JP2019019286A - Adhesive composition and optical semiconductor device - Google Patents

Abstract

To provide an adhesive composition having high adhesive force and capable of developing excellent packaging property.SOLUTION: The adhesive composition comprises [A] an epoxy resin having a bis-phenol skeleton, [B] a diluting monomer comprising an alicyclic epoxy compound, [C] a photo-cationic polymerization initiator comprising a bis-sulfonium salt [C1] and a monosulfonium salt [C2], [D] a thermal-cationic polymerization initiator, [E] a silane coupling agent, and [F] hydrophobic silica particles. A mass ratio of [C1] and [C2] is 4:1 to 1:1; the content of [A] with respect to total 100 pts.mass of [A] and [B] is 10 to 40 pts.mass; and with respect to total 100 pts.mass of [A] to [E], the content of [C] is 0.2 to 0.6 pts.mass, the content of [D] is 0.05 to 0.25 pts.mass, the content of [E] is 0.35 to 0.8 pts.mass, and the content of [F] is 100 to 400 pts.mass.SELECTED DRAWING: None

Description

  The present invention relates to an adhesive composition and an optical semiconductor device.

  Conventionally, a laser module including a lens that converts or condenses laser light emitted from a laser light source into parallel light is known. In a conventional laser module, the lens is housed in a metal frame with the laser light incident surface and light exit surface exposed, and is mounted by fixing the metal frame to the substrate with a solder material. It was. However, the metal frame is an obstacle to realizing miniaturization and cost reduction of the laser module. For this reason, in recent years, a metal frame has been eliminated and a lens is adhered to a substrate using a resin adhesive (see Patent Documents 1 and 2).

JP 2003-147321 A JP 2004-126319 A

  When mounting optical components on a highly integrated mounting board, generally UV curing adhesive is used, and the optical components are temporarily fixed by irradiating with ultraviolet rays, and then the heating process (thermosetting (Or heat curing), a technique of increasing the adhesive force of the temporarily fixed optical component is employed. On the other hand, in the case of a highly integrated mounting board, it is necessary to mount the optical components in a very close positional relationship with each other. Depending on the mounting status between the components, the ultraviolet light necessary for temporary fixing is applied to the adhesive. On the other hand, the optical component is fixed to the mounting substrate or the like in a situation where the irradiation is not sufficient. Thereafter, the mounting substrate including the optical component is heated, so that the thermosetting rapidly progresses around a portion where the amount of ultraviolet irradiation light is small, and a thermal stress is applied to the optical component. As a result, there may be a deviation in the optical component having high mounting accuracy around the portion where the adhesive curing reaction has not progressed in the temporary fixing stage.

  Then, an object of this invention is to provide the adhesive composition which has high adhesive force and can express the outstanding mountability, and the optical semiconductor device obtained using the said composition.

  As a result of intensive studies on the resin composition of light and thermosetting adhesives to solve the above problems, the present inventors have completed the present invention.

  An adhesive composition according to an embodiment of the present invention includes [A] an epoxy resin having a bisphenol skeleton, [B] a diluting monomer containing an alicyclic epoxy compound, [C] a bissulfonium salt [C1] and a mono A photocationic polymerization initiator containing a sulfonium salt [C2], [D] a thermal cationic polymerization initiator, [E] a silane coupling agent, and [F] hydrophobic silica particles, and [C1] and [C1] C2] has a mass ratio of 4: 1 to 1: 1, and the content of [A] is 10 to 40 parts by mass with respect to 100 parts by mass of the total amount of [A] and [B]. , [B], [C], [D] and [E] with respect to 100 parts by mass in total, the content of [C] is 0.2 to 0.6 parts by mass, and the content of [D] is 0.05 to 0.25 parts by mass, [E] content is 0.35 to 0.8 parts by mass, and [F] content is 00-400 is parts by mass.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the adhesive composition which has high adhesive force and expresses the outstanding mountability, and the optical semiconductor device obtained using the said composition. More specifically, the adhesive composition according to the present invention, in a situation where the optical component and electronic component group is highly dense, even when the optical component is actively aligned at a predetermined location, with a smaller amount of ultraviolet light, Provides an optical communication device with excellent optical characteristics that undergoes a curing reaction necessary for temporary fixing of optical components, and that the optical components hardly cause mounting displacement due to additional ultraviolet irradiation or thermal curing. it can.

  Hereinafter, although the form for implementing this invention is demonstrated in detail, this invention is not limited to the following embodiment.

  The adhesive composition of the present embodiment includes: [A] an epoxy resin having a bisphenol skeleton, [B] a dilutable monomer containing an alicyclic epoxy compound, [C] bissulfonium salt [C1] and a monosulfonium salt [ C2] containing a photocationic polymerization initiator, [D] a thermal cationic polymerization initiator, [E] a silane coupling agent, and [F] hydrophobic silica particles. In the adhesive composition, the mass ratio of [C1] and [C2] is 4: 1 to 1: 1, and the content of [A] with respect to 100 parts by mass of the total amount of [A] and [B] Is 10 to 40 parts by mass, and the content of [C] is 0.2 to 0 with respect to 100 parts by mass of the total amount of [A], [B], [C], [D] and [E]. .6 parts by mass, [D] content of 0.05 to 0.25 parts by mass, [E] content of 0.35 to 0.8 parts by mass, and [F] content of 100 to 400 parts by mass Part.

  The adhesive composition of the present embodiment has a high adhesive force and can exhibit excellent mountability by including the above configuration.

(1) Component [A]
Component [A] is an epoxy resin having a bisphenol skeleton. By component [A], the mechanical strength and durability required for fixing the optical component can be imparted to the adhesive composition of the present embodiment.

  Examples of the component [A] include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, and bisphenol S type epoxy resin. These epoxy resins can be obtained by reacting bisphenol compounds such as bisphenol A, bisphenol F, bisphenol AD, and bisphenol S with epichlorohydrin in the presence of an alkali catalyst. Among them, the component [A] preferably contains a bisphenol A type epoxy resin or a bisphenol F type epoxy resin, and more preferably contains a bisphenol A type epoxy resin.

  Examples of commercially available components [A] include YP-115, YP-127, YP-128 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd .; jER825, jER827, jER828, jER1001, jER1002, jER1003, jER1055 manufactured by Mitsubishi Chemical Corporation , JER1007, jER1009, jER1010, jER1256, jER4250, jER4275, jER1256B40, and the like.

  The weight average molecular weight (Mw) of the component [A] is preferably 200 to 800, more preferably 300 to 500, from the viewpoints of curability and viscosity of the adhesive composition. The Mw of the component [A] can be measured using, for example, gel permeation chromatography (GPC).

(2) Component [B]
Component [B] is a dilutable monomer containing an alicyclic epoxy compound. Here, the dilutable monomer in the present embodiment refers to a component that can lower the viscosity and improve the fluidity by being blended in the adhesive composition.

  An alicyclic epoxy compound is a compound having an alicyclic structure and an epoxy group. As an alicyclic epoxy compound, for example, a compound having an epoxy group (alicyclic epoxy group) composed of two adjacent carbon atoms and oxygen atoms constituting the alicyclic ring, an epoxy group is directly bonded to the alicyclic ring. Examples thereof include bonded compounds. The compound having an alicyclic epoxy group can be arbitrarily selected from known ones. As the alicyclic epoxy group, a cyclohexene oxide group is preferable. Examples of the compound having an alicyclic epoxy group include 3,4,3 ′, 4′-diepoxybicyclohexane, compounds represented by the following formulas (b1) to (b4), and the like. Examples of the alicyclic epoxy compound include trade names “Celoxide 2021P”, “Celoxide 2081 (ε-caprolactone modified 3 ′, 4′-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate)” (above, Daicel Corporation). (Commercially available) can also be used.

  Component [B] may contain another epoxy compound that functions as a diluting monomer together with the alicyclic epoxy compound. Examples of other epoxy compounds include 2,2-bis (4-glycidyloxyphenyl) propane.

  The viscosity of component [B] is preferably 0.1 to 2 Pa · s at 25 ° C.

(3) Component [C]
Component [C] is a photocationic polymerization initiator which is a photopolymerization initiator, and includes a bissulfonium salt [C1] and a monosulfonium salt [C2]. The photocationic polymerization initiator according to the present embodiment is an onium salt that releases a Lewis acid upon irradiation with energy rays. Bissulfonium salt [C1] and monosulfonium salt [C2] are salts of a cation and an anion.

  The cation of component [C1] is a compound having two sulfonio groups. The sulfur atom constituting the sulfonio group is preferably bonded to the aromatic ring. The aromatic ring may be substituted with a fluorine atom, ethylene glycol or the like. Examples of the aromatic ring include a benzene ring. Examples of the cation of the component [C1] include compounds represented by the following formulas (1) to (3).

  The cation of component [C2] is a compound having one sulfonio group. The sulfur atom constituting the sulfonio group is preferably bonded to the aromatic ring. The aromatic ring may be substituted with a fluorine atom or the like. Examples of the aromatic ring include a benzene ring. Examples of the cation of the component [C2] include compounds represented by the following formulas (4) to (7).

The anion of component [C1] and component [C2] can be represented by the general formula: LM _b ⁻ . L is a metal or a semimetal, and examples thereof include elements such as B, P, As, Sb, Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V, Cr, Mn, and Co. M is a halogen atom, and b is an integer of 3 to 7.

Examples of the anion include tetrakis (pentafluorophenyl) borate, tetra (3,5-difluoro-4-methoxyphenyl) borate, tetrafluoroborate (BF ₄ ⁻ ), hexafluorophos from the viewpoint of sensitivity and availability. Examples include feto (PF ₆ ⁻ ), hexafluoroantimonate (SbF ₆ ⁻ ), hexafluoroarsenate (AsF ₆ ⁻ ), and hexachloroantimonate (SbCl ₆ ⁻ ).

  Component [C1] is preferably an aromatic bissulfonium salt. Examples of the aromatic bissulfonium salt are represented by the following formulas (C1-1), (C1-2), (C1-3), (C1-4), (C1-5), and (C1-6). Compounds. From the viewpoint of storage stability of the adhesive composition, the component [C1] preferably contains at least one selected from the group consisting of compounds represented by the following formulas (C1-1) to (C1-6). preferable.

  Component [C2] is preferably an aromatic monosulfonium salt. Examples of the aromatic monosulfonium salt include compounds represented by the following formulas (C2-1), (C2-2), (C2-3), and (C2-4). From the viewpoint of the curing rate, the component [C2] more preferably contains at least one selected from the group consisting of compounds represented by the following formulas (C2-1) to (C2-4).

  The component [C], which is a photocationic polymerization initiator, generally does not initiate the polymerization reaction unless it is irradiated with a certain amount of ultraviolet light. However, when the component [C1] and the component [C2] are compared, Even when irradiated, there is a difference in the cleavage reaction of each component.

  Since component [C1] has two sulfonio groups, as shown in the following reaction formula, the cation part (cation) absorbs ultraviolet rays to generate two ionic radicals by irradiation with ultraviolet rays, and then generates two ionic radicals. The photoacid is generated by the hydrogen abstraction reaction of the ionic radical. Since two molecules of photoacid are generated from the component [C1], the curing rate is increased.

  Since component [C2] has one sulfonio group, as shown in the following reaction formula, the cation moiety absorbs ultraviolet rays to generate one ionic radical by irradiation with ultraviolet rays, and then generates ionic radicals. Photoacids are generated by radical hydrogen abstraction reaction. Since one molecule of photoacid is generated from the component [C2], the curing rate is slower than that of the component [C1].

上記反応式中、Ｘは、アニオン部（陰イオン）を示す。

In the above reaction formula, X represents an anion part (anion).

  The mass ratio ([C1]: [C2]) of the component [C1] and the component [C2] contained in the adhesive composition of the present embodiment is 4: 1 to 1: 1. When the ratio of the component [C1] to the component [C2] exceeds 4, even in the absence of ultraviolet rays, photoacid is easily generated due to ionic impurities contained in the adhesive composition, and the adhesive composition Increases in viscosity, and the application accuracy of the adhesive composition decreases. Further, when the ratio of the component [C1] to the component [C2] is less than 1, the photoacid generation efficiency is low, so that a high amount of ultraviolet rays is required to mount the optical component, and the adhesive caused by excessive ultraviolet irradiation Due to the heat of reaction of the composition itself, a part of the thermal cationic polymerization initiator as the component [D] is cleaved, and curing shrinkage easily proceeds unexpectedly at the stage of ultraviolet curing. [C1]: By setting [C2] to 4: 1 to 1: 1, the viscosity of the adhesive composition can be reduced even when left in a certain environment (for example, low temperature) while exhibiting a high curing rate even with weak ultraviolet rays. The rise is suppressed, and stable applicability can be realized.

(4) Component [D]
The thermal cationic polymerization initiator is also called a thermal acid generator, a thermal curing agent, or a thermal cation generator, and exhibits a substantial function as a curing agent when reaching the curing temperature in the composition.

  As the component [D], those capable of exhibiting a function as a curing agent at a relatively low temperature are suitable, and specifically, those capable of curing at 140 ° C. or lower are preferred. As a result, it is possible to suppress warpage and cracking of the adherend due to the difference in shrinkage between the cured product of the adhesive composition and the adherend, and the adherend is compared with an inorganic material such as glass. Even if it is made of a resin material having low heat resistance, the influence on the adherend due to heating in the thermosetting step can be reduced.

  When a polymerization initiator that can be cured at a low temperature (for example, a temperature lower than 80 ° C.) is used, component [D] cures the adhesive composition in the temporary fixing stage due to the reaction heat of the resin generated in the photocuring stage. May increase the degree of cure shrinkage. Therefore, as component [D], what functions as a hardening | curing agent at 100-160 degreeC is desirable.

  Examples of component [D] include benzylsulfonium salt, thiophenium salt, thioranium salt, benzylammonium, pyridinium salt, hydrazinium salt, carboxylic acid ester, sulfonic acid ester, and amine imide.

  Commercially available components [D] include, for example, Adeka Opton CP77 and Adeka Opton CP66 manufactured by ADEKA Corporation; CI-2639 and CI-2624 () manufactured by Nippon Soda Co., Ltd .; 60L, Sun-Aid SI-80L, Sun-Aid SI-100L, etc. are mentioned.

  In addition, you may use component [C] and [D] by melt | dissolving in acetonitrile, propylene carbonate, etc. in order to improve compatibility with component [A] and [B].

(4) Component [E]
Component [E] is a silane coupling agent blended in the adhesive composition of the present embodiment for the purpose of improving the adhesion to a substrate or the like. As component [D], for example, at least one silane coupling agent selected from the group consisting of vinyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane is preferable. -Glycidoxypropyltrimethoxysilane is more preferred.

(5) Component [F]
Component [F] is hydrophobic silica particles. The component [F] is preferably selected in consideration of the compatibility with the resin component and the filling rate.

  The shape of the component [F] is preferably a substantially sphere. The average particle size of the component [F] is preferably 0.1 to 10 μm, and more preferably 0.1 to 5 μm. Examples of commercially available products corresponding to the component [F] include AEROSIL R 972, 974, 104, 202, 805, 7200, 711 manufactured by Nippon Aerosil Co., Ltd., and WACKER HDK H18 manufactured by Asahi Kasei Corporation.

  As the component [F], particles having an organic substance coated on the outer periphery of silica fine particles may be used. The particle size of such silica particles may be 0.01 to 10 μm. For example, since silica particles whose outer periphery is coated with stearic acid have high hydrophobicity, the degree of polarity of the components [A] and [B] constituting the base resin contained in the adhesive composition can be reduced.

  The average particle diameter of each silica particle can be measured by a known technique (laser diffraction method / laser scattering method).

  In this embodiment, the adhesive composition may contain a filler, an antifoaming agent, a leveling agent, a solvent, and the like as necessary in addition to the components [A] to [F].

  Content of component [A] in an adhesive composition is 10-40 mass parts with respect to 100 mass parts of total amounts of component [A] and [B], and 15-30 mass parts is preferable. When the content of the component [A] is less than 10 parts by mass, the toughness of the cured product of the adhesive composition tends to be insufficient, and when the content is more than 30 parts by mass, the Tg decreases and the heat resistance is reduced. It tends to decrease.

  Content of component [B] in an adhesive composition is 60-90 mass parts with respect to 100 mass parts of total amounts of component [A] and [B], and 70-85 mass parts is preferable. When the component [B] is less than 50 parts by mass, it becomes difficult to obtain the mechanical properties (Young's modulus) of the cured product of the adhesive composition. When the component [B] is more than 90 parts by mass, the adhesive composition is cured. The surface hardness of objects tends to increase and become brittle.

  The content of the component [C] in the adhesive composition is represented by the components [A], [B], [C], [D] and [E] (hereinafter referred to as “components [A] to [E]”). Is 0.2 to 0.6 parts by mass, and preferably 0.2 to 0.5 parts by mass with respect to 100 parts by mass in total. When the amount of the component [C] is less than 0.2 parts by mass, the progress of the cationic polymerization reaction is delayed, and in order to obtain the adhesive force necessary for temporarily fixing the optical component, the tact time of ultraviolet irradiation is increased, and the productivity is increased. It tends to decrease. On the other hand, when the component [C] exceeds 0.6 parts by mass, excessive photoacid is generated by ultraviolet irradiation, and at the same time, a large amount of counter anions are also generated in the adhesive, increasing the outgas generation amount, May affect electronic and optical components.

  Content of component [D] in an adhesive composition is 0.05-0.25 mass part with respect to 100 mass parts of total amounts of component [A]-[E], 0.05-0 .2 parts by mass are preferred. When the component [D] is less than 0.05 parts by mass, the curing reaction by heat does not proceed sufficiently, and the region where the optical components are mounted at a high density and the region is not irradiated with ultraviolet rays at all. The adhesive composition may remain uncured and the reliability of the entire optical component may be reduced. On the other hand, when the amount of the component [D] is more than 0.25 parts by mass, the crosslinking reaction further proceeds in a region where the curing reaction (crosslinking reaction) has been triggered by the component [C], and the cured product becomes brittle. There is a tendency.

  Content of component [E] in an adhesive composition is 0.35-0.8 mass part with respect to 100 mass parts of total amounts of component [A]-[E], 0.4-0 .7 parts by mass is preferred. When the component [E] is less than 0.35 parts by mass, an adhesive composition does not form an appropriate adhesive force between the optical component and the mounting substrate for fixing the optical component, and is left under an environmental test. Separation of objects may occur. On the other hand, when there are more components [E] than 0.8 mass part, the said components [E] may aggregate and hardening inhibition may arise.

  Content of component [F] in an adhesive composition is 100-400 mass parts with respect to 100 mass parts of total amounts of component [A]-[E], and 150-300 mass parts is preferable. When the content of the component [E] is less than 100 parts by mass, the cured product of the adhesive composition has insufficient mechanical properties (for example, a linear expansion coefficient), and an optical semiconductor using the adhesive composition It becomes difficult for the device to exhibit the desired optical performance. On the other hand, when there are more components [F] than 400 mass parts, the ratio for which the silica particle accounts in an adhesive composition becomes excess, and it becomes difficult to produce required adhesive force.

  The adhesive composition of the present embodiment preferably has a viscosity at room temperature (25 ° C.) of 15 to 55 Pa · s, more preferably 20 to 40 Pa · s. The viscosity of the adhesive composition can be measured using a viscometer (for example, TV-22 viscometer manufactured by Toki Sangyo Co., Ltd.). The adhesive composition of this embodiment exhibits thixotropy (structural viscosity) by containing the aforementioned components and having the above-described viscosity. The thixotropic coefficient of the adhesive composition is preferably 1.0 to 2.0, more preferably 1.0 to 1.5, from the viewpoint of the form stability of the adhesive composition at the time of application. .

  In order for the optical component to be fixed to a predetermined location on the mounting substrate through an adhesive that is cured by UV irradiation, the optical component and the adhesive are brought into contact with each other due to curing shrinkage of the adhesive during UV irradiation. It is important that the stress generated on the surface does not become non-uniform. In order to prevent this non-uniformity, it is important to uniformly wet the bottom surface of the optical component with an adhesive without a gap. Optical components are required to be mounted with high density, but with regard to multiple optical components, optical components that will be mounted later are only irradiated with extremely weak ultraviolet rays even in areas where the adhesive is wet. As a result, the curing reaction of the adhesive becomes insufficient, and it becomes difficult to obtain good characteristics. Therefore, in order to obtain high mounting accuracy even with minute UV rays, it is required that the adhesive has a high temporary fixing accuracy for fixing the optical component. To achieve this, even in weak light, the optical component is in a predetermined mounting position. A material having a mounting performance capable of fixing the substrate, that is, a material having a high curing rate even under irradiation with ultraviolet rays with low illuminance is essential.

  On the other hand, the demand for miniaturization of optical semiconductor devices has increased, and the integration density of optical components on a mounting substrate has increased. That is, it is important to fix the optical component with high accuracy in a narrow area. In particular, when optical components are mounted in highly dense areas, most of the ultraviolet rays are absorbed by the optical components, and if the optical components are thick or high, the adhesive that has oozed out to the outer periphery of the optical components Ultraviolet rays hardly reach the fret portion, and the adhesion reaction necessary for mounting the optical component may not proceed. In addition, for the purpose of developing the adhesive force necessary to mount optical components, the curing reaction proceeds excessively when irradiated with strong ultraviolet rays, and the curing shrinkage of the adhesive exceeding the expected due to the generated reaction heat May occur. Therefore, an adhesive that cures the frets on the outer periphery of the optical component in a short irradiation time is required even with extremely weak ultraviolet rays.

  Further, in addition to the high integration of the optical components described above, it is necessary to improve the fixing accuracy of the optical components themselves. For example, when mounting a microlens as an optical component, not only the mounting position shift (horizontal direction) of the optical component in the area within the mounting substrate but also the mounting position (vertical direction) between the lens center and the mounting substrate It is necessary to minimize the positional deviation. In addition, since the thixotropy is high, the wettability with the mounting substrate is generally deteriorated, and the adhesive force between the mounting substrate and the adhesive is also lowered, which causes a problem in terms of reliability.

  In view of the above-mentioned problems, the inventors blended a predetermined amount of components (A) to (E) as a base resin, and in particular, a plurality of photocationic polymerization initiators involved in the curing rate during ultraviolet irradiation at a predetermined ratio. By using it, it is possible to obtain high optical component mounting accuracy even after UV irradiation and after thermosetting, while ensuring high adhesive force on the adhesive surface of the optical component even in the situation where optical components are mounted at high density It has succeeded in finding an adhesive composition that can be used.

The optical semiconductor device of this embodiment includes a mounting substrate and an optical component mounted on the mounting substrate via a cured product of the adhesive composition. Specifically, such an optical semiconductor device is manufactured as follows. First, a mounting substrate is prepared, and an optical component in which an adhesive composition is applied to an adhesive surface is placed on a predetermined position of the mounting substrate. Next, low-illuminance ultraviolet light (for example, 25 mW / cm ² ) is irradiated for a certain period of time (for example, 15 to 30 seconds) to temporarily fix the optical component. Next, high-intensity ultraviolet rays (for example, 300 mW / cm ² ) are irradiated for a certain time (for example, 1 to 2 minutes), and the optical component is permanently fixed. Finally, in order to release the thermal strain due to ultraviolet irradiation and improve the adhesive strength between the mounting substrate and the adhesive composition, predetermined thermosetting (for example, the application temperature is 100 to 120 ° C. and the standing time is 1 to 3 hours) I do.

  Thereby, an optical semiconductor device provided with a mounting substrate and an optical component mounted on the mounting substrate by a cured product of the adhesive composition by ultraviolet curing and thermosetting reactions can be obtained. Examples of the mounting substrate include aluminum nitride, alumina, quartz, silicon, and the like. Examples of the optical semiconductor device include optical transmission / reception modules such as TOSA and ROSA.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

(Preparation of adhesive composition)
Example 1
The following components were blended and stirred to prepare a desired adhesive composition.
Component [A]: 25 parts by mass of bisphenol A type epoxy resin (jER828 / Mitsubishi Chemical Corporation) Component [B]: 3 ′, 4′-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Celoxide 2021P / stock) 74 parts by mass of component [C1]: bis [4- (diphenylsulfonio) phenyl] sulfide 0.2 parts by mass of hexafluoroantimonate [C2]: (4-phenylthiophenyl) diphenylsulfonium 0.1 parts by mass of fluoroantimonate [D]: sulfonium salt type thermal cationic polymerization initiator (SI-100L / manufactured by Sanshin Chemical Industry Co., Ltd.) 0.1 parts by mass of component [E]: 3-glycol Sidpropyltrimethoxysiloxane (KBM403 / Shin-Etsu Chemical Co., Ltd.) 0.6 parts by mass of silica component: 300 parts by mass of hydrophobic silica particles (Aerosil R972 / Nippon Aerosil Co., Ltd.)

Examples 2-3 and Comparative Examples 1-2
An adhesive composition was prepared in the same manner as in Example 1 except that each component was changed as shown in Table 1.

(Various evaluations)
The following evaluation was performed with respect to the adhesive composition obtained in each Example and Comparative Example. The evaluation results are summarized in Table 1.

1) Measurement of Viscosity of Composition Using a TV-22 viscometer (manufactured by Toki Sangyo Co., Ltd.), the viscosity (Pa · s) at 25 ° C. of the adhesive composition was measured at a rotor rotation speed of 5 rpm.

2) Wettability A commercially available dispenser was filled with the adhesive composition, and a certain amount of the adhesive composition (about 50 μg) was applied to a predetermined substrate. After about 30 minutes, wetting and spreading of the adhesive composition to the mounting substrate was confirmed. If the wetting spread of the adhesive composition is φ0.5 to 0.8 μm, it is judged that it exhibits a good coating property. It was judged that.

3) Optical axis displacement amount A light source (for example, a semiconductor laser) was placed on the positioning mark on the mounting substrate and fixed with solder or the like. Then, in consideration of the condensing point of the collimating lens mounted on the mounting substrate, a certain amount of the adhesive composition was applied to a predetermined portion from the light source in the light emitting direction of the light source. Thereafter, the probe or the like was brought into contact with the light source, and the collimating lens was held by the alignment equipment in a state where a weak current was passed, and the position was adjusted on the adhesive composition coated with the optical lens. At this time, the aspherical lens disposed in the vicinity of the emission end face of the laser light source converts the laser light emitted from the laser light source into parallel light, and the laser light converted into the parallel light is blown into a predetermined distance space, so that a predetermined distance is obtained. To a near infrared CCD camera (C3077-80 / manufactured by Hamamatsu Photonics Co., Ltd.). The amount of displacement of the collimator lens was converted from the amount of change in parallel light during ultraviolet irradiation obtained via a near-infrared CCD camera. When converting the amount of displacement, prior to fixing the adhesive composition by ultraviolet irradiation, the lens is operated and moved using a predetermined alignment device, and the amount of displacement of the collimated light center displayed on the camera is read. It was. From the converted amount of the read value, the amount of displacement of the lens at the time of ultraviolet irradiation (temporary fixation, permanent fixation) and after thermosetting was calculated.
In order to have high optical component mounting accuracy in a state where the optical components are densely integrated, the positional deviation of the optical components at the temporary fixing stage in ultraviolet irradiation is less than 0.2 μm, and the optical components at the final fixing stage It is preferable that the positional deviation is less than 0.4 μm and the positional deviation of the optical component in the thermosetting (curing) stage is less than 0.5 μm.

4) Adhesive strength evaluation After applying a certain amount of the adhesive composition (80 to 100 μg) on a predetermined mounting substrate (eg, alumina), an optical component is used by using an aligning device (manufactured by Fukuko System Co., Ltd.). After bringing the bottom surface (1.0 × 0.6 mm) of the collimating lens (1.0 × 1.0 × 0.6 mm shape / Alps Electric Co., Ltd.) into contact with the mounting substrate, ultraviolet rays are irradiated, Thermal curing was performed off-line to produce a sample for evaluating adhesive strength. Next, using the predetermined dysia tester (manufactured by XYZTEC / Condor EZ series), the fracture strength of the cured product of the adhesive composition was measured in an atmosphere of a temperature of 25 ± 2 ° C. and a humidity of 50 ± 10%. The average value was defined as the adhesive strength of the adhesive composition.

  The composition of the present invention is suitable for mounting an optical component constituting an optical transmission device on a predetermined mounting substrate.

  The adhesive composition of the present invention is suitably used when an optical component group mounted in an optical transmission / reception device is fixed on a predetermined substrate with high accuracy.

Claims (4)

[A] an epoxy resin having a bisphenol skeleton;
[B] a dilutable monomer containing an alicyclic epoxy compound;
[C] a cationic photopolymerization initiator containing a bissulfonium salt [C1] and a monosulfonium salt [C2];
[D] a thermal cationic polymerization initiator;
[E] a silane coupling agent;
[F] hydrophobic silica particles;
Containing
The mass ratio of [C1] and [C2] is 4: 1 to 1: 1,
The content of [A] is 10 to 40 parts by mass with respect to 100 parts by mass of the total amount of [A] and [B],
The content of [C] is 0.2 to 0.6 mass with respect to 100 mass parts of the total amount of [A], [B], [C], [D] and [E]. Parts, the content of [D] is 0.05 to 0.25 parts by mass, the content of [E] is 0.35 to 0.8 parts by mass, and the content of [F] is 100 to 400 parts by mass. Part of the adhesive composition. Said [C1] consists of a compound represented by following formula (C1-1), (C1-2), (C1-3), (C1-4), (C1-5) and (C1-6). Including at least one selected from the group,
The said [C2] contains at least 1 sort (s) chosen from the group which consists of a compound represented by following formula (C2-1), (C2-2), (C2-3) and (C2-4). The adhesive composition according to 1.

  The adhesive composition according to claim 1 or 2, wherein the weight average molecular weight of [A] is 200 to 800.   An optical semiconductor device comprising: a mounting substrate; and an optical component mounted on the mounting substrate via a cured product of the adhesive composition according to claim 1.