KR20230165351A - silver-containing paste - Google Patents

Abstract

The silver-containing paste of the present invention contains silver-containing particles, a cyanamide derivative, a solvent, (A) an epoxy compound having two or more epoxy groups in the molecule, and (B) two or more polymerizable double bonds in the molecule. Among (meth)acrylic compounds, at least one or both polyfunctional compounds are included.

Description

silver-containing paste

The present invention relates to a silver-containing paste.

A technique for manufacturing a semiconductor device using a thermosetting resin composition containing metal particles is known, with the intention of improving the heat dissipation of the semiconductor device. By including metal particles having a higher thermal conductivity than the resin in the thermosetting resin composition, the thermal conductivity of the cured product can be increased.

Patent Document 1 discloses a paste-like silver-containing particle composition consisting of surface-coated predetermined sinterable silver-containing particles, a volatile dispersion medium, and two specific types of resin powder. This document describes sintering a paste-like silver-containing particle composition at a temperature of 100°C or more and 250°C or less in a predetermined atmosphere. In addition, it is described that the paste-like silver-containing particle composition has good storage stability and provides a joined body with excellent adhesive strength to a metal member.

Patent Document 2 discloses a paste-like adhesive composition containing metal particles that cause sintering through heat treatment to form a particle-connected structure, and a resin having a decomposition start temperature of 40°C or more and 250°C or less. In this document, it is described that the sintered body of the paste-like adhesive composition has excellent metal adhesion.

Patent Document 1: Japanese Patent Publication No. 2019-189936 Patent Document 2: Japanese Patent Publication No. 2018-98272

However, as a result of examination by the inventor, the silver-containing paste described in the above document had room for improvement in terms of adhesion between the lead frame and the chip when bonding a semiconductor chip to a metal surface such as a lead frame, for example. .

The present inventors conducted further studies based on these findings and found that by appropriately selecting a resin with properties that assist sintering of metal particles and adding an adhesion aid, the adhesion between the lead frame and the chip was improved. This improvement was discovered and the present invention was completed.

According to the present invention,

silver-containing particles,

cyanamide derivatives,

Solvent,

Among (A) epoxy compounds having two or more epoxy groups in the molecule, and (B) (meth)acrylic compounds containing two or more polymerizable double bonds in the molecule, silver-containing compounds including polyfunctional compounds consisting of at least one or both sides. Paste is provided.

According to the present invention, a silver-containing paste having excellent adhesion between a lead frame and a chip is provided.

<Silver-containing paste>

An outline of the silver-containing paste according to the present embodiment will be described.

The silver-containing paste according to the present embodiment contains silver-containing particles, a cyanamide derivative, a solvent, (A) an epoxy compound having two or more epoxy groups in the molecule, and (B) two or more polymerizable double bonds in the molecule. Among the (meth)acrylic compounds included, at least one or both polyfunctional compounds are included.

In this embodiment, the adhesion between the lead frame and the chip is improved by including a cyanamide derivative. Although the detailed mechanism is not clear, this is thought to be due to the polarity of the cyanamide derivative.

The cyanamide derivative has two or more lone pairs of nitrogen atoms in the molecule, and also has a nitrogen atom in the cyano group. By having this nitrogen atom, the cyanamide derivative has strong polarity, so it acts as an adhesion aid to the lead frame or chip. It is thought that by attaching such a cyanamide derivative to the surface of the silver-containing particles, the affinity between the silver-containing particles and the lead frame and chip is improved, and as a result, the adhesion between the lead frame and chip during sintering is improved.

At this time, the multifunctional compound used in the silver-containing paste in this embodiment is (A) an epoxy compound having two or more epoxy groups in the molecule, and (B) (meth)acrylic containing two or more polymerizable double bonds in the molecule. By using a polyfunctional compound consisting of at least one or both of the compounds, the cyanamide derivative becomes easy to be introduced into the polyfunctional compound, and the adhesion between the silver-containing particles and the lead frame and chip by the cyanamide derivative is improved. You can do whatever suits you.

Hereinafter, each component of the silver-containing paste according to the present embodiment will be described.

[Silver-containing particles]

The silver-containing paste according to this embodiment contains silver-containing particles.

The silver-containing particles according to the present embodiment are sintered silver-containing particles that cause sintering (sintering) by heat treatment to form a particle connecting structure (sintering structure).

In particular, since the silver-containing paste contains silver-containing particles, especially silver-containing particles with a relatively small particle size and relatively large specific surface area, a sintering structure is likely to be formed even during heat treatment at a relatively low temperature (about 180°C). The preferred particle size will be described later.

The upper limit of the temperature at which the silver-containing particles according to the present embodiment cause sintering by heat treatment is preferably 260°C or lower, more preferably 250°C or lower, and still more preferably 240°C or lower. When the upper limit of the temperature that causes sintering is below the above upper limit, the adhesion between the lead frame and the chip becomes more suitable in the electronic device using the silver-containing paste of this embodiment.

Moreover, the lower limit of the temperature that causes sintering is preferably 160°C or higher, more preferably 165°C or higher, and still more preferably 170°C or higher. When the lower limit of the temperature that causes sintering is equal to or higher than the above lower limit, high-temperature reliability becomes more suitable in the electronic device using the silver-containing paste of this embodiment.

The shape of the silver-containing particles is not particularly limited. The preferred shape is spherical, but non-spherical shapes, such as ellipsoidal shapes, flat shapes, plates, flakes, needles, scales, agglomerates, and polyhedral shapes, may be used. The silver-containing particles may contain at least one type of silver-containing particle of these shapes.

In this embodiment, it is preferable to contain two or more types selected from spherical, flake, scale, aggregate, and polyhedral-shaped silver-containing particles. As a result, since the contact rate between silver-containing particles is further improved, a network is easily formed after sintering of the silver-containing paste, and heat dissipation is more suitable in an electronic device using the silver-containing paste of the present embodiment. do.

In addition, in this embodiment, “spherical shape” is not limited to a perfect sphere, but also includes a shape with slight irregularities on the surface, etc.

The surface of the silver-containing particles may be treated with carboxylic acid, a saturated fatty acid with 4 to 30 carbon atoms, a monovalent unsaturated fatty acid with 4 to 30 carbon atoms, or a long-chain alkylnitrile.

The silver-containing particles may be (i) silver particles (silver powder) substantially composed only of silver, or (ii) particles composed of silver and components other than silver. Additionally, (i) and (ii) may be used together as metal-containing particles.

In this embodiment, the particles composed of silver and components other than silver may include silver-coated resin particles whose surfaces are coated with silver. In silver-coated resin particles, the silver layer may cover at least a portion of the surface of the resin particles. Of course, silver may cover the entire surface of the resin particle. Examples of such silver-coated resin particles include silver-plated silicone resin.

Examples of the “resin” in the silver-coated resin particles include silicone resin, (meth)acrylic resin, phenol resin, polystyrene resin, melamine resin, polyamide resin, and polytetrafluoroethylene resin. Of course, resins other than these may be used. Moreover, only one type of resin may be used, and two or more types of resin may be used together.

The silicone resin may be particles composed of organopolysiloxane obtained by polymerizing organochlorosilane such as methylchlorosilane, trimethyltrichlorosilane, and dimethyldichlorosilane. Moreover, a silicone resin whose basic skeleton has a structure obtained by additionally three-dimensionally crosslinking organopolysiloxane may be used.

The (meth)acrylic resin may be a resin obtained by polymerizing a monomer containing (meth)acrylic acid ester as a main component (50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more). Examples of (meth)acrylic acid ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and Uryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-propyl (meth)acrylate, chloro-2-hydroxyethyl (meth)acrylate, diethylene glycol mono(meth)acrylate, methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, dicyclofentanyl (meth)acrylate, dicyclopentenyl ( At least one compound selected from the group consisting of meth)acrylate and isobornyl (meth)acrylate can be mentioned. Additionally, the monomer component of the acrylic resin may contain a small amount of other monomers.

Various functional groups may be introduced into silicone resin or (meth)acrylic resin. The functional group that can be introduced is not particularly limited. For example, epoxy group, amino group, methoxy group, phenyl group, carboxyl group, hydroxyl group, alkyl group, vinyl group, mercapto group, etc.

The portion of the resin particle in the silver-coated resin particle may contain various additive components, such as a low stress modifier. As low-stress modifiers, butadiene styrene rubber, butadiene acrylonitrile rubber, polyurethane rubber, polyisoprene rubber, acrylic rubber, fluorine rubber, liquid organopolysiloxane, liquid polybutadiene, etc. Liquid synthetic rubber, etc. can be mentioned.

The median diameter D ₅₀ of the silver-containing particles is, for example, 0.001 to 1000 μm, preferably 0.01 to 100 μm, and more preferably 0.1 to 20 μm. By setting D ₅₀ to an appropriate value, it is easy to achieve a balance between thermal conductivity, sinterability, resistance to heat cycles, etc. Additionally, by setting D ₅₀ to an appropriate value, the workability of coating/adhering can be improved.

The particle size distribution (horizontal axis: particle diameter, vertical axis: frequency) of the silver-containing particles may be unimodal or multimodal.

(i) The median diameter D ₅₀ of particles made substantially only of silver is, for example, 0.8 μm or more, preferably 1.0 μm or more, and more preferably 1.2 μm or more. As a result, the sintering structure can be made strong, and the adhesion between the lead frame and the chip can be made more suitable in the electronic device using the silver-containing paste in this embodiment.

Additionally, (i) the median diameter D ₅₀ of the particles substantially consisting only of silver is, for example, 10.0 μm or less, preferably 8.0 μm or less, and more preferably 6.0 μm or less. As a result, it is possible to further improve the ease of sintering, improve the uniformity of sintering, etc.

(ii) The median diameter D ₅₀ of the particles made of silver and components other than silver is, for example, 0.5 μm or more, preferably 1.5 μm or more, and more preferably 2.0 μm or more. Thereby, it is easy to set the storage modulus to an appropriate value.

Moreover, (ii) the median diameter D ₅₀ of the particles made of silver and components other than silver is, for example, 20 μm or less, preferably 15 μm or less, and more preferably 10 μm or less. As a result, it is possible to further improve the ease of sintering, improve the uniformity of sintering, etc.

The median diameter D ₅₀ of the silver-containing particles can be determined, for example, by performing particle image measurement using a flow-type particle image analysis device FPIA (registered trademark)-3000 manufactured by Sysmex Corporation. More specifically, the particle size of the silver-containing particles can be determined by measuring the median diameter on a volume basis using this device in a wet manner.

The content of silver-containing particles in the silver-containing paste is preferably 80.0 mass% or more and 99.0 mass% or less, more preferably 82.5 mass% or more and 97.5 mass% or less, more preferably 80.0 mass% or more and 99.0 mass% or less, based on 100 mass% of solid content excluding the solvent described later. In other words, it is 85.0 mass% or more and 95 mass% or less.

When the content of silver-containing particles in the silver-containing paste of this embodiment is within the range, the sintering structure can be made strong, and in the electronic device using the silver-containing paste of this embodiment, a lead frame And the adhesion between chips can be made more suitable.

Among the silver-containing particles, particles substantially consisting only of silver can be obtained from, for example, DOWA High Tech, Fukuda Kinzoku Hakuhun Kogyo, etc. In addition, silver-coated resin particles can be obtained from, for example, Mitsubishi Materials, Sekisui Chemicals, Sanno Co., Ltd., etc.

In this embodiment, the specific surface area of the silver-containing particles is preferably 0.10 m ² /g or more, more preferably 0.15 m ² /g or more, and still more preferably 0.20 m ² /g or more. The upper limit is not particularly limited, but may be 2.0 m ² /g or less from the viewpoint of availability. The specific surface area of silver-containing particles is the average value when two or more types of silver-containing particles are included. The specific surface area of the silver-containing particles is the BET specific surface area measured using an automatic specific surface area measuring device.

When the specific surface area of the silver-containing particles of the present embodiment is within the range, the sintering structure can be made strong, and in the electronic device using the silver-containing paste of the present embodiment, the adhesion between the lead frame and the chip is improved. This can be done with something more suitable.

In this embodiment, from the viewpoint of the effect of the present invention, it is more preferable to use two or more types of silver-containing particles with different specific surface areas.

In addition, the tap density of the silver-containing particles is preferably 4.0 g/cm ³ or more, more preferably 4.5 g/cm ³ or more, further preferably 5.0 g/cm ³ or more, particularly preferably 5.5 g/cm 3 or more. It can be done with ³ or more. The upper limit is not particularly limited, but can be set to 8.0 g/cm ³ or less.

Tap density is measured according to ISO 3953-1985(E) “Method for measuring metal powder-tap density.”

With this tap density, it is easy to set the paste viscosity to an appropriate value.

[Cyanamide derivative]

The silver-containing paste according to the present embodiment further contains a cyanamide derivative.

As described above, the cyanamide derivative improves the affinity between the silver-containing particles and the lead frame and chip, and consequently improves the adhesion between the lead frame and chip during sintering.

Usually, cyanamide derivatives act as a curing accelerator when added to the multifunctional compound described later. On the other hand, the cyanamide derivative in the present embodiment has a function as an adhesion aid to improve the adhesion between the lead frame and the chip, and by further adding a curing accelerator other than the cyanamide derivative, the silver according to the present embodiment It is possible to achieve both the mechanical properties of the containing paste and the adhesion between the lead frame and the chip.

Examples of cyanamide derivatives include dicyandiamide; guanidine; Guanidine salts such as guanidine sulfamate and guanidine phosphate; melamine; Dicyandiamidine, biguanide, etc. can be mentioned. These may be used individually or in combination of two or more. Among these, from the viewpoint of adhesion between the lead frame and chip during sintering, it is preferable to include one or two or more types selected from dicyandiamide, guanidine, guanidine salt, melamine, and dicyandiamidine, Dicyanediamide is more preferred.

The upper limit of the content of the cyanamide derivative is preferably 3 parts by mass or less, more preferably 2.7 parts by mass or less, when the content of the polyfunctional compound according to the present embodiment described later is 100 parts by mass. Typically, it is 2.5 parts by mass or less. By setting the content of the cyanamide derivative below the above upper limit, the heat dissipation properties of the silver-containing paste can be made more suitable.

The lower limit of the content of the cyanamide derivative is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, when the content of the polyfunctional compound according to the present embodiment described later is 100 parts by mass. Typically, it is 0.1 part by mass or more. By setting the content of the cyanamide derivative to the above lower limit or more, the adhesion between the lead frame and the chip during sintering can be made more suitable.

[solvent]

The silver-containing paste according to this embodiment further contains a solvent.

By using a solvent, for example, the fluidity of the silver-containing paste can be adjusted and the workability when forming an adhesive layer on a substrate can be improved.

Solvents include, for example, ethyl alcohol, propyl alcohol, butyl alcohol, pentyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether. , ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol Monobutyl ether, methyl methoxybutanol, α-terpineol, β-terpineol, hexylene glycol, benzyl alcohol, 2-phenylethyl alcohol, isopalmityl alcohol, isostearyl alcohol, lauryl Alcohols such as ethylene glycol, propylene glycol, ethylhexyl glycol, butylpropylene triglycol, or glycerin; Acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diacetone alcohol (4-hydroxy-4-methyl-2-pentanone), 2-octanone, isophorone (3,5,5-trimethyl Ketones such as -2-cyclohexen-1-one) or diisobutyl ketone (2,6-dimethyl-4-heptanone); Ethyl acetate, butyl acetate, diethyl phthalate, dibutyl phthalate, acetoxyethane, methyl butyrate, methyl hexanoate, methyl octanoate, methyl decanoate, methyl cellosolve acetate, ethylene glycol monobutyl ether acetate, Esters such as propylene glycol monomethyl ether acetate, 1,2-diacetoxyethane, tributyl phosphate, tricresyl phosphate, or tripentyl phosphate; Tetrahydrofuran, dipropyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, ethoxyethyl ether , ethers such as 1,2-bis(2-diethoxy)ethane or 1,2-bis(2-methoxyethoxy)ethane; Ester ethers such as acetic acid 2-(2-butoxyethoxy)ethane; ether alcohols such as 2-(2-methoxyethoxy)ethanol; Hydrocarbons such as toluene, xylene, n-paraffin, isoparaffin, dodecylbenzene, turpentine, kerosene, or light oil; Nitriles such as acetonitrile or propionitrile; Amides such as acetamide or N,N-dimethylformamide; Examples include low molecular weight volatile silicone oil or volatile organic modified silicone oil.

These may use only one type of solvent, or may use two or more types of solvents together.

The boiling point of the solvent is preferably 150°C or higher, more preferably 170°C or higher, and even more preferably 200°C or higher. The upper limit of the boiling point is not particularly limited as long as it disappears through sintering, and in this embodiment, it can be 300°C or lower.

By keeping the boiling point of the solvent within the above range, workability when adhering a silver-containing paste to a substrate can be made more suitable.

The solvent may be included in 100 mass% of the silver-containing paste of the present embodiment, preferably 1 mass% or more and 10 mass% or less, more preferably 2 mass% or more and 8 mass% or less. By keeping the solvent content within the above range, workability when adhering a silver-containing paste to a substrate can be made more suitable.

[Multifunctional compounds]

The silver-containing paste according to this embodiment contains a polyfunctional compound.

The polyfunctional compound according to the present embodiment is at least one or both of (A) an epoxy compound having two or more epoxy groups in the molecule, and (B) a (meth)acrylic compound containing two or more polymerizable double bonds in the molecule. It is a multifunctional compound made up of By using a multifunctional compound, it becomes easy to form a sintering structure between silver-containing particles due to the aggregation effect of the resin.

The epoxy compounds according to the present embodiment include, for example, phenol novolak-type epoxy compounds, cresol novolac-type epoxy compounds, cresolnaphthol-type epoxy compounds, biphenyl-type epoxy compounds, biphenyl aralkyl-type epoxy compounds, phenoxy compounds, Naphthalene skeletal epoxy compound, bisphenol A type epoxy compound, bisphenol F type epoxy compound, diallyl bisphenol A type epoxy compound, bisphenol A type diglycidyl ether type epoxy compound, bisphenol F type diglycidyl ether type epoxy compound, Bisphenol S type diglycidyl ether type epoxy compound, o-allyl bisphenol A type diglycidyl ether, 3,3',5,5'-tetramethyl 4,4'-dihydroxybiphenyl diglycy Diel ether type epoxy compound, 1,1,2,2-tetrakis(hydroxyphenyl)ethane type epoxy compound, 4,4'-dihydroxybiphenyl diglycidyl ether type epoxy compound, bromine type cresol novolak Epoxy compounds such as bisphenol D diglycidyl ether type epoxy compounds, glycidyl ether of 1,6-naphthalenediol, and triglycidyl ether of aminophenols can be mentioned. These may be used individually or in combination of two or more. Moreover, among these, it is preferable to contain one type or both selected from a bisphenol A-type epoxy compound and a bisphenol F-type epoxy compound, and it is more preferable to contain a bisphenol F-type epoxy compound. By selecting the epoxy compound from the above types, the ease of sintering can be further improved, the sintering uniformity can be improved, etc.

Additionally, the epoxy compound can be either solid or liquid at 25°C.

Examples of the (meth)acrylic compound according to the present embodiment include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, and triethylene glycol di(meth)acrylate. , bifunctional (meth)acrylates such as tetraethylene glycol di(meth)acrylate and polyethylene glycol di(meth)acrylate; tri- or more-functional polyfunctional (meth)acrylates such as trimethylolpropane tri(meth)acrylate and pentaerythritol tri(meth)acrylate; Bifunctional or higher epoxy (meth)acrylate; Bifunctional or higher urethane (meth)acrylate; Bifunctional or higher polyester (meth)acrylate can be mentioned. These may be used individually or in combination of two or more. Moreover, among these, it is preferable to include one or both of them selected from difunctional (meth)acrylate and trifunctional or more polyfunctional (meth)acrylate, such as ethylene glycol di(meth)acrylate and diethylene. Bifunctional (meth)acrylate such as glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and polyethylene glycol di(meth)acrylate. ) It is more preferable that it contains acrylate, and it is more preferable that it contains ethylene glycol di(meth)acrylate. By selecting a (meth)acrylic compound from the above types, the ease of sintering can be further improved, the sintering uniformity can be improved, etc.

In the present embodiment, the lower limit of the content of the polyfunctional compound is not particularly limited, but for example, it may be contained in 1% by mass or more, 3% by mass or more, or 5% by mass, based on the total solid content of the silver-containing paste. You may include more than %. As a result, appropriate mechanical properties as a cured product can be exhibited.

In addition, the upper limit of the content of the polyfunctional compound is not particularly limited, but for example, it may be contained in 20% by mass or less, 15% by mass or less, and 10% by mass or less with respect to the total solid content of the silver-containing paste. do.

In this embodiment, the lower limit of the glass transition temperature (Tg) of the cured product of the polyfunctional compound is not particularly limited, but may be, for example, 60°C or higher, 65°C or higher, or 70°C or higher. do. The upper limit of this glass transition temperature (Tg) is not particularly limited, but may be, for example, 300°C or lower, 290°C or lower, or 280°C or lower. Thereby, heat resistance is obtained.

In this embodiment, as a method for measuring the glass transition temperature, for example, a thermomechanical analysis device (TMA SS7100, manufactured by SII Nanotechnology) is used.

[Other ingredients]

The silver-containing paste according to the present embodiment may optionally contain a curing agent, a curing accelerator, a plasticizer, an initiator, an antioxidant, a dispersant, an inorganic filler such as silica or alumina, another elastomer such as a silicone resin or butadiene rubber, a coupling agent, Components such as an initiator, antifoaming agent, leveling agent, and fine silica (thixoadjuster) may be added. The content of these components can be appropriately set depending on the purpose for which the silver-containing paste is applied.

(hardener)

The silver-containing paste according to the present embodiment may contain, for example, a curing agent. The curing agent is not particularly limited as long as it promotes the polymerization reaction of a polyfunctional compound (for example, an epoxy compound). As a result, the polymerization reaction of the multifunctional compound can be promoted, contributing to the improvement of mechanical properties obtained by using the silver-containing paste.

The curing agent of the present embodiment can be appropriately selected and used among known curing agents for polyfunctional compounds. Specifically, examples include phenol resin-based curing agents, amine-based curing agents, acid anhydride-based curing agents, and mercaptan-based curing agents. These may be used individually or two or more types may be used in combination.

Examples of the phenol resin-based curing agent include novolak-type phenols such as phenol novolak resin, cresol novolak resin, naphthol novolak resin, aminotriazine novolak resin, novolak resin, and trisphenylmethane-type phenol novolak resin. profit; Modified phenol resins such as terpene-modified phenol resins and dicyclopentadiene-modified phenol resins; Aralkyl type resins such as phenol aralkyl resin having a phenylene skeleton and/or biphenylene skeleton, and naphthol aralkyl resin having a phenylene skeleton and/or biphenylene skeleton; Bisphenol resins having a bisphenol skeleton such as bisphenol A and bisphenol F; A resol-type phenol resin or the like can be used. These may be used individually or in combination of two or more. Moreover, among these, those containing bisphenol resins having a bisphenol skeleton such as bisphenol A and bisphenol F are preferable, and bisphenol resins having a bisphenol F skeleton are more preferable. By selecting the curing agent from the above types, the mechanical properties obtained using the silver-containing paste can be improved, and the adhesion between the lead frame and the chip can be improved.

The amine-based curing agent may include, for example, a compound having a tertiary amino group. Compounds having a tertiary amino group include, for example, tertiary amines such as benzyldimethylamine (BDMA), and imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole (EMI24). , pyrazoles such as pyrazole, 3,5-dimethylpyrazole, pyrazoline, triazole, 1,2,3-triazole, 1,2,4-triazole, 1,2,3-benzotriazole Imidazolines such as triazoles, imidazoline, 2-methyl-2-imidazoline, and 2-phenylimidazoline may be included, and may include one or two or more types selected from these. You can.

The upper limit of the content of the curing agent contained in the silver-containing paste according to the present embodiment is not particularly limited, but, for example, is preferably 25 parts by weight or less, and is preferably 5 parts by weight or less per 100 parts by weight of the polyfunctional compound. Preferred, 3 parts by weight or less is more preferable, and 1 weight part or less is particularly preferable. The lower limit of the content of this curing agent is not particularly limited, but for example, 0 part by weight or more is preferable, and from the viewpoint of improving the mechanical properties of the silver-containing paste, 0.1 part by weight or more is more preferable.

(curing accelerator)

The silver-containing paste according to the present embodiment may contain a curing accelerator. Here, the curing accelerator may include a curing accelerator other than the cyanamide derivative described above. The curing accelerator according to the present embodiment is not particularly limited, and examples include polyamine-based curing accelerators, imidazole-based curing accelerators, and salts of triphenylphosphine or tetraphenylphosphine. Among these, the curing accelerator according to the present embodiment preferably contains at least one selected from polyamine-based curing accelerators and imidazole-based curing accelerators, and more preferably contains an imidazole-based curing accelerator.

The upper limit of the content of the curing accelerator contained in the silver-containing paste according to the present embodiment is not particularly limited, but for example, it is preferably 5 parts by weight or less, and 4 parts by weight or less per 100 parts by weight of the polyfunctional compound. It is more preferable, 3 parts by weight or less is more preferable, and 2 parts by weight or less is still more preferable. In addition, the lower limit of the content of the curing accelerator is not particularly limited, but for example, 0 parts by weight or more is preferable, and from the viewpoint of improving the mechanical properties of the silver-containing paste, 0.1 parts by weight or more is preferable, and 0.3 parts by weight or more is preferable. More is more preferable, and 0.5 parts by mass or more is more preferable.

(plasticizer)

The silver-containing paste according to the present embodiment may contain a plasticizer. The plasticizer according to the present embodiment is not particularly limited, but includes, for example, polyalkylene glycol plasticizers such as aromatic carboxylic acid esters, aliphatic monocarboxylic acid esters, aliphatic dicarboxylic acid esters, aliphatic tricarboxylic acid esters, phosphoric acid triesters, and petroleum resins. , epoxy plasticizer, castor oil-based plasticizer, neopentyl glycol dibenzoate, diethylene glycol dibenzoate, triethylene glycol di-2-ethylbutyrate, polyoxyethylene diacetate, polyoxyethylene diacetate. (2-ethylhexanoate), polyol esters such as polyoxypropylene monolaurate, polyoxypropylene monostearate, polyoxyethylene dibenzoate, and polyoxypropylene dibenzoate, aliphatic carboxylic acid esters such as butyl oleate, and acetyl Oxy acid esters such as triethyl citrate, tributyl acetylcitrate, ethoxycarbonylmethyl dibutyl citrate, di-2-ethylhexyl citrate, methyl acetylricinoleate or butyl acetylricinoleate, soybean oil, soybean oil fatty acid, soybean oil fatty acid Ester, epoxidized soybean oil, rapeseed oil, rapeseed oil fatty acid, rapeseed oil fatty acid ester, epoxidized rapeseed oil, linseed oil, linseed oil fatty acid, linseed oil fatty acid ester, epoxidized linseed oil, plant oil-based compounds such as palm oil or palm oil fatty acid, pentaerythritol, Soritol, polyacrylic acid ester, silicone oil or paraffin, olefin oxide, butyl glycidyl ether, hexyl glycidyl ether, 2-ethylhexyl glycidyl ether, alkyl glycidyl ether, alkyl phenol mono. Glycidyl ether, cresyl glycidyl ether, p-n-butyl-phenyl glycidyl ether, p-tert-butyl-phenyl glycidyl ether, nonylphenyl glycidyl ether, palm fatty acid glycidyl ether Dyl ether, allyl glycidyl ether, glycidyl, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, alkane acid glycidyl ester, Ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, etc. are mentioned.

The content of the plasticizer is preferably 5% by mass or less, and more preferably 2% by mass or less, based on the total mass of the silver-containing paste. If the content of the plasticizer is below the above upper limit, the adhesiveness of the silver-containing paste can be made more suitable. Moreover, the lower limit of the content of the plasticizer is not particularly limited, but is, for example, 0% by mass or more.

(Coupling agent)

The silver-containing paste according to the present embodiment may contain a coupling agent. The coupling agent according to the present embodiment is not particularly limited, and examples include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, and dimethyldimethoxysilane. Ethoxysilane, phenyltriethoxysilane, n-propyltriethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane alkoxysilanes such as; chlorosilanes such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, and phenyltrichlorosilane; hexamethyldisilazane; Methacryloxypropyltriethoxysilane, Methacryloxypropyltrimethoxysilane, Methacryloxypropylmethyldiethoxysilane, Methacryloxypropylmethyldimethoxysilane, Vinyltriethoxysilane, Vinyl Alkoxysilanes such as trimethoxysilane, vinylmethyldimethoxysilane, and glycidoxypropyltrimethoxysilane; chlorosilanes such as vinyltrichlorosilane and vinylmethyldichlorosilane; Divinyltetramethyldisilazane can be mentioned.

The content of the coupling agent contained in the silver-containing paste according to the present embodiment is preferably 5 parts by mass or less, and is more preferably 4 parts by mass or less, when the mass of the polyfunctional compound in the silver-containing paste is 100 parts by mass. It is preferable, and 3 parts by mass or less is more preferable. If the content of the coupling agent is below the above upper limit, the adhesiveness of the silver-containing paste can be made more suitable.

(initiator)

The silver-containing paste according to the present embodiment may contain an initiator. Examples of the initiator include a radical polymerization initiator. As a result, for example, when the compound to be polymerized by heating includes a compound having a radically polymerizable double bond in the molecule, polymerization of the compound can be promoted. Radical polymerization initiators include, for example, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, oxalic acid peroxide, 2,5 -Dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, 1-cyclohexyl-1-methylethylperoxy 2-ethylhexanoate, tert-hexylperoxy 2-ethylhexanoate , tert-butyl peroxy 2-ethylhexanoate, m-toluyl peroxide, benzoyl peroxide, methyl ethyl ketone peroxide, acetyl peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, cumenhyde. It may include one or two or more types selected from roperoxide, dicumyl peroxide, tert-butyl perbenzoate, parachlorobenzoyl peroxide, and cyclohexanone peroxide.

The content of the initiator contained in the silver-containing paste according to the present embodiment is preferably 10 parts by mass or less, more preferably 7 parts by mass, when the mass of the polyfunctional compound in the silver-containing paste is 100 parts by mass. or less, more preferably 5 parts by mass or less. If the content of the initiator is below the above upper limit, the mechanical properties of the silver-containing paste can be made more suitable. Moreover, the lower limit of the content of the initiator contained in the silver-containing paste according to the present embodiment is not particularly limited, but when the mass of the polyfunctional compound in the silver-containing paste is 100 parts by mass, it is preferably 0.5 parts by mass or more. , more preferably 1 part by mass or more, further preferably 2 parts by mass or more.

<Properties and properties of silver-containing paste>

Next, the properties and physical properties of the silver-containing paste according to the present embodiment will be described.

The silver-containing paste according to the present embodiment is preferably in a paste form at 20°C. That is, the silver-containing paste according to the present embodiment can adhere to a substrate or the like like glue, preferably at 20°C. As a result, the silver-containing paste according to the present embodiment can be suitably used as an adhesive for semiconductor elements, etc.

Of course, depending on the applied process, etc., the silver-containing paste according to the present embodiment may be in the form of a relatively low viscosity varnish or the like.

Using the silver-containing paste according to the present embodiment, the lower limit of the die shear strength measured according to the following <Measurement Method> is preferably 1.5 N/mm ² or more at 260°C, and more preferably 1.9 N/mm 2 or more. mm ² or more, more preferably 2.2N/mm ² or more. As a result, the adhesion strength to the lead frame when using the silver-containing paste according to the present embodiment increases, and the adhesion between the lead frame and the chip can be improved.

<Measurement method>

A silver-containing paste is applied on a copper substrate to form a coating film, and a 7×7 mm silicon chip with a gold-plated surface is placed on the coating film. After that, the temperature is raised from 30°C to 200°C over 60 minutes, and then heat treatment is performed at 200°C for 120 minutes. As described above, the silver-containing paste is cured, and the silicon chip is bonded to the substrate.

Thereafter, the measurement sample is treated in a constant temperature and humidity bath at 60°C and 60% humidity for 48 hours, and the die shear strength (N/mm ² ) is measured at 260°C using a die shear tester.

In addition, the upper limit of the die shear strength is not particularly limited, but is, for example, 100 N/mm ² or less at 260°C.

In this embodiment, as a method for measuring die shear strength, for example, a die shear tester (DAGE-4000 type, manufactured by Nordson Advanced Technology Co., Ltd.) can be used.

In a preferred aspect of the present embodiment, the silver-containing paste according to the present embodiment has a lower limit value of 0.5 rpm viscosity η _0.5 when measured using a BF type viscometer at a temperature of 25° C. and a shear rate of 0.5 rpm, It is preferably 20 Pa·s or more, more preferably 25 Pa·s or more, and even more preferably 30 Pa·s or more. This prevents the silver-containing paste from expanding onto the substrate when affixed, thereby preventing short circuits with chips of other systems.

In addition, the upper limit of η _0.5 is not particularly limited, but is, for example, 300 Pa·s or less.

In a preferred aspect of the present embodiment, the lower limit of the 5 rpm viscosity η ₅ when measured using a BF type viscometer at a temperature of 25°C and a shear rate of 5 rpm using a BF type viscometer is 5 Pa. It is preferably s or more, more preferably 5.5 Pa·s or more, and even more preferably 6 Pa·s or more. This prevents the silver-containing paste from expanding onto the substrate when affixed, thereby preventing short circuits with chips of other systems.

In addition, the upper limit of η ₅ is not particularly limited, but for example, it is 40 Pa·s or less, may be 35 Pa·s or less, and may be 30 Pa·s or less.

In a preferred aspect of the present embodiment, the lower limit of the viscosity ratio of the η ₅ and the η _0.5 expressed by the following formula (1) in the silver-containing paste according to the present embodiment is preferably 2 or more, and more preferably is 2.5 or more, and more preferably 3 or more.

Viscosity ratio = η _0.5 /η ₅ (1)

When the viscosity ratio is more than the above lower limit, workability when adhering a silver-containing paste to a substrate can be made more suitable.

In addition, the upper limit of the viscosity ratio is not particularly limited, but is, for example, 10 or less.

In a preferred aspect of the present embodiment, the lower limit of the storage elastic modulus of the silver-containing paste according to the present embodiment is preferably 2000 MPa or more as measured at a frequency of 1 Hz and a temperature of 25°C using a dynamic viscoelasticity measuring device. , more preferably 2500 MPa or more, more preferably 3000 MPa or more, and still more preferably 4000 MPa or more. When the storage elastic modulus is more than the above lower limit, the stability of the connection between the lead frame and the chip using the silver-containing paste can be made more suitable.

Moreover, the upper limit of the storage modulus is preferably 20,000 MPa or less, more preferably 17,500 MPa or less, further preferably 15,000 MPa or less, further preferably 10,000 MPa or less, and even more preferably 8,000 MPa or less. When the storage elastic modulus is below the upper limit, the adhesion strength to the lead frame when using the silver-containing paste according to this embodiment increases, and the adhesion between the lead frame and the chip can be improved.

Additionally, as a dynamic viscoelasticity measuring device used to measure the storage elastic modulus, a known device can be used. Known devices include, for example, the dynamic viscoelasticity measuring device DMS6100 manufactured by SII Nanotechnology, Inc., and the dynamic viscoelasticity measuring device HAAKE MARS manufactured by THERMO SCIENTIFIC.

In a preferred aspect of the present embodiment, the lower limit of the thermal conductivity of the silver-containing paste according to the present embodiment as measured by the laser flash method is preferably 10 W/mK or more, and more preferably 12 W/mK or more, More preferably, it is 14W/mK or more. When the thermal conductivity is more than the above lower limit, high-temperature reliability becomes more suitable in the electronic device using the silver-containing paste in this embodiment.

Additionally, the upper limit of the thermal conductivity is not particularly limited, but is, for example, 200 W/mK or less.

Additionally, a known device can be used as a laser flash method thermal constant measurement device used to measure thermal conductivity. Known devices include, for example, the laser flash method thermal constant measurement device LFA447 manufactured by NETZSCH.

<Use of silver-containing paste>

The silver-containing paste according to this embodiment can be used for various uses. Examples include die attach materials and conductive pastes. As a die attach material, for example, it may be used in electronic devices, and more preferably, it may be used in semiconductor devices. Typical examples of conductive pastes include jumper circuits and through-hole conductors of printed circuit boards, additive circuits, conductor circuits of touch panels, resistor terminals, solar cell electrodes, tantalum capacitor electrodes, film capacitor electrodes, and chip-type ceramics. Examples include formation of external electrodes or internal electrodes of electronic components, use as an electromagnetic wave shield, etc. In addition, as a replacement for solder, in addition to use as a conductive adhesive for mounting semiconductor elements and electronic components on a board, it is also used as a replacement for the solder portion of a grid electrode of a type that covers the surface of the high-temperature fired silver electrode of a solar cell with solder. You can also use it.

The silver-containing paste according to the present embodiment can be cured into a cured product. The cured product of this embodiment can be used for various purposes. For example, it is used in electronic devices. That is, the electronic device according to the present embodiment includes a cured body of the silver-containing paste of the present embodiment and an electronic component to which the cured body is bonded.

Since the cured product of this embodiment contains silver particles, it can be applied to parts of various electronic devices in which electrodes and wiring are formed. Additionally, it can be suitably used for filling through holes and via holes of printed wiring boards.

Of course, the uses mentioned here are examples of embodiments, and it goes without saying that applications other than these can be applied while adjusting the composition of the silver-containing paste.

<Method for producing silver-containing paste>

Next, the manufacturing method of the silver-containing paste according to this embodiment will be described.

The silver-containing paste of this embodiment can be manufactured by kneading and mixing each of the components described above. This mixing may be performed using, for example, a kneading device such as a kneader, a three-roll mill, or a nozzle, or various stirring devices.

In addition, the method for producing a cured body of the silver-containing paste according to the present embodiment includes a step of preparing the silver-containing paste according to the present embodiment by mixing silver particles and a resin, and heat-treating the silver-containing paste to prepare the silver particle. It has a process that causes sintering to form a particle-connected structure.

In this embodiment, since a resin having characteristics that assist sintering is selected, it becomes possible to improve manufacturing process characteristics, such as lowering the sintering temperature or shortening the sintering time in the curing process. . That is, even if low temperature or short-time sintering conditions are adopted in the curing process, it becomes possible to achieve both low resistance and adhesion to the silver-containing paste.

The silver-containing paste according to the present embodiment is preferably sintered by heat treatment at 260°C or lower and 160°C or higher. In this embodiment, the upper limit of the sintering temperature is not particularly limited, but for example, 260°C or lower is preferable, 250°C or lower is more preferable, and 240°C or lower is particularly preferable. In addition, the lower limit of the sintering temperature is not particularly limited, but for example, 160°C or higher is preferable, 165°C or higher is more preferable, and 170°C or higher is particularly preferable.

Moreover, in this embodiment, the lower limit of the sintering time is not particularly limited, but for example, 15 minutes or more is preferable, 18 minutes or more is more preferable, and 20 minutes or more is still more preferable. The upper limit of the sintering time is not particularly limited, but for example, 60 minutes or less is preferable, 55 minutes or less is more preferable, and 50 minutes or less is particularly preferable.

Although embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted. In addition, the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. within the range that can achieve the purpose of the present invention are included in the present invention.

Example

[Preparation of varnish]

For each Examples 1 to 4 and Comparative Examples 1 to 3, varnishes were prepared. This preparation was performed by uniformly mixing each component according to the formulation shown in Table 1. In addition, the details of the components shown in Table 1 are as follows. In addition, each component in Table 1 is indicated by the number of blended ingredients. “-” in the table indicates measurement is not possible.

(Epoxy compound)

Epoxy compound 1: Bisphenol F type liquid epoxy compound, RE-303S, manufactured by Nippon Kayaku Co., Ltd.

(acrylic compound)

Acrylic compound 1: ethylene glycol dimethacrylate, light ester EG, manufactured by Kyoei Chemical Co., Ltd.

(hardener)

Curing agent 1: Bisphenol resin with bisphenol F skeleton, DIC-BPF (solid at room temperature 25°C), manufactured by DIC Corporation

(Cyanamide derivative)

Cyanamide derivative 1: Dicyandiamide, EH-3636AS, manufactured by ADEKA Co., Ltd.

(curing accelerator)

Curing accelerator 1: Polyamine-based curing accelerator, EH-5057P, manufactured by Adeka Co., Ltd.

Curing accelerator 2: Imidazole-based curing accelerator, 2PHZ-PW, manufactured by Shikoku Kasei Co., Ltd.

(initiator)

Initiator 1: Dicumyl Peroxide, Pacadox BC, Kayaku Nurion Co., Ltd.

[Preparation of silver-containing paste]

Next, a silver-containing paste was prepared using the varnishes prepared in each of Examples 1 to 4 and Comparative Examples 1 to 3. 13.0 parts by mass of the varnish prepared in each of Examples 1 to 4 and Comparative Examples 1 to 3, silver powder as silver-containing particles (scale-shaped silver, D ₅₀ : 6.0 μm, manufactured by Fukuda Kinzoku Hakuhun Kogyo Co., Ltd., sintering temperature: 200 ℃, tap density: 5.5 g/cm ³ , specific surface area: 0.2 m ² /g) 65 parts by mass, silver-plated silicone resin particles (manufactured by Mitsubishi Materials, heat-resistant/surface-treated 10 μm product, spherical shape, D ₅₀ : 10 μm, sintered) Temperature: 210°C, tap density: 5.5g/cm ³ ) A total of 100 parts by mass of 20 parts by mass and 2.0 parts by mass of butylpropylene triglycol (BFTG, manufactured by Nippon New Kazai Co., Ltd., boiling point: 274°C) as a solvent were mixed, The silver-containing pastes in each of Examples 1 to 4 and Comparative Examples 1 to 3 were used.

[evaluation]

Each Example and each Comparative Example was evaluated using the following method. The results are shown in Table 1.

(thermal conductivity)

The silver-containing pastes in Examples 1 to 4 and Comparative Examples 1 to 3 were applied to a square mold with a thickness of about 1 mm and a side length of 10 mm, the temperature was raised from 30°C to 200°C over 60 minutes, and then the temperature was increased to 200°C. A test piece of the cured product was prepared by heating at ℃ for 120 minutes. After preparing the cured product test piece, the thermal diffusivity was measured using a laser flash method thermal constant measuring device LFA447 manufactured by NETZSCH, and the thermal conductivity was calculated from the specific heat and specific gravity.

(Volume resistivity)

The silver-containing paste in each of Examples 1 to 4 and Comparative Examples 1 to 3 was applied on a substrate to a thickness of 0.1 mm × width 4 mm × length 50 mm, and the temperature was raised from 30°C to 200°C over 60 minutes. It was then heated at 200°C for 120 minutes. Next, the resistance value was measured by placing the measurement terminals on the top and bottom of the board. The measured length was 40 mm. Afterwards, the measured resistance value was converted into volume resistivity.

(storage modulus)

The silver-containing paste in each of Examples 1 to 4 and Comparative Examples 1 to 3 was applied to a mold measuring about 0.1 mm A strip-shaped sample for evaluation was obtained by heating at ℃ for 120 minutes. Using this sample, the storage elastic modulus (E') at 25°C was measured by DMA (dynamic viscoelasticity measurement, DMS6100 manufactured by SII Nanotechnology, tensile mode) under the conditions of a temperature increase rate of 5°C/min and a frequency of 1Hz.

(viscosity)

For the silver-containing pastes in each of Examples 1 to 4 and Comparative Examples 1 to 3, the viscosity at room temperature 25°C was measured using a BF type viscometer (manufactured by Brookfield Engineering, model DV3T), Measurements were made immediately after production of the silver-containing paste. As for the measurement order at this time, measurement was performed in the order of shear rate of 0.5 rpm, followed by shear rate of 5 rpm. The unit of viscosity is Pa·s.

(adhesion)

As an indicator of adhesion, die shear strength was measured by the following method.

The silver-containing pastes in each of Examples 1 to 4 and Comparative Examples 1 to 3 were applied onto a copper substrate, and a 7 mm x 7 mm x 0.35 mm silicon chip with surface gold plating was mounted on it so that the paste thickness was 15 μm. After that, the temperature was raised from 30°C to 200°C over 60 minutes, and then heat treatment was performed at 200°C for 120 minutes. As described above, the silver-containing paste was cured, and the silicon chip was bonded to the substrate.

Thereafter, the measurement sample was treated in a constant temperature and humidity chamber at 60°C and 60% humidity for 48 hours, and using a die shear tester (model DAGE-4000, manufactured by Nordson Advanced Technology Co., Ltd.), test speed: 500 μm. The die shear strength (N/mm ² ) was measured at 260°C under conditions of /sec.

In Examples 1 to 4, the die shear strength with the copper plate was unusually high compared to Comparative Examples 1 to 3, and the silver-containing paste of Examples 1 to 4 contained silver with excellent adhesion between the lead frame and the chip. It was paste.

This application claims priority based on Japanese Patent Application No. 2021-082513 filed on May 14, 2021, and the entire disclosure thereof is incorporated herein by reference.

Claims (12)

silver-containing particles,
cyanamide derivatives,
Solvent,
Among (A) epoxy compounds having two or more epoxy groups in the molecule, and (B) (meth)acrylic compounds containing two or more polymerizable double bonds in the molecule, silver-containing compounds including polyfunctional compounds consisting of at least one or both sides. paste. The silver-containing paste according to claim 1, comprising:
A silver-containing paste wherein the cyanamide derivative includes one or two or more types selected from dicyandiamide, guanidine, guanidine salt, melamine, and dicyandiamidine. The silver-containing paste according to claim 1 or claim 2, comprising:
A silver-containing paste wherein the content of the cyanamide derivative is 0.01 parts by mass or more and 3 parts by mass or less when the content of the polyfunctional compound is 100 parts by mass. The silver-containing paste according to any one of claims 1 to 3,
A silver-containing paste in which the (A) epoxy compound having two or more epoxy groups in the molecule contains one or both of a bisphenol A-type epoxy compound and a bisphenol F-type epoxy compound. The silver-containing paste according to any one of claims 1 to 4, comprising:
further comprising a hardener,
A silver-containing paste in which the curing agent contains a bisphenol resin. The silver-containing paste according to any one of claims 1 to 5, comprising:
A silver-containing paste wherein the silver-containing particles are silver-containing particles that cause sintering at a temperature of 160°C or higher and 260°C or lower. The silver-containing paste according to any one of claims 1 to 6,
A silver-containing paste having a die shear strength of 1.5 N/mm ² or more and 100 N/mm ² or less, as measured according to the <Measurement Method> below.
<Measurement method>
A silver-containing paste is applied on a copper substrate to form a coating film, and a 7×7 mm silicon chip with a gold-plated surface is placed on the coating film. After that, the temperature is raised from 30°C to 200°C over 60 minutes, and then heat treatment is performed at 200°C for 120 minutes. The silver-containing paste was cured as described above, and a silicon chip was bonded to the substrate, which was used as a measurement sample.
Thereafter, the measurement sample was treated in a constant temperature and humidity chamber at 60°C and 60% humidity for 48 hours, and then die sheared at 260°C using a die shear tester (model DAGE-4000, manufactured by Nordson Advanced Technology Co., Ltd.). Shear strength (N/mm ² ) is measured. The silver-containing paste according to any one of claims 1 to 7,
A silver-containing paste whose viscosity η _{0.5 at 0.5 rpm is 20 Pa·s or more and 300 Pa·s or less when the silver-containing paste is measured using a BF type viscometer while stirring at a temperature of 25°C and a shear rate of 0.5} rpm. The silver-containing paste according to any one of claims 1 to 8,
The silver-containing paste has a 5-rpm viscosity η ₅ of 5 Pa·s or more and 40 Pa·s or less, when the silver-containing paste is measured using a BF type viscometer while stirring at a temperature of 25° C. and a shear rate of 5 rpm. The silver-containing paste according to any one of claims 1 to 9,
In the silver-containing paste, the 0.5 rpm viscosity η _0.5 when measured using a BF type viscometer and stirring at a temperature of 25°C and a shear rate of 0.5 rpm, expressed by the formula (1) below, and a BF type viscometer. A silver-containing paste having a viscosity ratio of η ₅ of 2 to 10 as measured while stirring at a temperature of 25° C. and a shear rate of 5 rpm.
Viscosity ratio = η _0.5 /η ₅ (1) The silver-containing paste according to any one of claims 1 to 10,
A silver-containing paste having a storage modulus of 2000 MPa or more and 20000 MPa or less, measured at a frequency of 1 Hz and a temperature of 25°C using a dynamic viscoelasticity measuring device. The silver-containing paste according to any one of claims 1 to 11, comprising:
A silver-containing paste with a thermal conductivity of 10 W/mK or more and 200 W/mK or less, as measured by the laser flash method.