JPH11293202A - Apparatus and method for lamination - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for laminating two substrates at an improved precision by positioning one substrate set on a fine adjustment stage supported by a holder through an elastic body by the fine positioning of the stage and laminating it with the other vertical substrate. SOLUTION: A device for finely positioning one substrate (lower substrate) in the directions of the X and Y axes and in the direction of a rotation θ about the Z axis is the one composed of a fine adjustment stage 2 supported at its four corners by a holder 3 through elastic bodies (fine adjustment springs 26) each having high rigidity in the direction of the Z axis and having low rigidity in the XY plane, and at least three piezoelectric actuators 27Xa , 27Xb , and 27Y and at least three electrostatic capacitance displacement meters 28Xa , 28Xb and 28Y which detect displacements of the stage 2 from the holder are provided between the holder 3 and the stage 2. The drive voltages applied to the actuators 27Xa , 27Xb , and 27Y are controlled according to the outputs from the displacement meter, and the stage 2 is finely positioned to position the one substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding apparatus and a bonding method, and more particularly to a bonding apparatus and a method which are useful when applied to a substrate bonding apparatus of a thin display device using a liquid crystal such as an LCD (Liquid Crystal Display) or a plasma addressing LCD. It is.

[0002]

2. Description of the Related Art Conventionally, a thermosetting resin has been used as an adhesive for an LCD bonding apparatus. Therefore, a heating / pressing device was also required for the bonding device.

[0003]

However, since a thermosetting resin having a strong adhesive force and a high curing force is used, the heating temperature is set at 40.
It is necessary to increase the temperature to about 0 ° C., and this raises a problem that it is difficult to secure the bonding accuracy due to an increase in the temperature of the apparatus and accompanying thermal deformation. In particular, recent L
As the definition of CDs becomes higher, there is a demand for an improvement in bonding accuracy, and a bonding apparatus using a thermosetting resin has reached the limit of bonding accuracy.

For this reason, recently, a bonding apparatus using an ultraviolet curing resin has been studied. However, a plurality of bonding apparatuses such as alignment of upper and lower two substrates at the time of bonding, ultraviolet irradiation, and uniform pressure bonding of the substrates have been studied. Since it is difficult to realize a device that satisfies the required functions of the above, a bonding device using an ultraviolet curable resin is in a research stage and has not been put to practical use yet.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-mentioned prior art, and provides a bonding apparatus and method satisfying necessary functions such as alignment of two substrates at the time of bonding, ultraviolet irradiation, and uniform pressure bonding of the substrates. As an issue.

[0006]

Means for Solving the Problems A first method for solving the above problems is described below.
The bonding apparatus according to the present invention is an apparatus for bonding two substrates by bringing the two substrates close to each other in a Z-axis direction, and sets one of the substrates in an X-axis direction and a Y-axis in an XY plane orthogonal to the Z-axis direction. As a device for fine positioning in the direction and the rotation θ direction around the Z axis, a fine movement stage in which four corners are supported via elastic bodies by a holder is provided, and the elastic body has high rigidity in the Z axis direction. Having a small rigidity in the XY plane, and providing at least three or more piezoelectric actuators between the holder and the fine movement stage;
At least three or more displacement meters for detecting displacement of the fine movement stage with respect to the holder are provided, and a control device for controlling a voltage applied to the piezoelectric actuator based on an output of the displacement meter is provided, and the control device is installed on the fine movement stage. The fine positioning of the one substrate in the X-axis direction, the Y-axis direction, and the θ direction is performed.

In the bonding apparatus according to a second aspect of the present invention, an ultraviolet transmitting plate is provided in an opening of a case, and a photographing device such as a microscope or a camera is installed in the case and a substrate is bonded through the ultraviolet transmitting plate. Any one of an exhaust device that exhausts air from inside the case and a pressurized air supply device that supplies pressurized air into the case, in which an alignment error is detected and an ultraviolet lamp is provided in the case. Means for switching whether or not the case is connected is provided, and the substrate is adsorbed on the ultraviolet transmitting plate by exhausting air by the exhaust device, or the substrate is pressurized by supplying compressed air by the compressed air supply device. A plurality of through-holes are provided in the ultraviolet transmitting plate for forming a gap between the ultraviolet transmitting plate and the substrate when the substrate is pressed. One wherein the outer peripheral portion of the substrate provided with the means for sealing.

Further, the bonding method according to the third invention is characterized in that
Alternatively, when two substrates are bonded by a sealing material using the bonding device of the second invention, a curing reaction occurs by irradiation of energy rays such as UV as an essential component of the sealing material, and then the reaction heat during the curing. The curing reaction is continuously performed in a chain reaction with the cation and a sealing material using a resin composition that enables curing regardless of the presence or absence of the thick and energy ray shielding filler and the attenuating filler is used. It is characterized by the following.

[0009]

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

FIG. 1 is an explanatory view of the overall structure of a bonding apparatus according to an embodiment of the present invention, and FIG. 2 is an explanatory view showing the structure and operation of an ultra-precision alignment apparatus which is a main component of the bonding apparatus. FIG. 3 is a view for explaining the action of pressurization and ultraviolet curing of the bonding apparatus.

<Structure> As shown in FIG. 1, a lower substrate 1 is mounted on a fine movement stage 2 (see FIG. 2 and detailed later) which is a main component of an ultra-precision alignment apparatus 30, and after positioning, the fine movement stage 2 Are sucked on the upper surface of the fine movement stage 2 by air suction holes (not shown) provided in the fine movement stage 2. The fine movement stage 2 is a fine movement spring (not shown in FIG. 1; see FIG. 2).
, And is supported on the upper surface of the XY table 4.

The slide 5 is slidably guided in the Z-axis direction (arrow Z direction) by a guide (not shown), and is driven and positioned in the Z-axis direction by a drive device (not shown). A disc-shaped case top plate 7 is fixed to the lower surface of the slide 5, and the top plate 7 is fixed to a cylindrical case 6. An ultraviolet transmitting plate 9 is attached to a lower end of the case 6 via an attaching plate 8. UV transmission plate 9
Is made of a material having a high ultraviolet transmittance, such as quartz or Vycor, and is firmly adhered to the mounting plate 8. The mounting plate 8 is fixed to a lower end of the case 6 by a bolt (not shown).

An ultraviolet lamp 10 is provided in the upper part of the case 6.
And an ultraviolet lamp unit 12 including a box 11 for accommodating the ultraviolet lamp 10. The ultraviolet lamp 10 is supplied with power from a power supply 23 via power lines 24 and 25, and is turned on and power controlled. The top plate 7 and the slide 5 are provided with ventilation holes 21a, 21b, 22a, 22b, respectively.
Cooling air is recirculated into the box 11 through these ventilation holes 21a, 21b, 22a, 22b so that the ultraviolet lamp 10 can be air-cooled.

A movable member 15 is provided outside the case 6, and the movable member 15 is moved along the Z-axis by arrows (a, b) by a device (actuator) (not shown) provided on the slide 5. It is designed to move up and down. The case 6 and the movable member 15 are provided with a through hole 16. The inside of the case 6 is negatively evacuated by evacuating the air in the case 6 from the through hole 16 in the direction of arrow c by a vacuum exhaust device (not shown). Then, the upper substrate 18 is adsorbed to the ultraviolet transmitting plate 9 by a plurality of through holes 17 provided in the ultraviolet transmitting plate 9. The through-hole 16 (ie, the case 6) can be connected not only to a vacuum exhaust device (not shown) but also to a pressurized air supply device (not shown) by a switching valve (not shown).

A seal holding member 19 is fixed to the lower end of the movable member 15.
The inner circumference of the seal 2 is slidably in contact with the ultraviolet transmitting plate 9.
0 is held.

A microscope 13 is provided inside the case 6.
a and 13b are provided, and these microscopes 13a and 13b are optical fibers 14a and 14b, respectively.
b, it is connected to an image processing device (not shown) outside the case 6. The microscopes 13a and 13b are
It is provided for photographing a matching mark (not shown) of the upper substrate 18 and the lower substrate 1.

Here, the configuration of the ultra-precision alignment device 30 will be described with reference to FIG.

As shown in FIG. 2, the fine moving stage 2 has four corners supported by a holder 3 via fine moving springs 26. The fine movement spring 26 has a sufficient rigidity in a direction perpendicular to the paper surface of FIG. 2, that is, in the Z-axis direction, and has a flexible structure in the paper surface, that is, in an XY plane orthogonal to the Z-axis direction. The fine movement stage 2 is supported with high rigidity in the Z-axis direction,
It is supported so as to be movable and rotatable in a plane.

Between the holder 3 and the fine movement stage 2, 3
Two piezoelectric actuators 27Y, 27Xa, 27Xb are provided. The piezoelectric actuator 27Y is provided in the Y-axis direction, and the piezoelectric actuators 27Xa and Xb are provided in the X-axis direction. The displacement of the fine movement stage 2 with respect to the holder 3 is determined by three capacitance type displacement meters 28Y,
28Xa and 28Xb. Outputs of the capacitance type displacement meters 28Y, 28Xa, 28Xb are fed back to a control device (not shown), and a drive voltage is applied to the piezoelectric actuators 27Y, 27Xa, Xb according to a difference from a command value (not shown). ing.

That is, the fine rotation control of the fine movement stage 2 around the Z axis, that is, the fine rotation control in the θ direction and the fine positioning control in the X axis direction are performed by applying the drive voltage applied to the two piezoelectric actuators 27Xa and 27Xb to the two capacitive displacements. 28Xa, 2 in total
The control is performed by the control device based on the output of 8Xb. Further, the minute positioning control in the Y-axis direction is performed by applying a driving voltage applied to the piezoelectric actuator 27Y to
The control is performed by the control device based on the output of the capacitance type displacement meter 28Y.

The lower substrate 1 is coated with a glass ball having a small variation in diameter and a sealing material made of an ultraviolet curable resin. As the ultraviolet curable resin, a curing reaction is caused by irradiation of energy rays such as UV. A resin composition that occurs, and then the curing reaction is continuously performed in a chain reaction with the heat of reaction and cations during curing, and enables curing regardless of the presence of thick and energy ray shielding fillers and attenuating fillers. It is preferred to use In addition, such U
The resin composition in which the curing reaction continues in a chain reaction by irradiation with energy rays such as V is a known resin composition which has been registered as a patent.

<Operation / Effect> According to the bonding apparatus having the above structure, the upper substrate 18 and the lower substrate 1 are bonded as follows.

First, at the rising end of the slide 5, the upper substrate 1 is moved by a substrate transfer device (not shown) according to an existing technology.
8 is pressed against the ultraviolet transmitting plate 9, and the upper substrate 18 is attracted to the ultraviolet transmitting plate 9 by evacuation in the direction of arrow c by a vacuum evacuation device (not shown), and then the substrate transfer device is retracted. The lower substrate 1 is previously set on the fine movement stage 2 by a substrate transfer device (not shown), and the slide 5 is lowered by a driving device (not shown) to
Slide 5 at a position where the gap between
Is positioned. The gap δ at this time is 10 μm
Set as follows.

Subsequently, the alignment between the upper substrate 18 and the lower substrate 1 is performed as follows. In general, a matching mark is provided on each of two substrates in a substrate of an LCD or a plasma addressing LCD. Then, the matching marks of the upper and lower substrates 18 and 1 are photographed by the microscopes 13a and 13b. Microscopes 13a, 13b
Therefore, the photographed image is sent to an image processing device (not shown) and subjected to image processing. Based on the image processing result, the alignment correction amounts ΔX, X,
ΔY and Δθ are calculated by a control device (not shown), and these correction amounts ΔX, ΔY, Δθ and the capacitance type displacement meters 28Y, 28
By controlling the driving voltage applied to the piezoelectric actuators 27Y, 27Xa, 27Xb based on the outputs of the 8Xa, 28Xb, the fine positioning control of the fine movement stage 2 in the X-axis direction, the Y-axis direction, and the θ direction is performed, and the upper substrate 18 is controlled.
And the lower substrate 1 are aligned.

Next, pressurization and ultraviolet curing of the upper and lower substrates 18 and 1 will be described. A sealing material (not shown) is applied to the lower substrate 1 in advance. The sealing material is a paste in which a glass ball having a small variation in diameter and an ultraviolet curable resin are kneaded, and is applied to the upper substrate 18 by screen printing. It is applied so as to have a uniform film thickness.

As shown in FIG. 3, when the movable member 15 is lowered in the direction of arrow ah by an actuator (not shown), the seal 20 comes into contact with the upper substrate 18, and the outer peripheral portion of the upper surface of the upper substrate 18 is pressed to be sealed. A gap 31 is formed between the upper substrate 18 and the ultraviolet transmitting plate 9. In this state, when the through hole 16 (that is, the case 6) is connected to a pressurized air supply device (not shown) by switching with a switching valve (not shown), pressurized air is supplied from the pressurized air supply device through the through hole 16 to an arrow f. Is supplied to the case 6 and the compressed air is supplied to the plurality of through holes 1 of the ultraviolet transmitting plate 9.
7, the space 31 between the upper substrate 18 and the ultraviolet transmitting plate 9 is filled. As a result, the back surface (upper surface) of the upper substrate 18 is uniformly pressed by the pressurized air.

Next, when power is supplied from a power source 23 via power lines 24 and 25 to turn on the ultraviolet lamp 10 and recirculate cooling air in the directions of arrows h and i, the ultraviolet lamp 10 operates stably. And the ultraviolet rays 29 are in the box 11,
The ultraviolet transmission plate 9 and the upper substrate 18 are transmitted through the upper substrate 18.
The upper substrate 18 and the lower substrate 1 are bonded together by irradiating a sealing material (not shown) between the substrate 1 and the lower substrate 1 to cure the ultraviolet curing resin in the sealing material.

At this time, as an ultraviolet curable resin used for the sealing material, a curing reaction occurs by irradiation of energy rays such as UV, and then the curing reaction is continuously performed in a chain reaction by the reaction heat and the cation during the curing. If a resin composition capable of curing regardless of the presence of thick and energy ray shielding fillers and attenuating fillers is used, the curing reaction due to its own curing reaction heat and cations occurs continuously, Strength is box 11, ultraviolet transmitting plate 9, upper substrate 1
8 and the glass ball in the sealing material
There is no uncured portion, and the sealing material can be sufficiently cured.

Therefore, according to the bonding apparatus according to the present embodiment, the following effects enhance the accuracy and efficiency of bonding the LCD and the plasma addressing LCD, and enable the bonding to meet the needs for high definition LCD. A matching device can be provided.

(1) Thermal displacement, which has been a problem in a conventional bonding device using a thermosetting resin and a heating / pressing device (hot press), is reduced, and ultra-precision alignment without friction and backlash is performed. By means of the device 30
Substrate displacement of substrate bonding is reduced, and bonding accuracy is remarkably improved.

(2) A series of bonding steps such as adsorption of the upper substrate 18, alignment of the upper and lower substrates 18, 1 and uniform pressing of the upper substrate 18, ultraviolet curing, etc., can be continuously performed in one apparatus. As it can be done, the bonding efficiency is high.

(3) As an ultraviolet curing resin, which is an essential component of the sealing material, a curing reaction is caused by irradiation of energy rays such as UV, and then the curing reaction is continued in a chain reaction by the reaction heat and cation during curing. By using a resin composition that can be cured regardless of the presence or absence of the thick-walled and energy-ray shielding filler and the attenuating filler, the ultraviolet intensity can be reduced by the box 11, the ultraviolet transmitting plate 9, the upper substrate 18, and the seal. Even if it is reduced by the glass ball in the material, the sealing material can be sufficiently cured without any uncured portions.

[0033]

As described above in detail with the embodiments of the present invention, the bonding apparatus of the first invention is an apparatus for performing bonding by bringing two substrates closer in the Z-axis direction. As an apparatus for minutely positioning one of the substrates in the X-axis direction, the Y-axis direction, and the rotation θ direction around the Z-axis in an XY plane orthogonal to the Z-axis direction, four corners of the substrate are held through elastic bodies. A fine movement stage supported and supported, wherein the elastic body has a high rigidity in the Z-axis direction and a small rigidity in the XY plane, and at least three elastic bodies are provided between the holder and the fine movement stage. The above-described piezoelectric actuator is provided, and at least three or more displacement meters for detecting displacement of the fine movement stage with respect to the holder are provided, and a voltage applied to the piezoelectric actuator is controlled based on an output of the displacement meter. A control device which is provided, the X-axis direction of the one substrate and disposed on the fine movement stage,
It is characterized in that minute positioning in the Y axis direction and the θ direction is performed.

Therefore, according to the bonding apparatus of the first aspect of the present invention, the plane displacement of the bonding of the substrates is reduced by the fine positioning apparatus in the X-axis direction, the Y-axis direction, and the θ-direction without friction and backlash. The alignment accuracy is significantly improved.

In the bonding apparatus according to the second aspect of the present invention, an ultraviolet transmitting plate is provided in an opening of a case, and a photographing device such as a microscope or a camera is installed in the case and a substrate is bonded through the ultraviolet transmitting plate. Any one of an exhaust device that exhausts air from inside the case and a pressurized air supply device that supplies pressurized air into the case, in which an alignment error is detected and an ultraviolet lamp is provided in the case. Means for switching whether or not the case is connected is provided, and the substrate is adsorbed on the ultraviolet transmitting plate by exhausting air by the exhaust device, or the substrate is pressurized by supplying compressed air by the compressed air supply device. A plurality of through-holes are provided in the ultraviolet transmitting plate for forming a gap between the ultraviolet transmitting plate and the substrate when the substrate is pressed. One wherein the outer peripheral portion of the substrate provided with the means for sealing.

Therefore, according to the bonding apparatus of the second invention, the thermal displacement, which has been a problem in the conventional bonding apparatus using a thermosetting resin and a heating / pressing device (hot press), is reduced. Further, since a series of bonding steps such as adsorption of the substrate, uniform pressing of the substrate, and ultraviolet curing can be continuously performed in one apparatus, the bonding efficiency is high.

Further, the bonding method according to the third invention is characterized in that
Alternatively, when two substrates are bonded by a sealing material using the bonding device of the second invention, a curing reaction occurs by irradiation of energy rays such as UV as an essential component of the sealing material, and then the reaction heat during the curing. The curing reaction is continuously performed in a chain reaction with the cation and a sealing material using a resin composition that enables curing regardless of the presence or absence of the thick and energy ray shielding filler and the attenuating filler is used. It is characterized by the following.

Therefore, according to the laminating method of the third invention, even if the ultraviolet intensity is reduced by the ultraviolet transmitting plate or the like, the sealing material can be sufficiently cured without any uncured portions.

According to the bonding apparatus and method of the first, second, and third aspects of the present invention, the accuracy and efficiency of bonding substrates of LCDs and plasma addressing LCDs are improved by the above-described effects, and the height of the LCD is improved. It is possible to provide a bonding apparatus that can meet the needs for finer definition.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an overall configuration of a bonding apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration and an operation of an ultra-precision alignment device which is a main component of the bonding device.

FIG. 3 is an explanatory diagram of an action of pressurization and ultraviolet curing of the bonding apparatus.

[Explanation of symbols]

 Reference Signs List 1 lower substrate 2 fine movement stage 3 holder 4 XY table 5 slide 6 case 7 top plate 8 mounting plate 9 ultraviolet transmission plate 10 ultraviolet lamp 11 box 12 ultraviolet lamp unit 13a, 13b microscope 14a, 14b optical fiber 15 movable member 16, Reference Signs List 17 through hole 18 upper substrate 19 seal holding member 20 seal 21a, 21b, 22a, 22b vent hole 23 power supply 24, 25 power line 26 fine movement spring 27Y, 27Xa, 27Xb piezoelectric actuator 28Y, 28Xa, 28Xb electrostatic capacitance displacement meter 30 Ultra-precision alignment equipment 31 air gap

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Nobuya Hayashi No. 1, Takamichi, Iwazuka-cho, Nakamura-ku, Nagoya-shi, Aichi Nagoya Research Laboratory, Mitsubishi Heavy Industries, Ltd.

Claims (3)

[Claims] 1. An apparatus for bonding two substrates by bringing them close to each other in a Z-axis direction, wherein one of the substrates is placed in an X-axis direction, a Y-axis direction, and an XY plane orthogonal to the Z-axis direction. As a device for fine positioning in the rotation θ direction around the Z axis,
A fine movement stage in which four corners are supported by elastic members via elastic members is provided, and the elastic members have high rigidity in the Z-axis direction and small rigidities in the XY plane,
At least three or more piezoelectric actuators are provided between the holder and the fine movement stage, and at least three or more displacement meters for detecting displacement of the fine movement stage with respect to the holder are provided, and based on an output of the displacement meter. A control device for controlling a voltage applied to the piezoelectric actuator to perform fine positioning of the one substrate mounted on the fine movement stage in the X-axis direction, the Y-axis direction, and the θ-direction. Bonding device. 2. An ultraviolet transmitting plate is provided at an opening of the case,
A photographing device such as a microscope or a camera is installed in the case to detect an alignment error in bonding the substrates via the ultraviolet transmitting plate, and an ultraviolet lamp is provided in the case and the inside of the case is provided. Means for switching whether the case is connected to an exhaust device for exhausting air from the air or a pressurized air supply device for supplying pressurized air into the case, wherein the ultraviolet transmitting plate is provided by exhausting air by the exhaust device. A plurality of through holes for adsorbing the substrate or pressing the substrate by supply of pressurized air by the pressurized air supply device are provided in the ultraviolet transmission plate, and the ultraviolet transmission plate is used when the substrate is pressed. A bonding device that forms a gap between the substrate and the substrate and seals an outer peripheral portion of the substrate. 3. When the two substrates are bonded by a sealing material using the bonding apparatus according to claim 1 or 2, a curing reaction is performed by irradiation with energy rays such as UV as an essential component of the sealing material. A resin composition that occurs, and then the curing reaction is continuously performed in a chain reaction with the heat of reaction and cations during curing, and enables curing regardless of the presence of thick and energy ray shielding fillers and attenuating fillers. A bonding method, characterized by using a sealing material using (1).