JP4472134B2 - Adhesive for electronic parts - Google Patents

Description

【００４０】
【発明の効果】
本発明によれば、塗布直後の形状を維持でき、高速供給プロセスでも硬化反応の部分的な進行による物性の変化を生じず、塗布量および塗布形状が安定し、熱硬化特性と貯蔵安定性にも優れた接着剤を得ることができる。
【図面の簡単な説明】
【図１】ディスペンス方式で回路基板へ疎水性球状無機充填剤、親水性球状無機充填剤およびマイクロカプセル硬化剤を含有する本発明のエポキシ系接着剤を塗布した瞬間（ａ）および塗布後一定時間経過したとき（ｂ）の状態を示す図である。
【図２】ディスペンス方式で回路基板へ不定形充填剤および粉末硬化剤を含有する従来のエポキシ系接着剤を塗布した瞬間（ｃ）および塗布後一定時間経過したとき（ｄ）の状態を示す図である。
【図３】ディスペンス方式で回路基板へ不定形充填剤およびマイクロカプセル硬化剤を含有する従来のエポキシ系接着剤を塗布した瞬間（ｅ）および塗布後一定時間経過したとき（ｆ）の状態を示す図である。
【符号の説明】
１ エポキシ樹脂
２ マイクロカプセル硬化剤
３ 疎水性球状無機充填剤
４ 親水性球状無機充填剤
５ 粉末硬化剤
６ 不定形充填剤
７ 塗布ノズル
８ 回路基板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an adhesive for an electronic component used for manufacturing an electronic component, mounting the electronic component on a circuit board, and forming a circuit on the circuit board.
[0002]
[Prior art]
Conventionally, various adhesives for electronic components (hereinafter referred to as adhesives) have been used for mounting electronic components. As a method for curing the adhesive, there are a photocuring method in which an ultraviolet ray or the like is irradiated to cause a curing reaction, and a heat curing method in which a curing reaction is caused by heating. Among these, examples of the adhesive used in the thermosetting method include an epoxy adhesive and a phenol adhesive. Among these, epoxy adhesives are widely used for mounting electronic components on circuit boards because they are excellent in adhesive strength and heat resistance.
[0003]
In response to the demand for higher speed and higher accuracy in the manufacturing process of electronic equipment, there is a demand for faster curing reactions and supply processes of epoxy adhesives. If the curing reaction of the adhesive is slow, the adhesive cannot maintain the shape immediately after application and spreads on the substrate. Therefore, conventionally, in the adhesive used for the thermosetting method, the thermosetting characteristics are adjusted by the size of the constituent molecule of the curing agent and the blending amount of the curing agent. For example, if the molecule of the curing agent is reduced, the reaction rate between the curing agent and the epoxy resin can be increased.
[0004]
Conventionally, as such an epoxy adhesive, an epoxy resin in which a powder curing agent, an amorphous filler, and the like are dispersed is used.
Here, as the epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a novolac type epoxy resin, or the like is generally used.
[0005]
Moreover, as a powder hardening | curing agent, the polymer which has active hydrogen in a molecule | numerator, such as aliphatic polyamine, amine adduct, polyamide, polysulfide, and polymercaptan, is generally used. Since these hardly dissolve in the epoxy resin at room temperature, they can be dispersed in the epoxy resin as a powder.
[0006]
In addition, silica, talc, mica, alumina, etc. are used as the irregular filler to be mixed in the adhesive to adjust the viscosity properties of the adhesive before curing and to ensure the mechanical strength of the adhesive after curing. It is done. Most of these particles have an irregular shape. Moreover, these particle diameters are generally about 1-10 micrometers.
[0007]
However, when the molecular weight of the powder curing agent is reduced or the blending amount is increased, curing at a low temperature and in a short time is possible, but the storage stability of the adhesive is lowered. On the contrary, when the molecule of the powder curing agent is increased or the blending amount is decreased, the storage stability of the adhesive is improved, but curing at a high temperature and for a long time is necessary. And if it heats for a long time at high temperature, an adhesive agent will spread further on a board | substrate.
[0008]
In FIG. 2, when the conventional adhesive in which the powder curing agent 5 and the amorphous filler 6 are dispersed in the epoxy resin 1 is applied to the circuit board 8 through the application nozzle 7 (c) and when a certain time has elapsed after application ( The state of d) is shown. As shown in FIG. 2D, the conventional adhesive cannot maintain the shape immediately after application as time passes, and it becomes difficult to bond high-precision electronic components.
[0009]
As a method for supplying the adhesive onto the circuit board, there are a dispensing method, a printing method, a transfer method, a jet method, a dip method, and the like. FIG. 2 shows an example of the dispensing method, but the dispensing method includes an air method for discharging by air pressure and a screw method (screw type) for discharging by rotating a screw.
[0010]
On the other hand, a technique for microencapsulating a curing agent is known as a technique for achieving both thermosetting characteristics and storage stability of an adhesive. This is a technique in which the curing agent is coated with a thin film of an inorganic substance or oil or fat instead of increasing the molecule of the curing agent. Hereinafter, a microcapsule containing an epoxy resin curing agent is referred to as a microcapsule curing agent.
[0011]
The adhesive using a microcapsule curing agent does not cause a curing reaction unless the thin film forming the capsule part is destroyed by heating, shearing force, etc. Even if the amount of the agent is increased, the storage stability at room temperature or lower is not impaired. Since the capsule portion can be easily broken by heating or applying a shearing force, the curing reaction proceeds quickly, and curing at a low temperature and in a short time is possible.
[0012]
[Problems to be solved by the invention]
However, if the operating speed of the adhesive supply device is increased in the supply process, a large shear is applied to the adhesive, or the capsule portion of the microcapsule hardener is contacted with the particles of the amorphous filler and destroyed. As a result, the curing reaction partially proceeds. And the application quantity and application shape of an adhesive agent become unstable and become a cause which produces a defective article in a post process.
[0013]
Moreover, even if the curing rate of the adhesive is increased, it is still difficult for the adhesive to maintain the shape immediately after application, and further improvement is required.
In FIG. 3, when the conventional adhesive in which the microcapsule curing agent 2 and the amorphous filler 6 are dispersed in the epoxy resin 1 is applied to the circuit board 8 through the application nozzle 7 (e) and when a certain time has elapsed after application. The state of (f) is shown.
[0014]
Another cause of the unstable application amount and application shape of the adhesive is variation in the particle shape of the amorphous filler compounded in the adhesive. Since the amorphous fillers conventionally used include particles of various shapes, it is considered that the physical properties of the adhesive are likely to vary.
[0015]
In view of the above problems, the present invention can maintain the shape immediately after coating, does not cause changes in physical properties due to partial progress of the curing reaction even in a high-speed supply process, the coating amount and the coating shape are stable, and the thermosetting characteristics It aims at providing the adhesive agent excellent also in the storage stability.
[0016]
[Means for Solving the Problems]
The present invention relates to an adhesive for electronic parts comprising a liquid epoxy resin, a microcapsule curing agent, a hydrophobic spherical inorganic filler, and a hydrophilic spherical inorganic filler.
Here, the microcapsule curing agent is obtained by coating a curing agent made of a polymer having active hydrogen in a molecule such as aliphatic polyamine, amine adduct, polyamide, polysulfide, polymercaptan, etc., with an inorganic or oily thin film. .
[0017]
The average particle size of the microcapsule curing agent is 5 to 10 μm . Thus, hardly causes breakage of the capsule portion during the adhesive application, is easy to discharge the adhesive yarn breakage often, is it stabilize the shape of the applied adhesive.
Moreover, the thickness of a capsule part is 0.5-1 micrometer . Accordingly, high strength of the capsule parts against shear force, moreover, by heating at a relatively low temperature, the capsule part you proceeded easily curing reaction is destroyed. Therefore, an adhesive suitable for an electronic part having low heat resistance can be obtained.
The content of the microcapsule curing agent in the adhesive of the present invention is preferably 10 to 30% by weight in terms of a good balance between the thermosetting characteristics of the adhesive and the storage stability. Moreover, it is preferable that content of the net hardening | curing agent except a capsule part is 5 to 20 weight%.
[0018]
The average particle diameter of the primary particles of the hydrophobic spherical inorganic filler and the hydrophilic spherical inorganic filler is 5 to 20 nm, so that the adhesive can be easily discharged and the thread breakage is good. This is preferable in that the shape is stable.
The primary particles of the hydrophobic spherical inorganic filler and the primary particles of the hydrophilic spherical inorganic filler are usually aggregated to form secondary particles. The average particle diameter of the secondary particles is 0.1 to 0.5 μm . Thus, hardly causes breakage of the capsule portion of the microcapsule curing agent during the adhesive application, is easy to discharge the adhesive yarn breakage often, it is you stabilize the shape of the applied adhesive.
From the same viewpoint, it is preferable that both the hydrophobic spherical inorganic filler and the hydrophilic spherical inorganic filler have a specific surface area of 50 to 400 m ² / g.
[0019]
The content of the hydrophobic spherical inorganic filler in the adhesive of the present invention, Ru 2-8 wt% der. Thus, the strength of the viscosity of the adhesive and thixotropic optimization and adhesive after curing Ru secured.
Furthermore, from the same viewpoint, the content of the hydrophilic spherical inorganic filler in the adhesive of the present invention, Ru 1-5 wt% der.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
When the adhesive of the present invention containing the hydrophobic spherical inorganic filler, the hydrophilic spherical inorganic filler and the microcapsule curing agent is applied to the circuit board 8 through the coating nozzle 7 (a) and when a certain time has elapsed after application ( The state of b) is shown in FIG. As shown in FIG. 1B, the adhesive of the present invention has the greatest feature in that the shape immediately after application is stable.
Here, in FIG. 1, 3 is a hydrophobic spherical inorganic filler, and 4 is a hydrophilic spherical inorganic filler. With these combinations, in the present invention, in addition to the shape stability of the applied adhesive, both excellent thermosetting properties and storage stability can be achieved.
[0021]
In the present invention, a microcapsule curing agent, a hydrophilic spherical inorganic filler, and a hydrophobic spherical inorganic filler are blended with the epoxy resin in the following proportions.
The microcapsule curing agent is preferably blended in an amount of 10 to 50 parts by weight with respect to 100 parts by weight of the epoxy resin.
Moreover, it is preferable to mix | blend 1-8 weight part of hydrophilic spherical inorganic fillers with respect to 100 weight part of epoxy resins.
Furthermore, it is preferable to mix 2 to 13 parts by weight of the hydrophobic spherical inorganic filler with respect to 100 parts by weight of the epoxy resin.
In addition, if necessary, a colorant, a storage stabilizer, a reaction accelerator and the like may be blended with the adhesive of the present invention.
[0022]
Among the aliphatic polyamines, amine adducts, polyamides, polysulfides, polymercaptans and the like used for the microcapsule curing agent, polymercaptan is particularly preferable. And as a polymercaptan, a trioxane trimethylene mercaptan compound is mentioned, for example.
Specific examples of the thin film constituting the capsule portion of the microcapsule curing agent include, for example, an oil film obtained by interfacial polymerization of a sebacoyl chloride solution and a triethylenetetraamine aqueous solution.
[0023]
In the present invention, a hydrophilic spherical inorganic filler and a hydrophobic spherical inorganic filler are used in combination in order to obtain effects such as the stability of the adhesive application shape. These fillers are generally composed of silica, talc, mica, alumina and the like.
Typical examples of the hydrophilic spherical inorganic filler include ordinary spherical silica and spherical alumina. That is, these usually have many defects and hydroxyl groups on the surface, and can be used as hydrophilic spherical inorganic fillers in the present invention. Further, typical examples of the hydrophobic spherical inorganic filler include those obtained by subjecting the surface of normal spherical silica or spherical alumina to a hydrophobic treatment.
[0024]
As the hydrophobization treatment, there is a method of hydrophobizing the filler surface by immersing a spherical inorganic filler in silicon oil or the like.
In the case of a hydrophobic spherical inorganic filler, the number of hydroxyl groups per unit surface area is preferably 10 ¹⁶ / m ² or more and less than 10 ¹⁸ / m ² .
In the case of a hydrophilic spherical inorganic filler, the number of hydroxyl groups per unit surface area is preferably 10 ¹⁸ / m ² or more and 10 ¹⁹ / m ² or less.
[0025]
【Example】
The adhesive of the present invention can be obtained by appropriately mixing the above components. Below, based on an Example, the adhesive agent of this invention is demonstrated further more concretely.
[0026]
Example 1
21. Polyamide microcapsule curing agent (diameter 6.5 μm, capsule part thickness 0.7 μm) in 76.0 g of bisphenol F type epoxy resin (epoxy equivalent 162, viscosity 1.6 Pa · s (25 ° C.)) 0 g was dispersed at room temperature. Hydrophobic spherical inorganic filler (Nippon Aerosil Co., Ltd. silica treated with silicon oil, Aerosil RY200 (trade name), average primary particle size 12 nm, average secondary particle size 0. 3 μm, specific surface area 100 ± 20 m ^{2 /} g) 3.0 g and hydrophilic spherical inorganic filler (silica manufactured by Nippon Aerosil Co., Ltd., Aerosil # 200 (trade name), average primary particle size 12 nm, average secondary particles 1.0 μg in diameter 0.3 μm, specific surface area 200 ± 25 m ^{2 /} g), kneaded for 30 minutes at room temperature using an electric mortar, and further defoamed with stirring in vacuum for 15 minutes to obtain an adhesive It was.
[0027]
Next, the obtained adhesive was repeatedly applied on a 10,000-point epoxy substrate. At this time, the target was set in a circular dot shape having a diameter of 0.6 mm. And about 100 arbitrary points | pieces, the average value and standard deviation of the coating diameter and the coating height were measured. Table 1 shows the results.
[0028]
As a coating device, tact 0.07 sec / time, screw pitch 2.0 mm, screw groove depth 0.3 mm, cylinder inner diameter of screw type unit 3 mm, screw rotation speed 150 rpm, screw rotation time 15 ms / time and nozzle inner diameter A 0.33 mm screw dispenser was used.
[0029]
Example 2
25.0 g of polysulfide microcapsule curing agent (diameter 6.0 μm, capsule part thickness 0.8 μm) in 65.0 g of bisphenol A type epoxy resin (epoxy equivalent 187, viscosity 15 Pa · s (25 ° C.)) Dispersed at room temperature. Hydrophobic spherical inorganic filler (Nippon Aerosil Co., Ltd. silica treated with silicon oil, Aerosil RY200 (trade name), average primary particle size 12 nm, average secondary particle size 0. 3 μm, specific surface area 100 ± 20 m ^{2 /} g) 7.0 g and hydrophilic spherical inorganic filler (Nippon Aerosil Co., Ltd. silica treated with silicon oil, Aerosil # 380 (trade name), average primary particles A diameter of 7 nm, an average secondary particle diameter of 0.2 μm, and a specific surface area of 380 ± 20 m ^{2 /} g) were added in an amount of 3.0 g, and kneaded and degassed in the same manner as in Example 1 to obtain an adhesive. And the measurement similar to Example 1 was performed. Table 1 shows the results.
[0030]
Example 3
In 75.0 g of bisphenol F type epoxy resin (epoxy equivalent 162, viscosity 1.6 Pa · s (25 ° C.)), ethylenediamine microcapsule curing agent (diameter 8.0 μm, capsule part thickness 0.7 μm) 15. 0 g was dispersed at room temperature. Hydrophobic spherical inorganic filler (Nippon Aerosil Co., Ltd. silica treated with silicon oil, Aerosil RX200 (trade name), average primary particle size 12 nm, average secondary particle size 0. 3 μm, specific surface area 140 ± 25 m ^{2 /} g) 5.0 g and hydrophilic spherical inorganic filler (silica manufactured by Nippon Aerosil Co., Ltd., Aerosil # 130 (trade name), average primary particle diameter 16 nm, average secondary particles 5.0 g of a diameter of 0.1 μm and a specific surface area of 130 ± 25 m ^{2 /} g) was added and kneaded and defoamed in the same manner as in Example 1 to obtain an adhesive. And the measurement similar to Example 1 was performed. Table 1 shows the results.
[0031]
Example 4
In a mixture of 41.0 g of bisphenol A type epoxy resin (epoxy equivalent 187, viscosity 15 Pa · s (25 ° C.)) and 41.0 g of bisphenol F type epoxy resin (epoxy equivalent 162, viscosity 1.6 Pa · s (25 ° C.)) Then, 10.0 g of an ethylenediamine microcapsule curing agent (diameter 7.5 μm, film thickness 0.6 μm) was dispersed at room temperature. Hydrophobic spherical inorganic filler (Nippon Aerosil Co., Ltd. silica treated with silicon oil, Aerosil RX200 (trade name), average primary particle size 12 nm, average secondary particle size 0. 3 μm, specific surface area 140 ± 25 m ^{2 /} g) 5.0 g, and hydrophilic spherical inorganic filler (Alumina, Nippon Aerosil Co., Ltd., aluminum oxide C (trade name), average primary particle size 13 nm, average secondary particles 3.0 g of a diameter of 0.1 μm and a specific surface area of 100 ± 25 m ^{2 /} g) was added and kneaded and defoamed in the same manner as in Example 1 to obtain an adhesive. And the measurement similar to Example 1 was performed. Table 1 shows the results.
[0032]
Example 5
17.0 g of a polymercaptan microcapsule curing agent (diameter: 8.5 μm, film thickness: 0.9 μm) in 78.0 g of a phenol novolac type epoxy resin (epoxy equivalent: 159, viscosity: 10 Pa · s (25 ° C.)) at room temperature Dispersed. Hydrophobic spherical inorganic filler (Nippon Aerosil Co., Ltd. silica treated with silicon oil, Aerosil RY200 (trade name), average primary particle size 12 nm, average secondary particle size 0. 3 μm, specific surface area 100 ± 25 m ^{2 /} g) ^2.5 g, and hydrophilic spherical inorganic filler (Alumina, Nippon Aerosil Co., Ltd., aluminum oxide C (trade name), average primary particle size 13 nm, average secondary particles 4.5 g of a diameter of 0.1 μm and a specific surface area of 100 ± 25 m ^{2 /} g) was added and kneaded and defoamed in the same manner as in Example 1 to obtain an adhesive. And the measurement similar to Example 1 was performed. Table 1 shows the results.
[0033]
Example 6
Disperse 20.0 g of polysulfide microcapsule curing agent (diameter 6.0 μm, film thickness 0.8 μm) in 73.5 g of bisphenol A type epoxy resin (epoxy equivalent 187, viscosity 15 Pa · s (25 ° C.)) at room temperature. I let you. Hydrophobic spherical inorganic filler (Nippon Aerosil Co., Ltd. silica treated with silicon oil, Aerosil RX200 (trade name), average primary particle size 12 nm, average secondary particle size 0. 3 μm, specific surface area 140 ± 20 m ^{2 /} g) 5.0 g and hydrophilic spherical inorganic filler (silica manufactured by Nippon Aerosil Co., Ltd., Aerosil # 130 (trade name), average primary particle diameter 16 nm, average secondary particles 1.5 g of a diameter of 0.1 μm and a specific surface area of 130 ± 20 m ^{2 /} g) was added, and kneaded and degassed in the same manner as in Example 1 to obtain an adhesive. And the measurement similar to Example 1 was performed. Table 1 shows the results.
[0034]
Example 7
In 67.0 g of bisphenol F type epoxy resin (epoxy equivalent 162, viscosity 1.6 Pa · s (25 ° C.)), 25.0 g of an ethylenediamine microcapsule curing agent (diameter 8.0 μm, film thickness 0.7 μm) was added at room temperature. And dispersed. Hydrophobic spherical inorganic filler (Nippon Aerosil Co., Ltd. silica treated with silicon oil, Aerosil RX200 (trade name), average primary particle size 12 nm, average secondary particle size 0. 3 μm, specific surface area 140 ± 25 m ^{2 /} g) 6.0 g and hydrophilic spherical inorganic filler (silica manufactured by Nippon Aerosil Co., Ltd., Aerosil # 200 (trade name), average primary particle size 12 nm, average secondary particles 2.0 g of a diameter of 0.3 μm and a specific surface area of 200 ± 25 m ^{2 /} g) was added, and kneaded and degassed in the same manner as in Example 1 to obtain an adhesive. And the measurement similar to Example 1 was performed. Table 1 shows the results.
[0035]
Example 8
In a mixture of 30.0 g of bisphenol A type epoxy resin (epoxy equivalent 187, viscosity 15 Pa · s (25 ° C.)) and 38.5 g of bisphenol F type epoxy resin (epoxy equivalent 162, viscosity 1.6 Pa · s (25 ° C.)) 25.0 g of an ethylenediamine microcapsule curing agent (diameter 7.5 μm, film thickness 0.6 μm) was dispersed at room temperature. Hydrophobic spherical inorganic filler (Nippon Aerosil Co., Ltd. silica treated with silicon oil, Aerosil RY200 (trade name), average primary particle size 12 nm, average secondary particle size 0. 3 μm, specific surface area 100 ± 25 m ^{2 /} g) 5.0 g and hydrophilic spherical inorganic filler (Alumina manufactured by Nippon Aerosil Co., Ltd., aluminum oxide C (trade name), average primary particle size 13 nm, average secondary particles 1.5 g of a diameter of 0.1 μm and a specific surface area of 100 ± 25 m ^{2 /} g) was added and kneaded and defoamed in the same manner as in Example 1 to obtain an adhesive. And the measurement similar to Example 1 was performed. Table 1 shows the results.
[0036]
Example 9
In 64.0 g of phenol novolac type epoxy resin (epoxy equivalent 159, viscosity 10 Pa · s (25 ° C.)), 25.0 g of a polymercaptan microcapsule curing agent (diameter 8.5 μm, film thickness 0.9 μm) at room temperature. Dispersed. To the obtained mixture, hydrophobic spherical inorganic filler (silica manufactured by Nippon Aerosil Co., Ltd., Aerosil R974 (trade name), average primary particle size 12 nm, average secondary particle size 0.25 μm, specific surface area 170 ± 20 m ^{2 /} g) 7.5 g and hydrophilic spherical inorganic filler (Nippon Aerosil Co., Ltd. alumina, aluminum oxide C (trade name), average primary particle size 13 nm, average secondary particle size 0.1 μm, specific surface area 100 ± 25 m ^{2 /} g) 3.5 g was added, and kneaded and degassed in the same manner as in Example 1 to obtain an adhesive. And the measurement similar to Example 1 was performed. Table 1 shows the results.
[0037]
<< Comparative Example 1 >>
Disperse 10.0 g of ethylenediamine microcapsule curing agent (diameter: 5.0 μm, film thickness: 1.0 μm) in 50.0 g of bisphenol A type epoxy resin (epoxy equivalent 187, viscosity 15 Pa · s (25 ° C.)) at room temperature. I let you. 30.0 g of amorphous talc (manufactured by Nistron, Ltd., Mistron CB (trade name)) was added to the resulting mixture, and kneaded and degassed in the same manner as in Example 1 to obtain an adhesive. And the measurement similar to Example 1 was performed. Table 1 shows the results.
However, during the application, a curing reaction occurred inside the screw-type head, and only 4016 points could be applied.
[0038]
From Table 1, the adhesive for electronic parts comprising a liquid epoxy resin, a microcapsule curing agent, a hydrophobic spherical inorganic filler and a hydrophilic spherical inorganic filler has a coating amount and a coating shape which are more than those using an amorphous filler. It can be seen that there is little variation and that the quality is stable without hardening inside the screw head.
[0039]
[Table 1]

[0040]
【The invention's effect】
According to the present invention, the shape immediately after coating can be maintained, the physical properties do not change due to partial progress of the curing reaction even in the high-speed supply process, the coating amount and the coating shape are stable, and the thermosetting characteristics and the storage stability are achieved. In addition, an excellent adhesive can be obtained.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows a moment when an epoxy adhesive of the present invention containing a hydrophobic spherical inorganic filler, a hydrophilic spherical inorganic filler and a microcapsule curing agent is applied to a circuit board by a dispensing method (a) and a certain time after application. It is a figure which shows the state of (b) when it passes.
FIG. 2 is a diagram showing a state (c) when a conventional epoxy adhesive containing an amorphous filler and a powder hardener is applied to a circuit board by a dispensing method, and a state (d) when a certain time has elapsed after application. It is.
FIG. 3 shows the state (e) when a conventional epoxy adhesive containing an amorphous filler and a microcapsule curing agent is applied to a circuit board by a dispensing method, and when a certain time has elapsed after application (f). FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Epoxy resin 2 Microcapsule hardening agent 3 Hydrophobic spherical inorganic filler 4 Hydrophilic spherical inorganic filler 5 Powder hardening agent 6 Amorphous filler 7 Application nozzle 8 Circuit board

Claims (4)

Microcapsules containing a liquid epoxy resin, a curing agent for epoxy resin, Ri Do hydrophobic spherical inorganic filler and a hydrophilic spherical inorganic filler,
The average particle size of the microcapsules containing the epoxy resin curing agent is 5 to 10 μm,
The thickness of the capsule part of the microcapsule containing the epoxy resin curing agent is 0.5 to 1 μm,
The average particle diameter of secondary particles formed by agglomerating primary particles of the hydrophobic spherical inorganic filler and secondary particles formed by agglomeration of primary particles of the hydrophilic spherical inorganic filler are both 0.1. ~ 0.5 μm,
The content of the hydrophobic spherical inorganic filler is 2 to 8% by weight,
The adhesive for electronic components content Ru 1-5 wt% der hydrophilic spherical inorganic filler. The adhesive for electronic components according to claim 1 Symbol placement content of the microcapsules is 10 to 30 wt% of an epoxy resin curing agent. The adhesive for electronic components according to claim 1 or 2 , wherein the average particle diameter of primary particles of the hydrophobic spherical inorganic filler and the hydrophilic spherical inorganic filler is 5 to 20 nm. The adhesive for electronic parts according to any one of claims 1 to 3 , wherein the hydrophobic spherical inorganic filler and the hydrophilic spherical inorganic filler each have a specific surface area of 50 to 400 m ² / g.

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