WO2008029584A1

WO2008029584A1 - Adhesive composition, adhesive film and method for producing the adhesive composition

Info

Publication number: WO2008029584A1
Application number: PCT/JP2007/065347
Authority: WO
Inventors: Takahiro Asai; Koichi Misumi; Atsushi Miyanari; Yoshihiro Inao; Akihiko Nakamura; Koji Saito
Original assignee: Tokyo Ohka Kogyo Co., Ltd.
Priority date: 2006-09-07
Filing date: 2007-08-06
Publication date: 2008-03-13
Also published as: JP2008063463A; TW200815553A

Abstract

Disclosed is an adhesive composition which is mainly composed of a polymer obtained by copolymerizing a monomer composition containing styrene, a (meth)acrylic acid ester having a cyclic structure and a (meth)acrylic acid alkyl ester having a chain structure. The monomer composition may additionally contain a styrene macromonomer, thereby improving heat resistance, adhesion strength under high temperature conditions, alkali resistance, and easy releasability after a high-temperature process. Consequently, there can be obtained an adhesive composition having high heat resistance, adhesion strength under high temperature conditions, alkali resistance, and easy releasability after a high-temperature process.

Description

Specification

Adhesive composition, adhesive film, and method for producing the adhesive composition

[0001] The present invention relates to an adhesive composition, an adhesive film, and a method for producing the adhesive composition. More specifically, an adhesive composition, an adhesive film, and an adhesive composition for temporarily fixing a sheet or a protective substrate to the semiconductor product in a process such as grinding a semiconductor product such as a semiconductor wafer or an optical system product. The present invention relates to a method for producing the adhesive composition.

Background art

[0002] In recent years, with the enhancement of functions of mobile phones, digital AV devices, IC cards, etc., there is an increasing demand for smaller, thinner, and higher-integrated semiconductor silicon chips (hereinafter referred to as chips). . For example, there is a demand for thinner integrated circuits that integrate a plurality of chips, such as CSP (chip size package) and MCP (multi-chip package). Among them, the system 'in' package (SiP), in which multiple semiconductor chips are mounted in one semiconductor package, makes the mounted chips smaller, thinner, and highly integrated, improving the performance of electronic equipment. It has become a very important technology for realizing miniaturization and weight reduction.

[0003] In order to meet the needs for thin products, it is necessary to reduce the chip to 150 m or less. Furthermore, it is necessary to thin the chip to less than lOO ^ m for CSP and MCP and 50 m for IC cards.

[0004] Conventionally, SiP products use a technique in which bumps (electrodes) and circuit boards for each stacked chip are wired by wire bonding technology. In addition, in order to meet such demands for thinning and high integration, it is also necessary to have a through-electrode technology in which chips with through-electrodes are stacked, and bumps are formed on the backside of the chip, which is not possible with wire bonding technology. Na

[0005] For example, a thin chip is formed by slicing a high-purity silicon single crystal or the like into a wafer, and then forming an integrated circuit by etching a predetermined circuit pattern such as an IC on the wafer surface. In addition, the semiconductor wafer is manufactured by grinding the back surface of the obtained semiconductor wafer with a grinder and dicing the semiconductor wafer after grinding to a predetermined thickness to form chips. At this time, the predetermined thickness is about 100 to 600 111. Furthermore, when forming the through electrode, it is ground to a thickness of 50 to 100 m.

[0006] In the manufacture of semiconductor chips, the semiconductor wafer itself is thin and fragile, and the circuit pattern has irregularities, so that it is easily damaged when an external force is applied during conveyance to the grinding process or dicing process. Also, in the grinding process, grinding is performed while removing generated polishing debris and cleaning the backside of the semiconductor wafer with purified water in order to remove heat generated during polishing. At this time, it is necessary to prevent the circuit pattern surface from being contaminated by the purified water used for cleaning.

[0007] Therefore, in order to protect the circuit pattern surface of the semiconductor wafer and prevent the semiconductor wafer from being damaged, polishing work is performed after a processing adhesive film is attached to the circuit pattern surface.

[0008] Also, at the time of dicing, a protective sheet is attached to the back side of the semiconductor wafer, dicing is performed with the semiconductor wafer adhered and fixed, and the resulting chip is picked up from the film substrate side with a needle and picked up. It is fixed on the die pad.

[0009] Examples of such processing adhesive films and protective sheets include base films such as polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), and ethylene acetate butyl copolymer (EVA). There are known those provided with an adhesive layer formed from an adhesive composition (for example, Patent Document 1, Patent Document 2, and Patent Document 3).

[0010] Further, instead of the processing adhesive film and the protective sheet, a protective substrate in which a ladder type silicone oligomer is impregnated with an aluminum nitride-boron nitride pore sintered body is used, and the protective substrate and the semiconductor wafer are bonded to the thermoplastic film. The structure which adhere | attaches using is also disclosed (patent document 4). In addition, a material such as alumina, aluminum nitride, boron nitride, or silicon carbide having substantially the same thermal expansion coefficient as that of the semiconductor wafer is used as the protective substrate, and polyimide or the like is used as an adhesive for bonding the protective substrate and the semiconductor wafer. As a method for applying this adhesive using a thermoplastic resin, a method of forming a film having a thickness of 10 to 100 m, and a method of spin-coating an adhesive composition and drying to form a film of 20 m or less Has been proposed (special Permissible literature 5).

[0011] In addition, with the increase in the number of layers of semiconductor elements, a protective substrate is bonded to the surface of a semiconductor wafer on which a circuit is formed using an adhesive composition, the back surface of the semiconductor wafer is polished, and thereafter Then, the process of etching the polished surface to a mirror surface and forming a back side circuit on this mirror surface is being carried out. In this case, the protective substrate remains adhered until the back side circuit is formed (Patent Document 6).

Patent Document 1: Japanese Published Patent Publication “Japanese Unexamined Patent Publication No. 2003-173993 (Publication Date: June 20, 2003)”

Patent Document 2: Japanese Patent Publication “JP 2001-279208 (Publication Date: October 10, 2001)”

Patent Document 3: Japanese Patent Publication “Japanese Unexamined Patent Publication No. 2003-292931 (Publication Date: October 15, 2003)”

Patent Document 4: Japanese Patent Publication “JP 2002-203821 Publication (Publication Date: July 19, 2002)”

Patent Document 5: Japanese Published Patent Publication “JP 2001-77304 (Publication Date: March 23, 2001)”

Patent Document 6: Japanese Patent Publication “JP-A 61-158145 (Publication Date: July 17, 1986)”

Disclosure of the invention

[0012] However, the conventional pressure-sensitive adhesive film for processing described above is insufficient in adhesive strength in a high-temperature environment to be used in a process that requires a high-temperature process and a high-vacuum process, such as formation of a through electrode, There are problems of adhesion failure due to gas generation in a high vacuum environment, and peeling failure such as residue remaining at the time of peeling after the high temperature process.

[0013] For example, in the formation of the through electrode, when a bump is formed on a semiconductor chip and then the semiconductor chips are connected, a process of heating to about 200 ° C. to make a higher vacuum state is required. However, the adhesive composition constituting the adhesive layer of the protective tape according to Patent Document 1 and Patent Document 2 is not resistant to a high temperature of 200 ° C. Also, by heating Since gas is generated in the adhesive layer, adhesion failure occurs.

[0014] Further, a thin semiconductor wafer requires a force S to be peeled from the protective substrate after grinding or dicing. However, the adhesive composition constituting the adhesive layer of the protective tape disclosed in Patent Document 3 is an epoxy resin composition, and the epoxy resin is altered and cured at a high temperature of 200 ° C. There is a problem that a residue remains at the time of peeling, resulting in peeling failure.

[0015] Furthermore, the thermoplastic film used for bonding the protective substrate and the semiconductor wafer according to Patent Document 4 and Patent Document 5 generates a gas derived from moisture that has absorbed moisture, thus causing a problem of poor adhesion. . In the semiconductor substrate processing method according to Patent Document 6 described above, a mirroring process using an etching solution or a metal film formation by vacuum deposition is performed. Therefore, an adhesive composition for bonding a protective substrate and a semiconductor wafer includes: Heat resistance and peelability are required. However, Patent Document 6 does not disclose the composition of the adhesive composition at all.

[0016] Further, according to the investigation by the present inventors, an adhesive using an acrylic resin material is preferable in processing a semiconductor wafer or a chip because it has good crack resistance. However, it has been found that the adhesive using such an acrylic resin material has the following problems.

[0017] (1) When the adhesive layer and the protective substrate are thermocompression bonded, the moisture absorbed by the adhesive layer becomes a gas and foam-like peeling occurs at the adhesive interface, resulting in low adhesive strength in a high temperature environment. . Moreover, the generation of such gas not only reduces the adhesive strength in a high temperature environment, but also hinders the creation or maintenance of the vacuum environment when performing a processing process under vacuum conditions.

[0018] (2) When the semiconductor wafer has a step of contacting an alkaline liquid such as an alkaline slurry or an alkaline developer, the contact surface of the adhesive composition is deteriorated due to peeling, dissolution, dispersion or the like by the alkaline liquid. End up.

[0019] (3) When heated to about 200 ° C, the heat resistance is low, and therefore the adhesive composition is denatured, resulting in inferior peeling such as formation of an insoluble substance in the stripping solution.

[0020] The present invention has been made in view of the above-mentioned problems, and the object thereof is as follows: In particular, it has high adhesive strength at 140 ° C to 200 ° C, high heat resistance, and alkali resistance, and further, a processing process in a high temperature and / or high vacuum environment (hereinafter simply referred to as "high temperature process") It is an object of the present invention to provide an adhesive composition that can be easily peeled off from a semiconductor wafer, a chip and the like even after passing through.

[0021] In a first aspect of the present invention, a monomer composition containing styrene, a (meth) acrylic acid ester having a cyclic structure, and a (meth) acrylic acid alkyl ester having a chain structure is used. An adhesive composition comprising a polymer formed by polymerization as a main component, wherein the monomer composition further comprises a styrene macromonomer.

[0022] In a second aspect of the present invention, the styrene macromonomer comprises a styrene block structure and organic groups located at both ends of the styrene block structure, and at least one of the organic groups is an organic group. Is a styrene macromonomer having a carbon-carbon double bond.

[0023] In a third aspect of the present invention, the styrene macromonomer is represented by the following formula (5):

[0024] [Chemical 1]

[0025] (R ⁷ and R ⁸ each independently represents an organic group having at least one carbon-carbon double bond; carbon number !! to 10 and may contain an oxygen atom). It is an adhesive composition characterized by being a styrene macromonomer.

[0026] In a fourth aspect of the present invention, when the total amount of the monomer composition is 100 parts by mass, the total amount of the styrene and the styrene macromonomer is 30 to 90 parts by mass, and the styrene The amount of the macromonomer is within the range of the total amount, and is 5 to 40 parts by mass.

[0027] A fifth aspect of the present invention is an adhesive film comprising an adhesive layer containing any one of the adhesive compositions described above on a film. [0028] A sixth aspect of the present invention is a monomer comprising styrene, a (meth) acrylic acid ester having a cyclic structure, a (meth) acrylic acid alkyl ester having a chain structure, and a styrene macromonomer. A method for producing an adhesive composition comprising as a main component a polymer obtained by copolymerizing a body composition, the styrene macromonomer comprising the styrene, the (meth) acrylic ester, and the (meth) A method for producing an adhesive composition comprising mixing before completion of a copolymerization reaction with an alkyl acrylate.

[0029] In a seventh aspect of the present invention, the styrene macromonomer is prepared by initiating a copolymerization reaction between the styrene, the (meth) acrylic acid ester, and the (meth) acrylic acid alkyl ester. , And a method for producing an adhesive composition.

[0030] In an eighth aspect of the present invention, after the copolymerization reaction of the styrene, the (meth) acrylic acid ester, and the (meth) acrylic acid alkyl ester is started, the styrene macro monomer is used. In another aspect of the present invention, there is provided a method for producing an adhesive composition, which is introduced in a batch or divided into a plurality of batches.

[0031] Other objects, features, and advantages of the present invention will be fully understood from the following description. The advantages of the present invention will become apparent from the following description with reference to the accompanying drawings.

Brief Description of Drawings

FIG. 1 is a diagram showing the results of comparing the adhesive strength of an adhesive composition obtained by adding a styrene macromonomer to a monomer composition under different temperature conditions in Examples of the present invention. . BEST MODE FOR CARRYING OUT THE INVENTION

[0033] An embodiment of the present invention will be described as follows.

In this embodiment, a monomer composition containing styrene, (meth) acrylic acid ester having a cyclic structure, and (meth) acrylic acid alkyl ester having a chain structure is copolymerized. A styrene macromonomer is further mixed with the above-mentioned monomer composition. In this embodiment, the monomer composition is further provided with a technical means of mixing a carboxylic acid having an ethylenic double bond and a bifunctional monomer, and a styrene block segment in the polymer. Use technical means. Therefore, in the present embodiment, each of the above technical means will be described, but the adhesive composition according to the present invention is not limited to the embodiment described later. For example, technical means described later may be combined as appropriate. By combining each technical means, the adhesive composition has superior adhesive strength, heat resistance, alkali resistance, and ease of peeling after high temperature process in high temperature environment (especially 140 ° C ~ 200 ° C) You can get things.

[Raw material of monomer composition and structure of polymer as main component]

The adhesive composition according to the present embodiment includes a monomer composition containing styrene, (meth) acrylate having a cyclic structure, and (meth) acrylic acid alkyl ester having a chain structure. The main component is a polymer obtained by copolymerization of With this configuration, the adhesive composition has a certain degree of heat resistance, adhesive strength in a high temperature environment, alkali resistance, and ease of peeling after a high temperature process.

[0037] The monomer component further includes a carboxylic acid having an ethylenic double bond described later, a bifunctional monomer, and a styrene macromonomer, and the polymer has a styrene block segment described later. This further improves the adhesive strength, heat resistance, etc. in a high temperature environment.

In the present specification, the “main component” means that the content is higher than that of any other component contained in the adhesive composition. Therefore, the content of the main component is not limited as long as it is the largest amount among the components contained in the adhesive composition, but preferably the mass of the adhesive composition is 100%. In terms of parts by mass, the content of the main component is preferably 50 parts by mass or more and 100 parts by mass or less, and more preferably 70 parts by mass or more and 100 parts by mass or less. If it is 50 parts by mass or more, the effects related to the high heat resistance, high adhesive strength in a high temperature environment, alkali resistance, and ease of peeling provided in the adhesive composition are exhibited well.

[0039] (Styrene)

The adhesive composition according to the present embodiment contains styrene in the monomer composition. Since the above styrene does not deteriorate even in a high temperature environment of 200 ° C. or higher, the heat resistance of the adhesive composition is improved. [0040] The amount of styrene mixed is not limited as long as the copolymerization reaction proceeds with other compounds contained in the monomer composition. However, when the total amount of the styrene, the monomer composition containing the (meth) acrylic acid ester and the (meth) acrylic acid alkyl ester is 100 parts by mass, the mixing amount of the styrene is 10 to The amount is preferably 50 parts by mass, more preferably 20 to 40 parts by mass. If it is 10 parts by mass or more, it is possible to further improve the heat resistance, and if it is 50 parts by mass or less, the force S can suppress the decrease in crack resistance.

[0041] ((Meth) acrylic acid ester having a cyclic structure)

The adhesive composition according to the present invention contains (meth) acrylic acid ester having a cyclic structure in the monomer composition. Thereby, the heat resistance of the adhesive composition is improved. Also

By including the above (meth) acrylic acid ester, it is possible to reduce the required amount of allylic acid in the adhesive composition and to ensure good releasability with a stripping solution.

[0042] The mixing amount of the (meth) acrylic acid ester is not limited as long as the copolymerization reaction proceeds with other compounds contained in the monomer composition. However, when the total amount of the styrene, the (meth) acrylic acid ester, and the monomer composition containing the (meth) acrylic acid alkyl ester is 100 parts by mass, the (meth) acrylic acid ester It is preferable that the mixing force is from 60 to 60 parts by mass, and more preferably from 10 to 40 parts by mass. If it is 5 parts by mass or more, the heat resistance can be further improved, and if it is 60 parts by mass or less, good peelability can be obtained.

[0043] The (meth) acrylic acid ester has a structure in which a hydrogen atom of a carboxyl group in (meth) acrylic acid is substituted with a cyclic group or an organic group having a cyclic group. The organic group having the cyclic group is not particularly limited, but an alkyl group in which one hydrogen atom is substituted with a cyclic group is preferable.

[0044] The cyclic group may be an aliphatic cyclic group that may be, for example, an aromatic monocyclic group or polycyclic group obtained by removing one or more hydrogen atoms from benzene, naphthalene, or anthracene. It may be a group. The cyclic group may further have a substituent described later.

[0045] The cyclic structure serving as a basic ring of the cyclic group is not limited to being composed of only carbon atoms and hydrogen atoms, and may include oxygen atoms and nitrogen atoms, A hydrocarbon group consisting of only atoms is preferred. The hydrocarbon group may be saturated or unsaturated, but is preferably saturated. Furthermore, an aliphatic polycyclic group is preferable.

[0046] Specific examples of the aliphatic cyclic group include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, dicycloalkane, tricycloalkane, and tetracycloalkane. Etc. can be illustrated. More specifically, examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. It is done. Of these, groups in which one or more hydrogen atoms have been removed from cyclohexane or dicyclopentane are preferred. In addition, the cyclohexane and dicyclopentane further have a substituent described later! /, Or may be! /.

[0047] Examples of the substituent include a polar group such as a hydroxyl group, a carboxyl group, a cyano group, and an oxygen atom (= 0), and a linear or branched lower alkyl group having 1 to 4 carbon atoms. When the cyclic group further has a substituent, it is preferable to have the polar group, the lower alkyl group, or both the polar group and the lower alkyl group! /. As the polar group, an oxygen atom (= ◯) is particularly preferable.

[0048] The alkyl group in the alkyl group in which one of the hydrogen atoms is substituted with a cyclic group is preferably an alkyl group having 1 to 12 carbon atoms. Examples of the (meth) acrylic acid ester having such a cyclic structure include cyclohexyl lu 2-propyl acrylate.

[0049] The (meth) acrylic acid ester having a cyclic structure includes, for example, phenoxy acetyl acrylate and phenoxy propyl acrylate.

[0050] Here, "aliphatic" in this specification is a relative concept with respect to aromatics, and is defined to mean groups, compounds, and the like that do not have aromaticity. For example, “aliphatic cyclic group” means a monocyclic group or polycyclic group having no aromaticity.

[0051] The (meth) acrylic acid ester is a (meth) acrylic acid ester having a cyclic structure with a substituent on the cyclic structure and a substituent on the cyclic structure! /, (Meth) acrylic acid esters including (meth) acrylic acid esters having a cyclic structure. [0052] It has a cyclic structure having a substituent on the cyclic structure ((Memethata)) and aesacrylyl aacrylyl phosphate Do not have a substituent group on the cyclic structure? /// Have a cyclic structure ((Memetata)) In addition to the fact that it contains essteryl aacrylyl acrylate at the same time, this improves the heat resistance and heat resistance and the flexibility. Can be completed. .

[0053] ((consisting of chain-chain structure ((Memethata)) aalkylyl laurate, ester)

The adhesive / adhesive agent assembly composition according to the present invention is the same as the above-mentioned mono-monomeric assembly assembly composition, whether it is a chain chain structure. Including ranaruru ((memetata)) alkrylyl oxalate. . According to this, the softness and softness of the adhesive / adhesive agent layer obtained from the adhesive / adhesive agent composition composition, the resistance to kraclack and the like. However, it will improve. .

[0054] The amount of the mixture of the above ((memethata)) aalkoxylruylate aralkylyl estesterl is included in the above-mentioned monomeric composition composition. As long as the co-polymerization reaction with other chemical compounds is progressed, it is not limited as long as the reaction proceeds. And the above-mentioned styrene-ethylene, and the above-mentioned ((Memethata)) aacrylyl oxalate, and the above-mentioned ((Memethata)) alkaryl laurate. Assuming that the total amount of the composition including the monomeric monomer composition composition is 110000 mass parts, the above ((Memethata)) aalklyluric acid The amount of mixture of Lulu-Esteel is 1100 to 6600 mass Oh Ruru here and transgressions in in parts unit is good to good good Mamashi. . If more than 1100 parts by mass, it will further improve the softness and softness resistance of the resulting adhesive layer. If this is possible, and if it is less than 6600 mass parts or less, if the heat and heat resistance is lowered, peeling and peeling will occur. It is possible to suppress the defects and moisture absorption and hygroscopic properties. .

[0055] In the present specification, the above-mentioned ((Memethata)) aacrylyl oxalate is a alkaryl laurate having a carbon number of 1155 to 2200. An aacrylyl group having an aralkylyl group and having a long chain chain aralkylyl ester and carbon carbon number of 11 to ~; having 1144 aralkylyl groups It means Aacrylyl-type Aarruquikiruru Essuteruru. .

[0056] In the above-mentioned aacrylyl-based long and long chain chain aralkylkiles estesterl, the aralkylkiluyl group is nn--pepentanthadedecylyl group, n _n- —Hexoxadedecylyl group, _nn ——Heptaptadedecylyl group, _nn ——Noctanadecylyl group, _nn ——Nonanadecdecyl group, n _n ——Aalkyryl and / or memetatacrylyl acid, such as AECOCOSICYLYL GROUP, etc.

. . Incidentally, the aralkyloxyl group may be branched. .

[0057] The above-mentioned aacrylyl-based aralkylkiluyl ester having an aralkylkiluyl group of 1144 to 11; Examples of publicly known and known aacrylyl-based aaralkylkiles and estesterl are used for existing aacrylyl-based adhesives. . For example, the aralkyloxyl group, methytilyl group, ethityryl group, propylopyryl group, butylbutyryl group, 22-ethyloxyhexole group, isoisooct From octylyl group, isosonononyl group, isosodecenocinole group, dodedecinonorelle group, lauraurilyl group, totrilidedecyl group, etc. Examples thereof include aralkylyl acid ester, which is an acacrylyluric acid or memethacrylicuric acid. .

[0058]

The monomer composition further contains a styrene macromonomer. This increases the average molecular weight of the resulting adhesive composition. Furthermore, dissociation of molecular chains in the adhesive composition in a high temperature environment is suppressed. Therefore, the heat resistance of the adhesive composition, the adhesive strength in a high temperature environment (especially 140 ° C. to 200 ° C.), and the ease of peeling after a high temperature process can be further improved. In addition, since the content of the carboxyl group that causes a decrease in alkali resistance in the polymer can be kept low, the adhesive composition containing this as a main component has a high level of alkali resistance.

[0059] The styrene macromonomer is not limited as long as it has a styrene block structure in its structure and can be copolymerized with other components in the monomer composition. It is more preferable that the styrene block structure is composed of organic groups located at both ends of the styrene block structure, and at least one of the organic groups is a styrene macromonomer having a carbon-carbon double bond. Is the following formula (5)

[0060] [Chemical 2]

[0061] (R ⁷ and R ⁸ are each independently an organic group having at least one carbon-carbon double bond, carbon number;! To 10 and may contain an oxygen atom). Macro monomer.

[0062] The number of styrenes constituting the styrene block structure in the styrene macromonomer is not particularly limited, depending on the properties of the adhesive composition such as the desired adhesive strength and heat resistance. It may be determined, but 20 to 100 is preferable, and 50 to 70 is more preferable.

[0063] Specific examples of the styrene macromonomer include macromonomer (manufactured by Toagosei Co., Ltd., grade: AS-6S) and macromonomer (manufactured by Toagosei Co., Ltd., grade: AN-6S). . These may be used alone or in combination of two or more. Yes. The copolymerization of these styrene macromonomers with the other components in the monomer composition proceeds favorably, and the structure of the polymer obtained after the copolymerization becomes stable. Therefore, dissociation between molecular chains can be prevented, so that heat resistance and adhesive strength in a high temperature environment are improved.

[0064] The amount of the styrene macromonomer may be appropriately set according to the properties of the adhesive composition such as the desired adhesive strength and heat resistance, but the total amount of the monomer composition is 100 mass. The total amount of the styrene and the styrene macromonomer is 30 to 90 parts by mass, preferably 40 to 60 parts by mass, and the amount of the styrene macromonomer is within the range of the total amount, More preferably, it is 5 to 40 parts by mass, and the total amount of the styrene and the styrene macromonomer is 30 to 90 parts by mass, and the amount of the styrene macromonomer is within the range of the total amount. And 10 to 20 parts by mass. If it is this range, it can be said that the said adhesive composition is a suitable ratio of styrene and a styrene macromonomer. That is, the adhesive composition can obtain both the effect of improving the heat resistance by styrene and the effect of improving the adhesive strength in a high temperature environment by the styrene macromonomer described above.

[0065] The timing of mixing the styrene macromonomer is limited as long as the styrene macromonomer and a component other than the styrene macromonomer in the monomer composition can undergo a copolymerization reaction. It ’s not something.

That is, after the styrene macromonomer is previously mixed with the monomer composition before the start of the copolymerization reaction, the copolymerization reaction of other components may be started, and then the copolymerization is performed. The styrene macromonomer may be mixed before the reaction is completed. In addition, it is preferable to mix the styrene macromonomer after starting the copolymerization reaction of the monomer composition other than the styrene macromonomer. More preferably, batch mixing is performed. By mixing in this way, it is possible to unevenly distribute the places where the styrene block structure derived from the styrene macromonomer is concentrated in the above-mentioned adhesive composition, thereby further suppressing the dissociation of molecular chains in a high temperature environment. As a result, the adhesive strength in a high temperature environment is improved.

In this specification, “initiating a copolymerization reaction” means the above-described copolymerization reaction. In the above-mentioned monomer composition obtained by mixing a compound other than the compound to be mixed after starting the polymerization, it refers to the time when the copolymerization reaction starts.

[0068] When actually producing the adhesive composition, when the mixing of the compounds constituting the monomer composition intended to be mixed in advance is completed, the above-mentioned "copolymerization reaction is performed." It may be the time to “start”. When a reactor equipped with a stirrer is used for the copolymerization reaction, all kinds of compounds intended to be mixed in advance may be used as the time when stirring is started after at least a part of each of the compounds is supplied to the reactor. When setting the reaction temperature for a given copolymerization reaction, use a polymerization initiator that is the same as the time when heating to that temperature is started.

[0069] Since the effect of the present invention can be obtained even when any of the above points is set to "start of copolymerization reaction", "copolymerization reaction" is appropriately selected according to the production equipment, conditions, and the like of the adhesive composition. It is sufficient to set the time point of “start of” and control subsequent processes.

In the present specification, “termination of the copolymerization reaction” refers to a point in time when a desired copolymerization reaction is achieved. Specifically, the adhesive composition may be produced at the time when the stirring is stopped or when the cooling is started from the reaction temperature or the like! /.

[0071] (Carboxylic acid having an ethylenic double bond)

The monomer composition may further contain a carboxylic acid having an ethylenic double bond. The adhesive composition obtained by including the carboxylic acid having an ethylenic double bond has improved adhesive strength at high temperatures, particularly in an environment of 140 ° C to 200 ° C, and has undergone a high temperature process. Even later, it can be easily peeled off. The above-mentioned adhesion at the interface between the adhesive composition and the adherend surface to which the adhesive composition is applied by increasing the number of hydroxyl groups (polar groups) derived from the carboxylic acid in the adhesive composition. This is because the polarity of the adhesive composition is improved, and further, the dissociation of molecular chains in the adhesive composition in a high temperature environment is suppressed.

The carboxylic acid is not limited as long as it has an ethylenic double bond and can be copolymerized with other monomer components, but the following general formula (1)

[0073] [Chemical 3]

1 /,

R ~~ hCOOH) _m . (R ¹ represents an organic group having 2 to 20 carbon atoms and having a (meth) atallyloyl group or a bur group, and may contain an oxygen atom. M represents an integer of 1 to 3.)

And more preferably (meth) acrylic acid or the following general formula (2)

[0075] [Chemical 4]

[0076] (R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ³ represents a carbon number;! To 5 divalent alkyl group or a cyclic structure having 4 to 4 carbon atoms. Represents a divalent organic group of 20 and may contain an oxygen atom.)

It is a carboxylic acid represented by Specific examples of the carboxylic acid represented by the general formula (2) include those in which R ³ has a group obtained by removing two hydrogen atoms from cyclohexane, norbornane, tricyclodecane or tetracyclododecane. These may be used alone or in combination of two or more. Among these, (meth) acrylic acid is more preferable. Copolymerization of these carboxylic acids with other components in the monomer composition proceeds favorably, and the polymer structure obtained after copolymerization becomes stable. Therefore, dissociation between molecular chains can be prevented, so that heat resistance and adhesive strength in a high temperature environment are improved.

[0077] The mixing amount of the carboxylic acid may be appropriately set according to the properties of the target adhesive composition such as adhesive strength, but the styrene, the (meth) acrylic ester, and the ( When the total amount of the meth) acrylic acid alkyl ester is 100 parts by mass, it is preferably! To 10 parts by mass. If it is 1 part by mass or more The heat resistance of the resulting adhesive composition and the adhesive strength in a high temperature environment can be further improved. Further, if it is 10 parts by mass or less, the hygroscopicity of the adhesive composition can be suppressed and gelation can be prevented. By reducing the amount of carboxyl groups of the adhesive composition, alkali resistance is also improved. To do.

The timing for mixing the carboxylic acid is not limited as long as the carboxylic acid and a component other than the carboxylic acid in the monomer composition can be copolymerized.

[0079] That is, after starting the copolymerization reaction of other components, which may be mixed with the other monomer composition before starting the copolymerization reaction in advance. The carboxylic acid may be mixed before the copolymerization reaction is completed! /.

[0080] The copolymerization reaction may be started after the carboxylic acid, the styrene, the (meth) acrylic acid ester, and the (meth) acrylic acid alkyl ester are mixed in advance. I like it! By copolymerizing the monomer composition in which the carboxylic acid is mixed in advance, the carboxylic acid is randomly copolymerized with other components. For this reason, the polar group is present uniformly in the adhesive composition, the polarity of the adhesive composition at the interface is further improved, and the molecular chains in the adhesive composition are dissociated in a high-temperature environment. Furthermore, since it is suppressed, the adhesive strength is further improved.

[0081] (Bifunctional monomer)

The monomer composition may further contain a bifunctional monomer. By including the bifunctional monomer, in the resulting adhesive composition, the constituent molecules are cross-linked through the bifunctional monomer. By crosslinking, a three-dimensional structure is taken and the mass average molecular weight of the adhesive composition is increased. In general, in the technical field of adhesives, it is known that the internal energy of an adhesive composition is improved when the weight average molecular weight of the constituent molecules increases. In addition, it is known that the internal energy is also a factor in the level of adhesive strength in a high-temperature environment. Further, when the mass average molecular weight of the adhesive composition is increased, the apparent glass transition point is also increased, thereby improving the adhesive strength. In other words, when the monomer composition further contains a bifunctional monomer, the mass average molecular weight of the adhesive composition is increased, and the adhesive strength in a high temperature environment is improved. To do.

[0082] Further, since the monomer composition contains a bifunctional monomer, dissociation of molecular chains in the adhesive composition in a high-temperature environment is suppressed. As a result, the adhesive strength at high temperatures is improved, and it is possible to easily peel off even after a high temperature process. In addition, since the content of the carboxyl group that causes a decrease in alkali resistance in the polymer can be kept low, the adhesive composition containing this as a main component has high alkali resistance.

[0083] Accordingly, there is provided an adhesive composition that has high heat resistance, alkali resistance, and high adhesive strength in a high temperature environment (especially 140 ° C to 200 ° C) and can be easily peeled off even after a high temperature process. Touch with force S.

[0084] In this specification, the bifunctional monomer refers to a compound having two functional groups. That is, the bifunctional monomer is not limited as long as it is a compound having two functional groups, but the following general formula (3)

[0085] [Chemical 5]

1 4 2

X R X (3)

[0086] (R ⁴ represents a divalent alkyl group having 2 to 20 carbon atoms or a divalent organic group having 6 to 20 carbon atoms having a cyclic structure, and may contain an oxygen atom. X ¹ And X ² each independently represents a (meth) attalyloyl group or a bur group.

It is preferably at least one bifunctional monomer selected from the group consisting of compounds represented by: Examples of the compound represented by the above general formula (3) include dimethylol-tricyclodecane ditalylate, neopentyl glycol ditalylate, 1,9-nonanediol atalylate, naphthalene ditalylate, and the following formula (4)

[0087] [Chemical 6]

[0088] (R ⁵ and R ⁶ each independently represents ethylene oxide or propylene oxide. N and s are each independently an integer of 0 to 4)

The compound shown by these is mentioned. These may be used alone or as a mixture of two or more.

[0089] Among these, from the group consisting of dimethylol-tricyclodecane diatalylate, neopentylglycol diatalylate, 1,9-nonanediol acrylate, naphthalene diacrylate, and the above formula (4) More preferably, it is at least one bifunctional monomer selected. These bifunctional monomers crosslink with other monomer composition components and have a stable crosslinked structure. Therefore, an adhesive composition having further improved adhesive strength and heat resistance under a high temperature environment can be obtained.

[0090] The amount of the bifunctional monomer may be appropriately set according to the properties of the target adhesive composition such as adhesive strength, but the styrene, the (meth) acrylic acid ester, and the above When the total amount of the (meth) acrylic acid alkyl ester is 100 parts by mass, it is preferably 0.;! To 0.5 parts by mass, more preferably 0 .;! To 0.3 parts by mass. is there. 0 to; 0.5 to 5 parts by mass, the adhesive strength and heat resistance of the resulting adhesive composition in a high temperature environment can be further improved, and moisture absorption can be suppressed. Gelation of the composition can be prevented.

[0091] It is most preferable that the bifunctional monomer is mixed in advance with another monomer composition before the start of the copolymerization reaction. When mixed after the start of the copolymerization reaction of other monomer compositions, substantially the same effect can be obtained.

The polymer which is the main component of the adhesive composition according to the present embodiment may have a styrene block segment.

[0093] The adhesive composition mainly composed of a polymer having a styrene block segment can prevent gas generation at the interface between the adhesive composition and the adherend. Therefore, it is possible to obtain an adhesive composition having improved adhesive strength in a high temperature environment by preventing peeling of the adhesive composition due to gas generation at the interface during heating and vacuum.

[0094] Further, dissociation of molecular chains in the adhesive composition in a high temperature environment is suppressed. Therefore, alteration of the adhesive composition in a high temperature environment can be prevented. Therefore, the adhesive strength is improved, and even after a high temperature process, it can be easily peeled off.

[0095] Further, even if the amount of the carboxylic acid used is slightly reduced, effects such as improvement of heat resistance can be obtained, so that the alkali resistance of the adhesive composition containing the same as the main component is further improved. Can be made.

Accordingly, the heat resistance, the adhesive strength in a high temperature environment (especially 140 ° C. to 200 ° C.), and the ease of peeling after the high temperature process can be further improved.

[0097] The "styrene block segment" in the present specification refers to a site where styrene is copolymerized in block units in the polymer. Here, when styrene is added after the polymerization is started, the copolymerization of other components is almost completed, so that a block body of only the styrene is formed. Therefore, it can be said that the styrene block segment is a block copolymer obtained by polymerizing only styrene added after the polymerization of other monomer components is started.

Yes

[0098] The adhesive composition mainly composed of a polymer having a styrene block segment can prevent gas generation at the interface between the adhesive composition and the adherend. Therefore, it is possible to obtain an adhesive composition having improved adhesive strength in a high temperature environment by preventing peeling of the adhesive composition due to gas generation at the interface during heating and vacuum.

[0099] The styrene block segment is formed by the styrene by mixing all or a part of the styrene, the remainder of the styrene, the (meth) acrylic acid ester, and the (meth) attalinoleic acid alkyl ester. After starting the copolymerization reaction and before ending the copolymerization reaction, the copolymerization reaction system, i.e., the reactor in which the copolymerization reaction is carried out in a batch or divided into multiple batches Etc. are mixed.

[0100] The amount of styrene forming the styrene block segment is adjusted by the amount of styrene added after the start of the copolymerization reaction. The amount of the styrene used in the production of the adhesive composition according to the present embodiment may be appropriately set according to the properties of the adhesive composition such as desired adhesive strength and heat resistance! When the total amount of is 100 parts by mass, 5 to 80 parts by mass is preferable, and 10 to 30 parts by mass is more preferable. [0101] Furthermore, it is preferable that the styrene added after the copolymerization reaction is started has the ability to reduce all the styrene at once, that is, the entire amount of the styrene. Further, it is preferable to add before half of the time required for the copolymerization reaction. By doing so, the styrene block segment is suitably formed in the adhesive composition by densely copolymerizing the styrene.

[0102] (Ingredients other than main components in adhesive composition)

The adhesive composition according to the present embodiment may be mixed with morpholine such as acrylamide attalyloyl morpholine such as dimethyl acrylamide as another additive component. These blends can be expected to improve both heat resistance and adhesion.

[0103] In the adhesive composition according to the present embodiment, additional additives for improving the performance of miscible additives, for example, an adhesive, as long as the essential characteristics of the present invention are not impaired. It can be applied with a force S to add resin, plasticizer, adhesion aid, stabilizer, colorant, surfactant, etc. that are commonly used.

[0104] Further, the adhesive composition may be diluted with an organic solvent for viscosity adjustment without impairing the essential characteristics of the present invention! Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; ethylene glycol, ethylene glycol monoacetate, ethylene glycol nore, diethylene glycol nore monoacetate, Polyhydric alcohols such as propylene glycol nole, propylene glycol monoacetate, dipropylene glycol or dipropylene glycol monoacetate monomethino ethenore, monoethino ethenore, monopropino reetenole, monobutyl ether or monophenyl ether And cyclic derivatives such as dioxane; and methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methoxy Examples include esters such as methyl propionate and ethoxy propionate. These may be used alone or as a mixture of two or more. In particular, ethylene glycol, ethylene glycol monoacetate, diethylene glycolol, diethylene glycolol monoacetate, propylene glycolol, propylene glycolol monoacetate, dipropylene glycololene or dipropylene glycololmonoacetate monomethylol esterol, Monoethino Rete Nore Polyhydric alcohols such as monopropyl ether, monobutyl ether or monophenyl ether and derivatives thereof are preferred.

[0105] The amount of the organic solvent used is appropriately set according to the film thickness to which the adhesive composition is applied. It is not particularly limited. Generally, it is used so that the solid content concentration of the adhesive composition is 20 to 70% by mass, preferably 25 to 60% by mass.

[0106] As described above, as an adhesive composition for solving the problems of the conventional adhesives described above, a monomer composition component and a preferred structure of a polymer obtained by copolymerization thereof are used. Etc. were explained. These can be combined as appropriate, and by combining these, the effects of higher heat resistance and alkali resistance, ease of peeling, and reduction in the amount of gas generated during heating and vacuum should be exhibited. Needless to say.

[Copolymerization reaction]

The copolymerization reaction of the monomer composition is not particularly limited as long as it is performed by a conventionally known method. For example, the adhesive composition according to the present invention can be obtained by stirring the monomer composition using an existing stirring device.

[0108] The temperature condition in the copolymerization reaction is not limited as long as it is appropriately set. It is preferably 60 to 150 ° C, and more preferably 70 to 120 ° C.

[0109] In the copolymerization reaction, a solvent may be appropriately used. As the solvent, the above organic solvent can be used, and among them, propylene glycol “monomethyl ether” acetate (hereinafter referred to as “PGMEA”) is preferable.

[0110] In the copolymerization reaction according to the present embodiment, a polymerization initiator may be used as appropriate. Polymerization initiators include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), dimethyl 2,2'-azobisisobutyrate, 1,1 ' Azo compounds such as azobis (cyclohexan 1 carbonitryl), 4,4'-azo bis (4-cyananovaleric acid); decanol peroxide, lauroyl peroxide, benzoyl peroxide, bis (3, 5, 5 —Trimethylhexanoyl) peroxide, succinic peroxide, tert-butenoreperoxy 2-ethenorehexanoate, tert-butenoreperoxypivalate, 1,1,3,3 tetramethylbutylperoxy-2-ethylhexanoate, etc. Organic peracid A compound. These may be used alone or as a mixture of two or more. Further, the amount of the polymerization initiator used is not particularly limited as long as it is appropriately set according to the combination of the monomer compositions and reaction conditions.

[0111] [Adhesive film]

The adhesive composition according to the present invention described above can be used in various ways depending on the application. For example, in a liquid state, a method of forming an adhesive layer by applying onto a workpiece such as a semiconductor wafer may be used, or an adhesive film according to the present invention, that is, a film such as a flexible film in advance. An adhesive layer containing any one of the above adhesive compositions is formed on the substrate and dried, and this film (adhesive film) is attached to a workpiece (adhesive film method). You can use it!

[0112] Thus, the adhesive film according to the present invention includes an adhesive layer containing any one of the above-described adhesive compositions on the film.

[0113] Therefore, when the monomer composition further contains the styrene macromonomer, the average molecular weight of the adhesive composition constituting the adhesive layer is increased, and the adhesive layer is And a styrene block structure derived from the styrene macromonomer. This suppresses dissociation of molecular chains in the adhesive composition in a high temperature environment. Therefore, it is possible to obtain an adhesive film that can be easily peeled even after a high-temperature process, as well as having high heat resistance, alkali resistance, and high adhesive strength in a high-temperature environment.

[0114] When the monomer composition further contains a carboxylic acid having an ethylenic double bond, a polar group is introduced into the adhesive layer. When the bifunctional monomer is contained, the molecules constituting the adhesive layer are cross-linked by the bifunctional monomer. In addition, when the polymer as the main component of the adhesive layer has a styrene block segment! /, The interface between the adhesive composition and the surface to be bonded is applied. The generation of gas can be prevented.

[0115] Therefore, an adhesive film having higher heat resistance, adhesive strength in a high-temperature environment, and alkali resistance and excellent in ease of peeling can be obtained.

[0116] The adhesive film may be used by further covering the adhesive layer with a protective film. In this case, the adhesive that peels off the protective film on the adhesive layer and is exposed on the workpiece After the layers are stacked, the adhesive layer can be easily provided on the workpiece by peeling the film from the adhesive layer.

[0117] Therefore, when the above adhesive film is used, the film thickness uniformity and the surface smoothness are good as compared with the case where the adhesive composition is directly formed on the workpiece to form the adhesive layer. The ability to form a layer.

[0118] As the film used for the production of the adhesive film, the adhesive layer formed on the film can be peeled off from the film, and the adhesive layer is placed on a surface to be treated such as a protective substrate or a wafer. The release film is not limited as long as it can be transferred. For example, a flexible film made of a synthetic resin film such as polyethylene terephthalate having a film thickness of 15 to 125 μm, polyethylene, polypropylene, polycarbonate, polychlorinated butyl, and the like can be mentioned. If necessary, the film is preferably subjected to a release treatment so as to facilitate transfer.

[0119] The method for forming the adhesive layer on the film is not limited as long as a known method is appropriately used depending on the desired film thickness and uniformity of the adhesive layer. Applicator. Nor coater. Adhesive according to the present invention such that the dry film thickness of the above-mentioned adhesive layer is 10 to 1000 on the film using a wire coater, a ronore coater, a curtain flow coater or the like. The method of apply | coating a composition is mentioned. Among these, a roll coater is preferable because it has excellent film thickness uniformity and can form a thick film efficiently.

[0120] When the protective film is used, the protective film is not limited as long as it can be peeled off from the adhesive layer strength. For example, polyethylene terephthalate film, polypropylene film, polyethylene A film is preferred. Each of the protective films is preferably coated or baked with silicon. This is because peeling from the above adhesive layer becomes easy. The thickness of the protective film is not particularly limited, but is preferably 15 to 125 m. This is because the flexibility of the adhesive film provided with the protective film can be secured.

[0121] The method of using the adhesive film is not particularly limited. For example, when a protective film is used, the adhesive layer exposed on the workpiece is peeled off after removing the protective film. There is a method in which the adhesive layer is thermocompression-bonded to the surface of the workpiece by moving the heating roller over the film (the back side of the surface on which the adhesive layer is formed). At this time, the protective film peeled off from the adhesive film can be stored and reused by winding it in a roll with a winding roller or the like.

[0122] The adhesive composition of this embodiment is not particularly limited as long as it is used as an adhesive composition for bonding applications. However, a protective substrate for precision processing of a semiconductor wafer is used as a semiconductor wafer. It can be suitably used as an adhesive composition for bonding to a substrate such as. The adhesive composition of the present invention can be suitably used as an adhesive composition for adhering the substrate to a support plate, particularly when grinding and thinning a substrate such as a semiconductor wafer ( For example, Japanese Published Patent Publication “JP 2005-191550 A”).

[0123] Stripping solution

As a stripping solution for removing the adhesive composition according to the present embodiment, a force capable of using a commonly used stripping solution, in particular, a stripping solution mainly composed of PGMEA, ethyl acetate, and methyl ethyl ketone is an environmental load. It is preferable in terms of peelability.

Example

[0124] Hereinafter, examples in which the adhesive strength and the like of the adhesive composition according to the present invention have been confirmed will be described.

[0125] It should be noted that the adhesive compositions according to the following examples and comparative examples were evaluated based on heat resistance, hygroscopicity, flexibility, adhesive strength under different temperature conditions, and gas generation amount at 200 ° C ( Hereinafter, the measurement was performed by measuring “degas”. These measurement methods are described below.

[0126] (Measurement method of heat resistance, hygroscopicity, outgas)

After applying each adhesive composition according to Examples and Comparative Examples described later on a silicon wafer, each coating film was heated from 40 ° C. to 250 ° C., and the degassing amount from the coating film was reduced. Measured and evaluated by the amount of gas.

[0127] The reason why the heat resistance and hygroscopicity can be evaluated based on the degassing amount is as follows. In other words, the degassing amount measured up to 100 ° C is derived from water vapor or its azeotropic gas. The water vapor or azeotropic gas thereof is moisture absorbed by the adhesive composition. Therefore, the hygroscopicity can be evaluated by the amount of degassing measured up to 100 ° C. Further, the degassing amount measured at 100 ° C. or higher is derived from a gas generated by the thermal decomposition of the adhesive composition itself. Therefore, the heat resistance of the adhesive composition can be evaluated by the amount of degassing at 100 ° C or higher, particularly around 200 ° C.

[0128] The TDS method (Thermal Desorption Spectroscopy method, temperature-programmed desorption analysis method) was used to measure the degassing amount. EMD-WA1000 manufactured by Electronic Science Co., Ltd. was used as the TDS measurement device (emission gas measurement device).

The measurement conditions of the TDS apparatus were as follows: Width: 100, Center Mass Number: 50, Gain: 9, Scan Speed: 4, Emult Volt: 1.3 KV.

[0130] Evaluation of heat resistance is as follows: strength at 200 ° C, strength (Indensity) required by the above TDS measuring device is 100000 or less, and residue is not observed with a metal microscope. Is not observed with a metallurgical microscope, Δ is 100000 or more, and X is when the residue is observed with a metallurgical microscope.

[0131] The hygroscopicity was evaluated as ◯ when the above-mentioned strength (Indensity) at 100 ° C was 10,000 or less, and X when it was 10,000 or more.

[0132] In addition, the evaluation of the outgas is performed at 200 ° C with the strength required by the above TDS measuring device.

(Indensity) When the force is 00000 or less, it is marked as ◯, and when it is above 100,000, it is marked as X.

[0133] (Adhesive strength at each temperature)

The adhesive compositions according to Examples and Comparative Examples were applied on a silicon wafer and then dried at 150 ° C. for 3 minutes. Next, after the glass substrate was bonded at 200 ° C under a load of 1 kg, the glass substrate was pulled, and the adhesive strength when peeled off from the silicon wafer was measured using the vertical motorized measuring stand “MX-500N” (Made by Imada Co., Ltd.).

[0134] (Evaluation of flexibility)

Each adhesive composition was applied on a 6-inch silicon wafer using a spinner at lOOOrpm for 25 seconds, and then heated on a hot plate at 200 ° C for 3 minutes to obtain a coating layer on the silicon wafer. It was. Next, the presence or absence of cracks in the coating layer was visually observed. The thickness of the silicon wafer used should be 15 μm. [0135] (Evaluation of alkali resistance)

For alkali resistance, the adhesive compositions according to Examples and Comparative Examples were applied on a silicon wafer and then dried at 200 ° C. for 3 minutes. Next, it was immersed in a 2.38 mass% TMAH (tetramethyl ammonium hydroxide) aqueous solution, and it was visually observed whether or not the applied film was dissolved. The case where the dissolution of the applied film was not confirmed by visual inspection was marked with ◯, and the confirmed film was marked with X.

[Examples 1 and 2]

Adhesive composition using a monomer composition containing styrene, a (meth) acrylic acid ester having a cyclic structure, and a (meth) acrylic acid alkyl ester having a chain structure, and further containing a styrene macromonomer The properties of (Examples 1 and 2) and the adhesive composition using V and monomer compositions (Comparative Example 1) containing no styrene macromonomer were compared.

[0137] As the styrene macromonomer used in Examples 1 and 2, the styrene macromonomer obtained from Toagosei Co., Ltd. (product name: macromonomer, grade: AS-6S, styrene macromonomer having a methacryloyl group, molecular weight) : 6000, hereinafter referred to as “MCST”).

[0138] Table 1 shows the compositions of the monomer compositions in Examples 1 and 2 and Comparative Example 1 and the average molecular weights of the adhesive compositions obtained by polymerizing the monomer compositions.

[0139] [Table 1]

[0140] The adhesive composition according to Example 1 was obtained as follows.

[0141] In a 300 ml four-necked flask equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen introduction tube, 53.85 g of PGMEA as a solvent and, as shown in Table 1, phenoxy as a monomer monomer. Tyl acrylate 20g, methyl methacrylate 15g, n-butyl methacrylate 13g, styrene 40g and MCST 12g were charged, and N blowing was started. Polymerize by starting stirring

2

After stirring, the temperature was raised to 90 ° C with stirring, and 38.45 g of PGMEA and a mixture of t-butylperoxy-2-ethylhexanoate l.Og as a polymerization initiator were added from a dropping nozzle over 2 hours. And continuously dripped. The dropping speed was constant.

[0142] The polymerization reaction solution obtained after completion of the dropping was aged for 1 hour at 90 ° C, and then a mixture of 25.10 g of PGME A and 0.3 g of t-butylperoxy-2-ethylhexanoate was added over 1 hour. It was dripped. Thereafter, the polymerization reaction solution was further aged for 1 hour at 90 ° C, and then 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate l.Og was added all at once.

[0143] Next, the polymerization reaction solution was aged at 90 ° C for 3 hours as it was, then the polymerization reaction solution was heated until reflux of the solvent was observed, and then aged for 1 hour to complete the polymerization. .

[0144] The adhesive composition according to Example 2 was obtained as follows.

[0145] In a 300 ml four-necked flask equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen introduction tube, 60.62 g of PGMEA as a solvent, 20 g of phenoxychetyl acrylate as a monomer monomer, methacrylic acid Charge 15 g of methyl, 13 g of n-butyl methacrylate, and 40 g of styrene.

2 Blowing started. Polymerization was started by starting stirring, and the temperature was raised to 90 ° C while stirring.After that, a mixed solution consisting of 30.20 g of PGMEA and 12 g of MCST as a monomer monomer, 30.20 g of PGMEA and t_ A mixed solution consisting of butyl peroxy 2-ethylhexanoate l.Og was continuously dropped over 2 hours from each of the separate dropping nozzles. The dropping speed was constant throughout the dropping.

[0146] The polymerization reaction solution obtained after completion of the dropping was aged for 1 hour at 90 ° C, and then a mixture of 33.6 g of PGME A and 0.2 g of t-butylperoxy-2-ethylhexanoate was taken for 1 hour. And dripped. Thereafter, the polymerization reaction solution was further aged for 1 hour at 90 ° C., and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate l.Og was added all at once.

[0147] Next, the polymerization reaction solution was aged for 3 hours at 90 ° C, and then the polymerization reaction solution was heated until reflux of the solvent was observed, and then aged for 1 hour to complete the polymerization. .

[0148] The adhesive composition according to Comparative Example 1 was the same as Example 1 except that MCST 12g was not included. Obtained by the method.

Thus, in Table 1, “MCST (first half of synthesis)” indicates that the copolymerization reaction was started after mixing all the monomer compositions in advance, and “MCST (second half of synthesis)”. And the blowing of N

2 shows that the MCST was added to the flask after the temperature was raised to 90 ° C.

[0150] In Examples 1 and 2 and Comparative Example 1 described above, the outgas, heat resistance, flexibility, hygroscopicity, and alkali resistance were compared. The results are shown in Table 2.

[0151] [Table 2]

[0152] In Examples 1 and 2 and Comparative Example 1, the adhesive strengths at 23 ° C, 140 ° C, and 200 ° C were compared. The results are shown in Table 3 and Fig. 1. In FIG. 1, the horizontal axis indicates each temperature condition, and the vertical axis indicates the adhesive strength (kgf / cm ² ).

[0153] [Table 3]

As described above, the adhesive composition according to the present invention includes styrene, a (meth) acrylic acid ester having a cyclic structure, and a (meth) acrylic acid alkyl ester having a chain structure. An adhesive composition mainly comprising a polymer obtained by copolymerizing a product, wherein the monomer composition further contains a styrene macromonomer. Therefore, when the obtained adhesive composition has a styrene block structure derived from the styrene macromonomer, the average molecular weight of the adhesive composition is increased. Furthermore, dissociation of molecular chains in the adhesive composition in a high temperature environment is suppressed. In the polymer In this case, the carboxyl group content that causes a decrease in alkali resistance can be kept low.

[0155] Therefore, an adhesive composition that can be easily peeled even after a high-temperature process with high heat resistance, adhesive strength in a high-temperature environment (especially 140 ° C to 200 ° C), and high alkali resistance. If you are able to provide power, you will have a good effect.

[0156] Further, as described above, the adhesive film according to the present invention includes an adhesive layer containing any one of the above-described adhesive compositions on the film.

[0157] Therefore, when the monomer composition contains a styrene macromonomer, the average molecular weight of the adhesive composition constituting the adhesive layer is increased, and the adhesive layer has the styrene macromonomer. It has a monomer-derived styrene block structure. Thereby, dissociation of the molecular chains in the adhesive composition in a high temperature environment is suppressed. Therefore, it is possible to obtain an adhesive film that has high heat resistance, high adhesive strength in a high temperature environment, and alkali resistance and can be easily peeled even after a high temperature process.

[0158] In addition, as described above, the method for producing the adhesive composition according to the present invention includes the above styrene macro monomer, the above styrene, the above (meth) acrylic acid ester, and the above (meth) attalinoleic acid alkyl ester. Until the copolymerization reaction is completed. Therefore, the obtained adhesive composition has a styrene block structure derived from a styrene macromonomer. Therefore, the average molecular weight of the obtained adhesive composition is increased. Therefore, the adhesive strength in a high temperature environment is improved.

[0159] Furthermore, in the adhesive composition, dissociation of the molecular chains in the adhesive composition in a high temperature environment is suppressed. As a result, the adhesive strength is improved and the adhesive composition can be prevented from being deteriorated in a high-temperature environment. Therefore, the heat resistance is improved, and further, it can be easily peeled even after a high-temperature process. In addition, the content of carboxyl groups that cause a decrease in alkali resistance in the polymer can be kept low.

[0160] Therefore, an adhesive composition that can be easily peeled even after a high-temperature process has high heat resistance, adhesive strength in a high-temperature environment (especially 140 ° C to 200 ° C), and high alkali resistance. If you are able to provide power, you will have a good effect.

[0161] Specific embodiments or examples made in the Detailed Description of the Invention are The technical contents of the present invention are clarified, and should not be construed in a narrow sense by limiting only to such specific examples, and within the scope of the claims described below. Ni! /, Te, Les, Ro! /, Can be changed and implemented.

Industrial applicability

The adhesive composition and adhesive film according to the present invention have high! /, Heat resistance and alkali resistance, low hygroscopicity, less gas generated during heating, and easy peeling with a stripping solution. it can. Therefore, it can be used with a force S that is suitable for processing a semiconductor wafer or chip through a process using various chemicals such as a high temperature process, a high vacuum process, and an alkali.

Claims

The scope of the claims

[1] A main component is a polymer obtained by copolymerizing a monomer composition containing styrene, (meth) acrylic acid ester having a cyclic structure, and (meth) acrylic acid alkyl ester having a chain structure. An adhesive composition comprising:

The above-mentioned monomer composition further contains a styrene macromonomer.

[2] The styrene macromonomer power, the styrene block structure, and organic groups located at both ends of the styrene block structure,

2. The adhesive composition according to claim 1, wherein at least one of the organic groups is a styrene macromonomer having a carbon-carbon double bond.

[3] The styrene macromonomer is represented by the following formula (5):

[Chemical 1]

(R ⁷ and R ⁸ are each independently a styrene macromonomer having at least one carbon-carbon double bond; carbon number;! Represents an organic group having 10 to 10 and may contain an oxygen atom) The adhesive composition according to claim 2, wherein the adhesive composition is present.

[4] When the total amount of the monomer composition is 100 parts by mass, the total amount of the styrene and the styrene macromonomer is 30 to 90 parts by mass, and the amount of the styrene macromonomer is within the range of the total amount. The adhesive composition according to any one of claims 1 to 3, wherein the adhesive composition is 5 to 40 parts by mass.

[5] An adhesive film comprising an adhesive layer containing the adhesive composition according to any one of claims;! To 4 on the film.

[6] A monomer composition comprising styrene, a (meth) acrylic acid ester having a cyclic structure, a (meth) acrylic acid alkyl ester having a chain structure, and a styrene macromonomer. A method for producing an adhesive composition comprising a polymer as a main component, wherein the styrene macromonomer comprises a copolymer of the styrene, the (meth) acrylic acid ester, and the (meth) acrylic acid alkyl ester. A method for producing an adhesive composition, comprising mixing until the polymerization reaction is completed.

[7] The styrene macromonomer is mixed after the copolymerization reaction of the styrene, the (meth) acrylic acid ester, and the (meth) acrylic acid alkyl ester is started. 6. A method for producing the adhesive composition according to 6.

[8] After the copolymerization reaction of the styrene, the (meth) acrylic acid ester, and the alkyl (meth) acrylate is started, the styrene macromonomer is collectively or divided into a plurality of times. The method for producing an adhesive composition according to claim 6 or 7, wherein the adhesive composition is introduced batchwise.