JPH04367522A - Production of substrate equipped with quartz glass film - Google Patents

Abstract

PURPOSE:To make it possible to form a glass film having >=5mum thickness. CONSTITUTION:A liquid 4 insoluble in water and having a specific gravity larger than that of water is put in a vessel 1 and a glass substrate 5 is allowed to float on the liquid 4 and simultaneously water 8 is charged and a metal alkoxide solution 9 diluted with the a solvent is put on the water 4 to form a wet gel film 10 on the interface between the metal alkoxide solution 9 and water 8 and then water in the vessel 1 is discharged and the get film 10 is allowed to stand on a substrate 5 floated on the liquid 4 and the gel film 8 is dried together with the substrate 5 and sintered to produce the objective substrate.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a glass film-coated substrate in which a transparent glass film is formed on the surface of the substrate with good adhesion.

0002

2. Description of the Related Art The sol-gel method, which forms a glass film on a substrate using a metal alkoxide solution, is attracting attention. Conventionally, as an example of forming a glass film using this sol-gel method,
A metal alkoxide solution is applied onto a substrate such as glass by dip coating or spin coating, and after drying,
By heating, a transparent and uniform glass film with a thickness of 0.1 to 0.3 μm is obtained. Furthermore, a maximum film thickness of 0.5 μm has been achieved by adding a thickener (Study on the properties of coating films using metal alkoxides, Journal of the Ceramics Association, 90 [6], 1982).

[0003] The above numerical values are the film thickness values that can be formed by a single operation of dipping, drying, and heating. As a method to achieve an even thicker film, a method of reducing the thickness of the film formed per one operation and repeating the operation many times has been considered.
A film thickness on the order of μm has been obtained.

0004

[Problems to be Solved by the Invention] As described above, the film thickness of approximately 1.5 μm is the limit in forming a glass film using the conventional dip coating method or spin coating method, and attempts have been made to achieve a film thickness larger than that. It is known that this causes defects such as cracks and peeling. That is, it has been impossible to form a glass film with a thickness of 5 μm or more on a substrate.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for manufacturing a glass film-coated substrate, which solves the above-mentioned problems and can form a glass film with a thickness of 5 μm or more.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a container in which a liquid that is insoluble in water and has a higher specific gravity than water is placed in a container, a glass substrate is floated on the liquid, and water is also placed in the container. A metal alkoxide solution diluted with a solvent is poured onto the water to form a wet gel film at the interface between the metal alkoxide solution and the water, and then the inside of the container is drained and the gel film is placed on the substrate floating in the liquid. The gel film is allowed to stand still, and the gel film is dried along with the substrate, and then sintered.

[0007]

[Function] A liquid that is insoluble in water and has a higher specific gravity than water, water, and a metal alkoxide solution are placed in layers in the container, and a glass substrate floats on top of the liquid in the bottom layer. A wet gel film is formed at the interface.

[0008] Once the gel film is formed, the gel film is lowered and placed on the substrate by draining the water in the container, so that the gel film can be easily left still on the substrate. At this time, since the substrate is floating on the liquid, the gel film can be placed horizontally on the substrate even if the container is not installed horizontally.

[0009] Since the gel film is dried on the substrate surface and then sintered, the imbalance in shrinkage of the film due to sintering is alleviated, the internal stress generated in the film is small, and cracks and No defects such as peeling occur.

[0010] As described above, it becomes possible to form a transparent glass film with a thickness of 5 μm or more on the surface of the substrate.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a process diagram for explaining the method of the present invention, which includes the steps of forming a wet gel film 10 on the surface of water 8 in a container 1 as shown in (a), and (b) A step of placing the gel film 10 on the surface of the glass substrate 5 as shown in (c), a step of drying the gel film 10 as shown in (d), and a step of sintering the dried gel film 10 as shown in (d). The process consists of four steps: forming the glass film 13.

First, to explain step (a), 1 is a cylindrical reaction vessel 1, and the side wall of this vessel 1 is provided with a drain port 3 having a drain valve 2 at a position slightly higher than the bottom. ing. The reason why the drain port 3 is provided at a higher position than the bottom of the container 1 is because the liquid 4 is stored in a reservoir 6 for keeping the substrate 5 floating when draining the inside of the container 1, as will be described later.
This is to ensure that. Note that a drain port may also be provided at the bottom of the container 1 for draining the liquid 4 remaining in the reservoir 6.

A liquid 4 that is insoluble in water (does not mix with water) and has a higher specific gravity than water is placed in the container 1. In this example, Fluorinert (FC-40) manufactured by Sumitomo 3M Ltd. was used as the liquid 4, and about 30g was placed in the container 1.
I put it in.

Next, a glass substrate 5 is floated on the liquid 4. In order to ensure that the substrate 5 floats on the surface of the liquid 4, a floating plate 7 made of styrene foam was attached to the back surface of the substrate 5. Further, as the substrate 5, a 3-inch quartz glass plate with a thickness of 1 mm was used.

Next, water 8 is poured onto the liquid 4. Water 8 has a pH adjusted to a range of 3 to 13 and a weight of 5 to 3.
A range of 0g is preferable. In this example, water 8
The pH of the sample was set to 10.5, and the weight was set to 20 g.

Next, a metal alkoxide solution 9 diluted with a solvent is poured onto the water 8. Examples of metal alkoxides include Si(OCH3)4, Si(OC2H5)
4, Si(OC4H9)4, or the like. As a solvent, benzene,
Any hydrocarbon solvent such as pentane, hexane, cyclohexane, etc. that dissolves the metal alkoxide liquid, is insoluble in water, and has a specific gravity lower than that of water may be used. In this example, a metal alkoxide solution 9 in which 7.5 g of Si(OCH3)4 was dissolved in 5 g of hexane was used.

[0018] Then, a lid (not shown) is placed on the top of the container 1 and the container 1 is left for a predetermined period of time. The appropriate standing time is in the range of 5 to 30 hours, and in this example it was 15 hours. As a result, a wet gel film 10 is formed at the interface between the water 8 and the solution 9.

Next, the drain valve 2 is opened to drain the liquid 4 in the container 1.
, the water 8 and the solution 9 are gradually drained from the drain port 3, and the gel film 10 is lowered and statically placed on the upper surface of the substrate 4. In this case, as shown in FIG. 1(b), there is a liquid 4 at the bottom of the container 1.
Since the reservoir 6 is provided, the glass substrate 5 remains floating on the liquid 4 until the end. Therefore, even if the container 1 is not placed precisely horizontally, the substrate 5 floats on the surface of the liquid 4 and is always maintained horizontally, unlike when the substrate is fixed to a fixed part such as a support stand. The gel film 10 can be placed horizontally and precisely on the surface of the substrate 5.

Next, as shown in (c), the gel film 10 together with the substrate 5 is transferred to a petri dish 11, and dried at a temperature of about 20° C. for 48 hours to remove moisture. Then, the dried gel film 11 was transferred together with the substrate 5 to an electric furnace 12, and
By heating and sintering at a temperature of 0 to 1500 DEG C. for 2 hours, a glass film coated substrate is obtained in which a transparent SiO2 glass film 13 is formed on the surface of the substrate 4 with good adhesion. According to this example, it was possible to successfully form the glass film 13 on the substrate 5, which is 10 μm, which is unprecedentedly thick.

[0021] By using the method of the present invention, it is also possible to form the glass film 13 having a composition containing various dopants.
Further, the glass film 13 can also be formed on the surface of the substrate 5 whose surface has a complicated shape.

[0022]

In summary, according to the present invention, a wet gel film formed at the interface between water and a metal alkoxide solution in a container is horizontally spread onto a substrate floating on the liquid by draining the water in the container. By drying the gel film along with the substrate and sintering it, a transparent glass film with a thickness of 5 μm or more can be formed on the substrate surface with good adhesion.

[Brief explanation of drawings]

FIG. 1 is a process diagram showing a method for manufacturing a glass film-coated substrate according to the present invention.

[Explanation of symbols]

1 Container 4. Liquid 5 Glass substrate 8 Water 9 Alkoxide solution 10 Gel membrane

Claims (2)

[Claims] Claim 1: A liquid that is insoluble in water and has a higher specific gravity than water is placed in a container, a glass substrate is floated on top of the liquid, water is also placed in the container, and a metal alkoxide solution diluted with a solvent is placed on top of the water. After a wet gel film is formed at the interface between the metal alkoxide solution and water, the water in the container is drained, the gel film is placed on a substrate floating in the liquid, and the gel film is dried together with the substrate. A method for manufacturing a substrate with a glass film, characterized by sintering the substrate. 2. Claim 1, wherein the glass substrate has a floating plate on its back surface for floating on the liquid.
A method for manufacturing a glass film-coated substrate according to .