WO2013069919A1 - Display panel and display device having same - Google Patents

Abstract

The present invention relates to a display panel and display device having same. More particularly, the prevent invention relates to a display panel including: a substrate; and an anisotropic conductive film disposed on the substrate, wherein the anisotropic conductive film includes a particulate core material, and conductive particles including a conductive layer disposed on a surface of the particulate core material, and a modulus ratio (B/A) of a modulus (B) of the particulate core material to a modulus (A) of the substrate is less than 1, and to a display device having the same.

Description

Display panel and display device including same

The present invention relates to a display panel and a display device including the same. More specifically, the present invention relates to a display panel including an anisotropic conductive film and a substrate and a display apparatus including the same, which are capable of preventing separation of the conductive particles when pressing the anisotropic conductive film formed on the substrate and eliminating the problem of lowering the conductivity. It is about.

In the electronic packaging of LCDs, PDPs, OLEDs, etc., the necessity of connecting a large number of electrodes at one time with a narrow gap is increasing as the circuit becomes extremely fine and the connection density increases. In particular, in the packaging of liquid crystal displays (LCDs), conductive adhesives are used for mechanical and electrical connection between a flexible printed circuit (FPC) and a glass display.

The conductive adhesive includes an isotropic conductive adhesive and an anisotropic conductive film (ACF). In the anisotropic conductive film used mostly, monodisperse electroconductive particle is contained in the form disperse | distributed to thermosetting or thermoplastic insulating resin. The electroconductive particle contains the monodisperse polymer particle (henceforth a core material) comprised from polystyrene, polymethylmethacrylate, and an amino resin polymer. Japanese Patent Application Laid-open No. Hei 16-123842 discloses a process of producing an initial condensate, which is an amino resin precursor, by reacting an amino compound with formaldehyde, dyeing, emulsifying and curing to prepare colored amino resin crosslinked particles. Described. The surface of this core material is coated with a conductive material. In general, electroless plating is mainly used as a method of plating metal materials (Ni and Au). In order to perform such an electroless plating method, a process of pretreating the polymer particles to be plated in a state suitable for plating is important. This pretreatment process consists of etching, conditioning, sensitization, activation, and predeposition processes in that order.

When anisotropically conductive films containing conductive particles containing core materials such as polystyrene-based resins, poly (meth) acrylate-based resins, amino resins, polyurethane-based resins, etc. are applied to glass substrates, commercial PCBs and the like, there is no particular problem. In the process, high strength polymer materials have advantages of being relatively hard or having few deformations, but problems such as high initial resistance or breakage or cracking of particles occur. In addition, when the polymer composite particles are relatively soft and easily deformable polymer such as acrylic resin or polyurethane resin, the initial conductivity is good but easily deformed and excessively crushed, so that the conductive particles undergo plastic deformation during thermocompression. There is a problem.

In recent years, as development of flexible displays has progressed, various materials in addition to glass substrates are being examined, requiring changes to core materials. In addition to thermal or UV curable materials, studies have been made on materials with significantly low strength. In this case, as a substrate having a much lower modulus is used as a lower substrate, new problems arise such that the conductive particles of the anisotropic conductive film are separated or electrically shorted to the lower substrate during the compression process, and thus a solution is required. It is becoming.

It is an object of the present invention to provide a display panel which prevents conductive particles from being separated from the anisotropic conductive film even if the anisotropic conductive film is pressed onto the substrate.

Another object of the present invention is to provide a display device including the display panel.

Display panel according to an aspect of the present invention is a substrate; And an anisotropic conductive film formed on the substrate, wherein the anisotropic conductive film comprises: a particulate core material; And conductive particles including a conductive layer formed on the surface of the particulate core material, wherein a modulus ratio (B / A) of the modulus (B) of the particulate core material to the modulus (A) of the substrate may be less than about 1 have.

The substrate may include one or more of glass, silicone, acrylic resin, epoxy resin, polyester resin, polyethersulfone resin, polyarylate resin, polycarbonate resin, and polyimide resin.

The modulus of the particulate core material may be about 0.1 MPa-1.0 GPa.

The modulus of the substrate can be about 0.1 MPa-75 GPa.

The substrate is a glass substrate, and the modulus ratio may be about 0.15 x 10 ^-5-0.01 .

The substrate may be a silicon-based substrate having a modulus of about 0.1 MPa-15 MPa.

The particulate core material may include a silicone-based resin.

The silicone resin may include one or more of polyalkylsiloxane, polyarylsiloxane, polyalkylarylsiloxane, silicone rubber.

The particulate core material is styrene-butadiene rubber (SBR), butadiene-based rubber, isoprene-based rubber, chloroprene, neoprene rubber, ethylene-propylene-diene terpolymer, styrene-ethylene-butylene-styrene (SEBS) block copolymer, styrene Ethylene-propylene-styrene (SEPS) block copolymers, acrylonitrile-butadiene rubber (NBR), hydrogenated nitrile rubber (HNBR), or fluorinated rubber It may further include the above.

The particulate core material may have a particle diameter of about 2 μm-20 μm.

The conductive layer may include at least one of a conductive polymer layer and a metal layer.

The conductive layer may be one in which the metal layer is sequentially stacked on the conductive polymer layer.

The conductive polymer layer may include one or more of polypyrrole, polyaniline, polythiophene, and derivatives thereof.

The conductive polymer layer may have a thickness of about 1 nm to 500 nm.

The metal layer may include at least one of Ni, Au, Ag, Cu, Zn, Cr, Al, Co, Sn, Pt, and Pd.

The metal layer may have a thickness of about 10 nm to 300 nm.

The metal layer may be a single layer or a multilayer.

A display device according to another aspect of the present invention may include the display panel.

The present invention provides a display panel which prevents conductive particles from being separated from the anisotropic conductive film even when the anisotropic conductive film is pressed onto the substrate.

1 is a cross-sectional view of a display panel of one embodiment of the present invention.

2 is a conceptual diagram of a state before pressing the driver IC to the display panel.

3 is a conceptual diagram of a state in which a driver IC is pressed on the display panel.

It is a schematic sectional drawing of the anisotropic conductive film containing the electroconductive particle of this invention.

5 is a schematic cross-sectional view of the conductive particles of one embodiment of the present invention.

6 is a schematic cross-sectional view of conductive particles of another embodiment of the present invention.

7 is a schematic cross-sectional view of conductive particles of yet another embodiment of the present invention.

As used herein, "modulus" means storage modulus, and modulus is a value measured under a frequency of about 0.01 Hz to 100 Hz in a bending mode, a constant load up to about 16 N, and a strain amplitude of about 0.1 to 240 μm. It may mean.

Display panel according to an aspect of the present invention is a substrate; And an anisotropic conductive film formed on the substrate, wherein the anisotropic conductive film comprises: a particulate core material; And a conductive layer formed on the surface of the particulate core material, wherein the modulus ratio (B / A) of the modulus (B) of the particulate core material to the modulus (A) of the substrate may be less than about 1.

When the anisotropic conductive film is pressed onto the substrate in the manufacturing process of the conventional display panel, the conductive particles included in the anisotropic conductive film may be separated from the anisotropic conductive film to the substrate, or the connection between the bump of the driver IC and the substrate electrode may be difficult. Could have been. This is more serious in recent years when applying a flexible substrate for securing flexibility.

In contrast, the display panel of the present invention may include an anisotropic conductive film containing conductive particles such that the above-described separation problem or connection problem does not occur. This may be due to making the modulus of the particulate core material of the present invention smaller than the modulus of the substrate.

When the modulus ratio is 1 or more, when the anisotropic conductive film containing the conductive particles is pressed onto the substrate, the conductive particles may be separated from the anisotropic conductive film or the conductivity may not be easily secured. Preferably, the modulus ratio may be about 0.4 or more and less than one.

1 is a cross-sectional view of a display panel of one embodiment of the present invention.

Referring to FIG. 1, the display panel 100 may have a structure in which an anisotropic conductive film 5 including conductive particles 4 is stacked on a substrate 10 on which electrodes 9 are formed.

2 and 3 respectively show a state before and after the driver IC 20 in which the bumper 8 is formed on the display panel of one embodiment of the present invention is pressed. 2 and 3, when the driver IC 20 having the bumper 8 is compressed, excessive or insufficient conductivity between the bumper 20 of the driver IC 20 and the conductive particles 4 in the substrate 10 is reduced. You can control the connection. That is, the display may be realized by minimizing a defect such as an electrical short generated when an abnormal connection between the bumper and the bumper of the driver IC and the substrate electrode to be connected to the driver IC or other substrate electrodes occurs. According to FIG. 3, even when compressed, the conductive particles are densely concentrated in the bumps as compared with FIG. 2 without being separated from the anisotropic conductive film, thereby minimizing a poor electrical conduction.

Board

The substrate may include both a glass substrate and a flexible substrate. Specifically, the substrate is one of a polyester resin, a polyether sulfone resin, a polyarylate resin, a polycarbonate resin, a polyimide resin, including a glass, a silicone, an acrylic resin, an epoxy resin, a polyethylene terephthalate, a polyethylene naphthalate, and the like. It may contain the above.

The modulus of the substrate can be about 0.1 MPa-75 GPa.

In one embodiment, the substrate may be a silicon-based substrate having a modulus of about 0.1 MPa-15 MPa.

In another embodiment, the substrate can be a glass substrate having a modulus of about 65 GPa-75GPa.

Regardless of the type of the substrate, the modulus ratio may be less than about 1.

In one embodiment, the substrate can be a glass substrate, wherein the ratio of the modulus can be less than about 1, preferably about 0.15 x 10 ^-5-0.01 .

In another embodiment, the substrate may be a flexible substrate including silicon-based or the like, wherein the ratio of the modulus may be less than about 1, preferably about 0.4 or more and less than 1.

The substrate may have a thickness of about 30 μm-200 μm.

An electrode may be formed on the substrate surface to connect the driver IC and the bumper to the substrate.

Anisotropic conductive film

The anisotropic conductive film can contain the said electroconductive particle.

4 is a schematic cross-sectional view of an anisotropic conductive film according to an embodiment of the present invention. According to FIG. 4, the anisotropic conductive film 5 comprises a matrix 6; And conductive particles 4 included in the matrix 6.

The conductive particles are fine particle core; And a conductive layer formed on the surface of the particulate core material, wherein the conductive layer may include at least one of a conductive polymer layer and a metal layer.

The particulate core material may have a modulus of about 0.1 Mpa-1.0 GPa, preferably about 1 Mpa-10 MPa. Within this range, the conductive particles can be prevented from being separated from the anisotropic conductive film or the conductivity deteriorated in the process of pressing the anisotropic conductive film containing the conductive particles onto the substrate.

The particulate core material may be monodisperse. That is, the particle size distribution of the electroconductive particle containing a particulate core material can be uniform. When the particle size distribution is uniform, it is excellent in electrical conductivity.

The particulate core material may have an average particle diameter of about 2 μm to 20 μm, preferably about 2 μm to 7 μm. Within this range, the function as conductive particles may not be lost, and short circuits between adjacent electrodes may not occur.

The particulate core material may include particles including a silicone-based resin.

By using a silicone-based resin, the conductive particles can be efficiently compressed onto the substrate, and by controlling the ratio between the conductive particles and the modulus of the substrate through the interconnection between the conductive particles, the conductive layer is appropriately connected during the compression to form the conductive particles. It is possible to solve the problem of the deterioration of conductivity caused by the departure and the potential failure.

The silicone resin may include at least one of polyalkylsiloxane, polyarylsiloxane, polyalkylarylsiloxane, and silicone rubber including polydimethylsiloxane.

In addition to the silicone resin, the particulate core material includes styrene-butadiene rubber (SBR), butadiene rubber, isoprene rubber, chloroprene rubber, neoprene rubber, ethylene-propylene-diene terpolymer, styrene-ethylene-butylene-styrene (SEBS ) Block copolymers, styrene-ethylene-propylene-styrene (SEPS) block copolymers, acrylonitrile-butadiene rubber (NBR), hydrogenated nitrile rubber (HNBR) and florinated rubber It may further include one or more of Fluorinated Rubber.

The shape of the particulate core material is not limited, but may be spherical.

A conductive layer may be stacked on the particulate core material to impart conductivity. Specifically, the conductive layer may include at least one of a conductive polymer layer and a metal layer.

5 to 7 are schematic cross-sectional views of the conductive particles of the embodiment of the present invention.

As shown in FIG. 5, the electroconductive particle 4 is the fine particle core 1; And it may include a conductive polymer layer (2) formed on the particulate core material (1).

As shown in FIG. 6, the electroconductive particle 4 is the fine particle core 1; And a metal layer 3 formed on the particulate core material 1.

In addition, the conductive layer may be formed of a conductive polymer layer and a metal layer sequentially. That is, as shown in FIG. 7, the conductive particles 4 include the fine particle core 1; And a conductive polymer layer (2) formed on the particulate core material (1); And a metal layer 3 formed on the conductive polymer layer 2.

The conductive polymer layer may include one or more of polypyrrole, polyaniline, polythiophene, and derivatives thereof.

The conductive polymer layer may have a thickness of about 1 nm to 500 nm, preferably about 10 nm to 200 nm. Within the above range, conductivity can be imparted and can be used for an anisotropic conductive film.

The metal layer may include at least one of Ni, Au, Ag, Cu, Zn, Cr, Al, Co, Sn, Pt, and Pd.

The metal layer may have a thickness of about 10 nm to 300 nm, preferably about 80 nm to 200 nm. Within the above range, conductivity can be imparted and can be used for an anisotropic conductive film.

The conductive polymer layer or the metal layer may have a single layer structure or a multilayer structure of two or more layers of different kinds of metals. In particular, when the metal layer is a single layer or continuous multilayer structure of a dissimilar metal material, for example, Ni / Au alloy, the coating property on the surface of the particulate core material, the stability of the metal material and the conductivity thereof may be improved.

The shape of the conductive particles is not limited, but may be spherical particles.

The said electroconductive particle can be manufactured by a conventional method. For example, (a) forming a particulate core material using a composition comprising a silicone-based resin; And (b) forming a conductive layer including at least one of a conductive polymer layer and a metal layer on the surface of the particulate core material.

Step (a) may be to form a monodisperse crosslinked particulate core material by suspension polymerization, precipitation polymerization, dispersion polymerization, seed polymerization, multistage seed polymerization or direct molding. However, this is only a general manufacturing method of the fine particles, and the present invention is not limited thereto. The direct molding method may mean a molding method that is not made in a solution.

Step (b) may be to form a conductive polymer layer on the surface of the particulate core material by dispersing the particulate core material in a dispersion solvent together with a dispersion stabilizer, by adding a monomer and an initiator for the conductive polymer to react.

The dispersion stabilizer of step (b) serves to stabilize the dispersion of the polymer particles in a dispersion solvent, polyvinylpyrrolidone, polyvinyl alcohol, ionic or nonionic interface having water dispersibility or alcohol dispersibility An activator or the like can be used alone or in combination. As the dispersion solvent, an alcohol solvent or water can be used, and as an initiator, APS ((NH ₄ ) ₂ S ₂ O ₈ ), KSP (K ₂ S ₂ O ₈ ), FeCl ₃ and the like can be used.

In step (b), a metal catalyst may be deposited on the surface of the conductive polymer layer and then electroless plated to form a metal layer. Pd catalyst is preferably used as the metal catalyst. Pd particles may be deposited on the surface and subjected to metal electroless plating to form a metal layer.

The conductive particles may be included in about 1-5% by weight of the anisotropic conductive film. Within this range, it is possible to maintain the insulating properties and to maintain the circuit-to-circuit connection performance, which is the original role of the conductive particles.

The matrix of the anisotropic conductive film may include a resin that is commonly used in manufacturing an anisotropic conductive film. For example, the matrix of the anisotropic conductive film may include an epoxy-based, (meth) acrylate-based, and the like.

The thickness of the anisotropic conductive film may be about 10㎛-40㎛.

Another aspect of the invention may include a display panel. The device is not particularly limited as long as the device may include the display panel. For example, the device may include a display device (eg, a flexible display device).

The present invention will be described in more detail with reference to the following examples. However, this is only for the detailed description as one possible embodiment of the present invention, the present invention is not limited thereto.

Example 1

A conductive polymer layer made of polythiophene was formed on the particulate core material of Table 1 to prepare particles having a particle diameter of 3-4 μm. Ni coating was applied to the surface of the particles to form a Ni coating at a thickness of 100 ± 10 nm, and then Au was coated at a thickness of 50 ± 5 nm to prepare conductive particles. Anisotropic conductivity by curing a composition comprising conductive particles, acrylic copolymer, acrylate modified urethane resin, acrylonitrile butadiene copolymer, isocyanuric acid ethylene oxide modified diacrylate, silica particles and lauroyl peroxide A film was prepared. The anisotropic conductive film was crimped | bonded to the board | substrate of following Table 1, and the board | substrate with an anisotropic conductive film was formed.

Force was applied at 185 ° C. for 5 seconds at 5 MPa. The conductivity (conductivity) was measured to evaluate whether the conductive particles were separated. When detachment of electroconductive particle generate | occur | produces, electroconductivity becomes low.

Example 2

A substrate on which an anisotropic conductive film was formed was prepared in the same manner as in Example 1, except that the particulate core material of Table 1 and the substrate of Table 1 were used. The force was measured at 185 ° C. for 5 seconds at 5 MPa to measure conductivity.

Example 3

A substrate on which an anisotropic conductive film was formed was prepared in the same manner as in Example 1, except that the particulate core material of Table 1 and the substrate of Table 1 were used. Conductivity was measured by applying a force at 185 ° C. at 20 MPa for 5 seconds.

Comparative Example 1

A substrate on which an anisotropic conductive film was formed was prepared in the same manner as in Example 1, except that the particulate core material of Table 1 and the substrate of Table 1 were used. Conductivity was measured by applying a force at 185 ° C. at 20 MPa for 5 seconds.

The modulus (storage modulus) of the particulate core and the substrate was measured using DMA 242C, and the modulus was measured under a frequency of 0.01 to 100 Hz, constant load up to 16 N, and strain amplitude of 0.1 to 240 μm in bending mode.

 The conductivity measurement results are shown in Table 1 below.

Table 1

	Example 1	Example 2	Example 3	Comparative Example 1
Particulate heartwood	Silicone	Silicone	Silicone	Polycarbonate
Modulus of particulate core material (B)	2 MPa	2 MPa	10 MPa	50 MPa
Board	Glass	Silicone	Silicone	Silicone
Modulus (A) of the board	70 GPa	5 MPa	12 MPa	10 MPa
Modulus Ratio (B / A)	2.86 x 10 -5	0.4	0.83	5
Conductivity	3-5 m	3-5 m	6-12 mΩ	Not detectable

As shown in Table 1, the problems such as the separation of the conductive particles in the pressurized pressure conditions of Examples 1 to 3 did not occur, the conductivity having a constant resistance value is secured to effectively secure the lower electrode between the DRIVE IC and the substrate The signal transmission is good. On the contrary, in the case of Comparative Example 1, almost all of the conductive particles were separated, the resistance value became infinite, and conductivity was not secured.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be manufactured in various forms, and a person of ordinary skill in the art to which the present invention pertains has the technical idea of the present invention. However, it will be understood that other specific forms may be practiced without changing the essential features. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims (18)

1. Board; And an anisotropic conductive film formed on the substrate,

   The anisotropic conductive film is a particulate core material; And conductive particles including a conductive layer formed on a surface of the particulate core material,

   And a modulus ratio (B / A) of modulus (B) of the particulate core material to modulus (A) of the substrate.
2. The display panel of claim 1, wherein the substrate comprises at least one of glass, silicone, acrylic resin, epoxy resin, polyester resin, polyethersulfone resin, polyarylate resin, polycarbonate resin, and polyimide resin.
3. The display panel of claim 1, wherein the particulate core has a modulus of about 0.1 MPa-1.0 GPa.
4. The display panel of claim 1, wherein the substrate has a modulus of about 0.1 MPa-75 GPa.
5. The display panel of claim 1, wherein the substrate is a glass substrate and the modulus ratio is about 0.15 × 10 ⁻⁵ −0.01.
6. The display panel of claim 1, wherein the substrate is a silicon-based substrate having a modulus of about 0.1 MPa-15 MPa.
7. The display panel of claim 1, wherein the particulate core material comprises a silicone resin.
8. The display panel of claim 7, wherein the silicone resin comprises at least one of polyalkylsiloxane, polyarylsiloxane, polyalkylarylsiloxane, and silicone rubber.
9. According to claim 7, wherein the particulate core material is styrene-butadiene rubber (SBR), butadiene-based rubber, isoprene-based rubber, chloroprene, neoprene rubber, ethylene-propylene-diene terpolymer, styrene-ethylene-butylene-styrene (SEBS ) Block copolymers, styrene-ethylene-propylene-styrene (SEPS) block copolymers, acrylonitrile-butadiene rubber (NBR), hydrogenated nitrile rubber (HNBR), florinated rubber Display panel further comprising at least one of (Fluorinated Rubber).
10. The display panel of claim 1, wherein the particulate core material has a particle diameter of about 2 μm-20 μm.
11. The display panel of claim 1, wherein the conductive layer comprises at least one of a conductive polymer layer and a metal layer.
12. The display panel of claim 11, wherein the conductive layer is formed by sequentially stacking the metal layer on the conductive polymer layer.
13. The display panel of claim 11, wherein the conductive polymer layer comprises at least one of polypyrrole, polyaniline, polythiophene, and derivatives thereof.
14. The display panel of claim 11, wherein the conductive polymer layer has a thickness of about 1 nm to 500 nm.
15. The display panel of claim 11, wherein the metal layer comprises at least one of Ni, Au, Ag, Cu, Zn, Cr, Al, Co, Sn, Pt, and Pd.
16. The display panel of claim 11, wherein the metal layer has a thickness of about 10 nm to 300 nm.
17. The display panel of claim 11, wherein the metal layer is a single layer or a multilayer.
18. 18. A display device comprising the display panel of claim 1.

Images