JPH08136937A - Method for pressurizing and heating glass substrate for liquid crystal display plate and device therefor - Google Patents

Abstract

PURPOSE: To provide a method and device for pressurizing and heating capable of uniformly heating the entire surface of glass substrates and acting the pressurization of these glass substrates as uniformly distributed load as well. CONSTITUTION: Two sheets one set of the glass substrates 23 which are aligned and temporally fixed are clamped by a pair of flexible sheets 7, 12 having heating elements 8, 13 to generate heat when energized. These glass substrates 23 are held in a hermetic space and the pressure in this space is reduced to bulge the sheets 7, 12 to the mating surface side, by which two sheets of the clamped substrates 23 are pressurized. In addition, the heating elements 8, 13 are energized to heat the sealing material 22 interposed between the glass substrates 23, by which the sealing material is pressurized and cured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure heating method and a pressure heating apparatus for a glass substrate for a liquid crystal display plate, and more specifically, the upper and lower glass substrates having a sealing material sandwiched therebetween are bonded together by marking. In addition, the present invention relates to a pressurizing and heating method and apparatus for pressurizing and hardening the sealing material up to a predetermined gap between the upper and lower temporarily fixed glass substrates.

[0002]

2. Description of the Related Art A liquid crystal display (LCD) is maintained at a predetermined distance between two glass substrates coated with a transparent conductive electrode by using a spacer having a thickness of several μm. Liquid crystal is sealed in, and the two glass substrates are stuck together without misalignment by alignment marks.

By the way, the two glass substrates constituting the liquid crystal display panel have spacers scattered on one of the glass substrates, and heat is applied to the inner surface of the other glass substrate (the surface facing the one glass substrate). A sealant made of a curable resin is attached, and the upper and lower glass substrates are bonded together by performing a mark alignment by a bonding device, and the upper and lower glass substrates are temporarily fixed so as not to be separated. Then, the pair of glass substrates temporarily bonded and bonded is pressurized and heat-treated to press the sealing material to the gap between the upper and lower glass substrates to the particle size of the spacer, thereby curing the sealing material.

[0004] The conventional device for curing the sealing material is as follows.
Plural sets of two glass substrates, which have been bonded together, are stacked, set on a jig and pressed, and then placed in a heating furnace to heat and cure the sealing material.

[0005]

However, when two glass substrates are set in a jig, pressurized and put in a heating furnace to heat the glass substrates, the heat conduction due to the heating is the same as that around the glass substrates. There is a temperature difference in the central portion, and there is a problem in that the upper and lower glass substrates that are aligned due to the difference in thermal expansion move in the horizontal direction to cause an error. In order to eliminate this, the heating time and the heating temperature are adjusted, but in this case, there is a problem that workability is lowered and productivity is lacking.

Further, the sealing material is melted and hardened by heating the pair of glass substrates temporarily bonded together by heating, but at the time of heating, the pair of glass substrates is pressed between the glass substrates. The gap is set to a predetermined gap (corresponding to the particle diameter of the spacer), but since the pressure is set on a jig and mechanical means such as a cylinder device or a screw mechanism is used, the entire device is There is a problem that it becomes large. Moreover, it is difficult to apply a pressing force uniformly to the entire glass substrate by such mechanical means,
Therefore, there is a problem that it is difficult to make the gap constant.

The present invention has been made in view of the problems of the above-mentioned conventional techniques, and an object thereof is to uniformly heat the entire surface of a glass substrate and to pressurize the glass substrate. It is an object of the present invention to provide a pressurizing and heating method and apparatus that can act as a uniformly distributed load.

[0008]

The technical means taken by the method of the present invention to achieve the above object is a heating method of heating and pressurizing a sealing material interposed between two glass substrates to cure it. And a pair of flexible thin plates provided with a heating element that generates heat when energized.
A pair of glass substrates is sandwiched and the glass substrates are held in an enclosed space, the space is decompressed, the thin plates are bulged to the mating surface side, and two sandwiched glass substrates are added. It is characterized in that the sealing material interposed between the glass substrates is heated and pressed by applying pressure and energizing the heating element.

Further, the technical means taken by the device of the present invention for carrying out the method is to stretch a flexible thin plate on the frame,
A pair of surface plates is formed by attaching a heating element that generates heat when electricity is applied to the front surface or the back surface of the thin plate. One of the pair of surface plates is a fixed surface plate, and the other is a surface plate facing the fixed surface plate. The heating element is made of an insulating material, and is equipped with a depressurizing means for depressurizing a closed space formed by joining a pair of the surface plates. A sheet heating element with a conductive member attached to a thin plate is effective

The thin plate stretched over the frame of the fixed surface plate and the movable surface plate is a metal thin plate having a plate thickness of 30 μm to 200 μm (for example, a stainless steel thin plate) or a synthetic resin thin plate having a high Young's modulus (for example, a polycarbonate thin plate). Examples thereof include thin plates) and rubber thin plates. Further, the decompression means for decompressing the closed space defined by the attachment of the fixed platen and the movable platen is communicated with one of the platens, for example, the frame of the fixed platen and the closed space. A through-hole is opened, and a vacuum pump is connected to the through-hole to form it. Further, the heating device according to the present invention includes a vertical type that horizontally supports a glass substrate and vertically moves a surface plate, or a horizontal type that horizontally moves a surface plate with a glass substrate flat. It does not matter which of them.

[0011]

According to the above means, a pair of surface plates are attached to each other, a pair of glass substrates is sandwiched between the thin plates of both surface plates, and the pressure in the closed space holding the glass substrates is reduced. The flexible thin plate under the action of atmospheric pressure bulges toward the mating surface side, and a uniformly distributed load acts on the glass substrates, so that the sealing material interposed between the glass substrates is crushed until a predetermined gap is formed. In addition, the thin plates on both surface plates swell toward the mating surface side when depressurized to become drum skins, and the surface plates have a cushioning function. Therefore, the glass substrate is pressurized through a buffering action, whereby a uniform distributed load is applied to the glass substrate, and the load acts only in the direction perpendicular to the surface of the glass substrate, and the two glass plates are pressed. The gap between the substrates is formed uniformly.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. A pressurizing and heating device A includes a machine frame 1, a fixed surface plate 2 fixed to the lower side of the machine frame 1, and its fixing. The movable surface plate 3 arranged above the surface plate 2, the driving means 4 for moving the movable surface plate 3 up and down, and the movable surface plate 3 lowered to a predetermined position are fixed to the fixed surface plate 2 by joining them together. Two pieces 1 placed on the surface plate 2
A pair of temporarily bonded glass substrates a and b are held in a closed space, and a pressure reducing means 5 is used to reduce the pressure in the closed space, and the entire apparatus is formed vertically.

A fixed platen 2 installed and fixed on the lower side of the machine frame 1 is formed by a thin plate 7 stretched and fixed so as to close the opening of a metal frame body 6 having a rectangular annular plane shape. Has been done. A heating element 8 is attached and fixed to the surface of the thin plate 7, and the outer peripheral edge 6 ′ of the frame 6 is projected above the tension surface of the thin plate 7, whereby the thin plate 7 and the frame A recess 9 is defined by the outer peripheral edge 6 ′ of 6 and a set of two glass substrates is accommodated in the recess 9. Further, the outer peripheral edge 6 ′ has a through hole 10 communicating with the inside of the recess 9.
, The outer opening of the through hole 10 is connected to the vacuum pump P of the pressure reducing means 5, and the inner opening of the through hole 10 communicates with an annular groove 14 formed so as to surround the thin plate 7, and a movable surface plate described later. The thin plate 7 can be bulged to the mating surface side by depressurizing the inside of the concave portion 9 which is fixed to the fixed surface plate 2 and sealed. Further, a packing 15 such as an O-ring is fixed to the upper surface of the outer peripheral edge 6'so that it is fixed to the movable surface plate 3 so as to establish a sealed state.

The thin plate 7 attached to the frame 6 has a plate thickness of 30.
A stainless steel thin plate having a thickness of μ to 200 μ is used and is fixed to the frame body 6 by welding or with an adhesive. The heating element 8 attached and fixed to the surface of the thin plate 7 is a surface on which a conductor, for example, carbon is printed on a thin plate (plate thickness 100 μ to 300 μ) of a heat-resistant insulator such as ceramic, quartz, or synthetic resin material. The heating element is formed in the form of a heat generating element, and is configured to generate heat when the power source is connected to the electrical conductor and is energized.

The movable surface plate 3 which is arranged above the fixed surface plate 2 and moves up and down in the vertical direction has an opening in a metal frame body 11 having a rectangular annular planar shape, like the fixed surface plate 2 described above. A thin plate 12 is stretched and fixed so as to be closed. A heating element 13 is attached and fixed to the surface of the thin plate 12, and the outer periphery of the frame 11 is formed in a stepped manner so as to be fitted and fitted to the frame 6 of the fixed surface plate 2 described above. ing. Further, the frame 11 of the movable surface plate 3 has an annular groove surrounding the thin plate 12.
16 is formed so that the depressurizing action by operating the vacuum pump acts evenly on the outer peripheral portion surrounding the glass substrate.

The thin plate 12 attached to the frame 11 has a plate thickness of 30.
A stainless steel thin plate having a thickness of μ to 200 μ is used and is fixed to the frame body 11 by welding or with an adhesive. The heating element 13 attached and fixed to the surface of the thin plate 12 is a surface on which a conductor such as carbon is printed on a thin plate (plate thickness 100 μ to 300 μ) made of a heat-resistant insulator such as ceramic, quartz, or synthetic resin material. The heating element is formed in the form of a heat generating element, and is configured to generate heat when the power source is connected to the electrical conductor and is energized. The heating element 8 provided on the fixed surface plate 2 and the heating element 13 provided on the movable surface plate 3 are provided with a conductor on a thin plate of an insulating material so that the entire surface of the glass substrate can be uniformly heated. It goes without saying that it will be done.

The driving means 4 for vertically moving the movable platen 3 constructed as described above is screwed to the nut member 17 rotatably mounted on the upper portion of the machine frame 1 at a fixed position. Together with a screw rod 18 that is prevented from rotating, and a motor 19 that rotates the nut member 17,
Is transmitted to the nut member 17 via a power transmission member such as a chain or a belt, whereby the nut member 17
A threaded rod 18 that is screwed with is formed so as to move up and down in the axial direction. Further, the lower part of the screw rod 18 is formed so as to be hooked and unhooked by a hanging frame 20 fixedly attached to the upper surface of the frame 11 of the movable platen 3. Further, the above-mentioned nut member 17 and screw rod
The 18 hanging mechanisms are installed at the corners of the surface plate 3 so that the movable surface plate 3 can be moved up and down in a horizontal state.

Therefore, the motor 19 is driven to drive the nut member.
When 17 is rotated at a fixed position, the screw rod 18 which is stopped from rotation is extended downward along the axial direction, and the movable surface plate 3 suspended via the suspension frame 20 is fitted and fixed to the fixed surface plate 2. Then, a set of two glass substrates placed on the heating element 8 of the fixed surface plate 2 is housed and held in the closed space. still,
In the illustrated embodiment, when the movable platen 3 is attached to the fixed platen 2, the thin plate 12 of the movable platen 3 is brought into contact with the upper surface of the glass substrate. Of course, the surface plates may be attached to each other without contacting the upper surface of the substrate. Then, when the screw rod 18 is further extended downward, the engagement between the screw rod 18 and the suspension frame 20 is released, and the movable platen 3 is placed on the glass substrate in a free state. A packing 15 and 3 are joined together in a sealed state.

The mechanism for moving the movable platen 3 up and down with respect to the fixed platen 2 is not limited to the above-described structure.
Other means may of course be used, and a heat insulating material should be attached on the side opposite to the heating elements so that the heat of the heating elements 8 and 13 mounted on the fixed surface plate 2 and the movable surface plate 3 acts on the glass substrate side. Is optional. In the case where the heating elements 8 and 13 are attached and fixed to the back sides of the thin plates 7 and 12, the heat insulating material is attached to the back side of the heating elements.

The pair of glass substrates 23 supplied to the pressurizing and heating device configured as described above are preliminarily adhered by the adhering device with the glass substrates a and b being marked, and between the glass substrates. A spacer 21 of several μm is inserted, and a sealing material 22 made of a thermosetting resin is attached along the periphery of the glass substrate. The gap between both glass substrates a and b is pressed to about 15 μm and temporarily fixed. It is fixed. Then, one set of the two glass substrates 23 is placed on the fixed surface plate 2 of the pressure heating device, and then the driving means 4 is operated to lower the movable surface plate 3 to move the movable surface plate 3 Fixed surface plate 2
The heating element 13 of the movable platen 3 is brought into contact with the upper surface of the glass substrate a, and the driving means 4 is further operated to release the engagement between the screw rod 18 and the suspension frame 20. The board 3 is placed on the glass substrate a in a free state (see FIG. 7). Next, the vacuum pump P of the decompression means 5 is operated to reduce the pressure in the recessed portion 9 of the fixed surface plate 2 which is hermetically sealed, and the thin plate 7 of the fixed surface plate 2 and the thin plate 12 of the movable surface plate 3 on which the atmospheric pressure acts.
Respectively pressurize a pair of glass substrates 23 that are swelled and sandwiched between the mating surfaces, and at the same time energize the heating elements 8 and 13 to crush the sealing material 22 to the grain size of the spacer 21 and to seal the sealing material. 22 is heated and hardened, and the gap between the glass substrates a and b is set to about 5 μm (see FIG. 8). The heat treatment is about 1
It is about 10 minutes at 40 ℃ -180 ℃. Here, since the fixed surface plate 2 and the movable surface plate 3 have a structure in which a flexible thin plate is stretched over the annular frame as described above, the glass substrates a and b are
Is pressed by an elastic body, a uniformly distributed load acts on the glass substrate, and the sealing material 22 is uniformly crushed, so that the gap between the glass substrates a and b is kept constant.
High quality products are completed. Although the above-mentioned embodiment has been described as a vertical type, the pressurizing and heating device of the present invention may be a horizontal type, and this device may be used as a single unit. Since it may take about 10 minutes, a plurality of units (for example, 10 units) may be arranged in an annular shape and moved by a chain or the like, which has the advantage of improving work efficiency and productivity.

[0021]

The method of pressurizing and heating the glass substrate for a liquid crystal display plate of the present invention is the method according to claim 1, whereby a uniform distributed load can be applied to the entire glass substrate, and the load is the same as that of the glass substrate. It acts only in the direction perpendicular to the surface, and since the glass substrates can be heated uniformly, the upper and lower glass substrates can be prevented from being displaced, and the gap can be kept constant. Further, since the heating is performed by the heating element provided on the surface plate, the heating is stabilized and the heating time can be shortened.

Further, since the apparatus for carrying out the method has the structure described in claim 2, the mechanism for pressing the glass substrate can be greatly simplified and downsized as compared with the conventional mechanical means. Further, when the heating element is a planar heating element as described in claim 3, it is possible to uniformly heat the entire surface of the glass substrate, thereby preventing the displacement of the upper and lower glass substrates and stabilizing the quality. Processing can be performed.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional front view showing an embodiment of a pressure heating device according to the present invention.

FIG. 2 is a flat bottom view taken along the line 2-2 of FIG.

FIG. 3 is a partially enlarged sectional view of a movable surface plate.

FIG. 4 is a partially enlarged sectional view of a fixed surface plate.

FIG. 5 is a vertical cross-sectional front view of a state in which a movable surface plate is attached to a fixed surface plate.

FIG. 6 is a plan view showing an upper surface of a machine frame to which a drive mechanism for moving a movable platen up and down is attached.

FIG. 7 is a partially enlarged cross-sectional view of a state in which both constant plates are attached to each other.

FIG. 8 is a cross-sectional view showing a state in which the sealed space is depressurized to press the glass substrate from the state of FIG. 7.

[Explanation of symbols]

A ... Pressurizing and heating device 1 ... Machine frame 2 ... Fixed surface plate 3 ... Movable surface plate 4 ... Driving means 5 ... Decompression means (vacuum pump) 6, 11 ... Frame body 7, 12 ... Thin plate 8, 13 ... Heating element 9 … Recesses 22… Sealant 23… A set of two glass substrates

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshio Sekikawa 2-9 Kandanishikicho, Chiyoda-ku, Tokyo Shin-Etsu Engineering Co., Ltd. (72) Ichiei Uchiyama 2-9-Kandanishikicho, Chiyoda-ku, Tokyo Shinetsu Engineering Co., Ltd.

Claims (3)

[Claims] 1. A heating method for heating and pressurizing a sealing material interposed between two glass substrates to cure the sealing material, which comprises a pair of flexible thin plates provided with a heating element that generates heat when energized.
A set of two glass substrates, which are aligned and temporarily fixed, are sandwiched to hold the glass substrates in a closed space, the space is decompressed, and the thin plate is bulged to the mating surface side. Pressurizing two glass substrates sandwiched together, and energizing a heating element to heat and pressurize a sealing material interposed between the glass substrates to cure the glass substrate for a liquid crystal display panel. Heating method. 2. A pair of surface plates is formed by stretching a flexible thin plate on a frame body, and attaching a heating element that generates heat when energized to the front surface or the back surface of the thin plate to form a pair of surface plates. One is a fixed surface plate, and the other is a movable surface plate facing the fixed surface plate and widely and narrowly variable with respect to the fixed surface plate. Further, the pressure in the closed space formed by the attachment of the pair of surface plates is reduced. A device for pressurizing and heating a glass substrate for a liquid crystal display panel, which is characterized by being equipped with a decompression means. 3. The pressurizing and heating device for a glass substrate for a liquid crystal display plate according to claim 2, wherein the heating element is a planar heating element in which a conductive member is attached to a thin plate made of an insulating material.