JP2003012344A - Non-alkali glass substrate and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma address liquid crystal display device (PALC) with good display quality while reducing cross-talk phenomenon. SOLUTION: A non-alkali glass substrate of 40 μm or less thickness is used as an intermediate substrate of PALC. This non-alkali glass substrate is obtained by laminating a non-alkali glass substrate 1 with 50 μm or more thickness onto a supporting body 2 and chemically grinding the outer surface until the thickness becomes 40 μm or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma addressed liquid crystal display device. Further, the present invention relates to a non-alkali glass substrate that can be used as an intermediate substrate of a plasma addressed liquid crystal display device and a manufacturing method thereof.

[0002]

2. Description of the Related Art Plasma addressed liquid crystal display devices (hereinafter referred to as
Also called PALC. ) 100, the liquid crystal cell 101 and the plasma cell 102, as shown in FIG.
It has a structure of being laminated via. Plasma cell 1
02 is a plasma cell substrate 104 and an intermediate substrate 103
And a plurality of partition walls 105 arranged in stripes between them. A discharge gas that can be ionized by discharge is sealed in a plasma channel 106 defined by a space sealed by the adjacent partition wall 105, the plasma cell substrate 104, and the intermediate substrate 103. Each of the plurality of plasma channels 106 has a discharge electrode (anode 107) formed on the plasma cell substrate 104.
And a cathode 108).

The liquid crystal cell 101 comprises a liquid crystal cell substrate 109, an intermediate substrate 103, and a liquid crystal layer 11 provided between them.
Has 0 and. On the liquid crystal layer 110 side of the liquid crystal cell substrate 109, a plurality of stripe-shaped signal electrodes 111 parallel to each other.
Are formed so as to intersect the plasma channel 106. Further, the liquid crystal cell substrate 109 has a signal electrode 111.
The colored layer 112 provided corresponding to is provided on the liquid crystal layer 110 side.

The operating principle of PALC is as follows.
By generating plasma between the anode 107 and the cathode 108, the inside of the plasma channel 106 is made equipotential, and the switch of the virtual electrode 114 is turned on. As a result, a potential difference is generated between the signal electrode 111 and the virtual electrode 114, and the video signal given from the signal electrode 111 is written in the liquid crystal layer 110. Image display is performed by transmitting light from a backlight (not shown) through the liquid crystal layer 110 and the coloring layer 112 corresponding to a predetermined pixel.

By the way, the voltage applied to the liquid crystal cell 101 (hereinafter, also referred to as cell voltage), that is, the signal electrode 11
If the voltage applied between 1 and the virtual electrode 114 is large, a crosstalk phenomenon occurs and the image quality deteriorates. If the cell voltage can be lowered while maintaining the effective voltage applied to the liquid crystal layer 110 (hereinafter, also referred to as liquid crystal voltage), only the crosstalk phenomenon can be reduced without changing the display state. . Therefore, it is required to reduce the cell voltage by making the intermediate substrate 103 as thin as possible.

[0006]

At present, as a glass substrate which is industrially available, there is a glass substrate having a thickness of 30 μm (product name D263, manufactured by Schott). But D2
63 is an alkali-containing glass with a resistivity of 1.6 × 1
^{0 8 Ω · cm (250 ℃} ) and small. Therefore, D2
When 63 is used as the intermediate substrate 103, the liquid crystal layer 110
The DC offset voltage applied to the
It may adversely affect the reliability of PALC.

[0007] Therefore, the present inventors have found that
The idea of using a Lucari glass substrate as an intermediate substrate was reached.
For example, the product name AF45 manufactured by Schott has a resistivity of 6 ×.
10 ¹³Since it is as large as Ω · cm (250 ° C), the AF45
When used as the intermediate substrate 103, it is applied to the liquid crystal layer 110.
The DC offset voltage generated is negligible.
You can

However, alkali-free glass has a higher glass softening temperature than alkali-containing glass. For example, while the glass softening temperature of D263 of alkali-containing glass is 736 ° C., AF4 of non-alkali glass is used.
That of 5 is 883 ° C. Since the glass substrate is manufactured under conditions in which the temperature is controlled so that it has a constant viscosity,
Alkali-free glass having a high glass softening temperature can only be obtained in a thickness larger than that of alkali-containing glass. For example, D263 of alkali-containing glass is 30
It is possible to obtain a product with a thickness of μm, but the thickness of the non-alkali glass AF45 is limited to 50 μm.

On the other hand, a technique for thinning the intermediate substrate of PALC is disclosed in, for example, Japanese Patent Laid-Open No. 2000-39853. The publication describes that after bonding an intermediate substrate having a film thickness to a discharge cell substrate, the surface of the intermediate substrate on the liquid crystal layer side is chemically polished.

However, in the method described in the publication,
Since it is necessary to protect the terminal portions and the like as a pre-preparation for performing the chemical polishing treatment, and it is necessary to remove the protective material after the polishing treatment, complicated work is required and it is not preferable in terms of manufacturing efficiency. Further, since unevenness of about 0.1 μm occurs on the surface of the intermediate substrate that has been subjected to the polishing treatment, the thickness (cell gap) of the liquid crystal layer becomes uneven. This allows
The voltage applied to the liquid crystal layer may become non-uniform, display unevenness may occur, and display quality may be degraded.

The present invention has been made in view of the above problems, and an object thereof is to provide a PALC capable of obtaining a good display quality while reducing the crosstalk phenomenon. Another object of the present invention is to provide a non-alkali glass substrate that is preferably used for the PALC of the present invention and a method for manufacturing the same.

[0012]

The alkali-free glass substrate according to the first aspect of the present invention is an alkali-free glass substrate having a thickness of 40 μm or less.

In the alkali-free glass substrate according to the second aspect of the present invention, a step of adhering an alkali-free glass substrate having a thickness of 50 μm or more to a support, and a surface of the alkali-free glass substrate opposite to the support side are provided. A non-alkali glass substrate having a thickness of 40 μm or less, which is manufactured by a method for manufacturing a non-alkali glass substrate, including a step of chemically polishing the thickness of the non-alkali glass substrate to 40 μm or less. As the alkali-free glass substrate having a thickness of 50 μm or more, in addition to AF45 described above, # 70 manufactured by Corning
59 and # 1737, OA-2 and OA manufactured by Nippon Electric Glass Co., Ltd.
-10, NA-45 and NA-3 manufactured by NH Techno Glass Co., Ltd.
5, AN635 and AN100 manufactured by Asahi Glass Co., Ltd. are exemplified.

The alkali-free glass substrate according to the second aspect of the present invention may further include a step of separating the alkali-free glass substrate and the support side after the polishing step.

In the present specification, "alkali-free glass"
Is SiO₂Containing 45% by weight or more of R₂O (R is Al
The content of the alkali component represented by (potassium metal) is 0.5
% Glass, preferably 0.1% by weight or less
U In the present specification, "alkali-free glass" means SiO 2.
₂Containing almost 100% by weight and substantially containing other components
Not including quartz glass. In this specification,
Potash glass "is Ba ₂O₃, Al₂O₃Or BaO
30% by weight or less (preferably 25% by weight or less),
20% by weight of MO (M is an alkaline earth metal other than Ba)
The following may be included (preferably 15% by weight or less).
As the glass having such a composition, the above Schott
AF45, Corning # 7059, NEC
OA-2 made by Glass Co., NA-4 made by NH Techno Glass Co., Ltd.
5, Asahi Glass Co., Ltd. AN635 etc. are illustrated.

The thickness of the alkali-free glass substrate of the present invention is 4
It is 0 μm or less, preferably 30 μm or less, and the plate thickness deviation on one substrate is about ± 5%. The lower limit of the thickness of the alkali-free glass substrate is not particularly limited, and the thinner the substrate, the more preferable. However, since irregularities of approximately 0.1 μm occur on the chemically polished surface of the glass substrate,
The thickness of the alkali-free glass substrate needs to be larger than 0.1 μm. Also, from the viewpoint of handleability,
It is preferable that the thickness be as large as 1 μm or more, 5 μm or more, 10 μm or more, 20 μm or more, and further 25 μm or more.

The alkali-free glass substrate of the present invention is 250
The resistivity at 0 ° C. is preferably 1 × 10 ¹³ Ω · cm or more. For example, AF45 manufactured by Schott, # 7059 manufactured by Corning, and OA- manufactured by Nippon Electric Glass Co., Ltd.
2. NH-45 manufactured by NH Techno Glass Co., and AN635 manufactured by Asahi Glass Co., Ltd. are all alkali-free glasses having a resistivity at 250 ° C. of 1 × 10 ¹³ Ω · cm or more. It is preferably used as a substrate. The resistivity can be measured according to JIS R3256: 1998.

The alkali-free glass substrate of the present invention may have an area of 2400 cm ² or more, preferably 4800 cm ² or more.

In the method for producing an alkali-free glass substrate of the present invention, a step of bonding an alkali-free glass substrate having a thickness of 50 μm or more to a support, and a surface of the alkali-free glass substrate opposite to the support side are chemically treated. Polishing to reduce the thickness of the alkali-free glass substrate to 40 μm or less. Preferably, the method further includes a step of separating the non-alkali glass substrate and the support side after the polishing step. The above alkali-free glass is used as the alkali-free glass substrate having a thickness of 50 μm or more. The upper limit of the thickness of the non-alkali glass substrate is not particularly limited and is appropriately determined from the viewpoints of economy, workability and the like. For example, an alkali-free glass substrate having a thickness of 50 μm or more and 100 μm or less can be used.

In the PALC according to the first aspect of the present invention, a plurality of plasma channels are defined by a plasma cell substrate having a plurality of partition walls and an intermediate substrate, and a liquid crystal layer is sandwiched between the intermediate substrate and the liquid crystal cell substrate. The intermediate substrate is a non-alkali glass substrate according to the first or second aspect of the present invention.

In the PALC according to the second aspect of the present invention, a plurality of plasma channels are defined by a plasma cell substrate having a plurality of partition walls and an intermediate substrate, and a liquid crystal layer is sandwiched between the intermediate substrate and the liquid crystal cell substrate. The intermediate substrate is an alkali-free glass substrate according to the second aspect of the present invention, and the chemically polished surface of the alkali-free glass substrate faces the plasma cell substrate.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, the non-alkali glass substrate is chemically polished,
It may be mechanically polished. Alternatively, a CMP (chemical mechanical polishing) method using a liquid slurry containing fine particles may be used.

[Embodiment 1] In the present embodiment, a thickness of 50
As a non-alkali glass substrate having a thickness of μm (hereinafter, also simply referred to as a glass substrate), AF45 manufactured by Schott is used to manufacture a non-alkali glass substrate having a thickness of 40 μm or less. This glass substrate is 42 type (diagonal 106 cm, width 930 m)
m × length 523 mm, area 4864 cm ² ) It has vertical and horizontal dimensions applicable to a display. The glass substrate is chemically polished while being held on a support. FIG. 1 is a diagram showing a state in which the glass substrate 1 is held by the support body 2.
1A is a plan view, and FIG. 1B is a sectional view taken along the line BB ′.

Since the support 2 is used for chemically polishing the glass substrate 1 and holding it so that the glass substrate 1 is not cracked during cleaning, a flat substrate having etching resistance is desirable. The support 2 is a plastic substrate such as polyethylene, Teflon (registered trademark), polyurethane, or polyvinyl chloride, a glass substrate, or a resin film that can be attached with a laminator, such as PET (polyethylene terephthalate) or PES (polyether sulfone). , TAC (triacetyl cellulose) and the like are suitable.

In this embodiment, a soda glass substrate having a thickness of 2 mm is used because it has a flat surface, has sufficient strength to withstand the etching process / cleaning process, and is inexpensive. The soda glass substrate is immersed in an etching solution used for chemical polishing. Since the etching amount is about 20 μm at most, the glass substrate 1 can be sufficiently held if the thickness is about 2 mm. The thickness of the support 2 is not limited to the above value, and
A suitable thickness can be freely selected according to the vertical and horizontal dimensions of the. In this embodiment, the vertical and horizontal dimensions of the support 2 are almost the same as the dimensions of the glass substrate 1, but may be larger than the glass substrate 1.

The support 2 may be provided with an air vent hole 3 for removing air remaining in the gap between the glass substrate 1 and the support 2 when the glass substrate 1 and the support 2 are bonded together. The air vent hole 3 is preferably provided near the center of the support 2. The size and number of the air vent holes 3 are not particularly limited, and for example, one hole having a diameter of about 1 mm is provided.

(Laminating Step) Next, the step of attaching the glass substrate 1 to the support 2 will be described. First,
As shown in FIG. 1, the adhesive 4 is applied to the outer periphery of one surface of the support 2. The adhesive 4 can be applied by a known application method such as dispenser application or screen printing.
In this embodiment, a one-component epoxy resin is used as the adhesive 4, but the adhesive is not limited to this. Glass substrate 1 to support 2
Adhesive 4 that can be stuck to the glass substrate 1, has resistance to an etching solution, can hold the stuck state in the etching process / washing process, and does not remain on the glass substrate 1 after being peeled from the support 2 is preferable. Used for.
The coating thickness of the adhesive 4 is appropriately determined in consideration of the type of the adhesive 4 and the like, and is about 10 μm in this embodiment. Although the adhesive 4 is applied to the outer periphery of the support 2 in the present embodiment, the adhesive 4 may be applied to the entire surface of the support 2.

A spacer 5 is provided on the adhesive-coated surface of the support 2 inside the area coated with the adhesive 4. The spacers 5 are provided for the purpose of reducing residual air when the glass substrates 1 are bonded together and eliminating unevenness on the surface of the glass substrates 1 after bonding. As the spacer 5, one made of paper or non-woven fabric is used. The thickness of the spacer 5 is preferably thinner than the coating thickness of the adhesive 4.

The glass substrate 1 is attached to the support 2 via the adhesive 4.
Then, the surface of the glass substrate 1 is pressed by a rubber roller. As a result, the unevenness and wrinkles remaining on the surface of the glass substrate 1 can be removed and the surface can be flattened, so that the surface of the glass substrate 1 is uniformly etched in the subsequent etching step, and the occurrence of uneven plate thickness is suppressed. can do. The air vent hole 3 of the support 2 is closed with a sheet-shaped small piece 6 such as a vinyl chloride tape so that the etching solution does not enter the gap between the glass substrate 1 and the support 2.

(Chemical Polishing Step) Next, the glass substrate 1 attached to the support 2 is immersed in a chemical polishing liquid (etching liquid) for a predetermined time to have a thickness of 40 μm or less, preferably 30 μm. The surface of the glass substrate 1 opposite to the side of the support 2 is chemically polished (etched) until the following.

As the chemical polishing liquid, an aqueous solution containing hydrofluoric acid, buffered hydrofluoric acid and the like, to which a pH adjusting agent, a viscosity adjusting agent and the like are added, is used. During the chemical polishing, the chemical polishing liquid in the vicinity of the contact portion is sufficiently stirred so that the chemical polishing liquid on the glass surface where the chemical reaction is occurring is renewed, and the chemical polishing liquid is attached to the support 2. The glass substrate 1 in the attached state is swung. This prevents uneven etching on the surface of the glass substrate 1,
It is possible to suppress the attachment of the reactive organism to the surface. Therefore, it is possible to suppress the occurrence of irregularities on the surface of the glass substrate 1 and reduce the plate thickness while maintaining the initial smooth surface state. After the chemical polishing is completed, the chemical polishing liquid on the surface of the glass substrate 1 is washed off with water.

(Separation Step) The glass substrate 1 attached to the support 2 is immersed in a stripping solution to separate the glass substrate 1 having a reduced thickness from the support 2 and take it out. Although methylene chloride is used as the stripping solution in the present embodiment, a suitable stripping solution can be selected depending on the type of the adhesive 4 used.

The separated glass substrate 1 is washed with a known washing liquid such as water or an organic solvent and dried to obtain a non-alkali glass substrate having a thickness of 40 μm or less, preferably 30 μm or less. This non-alkali glass substrate is
Besides being suitably used as an intermediate substrate of PALC, it can be used as a cover glass for a photo sensor or a CCD (Charge Coupled Device).

[Embodiment 2] A PALC using an alkali-free glass substrate of Embodiment 1 as an intermediate substrate will be described with reference to FIGS. 2 and 3. PAL of this embodiment
C100 is 42 type (diagonal 106 cm, width 930 mm x
It is a display having a length of 523 mm and an area of 4864 cm ² .

The PALC 100 has a structure in which a liquid crystal cell 101 and a plasma cell 102 are laminated via an intermediate substrate 103. The plasma cell 102 has a plasma cell substrate 104, an intermediate substrate 103, and a plurality of partition walls 105 arranged in stripes between them. A discharge gas that can be ionized by discharge is sealed in a plasma channel 106 defined by a space sealed by the adjacent partition wall 105, the plasma cell substrate 104, and the intermediate substrate 103. Multiple plasma channels 1
Each of 06 is a discharge electrode (anode 107 and cathode 108) formed on the plasma cell substrate 104.
have.

The liquid crystal cell 101 includes a liquid crystal cell substrate 109, an intermediate substrate 103, and a liquid crystal layer 11 provided between them.
Has 0 and. On the liquid crystal layer 110 side of the liquid crystal cell substrate 109, a plurality of stripe-shaped signal electrodes 111 parallel to each other.
Are formed so as to intersect the plasma channel 106. Further, the liquid crystal cell substrate 109 has a signal electrode 111.
The colored layer 112 provided corresponding to is provided on the liquid crystal layer 110 side. The colored layer 112 is typically a red, green and blue layer.

As the liquid crystal layer 110, for example, TN (Tw
A liquid crystal layer of isted Nematic mode is used, but ASM (Axially Symmetric aligned Micr) is used for widening the viewing angle.
A liquid crystal layer of an ocell) mode or a VA (Vertical Alignment) mode may be used, or a liquid crystal layer of various conventional display modes may be used.

A method of manufacturing the PALC 100 of this embodiment will be described. First, a method of manufacturing the plasma cell 102 will be described. An anode 107 and a cathode 108 facing each other are formed on the plasma cell substrate 104 at predetermined intervals. The anode 107 and the cathode 108 can be formed by a screen printing method using a conductive paste (eg, nickel paste, aluminum paste, silver paste).

The plurality of partition walls 105 are connected to the plasma cell substrate 1
It is formed in a stripe shape on 04. The partition wall 105 is formed by a screen printing method using a thick film paste, for example. The thick film paste contains low melting glass, ceramic filler, organic binder, solvent and black pigment. After screen printing thick film paste, about 100 ℃ ~ 1
By repeating the process of drying at 50 ° C. about 10 times, the partition wall 105 having a height of about 200 μm is formed.

Plasma cell substrate 104 and intermediate substrate 103
And are bonded by a known method using a known frit material with the chemically polished surface of the intermediate substrate 103 facing the plasma cell substrate 104 side.

The inside of the plasma channel 106 is evacuated by evacuating from the evacuation tube (tip tube) (~ 10 ^-7 Torr).
(Up to about 1.3 × 10 ⁻⁵ Pa)). A plurality of plasma channels are formed by injecting a discharge gas into the interior and heating and melting the tip tube to seal it.

Next, a method of manufacturing the liquid crystal cell 101 will be described. A liquid crystal cell substrate (for example, a glass substrate) 109 having a colored layer 112 and a plurality of stripe-shaped signal electrodes 111 parallel to each other is prepared. Colored layer 11
2 is formed by a dyeing method, a pigment dispersion method, a printing method, an electrodeposition method, or the like. The signal electrode 111 is formed by sputtering using ITO, for example. Next, in the case of the TN mode, a horizontal alignment material is applied to the sides of the intermediate substrate 103 and the liquid crystal cell substrate 109 that face the liquid crystal layer 110, and about 2
After firing at 00 ° C., rubbing treatment is performed. In the case of ASM mode or VA mode, a vertical alignment material may be used instead of the horizontal alignment material, and the rubbing process may not be performed. Known materials can be used as the horizontal alignment material and the vertical alignment material. The present invention is not limited to the above-mentioned display modes and can be applied to various conventional display modes. Therefore, an aligning material and an alignment treatment method may be appropriately selected depending on the mode to be used.

An intermediate substrate 1 is formed by using a sealing material (not shown).
03 and the liquid crystal cell substrate 109 are bonded together. A known material can be used as the sealing material, and for example, a thermosetting resin, an ultraviolet curing resin, or a mixture thereof is used. At this time, the intermediate substrate 103 and the liquid crystal cell substrate 10
Sprinkle the spacer between 9 and.

After that, a liquid crystal material is injected between the intermediate substrate 103 and the liquid crystal cell substrate 109, and the injection port is sealed with, for example, an ultraviolet curable resin. As a liquid crystal material,
A known liquid crystal material having a positive dielectric anisotropy is used in the TN mode, and a known liquid crystal material having a negative dielectric anisotropy is used in the ASM mode or the VA mode. Note that the present invention is not limited to the above-mentioned display modes and can be applied to various conventional display modes, and therefore a liquid crystal material may be appropriately selected depending on the mode to be used.

As described above, three continuous picture element regions 112R along one plasma channel 106,
PALC 100 having 112G and 112B (corresponding to red, green, and blue, respectively, and a black matrix 113 is formed between adjacent pixel regions).
Is manufactured.

Next, the relationship between the thickness of the intermediate substrate and the cell voltage in PALC will be described. FIG. 4 is a graph showing a simulation of the relationship between the cell voltage required to set the effective voltage (liquid crystal voltage) applied to the liquid crystal layer to 7.5 V and the thickness of the intermediate substrate. Simulation is performed for each thickness (cell gap).

For example, in a PALC having a cell gap of 6 μm, when an intermediate substrate having a thickness of 50 μm is used, it is necessary to set the cell voltage to about 70V in order to set the liquid crystal voltage to 7.5V. However, in this case, the crosstalk phenomenon may occur, and it is clear from other tests by the present inventors that the cell voltage is preferably about 50 V in order to sufficiently reduce the crosstalk phenomenon. It was Therefore, in this case, it is understood from FIG. 4 that the thickness of the intermediate substrate is preferably about 30 μm or less.

As can be seen from FIG. 4, the cell voltage decreases as the thickness (cell gap) of the liquid crystal layer increases. Therefore, when the cell gap is 7 μm or more,
By using the intermediate substrate having a thickness of 40 μm or less, the cell voltage can be set to about 50 V or less, and the crosstalk phenomenon can be sufficiently reduced.

[Other Embodiments] In the first embodiment, the alkali-free glass substrate suitable for the 42-inch (diagonal 106 cm) display is described, but the size of the display is not limited to this, and the 30-inch (diagonal 76 cm, diagonal 76 cm, Horizontal 664 mm x Vertical 374
mm, area 2483 cm ² ), 50 type (diagonal 127c
m) and 61-inch (diagonal 155 cm) displays. In the method for producing an alkali-free glass substrate of the present invention, the larger the size of the glass substrate, the more advantageous the effect. That is, the larger the size of the glass substrate, the more difficult it becomes to perform uniform polishing by mechanical polishing, whereas the chemical polishing enables uniform polishing. Further, according to the present invention, it was difficult to mass produce about 2500.
An alkali-free glass substrate having an area of cm ² or more can be manufactured. Moreover, a large-screen PALC can be manufactured by using this alkali-free glass substrate as an intermediate substrate.

[0050]

According to the present invention, it is possible to provide a PALC which can obtain a good display quality while reducing the crosstalk phenomenon.

[Brief description of drawings]

FIG. 1 is a diagram showing a state in which a glass substrate 1 according to Embodiment 1 is held by a support body 2, FIG. 1 (a) is a plan view, and FIG.
(B) is a BB 'line sectional view.

FIG. 2 is a sectional view schematically showing a PALC 100 according to a second embodiment.

FIG. 3 is a plan view schematically showing a PALC 100 according to a second embodiment.

FIG. 4 is a graph showing a simulation of the relationship between the cell voltage and the thickness of the intermediate substrate.

[Explanation of symbols]

1 glass substrate 2 support 3 air vent holes 4 adhesive 5 spacers 6 Sheet-like pieces 103 intermediate substrate

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) C03C 3/085 C03C 3/085 3/087 3/087 3/089 3/089 3/091 3/091 ( 72) Inventor Toshiyuki Fujine 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Prefecture Sharp Corporation (72) Inventor Noriaki Nakamura 22-22, Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture (72) Inventor Kazuo Nigami 2-3-2, Keihinjima, Ota-ku, Tokyo F-term in Sanwa Frost Industry Co., Ltd. (reference) 2H089 HA36 QA16 2H090 JA09 JB02 JC01 JD09 4G059 AA08 AB01 AB09 AB11 AC30 BB04 BB16 4G062 AA01 BB02 BB05 BB06 DA05 DA05 DA07 DA08 DB01 DB02 DB03 DB04 DC01 DC02 DC03 DC04 DD01 DE01 DF01 EA01 EA02 EA10 EB01 EB02 EC01 EC02 ED01 ED02 ED03 ED04 EE01 EE02 EE03 EE04 EF01 EF02 EF03 EF01 FA01 FE04 FA01 FA01 FA01 FA01 FA01 FA01 FA01 FD01 FE01 FF01 FG01 FH01 FJ01 FK01 FL01 GA01 GA10 GB01 GC01 GD01 GE01 HH01 HH03 HH05 HH07 HH09 HH11 HH13 HH15 HH17 HH20 JJ01 JJ03 JJ05 JJ07 JJ05 JJ07 JJ05 BB07 NN40

Claims (10)

[Claims] 1. A non-alkali glass substrate having a thickness of 40 μm or less. 2. A step of laminating an alkali-free glass substrate having a thickness of 50 μm or more to a support, and chemically polishing the surface of the alkali-free glass substrate opposite to the support to obtain the alkali-free glass substrate. A thickness of 40 μm or less, and a non-alkali glass substrate having a thickness of 40 μm or less, which is produced by a method for producing an alkali-free glass substrate. 3. The alkali-free glass substrate according to claim 2, further comprising a step of separating the alkali-free glass substrate and the support side after the polishing step. 4. The alkali-free glass substrate according to claim 1, wherein the alkali component is 0.5% by weight or less. 5. The resistivity at 250 ° C. is 1 × 10 ¹³ Ω.
-The alkali-free glass substrate according to any one of claims 1 to 4, which has a size of not less than cm. 6. The alkali-free glass substrate according to claim 1, which has an area of 2400 cm ² or more. 7. A step of laminating a non-alkali glass substrate having a thickness of 50 μm or more to a support, and chemically polishing the surface of the non-alkali glass substrate opposite to the support to form the non-alkali glass substrate. And a step of reducing the thickness of the substrate to 40 μm or less. 8. The method for producing an alkali-free glass substrate according to claim 7, further comprising a step of separating the alkali-free glass substrate and the support side after the polishing step. 9. A plasma addressed liquid crystal display device in which a plurality of plasma channels are defined by a plasma cell substrate having a plurality of partition walls and an intermediate substrate, and a liquid crystal layer is sandwiched between the intermediate substrate and the liquid crystal cell substrate. A plasma addressed liquid crystal display device in which the intermediate substrate is the alkali-free glass substrate according to any one of claims 1 to 6. 10. A plasma addressed liquid crystal display device in which a plurality of plasma channels are defined by a plasma cell substrate having a plurality of partition walls and an intermediate substrate, and a liquid crystal layer is sandwiched between the intermediate substrate and the liquid crystal cell substrate. The intermediate substrate is the alkali-free glass substrate according to claim 2 or 3, and the chemically-polished surface of the alkali-free glass substrate faces the plasma cell substrate. Liquid crystal display device.