KR102615097B1 - Adhesive composition and structure for circuit connection - Google Patents

Abstract

It contains particles containing (A) a radically polymerizable compound, (B) a radical generator, and (C) at least one metal compound selected from the group consisting of metal hydroxides and metal oxides, wherein the metal compound is aluminum. , an adhesive composition for circuit connection containing at least one member selected from the group consisting of 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 the same.

In recent years, various adhesives have been used to fix electronic components or connect circuits in fields such as semiconductors and liquid crystal displays. In these applications, density and precision are gradually increasing, and adhesives are required to have high adhesiveness or reliability. In particular, circuit connection materials include the connection between a liquid crystal display and TCP, the connection between an FPC and a TCP, the connection between an FPC and a printed wiring board, the connection between a semiconductor silicon chip and a substrate, the connection between an FPC and a touch panel module, the connection between an FPC and an FPC, etc. Anisotropic conductive adhesives containing conductive particles are used.

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

Additionally, in recent years, with the high integration of semiconductor elements and the high precision of display elements, the pitch between elements and interconnections has become narrow, and there is a risk of adversely affecting surrounding members due to heat during curing. In addition, in order to reduce costs, it is necessary to improve throughput, so that adhesion can be achieved at low temperatures (90 to 170°C) and in a short period of time (within 1 hour, preferably within 40 seconds, more preferably within 20 seconds). Adhesion through low-temperature, short-time curing (low-temperature rapid curing) is required. In order to achieve this low-temperature, short-time curing, it is necessary to use a thermal potential catalyst with low activation energy, but it is known to be very difficult to achieve both storage stability at around room temperature.

Therefore, in recent years, radical curing adhesives (for example, radical curing adhesives using a (meth)acrylate derivative and peroxide, which is a radical polymerization initiator, in combination) have been attracting attention. In the radical curing system, short-time curing is possible because radicals, which are reactive species, are very reactive, and the adhesive exists stably below the decomposition temperature of the radical polymerization initiator, so low-temperature short-time curing and storage stability (e.g. It is a curing system that achieves both stability and storage at room temperature. Additionally, since the radical curing system does not use ionic polymerization like epoxy curing systems such as cationic-epoxy curing systems and anionic-epoxy curing systems, it has an advantage over epoxy curing systems when a general high temperature and high humidity test is performed. It has the characteristic of excellent corrosion resistance. On the other hand, in cation-epoxy curing or anion-epoxy curing adhesives, the corrosion may be suppressed by adding metal hydroxides or metal oxides (for example, see Patent Documents 1 to 4 below).

Japanese Patent Publication No. 2006-199778 Japanese Patent Publication No. 2012-46756 Japanese Patent Publication No. 2012-46757 Japanese Patent Publication No. 2012-41544 International Publication No. 2009/063827

In recent years, wearable terminals (terminals worn on the body) and display terminals (smartphones, tablets, smart watches, etc.) with high durability as an added value have been increasing. Regarding the circuit connection materials for the structural members of these terminals, salt water such as sweat or sea water is assumed, and even when the structure obtained using the circuit connection material is exposed to salt water, it has excellent connection reliability, that is, excellent salt water resistance (against salt water). resistance) is required.

The purpose of the present invention is to provide an adhesive composition for circuit connection that makes it possible to obtain a structure with excellent salt water resistance, and a structure using the same.

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

According to the adhesive composition for circuit connection according to the present invention, a structure having excellent salt water resistance (excellent connection reliability even when exposed to salt water (sweat, sea water, etc.)) can be obtained. As a result, excellent reliability can be obtained even in harsh environments such as wearable applications. Additionally, according to the adhesive composition for circuit connection according to the present invention, low-temperature, short-time connection can also be achieved. Therefore, it is possible to use adherends made of materials with low heat resistance, such as polyethylene terephthalate (PET) and polycarbonate (PC), thereby expanding the selection of adherends.

Methods for evaluating salt water resistance (resistance to salt water) include JIS Z 2371 (2000 Salt Spray Test Method); ISO 9227(2006 Corrosion tests in artificial atmospheres-Salt spray tests.); Soaking in 5% salt water; Methods such as immersing it in salt water and then placing it in a high-temperature, high-humidity tank are being used. As a result of the present inventors' verification, when the above test regarding salt water resistance was performed on the structure obtained by connecting with the adhesive composition for circuit connection, the adhesive composition for circuit connection of the radical curing type was cation-epoxy curing type or anion-epoxy curing type. It was found that the salt water resistance was low compared to the cured adhesive composition for circuit connection. Since the polarity of the adhesive composition for circuit connection of the radical curing system is low and the adhesion of the interface between the adherend (substrate, etc.) and the adhesive composition is low, ionic components in the salt water easily penetrate into the interface, causing adhesion inhibition. I think so. For example, when a polymer of a radically polymerizable compound has a carbon-carbon bond (CC) as its main skeleton, it tends to have low polarity. In particular, when the adherend has an insulating material portion containing an insulating material such as SiO ₂ or _SiN Since it is difficult to get wet with the adhesive composition for circuit connection, adhesion inhibition is likely to occur, which significantly reduces the reliability of the structure.

As a result of repeated studies, the present inventors have found that the salt water resistance of the structure is significantly improved by using a metal hydroxide containing a specific metal element or particles containing a metal oxide in a radical curing adhesive composition for circuit connection. I found something I could do. This is thought to be due to factors such as the metal hydroxide or metal oxide increasing the polarity of the adhesive composition itself and the metal hydroxide or metal oxide capturing ionic components that cause adhesion inhibition to suppress adhesion inhibition.

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

The adhesive composition for circuit connection according to the present invention may further contain a silane coupling agent. The adhesive composition for circuit connection according to the present invention may further contain electrically conductive particles.

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

The structure of the present invention includes 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 may be electrically connected, and the circuit connection member may include the adhesive composition or a cured product thereof.

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

According to the present invention, application of the adhesive composition or its cured product to structures (circuit connection structures, etc.) or their production can be provided. According to the present invention, application of the adhesive composition or its cured product to circuit connections can be provided. According to the present invention, application of the structure for wearable purposes can be provided.

1 is a schematic cross-sectional view showing one embodiment of the structure of the present invention.
Figure 2 is a schematic cross-sectional view showing another embodiment of the structure of the present invention.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments at all.

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)acryloyl” and “(meth)acrylic acid.” Unless otherwise specified, the materials illustrated below may be used individually or in combination of two or more types. 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 multiple substances corresponding to each component exist in the composition. The numerical range indicated using “to” indicates a range that includes the numerical values written before and after “to” as the minimum and maximum values, respectively. “A or B” may include either A or B, and may include both. “Room temperature” means 25°C.

In the numerical range described in stages in this specification, the upper or lower limit of the numerical range at a certain level may be replaced with the upper or lower limit of the numerical range at another level. In addition, in the numerical range described in this specification, the upper or lower limit of the numerical range may be replaced with the value shown in the examples.

<Adhesive composition>

The adhesive composition of the present embodiment is at least selected from the group consisting of (A) a radically polymerizable compound (radically polymerizable material, radically reactive component), (B) a radical generator, and (C) a metal hydroxide and a metal oxide. It is an adhesive composition for circuit connection containing particles containing one type of metal compound. Below, each component is explained.

(Radically polymerizable compound)

A radically polymerizable compound is a compound having a functional group capable of radical polymerization. Examples of such radically polymerizable compounds include (meth)acrylate compounds, maleimide compounds, citraconimide compounds, and nadiimide compounds. “(meth)acrylate compound” means a compound having a (meth)acryloyl group. The radically polymerizable compound may be used in the form of a monomer or oligomer, or a monomer and an oligomer may be used in combination. A radically polymerizable compound may be used individually by 1 type, or may be used 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 di(meth)acrylate, and diethylene. Glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, 2-hydroxy-1,3-di(meth)acryloxypropane, 2,2- Bis[4-((meth)acryloxymethoxy)phenyl]propane, 2,2-bis[4-((meth)acryloxypolyethoxy)phenyl]propane, dicyclopentenyl (meth)acrylate, tri Cyclodecanyl (meth)acrylate, tris((meth)acryloyloxyethyl)isocyanurate, isocyanuric acid EO-modified di(meth)acrylate, isocyanuric acid EO-modified tri(meth)acrylate , urethane (meth)acrylate, etc. As a radically polymerizable compound other than a (meth)acrylate compound, for example, a compound described in Patent Document 5 (International Publication No. 2009/063827) can be suitably used. A (meth)acrylate compound may be used individually by 1 type, or may be used in combination of 2 or more types.

As a radically polymerizable compound, a (meth)acrylate compound is preferable and urethane (meth)acrylate is more preferable from the viewpoint of obtaining more excellent salt water resistance. 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.

In addition, as the radically polymerizable compound, it is preferable to use a radically polymerizable compound having a phosphate ester structure represented by the general formula (I) below, and the radically polymerizable compound such as a (meth)acrylate compound and the formula (I) It is more preferable to use together a radically polymerizable compound having a phosphoric acid ester structure represented by I). In these cases, the adhesive strength to the surface of an inorganic material (metal, etc.) improves, so they are suitable for, for example, adhesion between circuit electrodes.

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

The radically polymerizable compound having the phosphoric acid ester structure is obtained, for example, by reacting phosphoric acid anhydride with 2-hydroxyethyl (meth)acrylate. Specific examples of the radically polymerizable compound having the phosphoric acid ester structure include mono(2-(meth)acryloyloxyethyl)acid phosphate, di(2-(meth)acryloyloxyethyl)acid phosphate, etc. . The radically polymerizable compound having a phosphoric acid ester structure represented by formula (I) may be used individually or in combination of two or more types.

The content of the radically polymerizable compound having a phosphoric acid ester structure represented by formula (I) is 100 mass of the radically polymerizable compound (total amount of components corresponding to the radically polymerizable compound. The same applies hereinafter) from the viewpoint of obtaining better salt water resistance. With respect to parts, 20 parts by mass or less is preferable, and 10 parts by mass or less is more preferable. The content of the radically polymerizable compound having a phosphoric acid ester structure represented by formula (I) is 100 parts by mass in total of the radically polymerizable compound and the film forming material (components used as necessary) from the viewpoint of obtaining better salt water resistance. Relative to this, 20 parts by mass or less is preferable, and 10 parts by mass or less is more preferable.

The radically polymerizable compound may contain allyl (meth)acrylate. In this case, the content of allyl (meth)acrylate is preferably 0.1 to 10 parts by mass, and 0.5 to 5 parts by mass, based on a total of 100 parts by mass of the radical polymerizable compound and the film forming material (components used as necessary). It is more desirable.

The content of the radically polymerizable compound is preferably within the following range based on the total mass of the adhesive component of the adhesive composition (solid content other than conductive particles in the adhesive composition; the same applies hereinafter) of the adhesive composition from the viewpoint of obtaining better salt water resistance. The content of the radically polymerizable compound is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more. The content of the radically polymerizable compound is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. From these viewpoints, the content of the radically polymerizable compound is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, and even more preferably 30 to 70% by mass.

(Radical generator)

A radical generator is a curing agent (radical polymerization initiator, etc.) that generates free radicals by decomposition by heat, light (UV, etc.), ultrasound, electromagnetic waves, etc.

Examples of radical generators include peroxides (organic peroxides, etc.) and azo compounds. The radical generator is appropriately selected depending on the intended connection temperature, connection time, potable time, etc. The 10-minute half-life temperature of the radical generator is preferably 40°C or higher, and more preferably 60°C or higher, from the viewpoint of high reactivity and improvement of pot life. The 1-minute half-life temperature of the radical generator is preferably 180°C or lower, and more preferably 170°C or lower, from the viewpoint of high reactivity and improvement of pot life. From the viewpoint of high reactivity and improvement of pot life, the radical generator is preferably an organic peroxide with a half-life temperature of 40°C or higher for 10 minutes and a half-life temperature of 180°C or lower for 1 minute, and a half-life temperature of 60°C or higher for 10 minutes. , Furthermore, organic peroxides with a 1-minute half-life temperature of 170°C or lower are more preferable.

Specific examples of peroxides, which are curing agents that generate free radicals by heat, include diacyl peroxide (benzoyl peroxide, etc.), peroxydicarbonate, peroxy ester, peroxy ketal, dialkyl peroxide, hydroperoxide, and silyl peroxide. Seeds, etc. can be mentioned.

As a radical generator, from the viewpoint of suppressing corrosion of electrodes (circuit electrodes, etc.), a curing agent containing a concentration of chlorine ions and organic acids of 5000 ppm or less is preferable, and a curing agent containing less organic acid generated after thermal decomposition is more preferable. Specific examples of such curing agents include diacyl peroxide, peroxydicarbonate, peroxy ester, dialkyl peroxide, hydroperoxide, silyl peroxide, etc., and from the viewpoint of obtaining high reactivity, diacyl peroxide is used. , at least one type selected from the group consisting of peroxydicarbonate and peroxy ester is preferable. The curing agent that generates free radicals by heat may be used individually, or may be used in combination of two or more types.

Examples of peroxyesters include cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, and t-hexyl. Silperoxyneodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2- Ethylhexanoylperoxy)hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate Noate, t-butylperoxyisobutyrate, 1,1-bis(t-butylperoxy)cyclohexane, t-hexylperoxyisopropylmonocarbonate, t-butylperoxy-3,5,5- Trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di(m-toluoylperoxy)hexane, t-butylperoxyisopropylmonocarbonate, t-butylper Oxy-2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, t-butyl peroxy acetate, etc. are mentioned. Peroxyesters may be used individually, or two or more types may be used in combination. As a curing agent other than the peroxyester that generates free radicals by heat, for example, a compound described in Patent Document 5 (International Publication No. 2009/063827) can be suitably used.

Examples of azo-based compounds that are curing agents that generate free radicals by heat include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), and 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-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-hydroxymethylpropionitrile) , 2,2'-azobis[2-(imidazoline-2-yl)propane], etc.

As a curing agent that generates free radicals by light, a compound that generates radicals by light with a wavelength of 150 to 750 nm can be used. As such compounds, from the viewpoint of high sensitivity to light irradiation, literature [Photoinitiation, Photopolymerization, and Photocuring, J.-P. The α-acetoaminophenone derivatives and phosphine oxide derivatives described in Fouassier, Hanser Publishers (1995), pages 17 to 35 are preferred. The curing agent that generates free radicals by light may be used individually or in combination of two or more types.

The radical generator may be used individually, or may be used in combination of two or more types. A curing agent that generates free radicals by heat (peroxide, azo compound, etc.) 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. may be used in combination. Additionally, the radical generator may be microencapsulated by covering it with a polyurethane-based or polyester-based polymer material. Microencapsulated hardeners are preferred because their pot life is extended.

The content of the radical generator is preferably within the following range from the viewpoint of easily obtaining a sufficient reaction rate when the connection time is 25 seconds or less. The content of the radical generator is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, and even more preferably 1 part by mass or more, based on 100 parts by mass of the radically polymerizable compound. The content of the radical generator is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and still more preferably 20 parts by mass or less, per 100 parts by mass of the radically polymerizable compound. From these viewpoints, the content of the radical generator is preferably 0.1 to 40 parts by mass, more preferably 0.5 to 30 parts by mass, and even more preferably 1 to 30 parts by mass, based on 100 parts by mass of the radically polymerizable compound. .

The content of the radical generator is preferably within the following range from the viewpoint of easily obtaining a sufficient reaction rate when the connection time is 25 seconds or less. The content of the radical generator is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, based on a total of 100 parts by mass of the radical polymerizable compound and the film forming material (components used as necessary). It is more desirable to have more than wealth. The content of the radical generator is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and 20 parts by mass, based on a total of 100 parts by mass of the radical polymerizable compound and the film forming material (components used as necessary). It is more preferable that it is less than 100%. From these viewpoints, the content of the radical generator is preferably 0.1 to 40 parts by mass, and 0.5 to 30 parts by mass, based on a total of 100 parts by mass of the radical polymerizable compound and the film forming material (components used as necessary). It is more preferable, and it is still more preferable that it is 1 to 20 parts by mass.

When the connection time is not limited, the content of the radical generator is preferably within the following range from the viewpoint of easily obtaining a sufficient reaction rate. The content of the radical generator is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, and even more preferably 1 part by mass or more, based on 100 parts by mass of the radically polymerizable compound. The content of the radical generator is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and still more preferably 15 parts by mass or less, based on 100 parts by mass of the radically polymerizable compound. From these viewpoints, the content of the radical generator is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, and even more preferably 1 to 15 parts by mass, based on 100 parts by mass of the radically polymerizable compound. .

When the connection time is not limited, the content of the radical generator is preferably within the following range from the viewpoint of easily obtaining a sufficient reaction rate. The content of the radical generator is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, based on a total of 100 parts by mass of the radical polymerizable compound and the film forming material (components used as necessary). It is more desirable to have more than wealth. The content of the radical generator is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and 15 parts by mass, based on a total of 100 parts by mass of the radical polymerizable compound and the film forming material (components used as necessary). It is more preferable that it is less than 100%. From these viewpoints, the content of the radical generator is preferably 0.1 to 30 parts by mass, and 0.5 to 20 parts by mass, based on a total of 100 parts by mass of the radical polymerizable compound and the film forming material (components used as necessary). It is more preferable, and it is still more preferable that it is 1 to 15 parts by mass.

(Particles containing metal hydroxides or metal oxides)

The adhesive composition of this embodiment contains particles (hereinafter referred to as “component (C)” in some cases) containing at least one type of metal compound selected from the group consisting of metal hydroxides and metal oxides. (C) Component may contain a metal hydroxide or may contain a metal oxide. The metal compound is a metal hydroxide or a metal element constituting a metal oxide, and includes at least one selected from the group consisting of aluminum, magnesium, zirconium, bismuth, calcium, tin, manganese, antimony, silicon, and titanium.

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 better salt water resistance, the oxide is preferably at least one selected from the group consisting of silicon oxide, aluminum oxide, magnesium oxide, antimony oxide, tin oxide, titanium oxide, manganese oxide, and zirconium oxide. (C) Component may be used individually by 1 type, or may be used in combination of 2 or more types. Particles containing a metal hydroxide and particles containing a metal oxide may be used together.

(C) The average primary particle size of the component is determined from the viewpoint of obtaining excellent dispersibility in the adhesive composition and high adhesion to the adherend, preventing corrosion of the adherend, obtaining the ability to capture ionic components, and large particles. From the viewpoint of suppressing short circuit (short circuit when component (C) becomes a foreign matter), it is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 1 μm or less. By decreasing the average primary particle size of the component (C), the specific surface area of the entire component (C) in the adhesive composition increases, resulting in the effect of obtaining high adhesion to the adherend, the effect of preventing corrosion of the adherend, and the ionic component It is thought that the effect of obtaining the capturing ability is achieved. The average primary particle size of the component (C) may be 0.5 μm or more and may be 1 μm or more. (C) The average primary particle size of component can be measured, for example, using a scanning electron microscope.

The content of component (C) is preferably in the following range based on the total mass of the adhesive components of the adhesive composition. From the viewpoint of obtaining more excellent salt water resistance, the content of component (C) is preferably 0.1% by mass or more, more preferably 1% by mass or more, further preferably 2% by mass or more, and especially preferably 3% by mass or more. And, it is very preferable that it is 4% by mass or more. The content of component (C) is preferably 50% by mass or less, more preferably 10% by mass or less, and more preferably 5% by mass, from the viewpoint of obtaining excellent dispersibility and easily suppressing short circuits resulting from aggregated particles. It is more preferable that it is below. From these viewpoints, the content of component (C) is preferably 0.1 to 50% by mass, more preferably 1 to 50% by mass, further preferably 2 to 10% by mass, and 3 to 10% by mass. It is especially preferable that it is 4-5 mass % and it is very preferable.

The content of component (C) is preferably within the following range per 100 parts by mass of the radically polymerizable compound. From the viewpoint of obtaining more excellent salt water resistance, the content of component (C) is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, further preferably 2 parts by mass or more, and especially preferably 3 parts by mass or more. It is very preferable that it is 4 parts by mass or more, it is very preferable that it is 5 parts by mass or more, and it is even more preferable that it is 7 parts by mass or more. The content of component (C) is preferably 200 parts by mass or less, more preferably 100 parts by mass or less, from the viewpoint of obtaining excellent dispersibility and easily suppressing short circuits resulting from aggregated particles, and 50 parts by mass. It is more preferable that it is less than 30 parts by mass, it is especially preferable that it is 30 parts by mass or less, it is very preferable that it is 20 parts by mass or less, and it is very preferable that it is 10 parts by mass or less. From these viewpoints, the content of 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, and especially preferably 3 to 50 parts by mass. It is very preferable that it is 4 to 30 parts by mass, it is very preferable that it is 5 to 20 parts by mass, and it is even more preferable that it is 7 to 10 parts by mass.

(Silane coupling agent)

The adhesive composition of this embodiment may contain a silane coupling agent. By using a silane coupling agent, the adhesion of the adhesive composition (adhesion to glass, etc.) can be increased. Silane coupling agents include, for example, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-(meth)acryloxypropyl. Methyldimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, N-2-(amino Ethyl)-3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureide propyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanate propyltri Ethoxysilanes and condensates thereof can be mentioned.

The content of the silane coupling agent is preferably 0.1 to 10% by mass, more preferably 0.25 to 5% by mass, based on the total mass of the adhesive components of the adhesive composition. If the content of the silane coupling agent is 0.1% by mass or more, the effect of suppressing the generation of peeling bubbles at the interface between the circuit member and the circuit connection material tends to be further increased. If the content of the silane coupling agent is 10% by mass or less, the potable time of the adhesive composition tends to be long.

(Film former)

The adhesive composition of this embodiment may contain a film forming material as needed. When the liquid adhesive composition is solidified into a film form, the film forming material improves the handleability of the film under normal conditions (at room temperature and pressure) and provides properties such as being less likely to tear, less likely to crack, and more difficult to stick to the film. can be granted. Examples of film forming materials include phenoxy resin, polyvinyl formal, polystyrene, polyvinyl butyral, polyester, polyamide, xylene resin, and polyurethane. Among these, phenoxy resin is preferable from the viewpoint of excellent adhesion, compatibility, heat resistance, and mechanical strength. Film forming materials may be used individually, or may be used in combination of two or more types.

Examples of the phenoxy resin include a resin obtained by centrally adding a bifunctional epoxy resin and a bifunctional phenol, and a resin obtained by reacting the bifunctional phenol with epihalohydrin until polymerization. Phenoxy resin can be obtained, for example, by reacting 1 mole of difunctional phenols and 0.985 to 1.015 moles of epihalohydrin in a non-reactive solvent at a temperature of 40 to 120° C. in the presence of a catalyst such as an alkali metal hydroxide. there is. As a phenoxy resin, from the viewpoint of excellent mechanical and thermal properties of the resin, in particular, the mixing equivalence ratio of the bifunctional epoxy resin and the difunctional phenol is set to epoxy group/phenol hydroxyl group = 1/0.9 to 1/1.1, and the alkali metal In the presence of a catalyst such as a compound, an organophosphorus compound, or a cyclic amine compound, the reaction solid content is 50% by mass or less in an organic solvent (amide-based, ether-based, ketone-based, lactone-based, alcohol-based, etc.) with a boiling point of 120°C or higher. A resin obtained by subjecting the resin to a central addition reaction by heating to 50 to 200° C. under conditions is preferred. Phenoxy resins may be used individually, or may be used in combination of two or more types.

Examples of the bifunctional epoxy resin include bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol AD-type epoxy resin, bisphenol S-type epoxy resin, biphenyl diglycidyl ether, and methyl-substituted biphenyl diglycidyl ether. You can. Bifunctional phenols are compounds having two phenolic hydroxyl groups. Examples of difunctional phenols include bisphenols such as hydroquinones, bisphenol A, bisphenol F, bisphenol AD, bisphenol S, bisphenol fluorene, methyl-substituted bisphenol fluorene, dihydroxybiphenyl, and methyl-substituted dihydroxybiphenyl. You can. The phenoxy resin may be modified (for example, epoxy modified) with a radically polymerizable functional group or another reactive compound.

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

(conductive particle)

The adhesive composition of this embodiment may further contain electrically conductive particles. Constituent materials of the conductive particles include metals such as gold (Au), silver (Ag), nickel (Ni), copper (Cu), solder, and carbon. Additionally, coated conductive particles may be formed by using a non-conductive resin, glass, ceramic, plastic, etc. as the core and covering the core with the metal (metal particles, etc.) or carbon. Since coated conductive particles (e.g., conductive particles with a plastic core) or heat-fused metal particles have deformability by heating and pressurizing, they eliminate fluctuations in the height of the circuit electrodes when connected and maintain contact with the electrodes during connection. This is desirable because reliability improves as the contact area increases.

The average particle diameter of the conductive particles is preferably 1 to 30 μm from the viewpoint of excellent dispersibility and conductivity. The average particle diameter of the conductive particles can be measured using, for example, instrumental analysis such as laser diffraction. From the viewpoint of excellent conductivity, the content of the conductive particles is preferably 0.1 part by mass or more, and more preferably 1 part by mass or more, per 100 parts by mass of the adhesive component of the adhesive composition. From the viewpoint of easily suppressing short circuit of electrodes (circuit electrodes, etc.), the content of conductive particles is preferably 100 parts by mass or less, and more preferably 50 parts by mass or less, with respect to 100 parts by mass of the adhesive component of the adhesive composition. From these viewpoints, the content of the conductive particles is preferably 0.1 to 100 parts by mass, and more preferably 1 to 50 parts by mass.

(Other ingredients)

The adhesive composition of this embodiment may contain a polymerization inhibitor, such as hydroquinone and methyl ether hydroquinone, as needed.

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

The adhesive composition of this embodiment may contain coated fine particles in which the surfaces of the conductive particles are coated with a polymer resin or the like. When such coated fine particles are used in combination with the above-described conductive particles, even when the content of conductive particles increases, short-circuiting due to contact between conductive particles is easily suppressed, and the insulation between adjacent circuit electrodes can be improved. The above-mentioned coated fine particles may be used alone without using conductive particles, or the coated fine particles and conductive particles may be used together.

The adhesive composition of the present embodiment contains rubber particles, fillers (excluding component (C)), softeners, accelerators, anti-aging agents, colorants, flame retardants, thixotropic agents, coupling agents, phenol resins, melamine resins, isocyanates, etc. It may contain The adhesive composition of this embodiment may appropriately contain additives such as an adhesion improver (excluding the coupling agent), a thickener, a leveling agent, a colorant, and a weather resistance improver.

The rubber fine particles are preferably particles that have an average particle diameter of 2 times or less than that of the conductive particles and a storage elastic modulus at room temperature of 1/2 or less of the storage elastic modulus at room temperature of the conductive particles and the adhesive composition. In particular, when the material of the rubber particles is silicone, acrylic emulsion, SBR, NBR, or polybutadiene rubber, it is preferable to use the rubber particles individually or in a mixture of two or more types. Three-dimensional crosslinked rubber fine particles have excellent solvent resistance and are easily dispersed in the adhesive composition.

Fillers can improve electrical characteristics (connection reliability, etc.) between circuit electrodes. As a filler, for example, particles having an average particle diameter of 1/2 or less of the average particle diameter of the conductive particles can be suitably used. When non-conductive particles are used in combination with a filler, particles with an average particle diameter smaller than that of the non-conductive particles can be used as the filler. The content of the filler is preferably 5 to 60% by mass based on the total mass of the adhesive components of the adhesive composition. When the content is 60% by mass or less, the effect of improving connection reliability tends to be more fully obtained. When the content is 5% by mass or more, the effect of adding the filler tends to be sufficiently obtained.

The adhesive composition of this embodiment can be used in paste form if it is liquid at room temperature. When the adhesive composition is in a solid state at room temperature, in addition to using it by heating, it may be made into a paste using a solvent. The solvent that can be used is not particularly limited as long as it is not reactive with the components in the adhesive composition and shows sufficient solubility. The solvent is preferably one with a boiling point of 50 to 150°C at normal pressure. If the boiling point is 50°C or higher, the solvent has little volatility at room temperature, so it can be used even in an open system. If the boiling point is 150°C or lower, it is easy to volatilize the solvent, so good reliability is obtained after adhesion.

The adhesive composition of this embodiment may be in a film form. A film-like adhesive composition can be obtained by applying a solution of the adhesive composition containing a solvent, etc., as needed, onto a fluororesin film, a polyethylene terephthalate film, or a peelable substrate (release paper, etc.), and then removing the solvent, etc. Additionally, a film-like adhesive composition can be obtained by impregnating a substrate such as a non-woven fabric with the solution, placing it on a peelable substrate, and then removing the solvent. Using the adhesive composition in the form of a film is more convenient from the viewpoint of excellent handling properties, etc. The thickness of the film-like adhesive composition may be 1 to 100 μm or 5 to 50 μm.

The adhesive composition of this embodiment can be bonded, for example, by applying pressure along with heating or light irradiation. By using heating and light irradiation together, bonding can be achieved at a lower temperature and in a shorter time. The light irradiation is preferably irradiated with light in a wavelength range of 150 to 750 nm. The light source may be a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp (such as an ultra-high pressure mercury lamp), a xenon lamp, or a metal halide lamp. The irradiation amount may be 0.1 to 10 J/cm ² . The heating temperature is not particularly limited, but a temperature of 50 to 170°C is preferable. The pressure is not particularly limited as long as it does not damage the adherend, but is preferably 0.1 to 10 MPa. Heating and pressurization are preferably performed within the range of 0.5 seconds to 3 hours.

The adhesive composition of this embodiment may be used as an adhesive for the same type of adherend, or may be used as an adhesive for different types of adherends with different thermal expansion coefficients. Specifically, circuit connection materials such as anisotropic conductive adhesive, silver paste, silver film, etc.; It can be used as a semiconductor device adhesive material such as elastomer for CSP, underfill material for CSP, and LOC tape.

<Structure and its manufacturing method>

The structure (circuit connection body) of this embodiment includes the adhesive composition of this embodiment or its cured product. The structure of this embodiment is, for example, a semiconductor device such as a circuit connection structure. In one form of the structure of this embodiment, the circuit connection structure is disposed between a first circuit member having a first circuit electrode, a second circuit member having a second circuit electrode, and between the first circuit member and the second circuit member. Provided with a circuit connection member. The first circuit member has, for example, a first substrate and a first circuit electrode disposed on the first substrate. The second circuit member has, 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 be provided with the adhesive composition of the present embodiment or a cured product thereof, and a member (substrate, etc.) without a circuit electrode may be used instead of the circuit member of the circuit connection structure.

The structure manufacturing method of this embodiment includes a step of curing the adhesive composition of this embodiment. As one form of the structure manufacturing method of the present embodiment, the manufacturing method of the circuit connection structure includes the adhesive of the present embodiment between the first circuit member having the first circuit electrode and the second circuit member having the second circuit electrode. It includes a placement step of arranging the composition, a heating and pressing step of pressing the first circuit member and the second circuit member to electrically connect the first circuit electrode and the second circuit electrode, and heating and curing the adhesive composition. . In the arrangement process, the first circuit electrode and the second circuit electrode may be arranged to face each other. In the heating and pressing process, the first circuit member and the second circuit member can be pressed in directions opposing each other. The structure manufacturing method of the present embodiment is to interpose the adhesive composition of the present embodiment between the circuit electrode of the semiconductor element facing each other and the circuit electrode of the semiconductor mounting substrate, press the opposing circuit electrodes, and form a bond between the electrodes in the pressing direction. It may be electrically connected.

Hereinafter, using the drawings, a circuit connection structure and its manufacturing method will be described as one form of this embodiment. Figure 1 is a schematic cross-sectional view showing one embodiment of the 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 that face each other, and the circuit member 20 and A circuit connection member 10 is disposed between the circuit members 30 to connect them. The circuit connection member 10 contains a cured product of the adhesive composition of this embodiment.

The circuit member 20 includes a substrate (first substrate) 21 and a circuit electrode (first circuit electrode) 22 disposed on the main surface 21a of the substrate 21. In some cases, an insulating layer (not shown) may be disposed on the main surface 21a of the substrate 21.

The circuit member 30 includes a substrate (second substrate) 31 and a circuit electrode (second circuit electrode) 32 disposed on the main surface 31a of the substrate 31. In some cases, an insulating layer (not shown) may be disposed on the main surface 31a of the substrate 31.

The circuit connection member 10 contains an insulating material (cured product of components excluding conductive particles) 10a and conductive particles 10b. The conductive particles 10b are arranged at least between the circuit electrodes 22 and 32 that face each other. In the circuit connection structure 100a, the circuit electrode 22 and the circuit electrode 32 are electrically connected through the conductive particles 10b.

The circuit members 20 and 30 have one or more circuit electrodes (connection terminals). As the circuit members 20 and 30, for example, members having electrodes that require electrical connection can be used. Circuit members include chip components such as semiconductor chips (IC chips), resistor chips, and condenser chips; Substrates such as printed boards and semiconductor mounting boards can be used. Combinations of the circuit members 20 and 30 include, for example, a semiconductor chip and a semiconductor mounting substrate. Materials for the substrate include, for example, inorganic materials such as semiconductors, glass, and ceramics; Organic substances such as polyimide, polyethylene terephthalate, polycarbonate, (meth)acrylic resin, and cyclic olefin resin; A composite of glass, epoxy, etc. can be mentioned. The substrate may be a plastic substrate.

Figure 2 is a schematic cross-sectional view showing another embodiment of the structure. The circuit connection structure 100b shown in FIG. 2 has the same configuration as the circuit connection structure 100a except that the circuit connection member 10 does not contain conductive particles 10b. In the circuit connection structure 100b shown in FIG. 2, the circuit electrode 22 and the circuit electrode 32 are electrically connected by direct contact without passing through conductive particles.

The circuit connection structures 100a and 100b can be manufactured, for example, by the following method. First, when the adhesive composition is in a paste form, a resin layer containing the adhesive composition is disposed on the circuit member 20 by applying and drying the adhesive composition. When the adhesive composition is in the form of a film, a resin layer containing the adhesive composition is disposed on the circuit member 20 by attaching the film-shaped adhesive composition to the circuit member 20 . Subsequently, the circuit member 30 is placed on the resin layer disposed on the circuit member 20 so that the circuit electrodes 22 and 32 are opposed to each other. Then, by subjecting the resin layer containing the adhesive composition to heat treatment or light irradiation, the adhesive composition is cured and a cured product (circuit connection member 10) is obtained. As a result, the circuit connection structures 100a and 100b are obtained.

Example

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

<Production of circuit connection material on film>

(Example 1)

50 g of phenoxy resin (brand name: PKHC, manufactured by Union Carbide Co., Ltd., weight average molecular weight 45000) was dissolved in a mixed solvent of toluene/ethyl acetate (mass ratio: 50/50) to obtain a phenoxy resin solution with a solid content of 40% by mass. prepared. As radically polymerizable compounds, isocyanuric acid EO-modified diacrylate (brand name: M-215, manufactured by Toagosei Co., Ltd.), 2-methacryloyloxyethyl acid phosphate (phosphoric acid ester, brand name: Light Ester P- 2M, manufactured by Kyoesha Chemical Co., Ltd.) and urethane acrylate (product name: U-2PPA, manufactured by Shinnakamura Chemical Co., Ltd.) were used. As a silane coupling agent, 3-methacryloxypropyltrimethoxysilane (brand name: KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.) was prepared. As a radical generator, benzoyl peroxide (brand name: Naifer BMT-K40, manufactured by Nichiyu Corporation, half-life temperature for 1 minute: 131.1°C, half-life temperature for 10 minutes: 73°C) was prepared. As component (C), aluminum hydroxide (Al(OH) ₃ ) particles with an average primary particle diameter of 1 μm were prepared.

The solid mass of the above materials is phenoxy resin/isocyanuric acid EO modified diacrylate/2-methacryloyloxyethyl acid phosphate/urethane acrylate/silane coupling agent/radical generator/component (C) is 50g/ Adhesive composition-containing solution A was prepared by mixing at a ratio of 27g/5g/20g/3g/3g/5g. Additionally, conductive particles with an average particle diameter of 5 μm and a specific gravity of 2.5, which had a 0.2 μm thick nickel layer on the surface of the polystyrene particles (nuclei), were produced. A liquid containing a circuit connection material was prepared by dispersing 5 parts by mass of conductive particles into 100 parts by mass of the adhesive composition-containing liquid A.

Using a coating device, the liquid containing the circuit connection material is applied onto a PET film with a thickness of 50 μm and one side of which has been surface treated, and then dried with hot air at 70° C. for 3 minutes to form a circuit on the PET film with a thickness of 20 μm. Obtained connection materials.

(Example 2)

A film-like circuit connection material was produced in the same manner as in Example 1, except that the component (C) was changed to magnesium hydroxide (Mg(OH) ₃ ) particles with an average primary particle size of 1 μm.

(Example 3)

A film-like circuit connection material was produced in the same manner as in Example 1, except that the component (C) was changed to magnesium oxide ( _Mg2O3 ) particles with an average primary particle size of 1 μm.

(Example 4)

A film-like circuit connection material was produced in the same manner as in Example 1, except that the component (C) was changed to zirconium oxide (ZrO ₂ ) particles with an average primary particle size of 1 μm.

(Comparative Example 1)

A film-shaped circuit connection material was produced in the same manner as in Example 1, except that component (C) was not used.

<Evaluation of peeling (evaluation of salt spray test)>

Through the film-shaped circuit connection material obtained by the above manufacturing method, a flexible circuit board (FPC) having 500 copper circuits with a line width of 75 μm, a pitch of 150 μm, and a thickness of 18 μm, and a silicon nitride (SiN _x ) with a thickness of 0.5 μm are formed. A thin layer of glass plate (thickness 0.7 mm) was connected over a width of 2 mm by heating and pressing at 170°C and 3 MPa for 20 seconds using a heat compression device (heating method: constant heat type, manufactured by Doré Engineering Co., Ltd.). Thus, a circuit connection structure was produced. Using a salt spray tester (manufactured by Suga Chemical Co., Ltd.), a salt spray test was performed on the circuit connection structure for 24 hours in accordance with JIS Z 2371. The appearance of the connection part before and after the test was observed to evaluate the presence or absence of peeling. The case where peeling was not observed was evaluated as “A”, and the case where peeling was observed was evaluated as “B.” The evaluation results are shown in Table 1.

From the above, it is confirmed that in the Examples, compared with the Comparative Examples, good adhesion (salt water resistance) to the surface of the adherend (inorganic substrate) can be maintained even after salt water spraying. Additionally, in the examples, it is confirmed that good adhesion (salt water resistance) can be maintained while achieving low-temperature, short-time connection.

10… Circuit connection member, 10a... Insulating material, 10b... Conductive particle, 20… First circuit member, 21... First substrate, 21a... If you give it, 22… First circuit electrode, 30... Second circuit member, 31... Second substrate, 31a... If you give it, 32… Second circuit electrodes, 100a, 100b... Circuit connection structure.

Claims (7)

(A) radically polymerizable compound, (B) radical generator, (C) aluminum hydroxide (Al(OH) ₃ ) particles, magnesium hydroxide (Mg(OH) ₃ ) particles, magnesium oxide (Mg ₂ O ₃ ) Contains particles or zirconium oxide (ZrO ₂ ) particles and a silane coupling agent,
An adhesive composition for circuit connection, wherein the content of the silane coupling agent is 0.1 to 10% by mass based on the total mass of adhesive components of the adhesive composition for circuit connection. The adhesive composition for circuit connection according to claim 1, wherein the average primary particle size of the component (C) is 10 μm or less. The adhesive composition for circuit connection according to claim 1 or 2, further comprising electrically conductive particles. A structure comprising the adhesive composition for circuit connection according to claim 1 or 2 or a cured product thereof. a first circuit member having a first circuit electrode;
a second circuit member having a second circuit electrode;
It has 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,
A structure in which the circuit connection member contains the adhesive composition for circuit connection according to claim 1 or 2 or a cured product thereof. delete delete

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