JP2016194581A - Anisotropic conductive connector and display using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress curvature of a glass substrate in a display area to eliminate display unevenness.SOLUTION: An anisotropic conductive connector comprises a substrate 12 that is provided with a display area 6 and an electronic component 18 that is connected along one side 6a of the display area 6 in an anisotropic conductive manner, and a ratio of the length (L1) of the one side 6a of the display area 6 to which the electronic component 18 is connected to the length (L2) of the electronic component 18 along the one side of the display are 6 (L1/L2) is 1.2 or less.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a connection structure between a substrate mainly used in an image display device and an electronic component such as an IC chip, and in particular, an anisotropic conductive connector in which an electronic component is connected using an anisotropic conductive adhesive, and The present invention relates to a display device using the same.

  In a display device such as a liquid crystal display device, liquid crystal driving is performed on a glass substrate on which a display area is formed by using an anisotropic conductive film (ACF) due to demands for fine connection and productivity improvement. A so-called COG (Chip On Glass) that directly mounts an IC chip such as a general-purpose IC is used.

  An anisotropic conductive film is a film in which conductive particles are mixed in a binder resin, and heat conduction is performed between two conductors to provide electrical continuity between the conductors with the conductive particles. Resin maintains the mechanical connection between the conductors.

  When mounting an IC chip on a glass substrate through such an anisotropic conductive film, first, the anisotropic conductive film is temporarily pasted onto the transparent electrode drawn out in the vicinity of the display area of the glass substrate by a temporary crimping means. To do. Subsequently, after electronic components are mounted on a glass substrate via an anisotropic conductive film to form a temporary connection body, the IC chip is moved to the transparent electrode side together with the anisotropic conductive film by a thermocompression bonding means such as a thermocompression bonding head. Heat and press. By the heating by the thermocompression bonding head, the anisotropic conductive film undergoes a thermosetting reaction, whereby the IC chip is bonded onto the transparent electrode.

  Here, in COG mounting, when the IC chip is thermocompression bonded by thermocompression bonding means, there is a problem that the IC chip and the glass substrate warp in a concave shape due to a difference in thermal expansion coefficient between the IC chip and the glass substrate. The warpage of the glass substrate reaches the display area provided in the vicinity of the IC chip, and the gap of the liquid crystal layer is locally changed due to the deformation distortion of the display area, so that the display surface located around the mounting part of the IC chip. Display unevenness occurs. This tendency is prominent in the vicinity of the outside of the edge of the IC chip where the influence of the warpage of the IC chip becomes large, and more prominent as the glass substrate becomes thinner as the display device becomes smaller and thinner. appear.

  In response to such deterioration of display quality due to warping of the glass substrate, a highly rigid deformation suppressing member is mounted between the display area of the glass substrate and the IC chip to locally increase the rigidity and suppress deformation of the glass substrate. A method for suppressing the deformation of the glass substrate by mounting a dummy chip on the back surface of the glass substrate according to the position where the IC chip is anisotropically conductively connected, and a dummy bump for suppressing the deformation at the center of the IC chip. Proposed methods have been proposed.

JP 2008-20836 A

  In recent years, mobile devices such as smart phones and tablet terminals are becoming smaller and thinner. In addition, so-called wearable terminals that are worn on the human body are being actively developed, and display devices are increasingly required to be smaller, thinner, and more functional, and high-density mounting is progressing. Accordingly, a transparent substrate (corresponding to the glass substrate described above) provided with a display area is narrowed and an IC chip mounting area is also narrowed.

  Therefore, in order to suppress deformation of the transparent substrate, for example, when the transparent substrate is a glass substrate, a method of mounting a highly rigid deformation suppressing member between the display area of the glass substrate and the IC chip, or an IC chip A method of mounting a dummy chip on the back surface of the glass substrate in accordance with the position where the anisotropic conductive connection is made leads to an increase in the size of the display device itself, which is not preferable. Even if the transparent substrate is, for example, a plastic substrate, deformation due to heat is similarly a concern.

  Therefore, the present invention provides an anisotropic conductive connection that can suppress deformation (warping) of a transparent substrate in a display region and eliminate display unevenness in anisotropic conductive connection of an electronic component such as an IC chip. An object of the present invention is to provide an anisotropic conductive connection body that can be reduced in size and thickness, and a display device using the same.

  In order to solve the above-described problem, an anisotropic conductive connector according to the present invention includes a substrate provided with a display region and an electronic component that is anisotropically conductively connected along one side of the display region. The ratio (L1 / L2) of the length (L1) of one side of the display area to which the electronic component is connected and the length (L2) along the one side of the display area of the electronic component ) Is 1.2 or less.

  A display device according to the present invention is a display device including the above-described anisotropic conductive connector.

  According to the present invention, when an electronic component is thermocompression-bonded by thermocompression bonding means, even if the electronic component and the substrate warp in a concave shape due to a difference in thermal expansion coefficient between the electronic component and the substrate, the electronic component having a large influence of warping The vicinity of the outside of the end in the longitudinal direction covers the frame region, and distortion to the display region is suppressed. Therefore, according to the present invention, it is possible to prevent deterioration in display quality in the display area.

FIG. 1 is a cross-sectional view showing a process of connecting an electronic component to a transparent substrate of a liquid crystal display panel to which the present invention is applied. FIG. 2 is a plan view showing a transparent substrate on which electronic components are mounted. FIG. 3 is a plan view showing a mounting portion of the transparent substrate. FIG. 4 is a cross-sectional view showing a connection process of an electronic component to which the present invention is applied. FIG. 5 is a plan view showing a mounting surface of the electronic component. FIG. 6 is a cross-sectional view showing an anisotropic conductive film.

  Hereinafter, an anisotropic conductive connector to which the present invention is applied and a display device using the same will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention. Further, the drawings are schematic, and the ratio of each dimension may be different from the actual one. Specific dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[LCD panel]
Hereinafter, a liquid crystal display panel in which an IC chip for driving a liquid crystal as an electronic component is mounted on a glass substrate (an example of a transparent substrate) will be described as an example of a connection body to which the present invention is applied. As shown in FIG. 1, the liquid crystal display panel 10 includes two transparent substrates 11 and 12 made of a glass substrate and the like, and the transparent substrates 11 and 12 are bonded to each other by a frame-shaped seal 13. . In the liquid crystal display panel 10, the liquid crystal 14 is sealed in a space surrounded by the transparent substrates 11 and 12 to form a panel display unit 15.

  The transparent substrates 11 and 12 have a pair of striped transparent electrodes 16 and 17 made of ITO (indium tin oxide) or the like on both inner surfaces facing each other so as to intersect each other. The transparent electrodes 16 and 17 are configured such that a pixel as a minimum unit of liquid crystal display is configured by the intersection of the transparent electrodes 16 and 17.

  Of the transparent substrates 11 and 12, one transparent substrate 12 is formed to have a larger planar dimension than the other transparent substrate 11, and as shown in FIG. 2, the display region 6 in which the panel display unit 15 is formed. A mounting portion 27 on which the liquid crystal driving IC 18 is mounted as an electronic component via the anisotropic conductive film 1 is provided along one side 6 a of the display area 6. Around the display area 6, a seal 13 such as a double-sided adhesive tape that joins the opposite outer edges of the liquid crystal display panel 10 and a front panel such as glass or an acrylic plate along the outer edge of the transparent substrate 12. A frame area 7 is provided. In the transparent substrate 12, the mounting portion 27 is provided on the edge 12 a of the transparent substrate 12, and the display region 6 and the mounting portion 27 are partitioned by the frame region 7.

  3 and 4, the mounting unit 27 includes an input terminal row 20 in which a plurality of input terminals 19 of the transparent electrode 17 are arranged and two output terminal rows in which a plurality of output terminals 21 are arranged. 22. A substrate-side alignment mark 31 is formed so as to overlap the IC-side alignment mark 32 provided on the liquid crystal driving IC 18.

[LCD driving IC]
The liquid crystal driving IC 18 can selectively apply a liquid crystal driving voltage to the pixels to change the alignment of the liquid crystal partially and perform a predetermined liquid crystal display. As shown in FIGS. 4 and 5, the liquid crystal driving IC 18 has an input in which a plurality of input bumps 23 electrically connected to the input terminals 19 of the transparent electrode 17 are arranged on the mounting surface 18 a of the transparent substrate 12. An output bump row 26 in which a plurality of output bumps 25 that are electrically connected to the bump row 24 and the output terminal 21 of the transparent electrode 17 are arranged is formed. As the input bumps 23 and the output bumps 25, for example, copper bumps, gold bumps, or copper bumps plated with gold are suitably used.

  The liquid crystal driving IC 18 includes, for example, an input bump row 24 in which the input bumps 23 are arranged in a row along one side edge of the mounting surface 18a in the longitudinal direction, and a width direction orthogonal to the arrangement direction of the output bumps 25. Two parallel output bump rows 26 are formed substantially in parallel.

  Further, as shown in FIG. 5, the liquid crystal driving IC 18 has an input bump row 24 formed along one side edge of the mounting surface 18a, and outputs along the other side edge facing the one side edge. A bump row 26 is formed. The input / output bumps 23 and 25 and the input / output terminals 19 and 21 provided on the mounting portion 27 of the transparent substrate 12 are aligned and connected to the transparent substrate 12 and the liquid crystal driving IC 18. Connected.

[Length ratio between display area and liquid crystal display IC]
Here, as shown in FIG. 2, the liquid crystal display panel 10 has a length (L1) of one side 6a of the display area 6 to which the liquid crystal driving IC 18 is connected and the display area 6 of the liquid crystal driving IC 18. The ratio (L1 / L2) to the length (L2) along one side 6a is 1.2 or less.

  Thereby, when the liquid crystal display panel 10 is thermocompression-bonded by the thermocompression bonding means, the liquid crystal drive IC18 and the transparent substrate 12 become concave due to the difference in thermal expansion coefficient between the liquid crystal drive IC18 and the transparent substrate 12. Even in the case of warping, the vicinity of the outer end in the longitudinal direction of the liquid crystal driving IC 18 that is greatly affected by the warping is applied to the frame region 7, and distortion to the display region 6 is suppressed. Therefore, the liquid crystal display panel 10 can prevent display quality from deteriorating in the display area 6.

  When the ratio (L1 / L2) of the length (L1) of one side 6a of the display area 6 to the length (L2) of the liquid crystal driving IC 18 is 1.2 or more, the liquid crystal driving IC 18 is warped by thermocompression bonding. When this occurs, the display area 6 of the transparent substrate 12 is also distorted due to the warp of the liquid crystal driving IC 18, and the gap between the backlight and the display area 6 becomes non-uniform. For this reason, display unevenness may occur.

  Further, the ratio (L1 / L2) between the length (L1) of the side 6a of the display area 6 and the length (L2) of the liquid crystal driving IC 18 is set to 1.2 or less, which is caused by the warp of the liquid crystal driving IC 18. Since the influence on the display area 6 can be suppressed, the liquid crystal driving IC 18 can be mounted close to the display area 6. Therefore, the liquid crystal display panel 10 can reduce the area of the mounting portion 27 provided on the edge portion 12a of the transparent substrate 12, and the display device using the liquid crystal display panel 10 can be downsized.

  In the liquid crystal display panel 10, the ratio (L1 / L2) of the length (L1) of the one side 6a of the display area 6 to the length (L2) of the liquid crystal driving IC 18 is preferably 0.8 or more. When the ratio (L1 / L2) is 0.8 or less, it is of course possible to suppress display unevenness, but the area outside the display area 6 including the frame area 7 is expanded with respect to the display area 6, and the liquid crystal display panel 10. There is a risk of hindering the overall size reduction.

  Further, the liquid crystal display panel 10 includes an end of one side 6a of the display region 6 on the side where the liquid crystal driving IC 18 is connected and an end of the liquid crystal driving IC 18 in the direction along the one side 6a. The distance D in the direction, that is, the direction along the one side 6a of the display area 6 of the liquid crystal driving IC 18 is preferably ± 0.1 L2. Here, the distance D starts from the end in the direction along the one side 6a of the display area 6 of the liquid crystal driving IC 18 and the end on the same side as the starting point of the liquid crystal driving IC of the one side 6a of the display area 6 The case where the liquid crystal driving IC is located on the same side as the starting end of the liquid crystal driving IC and the position extending from the end is defined as +, and the liquid crystal driving IC is retracted from the end opposite to the starting end of the liquid crystal driving IC. When it is in a position (FIG. 2), it is set as-.

  The end of the liquid crystal driving IC 18 is positioned at a distance of ± 0.1 L2 or less from the end of the one side 6a of the display area 6 so that the vicinity of the outer end of the liquid crystal driving IC 18 covers the display area 6. The display area 6 is not affected by the warp of the liquid crystal driving IC 18. In addition, the end of the liquid crystal driving IC 18 does not protrude greatly into the frame region 7, and the downsizing of the transparent substrate 12 is not impaired.

  Further, the liquid crystal display panel 10 has both ends of one side 6a of the display area 6 on the side where the liquid crystal driving IC 18 is connected and both ends in the direction along the one side 6a of the display area 6 of the liquid crystal driving IC 18. The distances D are preferably equal. Since the distance D is equal between one side 6a of the display area 6 and each end of the liquid crystal driving IC 18, the influence on the transparent substrate 12 due to the warpage of the liquid crystal driving IC 18 with respect to the transparent substrate 12 can be leveled.

  Thus, in the liquid crystal display panel 10, the ratio (L1 / L2) of the length (L1) of the side 6a of the display area 6 to the length (L2) of the liquid crystal driving IC 18 is 1.2 or less. Thus, the number of the input / output terminals 19 and 21 of the transparent substrate 12 and the input / output bumps 23 and 25 of the liquid crystal driving IC 18 can be increased as compared with the conventional IC chip, and the area of each terminal or bump can be increased. Can also be taken widely. Further, the pitch between adjacent terminals and bumps can be increased, and a short circuit between bumps and a short circuit between terminals due to continuous conductive particles 4 in fine pitch connection can be prevented.

  Furthermore, in the liquid crystal display panel 10, by setting the length of one side of the display area 6 and the length of the liquid crystal driving IC 18 within a predetermined range, distortion to the display area 6 is suppressed and display unevenness is suppressed. In addition, a highly rigid deformation suppressing member or dummy chip is not mounted on the frame region 7 or the mounting portion 27 of the transparent substrate 12. For this reason, even when the liquid crystal display panel 10 is applied to a so-called wearable terminal attached to a human body, it does not hinder downsizing and thinning. For example, the liquid crystal display panel 10 can be formed in a size of about 52 mm × 39 mm (2.5 inches) as the size of the display region 6 and can suppress display unevenness.

  Of course, the liquid crystal display panel 10 can be applied to a display area 6 having a size exceeding 2.5 inches or a size smaller than 2.5 inches. The size of the display area of the wearable terminal is preferably 0.8 inches or more, for example, from the viewpoint of the recognizability of the screen itself, and is preferably 3 inches or less in order not to increase the burden at the time of wearing.

[Ratio of length between transparent substrate and LCD driving IC]
The liquid crystal display panel 10 has a length of one side 12b where the liquid crystal driving IC 18 is connected along one side of the transparent substrate 12 at the edge 12a of the transparent substrate 12, and the liquid crystal driving IC 18 of the transparent substrate 12 is connected. The ratio (L3 / L2) between (L3) and the length (L2) along one side 6a of the display area 6 of the liquid crystal driving IC 18 is such that L2 is closer to L3 (total width) (L3 / When L2 is close to 1, an effect of reinforcing the wearable terminal itself by the liquid crystal driving IC 18 can be expected.

  Therefore, L3 / L2 is practically 1 or more, preferably larger than 1, more preferably larger than 1.05, and still more preferably 1.08. Further, since L2 is small (the liquid crystal driving IC 18 is short), the mounting area is reduced, which can contribute to the design of the entire mounting apparatus. Therefore, L3 / L2 is preferably 1.4 or less, and more preferably 1.2 or less.

  In addition, when reinforcing the wearable terminal itself, the centers of the lengths of L3 and L2 may be substantially matched. In this case, it is preferable that the center of L2 is within a range of ± 3% from the center of the length of L3.

  When L3 / L2 takes a value close to 1, the ends of the liquid crystal driving IC 18 overlap in the vicinity of the frame. The narrower the frame on the display screen, the smaller the ratio that the edge of the liquid crystal driving IC 18 and the frame can overlap. Therefore, in order to meet the demand for the appearance characteristics of a display device whose viewing distance is remarkably short, such as a narrow frame and a wearable terminal, such an aspect as described above is desirable.

  The length (L3) of the side 12b to which the liquid crystal driving IC 18 of the transparent substrate 12 is connected is preferably 12 mm or more and 63 mm or less. When the liquid crystal display panel 10 is applied to a wearable terminal, for example, the minimum size of the display area 6 is about 0.8 inch (short side: 10 mm), and the maximum size is from the viewpoint of visibility, operability, and reduction of the burden at the time of wearing. If it becomes about 3 inches (short side 43 mm), it is suitable for mounting on an arm (wrist) such as a watch. The frame is preferably 10 mm or less, and more preferably 1 mm or more, as an example, since there is a tradeoff in design and the like of the entire wearable terminal. Therefore, the length (L3) of the side 12b to which the liquid crystal driving IC 18 of the transparent substrate 12 is connected is preferably 12 mm or more and 63 mm or less.

  In addition, the liquid crystal driving IC 18 is formed with an IC side alignment mark 32 for alignment with the transparent substrate 12 by being superimposed on the mounting surface 18 a with the substrate side alignment mark 31. As the substrate-side alignment mark 31 and the IC-side alignment mark 32, various marks that can be aligned with the transparent substrate 12 and the liquid crystal driving IC 18 can be used.

  The liquid crystal driving IC 18 is connected to the input / output terminals 19 and 21 of the transparent electrode 17 formed on the mounting portion 27 using the anisotropic conductive film 1 as a circuit connecting adhesive. The anisotropic conductive film 1 contains conductive particles 4, and input / output bumps 23 and 25 of the liquid crystal driving IC 18 and input / output terminals 19 of the transparent electrode 17 formed on the mounting portion 27 of the transparent substrate 12. 21 is electrically connected through the conductive particles 4. The anisotropic conductive film 1 is thermocompression bonded by the thermocompression bonding head 33 to fluidize the binder resin, so that the conductive particles 4 are connected to the input / output terminals 19 and 21 and the input / output bumps 23 and 25 of the liquid crystal driving IC 18. The binder resin is cured in this state. Thereby, the anisotropic conductive film 1 electrically and mechanically connects the transparent substrate 12 and the liquid crystal driving IC 18.

  An alignment film 28 that has been subjected to a predetermined rubbing process is formed on both transparent electrodes 16 and 17, and the initial alignment of liquid crystal molecules is regulated by the alignment film 28. Further, a pair of polarizing plates 29a and 29b are disposed outside the transparent substrates 11 and 12, and the light transmitted from a light source (not shown) such as a backlight is transmitted by these polarizing plates 29a and 29b. The vibration direction is regulated.

[Anisotropic conductive film]
Next, the anisotropic conductive film 1 will be described. As shown in FIG. 6, an anisotropic conductive film (ACF) 1 usually has a binder resin layer (adhesive layer) 3 containing conductive particles 4 on a release film 2 as a base material. It is formed. The anisotropic conductive film 1 is a thermosetting adhesive or a photo-curing adhesive such as ultraviolet rays, and is attached to the mounting portion 27 where the input / output terminals 19 and 21 of the transparent substrate 12 of the liquid crystal display panel 10 are formed. In addition, the liquid crystal driving IC 18 is mounted and fluidized by being thermally pressed by the thermocompression bonding head 33, and the conductive particles 4 are opposed to the input / output terminals 19 and 21 of the transparent electrode 17 and the liquid crystal driving IC 18 inserted. The conductive particles 4 are crushed between the output bumps 23 and 25 and hardened in a state of being crushed by heating or ultraviolet irradiation. Thereby, the anisotropic conductive film 1 can connect the transparent substrate 12 and the liquid crystal driving IC 18 to make them conductive.

  In the anisotropic conductive film 1, conductive particles 4 are blended in a normal binder resin layer 3 containing a film-forming resin, a thermosetting resin, a latent curing agent, a silane coupling agent, and the like.

  The release film 2 that supports the binder resin layer 3 is made of, for example, a release agent such as silicone on PET (Poly Ethylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methylpentene-1), PTFE (Polytetrafluoroethylene), and the like. It coats and prevents the anisotropic conductive film 1 from drying, and maintains the shape of the anisotropic conductive film 1.

  The film-forming resin contained in the binder resin layer 3 is preferably a resin having an average molecular weight of about 10,000 to 80,000. Examples of the film forming resin include various resins such as an epoxy resin, a modified epoxy resin, a urethane resin, and a phenoxy resin. Among these, phenoxy resin is particularly preferable from the viewpoint of film formation state, connection reliability, and the like.

  It does not specifically limit as a thermosetting resin, For example, a commercially available epoxy resin, an acrylic resin, etc. are mentioned.

  The epoxy resin is not particularly limited. For example, naphthalene type epoxy resin, biphenyl type epoxy resin, phenol novolac type epoxy resin, bisphenol type epoxy resin, stilbene type epoxy resin, triphenolmethane type epoxy resin, phenol aralkyl type epoxy resin. Naphthol type epoxy resin, dicyclopentadiene type epoxy resin, triphenylmethane type epoxy resin and the like. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as an acrylic resin, According to the objective, an acrylic compound, liquid acrylate, etc. can be selected suitably. For example, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, epoxy acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, dimethylol tricyclodecane diacrylate, tetramethylene glycol tetraacrylate, 2-hydroxy- 1,3-diacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxyethoxy) phenyl] propane, dicyclopentenyl acrylate, tricyclo Examples include decanyl acrylate, tris (acryloxyethyl) isocyanurate, urethane acrylate, and epoxy acrylate. In addition, what made acrylate the methacrylate can also be used. These may be used individually by 1 type and may use 2 or more types together.

  The latent curing agent is not particularly limited, and examples thereof include various curing agents such as a heat curing type and a UV curing type. The latent curing agent does not normally react, but is activated by various triggers selected according to applications such as heat, light, and pressure, and starts the reaction. The activation method of the thermal activation type latent curing agent includes a method of generating active species (cation, anion, radical) by a dissociation reaction by heating, etc., and it is stably dispersed in the epoxy resin near room temperature, and epoxy at high temperature There are a method of initiating a curing reaction by dissolving and dissolving with a resin, a method of initiating a curing reaction by eluting a molecular sieve encapsulated type curing agent at a high temperature, and an elution / curing method using microcapsules. Thermally active latent curing agents include imidazole, hydrazide, boron trifluoride-amine complexes, sulfonium salts, amine imides, polyamine salts, dicyandiamide, etc., and modified products thereof. The above mixture may be sufficient. Among these, a microcapsule type imidazole-based latent curing agent is preferable.

  Although it does not specifically limit as a silane coupling agent, For example, an epoxy type, an amino type, a mercapto sulfide type, a ureido type etc. can be mentioned. By adding the silane coupling agent, the adhesion at the interface between the organic material and the inorganic material is improved.

[Conductive particles]
Examples of the conductive particles 4 include any known conductive particles used in the anisotropic conductive film 1. Examples of the conductive particles 4 include particles of various metals and metal alloys such as nickel, iron, copper, aluminum, tin, lead, chromium, cobalt, silver, gold, metal oxide, carbon, graphite, glass, ceramic, Examples include those in which the surface of particles such as plastic is coated with metal, or the surface of these particles is further coated with an insulating thin film. In the case where the surface of the resin particle is coated with metal, examples of the resin particle include an epoxy resin, a phenol resin, an acrylic resin, an acrylonitrile / styrene (AS) resin, a benzoguanamine resin, a divinylbenzene resin, a styrene resin, and the like. Can be mentioned. The size of the conductive particles 4 is preferably 1 to 10 μm, but the present invention is not limited to this.

  The shape of the anisotropic conductive film 1 is not particularly limited. For example, as shown in FIG. 6, the shape of the anisotropic conductive film 1 is a long tape shape that can be wound around the take-up reel 5, and is used by cutting a predetermined length. can do.

  Although the anisotropic conductive film 1 may be produced by any method, for example, it can be produced by the following method. An adhesive composition containing a film-forming resin, a thermosetting resin, a latent curing agent, a silane coupling agent, conductive particles and the like is prepared. An anisotropic conductive film 1 in which the binder resin layer 3 is supported on the release film 2 by applying the adjusted adhesive composition onto the release film 2 using a bar coater, a coating apparatus, and the like, and drying the oven composition or the like. Get.

  Moreover, although the above-mentioned embodiment demonstrated as an example the adhesive film which shape | molded the thermosetting resin composition which contained the electroconductive particle 4 suitably in the binder resin layer 3 as an adhesive agent in the present invention, Such an adhesive is not limited to this, and may be, for example, an insulating adhesive film made of only the binder resin layer 3. In addition, the adhesive according to the present invention has a configuration in which an insulating adhesive layer composed only of the binder resin layer 3 and a conductive particle-containing layer composed of the binder resin layer 3 containing the conductive particles 4 are laminated. it can. Further, the adhesive is not limited to such an adhesive film formed into a film, but an insulating adhesive composed of only a conductive adhesive paste in which conductive particles 4 are dispersed in a binder resin composition or a binder resin composition. It may be a paste. The adhesive according to the present invention includes any of the forms described above.

[Connection process]
Next, a connection process for connecting the liquid crystal driving IC 18 to the transparent substrate 12 will be described. First, the anisotropic conductive film 1 is temporarily attached on the mounting portion 27 where the input / output terminals 19 and 21 of the transparent substrate 12 are formed. Next, the transparent substrate 12 is placed on the stage of the connection device, and the liquid crystal driving IC 18 is disposed on the mounting portion 27 of the transparent substrate 12 via the anisotropic conductive film 1.

  Next, the thermocompression bonding head 33 heated to a predetermined temperature for curing the binder resin layer 3 is hot-pressed from above the liquid crystal driving IC 18 at a predetermined pressure and time. As a result, the binder resin layer 3 of the anisotropic conductive film 1 exhibits fluidity and flows out from between the mounting surface 18a of the liquid crystal driving IC 18 and the mounting portion 27 of the transparent substrate 12, and the conductive in the binder resin layer 3 The conductive particles 4 are sandwiched between the input / output bumps 23 and 25 of the liquid crystal driving IC 18 and the input / output terminals 19 and 21 of the transparent substrate 12 and are crushed.

  As a result, the conductive particles 4 are electrically connected between the input / output bumps 23 and 25 and the input / output terminals 19 and 21, and the binder resin heated by the thermocompression bonding head 33 in this state is cured. To do. Thereby, the liquid crystal display panel 10 in which electrical conductivity is ensured between the input / output bumps 23 and 25 of the liquid crystal driving IC 18 and the input / output terminals 19 and 21 formed on the transparent substrate 12 can be manufactured.

  The conductive particles 4 that are not between the input / output bumps 23 and 25 and the input / output terminals 19 and 21 are dispersed in the binder resin in the space between the adjacent input / output bumps 23 and 25 and are electrically insulated. Is maintained. Therefore, the liquid crystal display panel 10 is electrically connected only between the input / output bumps 23 and 25 of the liquid crystal driving IC 18 and the input / output terminals 19 and 21 of the transparent substrate 12. Further, the anisotropic conductive film 1 is not limited to the thermosetting type, and may be a photo-curing type or a photo-heat combined type adhesive as long as pressure connection is performed.

  Here, as described above, in the liquid crystal display panel 10 to which the present invention is applied, the length (L1) of the side 6a of the display area 6 to which the liquid crystal driving IC 18 is connected and the liquid crystal driving IC 18 The ratio (L1 / L2) to the length (L2) along one side 6a of the display area 6 is set to 1.2 or less.

  Therefore, in the liquid crystal display panel 10, when the liquid crystal driving IC 18 is thermocompression bonded by the thermocompression bonding head 33, the liquid crystal driving IC 18 and the transparent substrate 12 become concave due to the difference in thermal expansion coefficient between the liquid crystal driving IC 18 and the transparent substrate 12. Even in the case of warping, the vicinity of the outer end in the longitudinal direction of the liquid crystal driving IC 18 that is greatly affected by the warping is applied to the frame region 7, and distortion to the display region 6 is suppressed. Therefore, the liquid crystal display panel 10 can prevent display quality from deteriorating in the display area 6.

  Such a liquid crystal display panel 10 can be applied to various display devices such as so-called wearable terminals, mobile devices such as smart phones and tablet terminals, and stationary electronic devices that are worn on the human body. Further, the liquid crystal display panel 10 can appropriately set the diagonal size of the display area 6 according to the device to be applied. However, the diagonal size of the display area 6 is restricted due to the size restriction of the electronic components such as the liquid crystal driving IC 18. 20.3 mm (approximately 0.8 inches) or more is preferable, and approximately 63.5 mm (approximately 2.5 inches) is more preferable.

  Further, in the above description, the liquid crystal display panel 10 has electronic components mounted along one side 6a of the display area 6. However, in addition to this, another side, for example, another side along the other side facing the one side 6a of the display area 6 is provided. The electronic parts may be mounted. At this time, the ratio of the length of the other side to the length along the other side of the other electronic component is set to 1.2 or less.

  Next, examples of the present invention will be described. In this embodiment, the ratio (L1 / L1) of the length (L1) of one side of the display area to which the liquid crystal driving IC is connected and the length (L2) along one side of the display area of the liquid crystal driving IC. A liquid crystal display panel in which L2) was changed was formed and evaluated for the presence or absence of display unevenness (see FIG. 2).

  The transparent substrate of the liquid crystal display panel used in each example and comparative example has a thickness of 0.15 mm, the display area formed on the transparent substrate is 52 mm × 39 mm (2.5 inches), and the frame area surrounding the display area is 6 mm wide. is there. A liquid crystal driving IC was mounted along the short side of the display area using an anisotropic conductive film. The mounted liquid crystal driving ICs were rectangular and had a plurality of short sides of 2.0 mm and long sides of 12 to 45 mm, and the long sides were arranged along the short sides of the display area.

  Further, the liquid crystal driving IC has a distance D between the end of the short side of the display area where the liquid crystal driving IC is connected and the end of the long side of the liquid crystal driving IC at both ends of the long side. They were placed at the same position.

[Example 1]
In Example 1, a liquid crystal display panel in which anisotropic conductive connection was made along the short side of the display region using a liquid crystal driving IC having a long side of 38 mm was produced. The distance between the long side of the liquid crystal driving IC and the short side of the display area was 2 mm. The ratio (L1 / L1) between the length of the short side of the display area (L1 = 39 mm) and the length along the short side of the display area of the liquid crystal driving IC (L2 = 38 mm) of the liquid crystal display panel according to Example 1. L2) is 1.03.

[Example 2]
In Example 2, a liquid crystal driving IC having a long side length of 39 mm was used. The distance between the long side of the liquid crystal driving IC and the short side of the display area was 2 mm. In the liquid crystal display panel according to Example 2, the ratio (L1) between the length of the short side of the display area (L1 = 39 mm) and the length along the short side of the display area of the liquid crystal driving IC (L2 = 39 mm). / L2) is 1.00.

[Example 3]
In Example 3, a liquid crystal driving IC having a long side length of 40 mm was used. The distance between the long side of the liquid crystal driving IC and the short side of the display area was 2 mm. In the liquid crystal display panel according to Example 3, the ratio (L1) of the length of the short side of the display area (L1 = 39 mm) to the length along the short side of the display area of the liquid crystal driving IC (L2 = 40 mm). / L2) is 0.98.

[Example 4]
In Example 4, a liquid crystal driving IC having a long side length of 41 mm was used. The distance between the long side of the liquid crystal driving IC and the short side of the display area was 2 mm. In the liquid crystal display panel according to Example 4, the ratio (L1) between the length of the short side of the display area (L1 = 39 mm) and the length along the short side of the display area of the liquid crystal driving IC (L2 = 41 mm). / L2) is 0.95.

[Example 5]
In Example 5, a liquid crystal driving IC having a long side length of 45 mm was used. The distance between the long side of the liquid crystal driving IC and the short side of the display area was 2 mm. In the liquid crystal display panel according to Example 5, the ratio (L1) between the length of the short side of the display area (L1 = 39 mm) and the length along the short side of the display area of the liquid crystal driving IC (L2 = 45 mm). / L2) is 0.87.

[Comparative Example 1]
In Comparative Example 1, a liquid crystal driving IC having a long side length of 12 mm was used. The distance between the long side of the liquid crystal driving IC and the short side of the display area was 2 mm. The liquid crystal display panel according to Comparative Example 1 has a ratio (L1) between the length of the short side of the display area (L1 = 39 mm) and the length along the short side of the display area of the liquid crystal driving IC (L2 = 12 mm). / L2) is 3.25.

[Comparative Example 2]
In Comparative Example 2, a liquid crystal driving IC having a long side length of 25 mm was used. The distance between the long side of the liquid crystal driving IC and the short side of the display area was 2 mm. The liquid crystal display panel according to Comparative Example 2 has a ratio (L1) between the length of the short side of the display area (L1 = 39 mm) and the length along the short side of the display area of the liquid crystal driving IC (L2 = 25 mm). / L2) is 1.56.

[Comparative Example 3]
In Comparative Example 3, a liquid crystal driving IC having a long side length of 32 mm was used. The distance between the long side of the liquid crystal driving IC and the short side of the display area was 2 mm. The liquid crystal display panel according to Comparative Example 3 has a ratio (L1) between the length of the short side of the display area (L1 = 39 mm) and the length along the short side of the display area of the liquid crystal driving IC (L2 = 32 mm). / L2) is 1.22.

[Comparative Example 4]
In Comparative Example 4, a liquid crystal driving IC having a long side length of 12 mm was used. The distance between the long side of the liquid crystal driving IC and the short side of the display area was 4 mm. The liquid crystal display panel according to Comparative Example 4 has a ratio (L1) between the length of the short side of the display area (L1 = 39 mm) and the length along the short side of the display area of the liquid crystal driving IC (L2 = 12 mm). / L2) is 3.25.

  As shown in Table 1, in Examples 1 to 5, display unevenness was not observed over the entire display area, whereas in Comparative Examples 1 to 3, display unevenness was confirmed.

  In Examples 1 to 5, the ratio (L1 / L2) between the length (L1) of the short side of the display area and the length (L2) of the long side of the liquid crystal driving IC is 1.2 or less. Therefore, even when the liquid crystal driving IC and the transparent substrate warp in a concave shape, the vicinity of the outer edge in the longitudinal direction of the liquid crystal driving IC, which is greatly affected by warping, is applied to the frame area, and the display area is distorted. Is due to the suppression.

  On the other hand, in Comparative Examples 1 to 3, the ratio (L1 / L2) of the short side length (L1) of the display area to the long side length (L2) of the liquid crystal driving IC exceeds 1.2. Therefore, the influence of the warp of the liquid crystal driving IC and the transparent substrate reaches the display area, and the gap of the liquid crystal layer is locally changed by the deformation distortion of the display area, so that the display surface located around the IC chip mounting portion Display unevenness occurred.

  In Comparative Example 4, display unevenness could be suppressed. This is because the distance between the long side of the liquid crystal driving IC and the short side of the display area is as large as 4 mm. As a result, the liquid crystal display panel cannot be reduced in size.

DESCRIPTION OF SYMBOLS 1 Anisotropic conductive film, 2 Release film, 3 Binder resin layer, 4 Conductive particle, 5 Take-up reel, 6 Display area, 6a One side, 7 Frame area, 10 Liquid crystal display panel, 11 Transparent substrate, 12 Transparent substrate, 12a edge, 13 seal, 14 liquid crystal, 15 panel display, 16 transparent electrode, 17 transparent electrode, 18 liquid crystal driving IC, 18a mounting surface, 19 input terminal, 20 input terminal row, 21 output terminal row, 22 output terminal row , 23 Input bump, 24 Input bump row, 25 Output bump, 26 Output bump row, 27 Mounting part, 28 Alignment film, 29 Polarizing plate, 31 Substrate side alignment mark, 32 IC side alignment mark, 33 Crimp head

Claims (7)

A substrate provided with a display area;
An electronic component anisotropically conductively connected along one side of the display area,
The ratio (L1 / L2) of the length (L1) of one side of the display area where the electronic component is connected to the length (L2) along the one side of the display area of the electronic component is An anisotropic conductive connector that is 1.2 or less.   The distance D in the direction between the end of one side of the display area where the electronic component is connected and the end of the electronic component in the direction along the one side of the display area is ± 0.1 L2 The anisotropic conductive connector according to claim 1, wherein:   The distance D is equal at both ends of one side of the display area where the electronic component is connected and at both ends in the length direction along one side of the display area of the electronic component. Anisotropic conductive connector.   The ratio (L1 / L2) of the length (L1) of one side of the display area where the electronic component is connected to the length (L2) along the one side of the display area of the electronic component is The anisotropic conductive connector according to claim 1, which is 0.8 or more. The electronic component is connected along one side of the substrate,
A ratio (L3 / L2) of a length (L3) of one side of the substrate to which the electronic component is connected to a length (L2) along one side of the display area of the electronic component is 1 or more. The anisotropic conductive connector according to any one of claims 1 to 4, which is 4 or less.   The anisotropic connection structure according to claim 5, wherein a length (L3) of one side to which the electronic component of the substrate is connected is 12 mm or more and 63 mm or less.   The display apparatus provided with the anisotropic conductive connection body of any one of Claims 1-6.

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