JP2015127795A - Substrate bonding apparatus, apparatus for manufacturing display panel, and method for manufacturing display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly pressurize an adhesive layer to bring the adhesive layer into tight contact with a substrate, and to decrease generation of voids.SOLUTION: A substrate bonding apparatus 20 bonds a liquid crystal panel S1 and a protective panel S2 via an adhesive layer R1 formed on a surface of the liquid crystal panel S1, and the apparatus includes: a lower plate 22 as a supporting part to support the liquid crystal panel S1; an upper plate 23 as a holding part to hold the protective panel S2 at a position opposing to the liquid crystal panel S1; a lift mechanism 25 for bonding the liquid crystal panel S1 and the protective panel S2 via the adhesive layer R1 by driving the upper plate 23; and an elastic sheet 24 which is disposed on a surface of the lower plate 22, has a similar shape to an approximately equal size to the adhesive layer R1, and presses only an area of the liquid crystal panel S1 where the adhesive layer R1 is formed.

Description

  The present invention relates to a display panel manufacturing apparatus including a substrate bonding apparatus and a substrate bonding apparatus, and a display panel manufacturing method.

  A display panel used for a liquid crystal display, an organic EL display, or the like has a configuration in which two substrates, for example, a display panel such as a liquid crystal panel or an organic EL panel, and a protective panel (cover panel) are stacked. These two substrates are bonded together through an adhesive layer, for example. Such a display panel manufacturing apparatus includes an adhesive layer forming portion and a bonding portion. The adhesive layer is formed of an adhesive such as an adhesive or a sticky film, for example. For example, when an adhesive is used as the adhesive, the adhesive is applied to the surface of at least one of the substrates in the adhesive layer forming portion, and an adhesive layer having a predetermined thickness is formed. And in a bonding part, two board | substrates are laminated | stacked on both sides of an adhesive layer, and are bonded together.

JP 2012-73300 A

  The bonding part presses with the two substrates sandwiched therebetween. If this pressed part is not parallel or flat, non-uniform force is applied to the substrates during bonding, and voids may occur without the adhesive layer and the substrate being in close contact with each other. There is sex. In order to prevent the generation of voids, it is conceivable to increase the accuracy of each part of the substrate bonding apparatus that constitutes the bonding part, and to apply a uniform pressure to the substrate for lamination. However, such a highly accurate device is expensive.

  Further, the surface of the substrate may not necessarily be a uniform plane, or undulation may exist on the surface. In such a case, even if the substrate is pressed with a uniform force, a portion where the pressing force is not transmitted or a portion where the pressing force is excessively applied may occur. Furthermore, an error may occur in the parallelism and flatness of the upper and lower plates that sandwich and press the substrate. In such a case, there is a possibility that voids are generated because the substrate and the adhesive layer are not in close contact with each other. In particular, when an adhesive is used as the adhesive, the adhesive layer formed on the substrate surface is easily deformed. When a non-uniform force is applied to such an adhesive layer, there is a higher possibility that voids will occur between the adhesive layer and the substrate.

  The present invention has been proposed in order to solve the above-described problems. At low cost, the adhesive layer is uniformly pressed at the time of bonding the substrates, and the substrate and the adhesive layer are brought into close contact with each other. It aims at providing the display panel manufacturing apparatus and display panel manufacturing method provided with the board | substrate bonding apparatus which can reduce generation | occurrence | production, and a board | substrate bonding apparatus.

  In order to achieve the above-described object, a substrate bonding apparatus according to the present invention bonds a pair of substrates through an adhesive layer formed on the surface of at least one of the substrates. By driving at least one of the support portion, the holding portion, the holding portion that holds the second substrate at a position facing the first substrate, and at least one of the support portion and the holding portion, a pair is provided via the adhesive layer. A driving unit for bonding the substrates, and the adhesive layer of the first or second substrate, which is provided on the surface of the support unit or the holding unit, has a shape similar to that of the adhesive layer and substantially the same size And an elastic sheet that presses only the portion on which is formed.

  In the present invention, the surface of the elastic sheet that is in contact with the first or second substrate has a similar shape and substantially the same size as the surface of the adhesive layer that adheres to the first or second substrate.

  As one aspect of the present invention, the elastic sheet is made of a foamed resin having independent holes.

  The display panel manufacturing apparatus of the present invention manufactures a display panel in which a pair of substrates including a display panel are bonded via an adhesive layer, and an adhesive layer is provided on the surface of at least one of the pair of substrates. An adhesive layer forming portion to be formed, a bonding portion for bonding the pair of substrates through the adhesive layer, and the pair of substrates are conveyed between the application portion, the bonding portion, and the curing portion. A transfer unit, and the bonding unit includes a support unit that supports the first substrate, a holding unit that supports the second substrate at a position facing the first substrate, and the support unit. And at least one of the holding portions, the driving portion for bonding the pair of substrates through the adhesive layer, and the support portion or the holding portion, provided on the surface of the holding portion, and having a similar shape to the adhesive layer Have substantially the same size, And a resilient sheet for pressing only the portion where the adhesive layer is formed of first or second substrate.

  As an aspect of the present invention, the adhesive layer forming unit includes an adhesive application device that applies an adhesive to the surface of the at least one substrate to form the adhesive layer, and the adhesive application device includes the adhesive An adhesive application region is adjusted to form an adhesive layer having a surface that is similar in shape to the surface of the elastic sheet in contact with the first or second substrate and has the same size as the surface of the elastic sheet. .

  A method for manufacturing a display panel according to the present invention is a method for manufacturing a display panel by bonding a pair of substrates including a display panel via an adhesive layer, on the surface of at least one of the pair of substrates. A step of forming an adhesive layer, a step of supporting the first substrate by a support portion, a step of holding the second substrate by a holding portion at a position facing the first substrate, the support portion and the And a step of bonding a pair of substrates through the adhesive layer by driving at least one of the holding portions by a driving unit, and in the step of bonding the pair of substrates, the support portion or the holding portion Only a portion of the first or second substrate on which the adhesive layer is formed is pressed by an elastic sheet having a shape similar to that of the adhesive layer provided on the surface and having substantially the same size.

  According to the present invention, by laminating the substrate via the elastic sheet, even if there is an uneven portion or undulation on the surface of the substrate, or there is an error in the parallelism or flatness of the plate that presses the substrate, A pressing force can be uniformly transmitted to the adhesive layer between the substrates. In addition, by making the elastic sheet substantially the same size as the adhesive layer, the elastic sheet presses only the portion of the substrate where the adhesive layer is formed. Therefore, since the adhesive layer is pressed uniformly through the substrate and no extra force is applied to other portions, the adhesive layer can be sufficiently extended and closely adhered to the substrate to reduce the generation of voids. . Accordingly, a high-quality liquid crystal display panel can be manufactured at low cost, and a substrate bonding apparatus, a display panel manufacturing apparatus, and a display panel manufacturing method with improved manufacturing efficiency can be provided.

It is a schematic block diagram of the display panel manufacturing apparatus which concerns on embodiment of this invention. It is a figure which shows the structure and effect | action of an application part of a display panel manufacturing apparatus. It is a figure which shows the structure and effect | action of the bonding part of a display panel manufacturing apparatus. It is a schematic diagram explaining the effect | action of the elastic sheet at the time of bonding. It is a schematic diagram explaining the state of bonding which does not provide an elastic sheet. It is a schematic diagram explaining the state of bonding which provided the elastic sheet. It is a schematic diagram which shows the state of bonding when an elastic sheet is larger than an adhesive layer as a comparative example. It is a schematic diagram which shows the state of bonding when an elastic sheet is smaller than an adhesive layer as a comparative example. It is a figure which shows the structure and effect | action of the hardening part of a display panel manufacturing apparatus. It is a figure which shows the structure and effect | action of an application part in a pressure distribution measurement test. (A) is a pressure distribution diagram of Example 1, and (B) is a pressure distribution diagram of Example 4. FIG. (A) is a pressure distribution diagram of Comparative Example 2, and (B) is a pressure distribution diagram of Comparative Example 3. (A) is a pressure distribution diagram of the first pressure measurement test of Example 1 in Test 2, and (B) is a pressure distribution diagram of the 600th pressure measurement test of Example 1. FIG. (A) is a pressure distribution diagram of the first pressure measurement test of Example 2 in Test 2, and (B) is a pressure distribution diagram of the 600th pressure measurement test of Example 2. FIG. (A) is a pressure distribution diagram of the first pressure measurement test of Example 4 in Test 2, and (B) is a pressure distribution diagram of the 600th pressure measurement test of Example 4. FIG.

  Embodiments of the present invention (hereinafter referred to as embodiments) will be specifically described with reference to the drawings. In the embodiment, a liquid crystal display panel is used as an example of a display panel manufactured in a display panel manufacturing apparatus. In addition, as an example of a pair of substrates to be bonded in the substrate bonding apparatus, a liquid crystal panel that is a display panel and a protective panel that covers the liquid crystal panel are used. That is, a liquid crystal display panel is formed by laminating and bonding a liquid crystal panel and a protective panel via an adhesive layer.

  The adhesive layer can be formed by applying an adhesive to one or both surfaces of the liquid crystal panel and the protective panel. As the adhesive, for example, an adhesive using a resin or a pressure-sensitive adhesive film can be used. In the display panel manufacturing apparatus of this embodiment, the case where an adhesive layer is formed using an adhesive will be mainly described.

[Constitution]
(Display panel manufacturing equipment)
As shown in FIG. 1, the display panel manufacturing apparatus 100 includes a coating unit 1, a bonding unit 2, a curing unit 3, and a transport unit 4. The display panel manufacturing apparatus 100 also includes a control device 7. The control device 7 controls the operation of the devices constituting each unit and the substrate transport timing.

  The transport unit 4 includes a transport unit that transports the liquid crystal panel S1 and the protection panel S2 to each unit and a driving mechanism thereof. For example, a turntable, a conveyor, or the like can be used as the transfer means, but any apparatus may be used as long as it can transfer the substrate between the above-described units.

  The liquid crystal panel S <b> 1 and the protection panel S <b> 2 are carried into the display panel manufacturing apparatus 100 by the loader 5 and are carried by the carrying unit 4. A coating unit 1, a bonding unit 2 and a curing unit 3 are arranged along the transport unit 4, and are carried into and out of each part of the liquid crystal panel S1 and the protection panel S2 by pick-up means (not shown). The liquid crystal display panel L is manufactured through the steps described below in detail, and is unloaded from the display panel manufacturing apparatus 100 by the unloader 6.

(Applying part)
As shown in FIG. 2, the application unit 1 includes an adhesive application device 10 that applies an adhesive R to the surface of the substrate. In the present embodiment, the application unit 1 functions as an adhesive layer forming unit that forms an adhesive layer with the adhesive R on the surface of the substrate. The adhesive R may be applied to either one of the liquid crystal panel S1 and the protective panel S2 constituting the liquid crystal display panel, or to both. In the present embodiment, an example in which the adhesive R is applied to the surface of the liquid crystal panel S1 will be described.

  The adhesive coating device 10 is transported by the transport unit 4, and a stage 11 on which the liquid crystal panel S 1 carried into the coating unit 1 by a pickup unit (not shown) is placed, and a coating unit 12 disposed on the stage 11. A UV irradiation unit 13 is provided.

  The application unit 12 applies the adhesive R to the liquid crystal panel S1. The application unit 12 includes a tank T for storing the adhesive R and a dispenser 14 connected to the tank T through a pipe. As the dispenser 14, for example, a slit coater having a nozzle on a slit at the tip. Can be used. The dispenser 14 is configured to be movable on the stage 11 by a scanning device (not shown), and discharges the adhesive R accommodated in the tank T to the liquid crystal panel S1. Further, the application region of the adhesive R can be adjusted by the scanning device. Further, the coating unit 12 includes an advancing / retreating drive unit (not shown), and drives the coating unit 12 so as to be able to advance and retract with respect to the stage 11. Of course, the coating unit 12 and the stage 11 may be moved relatively, and the stage 11 may be driven.

  As shown in FIG. 2A, the coating unit 12 enters the stage 11 and discharges the adhesive R from the nozzle of the dispenser 14 to the liquid crystal panel S1. By scanning the dispenser 14 with a scanning device, the adhesive R is supplied over the entire surface of the liquid crystal panel S1. In addition, when a slit coater is used as the dispenser 14, as shown in FIG. When the application is completed, the application unit 12 is retracted from the stage 11.

  The UV irradiation unit 13 includes one or a plurality of lamps and LEDs that can emit ultraviolet rays (UV), and is disposed on the stage 11. As shown in FIG. 2C, the UV irradiation unit 13 performs UV irradiation on the adhesive R applied to the surface of the liquid crystal panel S1.

  In the present embodiment, the adhesive R uses an ultraviolet (UV) curable resin. Therefore, the adhesive R is cured by UV irradiation. However, the UV irradiation in this application part 1 is performed in the atmosphere with weak irradiation intensity or oxygen inhibition. Therefore, the adhesive R is in a so-called temporarily cured state that widely includes a state in which an uncured portion remains. That is, the UV irradiation unit 13 functions as a temporary curing unit of the display panel manufacturing apparatus. As a result, as shown in FIG. 2D, an adhesive layer R1 having a predetermined thickness, in which the adhesive R is temporarily cured, is formed on the surface of the liquid crystal panel S1. As described above, when a slit coater is used as the dispenser 14, the outer edge portion on the upper surface side of the adhesive layer R1 rises, and a dent is formed immediately inside.

  By being in the pre-cured state, the flow of the adhesive layer R1 is suppressed, and the application shape is prevented from being broken and the adhesive layer R1 is not protruded outside the panel during the time and the time of conveyance until the bonding described later. The In addition, since the uncured portion remains, the adhesiveness and cushioning properties of the adhesive layer R1 are maintained.

  However, even in the temporarily cured state, some fluidity remains in the adhesive layer R1. As described above, the adhesive R is applied so as to spread over the entire surface of the liquid crystal panel S1, but is applied so as to leave a slight edge portion of the liquid crystal panel S1. As a result, in bonding, which will be described later, the adhesive layer R1 spreads over a slightly remaining portion of the panel and prevents excessive protrusion to the outside of the panel.

  In the example of FIG. 2, the adhesive R is applied so as to leave a slight portion of the edge of the liquid crystal panel S1 in consideration of the extension of the adhesive layer R1 during bonding, but this is only an example. is there. Depending on the viscosity of the adhesive R and the hardness of the adhesive layer R1 after temporary curing, the adhesive may be applied so as to reach the edge of the liquid crystal panel S1.

  The liquid crystal panel S1 on which the adhesive layer R1 is formed is unloaded from the coating unit 1 by pick-up means (not shown), is transported by the transport unit 4, and is transported to the bonding unit 2. Here, the protective panel S <b> 2 is also carried into the bonding unit 2. The conveyance timing of the liquid crystal panel S1 and the protection panel S2 may be adjusted so that the liquid crystal panel S1 and the protective panel S2 can be joined at the bonding unit 2, and is not limited to one.

  For example, the protective panel S2 is carried into the display panel manufacturing apparatus 100 simultaneously with the liquid crystal panel S1, but the coating unit 1 passes through and is carried into the bonding unit 2 first. And while liquid crystal panel S1 is apply | coating the adhesive agent R in the application part 1, you may stand by in the bonding part 2. FIG. Alternatively, the protective panel S2 is carried into the display panel manufacturing apparatus 100 at a timing later than the liquid crystal panel S1, and is carried into the bonding unit 2 at the same timing as the liquid crystal panel S1 that has been applied by the coating unit 1. May be.

  In addition, when an adhesive film is used as the adhesive, the display panel manufacturing apparatus 100 may be provided with a film sticking part instead of the application part 1. In a film sticking part, an adhesive film is stuck on the surface of liquid crystal panel S1, for example. The pressure-sensitive adhesive film has a pressure-sensitive adhesive surface formed on both sides, and one of the pressure-sensitive adhesive surfaces is attached with a release paper. An adhesive layer can be formed by overlapping and sticking the adhesive surface to which the release paper is not attached to the surface of the liquid crystal panel S1, and peeling the release paper. An existing apparatus can be used for sticking the adhesive film and peeling the release paper. Moreover, instead of providing a film sticking part, before carrying in to the display panel manufacturing apparatus 100, you may stick the adhesive film to liquid crystal panel S1 previously.

(Lamination part)
As shown in FIG. 3A, the bonding unit 2 includes a substrate bonding apparatus 20 that laminates and bonds the liquid crystal panel S1 and the protective panel S2. The substrate bonding apparatus 20 has a configuration in which a lower plate 22 and an upper plate 23 are disposed to face each other in a chamber 21. The chamber 21 can move up and down. When the chamber 21 moves upward, the lower plate 22 and the upper plate 23 are opened to the outside, and the liquid crystal panel S1 and the protection panel S2 can be carried in. When moved downward, the lower plate 22 and the upper plate 23 are accommodated in the chamber 21, and a sealed space is formed inside the chamber 21. The chamber 21 can be adjusted in internal pressure by an exhaust means (not shown). That is, when the liquid crystal panel S1 and the protection panel S2 are carried in, the chamber 21 is lowered, the inside is sealed, the pressure is reduced, and the bonding is performed in a reduced pressure atmosphere.

  The lower plate 22 supports a substrate placed on the plate as a support portion. The upper plate 23 holds the substrate by a holding mechanism as a holding portion. In the present embodiment, as an example, a case will be described in which the liquid crystal panel S1 coated with the adhesive R is supported on the lower plate 22 and the protective panel S2 is held on the upper plate 23.

  As the holding mechanism for the upper plate 23, any holding mechanism that can be used at present or in the future, such as an electrostatic chuck, a mechanical chuck, a vacuum chuck, and an adhesive chuck, can be used. A plurality of chucks can be used in combination. The upper plate 23 is provided with an elevating mechanism 25 as a drive unit. By this elevating mechanism 25, the upper plate 23 is moved so as to be able to contact and separate from the lower plate 22, and the protective panel S2 held by the upper plate 23 is supported by the lower plate 22 as shown in FIG. The liquid crystal panel S1 is pressed and laminated. The liquid crystal panel S1 and the protective panel S2 are bonded together via an adhesive layer R1 formed on the surface of the liquid crystal panel S1, thereby forming a laminated panel S10.

  The lower plate 22 may be provided with a holding mechanism similar to the upper plate 23 so that the position of the placed liquid crystal panel S1 does not shift. An elastic sheet 24 is attached to the surface of the lower plate 22 on which the liquid crystal panel S1 is placed. The elastic sheet 24 is a sheet having a predetermined thickness, and protrudes from the surface of the lower plate 22 by the thickness. Therefore, the lower plate 22 supports the liquid crystal panel S1 through the elastic sheet 24.

  The elastic sheet 24 can be made of, for example, a soft resin. As the soft resin, for example, a foamed resin can be used. The foamed resin has a high elasticity because a large number of pores are formed inside and gas is contained in the pores. Furthermore, it is desirable that the pores formed inside the foamed resin are independent holes. The independent holes are independent holes that are closed one by one. On the other hand, a continuous hole in which one hole is connected to another hole is called a continuous hole. When the holes are continuous holes, the contained gas is easy to escape and the elasticity is difficult to maintain. If the pores are independent holes, the contained gas is difficult to escape and stable elasticity can be maintained for a long period of time. For example, foamed silicon can be used as the foamed resin in which the independent holes are formed. In addition, for example, resin rubber such as nitrile rubber, fluorine rubber, and urethane rubber, or resin gel such as silicon gel can be used as the soft resin.

  In addition, it is not always necessary that all the pores of the foamed resin are independent holes. If approximately 80% or more are independent holes, continuous holes may exist. Moreover, the hole may not exist in the front and back of the elastic sheet 24, and you may exist only inside. Moreover, the continuous hole may be formed in the front and back, and the inside may be formed with the independent hole. In this case, approximately 80 or more of the internal holes may be independent holes.

  The elastic sheet 24 is determined so as to have a shape similar to and substantially the same size as the adhesive layer R1 formed on the surface of the liquid crystal panel S1. Specifically, the upper surface of the elastic sheet 24, that is, the surface in contact with the liquid crystal panel S1, has a similar shape and substantially the same size as the surface of the adhesive layer R1 that is attached to the liquid crystal panel S1. The lower surface of the elastic sheet 24 that contacts the lower plate 22 is also preferably similar in shape to the upper surface, that is, approximately the same size as the adhesive layer R1. The thickness of the elastic sheet 24 may be the same as that of the adhesive layer R1, but may be different. When the liquid crystal panel S1 is placed on the lower plate 22, the adhesive layer R1 formed on the surface of the liquid crystal panel S1 is substantially the same as the elastic sheet 24 disposed on the lower plate 22 and the top surface. The liquid crystal panel S1 is aligned so as to overlap.

  How the elastic sheet 24 acts during bonding will be described with reference to FIG. As shown in FIG. 4A, when the upper plate 23 descends and presses the lower plate 22 via both panels, a reaction force that presses the upper plate 23 from the lower plate 22 is generated. Here, since the elastic sheet 24 is interposed between the lower plate 22 and the liquid crystal panel S1, the reaction force is transmitted from the liquid crystal panel S1 to the adhesive layer R1 via the elastic sheet 24. The adhesive layer R1 extends under pressure. As shown in FIG. 4B, the rise of the outer edge portion of the adhesive layer R1 is also crushed and reaches the outer edge of the panel. Similarly, the elastic sheet 24 receives a pressing force and extends due to elasticity.

  Here, a situation that may occur when the substrate bonding apparatus 20 does not include the elastic sheet 24 and the liquid crystal panel S1 is directly placed on the lower plate 22 will be described. As shown in FIG. 5A, when the liquid crystal panel S1 has waviness and its surface is not uniform, a slight gap is formed between the lower plate 22 and the liquid crystal panel S1. Occurs. Due to this gap, the pressing force of the lower plate 22 may not be uniformly transmitted to the adhesive layer R1. In particular, as described above, when a slit coat is used for applying the adhesive R, the outer edge portion of the adhesive layer R1 may be raised, and a recessed portion may be further formed on the inner side thereof. If this swell cannot be extended sufficiently, a recessed portion inside the swell may remain as shown in FIG. In particular, when pre-curing is performed after application of the adhesive and before bonding, the adhesive becomes difficult to extend, and the effect becomes significant.

  As described above, since the inside of the chamber 21 is depressurized, air does not often enter between the substrates, but if the adhesive layer R1 cannot be fully extended and a recessed portion remains, a bubble-like gap is left. (Vacuum bubbles) may be formed. Many of these vacuum bubbles are removed from the bonding section 2 and returned to atmospheric pressure, but are crushed and disappeared by atmospheric pressure. However, depending on the state of the adhesive, particularly the surface shape, it cannot be completely crushed. Some remain.

  On the other hand, when the bonding is performed in the atmosphere, air naturally exists in the remaining concave portion where the adhesive layer R1 cannot be fully extended, and bubbles are generated due to the repulsive force of the air. More possibilities. In the present embodiment, the above-described bubble-shaped gaps, that is, vacuum bubbles and bubbles are combined and expressed as voids.

  On the other hand, when the elastic sheet 24 is present, as shown in FIG. 6A, the elastic sheet 24 bends and follows the undulation, so that the pressing force of the lower plate 22 is uniform over the entire surface of the adhesive layer R1. Is transmitted to. As shown in FIG. 6 (B), the outer edge portion of the adhesive layer R1 is sufficiently extended, and is uniformed and made uniform including the inner recessed portion. This reduces the generation of voids.

  Furthermore, as described above, the elastic sheet 24 has a similar shape and substantially the same size as the adhesive layer R1, and the liquid crystal panel S1 is aligned so that the adhesive layer R1 substantially overlaps the elastic sheet 24 when viewed from above. . As a result, only the portion of the liquid crystal panel S1 where the adhesive layer R1 is formed is pressed, and no extra force is applied to the other portions. Alternatively, it can be avoided that a part of the portion where the adhesive layer R1 is formed is not sufficiently pressed. As a result, it is possible to prevent a situation where the adhesive layer R1 does not sufficiently extend or is obstructed.

  Here, as a comparative example, a situation that may occur when the elastic sheet 24 is larger than the adhesive layer R1 and smaller than the adhesive layer R1 will be described with reference to FIGS.

  As shown in FIG. 7, when the elastic sheet 24 is larger than the adhesive layer R <b> 1, the elastic sheet 24 excessively pushes up the edge portion of the liquid crystal panel S <b> 1 where the adhesive layer R <b> 1 is not formed. become. As a result, the edge portion of the liquid crystal panel S1 is bent, and a force that presses the adhesive layer R1 inward is applied. As a result, extension of the adhesive layer R1 toward the outer edge of the panel is hindered, and the rise of the outer edge is not sufficiently crushed, leaving a recessed portion, which may cause a void.

  As shown in FIG. 8, when the elastic sheet 24 is smaller than the adhesive layer R1, a portion that is not pressed by the elastic sheet 24 occurs in the adhesive layer R1. In particular, if the outer edge portion of the adhesive layer R1 is not pressed, the bulge of the outer edge portion is not crushed, and the recessed portion inside thereof may remain and voids may be generated.

  As described above, in both cases where the elastic sheet 24 is larger and smaller than the adhesive layer R1, the adhesive layer R1 does not sufficiently extend, and the possibility that voids are generated increases. On the other hand, in the present embodiment, since the elastic sheet 24 has a similar shape and approximately the same size as the adhesive layer R1, the adhesive layer R1 is uniformly pressed through the elastic sheet 24 and the adhesive layer R1 is formed. No extra force is applied to the non-panel part. As a result, the adhesive layer R1 extends to the outer edge of the panel, and the bulge and dent of the outer edge can be properly crushed, thereby reducing the generation of voids.

  In addition, although it is naturally derived from the object of the present embodiment, the “similar shape and substantially the same size” may mean that the shape and size of the adhesive layer R1 and the elastic sheet 24 may be the same, This means that they do not have to be completely identical. Even if there are some differences in the shape and size of the adhesive layer R1 and the elastic sheet 24, as shown in FIGS. 7 and 8, an extra force is applied to the portion of the liquid crystal panel S1 where the adhesive layer R1 is not formed. If the phenomenon is such that a void is not generated, or a phenomenon in which a void is not generated due to a portion that is not pressed against the adhesive layer R1, it is included in the “similar shape and substantially the same size”.

  Note that, depending on the shape and size of the substrate, the shape and size of the adhesive layer R1 formed on the surface also changes. Therefore, the elastic sheet 24 is preferably exchangeable depending on the type of substrate. For example, a base may be prepared and attached to the base with a double-sided tape or the like, and the base may be detachable from the plate. Or you may affix directly on the lower plate 22 at every exchange.

  The elastic sheet 24 is preferably one that can measure the hardness with at least an Asker C hardness meter. More preferably, the hardness of the elastic sheet may be 15 or more and 85 or less. This is because if the elastic sheet 24 is too soft, the elastic sheet 24 extends too much, and as shown in FIG. 7, the elastic sheet 24 becomes larger than the adhesive layer R1, and the extension of the adhesive layer R1 may be hindered. . Further, depending on the material of the elastic sheet 24, the stretched elastic sheet 24 may protrude and stick to the substrate side, and part of the adhesive layer R1 may be peeled off after releasing the pressure, resulting in the generation of voids. Further, the elastic sheet 24 is extremely crushed by the press and loses elasticity. On the contrary, if the hardness of the elastic sheet 24 is too high, there is a possibility that the liquid crystal panel S1 does not follow the undulation. Further, the hardness of the elastic sheet 24 may be set to 35 in order to make the elastic sheet 24 less susceptible to changes with time.

  In addition, when an adhesive film is used as the adhesive, it is unlikely that the adhesive layer R1 is raised as in the case where the adhesive R is used. However, if the liquid crystal panel S1 is undulated and uneven, a void may be generated between the adhesive film and the liquid crystal panel S1. Therefore, the generation of voids can be reduced by using the elastic sheet 24 as in the case of the adhesive R.

  The laminated panel S10 formed by bonding the liquid crystal panel S1 and the protective panel S2 is unloaded from the bonding unit 2 by pick-up means (not shown), is conveyed through the conveyance unit 4, and is loaded into the curing unit 3.

(Curing part)
As shown in FIG. 9, the curing unit 3 includes a curing device 30 that fully cures the adhesive layer R <b> 1 temporarily cured in the application unit 1. The curing device 30 includes a stage 31 on which the laminated panel S10 is placed, and a UV irradiation unit 33 disposed on the stage 31. The UV irradiation unit 33 is composed of one or a plurality of UV lamps, LEDs, and the like that can emit ultraviolet rays (UV). The irradiation intensity of the UV irradiation unit 33 is adjusted so that the ultraviolet rays necessary for completely curing the adhesive layer R1 temporarily cured in the application unit 1 can be irradiated. Of course, the same applies to the case where the adhesive layer without temporary curing is completely cured.

  In addition, when using an adhesive film as an adhesive material, the hardening part 3 is unnecessary. In addition, the display panel manufacturing apparatus may perform another process before or after the application unit 1, the bonding unit 2 and the curing unit 3. For this purpose, the display panel manufacturing apparatus is, for example, a positioning unit that images and aligns the appearance of the substrate before the coating unit 1 or the bonding unit 2, and a taping unit that packs the completed liquid crystal display panel. Etc. may be provided.

[Action]
The operation of the present embodiment having the above configuration will be described.

  First, as shown in FIG. 1, the liquid crystal panel S <b> 1 and the protection panel S <b> 2 are carried into the display panel manufacturing apparatus 100 by the loader 5 and are conveyed through the conveyance unit 4. The liquid crystal panel S1 is carried into the applicator 1 by pick-up means (not shown) and placed on the stage 11 of the adhesive applicator 10 as shown in FIG.

  When the liquid crystal panel S <b> 1 is placed on the stage 11, the coating unit 12 enters the stage 11. The adhesive R accommodated in the tank T is applied to the surface of the liquid crystal panel S1 through the dispenser 14 (FIG. 2A). By scanning with the scanning device, as shown in FIG. 2B, the adhesive R is applied so as to spread over the entire surface, leaving a slight marginal portion of the liquid crystal panel S1. When the application of the adhesive R is finished, the application unit 12 is retracted from the stage 11.

  Next, UV irradiation is performed on the adhesive R by the UV irradiation unit 13, and the adhesive R is in a temporarily cured state (FIGS. 2C and 2D). As a result, an adhesive layer R1 having a predetermined thickness is formed on the surface of the liquid crystal panel S1.

  The liquid crystal panel S1 on which the adhesive layer R1 is formed is unloaded from the coating unit 1 and is conveyed through the conveyance unit 4 again. Then, it carries in to the bonding part 2 by the pick-up means not shown, and is mounted in the lower plate 22 of the board | substrate bonding apparatus 20 as shown to FIG. 3 (A). At this time, it is placed so that the surface on which the adhesive layer R1 is formed faces upward. The protective panel S2 is also carried into the laminating section 2, transferred to the upper plate 23, and held by the holding mechanism. At this time, since the chamber 21 moves upward, the lower plate 22 and the upper plate 23 are opened. When the conveyance of both panels is completed, the chamber 21 is driven to be positioned below, and the lower plate 22 and the upper plate 23 are accommodated in the chamber 21. A sealed space is formed inside the chamber 21, and the inside of the sealed space is depressurized by an exhaust means (not shown).

  Then, as shown in FIG. 3B, the upper plate 23 descends toward the lower plate 22, and the protective panel S <b> 2 held by the upper plate 23 is supported by the lower plate 22. Press against S1. The adhesive layer R1 formed on the surface of the liquid crystal panel S1 is pressed against the lower plate 22 via the liquid crystal panel S1, and adheres to both panels, thereby bonding the two panels together. Even when there is a slight error in the parallelism and flatness of the upper and lower plates during the pasting, and even when the surface of the liquid crystal panel S1 is wavy, it is attached to the lower plate 22. Since the elastic sheet 24 conforms to the undulation, the adhesive layer R1 is pressed uniformly. In addition, since the elastic sheet 24 has a similar shape and substantially the same size as the adhesive layer R1, only the portion of the liquid crystal panel S1 where the adhesive layer R1 is formed is pressed, and an extra force is applied to other portions. Absent. As a result, the adhesive layer R1 is in close contact with the liquid crystal panel S1 and the protective panel S2, and the generation of voids is reduced.

  When the bonding of the liquid crystal panel S1 and the protective panel S2 is completed, the reduced pressure state is released, the chamber is moved upward, and the sealed space is opened. The laminated panel S10 is unloaded from the bonding unit 2 and is conveyed again by the conveyance unit 4. Subsequently, it is carried into the curing unit 3 by pick-up means (not shown). In the course of conveyance from the bonding unit 2 to the curing unit 3, the laminated panel S10 may be left in the air for a certain time. In this standing time, the laminated panel S10 is pressed and stabilized by the atmospheric pressure. Even if voids remain in the adhesive layer R1, the voids can be reduced by leaving them for a sufficient time.

  In the curing unit 3, as shown in FIG. 9, the laminated panel S <b> 10 is placed on the stage 31, and the UV irradiation unit 33 generates ultraviolet rays having a strength necessary for completely curing the temporarily cured adhesive layer R <b> 1. Irradiation completes the main curing of the adhesive layer R1.

  A test was performed on each example and comparative example of the display panel manufacturing apparatus and the substrate bonding apparatus of the present embodiment, and the characteristics were evaluated.

  In each example and comparative example, the overall configuration of the display panel manufacturing apparatus and the substrate bonding apparatus is the same, but the elastic sheet 24 was prepared with different shapes, sizes, materials, and hardnesses. .

[Test 1]
About each Example and the comparative example, the bonding test was done on condition of the following.
・ Pressing force during bonding: 3.0 kg / cm ²
-Substrate: glass, rectangular of 152.4 x 91.4 (mm), thickness 0.7mm
・ Atmospheric pressure at the time of bonding: 30Pa
・ Adhesive material: UV (UV) cured resin with a viscosity of 2900 mPa · s. Adhesive layer: about 150 × 90 (mm) (formed to have approximately the same shape (similar shape) and approximately the same size as the substrate)
・ Adhesive thickness: 200μm
-Elastic sheet: 3mm thick
-Temporary curing UV intensity: 631 mJ / cm ^{2 of} integrated light quantity
The UV curable resin for forming the adhesive layer was applied in a range approximately 1 mm inside from the outer edge of the substrate. By applying in this way, the adhesive layer has substantially the same shape and size as the substrate at the time of bonding.

After bonding, it was visually confirmed whether voids were generated between the substrate and the adhesive layer R1. For those with voids, the occurrence of voids was also confirmed. Table 1 below shows the conditions of the elastic sheets of each Example and Comparative Example and the presence or absence of voids.

  The hardness is measured with an Asker C hardness meter based on the Japan Rubber Association standard (SRIS0101). In addition, since the silicon gel of Example 3 was too soft, the hardness with an Asker C hardness meter was impossible to measure. As the silicon gel of Example 3, one having a penetration of 50 to 55 measured based on Japanese standard (JIS K2207) was used. As the elastic sheets 24 of Examples 1 to 4 and Comparative Example 4, those having the same size as the adhesive layer at the time of application of the ultraviolet curable resin, that is, 150 × 90 (mm) were used. As described above, the adhesive layer has almost the same shape and size as the substrate at the time of bonding, but the difference between each side with the elastic sheet 24 is about 1 to 2 mm, and the elastic sheet 24 and the adhesive layer have substantially the same shape. It can be said that they are almost the same size. The elastic sheet 24 of Comparative Example 2 was shorter than the adhesive layer R1 by 10 mm on each side. As the elastic sheet 24 of Comparative Example 3, a sheet 10 mm longer than each side of the adhesive layer R1 was used. In Comparative Example 1, bonding was performed without installing the elastic sheet 24.

  About Example 1, Example 4, Comparative Example 2, and Comparative Example 3, the measurement test of the pressure distribution at the time of bonding was also performed. The pressure distribution was measured under substantially the same conditions as the bonding test, but the adhesive layer R1 was not formed, and the tactile was placed between the upper plate 23 and the elastic sheet 24 of the substrate bonding apparatus 20 as shown in FIG. A sensor was placed. The pressure distribution applied to the substrate was measured by sandwiching the tactile sensor between the substrate held on the upper plate 23 and the substrate placed on the elastic sheet 24. FIG. 11A shows a pressure distribution diagram of the first embodiment, and FIG. 11B shows a pressure distribution diagram of the fourth embodiment. FIG. 12A shows a pressure distribution diagram of Comparative Example 2, and FIG. 12B shows a pressure distribution diagram of Comparative Example 3.

In each figure, the pressure distribution is divided into 16 numerical ranges of 0 to 100, where the reference pressure is 100, and each range is shown by the following color chart.
0 (dark blue) to 36 (light blue) to 50 (green) to 70 (yellow) to 94 (red) to 100 (pink)
However, since the drawing is a color chart converted into a gray scale display, there are some portions that are difficult to distinguish. For parts that are difficult to discern, supplement the explanation. In addition, FIGS. 12-14 similarly convert the color chart into a gray scale display.

The results of the test are examined below.
<With or without elastic sheet>
In Comparative Example 1 in which the elastic sheet 24 is not used, voids are generated in the vicinity of the central portion and the outer edge of the substrate, that is, the entire surface. Since the pressing force of the lower plate 22 was not uniformly transmitted to the adhesive layer R1, it is considered that voids were generated entirely. On the other hand, in Examples 1 to 4 using an elastic sheet, voids are not generated or are only partially generated. It can be seen that the generation of voids is greatly reduced by using the elastic sheet to uniformly transmit the pressing force of the lower plate 22 to the adhesive layer R1.

<About the shape and size of the elastic sheet>
In each of Example 1, Comparative Example 2, and Comparative Example 3, the elastic sheet 24 is configured using foamed silicon having a hardness of 35, but the shape and size of the elastic sheet 24 are changed. In Example 1, the elastic sheet 24 having the same shape and size as the adhesive layer R1 was used. In Comparative Example 2, an elastic sheet 24 smaller than the adhesive layer R1 was used. In Comparative Example 3, an elastic sheet 24 larger than the adhesive layer R1 was used. In Example 1, no void is generated. In Comparative Example 2 and Comparative Example 3, no void is generated in the central portion of the substrate, but a void is generated in the vicinity of the outer edge.

  As described above, when the elastic sheet 24 is smaller than the adhesive layer R1, a portion that is not pressed by the elastic sheet 24 occurs in the vicinity of the outer edge of the adhesive layer R1. In the pressure distribution diagram of Comparative Example 2 in FIG. 12 (A), the light-colored portions on the left and right sides in the diagram indicate weak pressures. In addition, the difference between the lower part and the upper part in the figure indicates that the pressing force is not uniform and is pressed with a slight inclination. As can be seen from this pressure distribution, the pressure is weak near the outer edge of the substrate. As a result, the bulge of the outer edge portion of the adhesive layer R1 is not crushed, leaving a dent, and it is considered that voids have occurred around the substrate.

  When the elastic sheet 24 is larger than the adhesive layer R1, the outer edge portion of the substrate is excessively pushed up by the elastic sheet 24 as described above. Therefore, it is considered that the extension of the adhesive layer R1 is inhibited and a void is generated in the vicinity of the outer edge. As can be seen from the pressure distribution diagram of Comparative Example 3 in FIG. 12B, there are portions with different colors on the upper and lower right sides in the diagram, and the pressure distribution of these portions of the substrate is unbalanced. I understand. The lower outer edge in the figure has a slightly strong pressure, but the white portion on the upper side and near the center has a low pressure. In the right and upper part of the figure, the part that appears slightly white is also weak in pressure. In the bonding test, the generation of voids was confirmed in the low pressure portion over almost the entire outer edge seen in the pressure distribution.

  On the other hand, in Example 1 using the elastic sheet 24 having the same shape and size as the adhesive layer R1, no voids are generated. As can be seen from the pressure distribution diagram of FIG. 11A, in Example 1, the pressure distribution is substantially uniform at 94% or more of the reference pressure. Therefore, it can be seen that the elastic sheet 24 is uniformly pressed at the portion of the substrate where the adhesive layer R1 is formed, and voids are effectively reduced.

<About the material of the elastic sheet>
In Example 1 and Example 2 in which foamed silicon was used as the material of the elastic sheet 24, no void was generated. Since foamed silicon has independent holes, it is considered that the foamed silicon has high elasticity due to the air contained therein and was able to press the adhesive layer R1 uniformly.

  On the other hand, although the urethane foam used in Comparative Example 4 has pores, voids are generated entirely. This is presumably because the urethane foam has continuous holes, the air contained therein is easy to escape, and the force pressing the adhesive layer R1 is weak.

  Examples 3 and 4 use silicon gel and nitrile rubber without voids. In both Example 3 and Example 4, voids are generated in part, but generation of the entire void can be prevented. Both silicon gel and nitrile rubber are considered to be able to reduce voids to some extent because they do not have pores but are elastic materials. However, another factor can be considered for the generation of voids in the silicon gel. Since silicon gel is a very soft material, the silicon gel stretched during bonding and protruded from the lower plate to the substrate side, and stuck to the substrate even after the pressure was released. Since part of the adhesive layer R1 was also peeled off when the adhered silicon gel was peeled off, a portion that was not adhered by the adhesive layer R1 was formed on one side of the substrate. As a result, it is thought that voids were generated.

  About Example 4 using nitrile rubber, although pressure distribution is shown in Drawing 11 (B), a low pressure part can be checked in a central part, a top, and a right edge in the figure. Although the center of the figure appears dark, this indicates a pressure of about 10% of the pressure reference value below the color chart, and it can be confirmed that the pressure is quite low. The thinly visible portions of the upper and right edges indicate a pressure of 50-70% of the pressure reference value. The portion surrounding the low pressure portion in the center shows a pressure that is almost 100% of the pressure reference value. That is, in Example 4, although there is an effect of reducing voids, it can be seen that the pressure difference is large.

<About the hardness of the elastic sheet>
As described above, in Example 3, the phenomenon that the adhesive layer R1 was partially peeled was confirmed, but one reason was that the silicon gel was so soft that it could not be measured with an Asker C hardness meter. it is conceivable that. From this result, it is desirable that the elastic sheet 24 has at least a hardness that can be measured with an Asker C hardness tester. Furthermore, since the elastic sheets 24 having the hardness of 15, 35, and 85 in Examples 1, 2, and 4 can confirm the effect of reducing voids, the hardness is desirably 15 or more and 85 or less.

[Test 2]
It is considered that the hardness of the elastic sheet 24 affects the change with time of the elastic sheet 24. Therefore, an endurance test was performed on Example 1 using foamed silicon having a hardness of 35, Example 2 using foamed silicon having a hardness of 15, and Example 4 using nitrile rubber having a hardness of 85.

As an endurance test, a bonding test was performed 600 times under the following conditions, and whether or not voids were generated in each example was confirmed in the first bonding and the 600th bonding.
・ Pressing force during bonding: 3.0 kg / cm ²
-Substrate: glass, rectangular of 152.4 x 91.4 (mm), thickness 0.7mm
・ Atmospheric pressure at the time of bonding: 30Pa
・ Adhesive: Adhesive film with a thickness of 150 μm ・ Adhesive layer: 152.4 × 91.4 (mm) (Adhesive film is cut to have the same shape and size as the substrate)
-Elastic sheet: 3mm thick
The durability test is almost the same condition as the bonding test of Test 1, but an adhesive film is used instead of the ultraviolet curable resin as an adhesive. Therefore, temporary hardening was not performed.

  Furthermore, 600 pressure distribution measurement tests were also performed on Example 1, Example 2, and Example 4 under the same conditions as in Test 1.

The results of each test are shown in Table 2 below.

  13A is a pressure distribution diagram in the first pressure distribution measurement test of Example 1, and FIG. 13B is a 600th pressure distribution diagram of Example 1. FIG. FIG. 14A is a pressure distribution diagram in the first pressure distribution measurement test of Example 2, and FIG. 14B is a 600th pressure distribution diagram of Example 2. 15A is a pressure distribution diagram in the first pressure distribution measurement test of Example 4, and FIG. 15B is a 600th pressure distribution diagram of Example 4. FIG.

  In Example 1 using foamed silicon having a hardness of 35, no voids were generated even after 600 times of bonding. Further, as can be seen from FIGS. 13A and 13B, the pressure distribution was almost uniform both at the first time and at the 600th time. Rather, the 600th time is more uniform. Therefore, it can be seen that foamed silicon having a hardness of 35 has little change with time.

  Even in Example 2 using foamed silicon having a hardness of 15, no voids were generated even after 600 times of bonding. However, as can be seen by comparing FIG. 14A and FIG. 14B, the pressure distribution was uniform at the first time, but at the 600th time, a white portion was generated at the top in the figure, The part where pressure is weak has occurred. That is, changes with time were observed in the foamed silicon having a hardness of 15.

  In Example 4 using nitrile rubber having a hardness of 85, no void was confirmed unlike the result of Test 1, but this is a uniform surface instead of an adhesive that forms a bulge at the edge as an adhesive. This is thought to be due to the use of an adhesive film. However, as shown in FIG. 15A, the pressure distribution has a white portion at the center and a weak pressure portion at the center of the substrate. In addition, at the 600th time, as shown in FIG. 15B, it can be seen that the white portion at the center is increased and the weak portion at the center is enlarged. Therefore, even if the adhesive film was used, generation | occurrence | production of the void was confirmed in the board | substrate center. That is, a change with time was observed in a nitrile rubber having a hardness of 85.

  From the above results, it is desirable that the hardness of the elastic sheet is greater than the hardness 15 and smaller than 85 in order to make the elastic sheet 24 less susceptible to the change with time. If the hardness is 15 or less, it is considered that the elastic sheet 24 is likely to sink due to changes over time, the adhesive layer cannot be sufficiently pressed, and the generation of voids may increase. Further, when the hardness is 85 or more, it is considered that the elastic sheet becomes harder due to a change with time, and the adhesive layer cannot be sufficiently pressed, and the generation of voids may increase. If the hardness of the elastic sheet 24 is 35, a more desirable result can be obtained. Of course, this is the desirability from the viewpoint of the influence of change over time. Even if the hardness is 15 or 85, voids can be appropriately reduced by periodically replacing the elastic sheet 24.

[effect]
(1) The board | substrate bonding apparatus 20 of this embodiment bonds liquid crystal panel S1 and protective panel S2 through the contact bonding layer R1 formed in the surface of liquid crystal panel S1, and supports liquid crystal panel S1. A lower plate 22 as a support portion, an upper plate 23 as a holding portion that holds the protective panel S2 at a position facing the liquid crystal panel S1, and a liquid crystal panel S1 through the adhesive layer R1 by driving the upper plate 23 And a lifting mechanism 25 for bonding the protective panel S2, and a portion provided on the surface of the lower plate 22, having substantially the same shape and size as the adhesive layer R1, and only the portion where the adhesive layer R1 of the liquid crystal panel S1 is formed. And an elastic sheet 24 that presses. Specifically, the surface of the elastic sheet 24 that contacts the liquid crystal panel S1 has a similar shape and substantially the same size as the surface of the adhesive layer R1 that adheres to the liquid crystal panel S1.

  By bonding the liquid crystal panel S1 and the protective panel S2 via the elastic sheet 24, there are uneven portions and undulations on the panel surface, and there are some errors in the parallelism and flatness of the upper plate 23 and the lower plate 22. Even if there is, the pressing force can be uniformly transmitted to the adhesive layer R1. Further, by making the elastic sheet 24 similar in shape and substantially the same size as the adhesive layer R1, only the portion of the liquid crystal panel S1 where the adhesive layer R1 is formed can be pressed. Therefore, no extra force is applied to the portion where the adhesive layer R1 is not formed, and the adhesive layer R1 extends sufficiently to adhere to the liquid crystal panel S1 and the protective panel S2, thereby reducing the generation of voids. Thereby, it is possible to manufacture the laminated panel S10 with few defects.

(2) The elastic sheet 24 may be made of a foamed resin having independent holes. High elasticity can be maintained for a long time because the elastic sheet includes an independent hole that encloses a gas and further prevents the gas from escaping. Thereby, generation | occurrence | production of a void can be reduced more.

(3) The display panel manufacturing apparatus 100 of this embodiment includes the above-described substrate bonding apparatus 20 as the bonding unit 2. Further, an adhesive application device 10 that forms an adhesive layer R1 by applying an adhesive R to the surface of the liquid crystal panel S1 is provided as the application unit 1, and the adhesive layer R1 of the laminated panel S10 bonded in the bonding unit 2 is cured. The curing device 30 is provided as the curing unit 3, and includes a transport unit 4 that transports the liquid crystal panel S <b> 1 and the protection panel S <b> 2 between the coating unit 1, the bonding unit 2, and the curing unit 3.

  As described in (1) above, since the generation of voids can be reduced in the substrate bonding apparatus 20, the display panel manufacturing apparatus 100 of the present embodiment can manufacture a liquid crystal display panel L with good quality. And manufacturing efficiency can be improved.

[Other Embodiments]
(1) In the above-described embodiment, the upper plate 23 of the substrate bonding apparatus 20 supports the liquid crystal panel S1 and the lower plate 22 holds the protective panel S2. However, the present invention is not limited to this. The lower plate 22 may support the protective panel S2, and the upper plate 23 may hold the liquid crystal panel S1.

(2) In the above-described embodiment, the adhesive R is applied to the surface of the liquid crystal panel S1, but may instead be applied to the surface of the protective panel S2. Or you may apply | coat to the surface of both liquid crystal panel S1 and protection panel S2.

(3) Although the elastic sheet 24 is attached to the lower plate 22 in the above-described embodiment, the elastic sheet 24 may be attached to the upper plate 23 instead. Alternatively, the elastic sheet 24 may be attached to both the lower plate 22 and the upper plate 23.

(4) In the above-described embodiment, the elevating mechanism is provided on the upper plate 23, but the elevating mechanism may be provided on the lower plate 22 instead. Alternatively, an elevating mechanism may be provided on both the lower plate 22 and the upper plate 23.

(5) In the above-described embodiment, the liquid crystal panel S1 and the protection panel S2 have been described as examples of the substrates to be bonded. However, the present invention is not limited to this, and various substrates can be used. For example, an organic EL panel or a touch panel for operation can be used. Further, a pair of substrates to be bonded is not limited to a pair. In addition to the liquid crystal panel and the protective panel, a touch panel may be bonded, or the protective panel may be bonded up and down, or three or more substrates or two or more substrates may be bonded.

(6) In the above-described embodiment, the application unit 1 and the bonding unit 2 of the display panel manufacturing apparatus are configured as the separate adhesive application device 10 and the substrate bonding device 20, but are configured as the same device. Also good. For example, the coating unit 12 and the UV irradiation unit 13 are movably provided in a chamber 21 in which the upper plate 23 and the lower plate 22 are arranged to face each other, and the lower plate 22 is used as the stage 11 of the coating unit 1. That is, after the adhesive R is applied to the liquid crystal panel S1 placed on the lower plate 22 and temporarily cured, the coating unit 12 and the UV irradiation unit 13 are retracted from the lower plate 22 and bonded. good.

(7) In the above-described embodiment, the elastic sheet 24 is replaced according to the shape and size of the substrate so that the elastic sheet 24 has a shape similar to that of the adhesive layer R1 formed on the substrate surface. However, instead, the application region of the adhesive layer R may be adjusted in the application unit 12 so that the adhesive layer R1 has a similar shape to the elastic sheet 24 and has substantially the same size. As a result, the elastic sheet 24 having a fixed shape and size can be used.

(8) In the above-described embodiment, the UV irradiation unit 13 is used as the temporary curing portion of the adhesive application device 10, but is not limited thereto. For example, an electromagnetic wave irradiation unit, a radiation irradiation unit, an infrared irradiation unit, or a heater can be used. Also for the adhesive to be used, a resin curable by electromagnetic waves, a resin curable by radiation, or a thermosetting resin can be used according to the mode of temporary curing.

(9) In the above-described embodiment, the necessity of crushing the swell when the slit coater is used as the dispenser 14 has been described, but the present invention can also be applied when a multi-nozzle is used. That is, when the adhesive is spread after being applied to the substrate in multiple rows by a multi-nozzle, irregularities are formed on the surface of the formed adhesive layer R1 due to traces of multi-nozzle discharge. Therefore, the unevenness can be crushed by uniformly pressing the adhesive layer R1 with the elastic sheet 24. In other words, the void-free bonding can be performed regardless of the application means and the state of waviness or deflection of the substrate, so that the product quality can be stabilized well and the manufacturing cost can be reduced.

(10) In the above-described embodiment, the application unit 1 performs temporary curing after the application of the adhesive R. However, for example, when the adhesive R has a high viscosity and the application shape is unlikely to collapse, the temporary curing is performed. It does not have to be done. Moreover, in the bonding part 2, the inside of the chamber 21 of the substrate bonding apparatus 20 is decompressed and bonded in a vacuum, but may be bonded in the air. In these cases, since it is not necessary to provide means necessary for forming a space for temporary curing or sealing and decompressing, the apparatus can be configured at a lower cost, and a display panel can be manufactured at a lower cost.

DESCRIPTION OF SYMBOLS 1 Application | coating part 2 Bonding part 3 Curing part 4 Conveying part 5 Loader 6 Unloader 7 Control apparatus 10 Adhesive application apparatus 11 Stage 12 Application unit 13 UV irradiation unit 14 Dispenser 20 Substrate bonding apparatus 21 Chamber 22 Lower plate 23 Upper plate 24 Elastic sheet 25 Elevating mechanism 30 Curing device 31 Stage 33 UV irradiation unit 40 Tactile sensor 100 Display panel manufacturing apparatus R Adhesive R1 Adhesive layer S1 Liquid crystal panel S2 Protective panel S10 Multilayer panel L Liquid crystal display panel T Tank

The display panel manufacturing apparatus of the present invention manufactures a display panel in which a pair of substrates including a display panel are bonded via an adhesive layer, and an adhesive layer is provided on the surface of at least one of the pair of substrates. An adhesive layer forming part to be formed, a bonding part for bonding the pair of substrates through the adhesive layer, and a transport part for transferring the pair of substrates between the adhesive layer forming part and the bonding part And the bonding unit includes a support unit that supports the first substrate, a holding unit that holds the second substrate at a position facing the first substrate, the support unit, and the By driving at least one of the holding parts, the driving part for bonding a pair of substrates through the adhesive layer is provided on the surface of the support part or the holding part, and is substantially the same in shape similar to the adhesive layer Having the size, the first or Comprising an elastic sheet to press only the portion where the adhesive layer is formed of a second substrate.

The application unit 12 applies the adhesive R to the liquid crystal panel S1. The application unit 12 includes a tank T that stores the adhesive R, and a dispenser 14 that is connected to the tank T via a pipe . As the dispenser 14, for example, a slit coater provided with a slit- like nozzle at the tip can be used. The dispenser 14 is configured to be movable on the stage 11 by a scanning device (not shown), and discharges the adhesive R accommodated in the tank T to the liquid crystal panel S1. Further, the application region of the adhesive R can be adjusted by the scanning device. Further, the coating unit 12 includes an advancing / retreating drive unit (not shown), and drives the coating unit 12 so as to be able to advance and retract with respect to the stage 11. Of course, the coating unit 12 and the stage 11 may be moved relatively, and the stage 11 may be driven.

In addition, it is not always necessary that all the pores of the foamed resin are independent holes. If approximately 80% or more are independent holes, continuous holes may exist. Moreover, the hole may not exist in the front and back of the elastic sheet 24, and you may exist only inside. Moreover, the continuous hole may be formed in the front and back, and the independent hole may be formed in the inside. In this case, approximately 80 % or more of the internal holes may be independent holes.

Here, a situation that may occur when the substrate bonding apparatus 20 does not include the elastic sheet 24 and the liquid crystal panel S1 is directly placed on the lower plate 22 will be described. As shown in FIG. 5A, when the liquid crystal panel S1 has waviness and its surface is not uniform, a slight gap is formed between the lower plate 22 and the liquid crystal panel S1. Occurs. Due to this gap, the pressing force of the lower plate 22 may not be uniformly transmitted to the adhesive layer R1. In particular, as described above, in the case of using a slit code data to the application of the adhesive R, it raised the outer edge of the adhesive layer R1 occurs, there may be a further part recessed inside occur. If this swell cannot be extended sufficiently, a recessed portion inside the swell may remain as shown in FIG. In particular, when pre-curing is performed after application of the adhesive and before bonding, the adhesive becomes difficult to extend, and the effect becomes significant.

As shown in FIG. 7, when the elastic sheet 24 is larger than the adhesive layer R1, the edge portion of the liquid crystal panel S1 where the adhesive layer R1 is not formed is excessively pushed up by the elastic sheet 24. As a result, the edge portion of the liquid crystal panel S1 is bent, and a force that presses the adhesive layer R1 inward is applied. As a result, extension of the adhesive layer R1 toward the outer edge of the panel is hindered, and the rise of the outer edge is not sufficiently crushed, leaving a recessed portion, which may cause a void.

The laminated panel S10 formed by bonding the liquid crystal panel S1 and the protective panel S2 is unloaded from the bonding unit 2 by pick-up means (not shown), conveyed by the conveyance unit 4 , and carried into the curing unit 3.

First, as shown in FIG. 1, the liquid crystal panel S1 and the protection panel S2 is loaded into the display panel manufacturing apparatus 100 by the loader 5 is conveyed by the conveyor 4. The liquid crystal panel S1 is carried into the applicator 1 by pick-up means (not shown) and placed on the stage 11 of the adhesive applicator 10 as shown in FIG.

The liquid crystal panel S1 on which the adhesive layer R1 is formed is unloaded from the coating unit 1 and is conveyed again by the conveying unit 4. Then, it carries in to the bonding part 2 by the pick-up means not shown, and is mounted in the lower plate 22 of the board | substrate bonding apparatus 20 as shown to FIG. 3 (A). At this time, it is placed so that the surface on which the adhesive layer R1 is formed faces upward. The protective panel S2 is also carried into the laminating section 2, transferred to the upper plate 23, and held by the holding mechanism. At this time, since the chamber 21 moves upward, the lower plate 22 and the upper plate 23 are opened. When the conveyance of both panels is completed, the chamber 21 is driven to be positioned below, and the lower plate 22 and the upper plate 23 are accommodated in the chamber 21. A sealed space is formed inside the chamber 21, and the inside of the sealed space is depressurized by an exhaust means (not shown).

When the bonding of the liquid crystal panel S1 and the protective panel S2 is completed, the reduced pressure state is released, the chamber is moved upward, and the sealed space is opened. Laminated panel S10 is carried out from the lamination unit 2, it is conveyed by the conveyance unit 4 again. Subsequently, it is carried into the curing unit 3 by pick-up means (not shown). In the course of conveyance from the bonding unit 2 to the curing unit 3, the laminated panel S10 may be left in the air for a certain time. In this standing time, the laminated panel S10 is pressed and stabilized by the atmospheric pressure. Even if voids remain in the adhesive layer R1, the voids can be reduced by leaving them for a sufficient time.

When the elastic sheet 24 is larger than the adhesive layer R1, the outer edge portion of the substrate is excessively pushed up by the elastic sheet 24 as described above. Therefore, it is considered that the extension of the adhesive layer R1 is inhibited and a void is generated in the vicinity of the outer edge. As can be seen from the pressure distribution diagram of Comparative Example 3 in FIG. 12B, there are portions with different colors on the upper and lower right sides in the diagram, and the pressure distribution of these portions of the substrate is unbalanced. I understand. The lower outer edge in the figure has a slightly strong pressure, but the white portion near the upper side and the center is weak. In the right and upper part of the figure, the part that appears slightly white is also weak in pressure. In the bonding test, the generation of voids was confirmed in the low pressure portion over almost the entire outer edge seen in the pressure distribution.

FIG. 13A is a pressure distribution diagram in the first pressure distribution measurement test of Example 1, and FIG. 13B is a pressure distribution diagram in the 600th pressure distribution measurement test of Example 1. FIG. FIG. 14A is a pressure distribution diagram in the first pressure distribution measurement test of Example 2, and FIG. 14B is a pressure distribution diagram in the 600th pressure distribution measurement test of Example 2. 15A is a pressure distribution diagram in the first pressure distribution measurement test of Example 4, and FIG. 15B is a pressure distribution diagram in the 600th pressure distribution measurement test of Example 4. FIG.

Claims (6)

A substrate laminating apparatus for laminating a pair of substrates via an adhesive layer formed on the surface of at least one substrate,
A support for supporting the first substrate;
A holding unit for holding the second substrate at a position facing the first substrate;
A drive unit that bonds a pair of substrates through the adhesive layer by driving at least one of the support unit and the holding unit;
Provided on the surface of the support portion or the holding portion, has a shape similar to that of the adhesive layer and has substantially the same size, and presses only the portion of the first or second substrate on which the adhesive layer is formed. A substrate bonding apparatus comprising: an elastic sheet.   The elastic sheet is characterized in that the surface in contact with the first or second substrate has a similar shape and substantially the same size as the surface of the adhesive layer attached to the first or second substrate. The board | substrate bonding apparatus of Claim 1.   The said elastic sheet is comprised from the foaming resin which has an independent hole, The board | substrate bonding apparatus of Claim 1 or 2 characterized by the above-mentioned. A display panel manufacturing apparatus in which a pair of substrates including a display panel are bonded together through an adhesive layer,
An adhesive layer forming portion for forming an adhesive layer on the surface of at least one of the pair of substrates;
A bonding portion for bonding the pair of substrates through the adhesive layer;
A transport unit that transports the pair of substrates between the coating unit, the bonding unit, and the curing unit;
The bonding part is
A support for supporting the first substrate;
A holding unit for supporting the second substrate at a position facing the first substrate;
A drive unit that bonds a pair of substrates through the adhesive layer by driving at least one of the support unit and the holding unit;
Provided on the surface of the support part or the holding part, and has only the same size as the adhesive layer and presses only the part of the first or second substrate on which the adhesive layer is formed. A display panel manufacturing apparatus comprising: an elastic sheet. The adhesive layer forming unit includes an adhesive application device that applies the adhesive to the surface of the at least one substrate to form the adhesive layer,
The adhesive application device adjusts the application area of the adhesive to have a surface that is similar in size to the surface of the at least one substrate that is similar to the surface of the elastic sheet that contacts the first or second substrate. The display panel manufacturing apparatus according to claim 4, wherein an adhesive layer having the following surface is formed. A manufacturing method for manufacturing a display panel by bonding a pair of substrates including a display panel via an adhesive layer,
Forming an adhesive layer on the surface of at least one of the pair of substrates;
Supporting the first substrate by the support portion;
Holding the second substrate by a holding portion at a position facing the first substrate;
Bonding a pair of substrates through the adhesive layer by driving at least one of the support part and the holding part with a drive part,
In the step of bonding the pair of substrates, an elastic sheet having a shape similar to that of the adhesive layer provided on the surface of the support portion or the holding portion and having substantially the same size is used to form the first or second substrate. A method for manufacturing a display panel, comprising pressing only a portion where the adhesive layer is formed.