. The manufacturing method of a touch panel integrated with a cover glass includes: providing a sheet shaped glass substrate; forming grooves in cut regions of the glass substrate; forming a chemical tempered layer on a surface of the glass substrate and groove portions through chemical tempering; and cutting the glass substrate along the groove.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various advantages and features of the present invention and methods accomplishing thereof will become apparent from the following description of embodiments with reference to the accompanying drawings. However, the present invention may be modified in many different forms and it should not be limited to the embodiments set forth herein. Rather, these embodiments may be provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numerals throughout the specification denote like elements.

Terms used in the present specification are for explaining the embodiments rather than limiting the present invention. Unless explicitly described to the contrary, a singular form includes a plural form in the present specification. The word “comprise” and variations such as “comprises” or “comprising,” will be understood to imply the inclusion of stated constituents, steps, operations and/or elements but not the exclusion of any other constituents, steps, operations and/or elements.

Further, the exemplary embodiments described in the specification will be described with reference to cross-sectional views and/or plan views that are ideal exemplification figures. In the drawings, the thickness of layers and regions is exaggerated for efficient description of the technical contents. Therefore, exemplified forms may be changed according to manufacturing technologies and/or tolerance. Therefore, the exemplary embodiments of the present invention are not limited to specific forms but may include the change in forms generated according to the manufacturing processes. For example, an etching region vertically shown may be rounded or may have a predetermined curvature.

Hereinafter, a touch panel integrated with a cover glass and a manufacturing method thereof according to exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1is a flow chart showing a manufacturing method of a touch panel integrated with a cover glass according to an exemplary embodiment of the present invention;FIG. 2is a process flow chart showing a manufacturing process of the touch panel integrated with a cover glass according to the exemplary embodiment of the present invention;FIG. 3is a flow chart showing a processing process of a glass substrate according to the exemplary embodiment of the present invention; andFIG. 4is a cross-sectional view showing a sheet shaped glass substrate according to the exemplary embodiment of the present invention. Referring toFIGS. 2A to 4, a glass substrate10, a groove20, a chemical tempered layer30, a black decoration40, a step coating layer42, an X-axis stripe type electrode44, an X-axis transparent coating layer45, a Y-axis stripe type electrode46, and a Y-axis transparent coating layer47are shown.

A touch screen panel is an input device of selecting an instruction content shown on a screen of an image display device, or the like, using a hand of the user or an object to allow order of the user to be input.

To this end, the touch screen panel converts a touch position provided in a front face of the image display device and directly touched by the hand of the user or the object into an electric signal. Therefore, the instruction content selected at the touch position is received as the input signal.

As described above, since the touch screen panel may substitute a separate input device connected to the image display device to be operated such as a keyboard and a mouse, a usage range of the touch screen panel has increased.

The touch panel is classified into a capacitive type touch panel, a resistive type touch panel, an infrared beam type touch panel, an integral strain gauge type touch panel, a surface acoustic wave type touch panel, and a piezo electric type touch panel according to an operation scheme thereof.

For example, describing a structure of a capacitive type touch screen panel, the capacitive type touch screen panel is configured of an upper transparent sheet on which an upper transparent film to which an electric field is applied in a Y-axis direction is formed so as to be attached to an upper plate of a display panel and a lower transparent sheet on which a lower transparent film to which the electric field is applied in an X-axis direction is formed.

The upper and lower transparent films may be made of a material having excellent transmittance and resistance of about several hundreds Ω, for example, indium tin oxide (ITO).

A lower portion of the upper transparent film is provided with the X-axis stripe type electrodes. These X-axis stripe type electrodes may be formed by printing silver (Ag) on the upper transparent film.

The X-axis stripe type electrodes may be formed on the upper transparent film and connected to a tail wiring having a pad terminal at a central portion of a lower edge of the upper transparent film to thereby receive power from the tail wiring.

Both sides of the lower transparent film are provided with the Y-axis stripe type electrodes. These Y-axis stripe type electrodes may be formed by printing silver (Ag) on the lower transparent film.

The Y-axis stripe type electrodes may be formed on the lower transparent film and connected to a tail wiring having a pad terminal at a central portion of a lower edge of the lower transparent film to thereby receive power from the tail wiring.

As described above, silver (Ag) electrode wirings are formed on upper and lower portions of the touch panel. A size of the touch panel depends on a wiring interval of the electrode as described above and a distance between the electrode and a distal end of the panel, and decoration ink is printed on window glass so that the tail wiring as described above is not shown on the outside.

Decoration printing of a bezel portion as describe above is generally performed by a silk screen printing method on the window glass several times.

As the demand for the capacitive type touch panel is increased, a structure of the touch panel is changed. According to the related art, a GG type touch panel and a GFF type touch panel that independently include a sensor part between a cover and a display has been mainly used, but recently, in order to improve characteristics and reduce cost, a product in which a cover glass or display has a function of the touch panel has been developed.

That is, an on-cell type touch panel in which a pattern layer is formed on a display substrate, an in-cell type touch panel in which a pattern layer is formed in display, a touch panel integrated with a cover glass (direct patterned window (DPW), glass 2 layer (G2), glass one module (G1M), one glass solution (OGS), advanced technology touch (ATT), or the like) are developed.

Among them, the touch panel integrated with a cover glass is expected as a measure for thinness and low cost.

As described above, a manufacturing method of a capacitive type touch panel integrated with a cover glass may be divided into a cell type manufacturing method and a sheet type manufacturing method, and each of the method has advantages and disadvantages.

The embodiment of the present invention, which is to solve problems of the sheet type manufacturing method, is characterized by minimizing a chip generated in a cut surface in order to significantly decrease a decrease in strength of the glass substrate during a process of cutting a sheet after manufacturing a sensor of the touch panel integrated with a cover glass.

To this end, in the manufacturing method of a touch panel integrated with a cover glass, a groove is formed in advance at a region of sheet glass scheduled to be cut, and then chemical tempering is performed, such that a solution does not smoothly flow in the groove, and ion substitution is not activated. As a result, a depth of layer (DoL) at this portion is not deeper than those of other surfaces.

Therefore, in the case in which cutting the sheet along the processed groove after manufacturing the sensor, the strength of the cover glass may be maintained.

As a cutting method of the groove, there are a laser cutting method, a water jet cutting method, an etching method, and the like. After cutting, a healing treatment such as etching treatment, brushing treatment, or the like, is performed, such that the decrease in the strength after tempering may be complemented.

In order to manufacture the touch panel integrated with a cover glass according to the present invention, first, a sheet shaped glass substrate10is provided (S100), and a groove20is formed in advance in a region of the glass substrate10to be cut (S200).

Next, the chemical tempering is performed, such that a chemical tempered layer30is stacked on a surface of the glass substrate10and a groove20portion (S300).

Finally, the glass substrate is cut, and particularly, the region of the groove20processed in advance is cut, such that strength of the glass substrate10cut in the cell unit may not be decreased.

The entire manufacturing process of the touch panel integrated with a cover glass is shown inFIG. 2.

As shown inFIG. 2B, black decoration40is printed on a back surface of the glass substrate chemical tempered as shown inFIG. 2A(provided with the chemical tempered30) (S310), and then the step coating layer42is formed so as to cover the black decoration40as shown inFIG. 2C(S320).

Then, a stacking of the transparent sheet (a portion shown by dotted line inFIG. 2) is performed.

That is, the X-axis stripe type electrode44is formed on the step coating layer42as shown inFIGS. 2D to 2I(S330), and the X-axis transparent coating layer45is formed so as to cover the stripe type electrode44as shown inFIG. 2M(S340). Therefore, the lower transparent sheet may be formed.

Again, the Y-axis stripe type electrode46is formed on the X-axis transparent coating layer45by performing the processes ofFIGS. 2D to 2I(S350), and the Y-axis transparent coating layer47is formed so as to cover the stripe type electrode46(S360). Therefore, the upper transparent sheet may be formed.

Here, the case in which the lower transparent sheet is formed with the X-axis stripe type electrode44and the upper transparent sheet is formed with the Y-axis strip type electrode46is described by way of example, but on the contrary, the lower transparent sheet may be formed with the Y-axis stripe type electrode and the upper transparent sheet may be formed with the X-axis strip type electrode.

Next, as shown inFIG. 2N, the glass substrate10is cut along the groove20formed in advance in the glass substrate10, such that the touch panel may be manufactured in the cell unit.

After cutting the glass substrate10, the healing treatment such as etching treatment, brushing treatment, or the like, may be performed as described above (S500).

The processes of forming the groove20in advance in the glass substrate10according to the present invention, performing the chemical tempering on the glass substrate10, and then cutting the glass substrate10are shown inFIGS. 3A to 3C.

That is, the groove20is formed in advance as shown inFIG. 3Bin the sheet shaped glass substrate10provided as shown inFIG. 3A, and the chemical tempering is performed thereon as shown inFIG. 3C, and then, the glass substrate10may be cut along the groove as described above.

In this case, in the manufacturing method of a touch panel according to the exemplary embodiment of the present invention, the glass substrate10is processed so that a thickness D of the chemical tempered layer30on the glass substrate10is thicker than a thickness d of the chemical tempered layer30on the groove20portion, as shown inFIG. 4.

The reason is that the solution does not smoothly flow in the groove, such that ion substitution is not activated, and as a result, the tempered layer on the groove20portion is formed not to be deeper than that of the tempered layer on the other surface, as described above.

As described above, as the glass substrate is processed so that D is more than d (D>d) as shown inFIG. 4, since the chemical tempered layer30on the groove20portion is not thick, it may be easy to cut the glass substrate10at the groove20portion, and the strength of the substrate10may be maintained since the chemical tempered layer30partially remains at side end surfaces of the glass substrate10after cutting.

Productivity (cutting facility) and stability (a degree of maintaining strength) of the glass substrate manufactured by cutting the glass substrate10according to the exemplary embodiment of the present invention in the cell unit may be adjusted by an aspect ratio between a kerf to a depth of the groove20processed in advance in the glass substrate10.

That is, when the aspect ratio is changed, an amount of ion substitution at the groove20portion is changed, such that a depth of the chemical tempered layer30in a width direction may be differently adjusted. The aspect ratio may be variously adjusted according to the cutting method of the glass substrate10.

As described above, the glass substrate10according to the exemplary embodiment of the present invention may be cut by the method such as the laser cutting method, the water jet cutting method, the etching method, and the like. The aspect ratio of the groove20formed in the glass substrate10may be adjusted to 1.0 to 3.0 according to the change of the cutting method.

Meanwhile, before the sensor process is carried out after processing the groove20in the glass substrate10, the groove20is filled with a resin, or the like, and then subsequent processes may be performed.

Therefore, the process may be performed equally to the case in which the groove is not processed so that a change in the shape of the glass substrate10by processing the groove20does not affect the subsequent processes. The resin filled in the groove may be removed after the process in the cell unit is completed.

FIGS. 5A and 5Bare cross-sectional views showing a cell shaped glass substrate according to the exemplary embodiment of the present invention;FIG. 6is conceptual view showing a chemical tempering process according to the exemplary embodiment of the present invention;FIG. 7is conceptual view showing a chemical tempered layer of a groove portion according to the exemplary embodiment of the present invention;FIGS. 8A and 8Care cross-sectional views showing grooves according to the exemplary embodiment of the present invention;FIGS. 9A to 9Fare photographs of the grooves ofFIGS. 8A to 8C;FIG. 10is a graph showing relationship of a thickness of the chemical tempered layer to an aspect ratio of each of the grooves ofFIGS. 8A to 9F; andFIG. 11is conceptual view showing a laser cutting process according to the exemplary embodiment of the present invention. Referring toFIGS. 5A to 11, a glass substrate10, grooves20, a processing part22, a chemical tempered layer30is shown.

As described above, the manufacturing method of a touch panel integrated with a cover glass may be divided into a cell type manufacturing method and a sheet type manufacturing method. Among them, the sheet type method, which is a method of cutting glass after chemical tempering the sheet shaped glass and manufacturing a touch sensor, may be preferable due to low cost and high productivity.

However, the sheet type method has a problem in that the strength of the glass may be decreased after cutting. The touch panel integrated with a cover glass according to the exemplary embodiment of the present invention may be manufactured by processing a region of the glass in the shape of the groove20in advance in to be finally cut, chemical tempering the glass, vertically adjusting a laser focus with respect to a non-tempered part of the groove20portion to modify non-tempered glass (SeeFIG. 11), and then apply relatively weak external force to cut the glass.

The chemical tempering process may be performed as shown inFIG. 6. In this case, since ion substitution at the portion at which the groove20is processed is not smoothly performed as shown inFIG. 5, this portion is tempered to have a DoL (See ‘d’ ofFIG. 5) shallower than a DoL (See ‘D’ ofFIG. 5) of the other portion.

Therefore, even though a glass substrate may not be cut at the existing DoL (for example, 50 μm), since the portion at which the groove20is processed has shallower DoL, the cutting may be performed.

In addition, since the side of the glass may be tempered in the cell unit along the shape of the process groove20, an area of the side that is not tempered may be significantly decreased, thereby making it possible to prevent the strength of the glass substrate from be decreased and increase the strength of the glass substrate.

Therefore, the touch panel integrated with a cover glass according to the present invention has a structure in which the chemical tempered layer30is stacked on the glass substrate10in the cell unit, but an edge of the glass substrate10is formed with a processed part20.

The chemical tempered layer30may be classified into a first chemical tempered layer30stacked on the surface of the glass substrate10and a second chemical tempered layer30bstacked on the processed part20. In the present embodiment, the touch panel is manufactured by processing and treating the glass substrate so that a thickness D of the first chemical tempered layer30is thicker than a thickness d of the second chemical tempered layer30as shown inFIG. 5A.

The glass substrate10according to the exemplary embodiment of the present invention may be formed in a square shape having a predetermined thickness as shown inFIG. 5B. Here, the processed parts20may be formed at the edge of the glass substrate10, that is, four sides of the square (3 to 6 surfaces inFIGS. 5A and5B).

The cell shaped glass substrate12according to the exemplary embodiment of the present invention may be formed by forming the groove20in advance in the sheet shaped glass substrate10, performing the chemical tempering on the glass substrate10, and then cutting the glass substrate10along the groove20.

Therefore, as shown inFIG. 5A, the second chemical tempered layer30bstacked on the portion (the processed part22) in which the groove20is processed may have a thickness decreased toward the end portion of the glass substrate12.

As described with reference toFIGS. 2A to 2O, the black decoration40may be printed in the cell unit on one surface of the sheet shaped glass substrate10, the step coating layer42may be formed thereon so as to cover the black decoration40, the X-axis transparent coating layer45including the X-axis stripe type electrodes44may be stacked on the step coating layer42, and the Y-axis transparent coating layer47including the Y-axis stripe type electrodes46may be stacked on the X-axis transparent coating layer45.

Further, as described above, the aspect ratio of the groove20formed in the glass substrate10may be 1.0 to 3.0, and the glass is modified by bringing the laser focus on the groove20portion and moving the laser focus along the groove20, such that the glass substrate10is cut, thereby forming the process part22according to the present embodiment as shown inFIG. 11.

FIGS. 8A to 8Cshow examples of the case in which the groove is formed in the glass substrate so as to have various aspect ratios. The chemical tempering (KNO3) was performed at 450° C. for 8 hours after heating the glass in advance to 400° C.

Depths of the grooves shown inFIGS. 8A to 8Cwere compared with each other, and the results were shown in the following Table 1.

In addition, the relationship of the thickness of the chemical tempered layer to the aspect ratio of each of the grooves inFIGS. 8A to 8Cis shown inFIG. 10.

As shown inFIGS. 8A to 10, the glass substrate is processed in a groove shape in advance and cut, such that the glass substrate that may not be cut at the depth of the tempered layer according to the related art may be cut (at the groove portion). In addition, the chemical tempered layers are partially formed on the sides of the glass substrate in the cell unit processed in the groove shape, such that the area of the side that is not tempered may be significantly decreased, thereby making it possible to increase the strength of the glass substrate.

With the touch panel integrated with a cover glass and the manufacturing method thereof according to the present invention, the touch panel may be manufactured in the cell unit by forming grooves in both surfaces of the sheet shaped tempered glass substrate, performing chemical tempering on the surface, and cutting the regions in which the grooves are formed, such that the cutting of the glass substrate may be easily performed, thereby making it possible to prevent the strength of the side of the tempered glass substrate from being reduced while having advantages such as low cost and high productivity.

The present invention has been described in connection with what is presently considered to be practical exemplary embodiments. Although the exemplary embodiments of the present invention have been described, the present invention may be changed or modified within the range of concept of the invention disclosed in the specification, the range equivalent to the disclosure and/or the range of the technology or knowledge in the field to which the present invention pertains. The exemplary embodiments described above have been provided to explain the best state in carrying out the present invention. Therefore, they may be carried out in other states known to the field to which the present invention pertains in using other inventions such as the present invention and also be modified in various forms required in specific application fields and usages of the invention. Therefore, it is to be understood that the invention is not limited to the disclosed embodiments. It is to be understood that other embodiments are also included within the spirit and scope of the appended claims.