JP2002167569A - Adhesive composition, adhesive composition for connecting circuit, connected unit and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an adhesive composition capable of preventing corrosion of an adherend composed of a metal and an inorganic material and accompanying decrease in reliability of an element, the adhesive composition for connecting a circuit, to provide a connected unit and a semiconductor device. SOLUTION: The adhesive composition comprises (a) a curable adhesive curable by photo-irradiation at 150-750 nm, or heating at 80-200 deg.C, or a combination of photo-irradiation and heating, (b) electroconductive particles and (c) a compound bearing at least one benzotriazole structure in the molecule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an adhesive composition, a circuit connection material, an adhesive composition for circuit connection, a connector, and a semiconductor device.

[0002]

2. Description of the Related Art In semiconductor devices and liquid crystal display devices,
Conventionally, various adhesives have been used for the purpose of bonding various members in the element. There are various demands for adhesives, including adhesiveness, heat resistance, and reliability in high temperature and high humidity conditions. The adherends used for bonding include printed wiring boards, organic base materials such as polyimide, circuit electrode surfaces formed of metals such as copper and aluminum, and inorganic materials such as ITO, and silicon wafers. A variety of substrates are used, and molecular design is required for each adherend. Conventionally, as an adhesive for the semiconductor element or the liquid crystal display element, a thermosetting resin using an epoxy resin having high adhesiveness and high reliability has been used. As a component of the resin, an epoxy resin, a curing agent such as a phenol resin reactive with the epoxy resin, and a heat latent catalyst for accelerating the reaction between the epoxy resin and the curing agent are generally used. The thermal latent catalyst is an important factor in determining the curing temperature and the curing speed, and various compounds have been used from the viewpoint of storage stability at room temperature and the curing speed when heated. The curing conditions in the actual process are 170-25.
The desired adhesion was obtained by curing at a temperature of 0 ° C. for 1 to 3 hours. However, with recent high integration of semiconductor elements and high definition of liquid crystal elements, the pitch between elements and between wirings has been narrowed, and there has been a possibility that heating during curing may adversely affect peripheral members. In order to further reduce costs, it is necessary to improve the throughput.
(100-170 ° C.), a short time (within 1 hour), in other words, low-temperature fast curing is required. In order to achieve this low-temperature rapid curing, it is necessary to use a heat latent catalyst having a low activation energy, and it is very difficult to have storage stability near room temperature. JP-A-11-60899 and JP-A-11-116778 disclose a method using photocationic polymerization of an epoxy resin as an adhesive having both storage stability and low-temperature curability. These methods are composed of an epoxy resin and a photoacid generator that generates a strong acid upon irradiation with light, and are cured by irradiating with light at room temperature.

[0003]

However, when an epoxy resin is used, the impurity ions remaining in the epoxy resin may not be adhered to metals such as copper and aluminum or ITO.
It is known that corrosion of a circuit electrode formed of an inorganic material such as the above is caused, and as a result, the function as a connection body is reduced. Furthermore, in the case of the cationic photopolymerization, since a strong acid such as Bronsted acid or Lewis acid is used as a polymerization catalyst, corrosion of a circuit electrode composed of a metal substrate or a metal and an inorganic material as an adherend is promoted, It is known to significantly reduce the reliability of the connection.

[0004] The present invention provides an adhesive composition and an adhesive composition for circuit connection, which prevent a decrease in the reliability of an element due to corrosion of an adherend composed of a metal and an inorganic material, and further exhibit excellent storage stability at room temperature. An object, a connector, and a semiconductor device are provided.

[0005]

According to the present invention, there are provided (a) 150 to
A curable adhesive that cures by irradiating light at 750 nm or heating at 80 to 200 ° C. or using light irradiation and heating in combination;
The adhesive composition essentially contains (b) conductive particles and (c) a compound having at least one benzotriazole structure in a molecule. Further, the present invention relates to (a) 150 to 750 nm
(C) a compound having at least one benzotriazole structure in a molecule with respect to 100 parts by weight of a curable adhesive which is cured by light irradiation or heating at 80 to 200 ° C. or a combination of light irradiation and heating. It is an adhesive composition containing 1 to 30 parts by weight. Further, the present invention provides a circuit which is interposed between substrates having circuit electrodes facing each other and presses the substrate having circuit electrodes facing each other to electrically connect the electrodes in the pressing direction. It is an adhesive composition for connection. Also,
The present invention is a connector connected by using the adhesive composition for circuit connection. Further, the present invention is a semiconductor device in which the adhesive composition is interposed between an electrode of a semiconductor element and a circuit electrode of a substrate for mounting a semiconductor, and a pressure is applied to electrically connect the electrodes in the pressing direction.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The curable adhesive (a) used in the present invention is irradiated with light of 150 to 750 nm or 80 to 750 nm.
There is no particular limitation as long as the composition is cured by heating at 200 ° C., or by using both light irradiation and heating, and a known composition can be used. As such a curable adhesive, for example, acryloyl group, methacryloyl group, allyl group,
A radical polymerization system comprising a resin having one or more radically polymerizable groups such as a maleimide group and a vinyl group and a polymerization initiator that generates a radical by irradiation with heat and / or light is exemplified. Further, epoxy resin and a resin having at least one phenolic hydroxyl group, thiol group, carboxyl group in the molecule and a curing accelerator, and a cationic polymerizable resin such as epoxy resin or vinyl ether resin and heat and
And / or a curing system comprising a polymerization initiator that generates cations by light irradiation.

The conductive particles (b) used in the present invention include metal particles such as Au, Ag, Ni, Cu, and solder, and carbon. Further, the core may be made of non-conductive glass, ceramic, plastic, or the like, and the core may be coated with the metal, metal particles, or carbon. In the case of conductive particles, the core of plastic, the core, the metal, metal particles or carbon coated or hot melt metal particles,
Since it has deformability by heating and pressing, the contact area with the electrode at the time of connection increases, and reliability is improved, and variations in the height of the electrode are absorbed, which is preferable because reliability is improved. In addition, fine particles in which the surfaces of these conductive particles are further coated with a polymer resin, etc., can suppress short-circuiting due to contact between particles when the amount of the conductive particles is increased, and improve insulation between electrode circuits. Therefore, these may be used singly or as a mixture with conductive particles.

The average particle size of the conductive particles is preferably 1 to 18 μm from the viewpoint of dispersibility and conductivity. The amount of the conductive particles to be used is not particularly limited, but is preferably 0.1 to 30% by volume, more preferably 0.1 to 10% by volume, based on 100 parts by total of the adhesive composition. . If this value is less than 0.1% by volume, the conductivity tends to be inferior, and if it exceeds 30% by volume, a short circuit tends to occur. The volume% is determined based on the volume of each component before curing at 23 ° C., but the volume of each component can be converted from weight to volume using specific gravity. In addition, put the component in a suitable solvent (water, alcohol, etc.) that does not dissolve or swell the component in a graduated cylinder, etc. You can also ask

As the compound (c) having one or more benzotriazole structures in the molecule used in the present invention, known compounds can be used without any particular limitation as long as they do not adversely affect the curable adhesive. As such compounds, for example, the following compounds (A) to (N) and derivatives thereof can be used.

[0010]

Embedded image

Further, as shown below, homopolymers and copolymers having a benzotriazole structure in the side chain or main chain of the polymer can be used. The molecular weight is preferably from 500 to 100,000 in terms of solubility in a solvent, compatibility with the curable adhesive, and the like.

[0012]

Embedded image These compounds can be used alone or in combination of two or more.

(C) The amount of the compound having one or more benzotriazole structures in the molecule is (a) 150 to 75
Curable adhesive 100 which is cured by light irradiation of 0 nm, heating at 80 to 200 ° C., or a combination of light irradiation and heating
Parts to 0.1 to 30 parts by weight, preferably 0.1 to 30 parts by weight.
5 to 15 parts by weight. If the amount exceeds this range,
Curability may be adversely affected.

The adhesive composition of the present invention may optionally contain additives such as an adhesion improver such as a coupling agent and a leveling agent.

The adhesive composition of the present invention may be appropriately added with various polymers for the purpose of increasing the viscosity or forming a film. The polymer used is not particularly limited, but (a) 15
A curable adhesive which is cured by light irradiation of 0 to 750 nm or heating at 80 to 200 ° C. or a combination of light irradiation and heating; (b) one or more conductive particles and (c) a benzotriazole structure in a molecule; It is essential that the compound has no adverse effect. Such polymers include polyimide resins, polyamide resins, bisphenol A-type phenoxy resins and bisphenol F-type phenoxy resins, general-purpose phenoxy resins such as bisphenol A / bisphenol F copolymerization-type phenoxy resins, polymethacrylates, polyacrylates, Polyimides, polyurethanes, polyesters, polyvinyl butyral, SBS and its modified epoxy, SEBS and its modified can be used. These can be used alone or in combination of two or more. Further, these polymers may contain a siloxane bond or a fluorine substituent. These can be suitably used as an adhesive composition as long as the resins to be mixed are completely compatible with each other or are in a state where microphase separation occurs and the mixture becomes cloudy. The larger the molecular weight of the polymer, the more easily the film can be formed, and the melt viscosity which affects the fluidity as an adhesive can be set in a wide range. Although the molecular weight is not particularly limited, a general weight average molecular weight is 5,000 to 15
It is preferably 10,000, and particularly preferably 10,000 to 80,000. If this value is less than 5,000, the film-forming properties tend to be poor, and if it exceeds 150,000, the compatibility with other components tends to be poor. The amount used is preferably 20 to 320 parts by weight based on 100 parts by weight of the curable adhesive (epoxy resin). If the amount is less than 20 parts by weight or more than 320 parts by weight, fluidity and adhesiveness tend to decrease.

The adhesive composition of the present invention can be used in the form of a paste when it is liquid at normal temperature. When it is solid at room temperature (25 ° C.), it may be used by heating, or may be made into a paste using a solvent. The solvent that can be used is not particularly limited as long as it has no reactivity with the adhesive composition and the additive, and shows sufficient solubility, but the boiling point at normal pressure is 50 to 150 ° C. Are preferred. When the boiling point is 50 ° C. or lower, the mixture may be volatilized when left at room temperature, and its use in an open system is restricted. If the boiling point is 150 ° C. or higher, it is difficult to volatilize the solvent, which may adversely affect the reliability after bonding.

The adhesive composition of the present invention can be used in the form of a film. A solution obtained by adding a solvent or the like as necessary to the adhesive composition is coated on a peelable substrate such as a fluororesin film, a polyethylene terephthalate film, release paper, or a substrate such as a nonwoven fabric is impregnated with the solution. It can be used as a film after being placed on a peelable substrate by removing a solvent or the like. Use in the form of a film is more convenient in terms of handling properties and the like.

The adhesive composition of the present invention can be adhered by light irradiation, heating, or simultaneous heating and pressing simultaneously with light irradiation. By using these together, bonding at a lower temperature and in a shorter time becomes possible. Light irradiation is 150-75
Irradiation light in a wavelength range of 0 nm is preferable, and curing can be performed using a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, or a metal halide lamp at an irradiation amount of 0.1 to 10 J / cm ² . The heating temperature is not particularly limited as long as it is lower than the decomposition point of the adhesive composition, but a temperature of 80 to 200C is preferable. The pressure is not particularly limited as long as the pressure does not damage the adherend, but is generally 0.1 to 0.1.
10 MPa is preferred. These heating and pressurizing are performed at 0.
It is preferable to carry out in the range of 5 seconds to 3 hours.

The adhesive composition of the present invention can be used as an adhesive for different kinds of adherends having different coefficients of thermal expansion. Specifically, circuit connection materials typified by anisotropic conductive adhesives, silver pastes, silver films, etc .; semiconductors such as flip chip anisotropic conductive materials for connecting semiconductor elements such as flip chips to printed wiring boards; It can be used as an element adhesive material.

Hereinafter, an example of connection between an anisotropic conductive film produced using the adhesive composition and the conductive particles of the present invention and an electrode will be described. An anisotropic conductive film is present between the opposing electrodes on the substrate, irradiated with light of 150 to 750 nm, and then heated and pressurized to obtain contact between the two electrodes and adhesion between the substrates, thereby establishing connection with the electrodes. I can do it. As a substrate on which electrodes are formed, inorganic materials such as semiconductors, glass, and ceramics, organic materials such as polyimide and polycarbonate, and combinations of these composite materials such as glass / epoxy can be used.

Since the adhesive composition and the adhesive composition for circuit connection of the present invention can prevent the corrosion of the electrode, the reliability after connecting the fine circuit can be remarkably improved.

[0022]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

(Example 1) Phenoxy resin (PKHC,
Union Carbide trade name, average molecular weight 45,000
0) 40 g is dissolved in 60 g of methyl ethyl ketone,
A solution having a solid content of 40% by weight was obtained. As acrylic resin,
Pentaerythritol triacrylate (A-TMM-
3. Using Shin-Nakamura Chemical Co., Ltd. and 2-methacryloyloxyethyl acid phosphate (P-2M, manufactured by Kyoeisha Chemical Co., Ltd.) and using lauroyl peroxide (Perloyl L, Nippon Yushi Co., Ltd.) as a catalyst. Benzotriazole (manufactured by Aldrich). Further, 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 0.02 μm was provided outside the nickel layer.
Conductive particles having a specific gravity of 2.5 were produced. PKH in solid weight ratio
50 parts of C, 50 parts of A-TMM-3, 2 parts of P-2M, 3 parts of the catalyst and 1 part of benzotriazole 1. Further, 1.5% by volume of conductive particles are mixed and dispersed. The film is applied using a coating device,
The thickness of the adhesive layer is 40μ by hot air drying at 10 ℃ for 10 minutes.
m of film adhesive was obtained. A 0.7 mm thick corning glass (# 7059, manufactured by Corning Incorporated) and a line width of 100 μm, a pitch of 200 μm, and a thickness of 35 μm on a printed circuit board were prepared using the film adhesive obtained by the above method.
A comb-shaped electrode in which a μm copper circuit is formed in a comb shape is connected to a thermocompression bonding apparatus (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.) at 160 ° C. and 2 MPa at 2 MPa.
The connection was performed over a width of 2 mm by heating and pressing for 0 seconds, and after a lapse of time, the pressure was released to produce a connected body. At this time, after the adhesive surface of the film adhesive is pasted on the comb-shaped electrode in advance, it is temporarily connected by heating and pressing at 70 ° C. and 0.5 MPa for 5 seconds, and then the fluororesin film is peeled off. It was connected to one of the adherends, Corning glass.

(Example 2) Phenoxy resin (manufactured by Union Carbide Co., Ltd., trade name PKHC, average molecular weight 45,000)
0) 40 g of toluene (boiling point 110.6 ° C,
SP value 8.90) / ethyl acetate (boiling point 77.1 ° C, SP
(Value 9.10) = 50/50 in a mixed solvent (60 g) to give a solution having a solid content of 40% by weight. Bisphenol type liquid epoxy resin (bisphenol A type epoxy resin, manufactured by Yuka Shell Epoxy Co., Ltd., Epicoat 828, epoxy equivalent: 184), epoxy acrylate oligomer (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: NK Oligo) as a curable monomer EA-1020), a mixture of hexafluorophosphate salts of triarylsulfonium as a catalyst (manufactured by Union Carbide Co., trade name Cyracure UVI)
-6990), dicumyl peroxide (manufactured by NOF CORPORATION, trade name Parkmill D), benzotriazole
(Manufactured by Aldrich) was used. Further, a nickel layer having a thickness of 0.2 μm is provided on the surface of the particles having polystyrene as a core, and a gold layer having a thickness of 0.02 μm is provided outside the nickel layer. The conductive particles have an average particle size of 5 μm and a specific gravity of 2.5. Was prepared. 50 PKHC at the solid weight ratio, Epicoat 828
25, NK Oligo EA-1020, 1, Cyracure UVI-6990, 1, Parkmill D, 1 and benzotriazole were added, and 1.5% by volume of conductive particles were further dispersed and dispersed. The fluororesin film was applied using a coating device, and dried with hot air at 70 ° C. for 10 minutes to obtain a film adhesive having an adhesive layer thickness of 40 μm. Using a film-like adhesive obtained by the above method, a 0.7 mm-thick coning glass (# 70)
59, manufactured by Corning Incorporated) and a comb-shaped electrode in which a copper circuit having a line width of 100 μm, a pitch of 200 μm, and a thickness of 35 μm is formed in a comb shape on a printed circuit board. 130 ° C, 2MPa using a mold, manufactured by Toray Engineering Co., Ltd.
, Heating and pressurizing for 20 seconds and ultraviolet irradiation from the side of the corning glass were performed simultaneously to connect over a width of 2 mm, and after a lapse of time, the pressure was released to produce a connected body. The amount of ultraviolet irradiation applied to the adhesive was 2.0 J / cm ² . At this time, after adhering the adhesive surface of the film-like circuit connection material on the corning glass in advance, the temperature is set to 70 ° C. and 0.5MPa.
Then, the connection was performed temporarily by heating and pressing at a for 5 seconds, and then the fluororesin film was peeled off and connected to the other comb-shaped electrode as the adherend. Further, at the time of connection for 20 seconds, ultraviolet irradiation for 17 seconds was started after elapse of 3 seconds after only heating / pressing was started, and two steps were simultaneously completed after 20 seconds of heating / pressing.

COMPARATIVE EXAMPLE 1 A film-like adhesive was prepared in the same manner as in Example 1 except that benzotriazole was not contained, and a comb-shaped electrode and a coning glass were heat-pressed to form a connector.

(Comparative Example 2) A film-like adhesive was prepared in the same manner as in Example 2 except that benzotriazole was not contained, and a comb-shaped electrode and a coning glass were heat-pressed to produce a connection body.

The initial resistance immediately after connection and the resistance of 85 ° C. and 85% R were obtained for the connection bodies prepared in Examples 1 and 2 and Comparative Examples 1 and 2.
The insulation resistance after exposure to a high temperature and high humidity state while applying a voltage of 100 V under the condition of H for 100 hours was evaluated. The insulation resistance was evaluated by measuring the resistance value after applying a voltage of 100 V to the connection body for 60 seconds with an insulation resistance meter (R8340 manufactured by Advantest Co., Ltd.) and taking the average of 50 points of resistance between adjacent circuits. The appearance was observed using a metallographic microscope immediately after the connection and after the moisture resistance test, and the results are shown in Table 1.

[0028]

[Table 1]

The joints obtained in Examples 1 and 2 maintained the initial insulation resistance even after the moisture resistance test, showed no change in appearance, and showed that they were good adhesives. In contrast, in the case of Comparative Examples 1 and 2 in which benzotriazole was not added, the insulation resistance after the moisture resistance test was low because the initial insulation resistance could not be maintained, and corrosion of the electrode was observed. Is low.

Example 3 Using the film adhesive of Example 1, gold bumps (height: 30 μm, number of bumps: 18)
4) The connection between the attached chip and a Ni / Au plated copper circuit printed circuit board (electrode height: 20 μm, substrate thickness 0.8 mm) was performed as shown below. One side of the film adhesive is applied to a copper circuit printed board at 60 ° C. and 0.5 MPa for 20 minutes.
The connection was made by heating and pressing for 2 seconds. Next, the bumps of the chip and the copper circuit printed circuit board are aligned with each other, the fluororesin film on the other surface of the film adhesive is peeled off, and the upper part of the chip is heated at 160 ° C. and 50 g / bump for 20 seconds. From below to produce a semiconductor device. The connection resistance after the semiconductor device was allowed to stand at 85 ° C. and 85% RH for 500 hours was measured. The maximum connection resistance per bump was 2 mΩ and the average connection resistance was 2 mΩ. Further, when the chip and the copper circuit printed board were peeled off and their appearance was observed, corrosion of the electrodes on the circuit board and the bumps on the chip were not recognized, and the results were good.

[0031]

According to the present invention, there is no corrosion of the circuit electrode due to ionic impurities and acid components in the adhesive, and the bonding can be performed at a low temperature in a short time, and the connection reliability is excellent. In addition, it is possible to provide an adhesive composition, an adhesive composition for circuit connection, a connector, and a semiconductor device having excellent storage stability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) H01L 21/60 311 H01L 21/60 311S (72) Inventor Masami Yusa 48 Wadai, Tsukuba-shi, Ibaraki Hitachi Chemical F-term in the Research Institute of Industrial Corporation (reference) 4J040 DD051 EC001 FA221 HA026 HA066 HA076 HA346 HA366 HC25 JA03 JB02 JB08 JB10 KA03 KA07 KA12 KA13 KA16 KA17 KA32 LA03 LA05 LA09 MA01 MA02 NA20 PA30 PA32 5F044 LL09 0511 DA03 DA301

Claims (5)

[Claims] 1. A curable adhesive which is cured by irradiation with light at 150 to 750 nm or heating at 80 to 200 ° C. or a combination of light irradiation and heating, (b) conductive particles, and (c) a benzotriazole structure. And a compound having at least one compound in a molecule. 2. (a) With respect to 100 parts by weight of a curable adhesive which is cured by irradiation with light of 150 to 750 nm or heating at 80 to 200 ° C. or a combination of light irradiation and heating, (c)
2. The adhesive composition according to claim 1, comprising 0.1 to 30 parts by weight of a compound having one or more benzotriazole structures in a molecule. 3. A circuit connecting adhesive composition which is interposed between substrates having opposing circuit electrodes and pressurizes the substrates having opposing circuit electrodes to electrically connect the electrodes in the pressing direction. 3. An adhesive composition for circuit connection, wherein the adhesive is the adhesive composition according to claim 1 or 2. 4. A connected body using the adhesive composition for circuit connection according to claim 3. 5. An adhesive composition according to claim 1, which is interposed between an electrode of a semiconductor element and a circuit electrode of a substrate for mounting a semiconductor, and pressurizes the adhesive composition to form a gap between the electrodes in the pressing direction. An electrically connected semiconductor device.