JP6657716B2 - Liquid composition for sealing, sealing material, and electronic component device - Google Patents

Description

  The present invention relates to a sealing liquid composition, a sealing material, and an electronic component device.

  2. Description of the Related Art Conventionally, in the field of sealing elements such as transistors and integrated circuits (ICs) in electronic component devices, a method of sealing with a sealing material including a resin in terms of productivity, cost, and the like. Is the mainstream. Epoxy resin compositions are widely used as sealing materials. The reason for this is that the epoxy resin is balanced in various properties such as workability, moldability, electrical properties, moisture resistance, heat resistance, mechanical properties, and adhesiveness to insert products.

  In an electronic device mounted on a bare chip such as a COB (Chip on Board), a COG (Chip on Glass), or a TCP (Tape Carrier Package), an epoxy resin composition which is liquid at room temperature (25 ° C.) is used as a sealing material. Widely used. In an electronic component device (flip chip) in which elements are directly bump-connected to a wiring board having ceramic, glass / epoxy resin, glass / imide resin, polyimide film or the like as a substrate, the bump-connected element and the wiring board An epoxy resin composition which is liquid at room temperature is also used as an underfill material for filling a gap between the epoxy resin composition and the underfill material. The epoxy resin composition plays an important role in protecting the device from temperature and humidity, mechanical external force, and the like.

  Curing of the underfill epoxy resin composition usually requires heating at a high temperature for a long time. However, in recent years, curing at a low temperature and in a short time for the purpose of improving productivity and workability has been demanded. From such a background, a specific epoxy compound, a curing agent containing a specific acid anhydride, and a specific amount of an inorganic filler, containing an epoxy resin for underfill which is cured by heat treatment at a low temperature for a short time. A liquid sealing material has been proposed (for example, see Patent Document 1).

JP 2013-28659 A

  However, the epoxy resin liquid encapsulant for underfill described in Patent Document 1 can be cured at a low temperature and in a short time, but the viscosity tends to increase with time, and the storage stability is not sufficient.

  The present invention has been made in view of such circumstances, is capable of curing at a low temperature in a short time, and has excellent storage stability. It is an object of the present invention to provide a sealing material made of the above, and an electronic component device having the sealing material.

Embodiments of the present invention are described below.
<1> A sealing liquid composition containing (A) an epoxy compound having an epoxy group, (B) an oxetane compound having an oxetane ring, (C) a polymerization initiator, and (D) an inorganic filler.

<2> The sealing liquid composition according to <1>, wherein the (C) polymerization initiator is a thermal polymerization initiator.

<3> The sealing liquid composition according to <2>, wherein the polymerization initiator (C) includes at least one compound selected from the group consisting of an ammonium salt, an amine salt, and a sulfonium salt.

<4> The polymerization initiator (C) is an antimonic hexafluoride, hexafluorophosphoric acid, trifluoromethanesulfonic acid, perfluorobutanesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, p-toluene <2> including a compound in which an anionic species selected from the group consisting of sulfonic acid, dodecylbenzenesulfonic acid, and tetrakis (pentafluorophenyl) boric acid and a cationic species represented by the following formula (1) are bonded. Or the liquid composition for sealing as described in <3>.

(Wherein, Y ₁ , Y ₂ , Y ₃ , and Y ₄ each independently represent a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms, or an aryl group. The alkyl group and the aryl group may have a substituent.)

<5> The content of the polymerization initiator (C) is 0.1 part by mass to 10 parts by mass with respect to a total of 100 parts by mass of the epoxy compound (A) and the oxetane compound (B). 1> The liquid composition for sealing according to any one of <4>.

<6> The sealing liquid composition according to any one of <1> to <5>, wherein the (D) inorganic filler has a maximum particle size of 50 µm or less.

<7> The sealing liquid composition according to any one of <1> to <6>, wherein the (D) inorganic filler has an average particle diameter of 0.1 μm to 4 μm.

<8> The sealing liquid composition according to any one of <1> to <7>, wherein the content of the inorganic filler (D) is 30% by mass to 70% by mass.

<9> The sealing liquid composition according to any one of <1> to <8>, which is used for element sealing of an electronic component device.

<10> A sealing material obtained by curing the sealing liquid composition according to any one of <1> to <9>.

<11> a substrate having a circuit layer;
An element disposed on the substrate and electrically connected to the circuit layer;
A sealing material according to <10>, disposed in a gap between the substrate and the element;
Electronic component device comprising:

  Advantageous Effects of Invention According to the present invention, a sealing liquid composition that can be cured at a low temperature in a short time and has excellent storage stability, a sealing material obtained by curing the sealing liquid composition, and this sealing An electronic component device having a material can be provided.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps and the like) are not essential unless otherwise specified, and unless it is deemed essential in principle. The same applies to numerical values and their ranges, and does not limit the present invention.

  In this specification, a numerical range indicated by using “to” indicates a range including numerical values described before and after “to” as a minimum value and a maximum value, respectively. Further, in the present specification, the content of each component in the composition, when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified, the plurality of substances present in the composition Means the total amount of In the present specification, the particle diameter of each component in the composition, when there are a plurality of types of particles corresponding to each component in the composition, unless otherwise specified, the plurality of types of particles present in the composition Mean the value for a mixture of Further, in this specification, the term “layer” includes, in a plan view, a configuration of a partly formed shape in addition to a configuration of a partly formed shape.

  As used herein, “room temperature” means 25 ° C. Further, in the present specification, “liquid” means a state showing fluidity at 25 ° C. Specifically, “liquid” means a state in which the viscosity measured by an E-type viscometer (cone angle 3 °, rotation number 100 times / minute) at 25 ° C. is 1000 Pa · s or less.

  Hereinafter, an example of an embodiment of a sealing liquid composition, a sealing material, and an electronic component device to which the present invention is applied will be described in detail.

[Liquid composition for sealing]
The sealing liquid composition of the present embodiment contains (A) an epoxy compound having an epoxy group, (B) an oxetane compound having an oxetane ring, (C) a polymerization initiator, and (D) an inorganic filler. The sealing liquid composition may contain other additives as necessary. By adopting the above configuration, the sealing liquid composition can be cured at a low temperature and in a short time, and has excellent storage stability. The reason is presumed as follows.

  Since the sealing liquid composition of the present embodiment contains the epoxy compound (A) and the oxetane compound (B), it can be cured at a low temperature and in a short time. The oxetane compound (B) has high reactivity, and it is difficult to obtain sufficient storage stability in a reaction system using an acid anhydride. In this regard, since the sealing liquid composition of the present embodiment contains the polymerization initiator (C), it is excellent in storage stability.

  Hereinafter, each component constituting the liquid composition for sealing will be described.

((A) epoxy compound)
The sealing liquid composition contains an epoxy compound having an epoxy group. One epoxy compound may be used alone, or two or more epoxy compounds may be used in combination.

  The epoxy compound having an epoxy group is not particularly limited as long as it is a compound having an epoxy group in a molecule. Preferred epoxy compounds include, for example, epoxy compounds having an alicyclic epoxy group or a glycidyl group.

The epoxy compound having an alicyclic epoxy group is not particularly limited as long as it is a compound having an alicyclic epoxy group in a molecule. As the alicyclic epoxy group, those formed by bonding an oxygen atom to two adjacent carbon atoms constituting a cyclic aliphatic skeleton, and those formed by bonding an oxygen atom to two non-adjacent carbon atoms Any of those formed can be used. From the viewpoints of reactivity and storage stability, it is preferable to use, as the alicyclic epoxy group, an alicyclic epoxy group formed by bonding an oxygen atom to two adjacent carbon atoms. The number of carbon atoms in the cyclic aliphatic skeleton is not particularly limited. The cyclic aliphatic skeleton is, for example, preferably a 5- to 8-membered ring, more preferably a 5- or 6-membered ring, and still more preferably a 6-membered ring.
Among the alicyclic epoxy groups, a 3,4-epoxycyclohexyl group represented by the following formula (I) is preferable. In the formula (I), * indicates a bonding position.

  The number of alicyclic epoxy groups in the epoxy compound having an alicyclic epoxy group is not particularly limited. The number of alicyclic epoxy groups is, for example, preferably from 2 to 6 from the viewpoint of heat resistance and flexibility after curing of the sealing liquid composition, and from the viewpoint of reducing the viscosity of the sealing liquid composition. From 2 to 4 are more preferable.

  When the number of alicyclic epoxy groups in the epoxy compound having an alicyclic epoxy group is two or more, the alicyclic epoxy groups may be bonded to each other with a single bond, or may be bonded via a linking group. May be. The type of the linking group that connects the alicyclic epoxy groups is not particularly limited. Examples of the linking group include a divalent hydrocarbon group, a carbonyl group (—CO—), an ether bond (—O—), an ester bond (—COO—), a carbonate bond (—OCOO—), and a combination thereof. Group. Examples of the divalent hydrocarbon group include, for example, a linear or branched alkylene group having 1 to 18 carbon atoms (preferably 1 to 6 carbon atoms) and a divalent alicyclic hydrocarbon group (particularly, Valent cycloalkylene group). Examples of the linear or branched alkylene group include a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, and a trimethylene group. Examples of the divalent alicyclic hydrocarbon group include, for example, 1,2-cyclopentylene group, 1,3-cyclopentylene group, cyclopentylidene group, 1,2-cyclohexylene group, Examples include a divalent cycloalkylene group (including a cycloalkylidene group) such as a 3-cyclohexylene group, a 1,4-cyclohexylene group, and a cyclohexylidene group.

Among the epoxy compounds having an alicyclic epoxy group, a compound represented by the following formula (I-1) (that is, 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate) is preferable. When the liquid composition for sealing contains the compound represented by the following formula (I-1), the liquid composition for sealing tends to have a low viscosity and have improved heat resistance after curing.
As the compound represented by the following formula (I-1), for example, commercially available products such as "Celoxide 2021P" (trade name, manufactured by Daicel Corporation) can be used.

  Note that as the epoxy compound having an alicyclic epoxy group, an epoxy compound having two epoxy groups in a molecule and only one of the two epoxy groups is an alicyclic epoxy group can also be used. Such epoxy compounds include, for example, limonene diepoxide (i.e., 1-methyl-4- (2-methyloxiranyl) -7-oxabicyclo [4.1.0] heptane). When the liquid composition for sealing contains limonene diepoxide, the liquid composition for sealing has a low viscosity and tends to have improved heat resistance after curing.

  The epoxy compound having a glycidyl group is not particularly limited as long as it is a compound having a glycidyl group represented by the following formula (II) in the molecule. In the formula (II), * indicates a bonding position.

  The number of glycidyl groups in the epoxy compound having a glycidyl group is not particularly limited. The number of glycidyl groups is, for example, preferably from 2 to 6 from the viewpoint of heat resistance and flexibility after curing of the sealing liquid composition, and from the viewpoint of lowering the viscosity of the sealing liquid composition, Number to four are more preferable.

  The epoxy compound having a glycidyl group includes, for example, naphthalene type epoxy resin; diglycidyl ether type epoxy resin such as bisphenol A, bisphenol F, bisphenol AD, bisphenol S, hydrogenated bisphenol A; and orthocresol novolak type epoxy resin. Epoxidized novolak resin obtained from a phenol compound and an aldehyde compound; and a glycidyl ester type epoxy resin obtained by reacting a polybasic acid such as phthalic acid or dimer acid with epichlorohydrin.

Among epoxy compounds having a glycidyl group, a compound represented by the following formula (II-1) (that is, bis (glycidyloxyphenyl) methane) and a compound represented by the following formula (II-2) (that is, 1 , 6-hexanediol diglycidyl ether) is preferred. When the liquid composition for sealing contains the compound represented by the following formula (II-1), the flexibility of the liquid composition for sealing after curing tends to be improved. In addition, when the liquid composition for sealing contains a compound represented by the following formula (II-2), the liquid composition for sealing becomes low in viscosity, and the filling property into the gap between the substrate and the element is improved. Tend to.
As the compound represented by the following formula (II-1), commercially available products such as “YDF-8170C” (trade name, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) can be used. As the compound represented by the following formula (II-2), commercially available products such as “SR-16HL” (trade name, manufactured by Sakamoto Pharmaceutical Co., Ltd.) can be used.

  The epoxy equivalent of the epoxy compound is not particularly limited. The epoxy equivalent of the epoxy compound is, for example, 50 g / eq. From the viewpoint of lowering the viscosity of the liquid composition for sealing and enabling curing at a low temperature in a short time. ~ 300 g / eq. Is preferably 60 g / eq. ~ 190 g / eq. Is more preferable, and 70 g / eq. ~ 180 g / eq. Is more preferable.

  The epoxy compound is preferably liquid at room temperature, but a solid compound at room temperature may be used in combination as long as the effects of the present invention are achieved. When the epoxy compound contains a compound that is solid at room temperature, the content is preferably 20% by mass or less in the total amount of the epoxy compound, for example, from the viewpoint of fluidity of the liquid composition for sealing, and is preferably 10% by mass. % Is more preferable.

  It is preferable that the amount of hydrolyzable chlorine in the epoxy compound is small because it is related to corrosion of metal wiring in an element such as an integrated circuit (IC). For example, in order to obtain a sealing liquid composition having excellent moisture resistance, the amount of hydrolyzable chlorine is preferably 500 ppm or less. Here, the amount of hydrolyzable chlorine was determined by dissolving 1 g of a sample epoxy compound in 30 mL of dioxane, adding 5 mL of a methanol solution containing 1 mol / L KOH, refluxing for 30 minutes, and then performing potentiometric titration. The values are scaled.

  The content of the epoxy compound in the sealing liquid composition is not particularly limited. From the viewpoint of reducing the viscosity of the sealing liquid composition and increasing the fluidity, the content of the epoxy compound is 30% by mass to 90% by mass in the total amount of the sealing liquid composition excluding the inorganic filler. Is preferably 35% by mass to 70% by mass, and more preferably 40% by mass to 60% by mass.

((B) oxetane compound)
The sealing liquid composition contains an oxetane compound having an oxetane ring. The oxetane compounds may be used alone or in combination of two or more.

The oxetane compound having an oxetane ring is not particularly limited as long as it has a oxetane ring in the molecule.
The oxetane compound preferably has a 3-oxetanyl group represented by the following formula (III), and may have another functional group as needed. In the formula (III), * indicates a bonding position.

  Examples of the oxetane compound include 3-ethyl-3-[(2-ethylhexyloxy) methyl] oxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3- (4-hydroxybutyl) oxymethyloxetane, 3-ethyl-3-hexyloxymethyloxetane, 3-ethyl-3-allyloxymethyloxetane, 3-ethyl-3-benzyloxymethyloxetane, 3-ethyl-3-methacryloxymethyloxetane, 3-ethyl-3- Monooxetane compounds such as carboxyoxetane and 3-ethyl-3-phenoxymethyloxetane; bis [1-ethyl (3-oxetanyl)] methyl ether, 4,4′-bis [3-ethyl- (3-oxetanyl) methoxymethyl ] Biphenyl, 1,4-bis (3-ethyl-3- Xetanylmethoxy) methylbenzene, xylylenebisoxetane, bis [(ethyl (3-oxetanyl)] methyl carbonate, bis [ethyl (3-oxetanyl)] ethyl adipate, bis [ethyl (3-oxetanyl)] methyl terephthalate Bis [ethyl (3-oxetanyl)] methyl 1,4-cyclohexanecarboxylate, bis {4- [ethyl (3-oxetanyl) methoxycarbonylamino] phenyl} methane, α, ω-bis- {3- [1- Dioxetane compounds such as ethyl (3-oxetanyl) methoxy] propyl (polydimethylsiloxane); and multi-oxetane compounds such as oligo (glycidyl oxetane-co-phenylglycidyl ether).

  Among the oxetane compounds, bis [1-ethyl (3-oxetanyl)] methyl ether and 4,4′-bis [3-ethyl- (3- Oxetanyl) methoxymethyl] biphenyl, 3-ethyl-3-[(2-ethylhexyloxy) methyl] oxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3- (4-hydroxybutyl) oxymethyloxetane, 1,4-bis (3-ethyl-3-oxetanylmethoxy) methylbenzene and xylylenebisoxetane are preferred, and bis [1-ethyl (3-oxetanyl)] methyl ether and 4,4′-bis [3-ethyl -(3-oxetanyl) methoxymethyl] biphenyl, 3-ethyl-3-[(2-ethylhexylio) ) Methyl] oxetane, 3-ethyl-3-hydroxymethyl oxetane, and 3-ethyl-3- (4-hydroxybutyl) oxymethyl-oxetane is more preferable.

In particular, the oxetane compound preferably contains a compound represented by the following formula (III-1) (that is, bis [1-ethyl (3-oxetanyl)] methyl ether). When the liquid composition for sealing contains a compound represented by the following formula (III-1), the fluidity of the liquid composition for sealing and heat resistance after curing tend to be improved.
As the compound represented by the following formula (III-1), commercially available products such as “Alonoxetane (registered trademark) OXT-221” (trade name, manufactured by Toagosei Co., Ltd.) can be used.

  The molecular weight of the oxetane compound is not particularly limited. The molecular weight of the oxetane compound is, for example, preferably from 100 to 500, and more preferably from 100 to 300, from the viewpoint of reducing the viscosity of the sealing liquid composition.

  The oxetane compound is preferably liquid at room temperature, but a solid compound at room temperature may be used in combination as long as the effects of the present invention are achieved. When the oxetane compound contains a compound that is solid at room temperature, the content is preferably 20% by mass or less in the total amount of the oxetane compound, for example, from the viewpoint of the fluidity of the liquid composition for sealing, and is preferably 10% by mass. % Is more preferable.

  The content of the oxetane compound in the sealing liquid composition is not particularly limited. The content of the oxetane compound is, for example, 10% to 95% by mass in the total amount of the sealing liquid composition excluding the inorganic filler from the viewpoint of lowering the viscosity of the sealing liquid composition and increasing the fluidity. Preferably, it is 15% by mass to 90% by mass, more preferably 30% by mass to 60% by mass.

  The total content of the epoxy compound and the oxetane compound in the sealing liquid composition is not particularly limited. The total content of the epoxy compound and the oxetane compound is, for example, 20% by mass to 70% by mass in the total amount of the liquid composition for sealing from the viewpoint of lowering the viscosity of the liquid composition for sealing and increasing the fluidity. Is preferably 30% by mass to 60% by mass, and more preferably 35% by mass to 55% by mass.

  The content ratio of the epoxy compound and the oxetane compound in the liquid composition for sealing is not particularly limited. The mass ratio of the epoxy compound / oxetane compound is, for example, preferably from 10.0 to 0.2, and more preferably from 2.0 to 0.6 from the viewpoint of reducing unreacted components and reducing the viscosity. More preferably, it is still more preferably 1.5 to 0.8.

((C) polymerization initiator)
The sealing liquid composition contains a polymerization initiator. As the polymerization initiator, one kind may be used alone, or two or more kinds may be used in combination.

  The polymerization initiator is not particularly limited. As the polymerization initiator, a compound that generates an acid or a base by the addition of heat or light can be used. Among the polymerization initiators, compounds that generate an acid catalyst when energy (heat or light at a specific temperature or higher) is externally applied are preferable. In particular, from the viewpoint of handleability, a thermal acid generator (Thermal Acid Generator: thermal polymerization initiator) is preferable.

  Examples of the thermal polymerization initiator include an ammonium salt, an amine salt, and a sulfonium salt, and preferably include at least one compound selected from the group consisting of an ammonium salt, an amine salt, and a sulfonium salt. In particular, it is preferable to contain an ammonium salt from the viewpoint of storage stability.

  Specifically, thermal polymerization initiators include antimony hexafluoride, hexafluorophosphoric acid, trifluoromethanesulfonic acid, perfluorobutanesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, p-toluenesulfonic acid , Dodecylbenzenesulfonic acid, and tetrakis (pentafluorophenyl) boric acid. The anion species (hereinafter, referred to as “specific anion species”) may be an amine salt, a quaternary ammonium salt, or the like.

  Further, the thermal polymerization initiator may be a compound in which the above-mentioned specific anion species and a cationic species represented by the following formula (1) are bonded.

In the above formula (1), Y ₁ , Y ₂ , Y ₃ , and Y ₄ are each independently a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms, or aryl. Represents a group. Preferably, at least one of Y ₁ , Y ₂ , Y ₃ , and Y ₄ is an aryl group.

  The alkyl group has 1 to 20 carbon atoms, and preferably 1 to 15 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a cyclohexyl group. Examples of the aryl group include a phenyl group.

  The alkyl group or the aryl group may have a substituent. Examples of the substituent which the alkyl group may have include a phenyl group, an alkoxy group having 1 to 15 carbon atoms, and a hydroxy group. When the alkyl group has a substituent, the carbon number of the alkyl group does not include the carbon number of the substituent. Examples of the substituent that the aryl group may have include, for example, an alkyl group having 1 to 15 carbon atoms, a hydroxyalkyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, and a phenylthio group. .

When _{three of} Y ₁ , Y ₂ , Y ₃ , and Y ₄ are groups other than a hydrogen atom, and the remaining one is a hydrogen atom, the thermal polymerization initiator has the following formula (1-1) or The compound represented by (1-2) may be used.

In the formulas (1-1) and (1-2), Y ₅ , Y ₆ , and Y ₇ are each independently a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms, Or an aryl group. The alkyl group or the aryl group may have a substituent. The alkyl group, the aryl group, and the substituent have the same meanings as in the above formula (1), and thus detailed description is omitted.

Further, the thermal polymerization initiator is a compound in which the above-mentioned specific anion species and a cationic species in which all of Y ₁ , Y ₂ , Y ₃ and Y _{4 in} the above formula (1) are groups other than hydrogen atoms are bonded. It may be.

Among these, as the thermal polymerization initiator, three or four of the specific anion species and Y ₁ , Y ₂ , Y ₃ and Y _{4 in} the formula (1) are groups other than hydrogen atoms. It preferably contains a compound bonded to a certain cationic species, and the cationic species wherein all of Y ₁ , Y ₂ , Y ₃ and Y _{4 in} the above formula (1) are a group other than a hydrogen atom. More preferably, the compound contains a compound bonded to

  The thermal polymerization initiator can control the strength of the acid generated by the addition of heat, depending on the type of anionic species contained in the thermal polymerization initiator, thereby controlling the curing temperature of the sealing liquid composition. be able to. For example, the thermal polymerization initiator may be an anionic species selected from the group consisting of antimony hexafluoride, hexafluorophosphoric acid, trifluoromethanesulfonic acid, perfluorobutanesulfonic acid, and tetrakis (pentafluorophenyl) borate. It may be included.

  The temperature at which the thermal polymerization initiator starts to generate an acid can be adjusted depending on the type of the cationic species contained in the thermal polymerization initiator.

  For example, the thermal polymerization initiator may be a compound that generates an acid by adding heat of 150 ° C. or less, or a compound that generates an acid by adding heat of 140 ° C. or less, and may be a compound that generates an acid by adding heat of 130 ° C. or less. It may be a compound that generates an acid. Further, the thermal polymerization initiator may be a compound that generates an acid by the addition of heat exceeding 100 ° C.

  When the sealing liquid composition is used in an electronic component device or the like, since the thermal stress on the element can be reduced by lowering the curing initiation temperature, a thermal polymerization initiator of 150 ° C. or lower is used. It is preferable to use a compound that generates an acid by the addition of

  In addition, the thermal polymerization initiator may be a compound that generates an acid by the addition of heat at a temperature equal to or higher than the glass transition temperature (Tg) of the resin contained in the sealing liquid composition. When a thermal polymerization initiator that generates an acid by adding heat at a temperature equal to or higher than the glass transition temperature (Tg) of the resin contained in the sealing liquid composition is used, the generated acid has a glass transition temperature (Tg). There is a tendency that the polymer is homogeneously present in the system of the sealing liquid composition heated as described above, and the cationic polymerization in the complex of the polymer and the inorganic filler generated by the polymerization can efficiently proceed. .

  Further, the thermal polymerization initiator is preferably neutral in a state where it is not subjected to the addition of heat. For example, the thermal polymerization initiator preferably has a pH of 6.0 to 8.0 (25 ° C.) in a state where heat is not added.

  As described above, since the thermal polymerization initiator is neutral in a state where it is not subjected to the addition of heat, the liquid composition for sealing tends to be hardly deteriorated in storage stability or hardly inhibited from hardening due to excess base. . For this reason, when the sealing liquid composition is used for an electronic component device, the adhesiveness and reliability tend to be hardly reduced.

  In view of the fact that the compound is neutral in a state where heat is not applied, the thermal polymerization initiator may be a compound in which the above-described specific anion species and a cationic species represented by the following formula (1-3) are bonded. .

In the above formula (1-3), Y ₁ , Y ₂ , and Y ₃ are each independently a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms, or an aryl group. Is shown. At least one of Y ₁ , Y ₂ and Y ₃ is preferably an aryl group. In the above formula (1-3), Ar represents an aryl group, and H represents a hydrogen atom of the aryl group. The alkyl group or the aryl group may have a substituent. The alkyl group, the aryl group, and the substituent have the same meanings as in the above formula (1), and thus detailed description is omitted.

When the thermal polymerization initiator is a compound in which the above-mentioned specific anion species and the cationic species represented by the above formula (1-3) are bonded, the thermal polymerization initiator is heated by heat as shown in the following formula. It undergoes a chemical transition within the molecule, generating an acid. In the following formulas, A ^- represents the specific anion species. This thermal polymerization initiator does not dissociate protons before it undergoes chemical transition by heat, so that the pH value does not deviate from a neutral range (for example, pH 6.0 to 8.0 (25 ° C.)).

Further, the thermal polymerization initiator binds the specific anionic species to a cationic species in which _three of Y ₁ , Y ₂ , Y ₃ and Y _{4 in} the formula (1) are groups other than a hydrogen atom. In the case of a compound that has been subjected to the addition of heat, the function as an anion catcher of the cationic species is excellent in a state where it is not subjected to the addition of heat, so that the effect on the alicyclic epoxy group, glycidyl group, and oxetanyl group is small, and the liquid composition for sealing is used. Tends to have improved storage stability (stability over time).

  In addition, the thermal polymerization initiator may be a tertiary amine salt of the specific anion. When the thermal polymerization initiator is a tertiary amine salt of the above-mentioned specific anionic species, the storage stability of the sealing liquid composition tends to be improved.

  Commercially available products of the thermal polymerization initiator include, for example, TAG-2278, CXC-1612, CXC-1821, CXC-1733, CXC-1738, TAG-2678, CXC-1614, TAG-2681, TAG-2690, CXC- 1742, TAG-2700, CXC-2700, and TAG-2710 (trade names, all manufactured by King Industries). Among them, CXC-1821 (that is, a quaternary ammonium salt having tetrakis (pentafluorophenyl) boric acid as an anion species) is preferable from the viewpoint of low-temperature curability and storage stability.

  The content of the polymerization initiator in the sealing liquid composition is not particularly limited. The content of the polymerization initiator is, for example, from the viewpoint of curability, preferably 0.1 parts by mass to 10 parts by mass, and more preferably 0.1 parts by mass to 5 parts by mass, based on 100 parts by mass of the total of the epoxy compound and the oxetane compound. A mass part is more preferred, and 0.3 mass parts-3 mass parts is still more preferred.

((D) inorganic filler)
The sealing liquid composition contains an inorganic filler. The type of the inorganic filler is not particularly limited, and a conventionally known inorganic filler can be used.

  Examples of the inorganic filler include fused silica, synthetic silica, crystalline silica, silica such as nanosilica, calcium carbonate, clay, alumina, silicon nitride, silicon carbide, boron nitride, calcium silicate, potassium titanate, aluminum nitride, beryllia, Powders of zirconia, zircon, fosterite, steatite, spinel, mullite, titania, aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, and the like, or spherical beads and glass fibers thereof are given. These inorganic fillers may be used alone or in combination of two or more.

Among them, fused silica is preferred as the inorganic filler, and spherical fused silica is more preferred from the viewpoint of fluidity and permeability into the fine gap of the liquid composition for sealing. In addition, as the inorganic filler, a material whose surface has been previously treated with a coupling agent or the like may be used as necessary.
In this specification, the fused silica is spherical when the sphericity satisfies the condition of 0.7 or more. As a method of measuring the sphericity, for example, image processing is performed with an electron microscope, and from the area and perimeter of the observed particles, (sphericity) = {4π × (area)} (perimeter) ² } A method of calculating the value can be used.

  Known coupling agents such as epoxy silane, mercapto silane, alkyl silane, various silane compounds such as vinyl silane, titanium compound, aluminum chelate compound, and aluminum zirconium compound as the coupling agent for treating the surface of the inorganic filler. No. Among these, it is preferable to use epoxy silane as the coupling agent.

  The maximum particle size of the inorganic filler is not particularly limited. The maximum particle size of the inorganic filler is, for example, 50 μm or less from the viewpoint of increasing the content of the inorganic filler while suppressing a rise in viscosity, and from the viewpoint of fillet moldability when the sealing liquid composition is used as an underfill material. Is more preferably 40 μm or less, and further preferably 30 μm or less.

The average particle size of the inorganic filler is not particularly limited. The average particle diameter of the inorganic filler is, for example, from the viewpoint of increasing the content of the inorganic filler while suppressing a rise in viscosity, and from the viewpoint of fillet moldability when the sealing liquid composition is used as an underfill material. It is preferably 1 μm to 4 μm, more preferably 0.2 μm to 3 μm, and even more preferably 0.3 μm to 2 μm.
In the present specification, the maximum particle diameter and the average particle diameter can be confirmed by measuring the weight cumulative particle size distribution using a laser light diffraction method. That is, the maximum particle size in the weight cumulative particle size distribution can be set as the maximum particle size, and the particle size at which the integrated distribution becomes 50% can be set as the average particle size.

  The content of the inorganic filler in the liquid composition for sealing is not particularly limited. For example, the content of the inorganic filler is preferably 30% by mass to 70% by mass, and more preferably 35% by mass to 65% by mass, based on the total amount of the liquid composition for sealing. When the content of the inorganic filler is 30% by mass or more, the strength of the cured product of the liquid composition for sealing tends to be further improved, and the reliability such as temperature cycle resistance tends to be further improved. Further, when the content of the inorganic filler is 70% by mass or less, the viscosity of the sealing liquid composition decreases, and the fluidity and permeability of the sealing liquid composition and the sealing liquid composition are reduced. When used as an underfill material, fillet moldability tends to be further improved.

(Coupling agent)
The liquid composition for sealing may contain a coupling agent as needed. When the liquid composition for sealing contains the coupling agent, the interfacial adhesion between the resin and the inorganic filler or between the resin and the component of the electronic component device can be further strengthened.
The coupling agent is not particularly limited, and may be appropriately selected from conventionally known ones. Examples of the coupling agent include silane compounds such as epoxy silane, mercapto silane, alkyl silane, and vinyl silane; and titanate compounds.

  Specific examples of the coupling agent include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxy. Silane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, γ Silane coupling agents such as chloropropyltrimethoxysilane, hexamethyldisilane, vinyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane; isopropyltriisostearoyl tita , Isopropyl tris (dioctyl pyrophosphate) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl phosphite) titanate, bis (dioctyl pyrophosphate) ) Oxyacetate titanate, bis (dioctyl pyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyl dimethacrylisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl isostearyl diacryl titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl Tricumylphenyl titanate, tetraisopropylbis (dioctyl) Phosphite), and the like titanate coupling agents such as titanates. These coupling agents may be used alone or in combination of two or more.

(Other additives)
The sealing liquid composition may contain other additives such as a dye, a coloring agent such as carbon black, a diluent, a leveling agent, a defoaming agent, a surfactant, an ion trapping agent, a stress relaxing agent, and a resin modifier. A filler may be contained as needed.

(Physical properties)
The viscosity of the sealing liquid composition is not particularly limited. The viscosity of the liquid composition for sealing is, for example, preferably from 0.05 Pa · s to 2.0 Pa · s at 25 ° C., and from 0.1 Pa · s to 1.0 Pa · s from the viewpoint of fluidity. More preferably, there is. The viscosity of the liquid composition for sealing at 25 ° C. is measured using an E-type viscometer (cone angle 3 °, rotation number 100 times / minute).

  Further, from the viewpoint of the filling property when filling the sealing liquid composition at 60 ° C. to 110 ° C. in a narrow gap of several tens of μm in applications such as an underfill material, the sealing liquid composition at 70 ° C. The viscosity is, for example, preferably 0.2 Pa · s or less, and more preferably 0.1 Pa · s or less. The viscosity at 70 ° C. of the liquid composition for sealing is measured using a rheometer (cone diameter: 25 mm, frequency: 1 Hz). As the rheometer, for example, "AR2000" (trade name, manufactured by TA instruments) is used.

In addition, the liquid composition for sealing preferably has a thixotropic index of, for example, 0.5 to 1.5, and more preferably 0.8 to 1.2. When the thixotropic index is in the above range, fillet moldability when the liquid composition for sealing is used as an underfill material tends to be improved.
The “thixotropic index” in the present specification is (viscosity at a rotation speed of 20 times / minute) / (rotation speed) when the viscosity is measured at 25 ° C. using an E-type viscometer (cone angle 3 °). (Viscosity at 100 times / minute).
The viscosity and thixotropic index of the liquid composition for sealing can be set to desired ranges by appropriately selecting the composition of the epoxy compound and the oxetane compound, the content of the inorganic filler, and the like.

The storage stability calculated by the following formula when the sealing liquid composition is stored at 25 ° C. for 24 hours is, for example, preferably 0% to 50%, more preferably 0% to 30%, and more preferably 0%. -20% is more preferable.
Storage stability (%) = 100 × ((viscosity after storage−viscosity before storage) / viscosity after storage)

(Method for preparing liquid composition for sealing)
The sealing liquid composition may be prepared by any method as long as the various components can be dispersed and mixed. As a general method, a liquid composition for sealing can be obtained by weighing the components, mixing and kneading using a mill, a mixing roll, a planetary mixer and the like, and defoaming as necessary. .

[Sealant]
The sealing material of the present embodiment is obtained by curing the above-described sealing liquid composition.
The sealing material can be obtained, for example, by applying the sealing liquid composition to a desired portion and then heating and curing the sealing liquid composition.

  The method for applying the sealing liquid composition is not particularly limited. Examples of the application method include a method using a dispenser such as an air dispenser, a jet dispenser, a screw type dispenser, and an auger type dispenser, a method using casting, and a method using printing such as screen printing.

The heating temperature and heating time of the sealing liquid composition are not particularly limited. The heating temperature is, for example, preferably from 90C to 150C, more preferably from 95C to 145C, and still more preferably from 100C to 140C. The heating time is, for example, preferably 5 minutes to 100 minutes, more preferably 7 minutes to 90 minutes, and still more preferably 10 minutes to 70 minutes.
The heating may be performed in one stage or may be performed in multiple stages. For example, after performing primary curing at 50 ° C. to 100 ° C. for 1 minute to 60 minutes, secondary curing at 80 ° C. to 140 ° C. for 1 minute to 60 minutes may be performed.

The glass transition temperature (Tg) of the sealing material is not particularly limited. In light of thermal stress, the glass transition temperature (Tg) of the sealing material is preferably, for example, 55C to 160C, more preferably 70C to 140C, and still more preferably 85C to 130C.
The glass transition temperature (Tg) of the sealing material was measured using a test piece (φ4 mm × 20 mm) using a thermomechanical analyzer (trade name “Q400”, manufactured by TA Instruments) at a load of 15 g and a measurement temperature of −50 ° C. It is measured under conditions of up to 220 ° C. and a heating rate of 5 ° C./min.

[Electronic component equipment]
The electronic component device of the present embodiment includes a substrate having a circuit layer, an element disposed on the substrate and electrically connected to the circuit layer, and the above-described element disposed in a gap between the substrate and the element. A sealing material. The electronic component device can be obtained, for example, by sealing the element with the above-described sealing material. Since the element is sealed with the above-described sealing material, the warpage of the electronic component device is reduced, and the temperature cycle resistance tends to be improved.

  Electronic components include support members such as lead frames, wired tape carriers, rigid wiring boards, flexible wiring boards, glass, silicon wafers, active elements such as semiconductor chips, transistors, diodes, and thyristors, capacitors, and resistors. And an electronic component device obtained by mounting a passive element such as a resistor array, a coil, and a switch, and sealing a necessary portion with the sealing material described above. Among electronic component devices, the present invention can be preferably applied to a rigid and flexible wiring board, and a semiconductor device in which a semiconductor element is flip-chip bonded to a wiring formed on glass by bump connection. As a specific example, an electronic component device such as a flip chip BGA (Ball Grid Array) / LGA (Land Grid Array), a COF (Chip On Film) or the like can be given.

  The above-described liquid composition for sealing is suitable as an underfill material for flip chips having excellent reliability. In the field of the flip chip in which the liquid composition for sealing is particularly suitable, the bump material for connecting the wiring board and the semiconductor element is not a conventional lead-containing solder but a lead-free solder such as Sn-Ag-Cu. A good reliability can be maintained even for a flip chip having a lead-free solder bump connection that is physically brittle compared to conventional lead solder. In addition, when a chip scale package such as a wafer level CSP (Chip Scale Package) is mounted on a substrate, the reliability can be improved by applying the above-described sealing liquid composition.

  Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, “parts” and “%” are based on mass.

(Examples 1 to 5, Comparative Examples 1 to 3)
(A) Epoxy compound / epoxy compound 1: 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate (trade name “CELLOXIDE 2021P” manufactured by Daicel Corporation)
Epoxy compound 2: bis (glycidyloxyphenyl) methane (bisphenol F type epoxy compound, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., trade name “YDF-8170C”)
Epoxy compound 3: 1,6-hexanediol diglycidyl ether (trade name "SR-16HL" manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.)

(B) Oxetane compound / oxetane compound: bis [1-ethyl (3-oxetanyl)] methyl ether (trade name "Aron Oxetane (registered trademark) OXT-221" manufactured by Toagosei Co., Ltd.)

(C) Polymerization initiator / polymerization initiator: quaternary ammonium salt having tetrakis (pentafluorophenyl) boric acid as an anion species (King Industries, trade name “CXC-1821”)

(D) Inorganic filler / inorganic filler: spherical fused silica having an average particle diameter of 0.6 μm, a maximum particle diameter of 25 μm, and a surface treated with an epoxysilane coupling agent (trade name “SE2200-, manufactured by Admatex Co., Ltd.) SEJ ")

(Other)
-Acid anhydride: methyl hexahydrophthalic anhydride (trade name "HN-5500", manufactured by Hitachi Chemical Co., Ltd.)
Coupling agent: γ-glycidoxypropyltrimethoxysilane (trade name “KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.)
-Colorant: carbon black (manufactured by Mitsubishi Chemical Corporation, trade name "MA100")

  The above components were blended so as to have the composition shown in Table 1, kneaded and dispersed with a three-roll mill and a vacuum mill, and the sealing liquid compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were obtained. Prepared. In addition, the compounding unit in a table | surface is a mass part, and "-" represents "no compounding." The content (% by mass) of the inorganic filler in the liquid composition for sealing was calculated from the amount of each component.

  With respect to the sealing liquid composition obtained above, various characteristics and various reliability were evaluated as follows. Table 2 shows the evaluation results.

(1) Storage stability The storage stability when the sealing liquid composition was stored at 25 ° C. for 24 hours was calculated according to the following formula. An E-type viscometer (cone angle 3 °, rotation number 100 times / min) was used for measuring the viscosity.
Storage stability (%) = 100 × ((viscosity after storage−viscosity before storage) / viscosity after storage)

(2) Tg and coefficient of thermal expansion (CTE)
The liquid composition for sealing was heated and cured at 130 ° C. for 30 minutes to prepare a test piece (φ4 mm × 20 mm). Using a thermomechanical analyzer (manufactured by TA Instruments, trade name “Q400”), the test piece was subjected to a load of 15 g, a measurement temperature of −50 ° C. to 220 ° C., and a glass transition temperature of 5 ° C./min. Tg) and coefficient of thermal expansion (CTE) were measured. The coefficient of thermal expansion in the temperature range below Tg was CTE1, and the coefficient of thermal expansion in the temperature range above Tg was CTE2. Tg and CTE show thermal stability, Tg is preferably around 100 ° C., and CTE1 and CTE2 are preferably as low as possible.

  As can be seen from Table 2, the liquid compositions for sealing of Examples 1 to 5 using the epoxy compound and the oxetane compound in combination and using the polymerization initiator were the sealing compositions of Comparative Examples 1 and 2. The curability at low temperature and short time was superior to the liquid composition. That is, the sealing liquid compositions of Examples 1 to 5 have a higher Tg of the cured product than the sealing liquid compositions of Comparative Examples 1 and 2 by the heat treatment at 130 ° C. for 30 minutes, The coefficient of thermal expansion decreased. The sealing liquid compositions of Examples 1 to 5 were superior in storage stability to the sealing liquid compositions of Comparative Examples 1 and 3.

On the other hand, the sealing liquid composition of Comparative Example 1 in which the oxetane compound was not used had much lower storage stability than the sealing liquid compositions of Examples 1 to 5. In addition, the liquid composition for sealing of Comparative Example 1 was inferior to the liquid compositions for sealing of Examples 1 to 5 in curability at a low temperature for a short time.
Moreover, the liquid composition for sealing of Comparative Example 2 in which the epoxy compound was not used was inferior to the curable liquid compositions for sealing of Examples 1 to 5 at low temperature and short time.
In addition, the liquid composition for sealing of Comparative Example 3 in which an oxetane compound was not used and an acid anhydride was used instead of the polymerization initiator was storage-stable compared to the liquid compositions for sealing of Examples 1 to 5. The sex was greatly inferior.

Claims (9)

(A) an epoxy compound having an epoxy group,
(B) an oxetane compound having an oxetane ring,
(C) a polymerization initiator, and (D) an inorganic filler,
The (A) epoxy compound contains a bisphenol F type epoxy compound, and the content of the bisphenol F type epoxy compound is 50% by mass or more based on the total amount of the (A) epoxy compound and the (B) oxetane compound. Yes,
Content of the (B) oxetane compound state, and are more than 30% by weight, based on the total weight of the (A) epoxy compound and the (B) oxetane compound,
(C) the polymerization initiator is a hexafluoroantimonic acid, hexafluorophosphoric acid, trifluoromethanesulfonic acid, perfluorobutanesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, p-toluenesulfonic acid, Including a compound in which an anionic species selected from the group consisting of dodecylbenzene sulfonic acid and tetrakis (pentafluorophenyl) boric acid and a cationic species represented by the following formula (1) are bound :
Liquid composition for underfill.


(Wherein, Y ₁ , Y ₂ , Y ₃ , and Y ₄ each independently represent a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms, or an aryl group. The alkyl group and the aryl group may have a substituent.) (A) an epoxy compound having an epoxy group,
(B) an oxetane compound having an oxetane ring,
(C) a polymerization initiator, and (D) an inorganic filler,
The (A) epoxy compound contains a bisphenol F type epoxy compound, and the content of the bisphenol F type epoxy compound is 50% by mass or more based on the total amount of the (A) epoxy compound and the (B) oxetane compound. Yes,
Content of the (B) oxetane compound state, and are more than 30% by weight, based on the total weight of the (A) epoxy compound and the (B) oxetane compound,
Wherein (D) the content of the inorganic filler Ru 30% to 70% by mass,
Liquid composition for underfill. (C) the polymerization initiator is antimonic hexafluoride, hexafluorophosphoric acid, trifluoromethanesulfonic acid, perfluorobutanesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, p-toluenesulfonic acid, 3. The compound according to claim 2, comprising a compound in which an anionic species selected from the group consisting of dodecylbenzenesulfonic acid and tetrakis (pentafluorophenyl) boric acid is bonded to a cationic species represented by the following formula (1). 4. Liquid composition for underfill.


(Wherein, Y ₁ , Y ₂ , Y ₃ , and Y ₄ each independently represent a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms, or an aryl group. The alkyl group and the aryl group may have a substituent.) The content of the (C) polymerization initiator is 0.1 part by mass to 10 parts by mass based on 100 parts by mass of the total of the (A) epoxy compound and the (B) oxetane compound. The underfill liquid composition according to claim 3 . The liquid composition for underfill according to any one of claims 1 to 4 , wherein the inorganic filler has a maximum particle diameter of 50 µm or less. The underfill liquid composition according to any one of claims 1 to 5 , wherein the inorganic filler (D) has an average particle diameter of 0.1 µm to 4 µm. The underfill liquid composition according to any one of claims 1 to 6 , which is used for element sealing of an electronic component device. A sealing material obtained by curing the underfill liquid composition according to any one of claims 1 to 7 . A substrate having a circuit layer;
An element disposed on the substrate and electrically connected to the circuit layer;
The sealing material according to claim 8 , which is disposed in a gap between the substrate and the element;
Electronic component device comprising: