KR102483283B1 - Joined body production method and connection method - Google Patents

Abstract

When manufacturing a bonded body by bonding the first bonding member and the second bonding member through the bonding resin material in a vacuum atmosphere, while preventing the displacement of the bonding position, the first and second bonding members and the bonding resin material Avoid excessive load. Under a vacuum atmosphere, the first bonding member 2 supported by the first bonding plate 11 and the second bonding member 3 supported by the second bonding plate 12 are connected through the bonding resin material 6 to a predetermined level. A step of joining with a joining pressure of , a step of reducing the joining pressure in a state where the first and second joining members 2 and 3 are clamped by the first and second joining plates 11 and 12, and changing the atmosphere to atmospheric pressure and a process of releasing the bonding pressure to the first and second bonding members 2 and 3.

Description

Manufacturing method of conjugate, connection method {JOINED BODY PRODUCTION METHOD AND CONNECTION METHOD}

The present technology provides a manufacturing method for manufacturing a joined body by bonding a first bonding member and a second bonding member through a bonding resin material in a vacuum atmosphere, and a manufacturing method of manufacturing a bonded body by bonding the first bonding member and the second bonding member through a bonding resin material. It is about how to connect. This application claims priority based on Japanese Patent Application No. 2016-125983 for which it applied in Japan on June 24, 2016, and this application is incorporated into this application by reference.

In an image display device such as a liquid crystal display panel used in an information terminal such as a smartphone, after disposing a photocurable resin composition between an image display member such as a liquid crystal display panel or an organic EL panel and a light-transmitting cover member, the composition It is manufactured by curing by irradiating ultraviolet rays to form a light-transmitting cured resin layer, and thereby adhering and laminating an image display member and a light-transmitting cover member.

A vacuum bonding method is used as a method for connecting an image display member and a light-transmitting cover member through a light-transmitting cured resin composition. 9 to 11 show examples of the vacuum bonding method. As shown in FIG. 9 , the light-transmitting cover member 50 is coated with the light-transmitting resin composition 51 on the bonding surface and properly cured, and then the first bonding plate 52 in the vacuum chamber 55 By this, the bonding surface is supported downward. In addition, the image display member 53 is supported with the bonding surface facing upward by the second bonding plate 54 within the vacuum chamber 55 .

Subsequently, the inside of the vacuum chamber 55 is evacuated to become a vacuum atmosphere. Then, as shown in FIG. 10 , the second bonding plate 54 is raised, and the image display member 53 is pressed against the light-transmitting cover member 50 via the light-transmitting resin composition 51 . By bonding the light-transmitting cover member 50 and the image display member 53 through the light-transmitting resin composition 51 in a vacuum atmosphere, air bubbles can be prevented from remaining on the bonding surface or in the light-transmitting cured resin layer.

Then, as shown in Fig. 11, the support of the light-transmitting cover member 50 by the first junction plate 52 is released, and the second junction plate 54 is lowered. In this state, the inside of the vacuum chamber 55 is opened to atmospheric pressure, and the bonded body 56 of the light-transmitting cover member 50 and the image display member 53 is taken out of the vacuum chamber 55 .

Thereafter, in the bonded body 56, the light-transmitting resin composition 51 is cured to complete an image display device of the light-transmitting cover member 50 and the image display member 53 connected via the light-transmitting cured resin layer. .

Japanese Unexamined Patent Publication No. 2014-118450

In recent years, the narrowing of the frame width of the image display device has progressed, and the demand for bonding accuracy between the light-transmitting cover member 50 and the image display member 53 has increased. However, in the vacuum bonding method, when atmospheric pressure is released, rapid pressure fluctuations and turbulence occur in the vacuum chamber 55, and in particular, when the light-transmitting resin composition 51 is liquid or gel, the light-transmitting cover member ( 50) and the image display member 53 are displaced from each other.

Although it is possible to reduce pressure fluctuations and air turbulence by lengthening the atmospheric pressure release time, it is difficult to completely suppress the movement of the light-transmitting cover member 50 bonded through the uncured light-transmitting resin composition 51, and furthermore, Due to the demand for shortening the tact, there is a limit to lengthening the atmospheric pressure opening time.

In addition, in order to eliminate the influence at the time of air introduction, a method of introducing air without lowering the joint plate is also conceivable. However, in this case, the bonding pressure is applied to the light-transmitting cover member 50 and the image display member 53 until the introduction of the atmosphere is completed, and the pressing time is required longer than necessary. For this reason, there is a risk of residual stress intervening in the light-transmitting resin composition 51, causing partial color unevenness, as well as an excessive load on the image display member whose thickness is progressing, resulting in warpage or damage. There is a risk of harm.

Therefore, the present technology prevents the displacement of the bonding position when bonding the first bonding member and the second bonding member through a bonding resin material in a vacuum atmosphere to produce a bonded body, and the first and second bonding members and the bonding It is an object of the present invention to provide a manufacturing method and connection method of a joined body capable of suppressing an excessive load on a resin material.

In order to solve the above problems, a method for manufacturing a joined body according to the present technology is a bonding resin material in which a first bonding member supported by a first bonding plate and a second bonding member supported by a second bonding plate are bonded in a vacuum atmosphere. A step of bonding with a predetermined bonding pressure through a bonding process, and then, in a state where the first and second bonding members are held by the first and second bonding plates, the first and second bonding plates are separated from each other, and the bonding is performed. It has the process of reducing pressure, the process of opening to atmospheric pressure from a vacuum atmosphere then, the process of releasing the bonding pressure with respect to the said 1st, 2nd bonding member then.

Further, in the connection method according to the present technology, a first bonding member supported by a first bonding plate and a second bonding member supported by a second bonding plate are joined by a predetermined bonding pressure through a bonding resin material in a vacuum atmosphere. a step of separating the first and second joining plates in a state where the first and second joining members are clamped by the first and second joining plates to reduce joining pressure; It has the process of opening from under atmosphere to atmospheric pressure, and then the process of releasing the bonding pressure with respect to the said 1st, 2nd bonding member.

According to the present technology, since the bonding pressure is reduced in a state where the first bonding member and the second bonding plate are clamped between the pair of bonding plates, and the atmosphere is released in this state, the atmosphere is released in a short time and rapidly inside the chamber. Even when a pressure fluctuation or air turbulence occurs, displacement of the bonding position between the first bonding member and the second bonding plate can be prevented. In addition, since the bonding pressure is reduced prior to release to the atmosphere, even if the bonding pressure is released after release to the atmosphere, warpage does not occur in the bonded body, and damage to the first and second bonding members can be prevented.

1 is a schematic cross-sectional view showing an example of an image display device.
2 is a cross-sectional view showing a light-transmitting cover member on which a light-blocking layer is formed.
3 is a cross-sectional view showing a state in which a light-transmitting resin composition is applied to the surface of a light-transmitting cover member.
Fig. 4 is a cross-sectional view showing a process of forming a pre-cured resin layer by irradiating ultraviolet rays to the light-transmitting resin composition applied to the surface of the light-transmitting cover member.
5 is a cross-sectional view showing a process of disposing an image display member and a light-transmitting cover member in a chamber.
Fig. 6 is a cross-sectional view showing a step of bonding an image display member and a light-transmitting cover member after setting the inside of the chamber to a vacuum atmosphere.
Fig. 7 is a cross-sectional view showing a process of completely separating the first and second bonding plates to release bonding pressure to the image display member and the light-transmitting cover member.
Fig. 8 is a cross-sectional view showing a step of final curing the pre-cured resin layer by irradiating ultraviolet rays to the bonded body of the image display member and the light-transmitting cover member.
9 is a cross-sectional view showing a process of disposing an image display member and a light-transmitting cover member in a chamber.
Fig. 10 is a cross-sectional view showing a step of bonding an image display member and a light-transmitting cover member after setting the inside of the chamber to a vacuum atmosphere.
Fig. 11 is a cross-sectional view showing a step of separating the first and second bonding plates completely to release the bonding pressure between the image display member and the light-transmitting cover member, and then releasing to the atmosphere.

Hereinafter, a manufacturing method and a connection method of an assembly to which the present technology is applied will be described in detail with reference to the drawings. In addition, this technology is not limited only to the following embodiment, It goes without saying that various changes are possible within the range which does not deviate from the summary of this technology. In addition, the drawing is typical, and the ratio of each dimension may differ from an actual thing. Specific dimensions and the like should be judged in consideration of the following description. In addition, it is needless to say that even between the drawings, portions having different dimensional relationships or ratios are included.

[Configuration of conjugate]

Hereinafter, a joint body to which the present technology is applied is one in which a first joint member and a second joint member are joined through a joint resin material. The image display device 1 will be described below as an example of the bonded body. As shown in FIG. 1, the image display device 1 is composed of a photocurable resin composition in which an image display member 2 as a first bonding member and a light-transmitting cover member 3 as a second bonding member are bonded resin materials. It is laminated through the light-transmitting cured resin layer 4 formed of.

[Image display member]

As the image display member 2, a liquid crystal display panel, an organic EL display panel, a plasma display panel, a touch panel, etc. are mentioned. Here, a touch panel means an image display/input panel in which a display element such as a liquid crystal display panel and a position input device such as a touch pad are combined.

[Light-transmitting cover member]

The light-transmitting cover member 3 only needs to have light-transmitting properties that allow viewing of an image formed on the image display member, and a plate-like material or sheet-like material such as glass, acrylic resin, polyethylene terephthalate, polyethylene naphthalate, or polycarbonate. can be heard These materials can be subjected to single-sided or double-sided hard coating treatment, antireflection treatment, and the like. Physical properties such as thickness and elasticity of the light-transmitting cover member 3 can be appropriately determined depending on the purpose of use.

In addition, a light-blocking layer 5 is provided on the periphery of the surface of the light-transmitting cover member 3 on the image display unit side to improve the brightness and contrast of displayed images. The light shielding layer 5 is obtained by applying a paint colored in black or the like by a screen printing method or the like, and then drying and curing it. As thickness of the light shielding layer 5, it is 5-100 micrometers normally.

[Bonding resin material]

As the photocurable resin composition 6 constituting the cured resin layer 4, a photocurable resin that is transparent and can be cured with ultraviolet light or visible light can be suitably used. The photocurable resin composition 6 preferably has a light transmittance of 400 nm or more after curing of 90% or more so as not to reduce the transmittance of the liquid crystal display device 1 . Moreover, the photocurable resin composition 6 contains the photocurable resin containing a monomer, a polymerization initiator, and the polymer for viscosity adjustment.

The photocurable resin composition 6 may be in any form such as liquid or gel, but is preferably liquid. Due to the fact that the photocurable resin composition 6 is liquid, for example, in the manufacturing method of the image display device 1 described later, on the surface of the light-shielding layer 5 and the light-transmitting cover member 3 on the light-shielding layer formation side. The formed level difference can be canceled more reliably. Here, it is preferable that the photocurable resin composition 6 is in a liquid state and has a viscosity of 0.01 to 100 Pa·s at 25° C. measured with a B-type viscometer.

Alternatively, the cured resin layer 4 may be formed of an optical clear adhesive (OCA) sheet in which the photocurable resin composition 6 is molded into a sheet shape. The optical adhesive sheet is manufactured by, for example, applying the photocurable resin composition 6 to a base material such as polyethylene terephthalate subjected to release treatment, drying to form an adhesive layer, and crosslinking as necessary.

An example of the photocurable resin composition 6 is described. The photocurable resin composition 6 according to the present embodiment comprises a photo-radically polymerizable poly(meth)acrylate (component (a)), a photo-radically polymerizable (meth)acrylate (component (b)), and a liquid phase. A softening agent containing a plasticizer (component (c)) or a tackifier (component (d)), and a photopolymerization initiator (component (e)) are contained. In addition, in this specification, (meth)acrylate is the meaning containing acrylic acid ester (acrylate) and methacrylic acid ester (methacrylate).

[Component (a)]

Preferable specific examples of the photo-radically polymerizable poly(meth)acrylate (component (a)) include (meth)acrylate-based oligomers having polyurethane, polyisoprene, polybutadiene, and the like in their backbones. Preferred specific examples of the (meth)acrylic oligomer having a polyurethane backbone include aliphatic urethane acrylate (EBECRYL 230 (molecular weight: 5000), Daicel Cytec; UA-1, Light Chemical Co.) and the like. . Moreover, as a preferable specific example of the (meth)acrylate oligomer of the polyisoprene skeleton, the esterified product of the maleic anhydride adduct of a polyisoprene polymer and 2-hydroxyethyl methacrylate (UC102 (polystyrene equivalent molecular weight 17000), Co., Ltd.) Kuraray; UC203 (polystyrene equivalent molecular weight 35000, Kuraray Co., Ltd.; UC-1 (molecular weight about 25000), Kuraray Co., Ltd.); and the like.

[Component (b)]

Preferable specific examples of the photo-radically polymerizable (meth)acrylate (component (b)) include 2-hydroxypropyl (meth)acrylate, benzyl acrylate, dicyclopentenyloxyethyl (meth)acrylate, isobornyl (meth)acrylate, octyl (meth)acrylate, etc. are mentioned.

[Component (c)]

The liquid plastic component (component (c)) does not photocur by itself by irradiation with ultraviolet rays, imparts flexibility to the cured resin layer or the temporarily cured resin layer after photocuring, and also between the cured resin layers or the temporarily cured resin layer to reduce the curing shrinkage of As such a liquid plastic component, at least one selected from the group consisting of a liquid polybutadiene plasticizer, a polyisoprene plasticizer, a phthalate ester plasticizer, and an adipic acid ester plasticizer is exemplified.

[Component (d)]

The tackifier (tackifier) (component (d)), similarly to component (c), imparts flexibility to the cured resin layer or pre-cured resin layer after photocuring, and the photocurable resin composition ( The initial adhesive strength (so-called adhesiveness) of the cured resin layer or the pre-cured resin layer formed from 6) is improved. Examples of the tackifier include terpene resins such as terpene resins, terpene phenol resins, and hydrogenated terpene resins; rosin resins such as natural rosin, polymerized rosin, rosin ester, and hydrogenated rosin; petroleum such as polybutadiene and polyisoprene; Resin etc. can be used. As a softening agent, at least either of component (c) or component (d) should just be contained.

[Component (e)]

As the photopolymerization initiator (component (e)), for example, 1-hydroxy-cyclohexylphenyl ketone (Irgacure 184, BASF Japan Co., Ltd.), 2-hydroxy-1-{4-[4-(2) -Hydroxy-2-methyl-propyronyl)benzyl]phenyl}-2-methyl-1-propan-1-one (Irgacure 127, BASF Japan Co., Ltd.), benzophenone, acetophenone, etc. there is.

If the addition amount of the photopolymerization initiator is too small, curing is insufficient during ultraviolet irradiation, and if it is too large, outgas due to cleavage increases and foaming problems tend to occur, based on 100 parts by mass of photo-radically polymerizable poly(meth)acrylate. , Preferably it is 0.1-10 mass parts, More preferably, it is 0.2-5 mass parts.

Further, in the photocurable resin composition 6, in addition to the components (a) to (e) described above, various additives can be blended within a range not impairing the effects of the present invention. For example, chain transfer agents such as 2-mercaptoethanol, lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, thioglycolic acid 2-ethylhexyl, 2,3 - Dimethylcapto-1-propanol, α-methylstyrene dimer, etc. can be blended. In addition, additives such as adhesion improvers such as silane coupling agents, antioxidants, and ultraviolet absorbers can be contained as necessary. Such a photocurable resin composition 6 can be produced by uniformly mixing the components (a) to (e) described above and various additives added as necessary according to a known mixing method. The addition amount of these additives can be appropriately set so as to obtain desired physical properties. Moreover, as a commercial item of a photocurable resin composition, the brand name "LCR1000-DM", "HSVR600", "HSVR330" (all manufactured by Decceria Rouge Co., Ltd.) etc. are mentioned, for example.

[Manufacturing process of conjugate]

Next, a process of manufacturing the image display device 1 by bonding the light-transmitting cover member 3 to the image display member 2 using the photocurable resin composition 6 will be described. First, in a vacuum atmosphere, the image display member 2 supported on the first bonding plate 11 and the light-transmitting cover member 3 supported on the second bonding plate 12 are mixed with a photocurable resin composition 6. It is bonded with a predetermined bonding pressure through

Specifically, as shown in FIG. 2, a light-transmitting cover member 3 having a light-blocking layer 5 formed on the periphery of one side is prepared, and as shown in FIG. 3, the light-transmitting cover member 3 A liquid photocurable resin composition 6 is applied to the surface 3a provided with the light shielding layer 5 to form a photocurable resin layer 7 . Here, the liquid phase indicates a viscosity of 0.01 to 100 Pa.s (25°C) with a B-type viscometer.

In addition, in this application step, it is preferable to apply the liquid photocurable resin composition 6 thicker than the thickness of the light shielding layer 5. By applying the photocurable resin composition 6 thicker than the thickness of the light-shielding layer 5, in the bonding step described later, even when there is a step in the thickness direction between the light-transmitting cover member 3 and the light-shielding layer 5 , Since the soft inside of the pre-cured photocurable resin composition 6 absorbs the level difference, bondability can be improved. In addition, you may perform application|coating of the photocurable resin composition 6 multiple times so that a required thickness may be obtained.

Next, as shown in FIG. 4 , the photocurable resin composition 6 is irradiated with ultraviolet rays to temporarily cure the photocurable resin composition 6 to form a temporarily cured resin layer 8 . As a result, a thin film is formed on the surface of the pre-cured resin layer 8 . It is preferable that the reaction rate of the surface of the pre-cured resin layer 8 is 60 to 80% or more. As a result, while maintaining the elastic modulus of the entire pre-cured resin layer 8 at a low elastic modulus that can be bonded, protrusion in the next bonding step can be suppressed and bondability can be improved.

Then, as shown in FIG. 5 , the image display member 2 and the light-transmitting cover member 3 are placed in the chamber 10 . In the chamber 10, the first and second bonding plates 11 and 12 are provided so that they can be closely spaced apart from each other by a lifting mechanism (not shown). The image display member 2 is supported by the first bonding plate 11 with the display portion facing upward. In addition, the light-transmitting cover member 3 is supported so that the surface 3a of the second bonding plate 12 on which the pre-cured resin layer 8 is formed faces downward and faces the display portion of the image display member 2.

In addition, in the first and second joint plates 11 and 12, one side is a metal plate and the other side is an adhesive rubber plate, and the side of the joint member supported by the rubber plate relative to the joint member supported by the metal plate is It promotes alignment adjustment. Further, the first and second bonding plates 11 and 12 support the bonding member by vacuum adsorption or mechanical chucking. In addition, known materials and supporting methods can be used for the first and second joining plates 11 and 12 .

[joining process]

Next, the air in the chamber 10 is evacuated with a pump or the like to obtain a predetermined vacuum atmosphere, and then, as shown in FIG. 6 , the first joint plate 11 is raised to raise the first and second air. The bonding plates 11 and 12 are brought close to each other, and the surface 3a of the image display member 2 and the light-transmitting cover member 3 on which the pre-cured resin layer 8 is formed is bonded together at a predetermined pressure and for a predetermined time. let it In addition, although the bonding temperature is set appropriately, it becomes 10 degreeC - 80 degreeC, for example.

Since a thin film is formed on the surface of the pre-cured resin layer 8, it is possible to prevent the uncured resin from flowing down when it is inverted. In addition, there are cases where minute irregularities due to the light shielding layer 5 and surface tension are formed on the periphery of the upper surface of the pre-cured resin layer 8, but since the inside of the pre-cured resin layer 8 is in a state close to liquid phase The resin layer 8 can be press-fitted.

In addition, by press-fitting the pre-cured resin layer 8 between the image display member 2 and the light-transmitting cover member 3 in a vacuum atmosphere, mixing of air bubbles can be prevented. In addition, since the thin film on the surface of the pre-cured resin layer 8 follows the surface of the image display member 2 by press-fitting of the pre-cured resin layer 8, it is possible to suppress generation of air bubbles and flatten minute irregularities. can

[Decompression process]

After a predetermined time has elapsed from the start of bonding, the first and second bonding plates 11 and 12 are separated slightly by lowering the first bonding plate 11 or the like, so that the image display member 2 and the light-transmitting cover member are separated. (3) reduces the bonding pressure in the state of being clamped by the first and second bonding plates 11 and 12; Thereby, the bonding pressure applied to the image display member 2 and the light-transmitting cover member 3 is reduced.

The degree of pressure reduction may be within a range in which the state in which the first and second bonding plates 11 and 12 are holding the image display member 2 and the light-transmitting cover member 3 can be maintained, for example, in the bonding process. You may reduce the pressure by 5 to 60% with respect to the predetermined bonding pressure in . In addition, since the degree of pressure reduction is different for the separation distance between the first and second joint plates 11 and 12 depending on the modulus of elasticity of the pre-cured resin layer 8, the photocurable resin composition to be used (6 ), the separation distance between the first and second junction plates 11 and 12 is appropriately set so as to achieve a predetermined decompression rate.

In addition, when the liquid photocurable resin composition 6 is used, since it is difficult to accurately measure the modulus of elasticity (Pa), the degree of pressure reduction is determined by the separation distance between the first and second bonding plates 11 and 12. . That is, the degree of pressure reduction is a range in which a state in which the first and second joint plates 11 and 12 are holding the image display member 2 and the light-transmitting cover member 3 can be maintained, and, for example, The first junction plate and the second junction plate are separated by 5 to 50 μm.

[Atmospheric release process]

Next, the atmosphere in the chamber 10 is set to atmospheric pressure. At this time, according to the present technology, the image display member 2 and the light-transmitting cover member 3 are chucked by the first and second bonding plates 11 and 12, respectively, and the first and second bonding plates 11 , 12), it is possible to prevent occurrence of a shift in the bonding position between the image display member 2 and the light-transmitting cover member 3. Therefore, by shortening the atmospheric release time, even when a sudden pressure fluctuation or air turbulence occurs in the chamber 10, it is possible to prevent the displacement of the bonding position between the image display member 2 and the light-transmitting cover member 3, and image display The manufacturing cycle of the device 1 can be shortened.

[Release process of bonding pressure]

Subsequently, as shown in FIG. 7 , the first and second joint plates 11 are further lowered while releasing the chucking of the light-transmitting cover member 3 by the second joint plate 12 . The two bonding plates 11 and 12 are completely separated to release the bonding pressure to the image display member 2 and the light-transmitting cover member 3 .

[Main curing process]

Thereafter, as shown in FIG. 8 , the bonded body of the image display member 2 and the light-transmitting cover member 3 is further irradiated with ultraviolet rays to fully cure the pre-cured resin layer 8 . Thus, an image display device 1 (FIG. 1) obtained by bonding the image display member 2 and the light-transmitting cover member 3 via the light-transmitting cured resin layer 4 is obtained. Further, as necessary, the pre-cured resin layer 8 between the light-shielding layer 5 of the light-transmitting cover member 3 and the image display member 2 is irradiated with ultraviolet rays, and the pre-cured resin layer 8 is seen. It may be hardened.

In the main curing step, the reaction rate of the photocurable resin composition 6 is preferably 90% or more, and more preferably 95% or more. By sufficiently curing the photocurable resin composition 6, the adhesive force between the light-transmitting cover member 3 and the image display member 2 can be improved.

[Effect of this skill]

According to the manufacturing process of the bonded body to which the present technology is applied, the bonding pressure is reduced in a state where the image display member 2 and the light-transmitting cover member 3 are clamped by the first and second bonding plates 11 and 12, and in this state Atmospheric release is performed. Therefore, even when the light-transmitting resin composition 6 is in liquid or gel form, it is possible to prevent a misalignment of the bonding position between the light-transmitting cover member 3 and the image display member 2.

In addition, since the light-transmitting cover member 3 and the image display member 2 are sandwiched between the first and second joint plates 11 and 12, the atmospheric release time is shortened to prevent sudden pressure fluctuations or turbulence in the chamber 10. Even when a gap occurs, the bonding position shift is prevented, so that the manufacturing cycle can be shortened.

In addition, since atmospheric release is performed in a state in which the bonding pressure between the image display member 2 and the light-transmitting cover member 3 is reduced, the first and second joint plates 11 and 12 are removed until the atmospheric release is completed. Even if it is clamped, excessive bonding pressure is not applied to the image display member 2 and the light-transmitting cover member 3. Therefore, in the image display device 1 manufactured by the manufacturing process to which the present technology is applied, there is no case where residual stress is locally intervened in the cured resin layer 4, which is caused by uneven stress in the cured resin layer 4. The occurrence of color stains can be prevented. In addition, the load on the image display member 2 and the light-transmitting cover member 3, which are being reduced in thickness, can also be reduced, and warpage or damage can be prevented.

In addition, in the above, after the photocurable resin composition 6 is applied to the light-transmitting cover member 3 and temporarily cured, the cloth and the earth are reversed and supported by the second joint plate 12, but supported by the first joint plate The liquid photocurable resin composition 6 may be applied to the image display member 2 or the light-transmitting cover member 3, bonded without temporary curing, and then photocured.

In addition to using the liquid or gel-like photocurable resin composition 6, an optical adhesive sheet in which the photocurable resin composition 6 is molded into a sheet shape may be used. The optical adhesive sheet has adhesiveness during the molding process and can maintain the bonding position of the image display member 2 and the light-transmitting cover member 3. (2) and in a state where the light-transmitting cover member 3 is held between the first and second bonding plates 11 and 12, the bonding pressure is reduced and released to the atmosphere, whereby displacement of the bonding position can be reliably prevented. In addition, it is possible to prevent excessive bonding pressure from being applied to the image display member 2 and the light-transmitting cover member 3 .

Example

Next, examples of the present technology will be described. In this Example, the liquid crystal display panel and the cover glass were connected in a vacuum atmosphere via a photocurable resin composition, and the amount of displacement after being released to the atmosphere was measured. As the cover glass, a glass having a thickness of 0.7 mm and a size of 5 inches was used. In addition, the number of samples of the connection body of the liquid crystal display panel and the cover glass according to each Example and Comparative Example was set to 10 pieces.

[Example 1]

In Example 1, a liquid optical elastic resin (LCR1000-DM, liquid viscosity: 4200 mPa·sec; manufactured by Decceria Luz Co., Ltd.) was used as the bonding resin material. This liquid optically elastic resin was applied to a cover glass, and the liquid crystal display panel was loaded and bonded while mechanically controlling the gap with the cover glass and the thickness of the resin in a vacuum atmosphere in a chamber. The coating thickness of the optical elastic resin was 100 μm, and the degree of vacuum in the chamber was 50 Pa.

After bonding, the distance between the bonding plate supporting the liquid crystal display panel and the bonding plate supporting the cover glass is separated by 5 μm, and the liquid crystal display panel and the cover glass bonded through the optical elastic resin are sandwiched between the pair of bonding plates. In this state, the joint pressure was reduced, and in this state, air release was performed. The standby opening time was 1 second.

After release to the atmosphere, the support of the liquid crystal display panel and the cover glass by the bonding plate is released, and the bonding pressure applied to the bonding body of the liquid crystal display panel and the cover glass is completely released by separating the pair of bonding plates, and the liquid crystal display panel As a result of measuring the amount of position shift between the cover glass and the cover glass, shift did not occur.

[Example 2]

In Example 2, a liquid optical elastic resin (HSVR330; manufactured by Decuseria Luz Co., Ltd.) was used as the bonding resin material. This liquid optical elastic resin was applied to a cover glass and temporarily cured by irradiation with ultraviolet rays to form a temporarily cured resin layer. Subsequently, it bonded to the liquid crystal display panel in a vacuum atmosphere within the chamber. The coating thickness of the optically elastic resin was 100 μm, the elastic modulus of the pre-cured resin layer was 1.60E+4 (Pa), the vacuum degree in the chamber was 50 Pa, and the bonding thrust was 500 N.

After bonding, the distance between the bonding plate supporting the liquid crystal display panel and the bonding plate supporting the cover glass is spaced apart to reduce bonding pressure by 30% in a state where the liquid crystal display panel and the cover glass are sandwiched between a pair of bonding plates. , in this state, air release was performed. The standby opening time was 1 second.

After release to the atmosphere, the support of the liquid crystal display panel and the cover glass by the bonding plate is released, and the bonding pressure applied to the bonding body of the liquid crystal display panel and the cover glass is completely released by separating the pair of bonding plates, and the liquid crystal display panel As a result of measuring the amount of position shift between the cover glass and the cover glass, shift did not occur.

[Example 3]

In Example 3, a liquid optical elastic resin (HSVR600; manufactured by Decuseria Luz Co., Ltd.) was used as the bonding resin material. This liquid optical elastic resin was applied to a cover glass and temporarily cured by irradiation with ultraviolet rays to form a temporarily cured resin layer. Subsequently, it bonded to the liquid crystal display panel in a vacuum atmosphere within the chamber. The coating thickness of the optically elastic resin was 100 μm, the elastic modulus of the pre-cured resin layer was 5.10E+4 (Pa), the vacuum degree in the chamber was 50 Pa, and the bonding thrust was 500 N.

After bonding, the distance between the bonding plate supporting the liquid crystal display panel and the bonding plate supporting the cover glass is spaced apart to reduce bonding pressure by 30% in a state where the liquid crystal display panel and the cover glass are sandwiched between a pair of bonding plates. , in this state, air release was performed. The standby opening time was 1 second.

After release to the atmosphere, the support of the liquid crystal display panel and the cover glass by the bonding plate is released, and the bonding pressure applied to the bonding body of the liquid crystal display panel and the cover glass is completely released by separating the pair of bonding plates, and the liquid crystal display panel As a result of measuring the amount of position shift between the cover glass and the cover glass, shift did not occur.

[Comparative Example 1]

In Comparative Example 1, after bonding, the support of the cover glass by the bonding plate was released, the pair of bonding plates were separated, and the bonding pressure applied to the bonding body of the liquid crystal display panel and the cover glass was completely released, and then released to the atmosphere. Other conditions are the same as in Example 1.

In Comparative Example 1, as a result of measuring the amount of displacement between the liquid crystal display panel and the cover glass, a displacement of 0.5 to 3 mm occurred.

[Comparative Example 2]

In Comparative Example 2, after bonding, the support of the cover glass by the bonding plate was released, the pair of bonding plates were separated, and the bonding pressure applied to the bonding body of the liquid crystal display panel and the cover glass was completely released, and then released to the atmosphere. Other conditions are the same as in Example 2.

In Comparative Example 2, as a result of measuring the amount of displacement between the liquid crystal display panel and the cover glass, a displacement of 0.03 to 0.3 mm occurred.

[Comparative Example 3]

In Comparative Example 3, after bonding, the support of the cover glass by the bonding plate was released, the pair of bonding plates were separated, and the bonding pressure applied to the bonding body of the liquid crystal display panel and the cover glass was completely released, and then released to the atmosphere. Other conditions are the same as in Example 3.

In Comparative Example 3, as a result of measuring the amount of displacement between the liquid crystal display panel and the cover glass, a displacement of 0.03 to 0.1 mm occurred.

[Comparative Example 4]

In Comparative Example 4, after bonding, bonding pressure was continued to be applied to the bonding body of the liquid crystal display panel and the cover glass until release to the atmosphere was completed, and then the bonding plate was released from supporting the liquid crystal display panel and the cover glass, The bonding pressure applied to the bonding body of the liquid crystal display panel and the cover glass was completely released by separating the pair of bonding plates. Other conditions are the same as in Example 2.

In Comparative Example 4, as a result of measuring the amount of displacement between the liquid crystal display panel and the cover glass, no displacement occurred, but warpage occurred in the bonded body.

As shown in Table 1, in Examples 1 to 3, the bonding pressure is reduced in a state where the liquid crystal display panel and the cover glass are held between a pair of bonding plates, and release to the atmosphere is performed in this state. It was possible to prevent displacement of the bonding position between the liquid crystal display panel and the cover glass, despite the rapid pressure fluctuation or turbulence occurring in the chamber by opening the chamber to the atmosphere in a short period of time.

In addition, since the bonding pressure is reduced prior to release to the atmosphere, even if the bonding pressure is released after release to the atmosphere, warpage does not occur in the bonded body and there is no fear of damaging the liquid crystal display panel or the cover glass.

On the other hand, in Comparative Examples 1 to 3, since the bonding pressure to the liquid crystal display panel and the cover glass was released, the liquid crystal display panel was released to the atmosphere due to rapid pressure fluctuations and turbulence in the chamber caused by the short-time release to the atmosphere. and the bonding position shift of the cover glass occurred. In Comparative Example 1, since the liquid optically elastic resin was interposed, the amount of displacement was increased compared to Comparative Examples 2 and 3 in which the optically elastic resin was temporarily cured.

In Comparative Example 4, since bonding pressure was applied to the liquid crystal display panel and the cover glass from bonding until release to the atmosphere was completed, displacement due to release to the atmosphere could be prevented, but bonding to the liquid crystal display panel and cover glass Excessive pressure was applied and warping occurred.

1: image display device
2: image display member
3: light-transmitting cover member
4: cured resin layer
5: light blocking layer
6: photocurable resin composition
7: photocurable resin layer
8: temporary curing resin layer
10: chamber
11: first joining plate
12: second junction plate

Claims (5)

bonding a first bonding member supported by the first bonding plate and a second bonding member supported by the second bonding plate under a vacuum atmosphere through a bonding resin material at a predetermined bonding pressure;
Then, in a state where the first and second bonding members are held by the first and second bonding plates, the first and second bonding plates are spaced apart in a state of maintaining a vacuum atmosphere to reduce the bonding pressure. The degree of is a range in which the first and second bonding plates can maintain a state in which the first and second bonding members are clamped;
Next, a step of opening to atmospheric pressure from a vacuum atmosphere;
Subsequently, there is a step of releasing the bonding pressure to the first and second bonding members;
1) The bonding resin material is temporarily cured, and in the step of reducing the bonding pressure for the first and second bonding members, the predetermined bonding pressure is reduced by 5 to 60%, or
2) The bonding resin material is in a liquid state, and in the step of reducing the bonding pressure for the first and second bonding members, the first bonding plate and the second bonding plate are spaced apart from each other by 5 to 50 μm,
The process of opening to atmospheric pressure is performed in a short time enough to generate rapid pressure fluctuations or turbulence in the chamber
Methods of making conjugates. The method of manufacturing a bonded body according to claim 1, wherein the first bonding member and the second bonding member are an image display member and a light-transmitting cover member, respectively, and the bonding resin material is entirely coated on the second bonding member. The method for producing a joined body according to claim 1 or 2, comprising a step of curing the joint resin material after joining the first and second joining members. The method for producing a joined body according to claim 1, wherein the bonded resin material is molded into a film shape. bonding a first bonding member supported by the first bonding plate and a second bonding member supported by the second bonding plate under a vacuum atmosphere through a bonding resin material at a predetermined bonding pressure;
Then, in a state where the first and second bonding members are held by the first and second bonding plates, the first and second bonding plates are spaced apart in a state of maintaining a vacuum atmosphere to reduce the bonding pressure, A step in which the degree is within a range in which the first and second joining plates can hold the first and second joining members;
Next, a step of opening to atmospheric pressure from a vacuum atmosphere;
Subsequently, there is a step of releasing the bonding pressure to the first and second bonding members;
1) The bonding resin material is temporarily cured, and in the step of reducing the bonding pressure for the first and second bonding members, the predetermined bonding pressure is reduced by 5 to 60%, or
2) The bonding resin material is in a liquid state, and in the step of reducing the bonding pressure for the first and second bonding members, the first bonding plate and the second bonding plate are spaced apart from each other by 5 to 50 μm,
The process of opening to atmospheric pressure is performed in a short time enough to generate rapid pressure fluctuations or turbulence in the chamber
connection method.

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