Patent Publication Number: US-2007096652-A1

Title: Methods for fabricating step-formed patterned layer and frbricating rib of plasma display panel

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention generally relates to a method for fabricating a patterned layer, and more particularly, to a method for fabricating a step-formed patterned layer.  
      2. Description of Related Art  
      Currently, the more popular patterning processes include screen printing process and photolithography/etching process. Conventionally, in the photolithography/etching process, a photo-resist layer, disposed on a layer, is patterned by using the photolithography process. Then, the layer is etched by using the patterned photo-resist layer as a mask so as to transfer the pattern of the patterned photo-resist layer onto this layer. Next, the patterned photo-resist layer is removed from the layer by using wet or dry etching methods, such as a chemical solution or plasma. In addition, the fabricating of a step-formed patterned layer requires two patterning processes, including repeating the screen printing process or the photolithography/etching process two times.  
      With the prosperous development of planar displays, the aforementioned patterning processes are frequently implemented in fabricating display panels, wherein, for example, the manufacturing of liquid crystal display panels or plasma display panels requires several patterning processes to from desired layers.  
      For example, conventionally, a spacer material layer is firstly formed on a substrate and a patterned photo-resist layer is formed on the spacer material layer in the manufacturing of ribs of the plasma display panels. After that, the spacer material layer is sandblasted by using the patterned photo-resist layer as a mask to form ribs.  
      The most commonly-seen rib structures include stripe-structure, waffle-structure, curve-structure, and step-formed structure. The step-formed ribs are good for ventilating so the time for ventilating can be shortened and impurities in the panels can be reduced. However, due to the limitation of the current development in patterning technology, it usually requires more than two patterning processes or other complicated processes to form the step-formed ribs. As a result, this increases the production costs and leads to low production efficiency.  
     SUMMARY OF THE INVENTION  
      Accordingly, the present invention is directed to a method for fabricating the ribs in the plasma panels in more simplified processes to form step-formed ribs.  
      The present invention is further directed to a method for forming the step-formed patterned layer. The processes are more simplified so as to promote better production efficiency.  
      Based on the above-mentioned or other objectives, the present invention provides a method for fabricating ribs in plasma panels. First, a substrate is provided on which a plurality of addressing electrodes covered with a dielectric layer are formed. A first spacer material layer is then formed on the dielectric layer. Next, a first patterned photo-resist dry film is formed on the first spacer material layer. Subsequently, a second spacer material layer is formed on the first spacer material layer and covers the first patterned photo-resist dry film. After that, a second patterned photo-resist dry film is formed on the second spacer material layer, wherein the patterns of the first patterned photo-resist dry film and the second patterned photo-resist dry film are different so as to define a plurality of discharging areas on the substrate and the second patterned photo-resist dry film further exposes the second spacer material layer over the first patterned photo-resist dry film. The addressing electrodes respectively pass through their corresponding discharging areas. Then, the second spacer material layer and the first spacer material layer are sandblasted by using the second patterned photo-resist dry film and the first patterned photo-resist dry film as a mask. Later, the second patterned photo-resist dry film and the first patterned photo-resist dry film are successively removed.  
      In one embodiment of the present invention, the first patterned photo-resist dry film, for example, comprises a plurality of parallel first striped patterns while the second patterned photo-resist dry film, for example, comprises a plurality of parallel second striped patterns. In addition, the extension direction of the first striped patterns intersects with that of the second striped pattern.  
      In one embodiment of the present invention, the extension direction of the aforesaid first striped patterns is, for example, perpendicular to that of the second striped patterns.  
      In one embodiment of the present invention, a method of forming the first spacer material layer is, for example, printing.  
      In one embodiment of the present invention, a method of forming the second spacer material layer is, for example, printing.  
      In one embodiment of the present invention, the discharging area has a grid shape.  
      In one embodiment of the present invention, the first spacer material has, for example, a same material as the second spacer material layer.  
      In one embodiment of the present invention, the first spacer material has a planar surface.  
      In one embodiment of the present invention, the second spacer material has a planar surface.  
      The present invention also provides a method for fabricating a step-formed patterned layer. First, a first patterned photo-resist dry film is formed on a first material layer. Next, a second material layer is formed on the first material layer and covers the first patterned photo-resist dry film. A second patterned photo-resist dry film is then formed on a second material layer, wherein the patterns of the first patterned photo-resist dry film and the second patterned photo-resist dry film are different and the second patterned photo-resist dry film further exposes the second material layer over the first patterned photo-resist dry film. Subsequently, the second material layer and the first material layer are partially removed by using the second patterned photo-resist dry film and the first patterned photo-resist dry film as a mask. Later, the first patterned photo-resist dry film and the second patterned photo-resist dry film are removed.  
      In one embodiment of the present invention, a method for forming the second material layer on the first material layer comprises printing.  
      In one embodiment of the present invention, a method for partially removing the first material layer and the second material layer comprises sandblasting the first material layer and the second material layer.  
      In one embodiment of the present invention, the second spacer material has, for example, a same material as the first spacer material layer.  
      In one embodiment of the present invention, the first spacer material has a planar surface.  
      In one embodiment of the present invention, the second spacer material has a planar surface.  
      Based on the foregoing description, the present invention can form a step-formed patterned layer only by means of the step-formed patterned photo-resist dry films accompanied with a removing step. Therefore, the processes of the present invention are more simplified and accelerated. In addition, if the technology is applied to fabricating the ribs in the plasma display panels, step-formed ribs can be formed. This improves ventilating, reduces impurities in the panels and also promotes the process yield.  
      The aforementioned objectives and other objectives, features, and advantages of the present invention will be more apparent and easily understood from the following detailed description of the embodiments of the invention when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.  
      FIGS.  1  is a flowchart of a process flow for fabricating a step-formed patterned layer of one embodiment of the present invention.  
      FIGS.  2 A˜ 2 E schematically shows cross-sectional views of a process flow for fabricating the step-formed patterned layer of one embodiment of the present invention.  
       FIG. 3  is a flowchart of a process flow for fabricating a spacer of a plasma display panel of one embodiment of the present invention.  
       FIGS. 4A-4G  schematically shows cross-sectional views of a process flow for fabricating the spacer of the plasma display panel of one embodiment of the present invention. 
    
    
     DESCRIPTION OF THE EMBODIMENTS  
      Referring to  FIGS. 1 and 2 A˜ 2 E, these figures schematically show a flowchart and cross-sectional views of a process flow for fabricating a step-formed patterned layer of one embodiment of the present invention.  
      First, as shown in  FIG. 2A , a first patterned photo-resist dry film  120  is formed on a first material layer  110 , wherein the first patterned photo-resist dry film  120  partially exposes the first material layer  110  (step S 1 ).  
      Next, as shown in  FIG. 1B , a second material layer  130  is formed on the first material layer  110  and covers the first patterned photo-resist dry film  120 , wherein the second material layer  130 , for example, is formed by printing (step S 2 ).  
      As shown in  FIG. 1C , a second patterned photo-resist dry film  140  is formed on the second material layer  130 , wherein the patterns of the first patterned photo-resist dry film  120  and the second patterned photo-resist dry film  140  are different and the second patterned photo-resist dry film  140  further exposes the second material layer  130  over the first patterned photo-resist dry film  120  (step S 3 ). In this embodiment, the second patterned photo-resist dry film  140 , for example, partially exposes the second material layer  130  disposed on the first patterned photo-resist dry film  120 . That is, the first patterned photo-resist dry film  120  is next to the second patterned photo-resist dry film  140 . Obviously, in other embodiments, the first patterned photo-resist dry film  120  and the second patterned photo-resist dry film  140 , for example, are not intersected or partially overlapped.  
      Then, as shown in  FIG. 2D , the second material layer  130  and the first material layer  110  are partially removed by using the second patterned photo-resist dry film  140  and the first patterned photo-resist dry film  120  as a mask (step S 4 ). For the techniques applied in the present invention, such as the sandblasting of the first material layer  110  and the second material layer  130  or others, for example, wet or dry etching, those skilled in the art may choose an appropriate aforementioned process based on the characteristics of the first material layer  110  and the second material layer  130 . Note that only the first material layer  110  underneath the second patterned photo-resist dry film  120 , the first material layer  110  underneath the second patterned photo-resist dry film  140 , and the second material layer  130  are left after the aforementioned removing step.  
      Afterwards, as shown in  FIG. 1E , the first patterned photo-resist dry film  120  and the second patterned photo-resist dry film  140  are peeled off (step S 5 ). As a result, the left first material layer  110  and the second material layer  130  constitute a step-formed patterned layer with a step-height h.  
      The following method for fabricating the ribs in the plasma display panels is used as an example to describe applications of the present invention. Referring to  FIGS. 3 and 4 A˜ 4 G, those figures schematically show a flowchart and cross-sectional views of a process flow for fabricating ribs in the plasma display panels of one embodiment of the present invention.  
      First of all, as shown in  FIG. 2A , a substrate  200  is provided, on which a plurality of addressing electrodes  202  and a dielectric layer  204  that covers the addressing electrodes  202  are formed (step W 1 ).  
      Next, as shown in  FIG. 4B  to  4 D, a first spacer material layer  210  is formed on the dielectric layer  204 . A first patterned photo-resist dry film  220  is then formed on the first spacer material layer  210 . Following that, a second spacer material layer  230  is formed on the first spacer material layer  210  and then the second spacer material layer  230  covers the first patterned photo-resist dry film  220  (steps W 2 -W 4 ). In this embodiment, the material of the second spacer material layer  230  is, for example, the same as that of the first spacer material layer  210 . In addition, the first spacer material layer  210  and the second spacer material layer  230  are, for example, formed by a printing method, thereby forming an evener surface.  
      Subsequently, as shown in  FIG. 4E , a second patterned photo-resist dry film  240  is formed on the second spacer material layer  230 , wherein the patterns of the first patterned photo-resist dry film  220  and the second patterned photo-resist dry film  240  are different and the second patterned photo-resist dry film  240  further exposes the second material layer  230  over the first patterned photo-resist dry film  220  (step W 5 ). A plurality of discharging areas (shown in  FIG. 4G ) are defined by means of the first patterned photo-resist dry film  220  and the second patterned photo-resist dry film  240  while the addressing electrodes  202  respectively pass through their corresponding discharging areas (shown in  FIG. 4G ).  
      It is noticed that the shape of the ribs formed by the present invention are determined by the patterns of the first patterned photo-resist dry film  220  and the second patterned photo-resist dry film  240 . For example, if a grid-shaped rib is to be formed in this embodiment, the first patterned photo-resist dry film  220  is constituted by, for example, a plurality of parallel first striped patterns  222 , and the second patterned photo-resist dry film  240  is constituted by, for example, a plurality of parallel second striped patterns  242 , wherein the extension direction of the first striped patterns  222  is perpendicular to that of the second striped patterns  242  and the second striped pattern  242  further exposes the second spacer material layer  230  over the first striped pattern  220 . In other embodiments of the present invention, the patterns of the first patterned photo-resist dry film  220  and the second patterned photo-resist dry film  240  can be different due to the shapes of the ribs. However, the detailed description is not repeated here.  
      Next, as shown in  FIG. 4F , the second spacer material layer  230  and the first spacer material layer  210  are sandblasted by using the second patterned photo-resist dry film  240  and the first patterned photo-resist dry film  220  as a mask (step W 6 ). Meanwhile, the second spacer material layer  230  exposed by the second patterned photo-resist dry film  240  is first removed. Following that, the first spacer material layer  210  exposed by the first patterned photo-resist dry film  220  and the second patterned photo-resist dry film  240  is also removed. Hence, only the first spacer material layer  210  underneath the first patterned photo-resist dry film  220 , the first spacer material layer  210  underneath the second patterned photo-resist dry film  240 , and the second spacer material layer  230  are left.  
      As shown in  FIG. 4G , the second patterned photo-resist dry film  240  and the first patterned photo-resist dry film  220  are then peeled off in sequence (step W 7 ). As a result, the remaining first spacer material layer  210  and remaining second spacer material layer  230  on the substrate can constitute step-formed ribs with a step-height h.  
      Note that the step-height h of the patterned layer (ribs) formed by the above-mentioned embodiment is determined by the thickness of the second (spacer) material layer. In more detail, if the patterned layer (ribs) with a larger height h is (are) formed, then the second (spacer) material layer can be formed with greater thickness. Furthermore, the present invention is not limited to only two layers of photo-resist dry film and material layers. Under a reasonable situation, the layers of the photo-resist dry film and material layers can also be increased to form the patterned layer (ribs) with more flexible heights.  
      In conclusion, the present invention at least provides the following features and advantages.  
      (1) A step-formed patterned layer is formed by using the step-formed photo-resist dry film accompanied by a removing step. Therefore, the processes are more simplified and accelerated so as to promote production efficiency.  
      (2) When the present invention is applied to the ribs of plasma display panels, the step-formed ribs can be formed. Therefore, this improves ventilating, reduces impurities in the panels, and further promotes the production yield.  
      It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.