KR20110136731A - Circuit connecting adhesive film and use thereof, circuit connecting structure and method for manufacturing the same and circuit member connecting method - Google Patents

Abstract

PURPOSE: An adhesive film for the circuit connection, a use thereof, a circuit connection structure, a producing method of the circuit connection structure, and a connection method of a circuit member are provided to prevent the deformation of a glass substrate by excellent connection reliability of the adhesive film. CONSTITUTION: An adhesive film(10) for the circuit connection comprises the following: a conductive adhesive layer(3b) including an adhesive composition(4b) and conductive particles(5); and an insulating adhesive layer(3a) without the conductive particles, including another adhesive composition(4a). The adhesive composition contains a film forming material having the glass transition temperature of 40-70 deg C, an epoxy resin, and a latent hardener.

Description

Adhesive film for circuit connection, its use, circuit connection structure, its manufacturing method, and connection method of circuit member {CIRCUIT CONNECTING ADHESIVE FILM AND USE THEREOF, CIRCUIT CONNECTING STRUCTURE AND METHOD FOR MANUFACTURING THE SAME AND CIRCUIT MEMBER CONNECTING METHOD}

This invention relates to the adhesive film for circuit connections, its use, a circuit connection structure, its manufacturing method, and the connection method of a circuit member.

Conventionally, the thermosetting adhesive film hardened | cured by heating is used, in order to connect a semiconductor element to the board | substrate, especially glass substrates for flat panel displays (FPD), such as a liquid crystal.

As a thermosetting adhesive film, what contains an epoxy resin which is a thermosetting resin is widely used, and since an epoxy resin turns into a high mechanical strength polymer when it hardens | cures by heating, a semiconductor element and a liquid crystal display are firm with the said adhesive film. Connection, a highly reliable electrical device is obtained. In recent years, compared with epoxy resin, the adhesive film containing the acrylate which can harden | cure at lower temperature is also used.

By the way, when a glass substrate and a semiconductor element are connected using an adhesive film, when heating an adhesive film, since a semiconductor element is heated and thermally expanded by heat conduction, a semiconductor element may be extended. For this reason, when the whole is cooled after completion | finish of heating, the elongated semiconductor element will shrink | contract, and deformation | transformation, such as curvature, may arise in the glass substrate which comprises FPD with the shrinkage. When deformation occurs in the glass substrate, confusion occurs in the display image of the display located at the deformed portion.

Various methods are known so far to suppress deformation such as warpage. For example, the connection method which interposes a film between a heating and a pressurizing tool and a semiconductor element (Japanese Unexamined-Japanese-Patent No. 2006-229124), or the method of heating after a heating and a pressurizing process (Japanese Patent Laid-Open No. 2004-200230) ) Is reported.

Moreover, the method of using the material which can relieve stress for an adhesive film is also known recently (Japanese Patent Laid-Open No. 2004-277573, Japanese Patent No. 3477367).

However, although deformation of the glass substrate can be suppressed by the use of a material that can relieve stress, there is a problem that connection reliability is lowered. Moreover, the film formability at the time of forming an adhesive film may fall, and it may become difficult to obtain an adhesive film stably. Moreover, especially as the thickness of a glass substrate and a semiconductor element becomes thin, it exists in the tendency for curvature (deformation of a glass substrate) to become easy to produce remarkably.

Therefore, the present invention can suppress deformation of the glass substrate while maintaining excellent connection reliability even when used for connecting a glass substrate with a thickness thinner than that of a conventional circuit board and a semiconductor element, and also has excellent film formability. It aims at providing the film and its use, the circuit connection structure using the same, its manufacturing method, and the connection method of a circuit member.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the said subject, when the deformation | transformation of a circuit member generate | occur | produces, it is after mounting (after hardening) that the internal stress of the adhesive film for circuit connections is too high, and that connection reliability falls after mounting It discovered that it originated in the part in which the elasticity modulus is too low in the adhesive film for circuit connections. In particular, when the elastic modulus is locally too low, it becomes difficult to maintain the flatness of the conductive particles between the opposing electrodes, and therefore, it has been found that the connection reliability tends to be lowered.

Based on these findings, the inventors further discovered that by using a film forming material having a predetermined glass transition temperature in the adhesive film for circuit connection, it was found that deformation of the substrate can be suppressed while maintaining high connection reliability. It was completed.

That is, this invention is an adhesive film for circuit connection which consists of an electrically conductive adhesive layer containing an adhesive composition and electroconductive particle, and an insulating adhesive layer containing an adhesive composition and not containing conductive particle, The adhesive composition contained in a conductive adhesive layer A first circuit electrode is formed on the main surface of the first circuit board having a thickness of 0.3 mm or less, comprising (a) a film forming material having a glass transition temperature of 40 to 70 ° C., (b) an epoxy resin, and (c) a latent curing agent. Electrically connecting the formed first circuit member and the second circuit member on which the second circuit electrode is formed on the main surface of the second circuit board having a thickness of 0.3 mm or less in a state where the first circuit electrode and the second circuit electrode are opposed to each other. An adhesive film for circuit connection is provided.

If it is such an adhesive film for circuit connections, since (a) film formation material which has predetermined glass transition temperature (henceforth "Tg") is used for an adhesive composition in a conductive adhesive layer, even after hardening a film, hardened | cured material The internal stress in the inside can be suppressed low, and the entire cured product can be made uniform and have sufficient elastic modulus. Thereby, even when used for the connection of the circuit members provided with the circuit board whose thickness is 0.3 mm or less, not only deformation | transformation of a circuit member can be suppressed but favorable connection reliability can be obtained. In addition, since the adhesive composition in the conductive adhesive layer contains (b) an epoxy resin and (c) a latent curing agent together with (a) the film forming material having a predetermined Tg, not only the film formability is excellent, Excellent heat resistance and adhesion can be realized.

Moreover, when the adhesive film for circuit connection is equipped with two layers of a conductive adhesive layer and an insulating adhesive layer, it becomes easy to capture | acquire electroconductive particle between opposing electrodes, and can improve connection reliability. As a result, good connection reliability can be obtained.

In the adhesive film for circuit connection of this invention, a conductive adhesive layer and / or an insulating adhesive layer may further contain (d) insulating particle. As a result, better connection reliability can be maintained.

The present invention also provides a first circuit member having a first circuit electrode formed on a main surface of a first circuit board having a thickness of 0.3 mm or less, and a second circuit electrode formed on a main surface of a second circuit board having a thickness of 0.3 mm or less. And a second circuit electrode disposed so as to face the first circuit electrode, and the second circuit electrode interposed between the first circuit member and the second circuit member electrically connected to the first circuit electrode. It provides a connection part and provides a circuit connection structure which is a hardened | cured material of the adhesive film for circuit connections of this invention.

If it is such a circuit connection structure, since a connection part contains the hardened | cured material of the adhesive film for circuit connections of this invention, internal stress in a circuit connection structure can be suppressed low and generation | occurrence | production of the part with too low elasticity modulus can be suppressed. For this reason, not only the deformation | transformation of a circuit member can be suppressed, but the outstanding connection reliability can be achieved.

The invention also provides a first circuit member in which a first circuit electrode is formed on a main surface of a first circuit board having a thickness of 0.3 mm or less and a second in which a second circuit electrode is formed on a main surface of a second circuit board having a thickness of 0.3 mm or less. Between a pair of circuit members provided with a circuit member, the process of obtaining a laminated body through the adhesive film for circuit connection of the said invention, and a pair of circuit by heating and pressurizing a laminated body and hardening the adhesive film for circuit connection. It provides the manufacturing method of the circuit connection structure provided between the member, Comprising: The process of forming the connection part which adhere | attaches a pair of circuit members so that the 1st circuit electrode and the 2nd circuit electrode arrange | positioned opposingly may be provided.

According to such a manufacturing method, the deformation | transformation of a circuit member can be suppressed and the circuit connection structure which can achieve the outstanding connection reliability can be manufactured.

The present invention also provides a first circuit member in which a first circuit electrode is formed on a main surface of a first circuit board having a thickness of 0.3 mm or less, and a second circuit electrode formed on a main surface of a second circuit board having a thickness of 0.3 mm or less. The first circuit and the adhesive film for circuit connection of the present invention disposed between the first circuit member and the second circuit member are heated and pressurized in a state in which the first circuit electrode and the second circuit electrode are disposed to face each other, and thereby the first circuit. A connection method of a circuit member is provided which electrically connects an electrode and a 2nd circuit electrode.

In the connection method of such a circuit member, since the hardened | cured material of the adhesive film for circuit connections which concerns on this invention is used for connection of a circuit member, while the internal stress in hardened | cured material is suppressed low, the electroconductivity between opposing electrodes can fully be ensured. have. For this reason, not only the deformation | transformation of a circuit member can be suppressed, but the circuit connection structure which has favorable connection reliability can be formed.

The present invention also provides an adhesive composition containing an adhesive composition and conductive particles, and an insulating adhesive layer containing an adhesive composition and no conductive particles, wherein the adhesive composition contained in the conductive adhesive layer is (a) a glass transition. A first circuit electrode formed on a main surface of a first circuit board having a thickness of 0.3 mm or less, of an adhesive film containing a film forming material having a temperature of 40 to 70 ° C., (b) an epoxy resin, and (c) a latent curing agent The circuit connection which electrically connects a circuit member and the 2nd circuit member in which the 2nd circuit electrode was formed on the main surface of the 2nd circuit board of thickness 0.3mm or less in the state which opposes the 1st circuit electrode and the 2nd circuit electrode. Provides a use for

By using such an adhesive film for circuit connection, even when it is used for the connection of the circuit members provided with the circuit board whose thickness is 0.3 mm or less, not only deformation | transformation of a circuit member can be suppressed but favorable connection reliability can be obtained. have.

When using such an adhesive film for circuit connection, a conductive adhesive layer and / or an insulating adhesive layer may further contain (d) insulating particle. As a result, better connection reliability can be maintained.

According to the present invention, even when used for the connection between a glass substrate thinner than a conventional circuit board and a semiconductor element, deformation of the glass substrate can be suppressed while maintaining excellent connection reliability, and also for circuit connection excellent in film formability. The adhesive film, its use, the circuit connection structure using the same, its manufacturing method, and the connection method of a circuit member can be provided. Especially in this invention, even when the circuit members of thickness 0.3mm or less are connected, the adhesive film for circuit connections which can achieve the said effect can be provided.

1: is a schematic cross section which shows the adhesive film for circuit connections which concerns on one Embodiment of this invention.
It is a schematic cross section which shows the laminated body which interposed the adhesive film for circuit connections which concerns on this embodiment between a pair of circuit member.
3: is a schematic cross section which shows the circuit connection structure which concerns on this embodiment.
It is a schematic cross section which shows the evaluation method of the curvature of a glass substrate.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described in detail, referring drawings as needed. However, this invention is not limited to the following embodiment.

<Adhesive film for circuit connection>

First, the adhesive film 10 for circuit connection of this embodiment is demonstrated with reference to FIG. 1: is a schematic cross section which shows the adhesive film for circuit connections which concerns on one Embodiment of this invention. The adhesive film 10 for circuit connection contains the adhesive composition 4a formed on the conductive adhesive layer 3b containing the adhesive composition 4b and the electroconductive particle 5, and the conductive adhesive layer 3b. It has an insulating adhesive layer 3a.

(Conductive adhesive layer)

The conductive adhesive layer 3b is (a) Tg 40-70 degreeC film forming material (henceforth "a component"), (b) epoxy resin (henceforth "b) Component), and (c) an adhesive composition (4b) comprising a latent curing agent (hereinafter referred to as "component (c)") and conductive particles (5).

The film forming material whose Tg which is (a) component is 40-70 degreeC is a polymer which has the effect | action which solidifies a liquid curable resin composition. By including a film forming material in curable resin composition, when shape | molding curable resin composition into a film form, the adhesive film which is easy to handle can be obtained without being easily torn, a crack, or sticking.

Examples of such film forming materials include at least one selected from the group consisting of phenoxy resins, polyvinyl formal resins, polystyrene resins, polyvinyl butyral resins, polyester resins, polyamide resins, xylene resins and polyurethane resins. 1 type of polymers are mentioned. Among these, phenoxy resins, polyurethane resins and polyvinyl butyral resins are preferable. These are excellent in compatibility with (b) component, and can provide the adhesiveness, heat resistance, and mechanical strength which the adhesive film 10 for circuit connections after hardening is excellent.

A phenoxy resin is obtained by making bifunctional phenols and epihalohydrin react until it becomes high molecular weight, or carrying out polyaddition reaction of bifunctional epoxy resin and bifunctional phenols. Specifically, 1 mole of bifunctional phenols and 0.985 to 1.015 mole of epihalohydrin can be obtained by reacting in a nonreactive solvent at a temperature of 40 to 120 ° C. in the presence of a catalyst such as an alkali metal hydroxide.

It is preferable to perform the polyaddition reaction which obtains a phenoxy resin by making the compounding equivalence ratio of bifunctional epoxy resin and bifunctional phenol into epoxy group / phenol hydroxyl group = 1 / 0.9-1 / 1.1. Thereby, the mechanical characteristic and thermal characteristic of the adhesive film 10 for circuit connections after hardening can be made favorable. In addition, this polyaddition reaction is carried out in organic solvents, such as an amide type, ether type, ketone type, lactone type, alcohol type, etc. which have a boiling point of 120 degreeC or more in presence of catalysts, such as an alkali metal compound, an organophosphorus compound, and a cyclic amine compound. It is preferable to make raw material solid content 50 mass parts or less, and to heat at 50-200 degreeC.

As a bifunctional epoxy resin used in order to obtain a phenoxy resin, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol S type epoxy resin, biphenyl diglycidyl ether, Methyl substituted biphenyl diglycidyl ether is mentioned. As bifunctional phenols, those having two phenolic hydroxyl groups, for example, hydroquinones, bisphenol A, bisphenol F, bisphenol AD, bisphenol S, bisphenol fluorene, methyl substituted bisphenol fluorene, dihydroxybiphenyl and methyl substituted Bisphenols, such as dihydroxy biphenyl, are mentioned.

The phenoxy resin may be modified with a radical polymerizable functional group or other reactive compound. The above-mentioned various phenoxy resins can be used individually or in combination of 2 or more types.

Polyurethane resins are elastomers having a urethane bond in the molecular chain, and are usually polybasic acids (terephthalic acid, isophthalic acid, phthalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, etc.), and dihydric alcohols (ethylene glycol, 1,4- With respect to the saturated polyester resin which has terminal hydroxyl group obtained by condensation reaction of butanediol, 1, 5- pentanediol, 1, 6- hexanediol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, etc., It is a linear polymer which reacted the active hydrogen group and the isocyanate group of diisocyanate compound (tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, cyclohexyl methane diisocyanate, etc.) in the substantially equivalent amount.

Such polyurethane resins include organic solvents such as esters (ethyl acetate, butyl acetate, etc.), ketones (methyl ethyl ketone, cyclohexanone, acetone, etc.), aromatics (toluene, xylene, benzene, etc.) and chlorine ( Soluble in tricylene, methylene chloride, and the like).

Polyvinyl butyral resin is an elastomer having a vinyl acetal unit in its molecular chain, and is usually obtained by polymerizing vinyl acetate and then performing an alkali treatment, and then reacting it with an aldehyde (metallic, ethanal, propanal, butanal, etc.). It is a linear polymer. It is preferable that the polyvinyl butyral resin used by this embodiment is 700-2500 degree of polymerization, and 65 mol% or more of butyralization degrees.

If the degree of polymerization is less than 700, the cohesion force of the polyvinyl butyral resin is insufficient, and the film formability is lowered. When the degree of polymerization is more than 2500, the resin fluidity at the time of crimping of the resin is insufficient, the conductive particles cannot be interposed properly between the electrodes of the adherend, and sufficient connection reliability is difficult to be obtained. Moreover, when the butyralization degree is less than 65 mol%, the ratio of a hydroxyl group or an acetyl group increases, and sufficient connection reliability becomes difficult to be obtained.

Although Tg of the film forming material which is (a) component is 40-70 degreeC, More preferably, it is 45-70 degreeC, More preferably, it is 50-70 degreeC. If it is such a film forming material which has Tg, since elastic deformation will absorb the internal stress which generate | occur | produces in the adhesive film 10 for circuit connections after hardening, and will reduce the amount of curvature of a circuit member, favorable connection reliability will be obtained.

It is preferable that it is 10-50 mass parts with respect to 100 mass parts of total mass of adhesive composition (4b), and, as for the compounding quantity of a film forming material, it is more preferable that it is 20-40 mass parts. By setting the amount of the film forming material in this range, the deformation (curvature amount) of the substrate can be further suppressed, and the adhesive film 10 for a circuit connection excellent in electrical connection property is provided.

As the film forming material has a higher molecular weight, film formability is easily obtained, and a melt viscosity that affects the fluidity of the adhesive composition 4b can be set in a wide range. As a weight average molecular weight (Mw) of a film forming material, 5000-150000 are preferable and 10000-80000 are especially preferable. If this value is 5000 or more, there exists a tendency for favorable film formability to be easy to be acquired, and if it is 150000 or less, there exists a tendency for favorable compatibility with other components to be easy to be obtained.

In addition, said "weight average molecular weight" means the value measured using the analytical curve by standard polystyrene from gel permeation chromatography (GPC) according to the conditions shown in following Table 1.

Examples of the epoxy resin (b) include epichlorohydrin, bisphenol-type epoxy resins derived from at least one selected from the group consisting of bisphenol A, bisphenol F, bisphenol AD and the like, epichlorohydrin and phenol novolac, and Epoxy novolak resin derived from one or both of cresol novolac, naphthalene-based epoxy resin having a skeleton containing a naphthalene ring and two or more in one molecule such as glycidylamine, glycidyl ether, biphenyl, alicyclic, etc. Various epoxy compounds etc. which have a glycidyl group can be used individually or in combination of 2 or more types. As for the epoxy resin, from the standpoint of preventing electromigration, it is preferable to use a high-purity product having reduced impurity ions (Na ⁺ , Cl ^−, etc.), hydrolyzable chlorine, etc. to 300 ppm or less.

Among the above epoxy resins, bisphenol-type epoxy resins are preferable because grades having different molecular weights are widely available and adhesiveness, reactivity, and the like can be arbitrarily set. Among bisphenol type epoxy resins, bisphenol F type epoxy resins are particularly preferable. The viscosity of a bisphenol F-type epoxy resin is low, and by using it in combination with a phenoxy resin, the fluidity | liquidity of the adhesive film 10 for circuit connections can be set easily and extensively. Moreover, bisphenol F-type epoxy resin also has the advantage that it is easy to provide favorable adhesiveness to the adhesive film 10 for circuit connections.

It is preferable that it is 5-50 mass parts with respect to 100 mass parts of total mass of adhesive composition (4b), and, as for the compounding quantity of an epoxy resin, it is more preferable that it is 20-40 mass parts. When the compounding quantity of an epoxy resin is less than 5 mass parts, when the circuit members are crimped together, the fluidity | liquidity of the adhesive film 10 for circuit connections tends to fall, and when it exceeds 50 mass parts, the adhesive film for circuit connections at the time of long-term storage (10) tends to deform.

As a latent hardening | curing agent which is (c) component, an imidazole series, a hydrazide system, an amine imide, and a dicyandiamide are mentioned, for example. These can be used individually or in combination of 2 or more types. The latent curing agent may also be combined with a decomposition accelerator, an inhibitor, and the like. In order to extend the pot life, it is preferable to coat the latent curing agent with a polyurethane-based, polyester-based polymer material or the like and microencapsulate it.

It is preferable that it is 10-200 mass parts with respect to 100 mass parts of epoxy resins, and, as for the compounding quantity of a latent hardening | curing agent, it is more preferable that it is 100-150 mass parts. Thereby, sufficient reaction rate can be obtained in hardening reaction. When the compounding quantity of a latent hardening | curing agent is less than 10 mass parts, sufficient reaction rate cannot be obtained and there exists a tendency for favorable adhesive strength and connection resistance to be difficult to be obtained. When the compounding quantity of a latent hardening | curing agent exceeds 200 mass parts, there exists a tendency for the fall of the fluidity | liquidity of the adhesive film 10 for circuit connections, an increase of connection resistance, the shortening of the usable time of the adhesive film 10 for circuit connections, etc. to arise. .

In the adhesive composition 4b, the conductive particles 5 are dispersed. Since the adhesive film 10 for circuit connection contains the electroconductive particle 5, since the nonuniformity of the position and height of a circuit electrode is absorbed by the deformation | transformation of the electroconductive particle 5, and a contact area increases, more stable electrical connection Can be obtained. In addition, when the adhesive film 10 for circuit connection contains the electrically-conductive particle 5, it may become possible for the electrically-conductive particle 5 to contact through through the oxide layer or the passivation layer of the circuit electrode surface, and to stabilize electrical connection. Can be planned further.

Examples of such conductive particles 5 include metal particles such as Au, Ag, Ni, Cu, solder, carbon particles, and the like. From the viewpoint of obtaining sufficient pot life, the outermost layer of the conductive particles 5 is preferably a noble metal such as Au, Ag, or a white metal, rather than transition metals such as Ni and Cu, among which Au is more preferable. In addition, the conductive particles 5 may be coated with surfaces of transition metals such as Ni with noble metals such as Au, and are formed by coating conductive layers such as metals described above on non-conductive glass, ceramics, plastics, and the like. The outermost layer may be a noble metal.

As the conductive particles 5, it is preferable to use particles formed by coating a conductive layer on plastic or hot melt metal particles. Since these particles have deformability by heating and pressurization, they can increase the contact area with the circuit electrode at the time of connection, or can absorb the thickness nonuniformity of the circuit terminal of a circuit member, and can improve the reliability of circuit connection.

It is preferable that the thickness of the coating layer of the noble metals provided in the outermost layer of the electroconductive particle 5 is 100 kPa or more. As a result, the resistance between the circuits to be connected can be sufficiently reduced. However, when providing the coating layer of noble metals on transition metals, such as Ni, it is preferable that the said thickness is 300 kPa or more. The reason for this is that a transition metal such as Ni is exposed to the adhesive film due to a deficiency of the coating layer of the noble metals generated at the time of mixing and dispersing the conductive particles 5, so that free radicals are generated by the redox effect of the transition metal. This is because the storage stability of the adhesive film 10 for circuit connection is lowered. On the other hand, the upper limit of the thickness of the coating layer of the noble metals is not particularly limited, but is preferably 1 µm or less in view of the production cost.

The average particle diameter of the electroconductive particle 5 needs to be smaller than the minimum space | interval of the adjacent electrode of the circuit member connected by the adhesive film 10 for circuit connections, and when there exists a nonuniformity of the height of a circuit electrode, It is preferable that it is larger than nonuniformity. It is preferable that it is 1-10 micrometers, and, as for the average particle diameter of the electroconductive particle 5, it is more preferable that it is 2-5 micrometers. If the average particle diameter is less than 1 µm, there is a tendency that the nonuniformity of the height of the circuit electrode cannot be coped, and the conductivity between the circuit electrodes tends to be lowered, and if it exceeds 10 µm, the insulation between adjacent circuit electrodes tends to be lowered.

In addition, the said "average particle diameter" means the value measured as follows. That is, the primary particles of the electrically conductive particles arbitrarily selected were observed (magnification: 5000 times) by a scanning electron microscope (SEM, manufactured by Hitachi Seisakusho Co., Ltd., product name: S-800), and the maximum and minimum diameters thereof were measured. Measure The square root of the product of this largest diameter and minimum diameter is made into the primary particle diameter of the particle | grains. And primary particle size is measured as mentioned above about 50 electrically chosen electroconductive particle arbitrarily, and makes the average value into the average particle diameter. In addition, the average particle diameter of (d) insulating particle mentioned later is measured similarly.

It is preferable to set it as 0.1-30 mass parts with respect to 100 mass parts of total mass of adhesive composition 4b, and, as for the compounding quantity of electroconductive particle 5, it is more preferable to set it as 0.1-20 mass parts. Thereby, the short circuit of the adjacent circuit by excessive conductive particle 5, etc. can be prevented.

Moreover, adhesive composition 4b may further contain additives, such as a softener, an antiaging agent, a flame retardant, a pigment | dye, a thixotropic agent, a silane coupling agent, depending on a use, for example.

(Insulating adhesive layer)

The adhesive composition 4a contained in the insulating adhesive layer 3a can be formed into a film, and should just be able to suppress deformation of a circuit member at the time of a circuit member connection, and is contained in the conductive adhesive layer 3b. It may be the same as or different from the adhesive composition (4b). However, it is preferable that the kind and compounding quantity of the above-mentioned component are adjusted so that the fluidity | liquidity of the insulating adhesive layer 3a may become larger than the fluidity | liquidity of the electroconductive adhesive bond layer 3b.

The conductive adhesive layer 3b and / or the insulating adhesive layer 3a may further contain (d) insulating particles (hereinafter, sometimes referred to as "(d) component"). Thereby, the internal stress in the adhesive layer is more alleviated after film curing. Moreover, it is more preferable that the insulating adhesive layer 3a contains (d) insulating particle.

Examples of such (d) insulating particles include inorganic particles such as silica and alumina or organic rubbers such as silicone rubber, methyl methacrylate butadiene styrene (MBS), acrylic rubber, polymethyl methacrylate, and polybutadiene rubber. And particles.

In addition to the above-mentioned (d) insulating particles, for example, acrylic resins, polyesters, polyurethanes, polyvinyl butyral, polyarylates, polystyrenes, NBR, SBR and silicone-modified resins, and the like and the like are included as components. The particle | grains which consist of a copolymer to mention are mentioned. As the insulating particles, organic fine particles having a molecular weight of 1 million or more or organic fine particles having a three-dimensional crosslinked structure are preferable. Such insulating particles have high dispersibility to the curable composition. In addition, "it has a three-dimensional crosslinked structure" shows here that a polymer chain has a three-dimensional mesh structure, and the insulating particle which has such a structure, for example, is a functional group which can couple the polymer which has a reaction point with this reaction point. It is obtained by treating with the crosslinking agent which has two or more. It is preferable that both the organic fine particles having a molecular weight of 1 million or more and the organic fine particles having a three-dimensional crosslinked structure have low solubility in a solvent. These insulating particles having low solubility in a solvent can remarkably obtain the above-described effects. In addition, from the viewpoint of remarkably obtaining the above-mentioned effects, the organic fine particles having a molecular weight of 1 million or more and the organic fine particles having a three-dimensional crosslinked structure include an alkyl (meth) acrylate-silicone copolymer, a silicone- (meth) acrylic acid copolymer or a composite thereof. It is preferable that it is the insulating particle which consists of. Moreover, as (d) component, insulating particles, such as polyamic-acid particle | grains and polyimide particle | grains as described in Unexamined-Japanese-Patent No. 2008-150573, can also be used, for example.

Moreover, the insulating particle which has a core-shell structure and differs in a composition in a core layer and a shell layer can also be used as (d) component. Specific examples of the core-shell insulating organic particles include particles in which an acrylic resin is grafted to a silicone-acryl rubber as a core, and particles in which an acrylic resin is grafted to an acrylic copolymer as a core. Further, core-shell silicon fine particles as described in International Publication No. 2009/051067, (meth) acrylic acid alkyl ester-butadiene-styrene copolymer or composite as described in International Publication No. 2009/020005, (meth) Insulating organic particles such as alkylacrylic acid alkyl ester-silicone copolymers or composites and silicone- (meth) acrylic acid copolymers or composites, core shell structural polymer particles as described in Japanese Patent Laid-Open No. 2002-256037 and Japanese Patent Laid-Open Rubber particles having a core shell structure as described in Japanese Patent Laid-Open No. 2004-18803 can also be used. These core-shell insulating particles may be used alone, or may be used in combination of two or more thereof. Moreover, it is preferable that such (d) insulating particle is about 0.01-2 micrometers in average particle diameter.

When the conductive adhesive layer 3b contains (d) insulating particles, the total amount of the (d) insulating particles and the conductive particles 5 is 80 parts by mass or less with respect to 100 parts by mass of the total mass of the adhesive composition 4b. It is preferable, and it is more preferable that it is 60 mass parts or less. When the total compounding quantity of insulating particle and conductive particle exceeds 80 mass parts, there exists a tendency for film formability and the adhesive force to an electrode to fall. In addition, when the insulating adhesive layer 3a contains (d) insulating particle, it is preferable that the compounding quantity of (d) insulating particle is 60 mass parts or less with respect to 100 mass parts of total mass of adhesive composition 4a, and 40 It is more preferable that it is below a mass part. When the compounding quantity of insulating particle exceeds 60 mass parts, there exists a tendency for the adhesiveness with respect to the electrode of film formation property and the electroconductive particle 5 to fall.

It is preferable that it is 3-12 micrometers, and, as for the thickness of the conductive adhesive layer 3b, it is more preferable that it is 5-10 micrometers. Moreover, it is preferable that it is 12-20 micrometers, and, as for the thickness of the insulating adhesive bond layer 3a, it is more preferable that it is 14-16 micrometers. Since each layer has such a thickness, workability, conductive particle trapping property, and connection reliability can be maintained satisfactorily.

Moreover, it is preferable that the thickness of the adhesive film 10 for circuit connections is 10-40 micrometers. If the thickness is less than 10 µm, the space between the adherends cannot be completely filled, and the adhesive force tends to be lowered. If the thickness exceeds 40 µm, the resin will leak out when pressed, and the peripheral components tend to be dirty.

Formation of the conductive adhesive layer 3b and the insulating adhesive layer 3a uses a mixture containing the adhesive composition 4b and the conductive particles 5 for the conductive adhesive layer 3b, and the insulating adhesive layer 3a. The mixture containing the adhesive composition (4a) is liquefied by dissolving or dispersing in an organic solvent, respectively, to prepare a coating liquid, and applying the coating liquid onto, for example, a peelable base material (support film), to thereby activate an active temperature of the curing agent. It can carry out by removing a solvent below.

As another method of forming the conductive adhesive layer 3b and the insulating adhesive layer 3a, the components of the conductive adhesive layer 3b and the insulating adhesive layer 3a are respectively heated to ensure fluidity, and then applied by applying a solvent. The method of making it into a liquid and apply | coating on a peelable base material and removing a solvent below the active temperature of a hardening | curing agent is mentioned.

The solvent used at this time is preferable from a viewpoint of the mixed solvent of an aromatic hydrocarbon solvent and an oxygen containing solvent improving the solubility of adhesive composition (4a) and (4b). Moreover, as a peelable base material, the polymer film which has heat resistance and solvent resistance, such as polyethylene terephthalate (PET), polypropylene, polyethylene, polyester, is mentioned, for example. Especially PET film etc. which were surface-treated to have mold release property are used preferably.

It is preferable that the thickness of a peelable base material is 20-75 micrometers. When this thickness is less than 20 micrometers, handling will become difficult at the time of press bonding, and when it exceeds 75 micrometers, there exists a tendency for the winding shift | offset between the adhesive film 10 for circuit connections and a peelable base material.

As a manufacturing method of the adhesive film 10 for circuit connections, for example, the method of laminating the conductive adhesive layer 4b and the insulating adhesive layer 4a which were formed as mentioned above, or the method of coating each layer sequentially Known methods, such as these, can be employ | adopted.

The adhesive film for circuit connection of this embodiment can be used as an anisotropic conductive adhesive which bonds a semiconductor element and comparatively hard board | substrates, such as glass, in mounting, such as COG (Chip On Glass; chip on glass).

For example, it can heat and pressurize in the state which interposed the adhesive film for circuit connections between circuit members, such as a glass substrate and a semiconductor element, and can electrically connect the circuit electrodes which both have. Here, the warp is particularly problematic when the circuit member having a thickness of 0.3 mm or less is used, and in this case, the adhesive film for circuit connection of the present embodiment can be used effectively.

That is, the adhesive composition containing the adhesive composition and the conductive adhesive layer containing the conductive particles, and the insulating adhesive layer containing the adhesive composition and not containing the conductive particles, the adhesive composition contained in the conductive adhesive layer (a) glass transition temperature 40 to An adhesive film comprising a film forming material at 70 ° C., (b) an epoxy resin, and (c) a latent curing agent, comprises a first circuit member having a first circuit electrode formed on a main surface of a first circuit board having a thickness of 0.3 mm or less. And a second circuit member having a second circuit electrode formed thereon on a main surface of a second circuit board having a thickness of 0.3 mm or less, for use in circuit connection in which the first circuit electrode and the second circuit electrode are electrically connected with each other. Can be.

In addition, when the thickness of the board | substrate is 0.2 mm or less, the problem of curvature becomes more remarkable. As a minimum of the thickness of the circuit board which can use the adhesive film for circuit connections of this embodiment, if each mechanical strength can be maintained, there will be no problem, it is preferable that it is 0.05 mm or more, and it is more preferable that it is 0.08 mm or more.

The circuit member, such as a glass substrate and a semiconductor element, is normally provided with many circuit electrodes (it may be single in some cases). By arranging at least a part of the circuit electrodes provided in the opposingly arranged circuit members, heating and pressurizing in the state which interposed the adhesive film for a circuit connection between the opposingly arranged circuit electrodes, the circuit electrodes arrange | positioned oppositely are electrically connected, and a circuit You can get connected structures.

Thus, by heating and pressurizing the opposingly arranged circuit members, the opposingly arranged circuit electrodes are electrically connected by either or both of the contact through the conductive particles and the direct contact.

<Circuit Connection Structure>

FIG. 2: is a schematic cross section which shows the laminated body 200 through which the adhesive film 10 for circuit connections which concerns on this embodiment was interposed between a pair of circuit member, ie, the board | substrate 1 and the semiconductor element 2, FIG. 3: is a schematic cross section which shows the circuit connection structure 100 which concerns on this embodiment obtained by heating and pressurizing the laminated body 200 shown in FIG.

The circuit connection structure 100 shown in FIG. 3 is the board | substrate 1 (1st circuit member) in which the wiring pattern 1b (1st circuit electrode) was formed on the main surface of the glass substrate 1a (1st circuit board). And a semiconductor element 2 (second circuit member) on which a bump electrode 2b (second circuit electrode) is formed on a main surface of the IC chip 2a (second circuit board), the substrate 1 and the semiconductor element. The hardened | cured material 6a and 6b (connection part) of the adhesive film 10 for circuit connections interposed between (2) are provided. In the circuit connection structure 100, the wiring pattern 1b and the bump electrode 2b are electrically connected in the state arrange | positioned opposingly.

The wiring pattern 1b is preferably formed of a transparent conductive material here. As the transparent conductive material, ITO (indium tin oxide) is typically used. The bump electrode 2b is formed of a material having a conductivity enough to function as an electrode (preferably at least one selected from the group consisting of gold, silver, tin, a metal of platinum group, and ITO). .

In the circuit connection structure 100, the opposing bump electrodes 2b and the wiring patterns 1b are electrically connected through the conductive particles 5. That is, the electrically-conductive particle 5 is electrically connected by contacting both the bump electrode 2b and the wiring pattern 1b directly.

Since the board | substrate 1 and the semiconductor element 2 are bonded by the hardened | cured material 6a and 6b of the adhesive film 10 for circuit connection, the circuit connection structure 100 is thin in the thickness of a circuit member. Also in the case of (0.3 mm or less), the curvature of the board | substrate 1 is fully suppressed and the outstanding connection reliability is obtained.

Such a circuit connection structure 100 can be manufactured through the following process. That is, the board | substrate 1 (1st circuit member) in which the wiring pattern 1b (1st circuit electrode) was formed on the main surface of the glass substrate 1a (1st circuit board) of thickness 0.3 mm or less and 0.3 mm or less in thickness Between a pair of circuit members provided with the semiconductor element 2 (2nd circuit member) in which the bump electrode 2b (2nd circuit electrode) was formed on the main surface of the IC chip 2a (2nd circuit board) of the The wiring pattern interposed between a pair of circuit members by the process of obtaining a laminated body through the circuit connection adhesive film of this embodiment, and hardening the adhesive film for circuit connection by heating and pressurizing a laminated body ( 1b) (1st circuit electrode) and bump electrode 2b (2nd circuit electrode) can be manufactured by the manufacturing method provided with the process of forming the connection part which adhere | attaches a pair of circuit members so that it may electrically connect.

<Connection method of the circuit member>

The circuit connection structure 100 is the board | substrate 1 in which the wiring pattern 1b was formed on the main surface of the glass substrate 1a, and the semiconductor element 2 in which the bump electrode 2b was formed on the main surface of the IC chip 2a. ) And the adhesive film 10 for circuit connection interposed between the board | substrate 1 and the semiconductor element 2 in the state which the wiring pattern 1b and the bump electrode 2b were arrange | positioned opposingly, and a wiring pattern It obtains by the method of electrically connecting (1b) and bump electrode 2b.

In this method, the adhesive film 10 for circuit connection formed on the peelable base material was heated and pressed in the state which bonded together on the board | substrate 1, and the adhesive film 10 for circuit connection was press-bonded, and the peelable base material was After peeling, the semiconductor element 2 is placed while aligning the circuit electrodes, and then heated and pressed to laminate the substrate 1, the adhesive film 10 for circuit connection, and the semiconductor element 2 in this order. Sieve 200 may be prepared.

The conditions which heat and pressurize the said laminated body 200 are according to the hardenability of adhesive composition 4a, 4b, etc. in the adhesive film 10 for circuit connections, etc., and the adhesive film 10 for circuit connections hardens | cures enough adhesiveness. Properly prepared so that strength is obtained.

According to the connection method of the circuit member using the adhesive film for circuit connections of this embodiment, even if the thickness of a circuit member is thin (0.3 mm or less), curvature of a circuit member can be suppressed and favorable connection reliability can be obtained.

[Example]

Hereinafter, an Example is given and this invention is demonstrated further more concretely. However, the present invention is not limited to these examples.

(1) Preparation of adhesive film for circuit connection

Each material for producing a conductive adhesive layer and an insulating adhesive layer was prepared as follows. About 10 mg of each film forming material was weighed, and Tg of the film forming material was measured in accordance with the provisions of JIS K7121-1987 on a DSC instrument (product name: Q1000) manufactured by TA Instruments.

(a) component: Tg 40-70 degreeC film forming material

"FX-316" (product of Toto Kasei, product name): phenoxy resin (Tg: 66 ° C)

"UR-4125" (Toyobo Corporation, product name): Polyester urethane (Tg: 68 ℃)

"UR-1350" (Toyobo Corporation, product name): Polyester urethane (Tg: 46 ℃)

"3000-K" (manufactured by Denki Chemical Co., Ltd., product name): polyvinyl butyral (Tg: 64 ° C)

(a) 'component: Film-forming materials other than (a) component

"UR-8300" (Toyobo Corporation, product name): Polyester urethane (Tg: 23 ℃)

"ZX-1356-2" (Toto Kasei Co., Ltd. product name): Phenoxy resin (Tg: 75 degreeC)

"PKHC" (manufactured by InChem, product name): phenoxy resin (Tg: 89 ° C)

"5000-D" (manufactured by Denki Chemical Co., Ltd., product name): polyvinyl butyral (Tg: 110 ° C)

"YP-50" (product of Toto Kasei, product name): phenoxy resin (Tg: 97 ° C)

(b) Component: epoxy resin

"850-S" (product made by DIC, product name): bisphenol A epoxy resin

(c): latent curing agent

"Novacure" (Asahi Kasei Chemicals, product name)

(d): insulating particles

"X-52-7030" (Shin-Etsu Silicone make, product name): Silicone composite (composite of silicone rubber and silicone resin)

(Conductive particles)

"Micro Pearl AU" (Sekisui Kagaku Co., product name)

(additive)

"SH6040" (Toray Dow Corning, trade name): Silane coupling agent

(Example 1)

<Conductive Adhesive Layer>

10 parts by mass of phenoxy resin "FX-316", 30 parts by mass of bisphenol A type epoxy resin "850-S", 40 parts by mass of latent curing agent "Novacure" and 1 part by mass of silane coupling agent "SH6040" 100 parts by mass of toluene After melt | dissolving in, 19 mass parts of electroconductive particle "micropearl AU" was added, and the coating liquid for conductive adhesive layer formation was produced.

Coating device (manufactured by Yasui Seiki Co., Ltd., product name: Precision Coating Machine) on a PET film having a thickness of 50 µm in which this coating liquid was subjected to a release treatment (heavy peeling treatment) on one side (the surface on which the coating liquid was applied). Was applied and hot air dried at 70 ° C. for 10 minutes to form a conductive adhesive layer having a thickness of 10 μm on the PET film.

<Insulating adhesive layer>

52 parts by mass of phenoxy resin "FX-316", 26 parts by mass of bisphenol A type epoxy resin "850-S", 18 parts by mass of latent curing agent "Novacure" and 1 part by mass of silane coupling agent "SH6040", solvent toluene 100 After melt | dissolving in a mass part, 3 mass parts of silicone microparticles | fine-particles "X-52-7030" were added, and the coating liquid for insulating adhesive layer formation was produced.

This coating solution was applied in the same manner to the above, and was applied to a PET film having a thickness of 50 µm on one side by using a coating device (manufactured by Yasui Seiki Co., Ltd., product name: precision coating machine), and 70 ° C. By hot-air drying for 10 minutes at, an insulating adhesive layer having a thickness of 15 μm was formed on the PET film.

<Adhesive film for circuit connection>

The electrically conductive adhesive layer and insulating adhesive layer obtained above were laminated by the roll laminator, heating at 50 degreeC, and the adhesive film for circuit connections whose thickness is 25 micrometers was obtained.

(Examples 2 to 6 and Comparative Examples 1 to 5)

Each component was added in the compounding ratio (mass part) shown in following Table 2, and it carried out similarly to Example 1 except having produced the coating liquid for conductive adhesive layer formation, and produced the adhesive film for circuit connections.

(2) Fabrication of circuit connection structure

<Preparation of substrate and semiconductor element>

As a board | substrate, what formed the wiring pattern (pattern width 50 micrometers, inter-electrode space 5 micrometers) of ITO (indium tin oxide) on the surface of a glass substrate (Corning # 1737, 38 mm x 28 mm, thickness 0.3 mm) was prepared. . As a semiconductor element, an IC chip (outer shape of 17 mm x 17 mm, thickness 0.3 mm, bump size 50 m x 50 m, space between bumps 50 m and bump height 15 m) was prepared.

<Connection of substrate and semiconductor element>

The connection of an IC chip and a glass substrate was performed as shown below using the adhesive film for circuit connection produced by the said Example and the comparative example. In addition, the heating crimp comprised with the stage (150 mm x 150 mm) and the tool (3 mm x 20 mm) containing a ceramic heater was used for connection.

First, the PET film on the conductive adhesive layer of the adhesive film for circuit connection (1.5 mm x 20 mm) was peeled off, and the conductive adhesive layer surface was heated on the glass substrate for 2 seconds under conditions of 80 ° C and 0.98 MPa (10 kgf / cm 2). It stuck by pressing. Subsequently, after peeling off the PET film on the insulating adhesive bond layer of the adhesive film for circuit connections, and positioning the bump of an IC chip and a glass substrate, conversion of the measured maximum achieved temperature of 190 degreeC and bump electrode area of the adhesive film for circuit connections was carried out. Under the pressure of 70 MPa, heating and pressurization were performed for 10 seconds from the IC chip upper side, the insulating adhesive bond layer was affixed on the IC chip, and the main connection of the chip | tip and glass substrate which interposed the adhesive film for circuit connection was performed.

(3) evaluation

(Film formability)

About the produced adhesive film for circuit connection, film formability was evaluated on the following references | standards. In addition, "it can be made into a film" means that the produced film does not tear easily, a crack, or sticks. The evaluation results of the film formability are shown in Table 2.

A: Can be made with film

B: can't with film

(Curvature)

It is a schematic cross section which shows the evaluation method of the curvature of a glass substrate. The circuit connection structure 100 shown in FIG. 4 is comprised from the board | substrate 1, the semiconductor element 2, and the hardened adhesive film 10 for circuit connections which bonds these. L is the height of the lower surface of the lower surface of the substrate 1 to a place 12.5 mm away from the center of the semiconductor element 2 when the height of the lower surface of the substrate 1 at the center of the semiconductor element 2 is 0. Indicates a large value. Evaluation of curvature performed L as an index | index. The smaller the value of L, the smaller the deflection. The case where the value of L was less than 15 micrometers was evaluated by "A" and the case where it is 15 micrometers or more as "B" in two steps. The evaluation results of the warpage are shown in Table 2.

In the preparation of the circuit connection structure, the thicknesses of the glass substrate and the IC chip were changed from 0.3 mm to 0.5 mm, respectively, and the connection using the adhesive film for circuit connection produced in the above examples and comparative examples was the same as described above. The conjugate was produced by the procedure. The curvature of the obtained bonded body was evaluated, and curvature was less than 15 micrometers in any bonded body.

(Connection reliability)

The resistance value between the circuit of a glass substrate and the electrode of a semiconductor element was measured using the produced circuit connection structure. The measurement was performed using a multimeter (device name: MLR21, manufactured by ETAC) after a THT test (Thermal Humidity Test) at a temperature of 85 ° C., a humidity of 85% RH, and 1000 hours. Based on the resistance value after the THT test, connection reliability was evaluated in two stages of A or B according to the following criteria. The measurement results of each circuit connection structure are shown in Table 3 below.

A: less than 10 Ω

B: 10 Ω or more

The adhesive film for circuit connection of this invention showed the outstanding characteristic also regarding any of film formation property, curvature, and connection reliability, even when used for the connection of thin circuit members.

One… Substrate, 1a... Glass substrate, 1b... Wiring pattern, 2... Semiconductor element, 2a... IC chip, 2b... Bump electrode, 3a... Insulating adhesive layer, 3b... Conductive adhesive layers, 4a, 4b... Adhesive composition, 5... Conductive particles, 6a, 6b... Hardened | cured material, 10... Adhesive film for circuit connection, 100... Circuit connection structure, 200. Laminate.

Claims (5)

It is an adhesive film for circuit connection provided with the electrically conductive adhesive layer containing an adhesive composition and electroconductive particle, and the insulating adhesive layer containing an adhesive composition and not containing conductive particle,
The adhesive composition contained in the said conductive adhesive layer contains the film forming material of (a) glass transition temperature of 40-70 degreeC, (b) epoxy resin, and (c) latent hardening | curing agent,
A first circuit member having a first circuit electrode formed on a main surface of a first circuit board having a thickness of 0.3 mm or less, and a second circuit member having a second circuit electrode formed on a main surface of a second circuit board having a thickness of 0.3 mm or less, The adhesive film for circuit connections for electrically connecting in the state which the said 1st circuit electrode and the said 2nd circuit electrode faced. The adhesive film for circuit connection of Claim 1 in which the said conductive adhesive layer and / or the said insulating adhesive layer further contain (d) insulating particle. A first circuit member having a first circuit electrode formed on a main surface of a first circuit board having a thickness of 0.3 mm or less,
A second circuit electrode is formed on the main surface of the second circuit board having a thickness of 0.3 mm or less, and the second circuit electrode is disposed to face the first circuit electrode, so that the second circuit electrode is connected to the first circuit electrode. A second circuit member which is electrically connected,
A connecting portion interposed between the first circuit member and the second circuit member.
And
The circuit connection structure whose said connection part is hardened | cured material of the adhesive film for circuit connections of Claim 1 or 2. A first circuit member having a first circuit electrode formed on a main surface of a first circuit board having a thickness of 0.3 mm or less and a second circuit member having a second circuit electrode formed on a main surface of a second circuit board having a thickness of 0.3 mm or less Between a pair of circuit members, the process of obtaining a laminated body through the adhesive film for circuit connections of Claim 1 or 2,
By heating and pressing the said laminated body and hardening the said adhesive film for circuit connections, the said 1st circuit electrode and the said 2nd circuit electrode interposed between the said pair of circuit members, and are electrically connected so that the said 2nd circuit electrode may be electrically connected Process of forming the connection part which adhere | attaches circuit members
The manufacturing method of the circuit connection structure provided with. A first circuit member having a first circuit electrode formed on a main surface of a first circuit board having a thickness of 0.3 mm or less,
A second circuit member having a second circuit electrode formed on a main surface of a second circuit board having a thickness of 0.3 mm or less,
The adhesive film for circuit connection of any one of Claims 1-5 arrange | positioned between the said 1st circuit member and the said 2nd circuit member.
Heating and pressurizing in a state where the first circuit electrode and the second circuit electrode are opposed to each other to electrically connect the first circuit electrode and the second circuit electrode.

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