JP2002190267A - Display device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device, which has a field emission type cold cathode formed with high speed vacuum micro elements for emitting electrons on the surface of one substrate of two substrates arranged face to face is spaced apart to each other with spacers, of which the spacers can be formed arbitrarily, and also to provide a manufacturing method of the display device. SOLUTION: In the display device having a field emission type cold cathode formed with high speed vacuum micro elements for emitting electrons on the surface of one of two substrates, spacers 21, 22 supporting a glass panel 14 are made with frit glass or polyamide resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 2
The present invention relates to a display device having a spacer for holding a gap between sheets and using a high-speed vacuum micro element, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, a flat type image display device using a high-speed vacuum micro element has been developed, and among them, a field emission type cold cathode image display device (FED; Field Em) has been developed.
issue Display). The development trend is for thinner and larger screens. This FED image display device has an emitter for emitting two-dimensional electrons on one side of two glass substrates opposed to each other, a phosphor screen is formed on the other glass substrate, and emission is performed from the emitter. A predetermined image is obtained by irradiating the phosphor screen with an electron beam. In this image display device, it is necessary to maintain a high vacuum between the emitter and the phosphor screen (between the glass substrates) so that the electron beam can be irradiated. Since the inside of this glass substrate is in a high vacuum, an external force is applied to the two glass substrates by the atmospheric pressure in the direction in which the glass comes into contact with each other, so that the glass substrates are deformed. Therefore, in order to prevent deformation of the glass substrate due to high vacuum and to maintain the gap between the glass substrates, a spacer for maintaining the gap is required.

As a method of manufacturing the spacer, for example, a method of forming a spacer by etching a silicon single crystal by an etching method is disclosed in Japanese Patent Application Laid-Open No. 9-167567.

[0004]

However, in the method of forming a spacer by selectively removing a silicon substrate by anisotropic etching of a silicon single crystal substrate, which is used in a semiconductor manufacturing technology or the like, the material is Since the spacer is formed by utilizing the anisotropy of the spacer, the shape and size of the spacer are restricted, and it is difficult to form a spacer having a desired aspect ratio with no restriction on the shape. It is difficult to reduce the size.

The present invention has been made in view of these circumstances, and has been described with reference to the surface of a substrate on one side of two substrates supported by spacers which are installed to face each other and have a desired interval between each other. It is an object of the present invention to provide a display device on which a high-speed vacuum micro element for emitting electrons is formed and a method for manufacturing the same.

[0006]

According to the first aspect of the present invention, electrons are applied to the surface of at least one side of two substrates which are installed to face each other and are spaced apart from each other and supported by spacers. In a display device using a field emission type cold cathode on which an element for emission is formed, the spacer is formed of frit glass.

[0007] According to the second aspect of the present invention,
A display device using a field emission type cold cathode in which an element for emitting electrons is formed on a surface of at least one of two substrates which are opposed to each other and are supported by a spacer at a distance from each other, The spacer is a display device formed of a polyimide resin.

[0008] According to the means of the invention of claim 3,
A first step of forming a polyimide resin layer on the surface of a gate layer laminated on the emitter via an insulating layer, and exposing an excimer laser beam to the polyimide resin layer via a mask in accordance with the pattern of the mask A second step of removing the polyimide resin layer by using a method described above, a third step of forming a spacer by injecting frit glass into the recess formed in the second step, and removing the polyimide resin remaining on the surface of the gate layer. A method for manufacturing a display device, comprising: a fourth step of irradiating an excimer laser beam through a second mask to remove the excimer laser light; and a fifth step of bonding a glass panel to the top of the spacer.

According to the means of the invention of claim 4,
A first step of forming a polyimide resin layer on the surface of a gate layer laminated on the emitter via an insulating layer, and exposing an excimer laser beam to the polyimide resin layer via a mask in accordance with the pattern of the mask To form a polyimide resin spacer by removing the polyimide resin layer.
And a third step of bonding a glass panel to the top of the spacer.

[0010]

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

FIG. 1 shows a first process of manufacturing a display device (FED) having a field emission type cold cathode which is a flat type image display device using a high-speed vacuum micro element which is a display device of the present invention. FIG. 2 is a flowchart illustrating an embodiment, and FIGS. 2 to 11 are configuration diagrams illustrating states in respective steps. Hereinafter, sequentially according to this flowchart,
Each step will be described.

First, a Ni emitter substrate 1 as shown in FIG. 2 is formed by a transfer molding method for transferring the shape of the precision mold by using a precision mold for molding (not shown) which has been manufactured in advance. S1). In the transfer molding method, a Ni film is formed by electroforming on the surface of a mold having an inverted shape of the emitter, and the mold and the Ni film are separated. Thereby, the metal protrusion formed on the surface of the Ni film is used as an emitter. In the FED image display device, a large number of pixels are required in accordance with the screen size, and more than 50 emitters are required for each pixel. The number of provided emitters is about 50 × 10 ⁶ .

Next, as shown in FIG. 3, a uniform insulating layer 2 of SiO ₂ is formed on the surface of the formed Ni emitter substrate 1 by CVD (vapor phase epitaxy) (S2). Further, on the surface of the SiO ₂ layer, for example, Ni, Cr,
By sputtering a conductive material such as W, FIG.
A uniform gate layer 3 is formed as shown in FIG. Thereafter, the gate layer 3 is subjected to line patterning to form a plurality of signal lines parallel to a predetermined direction (S3).

Next, predetermined portions of the gate layer 3 and the insulating layer 2 of SiO ₂ are selectively removed by dry etching so that the top of the Ni emitter substrate 1 is exposed as shown in FIG. An opening is provided in the gate 4. (S4).

Subsequently, as shown in FIG. 6, a polyimide resin layer 5 is formed on the gate layer 3 made of a conductive material with the gate 4 opened. As a method of forming the polyimide resin layer 5, a polyimide sheet is heated by a press device (not shown), and then placed on a layer of a conductive material which is already in the shape of an emitter, and pressed by a flat heating tool. hand,
Mold so that the surface is flat. Experiments have shown that Ni
In order to form the layer in a state where the emitter substrate 1 is completely pressed into the polyimide sheet, the polyimide sheet is heated to 230 ° C., which is slightly higher than the glass transition point, and the pressing force by the tool is 3. 0 to 3.5 kgf / mm
^{The number} may be set to ² (S5).

Next, as shown in FIG. 7, an insulating layer 6 is provided on the back surface of the Ni emitter substrate 1, and a cathode layer 7 is provided on the surface of the insulating layer 6 by a sputtering method. Is patterned so as to be a cross line with respect to the gate layer 3 to form a plurality of signal lines parallel to each other (S6).

Next, as shown in FIG. 8, a laser light source (not shown) is applied to a portion of the polyimide resin layer 5 where a spacer to be described later is to be formed via a metal mask 8 corresponding to the size and shape of the spacer. Then, an excimer laser beam is applied from the substrate, and ablation processing is performed to remove the excimer laser beam. As described later, the ablation processing by the laser light is performed when an ablation phenomenon caused by each material constituting each layer constituting the workpiece to be irradiated with excimer laser light, which is a high energy ray in the ultraviolet region, is caused. Since the processing is performed using the difference in the threshold value of the energy density, only the polyimide resin in a desired region is selectively removed without affecting the portion of the gate layer 3 (S7).

Next, as shown in FIG. 9, frit glass in a frit state is injected by a dispenser (not shown) into a portion of the polyimide resin layer 5 from which the polyimide resin has been removed by ablation using excimer laser light. Thereafter, the frit glass is solidified on the gate layer 3 by heating to 450 ° C. to form the spacers 12 of the frit glass. The top 12a of the spacer 12
It is preferable that the surface is flattened by polishing if necessary, since uniformity of height can be easily obtained. (S8).

Next, as shown in FIG. 10, the polyimide resin layer 5 at a position corresponding to the leg portion of the spacer 12 formed of frit glass is left as a guide 13 for preventing the spacer 12 from falling, and the other portions are removed. The polyimide resin layer 5 is removed by performing ablation processing by irradiation with excimer laser light. As a result, the spacer 12 made of frit glass provided with the guide 13 for preventing the fall is manufactured (S9).

Next, as shown in FIG.
A glass panel 14 is adhered to the top 12a of the glass plate and sealed in a furnace (not shown). In this case, the fluorescent screen of the glass panel 14 is bonded to the Ni emitter substrate 1 (S1).
0).

As described above, according to this embodiment, N
By subjecting the polyimide resin layer 5 formed on the i-emitter substrate 1 to an ablation process by irradiating excimer laser light, a portion of the polyimide resin corresponding to the spacer 12 for selectively maintaining a gap is removed. The spacer 12 can be formed by injecting the frit glass 11 into the removed portion.

Therefore, the shape of the spacer 12 is cylindrical,
The spacer 12 can be formed arbitrarily, such as a rectangular parallelepiped, and the aspect ratio (spacer height / spacer width) of the spacer 12 can be selected. be able to. By making the spacer 12 black, it can be used as a black stripe for dividing pixels.

The guide 1 for preventing the spacer 12 from falling down
By positively carbonizing the portion of the polyimide resin remaining as 3 by heating, the charge generated in the spacer 12 can be prevented.

Next, the second step of the manufacturing process of the display device of the present invention will be described.
An embodiment will be described. In the second embodiment, the spacer is formed of a polyimide resin.

FIG. 12 is a flowchart for the second embodiment. Note that this second embodiment is
Since the steps from S1 to S6 are the same as those in the first embodiment described above, the description of each step and the corresponding figures (FIGS. 2 to 7) in order to avoid duplication. Omitted.

After completing the steps S1 to S6 as described in the first embodiment, as shown in FIG. 13, the polyimide resin layer 5 other than the portion where the spacer 22 is formed is Mask 8 corresponding to size and shape
a (formed so that only the spacer 22 remains) and the mask 8b (formed so that only the guide 23 for preventing the spacer 22 from collapsing) is used to irradiate excimer laser light. It is formed by performing an ablation process to leave the polyimide resin so as not to cover the spacer 22 and the opening of the gate layer 3 at the junction between the spacer 22 and the gate layer 3 and the periphery thereof. Except for the fall prevention guide 23, the remaining polyimide resin layer 5 is removed. Thereby, the spacer 22 having a predetermined shape made of polyimide resin and the guide 2
3 is formed. Since the ablation process is performed by utilizing the difference in the threshold value of the energy density of the object to be irradiated with the excimer laser light, the gate layer 3 is not affected and the polyimide resin layer is not affected. Only the 5 irradiation locations can be selectively removed (S16).

Next, as shown in FIG.
The glass panel 14 is bonded and sealed to the top 22a.
In this case, the surface of the glass panel 14 where the phosphor is exposed is bonded to the emitter side (S17).

In the case of the second embodiment, the spacer 2
The polyimide resin layer 5 other than the portion corresponding to No. 2 is removed by ablation processing to produce a polyimide resin spacer 22. The polyimide resin is a material that can maintain the flatness of the surface that does not deform and flow due to heat applied when sealing the glass substrate,
Moreover, since it has adhesiveness, if it is used, the spacer 22 made of polyimide and the glass panel 14 can be directly bonded.

Next, ablation processing by excimer laser light used in each of the above embodiments will be described.

It is known that when a polymer is irradiated with excimer laser light, processed decomposed materials are instantaneously scattered, and evaporating processing can be performed under the influence of heat. This is called light ablation. Since the photon energy of the excimer laser is larger than that of the CO ₂ and YAG lasers, for example, when irradiating a polyimide resin, there is no trace that is peeled off during evaporation as compared with the CO ₂ or YAG laser,
In addition, it is reported that the processing can be controlled so that a sharp edge is obtained without heat influence on a peripheral portion of the processing.
(For example, Journal of the Japan Welding Society, Vol. 69, No. 3, Apr.
il 2000) Further, in processing, it is necessary to set an energy density necessary for the processing. Each substance has a threshold in energy density, so that irradiation with laser light below the threshold does not change the substance. For example, polyimide resin can be processed at an energy density of 0.5 J / cm ² at a speed of 0.3 m / pulse, but SiO ₂ cannot be processed under these processing conditions.

By utilizing the difference between the processing thresholds, it is possible to selectively process the workpiece. For example, when applied to a two-layer film formed of a polyimide layer and a copper layer, only the polyimide layer can be selectively removed. Journal of the Japan Welding Society, Vol. 69, No3, April
2000).

The present invention utilizes a selective removal processability for a polyimide resin when the irradiation conditions of the excimer laser beam are optimized, and performs an ablation process with the excimer laser beam to thereby provide a glass panel having a high shape selectivity. The spacer for supporting the gap is manufactured.

[0033]

According to the present invention, in an image display device using a high-speed vacuum micro element, a display device having a spacer having a shape suitable for holding a gap between two sheets placed opposite to each other can be obtained.

[Brief description of the drawings]

FIG. 1 is a flowchart according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram in a process of the first and second embodiments.

FIG. 3 is a configuration diagram in a process of the first and second embodiments.

FIG. 4 is a configuration diagram in a process of the first and second embodiments.

FIG. 5 is a configuration diagram in steps of the first and second embodiments.

FIG. 6 is a configuration diagram in a process of the first and second embodiments.

FIG. 7 is a configuration diagram in steps of the first and second embodiments.

FIG. 8 is a configuration diagram in a process of the first embodiment.

FIG. 9 is a configuration diagram in a step of the first embodiment.

FIG. 10 is a configuration diagram in a process of the first embodiment.

FIG. 11 is a configuration diagram in a step of the first embodiment.

FIG. 12 is a flowchart according to a second embodiment of the present invention.

FIG. 13 is a configuration diagram in a process of a second embodiment.

FIG. 14 is a configuration diagram in a process of a second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ni emitter substrate, 2 ... insulating layer, 3 ... gate layer, 4
... gate, 5 ... polyimide resin layer, 6 ... insulating layer, 7 ... cathode layer, 8 ... mask, 9 ..., 11 ... frit glass,
12, 22: spacer, 13, 23: guide for preventing falling, 14: glass panel

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Honda 33, Shinisogocho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside Toshiba Production Technology Center Co., Ltd. (72) Inventor Mitsuhiro Nishio 33, Shinisogocho, Isogo-ku, Yokohama-shi, Kanagawa Address Toshiba Production Technology Center (72) Inventor Fujio Takahashi 33 Shinisogocho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture F-Terminator Toshiba Production Technology Center F-term (reference) EF09 EG01 EH11

Claims (4)

[Claims] 1. A field emission cold cathode in which an element for emitting electrons is formed on the surface of at least one side of two substrates which are installed to face each other and supported by a spacer. In the display device, the spacer is:
A display device formed of frit glass. 2. A field emission cold cathode in which an element for emitting electrons is formed on the surface of at least one side of two substrates which are placed opposite to each other and supported by a spacer by a spacer. In the display device, the spacer is:
A display device formed of a polyimide resin. 3. A first step of forming a polyimide resin layer on a surface of a gate layer laminated on an emitter via an insulating layer, and irradiating the polyimide resin layer with excimer laser light via a mask. A second step of removing the polyimide resin layer in accordance with the pattern of the mask, a third step of injecting frit glass into the recesses formed in the second step to form spacers, and a step of remaining on the surface of the gate layer. A fourth step of irradiating the polyimide resin with an excimer laser beam through a second mask to remove the polyimide resin, and a fifth step of bonding a glass panel to the top of the spacer. Method. 4. A first step of forming a polyimide resin layer on a surface of a gate layer laminated on an emitter via an insulating layer, and irradiating the polyimide resin layer with excimer laser light via a mask. Manufacturing a display device, comprising: a second step of removing the polyimide resin layer according to a mask putter to form a polyimide resin spacer; and a third step of bonding a glass panel to the top of the spacer. Method.