JP2001133745A - Method of assembling substrate and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of assembling substrates capable of bonding the substrates to each other with high accuracy in a vacuum even in the case the substrates are made greater in size and smaller in thickness. SOLUTION: The one substrate to be bonded is held on another substrate to be bonded so as to face each other and both substrates are bonded to each other in a vacuum with an adhesive disposed at either of the substrates. The one substrate is held onto the other substrate by tacky adhesive means and the substrates are bonded to each other by narrowing the spacing in the vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for assembling substrates to be bonded in a vacuum chamber while holding and opposing the substrates to be bonded to each other and narrowing the gap in vacuum.

[0002]

2. Description of the Related Art In manufacturing a liquid crystal display panel, two glass substrates provided with a transparent electrode, a thin film transistor array, and the like are bonded with an adhesive (hereinafter, also referred to as a sealant) at an extremely close interval of about several micrometers. (Hereinafter, the substrate after bonding is referred to as a cell), and there is a step of sealing the liquid crystal in a space formed thereby.

In order to seal the liquid crystal, the liquid crystal is dropped on one of the substrates in which a sealing agent is drawn in a closed pattern so that no injection port is provided, and the other substrate is disposed on the one of the substrates. A method proposed in Japanese Patent Application Laid-Open No. 62-165622, in which the upper and lower substrates are brought close together in a vacuum, or a sealant is patterned by drawing a sealant so as to provide an injection port on one of the substrates. And a method proposed in Japanese Patent Application Laid-Open No. 10-26763 in which liquid crystal is injected from an injection port after bonding.

[0004]

In the above-mentioned prior art, both substrates are bonded in a vacuum before and after the pattern drawing of the sealant, but the substrates are bonded in a vacuum as in an atmospheric state. Suction and adsorption cannot be performed due to the pressure difference from the atmosphere.

Therefore, when the edge of the substrate located above (hereinafter, referred to as the upper substrate) is mechanically held, the central portion of the substrate is bent, and the bending is increasing the tendency of the substrate to become larger and thinner in recent years. It is getting bigger.

Prior to bonding, optical positioning is performed using alignment marks provided on the peripheral edges (ends) of the upper and lower substrates. The interval is widened, making it difficult to focus on the alignment mark and making accurate alignment difficult.

When bonding, the bent central portion of the upper substrate contacts the lower substrate (hereinafter, referred to as the lower substrate) before the peripheral portion, so that the distance between the substrates is kept constant. As a result, the spacers scattered between the substrates move and damage the alignment film formed on the substrates.

In addition, there is a tendency that the upper and lower substrates to be bonded are of the same size, and the sealing agent is provided at a position very near the peripheral edge of the substrate. In such a case, there is a problem that the margin for holding the upper substrate can hardly be removed. .

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for assembling a substrate which can be bonded with high precision in a vacuum even if the substrate is made large and thin.

Another object of the present invention is to assemble a substrate that can easily hold an upper substrate even when an adhesive is provided at the periphery of the substrate and that can be bonded without damaging an alignment film or the like. It is an object of the present invention to provide a method and an apparatus therefor.

[0011]

A feature of the present invention that achieves the above object is that an adhesive provided on one of the substrates to be bonded is held and opposed to the other substrate to be bonded. In this method, one of the substrates is held on the other substrate by an adhesive means, and the gap is reduced in vacuum to perform the bonding.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. 1 and 2, a substrate assembling apparatus 1 according to the present invention includes a lower chamber section T1 and an upper chamber section T.
An XYθ driving mechanism (not shown) is provided below the lower chamber section T1. By this XY drive mechanism, the lower chamber portion T1 moves the left and right X
It is possible to move in the axial direction and the Y-axis direction orthogonal to the X-axis. A table 4 on which the lower substrate 1a is mounted from the shaft 2 via the vacuum seal 3 by the θ drive mechanism.
Are rotatable horizontally with respect to the lower chamber unit 5. When the lower substrate 1a is mounted on the table 4, the lower substrate 1a has a structure in which the lower substrate 1a is mechanically positioned and fixed by pins and rollers, and a structure in which suction is performed by suction. Is omitted.

The upper chamber section T2 has a structure in which the upper chamber unit 6 and the pressurizing plate 7 therein can be independently moved up and down. That is, the upper chamber unit 6
Has a housing 8 with a built-in linear bush and a vacuum seal, and a frame 1 using a shaft 9 as a guide.
It is moved in the vertical Z-axis direction by a cylinder 11 fixed to zero.

The lower chamber portion T1 on the XYθ drive mechanism moves directly below the upper chamber portion T2 to move the upper chamber unit 6
Is lowered, the flange of the upper chamber unit 6 comes into contact with the O-ring 12 arranged around the lower chamber unit 5, and the O-ring 12 is integrated into a state of functioning as a vacuum chamber. Here, the ball bearing 13 installed around the lower chamber unit 5 adjusts the amount of crushing of the O-ring 12 due to vacuum, and can be set at an arbitrary position in the vertical direction. The amount of collapse of the O-ring 12 is set at a position where the inside of the vacuum chamber can be maintained at a vacuum and the maximum elasticity is obtained. The large force generated by the vacuum is received by the lower chamber unit 5 via the ball bearing 13, and the lower chamber unit T1 is easily finely moved within the elastic range of the O-ring 12 when the upper and lower substrates are bonded, which will be described later. Can be decided.

The housing 8 incorporates a vacuum seal that can move up and down without causing a vacuum leak to the shaft 9 even if the upper chamber unit 6 forms a vacuum chamber with the lower chamber unit 5 and deforms at atmospheric pressure. Therefore, the deformation of the vacuum chamber can absorb the force applied to the shaft 9, the deformation of the pressure plate 7 supported by the shaft 9 can be substantially prevented, and the upper substrate 1 b attached to the adhesive sheet 18 and the table 4 can be bonded while keeping parallel to the lower substrate 1a. The vertical movement of the pressure plate 7 is performed by a drive mechanism (not shown) installed above the shaft 9.

Numeral 14 denotes a vacuum pipe arranged on the side of the upper chamber unit 6, which is connected to a vacuum source by a vacuum valve and a pipe hose (not shown), and these are used when the inside of the vacuum chamber is depressurized and evacuated. . Reference numeral 15 denotes a gas purge valve and a tube, which are connected to a pressure source such as nitrogen gas (N ₂ ) or clean dry air, and are used to return the vacuum chamber to atmospheric pressure.

Next, the adhesive sheet 1 holding the upper substrate 1b
8 will be described. Upper chamber unit 6
Reference numeral 17 denotes a spindle, which is capable of driving and rotating the adhesive sheet 18 wound in a roll shape in the feed direction, free rotation, rotation in the feed direction in a state where a reverse torque is applied to the feed direction, and rotation and fixing. .

The adhesive sheet 18 is a roller 19 which can rotate freely.
Through a spindle 21, which is directed to the opposite rotatable roller 20 and is fixedly disposed relative to the roller 20.
Can be wound up. The spindle 21 can drive and rotate the adhesive sheet 18 in the winding direction, and
Reverse rotation and rotation fixation with torque applied in the winding direction are possible. The take-up spindle 21 fixed in position relative to the roller 20 can be driven horizontally in the direction of the spindle 17 while driving and rotating the adhesive sheet 18 in the take-up direction. Since the adhesive surface of the adhesive sheet 18 is wound so as to be on the lower side, when the upper substrate 1b is attached to the adhesive sheet 18, the lower substrate 1
a.

The rotation of the spindle 17 is performed by a motor 24 as shown in FIG. The rotation operation of the spindle 21 is performed by a motor 25, and the horizontal operation is performed by a ball nut 28 to which the motor 25 is fixed.
However, this is realized by the rotation and movement of the ball screw 26 driven by the motor 27. The guide for the horizontal movement of the ball nut 28 is not shown. Reference numerals 29 and 30 denote support bearings of the ball screw 26. The support bearing 29 is fixed to the upper chamber unit 6, and the support bearing 30 is a bracket 31 together with the motor 24 and the shaft of the roller 19.
To the upper chamber unit 6
It is structured to be fixed to.

Reference numerals 22a and 22b denote image recognition cameras which are installed to read alignment marks provided on the upper and lower substrates 1a and 1b. Reference numerals 23a and 23b denote transparent viewing windows, and holes 6a provided in the upper chamber unit 6.
6b is vacuum shut off.

Reference numerals 7a and 7b denote small-diameter holes provided in the pressure plate 7 for viewing alignment marks on the substrate. Here, the width of the adhesive sheet 18 is adjusted so that the adhesive sheet 18 does not block the visual field of the image recognition cameras 22a and 22b, as shown in FIG.
It is good to make it slightly smaller than the distance in the Y direction between a and 24b.

Next, a process of bonding substrates by the substrate assembling apparatus 1 will be described with reference to FIGS. FIG. 3A shows an initial state of the upper chamber portion T2 before the upper substrate 1b is held, and the spindle 21 is moved to the right in the figure with the adhesive sheet 18 spread, and the pressing plate 7 is moved. Is waiting upwards.

FIG. 3B shows a state in which the pressure plate 7 is lowered, brought into contact with the adhesive sheet 18, and then slightly lowered. At this time, the pressure-sensitive adhesive sheet 18 wound on the spindles 17 and 21 is sent out from both. The torque of the pressure-sensitive adhesive sheet 18 is controlled by the respective motors for rotating the spindles 17 and 21, and the pulling force is always applied. State. The pulling force is determined by the weight of the upper substrate 1b, and is set to such an amount that there is almost no gap between the upper substrate 1b and the pressing plate 7 even when the upper substrate 1b is attached and held, as shown in FIG.

After the upper substrate 1b is adhered and held on the adhesive sheet 18, the upper substrate 1b and the lower substrate 1a are attached to each other as shown in FIG.

First, as shown in FIG. 4A, the lower substrate 1a
The lower chamber unit T1 mounted on the table 4 is moved to just below the upper chamber unit T2, and the upper chamber unit 6 is lowered by the cylinder 11 as shown in FIG. O-ring 12 placed
Then, the upper and lower chamber portions T1 and T2 are integrated with each other by bringing the flange of the upper chamber unit 6 into contact with each other, and then vacuum evacuation is performed from the vacuum pipe 14.

The lower substrate 1a is positioned and fixed on the table 4. On the outer periphery of the lower substrate 1a, a sealant is drawn in a closed pattern, and an appropriate amount of liquid crystal is dripped on the inner side. ing.

When the inside of the vacuum chamber formed by integrating the upper chamber unit 6 and the lower chamber unit 5 reaches a predetermined degree of vacuum, as shown in FIG. 4C, the upper and lower substrates 1a and 1b are The vertical driving mechanism (not shown) on the shaft 9 is operated while performing the alignment, the pressing plate 7 is lowered, and the gap between the upper and lower substrates 1a and 1b is narrowed by a predetermined pressing force so as to be bonded at a desired interval.

At this time, as the pressure plate 7 descends, the adhesive sheet 18 wound on the spindles 17 and 21 is sent out from both.
Is in a state where an appropriate pulling force is always applied, so that the adhesive sheet 18 does not stretch or break. Due to this pulling force, the upper substrate 1b is almost in close contact with the pressure plate 7 via the adhesive sheet 18, and the central portion of the upper substrate 1b does not droop extremely, and the upper and lower substrates 1a and 1b are substantially parallel. Therefore, the central portion of the upper substrate 1b does not adversely affect the spacers scattered on the substrate 1a, and the substrates cannot be aligned.

Incidentally, the alignment of the substrates is performed by reading the alignment marks provided on the upper and lower substrates 1a, 1b with the image recognition cameras 22a, 22b from the viewing windows 23a, 23b provided in the upper chamber unit 6. The position is measured by the processing, and the XYθ driving mechanism (not shown) of the lower chamber portion T1 is finely moved to perform high-accuracy alignment. In this fine movement, the ball bearing 13 is maintained so that the vacuum is maintained without the O-ring 12 being extremely deformed.
Maintain the space between the upper and lower chamber units 6 and 5.

When the bonding is completed, a vacuum valve (not shown) connected to the vacuum pipe 14 is closed to open the gas purge valve 15, and N ₂ or clean dry air is supplied into the vacuum chamber to return to the atmospheric pressure. After that, the gas purge valve 15 is closed, and the process proceeds to the step of taking out the cells formed by bonding shown in FIG.

First, as shown in FIG. 5A, after the upper chamber unit 6 is raised by the cylinder 11, the pressure plate 7
To rise.

Since the adhesive sheet 18 is attached to the upper surface of the bonded upper substrate 1b, the operation of peeling the adhesive sheet 18 will be described below with reference to FIG.

This operation is performed by rotating the spindle 21 to wind up the adhesive sheet 18 and, at the same time, horizontally moving the adhesive sheet 18 in the direction of the rotation-fixed spindle 17 at a speed synchronized with the winding speed.

At this time, the pressure-sensitive adhesive sheet 18 is gradually and smoothly peeled off from the upper surface of the upper substrate 1 b, and is completely peeled off when the spindle 21 is closest to the spindle 17. It also works as a means.

The bonded lower substrate 1a is suction-adsorbed on the table 4, so that the lower substrate 1a does not shift or lift even while the adhesive sheet 18 is being peeled off.

When the above operation is completed, as shown in FIG. 5B, the lower chamber T1 is moved to the left side of the figure, and the cell pc formed by attaching the upper and lower substrates 1b and 1a from the table 4
Is removed, and the spindle 21 is horizontally moved rightward in a state where the spindle 21 is rotated and fixed in order to send out a new adhesive sheet 18 from the spindle 17 to prepare for the next bonding.

Next, a description will be given of substrate bonding in a substrate bonding apparatus according to another embodiment of the present invention with reference to FIG.

In FIG. 6, the same or corresponding components as those in the embodiment shown in FIGS. 1 to 5 are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, a chuck mechanism 45 for the adhesive sheet 18 is provided in place of the winding of the adhesive sheet 18 by the spindle 21, and the roller 1 on the spindle 17 side is provided.
9, the cutter 40 of the adhesive sheet 18 or the adhesive sheet 1
A drive mechanism for the chuck No. 8 is provided.

That is, in FIG. 6, for simplicity, the upper substrate 1b
Although not shown, after the substrates are bonded, the cutter base 43 supporting the cutter table 41 via the actuator 42 is raised by the actuator 44 to the lower end position of the blade of the cutter 40.

Next, the adhesive sheet 18 is applied to the outer periphery of the cell pc.
The cutter 40 is moved in the width direction (Y direction in the drawing) to cut the adhesive sheet 18 to which the upper substrate 1b is attached.

The chuck 45 releases the holding of the adhesive sheet 18, takes out the cell pc with the adhesive sheet 18 attached, and peels the adhesive sheet 18 from the cell pc at an appropriate time. Until this peeling, the adhesive sheet 18 functions as a protective film for the cell pc. If UV light is radiated to cure the sealant, most of the adhesive layer of the adhesive sheet 18 is made of U
Since the adhesive sheet 18 is deteriorated by V light, it is easy to peel off the adhesive sheet 18 at an appropriate time.

After taking out the cell pc, the cutter table 41
Is slightly lowered by the actuator 42, and the pressure-sensitive adhesive sheet 1
At the end of 8, a chucking margin for the chuck 45 is made. Cutter 40
Retreats (returns to the position shown in the drawing), the ball screw 26 rotates by the drive of the motor 27, and the chuck 45 goes to the roller 19 on the spindle 17 side, and the adhesive sheet 1
8 is gripped. A drive mechanism for holding the adhesive sheet 18 by the chuck 45 is built in the chuck 45.

Thereafter, the cutter base 43 is lowered by the actuator 44, the chuck 45 is moved to the right side in the figure by the motor 27, and the adhesive sheet 18 is fed out and kept horizontal, in preparation for holding the next upper substrate 1b.

Next, a description will be given of substrate bonding in a substrate bonding apparatus according to still another embodiment of the present invention with reference to FIG.

In FIG. 7, the same or corresponding components as those of the embodiment shown in FIGS. 1 to 5 are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 7, reference numeral 50 denotes an opening provided in the pressure plate 7, which is provided with an actuator 51 above, and an adhesive member 52 is provided at the tip of a shaft extending downward from the actuator 51. By the operation of the actuator 51,
The adhesive member 52 moves up and down in the opening 50.

The upper substrate 1b is held on the lower surface of the adhesive member 52 in close contact with the lower surface of the pressure plate 7 by its adhesive action. That is, the apertures 50 are provided in the pressure plate 7 at appropriate intervals and positions according to the size and shape of the upper substrate 1b so that the upper substrate 1b can be held so as to face the lower substrate 1a horizontally. I have.

The lower chamber portion T1 in which the lower substrate 1a is fixed on the table 4 is moved below the upper chamber portion T2 which holds the upper substrate 1b with the adhesive member 52.

Thereafter, as shown in FIG. 6B, the upper chamber unit 6 is lowered by the cylinder 11 to form a vacuum chamber with the lower chamber unit 5, and then the inside is decompressed and evacuated.

Next, the upper and lower substrates 1b and 1a are aligned, the pressing plate 7 is lowered by the shaft 9, and the upper substrate 1b is directly pressed by the pressing plate 7 to bond the upper and lower substrates 1b and 1a. Do. In this case, since the adhesive member 52 is provided in the opening 50, the pressing force is applied equally to the upper substrate 1b.

Upper substrate 1b of cell pc formed by bonding
When the adhesive member 52 is peeled from the adhesive member 52, the adhesive member 52 is raised (regressed) in the opening 50 by the actuator 51.
Then, since the peripheral portion of the opening 50 of the pressure plate 7 prevents the movement of the upper substrate 1b, the adhesive member 52 and the upper substrate 1b can be easily separated from each other, and the pressure plate 7 serves as a peeling means of the adhesive member 52. work.

Thereafter, nitrogen gas N ₂ , clean dry air, or the like is supplied into the vacuum chamber to return to atmospheric pressure while purging the inside, and the pressure plate 7 is raised to raise the upper chamber unit 6.
Is raised, and the lower chamber portion T1 is moved to the left side in the figure, and then the cell pc is taken out of the table 4.

According to this embodiment, since the adhesive member is built in the pressure plate 7, the inside of the upper chamber unit 6 is simplified, and the size of the vacuum chamber can be reduced, so that the time for decompression and vacuuming can be shortened, The number can be increased.

Further, since the central portion of the upper substrate 1b where the sag is caused can be lifted by the adhesive member built in the pressing plate 7, there is no fear that the central portion of the upper substrate bends and damages the alignment film and the like.

The present invention is not limited to the above embodiment, and an adhesive member may be charged into the table 4 and used for fixing the lower substrate 1a. Also, instead of the adhesive sheet 18, a plurality of adhesive tapes are installed along the two parallel sides of the upper substrate 1b so as to be movable in the upper chamber unit by a mechanism such as that shown in FIGS. Then, the upper substrate 1b may be held so as to be parallel to the lower substrate 1a.

In any of the embodiments, since the upper substrate is held on the main surface side, the slack in the central portion can be eliminated, and even if the sealant is provided just near the peripheral edge of the substrate, There is no problem with retention.

[0058]

As described above, according to the present invention,
Even if the substrate size becomes large and thin, the substrates can be bonded together with high precision in a vacuum.

Further, according to the present invention, even when an adhesive is provided at the periphery of the substrate, the upper substrate can be easily held and can be bonded without damaging the alignment film and the like.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a substrate assembling apparatus showing an embodiment of the present invention.

FIG. 2 is a perspective view of a driving mechanism of an adhesive sheet in the substrate assembling apparatus shown in FIG.

FIG. 3 is a sectional view of a main part showing an initial step of bonding both upper and lower substrates in the substrate assembling apparatus shown in FIG. 1;

FIG. 4 is a sectional view of a main part showing a step of bonding both upper and lower substrates in the substrate assembling apparatus shown in FIG. 1;

5 is a cross-sectional view of a main part showing a step of taking out a cell formed by bonding both upper and lower substrates in the substrate assembling apparatus shown in FIG. 1;

FIG. 6 is a perspective view of a main part showing a step of bonding both upper and lower substrates in a substrate assembling apparatus according to another embodiment of the present invention.

FIG. 7 is a cross-sectional view of a main part showing a step of bonding both upper and lower substrates in a substrate assembling apparatus according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate assembling apparatus 1a Lower substrate 1b Upper substrate 4 Table 5 Lower chamber unit 6 Upper chamber unit 7 Pressure plate 12 O-ring 13 Ball bearing 14 Vacuum piping 17,21 Spindle 18 Adhesive sheet

Continued on the front page (72) Inventor Masayuki Saito 5-2-2 Koyodai, Ryugasaki-city, Ibaraki Pref. Hitachi Techno Engineering Co., Ltd. (72) Inventor Akira Hirai 5-2-2 Koyodai, Ryugasaki-city, Ibaraki Pref. Hitachi Techno Engineering Development Laboratory Co., Ltd. F term (reference) 2H088 FA02 FA03 FA04 FA10 FA17 FA18 FA20 FA30 HA01 MA20 5G435 AA17 BB12 HH20 KK05

Claims (6)

[Claims] 1. A method of assembling a substrate in which one substrate to be bonded is held and opposed to the other substrate to be bonded and bonded in a vacuum with an adhesive provided on one of the substrates. Characterized in that the substrate is held on the other substrate, and the gap is reduced in vacuum to perform the bonding. 2. The method for assembling a substrate according to claim 1, wherein one of the substrates is held below the pressure plate by the adhesive force on the lower surface of the adhesive sheet, and the other substrate is held on a table. The adhesive sheet is subjected to a pulling force in a direction parallel to the main surface of one of the substrates to maintain the two substrates substantially parallel, and the distance between the pressure plate and the table is reduced to bond the two substrates via the adhesive sheet. A substrate assembling method. 3. The method for assembling a substrate according to claim 2, wherein the edge of the adhesive sheet is gripped by a chuck and moved horizontally to pull the adhesive sheet in a direction parallel to the main surface of one of the substrates. A method for assembling a substrate, comprising applying pressure and cutting the pressure-sensitive adhesive sheet in the width direction with a cutter after bonding the two substrates. 4. The method for assembling a substrate according to claim 1, wherein one of the substrates is held by an adhesive means built in a pressure plate,
A method of assembling a substrate, comprising: adhering both substrates and then retreating the adhesive means into the pressure plate. 5. One of the substrates is held above the inside of the vacuum chamber, and the other substrate to be bonded is held below the inside of the vacuum chamber so that both substrates are opposed to each other. In an apparatus for assembling a substrate in which the distance between both substrates is reduced and the substrates are attached to each other, an adhesive means for holding one substrate on the other substrate, and one substrate held by the adhesive means and the other located thereunder Means for reducing the distance between the substrates. 6. The substrate assembling apparatus according to claim 5, wherein the table holding the other substrate and the one substrate held by the adhesive means are pressed against the other substrate positioned therebelow. An assembling apparatus for a substrate, comprising: a pressure plate; and peeling means for peeling off an adhesive means from one substrate bonded to the other substrate.