CN112147803A

CN112147803A - Method for manufacturing bonded substrate and substrate bonding apparatus

Info

Publication number: CN112147803A
Application number: CN202010575918.4A
Authority: CN
Inventors: 新原康弘
Original assignee: Sharp Corp
Current assignee: Sharp Corp
Priority date: 2019-06-26
Filing date: 2020-06-22
Publication date: 2020-12-29

Abstract

In the present invention, the bonded substrate is carried out from the bonding apparatus without being bent. The method for manufacturing a bonded substrate includes: a bonding step of bringing a lower stage (23A) and an upper stage (23B) that face each other into close proximity and bonding a first substrate (14A) and a second substrate (14B) with a sealant (110) therebetween to form a bonded substrate (15); a bonded substrate separation step of maintaining the state in which the bonded substrate (15) is held by the upper stage (23B), and displacing the upper stage (23B) in the direction of separation from each other so as to generate a gap between the bonded substrate (15) and the lower stage (23A); and a bonded substrate carrying-out step of disposing the substrate conveying table (29) at the gap, releasing the holding by the upper stage (23B), placing the bonded substrate (15) on the substrate conveying table (29), pulling out the substrate conveying table (29), and carrying out the bonded substrate (15).

Description

Method for manufacturing bonded substrate and substrate bonding apparatus

Technical Field

The present invention relates to a method for manufacturing a bonded substrate and a substrate bonding apparatus.

Background

As a method of bonding two glass substrates constituting a liquid crystal panel, a method using a vacuum bonding apparatus is known. When the vacuum bonding apparatus is used, two glass substrates facing each other on which the sealant is applied can be precisely aligned and bonded in a vacuum container. Patent document 1 describes a vacuum bonding apparatus having a substrate stopper device for preventing a substrate fixed on an upper stage in a container from dropping. Patent document 2 discloses a substrate transfer apparatus that can carry in and out a tray on which a substrate is placed into a container of a vacuum bonding apparatus in order to prevent damage to the glass substrate when the glass substrate is carried into and out of the container.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2003-255356 patent document 2: japanese patent No. 5139604

Disclosure of Invention

Technical problem to be solved by the invention

At the end of the process using the vacuum bonding apparatus, the two substrates are aligned and temporarily bonded, and then the substrates are not completely fixed before the sealant is completely cured by the process of irradiating ultraviolet rays or the like. Therefore, if the substrates are bent before the sealing agent is completely cured, the relative positions of the two substrates may be shifted. In the configuration described in patent document 1, the arm provided in the loading unit is inserted below the substrate and lifted up, and the substrate is carried out from the container, and the temporarily bonded substrate may be bent at this time. In addition, in the structure described in patent document 2, there is no description about a method of transferring the substrate on the tray to another position.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a substrate bonding method and a substrate bonding apparatus capable of taking out a bonded substrate before final curing from a container without bending the bonded substrate.

Means for solving the problems

(1) One embodiment of the present invention is a method for manufacturing a bonded substrate, including: a sealant applying step of applying a sealant to a plate surface of at least one of the first substrate and the second substrate, the plate surface facing the other plate surface; a substrate setting step of placing the first substrate on a flat first stage and holding the second substrate in surface contact with the first substrate by a flat second stage located above the first stage so as to face the first substrate; a bonding step of bonding the first substrate and the second substrate with the sealant by displacing at least one of the first stage and the second stage which face each other in a direction of approaching each other to form a bonded substrate; a bonded substrate separation step of displacing at least one of the first stage and the second stage in a direction of separating from each other so that a gap is generated between the bonded substrate and the first stage while maintaining a state in which the bonded substrate is held by the second stage; and a bonded substrate carrying-out step of placing the bonded substrate on the substrate transport table while releasing the holding of the bonded substrate by the second stage, and pulling out the substrate transport table to carry out the bonded substrate, while disposing a substrate transport table at a gap between the bonded substrate and the first stage.

(2) In addition, according to an embodiment of the present invention, in addition to the configuration of the above (1), in the bonded substrate carrying-out step, the substrate conveying table has a flat plate shape, and the bonded substrate is placed on the plate surface of the substrate conveying table in a surface contact manner.

(3) In addition, according to one embodiment of the present invention, in addition to the configuration (1) or (2), the method for manufacturing a bonded substrate includes a vacuum suction step of making a space where the first substrate and the second substrate are present vacuum before the bonding step, and a vacuum release step of releasing the vacuum state after the bonding step.

(4) Another embodiment of the present invention is a substrate bonding apparatus including: a flat first stage on which a first substrate of a first substrate and a second substrate of which a plate surface on a side opposite to the other of at least one of the two substrates is coated with a sealant is placed; a flat second stage having a lower surface holding the second substrate in surface contact with the second stage, the second stage being arranged to face the first stage; a movement driving unit that relatively displaces at least one of the first stage and the second stage in a direction of approaching or separating from each other; and a plate-shaped substrate transfer table that inserts or pulls out the bonded substrate between the first stage and the second stage that holds the bonded substrate in a surface-contact manner, the bonded substrate being formed by bonding the first substrate and the second substrate, and that supports the bonded substrate in a surface-contact manner.

(5) In addition, an embodiment of the present invention is a substrate bonding apparatus, wherein, in addition to the configuration of the above (4), the first stage and the second stage are both arranged in a vacuum chamber.

Effects of the invention

According to the present invention, it is possible to reduce the occurrence of positional deviation between substrates constituting a bonded substrate due to bending of the bonded substrate before main curing of the sealant.

Drawings

Fig. 1 is a plan view schematically showing a liquid crystal display device.

Fig. 2 is a sectional view taken along line a-a of fig. 1.

Fig. 3 is a plan view of a bonded substrate including a plurality of liquid crystal panels.

Fig. 4 is a schematic plan view showing a planar structure of the array substrate in an enlarged manner.

Fig. 5 is a schematic plan view showing a planar structure of the CF substrate in an enlarged manner.

Fig. 6 is a plan view (without positional deviation) showing a state where the array substrate and the CF substrate are overlapped.

Fig. 7 is a plan view (with a positional deviation) showing a state where the array substrate and the CF substrate overlap.

Fig. 8 is a schematic view showing the configuration of the substrate bonding apparatus according to the present invention.

Fig. 9 is a schematic view of a substrate bonding apparatus in a bonding step.

Fig. 10 is a schematic view of a substrate bonding apparatus in a bonded substrate separation step.

Fig. 11 is a schematic view (1) of the substrate bonding apparatus in the bonded substrate carrying-out step.

Fig. 12 is a schematic view (2) of the substrate bonding apparatus in the bonded substrate carrying-out step.

Fig. 13 is a schematic view (3) of the substrate bonding apparatus in the bonded substrate carrying-out step.

Fig. 14 is a schematic view (4) of the substrate bonding apparatus in the bonded substrate carrying-out step.

Fig. 15 is a schematic view (5) of the substrate bonding apparatus in the bonded substrate carrying-out step.

Fig. 16 is a flowchart showing a process sequence before and after a conventional bonding process.

Fig. 17 is a flowchart showing the process sequence before and after the bonding process of the present invention.

Fig. 18 is a side view showing a bent state when the bonded substrate is lifted by the lift pins.

Fig. 19 is a perspective view showing a case where a fork-type substrate carrying-out table is used.

Fig. 20 is a side view of the bonded substrate held by suction of the upper stage.

Fig. 21 is a perspective view showing a case where a table-type substrate carrying-out table is used.

Detailed Description

< embodiment >

An embodiment of the present invention is explained with reference to fig. 1 to 21.

In the present embodiment, a manufacturing method of bonding substrates in which two glass substrates, i.e., a coupling array substrate (first substrate) 14A and a coupling CF substrate (second substrate) 11B for manufacturing a liquid crystal panel 11 are bonded in vacuum, and a vacuum bonding apparatus (substrate bonding apparatus) 20 are illustrated. The X-axis, Y-axis, and Z-axis are shown in a part of the drawings, and the axis directions are drawn as a common direction in the drawings. Wherein the Z-axis direction substantially coincides with the vertical direction, and the X-axis direction and the Y-axis direction substantially coincide with the horizontal direction. Unless otherwise stated, the description about the upper and lower is based on the vertical direction.

First, a configuration of the liquid crystal panel 11 included in the liquid crystal display device 10 will be described, where the liquid crystal panel 11 is a liquid crystal panel manufactured using a bonded substrate manufactured by the method or the device according to the present invention. As shown in fig. 1, the liquid crystal panel 11 is vertically long and rectangular in shape (rectangular shape) as a whole, and its panel surface is divided into a display area (active area) AA which can display an image and is disposed on the center side, and a non-display area (non-active area) NAA which is disposed on the outer peripheral side so as to surround the display area AA and is frame-shaped (frame-shaped) in plan view. The liquid crystal panel 11 includes at least a flexible substrate (external connection member) 12 that electrically connects the liquid crystal panel 11 and an external control circuit substrate, and a driver IC (panel driving section, driving circuit) 13 that drives the liquid crystal panel 11. The liquid crystal panel 11 has a short side direction aligned with the X-axis direction of each drawing, a long side direction aligned with the Y-axis direction of each drawing, and a thickness direction aligned with the Z-axis direction. In fig. 1, the one-dot chain line indicates the outline of the display area AA, and the area outside the one-dot chain line is the non-display area NAA.

Fig. 2 is a sectional view taken along line a-a of fig. 1. As shown in fig. 2, the liquid crystal panel 11 is configured such that a liquid crystal layer 11C including liquid crystal molecules, which are substances whose optical characteristics change with a change in an electric field, is sandwiched between an array substrate 11A and a CF substrate 11B, and a sealant 11D which is interposed between a pair of

substrates

11A and 11B so as to surround the liquid crystal layer 11C and seals the liquid crystal layer 11C.

Of the pair of

substrates

11A and 11B constituting the liquid crystal panel 11, the back side (back side) is an array substrate 11A, and the front side (front side) is a CF substrate 11B. The array substrate 11A and the CF substrate 11B are each formed by laminating various films on the inner surface side of a transparent glass substrate. The sealing agent 11D is made of, for example, a photocurable resin material such as an ultraviolet curable resin material, and has a substantially frame shape extending along the outer peripheral end of the CF substrate 11B (see fig. 1 and 2). The above is the configuration of the liquid crystal panel 11 manufactured using the bonded substrate manufactured by the method or the apparatus according to the present invention.

Next, the coupling array substrate 14A, the coupling CF substrate 14B, and the bonding substrate 15 used in manufacturing the liquid crystal panel 11 will be described with reference to fig. 3. Fig. 3 is a plan view of bonded substrate 15. After the coupling array substrate 14A and the coupling CF substrate 14B are manufactured separately, the liquid crystal layer 11C is interposed therebetween and these

substrates

14A, 14B are bonded to manufacture the bonded substrate 15. More specifically, in manufacturing the coupling array substrate 14A and the coupling CF substrate 14B, fine structures that form various films (metal films, insulating films, etc.) on a large mother glass substrate by a known photolithography method or the like are each patterned.

The coupling array substrate 14A having the plurality of array substrates 11A and the coupling CF substrate 14B having the plurality of CF substrates 11B are bonded by interposing the liquid crystal layer 11C therebetween and using the sealant 11D to manufacture the bonded substrate 15. Further, each of the

substrates

14A and 14B is provided with an alignment mark, the alignment mark is read by a camera, and the two substrates are bonded while being aligned.

The manufactured bonded substrate 15 has a horizontally long and thin shape as a whole, and a plurality of (8 in the present embodiment) liquid crystal panels 11 are arranged in the plane thereof, and then divided into a plurality of liquid crystal panels 11 by a dividing device.

Next, the fine structure formed on the plate surfaces of the array substrate 11A and the CF substrate 11B will be briefly described with reference to fig. 4 and 5. Fig. 4 and 5 show the array substrate 11A and the CF substrate 11B, respectively, as viewed from the back side (back side).

As shown in fig. 4, a plurality of TFTs (thin film transistors) 11F as switching elements and pixel electrodes 11G are arranged in a matrix (row and column) on the inner surface side (the liquid crystal layer 11C side, the side opposite to the CF substrate 11B) of the display region AA of the array substrate 11A, and gate wirings (scanning lines) 111 and source wirings (circuit portions, data lines, signal lines) 11J are arranged in a lattice around the TFTs 11F and the pixel electrodes 11G. The pixel electrode 11G is formed of a transparent conductor, for example, ITO (indium tin oxide) in a thin film shape. Therefore, the region of the array substrate 11A where the pixel electrode 11G is disposed transmits light and is also referred to as an opening 11H. Then, the TFT11F is driven based on various signals supplied to the gate wiring 111 and the source wiring 11J, respectively, and supply of a potential to the pixel electrode 11G is controlled. In the present embodiment, in each drawing, the extending direction of the gate wiring 111 coincides with the X-axis direction, and the extending direction of the source wiring 11J coincides with the Y-axis direction.

Fig. 5 is a view showing the CF substrate 11B when viewed from the back side (back side). On the inner surface side of the display area AA of the CF substrate 11B, a plurality of color filters 11K are arranged in a matrix at positions facing the pixel electrodes 11G of the array substrate 11A. The color filter 11K is formed by arranging three color films of the red filter 11KR, the green filter 11KG, and the blue filter 11KB in a predetermined order. A lattice-shaped light-shielding film (black matrix) 11L for preventing color mixing is formed between the filters of each color. As shown in fig. 6, the light shielding film 11L is disposed so as to overlap with the gate wiring 111 and the source wiring 11J in a plan view.

In the step of bonding the coupling array substrate 14A and the coupling CF substrate 14B, it is necessary to bond them in a vacuum atmosphere so as to prevent air bubbles from entering the liquid crystal layer 11C between the two substrates. Therefore, a vacuum bonding apparatus is used which can perform bonding in a vacuum atmosphere while performing alignment with high accuracy.

A vacuum bonding apparatus (substrate bonding apparatus) 20 according to the present embodiment will be described with reference to fig. 8. The vacuum bonding apparatus 20 includes: a vacuum chamber 21 composed of a lower chamber 21A and an upper chamber 21B; a pump 22 for discharging air in the vacuum chamber 21; and a lower stage (first stage) 23A and an upper stage (second stage) 23B that hold the substrate in vacuum chamber 21.

The vacuum chamber 21 has a structure that can be divided into two parts, a lower chamber 21A and an upper chamber 21B. When the two

chambers

21A, 21B are brought into close contact without a gap and then the pump 22 is evacuated, the inside can be kept at a vacuum. In addition, in a state where the two

chambers

21A and 21B are opened, the coupling array substrate 14A and the coupling CF substrate 14B can be carried in and out.

The lower stage 23A and the upper stage 23B have flat surfaces that contact the substrate, and are disposed inside the lower chamber 21A and the upper chamber 21B, respectively. The two

stages

23A and 23B can fix the coupling array substrate 14A and the coupling CF substrate 14B so that they cannot move on the stages, and in addition, can prevent them from falling by adsorbing and holding them. As a method of fixing or holding the coupling array substrate 14A or the coupling CF substrate 14B, for example, a method using a jig, a method using a vacuum chuck, an electrostatic chuck, a bonding pad, or the like is given, and a plurality of these may be combined. However, in either method, the two

stages

23A, 23B fix or hold the coupling array substrate 14A and the coupling CF substrate 14B in surface contact.

In the present embodiment, the coupled CF substrate 14B may be held down on the upper stage 23B using a vacuum chuck. As shown in fig. 8, upper stage 23B includes a plurality of suction pads 24 and vacuum holes 25 for vacuum-sucking suction pads 24. By vacuum suction from the vacuum holes 25, the upper stage 23B adsorbs the CF substrate 14B and holds it in surface contact so as not to fall. Further, since the suction pads 24 of the upper stage 23B are provided with fine holes and grooves as air passages for coupling the CF substrate 14B by vacuum suction, strictly speaking, the upper stage 23B cannot be said to be flat, and the upper stage 23B can be said to hold the coupled CF substrate 14B without surface contact. However, since these holes and grooves are minute, and since they do not bend the coupling CF substrate 14B and the attaching substrate 15, the upper stage 23B holds the coupling CF substrate 14B flat and in surface contact as described above.

The loading table 23B is displaceable in the vertical direction (z direction) by a cylinder (movement driving unit) 26. This makes it possible to displace the upper stage 23B so as to approach or separate from the lower stage 23A. Further, the lower stage 23A is relatively displaceable in the XY direction and the θ direction with the Z direction as an axis with respect to the upper stage 23B, by an XY θ stage (stage moving section) 27 disposed between the lower chamber 21A and the lower stage 23A. Thus, the relative positions of the two stages can be finely adjusted based on the alignment marks of the coupling array substrate 14A and the coupling CF substrate 14B that are fixed or held by the two

stages

23A and 23B, respectively, and after precise alignment is performed, the coupling array substrate 14A and the coupling CF substrate 14B can be bonded.

Next, the table-shaped arm (substrate transfer table) 29 will be described. The table-shaped arm 29 is a plate-shaped object having the same or larger plate surface than the bonded substrate 15, and the plate surface is flat. Further, it is assumed that the table-type arm 29 can be displaced in the horizontal direction (X-axis direction) between the lower stage 23A and the upper stage 23B to be inserted or pulled out without interfering with them. According to this configuration, the table-shaped arm 29 is inserted between the bonded substrate 15 held on the upper stage 23B and the lower stage 23A so that the upper stage 23B and the table-shaped arm 29 overlap each other in a plan view, and when the bonded substrate 15 held on the upper stage 23B is released, the bonded substrate 15 is separated from the upper stage 23B and is placed on the plate surface of the table-shaped arm 29 directly below. Thereafter, when the table-shaped arm 29 is pulled out from between the two

stages

23A and 23B, the bonded substrate 15 can be carried out of the vacuum bonding apparatus 20. Since the plate surface of the desk arm 29 is flat, the bonded substrate 15 placed on the plate surface is not bent at the time of carrying out.

The coupling array substrate 14A and the bonded CF substrate 14B are bonded by the sealant 11D in a vacuum atmosphere by the vacuum bonding apparatus 20 described above to form the bonded substrate 15. However, at this time, the sealant 11D interposed between the two

substrates

14A and 14B is not yet completely cured, and the two

substrates

14A and 14B are not completely fixed until the final curing is performed by ultraviolet irradiation or the like in a subsequent step. Therefore, if the bonded substrate 15 is bent before the sealant 11D is completely cured, the bonded substrates may be displaced after the relative positions are accurately adjusted.

Here, a relative positional relationship between the two substrates forming the bonded substrate 15 will be described. If the relative positional relationship between the coupling array substrate 14A and the coupling CF substrate 14B constituting the bonded substrate 15 in a plan view is appropriate, the gate wiring 111 and the source wiring 11J disposed on the array substrate 11A and the light shielding film 11L disposed on the CF substrate 11B are in a positional relationship overlapping in a plan view as shown in fig. 6. Further, fig. 6 and 7 show a state in which the liquid crystal panel 11 is viewed from the back side (back side), in which the array substrate 11A is directed to the front side and the CF substrate 11B is located on the back side.

However, when the relative positional relationship between the coupling array substrate 14A and the coupling CF substrate 14B is shifted in a plan view due to the occurrence of the above-described warpage, as shown in fig. 7, the light shielding film 11L of the CF substrate 11B overlaps the opening 11H (a portion fixed by the gate wiring 111 and the source wiring 11J) of the array substrate 11A, and thus a problem of a decrease in light transmittance occurs in the liquid crystal panel 11. In addition, depending on the magnitude of the shift, the color filters (11KR, 11KG, 11KB) of each color on the CF substrate 11B extend to openings adjacent to the opening 11H corresponding to 1. If the main curing is performed in this state, the liquid crystal panel 11 has a problem of color mixing in addition to the above-described decrease in light transmittance.

In fact, in recent years, the thickness of the mother glass substrate is being reduced, and the bonded substrate 15 is more easily bent than in the past. Also, as the liquid crystal panel 11 becomes higher and higher in definition and the pixel density is improved, the accuracy required for the alignment of the coupling array substrate 14A and the coupling CF substrate 14B becomes higher and higher. Therefore, the problem of the decrease in transmittance and the problem of mixing due to bending, which have not been problems so far, which occur during the period from the bonding to the main curing, become obvious.

In order to solve such a problem, after the coupling array substrate 14A and the coupling CF substrate 14B are bonded to each other in the vacuum bonding apparatus 20, the formed bonded substrate 15 is taken out of the vacuum chamber 21 without being bent, and then the process proceeds to a main curing step. For this reason, when the bonded substrate 15 is carried out from the vacuum chamber 21, it is effective to hold it from above or support it from below in surface contact with a flat surface.

Therefore, as will be described later, in the method for manufacturing a bonded substrate according to the present embodiment, the bonded substrate 15 is sucked and held downward by the flat upper stage 23B, and is placed on the flat stage at the time of carrying out, and the bonded substrate 15 is held or supported in surface contact.

Here, fig. 16 and 17 are flowcharts showing the sequence of steps before and after the bonding step, among the steps included in the conventional method for manufacturing a bonded substrate and the method for manufacturing a bonded substrate according to the present embodiment, respectively.

In the method for manufacturing a bonded substrate according to the present embodiment, the bonded substrate lifting step (step S40) performed by using the lift pins in the conventional manufacturing method is changed to the bonded substrate separating step (step S41) performed by the suction of the upper stage 23B. In the conventional manufacturing method, the yoke is used in the bonded substrate carrying-out step (step S50), but the manufacturing method according to the present embodiment is changed to carry out the bonded substrate by the table arm 29 (step S51). The method for manufacturing the bonded substrate according to the present embodiment will be described in detail below.

First, a sealant application step (step S10) in the method for manufacturing a bonded substrate according to the present embodiment shown in fig. 17 will be described. In the sealant applying step (step S10), the sealant 11D is applied to the plate surface on the side opposite to the other of at least one of the coupling array substrate 14A and the coupling CF substrate 14B. As described above, the sealant 11D is made of, for example, a photocurable resin such as an ultraviolet-curable resin, and is applied along the outer peripheral portion of the AA of the liquid crystal panel 11 without a gap (see fig. 1). Further, after the sealant 11D is applied, the liquid crystal is dropped in a region solidified by the sealant 11D.

Next, in the substrate setting step (step S20), as shown in fig. 8, the coupling array substrate 14A on which the sealant 11D is applied and liquid crystal is dropped is placed and fixed on the lower stage 23A. In addition, the CF substrate 14B is held coupled on the upper stage 23B. In the method according to the present embodiment, the coupling CF substrate 14B can be held in vacuum suction and surface contact by the plurality of suction pads 24 and vacuum holes 25 arranged on the lower surface of the upper stage 23B.

Next, as shown in fig. 9, in the vacuum suction step (step S25), the vacuum chamber 21 is sealed by bringing the lower stage 21A and the upper stage 21B into close contact with each other, and vacuum suction is performed by the pump 22. Then, in the bonding step (step S30), the upper stage 23B is lowered by the cylinder (movement driving unit) 26, and the coupling CF substrate 14B held by the upper stage 23B and the coupling array substrate 14A mounted on the lower stage 23A are bonded to each other via the sealant 11D. Thereby, the bonded substrate 15 is formed. At this time, based on the positional relationship of the alignment marks patterned on the coupling array substrate 14A and the coupling CF substrate 14B, the xy θ stage (stage moving unit) 27 is operated to displace the lower stage 23A in each direction of xy θ, and the upper stage 23B is lowered by the cylinder 26 while precisely adjusting the relative positions of the two substrates to bond the two substrates.

Next, in the vacuum releasing step (step S35), as shown in fig. 10, the vacuum chamber 21 is opened while the chamber is opened to the atmosphere. Then, in the bonded substrate separation step (step S41), upper stage 23B is raised while holding bonded substrate 15 on the lower side of upper stage 23B. Then, the bonded substrate 15 is lifted up together with the upper stage 23B, thereby generating a gap with the lower stage 23A. At this time, the bonded substrate 15 is held in surface contact by the flat upper stage 23B, and therefore does not bend.

Next, the bonded substrate carrying-out step (step S51) will be described with reference to fig. 11 to 15. First, the table-shaped arm (substrate transfer table) 29 is inserted into the gap between the bonded substrate 15 and the downloader table 23A (fig. 11) generated in the bonded substrate separation step (step S41). Next, the upper stage 23B is lowered to bring the bonded substrate 15 and the table-type arm 29 closer to each other (fig. 12), and the holding of the bonded substrate 15 by the upper stage 23B is released. Then, the bonded substrate 15 is placed on the plate surface of the table arm 29 (fig. 13). Then, at the time of carrying out described later, the upper stage 23B is raised and retracted so that the bonded substrate 15 or the table arm 29 does not interfere with the upper stage 23B (fig. 14), and then the table arm 29 is moved from between the two stages to the outside to carry out the bonded substrate 15 (fig. 15). At this time, as shown in fig. 21, the bonded substrate 15 is placed on the plate surface of the flat table-shaped arm 29 and supported in surface contact, and therefore is not bent.

After the bonded substrate 15 is carried out of the substrate bonding apparatus 20, the bonded substrate 15 is conveyed to a sealant main curing step (step S60), and the sealant 11D is main cured by treatment such as irradiation with ultraviolet rays.

In the conventional manufacturing method shown in fig. 16, the step corresponding to the bonded substrate separation step (step S41) is a bonded substrate lifting step (step S40) in which the bonded substrate 15 is lifted by using the plurality of lift pins 28 as shown in fig. 18. However, when the lift pins 28 support the bonded substrate from below, there is a problem that the load is concentrated on the head portions of the lift pins 28 and the bonded substrate 15 is bent like waves.

In addition, according to the conventional manufacturing method, when the bonded substrate 15 is lifted up by being supported from below by the lift pins, the shape of the substrate conveyance table 29 that can be inserted below the bonded substrate 15 is limited when the bonded substrate 15 is conveyed in the subsequent bonded substrate conveyance step (step S50). That is, in fig. 18 viewed from a certain X direction of the substrate transfer table 29, the shape that does not interfere with all of the bonded substrates 15, the lift pins 28, and the download table 23A, such as the portion indicated by the dashed-dotted line, needs to be, for example, a fork shape. Further, when the bonded substrate 15 is placed on the fork-shaped arm, as shown in fig. 17, the bonded substrate 15 is bent.

On the other hand, according to the substrate bonding method and the substrate bonding apparatus of the present embodiment, the bonded substrate 15 is first held in surface contact by the flat upper stage 23B after bonding, and therefore does not bend. In addition, unlike the supporting method using the lift pins, the bonded substrate 15 is held by the upper stage 23B as shown in fig. 20. Therefore, the arm can be inserted into the plate-like substrate transfer table 29 as shown by the three-dot chain line in fig. 20 without interfering with the insertion of the arm into the lower side of the bonded substrate 15. That is, according to the present embodiment, the table-shaped arm 29 shown in fig. 21 can be inserted between the bonded substrate 15 and the download table 23A.

Then, as shown in fig. 21, the bonded substrate 15 is carried out from between the two

stages

23A and 23B while being supported in surface contact by the flat table-shaped arm 29. Thereafter, the resultant is conveyed to a sealant main curing step (step S60). Therefore, according to such a method and apparatus, the bonded substrate 15 is not bent during the period from the bonding to the main curing, and the occurrence of the positional deviation between the array substrate and the CF substrate due to the bending of the bonded substrate 15 can be reduced.

As described above, the method for manufacturing the bonded substrate 15 according to the present embodiment includes: a sealant applying step of applying a sealant 11D to a plate surface of at least one of the first substrate 14A and the second substrate 14B, the plate surface facing the other plate surface; a substrate setting step of placing the first substrate 14A on a flat first stage 23A, and holding the second substrate 14B in surface contact with the first substrate 14A by a second stage 23B located above the first stage 23A; a bonding step of bonding the first substrate 14A and the second substrate 14B with the sealant 11D to form a bonded substrate 15 by displacing at least one of the first stage 23A and the second stage 23B facing each other in a direction of approaching each other; a bonded substrate separation step of displacing at least one of the first stage 23A and the second stage 23B in a direction of separating from each other so that a gap is generated between the bonded substrate 15 and the first stage 23A while maintaining a state in which the bonded substrate 15 is held by the second stage 23B; and a bonded substrate carrying-out step of placing the bonded substrate 15 on the substrate transport table 29 while releasing the holding of the bonded substrate 15 by the second stage 23B, and pulling out the substrate transport table 29 and carrying out the bonded substrate 15, while arranging the substrate transport table 29 at the gap between the bonded substrate 15 and the first stage 23A.

According to this method, the two substrates, the first substrate 14A and the second substrate 14B, are bonded together with the sealant 11D between the first stage 23A and the second stage 23B through the sealant applying step, the substrate setting step, and the bonding step, thereby forming the bonded substrate 15. Thereafter, in the bonded substrate separation step, the second substrate 14B (the upper substrate of the two substrates constituting the bonded substrate 15) is held on the second stage 23B in surface contact with each other, and the two

stages

23A and 23B are moved in the direction of separating from each other, so that the bonded substrate 15 held by the second stage 23B is separated from the first stage 23A, and a gap is generated between the lower surface of the bonded substrate 15 and the first stage 23A. At this time, the bonded substrate 15 is held in surface contact with the lower surface of the flat second stage 23B, and therefore does not bend. Further, in the bonded substrate carrying-out step, after the substrate transport table 29 is inserted into the gap, when the holding of the bonded substrate 15 by the second stage 23B is released, the bonded substrate 15 is separated from the second stage and is placed on the substrate transport table 29 immediately below. Then, the substrate transfer table 29 is pulled out, and the bonded substrate 15 is transferred to the main curing step of the sealing agent 11D. By doing so, it is possible to reduce the occurrence of positional deviation between the first substrate 14A and the second substrate 14B due to bending of the bonded substrate 15 before the main curing step.

In the method for manufacturing the bonded substrate 15 according to the present embodiment, the substrate transfer table 29 is flat in plate shape in the bonded substrate carrying-out step, and the bonded substrate 15 is placed on the plate surface of the substrate transfer table 29 in surface contact therewith.

By doing so, the bonded substrate 15 held on the second stage 23B is placed on the flat plate surface of the substrate transport table 29 after the holding is released, and therefore, is not bent in the bonded substrate carrying-out step. This can further reduce the occurrence of positional deviation between the first substrate 14A and the second substrate 14B due to bending of the bonded substrate 15 before the main curing step of the sealant 11D.

The method for manufacturing the bonded substrate 15 according to the present embodiment is characterized by including a vacuum suction step of vacuuming a space in which the first substrate 14A and the second substrate 14B are present before the bonding step, and a vacuum release step of releasing the vacuum state after the bonding step.

Depending on the application of the bonded substrate 15, the space between the two

substrates

14A and 14B surrounded by the sealant 11D may be filled with a liquid and air bubbles may not be allowed to mix in, in which case the bonding step needs to be performed in a vacuum. Therefore, by doing so, depending on the application of the bonded substrate 15, the bonding step can be performed not only in the atmosphere but also in a vacuum, and bubbles can be prevented from being mixed into the space between the two substrates filled with the liquid.

Further, the bonded substrate manufacturing apparatus according to the present embodiment includes: a flat first stage 23A on the upper surface of which the first substrate 14A of the first substrate 14A and the second substrate 14B is placed, and a plate surface on the side opposite to the other of at least one of the first substrate 14A and the second substrate 14B is coated with a sealant 11D; a flat second stage 23B whose lower surface holds the second substrate 14B in surface contact and which is arranged to face the first stage 23A; a movement driving unit that relatively displaces at least one of the first stage 23A and the second stage 23B in a direction to approach each other or in a direction to separate from each other; and a plate-shaped substrate transfer table 29 that is inserted into or pulled out from between the first stage 23A and the second stage 23B holding the bonded substrate 15 formed by bonding the first substrate 14A and the second substrate 14B in surface contact with each other, and that supports the bonded substrate 15 in surface contact with each other.

With such a configuration, the first substrate 14A placed on the first stage 23A and the second substrate 14A held by the second stage 23B can be arranged so as to face each other. The sealant 11D is applied to the surface of the other of the two or any of the substrates. Then, when at least one of the first stage 23A and the second stage 23B is moved in a direction to approach each other by the movement driving unit 26 so as to approach the two substrates, the two substrates are bonded by the sealant 11D, and the bonded substrate 15 is formed. Thereafter, while maintaining the second stage 23B holding the second substrate 14B (the upper substrate of the two substrates constituting the bonded substrate 15), the first stage 23A and the second stage 23B are displaced by the movement driving unit 26 so as to be separated. At this time, the second substrate 14B held on the second stage 23B has already been bonded to the first substrate 14A to form a set of bonded substrates 15, and therefore the bonded substrates 15 are displaced in a direction away from the first stage 23A while being held on the second stage 23B. Then, a gap is generated between the lower side of bonded substrate 15 and first stage 23A. At this time, the bonded substrate 15 is held in surface contact with the lower surface of the flat second stage 23B, and the bonded substrate 15 is not bent.

Next, if the substrate transport table 29 is inserted into the gap and the holding of the bonded substrate 15 by the second stage 23B is released, the bonded substrate 15 is placed on the substrate transport table 29. Then, when the substrate transport table 29 is pulled out from the gap between the two stages, the bonded substrate 15 can be carried out. Here, the substrate transfer table 29 has a plate shape, and the bonded substrate 15 placed thereon is supported in contact with the upper surface of the plate surface, so that the bonded substrate 15 is not bent. By doing so, the bonded substrate 15 is not bent until it is carried out from between the two stages after bonding. This can reduce the occurrence of positional deviation due to bending of the bonded substrate 15 before main curing.

< other embodiment >

The present invention is not limited to the embodiments described in the above description and drawings, and for example, the following embodiments are also included in the technical scope of the present invention.

(1) In the above embodiment, the coupling array substrate is disposed on the lower side and the coupling CF substrate is disposed on the upper side for bonding, but the coupling CF substrate may be disposed on the lower side and the coupling array substrate may be disposed on the upper side for bonding.

(2) In the above-described embodiment, the upper stage can be displaced in the Z direction by the cylinder (movement driving unit), and the lower stage can be displaced in the XY θ direction by the XY θ stage (stage moving unit). For example, the upload stage may be displaceable in the θ direction, or the download stage may be displaceable in the XYZ direction.

(3) The vacuum chamber may be divided into two parts, i.e., an upper chamber and a lower chamber, but is not limited to this configuration, and may be configured such that a lid portion capable of sealing the chamber is provided on an integrated chamber having an opening portion capable of carrying in and out the mother glass substrate.

Description of the reference numerals

10 liquid crystal display device

11 liquid crystal panel

11A array substrate (TFT substrate)

11B CF substrate (color filter substrate)

11C liquid crystal layer

11D sealant

11F TFT

11G Pixel electrode (transparent electrode)

11H opening part

11I grid Wiring (Scan line)

11J Source wiring (Signal line)

11K color filter

11KR Red Filter

11KG green filter

11KB blue filter

11L light shielding film (Black matrix, BM)

AA active region

NAA non-active area

12 flexible substrate

13 driver IC

14A coupling array substrate (first substrate)

14B coupling CF substrate (second substrate)

15 laminated substrate

20 vacuum bonding apparatus (substrate bonding apparatus)

21 vacuum chamber

21A lower chamber

21B upper chamber

22 pump

23A lower table (first table)

23B Upper table (second table)

24 suction cup

25 vacuum hole

26 Cylinder (Mobile driving part)

27 Xy theta stage (stage moving part)

28 lifting pin

29 substrate conveying table (desk type arm)

Claims

1. A method for manufacturing a bonded substrate, comprising:

a sealant applying step of applying a sealant to a plate surface of at least one of the first substrate and the second substrate, the plate surface facing the other plate surface;

a substrate setting step of placing the first substrate on a flat first stage and holding the second substrate in surface contact with the first substrate by a flat second stage located above the first stage so as to face the first substrate;

a bonding step of bonding the first substrate and the second substrate with the sealant by displacing at least one of the first stage and the second stage which face each other in a direction of approaching each other to form a bonded substrate;

a bonded substrate separation step of displacing at least one of the first stage and the second stage in a direction of separating from each other so that a gap is generated between the bonded substrate and the first stage while maintaining a state in which the bonded substrate is held by the second stage; and

and a bonded substrate carrying-out step of placing the bonded substrate on the substrate transport table while releasing the holding of the bonded substrate by the second stage, and pulling out the substrate transport table to carry out the bonded substrate, while disposing a substrate transport table in a gap between the bonded substrate and the first stage.

2. The method for manufacturing a bonded substrate according to claim 1,

in the bonded substrate carrying-out step, the substrate transport table has a flat plate shape, and the bonded substrate is placed on the plate surface of the substrate transport table in surface contact with the plate surface.

3. The method for manufacturing a bonded substrate according to claim 1 or 2,

a vacuum suction step of making a space where the first substrate and the second substrate are present vacuum, prior to the bonding step,

the bonding step is followed by a vacuum release step for releasing the vacuum state.

4. A substrate bonding apparatus, comprising:

a flat first stage on which the first substrate out of the first substrate and the second substrate is placed, the surface of at least one of the first substrate and the second substrate on the side opposite to the other substrate is coated with a sealant;

a flat second stage having a lower surface holding the second substrate in surface contact with the second stage, the second stage being arranged to face the first stage;

a movement driving unit that relatively displaces at least one of the first stage and the second stage in a direction of approaching or separating from each other; and

and a plate-shaped substrate transfer table that supports the bonded substrate by inserting or pulling out the bonded substrate in a surface-contact manner between the first stage and the second stage that holds the bonded substrate formed by bonding the first substrate and the second substrate in a surface-contact manner.

5. The substrate bonding apparatus according to claim 4,

the first stage and the second stage are both arranged in a vacuum chamber.