Patent Publication Number: US-2019172845-A1

Title: Array Structure, Manufacturing Method Thereof, Array Substrate and Display Device

Description:
The application is a divisional of U.S. patent application Ser. No. 14/409,316, filed on Dec. 18, 2014, which is a U.S. National Phase Entry of International Application PCT/CN2014/080453 filed on Jun. 20, 2014, designating the United States of America and claiming priority to Chinese Patent Application No. 201310571411.1, filed on Nov. 15, 2013. The present application claims priority to and the benefit of the above-identified applications and the above-identified applications are incorporated by reference herein in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to the field of display technology, and in particular to an array structure, a manufacturing method thereof, an array substrate based on the array structure, and a display device. 
     BACKGROUND 
     Currently, with the continuous improvement of the resolution of liquid crystal display panels, particularly as for liquid crystal display panels of small dimension, the improvement of the resolution means the increase of the quantity of pixels in unit length, namely PPI (pixels per inch), and hence the quantity of leading wires within the same space increases accordingly. 
     It is known to the inventor that, generally, the space for wiring is reduced as much as possible by adoption of alternate wiring for an IC (integrated circuit) to solve the problem of more and more IC pins.  FIG. 1  is a schematic view illustrating a gate layer and a source/drain (SD) metal layer which have wires thereof alternate with each other,  01  represents the gate layer and  02  represents the SD metal layer. The alternate wiring is performed through the gate layer and the SD metal layer, then through holes are formed in the gate layer and the SD metal layer by an exposing and etching process and finally wires are led out by an ITO (indium tin oxide) layer. The left side and the right side of  FIG. 2  are respectively sectional views of the gate layer and the SD metal layer which have wires thereof alternate with each other. In  FIG. 2  a gate signal access terminal includes a gate electrode  01 , a gate insulating (GI) layer ( 03 ), a passivation (PVX) layer  04  and a conductive film  05  (e.g., an ITO layer) which are formed on a substrate  00  in sequence. An SD signal access terminal includes the GI layer  03 , an SD metal layer  02 , the PVX layer  04  and the conductive film  05  which are formed on the substrate  00  in sequence. As the gate signal access terminal (pad) and the SD signal access terminal have different structures, the finally formed signal access terminals have different heights, and hence poor contact between IC bonding pads and IC pins can be caused. As illustrated in  FIG. 3 , the height of the conductive film  05  in the SD signal access terminal is greater than that of the conductive film  05  in the gate signal access terminal. Height difference occurs between the conductive films  05  in the IC bonding pads corresponding to adjacent IC pins  07 , and hence the contact areas between conductive balls  07  and the conductive films  05  in adjacent IC bonding pads are different and the applied forces are nonuniform. Thus, poor welding state can be caused and the conductivity can be reduced. 
     SUMMARY 
     The present disclosure provides a method for manufacturing an array structure, which method, before forming an SD metal layer on a GI layer, further includes: etching the GI layer at a position corresponding to an SD signal access terminal, and forming a through-hole structure in the GI layer. 
     Moreover, after etching the GI layer at the position corresponding to the SD signal access terminal, the method further includes: forming the SD metal layer, a PVX layer and a conductive film in sequence on the GI layer provided with the through-hole structure. 
     Furthermore, after forming the SD metal layer, the method further includes: performing a same etching to the SD metal layer at a position corresponding to the through-hole structure as the etching of forming the through-hole structure, forming the PVX layer on the SD metal layer continuously, performing a same etching as well, and finally forming the conductive film. 
     In order to solve the above-mentioned technical problem, the present disclosure further provides an array structure, which is manufactured by the above-mentioned method for manufacturing an array structure. 
     In order to solve the above-mentioned technical problem, the present disclosure further provides a display device, which includes an array substrate and a color filter substrate, and the array substrate is obtained by forming the above-mentioned array structure on a glass substrate. 
     In order to solve the above-mentioned technical problem, the present disclosure further provides a method for manufacturing an array structure, which method, after forming an SD metal layer on a GI layer, further includes: forming a through-hole structure in the SD metal layer to which a position where the SD signal access terminal is located corresponds. Gradual slopes are formed on both sides of the through-hole structure. 
     Moreover, the through-hole structure includes a main hole and compensation holes formed on both sides of the main hole. The compensation holes are smaller than the main hole. In addition, the main hole is fully-transparent and the compensation holes are not fully-transparent. 
     Moreover, the through-hole structure includes a main hole and half-transparent films formed on both sides of the main hole. The main hole is fully-transparent and the half-transparent films are not fully-transparent. 
     Moreover, the half-transparent films include a plurality of second half-transparent films with different transmittances; and the transmittances of the second half-transparent films are progressively decreased from the main hole as a start to the both sides. 
     Moreover, the through-hole structure provided with the main hole and the compensation holes or with the main hole and the half-transparent films is formed in the SD metal layer by a wet etching. Subsequently, a layer of photoresist with a slope is formed on the SD metal layer. The height of the photoresist is gradually reduced from the both sides to the main hole. The photoresist is subjected to an exposure and the SD metal layer is subjected to a dry etching. 
     Furthermore, after performing the dry etching to the SD metal layer, the method further includes: forming a PVX layer on the SD metal layer, performing a same slope etching to the PVX layer at a position corresponding to the through-hole structure, and finally forming a conductive film. 
     In order to solve the technical problem, the present disclosure further provides an array structure, which is manufactured by the above-mentioned method for manufacturing an array structure. 
     In order to solve the technical problem, the present disclosure further provides a display device, which includes an array substrate and a color filter substrate, and the array substrate is obtained by forming the array structure on a glass substrate. 
     Embodiments of the present disclosure provide an array structure, a manufacturing method thereof, an array substrate based on the array structure, and a display device, and before forming an SD metal layer on a GI layer, the method for manufacturing an array structure further includes: etching the GI layer at a position corresponding to an SD signal access terminal, and forming a through-hole structure in the GI layer; or after forming an SD metal layer on a GI layer, the method further includes forming a through-hole structure in the SD metal layer at a position corresponding to an SD signal access terminal, and in the method, gradual slopes are formed on both sides of the through-hole structure. The GI layer beneath the SD metal layer is etched, so that the height of the conductive film on the SD metal layer can be reduced. Or the SD metal layer is etched to form the through-hole structure provided with the gradual slopes on both sides thereof, so that the ITO layers in the SD signal access terminal and the gate signal access terminal in an alternate-wiring mode have same height, and hence the forces applied to conductive balls are more uniform and the conductivity is improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a gate layer and an SD layer which have wires thereof alternate with each other known by the inventor; 
         FIG. 2  is sectional views of a gate layer and an SD metal layer which have wires thereof alternate with each other known by the inventor; 
         FIG. 3  is sectional views of IC bonding pads of a gate layer and an SD metal layer which have wires thereof alternate with each other known by the inventor; 
         FIG. 4  is a flow chart of a method for manufacturing an array structure, provided by the embodiment 1 of the present disclosure; 
         FIG. 5  is a sectional view of an array structure provided by the embodiment 2 of the present disclosure; 
         FIG. 6  is a schematic view illustrating that IC pins and IC bonding pads are connected through an ACF in the embodiment 2 of the present disclosure; 
         FIG. 7  is a schematic view of an array substrate provided by the embodiment 2 of the present disclosure; 
         FIG. 8  is a sectional view of a mask applied in the embodiment 3 of the present disclosure; 
         FIG. 9  is a sectional view of a mask applied in the embodiment 3 of the present disclosure; 
         FIG. 10  is a schematic diagram illustrating a light distribution of a mask applied in the embodiment 3 of the present disclosure; 
         FIGS. 11 to 13  are schematic views illustrating a process of forming a through-hole structure provided with an inclined side wall in an SD layer, in a method for manufacturing an array structure, provided by the embodiment 3 of the present disclosure; 
         FIG. 14  is a flow chart of the method for manufacturing the array structure, provided by the embodiment 3 of the present disclosure; 
         FIG. 15  is a sectional view of an array structure provided by the embodiment 4 of the present disclosure; and 
         FIG. 16  is a sectional view of an array substrate provided by the embodiment 4 of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The technical solutions of the embodiments will be described in a clearly and fully understandable way in connection with the drawings related to the embodiments of the disclosure. Apparently, the described embodiments are just a part but not all of the embodiments of the disclosure. Based on the described embodiments herein, those skilled in the art can obtain other embodiment(s), without any inventive work, which should be within the scope of the disclosure. 
     Unless otherwise defined, all the technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. The terms “first,” “second,” etc., which are used in the description and the claims of the present application for disclosure, are not intended to indicate any sequence, amount or importance, but distinguish various components. Also, the terms such as “a,” “an,” etc., are not intended to limit the amount, but indicate the existence of at least one. The phrases “connect”, “connected”, etc., are not intended to define a physical connection or mechanical connection, but may include an electrical connection, directly or indirectly. “On,” “under,” “right,” “left” and the like are only used to indicate relative position relationship, and when the position of the object which is described is changed, the relative position relationship may be changed accordingly. 
     Embodiment 1 
     The embodiment of the present disclosure provides a method for manufacturing an array structure. Before the process of forming an SD metal layer on a GI layer, the method further includes: etching the GI layer at a position corresponding to an SD signal access terminal, and forming a through-hole structure in the GI layer. 
     In the method for manufacturing an array structure, before the process of preparing the SD metal layer, namely in the process of preparing the GI layer, the GI layer at a position corresponding to the SD signal access terminal (namely SD pad) is also subjected to same etching treatment. After etching, the increased height of the SD signal access terminal can be eliminated, and hence the height difference between the conductive films (ITO) in the gate signal access terminal and the SD signal access terminal can be reduced. Thus, the conductive films in the gate signal access terminal and the SD signal access terminal which are connected to adjacent IC pins have a same height, so that the forces applied to conductive balls on the conductive films are more uniform and the conductivity is improved. 
     For instance, in the embodiment, after the process of etching the GI layer at the position corresponding to the SD signal access terminal (SD Pad), the method further includes: forming a source/drain (SD) metal layer, a passivation (PVX) layer and a conductive film (ITO) in sequence on the gate insulating (GI) layer provided with a through-hole structure. 
     Moreover, the process of forming the source/drain (SD) metal layer, the passivation (PVX) layer and the conductive film (ITO) includes: etching the source/drain (SD) metal layer at a position corresponding to the through-hole structure in the GI layer, forming the passivation (PVX) layer on the source/drain (SD) metal layer continuously, etching the PVX layer at a position corresponding to the through-hole structure in the GI layer, and finally forming the conductive film (ITO) on the PVX layer. 
       FIG. 4  is a schematic flow chart of the method. As illustrated in  FIG. 4 , the method specifically includes the following steps: 
     S 1 : forming a GI layer on a glass substrate; 
     S 2 : etching the GI layer at a position corresponding to the SD signal access terminal, and forming a through-hole structure; and 
     S 3 : forming an SD layer on the GI layer, etching the SD layer at a position corresponding to the through-hole structure, forming a PVX layer on the SD layer, etching the PVX layer at a position corresponding to the through-hole structure, and finally forming an ITO layer on the PVX layer. 
     The above steps are the processing flow of the SD signal access terminal. The processing flow of the gate signal access terminal is as follows: namely as illustrated in  FIG. 2 , forming a gate layer on a glass substrate  00 , forming a gate electrode  01  by etching, forming a GI layer  03  on the gate electrode  01 , and etching the GI layer  03  at a position corresponding to the gate electrode  01  to form a through hole; then forming a PVX layer on the GI layer  03  subsequently, and forming a through hole at a position corresponding to the through hole by etching; and finally forming an ITO layer. 
     In the above method, partial GI layer  03  is etched at the position corresponding to the SD signal access terminal. When the SD metal layer is deposited, the SD metal layer in the SD signal access terminal is closer to the surface of the glass substrate, and hence the effect of increasing the height of the conductive film on the GI layer  03  at the position corresponding to the SD signal access terminal due to the existence of the GI layer  03  can be relieved. Subsequently, the deposition and etching of subsequent layers (namely the SD layer, the PVX layer and the conductive film) are performed, and finally the height of the conductive film in the SD signal access terminal can be reduced. Thus, the height difference between the conductive films in the gate signal access terminal and the SD signal access terminal can be reduced; the space uniformity between IC pins and IC bonding pads can be guaranteed; the forces applied to conductive balls between the IC pins and the IC bonding pads can be more uniform; and hence the conductivity can be improved. 
     Embodiment 2 
     The embodiment 2 of the present disclosure further provides an array structure manufactured by the manufacturing method provided by the embodiment 1 of the present disclosure, as illustrated in  FIG. 5 . The left side of the  FIG. 5  and the left side of the  FIG. 2  are identical, and both are a sectional view of a gate signal access terminal. The right side of  FIG. 5  is a sectional view of an SD signal access terminal. The SD signal access terminal in the array structure provided by the embodiment 2 of the present disclosure includes a GI layer  103 , an SD metal layer  102 , a PVX layer  104  and a conductive film  105  formed in sequence; a through-hole structure is formed in the GI layer  103  at a position corresponding to the SD metal layer  102 ; partial SD metal layer  102  is formed in the through-hole structure; and the through-hole structure is provided with an outward-inclined side wall. Both the SD metal layer  102  and the PVX layer  104  are provided with a concavity including an outward-inclined side wall at a position corresponding to the through-hole structure, namely at a position corresponding to the SD signal access terminal. Thus, the conductive film  105  is provided with a concavity at a position corresponding to the SD signal access terminal. 
       FIG. 6  is a sectional view illustrating that a thin-film transistor (TFT) array substrate provided with the above-mentioned array structure and an IC are connected to each other through ACF (anisotropic conductive film). As illustrated in  FIG. 6 , IC pins Q 1  on a TFT substrate U are connected to IC bonding pads Q 2  through conductive balls  106  in the anisotropic conductive film. 
     The embodiment further provides a display device, which includes an array substrate and a color filter substrate. The array substrate is obtained by forming the array structure provided by the embodiment 2 of the present disclosure on a glass substrate. 
       FIG. 7  is a sectional view of the array substrate provided by the embodiment. As illustrated in  FIG. 7 , the array structure shown in  FIG. 5  is formed on a glass substrate  100 . 
     The array substrate provided by the embodiment can achieve the reduction of the height difference between the conductive films in the gate signal access terminal and the SD signal access terminal, guarantee the space uniformity between IC pins and IC bonding pads, guarantee more uniform forces applied to the conductive balls between the IC pins and the IC bonding pads, and hence improve the conductivity. 
     Embodiment 3 
     The embodiment 3 of the present disclosure further provides a method for manufacturing an array structure. After the process of forming an SD metal layer (SD layer) on a GI layer, the method further includes: forming a through-hole structure in the SD metal layer at a position corresponding to an SD signal access terminal. Gradual slopes are formed on both sides of the through-hole structure. 
     In the method, the SD layer is deposited after the GI layer is formed on the glass substrate, and subsequently the SD layer at the position corresponding to the SD signal access terminal is etched. The method can also reduce the height of the conductive film in the SD signal access terminal, reduce the height difference between the conductive films in the gate signal access terminal and the SD signal access terminal, guarantee the space uniformity between the IC pins and the IC bonding pads, guarantee more uniform forces applied to the conductive balls between the IC pins and the IC bonding pads, and hence improve the conductivity. 
     In one example, as illustrated in  FIG. 8 , in the embodiment, a mask designed for forming the through-hole structure includes a main hole A and compensation holes B 1  and B 2  formed on both sides of the main hole. A pore diameter of the compensation holes B 1  and B 2  is smaller than that of the main hole A. In addition, the main hole A is fully-transparent and the compensation holes B 1  and B 2  are not fully-transparent. The pore diameter of the compensation holes B 1  and B 2  is usually much smaller than the resolution of an exposure machine. Light capable of running through the compensation holes B 1  and B 2  on both sides can overlap and enhance the light running through the main hole A in the center. Meanwhile, the light intensity can be gradually reduced from the main hole, as illustrated in  FIG. 10 . 
     In another example, as illustrated in  FIG. 9 , a mask includes a main hole A and half-transparent films C 1  and C 2  formed on both sides of the main hole A. The main hole A is fully-transparent and the half-transparent films C 1  and C 2  are not fully-transparent. 
     For instance, the half-transparent films C 1  and C 2  include a plurality of second half-transparent films with different transmittances. In the example as shown in  FIG. 9 , the half-transparent films C 1  and C 2  include three-level second half-transparent films with different transmittances, namely the half-transparent film C 1  includes three second half-transparent films C 11  to C 13  with different transmittances and the half-transparent film C 2  includes three second half-transparent films C 21  to C 23  with different transmittances. Moreover, the transmittances of the half-transparent films C 11  to C 13  and C 21  to C 23  are progressively decreased from the main hole A in the center to both sides, namely the transmittances of C 13 , C 12  and C 11  are decreased progressively and the transmittances of C 23 , C 22  and C 21  are also decreased progressively. This design of the main hole and the half-transparent films can guarantee that the light intensity can not rapidly reduce from the main hole, but gradually reduce from the main hole to both sides, namely the light intensity reduces gradually, as illustrated in  FIG. 10 . 
     For instance, by adoption of the mask including the main hole and the compensation holes or the main hole and the half-transparent films, the through-hole structure is formed in the SD metal layer at the position corresponding to the SD signal access terminal by photolithography and a wet etching. Gradual slopes are formed on both sides of the through-hole structure. As illustrated in  FIG. 11 , an SD metal layer  202  is formed on a GI layer  203 , and a photoresist PR is formed on the SD metal layer  202 . By adoption of the mask as shown in  FIGS. 8 and 9  for photolithography, the photoresist PR provided with the slopes is formed on the SD metal layer  202 , namely the photoresist PR at a position corresponding to the main hole of the mask is removed and the photoresist PR provided with the slopes is formed on both sides of the position. Subsequently, a wet etching is performed and a through hole is formed in the SD metal layer  202 , as illustrated in  FIG. 12 . Subsequently, a dry etching process is performed to the photoresist PR and the SD metal layer  202 . As the photoresist PB on the periphery of the through hole in the SD layer  202  has a slope shape, after the simultaneous dry etching of the photoresist PR and the SD metal layer  202 , a side wall of the through hole formed in the SD layer  202  is also provided with a similar gradual slope structure, as illustrated in  FIG. 13 . As the through hole of the SD metal layer  202  at the position corresponding to the SD signal access terminal is provided with a side wall including a gradual slope, the height of the conductive ball formed on the through hole is reduced; the space uniformity between the IC pin and the IC bonding pad is guaranteed; the contact area between the conductive ball and the conductive film is also increased; the contact area between the conductive film and the SD metal layer is also increased; and hence the conductivity is better. 
     For instance, after the dry etching process for the SD metal layer, the method further includes: forming a PVX layer on the SD metal layer, forming a through hole with a same inclined side wall in the PVX layer at a position corresponding to the through-hole structure in the SD metal layer, and finally forming a conductive film on the through hole. 
       FIG. 14  is a flow chart of the method provided by the embodiment. The method specifically includes the following steps. 
     S 1 ′: forming a GI layer on a glass substrate; 
     S 2 ′: forming an SD layer on the GI layer, performing a wet etching and a dry etching on the SD layer, and forming a through-hole structure provided with an outward-inclined side wall at a position corresponding to an SD signal access terminal; and 
     S 3 ′: forming a PVX layer on the SD layer, forming a through-hole structure provided with an outward-inclined side wall in the PVX layer at a position corresponding to the through-hole structure, and finally forming a conductive film on the through-hole structure. 
     The process of processing one side of the gate signal access terminal in the embodiment is the same with that of the embodiment 1. Thus, detailed description will be omitted herein. 
     In the method, as the through hole in the SD metal layer  202  at the position corresponding to the SD signal access terminal is provided with a side wall including a gradual slope, the height of the conductive ball formed on the through hole is reduced; the space uniformity between the IC pin and the IC bonding pad is guaranteed; the forces applied to the conductive balls between the IC pins and the IC bonding pads are more uniform; and hence the conductivity is improved. Moreover, the contact area between the conductive ball and the conductive film is increased; the contact area between the conductive film and the SD metal layer is also increased; and hence the conductivity is better. 
     Embodiment 4 
     The embodiment 4 of the present disclosure further provides an array structure manufactured by the manufacturing method provided by the embodiment 3 of the present disclosure, as illustrated in  FIG. 15 . The left side of  FIG. 15  and the left sides of  FIGS. 2 and 5  are identical, and each is a sectional view of a gate signal access terminal. The right side of  FIG. 15  is a schematic sectional view of an SD signal access terminal. The SD signal access terminal in the array structure provided by the embodiment 4 of the present disclosure includes a GI layer  203 , an SD metal layer  202 , a PVX layer and a conductive film  205  formed in sequence. A through-hole structure is formed in partial SD metal layer  202 . 
     Moreover, the embodiment further provides a display device, which includes an array substrate and a color filter substrate. The array substrate is obtained by forming the array structure provided by the embodiment 4 of the present disclosure on a glass substrate  200 . 
     The array substrate provided by the embodiment can reduce the height difference between the conductive films in the gate signal access terminal and the SD signal access terminal, guarantee the space uniformity between the IC pins and the IC bonding pads, guarantee more uniform forces applied to the conductive balls between the IC pins and the IC bonding pads, and hence improve the conductivity. 
     The foregoing embodiments are only intended to illustrate the present disclosure but not intended to limit the present disclosure. Various modifications and variations may also be made by those skilled in the art without departing from the spirit and scope of the present disclosure. Thus, all the equivalent technical solutions should be within the scope of the present disclosure. The scope o of the present disclosure shall be defined by the claims. 
     The application claims priority to the Chinese Patent Application No. 201310571411.1 filed on Nov. 15, 2013. The disclosure content of the Chinese Patent Application is incorporated herein as part of the application.