JP2017066256A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition capable of being cured at low temperature of 80°C or less and further excellent in adhesive strength or pot life.SOLUTION: There is provided an epoxy resin composition containing (A) an epoxy resin, (B) an isocyanate adduct type microcapsulation curing agent containing 1,4-diazabicyclo[2.2.2]octane (DABCO) as an active ingredient and (C) an inorganic filler, with an amount of DABCO in the (B) component of 0.75 to 2.5 pts.mass based on 100 pts.mass of the (A) component.SELECTED DRAWING: None

Description

  The present invention relates to an epoxy resin composition suitable for a sealing material for applications where thermosetting at low temperature, specifically, thermosetting at 80 ° C. or less is required.

Epoxy resins have excellent electrical insulating properties, mechanical strength, heat resistance, moisture resistance, adhesion, and other material properties. Therefore, epoxy resins are the main components, and curing agents and / or acceleration of the epoxy resins are used. An epoxy resin composition containing an agent is widely used as a sealing material such as underfill or an adhesive for electronic parts. Examples of the epoxy resin curing agent used for the above purpose include amine-based curing agents, phenol-based curing agents, and acid anhydride-based curing agents. On the other hand, examples of the epoxy resin curing accelerator used for the above-mentioned purpose include imidazoles.
In Patent Documents 1 and 2, by using a microcapsule type latent curing agent as a curing agent for an epoxy resin, both excellent low temperature curability and storage stability are achieved.

  In recent years, a member having low heat resistance is used for an adherend or the like, and curing at a lower temperature, specifically, curing at 80 ° C. or less, is required from the viewpoint of reducing environmental load. However, regarding the low temperature curability, in Examples of Patent Documents 1 and 2, it is said that the low temperature curability is good if the peak temperature derived from the heat of curing is less than 115 ° C. when measuring the curing characteristics. It cannot cope with curing at 80 ° C. or lower.

JP 2009-161751 A JP 2009-203453 A

  In order to solve the above-described problems of the prior art, an object of the present invention is to provide an epoxy resin composition that can be cured at a low temperature of 80 ° C. or lower and is excellent in adhesive strength and pot life.

In order to achieve the above object, the present invention provides:
(A) epoxy resin,
(B) an isocyanate adduct type microencapsulated curing agent containing 1,4-diazabicyclo [2.2.2] octane (1,4-diazabicyclo [2.2.2] octane (DABCO)) as an active ingredient,
An epoxy resin composition comprising (C) an inorganic filler, wherein the amount of DABCO in the component (B) is 0.75 to 2.5 parts by mass with respect to 100 parts by mass of the component (A). Offer things.

  In the epoxy resin composition of the present invention, the content of the component (B) is preferably 25 to 80 parts by mass with respect to 100 parts by mass of the component (A).

The epoxy resin composition of the present invention may further contain (D) a thickening inhibitor.
The thickening inhibitor of the component (D) is preferably at least one selected from the group consisting of boric acid esters, aluminum chelates, and organic acids.

  Moreover, this invention provides the resin cured | curing material obtained by heating the epoxy resin composition of this invention.

  Moreover, this invention provides the sealing material containing the epoxy resin composition of this invention.

  The present invention also provides a semiconductor device having a flip chip type semiconductor element encapsulated with the encapsulant of the present invention.

The epoxy resin composition of the present invention can be cured at a low temperature of 80 ° C. or lower, and is excellent in adhesive strength and pot life. Moreover, since the epoxy resin composition of the present invention can be cured at a low temperature of 80 ° C. or lower, the internal stress after curing can be reduced.
Due to these characteristics, the epoxy resin composition of the present invention can be used as a sealing material such as a wire sealing material and an underfill agent and an adhesive for electronic components.
In addition, since the epoxy resin composition of the present invention can be cured at a low temperature of 80 ° C. or less even if the content of the microencapsulated curing agent of the component (B) is reduced, the epoxy resin of the component (A) (C) The compounding ratio of the other component of a resin composition, such as an inorganic filler of a component, can be increased. Therefore, the range of the resin composition formulation design (particularly viscosity adjustment) is widened.

Hereinafter, the epoxy resin composition of the present invention will be described in detail.
The resin composition of the present invention contains the following components (A) to (C) as essential components.

Component (A): Epoxy Resin The epoxy resin (A) is a component that forms the main component of the epoxy resin composition of the present invention.
The epoxy resin as the component (A) may be one having two or more epoxy groups per molecule. Examples of the epoxy resin of component (A) include polyglycidyl ethers obtained by reacting polychlorophenols such as bisphenol A, bisphenol F, bisphenol AD, catechol and resorcinol, polyhydric alcohols such as glycerin and polyethylene glycol, and epichlorohydrin. , A glycidyl ether ester obtained by reacting a hydroxycarboxylic acid such as p-hydroxybenzoic acid or β-hydroxynaphthoic acid with epichlorohydrin, a polycarboxylic acid obtained by reacting a polycarboxylic acid such as phthalic acid or terephthalic acid and epichlorohydrin. Epoxy resin having a naphthalene skeleton such as glycidyl ester, 1,6-bis (2,3-epoxypropoxy) naphthalene, epoxidized phenol novolac resin, epoxidized crezo Novolac resins, epoxidized polyolefins, cyclic aliphatic epoxy resins, urethane modified epoxy resin, silicone-modified epoxy resins, but are not limited thereto.

Component (B): Microencapsulated curing agent (B) The microencapsulated curing agent of component (B) has 1,4-diazabicyclo [2.2.2] octane (1,4-diazabicyclo [2.2. 2] octane (DABCO)). 1,4-diazabicyclo [2.2.2] octane (DABCO) is also called 1,4-ethylenepiperazine or triethylenediamine.
The microencapsulated curing agent (B) contains DABCO as an active ingredient, whereby the epoxy resin composition can be cured at a low temperature of 80 ° C. or lower.
In the epoxy resin composition of the present invention, an isocyanate adduct type microencapsulated curing agent is used as the microencapsulated curing agent of the component (B). An isocyanate adduct type microencapsulated curing agent is a latent curing agent obtained by coating (microencapsulating) an isocyanate resin with an addition reaction to a powder containing an amine curing agent.
In the present invention, by using an isocyanate adduct type microencapsulated curing agent containing DABCO, the epoxy resin composition can be cured at a low temperature of 80 ° C. or lower, while the pot life of the epoxy resin composition is improved. When the component (B) is not directly in the form of a microencapsulated curing agent but directly contains DABCO, the pot life of the epoxy resin composition is significantly reduced.

In the epoxy resin composition of the present invention, the amount of DABCO in the component (B) is 0.75 to 2.5 parts by mass with respect to 100 parts by mass of the epoxy resin as the component (A).
When the amount of DABCO in the component (B) is less than 0.75 parts by mass with respect to 100 parts by mass of the epoxy resin of the component (A), low temperature curing at 80 ° C. or less becomes impossible.
On the other hand, if the amount of DABCO in the component (B) is more than 2.5 parts by mass with respect to 100 parts by mass of the epoxy resin of the component (A), the cured product becomes brittle and physical properties such as toughness tend to decrease. .
The amount of DABCO in the component (B) is preferably 1.0 to 2.0 parts by mass with respect to 100 parts by mass of the epoxy resin of the component (A).

In the epoxy resin composition of the present invention, the content of the microencapsulated curing agent of the component (B) is 25 to 80 parts by mass with respect to 100 parts by mass of the epoxy resin of the component (A). It is preferable in terms of maintaining low temperature curing and various physical properties after curing of the epoxy resin composition.
In the epoxy resin composition of the present invention, the content of the microencapsulated curing agent as the component (B) can be appropriately selected within the above range according to the required characteristics.
In the epoxy resin composition of the present invention, even when the content of the microencapsulated curing agent as the component (B) is 55 parts by mass or less, low temperature curing at 80 ° C. or less is possible. Further, the blending ratio of other components of the resin composition such as the inorganic filler of the component (C) can be increased. Therefore, the range of the resin composition formulation design (particularly viscosity adjustment) is widened. In this case, the content of the microencapsulated curing agent (B) is preferably 25 to 55 parts by mass and preferably 25 to 40 parts by mass with respect to 100 parts by mass of the epoxy resin (A). More preferred.
On the other hand, by setting the content of the microencapsulated curing agent of the component (B) to more than 55 parts by mass with respect to 100 parts by mass of the epoxy resin of the component (A), low temperature curing at 80 ° C. or less is extremely short. Can be achieved. Specifically, low temperature curing at 80 ° C. or less can be achieved in 30 minutes or less. In this case, the content of the microencapsulated curing agent of the component (B) is preferably more than 55 parts by weight to 80 parts by weight with respect to 100 parts by weight of the epoxy resin of the component (A). More preferably.

Component (C): Inorganic filler The linear expansion coefficient of the epoxy resin composition can be controlled by the inorganic filler (C). Examples of the inorganic filler of component (C) include silica fillers such as colloidal silica, hydrophobic silica, fine silica, and nano silica, acrylic beads, glass beads, urethane beads, bentonite, acetylene black, and ketjen black. Further, the average particle diameter of the inorganic filler (C) (the average maximum diameter when it is not granular) is not particularly limited, but it is 0.01 to 50 μm in the epoxy resin composition. Is preferable for uniform dispersion, and is preferable for reasons such as excellent injectability when the epoxy resin composition is used as a liquid sealing material such as underfill. If it is less than 0.01 μm, the viscosity of the epoxy resin composition increases, and the injectability may deteriorate when used as a liquid sealing material such as underfill. If it exceeds 50 μm, it may be difficult to uniformly disperse the filler in the epoxy resin composition. Moreover, from a viewpoint of protecting a copper wire from the thermal stress of the epoxy resin composition after curing, the average particle diameter of the component (C) is more preferably 0.6 to 10 μm. Commercially available products include high purity synthetic spherical silica manufactured by Admatechs (product name: SO-E5, average particle size: 2 μm; product name: SO-E2, average particle size: 0.6 μm), silica manufactured by Tatsumori (product name: FB7SDX, Average particle size: 10 μm), Micron silica (product name: TS-10-034P, average particle size: 20 μm), and the like. Here, the average particle diameter of the inorganic filler is measured by a dynamic light scattering nanotrack particle size analyzer. The inorganic filler of component (C) may be used alone or in combination of two or more.

  (C) It is preferable that content of the inorganic filler of a component is 20-65 mass parts with respect to a total of 100 mass parts of all the components of an epoxy resin composition, More preferably, 30-60 mass parts, Furthermore, Preferably, it is 30-40 mass parts. When the epoxy resin composition is used as a liquid sealing material such as an underfill, the linear expansion coefficient of the epoxy resin composition can be lowered and the injectability is avoided when it is 30 to 40 parts by mass. Can do.

  The epoxy resin composition of this invention may contain the component described below as needed other than the said (A)-(C) component.

(D) Component: Thickening inhibitor The resin composition of the present invention comprises a thickening inhibitor as the (D) component in order to improve storage stability at normal temperature (25 ° C) and lengthen the pot life. You may contain.
As the thickening inhibitor of component (D), at least one selected from the group consisting of boric acid esters, aluminum chelates, and organic acids has a high effect of improving storage stability at room temperature (25 ° C.). Therefore, it is preferable.

Examples of the boric acid ester include 2,2′-oxybis (5,5′-dimethyl-1,3,2-oxaborinane), trimethyl borate, triethyl borate, tri-n-propyl borate, triisopropyl borate, tri- n-butyl borate, tripentyl borate, triallyl borate, trihexyl borate, tricyclohexyl borate, trioctyl borate, trinonyl borate, tridecyl borate, tridodecyl borate, trihexadecyl borate, trioctadecyl borate, tris (2- Ethylhexyloxy) borane, bis (1,4,7,10-tetraoxaundecyl) (1,4,7,10,13-pentaoxatetradecyl) (1,4,7-trioxaundecyl) borane , Tribenzyl borate, trifeni Borate, tri -o- Toriruboreto, tri -m- Toriruboreto can be used triethanolamine borate.
In addition, since the boric acid ester contained as (D) component is liquid at normal temperature (25 degreeC), since a compound viscosity can be restrained low, it is preferable.
(D) When a boric acid ester is contained as a component, it is preferable that it is 0.1-8.9 mass parts with respect to 100 mass parts of total amounts of (A) component-(D) component, 0.1 It is more preferable that it is -4.4 mass parts, and it is still more preferable that it is 0.1-3.5 mass parts.

As the aluminum chelate, for example, aluminum trisacetylacetonate (for example, ALA: aluminum chelate A manufactured by Kawaken Fine Chemical Co., Ltd.) can be used.
When aluminum chelate is contained as the component (D), the amount is preferably 0.1 to 14.0 parts by mass with respect to 100 parts by mass of the total amount of the components (A) to (D). The amount is more preferably 13.0 parts by mass, and further preferably 0.1 to 12.0 parts by mass.

As the organic acid, for example, barbituric acid can be used.
When the organic acid is contained as the component (D), the amount is preferably 0.1 to 8.9 parts by mass with respect to 100 parts by mass of the total amount of the components (A) to (D). The amount is more preferably 7.1 parts by mass, and still more preferably 0.1 to 4.0 parts by mass.

(Other ingredients)
The epoxy resin composition of the present invention may further contain components other than the components (A) to (D) as necessary. Specific examples of such components include ion trapping agents, leveling agents, antioxidants, antifoaming agents, flame retardants, colorants, reactive diluents, and the like. The type and amount of each compounding agent are as usual.

  The resin composition of the present invention requires the above components (A) to (C) and, if included, the component (D), and other compounding agents to be blended as necessary at the same time or separately. Can be obtained by stirring, melting, mixing, and dispersing while applying heat treatment. The mixing, stirring, dispersing and the like devices are not particularly limited, and a raikai machine equipped with a stirring and heating device, a three-roll mill, a ball mill, a planetary mixer, a bead mill and the like can be used. . Moreover, you may use combining these apparatuses suitably.

The epoxy resin composition of the present invention can achieve low-temperature curing at 80 ° C. or less in a short time. Specifically, low temperature curing at 80 ° C. or less can be achieved in 60 minutes or less. In addition, as described above, by setting the content of the component (B) to more than 55 parts by mass with respect to 100 parts by mass of the epoxy resin of the component (A), low temperature curing at 80 ° C. or less is achieved in a very short time. it can. Specifically, low temperature curing at 80 ° C. or less can be achieved in 30 minutes or less.
Therefore, the epoxy resin composition of the present invention is suitable for a sealing material or an adhesive for electronic parts for applications requiring thermosetting at 80 ° C. or lower. When using as a sealing material, the form is not specifically limited, It can be used also as a liquid sealing material like an underfill, and it can be used also as a wire sealing material. Note that the semiconductor device of the present invention has a flip-chip type semiconductor element sealed with these sealing materials. The semiconductor element to be sealed here is not particularly limited to an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, a capacitor, and the like.

  When the resin composition of the present invention is used as a one-pack type adhesive, each component of the resin composition (that is, the above components (A) to (C), and if included, the above component (D) and Furthermore, you may mix | blend the said other compounding agent mix | blended as needed.

  The epoxy resin composition of the present invention has sufficient adhesive strength. Specifically, the adhesive strength (shear strength, cured at 80 ° C. for 60 min) measured by the procedure described later is preferably 15 kgf / chip or more, more preferably 20 kgf / chip, and 25 kgf / chip. Is more preferable.

  The epoxy resin composition of the present invention has good storage stability at room temperature and a long pot life. In this specification, the thickening rate after 24 hours storage measured by the procedure described in the examples described later or the thickening rate after 48 hours storage is used as an index of pot life. The epoxy resin composition of the present invention preferably has a viscosity increase rate after storage for 24 hours measured by the procedure described in the examples described later, of 1.2 times or less, and the viscosity increase rate after storage for 48 hours. It is more preferable that it is 1.2 times or less.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

(Preparation of epoxy resin composition)
The epoxy resin composition was prepared by mixing each component with the formulation shown in the following table. In addition, in the following table | surface, all the numbers which show the mixture ratio of (A) component-(D) component have shown the mass part.
Each component in the table is as follows.
(A) Component YDF8170: Bisphenol F type epoxy resin (manufactured by Nippon Steel Chemical Co., Ltd., epoxy equivalent 160)
ZX1658GS: cyclohexanedimethanol diglycidyl ether (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., epoxy equivalent 135)
EXA835LV: Bisphenol F type epoxy resin / bisphenol A type epoxy resin mixture (DIC Corporation, epoxy equivalent 165)
(B) Component HXA5945HP: NovaCure HXA5945HP (isocyanate adduct type microencapsulated curing agent containing DABCO as an active ingredient) (manufactured by Asahi Kasei E-Materials Co., Ltd., 3% by weight DABCO)
(B ′) Component DABCO: (manufactured by Tokyo Chemical Industry Co., Ltd.)
HXA3932HP: Novacure HXA3932HP (isocyanate adduct type microencapsulated curing agent containing 2-methylimidazole and diaminodiphenylmethane as active ingredients) (manufactured by Asahi Kasei E-Materials Corporation)
(C) Component SOE5: Silica filler (D50 = 2 μm) (manufactured by Admatechs Co., Ltd.)
SOE2: Silica filler (D50 = 0.6 μm) (manufactured by Admatechs Co., Ltd.)
Component (D) Triisopropyl borate (manufactured by Tokyo Chemical Industry Co., Ltd.)
Tripropyl borate (manufactured by Tokyo Chemical Industry Co., Ltd.)
Aluminum chelate: Aluminum chelate A (manufactured by Kawaken Fine Chemical Co., Ltd.)
Barbituric acid (manufactured by Tokyo Chemical Industry Co., Ltd.)

The adhesive strength (shear strength) of the prepared epoxy resin composition was measured by the following procedure. The results are shown in the table below.
(1) A sample is stencil-printed with a size of 2 mmφ on a glass epoxy substrate.
(2) A 2 mm × 2 mm Si chip is placed on the printed sample. This is heat-cured for 60 minutes at 80 ° C. using an air dryer.
(3) The shear strength was measured with a desktop universal testing machine (1605HTP manufactured by Aiko Engineering Co., Ltd.).
In the following table, the case where the adhesive strength was 15 kgf / chip or more was rated as ◯, and the case where it was less than 15 kgf / chip was marked as x. Moreover, what was able to thermoset was made into sclerosis | hardenability (circle), and what was not thermosetting was made into curability x.

About the prepared epoxy resin composition, the viscosity (Pa * s) in 25 degreeC was measured at 50 rpm using the Brookfield rotational viscometer HBDV-1 (spindle SC4-14 use). Next, when the epoxy resin composition was put in a sealed container and stored for 24 hours in an environment of 25 ° C. and 50% humidity, the viscosity at the time of storage for 48 hours was measured in the same procedure, and the viscosity immediately after preparation was measured. The ratio of thickening to be an index of pot life was calculated.
In the following table, the case where the thickening ratio after 24 hours is 1.2 times or less is Δ, and the case where the thickening ratio after 48 hours is 1.2 times or less is ○, and the thickening ratio after 24 hours is The case of exceeding 1.2 times was set as x.

Examples 1 to 3 are examples in which the amount of DABCO in the component (B) relative to 100 parts by mass of the epoxy resin of the component (A) was changed within the range of 0.75 to 2.5 parts by mass. 4 is an example in which the particle size of the inorganic filler of the component (C) is changed, Example 5 is an example in which the epoxy resin of the component (A) is changed, and Examples 6 and 7 are ( C) It is an Example which changed the quantity of the inorganic filler of a component, and Examples 8-10 are Examples which changed the thickening inhibitor of (D) component. In each of these examples, the adhesive strength (shear strength, 80 ° C., 60 min heat curing) is 15 kgf / chip or more, and the viscosity increase ratio after 48 hours storage as a pot life index is 1.2 times or less. It was. (D) In Example 11 which does not contain a component, although the pot life deteriorated compared with Examples 1-10, the pot life after 24 hours was favorable. Example 3 in which the amount of DABCO in the component (B) was about 2.4 parts by mass with respect to 100 parts by mass of the epoxy resin (A) was cured even when thermally cured at 80 ° C. for 30 minutes.
Comparative Example 1 in which DABCO was directly contained as the component (B ′) gelled during the preparation of the epoxy resin composition. Therefore, the evaluation of adhesive strength and thickening magnification during storage for 24 hours and 48 hours was not performed.
Comparative Example 2 using an isocyanate adduct type microencapsulated curing agent that contains 2-methylimidazole and diaminodiphenylmethane as active ingredients and does not contain DABCO as the component (B ′) is not cured by heat curing at 80 ° C. for 60 minutes. It was.

Claims (7)

(A) epoxy resin,
(B) an isocyanate adduct type microencapsulated curing agent containing 1,4-diazabicyclo [2.2.2] octane (1,4-diazabicyclo [2.2.2] octane (DABCO)) as an active ingredient,
An epoxy resin composition comprising (C) an inorganic filler, wherein the amount of DABCO in the component (B) is 0.75 to 2.5 parts by mass with respect to 100 parts by mass of the component (A). object.   The epoxy resin composition according to claim 1, wherein the content of the component (B) is 25 to 80 parts by mass with respect to 100 parts by mass of the component (A).   Furthermore, the epoxy resin composition of Claim 1 or 2 containing (D) thickening inhibitor.   The epoxy resin composition according to claim 3, wherein the thickening inhibitor of the component (D) is at least one selected from the group consisting of boric acid esters, aluminum chelates, and organic acids.   A cured resin product obtained by heating the epoxy resin composition according to claim 1.   The sealing material containing the epoxy resin composition in any one of Claims 1-4.   A semiconductor device having a flip chip type semiconductor element sealed with the sealing material according to claim 6.