Patent Publication Number: US-2011061904-A1

Title: Display array substrate and method of manufacturing display substrate

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the priority of Korean Patent Application No. 10-2009-0087089 filed on Sep. 15, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a display array substrate and a method of manufacturing the same, and more particularly, to a substrate in which substrates, applied to a display device, are arrayed, and a method of manufacturing substrate parts by cutting this array substrate. 
     2. Description of the Related Art 
     Recently, touch type personal portable devices detect whether a user touches display devices, and the entire devices vibrate according to a detection result indicating the user has touched the display devices. 
     Here, touch type display devices mean input devices that detect a contact position at which a user touches the surface of the display device, and perform the general control of an electronic device, including a display screen control on the basis of information on the detected contact position as input information. 
     The touch type display devices further include vibration elements providing a feedback through vibrations with respect to a touch made when a user touches the display devices. These vibration elements may be arranged on the edge of the display devices. 
     These touch type display devices may be divided into resistive overlay touch display devices and capacitive overlay touch display devices. In particular, capacitive overlay touch display devices that detect a contact position on the basis of changes in capacitance caused by a user&#39;s contact applied to a front face of a display window have been gradually used in a wide range of applications because of high durability and suitability for sliding-type inputs. 
     In these capacitive overlay display devices, transparent electrodes are provided on display substrates in order to detect changes in the capacitance. In order to manufacture these display substrates, a large-sized display array substrate is prepared and is cut into unit display substrates. 
     However, when the display array substrate is cut into the unit display substrates, forces generated during the cutting operation cause cracks around the transparent electrodes provided in the display substrates or delaminations around the cutting surfaces. Therefore, there is a need for techniques to solve these problems. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention provides a display array substrate and a method of manufacturing a display substrate that can prevent delaminations or cracks in a transparent electrode. 
     According to an aspect of the present invention, there is provided a display array substrate including: a substrate wafer having cutting grooves curved inward; and a transparent electrode coated over one surface of the substrate wafer, wherein shock, occurring when cutting the substrate wafer, is prevented from being transmitted to the transparent electrode by cutting the substrate wafer along the cutting grooves having a different height from the transparent electrode. 
     The cutting grooves may be provided in both surfaces of the substrate wafer. 
     The transparent electrode may include transparent electrodes coated over both surfaces of the substrate wafer. 
     The transparent electrode may be coated over one surface of the substrate wafer having the cutting grooves therein. 
     The transparent electrode may use at least one of ceramics, conductive polymer or a mixture containing carbon. 
     According to another aspect of the present invention, there is provided a method of manufacturing a display substrate, the method including: forming cutting grooves in one surface of a substrate wafer having a plurality of substrate parts, formed in a single body, in units of the substrate parts; forming a transparent electrode on the one surface of the substrate wafer; and cutting the array substrate along the cutting groves to manufacture the substrate parts having a predetermined size. 
     In the forming of the cutting grooves, the substrate wafer may pass through a roller having protrusions from an outer surface thereof to form cutting grooves in the substrate wafer. 
     In the forming of the cutting grooves, rollers having protrusions from outer surfaces thereof may be arranged to face each other, and the substrate wafer passes between the rollers to form cutting grooves in both surfaces of the substrate wafer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view illustrating a personal portable device to which a display substrate is applied according to an exemplary embodiment of the present invention; 
         FIG. 2  is a cross-sectional view illustrating the operating principle of the display substrate of  FIG. 1 ; 
         FIGS. 3 through 5  are cross-sectional views and front views illustrating a display array substrate and a method of manufacturing display substrates from the display array substrate; 
         FIG. 6  is a side view illustrating a method of forming cutting grooves in a display array substrate according to an exemplary embodiment of the present invention; 
         FIGS. 7A through 7C  are cross-sectional views and front views illustrating a display array substrate and a method of manufacturing the same according to another exemplary embodiment of the present invention; 
         FIGS. 8A through 8C  are cross-sectional views and front views illustrating a display array substrate and a method of manufacturing the same according to another exemplary embodiment of the present invention; and 
         FIGS. 9A through 9C  are cross-sectional views and front views illustrating a display array substrate and a method of manufacturing the same according to another exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A display array substrate and a method of manufacturing a display substrate will be described in detail with reference to  FIGS. 1 through 9 . Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. 
     The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
     In the drawings, the shapes and dimensions may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or like components. 
       FIG. 1  is a perspective view illustrating a personal portable device to which a display substrate is applied according to an exemplary embodiment of the invention.  FIG. 2  is a cross-sectional view illustrating the operating principle of the display substrate of  FIG. 1 . 
     Referring to  FIGS. 1 and 2 , a display substrate  20  may be mounted onto a display device that is formed on an entire surface of a personal portable device  10 , and may the above-described touch type display substrate. 
     The display substrate  20  may include a substrate part  30 , a transparent electrode  40  and a piezoelectric actuator (not shown). 
     The substrate part  30  is mounted onto the entire surface of the personal portable device  10  and may be formed of transparent materials such as reinforced glass or acryl uniform in thickness or dielectric constant. 
     The transparent electrode  40  is formed on one surface of the substrate part  30 . As shown in  FIG. 2 , the transparent electrode  40  detects changes in capacitance on the substrate part  30 . Therefore, when a user&#39;s body part, for example, the user&#39;s finger tips make contact with the substrate part  30  at a specific position, a change occurs in capacitance C formed between the transparent electrode  40  at the corresponding position and the contact surface of the body. On the basis of data about the change in the capacitance C, a control unit calculates the X-direction and Y-direction components of a contact position. 
     The transparent electrode  40  may be formed of at least one of ceramics, conductive polymer or a mixture containing carbon. 
     The piezoelectric actuator (not shown) may be designed to be driven according to a contact signal, and may be arranged at the side of the substrate part  30 . However, the position of the piezoelectric actuator is not limited thereto, and may vary according to the designers&#39; intentions. 
       FIGS. 3 through 5  are cross-sectional views and front views illustrating a display array substrate and a method of manufacturing display substrates from the display array substrate according to an exemplary embodiment of the invention. 
     Referring to  FIG. 3 through 5 , a display array substrate  100  includes a substrate wafer  110  and a transparent electrode  120 . 
     The substrate wafer  110  has a plurality of substrate part  30  formed in a single body, which can be applied to personal portable devices. The substrate wafer  110  has a large size so that the substrate wafer  110  is cut to substrate part  30  size. 
     Here, cutting grooves  112 , which are curved inward, may be provided in one surface of the substrate wafer  110 . Here, the cutting grooves  112  may be formed to define the outlines of the substrate parts  30  so that each block defined by the cutting grooves corresponds to the substrate part size. 
     The substrate wafer  110  may be formed of transparent materials such as reinforced glass or acryl uniform in thickness or dielectric constant. 
     The transparent electrode  120  may be coated over one surface of the substrate wafer  110 . Here, the one surface may refer to a surface in which the cutting grooves  112  are formed. Here, the transparent electrode  120  is also formed on one surface of each of the cutting grooves  112 . 
     Here, the cutting grooves  112  have a rectangular shape in cross-section. However, the invention is not limited thereto, and the cutting grooves  112  may have a circular shape in cross-section. 
     The transparent electrode  120  may be formed of at least one of ceramics, conductive polymer or a mixture containing carbon. Here, the conductive polymer may be polythiophene (PEDOT) or polyaniline, the ceramics may be ITO, IZO, AZO, GZO, FTO or ZnO, and the mixture containing carbon may be CNT, graphene or carbon black. 
     Therefore, in order to manufacture the substrate parts  30 , the substrate wafer  110  is cut along the cutting grooves  112 . Here, the substrate wafer  110  is cut along the cutting grooves  112  having a different height from the transparent electrode  120 , thereby preventing shock, occurring when cutting the substrate wafer  10 , from being directly transmitted to the transparent electrode  120 . 
     A method of manufacturing a display substrate will now be described. 
     Firs, as shown in  FIG. 3 , according to the method of manufacturing a display substrate, the cutting grooves  112  are formed in one surface of the substrate wafer  110  having the plurality of substrate parts  30  formed in a single body to define the individual substrate parts  30 . 
     Then, as shown in  FIG. 4 , the transparent electrode  120  may be formed on the one surface of the substrate wafer  110  in which the cutting grooves  112  are formed. 
     As shown in  FIG. 5 , the substrate wafer  110  is cut along the cutting grooves  112  in order to manufacture substrates having a predetermined size. 
     After the transparent electrode  120  is formed on the substrate wafer  110  in which the cutting grooves  112  are not formed, if the substrate wafer  110  is cut to the substrate part  30  size, delaminations or cracks of the transparent electrode  120  may occur around the cutting surfaces. 
     However, according to the display array substrate and the method of manufacturing a display substrate according to the embodiments of the invention, since the cutting grooves  112 , which are curved inward, are formed in the substrate wafer  110 , there is a height difference between the surfaces of the cutting grooves  112  and the substrate parts  30 . Furthermore, shock, occurring when the substrate wafer  110  is cut along the cutting grooves  112 , can be prevented from being directly transmitted to the transparent electrode formed on the surface of the substrate parts  30 . As a result, the durability of the display substrate can be increased. 
       FIG. 6  is a side view illustrating a method of forming cutting grooves in a display array substrate according to an exemplary embodiment of the invention. 
     Referring to  FIG. 6 , when the cutting grooves  112  are formed according to the method of manufacturing a display substrate, as the substrate wafer  110  passes between rollers  50  having protrusions  52  from outer surfaces thereof, the cutting grooves  112  are formed in the substrate wafer  110 . 
     Here, the positions at which the protrusions  52  are formed on the rollers  50  may vary according to intervals of the cutting grooves  112  formed in the substrate wafer  110 . 
     Therefore, when the substrate wafer  110  is automatically moved along a transfer device  60  in a direction toward the rollers  50  (arrow direction), the substrate wafer  110  and the protrusions  52  make contact with each other, whereby the cutting grooves  112  are formed in the substrate wafer  110 . 
     Therefore, an operator does not need to separately and individually form the cutting grooves  112  in the substrate wafer  110 . Through these processes, the cutting grooves  112  are automatically and continuously formed, thereby simplifying a manufacturing process and reducing manufacturing time. 
       FIGS. 7A through 7C  are cross-sectional views and front views illustrating a display array substrate and a method of manufacturing the substrate according to another exemplary embodiment of the invention. 
     First, as shown in  FIG. 7A , according to a method of manufacturing a display substrate according to this embodiment, cutting grooves  212  are formed in both surfaces of substrate wafer  210  having the plurality of substrate part  30 , formed in a single body, to thereby define the substrate parts  30 . 
     Here, the cutting grooves  212  can be formed in both surfaces of the substrate wafer  210  at the same time by arranging rollers having protrusions thereon at both sides and passing the substrate wafer  210  between the rollers arranged at both sides. 
     As shown in  FIG. 7B , the transparent electrode  120  may be formed on one surface of the substrate wafer  110  in which the cutting grooves  212  are formed. 
     Then, as shown in  FIG. 7C , in order to manufacture substrates having a predetermined size, the substrate wafer  210  is cut along the cutting grooves  212  to thereby manufacture the plurality of substrate parts  30 . 
     Therefore, in this embodiment, since the cutting grooves  212  are formed in both surfaces of the substrate wafer  210 , the substrate wafer  210  has a relatively smaller thickness at positions corresponding to the cutting grooves  212 , thereby facilitating the cutting operation. 
       FIGS. 8A through 8C  are cross-sectional views and front views illustrating a display array substrate and a method of manufacturing the substrate according to another exemplary embodiment of the invention. 
     First, as shown in  FIG. 8A , according to the method of manufacturing a display substrate, cutting grooves  312  may be formed in both surfaces of a substrate wafer  310  having substrate parts  30 , formed in a single body, to define the individual substrate parts  30 . 
     Here, the cutting grooves  312  can be formed in both surfaces of the substrate wafer  310  at the same time by passing the substrate wafer  310  between the above-described rollers. 
     Then, as shown in  FIG. 8B , the transparent electrodes  120  may be formed on both surfaces of the substrate wafer  310  in which the cutting grooves  312  are formed. 
     Further, as shown in  FIG. 8C , in order to manufacture substrates having a predetermined size, the substrate wafer  310  is cut along the cutting grooves  312  to thereby manufacture the plurality of substrate part  30 . 
     Therefore, in this case, the transparent electrodes  120  may be formed on both surfaces of the substrate part  30 . 
       FIGS. 9A through 9C  are cross-sectional views and front views illustrating a display array substrate and a method of manufacturing the same according to another exemplary embodiment of the invention. 
     First, as shown in  FIG. 9A , according to the method of manufacturing a display substrate according to this embodiment, cutting grooves  412  are formed in a lower surface of a substrate wafer  410  having the plurality of substrate parts  30 , formed in a single body, to define the outlines of substrate parts  30 . 
     Then, as shown in  FIG. 9B , the transparent electrode  120  may formed on the other surface opposite to one surface of the substrate wafer  410 , in which the cutting grooves  412  are formed. 
     Then, as shown in  FIG. 9C , in order to manufacture substrates having a predetermined size, the substrate wafer  410  is cut along the cutting grooves  412  to thereby manufacture the plurality of substrate part  30 . 
     Therefore, since the substrate wafer  410  has a smaller thickness at positions where the cutting grooves  412  are formed than other portions of the substrate wafer  410 , even when a relatively smaller force is applied, the substrate wafer  410  can be cut along the cutting grooves  412 . 
     As set forth above, according to exemplary embodiments of the invention, a display array substrate and a method of manufacturing a display substrate form cutting groves curved inward in a substrate wafer, so that shock, occurring when the substrate wafer is cut along the cutting grooves to manufacture display substrates, can be prevented from being directly transmitted to a transparent electrode, thereby increasing the durability of the display substrates. 
     While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.