TWI484504B - Anisotropic conductive film, method for producing the same and method for pressing circuit terminals - Google Patents

Description

Anisotropic conductive film, preparation method thereof, and method for pressing circuit terminal Field of invention

The present invention relates to an anisotropic conductive film. More particularly, the present invention relates to an anisotropic conductive film comprising a base film, a conductive adhesive layer and an insulating adhesive layer, wherein the conductive adhesive layer has a higher melt viscosity than the insulating adhesive layer. The difficulty in removing the release film by initial pressing can be solved while maintaining the number of effective conductive particles connected to the circuit terminals.

Background of the invention

The anisotropic conductive film means a film-like adhesive in which metal particles or metal-coated plastic particles are dispersed. Anisotropic conductive films are widely used in various fields of application, for example, circuit connections in the field of flat panel displays and component mounting in the field of semiconductor components. When the isotropic conductive film is inserted between the connected circuits, followed by hot pressing under a specific condition, the circuit terminals are electrically connected via the conductive particles, and an insulating adhesive resin is filled in the adjacent circuit terminals. The gap between the conductive particles is such that the insulating properties between the circuit terminals are achieved independently of each other.

In recent years, information technology (IT) components have become smaller in size and thickness and become lighter in weight, and the resolution of the flat panel display has gradually increased. Therefore, there is an increasing demand for a narrower circuit width in such components. However, the conductive particles present in the adhesive layer to connect the circuits tend to aggregate, inevitably causing the problem of short-circuiting of the electrons. In response to this problem, multi-level anisotropic conductive films have been commonly used in a wide variety of applications.

Fig. 1 illustrates a multi-layer anisotropic conductive film currently used. As illustrated in FIG. 1, the anisotropic conductive film has a multi-layer structure in which an insulating adhesive layer 1 and a conductive adhesive layer 2 are sequentially laminated on a release film 3, such as a polyparaphenylene. A film of ethylene diformate. The conductive adhesive layer 2 contains conductive particles 4 and has a higher melt viscosity than the insulating adhesive layer 1. When the multi-layer film is bonded between a glass and a film on a film (COF) (or a flexible printed circuit board (fPCB)), the conductive adhesive layer having a relatively high melt viscosity and the glass The insulating adhesive layer that is in contact and has a relatively low melt viscosity is in contact with the COF (or fPCB).

When the anisotropic conductive film is actually used to make a display, it is generally placed on the glass by hot pressing and fixed to the glass, and is initially pressed to remove the release film. This procedure is advantageous in increasing the number of conductive particles positioned on the terminals of the circuit, but is inferior to the insulating adhesive layer of the release film and is attributed to its higher melt viscosity during initial compression. Attached to the release film, making the release film difficult to remove.

Therefore, it is desirable to develop an anisotropic conductive film that can solve the problems encountered by the initial pressing while maintaining the number of effective conductive particles positioned on the circuit terminals.

Summary of invention

The present invention is directed to providing a one-way conductive film. In one embodiment, the anisotropic conductive film comprises a base film, a conductive adhesive layer is formed on the base film, and an insulating adhesive layer is formed on the conductive adhesive layer, wherein the conductive adhesive layer is at 100 ° C. The melt viscosity is higher than the insulating adhesive layer at 100 ° C.

In one embodiment, the conductive adhesive layer has a melt viscosity at 100 ° C. The ratio of the insulating adhesive layer to 100 ° C is from 2:1 to 100:1.

In an embodiment, the ratio of melt viscosity may range from 5:1 to 50:1.

In an embodiment, the insulating adhesive layer may have a melt viscosity of 10 to 1,000 Pa‧s at 100 °C.

In one embodiment, the conductive adhesive layer may have a melt viscosity of one of 50 to 100,000 Pa‧s at 100 °C.

Simple illustration

The above and other aspects, features and advantages of the present invention will become apparent from the following detailed description in conjunction with the accompanying drawings in which: FIG. 1 illustrates a conventional multi-level anisotropic conductive film; and FIG. 2 illustrates the invention in accordance with the present invention. An anisotropic conductive film of one exemplary embodiment.

Detailed description of the preferred embodiment

The present invention is directed to providing a isotropic conductive film comprising a base film, forming a conductive adhesive layer on the base film, and forming an insulating adhesive layer on the conductive adhesive layer, wherein the conductive adhesive layer is at 100 ° C The melt viscosity is higher than the insulating adhesive layer at 100 ° C.

Preferably, the ratio of the conductive adhesive layer at 100 ° C to the insulating adhesive layer at 100 ° C is from 2:1 to 100:1.

Fig. 2 illustrates the structure of an anisotropic conductive film according to an exemplary embodiment of the present invention. As illustrated in FIG. 2, the anisotropic conductive film has a structure in which a conductive adhesive layer 2 and an insulating adhesive layer 1 are sequentially laminated on a base film 3, such as polyethylene terephthalate. Ester film. The conductive adhesive layer 2 contains conductive particles 4 and has a higher melt viscosity than the insulating adhesive layer 1.

The conductive adhesive layer and the insulating adhesive layer have a melt viscosity measured at a strain of 5% and a frequency of 1 rad/s, using a parallel plate and a disposable aluminum plate (diameter = 8 mm) at 10 ° C / One of the min rates increases this temperature from 30 to 180 °C. In the anisotropic conductive film, the equivalent value measured at 100 ° C is defined as the melt viscosity of the conductive adhesive layer and the insulating adhesive layer.

The ratio of the melt viscosity may be adjusted to 2:1 to 100:1 by varying the melt viscosity of the conductive adhesive layer and the insulating adhesive layer. When the melt viscosity ratio at 100 ° C falls within the range defined above, the insulating adhesive layer is attributed to its high fluidity by virtue of the bond remaining in the gap between the circuit terminals, and is present in the conductive adhesive The conductive particles in the layer are positioned on the desired circuit terminals. Preferably, the ratio of the melt viscosity is from 5:1 to 50:1.

The conductive adhesive layer may have a melt viscosity of 50 to 100,000 Pa‧s at 100 °C.

The insulating adhesive layer may have a melt viscosity of 10 to 1,000 Pa‧s at 100 °C.

The ratio of the melt viscosity may be adjusted to the range defined above by fixing the melt viscosity of the insulating adhesive layer and varying the melt viscosity of the conductive adhesive layer. The melt viscosity of the conductive adhesive layer may vary by controlling the content of the polyurethane adhesive, the acrylic adhesive, and the nitrile butadiene rubber (NBR) resin, which are included in the conductive adhesive layer. In one of the adhesive systems, and by controlling the urethane acrylate content included in one of the conductive adhesive layer curable systems.

Details of the base film, the conductive adhesive layer, and the insulating adhesive layer of the anisotropic conductive film will be given.

Base film

The type of the base film is not particularly limited. A polyolefin-based film can be mainly used as the base film. Examples of materials suitable for the polyolefin film include polyethylene, polypropylene, ethylene/propylene copolymer, polybutene-1, ethylene/vinyl acetate copolymers, and poly Polyethylene/styrene butadiene rubber dopant and polyvinyl chloride. Polymers such as polyethylene terephthalate, polycarbonate, and poly(methyl methacrylate); thermoplastic elastomers such as polyurethane and polyamide-polyol copolymers; Mixtures of these can also be used.

The thickness of the base film can be selected within a suitable range, for example, from 10 to 50 μm.

Conductive adhesive layer

The conductive adhesive layer may include a binder system, a curable system, and a heat curing agent.

The conductive adhesive layer may include 45 to 80% by weight of the adhesive system, 15 to 40% by weight of the curable system, and 0.5 to 5% by weight of the heat curing agent.

The binder system used as the matrix of the film may include a nitrile butadiene rubber (NBR) resin, an acrylic resin, and a polyurethane resin.

The adhesive system may include 0 to 40% by weight of the nitrile butadiene rubber resin, 30 to 70% by weight of the acrylic resin, and 30 to 70% by weight of the polyurethane resin.

The NBR resin is a copolymer prepared by emulsion polymerization of acrylonitrile and butadiene. The content of acrylonitrile and butadiene in the copolymer and the polymerization method are not particularly limited. The NBR resin may have an average molecular weight of one weight of 50,000 to 2,000,000 g/mol.

The NBR resin may be present in an amount of from 0 to 10% by weight based on the solids content of the conductive adhesive layer. Within this range, the film can be formed satisfactorily. Preferably, the NBR resin is present in an amount of from 5 to 10% by weight.

The acrylic resin may be prepared by polymerization of an acrylic monomer with an optional monomer which is polymerizable with the acrylic monomer. For example, the acrylic resin may be selected from the group consisting of (meth) acrylates, (meth)acrylic acid, vinyl acetate, and thus modified acrylic acid having at least one C ₂ -C ₁₀ alkyl group. Prepared by polymerization of at least one monomer of the group consisting of monomers. The polymerization method is not particularly limited.

The acrylic resin may be present in an amount of from 0 to 40% by weight based on the solid content of the conductive adhesive layer. Within this range, the film can be formed satisfactorily and the melt viscosity ratio defined above can be obtained. The acrylic resin is preferably present in an amount of from 20 to 28% by weight.

The polyurethane resin is a polymer resin having a urethane bond and is supported by isophorone diisocyanate or polytetramethylene glycol. Prepared by polymerization of . The single system used for the polyurethane resin is not limited. The polyurethane resin may have an average molecular weight of one weight of 50,000 to 100,000 g/mol.

The polyurethane resin may be present in an amount of from 0 to 40% by weight based on the solid content of the conductive adhesive layer. Within this range, the film can be formed satisfactorily and the melt viscosity ratio defined above can be obtained. The polyurethane resin is preferably present in an amount of from 36 to 40% by weight.

The curable system may include at least one compound selected from the group consisting of urethane acrylates and (meth) acrylate monomers. Preferably, the curable system comprises a urethane acrylate.

The urethane acrylate comprises a urethane bond and a double bond at both ends. The urethane acrylate may be prepared by polymerization of diisocyanate, ethylene glycol, and the like. The polymerization for preparing the urethane acrylate is not particularly limited.

The urethane acrylate may have an average molecular weight of one weight of from 500 to 30,000 g/mol. Within this range, the film can be formed satisfactorily and is highly compatible.

The urethane acrylate may be present in an amount of from 12 to 50% by weight based on the solids content of the conductive adhesive layer. Within this range, the anisotropic conductive film is highly compatible. The urethane acrylate is preferably present in an amount of from 12 to 24% by weight.

The (meth) acrylate monomer acts as a reactive diluent in the anisotropic conductive film composition. The (meth) acrylate monomer may be selected from, but not particularly limited to, the group consisting of: 1,6-hexanediol mono(meth)acrylate, (meth)acrylic acid 2-hydroxyethyl ester, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, propyl 2-hydroxy-3-phenoxy (meth)acrylate (2- Hydroxy-3-phenyloxypropyl(meth)acrylate), 1,4-butanediol (meth)acrylate, 2-hydroxyethyl(meth)acryloyl phosphate,4 -Hydroxycyclohexyl(meth)acrylate, neopentyl glycol mono(meth)acrylate, trimethylolethane di(meth) Acrylate), trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, pentaerythritol hexa(meth)acrylate, dipentaerythritol hexa(methyl) Acrylate, glycerol di(meth) acrylate, hydrofurfuryl (meth) acrylate, isodecyl (meth) acrylate, 2-(2- ethoxy) (meth) acrylate base 2-(2-ethoxyethoxy)ethyl(meth) acrylate, methacrylate (meth) acrylate, lauryl (meth) acrylate, -2-benzene (meth) acrylate Oxyethyl ester, isodecyl (meth) acrylate, tridecyl (meth) acrylate, ethoxylated nonylphenol (meth) acrylate, ethylene glycol di(A) Acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,3-butanediol di Methyl) acrylate, tripropylene glycol di(meth) acrylate, ethoxylated bisphenol-A di(meth)acrylate, cyclohexanedimethanol di(methyl) Acrylate, phenoxy-t-glycol (meth)acrylate, 2-methacryloyloxymethyl phosphate, hydrogen phosphate 2-methacryloyloxyethyl phosphate, dimethyloltricyclodecane di(meth)acrylate, trimethylolpropane benzoate Trimethylolpropane benzoate acrylate, and mixtures thereof. The reactive diluent may be present in an amount of from 5 to 50% by weight based on the solids content of the electrically conductive adhesive layer. Preferably, the reactive diluent is present in an amount from 5 to 10% by weight.

The anisotropic conductive film may include a radical initiator. The free radical initiator may be a photopolymerization initiator, a heat curing agent, or a combination thereof. Preferably, the free radical initiator is a heat curing agent.

The heat curing agent may be present in an amount of from 0.5 to 5% by weight based on the solid content of the conductive adhesive layer. Within this range, sufficient reaction necessary for curing can occur to provide a suitable molecular weight, and therefore, in terms of adhesion strength and reliability, excellent physical properties can be expected after bonding.

Examples of the thermosetting agent suitable for use in the electroconductive adhesive layer include, but are not particularly limited to, a peroxide and an azo initiator. Examples of such peroxide initiators include, but are not limited to, lauryl peroxide, benzammonium peroxide, and cumene hydroperoxide. Examples of such azo initiators include, but are not limited to, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), dimethyl azobisisobutyrate [ Dimethyl 2,2'-azobis(2-methylpropionate)] with 2,2'-azobis(N-cyclohexyl-2-methylpropionamide)[2,2'-azobis(N-cyclohexyl-2- Methylpropionamide)].

The conductive adhesive layer may further include conductive particles. In this case, the conductive adhesive layer may include 45 to 80% by weight of the adhesive system, 15 to 40% by weight of the curable system, 0.5 to 5% by weight of the heat curing agent, and 1 Up to 30% by weight of the conductive particles.

The conductive particles act as a filler to impart electrical conductivity to the conductive adhesive layer.

The conductive particles may be present in an amount of from 1 to 30% by weight based on the solids content of the conductive adhesive layer. Within this range, suitable electronic communication can be established without the risk of short circuits. The content of the conductive particles is determined and may vary depending on the intended application of the anisotropic conductive film. Preferably, the electrically conductive particles are present in an amount from 1 to 5% by weight.

Examples of conductive particles suitable for use in the conductive adhesive layer include: metal particles such as gold (Au), silver (Ag), nickel (Ni), copper (Cu), and weld metal particles; carbon particles; metal coating Resin particles, such as polyethylene coated with gold (Au), silver (Ag), nickel (Ni), copper (Cu) and weld metal, polypropylene, polyester, polystyrene, polyvinyl alcohol, etc. a modified resin; and conductive particles coated with insulating particles.

There is no particular limitation on the size of the conductive particles. The diameter of the conductive particles is preferably in the range of 1 to 20 μm in terms of adhesion strength and connection reliability.

The conductive adhesive layer may have a melt viscosity of 50 to 100,000 Pa‧s at 100 °C. Within this range, the conductive adhesive layer is sufficiently viscous to minimize the flow of the conductive particles, which enables a large number of conductive particles to be positioned at the electrodes. The conductive adhesive layer preferably has a melt viscosity of from 500 to 10,000 Pa‧s. More preferably, the conductive adhesive layer has a melt viscosity of 5 to 100 times higher than that of the insulating adhesive layer.

The thickness of the conductive adhesive layer may be appropriately selected depending on the size of the conductive particles. For example, when the conductive particles have a size of 3 μm, the conductive particles may have a thickness of one of 4 to 6 μm.

Insulating adhesive layer

The insulating adhesive layer may include a binder system, a curable system, and a heat curing agent.

The insulating adhesive layer may include 20 to 60% by weight of the adhesive system, 35 to 75% by weight of the curable system, and 0.5 to 5% by weight of the heat curing agent.

The adhesive system acts as a substrate for the film. The adhesive system may include a nitrile butadiene rubber (NBR) resin, an acrylic resin, and a polyurethane resin.

The adhesive system may include 0 to 25% by weight of the NBR resin, 10 to 60% by weight of the acrylic resin, and 15 to 90% by weight of the polyurethane resin, with the insulating adhesive layer The solid content is based on the benchmark.

The details of the NBR resin, the acrylic resin and the polyurethane resin are the same as those described in the conductive adhesive layer.

The adhesive system is characterized in that the NBR resin, the acrylic resin and the polyurethane resin are respectively present in an amount of 0 to 10% by weight, 0 to 40% by weight, and 0 to 40% by weight, respectively. The solid content of the insulating adhesive layer is based on the reference. Within these ranges, the film can be formed satisfactorily. Preferably, the NBR resin, the acrylic resin and the polyurethane resin are present in an amount of 5 to 10% by weight, 5 to 15% by weight, and 10 to 30% by weight, respectively.

The curable system may include at least one compound selected from the group consisting of urethane acrylate and (meth) acrylate monomers. Preferably, the curable system comprises a urethane acrylate and a (meth) acrylate monomer.

The urethane acrylate may be present in an amount of from 40 to 80% by weight based on the solids content of the insulating adhesive layer. Within this range, the film can have the melt viscosity as defined above. Preferably, the urethane acrylate is present in an amount of from 40 to 60% by weight.

The (meth) acrylate monomer may be present in an amount of from 5 to 50% by weight based on the solid content of the insulating adhesive layer. Within this range, a suitable curing reaction occurs after bonding, which imparts high adhesion strength and high reliability to the anisotropic conductive film. Preferably, the (meth) acrylate monolith is present in an amount of from 5 to 10% by weight.

The heat curing agent may be present in an amount of from 0.5 to 5% by weight based on the solid content of the insulating adhesive layer. Within this range, sufficient reaction necessary for curing can occur to provide a suitable molecular weight, and therefore, in terms of adhesion strength and reliability, excellent physical properties can be expected after bonding. Preferably, the heat curing agent is present in an amount of from 1 to 3% by weight.

The insulating adhesive layer may have a melt viscosity of 10 to 1,000 Pa‧s at 100 °C. Within this range, the insulating adhesive layer is sufficiently flowable to allow the conductive particles of the conductive adhesive layer to be compressed between the electrodes by bonding without causing problems. Preferably, the insulating adhesive layer has a melt viscosity of 50 to 500 Pa‧s.

The thickness of the insulating adhesive layer is determined by the size and spacing of the gaps between the electrodes, and may typically range from 6 to 20 μm.

The present invention provides a method for fabricating an anisotropic conductive film. The method may include laminating a conductive adhesive layer on a base film and laminating an insulating adhesive layer on the conductive adhesive layer.

The details of the base film, the conductive adhesive layer and the insulating adhesive layer are as described above.

The present invention is directed to a method of pressing an anisotropic conductive film. The anisotropic conductive film has a structure in which a conductive adhesive layer and an insulating adhesive layer are sequentially laminated on a base film. The method includes preliminary pressing the anisotropic conductive film such that the insulating adhesive layer is in contact with a first circuit terminal, for example, a PCB terminal; removing the base film; and causing the conductive adhesive layer to be associated with, for example, COF by final pressing The second circuit terminal of the terminal is in contact to connect the first circuit terminal and the second circuit terminal. There are no restrictions on the pressing conditions. For example, the preliminary pressing may be performed at 1 to 2 MPa in 60 to 80 ° C for 1 to 2 seconds, and the final pressing may be performed at 2 to 5 MPa in the range of 2 to 5 MPa at 180 to 190 ° C second.

The invention provides a method of pressing a circuit terminal, comprising: preliminary pressing the anisotropic conductive film such that the insulating adhesive layer contacts the first circuit terminal, removing the base film, and causing the conductive by final pressing The adhesive layer is in contact with the second circuit terminal to connect the first circuit terminal and the second circuit terminal. There are no restrictions on the pressing conditions. For example, the preliminary pressing may be performed at 1 to 2 MPa in 60 to 80 ° C for 1 to 2 seconds, and the final pressing may be performed at 2 to 5 MPa in the range of 2 to 5 MPa at 180 to 190 ° C second.

Hereinafter, the configuration and function of the present invention will be explained in more detail with reference to the following examples and the like. The examples are provided for illustrative purposes only and are not to be construed as limiting the invention in any way. The disclosures that are not included herein are readily understood and appreciated by those skilled in the art, and thus the description thereof is omitted.

Example Preparation Example 1: Formation of a conductive adhesive layer

From 7 wt% of NBR resin (N-34, Nippon Zeon), 40% by weight of polyurethane adhesive (UN5500, Negami) and 28 wt% of alkyl methacrylate resin (weight average molecular weight = 90,000 g/mol, acid value = 2 KOH mg/mg) as an acrylic binder, which is a copolymer of MMA, BA and cyclohexyl methacrylate in toluene/butanone (30 vol%) One of the binder systems is composed of the system. 12 wt% of urethane acrylate (UN5507, Negami), 7.5 wt% of 2-hydroxyethyl (meth) acrylate as a reactive monomer, and 3 wt% of insulating conductive particles ( Sekisui) is prepared from a curable system consisting of 3 μm and made up of conductive particles. 2.5 wt% of oxidized laurel is used as a curing initiator. The adhesive system, the curable system, a mixture of the curing initiator and the conductive particles are used to form a conductive adhesive layer. The melt viscosity of the conductive adhesive layer was measured at 100 ° C using an ARES G2 rheometer (TA Instruments) under the following conditions: heating rate = 10 ° C / min, strain = 5%, frequency = 1 rad / s, Temperature zone = 30-180 °C. In order to measure the melt viscosity, a parallel plate was used with a disposable aluminum plate (diameter = 8 mm). The conductive adhesive layer was found to have a melt viscosity of 4,000 Pa‧s at 100 °C.

Preparation Example 2: Formation of an insulating adhesive layer

It consists of 7 wt% NBR resin (N-34, Nippon Zeon), 20 wt% polyurethane adhesive (UN5500, Negami) and 9 wt% acrylic adhesive (AOF-7000, Aekyung Chemical). One of the adhesive systems is prepared. From 56 wt% of urethane acrylate (NPC7007, Nanux Inc.) to 5.5 wt% of 2-hydroxyethyl (meth) acrylate as a reactive monomer in toluene/butanone (30 vol%) One of the components of the curable system is prepared. 2.5 wt% of oxidized laurel is used as a thermal curing initiator. The adhesive system, the curable system, and a mixture with the curing initiator are used to form an insulating adhesive layer. The melt viscosity of the insulating adhesive layer was measured by the same method as described in Preparation Example 1. The insulating adhesive layer was found to have a melt viscosity of 400 Pa‧s at 100 °C.

Preparation Example 3: Formation of a conductive adhesive layer

A conductive adhesive layer was formed in the same manner as in Preparation Example 1, except that the polyurethane adhesive, the acrylic adhesive and the urethane acrylate were 36 wt% and 20 wt%, respectively. And use one of 24 wt%. The melt viscosity of the conductive adhesive layer was measured by the same method as described in Preparation Example 1. The conductive adhesive layer was found to have a melt viscosity of 2,000 Pa‧s at 100 ° C.

Preparation Example 4: Formation of a conductive adhesive layer

A conductive adhesive layer was formed in the same manner as in Preparation Example 1, except that the polyurethane adhesive, the acrylic adhesive and the urethane acrylate were 20 wt% and 15 wt%, respectively. And one of the 45 wt% used. The melt viscosity of the conductive adhesive layer was measured by the same method as described in Preparation Example 1. The conductive adhesive layer was found to have a melt viscosity of 6,000 Pa‧s at 100 ° C.

Preparation Example 5: Formation of an insulating adhesive layer

An insulating adhesive layer was formed in the same manner as in Preparation Example 2 except that the polyurethane adhesive, the acrylic adhesive and the urethane acrylate were 20 wt% and 20 wt%, respectively. And one of the 45 wt% used. The melt viscosity of the insulating adhesive layer was measured by the same method as described in Preparation Example 1. The insulating adhesive layer was found to have a melt viscosity of 1,200 Pa‧s at 100 °C.

Example 1: Fabrication of an anisotropic conductive film

As illustrated in FIG. 2, the conductive adhesive layer formed in Preparation Example 1 and the insulating adhesive layer formed in Preparation Example 2 are sequentially laminated as one of the base films of poly(terephthalic acid). An ethylene conductive film is formed on the ethylene glycol film.

Example 2: Fabrication of an anisotropic conductive film

As illustrated in FIG. 2, the conductive adhesive layer formed in Preparation Example 3 and the insulating adhesive layer formed in Preparation Example 2 are sequentially laminated as one of the base films of poly(terephthalic acid). An ethylene conductive film is formed on the ethylene glycol film.

Comparative Example 1: Fabrication of an anisotropic conductive film

As illustrated in FIG. 1, the insulating adhesive layer formed in Preparation Example 2 and the conductive adhesive layer formed in Preparation Example 1 are sequentially laminated as one of the base films of poly(terephthalic acid). An ethylene conductive film is formed on the ethylene glycol film.

Comparative Example 2: Fabrication of an anisotropic conductive film

As illustrated in FIG. 2, the conductive adhesive layer formed in Preparation Example 4 and the insulating adhesive layer formed in Preparation Example 5 are sequentially laminated as one of the base films of poly(terephthalic acid). An ethylene conductive film is formed on the ethylene glycol film.

The details of the isotropic conductive film produced in Example 1-2 and Comparative Example 1-2 are shown in Table 1.

Experimental Example 1: Measurement of physical properties of an anisotropic conductive film

The physical properties of the isotropic conductive film produced in Example 1-2 and Comparative Example 1-2 were measured by the following methods. These results are shown in Table 2.

<Method for measuring physical properties>

1. Adhesion strength: Each of the isotropic conductive films is bonded to a metal electrode glass (Mo/Al/Mo structure) (Samsung Electronics) and a wafer on the film (COF) (Samsung) at a temperature of 185 ° C. Electronic) up to 4 seconds. The 90° peel strength of the anisotropic conductive film was measured using a universal testing machine (UTM).

2. Effective Particles: Each of the isotropic conductive films is bonded to a metal electrode glass (Mo/Al/Mo structure) (Samsung Electronics) and a wafer on the film (COF) at a temperature of 185 ° C (Samsung Electronic) up to 4 seconds. The images of the thirty regions of the electrode were taken using a microscope. The number of indentations on these areas is averaged to calculate the number of active particles.

3. Appearance: Each of the isotropic conductive films is bonded to a metal electrode glass (Mo/Al/Mo structure) (Samsung Electronics) and a wafer on the film (COF) (Samsung Electronics) at a temperature of 185 ° C. ) up to 4 seconds. The appearance of the anisotropic conductive film was observed under a microscope.

4. Reliability: Each of the isotropic conductive films is bonded to a metal electrode glass (Mo/Al/Mo structure) (Samsung Electronics) and a wafer on the film (COF) (Samsung) at a temperature of 185 ° C. Electronic) up to 4 seconds. After being in the chamber of 85 ° C / 85% RH for 250 hr, the appearance of the anisotropic conductive film was observed by the same method as described in 3.

5. Preliminary compression: Each of the isotropic conductive films is allowed to stand at 25 ° C for 1 hr. The four samples of the anisotropic conductive film were initially pressed to a metal electrode glass (Mo/Al/Mo structure) (Samsung Electronics) and a wafer on the film at different temperatures of 50, 60, 70 and 80 ° C at 1 MPa. (COFs) (Samsung Electronics) up to 1 sec. Each sample was immobilized for 30 min. The samples are judged to be "possibly suppressed" when the base film is easily removed, and is judged to be "impossible to suppress" when one part of the sample is separated from the base film or when the sample is When detached from the surface of the glass.

As can be seen from the results in Table 2, the base film was not easily removed from the film of Comparative Example 1, in which the base film, the insulating adhesive layer and the conductive adhesive layer were as the first The layers are stacked in this order as illustrated in the figure and initially pressed at a temperature of 50-80 °C. Further, comparing the film of Example 2, wherein the insulating adhesive layer has a melt viscosity higher than that of the conductive adhesive layer, exhibiting an unsatisfactory preliminary pressing result and the number of effective particles and adhesion after bonding Strength and reliability are disadvantageous.

Although the foregoing embodiments of the present invention have been described with reference to the accompanying drawings and drawings, the invention is not limited to the embodiments and may be embodied in various forms. It will be appreciated by those skilled in the art that the present invention may be practiced otherwise than as specifically described without departing from the spirit and scope of the invention. Therefore, it should be understood that the embodiments are considered as illustrative and not in a limiting sense.

1. . . Insulating adhesive layer

2. . . Conductive adhesive layer

3. . . Base film or release film

4. . . Conductive particle

Figure 1 illustrates a conventional multi-level anisotropic conductive film;

Fig. 2 illustrates an anisotropic conductive film according to an exemplary embodiment of the present invention.

1‧‧‧Insulating adhesive layer

2‧‧‧ Conductive adhesive layer

3‧‧‧base film

4‧‧‧ conductive particles

Claims (14)

An anisotropic conductive film comprising a base film, a conductive adhesive layer formed on the base film, and an insulating adhesive layer formed on the conductive adhesive layer, wherein the conductive adhesive layer has a melt viscosity at 100 ° C It is higher than the insulating viscosity of the insulating adhesive layer at 100 ° C, wherein the insulating adhesive layer has a temperature of 50 to 1,000 Pa at 100 ° C. The s melt viscosity. The anisotropic conductive film of claim 1, wherein the conductive adhesive layer has a melt viscosity at 100 ° C and the ratio of the insulating adhesive layer to a melt viscosity of 100 ° C is from 2:1 to 100:1. The anisotropic conductive film of claim 2, wherein the ratio of the melt viscosity is from 5:1 to 50:1. The anisotropic conductive film of claim 1, wherein the conductive adhesive layer has a temperature of 50 to 100,000 Pa at 100 ° C. One of the s melt viscosity. The anisotropic conductive film of claim 1, wherein the conductive adhesive layer or the insulating adhesive layer comprises a binder system, a curable system and a heat curing agent; the adhesive system comprises a nitrile butadiene rubber (NBR) resin, acrylic resin and polyurethane resin; and the curable system comprises a urethane acrylate and a (meth) acrylate monomer. The anisotropic conductive film of claim 5, wherein the conductive adhesive layer comprises 45 to 80% by weight of the adhesive system, 15 to 40% by weight of the curable system, and 0.5 to 5% by weight. The heat curing agent. Such as the anisotropic conductive film of claim 5, wherein the conductive The adhesive layer further contains conductive particles. The anisotropic conductive film of claim 7, wherein the conductive adhesive layer comprises 45 to 80% by weight of the adhesive system, 15 to 40% by weight of the curable system, and 0.5 to 5% by weight. The heat curing agent and 1 to 30% by weight of the conductive particles. The anisotropic conductive film of claim 5, wherein the adhesive system comprises 0 to 40% by weight of the NBR resin, 30 to 70% by weight based on the solid content of the conductive adhesive layer. The acrylic resin and 30 to 70% by weight of the polyurethane resin. The anisotropic conductive film of claim 5, wherein the insulating adhesive layer comprises 20 to 60% by weight of the adhesive system, 35 to 75% by weight based on the solid content of the insulating adhesive layer. The curable system and 0.5 to 5% by weight of the heat curing agent. The anisotropic conductive film of claim 6, wherein the adhesive system comprises 0 to 25% by weight of the NBR resin, and 10 to 60% by weight based on the solid content of the insulating adhesive layer. The acrylic resin and 15 to 90% by weight of the polyurethane resin. A method for manufacturing an anisotropic conductive film, comprising: laminating a conductive adhesive layer on a base film, and laminating an insulating adhesive layer on the conductive adhesive layer, wherein the conductive adhesive layer has a higher melt viscosity at 100 ° C than the The insulating adhesive layer has a melt viscosity at 100 ° C, wherein the insulating adhesive layer has a thickness of 50 to 1,000 Pa at 100 ° C. The s melt viscosity. The method of claim 12, wherein the conductive adhesive layer is The ratio of the melt viscosity at 100 ° C to the melt viscosity of the insulating adhesive layer at 100 ° C is from 2:1 to 100:1. A method of pressing a circuit terminal, comprising: preliminary pressing an anisotropic conductive film, wherein the anisotropic conductive film comprises a base film, a conductive adhesive layer is formed on the base film, and formed on the conductive adhesive layer An insulating adhesive layer to contact the insulating adhesive layer with the first circuit terminal; removing the base film; and contacting the conductive adhesive layer with the second circuit terminal by final pressing to connect the first circuit terminal to the a second circuit terminal; wherein the conductive adhesive layer has a melt viscosity at 100 ° C higher than a melt viscosity of the insulating adhesive layer at 100 ° C, wherein the insulating adhesive layer has a thickness of 50 to 1,000 Pa at 100 ° C. The s melt viscosity.