TW202313896A - Adhesive composition for circuit connection, and structure - Google Patents

Abstract

This adhesive composition for circuit connection contains (A) a radical-polymerizable compound, (B) a radical generator, and (C) particles including at least one type of metal compound selected from the group consisting of metal hydroxides and metal oxides. The metal compound includes at least one element selected from the group consisting of aluminum, magnesium, zirconium, bismuth, calcium, tin, manganese, antimony, silicon, and titanium.

Description

Adhesive composition and structure for circuit connection

The present invention relates to an adhesive composition for circuit connection and a structure using it.

In recent years, in the fields of semiconductors, liquid crystal displays, and the like, various adhesives have been used for fixing electronic components or performing circuit connections. In these applications, higher density and higher precision are being gradually advanced, and adhesives with high adhesiveness or high reliability are required. Especially as a circuit connection material, it is used in the connection of liquid crystal display and tape carrier package (Tape Carrier Package, TCP), the connection of flexible printed circuit (Flexible Printed Circuit, FPC) and TCP, the connection of FPC and printed wiring board, the connection of semiconductor silicon Anisotropic conductive adhesives containing conductive particles are used for the connection between chips and substrates, the connection between FPC and touch panel modules, and the connection between FPC and FPC.

Conventionally, thermosetting resins (epoxy resins, acrylic resins, etc.) exhibiting high adhesiveness and high reliability have been used for the adhesives. As constituent components of an adhesive using an epoxy resin, an epoxy resin and a latent curing agent that generates cationic species or anionic species reactive with the epoxy resin by heat or light are generally used. The latent curing agent is an important factor for determining the curing temperature and curing rate, and various compounds can be used from the viewpoint of storage stability at room temperature and curing rate when heated. In the actual process, for example, the desired adhesiveness is obtained by curing under the curing conditions at a temperature of 170° C. to 250° C. for 10 seconds to 3 hours.

Furthermore, in recent years, there has been a concern that with the high integration of semiconductor elements and the high-definition of display elements, the pitch between elements and wiring will be narrowed, and the heat during curing will adversely affect peripheral components. Furthermore, in order to reduce the cost, it is necessary to increase the throughput, requiring low temperature (90°C to 170°C) and short time (within 1 hour, preferably within 40 seconds, more preferably within 20 seconds) of the following. In other words, low-temperature short-time hardening (low-temperature rapid hardening) is required. It is known that in order to achieve this low-temperature short-time curing, it is necessary to use a thermally latent catalyst with low activation energy, but it is very difficult to achieve both storage stability near normal temperature.

Therefore, in recent years, attention has been paid to radical-curing adhesives (for example, radical-curing adhesives using a (meth)acrylate derivative and a peroxide as a radical polymerization initiator in combination). Radical hardening system can be cured in a short time because free radicals as active species are very reactive, and if the decomposition temperature of the radical polymerization initiator is lower than the decomposition temperature of the radical polymerization initiator, the adhesive exists stably, so its It is a hardening system that balances low-temperature short-time hardening and storage stability (such as storage stability near room temperature). Furthermore, the radical curing system has the following characteristics: it does not use ionic polymerization like the epoxy curing system such as cationic-epoxy curing system and anion-epoxy curing system. Excellent corrosion resistance in high temperature and high humidity test. On the other hand, in cationic-epoxy-curable or anionic-epoxy-curable adhesives, the corrosion may be suppressed by adding metal hydroxides or metal oxides (for example, refer to the following patent document 1 ~Patent Document 4). [Prior art literature] [Patent Document]

Patent Document 1: Japanese Patent Laid-Open No. 2006-199778 Patent Document 2: Japanese Patent Laid-Open No. 2012-46756 Patent Document 3: Japanese Patent Laid-Open No. 2012-46757 Patent Document 4: Japanese Patent Laid-Open No. 2012-41544 Patent Document 5: International Publication No. 2009/063827

[Problem to be Solved by the Invention] In recent years, portable terminals (portable terminals) and display terminals (smartphones, tablets, smart watches) with high durability as added value are increasing. The circuit connecting material for the constituent members of these terminals is required to have excellent connection reliability, that is, excellent Salt water resistance (tolerance to salt water).

An object of the present invention is to provide an adhesive composition for circuit connection capable of obtaining a structure having excellent salt water resistance, and a structure using the same. [Means to solve the problem]

The present invention relates to an adhesive composition for circuit connection, which contains (A) a radical polymerizable compound, (B) a radical generator, and (C) a compound selected from metal hydroxides and metal oxides. Particles of at least one metal compound in the group consisting of at least one metal compound selected from the group consisting of aluminum, magnesium, zirconium, bismuth, calcium, tin, manganese, antimony, silicon and titanium.

A structure having excellent salt water resistance (excellent connection reliability even when exposed to salt water (sweat, seawater, etc.)) can be obtained by the adhesive composition for circuit connection of the present invention. Therefore, excellent reliability can be obtained even in severe environments such as portable applications. Moreover, low-temperature short-time connection can also be realized by the adhesive composition for circuit connection of the present invention. Therefore, adherends made of materials with low heat resistance such as polyethylene terephthalate (PET) and polycarbonate (PC) can be used, thereby expanding the selection of adherends.

As a method for evaluating salt water resistance (resistance to salt water), conduct: Japanese Industrial Standards (JIS) Z 2371 (2000 salt spray test method); International Organization for standardization (ISO) 9227 (manual Atmosphere corrosion test-salt spray test 2006 (2006 Corrosion tests in artificial atmospheres-Salt spray tests.)); the method of soaking in 5% salt water; the method of putting it into a high-temperature and high-humidity tank after soaking in salt water, etc. As a result of verification by the inventors of the present invention, it was found that when the above-mentioned test about salt water resistance was performed on the structure connected by the adhesive composition for circuit connection, the cation-epoxy curing system or the anion- The salt water resistance of the radical-curing adhesive composition for circuit connection is lower than that of the epoxy-curable adhesive composition for circuit connection. It is considered that the polarity of the radical-curing adhesive composition for circuit connection is low, and the adhesiveness of the interface between the adherend (substrate, etc.) and the adhesive composition is low, and therefore, the ionic components in the salt water easily penetrate into the interface. , resulting in subsequent obstacles. For example, when a polymer of a radically polymerizable compound has a carbon-carbon bond (CC) as a main skeleton, the polarity tends to be low. In particular, when the adherend has an insulating material portion containing an insulating material such as SiO ₂ or SiN _x , the insulating material portion has a plurality of hydroxyl groups on the surface and is easily wetted by water (salt water, etc.). On the other hand, since the adhesive composition for circuit connection of a radical hardening system is difficult to get wet, it is easy to generate|occur|produce adhesion failure, and the reliability of a structure will fall remarkably.

The inventors of the present invention have made intensive studies, and as a result, it has been found that by using particles containing a metal hydroxide or metal oxide containing a specific metal element in a radical-hardening adhesive composition for circuit connection, the structure can be made The salt water resistance is significantly improved. In this regard, the following factors are considered: the polarity of the adhesive composition itself is increased by the metal hydroxide or metal oxide; and the metal hydroxide or metal oxide captures the ionic component that causes adhesion inhibition, thereby suppressing adhesion inhibition, and the like.

The said (C) component may contain the said metal hydroxide. The average primary particle size of the component (C) is preferably 10 μm or less.

The adhesive composition for circuit connection of this invention may further contain a silane coupling agent. The adhesive composition for circuit connection of this invention may further contain electroconductive particle.

The structure of the present invention includes the adhesive composition or its cured product.

The structure of the present invention may also be an embodiment including a first circuit member having a first circuit electrode, a second circuit member having a second circuit electrode, and a circuit member arranged between the first circuit member and the second circuit electrode. In the circuit connecting member between the two circuit members, the first circuit electrode and the second circuit electrode are electrically connected, and the circuit connecting member includes the adhesive composition or its cured product. [Effect of the invention]

According to the present invention, an adhesive composition for circuit connection capable of obtaining a structure having excellent salt water resistance, and a structure using the same can be provided.

According to the present invention, application of an adhesive composition or its cured product to a structure (circuit connection structure, etc.) or its manufacture can be provided. According to the present invention, the application of the adhesive composition or its cured product in circuit connection can be provided. The application of the structure in portable applications can be provided by the present invention.

Embodiments of the present invention will be described below, but the present invention is not limited by these embodiments.

In this specification, "(meth)acrylate" means at least one of acrylate and the corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryl" and "(meth)acryl". The materials exemplified below may be used alone or in combination of two or more unless otherwise particularly limited. The content of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified, when a plurality of substances corresponding to each component exist in the composition. The numerical range expressed using "-" shows the range which includes the numerical value described before and after "-" and makes it the minimum value and the maximum value, respectively. "A or B" may include either one of A and B, or may include both. "Normal temperature" means 25°C.

In the numerical ranges described step by step in this specification, the upper limit or lower limit of the numerical range of a certain step may be replaced with the upper limit or lower limit of the numerical range of another step. In addition, in the numerical range described in this specification, the upper limit or the lower limit of the numerical range may be replaced with the value shown in an Example.

＜Adhesive composition＞ The adhesive composition of this embodiment is an adhesive composition for circuit connection, which contains (A) a radical polymerizable compound (radical polymerizable substance, a radical reactive component), (B) a radical generating agent, and (C) Particles containing at least one metal compound selected from the group consisting of metal hydroxides and metal oxides. Each component is demonstrated below.

(radical polymerizable compound) The radically polymerizable compound is a compound having a radically polymerizable functional group. Examples of such radically polymerizable compounds include (meth)acrylate compounds, maleimide compounds, citraconimide compounds, and nadimide compounds. The term "(meth)acrylate compound" means a compound having a (meth)acryl group. The radically polymerizable compound may be used in the form of a monomer or an oligomer, or may be used in combination of a monomer and an oligomer. A radical polymerizable compound may be used individually by 1 type, and may use it in combination of 2 or more types.

Specific examples of (meth)acrylate compounds include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, isobutyl (meth)acrylate, ethylene glycol Alcohol di(meth)acrylate, diethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, 2-hydroxy -1,3-bis(meth)acryloxypropane, 2,2-bis[4-((meth)acryloxymethoxy)phenyl]propane, 2,2-bis[4- ((meth)acryloxypolyethoxy)phenyl]propane, dicyclopentenyl (meth)acrylate, tricyclodecanyl (meth)acrylate, isocyanuric acid tri(( Meth)acryloxyethyl) ester, EO-modified di(meth)acrylate, EO-modified tri(meth)acrylate, amine (meth)acrylic acid carbamate, etc. As the radically polymerizable compound other than the (meth)acrylate compound, for example, a compound described in Patent Document 5 (International Publication No. 2009/063827 ) can be suitably used. The (meth)acrylate compounds may be used alone or in combination of two or more.

From the viewpoint of obtaining more excellent salt water resistance, the radical polymerizable compound is preferably a (meth)acrylate compound, more preferably a (meth)acrylate urethane. From the viewpoint of improving heat resistance, the (meth)acrylate compound preferably has at least one substituent selected from the group consisting of a dicyclopentenyl group, a tricyclodecanyl group, and a triazine ring.

[式中，n表示1～3的整數，R表示氫原子或甲基] Furthermore, as the radical polymerizable compound, it is preferable to use a radical polymerizable compound having a phosphate ester structure represented by the following general formula (I), and it is more preferable to use the radical polymerizable compound such as a (meth)acrylate compound or the like. The polymerizable compound is used in combination with a radical polymerizable compound having a phosphate ester structure represented by formula (I). In these cases, since the adhesive strength to the surface of an inorganic substance (metal etc.) improves, it is suitable for bonding of circuit electrodes, for example. [chemical 1]

[wherein, n represents an integer of 1 to 3, and R represents a hydrogen atom or a methyl group]

The radical polymerizable compound which has the said phosphate ester structure can be obtained by making anhydrous phosphoric acid and 2-hydroxyethyl (meth)acrylate react, for example. Specific examples of the radically polymerizable compound having a phosphate ester structure include mono(2-(meth)acryloxyethyl)phosphate, di(2-(meth)acryloxyethyl)phosphate, and di(2-(meth)acryloxyethyl)phosphate. Ethyl) ester, etc. The radically polymerizable compound having a phosphate ester structure represented by formula (I) may be used alone or in combination of two or more.

From the viewpoint of obtaining more excellent salt water resistance, the content of the radically polymerizable compound having a phosphate ester structure represented by formula (I) is preferably The total amount of components. The same below) is 20 parts by mass or less, more preferably 10 parts by mass or less, per 100 parts by mass. From the standpoint of obtaining more excellent salt water resistance, the content of the radically polymerizable compound having a phosphate ester structure represented by formula (I) is preferably contained relative to the radically polymerizable compound and the film-forming material (if necessary, use The total of 100 parts by mass of components) is 20 parts by mass or less, more preferably 10 parts by mass or less.

The radically polymerizable compound may contain allyl (meth)acrylate. In this case, the content of allyl (meth)acrylate is preferably from 0.1 parts by mass to 100 parts by mass of the total of the radically polymerizable compound and film-forming material (components used if necessary). 10 parts by mass, more preferably 0.5 to 5 parts by mass.

From the viewpoint of obtaining more excellent salt water resistance, the radical polymerizability is based on the total mass of the adhesive components of the adhesive composition (solid content other than the conductive particles in the adhesive composition. The same applies hereinafter). The content of the compound is preferably in the following range. The content of the radically polymerizable compound is preferably at least 10% by mass, more preferably at least 20% by mass, further preferably at least 30% by mass. The content of the radically polymerizable compound is preferably at most 90% by mass, more preferably at most 80% by mass, further preferably at most 70% by mass. From these viewpoints, the content of the radically polymerizable compound is preferably from 10% by mass to 90% by mass, more preferably from 20% by mass to 80% by mass, still more preferably from 30% by mass to 70% by mass.

(free radical generator) The free radical generating agent is a curing agent (radical polymerization initiator, etc.) that can be decomposed by heat, light (ultraviolet (UV), etc.), ultrasonic waves, electromagnetic waves, etc. to generate free radicals.

Examples of the radical generating agent include peroxides (organic peroxides, etc.), azo compounds, and the like. The radical generating agent can be appropriately selected according to the target connection temperature, connection time, usage period, and the like. The 10-minute half-life temperature of the radical generating agent is preferably 40° C. or higher, more preferably 60° C. or higher, from the viewpoint of high reactivity and improvement in pot life. The 1-minute half-life temperature of the radical generating agent is preferably 180° C. or lower, more preferably 170° C. or lower, from the viewpoint of high reactivity and improved shelf life. From the standpoint of high reactivity and improved service life, the free radical generator is preferably an organic peroxide with a 10-minute half-life temperature of 40° C. or higher and a 1-minute half-life temperature of 180° C. or less, more preferably a 10-minute half-life temperature of Organic peroxides with a temperature of 60°C or higher and a half-life temperature of 1 minute of 170°C or lower.

Specific examples of peroxides as curing agents that generate free radicals by heat include diacyl peroxide (benzoyl peroxide, etc.), peroxydicarbonate, peroxyester, peroxyketal , dialkyl peroxide, hydrogen peroxide, silyl peroxide, etc.

From the standpoint of suppressing corrosion of electrodes (circuit electrodes, etc.), the free radical generating agent is preferably a curing agent containing chloride ions and organic acids at a concentration of 5000 ppm or less, more preferably an organic acid produced after thermal decomposition. Acid-less hardener. Specific examples of such curing agents include diacyl peroxide, peroxydicarbonate, peroxyester, dialkyl peroxide, hydrogen peroxide, and silyl peroxide. From a viewpoint, it is preferably at least one selected from the group consisting of peroxydiacyl, peroxydicarbonate, and peroxyester. The curing agents that generate free radicals by heat may be used alone or in combination of two or more.

Examples of peroxyesters include cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, and 1-cyclohexyl-1-methyl peroxyneodecanoate. Ethyl peroxyneodecanoate, tert-hexyl peroxyneodecanoate, tert-butyl peroxypivalate, 2-ethylhexanoate-1,1,3,3-tetramethylbutyl peroxide, 2,5 -Dimethyl-2,5-di(2-ethylhexylperoxy)hexane, 2-ethylhexanoic acid-1-cyclohexyl-1-methylethyl peroxide, 2- Tri-hexyl ethylhexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyisobutyrate, 1,1-bis(tert-butylperoxy)cyclohexane, tert-hexyl peroxyisopropyl monocarbonate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxylaurate, 2,5-dimethyl-2,5 - Di(m-cresylperoxy)hexane, tert-butyl peroxyisopropyl monocarbonate, tert-butyl peroxide 2-ethylhexyl monocarbonate, tert-hexyl peroxybenzoate , tertiary butyl peroxyacetate, etc. One type of peroxyester may be used alone, or two or more types may be used in combination. As a curing agent that generates free radicals by heat other than the peroxyester, for example, compounds described in Patent Document 5 (International Publication No. 2009/063827 ) can be used suitably.

Examples of azo-based compounds that can generate free radicals by heat include: 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1 ,1'-Azobis(cyclohexane-1-carbonitrile), 2,2'-Azobis(2,4-dimethylvaleronitrile), 2,2'-Azobis(2,4- Dimethyl-4-methoxyvaleronitrile), Dimethyl 2,2'-azobis(2-propionate methyl ester), 4,4'-azobis(4-cyanovaleric acid), 2,2'-Azobis(2-hydroxymethylpropionitrile), 2,2'-Azobis[2-(imidazolin-2-yl)propane], etc.

As a curing agent that generates free radicals by light, a compound that generates free radicals by light having a wavelength of 150 nm to 750 nm can be used. As such a compound, for example, photoinitiation, photopolymerization, and photocuring (Photoinitiation, Photopolymerization, and Photocuring) are preferred from the viewpoint of high sensitivity to light irradiation, J.-P. Fouassier, α-Acetamidophenone derivatives and phosphine oxide derivatives described on pages 17 to 35 of Hanser Publishers (1995). The curing agent that generates free radicals by light may be used alone or in combination of two or more.

The radical generating agent may be used alone or in combination of two or more. A curing agent (peroxide, azo compound, etc.) that generates free radicals by heat and a curing agent that generates free radicals by light may be used in combination. A radical generator, a decomposition accelerator, a decomposition inhibitor, etc. can also be used together. Furthermore, the radical generating agent can also be microencapsulated by covering it with a polyurethane-based or polyester-based polymer substance or the like. Microencapsulated sclerosing agents are preferred because they prolong usable life.

When the connecting time is 25 seconds or less, the content of the radical generating agent is preferably in the following range from the viewpoint of easily obtaining a sufficient reaction rate. The content of the radical generating agent is preferably at least 0.1 part by mass, more preferably at least 0.5 part by mass, and still more preferably at least 1 part by mass with respect to 100 parts by mass of the radically polymerizable compound. The content of the radical generating agent is preferably at most 40 parts by mass, more preferably at most 30 parts by mass, and still more preferably at most 20 parts by mass, relative to 100 parts by mass of the radically polymerizable compound. From these viewpoints, the content of the radical generating agent is preferably from 0.1 to 40 parts by mass, more preferably from 0.5 to 30 parts by mass, and still more preferably It is 1 mass part - 30 mass parts.

When the connecting time is 25 seconds or less, the content of the radical generating agent is preferably in the following range from the viewpoint of easily obtaining a sufficient reaction rate. The content of the radical generating agent is preferably at least 0.1 parts by mass, more preferably at least 0.5 parts by mass, and further preferably at least 0.1 parts by mass relative to a total of 100 parts by mass of the radically polymerizable compound and the film-forming material (components used as necessary). Preferably, it is at least 1 part by mass. The content of the radical generating agent is preferably at most 40 parts by mass, more preferably at most 30 parts by mass, and further preferably Preferably, it is 20 parts by mass or less. From these viewpoints, the content of the radical generating agent is preferably 0.1 to 40 parts by mass, more preferably Preferably, it is 0.5 mass part - 30 mass parts, More preferably, it is 1 mass part - 20 mass parts.

From the viewpoint of easily obtaining a sufficient reaction rate, the content of the radical generating agent in the case of not limiting the connection time is preferably in the following range. The content of the radical generating agent is preferably at least 0.1 part by mass, more preferably at least 0.5 part by mass, and still more preferably at least 1 part by mass with respect to 100 parts by mass of the radically polymerizable compound. The content of the radical generating agent is preferably at most 30 parts by mass, more preferably at most 20 parts by mass, and still more preferably at most 15 parts by mass, relative to 100 parts by mass of the radically polymerizable compound. From these viewpoints, the content of the radical generator is preferably from 0.1 to 30 parts by mass, more preferably from 0.5 to 20 parts by mass, and still more preferably It is 1 mass part - 15 mass parts.

From the viewpoint of easily obtaining a sufficient reaction rate, the content of the radical generating agent in the case of not limiting the connection time is preferably in the following range. The content of the radical generating agent is preferably at least 0.1 parts by mass, more preferably at least 0.5 parts by mass, and further preferably at least 0.1 parts by mass relative to a total of 100 parts by mass of the radically polymerizable compound and the film-forming material (components used as necessary). Preferably, it is at least 1 part by mass. The content of the radical generating agent is preferably at most 30 parts by mass, more preferably at most 20 parts by mass, and further preferably Preferably, it is 15 parts by mass or less. From these viewpoints, the content of the radical generating agent is preferably 0.1 to 30 parts by mass, more preferably Preferably, it is 0.5 mass part - 20 mass parts, More preferably, it is 1 mass part - 15 mass parts.

(Particles containing metal hydroxides or metal oxides) The adhesive composition of the present embodiment contains particles containing at least one metal compound selected from the group consisting of metal hydroxides and metal oxides (hereinafter referred to as “(C) component” as the case may be). (C) A component may contain a metal hydroxide, and may contain a metal oxide. The metal compound includes at least one selected from the group consisting of aluminum, magnesium, zirconium, bismuth, calcium, tin, manganese, antimony, silicon and titanium as metal elements constituting metal hydroxides or metal oxides.

From the viewpoint of obtaining better salt water resistance, the metal hydroxide is preferably at least one selected from the group consisting of aluminum hydroxide, magnesium hydroxide, and calcium hydroxide. From the viewpoint of obtaining more excellent salt water resistance, the oxide is preferably at least A sort of. (C) A component may be used individually by 1 type, and may use it in combination of 2 or more types. Particles containing metal hydroxides and particles containing metal oxides may also be used in combination.

From the viewpoint of obtaining excellent dispersibility in the adhesive composition and high adhesiveness to the adherend, the viewpoint of preventing the corrosion of the adherend, the viewpoint of obtaining the capture ability of ion components, and the suppression of short circuits caused by large particles From the viewpoint of (short circuit when component (C) becomes a foreign substance), the average primary particle diameter of component (C) is preferably 10 μm or less, more preferably 5 μm or less, and still more preferably 1 μm or less. The decrease in the average primary particle size of the component (C) increases the specific surface area of the component (C) in the adhesive composition as a whole, and it is considered that the effect of obtaining high adhesiveness to the adherend can be obtained by this. effect, the effect of preventing corrosion by adherends, and the effect of obtaining the capture energy of ion components. (C) The average primary particle diameter of a component may be 0.5 micrometer or more, and may be 1 micrometer or more. (C) The average primary particle diameter of a component can be measured, for example with a scanning electron microscope.

Based on the total mass of the adhesive components of the adhesive composition, the content of the component (C) is preferably within the following range. From the viewpoint of obtaining more excellent salt water resistance, the content of the component (C) is preferably at least 0.1% by mass, more preferably at least 1% by mass, further preferably at least 2% by mass, particularly preferably at least 3% by mass , preferably 4% by mass or more. The content of component (C) is preferably at most 50% by mass, more preferably at most 10% by mass, still more preferably at most 5% by mass, from the viewpoint of easily suppressing short circuits caused by aggregated particles by obtaining excellent dispersibility the following. From these viewpoints, the content of the component (C) is preferably from 0.1% by mass to 50% by mass, more preferably from 1% by mass to 50% by mass, still more preferably from 2% by mass to 10% by mass, particularly preferably 3% by mass. % by mass to 10% by mass, preferably 4% by mass to 5% by mass.

It is preferable that content of (C)component is the following range with respect to 100 mass parts of radically polymerizable compounds. From the viewpoint of obtaining more excellent salt water resistance, the content of the component (C) is preferably at least 0.1 parts by mass, more preferably at least 1 part by mass, further preferably at least 2 parts by mass, particularly preferably at least 3 parts by mass , very preferably at least 4 parts by mass, very preferably at least 5 parts by mass, and more preferably at least 7 parts by mass. The content of component (C) is preferably at most 200 parts by mass, more preferably at most 100 parts by mass, and still more preferably at most 50 parts by mass, from the viewpoint of easily suppressing short circuits caused by aggregated particles by obtaining excellent dispersibility At most, it is at most 30 parts by mass, very preferably at most 20 parts by mass, and very preferably at most 10 parts by mass. From these viewpoints, the content of the component (C) is preferably 0.1 to 200 parts by mass, more preferably 1 to 200 parts by mass, further preferably 2 to 100 parts by mass, particularly preferably 3 parts by mass. Parts by mass to 50 parts by mass, preferably 4 parts by mass to 30 parts by mass, very preferably 5 parts by mass to 20 parts by mass, more preferably 7 parts by mass to 10 parts by mass.

(silane coupling agent) The adhesive composition of this embodiment may also contain a silane coupling agent. By using a silane coupling agent, the adhesion of the adhesive composition (adhesion to glass, etc.) can be improved. Examples of silane coupling agents include: vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxy 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyl Propylmethyldiethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxy N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane Silanes and their condensates.

Based on the total mass of the adhesive components of the adhesive composition, the content of the silane coupling agent is preferably 0.1% by mass to 10% by mass, more preferably 0.25% by mass to 5% by mass. When content of a silane coupling agent is 0.1 mass % or more, there exists a tendency for the effect of suppressing the generation|occurrence|production of peeling bubbles in the interface of a circuit member and a circuit connection material to become larger. When content of a silane coupling agent is 10 mass % or less, there exists a tendency for the service life of an adhesive composition to become long.

(film forming material) The adhesive composition of this embodiment may contain a film forming material as needed. When the film-forming material solidifies the liquid adhesive composition into a film, it can improve the operability of the film under normal conditions (normal temperature and pressure), and provide the film with resistance to cracking, damage, and stickiness. and other characteristics. Examples of the film forming material include phenoxy resin, polyvinyl formaldehyde, polystyrene, polyvinyl butyral, polyester, polyamide, xylene resin, polyurethane and the like. Among them, phenoxy resin is preferable from the viewpoint of being excellent in adhesiveness, compatibility, heat resistance, and mechanical strength. The film forming material may be used alone or in combination of two or more.

Examples of the phenoxy resin include resins obtained by addition polymerization of bifunctional epoxy resins and bifunctional phenols, and resins obtained by reacting bifunctional phenols with epihalohydrins until they become polymerized. resin. Phenoxy resin, for example, can be prepared by 1 mole of 2-functional phenols and 0.985 moles to 1.015 moles of epihalohydrin in the presence of a catalyst such as an alkali metal hydroxide in a non-reactive solvent at 40°C to 120°C obtained by reacting at a temperature. From the standpoint of excellent mechanical properties and thermal properties of the resin, it is particularly preferable that the compounding equivalent ratio of the bifunctional epoxy resin and the bifunctional phenol be epoxy group/phenolic hydroxyl group=1/0.9 for the phenoxy resin ~1/1.1, in the presence of catalysts such as alkali metal compounds, organophosphorus compounds, and cyclic amine compounds, organic solvents (amides, ethers, ketones, and lactones) with a boiling point of 120°C or higher , alcohols, etc.), it is obtained by heating to 50° C. to 200° C. under the condition that the reaction solid content is 50% by mass or less to carry out an addition polymerization reaction. The phenoxy resins may be used alone or in combination of two or more.

Bifunctional epoxy resins include bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol AD epoxy resins, bisphenol S epoxy resins, biphenyl diglycidyl ether, methyl Substituted biphenyl diglycidyl ether, etc. Bifunctional phenols are compounds having two phenolic hydroxyl groups. Examples of bifunctional phenols include hydroquinones, bisphenol A, bisphenol F, bisphenol AD, bisphenol S, bisphenol stilbene, methyl-substituted bisphenol stilbene, dihydroxybiphenyl, Bisphenols such as substituted dihydroxybiphenyls, etc. Phenoxy resins can also be modified by free radical polymerizable functional groups or other reactive compounds (such as epoxy modification).

Based on the total mass of the adhesive components of the adhesive composition, the content of the film forming material is preferably 10% by mass to 90% by mass, more preferably 20% by mass to 60% by mass.

(conductive particles) The adhesive composition of the present embodiment may further contain conductive particles. Examples of the constituent material of the conductive particles include metals such as gold (Au), silver (Ag), nickel (Ni), copper (Cu), and solder, carbon, and the like. Furthermore, it may be a coated conductive particle which uses non-conductive resin, glass, ceramics, plastic, or the like as a core, and the core is coated with the above-mentioned metal (metal particles, etc.) or carbon. Coated conductive particles (for example, conductive particles with plastic as the core) or hot-melt metal particles are deformable due to heat and pressure, so that the height unevenness of the circuit electrodes is eliminated during connection, and the contact area with the electrodes is increased during connection , so reliability is improved and better.

The average particle diameter of the conductive particles is preferably from 1 μm to 30 μm from the viewpoint of excellent self-dispersibility and conductivity. The average particle diameter of electroconductive particle can be measured using machine analysis, such as a laser diffraction method, for example. From the viewpoint of excellent electrical conductivity, the content of the conductive particles is preferably at least 0.1 part by mass, more preferably at least 1 part by mass, based on 100 parts by mass of the adhesive component of the adhesive composition. The content of the conductive particles is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, based on 100 parts by mass of the adhesive component of the adhesive composition from the viewpoint of easily suppressing short circuiting of electrodes (circuit electrodes, etc.). From these viewpoints, the content of the conductive particles is preferably from 0.1 parts by mass to 100 parts by mass, more preferably from 1 part by mass to 50 parts by mass.

(other ingredients) The adhesive composition of this embodiment may contain polymerization inhibitors, such as hydroquinone and hydroquinone methyl ether, as needed.

The adhesive composition of this embodiment may further contain a homopolymer or a homopolymer obtained by polymerizing at least one monomer component selected from the group consisting of (meth)acrylic acid, (meth)acrylate, and acrylonitrile. copolymer. From the viewpoint of excellent stress relaxation, it is preferable that the adhesive composition of the present embodiment contains acrylic rubber obtained by polymerizing glycidyl (meth)acrylate having a glycidyl ether group, etc. things. From the viewpoint of improving the cohesion of the adhesive composition, the weight average molecular weight of the acrylic rubber is preferably 200,000 or more.

The adhesive composition of the present embodiment may also contain coated fine particles in which the surfaces of the conductive particles are coated with a polymer resin or the like. In the case where such coated fine particles are used in combination with the conductive particles, even when the content of the conductive particles increases, it is easy to suppress the short circuit caused by the contact of the conductive particles with each other, thus making the insulation between adjacent circuit electrodes sexual enhancement. The coated fine particles may be used alone without using the conductive particles, or the coated fine particles may be used in combination with the conductive particles.

The adhesive composition of this embodiment may also contain rubber microparticles, fillers (excluding (C) component), softeners, accelerators, anti-aging agents, colorants, flame retardants, thixotropic agents, coupling agents, phenolic Resin, melamine resin, isocyanate, etc. The adhesive composition of this embodiment may suitably contain additives such as an adhesion improving agent (excluding a coupling agent), a tackifier, a leveling agent, a colorant, and a weather resistance improving agent.

The rubber microparticles preferably have an average particle diameter twice or less than the average particle diameter of the conductive particles, and have a storage elastic modulus at room temperature that is 1/2 of the storage elastic modulus at room temperature of the conductive particles and the adhesive composition. the following particles. Especially when the rubber particles are made of silicone, acrylic emulsion, styrene-butadiene rubber (Styrene Butadiene Rubber, SBR), nitrile-butadiene rubber (NBR) or polybutadiene In the case of rubber, the fine rubber particles are preferably used alone or in combination of two or more. The three-dimensionally crosslinked rubber microparticles have excellent solvent resistance and are easily dispersed in the adhesive composition.

Fillers improve electrical characteristics (connection reliability, etc.) between circuit electrodes. As the filler, for example, particles having an average particle diameter of 1/2 or less of the average particle diameter of conductive particles can be suitably used. When using the filler which does not have electroconductivity together, the particle which has an average particle diameter or less of the particle which does not have electroconductivity can be used as a filler. Based on the total mass of the adhesive components of the adhesive composition, the content of the filler is preferably 5% by mass to 60% by mass. There exists a tendency for the improvement effect of connection reliability to be acquired more fully by making the said content into 60 mass % or less. There exists a tendency for the effect of adding a filler to fully be acquired by making the said content into 5 mass % or more.

When the adhesive composition of this embodiment is liquid at normal temperature, it can be used in paste form. When the adhesive composition is solid at normal temperature, it may be gelatinized using a solvent instead of being heated and used. The usable solvent is not particularly limited as long as it has no reactivity with the components in the adhesive composition and exhibits sufficient solubility. The solvent is preferably a solvent having a boiling point of 50°C to 150°C under normal pressure. If the boiling point is 50° C. or higher, the volatility of the solvent at room temperature is poor, so even an open system can be used. When the boiling point is 150° C. or lower, the solvent is easily volatilized, so good reliability can be obtained after bonding.

The adhesive composition of the present embodiment may also be in the form of a film. If necessary, a solution of an adhesive composition containing a solvent or the like is applied to a fluororesin film, a polyethylene terephthalate film, or a release substrate (release paper, etc.), and then the solvent or the like is removed. A film-like adhesive composition was obtained. And after impregnating the said solution in base materials, such as a nonwoven fabric, and mounting on a peelable base material, a film-form adhesive agent composition can be obtained by removing a solvent etc.. Using the adhesive composition in a film form is more convenient from the viewpoint of excellent handling properties and the like. The thickness of the film adhesive composition may be 1 μm to 100 μm, or 5 μm to 50 μm.

The adhesive composition of the present embodiment can be bonded, for example, by applying pressure together with heating or light irradiation. By using heating and light irradiation together, bonding can be performed at a low temperature for a short time. Light irradiation is preferably irradiated with light in a wavelength region of 150 nm to 750 nm. As the light source, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps (ultra-high pressure mercury lamps, etc.), xenon lamps, metal halide lamps, etc. can be used. The irradiation dose may be 0.1 J/cm ² to 10 J/cm ² . The heating temperature is not particularly limited, but is preferably a temperature of 50°C to 170°C. The pressure is not particularly limited as long as it is within a range that does not damage the adherend, but is preferably 0.1 MPa to 10 MPa. It is preferable to heat and pressurize in the range of 0.5 second - 3 hours.

The adhesive composition of the present embodiment may be used as an adhesive of the same type of adherend, or may be used as an adhesive of different types of adherends having different coefficients of thermal expansion. Specifically, it can be used as circuit connection materials represented by anisotropic conductive adhesives, silver pastes, silver films, etc.; elastomers for Chip Scale Package (CSP), underfill materials for CSP, lead wires on chips (Lead on Chip, LOC) tape, etc., are used for bonding semiconductor elements represented by materials, etc.

＜Structure and its manufacturing method＞ The structure (circuit connection body) of this embodiment contains the adhesive composition of this embodiment or its cured product. The structure of the present embodiment is, for example, a semiconductor device such as a circuit-connected structure. As one embodiment of the structural body of this embodiment, the circuit connection structural body includes a first circuit member having a first circuit electrode, a second circuit member having a second circuit electrode, and Electrical connections between components. The first circuit component includes, for example, a first substrate and a first circuit electrode disposed on the first substrate. The second circuit component includes, for example, a second substrate and a second circuit electrode disposed on the second substrate. The first circuit electrode and the second circuit electrode face each other and are electrically connected. The circuit connection member contains the adhesive composition of this embodiment or its cured product. The structure of the present embodiment may include the adhesive composition of the present embodiment or its cured product, and a member (substrate, etc.) that does not have circuit electrodes may be used instead of the circuit member of the circuit connection structure.

The method of manufacturing the structure of the present embodiment includes the step of curing the adhesive composition of the present embodiment. As one embodiment of the method of manufacturing the structure of the present embodiment, the method of manufacturing the circuit-connected structure includes: an arranging step, between a first circuit member having a first circuit electrode and a second circuit member having a second circuit electrode The adhesive composition of this embodiment is placed between, and the step of heating and pressing pressurizes the first circuit member and the second circuit member so that the first circuit electrode and the second circuit electrode are electrically connected, and the adhesive composition Heating is applied to harden it. In the arranging step, the first circuit electrode and the second circuit electrode may be arranged so that they face each other. In the heating and pressing step, pressure may be applied in a direction in which the first circuit member and the second circuit member face each other. The method of manufacturing the structure of the present embodiment may be such that the adhesive composition of the present embodiment is interposed between the circuit electrodes of the opposing semiconductor element and the circuit electrodes of the semiconductor mounting substrate, and the opposing circuit electrodes are bonded. A state in which the electrodes in the direction of pressure are electrically connected by pressing.

Hereinafter, the circuit connection structure and its manufacturing method will be described using the drawings as one embodiment of the present embodiment. FIG. 1 is a schematic cross-sectional view showing an embodiment of a structure. The circuit connection structure 100a shown in FIG. 1 includes a circuit member (first circuit member) 20 and a circuit member (second circuit member) 30 facing each other. The circuit of the component is connected to the component 10 . The circuit connection member 10 contains the cured product of the adhesive composition of this embodiment.

The circuit member 20 includes a substrate (first substrate) 21 and circuit electrodes (first circuit electrodes) 22 arranged on the main surface 21 a of the substrate 21 . On the main surface 21 a of the substrate 21 , an insulating layer (not shown) may also be arranged according to circumstances.

The circuit member 30 includes a substrate (second substrate) 31 and circuit electrodes (second circuit electrodes) 32 arranged on the main surface 31 a of the substrate 31 . On the main surface 31 a of the substrate 31 , an insulating layer (not shown) may also be arranged depending on circumstances.

The circuit connection member 10 contains an insulating substance (cured product of components other than conductive particles) 10a and conductive particles 10b. Conductive particle 10b is arrange|positioned at least between the circuit electrode 22 and the circuit electrode 32 which oppose. In the circuit connection structure 100a, the circuit electrode 22 and the circuit electrode 32 are electrically connected via the conductive particle 10b.

The circuit member 20 and the circuit member 30 have a single or a plurality of circuit electrodes (connection terminals). As the circuit member 20 and the circuit member 30 , for example, members including electrodes requiring electrical connection can be used. As the circuit member, wafer components such as semiconductor wafers (IC wafers), resistor wafers, and capacitor wafers; substrates such as printed circuit boards and semiconductor mounting substrates, and the like can be used. As a combination of the circuit member 20 and the circuit member 30, for example, a semiconductor wafer and a substrate for mounting a semiconductor can be used. Examples of substrate materials include inorganic substances such as semiconductors, glass, and ceramics; organic substances such as polyimide, polyethylene terephthalate, polycarbonate, (meth)acrylic resins, and cyclic olefin resins; glass and Compounds such as epoxy, etc. The substrate can also be a plastic substrate.

Fig. 2 is a schematic cross-sectional view showing another embodiment of the structure. The circuit connection structure 100b shown in FIG. 2 has the structure similar to the circuit connection structure 100a except that the circuit connection member 10 does not contain the conductive particle 10b. In the circuit connection structure 100b shown in FIG. 2 , the circuit electrodes 22 and the circuit electrodes 32 are in direct contact without conductive particles, and are electrically connected.

The circuit connection structure 100a and the circuit connection structure 100b can be manufactured by the following method, for example. First, when the adhesive composition is in a paste form, the adhesive composition is applied and dried to arrange a resin layer containing the adhesive composition on the circuit member 20 . When the adhesive composition is in the form of a film, the resin layer containing the adhesive composition is arranged on the circuit member 20 by sticking the film-like adhesive composition on the circuit member 20 . Next, the circuit member 30 is placed on the resin layer arranged on the circuit member 20 so that the circuit electrode 22 and the circuit electrode 32 are arranged to face each other. Next, heat treatment or light irradiation is performed on the resin layer containing the adhesive composition, whereby the adhesive composition is cured to obtain a cured product (circuit connection member 10 ). The circuit-connected structural body 100a and the circuit-connected structural body 100b are obtained by the above. [Example]

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

<Preparation of film-like circuit connection material> (Example 1) 50 g of phenoxy resin (trade name: PKHC, manufactured by Union Carbide Co., Ltd., weight average molecular weight: 45,000) was dissolved in toluene/ethyl acetate (mass ratio: 50/50) to prepare a phenoxy resin solution with a solid content of 40% by mass. As the radically polymerizable compound, isocyanuric acid EO-modified diacrylate (trade name: M-215, manufactured by Toagosei Co., Ltd.), 2-methacryloxyethyl phosphate (phosphate , trade name: Light ester (Light ester) P-2M, manufactured by Kyoeisha Chemical Co., Ltd.) and urethane acrylate (trade name: U-2PPA, manufactured by Shin-Nakamura Chemical Co., Ltd.). As a silane coupling agent, 3-methacryloxypropyltrimethoxysilane (trade name: KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.) was prepared. As a radical generator, benzoyl peroxide (trade name: NYPER-BMT-K40, manufactured by NOF Corporation, 1-minute half-life temperature: 131.1° C., 10-minute half-life temperature: 73° C.) was prepared. As the component (C), aluminum hydroxide (Al(OH) ₃ ) particles having an average primary particle diameter of 1 μm were prepared.

Phenoxy resin/isocyanuric acid EO modified diacrylate/2-methacryloxyethyl phosphate/acrylic urethane/silane coupling agent/free radical generator/ (C) The ingredients are mixed at a ratio of 50 g/27 g/5 g/20 g/3 g/3 g/5 g to prepare an adhesive composition containing liquid A. Furthermore, conductive particles having a nickel layer with a thickness of 0.2 μm, an average particle diameter of 5 μm, and a specific gravity of 2.5 were produced on the surface of the polystyrene particle (core). 5 parts by mass of conductive particles were dispersed with respect to 100 parts by mass of the adhesive composition-containing liquid A to prepare a circuit-connecting material-containing liquid.

On a 50 μm thick PET film surface-treated on one side, apply the circuit-connecting material-containing liquid using a coating device, and then dry it with hot air at 70°C for 3 minutes to obtain on the PET film A film-like circuit connection material with a thickness of 20 μm.

(Example 2) Except having changed (C) component into the magnesium hydroxide (Mg(OH) ₃ ) particle whose average primary particle diameter was 1 micrometer, it carried out similarly to Example 1, and produced the film-form circuit connection material.

(Example 3) Except having changed (C) component into the magnesium oxide ( _Mg2O3 ) particle whose average primary particle diameter was 1 _micrometer , it carried out similarly to Example 1, and produced the film-form circuit connection material.

(Example 4) Except having changed (C) component into the zirconia ( _ZrO2 ) particle whose average primary particle diameter was 1 micrometer, it carried out similarly to Example 1, and produced the film-form circuit connection material.

(comparative example 1) Except not using (C)component, it carried out similarly to Example 1, and produced the film-form circuit connection material.

<Peel evaluation (evaluation of salt spray test)> 500 copper circuits with a line width of 75 μm, a pitch of 150 μm, and a thickness of 18 μm were separated from the film-shaped circuit connecting material obtained by the above-mentioned production method. Flexible circuit board (FPC) and glass (thickness 0.7mm) formed with a thin layer of silicon nitride (SiN _x ) with a thickness of 0.5 μm, using a thermocompression bonding device (heating method: constant temperature type, Toray Engineering Co., Ltd. company) were heated and pressurized at 170°C and 3 MPa for 20 seconds to connect with a width of 2 mm to produce a circuit-connected structure. The circuit connection structure was subjected to a 24-hour salt spray test in accordance with JIS Z 2371 using a salt spray tester (manufactured by Suga Testing Instrument Co., Ltd.). The appearance of the connection portion before and after the test was observed, and the presence or absence of peeling was evaluated. The case where peeling was not observed was evaluated as "A", and the case where peeling was observed was evaluated as "B". Table 1 shows the evaluation results.

[Table 1] Example comparative example 1 2 3 4 1 composition Phenoxy resin 50 50 50 50 50 Isocyanuric acid EO modified diacrylate 27 27 27 27 27 2-Methacryloxyethyl Phosphate 5 5 5 5 5 Urethane Acrylate 20 20 20 20 20 3-Methacryloxypropyltrimethoxysilane 3 3 3 3 3 Benzoyl peroxide 3 3 3 3 3 Aluminum hydroxide particles 5 - - - - Magnesium Hydroxide Particles - 5 - - - Magnesium Oxide Particles - - 5 - - Zirconia particles - - - 5 - Strip evaluation before saline spray A A A A A after saline spray A A A A B

From the above, it was confirmed that in the examples, the adhesiveness to the surface of the adherend (inorganic substrate) was maintained favorably even after the salt spray was compared with the comparative examples. Furthermore, it was confirmed that in the examples, low-temperature short-time connection was achieved and adhesiveness (salt water resistance) was maintained well.

10: Circuit connection components 10a: insulating substance 10b: Conductive particles 20: First circuit component 21: First substrate 21a, 31a: main surface 22: The first circuit electrode 30: second circuit component 31: Second substrate 32: Second circuit electrode 100a, 100b: circuit connection structure

FIG. 1 is a schematic cross-sectional view showing an embodiment of the structure of the present invention. Fig. 2 is a schematic cross-sectional view showing another embodiment of the structure of the present invention.

Claims (8)

An adhesive composition for circuit connection comprising (A) a radical polymerizable compound, (B) a radical generator, and (C) a compound selected from the group consisting of metal hydroxides and metal oxides. particles of at least one metal compound, The metal compound includes at least one selected from the group consisting of aluminum, magnesium, zirconium, bismuth, calcium, tin, manganese, antimony, silicon and titanium. The adhesive composition for circuit connection according to claim 1, wherein the component (C) contains the metal hydroxide. The adhesive composition for circuit connection according to Claim 1 or Claim 2, wherein the average primary particle diameter of the component (C) is 10 μm or less. The adhesive composition for circuit connection according to any one of claim 1 to claim 3, which further contains a silane coupling agent. The adhesive composition for circuit connection according to Claim 4, wherein the content of the silane coupling agent is 0.1% by mass to 10% by mass based on the total mass of the adhesive components of the adhesive composition for circuit connection. The adhesive composition for circuit connection according to any one of claim 1 to claim 5, which further contains conductive particles. A structure comprising the adhesive composition for circuit connection according to any one of claim 1 to claim 6 or a cured product thereof. A structure comprising a first circuit member having a first circuit electrode, a second circuit member having a second circuit electrode, and a circuit connection member disposed between the first circuit member and the second circuit member, The first circuit electrode and the second circuit electrode are electrically connected, The circuit connection member includes the adhesive composition for circuit connection according to any one of claim 1 to claim 6 or a cured product thereof.

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