JP2000319620A - Liquid adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid adhesive composition which provides an electronic component device equipped with an excellent connection reliability and repairability. SOLUTION: The titled composition comprises (A) a liquid epoxy resin, (B) at least one granular thermoplastic resin chosen from a granular polymethacrylate resin and a granular polystyrene resin and (C) a microcapsule type accelerator wherein an accelerator is encapsulated in a wall membrane essentially comprising a polymer having a structural unit of the formula (wherein α and β are each H or a monovalent organic group).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid adhesive composition used for electronic parts and the like.

[0002]

2. Description of the Related Art In recent years, in various electronic component devices such as small portable devices, as a high-density mounting method of a semiconductor element, a direct chip using a bare chip such as a flip chip is used.
Attachment has received particular attention. In this flip-chip type electronic component device, for example, an adhesive composition is applied between a wiring board and a flip chip, and the applied composition is heated and pressed to perform electrical connection between opposing electrodes. As the adhesive composition, an epoxy resin as a main component, which contains a curing agent, a curing accelerator and the like is used.

[0003]

However, the above-mentioned adhesive composition is inferior in thixotropy because the curing agent and the curing accelerator used together with the epoxy resin are both in liquid form, and the liquid composition after application to a wiring board or the like is inferior. Drowsiness and uneven coating occur. Therefore, an electronic component device obtained by using this adhesive composition has a drawback in that it has poor conductivity and poor connection reliability.

Further, since the adhesive composition contains an epoxy resin as a main component, the adhesive strength between the wiring board and the flip chip is extremely high after the adhesive composition is cured by heating and pressurizing. If the connection failure occurs due to misalignment or the like, or if a failure occurs in the connection part after the electronic device incorporating the electronic component device is distributed on the market, the wiring board and the flip chip cannot be separated. Therefore, there is a problem that the electronic component device must be discarded, and the repairability is poor. In particular, in recent years, while recycling is required for global environmental protection, it is necessary to avoid discharging waste, and an electronic component device having excellent repairability has been desired.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a liquid adhesive composition capable of obtaining an electronic component device having excellent connection reliability and repairability.

[0006]

In order to achieve the above object, the liquid adhesive composition of the present invention comprises the following (A)
(C) The composition which contains a component is taken. (A) Liquid epoxy resin. (B) Particulate thermoplastic resin. (C) Particulate curing agent.

That is, the present inventors have intensively studied an adhesive composition that can obtain a desired electronic component device. In the course of the research, the liquid adhesive composition containing the liquid epoxy resin (component A), the particulate thermoplastic resin (component B), and the particulate curing agent (component C) was either a thermoplastic resin or a curing agent. Have also been found to be excellent in thixotropy, have no dripping or coating unevenness after application to a wiring board, and have an excellent connection reliability and repairability since they are in the form of particles. did.

[0008] The term "liquid" in the liquid adhesive composition of the present invention means that the adhesive composition is liquid (including paste) at room temperature.

By using a particulate curing accelerator together with the liquid epoxy resin (component A), the particulate thermoplastic resin (component B), and the particulate curing agent (component C), a liquid adhesive composition is obtained. Thixotropic properties can be further improved, dripping and uneven coating can be prevented, and connection reliability of the electronic component device can be further improved.

The above liquid epoxy resin (component A)
By using the specific microcapsule-type curing accelerator together with the particulate thermoplastic resin (B component) and the particulate curing agent (C component), the thixotropic property of the liquid adhesive composition can be further improved. It is possible to prevent dripping and uneven coating, and the connection reliability of the electronic component device is further improved.

When at least one of a particulate polymethacrylate resin and a particulate polystyrene resin is used as the particulate thermoplastic resin (component B), the repairability of the electronic component device is further improved.

When at least one of a particulate hydrazide compound and a particulate dicyandiamide is used as the particulate hardener (component C), the thixotropic properties of the liquid adhesive composition can be further improved, and Draining and uneven coating can be prevented, and the connection reliability of the electronic component device is further improved.

[0013]

Next, embodiments of the present invention will be described in detail.

The liquid adhesive composition of the present invention comprises a liquid epoxy resin (A component) and a particulate thermoplastic resin (B component).
And a particulate hardener (component (C)).

The liquid epoxy resin (component A) is not particularly limited as long as it has two or more epoxy groups in one molecule. For example, bisphenol A type, bisphenol F type, hydrogenated bisphenol A type , Bisphenol AF type, phenol novolak type and other liquid epoxy resins and derivatives thereof, liquid epoxy resins and derivatives thereof derived from polyhydric alcohol and epichlorohydrin, glycidylamine type, hydantoin type, aminophenol type, aniline type, toluidine type Glycidyl-type liquid epoxy resins and derivatives thereof (edited by the Editorial Committee for Practical Plastics Dictionary, Materials of Practical Plastics Dictionary, pp. 211-255), and liquids of the above-mentioned liquid epoxy resin and various glycidyl-type solid epoxy resins Give me a mixture That. These may be used alone or in combination of two or more.

The particulate thermoplastic resin (component (B)) is not particularly limited, but those containing no carboxyl group in the molecular structure are preferably used. That is, if there is a carboxyl group, the carboxyl group reacts with the epoxy group of the liquid epoxy resin (component A), and the liquid adhesive composition may gel during storage. Examples of such a particulate thermoplastic resin (component B) include a polymethacrylic acid ester resin such as polymethyl methacrylate (PMMA), a polystyrene resin, and a copolymer of methyl methacrylate and styrene. May be copolymerized with other monomers. These may be used alone or in combination of two or more. Among them, polymethacrylate resin and polystyrene resin are preferably used in that excellent repairability is obtained. Further, the above-mentioned particulate thermoplastic resin (component B)
Is usually used in an uncrosslinked state.

The maximum particle size of the particulate thermoplastic resin (component B) is preferably 20 μm or less. That is, if the maximum particle size exceeds 20 μm, the smoothness of the application surface may be impaired, or the needle hole may be blocked at the time of dispenser application. The average particle size of the particulate thermoplastic resin (B component) is preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 3 μm.
It is as follows. That is, if the average particle size exceeds 10 μm, the repairability may be reduced.

The above-mentioned particulate thermoplastic resin (component B) can be usually obtained by suspension polymerization, emulsion polymerization or the like.

The particulate hardener (component C) is not particularly limited, but those which do not dissolve in the liquid epoxy resin (component A) are preferably used. That is, the problem that the reaction gradually occurs during long-term storage at room temperature or the like and the viscosity increases does not occur, and long-term storage stability is excellent. Examples of such a particulate curing agent (component C) include hydrazide compounds and dicyandiamide. Examples of the hydrazide compound include, for example, carbohydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide,
Adipic dihydrazide, pimelic dihydrazide, suberic dihydrazide, azelaic dihydrazide, sebacic dihydrazide, dodecandiodihydrazide, hexadecandiodihydrazide, terephthalic dihydrazide, isophthalic dihydrazide, 2,6-naphthoic dihydrazide, 2,6-naphthoic dihydrazide Benzenedihydrazide,
Organic dihydrazides such as 1,4-naphthoic acid dihydrazide, 2,6-pyridine dihydrazide, 1,4-cyclohexane dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, iminodiacetic acid dihydrazide, N, N'-hexamethylenebissemicarbazide, itaconic acid dihydrazide and the like. Compounds, ethylenediaminetetraacetic acid tetrahydrazide, citric acid trihydrazide, 1,2,4-benzenetrihydrazide, 1,4,5,8-naphthoic acid tetrahydrazide, nitriloacetic acid trihydrazide, cyclohexanetricarboxylic acid trihydrazide, pyromeritium And polyfunctional hydrazide compounds such as acid trihydrazide.
These may be used alone or in combination of two or more. Among them, an organic dihydrazide compound having a melting point of 140 to 250 ° C is suitably used from the viewpoint of reactivity and storage stability.

As the particulate hardener (component C), an imidazole compound can be used together with the hydrazide compound, dicyandiamide and the like.
The imidazole compound is not particularly limited, but is preferably insoluble in the liquid epoxy resin (component A) for the same reason as described above. Examples of such imidazole compounds include 1-cyanoethyl-2-phenylimidazolium trimellitate,
4-diamino-6- [2'-methylimidazolyl-
(1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine isocyanuric acid adduct and the like. Or a combination of two or more.

The maximum particle size of the particulate hardener (component C) is preferably 20 μm or less. That is, the maximum particle size is 20μ.
If it exceeds m, the smoothness of the application surface may be impaired, or the hole of the needle may be blocked at the time of dispenser application. The average particle size of the particulate curing agent (component C) is preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 3 μm or less. That is, if the average particle size exceeds 10 μm, the repairability may be reduced.

The particulate hardener (component (C)) is generally obtained by classifying pulverized powder particles into a predetermined particle size by a conventionally known method such as sieve classification, airflow classification, or wet classification. Can be obtained at

The amount of the particulate hardener (component (C)) used is
For 100 mol of the liquid epoxy resin (A component),
It is preferably in the range of 20 to 150 moles, more preferably 3 moles.
It is from 0 to 100 mol, particularly preferably from 50 to 80 mol. That is, when the use amount of the particulate curing agent (component C) is less than 20 mol, the curing reaction becomes extremely slow, the curing time becomes long, and the glass transition temperature of the cured product of the liquid adhesive composition becomes remarkable. This is because there is a risk of lowering the reliability of the electronic component device using the same. Conversely, if the amount of the particulate hardener (component C) exceeds 150 moles, the economic efficiency becomes poor, and excessive heat generation during the hardening reaction may impair the reliability of the electronic component device. is there. The use ratio of the particulate curing agent (component C) may be appropriately selected from the range of the above-mentioned mixing ratio in such a manner that a desired curing rate can be obtained with respect to the mixture with the liquid epoxy resin (component A). For example, as an index of the curing speed, the amount used can be easily determined while measuring the gel time with a hot plate.

The total amount of the particulate hardener (component C) and the liquid epoxy resin (component A) used is usually set in the range of 50 to 90% by weight based on the total amount of the organic components of the liquid adhesive composition. And preferably 65 to 80% by weight. That is, if the total amount used is less than 50% by weight, the glass transition temperature of the cured product of the liquid adhesive composition may decrease, and the reliability of the electronic component device may decrease. This is because there is a possibility that the repairability may decrease.

The liquid adhesive composition of the present invention may contain a particulate curing accelerator in addition to the above-mentioned components A to C.

The particulate hardening accelerator is not particularly limited, but those which do not dissolve in the liquid epoxy resin (component A) are preferably used for the same reasons as for the particulate hardening agent (component C). . Examples of such a particulate curing accelerator include imidazole compounds and phosphine compounds such as tetraphenylphosphonium tetraphenylborate, methyltributylphosphonium tetraphenylborate, and methyltricyanoethylphosphonium tetraphenylborate. These may be used alone or in combination of two or more. As the imidazole-based compound, the same ones as described above are used.

The maximum particle size of the particulate hardening accelerator is 20 μm.
m or less is preferable. That is, if the maximum particle size exceeds 20 μm, the smoothness of the application surface may be impaired, or the needle hole may be blocked at the time of dispenser application. The average particle size of the particulate curing accelerator is preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 3 μm or less. That is, if the average particle size exceeds 10 μm, the repairability may be reduced.

The above-mentioned particulate hardening accelerator is generally obtained by classifying pulverized powder particles into a predetermined particle size by a conventionally known method such as sieve classification, airflow classification, wet classification, or the like. Can be.

There is no particular limitation on the proportion of the particulate hardening accelerator used, and the rate at which a desired curing rate can be obtained with respect to the mixture of the liquid epoxy resin (component A) and the particulate hardening agent (component C). May be selected as appropriate. For example, as an index of the curing speed, the amount used can be easily determined while measuring the gel time with a hot plate.

The total amount of the particulate hardening accelerator, the liquid epoxy resin (component A) and the particulate hardening agent (component C) is usually 50% of the total amount of the organic components of the liquid adhesive composition.
To 90% by weight, preferably 65 to 80% by weight.
% By weight. That is, if the total amount used is less than 50% by weight, the glass transition temperature of the cured product of the liquid adhesive composition may decrease, and the reliability of the electronic component device may decrease. This is because there is a possibility that the repairability may decrease.

The liquid adhesive composition of the present invention may contain a specific microcapsule-type curing accelerator together with the above components.

The specific microcapsule type curing accelerator is obtained by encapsulating a curing accelerator in a wall film mainly composed of a polymer having a structural unit represented by the following general formula (1). It is.

[0033]

Embedded image

In the general formula (1), the monovalent organic group represented by α and β is not particularly limited, and examples thereof include an alkyl group such as a methyl group, an ethyl group, and a propyl group. Of these, a methyl group is preferred. In the general formula (1), α and β both represent H
Is preferred.

The polymer having the structural unit represented by the general formula (1) is a polymer usually called a polyurea-based polymer. And the polymer having the specific structural unit,
For example, it can be obtained by a polyaddition reaction between polyvalent isocyanates and polyvalent amines. Alternatively, it can be obtained by reacting a polyvalent isocyanate with water.
In the reaction between the polyvalent isocyanate and water, first, an amine is formed by hydrolysis of the polyvalent isocyanate, and the amine reacts with an unreacted isocyanate group (a so-called self-polyaddition reaction). A polyarea polymer having the structural unit represented by the general formula (1) is formed.

The polyvalent isocyanate may be any compound having two or more isocyanate groups in the molecule. Specific examples thereof include m-phenylene diisocyanate, p-phenylene diisocyanate, and 2,4-tolylene diisocyanate. 2,6-tolylene diisocyanate, naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl diisocyanate,
3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, xylylene-1,4-diisocyanate, 4,4'-diphenylpropane diisocyanate,
Trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate,
Butylene-1,2-diisocyanate, cyclohexylene-1,2-diisocyanate, cyclohexylene-
Diisocyanates such as 1,4-diisocyanate, p
Phenylenediisothiocyanate, xylylene-1,
Diisothiocyanates such as 4-diisothiocyanate and ethylidene diisothiocyanate; tetraisocyanates such as 4,4'-dimethyldiphenylmethane-2,2 ', 5,5'-tetraisocyanate; hexamethylene diisocyanate and hexanetriol With an adjunct,
Adduct of 2,4-tolylene diisocyanate with prenz catechol, adduct of tolylene diisocyanate with hexanetriol, adduct of tolylene diisocyanate with trimethylolpropane, adduct of xylylene diisocyanate with trimethylolpropane, hexa Isocyanate preforms such as trimers of aliphatic polyvalent isocyanates such as adducts of methylene diisocyanate and trimethylolpropane, triphenyldimethylenetriisocyanate, tetraphenyltrimethylenetetraisocyanate, pentaphenyltetramethylenepentaisocyanate, and hexamethylenediisocyanate. Polymers and the like. These may be used alone or in combination of two or more.

Among the above polyvalent isocyanates, adducts of tolylene diisocyanate and trimethylol propane, and additions of xylylene diisocyanate and trimethylol propane are preferred from the viewpoint of film forming property and mechanical strength when preparing microcapsules. It is preferable to use an isocyanate prepolymer typified by a polymethylene polyphenylisocyanate such as a product, triphenyldimethylenetriisocyanate.

On the other hand, the polyvalent amine to be reacted with the above-mentioned polyvalent isocyanate may be any compound having two or more amino groups in the molecule, and specifically, diethylenetriamine, triethylenetetramine, tetraethylene Pentamine, 1,6-hexamethylenediamine, 1,
8-octamethylenediamine, 1,12-dodecamethylenediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, o-xylylenediamine, m-xylylenediamine, p-xylylenediamine, menthanediamine, Bis (4-amino-3-methylcyclohexyl) methane, isophoronediamine, 1,
Examples include 3-diaminocyclohexanone and spiroacetal diamine. These may be used alone or in combination of two or more.

The curing accelerator contained in the wall film is not particularly limited. However, from the viewpoint of workability in preparing microcapsules and characteristics of the obtained microcapsules, those which are liquid at normal temperature are used. Preferably, it is used. In addition,
In the present invention, the liquid at ordinary temperature includes, in addition to the case where the properties of the curing accelerator itself are liquid at ordinary temperature, also includes those which are dissolved or dispersed in any organic solvent or the like even if they are solid at ordinary temperature. It is the purpose.

The curing accelerator is not particularly limited as long as it is soluble or insoluble in the liquid epoxy resin (component A). Examples thereof include triphenylphosphine (TPP) and tributylphosphine. Phosphine compounds such as tris (dimethoxyphenyl) phosphine, tris (hydroxypropyl) phosphine, tris (cyanoethyl) phosphine, and phosphoniums such as tetraphenylphosphonium tetraphenylborate, methyltributylphosphonium tetraphenylborate, and methyltricyanoethylphosphonium tetraphenylborate Salt, imidazole, 2-methylimidazole, 2
-Ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4
-Methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-ethylimidazole, 1
-Benzyl-2-ethyl-5-methylimidazole, 2
-Phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-methylimidazoleazine, 2-heptadecylimidazole, 2-undecylimidazole,
2,4-diamino-6 ｛2′-methylimidazolyl-
(1) '-Ethyl-triazine isocyanuric acid adduct, N, N'-{2-methylimidazolyl- (1) -ethyl} dodecandioyldiazide, N, N '-{2-methylimidazolyl- (1) Imidazole compounds such as -ethyl} -aconsandioildiazide, dicyandiamide, 1,5-diazabicyclo (5,4,0) -7-undecene, 1,5-diazabicyclo (4,3,0) -5
And diazabicyclo compounds such as 1,4-diazabicyclo (2,2,2) -octane, tetraphenylborate salts, phenol novolak salts and 2-ethylhexane salts of the diazabicyclo compounds.
These may be used alone or in combination of two or more.

The organic solvent for dissolving the above-mentioned curing accelerator is not particularly limited as long as it is a liquid at ordinary temperature, but it is necessary to select a solvent which does not dissolve at least the wall film.
Specific examples include ethyl acetate, methyl ethyl ketone, acetone, methylene chloride, xylene, toluene, tetrahydrofuran and the like. It is also possible to use oils such as phenylxylylethane and dialkylnaphthalene.

The specific microcapsule-type curing accelerator can be prepared by a conventionally known method. In particular, it is necessary to form a wall film using an interfacial polymerization method and microencapsulate the same. It is preferable in terms of homogenization and adjustment of the wall thickness.

The method for producing the specific microcapsule-type curing accelerator will be specifically described below. First,
When a hardening accelerator liquid at room temperature is used as the core substance, polyvalent isocyanates are dissolved therein to obtain an oily solution. Then, the oily solution was dispersed in an aqueous phase in the form of oil droplets,
An O / W type (oil phase / water phase type) emulsion is prepared.
At this time, the particle size of each dispersed oil droplet is usually 0.05 to 5
The thickness is preferably set to about 00 μm, preferably about 0.05 to 50 μm, from the viewpoint of the stability of the emulsion during polymerization. Then, a polyvalent amine is added to and dissolved in the aqueous phase of the O / W emulsion, whereby the polyaddition reaction is carried out by interfacial polymerization with the polyvalent isocyanate in the oil phase. Alternatively, by heating the O / W emulsion, the polyvalent isocyanate in the oil phase reacts with water at the interface with the aqueous phase to generate an amine, followed by a self-polyaddition reaction. In this way, a wall film of microcapsules containing a polyurea-based polymer having the structural unit represented by the general formula (1) as a main component is formed. In the present invention, these two reactions may proceed simultaneously to form a wall film.

On the other hand, when a solid hardening accelerator is used as the core substance, the solid hardening accelerator is dissolved in the above-mentioned organic solvent to be liquid at room temperature, and then an emulsion is prepared in the same manner as above. In this case, the resulting emulsion is S / O
/ W type (solid phase / oil phase / water phase type) emulsion. The above-mentioned S / O / W emulsion is a case where the curing accelerator is lipophilic, and when the curing accelerator is hydrophilic, it is difficult to form the S / O / W emulsion. By performing the interfacial polymerization as an O / O type (oil phase / oil phase type) emulsion or an S / O / O type (solid phase / oil phase / oil phase type) emulsion by adjusting the solubility Good.

In the wall film forming step as described above, when the core substance is liquid, the polyvalent amine and water are freely diffused from the aqueous phase to the oil phase, and the polyvalent isocyanate is converted from the oil phase to the aqueous phase. Free diffusion is performed smoothly, so that a dense wall film with excellent separability is formed. However, if the core material is used as it is, free diffusion is not performed smoothly, and the dense wall It is difficult to obtain a film, and lacks uniformity of film quality.

The microcapsule-type curing accelerator thus obtained is incorporated into a wall film mainly composed of a polyurea-based polymer having a structural unit represented by the general formula (1).
It contains a curing accelerator as a core substance.
The microcapsule-type curing accelerator can be isolated by a conventionally known means, for example, a method of drying after centrifugation or a method of spray drying. At this time, if necessary, the organic solvent in the microcapsules can be removed by using a means such as drying under reduced pressure.

Further, as the polymer forming the wall film,
For example, by using a polyhydric alcohol in combination with the polyvalent isocyanate, a polyurethane having both urethane bonds
Polyurea can also be used.

The polyhydric alcohol may be any of aliphatic, aromatic and alicyclic, for example, catechol, resorcinol, 1,2-dihydroxy-4
-Methylbenzene, 1,3-dihydroxy-5-methylbenzene, 3,4-dihydroxy-1-methylbenzene, 3,5-dihydroxy-1-methylbenzene, 2,
4-dihydroxyethylbenzene, 1,3-naphthalene diol, 1,5-naphthalene diol, 2,7-naphthalene diol, 2,3-naphthalene diol, o,
o'-biphenol, p, p'-biphenol, bisphenol A, bis- (2-hydroxyphenyl) methane, xylylene diol, ethylene glycol, 1,3
-Propylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,1,1-trimethylolpropane, hexane Triol, pentaerythritol, glycerin, sorbitol and the like can be mentioned. These can be used alone or 2
Used in combination of more than one species.

In the specific microcapsule-type curing accelerator obtained as described above, the amount of the curing accelerator included in the wall film is preferably set to 5 to 70% by weight of the total weight of the microcapsules. Preferably 10 to 50% by weight
It is. That is, if the amount of the curing accelerator is less than 5% by weight, the curing reaction time becomes too long and the reactivity becomes poor. If the amount of the curing accelerator exceeds 70% by weight, the thickness of the wall film becomes too thin. This is because there is a possibility that the core material may have poor isolation and mechanical strength.

The average particle size of the specific microcapsule type curing accelerator is not particularly limited, and is usually 0.05 to 20.
It is set in the range of μm, preferably 0.1 to 10 μm. That is, if the average particle size of the microcapsule-type curing accelerator is out of the above range, dripping occurs, and good coating cannot be performed. The shape of the specific microcapsule-type curing accelerator is preferably spherical, but may be elliptical. If the microcapsules are not spherical in shape but have a uniform particle size, such as elliptical or flat, the simple average value of the longest and shortest diameters is defined as the average particle size.

In the curing method of the present invention, even when the wall film component is a relatively strong cross-linked structure, the heat dissolution (destruction) phenomenon of the microcapsules is at a very low temperature of 80 to 150 ° C. Since it occurs instantaneously, the curability (the release property of the core substance from inside the microcapsule) does not decrease even when the thickness of the wall film increases. In addition, the wall film during the curing process reacts and dissolves with the epoxy resin or the like as an adhesive component, so that the wall film component does not remain as a foreign substance (impurity) in the obtained cured product, and the heat resistance and the water resistance are improved. Does not adversely affect sex.

Further, by preserving trace amounts of amine compounds and amino groups remaining in the wall film of the microcapsule-type curing accelerator with various blocking agents such as acidic compounds, further storage stability can be achieved. it can.

The proportion of the microcapsule-type curing accelerator used is not particularly limited, but the liquid epoxy resin (A
Component) and a mixture of the particulate hardener (component C),
It is preferable to use them in such a ratio that a desired curing speed can be obtained. For example, the amount used can be easily determined as an index of the curing speed while measuring the gel time with a hot plate.

The microcapsule type curing accelerator, the liquid epoxy resin (component A), and the particulate curing agent (component C)
Is generally set in the range of 50 to 90% by weight, preferably 65 to 80% by weight, based on the total amount of the organic components of the liquid adhesive composition. That is, the total usage is 50
When the amount is less than 10% by weight, the glass transition temperature of the cured product of the liquid adhesive composition is lowered, and the reliability of the electronic component device may be reduced. When the amount exceeds 90% by weight, the repairability is reduced. This is because there is a fear.

The liquid adhesive composition of the present invention can also contain conductive particles together with the above components. When the above conductive particles are used in combination, anisotropic conductivity can be imparted to the liquid adhesive composition to form an anisotropically conductive liquid adhesive composition. The anisotropically conductive liquid adhesive composition is used for, for example, an electrical connection between a liquid crystal circuit board and a tape carrier package (TCP) of a driver IC, and a chip-on-glass (COG) connection method. And
It can be used for high-density semiconductor element mounting technology for small portable devices. When an anisotropically conductive liquid adhesive composition is used, conductive particles are microscopically and isotropically dispersed in the adhesive composition, and a plurality of opposing electrodes can be connected collectively. Can be improved in productivity.

The conductive particles are not particularly limited.
For example, metal particles such as gold, silver, nickel, copper, zinc, tin, tin-lead solder, solders of various compositions, indium, palladium, etc., and those obtained by subjecting these metal particles to gold plating, nickel plating, or the like can be used. Also, cross-linked polystyrene resin,
Cross-linked polymer nucleus (core) such as cross-linked epoxy resin, cross-linked phenol resin, cross-linked urethane resin, cross-linked polyester resin, cross-linked silicone resin, cross-linked acrylic resin, etc., which is subjected to gold plating, nickel plating, etc. (shell) It is also possible to use.

The maximum particle size of the conductive particles is preferably 20 μm or less, which is advantageous for narrow pitch connection.
μm or less is particularly preferred. That is, the maximum particle size is 20μ.
If it exceeds m, the smoothness of the application surface may be impaired, or the hole of the needle may be blocked at the time of dispenser application.

The amount of the conductive particles used is not particularly limited, but the electrodes used in the electronic component device are becoming narrower in pitch, and the average particle size of the conductive particles used for micro connection is close to monodispersion. Considering that it is preferable, the amount is preferably 0.1 to 10 parts by volume, more preferably 0.5 to 5 parts by volume, per 100 parts by volume of the liquid adhesive composition. That is, if the filling amount of the conductive particles is less than 0.1 part by volume, the connection reliability of the electronic component device may be reduced. If the filling amount exceeds 10 parts by volume, a short circuit (short circuit) occurs between the conductive particles. This is because the danger of the risk increases.

The liquid adhesive composition of the present invention can also contain inorganic particles together with the above-mentioned components. By mixing the inorganic particles, the thixotropic property can be increased or the coefficient of thermal expansion can be reduced. can do.
The inorganic particles are not particularly limited, and include, for example, silica powder such as fused silica and crystalline silica, alumina powder,
Examples thereof include silicon nitride powder, boron nitride powder, aluminum nitride powder, magnesia powder, and aluminum hydroxide powder, and these may be used alone or in combination of two or more.

The maximum particle size of the above inorganic particles is preferably 20 μm or less, which is advantageous in narrow pitch connection.
μm or less is more preferable, and particularly preferably 5 μm or less from the viewpoint that a connection failure between the electrodes does not occur. That is, if the maximum particle size exceeds 20 μm, the smoothness of the application surface may be impaired, or the needle hole may be blocked at the time of dispenser application.

The amount of the inorganic particles used is not particularly limited, but is preferably 100 parts by volume or less, more preferably 50 parts by volume or less, per 100 parts by volume of the liquid adhesive composition. That is, if the amount of the inorganic particles exceeds 100 parts by volume, the viscosity of the liquid adhesive composition may increase, and the coatability may decrease.

The liquid adhesive composition of the present invention contains a silane coupling agent together with the above components for the purpose of promoting adhesion to an adherend (electrode), strengthening interfacial adhesion with various inorganic particles, and the like. It is also possible to use them together. The silane coupling agent is not particularly limited, for example, β
-(3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, etc., and these can be used alone or in combination of two or more. Can be

The liquid adhesive composition of the present invention may contain, together with the above components, a flame retardant such as antimony trioxide, antimony pentoxide, or a brominated epoxy resin, or a flame retardant auxiliary, polyethylene wax, carnauba wax, or montan. A release agent such as a sun-based wax or an amide-based wax, a low-stressing agent such as a silicone compound, a coloring agent, and the like can be appropriately compounded without departing from the spirit of the present invention.

The liquid adhesive composition of the present invention is prepared by, for example, blending the above-mentioned components A to C and other components as necessary, mixing them using a three-roll mill, a homomixer, or the like.
It can be obtained by dispersing and, if necessary, defoaming under reduced pressure.

The application of the liquid adhesive composition of the present invention is not particularly limited, and can be used, for example, for joining electrodes of an electronic component device. That is, first, as shown in FIG. 1, a printed circuit board 1 having electrode pads 2 and a flip chip 3 having metal bumps 4 are prepared. Then, the liquid adhesive composition is applied to a predetermined position (the mounting portion of the flip chip 3) of the printed circuit board 1. Next, the electrode pads 2 of the printed circuit board 1 are formed by using a crimping connection device equipped with a heating tool such as a stage or a heating head having a positioning function of the facing electrodes,
After positioning so that the metal bumps 4 of the flip chip 3 are opposed to each other, the liquid adhesive composition is cured by heating and pressing under predetermined conditions. In this way, as shown in FIG. 1, the electrode pads 2 of the printed circuit board 1 and the metal bumps 4 of the flip chip 3 are electrically connected via the cured body 5 of the liquid adhesive composition. A connected electronic component device can be obtained.

The method for applying the liquid adhesive composition of the present invention is not particularly limited, and examples thereof include a screen printing method, a dispenser application method, and a transfer method. The amount of the liquid adhesive composition applied is not particularly limited, and is preferably set so that the thickness of the cured body 5 of the liquid adhesive composition is in the range of 1 to 200 μm.

In the above-mentioned method of manufacturing an electronic component device, the case where the liquid adhesive composition is applied to the wiring circuit board 1 and then the wiring circuit board 1 and the flip chip 3 are immediately heated and crimped is described. However, in an actual process, after the liquid adhesive composition is applied, there may be a case where several printed circuit boards (intermediate products) are stacked and stocked in that state. Therefore, it is preferable that the application surface of the liquid adhesive composition is not sticky, and therefore, after heating the printed circuit board (intermediate product) under predetermined conditions, leaving it at room temperature for a while to return to room temperature. It is preferred to do so. In this way, the application surface of the liquid adhesive composition is free of stickiness, and it becomes possible to work by overlapping several printed circuit boards (intermediate products).
Since volatile components such as residual moisture can be removed, it is possible to prevent voids in the cured product of the liquid adhesive composition.

The heating condition of the printed circuit board (intermediate product) is preferably not lower than the melting point (thermal deformation temperature) of the particulate thermoplastic resin (component B) and not higher than the reaction start temperature of the liquid epoxy resin (component A). Specifically, 80 to 110 ° C. × 1
About 2 minutes. Further, the heating is preferably performed using a hot plate or the like.

Next, another example of an electronic component device using the liquid adhesive composition of the present invention is shown in FIG. As shown,
In this electronic component device, the electrode pads 22 of the printed circuit board 21 and the metal bumps 24 of the flip chip 23 are electrically connected via the conductive particles 26 in the cured body 25 of the liquid adhesive composition. .

FIG. 3 shows still another example of an electronic component device using the liquid adhesive composition of the present invention. As shown in the drawing, the electronic component device is configured to include an LCD panel (glass substrate) 3 via conductive particles 36 in a cured body 35 of a liquid adhesive composition.
1 and the outer leads 33 of the tape carrier package are electrically connected. In the drawing, 37 is a glass substrate, 38 is an IC
The chip 39 is a sealing resin.

FIG. 4 shows another example of an electronic component device using the liquid adhesive composition of the present invention. As shown, the electronic component device includes a transparent electrode 42 on an LCD panel (glass substrate) 41 and a metal bump 44 of a flip chip 43 via conductive particles 46 in a cured body 45 of a liquid adhesive composition.
And are electrically connected. In the figure, 47
Is a glass substrate.

The electronic component device using the liquid adhesive composition of the present invention can be easily repaired, for example, as follows. This repair method will be specifically described using the electronic component device shown in FIG. 1 as an example. First, the repair portion of the printed circuit board 1 on which the flip chip 3 is mounted is heated to a predetermined temperature (a temperature higher than the glass transition temperature of the cured body of the liquid adhesive composition by about 50 ° C. or more) using a hot plate or the like. Then, the cured body 5 of the liquid adhesive composition is caused to undergo cohesive failure, and the printed circuit board 1 and the flip chip 3 are separated. Then, in the hardened body residual portion of the printed circuit board 1,
The absorbent cotton impregnated with the repair solvent is allowed to stand still and is heated at a predetermined temperature (room temperature or 40 to 50 ° C.) for a predetermined time to swell the hardened material residue. Then, the absorbent cotton is removed. The printed circuit board 1 can be reused by wiping well to remove the hardened material residue. Note that the repair solvent may be applied directly to the hardened material residue of the printed circuit board 1. On the other hand, the flip chip 3 is immersed in a predetermined container containing the repair solvent, heated at a predetermined temperature (room temperature or 40 to 50 ° C.) for a predetermined time to swell the cured product residue, and then methanol The flip chip 3 can be reused by wiping it well to remove the hardened material residue.

The above-mentioned repair solvent is preferably a ketone-based solvent, a glycol diether-based solvent, a nitrogen-containing solvent, or the like, and these may be used alone or in combination of two or more.

Examples of the ketone solvents include acetophenone, isophorone, ethyl-n-butyl ketone, diisobutyl ketone, diisopropyl ketone, diethyl ketone,
Cyclohexanone, di-n-propyl ketone, methyl oxide, methyl-n-amyl ketone, methyl isobutyl ketone, methyl ethyl ketone, methyl cyclohexanone, methyl-n-butyl ketone, methyl-n-propyl ketone, methyl-n-hexyl ketone, methyl-n Heptyl ketone, holone is preferred. These may be used alone or in combination of two or more.

As the glycol diether solvent, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, and triethylene glycol dimethyl ether are preferable. These may be used alone or in combination of two or more.

As the nitrogen-containing solvent, N, N'-dimethylformamide, N, N'-dimethylacetamide, N-methyl-2-pyrrolidone, N, N'-dimethylsulfoxide and hexamethylphosphortriamide are preferred. . These may be used alone or in combination of two or more.

Next, examples will be described together with comparative examples.

First, prior to Examples and Comparative Examples, the following components were prepared.

[Liquid epoxy resin (component A)] A liquid epoxy resin represented by the following structural formula (2) (purity: 99%,
Viscosity 2500 cps / 25 ° C, epoxy equivalent 168 g /
eq)

Embedded image

[Particulate thermoplastic resin (component B)] Polymethacrylate having a repeating unit represented by the following structural formula (3) (average particle size: 1 μm, average molecular weight: 3,000,
000, heat deformation temperature 107 ° C)

Embedded image

[Particulate curing agent (component C)] Dihydrazide represented by the following structural formula (4) (average particle size: 2 μm, melting point: 215 to 225 ° C.)

Embedded image

[Liquid curing agent] Methylnadic anhydride

[Microcapsule type curing accelerator] 10 parts by weight of an adduct of 3 mol of xylylene diisocyanate and 1 mol of trimethylolpropane (hereinafter abbreviated as "parts")
An oil phase was prepared by uniformly dissolving 4 parts of triphenylphosphine (TPP) represented by the following structural formula (5) as a curing accelerator. Further, an aqueous phase composed of 95 parts of distilled water and 5 parts of polyvinyl alcohol was separately prepared, and the oil phase prepared above was added thereto, followed by homomixer (8000 rpm).
And emulsified into an emulsion using a reflux tube,
It was charged into a polymerization reaction vessel equipped with a stirrer and a dropping funnel.
On the other hand, 13 parts of an aqueous solution containing 3 parts of triethylenetetramine was prepared, placed in a dropping funnel provided in the polymerization reaction vessel, and added dropwise to the emulsion in the polymerization reaction vessel.
Polymerization was carried out at 0 ° C. for 3 hours to prepare a microcapsule-type curing accelerator. Thus, a microcapsule-type curing accelerator having a polyurea wall film containing 30% by weight of triphenylphosphine (TPP) (average particle size: 2 μm)
Was prepared.

[0084]

Embedded image

[Particulate Curing Accelerator] Tetraphenylphosphonium tetraphenylborate (average particle size 3 μm, maximum particle size 6 μm)

[Liquid curing accelerator] 2,4,6-trisdimethylaminophenol

[Conductive Particles] Nickel particles (average particle diameter 3 μm)
m, maximum particle size 8μm)

[Inorganic Particles] Fused silica (average particle size 3 μm)
m, maximum particle size 5μm)

[0089]

Examples 1 to 7 and Comparative Examples 1 to 3 The components prepared above were blended in the proportions shown in Tables 1 and 2 below, and were homogeneously mixed and dispersed at room temperature using a three-roll mill. A composition was prepared.

Next, a test sample was prepared using the above adhesive composition as follows. That is, first, an FR-4 glass epoxy wiring board (thickness: 1 mm) in which 64 copper wiring pads having a diameter of 300 μm are opened (board-side electrodes) and 64 gold bump electrodes having a diameter of 100 μm are provided.
Silicon chips (thickness: 370 μm, size: 10
mm × 10 mm). Then, on the silicon chip mounting portion of the FR-4 glass epoxy wiring board,
The adhesive composition was applied to a thickness of 50 μm by screen printing using a metal mask. Then
The wiring board coated with the adhesive composition was heated for 1 minute on a hot platen at 100 ° C., and then returned to room temperature to eliminate the stickiness of the surface of the adhesive composition. Although heat treatment was performed, stickiness was not eliminated because the particulate thermoplastic resin was not blended). Then, the wiring board is suction-fixed to a predetermined position on a metal stage (non-heated), and the copper wiring pad (board-side electrode) of the wiring board and the gold bump electrode of the silicon chip face each other. After the alignment, a test sample was prepared by pressing with a load of 20 kg at 200 ° C. for 2 minutes using a pressure bonding device having a heating head.

[0091]

[Table 1]

[0092]

[Table 2]

Using the thus obtained adhesive compositions of Examples and Comparative Examples, comparative evaluation of thixotropic property was performed according to the following criteria. In addition, using the test samples using the adhesive compositions of Examples and Comparative Examples, in accordance with the criteria shown below, a comparative evaluation was made on the conduction failure rate, the repairability, the state of void generation during pressure bonding, and the contamination of the heating head. Was done. The results are shown in Tables 3 and 4 below. In addition, the contamination of the heating head means that the adhesive applied by chance around the chip at the time of pressure bonding is thick,
This refers to the phenomenon that the chip runs off the periphery of the chip and adheres to the heating head.

[Thixotropy] Using an E-type rotational viscometer,
Using a 3 ° cone rotor, the viscosity was measured at a rotation speed of 0.5 rpm and 1 rpm at a temperature of 25 ° C., and the ratio was defined as the thixotropic degree. The greater the degree of variability, the better the thixotropic property.

[Conduction failure rate] Using a thermal test apparatus,
Under the conditions of 30 ° C./10 minutes⇔ + 125 ° C./10 minutes, a temperature cycle test of the test sample was performed, and electrical continuity after 1000 cycles was examined. Then, 6 of the copper wiring pads (board-side electrodes) of the FR-4 glass epoxy wiring board.
All four were inspected for poor conduction. The result is
If at least one of the 64 electrodes had a conductive defect, the device was determined to be defective by indicating the number of defectives for 100 test samples.

[Repairability] The test sample used for the measurement of the above-mentioned conduction failure rate was heated on a hot plate at 200 ° C.
After the silicon chip was peeled off from the 4-glass epoxy wiring board, it was left at room temperature. Then, a repair solvent (a mixed solvent of an equal amount of N, N'-dimethylformamide and diethylene glycol dimethyl ether) is added to the remaining portion of the cured body of the adhesive composition remaining on the wiring board and the electrode portion of the silicon chip. Leave the absorbent cotton soaked and let it stand for 5 minutes.
Heated at 0 ° C. for 10 minutes. After that, remove the cotton wool and wipe well with methanol to remove the hardened residue.
The peelable test sample was again mounted with a silicon chip, the electrical conductivity was examined, and the repairability was evaluated. When the cured body residue can be completely peeled off and the electrical connection is complete, ◎, when the cured body residue is slightly left, but when the electrical connection is complete, ○, the cured body residue If there is a slight remaining thing and the electrical connection is incomplete,
The case where the hardened material residue could hardly be peeled off and the electrical connection was incomplete was indicated as x.

[0097]

[Table 3]

[0098]

[Table 4]

From the results shown in Tables 3 and 4, since the thermoplastic resin, the curing agent, and the curing accelerator are all in the form of particles, the Example product has excellent thixotropy of the adhesive composition. The test sample had no poor conductivity, good void formation, no contamination of the heating head, and excellent connection reliability.Because it uses a particulate thermoplastic resin, it has excellent repairability. It turns out that it is equipped with.

On the other hand, the product of Comparative Example 1 was inferior in the thixotropic property of the adhesive composition, so that the test sample using the same had a high rate of defective conduction, slightly generated voids, and reduced the contamination of the heating head. This indicates that the connection reliability is poor and the repairability is poor because no thermoplastic resin is used. In Comparative Example 2, since both the curing agent and the curing accelerator are in liquid form, the thixotropic property of the adhesive composition is inferior, and a test sample using the same has a high conduction failure rate, generates many voids, and is heated. Since the head is contaminated, it is understood that the connection reliability is poor and the repairability is poor because no thermoplastic resin is used. In Comparative Example 3, since both the curing agent and the curing accelerator were in liquid form, the thixotropic property of the adhesive composition was poor, and the test sample using this had a high rate of poor conduction, generated many voids, and was heated. Since the head is contaminated, the connection reliability is poor.

[0101]

As described above, the liquid adhesive composition of the present invention contains a liquid epoxy resin (component A), a particulate thermoplastic resin (component B), and a particulate curing agent (component C). It is. Thus, the liquid adhesive composition of the present invention has a thermoplastic resin and a curing agent, both of which are in the form of particles,
Excellent thixotropy, no dripping or uneven coating after application to wiring board etc. Therefore, an electronic component device using the liquid adhesive composition of the present invention has an extremely low conductivity defect rate and has excellent connection reliability. In addition, since the particulate thermoplastic resin (component B) acts as a repairability-imparting agent, the electronic component device has excellent repairability. Therefore, when a connection failure occurs due to a positional shift between the electrodes during the connection process, or when a failure or the like occurs in a connection portion after the electronic device incorporating the electronic component device is marketed, the electronic component device is used. Can be repaired very easily, and since there is no need to dispose of the electronic component device as in the related art, the recyclability is excellent.

Then, by using a particulate curing accelerator together with the liquid epoxy resin (component A), the particulate thermoplastic resin (component B), and the particulate curing agent (component C), the liquid adhesive composition is prepared. Thixotropic properties can be further improved, dripping and uneven coating can be prevented, and connection reliability of the electronic component device can be further improved.

Further, the liquid epoxy resin (component A),
By using the specific microcapsule-type curing accelerator together with the particulate thermoplastic resin (B component) and the particulate curing agent (C component), the thixotropic property of the liquid adhesive composition can be further improved. It is possible to prevent dripping and uneven coating, and the connection reliability of the electronic component device is further improved.

If at least one of a particulate polymethacrylate resin and a particulate polystyrene resin is used as the particulate thermoplastic resin (component B), the repairability of the electronic component device is further improved.

When at least one of a particulate hydrazide compound and a particulate dicyandiamide is used as the particulate curing agent (component C), the thixotropy of the liquid adhesive composition can be further improved. Draining and uneven coating can be prevented, and the connection reliability of the electronic component device is further improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an electronic component device using the liquid adhesive composition of the present invention.

FIG. 2 is a schematic view showing another example of an electronic component device using the liquid adhesive composition of the present invention.

FIG. 3 is a schematic view showing still another example of an electronic component device using the liquid adhesive composition of the present invention.

FIG. 4 is a schematic view showing another example of an electronic component device using the liquid adhesive composition of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 23/31 F-term (Reference) 4J040 DB032 DB062 DF052 EC061 EC071 EC121 EC161 HC12 HC15 HC22 JA01 JA05 JB02 KA02 KA03 KA16 LA08 NA19 4M109 AA01 BA04 CA04 EA03 EA12 EB02 5F044 LL09 LL11 RR17

Claims (5)

[Claims] 1. A liquid adhesive composition comprising the following components (A) to (C). (A) Liquid epoxy resin. (B) Particulate thermoplastic resin. (C) Particulate curing agent. 2. The liquid adhesive composition according to claim 1, further comprising a particulate curing accelerator. 3. A microcapsule type curing accelerator containing a curing accelerator contained in a wall film mainly composed of a polymer having a structural unit represented by the following general formula (1). The liquid adhesive composition according to claim 1. Embedded image 4. The particulate thermoplastic resin as the component (B) is at least one of a particulate polymethacrylate resin and a particulate polystyrene resin.
4. The liquid adhesive composition according to any one of 3. 5. The particulate curing agent as the component (C),
The liquid adhesive composition according to any one of claims 1 to 4, which is at least one of a particulate hydrazide compound and a particulate dicyandiamide.