JP3620939B2 - Method for forming partition wall of display panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for forming barrier ribs for manufacturing a display panel having barrier ribs in a display area, such as a plasma display panel (PDP).
[0002]
Display panels (thin display devices) such as PDPs and LCDs are used in various fields. In particular, a PDP having the characteristics of excellent visibility and high-speed display is suitable for high-definition display. Development of panel structures and manufacturing techniques is being promoted with the aim of improving display quality.
[0003]
[Prior art]
A PDP is a self-luminous display panel in which a pair of substrates (usually a glass plate) are arranged to face each other with a minute gap of about 150 to 200 μm, and a discharge space is formed inside by sealing the periphery. Among the matrix display type PDPs, the surface discharge type PDP suitable for color display has partition walls for partitioning discharge spaces for each display column. The barrier ribs prevent discharge coupling between columns and crosstalk of color reproduction. In recent years, an etching method is used for forming such partition walls instead of pattern printing. That is, after a uniform layer (so-called solid film) of a low-melting glass paste as a partition material is provided on a substrate and dried, and a cutting mask having a predetermined pattern is provided on the low-melting glass layer by photolithography. Then, the low melting point glass layer is patterned by sandblasting. A patterning method of spraying a cutting medium, such as sandblasting, is suitable for increasing the screen size in terms of productivity, and has higher patterning accuracy than wet etching. After patterning, the low-melting glass layer is baked to complete the partition walls.
[0004]
Conventionally, the plan view shape (masking pattern) of the cutting mask is substantially the same as the partition pattern. However, a predetermined margin was set for the dimensions in anticipation of shrinkage during firing after cutting. That is, a cutting mask having the same shape (similar shape) as the plan view shape of the partition walls has been used.
[0005]
[Problems to be solved by the invention]
FIG. 7 is a diagram for explaining a conventional problem.
As a barrier rib pattern for improving the display quality of the surface discharge type PDP, a belt-like pattern P91 meandering regularly as shown in FIG. 7A is divided into a portion having a large distance d and a portion having a small interval d between adjacent belt-like patterns P91. Has been proposed (Japanese Patent Application No. 7-202977). In this way, when the partition wall having a pattern having different partition wall distances d is formed by the conventional method, the cross-sectional shape of each partition wall 91 corresponding to the strip pattern P91 as shown in FIG. As a result, the partition wall 91 ′ is inclined as shown in FIG. 7C due to thermal contraction during subsequent firing, resulting in a problem that a partition wall having a desired shape in plan view cannot be obtained. The degree of inclination of the partition wall 91 ′ depends on the dimension conditions (height and aspect ratio) of the partition wall and the volume reduction rate of the partition wall material. Therefore, in order to reduce the inclination, it is necessary to optimize the structure and manufacturing conditions, such as reducing the aspect ratio or using a material with a small volume reduction rate.
[0006]
It is an object of the present invention to prevent shape loss at the stage of forming partition walls having different arrangement patterns depending on the positions in the display region, and to ease restrictions on the partition structure and partition material.
[0007]
[Means for Solving the Problems]
In patterning in which a cutting medium is sprayed like sandblast, the cutting speed in the depth direction is higher in a portion where the cutting surface (mask opening surface) is wide than in a narrow portion, and the substrate surface is exposed faster. The cutting medium that has collided with the hard substrate surface moves in the surface direction (lateral direction) and cuts the partition wall material below the cutting mask. For this reason, when a partitioning mask similar to the partition wall is used as in the prior art when forming partition walls with different partition wall intervals, the side cut amount at the region where the partition wall interval is large becomes large and the partition wall becomes asymmetrical. Therefore, in addition to the cutting mask corresponding to the partition wall shape, an auxiliary cutting mask for equalizing the mask interval is provided. Thereby, the nonuniformity of the side cut amount is reduced. When the cutting has progressed to an appropriate stage, the auxiliary cutting mask disappears naturally from the cutting surface, or the auxiliary cutting mask is selectively removed, and only the cutting mask is used thereafter, the desired plan view shape is obtained. Can be obtained.
[0008]
The method of the invention of claim 1 has a partition wall for partitioning the display area, and in order to manufacture a display panel having a structure in which the partition wall spacing in at least one direction differs depending on the position in the display area, A partition wall forming method for a display panel, in which a cutting mask having a plan view shape corresponding to the partition wall is provided on a partition wall material layer that spreads, and unnecessary portions of the partition wall material layer are removed by spraying a cutting medium . The overall plan view shape is orthogonal to the first direction so that a plurality of band-shaped patterns meandering along the first direction are arranged in such a manner that large and small portions of adjacent band-shaped patterns are alternately arranged. If a shape arranged in the second direction, a large portion of the gap, simultaneously with the formation of the cutting mask to equalize the mask intervals over the entire area of the display region An unnecessary cutting portion of the partition wall material layer is formed by sequentially performing a first cutting using the cutting mask and the auxiliary cutting mask and a second cutting using only the cutting mask. To be removed.
[0009]
According to the method of the invention of claim 2, the plane of the auxiliary cutting mask is blown so that the auxiliary cutting mask is blown away when the lower side cut amount of the auxiliary cutting mask accompanying the first cutting exceeds a certain amount. A visual shape is set, and the first cutting and the second cutting are continuously performed.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an exploded perspective view of a main part of a PDP 1 according to the present invention, and FIG. 2 is a plan view showing a matrix configuration.
[0012]
The PDP 1 is a surface discharge AC type PDP having a three-electrode structure in which the first and second display electrodes X and Y and the address electrode A correspond to the unit display element EU of the matrix display. Display electrodes X and Y, dielectric layer 17 and protective film 18 are provided on front glass substrate 11, and address electrode A, insulating layer 24, barrier rib 29 and phosphor layer are provided on rear glass substrate 21. 28R, 28G, and 28B are provided. The display electrodes X and Y are each composed of a transparent conductive film 41 and a metal film 42, and are alternately arranged with a constant interval (surface discharge gap).
[0013]
In the PDP 1, the planar view shape of the partition walls 29 that divide the discharge space 30 for each column is a belt shape that meanders regularly. As shown in FIG. 2, each partition wall 29 undulates with a constant period and amplitude in plan view, and the distance from the adjacent partition wall 29 is periodically constant along the direction of the column r (hereinafter referred to as the column direction). It arrange | positions so that it may become smaller than a value. The constant value is a dimension capable of suppressing discharge, and is determined by discharge conditions such as gas pressure. Since the partition walls 29 are spaced apart from each other, the space (column space) between the partition walls 29 is continuous across all the lines l on the display screen. Accordingly, it is possible to facilitate driving by priming in units of columns, to make the printing state of the phosphor layer uniform, and to facilitate exhaust. Further, the phosphor can be applied to the row space with a uniform thickness by using a screen printing method. In the PDP 1, an R (red) phosphor layer 28R, a G (green) phosphor layer 28G, and a B (blue) phosphor layer 28B are arranged in the order of RGB, one color for each column r. The emission color of each line l in the row r is the same.
[0014]
Here, in the column space, the surface discharge is not generated in the portion 31b having a small width in the direction of the line l (line direction), and the wide portion 31a substantially contributes to light emission. Therefore, subpixels EU are arranged every other column in each row l. When attention is paid to two adjacent rows l, the columns r in which the subpixels EU are arranged are alternately switched every column. That is, the subpixels EU are arranged in a staggered pattern in both the row direction and the column direction. In PDP 1, one pixel EG is configured by a total of three subpixels EU of adjacent RGB, and a three-color arrangement format for color display is a triangular (delta) arrangement format. The triangular arrangement has a width w of the sub-pixel EU larger than 1/3 of the pixel pitch p in the line direction, which is advantageous for higher definition than the in-line arrangement.
[0015]
FIG. 3 is a diagram showing a procedure for forming a partition wall, and FIG. 4 is a plan view showing a masking pattern at the start of cutting. The broken line in FIG. 4 indicates the position in the column direction corresponding to FIG.
A barrier rib material having a thickness of about 200 μm is formed by applying a PbO-based low-melting glass paste to almost the entire surface of the glass substrate 21 at the stage after the insulating layer 24 is formed so as to cover the address electrodes A, and drying the coating layer. Layer 291 is formed. Examples of the paste application method include a screen printing method, a bar coater method, a slot coater method, and a curtain coater method. Subsequently, a dry film photosensitive resist having a thickness of 30 to 50 μm is pressure-bonded to the surface of the partition wall material layer 291 at a temperature of 80 to 100 ° C. using a laminator. Then, pattern exposure and development are performed to simultaneously form a cutting mask 61 having a masking pattern corresponding to the partition wall 29 and an auxiliary cutting mask 62 unique to the present invention (FIG. 3A). Here, the auxiliary cutting mask 62 is a member for equalizing the mask intervals d1 and d3 over the entire display area in which the pixels EG are defined, and a portion having a large interval between adjacent cutting masks 61 as shown in FIG. That is, it is arranged in a region corresponding to the wide portion 31a described in FIG.
[0016]
Next, the partition wall material layer 291 is partially cut by sandblasting (FIG. 3B). That is, the partition wall material layer 291 is patterned using the cutting mask 61 and the auxiliary cutting mask 62. For example, glass powder having a particle size of about 10 to 30 μm is used as a cutting medium, and dry air or nitrogen gas is used as an injection medium. The injection pressure is 1.0 to 3 kg / cm ² . The entire display area is cut by relatively moving the spray nozzle and the glass substrate 21 in parallel.
[0017]
When a predetermined time elapses from the start of cutting and the side cut amount below the auxiliary cutting mask 62 exceeds a predetermined amount, the mechanical strength of the partition wall material layer 291 supporting the auxiliary cutting mask 62 is increased against the impact of sandblasting. The partition material is blown off together with the auxiliary cutting mask 62 (FIG. 3C). The cutting mask 61 remains without being blown away. This is because the auxiliary cutting masks 62 are interspersed and the ratio of the peripheral length to the area is larger than that of the strip-shaped cutting mask 62, and side cuts in all directions of 360 ° are generated. This is because the volume reduction of the partition wall material layer 291 proceeds rapidly. Here, the time from the start of cutting to the disappearance of the auxiliary cutting mask 62 is the cutting conditions (type of abrasive, particle size, blast pressure, etc.), film quality of the partition wall material layer (cutability, brittleness, etc.), It depends on the properties (thickness, hardness, brittleness, adhesion) of the mask and the shape (width, length, thickness) of the auxiliary cutting mask 62. Therefore, it is necessary to optimize the cutting conditions so that the auxiliary cutting mask 62 disappears at an appropriate time.
[0018]
Cutting continues even after the auxiliary cutting mask 62 disappears. That is, unnecessary portions of the partition wall material layer 291 are removed using only the cutting mask 61 [FIG. 3D]. The partition wall material exposed by the disappearance of the auxiliary cutting mask 62 is rapidly cut away. When the cutting is finished, the cutting mask 61 is chemically removed, and the partition wall material layer 292 patterned into a meandering strip shape is fired to complete the partition walls 29.
[0019]
5 and 6 are plan views showing other examples of the masking pattern.
In the example of FIG. 5, an annular auxiliary cutting mask 62 b is arranged in a portion having a large width in the line direction in a region between strip-shaped cutting masks 61 b extending while meandering in the column direction. If the area of the auxiliary cutting mask 62b is excessive, it may remain without being blown off during cutting. Therefore, the auxiliary cutting mask 62b is formed in an annular shape. In the example of FIG. 6, two rectangular auxiliary cutting masks 62c are arranged in a portion having a large width in the line direction in the region between the strip-shaped cutting masks 61c.
[0020]
In the above-described embodiment, the case where the meandering strip-shaped partition walls 29 are formed is illustrated. However, in the present invention, when the linear partition walls are arranged in a form other than equal intervals (unequally spaced), the column direction and the line direction. The present invention is also applicable to the case where grid-like partition walls having different partition wall intervals are provided. For example, when linear barrier ribs are arranged with a first gap and a second gap larger than the first gap, a linear auxiliary cutting mask is provided in a region corresponding to the second gap when patterning the barrier rib material layer. Form. If the width of the auxiliary cutting mask is selected to be smaller than the width of the cutting mask corresponding to the partition wall, the auxiliary cutting mask can be eliminated during the cutting. If the auxiliary cutting mask has a broken line shape, the width, length, and interval can be selected to optimize the disappearance time, and the mask design can be made better than a straight line where only the width can be selected. Increased freedom.
[0021]
【The invention's effect】
According to the first or second aspect of the present invention, the deformation of the partition wall in the formation stage of the partition pattern in which the partition wall space varies depending on the position in the display region is prevented, so that the restrictions on the partition wall structure and the partition wall material are alleviated. The
[0022]
According to invention of Claim 2, the special process for removing an auxiliary cutting mask becomes unnecessary, and productivity improves.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a main part of a PDP according to the present invention.
FIG. 2 is a plan view showing a matrix configuration.
FIG. 3 is a diagram showing a procedure for forming a partition wall;
FIG. 4 is a plan view showing a masking pattern at the start of cutting.
FIG. 5 is a plan view showing another example of a masking pattern.
FIG. 6 is a plan view showing another example of a masking pattern.
FIG. 7 is a diagram for explaining a conventional problem.
[Explanation of symbols]
1 PDP (display panel)
29 Partition wall 61 Cutting mask 62 Auxiliary cutting mask 291 Partition wall material layer d interval (distance between partitions)
d1, d3 Mask interval P91 Strip pattern

Claims (2)

In order to manufacture a display panel having a partition partitioning a display area and having a structure in which a partition spacing in at least one direction differs depending on a position in the display area, the partition is formed on a partition material layer extending over the entire display area. A partition mask forming method for a display panel, in which an unnecessary portion of the partition wall material layer is removed by spraying a cutting medium.
The entire planar shape of the cutting mask has a plurality of belt-like patterns meandering along the first direction, and the first and the second strips are arranged in such a manner that portions with large and small intervals between adjacent belt-like patterns are alternately arranged. When the shape is arranged in a second direction orthogonal to the direction,
Forming an auxiliary cutting mask for equalizing the mask interval over the entire display area at the same time as the formation of the cutting mask at the large interval ,
An unnecessary portion of the partition wall material layer is removed by sequentially performing a first cutting using the cutting mask and the auxiliary cutting mask and a second cutting using only the cutting mask. Partition wall forming method. The shape of the auxiliary cutting mask in plan view is set so that the auxiliary cutting mask is blown away when a side cut amount below the auxiliary cutting mask resulting from the first cutting exceeds a certain amount. The partition forming method for a display panel according to claim 1, wherein the cutting and the second cutting are continuously performed.

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