CN1970673B - Material for connecting circuit - Google Patents

Abstract

The adhesive composition of the present invention comprises a thermoplastic resin, a radical polymerizable compound, a first radical polymerization initiator whose half-life temperature in one minute is 90 to 145°C, and a second radical polymerization initiator whose half-life temperature in one minute is 150 to 175°C. Initiator. According to the present invention, it is possible to provide an adhesive composition, a circuit connecting material, and a circuit component that can be cured very quickly at a low temperature, have a wide process width during the curing process, and can obtain very stable adhesive strength and connection resistance. Connection structures and semiconductor devices.

Description

Circuit connection material

This application is a divisional application of the Chinese patent application with the filing date of the original application being May 9, 2005, the application number being 200510069479.5, and the title of the invention being "Adhesive composition, circuit connection material, connection structure of circuit components, and semiconductor device" .

technical field

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

Background technique

Conventionally, as adhesives for semiconductor elements and liquid crystal display elements, thermosetting resins such as epoxy resins having excellent adhesiveness, especially under high-temperature and high-humidity conditions, have been used (for example, refer to Japanese Patent Application Laid-Open No. 01-113480 Bulletin). 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, along with the high integration of semiconductor elements and the high-definition of liquid crystal elements, the narrowing of the pitch between elements and between wirings has progressed. When the above-mentioned adhesive is used for such a semiconductor element, etc., since the heating temperature during curing is high and the curing rate is slow, not only the desired connection site but also peripheral components are heated, which tends to cause damage to peripheral components, etc. Influence. In order to further reduce costs, it is necessary to increase productivity, and low temperature (100 to 170°C) and short time (1 hour or less), in other words, "low temperature fast curing" bonding is required.

On the other hand, in recent years, a radical curable adhesive that uses an acrylate derivative or a methacrylate derivative in combination with a peroxide as a radical polymerization initiator has attracted attention. Since this adhesive is cured and adhered by polymerization reaction with a radical which is a reactive species excellent in reactivity, it can be cured in a short time (for example, refer to JP-A-2000-203427).

However, since radical curing adhesives are excellent in reactivity, the process width at the time of curing tends to be narrowed. For example, when the above-mentioned radical-curable adhesive is used for electrically connecting semiconductor elements or liquid crystal display elements, even if the process conditions such as temperature and time for obtaining the cured product are slightly changed, the adhesive strength, connection resistance, etc. cannot be obtained stably. characteristic tendencies.

Contents of the invention

Therefore, the present invention provides an adhesive composition, a circuit connection material, and a connection structure for circuit components that can be cured very rapidly at low temperatures, have a wide process range during curing, and can obtain very stable adhesive strength and connection resistance. and semiconductor devices.

The adhesive composition of the present invention that solves the above-mentioned problems is characterized in that it contains a thermoplastic resin, a radical polymerizable compound, a first radical polymerization initiator with a half-life temperature of 90 to 145° C., and a half-life temperature of 150 to 150° C. The second radical polymerization initiator at 175°C.

Here, the "1-minute half-life temperature" refers to the temperature at which the half-life becomes 1 minute, and the "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. Such an adhesive composition containing a radically polymerizable compound is excellent in reactivity, and therefore can be cured in a very short time even at a low temperature. Furthermore, by using two kinds of radical polymerization initiators having different 1-minute half-life temperatures as the radical polymerization initiators, it is possible to widen the process width at the time of curing treatment. Therefore, even if the process temperature or time for obtaining the cured product obtained from such an adhesive composition varies, properties such as adhesive strength and connection resistance can be stabilized. In addition, it is also possible to suppress the deterioration of the properties of the cured product over time.

In addition, a radical-curable adhesive whose 1-minute half-life temperature is in the above-mentioned range generally has low activation energy, and thus tends to have poor storage stability. However, the cured product obtained from the adhesive composition of the present invention can also have more excellent storage stability than conventional ones. The present inventors think that this is because two radical polymerization initiators having different 1-minute half-life temperatures are used in the adhesive composition of the present invention.

In addition, if the adhesive composition of the present invention is used, the curing process can be performed in a short time, and the process width can be expanded, so even if the spacing between semiconductor elements, liquid crystal elements, and other elements and between wirings is narrowed, it can be prevented. Productivity can be improved by preventing damage to surrounding components by heating not only the desired connection site but also peripheral components.

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

In addition, since such a radically polymerizable compound uses a (meth)acryloyl group as a reactive group, strong adhesiveness can be obtained regardless of the material of the object to be adhered. Therefore, the adhesive composition of the present invention containing such a radically polymerizable compound is excellent in versatility, and can obtain more stable characteristics such as adhesive strength and connection resistance when used, for example, in semiconductor elements or liquid crystal display elements.

Furthermore, both the first radical polymerization initiator and the second radical polymerization initiator are preferably peroxyester derivatives with a molecular weight of 180-1000.

If the first radical polymerization initiator and the second radical polymerization initiator are all peroxyester derivatives of the same type and have a molecular weight within the above-mentioned numerical range, then the mutual compatibility is excellent, so the cured product obtained is Shows its overall more stable characteristics such as bond strength or connection resistance.

In addition, the adhesive composition of the present invention preferably contains 50 to 250 parts by mass of a radical polymerizable compound with respect to 100 parts by mass of a thermoplastic resin, and contains 0.05 to 30 parts by mass of a first radical polymerization initiator and a second radical polymerization initiator, respectively. Initiator. The adhesive composition of the present invention can exhibit the effects of the present invention more remarkably by containing the structural material in a mixing ratio within the above-mentioned range.

Furthermore, it is preferable to contain electroconductive particle in this adhesive composition. Such an adhesive composition can be electrically conductive. Thus, the adhesive composition can be used as a conductive adhesive in the electrical and electronic industries such as circuit electrodes and semiconductors. Furthermore, at this time, since the adhesive composition is conductive, the connection resistance after curing can be further reduced.

Moreover, as for the mixing 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. Such an adhesive composition can exhibit the effect of electroconductive particle more by containing electroconductive particle in the mixing ratio of the said range. For example, when used for connection of circuit electrodes, it can prevent non-conduction between opposite circuit electrodes or short circuit between adjacent circuit electrodes. Furthermore, the adhesive composition containing electroconductive particle in the said mixing ratio can also show the anisotropy of electrical connection, and can be used as an anisotropic electroconductive adhesive composition.

Furthermore, the circuit connecting material of the present invention is a circuit connecting material for electrically connecting opposing circuit electrodes, and is characterized in that the circuit connecting material contains the above-mentioned adhesive composition.

Such a circuit connection material can bond opposing circuit electrodes in a very short time even at a low temperature, and can expand the process range. Furthermore, the cured product obtained from such a circuit connecting material can stabilize properties such as adhesive strength and connection resistance even if the process temperature or time for obtaining the cured product varies. In addition, it is also possible to suppress the deterioration of the properties of the cured product over time. Furthermore, when this circuit connection material contains electroconductive particle in the above-mentioned mixing ratio, the anisotropy of electrical connection can be shown, and it can also be used as an anisotropic electroconductive circuit connection material for circuit electrodes.

In addition, the above-mentioned adhesive composition or circuit connection material is preferably formed into a film. Since the film-form adhesive composition or circuit-connecting material is excellent in handleability, productivity can be further improved.

In addition, the circuit component connection structure of the present invention includes a first circuit component having a first circuit electrode formed on a main surface of a first circuit substrate, and a second circuit electrode formed on a main surface of a second circuit substrate. The second circuit component, the circuit component of the circuit connection member which is provided between the main surface of the first circuit board and the main surface of the second circuit board and electrically connects the first circuit electrode and the second circuit electrode in a state of opposing arrangement The connection structure of the present invention is characterized in that the circuit connection member is a cured product of the above-mentioned circuit connection material.

Such a connection structure of circuit components can effectively utilize the electrically connected circuit electrodes. That is, since the above-mentioned circuit connection material capable of electrically connecting the first circuit electrode and the second circuit electrode is used, the circuit component having the connection structure of the present invention exhibits very stable characteristics with little fluctuation in quality. Furthermore, when cured|cured material of a circuit connection material contains electroconductive particle, connection resistance can be reduced. By mixing the conductive particles, it is possible to prevent non-conduction between opposing circuit electrodes or short circuit between adjacent circuit electrodes. Moreover, when electroconductive particle is contained in the said mixing ratio, the anisotropy of electrical connection can be shown, and it can also be used as an anisotropic circuit connection material.

In addition, the semiconductor device of the present invention is a semiconductor device provided with a semiconductor element, a substrate on which the semiconductor element is mounted, and a semiconductor element connecting member provided between the semiconductor element and the substrate and electrically connecting the semiconductor element and the substrate. The component is a cured product of the above-mentioned adhesive composition or a film-like adhesive.

In such a semiconductor device, since the cured product of the adhesive composition for electrically connecting the semiconductor element and the substrate is the cured product of the above-mentioned adhesive composition, it can exhibit very stable characteristics with little fluctuation in quality. Furthermore, when the hardened|cured material of an adhesive composition contains electroconductive particle, connection resistance can be reduced. By mixing the conductive particles, it is possible to prevent non-conduction between opposing semiconductor elements and substrates. Moreover, when electroconductive particle is contained in the said mixing ratio, the anisotropy of electrical connection will be shown and it can also be used as an anisotropic semiconductor.

Description of drawings

FIG. 1 is a schematic cross-sectional view showing an embodiment of a connection structure of circuit components of the present invention.

FIG. 2 is a schematic cross-sectional view showing an embodiment of the semiconductor device of the present invention.

Detailed ways

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as the case may be. Here, the same symbols are used for the same elements, and repeated explanations are omitted. In addition, in the following description, (meth)acrylate means acrylate or the 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 in one minute, and a second radical polymerization initiator having a half-life temperature of 150 to 175°C in one minute. Initiator.

Here, the thermoplastic resin related to the present invention is used to strengthen the bonding between objects to be bonded (hereinafter simply referred to as "adhered objects").

The thermoplastic resin used in the present invention is not particularly limited, and known ones can be used. Specifically, polyamides, phenoxy resins, poly(meth)acrylates, polyimides, polyurethanes, polyesters, polyvinyl butyrals, and the like can be used. These resins 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 if the mixed resins are completely compatible with each other or in a cloudy state due to microphase separation.

In addition, the larger the molecular weight of the thermoplastic resin, the easier it is to form a film described later, and the melt viscosity that affects the fluidity of the adhesive can also be set in a wide range. If the melt viscosity can be set in a wide range, when used for connecting semiconductor elements or liquid crystal elements, even if the pitch between elements and wiring is narrowed, it is possible to further prevent the adhesive from adhering to peripheral components and enable Productivity increases. However, if the molecular weight is greater than 150,000, the compatibility with other components tends to be poor, and if it is less than 5,000, the film formation tends to be insufficient when used as a film described later. Therefore, the molecular weight is preferably 5,000 to 150,000, more preferably 10,000 to 80,000 in terms of weight average molecular weight.

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

As the radically polymerizable compound used in the present invention, known compounds can be used without limitation as long as they have an alkenyl group in the molecule such as (meth)acryl, (meth)acryloyl, or vinyl. Among these, radically polymerizable compounds having a (meth)acryloyl group are preferred.

Specifically, examples of the radically polymerizable compound having a (meth)acryloyl group include epoxy (meth)acrylate oligomers, urethane (meth)acrylate oligomers, polyether (meth)acrylate oligomers, polyether (meth)acrylate oligomers, Oligomers such as acrylate oligomers, polyester (meth)acrylate oligomers, trimethylolpropane tri(meth)acrylate, polyethylene glycol di(meth)acrylate, polyalkylene Dicyclopentyl glycol di(meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl(meth)acrylate, neopentyl glycol di(meth)acrylate, dicyclopentyl glycol di(meth)acrylate, Pentaerythritol hexa(meth)acrylate, isocyanuric acid modified difunctional (meth)acrylate, isocyanuric acid modified trifunctional (meth)acrylate, 2,2'-bis(meth)acrylate ) polyfunctional (meth)acrylate compounds such as acryloyloxydiethyl phosphate, 2-(meth)acryloyloxyethyl acid phosphate, etc. These compounds may be used alone or in combination of two or more, if necessary.

By using a (meth)acryloyl group as a reactive group in this way, firm adhesion can be achieved regardless of the material of the object to be adhered. Examples of objects to be adhered include metals such as copper, aluminum, ITO (indium tin oxide), silicon nitride (SiN _x ), di Silicon oxide (SiO ₂ ), etc.

Furthermore, if the radically polymerizable compound has two or more (meth)acryloyl groups in its molecule, the heating time required for bonding can be further shortened, and the heating temperature required for bonding can be further reduced, so it is preferred. This is considered to be because the radical polymerizable compound has many (meth)acryloyl groups which are radical reactive groups in the molecule.

The mixing ratio of the radically polymerizable compound is preferably 50 to 250 parts by mass, more preferably 60 to 150 parts by mass with respect to 100 parts of the thermoplastic resin. If the mixing ratio of the radically polymerizable compound is less than 50 parts by mass, the heat resistance of the cured product of the adhesive composition to be adhered tends to decrease. If it exceeds 250 parts by mass, the adhesive composition is used as a film There is a tendency that the film formation becomes insufficient at the time of use.

In addition, the adhesive composition of the present invention contains a radical polymerization initiator. The radical polymerizable compound, once the radical polymerization reaction starts, proceeds a chain reaction to achieve firm curing, but since it is difficult to generate radicals at first, it contains a radical polymerization initiator that can relatively easily generate radicals.

In the present invention, as the radical polymerization initiator, a first radical polymerization initiator whose 1-minute half-life temperature is 90-145° C. and a second radical polymerization initiator whose 1-minute half-life temperature is 150-175° C. are used together.

As such a first radical polymerization initiator, if the 1-minute half-life temperature is 90 to 145° C., known compounds can be used. As the second radical polymerization initiator, if the 1-minute half-life temperature is 150 to 175° C., then Known compounds can be used.

Among them, both the first radical polymerization initiator and the second radical polymerization initiator are preferably peroxyester derivatives. If they are all peroxyester derivatives, they are excellent in compatibility with each other, so the obtained cured product exhibits more stable characteristics such as adhesive strength and connection resistance as a whole.

As the first radical polymerization initiator, specifically, cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, 1-cyclohexyl-1-methano Ethyl neodecyl peroxide, tert-hexyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, tert-butyl peroxytrimethylacetate, peroxy-2-ethylhexanoate-1,1 , 3,3-tetramethylbutyl ester, 2,5-dimethyl-2,5-bis(peroxy-2-ethylhexanoyl)hexane, tert-hexyl peroxy-2-ethylhexanoate , tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyneheptanoate, tert-amyl peroxy-2-ethylhexanoate, di-tert-butyl peroxide hexahydroterephthalate, peroxide Oxy-3,5,5-trimethylhexanoic acid tert-amyl ester, peroxyneodecanoic acid-3-hydroxy-1,1-dimethylbutyl ester, peroxy-2-ethylhexanoic acid 1,1, 3,3-tetramethylbutyl ester, neodecyl tert-pentyl peroxide, tert-amyl peroxy-2-ethylhexanoate, 2,2'-azo-bis-(2,4-dimethylpentyl nitrile), 1,1'-azo-bis-(1-acetoxy-1-phenylethane), 2,2'-azobisisobutyronitrile, 2,2-azo-bis-(2 -methylbutyronitrile), dimethyl-2,2'-azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), 1,1'-azobis(1 -cyclohexanenitrile).

Also, as the second radical polymerization initiator, specifically, tert-hexyl peroxyisopropyl monocarbonate, tert-butyl peroxymaleate, tert-butyl peroxy-3,5,5-trimethylhexanoate Butyl ester, tert-butyl peroxylaurate, 2,5-dimethyl-2,5-di-(peroxy-3-methylbenzoyl)hexane, peroxy-2-ethylhexyl monocarbonate tert-butyl peroxybenzoate, tert-hexyl peroxybenzoate, 2,5-dimethyl-2,5-di-(benzoyl peroxide)hexane, tert-butyl peroxybenzoate, trimethylhexyl peroxide Dibutyl diacid, tert-amyl peroxyn-octanoate, tert-amyl peroxyisononanoate, tert-amyl peroxybenzoate, etc.

In addition, the adhesive composition of the present invention may use a first radical polymerization initiator and a second radical polymerization initiator in combination, may use two or more first radical polymerization initiators, or may use two or more of them. The above second radical polymerization initiator.

The molecular weights of the first radical polymerization initiator and the second radical polymerization initiator are preferably 180 to 1,000 in 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 compatibility is excellent, so the obtained cured product exhibits more stable adhesive strength, connection resistance, etc. in its entirety characteristic.

The addition amount of the 1st radical polymerization initiator and the 2nd radical polymerization initiator is preferably 0.05-30 mass parts of one of them with respect to 100 parts of thermoplastic resins, and more preferably 0.05-30 mass parts of both. Moreover, it is especially preferable that both are 0.1-20 mass parts. If the addition amount of any one of the first radical polymerization initiator and the second radical polymerization initiator is less than 0.05 parts by mass, there is a tendency that radical polymerization initiation is insufficient. If the first radical polymerization initiator and the second radical polymerization initiator If the addition amount of any one of the base polymerization initiators exceeds 30 parts by mass, the storage stability tends to decrease.

In addition, in the present invention, the form of energy application is not particularly limited, and examples thereof include heat, electron beams, γ-rays, ultraviolet rays, and infrared rays.

The factors that allow the use of the adhesive composition of the present invention to obtain a cured product with very stable adhesive strength and connection resistance have not yet been clarified in detail. However, the present inventors believe that one of the factors is that by using two radical polymerization initiators having different half-life temperatures for 1 minute, a relatively stable radical polymerization rate can be obtained even if the process conditions are different. However, the factors are not limited to this.

The adhesive composition of the present invention preferably contains conductive particles. By containing electroconductive particles, electroconductivity can be imparted to this adhesive composition. Thus, it can be used as a conductive adhesive in the fields of electric industry and electronic industry such as circuit electrodes and semiconductors.

The conductive particles that can be used here are not particularly limited as long as they have electrical conductivity that enables electrical connection, and examples thereof include metals such as Au, Ag, Ni, Cu, and solder, and carbon. Alternatively, a core may be made of non-conductive glass, ceramics, plastic, or the like, and the core may be covered with the aforementioned metal or carbon. Among them, the case where the metal itself is a hot-melt metal, or the case where a plastic core is covered with metal or carbon is preferable. At this time, it will be easier to deform the cured product of the adhesive composition by heating or pressing, so when the electrodes are electrically connected, the contact area between the electrodes and the adhesive composition can be increased, and the conductivity between the electrodes can be improved. .

Moreover, the layered particle which covered the surface of this electroconductive particle further with a polymer resin can also be used. If conductive particles are added to the adhesive composition in the state of layered particles, even if the mixed amount of conductive particles is increased, because they are covered by resin, short circuits caused by contact between conductive particles can be further suppressed, and it is also possible Improves insulation between electrode circuits. In addition, these electroconductive particle and layered particle can also be used individually or in mixture of 2 or more types.

The average particle diameter of the electroconductive particles is preferably 1 to 18 μm from the viewpoint of dispersibility and conductivity. The mixing ratio of the conductive particles is preferably 0.1 to 30% by volume, more preferably 0.1 to 10% by volume relative to 100% by volume of the adhesive composition. If the value is less than 0.1% by volume, sufficient conductivity tends not to be obtained, and if it exceeds 30% by volume, a short circuit tends to be caused. In addition, the mixing ratio (volume %) of conductive particles is determined on the premise of the volume of each component before the adhesive composition is cured at 23°C. The volume of each component can be converted from weight to volume by using specific gravity. Alternatively, the component can be obtained by adding a suitable solvent (water, alcohol, etc.) that wets the component well into a container such as a measuring cylinder without dissolving or swelling the component, and calculating it from the increased volume.

In addition, to the adhesive composition of the present invention, it is preferable to add a coupling agent typified by an alkoxysilane derivative and a silazane, an adhesion enhancer, a leveling agent, and other adhesion aids. Thereby, the effect of this invention can be exhibited more notably, and it can also provide more favorable adhesiveness and handleability. 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 each independently represent hydrogen, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkane group having 1 to 5 carbon atoms. Oxycarbonyl or aryl, R ⁴ represents hydrogen or methyl, and n represents an integer of 1-10.

Further, in the general formula (1), it is preferred that R ¹ is an alkyl or aryl group with 1 to 5 carbon atoms, R ² and R ³ are each independently an alkoxy group with 2 to 3 carbon atoms, and n is 2 to 4, because its adhesiveness and connection resistance are more excellent. In addition, the compounds represented by the general formula (1) may be used alone or in combination of two or more.

In addition, other materials may be added to the adhesive composition of the present invention depending on the purpose of use. For example, an adhesiveness improving agent which improves the crosslinking ratio of an adhesive agent can also be used together. Thereby, the adhesive strength can be further improved. That is, to the radically polymerizable compound having a (meth)acryloyl group, a compound having a radically polymerizable functional group such as an allyl group, a maleimide group, and a vinyl group may be further added. Specifically, N-vinylimidazole, N-vinylpyridine, N-vinylpyrrolidone, N-vinylformamide, N-vinylcaprolactam, 4,4'-vinylidenebis(N,N-di methylaniline), N-vinylacetamide, N,N-dimethylacrylamide, N-isopropylacrylamide, N,N-diethylacrylamide, etc. In addition, these adhesiveness improving agents can be used individually or in mixture of 2 or more types.

Moreover, fluidity improvers, such as a monofunctional (meth)acrylate, can also be used together. Thereby, fluidity can be improved. Specifically, pentaerythritol (meth)acrylate, 2-cyanoethyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentene Oxyethyl (meth)acrylate, 2-(2-ethoxy)ethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, (meth)acrylic acid-2 -Ethylhexyl, n-hexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, isobornyl (meth)acrylate, iso(meth)acrylate Decyl ester, Isooctyl (meth)acrylate, n-Lauryl (meth)acrylate, 2-Methoxyethyl (meth)acrylate, 2-Phenoxyethyl (meth)acrylate, Tetrahydro Furfuryl alcohol (meth)acrylate, 2-(meth)acryloxyethyl phosphate, N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (Meth)acrylate, (meth)acryloylmorpholine. In addition, these fluidity improvers may be used alone or in combination of two or more.

Furthermore, a rubber-like material that improves adhesiveness may be used in combination. Thereby, stress can also 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, containing carboxyl, hydroxyl, ( Meth)acryloyl or morpholine-based acrylonitrile-butadiene rubber, carboxylated nitrile rubber, hydroxyl-terminated polyoxypropylene, alkoxysilyl-terminated polyoxypropylene, polyoxytetramethylene glycol, Polyalkylene glycol, polyε-caprolactone.

In addition, the rubber-based material is preferably a rubber-based material containing a highly polar functional group cyano group or carboxyl group in a side chain or terminal from the viewpoint of improving adhesiveness, and is more preferably a liquid material from the viewpoint of improving fluidity. Specifically, liquid acrylonitrile-butadiene rubber, liquid acrylonitrile-butadiene rubber containing carboxyl group, hydroxyl group, (meth)acryloyl group or morpholine group at the end of the polymer, liquid carboxylated nitrile rubber, More preferably, the content of acrylonitrile as a polar group is 10 to 60% by mass of the total amount of these rubber-like materials. In addition, these rubber-like materials may be used alone or in combination of two or more.

Furthermore, additives such as polymerization inhibitors typified by tert-butylcatechol, tert-butylphenol, p-methoxyphenol, etc. may also be used together. Storage stability can thereby be further 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 normal temperature, it can be made into a paste using a solvent instead of heating. The usable solvent is not particularly limited as long as it does not react with the adhesive composition and exhibits sufficient solubility, but is preferably a solvent having a boiling point of 50 to 150°C under normal pressure. If the boiling point is lower than 50° C., it tends to volatilize easily at room temperature, so the polymerization reaction must be carried out in a sealed environment, which tends to limit its use. In addition, when the boiling point is higher than 150° C., it becomes difficult to volatilize the solvent, and there is a tendency that sufficient adhesive strength cannot be obtained after bonding.

In addition, the adhesive composition of the present invention can also be used in the form of a film. The production method of the film is to apply a mixed solution in which a solvent is added to the adhesive composition on a release substrate such as a fluororesin film, a polyethylene terephthalate film, or a release paper, or to A base material such as woven fabric is impregnated with the mixed solution, placed on a release base material, and a film is obtained by removing the solvent or the like. In this way, the adhesive composition is made into a film, which is excellent in handling and more convenient.

In addition, an anisotropic conductive film can be obtained by adding conductive particles to the adhesive composition of the present invention to form a film. For example, the anisotropic conductive film is placed between opposing electrodes on a substrate, and both electrodes can be bonded and electrically connected by heating and pressing. Here, various combinations of inorganic substances such as semiconductors, glass, and ceramics, organic substances such as polyimide and polycarbonate, and composites of these substances such as glass/epoxy resin can be used as the substrate on which the electrodes are formed.

Furthermore, the adhesive composition of this invention can adhere|attach using heating and pressurization together. The heating temperature is preferably a temperature of 50 to 190°C. The pressure may be within a range that does not damage the adherend, and is preferably 0.1 to 10 MPa. These heating and pressurization are preferably performed within a range of 0.5 to 120 seconds.

Moreover, since the adhesive composition of this invention can react in a short time and is excellent in storage stability, it is suitable as a circuit connection material. For example, when electrically connecting the circuit electrodes of the first circuit member and the circuit electrodes of the second circuit member, the adhesive composition of the present invention is applied to one of the circuit electrodes in the state where these circuit members are arranged facing each other, and the adhesive composition of the present invention is applied to one of the circuit electrodes by a radical polymerization reaction. Electrically connected to another circuit electrode. Thus, if the adhesive composition is used as a circuit connection material, electrical connection can be performed in a short time, and properties such as adhesive strength and connection resistance can be stabilized even if the bonding process temperature or time varies. In addition, it is also possible to suppress the deterioration of the characteristics over time of the circuit-connecting material cured product. Furthermore, if this circuit connection material contains electroconductive particle, the anisotropy of electrical connection can be shown, and it can also be used as an anisotropic electroconductive circuit connection material for circuit electrodes.

Then, the circuit connecting material can also be used as a circuit connecting material of different types of adhered objects having different thermal expansion coefficients. Specifically, it can be used as a circuit connection material represented by anisotropic conductive adhesive, silver paste, silver film, etc., and can be used as an elastomer for CSP (Chip Scale Packaging), an underfill for CSP, LOC (Lead On Chip) ) Tape etc. are representative semiconductor element adhesive materials.

<Connection structure of circuit components>

Next, preferred embodiments of the circuit component connection structure of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing an embodiment of a circuit component connection structure of the present invention. As shown in FIG. 1 , the circuit component connection structure 1 of the present embodiment is provided with a first circuit component 20 and a second circuit component 30 facing each other, and between the first circuit component 20 and the second circuit component 30, a The circuit connecting member 10 electrically connects them. The first circuit component 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 . In addition, an insulating layer (not shown) may be formed on the main surface 21a of the circuit board 21 as the case may be.

On the other hand, the second circuit component 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 as the case may be.

As the first circuit member 20 and the second circuit member 30 , there are no particular limitations as long as they form electrodes that require electrical connection. Specifically, glass or plastic substrates, printed wiring boards, ceramic wiring boards, flexible wiring boards, semiconductor silicon wafers, etc., on which electrodes are formed, such as ITO used in liquid crystal displays, can be used in combination as necessary. Thus, in this embodiment, materials including printed circuit boards and organic substances such as polyimide, metals such as copper and aluminum, or ITO (indium tin oxide, indium tin oxide), silicon nitride (SiN _x ), silicon dioxide (SiO ₂ ) and other inorganic materials such as circuit components with various surface states.

The circuit connection member 10 contains an insulating substance 11 and conductive particles 7 . The electroconductive particle 7 is arrange|positioned not only between the opposing 1st circuit electrode 22 and the 2nd circuit electrode 32 but also between the main surfaces 21a and 31a. In the connection structure 1 of circuit components of this embodiment, the 1st circuit electrode 22 and the 2nd circuit electrode 32 are electrically connected via the electroconductive particle 7. As shown in FIG. Therefore, the connection resistance between the first circuit electrode 22 and the second circuit electrode 32 is sufficiently reduced. Therefore, the flow of electric current between the first circuit electrode 22 and the second circuit electrode 32 can be smoothed, and the function of the circuit can be fully exhibited. Moreover, the anisotropy of electrical connection can also be shown by making this electroconductive particle 7 into the above-mentioned mixing ratio.

In addition, when the circuit connection member 10 does not contain the electroconductive particle 7, in order to make a desired amount of electric current flow between the 1st circuit electrode 22 and the 2nd circuit electrode 32, these are electrically connected in direct contact or sufficiently close.

The circuit connecting member 10 is composed of a cured product of the circuit connecting material containing the above-mentioned adhesive composition, so the bonding strength of the circuit connecting member 10 to the first circuit member 20 or the second circuit member 30 becomes very high, and it can be used for a long time. Keep it that way. Therefore, the long-term reliability of the electrical characteristic between the 1st circuit electrode 22 and the 2nd circuit electrode 32 can be fully improved.

<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 this embodiment includes a semiconductor element 50 and a substrate 60 serving as a semiconductor supporting member, and a semiconductor element connecting member 40 is provided between the semiconductor element 50 and the substrate 60 to electrically connect them. Furthermore, the semiconductor element connection member 40 is laminated on the main surface 60 a of the substrate 60 , and the semiconductor element 50 is further laminated on the semiconductor element connection member 40 .

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

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

The semiconductor element connection member 40 contains an insulating substance 11 and conductive particles 7 . The electroconductive particle 7 is arrange|positioned 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 . Therefore, the connection resistance between the semiconductor element 50 and the circuit pattern 61 is sufficiently reduced. Therefore, the flow of electric current between the semiconductor element 50 and the circuit pattern 61 can be smoothed, and the function of a semiconductor can be fully exhibited. Moreover, the anisotropy of electrical connection can also be shown by making this electroconductive particle 7 into the above-mentioned mixing ratio.

In addition, when the semiconductor element connection member 40 does not contain the conductive particles 7, the semiconductor element 50 and the circuit pattern 61 are electrically connected in direct contact or sufficiently close to each other so that a desired amount of current can flow.

The semiconductor element connecting member 40 is composed of a cured product of the adhesive composition containing the above-mentioned adhesive composition, so the bonding strength of the semiconductor element connecting member 40 to the semiconductor element 50 and the substrate 60 becomes very high, and the bonding strength of the semiconductor element connecting member 40 can be maintained for a long period of time. state. Therefore, the long-term reliability of the electrical characteristics between the semiconductor element 50 and the substrate 60 can be sufficiently improved.

Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to this.

<Preparation of conductive particles>

A nickel layer with a thickness of 0.2 μm was provided on the surface of the polystyrene particles, and a gold layer with a thickness of 0.02 μm was further provided outside the nickel layer to produce conductive particles with an average particle diameter of 4 μm and a specific gravity of 2.5.

Example 1

50 parts by mass of phenoxy resin (average molecular weight 45,000, manufactured by Unionka-Bite Co., trade name: PKHC) was dissolved in 75 parts by mass of methyl ethyl ketone to obtain a solution with a solid content of 40% by mass.

Then, in this solution, 25 parts by mass of isocyanuric acid EO-modified diacrylate (manufactured by Toagosei Co., Ltd., trade name: M-215), 20 parts by mass of urethane were mixed as a radically polymerizable compound. Acrylate (manufactured by Kyoei Chemical Co., trade name: AT-600), 5 parts by mass of 2-(methyl)endenoyloxyethyl phosphate (manufactured by Kyoei Chemical Co., Ltd., trade name: Laitester P-2M) ; As a free radical initiator, mix 1.5 parts by mass of tert-hexyl peroxide 2-ethylhexanoate (1 minute half-life temperature is 132.6°C, produced by NOF Corporation, trade name: パヘキシルO), 1.5 parts by mass of peroxide tert-hexyl benzoate (half-life temperature of 1 minute: 160.3° C., manufactured by NOF Corporation, trade name: パヘキシル Z). The electroconductive particle was mixed and dispersed in the obtained liquid mixture so that it might become 1.5 volume %, and the adhesive composition A was obtained.

Next, the obtained adhesive composition A was coated on a fluororesin film with a thickness of 80 μm with surface treatment on one surface using known coating equipment, and dried with hot air at 70° C. for 10 minutes to obtain a film-shaped circuit connection with a layer thickness of 15 μm. Material A.

Example 2

Except that the mixing ratio of free radical polymerization initiator peroxy-2-ethylhexanoic acid tert-hexyl is 1 mass part, the mixing ratio of tert-hexyl peroxybenzoate is 2 mass parts, operate in the same manner as in Example 1, A film-like circuit-connecting material B was obtained.

Comparative example 1

Except that the mixing ratio of the free radical polymerization initiator tert-hexyl peroxy-2-ethylhexanoate is 3 parts by mass, and tert-hexyl peroxybenzoate is not used, the same operation is performed as in Example 1 to obtain a film-shaped circuit connecting material C.

Comparative example 2

Except not using tert-hexyl peroxy-2-ethylhexanoate as a radical polymerization initiator, and making the mixing ratio of tert-hexyl peroxybenzoate 3 parts by mass, the film was obtained in the same manner as in Example 1. Shaped circuit connection material D.

Comparative example 3

As a radical polymerization initiator, 3 parts by mass of diisopropyl peroxydicarbonate (1 minute half-life temperature: 88.3°C, manufactured by NOF Corporation, trade name: Perol IPP) was mixed in place of 2-ethyl peroxide Except for tert-hexyl hexanoate and tert-hexyl peroxybenzoate, it carried out similarly to Example 1, and obtained the film-form circuit connection material E.

<Evaluation method 1>

[Measurement of connection resistance]

表示。表1表示得到的结果。Using the film-like circuit connecting materials A to D obtained by the above-mentioned production method, 500 wires with a line width of 25 μm and a pitch of 50 μm were electrically connected with a width of 2 mm using a hot pressing device (heating method: constant heat type, manufactured by Donglen Jinyaling Co., Ltd.). A flexible printed circuit board (FPC) with copper circuit wiring with a thickness of 18 μm and glass (thickness 1.1 mm, surface resistance 20 Ω) formed with a thin layer of 0.2 μm indium tin oxide (ITO). The heating and pressing conditions at this time were heating temperatures of 160° C., 170° C., and 190° C., pressing pressure of 3 MPa, and heating and pressing time of 15 seconds. Immediately after bonding and after holding in a high-temperature, high-humidity chamber at 85° C. and 85% RH for 120 hours, the resistance value between the electrically connected circuits was measured using a multimeter. The resistance value is the average value of 150 points of resistance between adjacent circuits

express. Table 1 shows the obtained results.

<Evaluation method 2>

[Measurement of Adhesive Strength]

According to JIS-Z0237, the adhesive strength of the film-form circuit connection materials A-D obtained by the said manufacturing method was measured and evaluated by the 90 degree|times peeling method. Here, the measuring device of the adhesive strength used Tensilon UTM-4 (peeling speed 50 mm/min, 25 degreeC, the product of Toyo Balldoin Co., Ltd.). Table 2 shows the obtained results.

Table 1

The film-like circuit-connecting materials A and B of Examples 1 and 2 show a high temperature immediately after bonding at a heating temperature of 160 to 190°C and even after being kept in a high-temperature, high-humidity tank at 85°C and 85%RH for 120 hours. Good connection resistance and adhesive strength show good characteristics with respect to a wide range of heating temperatures. On the other hand, when the film-form circuit connecting material C of Comparative Example 1 of the present invention was not used, the connection resistance increased when heated at 170°C, kept at 85°C and 85% RH for 120 hours, and heated at 190°C. In addition, both immediately after bonding and after holding in a high-temperature, high-humidity chamber at 85°C and 85% RH for 120 hours compared with Examples 1 and 2, the adhesive strength showed lower values. Furthermore, the film-form circuit connection material D of the comparative example 2 showed high connection resistance at the time of heating at 160-170 degreeC, and showed a low value in adhesive strength.

<Evaluation method 3>

The film-like circuit connection materials A and E obtained in Example 1 and Comparative Example 3 were accommodated in a vacuum packaging material, and after being left at 40°C for 3 days, they were heated by the above-mentioned hot pressing device under the conditions of 160°C, 3MPa, and 10 seconds. Hot press FPC and ITO. According to Evaluation Methods 1 and 2, connection resistance and adhesive strength were measured for the obtained film. Table 2 shows the results.

Table 2

It can be seen from Table 2 that the film-shaped circuit connecting material A of Example 1 exhibits good connection resistance and adhesive strength before and after being placed at 40° C., and has excellent storage stability. On the other hand, the film-form circuit connection material E of the comparative example 3 which did not use this invention, after leaving it to stand at 40 degreeC for 3 days, connection resistance increased and adhesive strength was halved, and stability was not good.

According to the present invention, the curing process can be performed very quickly at low temperature, and the process width during the curing process is wide, and an adhesive composition, a circuit connecting material, and a circuit component that can obtain very stable adhesive strength and connection resistance can be provided. Connection structures and semiconductor devices.

Claims (3)

1. A circuit connecting material, which is a circuit connecting material for electrically connecting opposing circuit electrodes, characterized in that the circuit connecting material contains an adhesive composition, and the adhesive composition contains a thermoplastic resin, a radical polymerizable compound, a first radical polymerization initiator whose half-life temperature in 1 minute is 90 to 145°C, and a second radical polymerization initiator whose half-life temperature in 1 minute is 150 to 175°C, at least one of the radical polymerizable compounds It is a urethane (meth)acrylate oligomer. 2. The circuit connection material according to claim 1, wherein at least one of the radically polymerizable compounds is 2,2'-di(meth)acryloyloxy diethyl phosphate or 2-(Meth)acryloyloxyethyl acid phosphate. 3. The circuit connecting material according to claim 1 or 2, further comprising conductive particles.

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