JP2002203427A - Circuit connecting material, method for manufacturing circuit board using it, and circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric/electronic circuit connecting material more superior in low temperature quick curing property to the current epoxy resin base material and providing good bonding strength to a circuit member, and provide a method for manufacturing of a circuit board using this circuit connecting material, and the circuit board. SOLUTION: This circuit connecting material contains (1) silicone modified polyimide resin, (2) a radical polymerizable substance, (3) a curing agent generating a free radical by heating, as an essential ingredient, contains conductive particles, contains (1) 2-75 pts.wt. silicone modified polyimide resin, (2) 30-60 pts.wt. radical polymerizable substance, (3) 0.1-30 pts.wt. curing agent generating free radical by heating, and (4) 0-40 pts.wt. film forming material, and contains 0.1-30 vol.% conductive particles such as Au, Ag, or carbon to an adhesive component. In the method for manufacturing the circuit board, the circuit connecting material is interposed between a first connecting terminal and a second connecting terminal facing each other, and the first connecting terminal and the second connecting terminal are electrically connected by heating and pressing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a circuit connecting material using an adhesive composition and conductive particles, a method of manufacturing a circuit board using the same, and a circuit board.

[0002]

2. Description of the Related Art Epoxy resin adhesives have high adhesive strength and are excellent in water resistance and heat resistance.
It is frequently used in various applications such as electronics, architecture, automobiles, and aircraft. Among them, one-pack type epoxy resin-based adhesives are used in the form of a film, paste, or powder because they do not require mixing of a main agent and a curing agent and are easy to use. In this case, a specific performance is generally obtained by various combinations of the epoxy resin and the curing agent and the modifying agent. (For example, JP-A-62-141083).

[0003]

However, although the film adhesive disclosed in the above-mentioned Japanese Patent Application Laid-Open No. Sho 62-141083 is excellent in workability, it can be heated at about 140 to 180 ° C. with a connection time of about 20 seconds. 180-2 for 10 seconds
Heating of about 10 ° C. was required. The reason for this is that a catalyst-type curing agent that is inactive at room temperature is used for the purpose of obtaining good stability by achieving both short-time curing (rapid curing) and storage stability (preservability). This is because a sufficient reaction cannot be obtained during curing. In recent years, in the field of precision electronic devices, the density of circuits has been increasing, and the width of connection terminals,
The connection terminal interval is extremely narrow. For this reason, under the conventional connection condition of the circuit connection material using the epoxy resin system, there has been a problem that the wiring is dropped, peeled off or displaced. Further, there is a demand for a reduction in connection time in which connection can be made in 10 seconds or less in order to improve production efficiency. In order to satisfy these requirements, a low-temperature and fast-curing circuit connection material that can be cured at a low temperature in a short time is indispensable. (For example, JP-A-11-97825). However, the circuit connecting member has a problem in that the adhesive strength varies depending on the type of material constituting the circuit to be connected. In particular, when the substrate supporting the circuit terminals is made of an organic insulating material such as polyimide resin or glass, or the circuit member surface is coated with silicon nitride, silicone resin, or polyimide resin, or these resins adhere to the circuit member surface. In this case, there was a problem that the adhesive strength was significantly reduced. It is an object of the present invention to provide a circuit member comprising at least one selected from the group consisting of an organic insulating material and glass, and a silicon nitride or silicone substrate, wherein the substrate supporting the circuit terminals is made of at least one selected from the group consisting of: Resin, a particularly good adhesive strength is obtained for a circuit member coated or adhered with at least one selected from polyimide resins, a circuit connecting material for electric and electronic, a method of manufacturing a circuit board using the same, and a circuit board. To provide.

[0004]

According to the present invention, there is provided [1] a connection material which is interposed between opposed connection terminals and presses the opposed connection terminals to electrically connect the connection terminals in the pressing direction. (1) Silicon modified polyimide resin, (2)
A radical polymerizable substance, (3) a curing agent that generates free radicals by heating as an essential component, (1) 2 to 75 parts by weight of a silicone-modified polyimide resin, (2) 30 to 60 parts by weight of a radical polymerizable substance, (3) A) a circuit connecting material containing 0.1 to 30 parts by weight of a curing agent that generates free radicals upon heating, and (4) a film forming material of 0 to 40 parts by weight. [2] The circuit connection material according to [1], wherein the circuit connection material includes the components (1), (2), (3), and (4) and further (5) conductive particles as essential components. [3] (3) The curing agent according to the above [1] or [1], wherein the curing agent that generates free radicals by heating has a weight retention of 20% by weight or more after being left open for 24 hours at room temperature (25 ° C.) and normal pressure. The circuit connection material according to the above [2]. [4] (4) The circuit connecting material according to any one of [1] to [3], wherein the film forming material is a polyurethane resin. [5] (2) The circuit connecting material according to any one of [1] to [4], wherein the radical polymerizable substance is urethane acrylate. [6] Further, the elastic modulus at 25 ° C. is 0.1 to 100 MPa.
a) the silicone fine particles described in (1), (2),
(4) The circuit connecting material according to any one of the above [1] to [5], which contains 5 to 200 parts by weight based on 100 parts by weight of the total of the components. Further, the present invention provides [7] a first circuit member having a first connection terminal, and a second circuit member having a second connection terminal, the first connection member and the second connection terminal. The circuit connection material according to any one of the above [1] to [6] is interposed between the first connection terminal and the second connection terminal which are arranged to face each other, and are heated and pressurized. This is a method of manufacturing a circuit board for electrically connecting a first connection terminal and a second connection terminal that are arranged to face each other. [8] The method for manufacturing a circuit board according to [7], wherein the surface of at least one of the connection terminals is made of at least one selected from gold, silver, and platinum group metals.

[9] The method for manufacturing a circuit board according to the above [7] or [8], wherein the substrate supporting at least one connection terminal is made of at least one selected from an organic insulating material and glass. [10] The above [7] or the above, wherein at least one circuit member surface is coated or adhered with at least one selected from silicon nitride, a silicone compound, and a polyimide resin.

[9] The method for manufacturing a circuit board according to any one of [9]. In addition, the present invention relates to [11] above [7] to [1]
0] The circuit board obtained by the method for manufacturing a circuit board according to any one of the above.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The curing agent (3) used in the present invention, which generates free radicals by heating, is a compound which decomposes by heating a peroxide compound or an azo compound to generate free radicals. Is appropriately selected depending on the connection temperature, connection time, pot life, and the like.
Organic peroxide having a temperature of not less than 180 ° C. and a half-life of 1 minute of 180 ° C. or less is preferable, and an organic peroxide having a temperature of a half-life of 10 hours of not less than 60 ° C. and a half-life of 1 minute of 170 ° C. or less. Is more preferred. When the connection time is set to 10 seconds or less, the amount of the curing agent is not sufficient to obtain a sufficient reaction rate.
It is preferably 0.1 to 30 parts by weight, more preferably 1 to 20 parts by weight. If the amount of the curing agent is less than 0.1 part by weight, a sufficient reaction rate cannot be obtained, and good adhesive strength and small connection resistance tend to be hardly obtained. If the amount exceeds 30 parts by weight, the fluidity of the circuit connecting material tends to decrease, the connection resistance increases, and the pot life of the circuit connecting material tends to be short.

Examples of the organic peroxide include diacyl peroxides, peroxydicarbonates, peroxyesters, peroxyketals, dialkyl peroxides, hydroperoxides, and silyl peroxides. Examples of diacyl peroxides include isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinic peroxide, Benzoyl peroxytoluene, benzoyl peroxide and the like can be mentioned.

The peroxydicarbonates include di-n-propylperoxydicarbonate, diisopropylperoxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, and di-2-ethoxymethoxyperoxydicarbonate. Carbonate, di (2-ethylhexylperoxy) dicarbonate, dimethoxybutylperoxydicarbonate, di (3-methyl-3-
(Methoxybutylperoxy) dicarbonate.

The peroxy esters include cumyl peroxy neodecanoate, 1,1,3,3-tetramethylbutyl peroxy neodecanoate, 1-cyclohexyl-1-methylethyl peroxynodecanoate. , T-
Hexyl peroxy neodecanoate, t-butyl peroxy pivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanonate, 2,5-dimethyl-2,5-di (2 -Ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanonate, t-hexylperoxy-
2-ethylhexanonate, t-butylperoxy-2-
Ethyl hexanonate, t-butyl peroxyisobutyrate, 1,1-bis (t-butylperoxy) cyclohexane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethyl Hexanonate, t-butyl peroxylaurate, 2,
5-dimethyl-2,5-di (m-toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, t-
-Butyl peroxyacetate and the like.

[0009] Among peroxyketals, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (T-butyl peroxy)-
Examples include 3,3,5-trimethylcyclohexane, 1,1- (t-butylperoxy) cyclododecane, 2,2-bis (t-butylperoxy) decane, and the like.

[0010] Among the dialkyl peroxides, α ',
α'-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-
Examples thereof include 2,5-di (t-butylperoxy) hexane and t-butylcumyl peroxide.

The hydroperoxides include diisopropylbenzene hydroperoxide, cumene hydroperoxide and the like.

The silyl peroxides include t-butyltrimethylsilyl peroxide, bis (t-butyl) dimethylsilyl peroxide, t-butyltrivinylsilyl peroxide, bis (t-butyl) divinylsilyl peroxide, tris ( (t-butyl) vinylsilyl peroxide, t-butyltriallylsilyl peroxide, bis (t-butyl) diallylsilyl peroxide, tris (t-butyl) allylsilyl peroxide and the like.

Further, in order to suppress the corrosion of the connection terminals of the circuit member, chlorine ions and organic acids contained in the curing agent are 5% or less.
It is preferably at most 000 ppm, and more preferably an organic acid which is less generated after thermal decomposition.
In addition, since the stability of the prepared circuit connection material is improved, after leaving open for 24 hours under normal pressure at room temperature (25 ° C.),
It is preferable to have a weight retention of not less than% by weight. These can be used by mixing as appropriate. These free radical generators can be used alone or as a mixture, and a decomposition accelerator, an inhibitor and the like may be used as a mixture. A microcapsule obtained by coating these curing agents with a polyurethane-based or polyester-based polymer substance or the like is preferable because the pot life is extended.

The (1) silicon-modified polyimide resin used in the present invention has one or both of an acid dianhydride and a diamine having a siloxane skeleton, such as a tetracarboxylic dianhydride and a diamine having a siloxane skeleton. Is obtained by heating and condensing a polyamic acid synthesized by the addition reaction of the above, and from the viewpoint of solubility and film forming property, the weight average molecular weight is preferably about 10,000 to 150,000. At this time, the acid dianhydride and the diamine are appropriately selected from the viewpoint of solubility in a solvent and compatibility with the radically polymerizable material, and a mixture of multiple components can be used.

The (4) film-forming material used in the present invention includes polyurethane resin, polyvinyl formal resin, polystyrene resin, polyvinyl butyral resin, polyester resin, acrylic resin, polyamide resin, xylene resin, phenoxy resin and the like. These can be used in combination as appropriate. What is a film-forming material?
When the liquid material is solidified and the constituent composition is in the form of a film, the film is easy to handle and easily tears, breaks, or imparts mechanical properties that do not stick, such as in a normal state. It can be handled as a film. Further, the film forming material may be modified by a radical polymerizable functional group.

The polyurethane resin of the film-forming material used in the present invention is a resin obtained by reacting a diol having two hydroxyl groups in a molecule with a diisocyanate having two isocyanate groups, and is excellent in stress relaxation during curing. , The adhesiveness is improved due to the polarity. As the diol, those having a linear terminal hydroxyl group can be preferably used.Specifically, polyethylene adipate, polydiethylene adipate, polypropylene adipate, polybutylene adipate, polyhexamethylene adipate, polyneopentyl adipate, Polycaprolactone polyol, polyhexamethylene carbonate,
Examples include silicone polyol, acrylic polyol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like. These can be used alone or in combination of two or more. Further, a polyhydric alcohol can be used in combination. Examples of diisocyanates include isophorone diisocyanate, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, naphthalene-1,5-diisocyanate, p-
Examples include phenylene diisocyanate, 4,4'-methylenebiscyclohexyl diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate. These may be used alone or in combination.
The weight average molecular weight of the polyurethane resin is 10,000 to 1
000000 is preferred. Weight average molecular weight of 1000
If it is less than 0, the cohesive force of the circuit connecting material is reduced, and it tends to be difficult to obtain a sufficient adhesive strength. 1,000,000
If it exceeds 300, the mixing property and the fluidity tend to deteriorate. Further, when synthesizing a polyurethane resin from a diol and a diisocyanate, a polyhydric alcohol, an amine, an acid anhydride and the like may be blended and appropriately reacted, for example, an imide group-containing polyurethane obtained by reacting with an acid anhydride is This is preferable because the adhesiveness and heat resistance are improved. The polyurethane resin which is preferably used in the present invention may be modified with a radical polymerizable functional group or the like, and a resin modified with a radical polymerizable functional group is preferable since heat resistance is improved. Polyurethane resin preferably used in the present invention,
Those having a pour point in the range of 40 to 140 ° C. by the flow tester method are preferred. The pour point in the flow tester method is measured using a flow tester, and using a die having a diameter of 1 mm,
This is the temperature at which the cylinder starts to move when a pressure of 3 MPa is applied and the temperature is raised at a rate of 2 ° C./min. The polyurethane resin preferably used in the present invention has a pour point in the flow tester method within a range of 40 to 140 ° C, and more preferably 50 to 100 ° C. If the pour point in the flow tester method is lower than 40 ° C., the film formability and adhesiveness will be poor.

The (2) radical polymerizable substance used in the present invention is a substance having a functional group capable of polymerizing by radicals, and includes acrylate, methacrylate, and maleimide compounds. The radically polymerizable substance can be used in any state of a monomer and an oligomer, and the monomer and the oligomer can be used in combination. Specific examples of the acrylate include methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, tetramethylol methane tetraacrylate, and 2-hydroxy-1,3-diacrylate. Roxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, dicyclopentenyl acrylate, tricyclodecanyl acrylate, tris (Acryloyloxyethyl) isocyanurate, isocyanuric acid ethylene oxide-modified diacrylate, urethane acrylate and methacrylate corresponding thereto. That. These can be used alone or in combination. If necessary, a polymerization inhibitor such as hydroquinone or methyl ether hydroquinone may be appropriately used. It is preferable to have a dicyclopentanyl group and / or a tricyclodecanyl group and / or a triazine ring because heat resistance is improved. When a radical polymerizable substance having a phosphate ester structure is used in combination with the above-mentioned radical polymerizable substance, the adhesive strength on the surface of an inorganic substance such as a metal is preferably improved.

Radical polymerizable substances having a phosphate ester structure include phosphoric anhydride and 2-hydroxyethyl (meth)
Obtained as an acrylate reactant. Specific examples include mono (2-methacryloyloxyethyl) acid phosphate, di (2-methacryloyloxyethyl) acid phosphate, and the like. These can be used alone or in combination. Urethane acrylate has at least one urethane group in the molecule, and is obtained as a reaction product of a polyol such as polytetramethylene glycol and a polyisocyanate and a hydroxyl group-containing acrylic compound, and is preferable because it has excellent adhesion. .

The maleimide compound is a compound containing at least two maleimide groups in the molecule, for example, 1-methyl-2,4-bismaleimidebenzene, N,
N'-m-phenylenebismaleimide, N, N'-p-phenylenebismaleimide, N, N'-m-toluylenebismaleimide, N, N'-4,4-biphenylenebismaleimide, N, N'- 4,4- (3,3'-dimethylbiphenylene)
Bismaleimide, N, N'-4,4- (3,3'-dimethyldiphenylmethane) bismaleimide, N, N'-4,4-
(3,3′-diethyldiphenylmethane) bismaleimide, N, N′-4,4-diphenylmethanebismaleimide,
N, N'-4,4-diphenylpropanebismaleimide,
N, N'-4,4-diphenylether bismaleimide,
N, N′-3,3′-diphenylsulfonebismaleimide,
2,2-bis (4- (4-maleimidophenoxy) phenyl) propane, 2,2-bis (3-s-butyl-3,4- (4
-Maleimidophenoxy) phenyl) propane, 1,1-
Bis (4- (4-maleimidophenoxy) phenyl) decane, 4,4'-cyclohexylidene-bis (1- (4-maleimidophenoxy) -2-cyclohexylbenzene, 2,
2-bis (4- (4-maleimidophenoxy) phenyl)
Hexafluoropropane and the like can be mentioned.

In the present invention, (1) in the circuit connecting material
A silicon-modified polyimide resin, (2) a radical polymerizable substance, (3) a curing agent that generates free radicals by heating,
(4) Regarding the film forming material, (1) 2 to 75 parts by weight of the silicone-modified polyimide resin, (2) 30 to 60 parts by weight of the radical polymerizable substance, (3) a curing agent that generates free radicals by heating But 0.1 to 30 parts by weight (4)
The film forming material is used in an amount of 0 to 40 parts by weight, which is appropriately determined. Further, when the sum of (1) silicone-modified polyimide resin, (2) radically polymerizable substance, and (4) film forming material is 100 parts by weight,
It is preferable to add 5 to 200 parts by weight, and the amount is appropriately determined. (1) If the blending amount of the silicone-modified polyimide resin is less than 2 parts by weight, the effect of relaxing the stress at the time of curing the circuit connection material or at the time of heat load is poor and the adhesive strength is reduced. If the amount exceeds 75 parts by weight, connection reliability may be reduced. (2) If the compounding amount of the radical polymerizable substance is less than 30 parts by weight, the mechanical strength of the circuit connecting material after curing tends to decrease, and if it exceeds 60 parts by weight, the tackiness of the circuit connecting material before hardening. And handling becomes inferior. (3) If the amount of the curing agent that generates free radicals by heating is less than 0.1 part by weight, a sufficient reaction rate cannot be obtained as described above, and good adhesive strength and small connection resistance can be obtained. It tends to be difficult. If the amount exceeds 30 parts by weight, the fluidity of the circuit connecting material tends to decrease, the connection resistance increases, and the pot life of the circuit connecting material tends to be short. If (4) the amount of the film-forming material exceeds 40 parts by weight, the fluidity of the circuit connecting material tends to decrease and the connection resistance tends to increase. Preferably it is 1 to 40 parts by weight. The film-forming material may not be blended with (1) a silicone-modified polyimide resin, (2) a radical polymerizable substance, and (3) a curing agent that generates free radicals by heating, as long as a sufficient film can be formed. Further, the circuit connecting material of the present invention may contain a filler, a softener, an accelerator, an antioxidant, a coloring agent, a flame retardant, a thixotropic agent, a coupling agent, and the like.

It is preferable to include a filler since the connection reliability and the like can be improved. The maximum diameter of the filler is preferably smaller than the particle diameter of the conductive particles, and more preferably in the range of 5 to 60% by volume. If it exceeds 60% by volume, the effect of improving reliability is saturated. As the coupling agent, a vinyl group, an acryl group, an amino group, an epoxy group and an isocyanate group-containing material are preferable from the viewpoint of improving the adhesiveness.

The circuit connection material of the present invention can be connected by direct contact of the connection terminals facing each other at the time of connection even without conductive particles. When the conductive particles are contained, more stable connection can be obtained. . Au, A as the conductive particles
g, Ni, Cu, metal particles such as solder, carbon and the like. In order to obtain a sufficient pot life, the surface layer is Ni,
Instead of transition metals such as Cu, Au, Ag, and platinum group noble metals are preferable, and Au is more preferable. Further, the surface of a transition metal such as Ni may be coated with a noble metal such as Au. Further, it is preferable that the above-described conductive layer is formed on a non-conductive glass, ceramic, plastic, or the like by coating or the like, and the outermost layer is coated with a noble metal. In the case of using plastic as a nucleus or hot-melt metal particles, they have deformability due to heating and pressurization, so the contact area with the connection terminal increases at the time of connection, absorbing variations in the thickness of the connection terminal etc. and improving reliability. It is preferred. The thickness of the noble metal coating layer is preferably 100 ° or more in order to obtain good resistance. However, when a layer of a noble metal is provided on a transition metal such as Ni, free radicals are generated due to oxidation-reduction caused by a defect in the noble metal layer or a defect in the noble metal layer generated during mixing and dispersion of conductive particles, and the like. In order to cause a reduction in the life, the thickness is preferably 300 ° or more. When the thickness increases, their effects become saturated. Therefore, it is preferable to set the thickness to 1 μm at the maximum, but there is no limitation. The conductive particles are properly used in a range of 0.1 to 30% by volume based on 100 volumes of the adhesive component. In order to prevent a short circuit or the like in an adjacent circuit due to excessive conductive particles, the content is more preferably 0.1 to 10% by volume. In addition, when the circuit connection material of the present configuration is divided into two or more layers and separated into a layer containing a hardener generating free radicals and a layer containing conductive particles, the conventional high definition can be obtained. Thus, the pot life can be improved.

The circuit connecting material of the present invention is also useful as a film adhesive for bonding an IC chip to a chip mounting substrate and bonding electric circuits to each other. That is, a first circuit member having a first connection terminal, and a second circuit member having a second connection terminal, the first connection terminal and the second connection terminal are arranged facing each other, The circuit connection material (film adhesive) of the present invention is interposed between the first connection terminal and the second connection terminal disposed opposite to each other, and heated and pressurized, and the first connection terminal and the second connection terminal disposed opposite each other. The two connection terminals can be electrically connected. Examples of such connecting members include chip components such as a semiconductor chip, a resistor chip, and a capacitor chip, a printed board on which chip mounting and / or resist processing has been performed, and a TCP (tape) on which chip mounting and resist processing have been performed on a TAB tape. Carrier package),
There are liquid crystal panels and the like. Examples of the material of the connection member include silicone, gallium, and arsenic of semiconductor chips, glass, ceramics, polyimide resin, glass-epoxy resin composite, and plastic.

In the circuit connecting material of the present invention, the adhesive melts and flows at the time of connection, and after the connection of the connection terminals facing each other is obtained, the adhesive is hardened to maintain the connection. The fluidity of the adhesive is important. Is a factor. Using a glass having a thickness of 0.7 mm and a size of 15 mm × 15 mm, a circuit connecting material having a thickness of 35 μm and a size of 5 mm × 5 mm is sandwiched between the glasses, and is heated at 160 ° C., 2 MPa, and 1 MPa.
When the heating and pressurizing is performed in 0 seconds, the fluidity (B) expressed by using the initial area (A) and the area after the heating and pressurizing (B) /
The value of (A) is preferably from 1.3 to 3.0,
More preferably, it is 1.5 to 2.5. If it is less than 1.3, the fluidity is poor, and good connection cannot be obtained. If it is more than 3.0, bubbles are easily generated and the reliability is poor.

The circuit connection material of the present invention has a rising temperature (Ta) of an exothermic reaction of 70 to 110 when measured at a heating rate of 10 ° C./min using a differential scanning calorimeter (DSC).
Within the range of ° C., the peak temperature (Tp) is Ta + 5 to 30 ° C.
And the end temperature (Te) is preferably 160 ° C. or lower. By doing so, both low-temperature connectivity and storage stability at room temperature can be compatible.

The circuit connecting material of the present invention has a temperature of 25 ° C. after curing.
The storage elastic modulus is preferably 100 to 2000 MPa,
00 to 1500 MPa is more preferable. In this case, the internal stress of the resin after the connection is reduced, which is advantageous for improving the adhesive strength, and good conduction characteristics can be obtained.

According to the method for manufacturing a circuit board of the present invention, the first circuit member having the first connection terminal and the second circuit member having the second connection terminal are connected to the first connection terminal and the second connection member. The first connection terminal is disposed opposite to the first connection terminal, the circuit connection material is interposed between the first connection terminal and the second connection terminal disposed opposite to each other, and heated and pressurized. And the second connection terminal are electrically connected. Circuit members having connection terminals include semiconductor chip silicon and gallium.
Arsenic, glass, ceramics, composite material of glass and thermosetting resin, plastic film, plastic sheet, etc., formed a conductive metal foil via an adhesive on an insulating substrate to form a circuit including connection terminals A conductive circuit formed by plating or vapor deposition on an insulating substrate, or
Examples of a conductive circuit formed by applying a material such as a plating catalyst can be used. TAB tape, FPC, PPC
A typical example is a semiconductor chip having WB, ITO and connection pads.

When the conductive connection terminal in contact with the circuit connection material is a transition metal such as copper or nickel, free radicals are generated by an oxidation-reduction action, and the circuit connection material is temporarily adhered to the first connection terminal, and is fixed. If left for a long time, radical polymerization proceeds, the connection material becomes difficult to flow, and there is a possibility that sufficient electrical connection may not be performed at the time of full connection with the aligned second connection terminal. Therefore, it is preferable that the surface of at least one of the connection terminals is made of at least one selected from gold, silver, a platinum group metal or tin. A multilayer structure may be formed by combining a plurality of metals such as copper / nickel / gold. Furthermore, in the circuit board manufacturing method of the present invention, it is preferable that at least one of the connection terminals is formed directly on the plastic, and the plastic is preferably a polyimide resin. Examples of the plastic include films and sheets of polyethylene terephthalate resin, polyethylene naphthalate resin, polyether sulfone resin, polycarbonate resin, and polyimide resin, and by using these, the thickness of the circuit board is made thinner and moreover, the weight is reduced. be able to. By using the circuit connection material of the present invention, connection can be made at a low temperature, so that plastic having a relatively low glass transition temperature or melting point can be used, and a circuit board excellent in economy can be obtained. In order to reduce the thickness and weight, it is preferable that the connection member be made of a connection member that does not use an adhesive, and that a connection terminal that does not use an adhesive is directly provided on the plastic, rather than bonding a connection terminal made of a conductive material with a plastic that is a connection member.
A polyimide resin with a metal foil obtained by a direct coating method in which a resin solution is formed to a constant thickness directly on a metal foil such as a copper foil without using an adhesive is commercially available and can be suitably used. In addition, a material obtained by thermocompression bonding a film extruded directly from an extruder or the like into a film shape and a metal foil can also be used.

In the present invention, the circuit member which is excellent in low-temperature and quick-curing properties compared with the conventional epoxy resin system and which supports the circuit terminals is made of at least one kind selected from an organic insulating material and glass, and the surface is made of silicon nitride. A circuit connecting material for electric and electronic devices, and a method and a circuit for manufacturing a circuit board using the same, which provide particularly good adhesive strength to a circuit member coated or adhered with at least one selected from silicone resin and polyimide resin. Boards can be provided.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. (Example 1) [Synthesis of polyimide resin] As an acid dianhydride, 2,2-bis (4- (3,4-dicarboxyphenoxy) phenyl)
Propane dianhydride (26.1 g) was added to cyclohexanone 1
Dissolved in 20 g, and 2,2-bis (4- (4- (4-
Aminophenoxy) phenyl) propane (14.4
g), 1,3-bis (3-aminopropyl) -1,1,3,3
A solution of tetramethyldisiloxane (3.8 g) dissolved in 120 g of cyclohexanone was heated to a temperature of 50 ° C.
The solution was added dropwise to the flask of the acid dianhydride solution while adjusting so as not to exceed the above, and the mixture was further stirred for 10 hours after completion of the addition.
Next, a water retention tube was attached, 50 g of toluene was added, and 12
The temperature was raised to 0 ° C. and maintained for 8 hours to perform imidization. After cooling the obtained solution to room temperature, it was reprecipitated in methanol and the obtained precipitate was dried to obtain a weight average molecular weight of 3200.
No. 0 polyimide resin was obtained. This was dissolved in tetrahydrofuran to obtain a 20% by weight polyimide solution A.

As the radical polymerizable substance, dimethylol tricyclodecane diacrylate was used. A phenoxy resin (PKHC; trade name, manufactured by Union Carbide, weight average molecule: 45,000) was used as a film forming material. 20% by weight DO of lauroyl peroxide (weight retention of 97% by weight after leaving open for 24 hours at room temperature (25 ° C.) under normal pressure) as a curing agent that generates free radicals upon heating
The P solution was used. A nickel layer having a thickness of 0.2 μm was provided on the surface of the particles having polystyrene as a core, and a gold layer having a thickness of 0.04 μm was provided outside the nickel layer to produce conductive particles having an average particle diameter of 10 μm. 40 g of the silicone-modified polyimide resin A (as a solid content) synthesized above at a solid weight ratio, 39 g of dimethylol tricyclodecane diacrylate, 1 g of a phosphoric acid ester type acrylate (trade name of P2M manufactured by Kyoeisha Yushi Co., Ltd .; P2M), 20 g of a phenoxy resin , Lauroyl peroxide 5g (DOP
(Dioctyl phthalate) solution, and the conductive particles were further mixed and dispersed by 3% by volume, and a 80 μm-thick surface-treated PET (polyethylene terephthalate) film having one surface was coated using a coating apparatus. It was applied and dried with hot air at 70 ° C. for 10 minutes to obtain a circuit connection material having an adhesive layer thickness of 35 μm.

(Connection of Circuits) A flexible circuit board (two-layer FPC) in which 500 copper circuits having a line width of 50 μm, a pitch of 100 μm, and a thickness of 18 μm are formed on a polyimide film (thickness: 100 μm), and a polyimide, polyimide and copper foil Indium-tin oxide (ITO) is formed on a flexible circuit board (three-layer FPC) having a line width of 50 μm and a pitch of 100 μm (three-layer FPC) and a glass having a thickness of 1.1 mm in a three-layer configuration including an adhesive to be bonded and a copper foil having a thickness of 18 μm. An ITO substrate (surface resistance; <20Ω / □) formed by vapor deposition was heated at 160 ° C. for 3 hours using the above circuit connection material (adhesive composition).
It was heated and pressed at 10 MPa for 10 seconds and connected over a width of 2 mm. At this time, the liquid adhesive composition was applied on the ITO substrate, and the film-shaped adhesive composition was applied on the ITO substrate in advance, after the adhesive surface of the adhesive composition was adhered, and then heated to 70 ° C.
Temporarily connect by heating and pressing at 0.5 MPa for 5 seconds,
The PET film was peeled off and connected to the other FPC.

(Example 2) [Synthesis of urethane acrylate] 400 parts by weight of polycaprolactone diol having an average molecular weight of 800, 131 parts by weight of 2-hydroxypropyl acrylate, 0.5 parts by weight of dibutyltin dilaurate as a catalyst, and a polymerization inhibitor Hydroquinone monomethyl ether (1.0 part by weight) was heated and mixed at 50 ° C. while stirring. Next, 222 parts by weight of isophorone diisocyanate was added dropwise, and the temperature was raised to 80 ° C. with further stirring to carry out a urethanization reaction. After confirming that the conversion of NCO was 99% or more, the reaction temperature was lowered to obtain urethane acrylate B. [Synthesis of polyurethane resin] 450 parts by weight of polybutylene adipate diol having an average molecular weight of 2,000, and polyoxytetramethylene glycol 450 having an average molecular weight of 2,000
Parts by weight, 100 parts by weight of 1,4-butylene glycol, 4,000 parts by weight of methyl ethyl ketone, and uniform mixing.
The reaction was carried out at 70 ° C and the solid content was 20% by weight.
A polyurethane resin C solution of 50 poise (25 ° C.) was obtained. The weight average molecular weight of this polyurethane resin was 350,000, and the pour point by the flow tester method was 80 ° C. 40 g of the silicone-modified polyimide resin A (as a solid content) synthesized in Example 1, 39 g of the urethane acrylate B synthesized as described above, 20 g of the polyurethane resin C (as a solid content) synthesized as described above, and a phosphate ester type acrylate
A circuit connecting material was obtained in the same manner as in Example 1 except that the amount was 1 g, and a circuit board was produced.

Example 3 [Synthesis of Silicone Fine Particles] Methyltrimethoxysilane was added to an aqueous alcohol solution of pH 12 stirred at 300 rpm at 20 ° C., and hydrolyzed and condensed. The elastic modulus at 25 ° C. was 8 MPa, and the average particle size was 2 μm. Was obtained. 100 parts by weight of the obtained silicone fine particles were dispersed in 100 parts by weight of a mixed solvent of toluene / ethyl acetate = 50/50 in a weight ratio. 40 g of silicone-modified polyimide resin A (as solid content) synthesized in Example 1, 39 g of dimethylol tricyclodecane diacrylate, phenoxy resin 2
A circuit connecting material was obtained in the same manner as in Example 1 except that 0 g, 1 g of a phosphoric acid ester type acrylate, and 10 g of the silicone fine particles (as a solid content) synthesized above were used to produce a circuit board.

(Example 4) ITO glass was coated on the surface with ITO.
A circuit board using a circuit connection material having a thickness of 15 μm was obtained in the same manner as in Example 1 except that a liquid crystal panel having wirings provided at connection terminals was used.

Example 5 ITO glass was used to form a laminated substrate having a copper foil of 35 μm in a line width of 100 μm and a pitch of 2.
A printed circuit board (P) formed by patterning a copper circuit to 00 μm, applying a resist treatment, and applying a gold plating to the copper foil surface.
A circuit board using a circuit connecting material having a thickness of 15 μm was obtained in the same manner as in Example 1 except that WB) was used.

Comparative Example 1 Phenoxy resin (PKHC;
Union Carbide product name, weight average molecular weight 450
00), bisphenol A type epoxy resin (YL98
0; trade name of Yuka Shell Epoxy Co., Ltd.) and imidazole-based microcapsule type hardener (3941HP; trade name of Asahi Kasei Corporation).
A circuit connecting material was obtained in the same manner as in Example 1, except that the solid weight ratio of bisphenol A type epoxy resin / imidazole microcapsule type curing agent was 40/20/40.
A circuit board was manufactured.

Comparative Example 2 A circuit connecting material was obtained in the same manner as in Example 1 except that a phenoxy resin (PKHC) was used instead of the silicon-modified polyimide resin A, and a circuit board was produced.

Using the circuit connection materials and circuit boards obtained in Examples 1 to 4 and Comparative Examples 1 and 2, adhesive strength, connection resistance, preservability, insulation, fluidity of polyurethane resin, circuit connection material Was measured and evaluated for fluidity, elastic modulus after curing, and DSC measurement. The results are shown in Table 1. The measurement and evaluation methods were performed as follows. (Measurement of Adhesive Strength) The connected body (circuit board) of the circuit obtained above was peeled at a peeling speed of 50 mm / min in a direction of 90 °, and the adhesive strength was measured. The adhesive strength was 8 at the beginning of the circuit board production and 8
The measurement was performed after the sample was kept in a high-temperature and high-humidity bath at 5 ° C. and 85% RH for 500 hours. (Measurement of connection resistance) Using the above-mentioned circuit connection material, a flexible circuit board (FPC) in which 100 Sn-plated copper circuits each having a line width of 100 μm, a pitch of 200 μm, and a thickness of 18 μm were placed and one piece of ITO solid glass were used.
It was heated and pressurized at 60 ° C. and 3 MPa for 10 seconds and connected over a width of 2 mm. The resistance value between the adjacent circuits of the connection body was measured with a multimeter at the initial stage and after being kept in a high-temperature and high-humidity chamber at 85 ° C. and 85% RH for 500 hours. The resistance value is shown as an average of 50 resistances between adjacent circuits.

(Evaluation of Storage Property) The obtained circuit connection material was treated in a thermostat at 30 ° C. for 30 days, and the circuit was connected in the same manner as described above to evaluate the storage property. (Evaluation of Insulation) Using the obtained circuit connection material, a printed circuit board having a comb-shaped circuit in which 250 copper circuits having a line width of 100 μm, a pitch of 200 μm, and a thickness of 45 μm were alternately arranged, a line width of 100 μm, a pitch of 200 μm, and a thickness A flexible circuit board (FPC) having 500 18 μm copper circuits was heated and pressed at 160 ° C. and 3 MPa for 10 seconds, and connected over a width of 2 mm. A voltage of 100 V was applied to the comb-shaped circuit of this connection body, and the insulation resistance value after 500 hours of a high-temperature and high-humidity test at 85 ° C. and 85% RH was measured.

(Measurement of Pour Point of Polyurethane Resin) Flow Tester (CFT-100, manufactured by Shimadzu Corporation)
Using a die with a diameter of 1 mm and a pressure of 3 MPa at 2 ° C /
The temperature at which the cylinder began to move at a rate of temperature rise for one minute was measured and defined as the pour point. (Evaluation of fluidity of circuit connection material) Thickness 35 μm, 5 mm ×
Using a circuit connection material of 5 mm, this is 0.7 mm thick,
Sandwiched between 15mm x 15mm glass, 160 ℃, 2MP
a, Heating and pressurization was performed for 10 seconds. The value of the fluidity (B) / (A) was determined using the initial area (A) and the area (B) after the heating and pressurization, and was defined as the fluidity. (Elastic modulus after curing) The circuit connection material was immersed in oil at 160 ° C. for 1 minute to cure, and the storage elastic modulus of the cured film was measured using a dynamic viscoelasticity measuring device (temperature rise rate 5 ° C / min, 10 Hz) and the elastic modulus at 25 ° C. (Measurement of DSC) Using the obtained circuit connection material, the rising temperature of the exothermic reaction (Ta) was measured at 10 ° C./min using a differential scanning calorimeter (DSC, trade name 910, manufactured by TA Instruments). ), Peak temperature (Tp) and end temperature (Te) were determined.

[0042]

[Table 1]

In any of the examples, the initial value of the adhesive strength of the two-layer FPC is about 800 to 1100 N / m, and even after the moisture resistance test, it is about 900 to 1200 N / m, and there is no significant decrease in the adhesive strength. showed that. Comparative Example 1
The curing reaction was insufficient, and Comparative Example 2 had a low adhesive strength of about 200 N / m because the silicone-modified polyimide resin was not used. In any of the examples, the initial value of the adhesive strength of the three-layer FPC is about 1200 to 1400 N / m, and even after the moisture resistance test is 1200 to 1400 N / m.
There was no significant decrease in degree and adhesive strength, indicating good adhesiveness. In Comparative Example 1, the curing reaction was insufficient, and in Comparative Example 2, the silicone-modified polyimide resin was not used.
The adhesive strength was as low as about 00 N / m. The circuit connection material obtained in Example 1 has a low initial connection resistance and a small increase in resistance after a high-temperature and high-humidity test in any of the two-layer FPC and the three-layer FPC, showing good connection reliability. Was. In addition, the circuit connection materials of Examples 2, 3, 4, 5, and Comparative Example 2 also had good connection reliability. For these,
In Comparative Example 1, the bonding state was poor because the curing reaction was insufficient, and the initial connection resistance was high. As a result of evaluating the storage stability by connection resistance, in Examples 1 to 5, 3
Almost the same connection results were obtained in the state where the processing was not performed for 0 days (initial) and when the processing was performed. As for the insulation resistance, in Examples 1 to 5, good insulation of 1.0 × 10 ⁹ Ω or more was obtained, and no decrease in insulation was observed. Liquidity measurement results,
Example 1 was 1.9, and Example 2 was 2.2. The elastic modulus of the circuit connection material of Example 1 at 25 ° C. after curing was measured and found to be 900 MPa. The rising temperature of Example 1 was 89 ° C, the peak temperature was 107 ° C,
The end temperature was 148 ° C. Example 2 has a rising temperature of 92 ° C., a peak temperature of 106 ° C., and an end temperature of 150 ° C.
° C. This indicates that the composition is cured at a lower temperature, and that the storage stability is superior to the storage stability evaluation result. In the measurement of connection resistance, a copper circuit was prepared with and without Sn plating, and was temporarily connected to an FPC under the same conditions as in Example 1 using the circuit connection material prepared in Example 1. The main connection was made after standing, and the connection resistance was measured.
C) and 2.0 Ω (three-layer FPC), respectively, and 5 Ω (two-layer FP)
C) and 4Ω (three-layer FPC).

[0044]

As described above in detail, according to the present invention, a circuit connection for electric and electronic use which has excellent low-temperature and fast-curing properties, has a long pot life, and has a low circuit corrosiveness, compared with the conventional epoxy resin system. A material, a method for manufacturing a circuit board using the same, and a circuit board can be provided.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 3/32 H05K 3/32 B 3/36 3/36 A (72) Inventor Mitsugu Fujinawa Shimodate, Ibaraki 1150 Goshomiya, Gozamiya, Hitachi Chemical Co., Ltd. (72) Inventor Takashi Nakazawa Takashi Nakazawa 1150 Gozamiya, Oita, Shimodate, Ibaraki Pref. Goshomiya, Hitachi Chemical Co., Ltd. (72) Inventor Kazuyoshi Kojima, Ibaraki 1150 Goshomiya, Shimodate-shi F-term (reference) at Goshomiya Works, Hitachi Chemical Co., Ltd. 5F044 LL07 NN20 5G301 DA05 DA10 DA29 DA42 DA51 DA59 DD03

Claims (11)

[Claims] 1. A connection material interposed between opposed connection terminals and pressurizing the opposed connection terminals to electrically connect the connection terminals in the pressure direction, (1) a silicon-modified polyimide resin, (2) a radical polymerizable substance, and (3) a curing agent that generates free radicals by heating as essential components,
(1) 2 to 75 parts by weight of silicone modified polyimide resin,
(2) 30-60 parts by weight of a radical polymerizable substance, (3)
Curing agent that generates free radicals upon heating 0.1-3
0 parts by weight, (4) a circuit connecting material containing 0 to 40 parts by weight of a film forming material. 2. The circuit connection material according to claim 1, wherein the components (1), (2), (3) and (4) and (5) conductive particles are essential components. 3. The curing agent which generates free radicals upon heating is a curing agent having a weight retention of 20% by weight or more after leaving open for 24 hours at room temperature (25 ° C.) and normal pressure. Or the circuit connection material according to claim 2. 4. The circuit connecting material according to claim 1, wherein (4) the film forming material is a polyurethane resin. 5. The circuit connection material according to claim 1, wherein (2) the radically polymerizable substance is urethane acrylate. 6. An elastic modulus at 25 ° C. of 0.1 to 10
The silicone fine particles having a pressure of 0 MPa are mixed with the above (1),
5 to 20 based on a total of 100 parts by weight of the components (2) and (4)
The circuit connecting material according to any one of claims 1 to 5, which contains 0 parts by weight. 7. A first circuit member having a first connection terminal and a second circuit member having a second connection terminal are arranged with the first connection terminal and the second connection terminal facing each other. And between the first connection terminal and the second connection terminal disposed opposite to each other.
A method for manufacturing a circuit board, wherein the circuit connection material according to any one of claims 6 to 6 is interposed, and the first connection terminal and the second connection terminal arranged opposite to each other are electrically connected by heating and pressing. 8. The surface of at least one of the connection terminals is gold,
The method for manufacturing a circuit board according to claim 7, wherein the circuit board is made of at least one selected from silver and platinum group metals. 9. The method for manufacturing a circuit board according to claim 7, wherein the substrate supporting at least one connection terminal is made of at least one selected from an organic insulating material and glass. 10. The method for manufacturing a circuit board according to claim 7, wherein at least one surface of the circuit member is coated or adhered with at least one selected from silicon nitride, a silicone compound, and a polyimide resin. . 11. A circuit board obtained by the method for manufacturing a circuit board according to claim 7.