JP2001283736A - Flat display panel and processing method for display electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat display panel with a highly refinement that prevents a short and a wire-cut in a pitch convert portion of a small pitch display electrode for a higher refinement and renders no abnormal display. SOLUTION: The processing method is composed of forming an electrode pattern with a given shape through an exposure with a laser light on a photo resist coated on the treated substrate constituting a flat display panel and a display panel that has a numerous display electrodes arranged in a matrix. A flat display panel constitutes display electrodes arranged in a way that plural longitudinal electrodes and horizontal electrodes are arranged in matrix-like order, and converted with a pitch while the said display electrode reaches from the display region to an electrode attracting portion around a panel. A pitch convert portion of at least either the electrode for the longitudinal direction or the electrode for the horizontal direction, is composed in a crank-like pattern that has two or more bending portions with almost right angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat display panel having a large number of display electrodes arranged in a matrix, and a photoresist coated on a substrate to be processed, which constitutes the display panel, is exposed to laser light. And a method for forming an electrode pattern having a predetermined shape.

[0002] A flat display panel such as a plasma display panel has a structure in which a large number of display electrodes are arranged at a small pitch in order to display a fine image. Display electrodes tend to be finer and smaller in pitch in order to enhance image quality, and it is required to form such display electrodes with high precision.

[0003]

2. Description of the Related Art A display electrode of this type is formed by photolithography. This photolithography has an exposure step, which is performed by directly drawing an electrode pattern on a photoresist layer with a laser beam. Done.

A method for forming a display electrode by exposure using laser light will be described with reference to the drawings. FIG.
FIG. 3 is a schematic view of an exposure apparatus for explaining an exposure step.

The substrate 31 to be processed is placed on a movable stage 32 via a transport system (not shown) in a state where an electrode material and a photoresist are sequentially applied on the entire surface thereof. In this state, laser light emitted from the light source 33 is projected onto a desired position on the substrate 31 through the optical system 34 and the emission unit 35 to perform exposure.

The optical system 34 includes a plurality of reflection mirrors, polygon mirrors, and the like, and is controlled by the exposure control unit 36 to scan the laser beam in the Y direction. At the same time as performing such a scan, the movable stage 3
By moving the substrate 31 to be processed in the X direction by the method 2, a desired position can be irradiated with laser light.

The exposure control section 36 includes an electrode pattern memory 37 for storing preset electrode pattern data, and an exposure drive section 38 for driving according to the electrode pattern data.
And a stage driving section 39.

The display electrodes in the flat display panel are formed such that the horizontal electrodes and the vertical electrodes arranged in parallel overlap each other in a matrix, and the pitch is narrow at the electrode lead-out portions around the panel. Have been.

That is, the display electrode is connected to a drive circuit for driving the display electrode via the flexible cable, and the pitch of the lead portion is made smaller than the pitch of the display portion in order to secure the connection margin.

FIG. 6 is a plan view of a conventional flat display panel, FIG. 6 (a) is an overall view, and FIG. 6 (b) is an enlarged view of a pitch conversion section.

FIG. 6A is a diagram in which the vertical electrodes 42 are collectively expressed for each connection area, and the electrodes have a drawer 43 derived from the display unit on the lower side. In the conventional flat display panel, the pitch converter 45 from the display 44 to the drawer 43 has an oblique pattern as shown in the drawing. FIG.
This is more apparent in the enlarged view of (b). The vertical electrodes 4 arranged in parallel at a predetermined pitch P1 in the display unit 44
2, the pitch is gradually narrowed by a pitch converter 45 in an oblique pattern, and a connection cable 46
Is a pitch P2 at which the connection allowance can be secured.

In recent years, the pitch of the display electrodes has tended to be narrower due to higher definition, and the pitch converter 45 using the conventional oblique pattern has an adverse effect on the electrode formation by laser exposure.

[0013]

FIG. 7 is a diagram for explaining a problem of a conventional flat display panel, and shows a pitch conversion portion of a display electrode.

In the laser exposure, as described with reference to FIG.
Scanning is performed via the optical system 34 controlled by the laser beam 5, and depending on the beam diameter of the laser beam and the data format, FIG.
As shown in (a), the position at which the center of the laser beam is irradiated is limited to points called grids that are arranged in an orderly manner.

Therefore, in the conventional oblique pattern pitch converter 45, the angle of the pattern 48 and the grid 4
Depending on the position of 7, the laser beam is applied to a position shifted from the desired pattern, and an exposure state having unevenness is obtained as shown in FIG. 6B.

When such exposure is performed, if the pitch is small, there is a possibility that the pattern after development and etching is short-circuited between the projections between adjacent patterns.

Conversely, if the width of the pattern is reduced to secure the gap between the patterns, there is a possibility that the wire may break in the concave portions on both sides of the pattern.

Although it is physically possible to match the position of the grid 47 with the shape of the pattern 48, the angle differs for each of a plurality of patterns, and it is not possible to change the pitch or position of the grid depending on the location. Since it involves an enormous amount of data and causes a delay in exposure processing, it is difficult to practically perform the processing.

An object of the present invention is to solve the problems described above, to prevent short-circuit and disconnection in a pitch conversion section of a small-pitch display electrode for high definition, and to obtain a high-definition flat display panel without display abnormality. The purpose is.

[0020]

In a flat display panel according to the present invention, a plurality of vertical electrodes and horizontal electrodes are arranged in a matrix to form a display electrode, and the display electrode extends from the display area to the periphery of the panel. In a flat display panel in which the pitch is converted to reach the electrode extraction portion,
The pitch conversion portion of at least one of the vertical electrode and the horizontal electrode is a crank-shaped pattern having two or more bent portions at substantially right angles.

As described above, according to the present invention, since the pitch converting portion of the display electrode is a crank-shaped pattern having two or more bent portions at substantially right angles, there is no oblique portion, and the desired pattern edge can be removed. In addition, the laser beam irradiation position (grid) during exposure becomes constant.

Accordingly, since there is no unevenness in the pattern and the gap is constant between adjacent patterns, a display electrode with high accuracy without short-circuit or disconnection in the pitch converter can be obtained.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, display electrodes which are features of the flat display panel of the present invention will be described with reference to FIG. FIG. 1 is a plan view showing a flat display panel of the present invention. FIG. 1 (a) is an overall view, and FIG. 1 (b) is an enlarged view of a pitch conversion section.

FIG. 1A is a view in which vertical display electrodes 2 formed on a glass substrate 1 are collectively expressed for each connection area, and have a drawer 3 on the lower side. In the flat display panel of the present invention, the pitch converter 4 extending from the display area 6 to the drawer 3 has a crank pattern having a right-angle bent portion as shown in the drawing. This pitch converter 4 is more apparent in the enlarged view of FIG.

The display electrodes 2 arranged in parallel in the display area 6 at a predetermined pitch P 1 are converted in pitch by the crank pattern pitch conversion section 4, and
Then, the pitch P for securing the connection allowance of the connection cable 5
It is 2.

By forming the display electrode 2 having the pitch converter 4 having such a shape, even if the pitch is reduced for higher definition, it is possible to form an electrode without short-circuiting or disconnection with an adjacent pattern. be able to.

That is, as described with reference to FIG. 5 in the section of the prior art, the display electrode is formed by the exposure technique using laser light, and the crank pattern is used for the exposure using laser light. It becomes suitable.

The basis for this will be described below.

As described with reference to FIG. 5, the laser exposure is performed by exposing the laser light emitted from the light source 33 to the exposure control unit 3.
Scanning is performed via an optical system 34 controlled by the laser beam 6, and depending on the beam diameter of the laser beam and the data format, FIG.
As shown in (a), the position at which the center of the laser beam is irradiated is limited to points called grids that are arranged in an orderly manner.

By forming the pitch converter 4 in a crank pattern as in the present invention, the display electrode has only a linear portion, and the edge of the pattern is at a fixed position with respect to the grid arranged neatly. There are no irregularities in the points.

That is, the setting pattern 22 shown in FIG.
By irradiating a predetermined grid 21 with laser light, the exposure pattern shown in FIG. Thereafter, development and etching are performed to form a substantially linear display electrode.

With such a straight display electrode, the line width and pitch can be set as set, and disconnection and short circuit between adjacent patterns can be prevented.

An embodiment in which the present invention is applied to a plasma display panel will be described below with reference to FIGS.

FIGS. 3A and 3B are views showing a state in which a pair of glass substrates having display electrodes extending in different directions are superposed, FIG. 3A is an exploded perspective view, and FIG. 3B is a plan view. is there.

In the three-electrode surface discharge type PDP shown in FIG. 3A, a plurality of discharge sustaining electrodes (sustain electrodes) 12 extending in the horizontal direction (row direction of the display screen) are formed on a front substrate 11 serving as a display surface. A plurality of address electrodes 14 arranged in parallel and extending in the vertical direction (column direction of the display screen) on the rear substrate 13 are arranged in parallel.

In this embodiment, in both the sustaining electrode 12 and the address electrode 14, the pitch converter between the lead-out portion from the display area is replaced with the crank patterns 12a and 14a.
a.

The sustain electrode 12 of the front substrate 11 is made of an IT
It has a multilayer structure of a transparent electrode made of O (Indium Tin Oxide) and a bus electrode made of a low-resistance metal (for example, silver or Cr-Cu-Cr), but the transparent electrode is arranged only in the display area, The pitch conversion unit and the lead-out unit are composed of only bus electrodes.

Here, the exposure process of the bus electrode formed after patterning the transparent electrode will be described with reference to FIG.

Front substrate 11 on which transparent electrodes are formed and before exposure
A material layer of a bus electrode, for example, a multilayer film of Cr—Cu—Cr is formed thereon, and a negative photoresist is applied thereon. Such a front substrate 11 is set on a movable stage 32 shown in FIG.

The electrode pattern memory 37 of the exposure control unit 36 shown in FIG. 5 is preliminarily input with the bus electrode pattern data.
8 and the stage drive unit 39 are controlled to perform exposure. That is, the optical system 34 is operated by the exposure drive unit 38 to scan the laser beam in the Y direction of the substrate 31 to be processed, and at the same time, the movable stage 32 is operated by the stage drive unit 39 to slide the substrate 31 in the X direction. Then, a predetermined pattern is exposed.

At this time, since the pitch conversion section 12a is a crank pattern, it is possible to accurately expose the set pattern as described above.

After the exposure, the exposed portions of the photoresist are left as a mask, and the portions without the photoresist mask are etched in this state to form bus electrodes having a predetermined pattern.

On the other hand, the address electrodes 14 on the rear substrate 13
Is made of only a low-resistance metal (for example, silver or Cr—Cu—Cr), and can be patterned by the same method as that for the bus electrode.

As for the address electrode 14, since the pitch conversion section 14a is constituted by only a linear portion in a crank pattern, accurate exposure can be performed, and a set pattern can be formed with high accuracy.

As described above, the sustain electrode 1 is provided on the front substrate 11.
After the formation of No. 2, a dielectric layer and a protective film made of magnesium oxide (MgO) are formed although not shown. On the other hand, on the rear substrate 13, after the address electrodes 14 are formed, a dielectric layer, partition walls (ribs) for separating discharge spaces, phosphors, and seals are sequentially formed.

The front substrate 11 and the rear substrate 13 are overlapped with each other in a predetermined relationship, and sealed with a seal 15 in a state having a discharge space, thereby completing the display panel 10. As shown in FIG. 3B, the inside of the seal 15 is a display area 16 having a discharge space, and the display electrodes are extended to the outside.

The pitch converters 12a and 14a are provided with the seal 1
5 and has a predetermined pitch of the drawers.

As described above, in the present embodiment, the pitch conversion portions 12a of the discharge sustaining electrodes 12 and the address electrodes 14,
Since each of the crankshafts 14a has a crank pattern, it is possible to form a pattern without disconnection or short circuit in both of them.

FIG. 4 is a diagram showing a state in which the display panel 10 formed as described above is connected to a drive circuit for driving the display electrodes. FIG. 4 (a) is a perspective view, and FIG. It is sectional drawing.

A chassis 17 is fixed to the back surface of the rear substrate 13 of the display panel 10 by an adhesive or the like, and a plurality of (only one is shown in the figure) circuit boards 1 are mounted on the chassis.
8 is attached.

Such a circuit board 18 and the display panel 10
Are electrically connected by a flexible cable 19. FIG. 4 shows a state in which the address electrodes of the front substrate 11 and the circuit board 18 are connected.

The flexible cable 19 has a structure in which a plurality of conductive wires are provided in an insulating film, and only one terminal is exposed. The terminal portion is connected to a display electrode (address electrode) of a display panel (back substrate in the figure) by thermocompression bonding, and the other terminal portion is connected to the circuit board 18 via a connector (not shown).

The present embodiment has a structure in which both the sustaining electrode 12 and the address electrode 14 are alternately drawn and have leading portions at the top, bottom, left and right. In FIG. The electrode 14 shows only a part thereof.

In the present embodiment, the crank pattern is applied to both the sustain electrode 12 and the address electrode 14. However, the electrode width and the pitch may be different between the two, and only the electrode having a small pitch may be used. It can also be applied.

[0056]

As described above, according to the present invention, since the pitch converting portion of the display electrode is a crank-shaped pattern having two or more bent portions at substantially right angles, there is no oblique portion, and the desired pattern can be obtained. The laser beam irradiation position (grid) at the time of exposure becomes constant with respect to the edge.

Therefore, since there is no unevenness in the pattern and the gap is constant between adjacent patterns, a display electrode with high accuracy without short-circuit or disconnection in the pitch converter can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view showing a flat display panel of the present invention.

FIG. 2 is a diagram showing a pitch converter of a display electrode according to the present invention.

FIG. 3 is a PD for describing the first embodiment of the present invention.
It is a P schematic diagram.

FIG. 4 is a PD for explaining the first embodiment of the present invention.
It is P perspective view and sectional drawing.

FIG. 5 is a schematic view of an exposure apparatus.

FIG. 6 is a plan view showing a conventional flat display panel.

FIG. 7 is a diagram showing a pitch conversion unit of a display electrode according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Display electrode 3 Electrode extraction part 4 Pitch conversion part 5 Connection cable 6 Display area 10 Display panel 11 Front substrate 12 Discharge sustaining electrode 12a Pitch conversion part 13 Back substrate 14 Address electrode 14a Pitch conversion part 15 Seal 16 Display area 17 Chassis 18 Circuit board 19 Flexible cable 20 Plasma display device 21 Grid 22 Setting pattern 22a Exposure pattern

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuyuki Shuzono 3-2-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Fujitsu Hitachi Plasma Display Limited In-house (72) Inventor Tsuyoshi Adachi 3-chome Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa 2-1 Fujitsu Hitachi Plasma Display Limited In-house (72) Inventor Hidema Eifuku 1815 Tajiri, Kunitomi-cho, Higashi-Meguro-gun, Miyazaki Prefecture Inside Kyushu FIP Co., Ltd. F-term (reference) in Kyushu FCP Co., Ltd.

Claims (5)

[Claims] 1. A plane in which a plurality of vertical electrodes and horizontal electrodes are arranged in a matrix to constitute a display electrode, and the display electrode is pitch-converted from a display area to an electrode lead-out portion around the panel. The flat display panel according to claim 1, wherein a pitch converter of at least one of the vertical electrode and the horizontal electrode has a crank-shaped pattern having two or more bent portions at substantially right angles. 2. The method according to claim 1, wherein the vertical electrodes are address electrodes on a rear substrate forming the plasma display panel, and the horizontal electrodes are discharge sustaining electrodes on a front substrate forming the plasma display panel. 1
A flat display panel as described. 3. A resist mask is formed by exposing a photoresist applied on a substrate to be processed constituting a flat display panel to a laser beam, and a lower metal layer is etched using the resist mask. A display electrode forming method for forming an electrode pattern having a predetermined shape set in advance, comprising a pitch conversion unit extending from a display area to an electrode lead-out unit;
The pattern data of the pitch conversion unit is stored in an electrode pattern memory as a crank-shaped pattern having two or more bent portions at substantially right angles, and the photoresist is exposed by scanning a laser beam according to the pattern data in the memory. Forming a display electrode. 4. The pattern data in the electrode pattern memory includes: an exposure drive unit for driving an optical system that scans laser light in one direction; and a movable unit that slides a substrate to be processed in a direction orthogonal to the scan. 4. The display according to claim 3, wherein a predetermined pattern including the crank pattern is exposed by inputting the input to a stage driving unit for controlling a stage and moving the substrate to be processed simultaneously with scanning of the laser beam. Electrode formation method. 5. A flat display in which a plurality of display electrodes are arranged in parallel on a substrate, and the arrangement pitch of the electrodes is wide in a display region in the center of the substrate and narrow in an electrode lead-out region around the substrate. In a method of forming display electrodes of a panel by photolithography, when a pattern of the display electrodes is directly drawn on a photoresist layer by laser light and exposed, a display portion having a wide array pitch in the display electrodes and an electrode having a narrow array pitch are provided. A flat display panel, wherein each of the lead portions is formed by a linear pattern, and a pitch conversion portion connecting the display portion and the electrode lead portion is formed by a crank-shaped pattern having two or more bent portions at substantially right angles. Display electrode forming method.