JP2014148586A - Epoxy resin composition for sealing, electronic device, automobile, and method for manufacturing electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition for sealing capable of providing an electronic device having excellent long-term reliability.SOLUTION: An electronic device 100 includes: a wiring board 101; a plurality of electronic components 105 mounted to at least one surface 110 of the wiring board 101, in which at least one is a QFP-type package and has a gap 103 between the wiring board 101 and itself; and a sealing material 107 for collectively sealing the gap 103 between the QFP-type package and the wiring board 101, the plurality of electronic components 105, and the wiring board 101, wherein the sealing material 107 is filled in the gap 103. The epoxy resin composition for sealing is used for forming the sealing material 107 constituting the electronic device 100, and includes a thermosetting resin (A) containing an epoxy resin, a curing agent (B) and an inorganic filler (C).

Description

  The present invention relates to an epoxy resin composition for sealing, an electronic device, an automobile, and a method for manufacturing the electronic device.

  An electronic device such as an electronic control unit mounted on an automobile or the like is required to have a configuration that prevents intrusion of water, corrosive gas, and the like, and protects a wiring board and electronic components mounted on the wiring board.

Patent Document 1 (Japanese Patent Application Laid-Open No. 2010-67773) discloses a step of mounting an electronic component on a wiring board, and a first resin sealing step of sealing the electronic component mounted on the wiring board with a resin. Mounting the external connection terminals to electrically connect the electronic circuit on the wiring board and the external electronic circuit system to the wiring board; and resin sealing in the wiring board and the first resin sealing step And a second resin sealing step for integrally sealing the electronic component with a resin. The method for manufacturing an electric and electronic control device is described.
It is described that a thermosetting resin is used as the resin used in the first resin sealing step. Further, it is described that a thermoplastic resin is used in the second resin sealing step.

JP 2010-67773 A

  However, according to the study by the present inventors, for example, an electronic device obtained by the method described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2010-67773) is an electronic component mounted on a wiring board during a cooling / heating cycle. It has become clear that may peel off.

  Then, this invention makes it a subject to provide the epoxy resin composition for sealing which can implement | achieve the electronic device excellent in long-term reliability.

According to the present invention,
A wiring board;
A plurality of electronic components mounted on at least one surface of the wiring board, at least one of which is a QFP type package having a gap with the wiring board;
The gap between the QFP type package and the wiring board, the plurality of electronic components, and a sealing material that collectively seals the wiring board;
An epoxy resin composition for sealing used for forming the sealing material constituting the electronic device in which the sealing material is filled in the gap,
A thermosetting resin (A) containing an epoxy resin;
A curing agent (B);
An inorganic filler (C);
An epoxy resin composition for sealing is provided.

Moreover, according to the present invention,
A wiring board;
A plurality of electronic components mounted on at least one surface of the wiring board, at least one of which is a QFP type package having a gap with the wiring board;
The gap between the QFP type package and the wiring board, the plurality of electronic components, and a sealing material that collectively seals the wiring board;
With
The sealing material is a cured product of the epoxy resin composition for sealing, and an electronic device is provided in which the cured product is filled in the gap.

  Moreover, according to this invention, a motor vehicle provided with the said electronic device is provided.

Moreover, according to the present invention,
A mounting step of mounting a plurality of electronic components, at least one of which is a QFP type package, on at least one surface of the wiring board;
A sealing step of collectively sealing the gap formed between the QFP type package and the wiring board, the plurality of electronic components, and the wiring board using the epoxy resin composition for sealing;
A method for manufacturing an electronic device, comprising:

  ADVANTAGE OF THE INVENTION According to this invention, the epoxy resin composition for sealing which can implement | achieve the electronic device excellent in long-term reliability can be provided.

It is sectional drawing which shows an example of a structure of the electronic device 100 of embodiment which concerns on this invention. It is sectional drawing which shows an example of a structure of the electronic device 100 of embodiment which concerns on this invention. It is a cross-sectional enlarged view of the area | region A shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate. The figure is a schematic view and does not necessarily match the actual dimensional ratio. In addition, unless otherwise specified, “to” represents the following.

  FIG. 1 is a cross-sectional view showing an example of the configuration of an electronic device 100 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an example of the configuration of the electronic device 100 according to the embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view of region A shown in FIG. 1 and 2 are schematic views showing the electronic device 100, and the configuration of the electronic device 100 according to the present embodiment is not limited to that shown in FIGS.

The electronic device 100 is mounted on a wiring board 101 and at least one surface 110 of the wiring board 101, at least one of which is a plurality of QFP (Quad Flat Package) type packages having a gap 103 between the wiring board 101 and the electronic device 100. The electronic component 105 includes a gap 103 between the QFP type package and the wiring substrate 101, a plurality of electronic components 105, and a sealing material 107 that collectively seals the wiring substrate 101. The gap 103 is filled with a sealing material 107 that is a cured product of the sealing epoxy resin composition according to the present embodiment.
The epoxy resin composition for sealing according to the present embodiment is used for forming the sealing material 107 constituting the electronic device 100, and includes a thermosetting resin (A) containing an epoxy resin, a curing agent (B), An inorganic filler (C).
1 to 3 show a mode in which the gap 103 is filled with 100% of the sealing material 107, but in practice, it is sufficient that a part of the gap 103 is filled with the sealing material 107. , Need not be 100% filled.

  The electronic device 100 is an electronic control unit that is mounted on a vehicle such as a hybrid vehicle, a fuel cell vehicle, and an electric vehicle.

  Examples of the electronic component 105 mounted on the wiring board 101 include an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, a solid-state imaging device, a ceramic capacitor, a chip resistor, and a microcomputer. In the package of the electronic component 105 to be mounted, at least one of the plurality of electronic components 105 is a QFP type.

The wiring board 101 has at least one wiring layer (for example, four layers), and its size is, for example, 1.6 mmt × 60 mm × 60 mm.
As the wiring board 101, for example, a resin printed board (glass epoxy (FR4) board or the like) in which glass fiber or inorganic filler is blended with epoxy resin, polyimide resin or bismaleimide triazine resin, a flexible board made of polyimide or liquid crystal polymer, A ceramic substrate, a metal substrate, or the like is used.
The thickness of the wiring substrate 101 is, for example, not less than 1.0 mm and not more than 3.0 mm.

  As shown in FIG. 2, the electronic device 100 according to the present embodiment may further include an external connection component 109 that is electrically connected to an external device on at least one surface 110 of the wiring board 101. At this time, it is preferable that the sealing material 107 further collectively seals at least a part of the external connection component 109. Thereby, the connection reliability of the external connection component 109 can be improved.

  As a material of the external connection component 109, for example, copper, iron plated with tin, gold, nickel, zinc or the like, or an alloy thereof is used.

  In the electronic device 100 according to the present embodiment, the gap 103, the plurality of electronic components 105, and the wiring board 101 are collectively sealed with a sealing material 107. Thereby, the adhesiveness of the electronic component 105 and the wiring board 101 improves, and it can suppress that the electronic component 105 peels from the wiring board 101 at the time of a thermal cycle. As a result, the long-term reliability of the electronic device 100 can be improved.

Further, in the electronic device 100 according to this embodiment, the volume of the gap 103 is a, and the volume occupied by the cured product (sealing material 107) of the sealing epoxy resin composition according to this embodiment filled in the gap is defined. When b, the filling rate of the cured product calculated by b / a × 100 is preferably 5% or more and 95% or less, more preferably 10% or more and 90% or less, and further preferably 15%. It is 85% or less.
Here, the filling rate of the cured product can be measured by a transmission method of an ultrasonic survey apparatus (SAT) or observation of a cross-sectional polished sample. Among them, the transmission method of the ultrasonic probe (SAT) is preferable in that it can be measured nondestructively.

When the filling rate of the cured product is not more than the above upper limit value, the stress relaxation ability of the obtained sealing material 107 can be improved. If it does so, peeling and the generation | occurrence | production of a crack resulting from the difference of a thermal expansion coefficient with the wiring board 101 and the electronic component 105 can be suppressed.
Moreover, when the filling rate of the cured product is equal to or higher than the lower limit value, the adhesion between the electronic component 105 and the wiring substrate 101 is improved, and the electronic component 105 is prevented from being peeled off from the wiring substrate 101 during the thermal cycle. it can.
Therefore, when the filling rate of the cured product is within the above range, it is possible to improve the stress relaxation ability of the electronic device 100 while improving the adhesion between the electronic component 105 and the wiring substrate 101. As a result, the long-term reliability of the electronic device 100 can be further improved. The filling rate of the said hardened | cured material can be adjusted by adjusting the viscosity of the epoxy resin composition for sealing, for example.

(Epoxy resin composition for sealing)
Next, the sealing epoxy resin composition according to this embodiment will be described in detail.
The epoxy resin composition for sealing according to the present embodiment is used for forming the sealing material 107 constituting the electronic device 100, and includes a thermosetting resin (A) containing an epoxy resin, a curing agent (B), An inorganic filler (C). Hereinafter, each component will be described.

[Thermosetting resin (A)]
As the thermosetting resin (A), for example, an epoxy resin (A1), a phenol resin, an oxetane resin, a (meth) acrylate resin, an unsaturated polyester resin, a diallyl phthalate resin, or a maleimide resin is used. Among these, an epoxy resin (A1) excellent in curability, storage stability, heat resistance of the cured product, moisture resistance, and chemical resistance is preferably used.

The thermosetting resin (A) according to the present embodiment includes an epoxy resin (A1). The epoxy resin (A1) is not particularly limited in molecular weight and structure as long as it has two or more epoxy groups in one molecule.
Examples of the epoxy resin (A1) include novolak type epoxy resins such as phenol novolak type epoxy resins and cresol novolak type epoxy resins; bisphenol type epoxy resins such as bisphenol A type epoxy resins and bisphenol F type epoxy resins; N, N-di Aromatic glycidylamine type epoxy resins such as glycidylaniline, N, N-diglycidyltoluidine, diaminodiphenylmethane type glycidylamine, aminophenol type glycidylamine; hydroquinone type epoxy resin; biphenyl type epoxy resin; stilbene type epoxy resin; Methane-type epoxy resin; Triphenolpropane-type epoxy resin; Alkyl-modified triphenolmethane-type epoxy resin; Triazine nucleus-containing epoxy resin; Dicyclopenta En-modified phenol type epoxy resin; naphthol type epoxy resin; naphthalene type epoxy resin; naphthylene ether type epoxy resin; phenol aralkyl type epoxy resin having phenylene and / or biphenylene skeleton, naphthol aralkyl type epoxy having phenylene and / or biphenylene skeleton Examples thereof include epoxy resins such as aralkyl-type epoxy resins such as resins, and aliphatic epoxy resins such as alicyclic epoxies such as vinylcyclohexene dioxide, dicyclopentadiene oxide, and alicyclic diepoxy-adipade. These may be used alone or in combination of two or more.

  As the epoxy resin (A1), those containing a structure in which a glycidyl ether structure or a glycidylamine structure is bonded to an aromatic ring are preferable from the viewpoints of heat resistance, mechanical properties, and moisture resistance.

  Examples of the phenol resin include novolak type phenol resins such as phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, and resol type phenol resin.

  Although content of the thermosetting resin (A) which concerns on this embodiment is not specifically limited, Preferably it is 5 to 40 mass% with respect to 100 mass% of the total value of the epoxy resin composition for sealing. More preferably, it is 7 mass% or more and 20 mass% or less.

  Although content of the epoxy resin (A1) which concerns on this embodiment is not specifically limited, Preferably it is 70 to 100 mass% with respect to 100 mass% of thermosetting resins (A), More preferably It is 80 mass% or more and 100 mass% or less.

[Curing agent (B)]
The curing agent (B) is used to three-dimensionally crosslink the epoxy resin (A1) included as a preferred embodiment in the thermosetting resin (A). Although it does not specifically limit as a hardening | curing agent (B), For example, naphthenic acid salts, such as cobalt naphthenate, or a phenol resin can be used. The phenol resin-based curing agent is a monomer, oligomer, or polymer in general having two or more phenolic hydroxyl groups in one molecule, and its molecular weight and molecular structure are not particularly limited.
Examples of phenol resin-based curing agents include novolak-type phenol resins such as phenol novolak resin, cresol novolak resin, and naphthol novolak resin; polyfunctional phenol resins such as triphenolmethane type phenol resin; terpene-modified phenol resin, dicyclopentadiene Modified phenol resins such as modified phenol resins; Aralkyl resins such as phenol aralkyl resins having a phenylene skeleton and / or biphenylene skeleton, naphthol aralkyl resins having a phenylene and / or biphenylene skeleton; bisphenol compounds such as bisphenol A and bisphenol F; Phenol resins mainly composed of reaction products of benzaldehyde, formaldehyde and phenol; phenol resins represented by the following formula (12A) It is.

（式（１２Ａ）中、２つのＹは、それぞれ互いに独立して、下記式（１２Ｂ）または下記式（１２Ｃ）で表されるヒドロキシフェニル基を表し、Ｘは、下記式（１２Ｄ）または下記式（１２Ｅ）で表されるヒドロキシフェニレン基を表す。）

(In the formula (12A), two Y's each independently represent a hydroxyphenyl group represented by the following formula (12B) or the following formula (12C), and X represents the following formula (12D) or the following formula (It represents a hydroxyphenylene group represented by (12E).)

  These may be used alone or in combination of two or more. Among these, it is preferable to include at least one selected from the group consisting of a novolac-type phenol resin, a phenol aralkyl resin, a naphthol-type phenol resin, and a phenol resin mainly composed of a reaction product of hydroxybenzaldehyde, formaldehyde, and phenol. By using such a phenol resin-based curing agent, the balance of flame resistance, moisture resistance, electrical characteristics, curability, storage stability, and the like is improved. In particular, from the viewpoint of curability, the hydroxyl equivalent of the phenol resin-based curing agent can be, for example, 90 g / eq or more and 250 g / eq or less.

  Furthermore, examples of the curing agent that can be used in combination include a polyaddition type curing agent, a catalyst type curing agent, and a condensation type curing agent.

  Examples of polyaddition type curing agents include aliphatic polyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA), and metaxylenediamine (MXDA); diaminodiphenylmethane (DDM), m-phenylenediamine (MPDA), and diaminodiphenyl. Aromatic polyamines such as sulfone (DDS); polyamine compounds including dicyandiamide (DICY), organic acid dihydralazide, etc .; alicyclic acid anhydrides such as hexahydrophthalic anhydride (HHPA), methyltetrahydrophthalic anhydride (MTHPA); Acid anhydrides including aromatic acid anhydrides such as trimellitic acid (TMA), pyromellitic anhydride (PMDA), benzophenone tetracarboxylic acid (BTDA); polyphenols such as novolac-type phenolic resins and phenolic polymers Le compounds; polysulfide, thioester, polymercaptan compounds such as thioether; an isocyanate prepolymer, an isocyanate compound such as a blocked isocyanate; organic acids such as carboxylic acid-containing polyester resins.

  Examples of the catalyst-type curing agent include tertiary amine compounds such as benzyldimethylamine (BDMA) and 2,4,6-trisdimethylaminomethylphenol (DMP-30); 2-methylimidazole, 2-ethyl-4- Examples include imidazole compounds such as methylimidazole (EMI24); Lewis acids such as BF3 complexes.

  Examples of the condensation type curing agent include a urea resin such as a resole resin and a methylol group-containing urea resin; and a melamine resin such as a methylol group-containing melamine resin.

  In the case where such other curing agents are used in combination, the content of the phenol resin curing agent is preferably 20% by mass or more, and more preferably 30% by mass or more with respect to the total curing agent (B). Is more preferable, and 50% by mass or more is particularly preferable. Good fluidity | liquidity can be expressed, maintaining a flame resistance as a compounding ratio is more than the said lower limit. Moreover, the content of the phenol resin-based curing agent is not particularly limited, but is preferably 100% by mass or less with respect to the total curing agent (B).

  Although content of the hardening | curing agent (B) with respect to the epoxy resin composition for sealing is not specifically limited, 0.8 mass% or more with respect to 100 mass% of total values of the epoxy resin composition for sealing It is preferable that it is 1.5 mass% or more. By setting the blending ratio to be equal to or higher than the above lower limit value, good curability can be obtained. Moreover, content of the hardening | curing agent (B) with respect to the epoxy resin composition for sealing is although it does not specifically limit, 12 mass% or less with respect to 100 mass% of total values of the epoxy resin composition for sealing. It is preferable that it is 10 mass% or less.

  The phenol resin as the curing agent (B) and the epoxy resin (A1) as the thermosetting resin (A) are the number of epoxy groups (EP) in the total thermosetting resin (A) and the phenolic property of all phenol resins. It is preferable that the equivalent ratio (EP) / (OH) to the number of hydroxyl groups (OH) is 0.8 to 1.3. When the equivalent ratio is within the above range, sufficient curing characteristics can be obtained when the resulting sealing epoxy resin composition is molded. However, when a resin other than a phenol resin capable of reacting with an epoxy resin is used in combination, the equivalent ratio may be adjusted as appropriate.

[Inorganic filler (C)]
Examples of the inorganic filler (C) include fused silica such as fused crushed silica and fused spherical silica, crystalline silica, alumina, kaolin, talc, clay, mica, rock wool, wollastonite, glass powder, glass flake, and glass beads. Glass fiber, silicon carbide, silicon nitride, aluminum nitride, carbon black, graphite, titanium dioxide, calcium carbonate, calcium sulfate, barium carbonate, magnesium carbonate, magnesium sulfate, barium sulfate, cellulose, aramid, wood, phenolic resin molding material and Examples thereof include pulverized powder obtained by pulverizing a cured product of an epoxy resin molding material. Among these, silica such as fused crushed silica, fused spherical silica, and crystalline silica is preferable, and fused spherical silica is more preferable. Of these, calcium carbonate is preferable in terms of cost. As an inorganic filler (C), you may use by 1 type, or may use 2 or more types together.

The average particle diameter d ₅₀ in the volume-based particle size distribution measured by the laser diffraction / scattering particle size distribution measurement method of the inorganic filler (C) is preferably 0.01 μm or more and 75 μm or less, more preferably 0.1 μm or more and 50 μm or less. More preferably, it is 1 μm or more and 30 μm or less. Inorganic filler Average particle size d ₅₀ of (C) by the above range, thereby improving the filling property of the gap 103. The average particle size _{d 50} was a reduced volume average particle diameter with a laser diffraction type measuring device RODOS SR type (SYMPATEC HEROS & RODOS).

Further, in the encapsulated epoxy resin composition according to the present embodiment, the inorganic filler (C) may be an average particle size d ₅₀ comprises two or more spherical silica are different. Thereby, improvement of fluidity | liquidity and a filling property and coexistence of burr | flash suppression are attained.

Further, in the electronic device 100 according to the present embodiment, the maximum particle diameter of the inorganic filler (C) is _Dmax, and the QFP type package (one of the plurality of electronic components 105) and the wiring as shown in FIG. When the vertical distance of the gap 103 to the substrate 101 is W, W / D _max is preferably 0.2 or more and 3.0 or less, and more preferably 0.4 or more and 2.8 or less. When W / D _max is within the above range, the long-term reliability of the electronic device 100 can be further improved.
Here, the maximum particle diameter _Dmax in the present embodiment is defined as follows. First, the inorganic filler (C) is sieved using a mesh of a predetermined size. The size of the mesh used at this time is the maximum particle diameter _Dmax of the inorganic filler (C). When two or more kinds of spherical silica having different average particle diameters d ₅₀ are included, the spherical silica having the largest average particle diameter d ₅₀ usually has D _max .
The maximum particle diameter _Dmax of the inorganic filler (C) is preferably 20 μm or more and 200 μm or less, more preferably 30 μm or less and 150 μm or less.

  The vertical distance W is, for example, not less than 20 μm and not more than 200 μm. Here, the vertical distance W can be measured by a value obtained by subtracting the value of the QFP type package from the level difference between the QFP type package and the substrate measured by the laser displacement meter.

  In addition, the inorganic filler (C) is not particularly limited, but it is preferable to remove moisture adhering to the surface of the silica particles by drying in advance. If the water adhering to the surface of the silica particles is removed, the coupling agent can be uniformly bonded to the particle surface during the coupling agent treatment described later.

  The content of the inorganic filler (C) is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 100% by mass with respect to the total value of 100% by mass of the sealing epoxy resin composition. It is 65 mass% or more, Most preferably, it is 75 mass% or more. When it is at least the above lower limit value, an increase in moisture absorption and a decrease in strength associated with the curing of the resulting epoxy resin composition for sealing can be reduced. In addition, the content of the inorganic filler (C) is preferably 93% by mass or less, more preferably 91% by mass or less, with respect to 100% by mass of the total value of the epoxy resin composition for sealing. Preferably it is 90 mass% or less. When the amount is not more than the above upper limit, the resulting epoxy resin composition for sealing has good fluidity and good moldability. Therefore, the manufacturing stability of the electronic device 100 is increased, and the electronic device 100 having an excellent balance between yield and long-term reliability can be obtained.

  Further, when the inorganic filler (C) is used in combination with a metal hydroxide such as aluminum hydroxide and magnesium hydroxide as described later; zinc borate; zinc molybdate; antimony trioxide and the like. The total amount of the inorganic flame retardant and the inorganic filler (C) is preferably within the range of the content of the inorganic filler (C).

The inorganic filler (C) may be subjected to surface treatment with a coupling agent (F) such as a silane coupling agent (also referred to as a first coupling agent) in advance. Thereby, aggregation of an inorganic filler can be suppressed and favorable fluidity | liquidity can be obtained. Therefore, the filling property of the sealing epoxy resin composition into the gap 103 can be improved.
Moreover, since affinity with a resin component increases, the intensity | strength of the sealing material 107 formed using the epoxy resin composition for sealing can be improved.
Although it does not specifically limit as a 1st coupling agent used for the surface treatment of an inorganic filler (C), For example, an epoxy silane, an aminosilane, a ureido silane, a mercapto silane etc. are mentioned.

  Examples of the epoxy silane include γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, and the like. Is mentioned. Examples of aminosilanes include primary aminosilanes such as γ-aminopropyltriethoxysilane and γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, and N-β (aminoethyl). γ-aminopropylmethyldimethoxysilane, N-phenylγ-aminopropyltriethoxysilane, N-phenylγ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, N-6- ( Aminohexyl) secondary aminosilanes such as 3-aminopropyltrimethoxysilane, N- (3- (trimethoxysilylpropyl) -1,3-benzenedimethanane, etc. Examples of ureidosilane include γ- Ureidopropyltriethoxysilane, hexamethyldi Silazane, etc. may be used as a latent aminosilane coupling agent in which the primary amino moiety of aminosilane is protected by reacting with a ketone or aldehyde, and the aminosilane may have a secondary amino group. Examples of mercaptosilane include γ-mercaptopropyltrimethoxysilane and 3-mercaptopropylmethyldimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfide, and bis (3-triethoxysilylpropyl) disulfide. Examples of such a silane coupling agent exhibiting the same function as that of a mercaptosilane coupling agent by thermal decomposition are also included. These silane couplings Grayed agents may be used in combination of two or more be used one kind alone.

  Mercaptosilane is preferable from the viewpoint of continuous formability. From the viewpoint of fluidity, mercaptosilane and aminosilane are preferable, and mercaptosilane and secondary aminosilane are more preferable. Epoxysilane is preferable from the viewpoint of adhesion.

  An epoxy resin composition for sealing is obtained by appropriately selecting the type of the first coupling agent used for the surface treatment of such an inorganic filler (C) or by appropriately adjusting the blending amount of the first coupling agent. The fluidity and the strength of the sealing material 107 can be controlled.

The coupling treatment to the inorganic filler (C) can be performed, for example, as follows. First, the inorganic filler (C) and the silane coupling agent are mixed and stirred using a mixer. For example, a ribbon blender or the like can be used as the mixer. At this time, it is preferable to set the humidity in the mixer to 50% or less. By adjusting to such a spray environment, it is possible to suppress moisture from reattaching to the surface of the silica particles. Furthermore, it can suppress that water mixes in the coupling agent during spraying and the coupling agents react with each other.
Subsequently, the obtained mixture is taken out from the mixer and subjected to an aging treatment to promote the coupling reaction. The aging treatment is performed, for example, by leaving it for 7 days or more under the condition of 20 ± 5 ° C. By carrying out under such conditions, the coupling agent can be uniformly bonded to the surface of the silica particles. Then, the inorganic filler (C) to which the silane coupling process was performed is obtained by sieving and removing a coarse particle.
By using such surface-treated silica particles, the interfacial adhesive strength between the silica particles and the resin component can be improved. Furthermore, generation of microcracks in the sealing material 107 can be suppressed.

[Other ingredients]
The epoxy resin composition for sealing according to this embodiment may include a curing accelerator (D). The curing accelerator (D) only needs to accelerate the reaction between the epoxy group of the epoxy resin and the hydroxyl group of the phenol resin curing agent (B), and a generally used curing accelerator (D) is used. it can.

Specific examples of the curing accelerator (D) include phosphorus atom-containing compounds such as organic phosphines, tetra-substituted phosphonium compounds, phosphobetaine compounds, adducts of phosphine compounds and quinone compounds, adducts of phosphonium compounds and silane compounds; Representative examples include 1,8-diazabicyclo (5,4,0) undecene-7, amidine compounds such as imidazole, tertiary amines such as benzyldimethylamine, and quaternary onium salts of the above compounds, amidinium salts and ammonium salts. And nitrogen atom-containing compounds.
Among these, a phosphorus atom-containing compound is preferable from the viewpoint of curability, and from the viewpoint of balance between fluidity and curability, a tetra-substituted phosphonium compound, a phosphobetaine compound, an adduct of a phosphine compound and a quinone compound, a phosphonium compound A curing accelerator having a latent property such as an adduct of silane compound is more preferable. In view of fluidity, tetra-substituted phosphonium compounds are particularly preferable. From the viewpoint of solder resistance, phosphobetaine compounds, adducts of phosphine compounds and quinone compounds are particularly preferable, and in view of latent curability. An adduct of a phosphonium compound and a silane compound is particularly preferable. Further, from the viewpoint of continuous moldability, a tetra-substituted phosphonium compound is preferable. In view of cost, organic phosphine and nitrogen atom-containing compounds are also preferably used.

  Examples of the organic phosphine that can be used in the sealing epoxy resin composition according to the present embodiment include a first phosphine such as ethylphosphine and phenylphosphine; a second phosphine such as dimethylphosphine and diphenylphosphine; trimethylphosphine and triethylphosphine. And tertiary phosphine such as tributylphosphine and triphenylphosphine.

  Examples of the tetra-substituted phosphonium compound that can be used in the epoxy resin composition for sealing according to this embodiment include compounds represented by the following general formula (1).

  In the general formula (1), P represents a phosphorus atom, R1, R2, R3 and R4 each independently represents an aromatic group or an alkyl group, and A represents a functional group selected from a hydroxyl group, a carboxyl group and a thiol group. Represents an anion of an aromatic organic acid having at least one of the groups in the aromatic ring, and AH is an aromatic organic having at least one functional group selected from a hydroxyl group, a carboxyl group, and a thiol group in the aromatic ring Represents an acid, x and y are integers of 1 to 3, z is an integer of 0 to 3, and x = y.

Although the compound represented by General formula (1) is obtained as follows, for example, it is not limited to this. First, a tetra-substituted phosphonium halide, an aromatic organic acid and a base are mixed in an organic solvent and mixed uniformly to generate an aromatic organic acid anion in the solution system. Next, when water is added, the compound represented by the general formula (1) can be precipitated.
In the compound represented by the general formula (1), R1, R2, R3, and R4 bonded to the phosphorus atom are phenyl groups, and AH is bonded to the phosphorus atom from the viewpoint of excellent balance between the yield during synthesis and the curing acceleration effect. A compound having a hydroxyl group in an aromatic ring, that is, a phenol compound, and A is preferably an anion of the phenol compound. The phenol compounds are monocyclic phenol, cresol, catechol, resorcin, condensed polycyclic naphthol, dihydroxynaphthalene, (polycyclic) bisphenol A, bisphenol F, bisphenol S, biphenol having a plurality of aromatic rings. , Phenylphenol, phenol novolak and the like, and among them, phenol compounds having two hydroxyl groups are preferably used.

  Examples of the phosphobetaine compound that can be used in the sealing epoxy resin composition according to this embodiment include compounds represented by the following general formula (2).

  In General formula (2), X1 represents a C1-C3 alkyl group, Y1 represents a hydroxyl group, a is an integer of 0-5, b is an integer of 0-4.

  The compound represented by the general formula (2) is subjected to, for example, a step of bringing a triaromatic substituted phosphine that is a third phosphine into contact with a diazonium salt and substituting the diazonium group of the triaromatic substituted phosphine with the diazonium salt. can get. However, the present invention is not limited to this.

  Examples of the adduct of a phosphine compound and a quinone compound that can be used in the epoxy resin composition for sealing according to this embodiment include compounds represented by the following general formula (3).

  In General formula (3), P represents a phosphorus atom, R5, R6, and R7 represent a C1-C12 alkyl group or a C6-C12 aryl group mutually independently, R8, R9, and R10 represents a hydrogen atom or a C1-C12 hydrocarbon group mutually independently. R8 and R9 may be bonded to each other to form a ring.

  Examples of the phosphine compound used as an adduct of a phosphine compound and a quinone compound include an aromatic ring such as triphenylphosphine, tris (alkylphenyl) phosphine, tris (alkoxyphenyl) phosphine, trinaphthylphosphine, and tris (benzyl) phosphine. Those having a substituent or a substituent such as an alkyl group or an alkoxyl group are preferred. Examples of the substituent such as an alkyl group and an alkoxyl group include those having 1 to 6 carbon atoms. From the viewpoint of availability, triphenylphosphine is preferable.

  Moreover, o-benzoquinone, p-benzoquinone, anthraquinones are mentioned as a quinone compound used for the adduct of a phosphine compound and a quinone compound. Among these, p-benzoquinone is preferable from the viewpoint of storage stability.

  The adduct of a phosphine compound and a quinone compound can be obtained by, for example, contacting and mixing in a solvent in which both organic tertiary phosphine and benzoquinone can be dissolved. The solvent is preferably a ketone such as acetone or methyl ethyl ketone, which has low solubility in the adduct. However, the present invention is not limited to this.

  In the compound represented by the general formula (3), R5, R6 and R7 bonded to the phosphorus atom are phenyl groups, and R8, R9 and R10 are hydrogen atoms, that is, 1,4-benzoquinone and triphenyl A compound to which phosphine is added is preferable in that it reduces the elastic modulus during heating of the cured epoxy resin composition.

  Examples of the adduct of a phosphonium compound and a silane compound that can be used in the sealing epoxy resin composition according to this embodiment include compounds represented by the following general formula (4).

  In General formula (4), P represents a phosphorus atom and Si represents a silicon atom. R11, R12, R13 and R14 each independently represent an organic group having an aromatic ring or a heterocyclic ring, or an aliphatic group, and X2 is an organic group bonded to the groups Y2 and Y3. X3 is an organic group bonded to the groups Y4 and Y5. Y2 and Y3 represent a group formed by releasing a proton from a proton donating group, and groups Y2 and Y3 in the same molecule are bonded to a silicon atom to form a chelate structure. Y4 and Y5 represent a group formed by releasing a proton from a proton donating group, and groups Y4 and Y5 in the same molecule are bonded to a silicon atom to form a chelate structure. X2 and X3 may be the same as or different from each other. Y2, Y3, Y4, and Y5 may be the same as or different from each other. Z1 is an organic group having an aromatic ring or a heterocyclic ring, or an aliphatic group.

  In the general formula (4), examples of R11, R12, R13, and R14 include phenyl group, methylphenyl group, methoxyphenyl group, hydroxyphenyl group, naphthyl group, hydroxynaphthyl group, benzyl group, methyl group, ethyl group, An n-butyl group, an n-octyl group, a cyclohexyl group, etc. are mentioned. Among these, an aromatic group having a substituent such as a phenyl group, a methylphenyl group, a methoxyphenyl group, a hydroxyphenyl group, and a hydroxynaphthyl group or an unsubstituted aromatic group is preferable.

Moreover, in General formula (4), X2 is an organic group couple | bonded with Y2 and Y3. Similarly, X3 is an organic group bonded to the groups Y4 and Y5. Y2 and Y3 are groups formed by proton-donating groups releasing protons, and groups Y2 and Y3 in the same molecule are combined with a silicon atom to form a chelate structure. Similarly, Y4 and Y5 are groups formed by proton-donating groups releasing protons, and groups Y4 and Y5 in the same molecule are combined with a silicon atom to form a chelate structure. The groups X2 and X3 may be the same or different from each other, and the groups Y2, Y3, Y4, and Y5 may be the same or different from each other. The groups represented by -Y2-X2-Y3- and -Y4-X3-Y5- in general formula (4) are composed of groups in which a proton donor releases two protons. Is. Therefore, the proton donor is preferably an organic acid having at least two carboxyl groups or hydroxyl groups in the molecule, more preferably an aromatic compound having at least two carboxyl groups or hydroxyl groups on carbon constituting the aromatic ring, An aromatic compound having at least two hydroxyl groups on adjacent carbons constituting the aromatic ring is more preferable.
Examples of proton donors include catechol, pyrogallol, 1,2-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,2′-biphenol, 1,1′-bi-2-naphthol, salicylic acid, 1-hydroxy- Examples include 2-naphthoic acid, 3-hydroxy-2-naphthoic acid, chloranilic acid, tannic acid, 2-hydroxybenzyl alcohol, 1,2-cyclohexanediol, 1,2-propanediol, and glycerin. Among these, catechol, 1,2-dihydroxynaphthalene, and 2,3-dihydroxynaphthalene are more preferable from the viewpoint of easy availability of raw materials and a curing acceleration effect.

  Moreover, Z1 in General formula (4) represents the organic group or aliphatic group which has an aromatic ring or a heterocyclic ring. Specific examples thereof include aliphatic hydrocarbon groups such as methyl group, ethyl group, propyl group, butyl group, hexyl group or octyl group, and aromatic groups such as phenyl group, benzyl group, naphthyl group or biphenyl group. Examples thereof include reactive substituents such as a hydrocarbon group, a glycidyloxypropyl group, a mercaptopropyl group, an aminopropyl group, and a vinyl group. Among these, a methyl group, an ethyl group, a phenyl group, a naphthyl group, or a biphenyl group is more preferable from the viewpoint of thermal stability.

  An adduct of a phosphonium compound and a silane compound can be obtained, for example, as follows. First, a silane compound such as phenyltrimethoxysilane and a proton donor such as 2,3-dihydroxynaphthalene are added and dissolved in a flask containing methanol. Next, a sodium methoxide-methanol solution is dropped into the flask while stirring at room temperature. Next, when a solution prepared by dissolving a tetra-substituted phosphonium halide such as tetraphenylphosphonium bromide in methanol in methanol is added dropwise to the flask with stirring at room temperature, crystals are deposited. The precipitated crystals are filtered, washed with water, and vacuum dried to obtain an adduct of a phosphonium compound and a silane compound. However, it is not limited to this.

  Content of the hardening accelerator (D) which can be used for the epoxy resin composition for sealing according to the present embodiment is 0.1% by mass with respect to 100% by mass of the total value of the epoxy resin composition for sealing. The above is preferable. Sufficient curability can be acquired as content of a hardening accelerator (D) is more than the said lower limit. Moreover, content of a hardening accelerator (D) becomes like this. Preferably it is 3 mass% or less with respect to the total value of 100 mass% of the epoxy resin composition for sealing, More preferably, it is 1 mass% or less. Sufficient fluidity | liquidity can be obtained as content of a hardening accelerator (D) is below the said upper limit.

  In the epoxy resin composition for sealing according to this embodiment, a compound (E) (hereinafter simply referred to as “compound (E)”) in which a hydroxyl group is bonded to two or more adjacent carbon atoms constituting an aromatic ring. May be included). By using the compound (E), even when a phosphorus atom-containing curing accelerator having no latent property is used as the curing accelerator (D), the reaction during the melt-kneading of the epoxy resin composition for sealing is performed. The epoxy resin composition for sealing can be obtained stably. The compound (E) also has an effect of lowering the melt viscosity of the sealing epoxy resin composition and improving fluidity. As the compound (E), a monocyclic compound represented by the following general formula (5) or a polycyclic compound represented by the following general formula (6) can be used. These compounds may have a substituent other than a hydroxyl group.

  In General Formula (5), one of R15 and R19 is a hydroxyl group, and the other is a hydrogen atom, a hydroxyl group, or a substituent other than a hydroxyl group. R16, R17 and R18 are a hydrogen atom, a hydroxyl group or a substituent other than a hydroxyl group.

  In General formula (6), one of R20 and R26 is a hydroxyl group, and the other is a hydrogen atom, a hydroxyl group, or a substituent other than a hydroxyl group. R21, R22, R23, R24 and R25 are a hydrogen atom, a hydroxyl group or a substituent other than a hydroxyl group.

  Specific examples of the monocyclic compound represented by the general formula (5) include catechol, pyrogallol, gallic acid, gallic acid ester, and derivatives thereof. Specific examples of the polycyclic compound represented by the general formula (6) include 1,2-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, and derivatives thereof. Among these, a compound in which a hydroxyl group is bonded to each of two adjacent carbon atoms constituting an aromatic ring is preferable because of easy control of fluidity and curability. In consideration of volatilization in the kneading step, it is more preferable that the mother nucleus is a compound having a low volatility and a highly stable weighing naphthalene ring. In this case, specifically, the compound (E) can be a compound having a naphthalene ring such as 1,2-dihydroxynaphthalene, 2,3-dihydroxynaphthalene and derivatives thereof. These compounds (E) may be used individually by 1 type, or may use 2 or more types together.

  The content of the compound (E) is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, with respect to 100% by mass of the total value of the sealing epoxy resin composition. And more preferably 0.05% by mass or more. When the content of the compound (E) is not less than the above lower limit value, it is possible to obtain a sufficient viscosity reduction and fluidity improving effect of the epoxy resin composition for sealing. Further, the content of the compound (E) is preferably 2% by mass or less, and more preferably 0.8% by mass or less, with respect to 100% by mass of the total value of the sealing epoxy resin composition. More preferably, it is 0.5 mass% or less. When the content of the compound (E) is not more than the above upper limit, there is little possibility of causing a decrease in the curability of the sealing epoxy resin composition and a decrease in the physical properties of the cured product.

In the sealing epoxy resin composition according to the present embodiment, in order to further improve the adhesion between the epoxy resin (A1) and the inorganic filler (C), a cup is provided separately from the first coupling agent described above. A ring agent (F) (also referred to as a second coupling agent) can be further added. Any second coupling agent may be used as long as it reacts between the epoxy resin (A1) and the inorganic filler (C) to improve the interface strength between the epoxy resin (A1) and the inorganic filler (C). .
The second coupling agent is not particularly limited, and examples thereof include epoxy silane, amino silane, ureido silane, mercapto silane, and the like. In addition, the second coupling agent can be used in combination with the above-described compound (E) to increase the effect of the compound (E) to lower the melt viscosity of the sealing epoxy resin composition and improve the fluidity. It can be done.

  Examples of the epoxy silane include γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, and the like. Is mentioned. Examples of aminosilanes include primary aminosilanes such as γ-aminopropyltriethoxysilane and γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, and N-β (aminoethyl). γ-aminopropylmethyldimethoxysilane, N-phenylγ-aminopropyltriethoxysilane, N-phenylγ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, N-6- ( Aminohexyl) secondary aminosilanes such as 3-aminopropyltrimethoxysilane, N- (3- (trimethoxysilylpropyl) -1,3-benzenedimethanane, etc. Examples of ureidosilane include γ- Ureidopropyltriethoxysilane, hexamethyldi Silazane, etc. may be used as a latent aminosilane coupling agent in which the primary amino moiety of aminosilane is protected by reacting with a ketone or aldehyde, and the aminosilane may have a secondary amino group. Examples of mercaptosilane include γ-mercaptopropyltrimethoxysilane and 3-mercaptopropylmethyldimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfide, and bis (3-triethoxysilylpropyl) disulfide. Examples of such a silane coupling agent exhibiting the same function as that of a mercaptosilane coupling agent by thermal decomposition are also included. These silane couplings Grayed agents may be used in combination of two or more be used one kind alone.

  Mercaptosilane is preferable from the viewpoint of continuous formability. From the viewpoint of fluidity, mercaptosilane and aminosilane are preferable, and mercaptosilane and secondary aminosilane are more preferable. Epoxysilane is preferable from the viewpoint of adhesion.

  The content of the coupling agent (F) that can be used in the sealing epoxy resin composition according to the present embodiment (the total amount of the first coupling agent and the second coupling agent) is the epoxy resin composition for sealing. It is preferable that it is 0.01 mass% or more with respect to the total value of 100 mass% of a thing, It is more preferable that it is 0.05 mass% or more, It is further more preferable that it is 0.1 mass% or more. If the content of the coupling agent (F) is not less than the above lower limit, the interface strength between the epoxy resin (A1) and the inorganic filler (C) does not decrease, and good vibration resistance can be obtained. it can. Moreover, it is preferable that content of a coupling agent (F) is 1 mass% or less with respect to 100 mass% of total values of the epoxy resin composition for sealing, and it is 0.8 mass% or less. More preferably, it is 0.6 mass% or less. If the content of the coupling agent (F) is less than or equal to the above upper limit, the interface strength between the epoxy resin (A1) and the inorganic filler (C) does not decrease, and good vibration resistance can be obtained. it can. Moreover, if content of a coupling agent (F) is below the said upper limit, the water absorption of the hardened | cured material of the epoxy resin composition for sealing will not increase, and favorable rust prevention property can be acquired. .

  In the sealing epoxy resin composition according to the present embodiment, an inorganic flame retardant (G) may be added in order to improve flame retardancy. As the inorganic flame retardant (G), a metal hydroxide or a composite metal hydroxide that inhibits the combustion reaction by dehydrating and absorbing heat during combustion is preferable in that the combustion time can be shortened. Examples of the metal hydroxide include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, and zirconia hydroxide. The composite metal hydroxide is a hydrotalcite compound containing two or more metal elements, wherein at least one metal element is magnesium, and the other metal elements are calcium, aluminum, tin, titanium, iron Any metal element selected from cobalt, nickel, copper, or zinc may be used. As such a composite metal hydroxide, magnesium hydroxide / zinc solid solution is a commercially available product and is easily available. Of these, aluminum hydroxide and magnesium hydroxide / zinc solid solution are preferable from the viewpoint of continuous formability. An inorganic flame retardant (G) may be used independently or may be used 2 or more types. Further, for the purpose of reducing the influence on the continuous moldability, a surface treatment may be performed with a silicon compound such as a silane coupling agent or an aliphatic compound such as wax.

In the sealing epoxy resin composition according to the present embodiment, the concentration of ionic impurities is preferably 500 ppm or less, more preferably 300 ppm or less, even more preferably, with respect to the sealing epoxy resin composition. Is 200 ppm or less. Further, the concentration of the ionic impurity is not particularly limited, but is, for example, 0 ppb or more, more preferably 10 ppb or more, and further preferably 100 ppb or more with respect to the sealing epoxy resin composition according to the present embodiment. It is. Thereby, when the hardened | cured material of the epoxy resin composition for sealing which concerns on this embodiment is used for the sealing material 107, even if it processes at high temperature and high humidity, high rust prevention property can be hold | maintained.
Although it does not specifically limit as an ionic impurity which concerns on this embodiment, An alkali metal ion, alkaline-earth metal ion, a halogen ion etc., More specifically, a sodium ion, a chlorine ion, etc. are mentioned. The concentration of sodium ions is preferably 100 ppm or less, more preferably 70 ppm or less, and even more preferably 50 ppm or less with respect to the sealing epoxy resin composition according to the present embodiment. The concentration of chloride ions is preferably 100 ppm or less, more preferably 50 ppm or less, and further preferably 30 ppm or less with respect to the sealing epoxy resin composition according to the present embodiment. By setting it as said range, corrosion of the wiring board 101 and the electronic component 105 can be suppressed.
In this embodiment, ionic impurities can be reduced by using, for example, a highly pure epoxy resin. As described above, the electronic device 100 having excellent long-term reliability can be obtained.

  The concentration of ionic impurities can be determined as follows. First, the epoxy resin composition for sealing according to the present embodiment is molded and cured at 175 ° C. for 180 seconds and then pulverized by a pulverizer to obtain a cured powder. The obtained cured product powder can be measured using ICP-MS (inductively coupled plasma ion source mass spectrometer) after treating ions in pure water at 120 ° C. for 24 hours to extract ions in pure water.

  In the sealing epoxy resin composition according to the present embodiment, the content of alumina is preferably 10% by mass or less, and more preferably with respect to 100% by mass of the total value of the sealing epoxy resin composition. It is 7 mass% or less, More preferably, it is 5 mass% or less. The content of alumina is not particularly limited. For example, the content is preferably 0% by mass or more, more preferably 0.01% with respect to 100% by mass of the total value of the sealing epoxy resin composition according to the present embodiment. It is at least mass%, more preferably at least 0.1 mass%. By setting the content of alumina within the above range, the fluidity of the sealing epoxy resin composition according to the present embodiment can be improved and the weight can be reduced. In the present embodiment, 0 mass% allows a detection limit value.

  In the sealing epoxy resin composition according to this embodiment, in addition to the above-described components, ion scavengers such as hydrotalcites or hydrous oxides of elements selected from magnesium, aluminum, bismuth, titanium, and zirconium; carbon black Coloring agents such as bengara and titanium oxide; natural waxes such as carnauba wax; synthetic waxes such as polyethylene wax; mold release agents such as higher fatty acids such as stearic acid and zinc stearate and their metal salts or paraffin; polybutadiene compounds and acrylonitrile Low stress agents such as butadiene copolymer compounds, silicone oils, and silicone compounds such as silicone rubber; adhesion imparting agents such as thiazolines, diazoles, triazoles, triazines, pyrimidines and the like may be appropriately blended.

  The content of the colorant according to this embodiment is preferably 0.01% by mass or more and 1% by mass or less with respect to a total value of 100% by mass of the sealing epoxy resin composition according to this embodiment. Preferably they are 0.05 mass% or more and 0.8 mass% or less. By setting the content of the colorant within the above range, a step of removing colored impurities is unnecessary, and workability is improved. Therefore, the electronic device 100 with excellent yield is realized.

  Although content of the mold release agent which concerns on this embodiment is not specifically limited, Preferably it is 0.01 mass% or more with respect to the total value of 100 mass% of the epoxy resin composition for sealing which concerns on this embodiment, for example. Yes, more preferably 0.05% by mass or more. Further, the content of the release agent is not particularly limited, but for example, is preferably 1% by mass or less, more preferably 0.5% by mass or less, and further preferably 0.2% by mass or less. Preferably it is 0.1 mass% or less.

  The content of the low stress agent according to the present embodiment is preferably 0.01% by mass or more and 3% by mass or less with respect to 100% by mass of the total value of the sealing epoxy resin composition according to the present embodiment. More preferably, it is 0.05 mass% or more and 2 mass% or less. When the content of the low stress agent is within the above range, the stress relaxation ability of the obtained sealing material 107 can be improved. If it does so, peeling and the generation | occurrence | production of a crack resulting from the difference of a thermal expansion coefficient with the wiring board 101 and the electronic component 105 can be suppressed.

  The content of the ion scavenger according to this embodiment is preferably 0.01% by mass or more and 3% by mass or less with respect to the total value of 100% by mass of the sealing epoxy resin composition according to this embodiment. More preferably, it is 0.05 mass% or more and 2 mass% or less. When the content of the ion scavenger is within the above range, it is possible to suppress the occurrence of rust on the surfaces of the wiring board 101 and the electronic component 105. As a result, even at high temperature and high humidity, the adhesion at the interface between the wiring substrate 101 and the electronic component 105 and the sealing material 107 can be maintained for a long period of time.

  The content of the adhesion-imparting agent according to this embodiment is preferably 0.01% by mass to 3% by mass with respect to 100% by mass of the total value of the sealing epoxy resin composition according to this embodiment. More preferably, it is 0.05 mass% or more and 2 mass% or less. When the content of the adhesion-imparting agent is within the above range, the adhesion between the wiring board 101 and the electronic component 105 and the sealing material 107 can be improved. As a result, even at high temperature and high humidity, the adhesion at the interface between the wiring substrate 101 and the electronic component 105 and the sealing material 107 can be maintained for a long period of time.

(Method for producing epoxy resin composition for sealing)
Although the manufacturing method in particular of the epoxy resin composition for sealing which concerns on this embodiment is not restrict | limited, For example, it is performed as follows. First, a predetermined amount of the thermosetting resin (A), the curing agent (B), the inorganic filler (C), and preferably other additives are blended. Next, the blended material is uniformly pulverized and mixed at room temperature using, for example, a mixer, a jet mill, a ball mill or the like. Next, using a kneader such as a heating roll, a kneader, or an extruder, the sealing epoxy resin composition is melted and kneaded while being heated to about 90 to 120 ° C. Next, the epoxy resin composition for sealing after kneading is cooled and pulverized to obtain a solid epoxy resin composition for sealing in the form of granules or powder. By appropriately adjusting the conditions in these production steps, a sealing epoxy resin composition having a desired degree of dispersion and fluidity can be obtained.
As for the particle size of the powder or granule of the epoxy resin composition for sealing which concerns on this embodiment, 5 mm or less is preferable, for example. By setting the thickness to 5 mm or less, it is possible to suppress a filling failure at the time of tableting and an increase in tablet mass variation.

Furthermore, a tablet can be obtained by tablet-molding the powder or granule of the obtained epoxy resin composition for sealing. As an apparatus used for tableting, a single-shot or multiple rotary tableting machine can be used. The shape of the tablet is not particularly limited, but is preferably a columnar shape. There are no particular restrictions on the male, female, and environmental temperatures of the tableting machine, but 35 ° C. or lower is preferred. If it exceeds 35 ° C., the viscosity of the sealing epoxy resin composition increases due to the reaction, and the fluidity may be impaired. The tableting pressure is preferably in the range of 400 × 10 ^{4 to} 3000 × 10 ⁴ Pa. By making the tableting pressure not more than the above upper limit value, it is possible to suppress the occurrence of breakage immediately after tableting. On the other hand, by setting the tableting pressure to the lower limit value or more, it is possible to prevent the tablet from being broken during transportation because sufficient cohesive force cannot be obtained. There are no particular limitations on the material and surface treatment of the male and female molds of the tableting machine, and known materials can be used. Examples of the surface treatment include electric discharge machining, release agent coating, plating treatment, and polishing.

In the epoxy resin composition for sealing according to the present embodiment, the lower limit is preferably 10 Pa · s or more as to the higher viscosity when measured at a measurement temperature of 175 ° C. and a load of 10 kg using a higher viscosity measuring apparatus. More preferably, it is 12 Pa · s or more. On the other hand, the upper limit is preferably 50 Pa · s or less, more preferably 30 Pa · s or less, and further preferably 15 Pa · s or less. If it is more than the said lower limit, generation | occurrence | production of the void by the entrainment at the time of shaping | molding etc. can be suppressed. If it is below the said upper limit, favorable filling property can be obtained. Thereby, the electronic device 100 excellent in manufacturing stability is realized.
In the present embodiment, for example, the high viscosity is reduced by lowering the softening point of an epoxy resin or a curing agent, using a latent curing accelerator, or using fused spherical silica as a filler. be able to.

The gel time at 175 ° C. of the epoxy resin composition for sealing according to the present embodiment is preferably 10 seconds or more and 50 seconds or less, and more preferably 15 seconds or more and 45 seconds or less. If it is more than the said lower limit, a fillability can be improved. If it is below the upper limit, the molding cycle can be accelerated.
Moreover, in this Embodiment, the said gel time can be reduced by increasing the quantity of a hardening accelerator, for example. Thereby, the electronic device 100 excellent in manufacturing stability is realized.

The spiral flow of the sealing epoxy resin composition according to this embodiment is preferably 50 cm or more, more preferably 60 cm or more, and further preferably 80 cm or more. If it is more than the said lower limit, a filling property, especially the filling property to a perpendicular direction can be improved. The upper limit of the spiral flow is not particularly limited, but is preferably 200 cm or less, more preferably 150 cm or less, and particularly preferably 100 cm or less. Thereby, the electronic device 100 excellent in manufacturing stability is realized.
In the present embodiment, the spiral flow can be increased by, for example, using fused spherical silica as a filler, lowering the softening point of an epoxy resin or a curing agent, or reducing the amount of a curing accelerator.

When the curing torque of the epoxy resin composition for sealing according to the present embodiment was measured over time at a measurement temperature of 175 ° C. using a curast meter, T _{60 was} measured as the curing torque value 60 seconds after the start of measurement. When the maximum curing torque value until 300 seconds after the start is defined as T _max , the ratio T ₆₀ / T _max (%) of the curing torque value after 60 seconds from the measurement to the maximum curing torque value after 300 seconds after the measurement is It is preferably 40% or more, more preferably 45% or more, and further preferably 50% or more. The upper limit of the ratio of the curing torque values is not particularly limited, but is preferably 100% or less, and more preferably 95% or less. If it is more than the said lower limit, productivity improvement can be expected.
Moreover, in this embodiment, the ratio of the said hardening torque value can be increased by increasing the quantity of a hardening accelerator, for example. Thereby, the electronic device 100 excellent in manufacturing stability is realized.

Moreover, it is preferable that the glass transition temperature (Tg) of the hardened | cured material (sealing material 107) of the epoxy resin composition for sealing which concerns on this embodiment is 130 degreeC or more, and it is more preferable that it is 140 degreeC or more. . If it is more than the said lower limit, the reliability improvement of the electronic device 100 can be expected. Although it does not specifically limit as an upper limit of the said glass transition temperature (Tg), 200 degrees C or less is preferable and 190 degrees C or less is more preferable. Thereby, the electronic device 100 excellent in durability is realized.
Moreover, in this embodiment, the said glass transition temperature (Tg) can be increased by raising the softening point of an epoxy resin and a hardening | curing agent, for example.

It is preferable that the bending strength in 25 degreeC of the hardened | cured material (sealing material 107) of the epoxy resin composition for sealing which concerns on this embodiment is 70 Mpa or more, and it is more preferable that it is 100 Mpa or more. If it is more than the said lower limit, a crack etc. are hard to generate | occur | produce and a reliability improvement can be anticipated. Although it does not specifically limit as an upper limit of the said bending strength, 300 MPa or less is preferable and 250 MPa or less is more preferable. Thereby, the electronic device 100 excellent in durability is realized.
Moreover, in this Embodiment, the said bending strength can be increased by processing a coupling agent on the surface of a filler, for example.

The upper limit value of the flexural modulus at 25 ° C. of the cured product (encapsulant 107) of the sealing epoxy resin composition according to this embodiment is preferably 20 GPa or less, and more preferably 15 GPa or less. If it is below the above upper limit value, reliability improvement by stress relaxation can be expected. Although it does not specifically limit as a lower limit of the said bending elastic modulus, 5 GPa or more is preferable and 10 GPa or more is more preferable. Thereby, the electronic device 100 excellent in durability is realized.
In the present embodiment, for example, the bending elastic modulus can be reduced by increasing the amount of the low-stress agent added or reducing the amount of filler added.

The linear expansion coefficient (α1) in the region of 25 ° C. or higher and the glass transition temperature (Tg) or lower of the cured epoxy resin composition for sealing (encapsulant 107) according to this embodiment is 5 ppm / ° C. or higher and 25 ppm. / Ppm or less is preferable, and 10 ppm / ° C. or more and 20 ppm / ° C. or less is more preferable. Within the above range, the difference in thermal expansion from the electronic device 100 is small and the electronic component 105 can be prevented from falling off. Thereby, the electronic device 100 excellent in durability is realized.
Moreover, in this Embodiment, the said linear expansion coefficient ((alpha) 1) can be reduced by increasing the compounding quantity of a filler, for example.

The linear expansion coefficient (α2) in the region exceeding the glass transition temperature (Tg) of the cured epoxy resin composition for sealing (encapsulant 107) according to this embodiment is 10 ppm / ° C. or more and 100 ppm / ° C. or less. It is preferably 20 ppm / ° C. or more and 80 ppm / ° C. or less. Within the above range, the difference in thermal expansion from the electronic device 100 is small and the electronic component 105 can be prevented from falling off. Thereby, the electronic device 100 excellent in durability is realized.
Moreover, in this Embodiment, the said linear expansion coefficient ((alpha) 2) can be reduced by increasing the compounding quantity of a filler, for example.

(Electronic device manufacturing method)
The manufacturing method of the electronic device 100 according to the present embodiment includes a mounting step of mounting a plurality of electronic components 105, at least one of which is a QFP type package, on at least one surface 110 of the wiring board 101, and a sealing according to the present embodiment. A sealing step of collectively sealing the gap formed between the QFP type package and the wiring board 101, the plurality of electronic components 105, and the wiring board 101 using the epoxy resin composition for fixing.

  First, a plurality of electronic components 105, at least one of which is a QFP type package, is mounted on at least one surface 110 of the wiring board 101.

  The plurality of electronic components 105 are made of Sn / Pb eutectic solder, Sn / Ag / Cu-based lead-free solder, etc., and the wiring substrate 101 is passed through a reflow furnace at 200 to 260 ° C. Or mounted on one side.

  Further, it may further include a step of mounting an external connection component 109 that is electrically connected to an external device on at least one surface 110 of the wiring board 101. The external connection component 109 is mounted on the wiring board 101 by a method such as soldering or press fitting.

  Next, the gap formed between the QFP type package and the wiring board 101, the plurality of electronic components 105, the wiring board 101, and, if necessary, using the sealing epoxy resin composition according to the present embodiment. The external connection components 109 are collectively sealed.

  In the sealing step of batch sealing, for example, batch sealing can be performed by transfer molding using the sealing epoxy resin composition according to the present embodiment.

Next, transfer molding according to this embodiment will be described.
In transfer molding according to this embodiment, resin sealing is performed using, for example, a mold and a plunger. The filling space of the epoxy resin composition for sealing is defined by the mold. The wiring board 101 on which the electronic component 105 is mounted is placed on a mold, and resin sealing is performed by filling the epoxy resin composition for sealing.

  Specifically, first, the wiring substrate 101 on which the electronic component 105 is mounted is placed in a mold set at a predetermined temperature (for example, 150 to 190 ° C. Next, an epoxy resin composition for sealing with a plunger. Is injected and filled in the mold (filling space) at a predetermined molding pressure (for example, 3 to 10 MPa), and for example, resin sealing molding is performed for 60 to 150 seconds. , 150 to 190 ° C., 2 to 6 hours), whereby the electronic device 100 is obtained.

  The electronic device 100 of the present embodiment can be mounted on a vehicle such as a hybrid vehicle, a fuel cell vehicle, and an electric vehicle, for example.

  Hereinafter, the present embodiment will be described in detail with reference to examples. In addition, this embodiment is not limited to description of these Examples at all. Unless otherwise specified, “part” described below indicates “part by mass” and “%” indicates “% by mass”.

The raw material components used in each Example and each Comparative Example are shown below.
(Thermosetting resin (A))
Epoxy resin 1: Orthocresol novolac type epoxy resin (Nippon Kayaku Co., Ltd .: EOCN-1020-55, epoxy equivalent 200 g / eq, softening point 62 ° C.)
Epoxy resin 2: Biphenyl type epoxy resin (manufactured by Japan Epoxy Resin, YX4000H, epoxy equivalent 195 g / eq, melting point 105 ° C.)

(Curing agent (B))
Phenol resin-based curing agent: novolak-type phenol resin (manufactured by Sumitomo Bakelite, PR-HF-3, hydroxyl group equivalent 104 g / eq, softening point 80 ° C.)

(Inorganic filler (C))
Spherical silica 1 (average particle diameter d ₅₀ : 20 μm, maximum particle diameter d _max : 75 μm)
Spherical silica 2 (average particle diameter d ₅₀ : 15 μm, maximum particle diameter d _max : 45 μm)

(Curing accelerator (D))
Triphenylphosphine (manufactured by Hokuko Chemical Industries, TPP)

(Coupling agent (F))
Silane coupling agent 1: γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-403)
Silane coupling agent 2: γ-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-803)

(Other additives)
Mold release agent: Carnauba wax (Nikko Fine, Nikko Carnauba, melting point 83 ° C)
Ion scavenger: Hydrotalcite (manufactured by Kyowa Chemical Industry Co., Ltd., DHT-4H)
Colorant: Carbon black (manufactured by Mitsubishi Chemical Corporation, MA600)
Low stress agent 1: Silicone resin (Shin-Etsu Chemical Co., Ltd., KMP-594)
Low stress agent 2: Silicone oil (Toray Dow Corning, TZ-8120)
Inorganic flame retardant: Aluminum hydroxide (Sumitomo Chemical Co., Ltd., CL-303, average particle size d ₅₀ : 3.5 μm)

About each Example, what mixed each component according to the compounding quantity shown in Table 1 was mixed at normal temperature using the mixer, and the powdery intermediate body was obtained. The obtained powdery intermediate was loaded into an automatic supply device (hopper), and quantitatively supplied to a heating roll at 80 ° C. to 100 ° C. for melt kneading. The epoxy resin composition for sealing was obtained by cooling and grind | pulverizing after that. The tablet was obtained by tablet-molding the obtained epoxy resin composition for sealing using a shaping | molding apparatus.
About the obtained epoxy resin composition for sealing, the measurement and evaluation shown below were performed. The evaluation results are shown in Table 2.

(Evaluation item)
Spiral flow: A low pressure transfer molding machine (KTS-15, manufactured by Kotaki Seiki Co., Ltd.) is used for insert molding, and a spiral flow measurement mold conforming to ANSI / ASTM D 3123-72 is applied at 175 ° C. with an injection pressure of 6. The epoxy resin composition for sealing was injected under conditions of 9 MPa and a holding time of 120 seconds, and the flow length was measured. The spiral flow is a fluidity parameter, and the larger the value, the better the fluidity. The unit of spiral flow in Table 2 is cm.

[Geltime]
An epoxy resin composition for sealing is placed on a hot plate controlled at 175 ° C., and about 1 time / sec. With a spatula. Knead with the stroke. The time from when the sealing epoxy resin composition was melted by heat until it was cured was determined as the gel time. The unit of gel time in Table 2 is second.

[High viscosity viscosity]
About 2.5 g of the epoxy resin composition for sealing was made into a tablet shape (diameter 11 mm, height about 15 mm), and then measured using a Koka viscosity measuring device (CFT-500D, manufactured by Shimadzu Corporation). The measurement was performed using a nozzle (die) having a diameter of 0.5 mm and a length of 1.0 mm under the conditions of 175 ° C. and a load of 10 kg. The unit of Koka viscosity in Table 2 is Pa · s.

[Curast torque ratio]
60 seconds after the start of measurement, when the curing torque of the epoxy resin composition for sealing was measured over time at a measurement temperature of 175 ° C. using a curast meter (Orientec Co., Ltd., JSR curast meter IVPS type). The curing torque value is T ₆₀ , and the maximum curing torque value until 300 seconds after the start of measurement is T _max . The ratio T ₆₀ / T _max (%) of the curing torque value 60 seconds after the measurement start to the maximum curing torque value until 300 seconds after the measurement start was determined as the curast torque ratio. Torque in the curast meter is a parameter of thermal stiffness. For this reason, the larger the curast torque ratio, the better the curability.

[Glass-transition temperature]
A low-pressure transfer molding machine (KTS-30, manufactured by Kotaki Seiki Co., Ltd.) is used for insert molding, and an epoxy resin composition for sealing under conditions of a mold temperature of 175 ° C., an injection pressure of 9.8 MPa, and a curing time of 2 minutes. Was injection molded to obtain a test piece of 4 mm × 4 mm × 15 mm. After the obtained test piece was post-cured at 175 ° C. for 4 hours, the temperature was increased in a temperature range from 0 ° C. to 320 ° C. using a thermomechanical analyzer (manufactured by Seiko Denshi Kogyo Co., Ltd., TMA100). The linear expansion coefficient (α1) in the region below the glass transition temperature and the linear expansion coefficient (α2) in the rubber-like region are determined from the chart when measured at a rate of 5 ° C./min. At this time, the intersection of the extended lines of α1 and α2 was defined as the glass transition temperature. In Table 2, the unit of glass transition temperature is ° C., and the unit of linear expansion coefficient (α1, α2) is ppm / ° C.

[Bending strength and flexural modulus (25 ° C)]
Using a molding machine (manufactured by Kotaki Seiki Co., Ltd., KTS-30), the epoxy resin composition for sealing was injection molded under the conditions of a mold temperature of 175 ° C., an injection pressure of 9.8 MPa, and a curing time of 120 seconds. A molded product (cured product) having a thickness of 80 mm, a width of 10 mm, and a thickness of 4 mm was obtained. The obtained molded product was subjected to heat treatment at 175 ° C. for 4 hours as post-curing, and used as a test piece. The bending strength and the flexural modulus were measured in a 25 ° C. atmosphere according to JIS K 6911. The unit is MPa for bending strength and GPa for bending elastic modulus.

[Production of electronic devices]
First, an FR4 substrate (manufactured by Sumitomo Bakelite Co., Ltd., ELC-4762, thickness 1.6 mm, 60 mm × 60 mm) with a QFP type package (manufactured by LAPIS Semiconductor, ML610Q380, thickness 2.7 mm, 14 mm × 14 mm) at a peak temperature of 240 ° C., It was mounted with a peak temperature time of 10 seconds.
Subsequently, the substrate on which the obtained QFP type package was mounted was placed in a mold, and using a molding machine (KTS-30, manufactured by Kotaki Seiki Co., Ltd.), the mold temperature was 175 ° C., the injection pressure was 9.8 MPa, 20 The obtained epoxy resin composition for sealing was poured into a mold and molded under the conditions of seconds. Next, a curing treatment was performed at 175 ° C. for 120 seconds.

[Measurement of filling rate]
The filling rate of the sealing material (cured product of the epoxy resin composition for sealing) with respect to the gap between the QFP type package and the FR4 substrate was measured by a transmission method of an ultrasonic survey apparatus (SAT). Specifically, the image obtained by SAT was binarized, and the areas of the filled portion and the unfilled portion were calculated. Next, the volume V ₁ of the filled portion and the volume V _{2 of the} unfilled portion were calculated by multiplying each area by the gap height. Next, the filling rate was calculated from the following formula. Note that the gap height (vertical distance W) was measured by subtracting the value of the QFP package from the level difference between the QFP package and the substrate measured with a laser displacement meter.
Filling rate [%] = 100 × V ₁ / (V ₁ + V ₂ )

[Reliability evaluation of electronic devices]
The obtained electronic device was left in an environment of −40 ° C. for 30 minutes, and then left in an environment of 125 ° C. for 30 minutes. This operation was performed for a total of 1000 cycles, and the presence or absence of peeling between the QFP package and the FR4 substrate at the 500th and 1000th cycles was visually observed.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

DESCRIPTION OF SYMBOLS 100 Electronic device 101 Wiring board 103 Gap 105 Electronic component 107 Sealing material 109 External connection component 110 One side

Claims (18)

A wiring board;
A plurality of electronic components which are mounted on at least one surface of the wiring board, at least one of which is a QFP type package having a gap with the wiring board;
A sealing material that collectively seals the gap between the QFP type package and the wiring board, the plurality of electronic components, and the wiring board;
An epoxy resin composition for sealing used for forming the sealing material constituting the electronic device in which the sealing material is filled in the gap,
A thermosetting resin (A) containing an epoxy resin;
A curing agent (B);
An inorganic filler (C);
An epoxy resin composition for sealing, comprising: In the epoxy resin composition for sealing according to claim 1,
An epoxy resin composition for sealing, wherein an external connection component that is electrically connected to an external device is further mounted on at least one surface of the wiring board. The electronic device according to claim 1 or 2,
An epoxy resin composition for sealing, wherein the electronic device is used in an electronic control unit. In the epoxy resin composition for sealing according to any one of claims 1 to 3,
An epoxy resin composition for sealing, wherein the content of the inorganic filler (C) is 50% by mass or more with respect to 100% by mass of the total value of the epoxy resin composition for sealing. In the epoxy resin composition for sealing according to any one of claims 1 to 4,
The curing agent (B) includes at least one selected from the group consisting of a novolac type phenol resin, a phenol aralkyl resin, a naphthol type phenol resin, and a phenol resin mainly composed of a reaction product of hydroxybenzaldehyde, formaldehyde and phenol. An epoxy resin composition for sealing. In the epoxy resin composition for sealing according to any one of claims 1 to 5,
The epoxy resin composition for sealing whose bending elastic modulus in 25 degreeC of the hardened | cured material of the said epoxy resin composition for sealing is 5 GPa or more and 20 GPa or less. In the epoxy resin composition for sealing according to any one of claims 1 to 6,
The sealing epoxy resin composition has a high viscosity of 10 Pa · s or higher and 50 Pa · s or lower when measured at a measurement temperature of 175 ° C. and a load of 10 kg using a high viscosity viscosity measuring device. Epoxy resin composition. A wiring board;
A plurality of electronic components which are mounted on at least one surface of the wiring board, at least one of which is a QFP type package having a gap with the wiring board;
A sealing material that collectively seals the gap between the QFP type package and the wiring board, the plurality of electronic components, and the wiring board;
With
The electronic device according to claim 1, wherein the sealing material is a cured product of the sealing epoxy resin composition according to claim 1, and the gap is filled with the cured product. The electronic device according to claim 8.
An external connection component that is electrically connected to an external device is further mounted on at least one surface of the wiring board,
The electronic device, wherein the sealing material further collectively seals at least a part of the external connection components. The electronic device according to claim 8 or 9,
When the volume of the gap is a and the occupation volume of the cured product filled in the gap is b,
The electronic device in which the filling rate of the cured product calculated by b / a × 100 is 5% or more and 95% or less. The electronic device according to any one of claims 8 to 10,
2. When the maximum particle diameter of the inorganic filler (C) is D _max and the vertical distance of the gap between the QFP type package and the wiring board is W, W / D _max is 0.2 or more. An electronic device that is 0 or less. The electronic device according to claim 11.
The average particle size _{d 50} is 0.01μm or more 75μm or less, the electronic device. The electronic device according to claim 11 or 12,
Said W is an electronic device which is 20 micrometers or more and 200 micrometers or less. The electronic device according to any one of claims 8 to 13,
An electronic device in which the electronic device is used in an electronic control unit.   An automobile comprising the electronic device according to claim 8. A mounting step of mounting a plurality of electronic components, at least one of which is a QFP type package, on at least one surface of the wiring board;
A gap formed between the QFP type package and the wiring board using the sealing epoxy resin composition according to any one of claims 1 to 7, a plurality of the electronic components, and the wiring board Sealing process for collectively sealing,
A method for manufacturing an electronic device, comprising: In the manufacturing method of the electronic device according to claim 16,
A method for manufacturing an electronic device, further comprising a step of mounting an external connection component that is electrically connected to an external device on at least one surface of the wiring board. In the manufacturing method of the electronic device of Claim 16 or 17,
In the sealing step, a method for manufacturing an electronic device, wherein batch sealing is performed by transfer molding using the epoxy resin composition.

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