JP2005320455A - Adhesive composition, material for connecting circuit, connecting structure of circuit member and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition rapidly carrying out a radical polymerization reaction at a low temperature, having a wide process margin, excellent adhesive strength and connection resistance and further excellent storage stability and to provide a material for connecting circuits, a connecting structure of circuit members and a semiconductor device. <P>SOLUTION: The adhesive composition solving the problems comprises a thermoplastic resin, a radically polymerizable compound, a first radical polymerization initiator having 90-145°C half-life temperature for 1 min and a second radical polymerization initiator having 150-175°C half-life temperature for 1 min. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

  Conventionally, as an adhesive for a semiconductor element or a liquid crystal display element, a thermosetting resin such as an epoxy resin having excellent adhesiveness and particularly excellent adhesiveness even under high temperature and high humidity conditions has been used (for example, patents). Reference 1). Such an adhesive is cured by heating at a temperature of 170 to 250 ° C. for 1 to 3 hours to obtain adhesiveness.

  In recent years, with the high integration of semiconductor elements and the high definition of liquid crystal elements, the pitch between elements and between wirings is becoming narrower. When the above-described adhesive is used for such a semiconductor element or the like, since the heating temperature when curing is high and the curing speed is slow, not only the desired connection part but also the peripheral member is heated. There is a tendency to affect damage. In order to further reduce the cost, it is necessary to improve the throughput, and adhesion at low temperature (100 to 170 ° C.), short time (within 1 hour), in other words, “low temperature rapid curing” is required.

On the other hand, in recent years, radical curable adhesives using acrylate derivatives or methacrylate derivatives in combination with peroxides as radical polymerization initiators have attracted attention. Since this adhesive cures and adheres using a radical polymerization reaction, which is a reactive species with excellent reactivity, it can be cured in a relatively short time (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 01-113480 JP 2002-203427 A

  However, since the radical curable adhesive is excellent in reactivity, the process margin when performing the curing process tends to be narrowed. For example, in the case of using the above-mentioned radical curable adhesive to electrically connect a semiconductor element or a liquid crystal display element, if the process conditions such as the temperature and time when obtaining the cured product vary somewhat, the adhesive strength, There is a tendency that characteristics such as connection resistance cannot be obtained stably.

  Accordingly, the present invention provides an adhesive composition and a circuit connecting material that can be cured sufficiently quickly at a low temperature, have a wide process margin when performing the curing process, and provide sufficiently stable adhesive strength and connection resistance. A circuit member connection structure and a semiconductor device are provided.

  The adhesive composition of the present invention that solves the above problems includes a thermoplastic resin, a radical polymerizable compound, a first radical polymerization initiator having a 1-minute half-life temperature of 90 to 145 ° C., and a 1-minute half-life. And a second radical polymerization initiator having a temperature of 150 to 175 ° C.

  Here, “one-minute half-life temperature” refers to the temperature at which the half-life is 1 minute, and “half-life” refers to the time until the concentration of the compound decreases to half of the initial value.

  The adhesive composition of the present invention is a so-called radical curable adhesive composition containing a thermoplastic resin, a radical polymerizable compound, and a radical polymerization initiator. Thus, since the adhesive composition containing a radically polymerizable compound is excellent in reactivity, it can be cured in a sufficiently short time even at a low temperature. Further, by using two types of radical polymerization initiators having different half-life temperatures for 1 minute as radical polymerization initiators, it becomes possible to widen the process margin when performing the curing treatment. Therefore, the cured product obtained from such an adhesive composition can have stable properties such as adhesive strength and connection resistance even when the process temperature and time when the cured product is obtained fluctuate. . Moreover, the characteristic deterioration with time of the cured product can also be suppressed.

  Furthermore, radical curable adhesives having a one-minute half-life temperature in the above range generally have low activation energy and therefore tend to have poor storage stability. However, the cured product obtained from the adhesive composition of the present invention can be provided with more excellent storage stability than conventional ones. The present inventors believe that this is caused by using two types of radical polymerization initiators having different 1-minute half-life temperatures in the adhesive composition of the present invention.

  Furthermore, when the adhesive composition of the present invention is used, the curing process can be performed in a short time and the process margin can be widened, so that the pitch between elements such as semiconductor elements and liquid crystal elements and between wirings is reduced. Even if this is done, not only the desired connection portion but also the peripheral member can be heated to prevent the peripheral member from being affected, and the throughput can be improved.

  In the adhesive composition of the present invention, it is preferable that the radically polymerizable compound has two or more (meth) acryloyl groups in the molecule. When such an adhesive composition is used, the curing process can be performed in a shorter time. The present inventors presume that this is because the radically polymerizable compound has two or more (meth) acryloyl groups, which are radically reactive radical reactive groups.

  Furthermore, since such a radical polymerizable compound uses a (meth) acryloyl group as a reactive group, it can obtain strong adhesiveness regardless of the material of the adherend. Therefore, the adhesive composition of the present invention containing such a radically polymerizable compound is excellent in versatility, and has more stable characteristics such as adhesive strength and connection resistance even when used in, for example, a semiconductor element or a liquid crystal display element. Can be obtained.

  Furthermore, it is preferable that both the first radical polymerization initiator and the second radical polymerization initiator are peroxyester derivatives having a molecular weight of 180 to 1000.

  Since both the first radical polymerization initiator and the second radical polymerization initiator are the same kind of peroxyester derivative and have a molecular weight within the above numerical range, they are excellent in compatibility with each other, and thus can be obtained. The cured product exhibits characteristics such as adhesive strength and connection resistance that are more stable throughout.

  The adhesive composition of the present invention contains 50 to 250 parts by mass of a radical polymerizable compound with respect to 100 parts by mass of the thermoplastic resin, and the first radical polymerization initiator and the second radical polymerization initiator. It is preferable to contain 0.05-30 mass parts of each. This adhesive composition of this invention can exhibit the effect of this invention more notably by making the constituent material into the mixture ratio of said range.

  Further, the adhesive composition preferably contains conductive particles. Such an adhesive composition has conductivity. Then, this adhesive composition can be used as a conductive adhesive in the fields of electric industry and electronic industry such as circuit electrodes and semiconductors. Further, in this case, since the adhesive composition is conductive, the connection resistance after curing can be further reduced.

  Moreover, about the mixture ratio of this electroconductive particle, it is preferable to contain 0.5-30 mass parts of electroconductive particles with respect to 100 mass parts of thermoplastic resins. By setting the conductive particles to a blending ratio in the above range, such an adhesive composition can further exhibit the effect of the conductive particles. For example, when used for connection of circuit electrodes, it is possible to prevent electrical conduction between opposing circuit electrodes, or short circuit between adjacent circuit electrodes. Furthermore, the adhesive composition containing the conductive particles in the above blending ratio can also show anisotropy of electrical connection, and can be used as an anisotropic conductive adhesive composition. .

  And the circuit connection material of this invention is a circuit connection material for electrically connecting circuit electrodes which oppose, Comprising: A circuit connection material contains the adhesive composition mentioned above, It is characterized by the above-mentioned.

  Such a circuit connection material can bond the circuit electrodes facing each other in a sufficiently short time even at a low temperature, and can widen the process margin. Further, a cured product obtained from such a circuit connection material can stabilize characteristics such as adhesive strength and connection resistance even if the process temperature and time when the cured product is obtained fluctuate. Moreover, the characteristic deterioration with time of the cured product can also be suppressed. Furthermore, if this circuit connection material contains conductive particles in the above-mentioned blending ratio, it can exhibit electrical connection anisotropy and can be used as an anisotropic conductive circuit connection material for circuit electrodes. It is.

  Moreover, it is preferable that the adhesive composition or circuit connection material described above is formed in a film shape. Since the adhesive composition or circuit connecting material in the form of a film is excellent in handleability, the throughput can be further improved.

The circuit member connection structure of the present invention includes a first circuit member in which a first circuit electrode is formed on the main surface of the first circuit board, and a second circuit member on the main surface of the second circuit board. A second circuit member formed with the first circuit electrode, a first circuit board, a main surface of the second circuit board, and a second circuit electrode; A circuit connecting member for electrical connection in a state of being opposed to each other;
A circuit member connection structure comprising: the circuit connection member is a cured product of the circuit connection material described above.

  Such a connection structure of circuit members can effectively use electrically connected circuit electrodes. That is, since the circuit connection material described above is used so that the first circuit electrode and the second circuit electrode can be electrically connected, the circuit member having the connection structure of the present invention has a small variation in quality and is sufficiently Stable characteristics can be shown. Furthermore, when the hardened | cured material of a circuit connection material contains electroconductive particle, connection resistance can be made low. By blending these conductive particles, it is possible to prevent electrical conduction between opposing circuit electrodes, or short circuit between adjacent circuit electrodes. Further, if the conductive particles are contained in the above blending ratio, anisotropy of electrical connection is exhibited and an anisotropic circuit connection material can be obtained.

  According to another aspect of the present invention, there is provided a semiconductor device comprising: a semiconductor element; a substrate on which the semiconductor element is mounted; and a semiconductor element connecting member that is provided between the semiconductor element and the substrate and electrically connects the semiconductor element and the substrate. And a semiconductor element connection member is the hardened | cured material or film adhesive of the adhesive composition mentioned above, It is characterized by the above-mentioned.

  In such a semiconductor device, since the cured product of the adhesive composition that electrically connects the semiconductor element and the substrate is the cured product of the above-described adhesive composition, the variation in quality is small and sufficiently stable. Characteristics can be shown. Furthermore, when the hardened | cured material of adhesive composition contains electroconductive particle, connection resistance can be made low. By blending the conductive particles, it is possible to prevent the semiconductor element and the substrate that are opposed from being electrically conductive. Further, if the conductive particles are contained in the above-described blending ratio, anisotropy of electrical connection is exhibited, and an anisotropic semiconductor can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive composition and circuit connection which can perform a curing process sufficiently rapidly at low temperature, have a wide process margin at the time of performing a curing process, and can obtain sufficiently stable adhesive strength and connection resistance A material, a circuit member connection structure, and a semiconductor device can be provided.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings as the case may be. In addition, the same code | symbol shall be used for the same element and the overlapping description is abbreviate | omitted. In the following description, (meth) acrylate means acrylate or a corresponding methacrylate.

(Adhesive composition)
The adhesive composition of the present invention comprises a thermoplastic resin, a radical polymerizable compound, a first radical polymerization initiator having a half-life temperature of 90 to 145 ° C, and a half-life temperature of 150 to 175 ° C for 1 minute. It contains a certain second radical polymerization initiator.

  Here, the thermoplastic resin according to the present invention is used to strengthen the adhesion between objects to be bonded (hereinafter simply referred to as “adhered bodies”).

  As a thermoplastic resin used by this invention, a well-known thing can be used without a restriction | limiting in particular. Specifically, polyimide, polyamide, phenoxy resins, poly (meth) acrylates, polyimides, polyurethanes, polyesters, polyvinyl butyrals, and the like can be used. These may be used alone or in combination of two or more. Furthermore, these resins may have a siloxane bond or a fluorine substituent in the molecule. These can be suitably used as long as the resins to be mixed are completely compatible with each other or microphase separation occurs and the liquid becomes cloudy.

  Moreover, the later-described film can be easily formed as the molecular weight of the thermoplastic resin increases, and the melt viscosity that affects the fluidity as an adhesive can be set in a wide range. If the melt viscosity can be set in a wide range, even when the pitch between the elements and between the wirings is narrowed when used to connect a semiconductor element or a liquid crystal element, the adhesion of the adhesive to the peripheral members is further prevented. And throughput can be improved. However, if this molecular weight value exceeds 150,000, the compatibility with other components tends to be poor, and if it is less than 5000, film formation tends to be insufficient when used as a film described later. Therefore, this molecular weight is preferably 5000 to 150,000 as a weight average molecular weight, and more preferably 10,000 to 80,000.

  In addition, the radical polymerizable compound according to the present invention refers to a compound having a capability of generating a radical by applying some energy and polymerizing the radical by a chain reaction to form a polymer. This radical polymerization reaction generally proceeds more rapidly than cationic polymerization or anionic polymerization. Therefore, in the present invention using a radical polymerizable compound, polymerization can be performed in a relatively short time.

  As the radical polymerizable compound used in the present invention, a known compound can be used without particular limitation as long as it is a compound having an olefin in the molecule, such as a (meth) acryl group, a (meth) acryloyl group or a vinyl group. . Among these, a radically polymerizable compound having a (meth) acryloyl group is preferable.

  Specifically, the radical polymerizable compound having a (meth) acryloyl group includes an epoxy (meth) acrylate oligomer, a urethane (meth) acrylate oligomer, a polyether (meth) acrylate oligomer, a polyester (meth) acrylate oligomer, and the like. , Trimethylolpropane tri (meth) acrylate, polyethylene glycol di (meth) acrylate, polyalkylene glycol di (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, neopentyl glycol di (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, isocyanuric acid modified bifunctional (meth) acrylate, isocyanuric acid modified trifunctional (meth) acrylic Over DOO, 2,2'-di (meth) acryloyloxy diethyl phosphate, a polyfunctional (meth) acrylate compounds such as 2- (meth) acryloyloxyethyl acid phosphate. These compounds may be used alone or in admixture of two or more as required.

Thus, if a (meth) acryloyl group is used as a reactive group, strong adhesion can be achieved regardless of the material of the adherend. Examples of the adherend include organic substrates such as printed wiring boards and polyimides, metals such as copper and aluminum, ITO (indium tin oxide), silicon nitride (SiN), silicon dioxide (SiO ₂ ), and the like. .

  Furthermore, it is preferable that the radical polymerizable compound has two or more (meth) acryloyl groups in the molecule because the heating time required for adhesion can be shortened and the heating temperature required for adhesion can be further reduced. This is considered due to having more (meth) acryloyl groups which are radical reactive groups in the molecule of the radical polymerizable compound.

  Furthermore, the blending ratio of the radical polymerizable compound is preferably 50 to 250 parts by mass, and more preferably 60 to 150 parts by mass with respect to 100 parts of the thermoplastic resin. When the blending ratio of the radical polymerizable compound is less than 50 parts by mass, the heat resistance of the cured product of the adhesive composition imparted to the adherend tends to decrease. When the blending ratio exceeds 250 parts by mass, the adhesive composition When the film is used as a film to be described later, film formation tends to be insufficient.

  Moreover, the adhesive composition of this invention contains a radical polymerization initiator. Once a radical polymerization compound has started radical polymerization reaction, chain reaction proceeds and strong curing is possible. However, since it is relatively difficult to generate radicals at first, it is relatively easy to generate radicals. A radical polymerization initiator capable of being produced is contained.

  In the present invention, as the radical polymerization initiator, a first radical polymerization initiator having a one-minute half-life temperature of 90 to 145 ° C. and a second radical polymerization start having a one-minute half-life temperature of 150 to 175 ° C. Use the agent together.

  As the first radical polymerization initiator, a known compound can be used as long as the 1-minute half-life temperature is 90 to 145 ° C., and the second radical polymerization initiator is a 1-minute half-life temperature. If it is 150-175 degreeC, a well-known compound can be used.

  Among these, it is preferable that both the first radical polymerization initiator and the second radical polymerization initiator are peroxyester derivatives. If both are peroxyester derivatives, they are excellent in compatibility with each other, and the resulting cured product exhibits characteristics such as more stable adhesive strength and connection resistance throughout the whole.

  Specifically, as the first radical polymerization initiator, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperper Oxynoedecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2- Ethylhexanoate, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexa Noate, t-butylperoxyneoheptanoate, t-amylperoxy-2-ethylhexanoate, di-t-butylper Xylhexahydroterephthalate, t-amylperoxy-3,5,5-trimethylhexanoate, 3-hydroxy-1,1-dimethylbutylperoxyneodecanoate, 1,1,3,3-tetramethylbutyl Peroxy-2-ethylhexanoate, t-amylperoxyneodecanoate, t-amylperoxy-2-ethylhexanoate, 2,2′-azobis-2,4-dimethylvaleronitrile, 1, 1'-azobis (1-acetoxy-1-phenylethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), dimethyl-2,2'-azo Examples include bisisobutyronitrile, 4,4′-azobis (4-cyanovaleric acid), 1,1′-azobis (1-cyclohexanecarbonitrile), and the like. It is.

  Specific examples of the second radical polymerization initiator include t-hexyl peroxyisopropyl monocarbonate, t-butyl peroxymaleic acid, t-butyl peroxy-3,5,5-trimethylhexanoate. , T-butylperoxylaurate, 2,5-dimethyl-2,5-di (3-methylbenzoylperoxy) hexane, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2 , 5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxybenzoate, dibutylperoxytrimethyladipate, t-amylperoxynormal octoate, t-amylperoxyisononanoate, t- Examples include amyl peroxybenzoate.

  The adhesive composition of the present invention may be a combination of the first radical polymerization initiator and the second radical polymerization initiator, and two or more kinds of the first radical polymerization initiator may be used. Two or more second radical polymerization initiators can be used.

  The molecular weights of the first radical polymerization initiator and the second radical polymerization initiator are preferably 180 to 1000 as the weight average molecular weight. If both the first radical polymerization initiator and the second radical polymerization initiator have a molecular weight within the above numerical range, the resulting cured product has a more stable adhesive strength over the whole. And characteristics such as connection resistance.

  As for the addition amount of a 1st radical polymerization initiator and a 2nd radical polymerization initiator, it is preferable that either is 0.05-30 mass parts with respect to 100 parts of thermoplastic resins, and all are 0. It is still more preferable that it is 05-30 mass parts. Moreover, it is especially preferable that all are 0.1-20 mass parts. When the addition amount of either the first radical polymerization initiator or the second radical polymerization initiator is less than 0.05 parts by mass, radical polymerization tends not to be sufficiently started, and the first radical polymerization initiator And when the addition amount of either of 2nd radical polymerization initiators exceeds 30 mass parts, it exists in the tendency for storage stability to fall.

  In addition, although it does not specifically limit as a form of the energy provided in this invention, A heat | fever, an electron beam, a gamma ray, an ultraviolet-ray, infrared rays etc. are mentioned.

  The reason why a cured product having sufficiently stable adhesive strength and connection resistance can be obtained by using the adhesive composition of the present invention has not been clarified in detail at present. However, as one of the factors, the present inventors can obtain a relatively stable radical polymerization rate even under different process conditions by using two kinds of radical polymerization initiators having different 1-minute half-life temperatures. I think because. However, the factor is not limited to this.

  The adhesive composition of the present invention preferably contains conductive particles. By containing conductive particles, conductivity can be imparted to the adhesive composition. If it does so, it will become possible to use as a conductive adhesive in the field | areas of electric industry and electronic industry, such as a circuit electrode and a semiconductor.

  The conductive particles used here are not particularly limited as long as they have conductivity capable of obtaining electrical connection, and examples thereof include metals such as Au, Ag, Ni, Cu, and solder, and carbon. . Further, non-conductive glass, ceramic, plastic or the like may be used as a core, and the metal or carbon may be coated on the core. Among these, the case where the metal itself is a heat-meltable metal, or the case where the metal is coated with a metal or carbon with a plastic as a nucleus is preferable. In these cases, since it becomes easier to deform the cured product of the adhesive composition by heating or pressurization, the contact area between the electrode and the adhesive composition is increased when the electrodes are electrically connected to each other. And the conductivity between the electrodes can be improved.

  Moreover, you may use the layered particle | grains which coat | covered the surface of this electroconductive particle further with polymer resin. When conductive particles are added to the adhesive composition in the state of layered particles, even if the amount of conductive particles is increased, a short circuit occurs due to contact between the conductive particles because they are coated with resin. This can be further suppressed and the insulation between the electrode circuits can be improved. In addition, you may use these electroconductive particle and layered particle individually or in mixture of 2 or more types.

  The average particle diameter of the conductive particles is preferably 1 to 18 μm from the viewpoints of dispersibility and conductivity. The blending ratio of the conductive particles is preferably 0.1 to 30% by volume, more preferably 0.1 to 10% by volume with respect to 100% by volume of the adhesive composition. If this value is less than 0.1% by volume, sufficient conductivity may not be obtained, and if it exceeds 30% by volume, a short circuit tends to occur. In addition, although the mixture ratio (volume%) of electroconductive particle is determined based on the volume of each component before hardening | curing the adhesive composition in 23 degreeC, the volume of each component uses weight based on specific gravity. Increased by adding the component into a container such as a graduated cylinder containing a suitable solvent (water, alcohol, etc.) that wets the component well without dissolving or swelling the component or converting it into a volume. It can obtain | require by the method of calculating from a volume.

ここで、式中、Ｒ^１、Ｒ^２及びＲ^３はそれぞれ独立に水素、炭素数１〜５のアルキル基、炭素数１〜５のアルコキシ基、炭素数１〜５のアルコキシカルボニル基、又はアリール基を示し、Ｒ^４は水素、又はメチル基を示し、ｎは１〜１０の整数を示す。 Moreover, it is preferable to add adhesion assistants, such as a coupling agent represented by the alkoxysilane derivative and the silazane derivative, an adhesion improvement agent, and a leveling agent, to the adhesive composition of this invention. As a result, the effects of the present invention can be exhibited more remarkably, and even better adhesion and handleability can be imparted. Specifically, it is preferable to add a compound represented by the following general formula (1).

Here, in the formula, R ¹ , R ² and R ³ are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkoxycarbonyl group having 1 to 5 carbon atoms, or aryl. Represents a group, R ⁴ represents hydrogen or a methyl group, and n represents an integer of 1 to 10.

Furthermore, in this general formula (1), R ¹ is an alkyl group having 1 to 5 carbon atoms or an aryl group, R ² and R ³ are each independently an alkoxy group having 2 to 3 carbon atoms, and n is 2 Since it is excellent in adhesiveness and connection resistance as it is-4, it is preferable. In addition, the compound represented by General formula (1) may be used individually by 1 type, or 2 or more types may be mixed and used for it.

  In addition to the above, the adhesive composition of the present invention may contain other materials depending on the purpose of use. For example, you may use together the adhesive improvement agent which improves the crosslinking rate of an adhesive agent. Thereby, adhesive strength can be raised further. That is, in addition to a radical polymerizable compound having a (meth) acryloyl group, a compound having a radical polymerizable functional group such as an allyl group, a maleimide group, or a vinyl group may be added. Specifically, N-vinylimidazole, N-vinylpyridine, N-vinylpyrrolidone, N-vinylformamide, N-vinylcaprolactam, 4,4′-vinylidenebis (N, N-dimethylaniline), N-vinylacetamide N, N-dimethylacrylamide, N-isopropylacrylamide, N, N-diethylacrylamideacrylamide and the like. In addition, these adhesive improvement agents may be used individually by 1 type, or may mix and use 2 or more types.

  Moreover, you may use together fluidity improvers, such as a monofunctional (meth) acrylate. Thereby, fluidity | liquidity can be improved. Specifically, pentaerythritol (meth) acrylate, 2-cyanoethyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 2- (2- Ethoxyethoxy) ethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-hexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, Isobornyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (meth) acrylate, n-lauryl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-phenoxyethyl ( Acrylate), tetrahydrofurfuryl (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, Examples thereof include N-dimethylaminopropyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, and (meth) acryloylmorpholine. In addition, these fluidity improvers may be used individually by 1 type, or may mix and use 2 or more types.

  Furthermore, a rubber-based material that improves adhesiveness may be used in combination. As a result, the stress can be relaxed. Specifically, polyisoprene, polybutadiene, carboxyl-terminated polybutadiene, hydroxyl-terminated polybutadiene, 1,2-polybutadiene, carboxyl-terminated 1,2-polybutadiene, hydroxyl-terminated 1,2-polybutadiene, acrylic rubber, styrene-butadiene rubber, Hydroxyl-terminated styrene-butadiene rubber, acrylonitrile-butadiene rubber, carboxyl group, hydroxyl group, acrylonitrile-butadiene rubber containing carboxyl group, (meth) acryloyl group or morpholine group at the polymer end, carboxylated nitrile rubber, hydroxyl-terminated poly (oxypropylene), alkoxy Examples include silyl group-terminated poly (oxypropylene), poly (oxytetramethylene) glycol, polyolefin glycol, and poly-ε-caprolactone.

  The rubber-based material is preferably a rubber-based material containing a cyano group or a carboxyl group, which is a highly polar functional group, in the side chain or terminal from the viewpoint of improving adhesiveness, and further improving the fluidity. Therefore, it is more preferable that it is liquid. Specific examples include liquid acrylonitrile-butadiene rubber, liquid acrylonitrile-butadiene rubber containing a carboxyl group, hydroxyl group, (meth) acryloyl group or morpholine group at the polymer terminal, and liquid carboxylated nitrile rubber. Acrylonitrile which is a polar group The content is more preferably 10 to 60% by mass of the whole of these rubber-based materials. In addition, these rubber materials may be used individually by 1 type, or 2 or more types may be mixed and used for them.

  Furthermore, an additive such as a polymerization inhibitor represented by t-butylpyrocatechol, t-butylphenol, p-methoxyphenol and the like may be used in combination. Thereby, storage stability can further be improved.

  The adhesive composition of the present invention can be used in the form of a paste when it is liquid at room temperature. When it is solid at room temperature, it may be pasted by heating, or may be pasted using a solvent. The solvent that can be used is not particularly limited as long as it does not react with the adhesive composition and exhibits sufficient solubility, but a solvent having a boiling point of 50 to 150 ° C. at normal pressure is preferable. If the boiling point is less than 50 ° C., the solvent tends to volatilize easily at room temperature, so the radical polymerization reaction must be performed in a sealed environment, and the use tends to be limited. On the other hand, if the boiling point exceeds 150 ° C., it is difficult to volatilize the solvent, and sufficient adhesive strength tends not to be obtained after bonding.

  The adhesive composition of the present invention can also be used after it is formed into a film. This film is produced by applying a mixed solution obtained by adding a solvent to an adhesive composition onto a peelable substrate such as a fluororesin film, a polyethylene terephthalate film or a release paper, or a mixed solution on a substrate such as a nonwoven fabric. The film can be obtained by impregnating and placing on a peelable substrate and removing the solvent and the like. Thus, when the adhesive composition is in the form of a film, the handleability is excellent and it is more convenient.

  Moreover, when conductive particles are added to the adhesive composition of the present invention to produce a film, an anisotropic conductive film can be obtained. For example, the anisotropic conductive film is placed between opposing electrodes on the substrate, and both electrodes can be bonded and electrically connected by heating and pressurizing. Here, as the substrate on which the electrode is formed, an inorganic material such as a semiconductor, glass or ceramic, an organic material such as polyimide or polycarbonate, or a combination of these composites such as glass / epoxy can be applied.

  Furthermore, the adhesive composition of the present invention can be bonded by using both heating and pressing. The heating temperature is preferably 50 to 190 ° C. The pressure may be in a range that does not damage the adherend, and is preferably 0.1 to 10 MPa. These heating and pressurization are preferably performed in the range of 0.5 seconds to 120 seconds.

  Furthermore, since the adhesive composition of the present invention can react in a short time and is excellent in storage stability, it can be suitably used as a circuit connecting material. For example, when electrically connecting the circuit electrode of the first circuit member and the circuit electrode of the second circuit member, the adhesive composition of the present invention is applied to one of the circuit members in a state where these circuit members are arranged to face each other. It can be applied to the circuit electrode and electrically connected to the other circuit electrode by radical polymerization reaction. Thus, when the adhesive composition is used as a circuit connection material, electrical connection can be performed in a short time, and even if the process temperature and time during connection vary, the adhesive strength, connection resistance, etc. The characteristics can be stabilized. In addition, it is possible to suppress deterioration in characteristics of the cured circuit connection material over time. Furthermore, if this circuit connection material contains conductive particles, it can exhibit anisotropy of electrical connection and can also be used as an anisotropic conductive circuit connection material for circuit electrodes.

  The circuit connection material can also be used as a circuit connection material for different types of adherends having different thermal expansion coefficients. Specifically, it is used as a semiconductor element adhesive material typified by anisotropic conductive adhesives, silver paste, circuit connection materials typified by silver films, CSP elastomers, CSP underfill materials, LOC tapes, etc. Can do.

(Circuit member connection structure)
Next, a preferred embodiment of the circuit member connection structure of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing an embodiment of a circuit member connection structure of the present invention. As shown in FIG. 1, the circuit member connection structure 1 of the present embodiment includes a first circuit member 20 and a second circuit member 30 that face each other. Between these circuit members 30, a circuit connection member 10 is provided for electrically connecting them. The first circuit member 20 includes a first circuit board 21 and a first circuit electrode 22 formed on the main surface 21 a of the circuit board 21. Note that an insulating layer (not shown) may be formed on the main surface 21a of the circuit board 21 in some cases.

  On the other hand, the second circuit member 30 includes a second circuit board 31 and a second circuit electrode 32 formed on the main surface 31 a of the second circuit board 31. In addition, an insulating layer (not shown) may be formed on the main surface 31a of the circuit board 31 according to circumstances.

The first circuit member 20 and the second circuit member 30 are not particularly limited as long as electrodes that require electrical connection are formed. Specific examples include glass or plastic substrates with electrodes formed of ITO or the like used for liquid crystal displays, printed wiring boards, ceramic wiring boards, flexible wiring boards, semiconductor silicon chips, and the like. They can be used in combination. As described above, in the present embodiment, a material made of an organic material such as a printed wiring board or polyimide, a metal such as copper or aluminum, ITO (indium tin oxide), silicon nitride (SiN _x ), silicon dioxide (SiO ₂ ). Circuit members having various surface states such as inorganic materials such as the above can be used.

  The circuit connecting member 10 contains an insulating material 11 and conductive particles 7. The conductive particles 7 are disposed not only between the first circuit electrode 22 and the second circuit electrode 32 facing each other but also between the main surfaces 21a and 31a. In the circuit member connection structure 1 of the present embodiment, the first circuit electrode 22 and the second circuit electrode 32 are electrically connected via the conductive particles 7. For this reason, the connection resistance between the first circuit electrode 22 and the second circuit electrode 32 is sufficiently reduced. Therefore, the flow of current between the first circuit electrode 22 and the second circuit electrode 32 can be made smooth, and the functions of the circuit can be sufficiently exhibited. Moreover, it is also possible to show the anisotropy of electrical connection by setting the conductive particles 7 to the above-described mixing ratio.

  In addition, when the circuit connection member 10 does not contain the conductive particles 7, they are in direct contact with each other so that a desired amount of current flows between the first circuit electrode 22 and the second circuit electrode 32. It is electrically connected by making it close or sufficiently close.

  Since the circuit connection member 10 is composed of a cured product of a circuit connection material containing the adhesive composition, the adhesive strength of the circuit connection member 10 to the first circuit member 20 or the second circuit member 30 is sufficient. It becomes high and this state can be maintained for a long time. Therefore, the long-term reliability of the electrical characteristics between the first circuit electrode 22 and the second circuit electrode 32 can be sufficiently increased.

(Semiconductor device)
Next, embodiments of the semiconductor device of the present invention will be described. FIG. 2 is a schematic cross-sectional view showing an embodiment of the semiconductor device of the present invention. As shown in FIG. 2, the semiconductor device 2 of the present embodiment includes a semiconductor element 50 and a substrate 60 serving as a semiconductor support member, and these are electrically connected between the semiconductor element 50 and the substrate 60. A semiconductor element connection member 40 is provided to connect to the semiconductor element. The semiconductor element connection member 40 is stacked on the main surface 60 a of the substrate 60, and the semiconductor element 50 is further stacked on the semiconductor element connection member 40.

  The substrate 60 includes a circuit pattern 61, and the circuit pattern 61 is electrically connected to the semiconductor element 50 via the semiconductor connection member 40 on the main surface 60 a of the substrate 60 or directly. And these are sealed with the sealing material 70, and the semiconductor device 2 is formed.

  The material of the semiconductor element 50 is not particularly limited, but silicon, germanium group 4 semiconductor element, GaAs, InP, GaP, InGaAs, InGaAsP, AlGaAs, InAs, GaInP, AlInP, AlGaInP, GaNAs, GaNP, GaInNAs, GaInNP, III-V group compound semiconductor devices such as GaSb, InSb, GaN, AlN, InGaN, InNAsP, II-VI group compound semiconductor devices such as HgTe, HgCdTe, CdMnTe, CdS, CdSe, MgSe, MgS, ZnSe, ZeTe, and Various materials such as CuInSe (ClS) can be used.

  The semiconductor element connection member 40 contains the insulating substance 11 and the conductive particles 7. The conductive particles 7 are disposed not only between the semiconductor element 50 and the circuit pattern 61 but also between the semiconductor element 50 and the main surface 60a. In the semiconductor device 2 of the present embodiment, the semiconductor element 50 and the circuit pattern 61 are electrically connected via the conductive particles 7. For this reason, the connection resistance between the semiconductor element 50 and the circuit pattern 61 is sufficiently reduced. Therefore, the current flow between the semiconductor element 50 and the circuit pattern 61 can be made smooth, and the functions of the semiconductor can be fully exhibited. Moreover, it is also possible to show the anisotropy of electrical connection by setting the conductive particles 7 to the above-described mixing ratio.

  When the semiconductor element connecting member 40 does not contain the conductive particles 7, the semiconductor element 50 and the circuit pattern 61 are brought into direct contact with each other so that a desired amount of current flows or sufficiently close to the electric current. Connected.

  Since the semiconductor element connection member 40 is composed of a cured product of the adhesive composition containing the adhesive composition, the bonding strength of the semiconductor element connection member 40 to the semiconductor element 50 and the substrate 60 is sufficiently high. The state can be sustained for a long time. Therefore, the long-term reliability of the electrical characteristics between the semiconductor element 50 and the substrate 60 can be sufficiently increased.

  Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

(Adjustment of conductive particles)
A nickel layer is provided on the surface of the polystyrene particles so as to have a thickness of 0.2 μm, and a gold layer is provided outside the nickel layer so as to have a thickness of 0.02 μm. 5 conductive particles were produced.

[Example 1]
50 parts by mass of phenoxy resin (average molecular weight 45000, manufactured by Union Carbide, trade name: PKHC) was dissolved in 75 parts by mass of methyl ethyl ketone to obtain a solution having a solid content of 40% by mass.

  And as a radically polymerizable compound in this solution, 25 parts by mass of isocyanuric acid EO-modified diacrylate (manufactured by Toa Gosei Co., Ltd., trade name: M-215), urethane acrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: AT-600) 20 parts by mass, 5- (meth) acryloyloxyethyl phosphate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Light Ester P-2M) as a radical polymerization initiator, t-hexylperoxy-2-ethylhexa 1.5 parts by weight of noate (1 minute half-life temperature 132.6 ° C., manufactured by NOF Corporation, trade name: Perhexyl O), t-hexyl peroxybenzoate (1 minute half-life temperature 160.3 ° C., NOF 1.5 parts by mass of trade name: Perhexyl Z) Conductive particles were blended and dispersed in the obtained mixture so as to be 1.5% by volume to obtain an adhesive composition A.

  Next, the obtained adhesive composition A was applied to a fluororesin film having a thickness of 80 μm with one side surface-treated using a known coating apparatus, followed by hot-air drying at 70 ° C. for 10 minutes, A film-like circuit connecting material A having a thickness of 15 μm was obtained.

[Example 2]
Except that the blending ratio of the radical polymerization initiator t-hexylperoxy-2-ethylhexanoate was 1 part by mass and the blending ratio of t-hexylperoxybenzoate was 2 parts by mass, the same as in Example 1. Thus, a film-like circuit connecting material B was obtained.

[Comparative Example 1]
A film-like circuit connection was carried out in the same manner as in Example 1 except that the blending ratio of t-hexylperoxy-2-ethylhexanoate as a radical polymerization initiator was 3 parts by mass and t-hexylperoxybenzoate was not used. Material C was obtained.

[Comparative Example 2]
A film-like circuit was obtained in the same manner as in Example 1 except that the radical polymerization initiator t-hexylperoxy-2-ethylhexanoate was not used and the blending ratio of t-hexylperoxybenzoate was changed to 3 parts by mass. Connection material D was obtained.

[Comparative Example 3]
As radical polymerization initiator, instead of t-hexylperoxy-2-ethylhexanoate and t-hexylperoxybenzoate, diisopropyl peroxydicarbonate (1-minute half-life temperature 88.3 ° C, manufactured by NOF Corporation, product A film-like circuit connecting material E was obtained in the same manner as in Example 1 except that 3 parts by mass of name: Parroyl IPP) was blended.

(Evaluation method 1)
(Measurement of connection resistance)
A flexible circuit board (FPC) having 500 copper circuit wires having a line width of 25 μm, a pitch of 50 μm, and a thickness of 18 μm, and 0.2 μm of indium oxide, using the film-like circuit connecting materials A to D obtained by the above-described manufacturing method. Electrically connected to a glass (thickness 1.1 mm, surface resistance 20 Ω / □) formed with a thin layer of (ITO) over a width of 2 mm by a thermocompression bonding device (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.) did. The heating and pressing conditions at this time were 160 ° C., 170 ° C. and 190 ° C., a heating pressure of 3 MPa, and a heating and pressing time of 15 seconds. The resistance value between the electrically connected circuits was measured using a multimeter immediately after bonding and after being held in a high-temperature and high-humidity bath at 85 ° C. and 85% RH for 120 hours. The resistance value was expressed as an average (x + 3σ) of 150 resistances between adjacent circuits. The obtained results are shown in Table 1.

(Evaluation method 2)
(Measurement of adhesive strength)
The adhesive strength of the film-like circuit connecting materials A to D obtained by the above production method was measured and evaluated by a 90-degree peeling method according to JIS-Z0237. Here, Tensilon UTM-4 (peeling speed 50 mm / min, 25 ° C., manufactured by Toyo Baldwin) was used as an adhesive strength measuring device. The obtained results are shown in Table 2.

  Even when the film-like circuit connecting materials A and B of Examples 1 and 2 were heated at a temperature of 160 to 190 ° C. and immediately after being held in a high-temperature and high-humidity tank at 85 ° C. and 85% RH for 120 hours, It was found that good connection resistance and adhesive strength were exhibited, and good characteristics were exhibited over a wide range of heating temperatures. On the other hand, in the film-like circuit connecting material C of Comparative Example 1 that is not according to the present invention, the connection resistance is increased after holding at 85 ° C. and 85% RH for 120 hours at 170 ° C. and after heating at 190 ° C. And the adhesive strength showed a low value compared with Example 1, 2 immediately after adhesion | attachment, and after hold | maintaining for 120 hours in a 85 degreeC and 85% RH high-temperature / humidity tank. Furthermore, in the film-like circuit connecting material D of Comparative Example 2, the connection resistance when heated at 160 to 170 ° C. was high, and the adhesive strength was low.

(Evaluation method 3)
The film-like circuit connecting materials A and E obtained in Example 1 and Comparative Example 3 were accommodated in a vacuum packaging material and allowed to stand at 40 ° C. for 3 days. Thermocompression bonding was performed under conditions of 3 MPa for 10 seconds. The connection resistance and adhesive strength of the obtained film were measured according to Evaluation Methods 1 and 2. The results are shown in Table 2.

  In Table 2, it turned out that the film-form circuit connection material A of Example 1 shows favorable connection resistance and adhesive strength before and behind leaving at 40 degreeC, and is excellent in storage stability. On the other hand, in the film-like circuit connecting material E of Comparative Example 3 not according to the present invention, the connection resistance increases after leaving at 40 ° C. for 3 days, the adhesive strength is reduced by half, and the stability is not good. I understood.

It is a schematic sectional drawing which shows one Embodiment of the connection structure of the circuit member of this invention. It is a schematic sectional drawing which shows one Embodiment of the semiconductor device of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Connection structure of a circuit member, 2 ... Semiconductor device, 7 ... Conductive particle, 10 ... Circuit connection member, 11 ... Insulative substance, 20 ... 1st circuit member , 21 ... 1st circuit board, 22 ... 1st circuit electrode, 30 ... 2nd circuit member, 31 ... 2nd circuit board, 32 ... 2nd circuit electrode 40 ... Semiconductor element connecting member, 50 ... Semiconductor element, 60 ... Substrate, 61 ... Circuit pattern, 70 ... Sealing material.

Claims (11)

  A thermoplastic resin, a radically polymerizable compound, a first radical polymerization initiator having a one-minute half-life temperature of 90 to 145 ° C., and a second radical polymerization start having a one-minute half-life temperature of 150 to 175 ° C. And an adhesive composition.   The adhesive composition according to claim 1, wherein the radically polymerizable compound has two or more (meth) acryloyl groups in the molecule.   The adhesive composition according to claim 1 or 2, wherein both the first radical polymerization initiator and the second radical polymerization initiator are peroxyester derivatives having a molecular weight of 180 to 1000.   The radically polymerizable compound is contained in an amount of 50 to 250 parts by mass with respect to 100 parts by mass of the thermoplastic resin, and the first radical polymerization initiator and the second radical polymerization initiator are respectively added in an amount of 0.05 to 30. The adhesive composition according to any one of claims 1 to 3, wherein the adhesive composition is contained in parts by mass.   Furthermore, electroconductive particle is contained, The adhesive composition as described in any one of Claims 1-4 characterized by the above-mentioned.   The adhesive composition according to claim 5, wherein 0.5 to 30 parts by mass of the conductive particles are contained with respect to 100 parts by mass of the thermoplastic resin. A circuit connection material for electrically connecting opposing circuit electrodes,
The said circuit connection material contains the adhesive composition as described in any one of Claims 1-6, The circuit connection material characterized by the above-mentioned.   A film adhesive comprising the adhesive composition according to any one of claims 1 to 6 formed into a film.   A film-like circuit connecting material, wherein the circuit connecting material according to claim 7 is formed into a film shape. A first circuit member having a first circuit electrode formed on the main surface of the first circuit board;
A second circuit member having a second circuit electrode formed on the main surface of the second circuit board;
It is provided between the main surface of the first circuit board and the main surface of the second circuit board, and is electrically in a state where the first circuit electrode and the second circuit electrode are arranged to face each other. A circuit connection member to be connected;
A circuit member connection structure comprising:
8. The circuit member connection structure according to claim 7, wherein the circuit connection member is a cured product of the circuit connection material according to claim 7. A semiconductor element;
A substrate on which the semiconductor element is mounted;
A semiconductor element connecting member provided between the semiconductor element and the substrate and electrically connecting the semiconductor element and the substrate;
A semiconductor device comprising:
The said semiconductor element connection member is a hardened | cured material of the adhesive composition as described in any one of Claims 1-6, The semiconductor device characterized by the above-mentioned.

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