JP2004286821A - Device and method for bonding substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately bond substrates to form a large screen together in manufacture of a liquid crystal display panel and so on. <P>SOLUTION: In bonding upper and lower substrates 11, 12, placed opposite to each other and held between upper and lower stages 31, 32, together, for the purpose of preventing lowering of quality of the bonding caused by protrusions and recessions on surfaces of the respective stages 31, 32, for example the lower substrate 12 is held via an elastic member 4. When positioning is carried out in a state in which the upper substrate 11 is in contact with an adhesive 1a, it sometimes occurs that the elastic member 4 is deformed. If the bonding is carried out in a state in which the elastic member 4 is deformed, restoring force of the deformed elastic member 4 acts in a subsequent hardening step and positional accuracy between both bonded substrates 11, 12 is deteriorated. Therefore the bonding device is constructed so as to dissolve the deformation of the elastic member 4 prior to the hardening of the adhesive 1a. As a result, action of the restoring force of the elastic member 4 is avoided or suppressed and excellent bonding accuracy between the upper and lower substrates 11, 12 is obtained. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement in a substrate bonding apparatus and a bonding method for bonding two substrates to each other.
[0002]
[Prior art]
2. Description of the Related Art A liquid crystal display panel is manufactured by bonding two substrates made of glass with a liquid crystal member interposed therebetween. For bonding the substrates, an adhesive ( For example, a sealing agent) is applied.
[0003]
In order to form a high-definition liquid crystal display screen, it is necessary to bond two rectangular substrates with high accuracy. Therefore, alignment based on an imaging pattern of an alignment (positioning) mark of each substrate is required. It is desired that the two substrates be brought as close as possible. Thus, for example, in a vacuum chamber, the two substrates positioned and opposed by so-called pre-alignment are brought close to each other until the other substrate surface comes into contact with the adhesive applied to one substrate, Is in contact with the adhesive applied to the other substrate surface, a highly accurate alignment operation based on the alignment mark is performed.
[0004]
FIG. 11 is a front view of a main part of a conventional substrate bonding apparatus. FIG. 12 shows a state in which the upper and lower substrates in FIG. 11 are overlapped, and the upper substrate is brought into contact with the adhesive applied to the lower substrate in order to perform a highly accurate alignment operation based on the alignment marks formed on each substrate. It is a principal part expanded sectional view which shows the state which folded.
[0005]
As shown in FIG. 11, the upper substrate 11 and the lower substrate 12 to be attached are opposed to each other in a vacuum chamber 2 including an upper lid 21 and a lower lid 22, and the upper substrate 11 is placed on an upper stage (upper platen) 31. The lower substrate 12 is held on the lower surface, and is placed and held on a lower stage (lower surface plate) 32.
[0006]
In order for a uniform gap (gap) to be formed between the two substrates 11 and 12 and to bond them well, each of the substrates 11 and 12 has good flatness without waving, and has an uneven gap. It is required that the adhesive 1a be pressed in a state where (gap unevenness) is not formed.
[0007]
However, the glass substrates 11 and 12 themselves are thin and flexible, and have the property of being easily deformed as a whole. Also, it is not easy to obtain flatness over a large area of the stages 31, 32 having high rigidity by mechanical processing.
[0008]
Accordingly, gap unevenness may occur between the two substrates 11 and 12 bonded by the stages 31 and 32.
[0009]
Therefore, in the substrate bonding apparatus shown in FIG. 11, the lower substrate 12 is suction-held on the lower stage 32 via the plurality of elastic members 4, and the elastic members 4 are provided on the surfaces of the upper and lower stages 31, 32. Irregularities are absorbed and alleviated, so that the entire adhesive 1a is uniformly pressed between the upper and lower substrates 11 and 12.
[0010]
In the front view of FIG. 11, on the lower stage 32, the number of the elastic members 4 for sucking and holding the rectangular lower substrate 12 is one for sucking and holding the central part of the substrate and the other for sucking and holding the four corners of the substrate. This indicates that the number is four and four in total.
[0011]
In FIG. 11, a plurality (5) of the elastic members 4 are mounted and fixed on the lower stage 31, but an example in which the substrate is held via one sheet-like elastic member is known. (See Patent Document 1).
[0012]
Therefore, in the substrate bonding apparatus shown in FIG. 11, the lower stage 32 itself in the vacuum chamber 2 is connected to the operating shaft 5a of the XY-θ moving mechanism 5 disposed outside and below the lower lid 22. The relative position between the upper and lower substrates 11 and 12 held by suction can be adjusted in the horizontal direction.
[0013]
The upper stage 31 having the function of a pressure plate in the vacuum chamber 2 is connected to the press mechanism 6 mounted on the upper lid 21 and is configured to be movable in the direction of the arrow Z (up and down) in the figure.
[0014]
In the substrate bonding apparatus shown in FIG. 11, in order to bond the two substrates 11 and 12 with high accuracy via the adhesive 1a, the substrates 11 and 12 which are opposed to each other in the vacuum chamber 2 are pre-aligned. After the rough alignment, the upper stage 31 is lowered, and the lower surface of the upper substrate 11 contacts the adhesive 1a on the lower substrate 12, as shown in an enlarged view in FIG. In a state in which the gaps 12 face each other with a narrow gap H, a highly accurate alignment operation based on the alignment mark is performed again.
[0015]
That is, as shown in FIG. 12, in the alignment between the upper and lower substrates 11, 12 in a state where the substrates 11, 12 face each other at a narrow interval H, that is, in the alignment operation, as shown in FIG. Imaging devices 33, 33, such as CCD cameras, capture and capture the alignment marks 11a, 12a of the substrates 11, 12 through the light transmitting window 22a of the lower lid 22 and the through hole 32a of the lower stage 32. The photographing pattern is supplied to the controller 7.
[0016]
The controller 7 having received the supply of the photographing pattern of the alignment marks 11a and 12a detects the amount of displacement Δd between the substrates 11 and 12 in the horizontal plane by a pattern recognition method as shown in FIG. The XY-θ moving mechanism 5 is drive-controlled in such a manner that the displacement amount Δd becomes smaller and falls within a preset allowable range, preferably such that the displacement amount becomes zero. As a result, for example, as shown in FIG. 13, the alignment is performed in units of microns or submicrons so that the positional deviation amount Δd becomes almost zero.
[0017]
When the controller 7 drives the XY-θ moving mechanism 5, the lower substrate 12 sucked and held on the lower stage via the elastic member 4 is caused by the viscosity of the adhesive 1a between the lower substrate 12 and the upper substrate 11. Move against the resistance you do. At that time, since the XY-θ moving mechanism 5 attempts to move the lower substrate 12 against the resistance in the moving direction due to the adhesive 1a, at the time when the positioning operation of the substrates 11 and 12 is completed, As shown in FIG. 13, the elastic member 4 located between the lower substrate 12 and the lower stage 32 and having a lower rigidity than the lower stage 32 has a horizontal deformation amount of a distance Δk.
[0018]
After the elastic member 4 is deformed by the distance Δk and the upper and lower substrates 11 and 12 are aligned, the controller 7 pushes down the upper stage 31 in the direction (downward) indicated by the arrow Z in FIG. Since the pressure is applied for the set time and the adhesive 1a is crushed, the distance between the upper and lower substrates 11 and 12 is reduced to a distance h (h <H) as shown in FIG.
[0019]
Thereafter, the substrates 11 and 12 are released from the upper and lower stages 31 and 32, and the inside of the vacuum chamber 2 is returned to the atmospheric pressure, whereby the bonding is completed. The two substrates 11 and 12 after the bonding are completed are conveyed to a step of curing the adhesive 1a, and the adhesive 1a is cured.
[0020]
Although the positioning operation between the upper and lower substrates 11 and 12 has been described as being performed in one direction (X direction), the positioning correction in the XY-θ direction is actually performed on a horizontal plane. Is performed.
[0021]
As shown in FIG. 12, when the upper substrate 11 is in contact with the adhesive 1a and the upper and lower substrates 11, 12 are opposed to each other at an interval H, the lower surface of the upper substrate 11 is not limited to the adhesive 1a. The elastic member 4 may be in contact with the liquid crystal member 1b dropped on the display surface or a spacer (not shown). It may be deformed due to resistance in the movement direction due to contact with the object.
[0022]
[Patent Document 1]
JP-A No. 11-264895 (page 4)
[0023]
[Problems to be solved by the invention]
As described above, in the conventional substrate bonding apparatus and bonding method, the controller 7 sets the imaging pattern in advance based on the imaging patterns of the alignment marks 11a and 12a provided on the surfaces of both substrates 11 and 12. The drive of the XY-θ moving mechanism 5 is controlled so as to coincide within the set allowable range, and thereafter, the adhesive 1a is further pressed to bond the upper and lower substrates 11 and 12 together.
[0024]
In the positioning operation (alignment) at the time of the bonding, the elastic member 4 provided to form a uniform pressing force between the upper and lower substrates 11 and 12 is horizontal as shown in FIGS. The distance Δk is deformed in the direction.
[0025]
However, it takes time until the bonding operation is completed and the suction holding of the substrates 11 and 12 is released. During this time, the restoring force of the elastic member 4 deformed by the distance Δk causes the lower substrate 12 sucked and held to move. It acts as a force to move in the direction indicated by arrow X in FIG.
[0026]
Therefore, the lower substrate 12 that has been once aligned with the upper substrate 11 has an arrow shown in FIG. 14 due to the restoring force of the elastic member 4 acting until the suction holding of the substrates 11 and 12 is released. X, the amount of deformation of the elastic member 4 in the horizontal direction also decreases from the distance Δk to the distance Δn (Δn <Δk), as shown in FIG. Between 11 and 12, there occurs a phenomenon that a positional shift is caused in the horizontal direction (X direction) by a distance Δm. As a result, the positioning accuracy between the two substrates 11 and 12 may be out of the allowable range of the initial micron unit or submicron unit.
[0027]
Therefore, an object of the present invention is to provide a substrate bonding apparatus and a substrate bonding method that can perform appropriate and high-quality substrate bonding.
[0028]
[Means for Solving the Problems]
A first invention provides a substrate bonding apparatus for bonding an upper substrate held on an upper stage and a lower substrate disposed on the lower substrate and opposed to the upper substrate via an adhesive, An elastic member interposed between at least one of the upper stage and the upper substrate, or at least one of the lower stage and the lower substrate; a detecting unit for detecting a horizontal deformation amount of the elastic member; And a drive control unit for relatively moving the upper stage and the lower stage based on the amount of deformation detected by the control unit.
[0029]
According to the first aspect of the invention, there is provided detecting means for detecting the amount of deformation of the elastic member in the horizontal direction, and the drive control means controls the upper stage and the lower stage based on the amount of deformation detected by the detecting means. Since it can be relatively moved, the action by the restoring force of the elastic member, that is, the action of returning the upper and lower substrates to the state before the alignment is performed can be reduced or avoided, and the upper and lower substrates are in a state where the displacement is small. Then, it is bonded with high precision.
[0030]
A second invention is a substrate bonding apparatus for bonding an upper substrate held on an upper stage and a lower substrate disposed on the lower substrate and opposed to the upper substrate via an adhesive, An elastic member interposed between at least one of the upper stage and the upper substrate, or at least one of the lower stage and the lower substrate, and between the upper stage and the upper substrate sandwiching the elastic member, or a lower substrate Detecting means for detecting a horizontal displacement amount between the lower stage and a drive control means for relatively moving the upper stage and the lower stage based on the displacement amount detected by the detecting means; It is characterized by having.
[0031]
According to the second aspect, a detecting means for detecting a horizontal displacement amount between the upper stage and the upper substrate sandwiching the elastic member, or between the lower substrate and the lower stage also sandwiching the elastic member. And the drive control means relatively moves the upper stage and the lower stage based on the amount of displacement detected by the detection means. A decrease in alignment accuracy can be avoided or suppressed. Therefore, the action of the elastic member due to the restoring force, that is, the action of returning the upper and lower substrates to a state before the alignment is performed is reduced or avoided, and the upper and lower substrates are bonded with high accuracy with a small displacement.
[0032]
According to a third aspect, an elastic member is interposed between at least one of an upper stage and an upper substrate held by the upper stage or between a lower stage and a lower substrate held by the lower stage, The substrate and the lower substrate are subjected to a positioning operation in a state where they are in contact with each other via an intermediary such as an adhesive, and in a method of bonding a substrate to be bonded via an adhesive, the upper substrate and the lower substrate A first step of superposing through the intervening object, and after the first step, controlling a relative position between the upper stage and the lower stage, and between the upper substrate and the lower substrate A second step of performing the positioning operation of the elastic member, a third step of detecting a horizontal deformation amount of the elastic member after the second step, and a step of detecting the amount of deformation of the elastic member after the third step. The upper stage in the direction in which the amount of deformation decreases Characterized in that comprising a fourth step for relatively moving said lower stage.
[0033]
According to the third aspect, in the third step, the amount of deformation of the elastic member in the horizontal direction is detected, and in the fourth step, the upper stage and the lower stage are moved in a direction in which the amount of deformation of the elastic member decreases. Since the relative movement is performed, similarly to the first invention, it is possible to suppress or avoid a reduction in the positioning accuracy between the upper and lower substrates to be bonded due to the action of the restoring force of the elastic member.
[0034]
In a fourth aspect, an elastic member is interposed between at least one of an upper stage and an upper substrate held by the upper stage, or at least one of a lower stage and a lower substrate held by the lower stage, The substrate and the lower substrate are subjected to a positioning operation in a state where they are in contact with each other via an intermediary such as an adhesive, and in a method of bonding a substrate to be bonded via an adhesive, the upper substrate and the lower substrate A first step of superposing through the intervening object, and after the first step, controlling a relative position between the upper stage and the lower stage, and between the upper substrate and the lower substrate A second step of performing the positioning operation of the above, after the second step, between the upper substrate and the lower substrate between the substrate held via the elastic member and the stage holding the substrate Based on the deformation of the elastic member A third step of obtaining a horizontal positional shift amount, and after the third step, a fourth step of relatively moving the upper stage and the lower stage in a direction in which the horizontal positional shift amount decreases. And the step of:
[0035]
As described above, the fourth aspect of the present invention is based on the amount of misalignment between the upper stage and the upper substrate, or between the lower stage and the lower substrate, sandwiching the elastic member, determined in the third step. Since the lower stage is relatively moved (fourth step), it is possible to suppress or avoid a reduction in the positioning accuracy between the upper and lower substrates to be bonded due to the action of the restoring force of the elastic member. .
[0036]
In a fifth aspect, an elastic member is interposed between at least one of the upper stage and the upper substrate held by the upper stage, or between the lower stage and the lower substrate held by the lower stage, The upper substrate and the lower substrate are subjected to a positioning operation in a state where they are brought into contact with each other through an intervening substance such as an adhesive, and in a method of bonding a substrate to be bonded through an adhesive, the upper substrate and the lower substrate are bonded together. A first step of superimposing the substrate with the interposition of the inclusion, and after the first step, controlling a relative position between the upper stage and the lower stage, the upper substrate and the lower substrate And a second step of releasing at least one of the holding of the upper substrate by the upper stage and the holding of the lower substrate by the lower stage after the second step of performing the positioning operation during the second step. Step 3 After the third step, characterized by comprising a fourth step of bonding said lower substrate and the upper substrate.
[0037]
As described above, according to the fifth aspect, prior to the fourth step of bonding the upper substrate and the lower substrate, in the third step, the holding of the upper substrate by the upper stage or the holding of the lower substrate by the lower stage Is released by releasing at least one of them, so that the effect of the restoring force of the elastic member deformed at the time of the positioning operation can be reduced or avoided, and the upper and lower substrates are accurately bonded.
[0038]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a substrate bonding apparatus and a substrate bonding method according to the present invention will be described in detail with reference to FIGS. The same components as those of the conventional substrate bonding apparatus and the conventional substrate bonding method shown in FIGS. 11 to 15 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0039]
That is, FIG. 1 is a front view showing a first embodiment of the substrate bonding apparatus according to the present invention.
[0040]
As shown in FIG. 1, in the substrate bonding apparatus according to the first embodiment, an upper stage 11 and a lower substrate 12 are opposed to each other in a vacuum chamber 2 including an upper lid 21 and a lower lid 22. 31 and the lower stage 32 respectively.
[0041]
Although the upper substrate 11 is directly held by suction on the upper stage 31, a plurality (5) of the upper and lower stages 31 and 32 are used in order to absorb irregularities on the surfaces of the upper and lower stages 31 and 32 and to prevent poor bonding of the adhesive 1a due to the irregularities. The lower substrate 12 is suction-held on the lower stage 32 via the elastic member 4.
[0042]
As shown in an enlarged perspective view of FIG. 2, all of the plurality (5) of the elastic members 4 have a flat rectangular shape, and are exhausted from the lower stage 32 for the suction chuck. 4 a is configured to adsorb the lower substrate 12 placed on the elastic member 4. As shown in FIG. 2, a known strain gauge 8 is built in the elastic member 4 that sucks and holds the central portion of the lower substrate 12, and the elastic member 4 itself receives horizontal mechanical force when receiving a mechanical external force. When deformed in the direction, the flexible strain gauge 8 detects the amount of change in the horizontal direction of the elastic member 4 and supplies the detected data to the controller 7 as shown in FIG. It is connected.
[0043]
FIG. 3 is a plan view of the elastic member 4 shown in FIG. 2 cut along line AA in the direction of the arrow, and showing the built-in strain gauge 8 as viewed from above.
[0044]
The sensor disclosed in, for example, Japanese Patent Application Laid-Open No. 6-397350 can be applied to the strain gauge 8 of this embodiment. That is, in the strain gauge 8, four electrode bodies 81, 82, 83, and 84, which form a pair with a pressure-sensitive resistor sandwiched therebetween in the vertical (Z-axis) direction, are arranged at intervals of 90 degrees, and the X-axis in the horizontal direction is arranged. The mechanical moment accompanying the deformation of the elastic member 4 received around the periphery and around the Y axis is converted into a voltage value and output, and supplied to the controller 7.
[0045]
The lower stage 32 on which the elastic member 4 is mounted is fixed to the XY-θ moving mechanism 5 and moves in a horizontal plane to adjust the relative position between the upper and lower substrates 11 and 12 as in the related art. Is configured.
[0046]
In the first embodiment, the strain gauge 8 is built in the elastic member 4 at the center of the lower substrate 11, but all or four of the elastic members 4 provided at the four corners including the center are provided. Among the plurality of elastic members 4, the strain gauge 8 can be built in any selected elastic member 4.
[0047]
Therefore, in the positioning operation of the opposing substrates 11 and 12, for example, after pre-alignment, first, the controller 7 controls the press mechanism 6 to lower the upper stage 21 and, as shown in an enlarged manner in FIG. The operation is performed so that the substrates 11 and 12 are opposed to each other with a narrow gap H, and the upper substrate 11 is slightly in contact with the adhesive 1 a on the lower substrate 12.
[0048]
In the state shown in FIG. 4, similarly to the conventional case, imaging devices 33, 33 installed below photograph alignment (positioning) marks 11 a, 12 a of the substrates 11, 12, and control the photographing pattern by a controller. 7
[0049]
The controller 7 which has received the supply of the photographing pattern detects the positional deviation amount Δd between the substrates 11 and 12 by pattern recognition, and the positional deviation amount Δd falls within a preset allowable range, preferably the positional deviation amount. The drive of the XY-θ moving mechanism 5 is appropriately controlled so that the amount Δd becomes close to zero and bonding is performed with high accuracy.
[0050]
At this time, the XY-θ moving mechanism 5 moves the lower substrate 12 against the contact resistance between the adhesive 1a, the liquid crystal member 1b, etc. and the upper substrate 11, as shown in FIG. The elastic member 4 between the lower substrate 12 and the lower stage 32 is deformed in the horizontal direction by a distance Δk, and the amount of deformation of the distance Δk is detected by a built-in strain gauge 8. Supplied to
[0051]
At this time, assuming that there is no slip between the lower substrate 12 and the elastic member 4, the controller 7 detects the slip between the lower stage 32 and the lower substrate 12 based on the detection signal as shown in FIG. The amount of deviation between the state and the state shown in FIG. 5 can be obtained.
[0052]
Next, the controller 7 controls the drive of the press mechanism 6 and pushes down the upper stage 31 in the direction (downward) indicated by the arrow Z in FIG. 5 so that the upper and lower substrates 11 and 12 are kept for a preset time. , The distance between the upper and lower substrates 11 and 12 is further reduced.
[0053]
Before the controller 7 pushes down the upper stage 31, the controller 7 drives the XY-θ moving mechanism 5 based on the detection signal of the deformation amount (distance Δk) from the strain gauge 8, and The lower stage 32 is controlled to move in a direction in which the deformation amount (distance Δk) of the member 4 decreases.
[0054]
Thereby, as shown in FIG. 7, the deformation of the elastic member 4 on the XY-θ plane is eliminated.
[0055]
That is, according to the first embodiment, the restoring force caused by the deformation of the elastic member 4 based on the alignment adjustment (alignment) is eliminated or greatly reduced, so that the upper and lower substrates 11, 12 are aligned. The position is shifted by the restoring force of the elastic member 4 between the time when the adjustment is completed and the above-described lower operation of the upper stage 31 is performed and the upper and lower substrates 11 and 12 are released from the upper and lower stages 31 and 32. Instead, they are bonded together while maintaining a state of high-accuracy alignment.
[0056]
In the first embodiment shown in FIG. 1, the five elastic members 4 are mounted on the upper surface of the rectangular lower stage 32, and the strain gauge 8 is built in only one of the central portions. For example, when the strain gauges 8 are built in all the five elastic members 4, the controller 7 controls the deformation amounts detected by the plurality of strain gauges 8, for example, an average value or a center value. The value may be calculated and, based on the average value or the median value, the movement may be controlled in the direction in which the amount of positional deviation (distance Δk) in the horizontal direction (shown in FIG. 5 or FIG. 6) becomes smaller.
[0057]
The positioning operation in the horizontal direction (XY-θ direction) can be divided into a positioning operation in the XY (perpendicular) direction and a positioning operation in the θ (turning) direction. .
[0058]
In the alignment in the XY directions, any of the elastic members 4 can be detected as the amount of deformation in the same direction (XY directions). The amount of operation on the XY-θ moving mechanism 5 can be obtained by a simple operation of calculating a value.
[0059]
On the other hand, in the alignment in the θ direction, the amount of deformation in the X and Y directions of the elastic member 4 detected at the center of the substrate, which is the center of rotation of the substrate, is extremely small. An elastic member 4 having a built-in strain gauge 8 is provided, and the detected value of the amount of deformation in each of the strain gauges 8 provided at the four corners in the X and Y directions is used to determine the angle between the lower stage 32 and the lower substrate 12 in the θ direction. The amount of displacement is geometrically determined, and the amount of operation in the direction in which the amount of deformation of the elastic member 4 at each of the four corners is reduced can be determined.
[0060]
In the first embodiment, the amount of deformation of the elastic member 4 due to the positioning operation is configured to be detected by the strain gauge 8, but the amount of deformation of the elastic member 4 corresponds to the lower substrate 12 shown in FIG. The difference is the difference between the positional relationship between the lower substrate 32 and the lower stage 32 shown in FIG.
[0061]
That is, eliminating the distortion of the elastic member 4 means returning the positional relationship between the lower substrate 12 and the lower stage 32 from the state of FIG. 5 to the state of FIG.
[0062]
Therefore, without providing the strain gauge 8 on the elastic member 4, the state before the alignment between the lower substrate 12 and the lower stage 32 sandwiching the elastic member 4 in the vertical direction (result of deformation of the elastic member 4 is caused. Also, the purpose can be similarly achieved by detecting the amount of displacement after the alignment and controlling the position of the lower stage 32 in a direction in which the detected value becomes zero.
[0063]
Therefore, in the method of detecting the amount of displacement between the lower substrate 12 and the lower stage 32 with the elastic member 4 interposed therebetween, the alignment marks 12a of the lower substrate 12 captured by the imaging devices 33, 33 are shown in FIG. The position on the XY coordinate axis photographed in the state (before alignment) and the XY coordinate axis after deformation of the elastic member 4 (by alignment) as shown in FIG. 5 or FIG. The controller 7 may calculate the amount of deviation from the position, and perform correction control of the XY-θ moving mechanism 5 based on the calculated amount.
[0064]
Furthermore, in this embodiment, the lower stage 32 is moved in order to eliminate the deformation of the elastic member 4, but an XY-θ moving mechanism is incorporated in the upper stage 31 to move the upper stage 31. Then, the lower substrate 12 may be moved.
[0065]
Alternatively, the XY-θ moving mechanism may be connected to both the upper and lower stages 31 and 32 and incorporated so that the operation of correcting the amount of displacement with respect to the elastic member 4 may be shared and performed. At this time, the elastic member 4 may be attached to one or both of the upper and lower stages 31 and 32, and may be operated so that the amount of deformation of the elastic member 4 during the bonding operation is returned to zero.
[0066]
Next, a procedure (step) of bonding two substrates using the substrate bonding apparatus of the first embodiment shown in FIG. 1 will be described below with reference to a flowchart shown in FIG. Note that the upper and lower substrates 11 and 12 are supplied into the vacuum chamber 2 and are sucked and held by the upper and lower stages 31 and 32, and the inside of the vacuum chamber 2 has been reduced to a vacuum state.
[0067]
First, in the first step, the upper and lower substrates 11 and 12 are overlapped via the adhesive 1a (step 8A).
[0068]
In the second step, a positioning operation is performed in a direction in which the amount of displacement between the upper and lower substrates 11 and 12 is reduced (step 8B).
[0069]
Next, in a third step, the amount of deformation of the elastic member 4 caused by the positioning operation of the two substrates 11 and 12 is detected (Step 8C).
[0070]
Next, in a fourth step, the lower stage 12 is moved and adjusted in a direction in which the amount of deformation of the elastic member becomes zero (Step 8D).
[0071]
Thereafter, as a fifth step, the upper and lower substrates 11 and 12 are further pressed for a preset time (step 8E).
[0072]
Further, in the sixth step, the upper and lower substrates 11, 12 are released from the upper and lower stages 31, 32, and the inside of the vacuum chamber 2 is returned to the atmospheric pressure (step 8F).
[0073]
After the inside of the vacuum chamber 2 is returned to the atmospheric pressure, the upper stage 31 is raised, and the bonded substrates 11 and 12 are taken out of the vacuum chamber 2 by a transfer robot (not shown). To the next step.
[0074]
In the above description of the procedure, after the lower stage 12 is moved and adjusted (Step 8D), the adhesive 1a is further pressed to bond the upper and lower substrates (Step 8E). The method for bonding the substrates according to the first embodiment is only required to prevent the restoring force of the elastic member 4 deformed during the positioning operation from acting between the aligned substrates 11 and 12. It may be performed at least until either the suction holding of the upper substrate 11 by the upper stage 31 or the suction holding of the lower substrate 12 by the lower stage 32 is released, and even if Step 8D is executed during Step 8E. The purpose can be achieved as well. However, the operation of eliminating the deformation of the elastic member 4 is preferably performed in the order of Step 8B → Step 8C → Step 8D as described above, since the effect of preventing the displacement due to the restoring force increases when the operation is performed as soon as possible.
[0075]
When the upper and lower substrates 11 and 12 are aligned, not only the adhesive 1a in contact with the upper substrate 11 but also the viscous liquid crystal member 1b and the spacer are in contact with the upper substrate 11. The member 4 is deformed in addition to the contact resistance between the adhesive 1a, the liquid crystal member 1b, and the like and the upper substrate 11, and resists the inherent viscosity of the liquid crystal member 1b, the spacer, etc. as well as the adhesive 1a.
[0076]
In other words, in the positioning operation of the upper and lower substrates 11 and 12, not only the elastic member 4 but also the adhesive 1a and the liquid crystal member 1b are deformed with viscosity.
[0077]
Accordingly, the controller 7 operates the XY-θ moving mechanism 5 to return the deformation amount Δk of the elastic member 4 itself to zero, so that there is no apparent displacement between the upper and lower substrates 11 and 12. Even if it looks like it is, a reaction due to the viscosity of the adhesive 1a or the liquid crystal member 1b deformed during the alignment operation acts, and a new displacement occurs between the upper and lower substrates 11 and 12. It is also conceivable to let them.
[0078]
In order to avoid this phenomenon, the controller 7 sets, for example, a coefficient σ (0 <σ <1) in the moving operation amount for eliminating the change amount Δk of the elastic member 4 in anticipation of the reaction of the adhesive 1a or the like. A restriction such as multiplication may be provided. The coefficient σ can be determined, for example, based on the result of experimentally determining the amount of displacement between the upper and lower substrates 11, 12 caused by the reaction of the adhesive 1a or the like after correcting the deformation amount Δk of the elastic member 4. it can.
[0079]
Alternatively, when the controller 7 drives the XY-θ moving mechanism 5 to perform the positioning operation, the position deviation amount predicted in advance by the reaction (restoring force) of the adhesive 1a, the liquid crystal member, or the like. In other words, by performing a positioning operation taking into account the return amount, for example, by performing a positioning operation in which the return amount is added, the bonding is finally completed with a positional deviation amount within a permissible range in micron units or sub-micron units. Adjustment control can be performed.
[0080]
Next, in the first embodiment described above, the controller 7 moves and adjusts the lower stage 32 (or the upper stage 31) to eliminate the deformation of the elastic member 4, but the lower substrate 12 and the lower stage 32 (or between the upper substrate 11 and the upper stage 31), that is, even if the suction holding to at least one of the substrates 11 and 12 is temporarily canceled, the elastic member 4 Since the restrained state of the deformation is released, the object can be similarly achieved.
[0081]
FIG. 9 shows a procedure (step) of a substrate bonding method according to the second embodiment of the present invention for temporarily canceling substrate holding in order to eliminate a reaction due to deformation of the elastic member 4 or the like at the time of an alignment operation. ). Note that the substrate bonding apparatus employing this method is different from the substrate bonding apparatus shown in FIG. 1 only in that the strain gauge 8 is not necessarily required in the elastic member 4. Since the configuration is the same, a description will be given also with reference to the configuration of FIG. Note that the upper and lower substrates 11 and 12 are supplied into the vacuum chamber 2 and are sucked and held by the upper and lower stages 31 and 32, and the inside of the vacuum chamber 2 has been reduced to a vacuum state.
[0082]
That is, first, in the first step, the upper and lower substrates 11 and 12 are overlapped via the adhesive 1a (step 9A).
[0083]
In the second step, a positioning operation is performed so that the amount of displacement between the upper and lower substrates 11 and 12 is reduced (step 9B).
[0084]
Next, in a third step, at least one of the substrates 11 and 12 is released from the stage by suction (step 9C).
[0085]
Next, in the fourth step, the stage that has released the suction holding is sucked and held again by the stage, and the upper and lower substrates 11, 12 are further pressed for a preset time (step 9D). In this manner, by holding the released substrate by suction again, when the substrates 11 and 12 are pressed, it is possible to prevent the displacement between the substrates 11 and 12 due to the pressing.
[0086]
Further, in the fifth step, the upper and lower substrates 11, 12 are released from the upper and lower stages 31, 32, and the inside of the vacuum chamber 2 is returned to the atmospheric pressure (step 9E). After the inside of the vacuum chamber 2 is returned to the atmospheric pressure, the upper stage 31 is raised, and the bonded substrates 11 and 12 are taken out of the vacuum chamber 2 by a transfer robot (not shown). And so on.
[0087]
As described above, at the time of performing the third step (step 9C), the controller 7 causes the stage (at least one of the stage 31 and the stage 32) to be attracted to the two substrates 11 and 12 after the alignment. For example, control of an exhaust pump connected to each suction hole or temporary release control of the electrostatic chuck is performed so as to release the holding. As a result, at least one of the constraints between the two stages 31 and 32 is released from the constraint on the elastic member 4, so that the deformation of the elastic member 4 due to the positioning operation is released, and the elastic member 4 is caused by the restoring force. Thus, it is possible to avoid the deterioration of the positioning accuracy between the two substrates 11 and 12.
[0088]
In the second embodiment, after releasing the suction or the like, the frictional resistance between the separated upper stage 31 and the upper substrate 11 is determined by the lower substrate 12 and the elastic member 4 on which the lower substrate 12 is placed. Since the frictional resistance between the elastic members 4 and the like is smaller, the restoring action of the elastic member 4 and the like is performed more smoothly when the holding of the substrate 11 is released on the upper stage 31 side.
[0089]
In the above description, the upper stage 31 releases the holding of the substrates 11 and 12 in a state where the upper substrate 11 is pressed down. However, in order to make the releasing operation more reliable, the upper stage 31 is not limited to simply releasing the suction or the like. Instead, for example, the press mechanism 6 may be momentarily raised slightly to operate the upper stage 31 such that the pressing force on the upper substrate 11 is smaller or the pressing force becomes zero.
[0090]
The controller 7 in the first and second embodiments performs a positioning operation at the time of the bonding operation based on the photographing pattern of the alignment mark (Steps 8B and 9B), and then deforms by the positioning operation. The control is performed so that the deformed elastic member 4 is eliminated and the restoring force of the deformed elastic member 4 does not deteriorate the bonding accuracy of the two substrates.
[0091]
That is, the controller 7 controls the driving of the XY-θ moving mechanism 5 to align the lower substrate 12 with the upper substrate 11 based on the displacement data between the substrates 11 and 12 based on the photographing pattern. Since the Y-θ moving mechanism 5 moves and adjusts the lower substrate 12 via the elastic member 4 which is an elastic body, the elastic member 4 is deformed as described above, and the alignment operation requires a little time.
[0092]
The controller 7 determines the relationship between the amount of displacement between the substrates 11 and 12 and the amount of deformation of the elastic member 4 in advance by experiments or the like, so that the controller 7 can take into account the deformation of the elastic member 4. By controlling the θ moving mechanism 5, the positioning operation can be performed smoothly and quickly.
[0093]
That is, in the third embodiment of the substrate laminating apparatus and the laminating method according to the present invention, the controller 7 is different from the first and second embodiments in that the controller 7 is based on the photographing pattern of the alignment mark. The amount of deformation of the elastic member 4 at the time of correcting the amount of displacement detected is read out from data obtained in advance and added to the detected amount of displacement, and the XY-θ moving mechanism 5 is drive-controlled.
[0094]
That is, the controller 7 obtains, in an experiment or the like, data corresponding to the amount of displacement between the substrates 11 and 12 at the time of bonding and the amount of deformation of the deformable elastic member 4 as a result of correcting the amount of displacement. , Stored in the built-in ROM, etc.
Therefore, a procedure (step) of the method for bonding substrates according to the third embodiment will be described with reference to a flowchart shown in FIG. Note that the upper and lower substrates 11 and 12 are supplied into the vacuum chamber 2 and are sucked and held by the upper and lower stages 31 and 32, and the inside of the vacuum chamber 2 has been reduced to a vacuum state.
[0095]
First, in the first step, the upper and lower substrates 11, 12 are overlapped via the adhesive 1a (step 10A).
[0096]
In the second step, the amount of displacement between the upper and lower substrates 11, 12 is detected (step 10B).
[0097]
In the third step, the amount of deformation of the elastic member 4 that is deformed when the lower substrate 12 is moved is determined in advance based on the detected amount of displacement so that the amount of displacement is within a set allowable range. The data is read out from data stored in a ROM or the like obtained by an experiment or the like (step 10C).
[0098]
In the fourth step, the controller 7 adjusts the movement correction amount for the lower stage 32 in consideration of the displacement amount detected in the second step and the deformation amount of the elastic member 4 obtained in the third step (for example, A correction amount (a correction amount obtained by adding the deformation amount of the elastic member 4 obtained in the third step to the positional deviation amount detected in the second step) is calculated (step 10D).
[0099]
In the fifth step, the controller 7 controls the XY-θ moving mechanism 5 to drive the lower stage 32 by the movement correction amount calculated in the fourth step (Step 10E).
[0100]
Next, in a sixth step, the controller 7 determines whether or not the amount of displacement between the upper and lower substrates 11 and 12 is within a preset allowable range by using the alignment marks 11a and 12a by the imaging devices 33 and 33. (Step 10F).
[0101]
In the seventh step, when it is determined in the sixth step that the positional displacement amount between the upper and lower substrates 11 and 12 falls within a preset allowable range (YES), the controller 7 sets the third position to the third position. Based on the amount of deformation of the elastic member 4 obtained in the step, the lower stage 32 is moved in a direction in which the amount of deformation of the elastic member 4 becomes zero (step 10G). Subsequently, in the eighth step, the controller 7 Then, the adhesive 1a is further pressed, and the press mechanism 6 is controlled so as to press both substrates 11 and 12 for a preset time (step 10H).
[0102]
Finally, in a ninth step, the upper and lower substrates 11, 12 are released from the upper and lower stages 31, 32, and the inside of the vacuum chamber 2 is returned to the atmospheric pressure (step 10I).
[0103]
After the inside of the vacuum chamber 2 is returned to the atmospheric pressure, the upper stage 31 is raised, and the bonded substrates 11 and 12 are taken out of the vacuum chamber 2 by a transfer robot (not shown). It is transported to the next process such as a curing process.
[0104]
In the sixth step, when it is determined that the amount of displacement between the upper and lower substrates 11 and 12 is not within the preset allowable range (NO), the process returns to the second step (step 10B) and control is performed. The device 7 performs the operation of detecting the amount of displacement between the upper and lower substrates 11 and 12 again, and thereafter repeats the above-described procedure.
[0105]
As described above, in the third embodiment, in the positioning operation between the upper and lower substrates 11 and 12, the lower stage 32 is moved in consideration of the amount of deformation of the elastic member 4, so that the positioning operation is speeded up. Can be achieved.
[0106]
In the above description, the operation of eliminating the deformation in the elastic member 4 after the elastic member 4 is deformed and the alignment is performed is the same as the method described in the first embodiment and the second embodiment. Can be adopted.
[0107]
Therefore, according to the third embodiment, it is possible to avoid or suppress the deterioration of the positional accuracy between the upper and lower substrates 11 and 12 after the alignment through a smooth and efficient alignment operation. .
[0108]
In each of the above-described embodiments, a total of five elastic members 4, one in the center and one in each of the four corners, are arranged on the rectangular substrates 11 and 12, respectively. However, these numbers can be appropriately increased or decreased according to the substrate size. Also, the arrangement position may be such that all the elastic members 4 can correspond to either large or small substrates, and the elastic members 4 to be employed can be appropriately selected according to the substrate size. .
[0109]
In the above description, the elastic members 4 are provided at the center and the four corners of the substrates 11 and 12. However, in the case of multiple display, the elastic members 4 may be provided at the center and the four corners for each display surface. .
[0110]
Furthermore, in the description of each of the above-described embodiments, the upper substrate 11 is moved downward while the upper substrate 11 and the lower substrate 12 are aligned, but the lower substrate 12 is moved upward. Further, the XY-θ moving table may be provided on the upper stage 31 side instead of the lower stage 32 side, or may be configured and installed on both sides to share the moving operation in the XY-θ direction. May be performed. In this case, it goes without saying that the imaging device 33 can also be appropriately configured and arranged in accordance with those mechanisms.
[0111]
Further, the elastic member 4 having the built-in strain gauge 8 may be attached not only to the lower stage but also to the upper stage or both upper and lower stages.
[0112]
Also, the pressing operation on the adhesive 1a between the upper substrate 11 and the lower substrate 12 after the alignment is performed by using the pressure difference between the upper and lower substrates 11 and 12 due to the pressure increase in the vacuum chamber 2 without using the press mechanism 6. You can also do it.
[0113]
In addition, although an example has been described in which the alignment is performed in a state where the upper substrate 11 is in contact with the adhesive 1a applied to the lower substrate 12, the upper substrate 11 or the lower substrate 12 has a liquid crystal member other than the adhesive 1a. Since other inclusions such as 1b are applied, the upper and lower substrates 11 and 12 are aligned by contacting only the liquid crystal member 1b or by contacting both the adhesive 1a and the liquid crystal member 1b. It is possible to do it.
[0114]
Even in such a case, when the upper and lower substrates 11 and 12 are aligned, the elastic member 4 between the lower substrate 12 and the lower stage 32 is exposed to the viscosity of the liquid crystal member 1b or both of the liquid crystal member 1b and the adhesive 1a. The above-described embodiment can be applied because the resistance in the moving direction is caused.
[0115]
After the upper and lower substrates 11 and 12 are pressed by the upper stage 31 for a preset time, the suction holding of the upper and lower substrates 11 and 12 by the upper and lower stages 31 and 32 is released. However, the present invention is not limited to this. After the inside of the vacuum chamber 2 is returned to the atmospheric pressure, or in the process of returning to the atmospheric pressure, the upper and lower substrates 31 and 32 are moved by the upper and lower stages 31 and 32. The suction holding may be released.
[0116]
The release of the suction holding of the upper and lower substrates 11 and 12 by the upper and lower stages 31 and 32 may be performed simultaneously or at different timings.
[0117]
When the elastic modulus of the elastic member 4 is not isotropic, the elastic members 4 are preferably arranged so that the longitudinal elastic modulus is smaller than the transverse elastic modulus. In this way, the elastic member 4 is configured to be flexible in bonding the upper and lower substrates 11 and 12 and to be robust in the alignment direction of the upper and lower substrates 11 and 12 during the alignment operation. Therefore, the deformation at the time of the positioning operation can be minimized while properly absorbing the unevenness between the upper and lower stages 31, 32.
[0118]
Further, the stage 32 in the vacuum chamber 2 can also have a function of transferring the upper and lower substrates 11 and 12. That is, although not shown, a large number of lift pins which are driven by a drive source such as an air cylinder and move up and down are arranged toward the surface of the lower stage 32 so as to avoid the elastic member 4, and the lift pins move up and down. Thus, the transfer of the lower substrate 12 to the lower stage 32 can be performed efficiently.
[0119]
According to the substrate bonding apparatus and the substrate bonding method of the present invention described above, the elastic member for uniform and high-quality bonding is deformed by the positioning operation, and the restoring force is reduced by the bonding accuracy. Can be prevented from deteriorating, and excellent effects can be obtained by adopting it in a manufacturing process of a liquid crystal substrate or the like.
[0120]
【The invention's effect】
As described above, according to the present invention, high-precision bonding can be efficiently performed even on a large-sized glass substrate. Excellent effects can be obtained.
[Brief description of the drawings]
FIG. 1 is a front view of a main part showing a first embodiment of a substrate bonding apparatus according to the present invention.
FIG. 2 is an enlarged perspective view of an elastic member of the device shown in FIG.
FIG. 3 is a plan view of the device shown in FIG. 2 taken along line AA in an arrow direction.
FIG. 4 is an enlarged front view of a main part of the first embodiment shown in FIG. 1;
FIG. 5 is an enlarged front view of a main part showing a state where the substrate is aligned from the state shown in FIG. 4;
6 is an enlarged front view of a main part showing a state where the upper substrate 11 has pressed the adhesive 1a from the state shown in FIG. 5;
7 is an essential part enlarged front view showing a state where the amount of deformation of the elastic member 4 shown in FIG. 6 is set to zero.
FIG. 8 is a flowchart showing a method for bonding substrates in the first embodiment shown in FIG. 1;
FIG. 9 is a flowchart illustrating a method of bonding substrates according to the second embodiment of the present invention.
FIG. 10 is a flowchart illustrating a method of bonding substrates according to a third embodiment of the present invention.
FIG. 11 is a main part front view showing a conventional substrate bonding apparatus.
FIG. 12 is an enlarged front view of a main part of the device shown in FIG. 11;
13 is an essential part enlarged front view showing a state where the substrate is aligned from the state shown in FIG. 12;
14 is an essential part enlarged front view showing a state where the upper substrate 11 has pressed the adhesive 1a in the state shown in FIG. 13;
15 is an essential part enlarged front view showing a state where a restoring force is applied to the elastic member 4 in the state shown in FIG.
[Explanation of symbols]
11 Upper substrate
12 Lower substrate
1a Adhesive (inclusion)
1b Liquid crystal member (inclusion)
2 vacuum chamber
21,22 Upper and lower lids (vacuum tank)
31 Upper Stage
32 Lower Stage
33 Imaging equipment
4 elastic members
5 XY-θ moving mechanism
6 Press mechanism
7 Controller
8 strain gauge

Claims (9)

An upper substrate held on the upper stage, and a lower substrate held on the lower stage disposed opposite to the upper substrate, in a substrate bonding apparatus for bonding via an adhesive,
An elastic member interposed between at least one of the upper stage and the upper substrate or between the lower stage and the lower substrate,
Detecting means for detecting a horizontal deformation amount of the elastic member;
A substrate bonding apparatus comprising: a drive control unit that relatively moves an upper stage and a lower stage based on the amount of deformation detected by the detection unit. An upper substrate held on the upper stage, and a lower substrate held on the lower stage disposed opposite to the upper substrate, in a substrate bonding apparatus for bonding via an adhesive,
An elastic member interposed between at least one of the upper stage and the upper substrate or between the lower stage and the lower substrate,
Detection means for detecting the amount of horizontal displacement between the upper stage and the upper substrate, or between the lower substrate and the lower stage, sandwiching the elastic member;
A substrate bonding apparatus comprising: a drive control unit that relatively moves an upper stage and a lower stage based on the displacement amount detected by the detection unit. 3. The substrate bonding apparatus according to claim 2, wherein the detection unit is configured by a strain gauge that measures an amount of deformation of the elastic member. 4. The drive control unit according to claim 2, wherein the drive control unit is configured to limit a relative movement amount between the upper stage and the lower stage based on the displacement amount. Substrate bonding device. An elastic member is interposed between at least one of the upper stage and the upper substrate held by the upper stage, or at least one of the lower stage and the lower substrate held by the lower stage, and the upper substrate and the lower substrate In the method of bonding a substrate to be bonded through an adhesive, performing a positioning operation in a state of being contacted via an intermediary such as an adhesive,
A first step of superimposing the upper substrate and the lower substrate with the intervening object interposed therebetween;
After the first step, a second step of controlling a relative position between the upper stage and the lower stage and performing a positioning operation between the upper substrate and the lower substrate;
A third step of detecting a horizontal deformation amount of the elastic member after the second step;
A fourth step of relatively moving the upper stage and the lower stage in a direction in which the amount of deformation of the elastic member is reduced after the third step. . An elastic member is interposed between at least one of the upper stage and the upper substrate held by the upper stage, or at least one of the lower stage and the lower substrate held by the lower stage, and the upper substrate and the lower substrate In the method of bonding a substrate to be bonded through an adhesive, performing a positioning operation in a state of being contacted via an intermediary such as an adhesive,
A first step of superimposing the upper substrate and the lower substrate with the intervening object interposed therebetween;
After the first step, a second step of controlling a relative position between the upper stage and the lower stage and performing a positioning operation between the upper substrate and the lower substrate;
After the second step, a horizontal displacement between the upper substrate and the lower substrate, which is held via the elastic member and the stage holding the substrate, is caused by a deformation of the elastic member. A third step of determining the quantity;
A fourth step of relatively moving the upper stage and the lower stage in a direction in which the amount of displacement in the horizontal direction is reduced after the third step. Method. 7. The method according to claim 6, wherein the third step calculates a displacement amount based on a deformation amount of the elastic member measured by a strain gauge. 8. The method according to claim 6, wherein the fourth step relatively moves the upper stage and the lower stage with a restriction. 9. An elastic member is interposed between at least one of the upper stage and the upper substrate held by the upper stage, or at least one of the lower stage and the lower substrate held by the lower stage, and the upper substrate and the lower substrate In the method of bonding a substrate to be bonded through an adhesive, performing a positioning operation in a state of being contacted via an intermediary such as an adhesive,
A first step of superimposing the upper substrate and the lower substrate with the intervening object interposed therebetween;
After the first step, a second step of controlling a relative position between the upper stage and the lower stage and performing a positioning operation between the upper substrate and the lower substrate;
After the second step, a third step of releasing at least one of holding the upper substrate by the upper stage or holding the lower substrate by the lower stage;
And a fourth step of bonding the upper substrate and the lower substrate after the third step.

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