JP2012046722A - Adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive composition which can keep high bond strength without being peeled off even under high-temperature conditions such as a solder reflow but can be easily peeled off without doing damage to an adherend when the adhesive composition has become unnecessary.SOLUTION: The adhesive composition comprises: a compound that contains an ethylene glycol skeleton and that has cationically polymerizable reactive groups at both terminals; a compound that contains a propylene glycol skeleton and that has cationically polymerizable reactive groups at both terminals; a silicone compound that has the cationically polymerizable reactive groups; and a cationic photopolymerization initiator.

Description

The present invention relates to an adhesive composition that can maintain a high adhesive force without causing peeling even under a high temperature environment such as solder reflow, and can be easily peeled off without damaging an adherend when it becomes unnecessary.

The performance required of adhesives varies depending on the application, but depending on the application, it can be firmly adhered and fixed to the adherend as long as necessary, but it must be easily peeled off after use. There is.
For example, in an electronic material manufacturing method, an electronic component or wiring is fixed on a support plate such as a metal plate such as SUS, a glass plate, or a silicon wafer by using an adhesive, and processing such as alkali etching or plating is performed. After that, a solder reflow process is performed in which the solder is melted by applying a temperature of 200 ° C. or higher to conduct conductive connection. In these series of steps, high adhesive strength is required so that electronic components and wiring do not shift. On the other hand, after the series of steps is completed, it is required to peel the electronic material from the support plate without leaving glue.

As a highly adhesive and easily peelable adhesive, for example, Patent Document 1 discloses an adhesive in which a foaming agent such as a heat-expandable microcapsule is blended in the adhesive. When such an adhesive is heated, the entire adhesive is foamed by the foaming agent, and the adhesive area with the adherend is reduced, so that the adhesive can be easily peeled off. However, such a foam-type easily peelable adhesive has a problem that it foams and peels during heating in the solder reflow process.

Patent Document 2 discloses an adhesive in which a gas generating agent such as an azo compound or an azide compound is blended in a curable adhesive. When such an adhesive is irradiated with ultraviolet rays or heated, the adhesive is cured, and the gas generated from the gas generating agent is released to the adhesion surface with the adherend, and at least a part of the adhesion surface is peeled off. Therefore, it can be easily peeled off. However, the adhesive described in Patent Document 2 also has a problem in that gas is generated from the gas generating agent during heating in the solder reflow process and is peeled off.

JP 2001-131507 A JP 2003-231867 A

The present invention provides an adhesive composition that can maintain a high adhesive force without causing peeling even in a high-temperature environment such as solder reflow, and can be easily peeled off without damaging an adherend when it becomes unnecessary. The purpose is to do.

The present invention relates to a compound having an ethylene glycol skeleton and a cation polymerizable reactive group at both ends, a compound having a propylene glycol skeleton and a cation polymerizable reactive group at both ends, a silicone compound having a cation polymerizable reactive group, And an adhesive composition containing a photocationic polymerization initiator.
The present invention is described in detail below.

The present inventor includes a compound having an ethylene glycol skeleton and a cation polymerizable reactive group at both ends, a compound having a propylene glycol skeleton and a cation polymerizable reactive group at both ends, and a silicone compound having a cation polymerizable reactive group In addition, the adhesive composition containing the cationic photopolymerization initiator can exhibit a high adhesive force without causing peeling even in a high-temperature environment such as solder reflow, but without being left with glue simply by being immersed in warm water. The present inventors have found that it can be easily peeled off and have completed the present invention.

The adhesive composition of the present invention comprises, as an adhesive component, a compound having an ethylene glycol skeleton and a cation polymerizable reactive group at both ends (also referred to as a cation polymerizable compound (A) in the present specification) and a propylene glycol skeleton. And a compound having a cationically polymerizable reactive group at both ends (also referred to as a cationically polymerizable compound (B) in the present specification). Since these cationically polymerizable compounds have an ethylene glycol skeleton or a propylene glycol skeleton, all have high hydrophilicity. By using two kinds of such cationically polymerizable compounds having high hydrophilicity, high adhesive force can be maintained even in a high temperature environment, but when it becomes unnecessary, the adherend can be damaged simply by immersing in warm water. Can be easily peeled off.

The cationic polymerizable compound (A) is an essential component for imparting high adhesive force to the adhesive composition of the present invention even in a high temperature environment.
The cationic polymerizable reactive group in the cationic polymerizable compound (A) is not particularly limited, and examples thereof include an epoxy group, an oxetane group, an alicyclic epoxy group, and a vinyl ether group.
The cationically polymerizable compound (A) is not particularly limited, and examples thereof include an epoxy resin represented by the following general formula (1).

In the general formula (1), n represents an integer.
In the above general formula (1), n is not particularly limited, but there is no commercially available product exceeding 22 at the present time, so the substantial upper limit is 22. The preferable range of n is 5-15. When n exceeds 15, it may be difficult to prepare an adhesive composition, and the peelability of the adhesive composition in warm water may be reduced. This is presumably because when n exceeds 15, the crystallinity of the polyethylene glycol chain increases. A more preferable upper limit of n is 13.

Examples of the epoxy resin represented by the general formula (1) include Denacol EX-810 (n = 1), Denacol EX-850 (n = 2), Denacol EX-821 (n = 4), and Denacol EX-830. (N = 9), Denacol EX-841 (n = 13), Denacol EX-861 (n = 22), and the like are commercially available from Nagase ChemteX Corporation. Epolite 40E (n = 1), Epolite 100E (n = 2), Epolite 200E (n = 4), Epolite 400E (n = 9), etc. are commercially available from Kyoeisha Chemical Company.

The cationic polymerizable compound (B) is an essential component for imparting the ability to peel off in warm water to the adhesive composition of the present invention.
The cationic polymerizable reactive group in the cationic polymerizable compound (B) is not particularly limited, and examples thereof include an epoxy group, an oxetane group, and a vinyl ether group.
The cationically polymerizable compound (B) is not particularly limited, and examples thereof include an epoxy resin represented by the following general formula (2).

In the general formula (2), m represents an integer.
In the above general formula (2), m is not particularly limited, but since there is no commercially available product exceeding 11 at present, the substantial upper limit is 11. When m exceeds 11, it may be difficult to prepare an adhesive composition, and the adhesive composition may become solid at room temperature. The preferable range of m is 2 to 11, and the more preferable range is 3 to 11.

Examples of the epoxy resin represented by the general formula (2) include Denacol EX-911 (m = 1), Denacol EX-941 (m = 2), Denacol EX-920 (m = 3), Denacol EX-931. (M = 11) is commercially available from Nagase ChemteX Corporation, and Epolite 70P (m = 1), Epolite 200P (m = 3), Epolite 400P (m = 7), etc. are commercially available from Kyoeisha Chemical Co., Ltd. .

The preferable lower limit of the compounding amount of the cationic polymerizable compound (B) with respect to 100 parts by weight of the cationic polymerizable compound (A) is 30 parts by weight, and the preferable upper limit is 5000 parts by weight. If the blending amount of the cationic polymerizable compound (B) is less than 30 parts by weight, the time required for peeling may be extremely long even if the resulting adhesive composition is immersed in warm water. When the compounding quantity of the said cation polymeric compound (B) exceeds 5000 weight part, the adhesive composition obtained will become difficult to harden | cure and adhesive force may fall. The more preferred lower limit of the amount of the cationic polymerizable compound (B) to 100 parts by weight of the cationic polymerizable compound (A) is 50 parts by weight, the more preferred upper limit is 2000 parts by weight, and the still more preferred lower limit is 100 parts by weight. A more preferred upper limit is 1500 parts by weight.

The adhesive composition of the present invention contains a silicone compound having a cationic polymerizable reactive group.
When the adhesive composition of the present invention contains the silicone compound having the cationic polymerizable reactive group, a semiconductor substrate is bonded onto a support plate such as a glass plate or a silicon wafer using the adhesive composition of the present invention. In this case, the adhesive composition adheres to the support plate side when it is immersed in hot water and peeled off, and can be easily peeled off without leaving adhesive residue on the semiconductor substrate side. The reason is presumed as follows.
Since the adhesive composition of the present invention contains the silicone compound having the cationic polymerizable reactive group, the cured product has a silicone skeleton in the structure. For this reason, for example, compared with the case where a silicone compound having no cationically polymerizable reactive group is added alone to the adhesive composition, the adhesiveness as a whole of the cured product to the support plate is increased and immersed in warm water. Then, when peeling off, it is easier to adhere to the support plate side than to the semiconductor substrate side, and it can be easily peeled off without leaving glue on the semiconductor substrate side.

Moreover, since the adhesive composition of this invention contains the silicone compound which has the said cation polymerizable reactive group, the hardened | cured material has a silicone frame | skeleton in a structure and is excellent also in heat resistance. For this reason, when a semiconductor substrate is bonded onto a support plate such as a glass plate or a silicon wafer using the adhesive composition of the present invention, the cured product of the adhesive composition of the present invention is in a high-temperature environment such as solder reflow. However, thermal decomposition is suppressed, and for example, it is possible to prevent problems such as decomposition products that cannot be peeled off even when immersed in warm water adhere to the semiconductor substrate.

The cationic polymerizable reactive group in the silicone compound having the cationic polymerizable reactive group is not particularly limited, and examples thereof include an epoxy group, an oxetane group, and a vinyl ether group.

The silicone compound having a cationic polymerizable reactive group is not particularly limited, but when the adhesive composition of the present invention is a cured product having a thickness of 100 μm, the light transmittance at a visible light wavelength of 600 nm of the cured product is 20% or more. It is preferable to select a silicone compound having the above cationic polymerizable reactive group. When a silicone compound having a cationically polymerizable reactive group that causes the light transmittance at a visible light wavelength of 600 nm of the cured product to be less than 20% is used, even if the resulting adhesive composition is irradiated with light, The curing reaction may not sufficiently proceed due to scattering, and the compatibility of the silicone compound having the cationic polymerizable reactive group with the cationic polymerizable compound (A) and the cationic polymerizable compound (B) is poor. Thus, even when strong light is irradiated to the resulting adhesive composition, the silicone skeleton cannot be present in the entire cured product, and adhesion to the support plate may be reduced.

Specifically, a silicone compound having an epoxy group is preferable as the silicone compound having a cationic polymerizable reactive group.
The silicone compound having an epoxy group is not particularly limited, and may be a silicone compound having an epoxy group in a side chain or a silicone compound having an epoxy group at a terminal.

Although the silicone compound which has an epoxy group in the said side chain is not specifically limited, The silicone compound which has a structural unit represented by following General formula (3) is preferable.
R ¹ R ² SiO _2/2 (3)
In General Formula (3), R ¹ represents an epoxy group-containing group, and R ² represents a linear or branched hydrocarbon group having 1 to 8 carbon atoms or a fluorinated product thereof.

The epoxy group-containing group is not particularly limited, but is preferably a glycidyl group-containing group, and is preferably not an epoxycyclohexyl group-containing group.
The glycidyl group-containing group is not particularly limited. For example, 2,3-epoxypropyl group, 3,4-epoxybutyl group, 4,5-epoxypentyl group, 2-glycidoxyethyl group, 3-glycidoxy A propyl group, 4-glycidoxybutyl group, etc. are mentioned.

The linear or branched hydrocarbon group having 1 to 8 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group. N-heptyl group, n-octyl group, isopropyl group, isobutyl group, sec-butyl group, t-butyl group, isopentyl group, neopentyl group, t-pentyl group, isohexyl group and the like.

The silicone compound having an epoxy group in the side chain may have a structural unit other than the structural unit represented by the general formula (3).
Examples of the structural unit other than the structural unit represented by the general formula (3) include a structural unit represented by the following general formula (4), a structural unit represented by the following general formula (5), and the like. The structural unit represented by the following general formula (4) and the structural unit represented by the following general formula (5) may be contained alone in the silicone compound having an epoxy group in the side chain. More than one species may be included.
R ³ R ⁴ SiO _2/2 (4)
R ⁵ SiO _3/2 (5)
In general formulas (4) and (5), R ^{3 to} R ⁵ each represents a linear or branched hydrocarbon group having 1 to 8 carbon atoms or a fluorinated product thereof, and these may be the same as each other. Well, it can be different.

The silicone compound having an epoxy group at the terminal is not particularly limited, and includes, for example, the structural unit represented by the general formula (4) or the structural unit represented by the general formula (5) singly or in combination. Examples include a silicone compound having an epoxy group-containing group at the end of the compound.

The epoxy equivalent of the silicone compound having an epoxy group is not particularly limited, but a preferable lower limit is 100 and a preferable upper limit is 5000. When the epoxy equivalent is less than 100, the cured product of the obtained adhesive composition does not sufficiently incorporate the silicone compound having the epoxy group, the ratio of the silicone skeleton in the structure is reduced, and the adhesion to the support plate May decrease. When the epoxy equivalent exceeds 5000, the compatibility of the silicone compound having the epoxy group with the cationic polymerizable compound (A) and the cationic polymerizable compound (B) is deteriorated, and the resulting adhesive composition The light transmittance of the cured product may become too small. The more preferable lower limit of the epoxy equivalent of the silicone compound having an epoxy group is 150, and the more preferable upper limit is 1000.

A method for synthesizing the silicone compound having an epoxy group is not particularly limited. For example, an epoxy group-containing group is added to the silicone resin by a hydrosilylation reaction between a silicone resin having a SiH group and a vinyl compound having an epoxy group-containing group. And a method in which a siloxane compound and a siloxane compound having an epoxy group-containing group are subjected to a condensation reaction.
Specific examples of the siloxane compound having an epoxy group-containing group include 3-glycidoxypropyl (methyl) dimethoxysilane, 3-glycidoxypropyl (methyl) diethoxysilane, 3-glycidoxypropyl ( Dialkoxysilanes such as methyl) dibutoxysilane, 2- (3,4-epoxycyclohexyl) ethyl (methyl) dimethoxysilane, 2,3-epoxypropyl (methyl) dimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltributoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 2,3-epoxypropyltrimeth Shishiran, trialkoxysilane such as 2,3-epoxy propyl triethoxy silane.

The molecular weight of the silicone compound having a cationically polymerizable reactive group is not particularly limited, but a preferable lower limit is 300 and a preferable upper limit is 5000. When the molecular weight is less than 300, the cured product of the obtained adhesive composition may have poor adhesion to the support plate. When the molecular weight exceeds 5000, the compatibility of the silicone compound having the cationic polymerizable reactive group with the cationic polymerizable compound (A) and the cationic polymerizable compound (B) is deteriorated, and the resulting adhesive composition is obtained. The silicone compound having the cationically polymerizable reactive group in the product may be separated into layers, or the light transmittance of the cured product of the resulting adhesive composition may be too small.

The commercial item of the silicone compound having the cationic polymerizable reactive group is not particularly limited. For example, an epoxy group is added to a side chain such as trade names “X-22-343” and “KF-101” manufactured by Shin-Etsu Chemical Co., Ltd. And a silicone compound having an epoxy group at both ends such as a trade name “X-22-163” manufactured by Shin-Etsu Chemical Co., Ltd.

The amount of the silicone compound having a cationic polymerizable reactive group is not particularly limited, but the preferred lower limit is 0 with respect to 100 parts by weight of the total of the cationic polymerizable compound (A) and the cationic polymerizable compound (B). 0.1 parts by weight, and the preferred upper limit is 100 parts by weight. When the blending amount of the silicone compound having a cationic polymerizable reactive group is less than 0.1 parts by weight, the cured product of the obtained adhesive composition has a reduced ratio of the silicone skeleton in the structure and adheres to the support plate. May decrease. When the blending amount of the silicone compound having a cationic polymerizable reactive group exceeds 100 parts by weight, the blending amounts of the cationic polymerizable compound (A) and the cationic polymerizable compound (B) are relatively lowered and obtained. The adhesive strength of the adhesive composition or the ability to peel off in warm water may decrease, the compatibility of each compounding component will decrease, and good film properties will be obtained when filming the resulting adhesive composition It may not be obtained. The amount of the silicone compound having a cationic polymerizable reactive group is more preferably 2 parts by weight with respect to a total of 100 parts by weight of the cationic polymerizable compound (A) and the cationic polymerizable compound (B). A more preferred upper limit is 70 parts by weight.

The adhesive composition of the present invention contains a photocationic polymerization initiator.
The cationic photopolymerization initiator is not particularly limited as long as it is a compound that generates a protonic acid or a Lewis acid by light irradiation, and may be an ionic photoacid generating type or a nonionic photoacid generating type. Good.

The ionic photoacid-generating photocationic polymerization initiator is not particularly limited, and examples thereof include onium salts such as aromatic diazonium salts, aromatic halonium salts, and aromatic sulfonium salts, iron-allene complexes, titanocene complexes, and arylsilanols. -Organometallic complexes such as aluminum complexes. These ionic photoacid-generating photocationic polymerization initiators may be used alone or in combination of two or more.

Commercially available products of the ionic photoacid-generating photocationic polymerization initiator are not particularly limited. For example, “Adekaopter” such as “Adekaoptomer SP150” and “Adekaoptomer SP170” manufactured by Asahi Denka Kogyo Co., Ltd. Mer ”series, the product name“ UVE-1014 ”manufactured by General Electronics Co., Ltd., the product name“ CD-1012 ”manufactured by Sartomer, and the product name“ CPI-100P ”manufactured by San Apro.

The nonionic photoacid-generating photocationic polymerization initiator is not particularly limited, and examples thereof include nitrobenzyl ester, sulfonic acid derivative, phosphoric acid ester, phenolsulfonic acid ester, diazonaphthoquinone, and N-hydroxyimidophosphonate. Can be mentioned. These nonionic photoacid-generating photocationic polymerization initiators may be used alone or in combination of two or more.

Although the compounding quantity of the said photocationic polymerization initiator is not specifically limited, A preferable minimum is 0.1 weight part with respect to a total of 100 weight part of the said cationic polymerizable compound (A) and the said cationic polymerizable compound (B). The preferred upper limit is 10 parts by weight. If the amount of the photocationic polymerization initiator is less than 0.1 parts by weight, the cationic polymerization reaction may not proceed sufficiently or the reaction may be slow. When the content of the photocationic polymerization initiator is more than 10 parts by weight, the cationic polymerization reaction becomes too fast, and workability may be deteriorated or a non-uniform cured product may be obtained. The blending amount of the photocationic polymerization initiator is more preferably 0.3 parts by weight, more preferably a lower limit relative to 100 parts by weight of the total of the cationically polymerizable compound (A) and the cationically polymerizable compound (B). The upper limit is 5 parts by weight.

The combination of the silicone compound having the cationic polymerizable reactive group and the photo cationic polymerization initiator is 95.2% by weight of the silicone compound having the cationic polymerizable reactive group, and 4.8% by weight of the photo cationic polymerization initiator. It is preferable that the mixture is a combination such that the calorific value observed while irradiating with an ultraviolet ray using an optical DSC apparatus is 40 J / g or more.
When the calorific value satisfies such a range, it can be said that the silicone compound having the cationic polymerizable reactive group and the photo cationic polymerization initiator are a combination capable of exhibiting a relatively high fast curability. Therefore, when the calorific value satisfies the above range, the obtained adhesive composition is excellent in fast curability, and specifically, for example, can exhibit a sufficient adhesive force within 5 hours after ultraviolet irradiation. .
When the heat generation amount is less than 40 J / g, the resulting adhesive composition may have a reduced fast curability. The calorific value is more preferably 65 J / g or more.

The mixture of 95.2% by weight of the silicone compound having a cationically polymerizable reactive group and 4.8% by weight of the cationic photopolymerization initiator has a heating value observed while irradiating with an ultraviolet ray using an optical DSC apparatus. The upper limit is not particularly limited, but is preferably 1000 J / g or less.

In this specification, the calorific value observed while irradiating ultraviolet rays using an optical DSC apparatus means the calorific value obtained from an exothermic curve obtained by irradiating a sample with ultraviolet rays using the optical DSC apparatus. As an optical DSC apparatus, for example, an optical DSC apparatus (DSC apparatus Q100 manufactured by TA Instruments Co., Ltd., refrigerator RSC, optical DSC adapter PCA, USHIO spotlight irradiator SP3, light guide AF-12NQ-X ) And the like.
1 and 2 show an example of an exothermic curve obtained by irradiating a mixture of a silicone compound having a cationic polymerizable reactive group and a photo cationic polymerization initiator with ultraviolet rays using an optical DSC apparatus. In FIGS. 1 and 2, the area of the hatched portion corresponds to the amount of heat generated while irradiating ultraviolet rays using an optical DSC apparatus. As shown in FIG. 1, when the exothermic peak time (time for the exothermic curve to reach a peak) is short and the calorific value (area of the hatched portion) is large, the silicone compound having the cationically polymerizable reactive group and the photocationic polymerization initiator are used. The photoreaction rate is fast, and the time until the exothermic curve shows a constant value is also short. On the other hand, when the exothermic peak time (time for the exothermic curve to reach the peak) is long and the calorific value (area of the hatched portion) is small as shown in FIG. 2, the silicone compound having the cationically polymerizable reactive group and the photocationic polymerization are used. The photoreaction rate with the initiator is slow, and it takes time until the exothermic curve shows a constant value.

The adhesive composition of the present invention may further contain a compound having both a radical polymerizable reactive group and a cationic polymerizable reactive group as a crosslinking agent, and a photo radical polymerization initiator.

By containing the said photoradical polymerization initiator, in the adhesive composition obtained, radical polymerization is rapidly started by light irradiation. As a result, the radical polymerizable reactive groups of the compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group are polymerized to form a polymer having the cationic polymerizable reactive group as a side chain. On the other hand, the photocationic polymerization initiator is also activated by light irradiation, but the cationic polymerization is caused by the presence of the ethylene glycol skeleton in the cationic polymerizable compound (A) and the propylene glycol skeleton in the cationic polymerizable compound (B). Since it is delayed, it proceeds very slowly.
For this reason, in the adhesive composition obtained by containing the compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group and the photo radical polymerization initiator, first, by radical polymerization After the polymer having a cationic polymerizable reactive group as a side chain is sufficiently formed, the cationic polymerizable reactive group, the cationic polymerizable compound (A), the cationic polymerizable compound (B), and the cationic polymerization A very large network structure is formed by reaction with a silicone compound having a reactive reactive group.

By containing a compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group and a photo radical polymerization initiator, the cured product of the resulting adhesive composition has a very large network structure. Can be very flexible. When a semiconductor substrate is bonded onto a support plate using such an adhesive composition, the cured product of the adhesive composition has a high followability to deformation of the semiconductor substrate even in a high-temperature environment such as solder reflow. Problems such as separation of the substrate from the support plate can be prevented.

The radical polymerizable reactive group in the compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group is not particularly limited, and examples thereof include a (meth) acryl group, a vinyl group, and allyl.
The cationic polymerizable reactive group in the compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group is not particularly limited. For example, cyclic ether groups such as epoxy groups and oxetane groups, hydroxyl groups, vinyl ether groups, episulfide groups And an ethyleneimine group.

The compound having both the radically polymerizable reactive group and the cationically polymerizable reactive group is not particularly limited, but is excellent in compatibility with the cationically polymerizable compound (A) and the cationically polymerizable compound (B). A compound in which a radical polymerizable reactive group and a cationic polymerizable reactive group are bonded via an ether skeleton is preferable.
More specifically, examples of the compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group include 2- (2-vinyloxyethoxy) ethyl acrylate and 2- (2-vinyloxy) methacrylate. And ethoxy) ethyl. Incidentally, 2- (2-vinyloxyethoxy) ethyl acrylate and 2- (2-vinyloxyethoxy) ethyl methacrylate are commercially available from Nippon Shokubai Co., Ltd. under the trade names “VEEA” and “VEEM”, respectively. Compounds can also be used.

Further, the compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group is synthesized by, for example, a reaction between a compound having a radical polymerizable reactive group and a compound having a cationic polymerizable reactive group. Also good. Examples of such a reaction include a reaction between (meth) acrylic acid chloride and diethylene glycol monovinyl ether, a reaction between (meth) acrylic acid chloride and 2-hydroxyethyl vinyl ether, and the like.

The compounding amount of the compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group is not particularly limited, but a total of 100 parts by weight of the cationic polymerizable compound (A) and the cationic polymerizable compound (B). On the other hand, the preferred lower limit is 0.1 parts by weight and the preferred upper limit is 10 parts by weight. When the compounding amount of the compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group is out of the above range, the cured product of the adhesive composition forms a very large network structure as described above. The semiconductor substrate may not be sufficiently flexible, and the semiconductor substrate may be peeled off under a high temperature environment such as solder reflow. The compounding amount of the compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group is based on 100 parts by weight of the total of the cationic polymerizable compound (A) and the cationic polymerizable compound (B). A more preferred lower limit is 0.5 parts by weight, and a more preferred upper limit is 5 parts by weight.

The radical photopolymerization initiator is not particularly limited, for example, benzoins such as benzoin and benzoin methyl ether, benzophenones such as benzophenone, methylbenzophenone, 4,4′-dichlorobenzophenone, 4,4′-bisdiethylaminobenzophenone, Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, N, N-dimethylaminoacetophenone, 2-methyl-1- [4- (methylthio ) Acetophenones such as phenyl] -2-morpholinopropan-1-one, 2-methylanthraquinone, 2-ethylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone, etc. Anthraquinones, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, thioxanthones such as 2,4-diisopropylthioxanthone, 2-isopropylthioxanthone, ketals such as acetophenone dimethyl ketal, benzyldimethyl ketal, etc. Is mentioned. Among these, the trade name “IRGACURE907” manufactured by BASF is preferable.

The blending amount of the radical photopolymerization initiator is not particularly limited, but a preferable lower limit is 0.01 weight with respect to a total of 100 parts by weight of the cationic polymerizable compound (A) and the cationic polymerizable compound (B). Parts, and the preferred upper limit is 5 parts by weight. When the blending amount of the photo radical polymerization initiator is less than 0.01 parts by weight, the radical polymerization reaction may not sufficiently proceed or the reaction may be delayed. When the compounding amount of the photo radical polymerization initiator exceeds 5 parts by weight, a decomposition product of the photo radical initiator may become an impurity and cause outgassing. The blending amount of the radical photopolymerization initiator is more preferably 0.05 parts by weight, more preferably a lower limit with respect to 100 parts by weight of the total of the cationic polymerizable compound (A) and the cationic polymerizable compound (B). The upper limit is 2 parts by weight.

In addition, in the adhesive composition of this invention, a thermal radical polymerization initiator may be used together as needed. The thermal radical polymerization initiator is not particularly limited. For example, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis-2,4 -Dimethylvaleronitrile, 1,1'-azobis-1-cyclohexanecarbonitrile, dimethyl-2,2'-azobisisobutyrate, 4,4'-azobis-4-cyanovaleric acid, 2,2'-azobis (2-amidinopropene) dihydrochloride, 2-tert-butylazo-2-cyanopropane, 2,2′-azobis (2-methylpropionamide) dihydrate, 2,2′-azobis (2,4,4) Azo compounds such as 4-trimethylpentane), tert-butylperoxyneodecanoate, tert-butylperoxypivalate, tert-butylperoxy-2-ethyl Xanoate, tert-butyl peroxyisobutyrate, tert-butyl peroxylaurate, tert-butyl peroxyisophthalate, tert-butyl peroxyacetate, tert-butyl peroxyoctoate, tert-butyl peroxybenzoate, etc. Peroxyesters, diacyl peroxides such as benzoyl peroxide, hydroperoxides such as cumene hydroperoxide, methyl ethyl ketone peroxide, potassium persulfate, 1,1-bis (tert-butylperoxy) -3, Examples include 3,5-trimethylcyclohexane, dialkyl peroxides or peroxydicarbonates, hydrogen peroxide, and the like.

When the adhesive composition of the present invention contains a compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group, and the photo radical polymerization initiator, the adhesive composition of the present invention comprises: Furthermore, it is preferable to contain a silicone compound having a radical polymerizable reactive group.

In the adhesive composition obtained by containing the silicone compound having the radical polymerizable reactive group, the compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group by light irradiation, and the radical It reacts quickly with a silicone compound having a polymerizable reactive group. This prevents the formation of a polymer composed only of a compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group, and reliably introduces a silicone skeleton into the structure of the cured product. Can do.
In addition, since the silicone compound having a radical polymerizable reactive group is highly reactive, the curing reaction of the resulting adhesive composition proceeds sufficiently, and bonding can be performed satisfactorily without heating in subsequent steps. .

The radical polymerizable reactive group in the silicone compound having the radical polymerizable reactive group is not particularly limited, and for example, the same as the radical polymerizable reactive group in the compound having both the radical polymerizable reactive group and the cationic polymerizable reactive group. And the radical polymerizable reactive group.

Specifically, the silicone compound having a (meth) acryl group is preferable as the silicone compound having a radical polymerizable reactive group.

The acrylic equivalent of the silicone compound having the (meth) acryl group is not particularly limited, but a preferable lower limit is 100 and a preferable upper limit is 15000. When the acrylic equivalent is less than 100, the cured product of the resulting adhesive composition is not sufficiently incorporated with the silicone compound having the (meth) acrylic group, and the ratio of the silicone skeleton in the structure is reduced, thereby supporting Adhesion to the plate may be reduced. When the acrylic equivalent exceeds 15000, the compatibility between the silicone compound having the (meth) acrylic group, the cationic polymerizable compound (A) and the cationic polymerizable compound (B) is deteriorated, and the resulting adhesive is obtained. The light transmittance of the cured product of the composition may be too small. The acrylic equivalent of the silicone compound having the (meth) acryl group has a more preferable lower limit of 150, a more preferable upper limit of 10,000, a still more preferable upper limit of 5000, and a still more preferable upper limit of 1000.

The method for synthesizing the silicone compound having the (meth) acrylic group is not particularly limited. For example, the silicone compound is obtained by a hydrosilylation reaction between a silicone resin having a SiH group and a vinyl compound having a (meth) acrylic group-containing group. Examples thereof include a method for introducing a (meth) acryl group-containing group into a resin, a method for causing a siloxane compound to undergo a condensation reaction with a siloxane compound having a (meth) acryl group-containing group.

The molecular weight of the silicone compound having a radical polymerizable reactive group is not particularly limited, but a preferable lower limit is 300 and a preferable upper limit is 5000. When the molecular weight is less than 300, the cured product of the obtained adhesive composition may have poor adhesion to the support plate. When the molecular weight exceeds 5000, the compatibility between the silicone compound having a radical polymerizable reactive group, the cationic polymerizable compound (A) and the cationic polymerizable compound (B) is deteriorated, and the resulting adhesive composition is obtained. The silicone compound having the radical polymerizable reactive group in the product may be separated into layers, or the light transmittance of the cured product of the resulting adhesive composition may be too small.

The commercial item of the silicone compound which has the said radical polymerizable reactive group is not specifically limited, For example, Shin-Etsu Chemical Co., Ltd. "X-22-164 (acryl equivalent 190)", "X-22-164AS (acryl equivalent 450) ) "," X-22-164A (acrylic equivalent 860) "," X-22-164B (acrylic equivalent 1630) "," X-22-164C (acrylic equivalent 2370) "," X-22-164E (acrylic) Equivalent 3900) ”and other silicone compounds having methacrylic groups at both ends,“ X-22-174DX (acrylic equivalent 4600) ”,“ X-22-2426 (acrylic equivalent 12000) ”,“ X ”manufactured by Shin-Etsu Chemical Co., Ltd. -222-2475 (acrylic equivalent 420) "and other silicone compounds having a methacryl group at one end," X-2 "manufactured by Shin-Etsu Chemical Co., Ltd. A silicone compound having an acrylic group at both ends, such as “-2445 (acrylic equivalent 1600)”, “X-22-1602 (acrylic equivalent 1600)”, “X-22-1603 (acrylic equivalent 1150)”; A silicone compound having an acrylic group at both ends and side chains, such as “-2457”, and an acrylic group in side chains such as “X-22-2458 (acrylic equivalent 470)”, “X-22-2459 (acrylic equivalent 930)” And a silicone compound having a group.

The adhesive composition of the present invention may further contain polyethylene glycol. Polyethylene glycol functions as a plasticizer in the adhesive composition of the present invention. That is, by containing polyethylene glycol, the adhesive composition of the present invention can exhibit higher adhesive strength and higher peelability in warm water.
Further, when the compatibility of the cationic polymerizable compound (A), the cationic polymerizable compound (B) and the silicone compound having the cationic polymerizable reactive group is poor, the adhesive composition becomes turbid and irradiated with light. In some cases, light does not reach the interior sufficiently and poor curing occurs. Even in such a case, polyethylene glycol plays a role as a compatibilizing agent and can prevent the adhesive composition from becoming cloudy.

The preferable lower limit of the polymerization degree of the polyethylene glycol is 2, and the preferable upper limit is 50. When the polymerization degree of the polyethylene glycol is less than 2, the polyethylene glycol may be diffused when the adhesive composition is heated to a high temperature. When the polymerization degree of the polyethylene glycol exceeds 50, the blended curable component may not be cured. The more preferable lower limit of the polymerization degree of the polyethylene glycol is 5, and the more preferable upper limit is 30.

The adhesive composition of the present invention may further contain additives such as particles having an average particle diameter of 3 to 300 μm and a uniform particle diameter, if necessary.

The method for producing the adhesive composition of the present invention is not particularly limited. For example, the cationic polymerizable compound (A), the cationic polymerizable compound (B), the silicone compound having a cationic polymerizable reactive group, and light as described above. The method etc. which knead | mix a cationic polymerization initiator and another component by a conventionally well-known method are mentioned.

The adhesive composition of the present invention contains a cationically polymerizable adhesive component and a photocationic polymerization initiator, and the cationic polymerization by these components proceeds very slowly. By bonding together, the semiconductor substrate or the like can be fixed even with a support plate that does not transmit light such as SUS. Moreover, since the adhesive composition of the present invention contains a silicone compound having a cationic polymerizable reactive group as an adhesive component, the adhesive composition of the present invention is used on a support plate such as a glass plate or a silicon wafer. When the semiconductor substrates are joined, the adhesive composition adheres to the support plate side when being immersed in hot water and peeled off, and can be easily peeled off without leaving adhesive residue on the semiconductor substrate side. Furthermore, when a semiconductor substrate is bonded on a support plate such as a glass plate or a silicon wafer using the adhesive composition of the present invention, the cured product of the adhesive composition of the present invention is in a high temperature environment such as solder reflow ( (200 to 300 ° C.), the thermal decomposition is suppressed. For example, it is possible to prevent a problem that a decomposition product that cannot be peeled off even when immersed in warm water adheres to the semiconductor substrate. And when it becomes unnecessary after a series of processes, it can peel easily without damaging an adherend by immersing in warm water (25-85 ° C).

According to the present invention, an adhesive composition that can maintain a high adhesive force without causing peeling even in a high temperature environment such as solder reflow, and can be easily peeled off without damaging the adherend when no longer needed. Can be provided.

An example of an exothermic curve obtained by irradiating a mixture of a silicone compound having a cationically polymerizable reactive group and a photocationic polymerization initiator with ultraviolet rays using an optical DSC apparatus is shown. An example of an exothermic curve obtained by irradiating a mixture of a silicone compound having a cationically polymerizable reactive group and a photocationic polymerization initiator with ultraviolet rays using an optical DSC apparatus is shown.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Reference example)
0.05 g of WPI-113 (manufactured by Wako Pure Chemical Industries, Ltd.) as a photocationic polymerization initiator was added to 1 g of a silicone compound having a cationically polymerizable reactive group shown in Table 1 and dissolved to prepare a sample. 1 mg of sample is added to an aluminum pan for optical DSC, and an optical DSC device (DSC device Q100 manufactured by TA Instruments, refrigerator RSC, optical DSC adapter PCA, USHIO spotlight irradiator SP3, light guide AF) The exothermic peak time (minutes) and calorific value (J / g) were determined from the exothermic curve obtained by irradiating ultraviolet rays using (-12NQ-X). The results are shown in Table 1.

The combination of the silicone compound having a cationic polymerizable reactive group and the photocationic polymerization initiator is a combination that increases the calorific value as determined in the above Reference Example, specifically, the calorific value is 40 J / g. A combination as described above is preferable. Thereby, quick-curing property improves the adhesive composition.

Example 1
Denacol EX-821 (manufactured by Nagase ChemteX Corporation, n = 4 epoxy resin in the above general formula (1)) as a cationic polymerizable compound (A) 25 parts by weight, and Denacol EX-931 as a cationic polymerizable compound (B) (Nagase ChemteX Corporation, m = 11 epoxy resin in the above general formula (2)) 175 parts by weight, and as a silicone compound having a cationic polymerizable reactive group, a silicone compound X having a side chain epoxy group An adhesive composition was prepared by blending 50 parts by weight of -22-343 (epoxy equivalent 525, manufactured by Shin-Etsu Chemical Co., Ltd.) and 5 parts by weight of CPI-100P (manufactured by San Apro) as a photocationic polymerization initiator. .
Moreover, the silicone compound X-22-343 (epoxy equivalent 525, the Shin-Etsu Chemical Co., Ltd. product) which has a side chain epoxy group as a silicone compound which has a cationically polymerizable reactive group 95.2 weight%, and a photocationic polymerization initiator Of CPI-100P (manufactured by San Apro Co., Ltd.), 4.8% by weight, separately prepared, optical DSC device (TA Instrument DSC device Q100, refrigerator RSC, optical DSC adapter PCA, USHIO INC.) The calorific value (J / g) was determined from the exothermic curve obtained by irradiating with ultraviolet rays using a spotlight irradiator SP3 (light guide AF-12NQ-X).

(Examples 2 to 17, Comparative Examples 1 to 4)
An adhesive composition was prepared in the same manner as in Example 1 except that the types and amounts of each component were changed as shown in Table 2, 3, 4 or 5. Further, the calorific value (J / g) was determined in the same manner as in Example 1.

(Evaluation)
The following evaluation was performed about the adhesive composition prepared by the Example and the comparative example. The results are shown in Table 2, 3, 4 or 5.

(1) Adhesive strength measurement 0.001 g of adhesive composition is applied to a slide glass having a length of 8 cm, a width of 2 cm, and a thickness of 1.5 mm, and a dose of 1000 mJ / cm ² (365 nm) of integrated light quantity is applied with a high-pressure mercury lamp. Irradiated. After irradiation, slide glasses of the same size were stacked on a cross. Thereafter, the sample was further heated in an oven at 80 ° C. for 30 minutes to obtain a sample (before heating). The adhesion area at this time was 4 mm ² .
Next, the sample (before heating) was passed through a reflow furnace (Nihon Antom Co., Ltd., UNI5016F) and exposed to high temperature to obtain a sample (after heating). In addition, when the thermocouple was mounted | worn with the sample and the temperature history in the reflow furnace was confirmed, 250-260 degreeC was 3 minutes, 260-280 degreeC was 2 minutes, and 280-283 degreeC was 1 minute.
The tensile shear force (kgf / cm ² ) of the sample (before heating) and the sample (after heating) was measured according to JIS K6850. The measurement was performed with a universal testing machine under conditions of a temperature of 23 ° C., a humidity of 55%, and a pulling speed of 10 mm / min.

(2) Peel test A 0.2 g adhesive composition was applied to a glass epoxy substrate on which an electrode having a length of 7 cm, a width of 3 cm, and a thickness of 1.0 mm was formed, and an integrated light quantity of 1000 mJ / cm ² ( A dose of 365 nm). After irradiation, a slide glass having a length of 7.5 cm, a width of 5.3 cm, and a thickness of 1 mm was overlaid. Thereafter, the sample was further heated in an oven at 80 ° C. for 30 minutes to obtain a sample (before heating). The adhesion area at this time was 21 cm ² .
Next, the sample (before heating) was passed through a reflow furnace (Nihon Antom Co., Ltd., UNI5016F) and exposed to high temperature to obtain a sample (after heating). In addition, when the thermocouple was mounted | worn with the sample and the temperature history in the reflow furnace was confirmed, 250-260 degreeC was 3 minutes, 260-280 degreeC was 2 minutes, and 280-283 degreeC was 1 minute.
1.5 L of water was added to a 2 L beaker, and the beaker was kept at a temperature of 80 ° C. with a water bath. A sample (before heating) and a sample (after heating) were put into this warm water, and the time (minutes) until the glass epoxy substrate and the slide glass were peeled was measured.

(3) Reflow oven test width 0.3 cm of an adhesive composition is applied to a glass substrate having a width of 5 cm, a length of 8 cm, and a thickness of 1.2 mm, and a dose of 1000 mJ / cm ² (365 nm) of integrated light quantity using a high-pressure mercury lamp. Was irradiated. After irradiation, a glass epoxy substrate was overlaid. Thereafter, the sample was further heated in an oven at 80 ° C. for 30 minutes to obtain a sample (before heating). The adhesion area at this time was 21 cm ² .
Next, the sample (before heating) was passed through a reflow furnace (Nihon Antom Co., Ltd., UNI5016F) and exposed to high temperature to obtain a sample (after heating). In addition, when the thermocouple was mounted | worn with the sample and the temperature history in the reflow furnace was confirmed, 250-260 degreeC was 3 minutes, 260-280 degreeC was 2 minutes, and 280-283 degreeC was 1 minute.
The sample (after heating) after charging the reflow furnace was observed from the glass substrate side, and the float between the glass epoxy substrate and the glass substrate was observed. The case where the floating area of the glass epoxy substrate and the glass substrate is 5% or less of the entire bonding area, ◎ if it exceeds 5% and does not reach 15%, ○ if it is 15% or more It was.

(4) Adhesive remaining state after immersion in hot water The sample (after heating) in the reflow furnace test in (3) above was put into a beaker containing 85 ° C. hot water. After immersing for 30 minutes, after the glass substrate and the glass epoxy substrate were peeled off, the adhesive residue state of the adhesive composition remaining on the glass epoxy substrate side was observed. A case where the adhesive remaining area was 5% or less of the entire bonding area was evaluated as “A”, a case where it exceeded 5% and less than 15%, and a case where it was 15% or more.

(5) Light transmittance The adhesive composition was cast on a release PET film and irradiated with a dose of 5000 mJ / cm ² (365 nm) with a high-pressure mercury lamp. After irradiation, it was heated at 85 ° C. for 1 hour to obtain a cured product having a thickness of 100 μm. About the obtained hardened | cured material, the light transmittance (%) in visible-light wavelength 600nm was measured by measuring the transmitted light of 800 nm-400 nm with a spectrophotometer (made by Hitachi High-Technology company).

(6) When the fast-curing adhesive composition is solidified within 2 hours after irradiation with ultraviolet rays, ◎ When solidified within 2 hours to 5 hours, ○ When not solidified after 5 hours Was evaluated as x.

According to the present invention, an adhesive composition that can maintain a high adhesive force without causing peeling even in a high temperature environment such as solder reflow, and can be easily peeled off without damaging the adherend when no longer needed. Can be provided.

Claims (6)

A compound having an ethylene glycol skeleton and a cation polymerizable reactive group at both ends, a compound having a propylene glycol skeleton and a cation polymerizable reactive group at both ends, a silicone compound having a cation polymerizable reactive group, and a photocation An adhesive composition comprising a polymerization initiator. The compound having an ethylene glycol skeleton and a cation polymerizable reactive group at both ends is an epoxy resin represented by the following general formula (1), and has a propylene glycol skeleton and a cation polymerizable reactive group at both ends. The adhesive composition according to claim 1, wherein the compound is an epoxy resin represented by the following general formula (2).

In general formula (1), n represents an integer.

In general formula (2), m represents an integer. The combination of a silicone compound having a cationic polymerizable reactive group and a photocationic polymerization initiator is a mixture of 95.2% by weight of the silicone compound having a cationically polymerizable reactive group and 4.8% by weight of the photocationic polymerization initiator. The adhesive composition according to claim 1, wherein the heat generation amount observed while irradiating ultraviolet rays using an optical DSC apparatus is 40 J / g or more. The adhesive composition according to claim 1, 2 or 3, further comprising a compound having both a radical polymerizable reactive group and a cationic polymerizable reactive group, and a photo radical polymerization initiator. The adhesive composition according to claim 4, further comprising a silicone compound having a radical polymerizable reactive group. 6. The adhesive composition according to claim 1, wherein when the cured product has a thickness of 100 μm, the cured product has a light transmittance of 20% or more at a visible light wavelength of 600 nm. .

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