JP3973903B2 - Substrate bonding method and substrate bonding apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate bonding method and a substrate bonding apparatus in which two substrates are bonded together with an adhesive.
[0002]
[Prior art]
In the manufacturing process of flat panel displays and the like typified by liquid crystal display panels, substrates are bonded together by sealing and bonding liquid crystals (fluids) between two opposing glass substrates using a sealing material as an adhesive. Is done.
[0003]
Such a bonding operation is performed according to the following procedure.
[0004]
First, a sealing material is applied in advance to one of the two glass substrates in an endless frame shape. Then, a predetermined amount of liquid crystal is dropped on a portion of either the substrate coated with the sealing material or the substrate not coated with the other substrate and in the region surrounded by the sealing material. And apply.
[0005]
Next, the two substrates are brought close to a distance substantially equal to the coating height of the sealing material, and in this state, along the opposing surfaces of the two glasses using a position detection device such as an image recognition device using a camera. Detect relative displacement in direction. When a relative displacement is detected between the two glass substrates, the two glass substrates are relatively moved in a direction along the facing surface to correct the displacement.
[0006]
When the correction of the positional deviation is completed, the two glass substrates are relatively brought close to each other and bonded together with a predetermined pressing force.
[0007]
[Problems to be solved by the invention]
By the way, the liquid crystal is applied to a plurality of application locations on the glass substrate so as to be applied evenly on the glass substrate, but the amount of liquid crystal applied at each application location is simply that glass substrate. The total amount of liquid crystal that needs to be applied is determined by equally dividing the number of application portions.
[0008]
Therefore, depending on the amount and viscosity of the liquid crystal applied to each application location, the applied height of the applied liquid crystal may be higher than the applied height of the sealing material.
[0009]
In such a case, when the two glass substrates are brought close to each other to a distance substantially equal to the coating height of the sealing material for alignment, the substrate on which the liquid crystal is not applied comes into contact with the liquid crystal. There was a thing. And the surface tension, viscosity, etc. of this liquid crystal become a resistance in moving the two glass substrates relative to each other along the facing surface, and the alignment of the two glass substrates cannot be performed accurately. There was a problem that the bonding accuracy of the glass substrate was lowered.
[0010]
An object of this invention is to provide the board | substrate bonding method and board | substrate bonding apparatus which can perform the relative position of two board | substrates bonded together with sufficient precision.
[0011]
[Means for Solving the Problems]
The present invention relates to the other end of at least one of the two substrates prior to bonding through the adhesive in a state where the endlessly coated substrate and another substrate are aligned. The fluid is applied to a portion of the surface facing the substrate, which is in a region surrounded by the adhesive when the two substrates are bonded together, and applied to the substrate. Inspecting the height of the adhesive with respect to the application height of the adhesive, determining whether the application state of the fluid with respect to the substrate is good or not based on the inspection result, and determining whether to bond the substrates. It is characterized by.
[0012]
[Action]
According to the present invention, the fluid applied to the substrates to be bonded is applied in a plurality of application locations so that the height thereof is lower than the application height of the adhesive applied to the substrate.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 is a front view showing the configuration of a substrate bonding apparatus according to the present invention, and FIG. 2 is a front sectional view of a glass substrate coated with liquid crystal.
[0015]
In the figure, a substrate bonding apparatus 1 includes a coating unit 3 for liquid crystal (fluid) 2 and a bonding unit 5 for glass substrates 4a and 4b.
[0016]
The coating unit 3 supports a glass substrate 4a coated with a sealing material 6 as an adhesive, and moves up and down on a substrate stage 7 and a portal frame 8 that are movable in the X and Y directions by an XY moving device (not shown). It has a coating head 9 for dropping the liquid crystal supported freely, and a control device 10 for controlling the discharge amount (discharge state) of the liquid crystal 2 by the coating head 9.
[0017]
The coating head 9 includes a syringe 9 a that stores the liquid crystal 2 and a nozzle 9 b that discharges the liquid crystal 2, and discharges a predetermined amount of the liquid crystal 2 from the nozzle 9 b under the control of the control device 10.
[0018]
In addition, a storage unit 11 and an input unit 12 are connected to the control device 10. The storage unit 11 stores data representing the relationship between the application amount of the liquid crystal 2 and the application height according to the viscosity of the liquid crystal 2. The input unit 12 inputs and sets conditions such as the total amount of the liquid crystal 2 applied to one glass substrate 4a, the viscosity of the liquid crystal 2 and the coating height of the sealing material 6. For example, a touch panel, a keyboard, etc. Used.
[0019]
The data representing the relationship between the application amount and the application height of the liquid crystal 2 according to the viscosity is specifically, for example, if the application amount of the liquid crystal 2 is the same, the higher the viscosity, the higher the application height. If the viscosity is the same and the viscosity is the same, the data created on the basis of the measurement results from experiments and geometric calculations according to the regularity that the coating height tends to increase as the coating amount increases. It is.
[0020]
As a result, the control device 10 includes the data stored in the storage unit 11 based on conditions such as the total amount of the liquid crystal 2 input by the input unit 12, the viscosity of the liquid crystal 2, and the coating height of the sealing material 6. Then, the application amount of the liquid crystal 2 suitable for the conditions is selected and the number of application portions of the liquid crystal 2 on the glass substrate 4a is calculated and determined. Specifically, for example, from the data corresponding to the input viscosity, the application amount of the liquid crystal 2 in which the application height is smaller than the input application height of the sealing material 6, that is, the liquid crystal applied to one application location. The coating amount of 2 is selected and determined. Further, the number of application portions of the liquid crystal 2 on the glass substrate 4a is calculated based on the obtained application amount and the total amount of the liquid crystal 2 to be applied to the glass substrate 4a. Moreover, the control apparatus 10 calculates and sets the position of each application | coating location so that the calculated number of application | coating locations may be arrange | positioned substantially equally within the area | region enclosed with the sealing material 6 on the glass substrate 4a.
[0021]
The bonding unit 5 includes a lower substrate stage 13 that holds the lower glass substrate 4a and an upper substrate stage 14 that holds the upper glass substrate 4b. The lower substrate stage 13 and the upper substrate stage 14 are disposed so that the holding surfaces of the glass substrates 4a and 4b are opposed to each other, and are moved toward and away from each other by a moving device (not shown) and the holding surface. It is relatively movable in the direction along the direction (XY direction).
[0022]
Next, the operation will be described.
[0023]
First, a glass substrate 4 a on which a sealing material is applied in an endless frame shape along the outer periphery is supplied onto the substrate stage 7 by a not-shown transport device.
[0024]
When the glass substrate 4 a is supplied onto the substrate stage 7, the substrate stage 7 is moved so that the application locations set by the control device 10 are sequentially positioned below the nozzles 9 b of the application head 9. On the other hand, the application head 9 discharges a set amount of the liquid crystal 2 from the nozzle 9b and drops it on the glass substrate 4a every time each application location is positioned below the nozzle 9b under the control of the control device 10. Is done.
[0025]
At this time, since the application amount of the liquid crystal 2 applied to each application location is set based on the viscosity of the liquid crystal 2 and the application height of the sealing material 6, as shown in FIG. The height h is formed to be lower than the coating height H of the sealing material 6.
[0026]
When the application of the liquid crystal 2 to all the application locations is completed, the glass substrate 4a on which the liquid crystal 2 has been applied is transferred from the substrate stage 7 to the lower substrate stage 13 by a transfer device (not shown). The glass substrate 4a transferred onto the lower substrate stage 13 is held on the lower substrate stage 13 by suction holding means (not shown).
[0027]
At this time, as shown in FIG. 1, the glass substrate 4b to be bonded to the glass substrate 4a is already supplied to the upper substrate stage 14, and is sucked and held on the upper substrate stage 14 by a suction holding means (not shown). It is assumed that
[0028]
Next, the lower substrate stage 13 and the upper substrate stage 14 are moved in a direction in which they are relatively close to each other (vertical direction), and the glass substrate 4a and the glass substrate 4b are arranged at an interval substantially equal to the coating height of the sealing material 6. Is done.
[0029]
Then, in this state, a relative position shift in the direction (horizontal direction) along the opposing surfaces of the glass substrate 4a and the glass substrate 4b using a position detection device by an image recognition device using a camera (not shown). Is detected.
[0030]
As a result of detection by the position detection device, if there is a displacement between the two glass substrates 4a, 4b, the lower substrate stage 13 and the upper substrate stage 14 are moved in the XY directions so as to eliminate this displacement. Move it relatively with.
[0031]
After correcting the positional deviation, the lower substrate stage 13 and the upper substrate stage 14 are relatively brought close to each other, and the two glass substrates 4a and 4b are bonded together with a predetermined pressing force.
[0032]
After the bonding of the two glass substrates 4a and 4b is completed, the holding of the glass substrate 4b by the upper substrate stage 14 is released, and the lower substrate stage 13 and the upper substrate stage 14 are separated from each other. Thereafter, the holding of the glass substrate 4a by the lower substrate stage 13 is released, the glass substrates 4a and 4b bonded from above the lower substrate stage 13 are discharged, and a series of steps of the bonding operation is completed.
[0033]
When the glass substrates 4a and 4b are aligned, the two glass substrates 4a and 4b are arranged at intervals substantially equal to the coating height of the sealing material 6 according to the following (1) and (2). Depending on the reason.
[0034]
(1) High precision is required for bonding the glass substrates 4a and 4b, and the camera used for the position detection device is also a high-magnification camera, so that the depth of focus of the camera is relatively shallow. Yes. Therefore, in order to simultaneously position the two glass substrates 4a and 4b within the focal depth of the camera, it is necessary to bring the two glass substrates 4a and 4b as close as possible.
[0035]
(2) In order to bond the two glass substrates 4a and 4b with high accuracy, it is necessary to minimize the amount of movement of the lower substrate stage 13 and the upper substrate stage 14 after alignment, that is, the amount of movement in the vertical direction as much as possible. For this purpose, it is necessary to align the two glass substrates 4a and 4b as close as possible.
[0036]
According to the above embodiment, the application height h of the liquid crystal 2 applied on the glass substrate 4a is formed lower than the application height H of the sealing material 6 applied on the glass substrate 4a. Even when the substrates 4a and 4b are brought close to the interval substantially equal to the coating height of the sealing material 6 for alignment, the liquid crystal 2 applied to the glass substrate 4a can be prevented from coming into contact with the other glass substrate 4b. . As a result, when the positional deviation between the two glass substrates 4a and 4b is corrected, the surface tension and viscosity of the liquid crystal 2 cause the two glass substrates 4a and 4b, that is, the lower substrate stage 13 and the upper substrate stage 14 to move. It is possible to prevent the positioning of the two glass substrates 4a and 4b from being hindered without causing a movement resistance when relatively moving in the XY directions. Therefore, it is possible to align the glass substrates 4a and 4b with high accuracy.
[0037]
In addition, when the two glass substrates 4a and 4b are brought close to an interval substantially equal to the coating height of the sealing material 6 for alignment, the upper glass substrate 4b is temporarily applied to the lower glass substrate 4a. Even if it contacts the material 6, the coating height h of the liquid crystal 2 applied on the glass substrate 4 a is formed to be lower than the coating height H of the sealing material 6. Can be prevented from coming into contact with the liquid crystal 2. Even in such a case, compared with the case where the upper glass substrate 4b is in contact with both the sealing material 6 and the liquid crystal 2 which may have occurred in the past, the upper substrate stage 13 and the upper substrate stage 13 are corrected in order to correct the positional deviation. Since the movement resistance generated when the substrate stage 14 is moved relative to the XY direction can be reduced, the glass substrates 4a and 4b can be accurately aligned.
Further, the application amount of the liquid crystal 2 is determined based on the viscosity of the liquid crystal 2 and the application height of the sealing material 6, and the number of application locations on the glass substrate 4a is determined from the determined application amount. When the viscosity of the liquid crystal 2 is relatively high and difficult to spread by pressing, the application amount for one application location is small and the number of application locations is set large. As a result, the range of spread required for the liquid crystal 2 applied to each application location can be reduced. Therefore, even if the liquid crystal 2 has a high viscosity and is relatively difficult to spread, Between the glass substrates 4a and 4b.
[0038]
Next, a second embodiment will be described with reference to FIG.
[0039]
In the second embodiment, a coating state inspection device 15 for liquid crystal 2 is provided in the coating unit 3 of the substrate bonding device 1 shown in FIG.
[0040]
The application state inspection device 15 includes a camera 16 and an image processing device 17, and the camera 16 is attached to the application head 9.
[0041]
The camera 16 picks up an image of the liquid crystal 2 discharged from the nozzle 9b of the application head 9 and applied onto the glass substrate 4a. The image processing device 17 determines whether the application state of the liquid crystal 2 is good or not based on the imaging data of the camera 16.
[0042]
That is, the image processing device 17 detects the application area of the liquid crystal 2 from the imaging data of the camera 16, and the liquid crystal 2 for one application location is determined based on whether or not the application area is equal to or larger than a preset reference area. The quality of the applied state is determined. That is, when a coating area larger than the reference area cannot be obtained even though a predetermined amount of the liquid crystal 2 is applied, the viscosity of the liquid crystal 2 increases as a result of the influence of external factors such as temperature. Since it is considered that the height is higher than the coating height of the sealing material 6, it is determined to be defective.
[0043]
Here, the reference area refers to, for example, the liquid crystal 2 for one application location determined by the control device 10 based on the viscosity of the liquid crystal 2 input by the input unit 12 and the application height of the sealing material 6. It can be calculated geometrically from the coating amount and coating height.
[0044]
In addition, the application state inspection device 15 determines whether the application state of the liquid crystal 2 applied for each application location is good or not, and transmits a determination result for each application location to the control device 10. The control apparatus 10 determines the quality of the application state of the liquid crystal 2 with respect to the glass substrate 4a based on the determination results at all application locations. That is, if the ratio of the application locations where the application state is determined to be good with respect to the number of all application locations is greater than or equal to a preset ratio (set ratio), the application state of the liquid crystal 2 to the glass substrate 4a is good. Judge that there is. On the other hand, if the ratio of the application locations where the application state is determined to be good with respect to the number of all application locations is less than the preset ratio, it is determined that the application state of the liquid crystal 2 on the glass substrate 4a is defective. .
[0045]
When the application state is determined to be good, the glass substrate 4a is transferred to the bonding unit 5 (FIG. 1), and when it is determined to be defective, the glass substrate 4a is transferred to a discharge unit (not shown). .
[0046]
Here, it is conceivable that the set ratio is determined in consideration of the following.
[0047]
That is, when the two glass substrates 4a and 4b are brought close to each other in order to align the two glass substrates 4a and 4b, some of the liquid crystals 2 applied to the application locations on the glass substrate 4a. Even if the glass substrate 4b comes into contact with the upper glass substrate 4b, the movement resistance in the direction along the opposing surfaces of the glass substrates 4a and 4b caused thereby hinders the relative movement between the lower substrate stage 13 and the upper substrate stage 14. If it is not, it is good. And it is thought that the movement resistance mentioned above becomes so large that the viscosity of the liquid crystal 2 becomes high, and becomes so small that it becomes low. Therefore, when the viscosity of the liquid crystal 2 is high, the set ratio can be set high, and when the viscosity of the liquid crystal 2 is low, the set ratio can be set lower than when the viscosity is high. . Note that these setting ratios can be easily determined by experiments or the like.
[0048]
According to the second embodiment, the following effects are obtained in addition to the effects of the first embodiment.
[0049]
That is, the quality of the application state of the liquid crystal 2 applied to each application location of the glass substrate 4a is determined, and the quality of the application state of the liquid crystal 2 to the glass substrate 4a is determined based on the determination result at each application location. In addition, since the glass substrate 4a determined to be defective in application state is discharged, it is possible to prevent the glass substrate 4a in which the application state of the liquid crystal 2 is defective from being transferred to the bonding unit 5. Therefore, since only the glass substrate 4a in which the application state of the liquid crystal 2 is determined to be good is transferred to the bonding unit 5, the two glass substrates 4a and 4b can be bonded with higher accuracy.
[0050]
Needless to say, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention.
[0051]
For example, in the above-described embodiment, the application head 9 that discharges the liquid crystal 2 from the nozzle 9a has been described as the application device for the liquid crystal 2. However, the present invention is not limited to this. It may be used.
[0052]
The lower substrate stage 13 and the upper substrate stage 14 only need to be relatively movable in the direction in which the holding surfaces of the glass substrates 4a and 4b come in contact with and away from each other and in the direction along the holding surface. Therefore, either one of the lower substrate stage 13 and the upper substrate stage 14 may be moved, or both of them may be moved, and the movement in each moving direction may be changed. And the upper substrate stage 14 may be shared. Further, in addition to movement in the direction along the holding surface, rotational movement in the direction along the holding surface may be possible.
[0053]
Moreover, although the control apparatus 10 demonstrated and demonstrated in the example which selects and determines the coating amount etc. of the liquid crystal 2 from the data memorize | stored in the memory | storage part 11 based on the conditions input from the input part 12, control apparatus 10 demonstrated. However, it is not limited to the automatic setting, and the operator may input and set data such as the application amount.
[0054]
Moreover, although the example which determines the quantity of the liquid crystal 2 apply | coated to one application location mainly based on the viscosity of the liquid crystal 2 was demonstrated, it is not restricted to this, For example, the liquid crystal 2 of the glass substrate surface The application amount may be determined according to the degree of repelling. That is, when the glass substrate is in a surface state that has a strong tendency to repel (difficult to spread) the liquid crystal 2 and when the liquid crystal 2 is easy to conform (easy to spread), the application amount of the liquid crystal 2 to the glass substrate that is easy to spread is set large. It is considered possible.
[0055]
Moreover, although the example which apply | coats the liquid crystal 2 on the glass substrate 4a in which the sealing material 6 was apply | coated was demonstrated, it is not restricted to this, The liquid crystal 2 is applied to the glass substrate 4b in which the sealing material 6 is not apply | coated. The glass substrate 4a coated with the sealing material 6 may be held on the upper substrate stage 14 so that the surface coated with the sealing material 6 faces down.
[0056]
In the above-described embodiment, no particular explanation has been given, but the application of the liquid crystal 2 on the glass substrate 4a in advance and then bonding the glass substrates 4a and 4b is generally referred to as a dropping method. However, bonding of substrates by such a dropping method is usually performed in a vacuum. Therefore, the present invention is also applicable to a bonding apparatus that bonds two glass substrates 4a and 4b in such a vacuum.
[0057]
【The invention's effect】
According to the present invention, the relative alignment of two substrates to be bonded can be performed with high accuracy.
[Brief description of the drawings]
FIG. 1 is a front view showing a configuration of a substrate bonding apparatus according to the present invention.
FIG. 2 is a front sectional view of a glass substrate coated with liquid crystal.
FIG. 3 is a perspective view illustrating a configuration of a coating unit including a coating state inspection device.
[Explanation of symbols]
1 Bonding device 2 Liquid crystal (fluid)
3 Coating unit 4a, 4b Glass substrate 5 Bonding unit 6 Sealing material (adhesive)
7 Substrate stage 9 Application head 10 Control device 11 Storage unit 12 Input unit 13 Lower substrate stage 14 Upper substrate stage 15 Application state inspection device 16 Camera

Claims (4)

Prior to bonding the two substrates in an aligned state via an adhesive applied endlessly to either one of the two substrates, the other of at least one of the two substrates In the method of laminating a substrate, which is a surface facing the substrate, and a fluid is applied to a portion that is in a region surrounded by the adhesive when the two substrates are bonded together.
Comparing and discriminating between the coating height of the fluid applied to the substrate and the coating height of the adhesive, and determining whether or not to bond the substrates based on the discrimination result Bonding method. Prior to bonding the two substrates in an aligned state via an adhesive applied endlessly to either one of the two substrates, the other of at least one of the two substrates In the substrate bonding apparatus for applying a fluid to a portion that is a surface facing the substrate and is in a region surrounded by the adhesive when the two substrates are bonded together,
An applicator for applying the fluid;
A control device for controlling the discharge state of the fluid by the coating device;
An application state inspection device that compares and discriminates the application height of the fluid applied to the substrate by the application device and the application height of the adhesive;
The substrate bonding apparatus , wherein the control device determines whether or not to bond the substrates based on a determination result by the application state inspection device. The control device stops bonding of the substrates when the application state inspection device determines that the application height of the fluid is higher than the application height of the adhesive. The board | substrate bonding apparatus of description. A storage unit for storing data representing the relationship between the application amount of the fluid and the application height according to the viscosity of the fluid;
A setting unit for setting the viscosity of the fluid and the application height of the adhesive ;
The control device selects and determines the fluid application amount based on the viscosity set in the setting unit and the adhesive application height from the data stored in the storage unit, and determines The substrate bonding apparatus according to claim 2, wherein a discharge state of the fluid by the coating apparatus is controlled so that the fluid is applied in an applied amount .

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