JP2014101495A - Adhesive composition and adhesion method thereof, and peeling method after adhesion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive composition that offer an adhesion force with which the adhesion and peeling can be performed by rapid adhesion work and which can withstand the mechanical treatment such as grinding during the processing in which silicon substrate is adhered to support substrate and then peeled, when manufacturing semiconductor devices, especially when fabricating silicon through electrodes (TSV).SOLUTION: According to the method, adhere using an adhesive composition that contains a hydrolysis condensate of alkoxysilane having photopolymerizable group, a photoinitiator, and an ultraviolet absorption foaming agent, and then, peel. The photopolymerizable group is selected from the group consisting of an acryloyl group, a methacryloyl group and a vinyl group. The ultraviolet absorption foaming agent is a diketone compound or diazonium salt.

Description

  The present invention relates to an adhesive composition, a bonding method thereof, and a peeling method after bonding. In particular, the present invention relates to an adhesive composition for manufacturing a semiconductor device on which an integrated circuit (Integrated Circuit, hereinafter referred to as IC) pattern is formed, an adhesion method thereof, and a peeling method after adhesion. The present invention relates to an adhesive composition useful for a three-dimensional mounting technique for achieving high integration of semiconductor devices by stacking, a bonding method thereof, and a peeling method after bonding. Particularly preferably, in the manufacture of a semiconductor device using a through silicon via (Through Silicon Via, hereinafter sometimes referred to as TSV) for electrically connecting semiconductor chips to be stacked, silicon on which a semiconductor chip is formed The present invention relates to an adhesive composition, a bonding method thereof, and a peeling method after bonding, which are bonded to a glass substrate to support a silicon substrate when polishing the substrate.

  In semiconductor devices, miniaturization of IC patterns has led to higher performance such as downsizing, multi-functionality, and higher speed. However, there is a concern about technical limitations in the miniaturization of IC patterns, so that two-dimensionally arranged semiconductor chips are stacked in the thickness direction to form a three-dimensional arrangement, and the semiconductor chips are three-dimensionally mounted. Three-dimensional mounting technology for achieving high integration of semiconductor devices has attracted attention. For example, Non-Patent Document 1 describes the trend of research and development of TSV technology for mounting three-dimensional large scale integration (hereinafter sometimes referred to as LSI). Has been reported.

  In three-dimensional mounting, a system in package (hereinafter referred to as SiP) is a method of packaging a plurality of semiconductor chips made of highly integrated semiconductor devices such as LSIs as a single semiconductor device by electrically connecting them by wire bonding of fine metal wires. A three-dimensional mounting technology called “sometimes called” has been put into practical use. However, in the three-dimensional mounting of a semiconductor chip by SiP, a space for wire bonding is required outside the semiconductor chip. The need for space is disadvantageous for miniaturization of the semiconductor chip. As a technique for eliminating the space and further increasing the integration degree, there is a three-dimensional mounting technique using a through silicon via (TSV) penetrating through the semiconductor chip in the vertical direction.

  In the three-dimensional mounting technology using TSV, substrate processing for obtaining TSV in a semiconductor device in which semiconductor chips are stacked includes, for example, a step of digging a hole groove in a silicon substrate on which an IC pattern is formed, and then the back surface of the silicon substrate. Is thinly polished to obtain a through hole through which the hole groove penetrates, and then a step of obtaining a semiconductor device in which the silicon substrate from which the through hole is obtained is bonded and laminated. Thereafter, TSVs are formed in the through holes.

  Among these, in the process of thinly polishing the back surface of the silicon substrate to obtain a through hole, it is necessary to polish the silicon substrate on which the IC pattern is formed in a state of being attached to a support called a support substrate with an adhesive. . As the support substrate, a glass substrate is usually used because it is easily available and inexpensive. The silicon substrate thinned by polishing the back surface is removed from the support substrate and laminated, and the TSV is processed into the through hole to three-dimensionally mount the semiconductor chip. In this way, a semiconductor device in which semiconductor chips on which IC patterns are formed is laminated is obtained.

  The properties required for the adhesive used in the above process include good adhesion between the silicon substrate and the support substrate, heat resistance, and the silicon substrate is polished and the hole groove processed portion is used as a through-hole. After the support substrate is peeled off, there is no adhesion residue with an adhesive attached to the silicon substrate side, or it can be easily removed, if any. At this time, it is preferable that the peeling method for peeling the support substrate from the silicon substrate is simple.

  Patent Documents 1 to 4 disclose adhesives that can be used for TSV formation.

  For example, in Patent Document 1, a specific thermoplastic composition is dispersed or dissolved in a solvent. An active wafer is bonded to a carrier wafer or a substrate, and the active wafer or its activity is processed during subsequent processing or handling. A method of using a bonding composition (adhesive) that is useful for protecting a site is disclosed. The bonding composition forms a bonding layer, which has chemical and heat resistance and can be softened so that the wafer can be slid and separated at an appropriate stage of the manufacturing process. It is said. At the time of separation (peeling), the bonding composition is softened at a high temperature, the two substrates are peeled off by mechanical force, and finally the adhesive residue adhering to the silicon substrate is washed with a solvent.

  Patent Document 2 discloses an adhesive composition mainly composed of a polymer obtained by copolymerizing a monomer composition containing a monomer having a maleimide group, and further includes a thermal polymerization inhibitor. An adhesive composition is disclosed, wherein two substrates are immersed in an organic solvent at the time of peeling, and the adhesive is dissolved simultaneously with peeling.

  Patent Document 3 discloses a method and apparatus for separating a device wafer mounted in reverse from a carrier substrate. In this method, an adhesive is used only on the outer peripheral portion of a silicon substrate, which is a wafer, and the inside of the silicon substrate is supported by using a resin that does not develop an adhesive force so that no adhesive residue is generated inside.

  Patent Document 4 discloses a polymerizable polymer and an adhesive composition that has high adhesive force and can be easily peeled off and has excellent heat resistance, and an adhesive tape using the same. An adhesive composition comprising an adhesive component comprising a photocurable adhesive containing a photopolymerization initiator and a tetrazole compound or a salt thereof, and an adhesive tape using the adhesive composition are disclosed. When this adhesive tape is irradiated with light, a gas (nitrogen) is generated from the tetrazole compound or its salt, and the soft adhesive component is foamed by the generated gas and the surface is uneven to form a surface. Stress is generated, and the adhesion area with the adherend is reduced to cause peeling.

Special table 2010-53385 gazette JP 2010-24435 A JP 2012-4522 A JP 2012-67317 A

Takashi Yoshinaga, Science & Technology Trends, April, 2010, p. 23-p. 34 J. et al. Stratting, Tetrahedron Letters, no. 5, 1969, p. 125-p. 128 Hidemitsu Uno, Tetrahedron Letters, 46, 2005, p. 1981-p. 1983 Hiroko Yamada, Chem. Eur. J. et al. 2005, 11, p. 6212-p. 6220

  When a semiconductor device is manufactured, particularly when a silicon through electrode (TSV) is processed, when the silicon substrate is bonded to a support substrate and peeled after predetermined processing, an adhesive residue remains on the silicon substrate, and the adhesive residue needs to be removed. It sometimes occurred. Adhesives are required to be able to bond quickly, have adhesive strength and heat resistance that can withstand mechanical processing such as substrate polishing after bonding, and can be easily peeled after predetermined processing.

  An object of this invention is to provide the adhesive composition which satisfy | fills the said request | requirement, its adhesion | attachment method, and the peeling method after adhesion | attachment.

  The present invention includes the following inventions 1 to 8.

[Invention 1]
An adhesive composition comprising a hydrolysis-condensation product of an alkoxysilane having a photopolymerizable group, a photopolymerization initiator, and an ultraviolet absorbing foaming agent.

[Invention 2]
The adhesive composition of Invention 1, wherein the photopolymerizable group is a photopolymerizable group containing at least one group selected from the group consisting of an acryloyl group, a methacryloyl group, and a vinyl group.

[Invention 3]
The adhesive composition of Invention 1 or Invention 2, wherein the ultraviolet absorbing foaming agent is a diketone compound or a diazonium salt.

[Invention 4]
An adhesion method in which the adhesive composition of the inventions 1 to 3 is sandwiched between substrates, and the adhesive composition is irradiated with light to cure the adhesive composition and bond the substrates together.

[Invention 5]
The bonding method according to invention 4, wherein bonding the substrates together is bonding a silicon substrate and a glass substrate.

[Invention 6]
The bonding method of the invention 4 or the invention 5, wherein the adhesive composition is cured by irradiating light having a wavelength of 300 nm or more and 900 nm or less for a sufficient time for bonding to bond the substrates together.

[Invention 7]
The adhesion method of invention 4-6 including the process of apply | coating the hydrolysis-condensation product of the alkoxysilane which has a photopolymerizable group to the adhesion surface of a glass substrate.

[Invention 8]
A silicon substrate and a glass substrate that are bonded using the adhesive composition of the inventions 1 to 4 are irradiated with light having a wavelength of 200 nm or more and 420 nm or less to fire an ultraviolet absorbing foaming agent and peeled off. Peeling method.

  Adhesion by the adhesive composition of the present invention can be carried out by irradiating the adhesive composition with light and curing it, so that the substrate or the like can be adhered quickly. For example, after placing an adhesive composition between a glass substrate and a silicon substrate, the glass substrate and the silicon substrate are adhered by irradiating light from the glass substrate side to cure the adhesive composition.

  When the adhesive bonded by the adhesive composition of the present invention is irradiated with ultraviolet rays, the ultraviolet absorbing foaming agent in the adhesive composition is chemically changed by the action of ultraviolet rays to generate gas, and the adhesive composition By bubbling in, the adhesive can be separated. For example, if the adhesive is a silicon substrate and a glass substrate, they can be separated (peeled) by ultraviolet irradiation, and the adhesive residue after peeling is not confirmed on the silicon substrate at least visually, that is, the effect that it does not remain. There is.

It is explanatory drawing of the adhesion | attachment and peeling process of a glass substrate and a silicon substrate, (A) is the schematic before adhesion | attachment, (B) is the schematic after adhesion, (C) It is the schematic after peeling.

  The adhesive composition of the present invention, the method of use thereof, and the peeling method after bonding can be quickly bonded by light irradiation, and the bonded substrate has an adhesive strength and heat resistance that can withstand polishing, etc. Since it can be easily peeled off by light irradiation when not required, it is suitable, for example, for semiconductor device manufacturing applications, and preferably used in an adhesive composition for semiconductor device manufacturing, its bonding method, and a peeling method after bonding. . More preferably, it is adopted in an adhesive composition for manufacturing a semiconductor device having a through silicon via (TSV), a method for using the same, and a peeling method after adhesion. In the present invention, the ultraviolet absorbing foaming agent is a gas generated by the action of absorbed light when irradiated with near ultraviolet light having a wavelength of 200 nm or more and 380 nm or less, or light in the vicinity of ultraviolet light having a wavelength of 380 nm or more and 420 nm or less. , Refers to a foaming agent that foams. Hereinafter, unless otherwise specified, light having a wavelength of 200 nm or more and 420 nm or less is simply referred to as ultraviolet light. The adhesive composition of the present invention, the method of using the same, and the peeling method after bonding will be described below.

  As shown in FIG. 1, when the silicon substrate G and the glass substrate G are bonded and separated, a hydrolytic condensate of alkoxysilane having a methacryloyl group, a photopolymerization initiator, and an ultraviolet absorbing foaming agent are used as the adhesive composition. If the glass substrate G in which the coating layer 1 is formed on the glass substrate G is used using the adhesive composition containing the silicon substrate G and the glass substrate G, the silicon substrate G and the glass substrate G are quickly bonded with light, and by irradiation with ultraviolet rays, Peeling can be performed without leaving an adhesive residue on the silicon substrate. Moreover, since the adhesive composition of this invention uses the hydrolysis-condensation product of the alkoxysilane excellent in heat resistance, it is excellent in heat resistance. In the present invention, photopolymerization includes radical polymerization that proceeds by irradiating light to a photopolymerization initiator that generates radicals by light irradiation, and the photopolymerizable group refers to photopolymerization initiator by light irradiation. It includes groups that polymerize starting from a chemical species such as a generated radical.

1. Adhesive composition The adhesive composition of this invention contains the hydrolysis-condensation product of the alkoxysilane which has a photopolymerizable group, a photoinitiator, and a ultraviolet absorption foaming agent. In the adhesive composition of the present invention, the hydrolyzed condensate of alkoxysilane having a photopolymerizable group can be produced by a conventionally known sol-gel method, and the raw material compound is easily available. It can be suitably used for the adhesive composition. The photopolymerizable group is preferably a photopolymerizable group containing at least one group selected from the group consisting of an acryloyl group, a methacryloyl group and a vinyl group. The hydrolysis-condensation product of the hydrolysis-condensation product of the alkoxysilane having the photopolymerizable group can be obtained by hydrolytic condensation of the alkoxysilane having the photopolymerizable group, which is a raw material.

  The adhesive composition of the present invention is a photopolymerization initiator that generates a radical for polymerizing and curing a hydrolysis-condensation product of an alkoxysilane having a photopolymerizable group to adhere the adhesive. It contains a UV-absorbing foaming agent that generates gas in the polymer of the hydrolyzed condensate of alkoxysilane having a polymerizable group and foams to release adhesion.

  In the adhesive composition of the present invention, the photopolymerization initiator is a photoradical polymerization initiator that generates radicals by irradiation with light, preferably irradiation with light having a wavelength of 300 nm or more and 900 nm or less. The ultraviolet absorbing foaming agent is preferably a foaming agent that generates gas by the action of light and foams when irradiated with light having a wavelength of 200 nm or more and 420 nm or less.

  Hereinafter, each element of the adhesive composition of the present invention will be described.

1-1. Hydrolysis condensate of alkoxysilane having photopolymerizable group The hydrolysis condensate of alkoxysilane having a photopolymerizable group of the present invention is an alkoxysilane represented by the following general formula (1) or general formula (2). Is a condensate obtained by hydrolytic condensation using at least one of each.

Formula _{^{(1) :( R 1) x}} Si (OR 2) 4-x
(In Formula (1), R ¹ is each independently a methyl group or a phenyl group, R ² is each independently a methyl group or an ethyl group, and x is an integer of 0-3.)
Formula (2): (R ³ ) _x Si (OR ⁴ ) _4-x
(In Formula (2), R ³ is a photopolymerizable group, R ⁴ is independently a methyl group or an ethyl group, and R ³ is independently a group consisting of an acryloyl group, a methacryloyl group, and a vinyl group. And at least one group selected from x, x is an integer of 1 to 3.)
For example, phenyltrimethoxysilane (R ¹ = phenyl group, R ² = methyl group, x = 1) and dimethyldiethoxysilane (R ¹ = methyl group, R ² = ethyl) as alkoxysilanes represented by formula (1) Group, x = 2), and water obtained from 3- (trimethoxysilyl) propyl methacrylate (R ³ = propyl methacrylate group, R ⁴ = methyl group, x = 1) as an alkoxysilane represented by formula (2) The decomposition condensate is considered to have the partial structure shown below. In addition, the wavy line in a figure means that the coupling | bonding is continuing.

1-2. Photopolymerization initiator The photopolymerization initiator used in the adhesive composition of the present invention is preferably a photoradical polymerization initiator that generates radicals by light irradiation.

  In radical photopolymerization initiators, radicals are generated by using an intramolecular cleavage type in which intramolecular bonds are cleaved by absorption of high energy rays to generate radicals and hydrogen donors such as tertiary amines and ethers. Any of these may be used in the present invention. For example, 2-hydroxy-2-methyl-1-phenylpron-1-one (product name: Darocur 1173, manufactured by Ciba Specialty Chemicals Co., Ltd.), which is an intramolecular cleavage type, is irradiated by light irradiation (particularly, light in the ultraviolet region). , A carbon-carbon bond is cleaved to generate a radical. As the hydrogen abstraction type, benzophenone, methyl orthobenzoin benzoate, 4-benzoyl-4'-methyldiphenyl sulfide, camphorquinone, and the like generate radicals by bimolecular reaction with a hydrogen donor. By the action of these radicals, the double bond of acryloyl group, methacryloyl group or vinyl group is cleaved and polymerized.

  In particular, camphorquinone has a light absorption wavelength in the vicinity of 470 nm, and is inactive against irradiation with ultraviolet rays having a wavelength of 20 nm or more and 420 nm or less, so that the polymerization initiation contained in the adhesive composition of the present invention is initiated. It is a particularly preferred radical photopolymerization initiator for use as an agent. In addition, when using camphor quinone, it is preferable to use together an amine compound as a polymerization accelerator for accelerating | stimulating adhesion | attachment, for example, 2- (dimethylamino) ethyl methacrylate can be illustrated.

The radical photopolymerization initiator as the photopolymerization initiator contained in the adhesive composition of the present invention is not particularly limited as long as it is a compound that generates radicals by absorbing light, and a commercially available radical photopolymerization initiator is used. be able to. For example, from the radical radical polymerization initiator Darocur series manufactured by Ciba Specialty Chemicals Co., Ltd., from 2-hydroxy-2-methyl-1-phenyl-propan-1-one (trade name, Darocur 1173), Darocur TPO or Irgacure series, 2-Hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one (trade name Irgacure 127), 1-hydroxy-cyclohexyl- Phenyl-ketone (trade name, Irgacure 184), 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one (trade name, Irgacure 2959), 2-benzyl -2-dimethylamino-1- (4-mol Olinophenyl) -butanone-1 (trade names, Irgacure 369, Irgacure 379, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone ( Irgacure 379EG), a mixture of oxyphenylacetic acid and 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester, oxyphenylacetic acid and 2- (2-hydroxyethoxy) ethyl ester (trade name, Irgacure 754), 2-methyl- 1- (4-methylthiophenyl) -2-morpholinopropan-1-one (trade name, Irgacure 907), Irgacure 1700, Irgacure 1800, Irgacure 1850, Irgacure 1870, bis (2,4,6-trimethylben Yl) -phenylphosphine oxide (trade name, Irgacure 819), bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl)- Phenyl) titanium (trade name, Irgacure 784) or Irgacure 4265 can be used.

  A sensitizer may be added to the radical photopolymerization initiator contained in the adhesive composition of the present invention for the purpose of improving the absorption efficiency of light having a wavelength of 300 nm or more and 900 nm or less.

  For example, radical generation is promoted by adding as photosensitizer a photosensitizing agent, a trade name P3B, BP3B, N3B, or MN3B, which is an organoboron compound, and a specific photosensitive dye. it can. Examples of the photosensitive dye in this case include a trade name IRT or IR13F manufactured by Showa Denko KK, which is a near infrared absorbing dye.

  Other examples of the sensitizer include anthracene, 2-ethyl-9,10-dimethoxyanthracene, and 2-isopropylthioxanthone. Examples of commercially available sensitizers include Nippon Kayaku Co., Ltd., trade name, KAYACURE DETX-S. The product name IRT and IR13F by Showa Denko KK can be illustrated.

1-3. Ultraviolet absorbing foaming agent The adhesive composition of the present invention uses an ultraviolet absorbing foaming agent that generates gas. The ultraviolet absorbing foaming agent is a compound that absorbs ultraviolet rays having a wavelength of 200 nm or more and 420 nm or less, chemically changes by the action of ultraviolet rays, and generates a gas. For example, an organic compound having a diketone skeleton or a diazonium salt ( -N ₂ ⁺⁾ and the like.

The organic compound having a diketone skeleton includes anthracene diketone having the chemical structure (2) and pentacene diketone having the chemical structure (3) shown below. These compounds are known compounds whose synthesis methods are disclosed in Non-Patent Documents 2, 3, and 4.

  Examples of the diazonium salt include 4-diazodiphenylamine sulfate or p-morpholinobenzenediazonium tetrafluoroborate.

1-4. Other Additives A compound having a polar group may be added to the adhesive composition of the present invention for the purpose of controlling the adhesive force such as improving the adhesive force between the silicon substrate and the adhesive composition. For example, methacrylic acid (2-hydroxyethyl), pentaerythritol triacrylate (trade name, Biscoat # 300, manufactured by Osaka Organic Chemical Industry Co., Ltd.), epoxy acrylate (trade name, Biscoat # 540, manufactured by Osaka Organic Chemical Industry Co., Ltd.) , Tri (2-acryloyloxyethyl) phosphate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name, biscoat 3PA), or bis (2-methacryloyloxyethyl) phosphate ester (manufactured by Nippon Kayaku Co., Ltd., trade name, KAYAMER) By adding a compound having a polar group, such as PM-2) or pentaerythritol tetrakis-3-mercaptobutyrate (trade name, Karenz MTPE1 manufactured by Showa Denko KK), stronger adhesion is possible.

  The said compound is 1 mass% or more and 50 mass with respect to the total mass of the adhesive composition which consists of a hydrolyzed condensate of the alkoxysilane which has a photopolymerizable group, a photoinitiator, and an ultraviolet-absorption foaming agent. % Or less can be added. If the amount is less than 1% by mass, there is no effect of improving the adhesive force, and it is not necessary to add more than 50% by mass. Hydrolysis condensates of alkoxysilanes having a photopolymerizable group, photopolymerization initiators, ultraviolet absorbing foaming agents There is a risk of inhibiting the action.

1-5. Composition ratio of adhesive composition The composition ratio of the adhesive composition of the present invention contains a hydrolysis-condensation product of an alkoxysilane having a photopolymerizable group, a photopolymerization initiator, and an ultraviolet absorbing foaming agent, and is in a mass ratio. A hydrolytic condensate of an alkoxysilane having a photopolymerizable group, a photopolymerization initiator and an ultraviolet absorbing foaming agent are hydrolyzed condensates of an alkoxysilane having a photopolymerizable group: photopolymerization initiator: ultraviolet absorption The foaming agent is preferably in the range of 50.0% to 98.0%: 0.1% to 10.0%: 1.0% to 49.9%. Outside this range, problems such as weak adhesion and excessive foaming are likely to occur. Further, when an additive is added to the adhesive composition of the present invention, a hydrolysis condensate of an alkoxysilane having a photopolymerizable group, a photopolymerization initiator, which is a component obtained by removing the additive from the adhesive composition, It is preferable that the additive is added in an amount of 1% or more and 50% or less with respect to the total mass ratio of the adhesive composition composed of three types of ultraviolet absorbing foaming agents.

2. Adhesion Method An adhesion method using the adhesive composition of the present invention will be described. In particular, a method for bonding a silicon substrate and a support substrate in through-hole processing for TSV in the three-dimensional mounting technology will be described.

  The present invention is an adhesion method in which substrates are adhered to each other with the above adhesive composition. When this bonding method is used for through-hole processing in the three-dimensional mounting technology using TSV, the substrates to be bonded are a silicon substrate for IC pattern processing and an inexpensive glass substrate as a support substrate for supporting the silicon substrate when polishing. It is preferable that the adhesive composition disposed between these substrates is irradiated with light having a wavelength of 300 nm or more and 900 nm or less, for example, to change the photopolymerization initiator chemically to initiate radical polymerization and adhesion. It is preferable to polymerize and cure the adhesive composition to bond the substrates together. Under the present circumstances, in order to improve the adhesive strength with an adhesive composition, it is preferable to apply beforehand the hydrolysis condensate of the alkoxysilane which has the above-mentioned photopolymerizable group to the adhesive surface of a glass substrate.

  Hereinafter, the bonding method using the adhesive composition of the present invention in the three-dimensional mounting technology of a semiconductor chip by TSV will be described with reference to FIG. 1, but the implementation of the bonding method using the adhesive composition of the present invention will be described. The form is not limited to FIG.

  FIG. 1 is an explanatory view of the bonding and peeling process between a glass substrate and a silicon substrate, (A) is a schematic diagram before bonding, (B) is a schematic diagram after bonding, and (C) is after peeling. FIG.

  That is, the preferred embodiment of the bonding method using the adhesive composition of the present invention in the three-dimensional semiconductor chip mounting technology by TSV is an alkoxysilane having a photopolymerizable group as shown in FIG. 1 is applied to one side of the glass substrate G as a support substrate in advance and the silicon substrate S having the adhesive composition layer 2 of the present invention is overlaid. In this bonding method, the glass substrate G and the silicon substrate S are bonded by irradiating the adhesive composition layer 2 with light having a wavelength of 300 nm or more and 900 nm or less, for example, after the laminated state shown in B). In bonding, the surfaces of the glass substrate G and the silicon substrate S are preferably clean.

2-1. Support Substrate In the three-dimensional mounting technology using TSV, a glass substrate or a quartz substrate is used as a support substrate to be bonded to the silicon substrate S. Examples of the glass type of the glass substrate include soda lime glass, alkali-free glass, borosilicate glass, aluminosilicate glass, fused quartz glass, and synthetic quartz glass. It is preferable to use alkali-free glass, fused silica glass, or synthetic quartz glass because it does not contain alkali components that may soak the semiconductor chip, and has been used in semiconductor manufacturing. It is more preferable to use alkali-free glass. Moreover, when using soda-lime glass containing an alkali component, it is preferable to previously form an alkali barrier film on the glass surface that prevents elution of the alkali component. The alkali barrier film need only be dense and free of pinholes, and can be formed on the glass surface by vacuum deposition, sputtering, thermal decomposition film formation, sol-gel method, or the like. In this case, it is preferable to use a silica film obtained by firing colloidal silica or the like because the alkali barrier film has good adhesion to the glass substrate.

2-2. Pre-adhesion process [formation of coating layer on glass substrate in advance]
In the three-dimensional mounting technology based on TSV, as shown in FIG. 1, when bonding with the adhesive composition of the present invention, hydrolysis of alkoxysilane having a photopolymerizable group is carried out on a support substrate, for example, a glass substrate G. It is preferable to form a coating layer 1 in which a cast solution in which a condensate is dissolved in an organic solvent is applied in advance. Further, after coating, the organic solvent is removed from the coating layer 1 by heating, and the condensate is heated as it is. It is preferable to form the coating layer 1 on the surface of the glass substrate by curing.

  In this case, the photopolymerizable group is preferably a polymerizable group that is the same as or similar to the polymerizable group contained in the adhesive composition layer 2. For example, when a methacryloyl group is used as a polymerizable group in the adhesive composition 2 used for the subsequent adhesion of the glass substrate G and the silicon substrate S, the photopolymerizability is applied to the glass substrate and used for the coating layer 1 in advance. The hydrolysis condensate of alkoxysilane having a group preferably contains a methacryloyl group or an acryloyl group. Thus, by using the same or similar photopolymerizable group as the photopolymerizable group, the coating layer 1 on the glass substrate obtained by previously applying the hydrolysis-condensation product of the alkoxysilane having the photopolymerizable group; It becomes possible to form a chemical bond at an adhesive interface with the adhesive composition layer 2 of the silicon substrate formed by applying the adhesive composition of the present invention, thereby making it more firmly adhered. The coating layer 1 has a large number of silanol groups (—SiOH), adheres extremely strongly to the glass surface, and chemically bonds to the adhesive composition layer 2. Specifically, the silanol group of the hydrolysis condensate of alkoxysilane having a polymerizable group is bonded to the silanol group on the surface of the glass substrate, and strong adhesion is obtained.

  When forming the coating layer 1, it is preferable to apply the cast solution to the glass substrate G after making the surface of the glass substrate G hydrophilic. Any method may be used for hydrophilizing the surface of the glass substrate G. For example, a glass substrate by wet polishing of the glass substrate G surface with ceria, ultraviolet light (UV) irradiation, ozone or oxygen plasma contact. Examples include dry treatment for decomposing organic substances on the surface of G, and piranha treatment for cleaning the surface of glass substrate G with a solution in which concentrated sulfuric acid and 30% by mass hydrogen peroxide solution are mixed at a mass ratio of 3: 1. Any method may be used as long as the conversion process can be performed.

  When the coating layer 1 is formed on the glass substrate G, the organic solvent used for the casting liquid is not particularly limited as long as it is an organic solvent that can dissolve the hydrolysis condensate. For example, propylene glycol methyl ether acetate (hereinafter sometimes abbreviated as PGMEA), propylene glycol monomethyl ether (hereinafter sometimes abbreviated as PGME), and the like. . Any coating method may be used as long as a flat thin film can be formed on the glass substrate G. Examples of the coating method include spin coating, dip coating, bar coating, roll coating, and slit coating. Among these methods, it is preferable to use a spin coat method which is generally used in a semiconductor manufacturing process and can obtain good flatness on a coated surface. The thickness of the coating layer 1 is not particularly limited. However, when the film is formed by a spin coating method, a film having a thickness of 0.5 μm to 3 μm is easily formed.

  A photopolymerization initiator can also be added to the cast solution. In this case, a chemical bond is formed in a wider range between the coating layer 1 and the adhesive composition layer 2 by irradiation of light at the time of adhesion, and strong adhesion can be expected, and a photopolymerization initiator is added. It is preferable.

2-3. Adhesion process The coating method for applying the adhesive composition of the present invention to the glass substrate G or silicon substrate S to provide the adhesive composition layer 2 includes spin coating, roll coating, slit coating, and screen printing. Method or inkjet method. In addition, using a dispenser or the like, with the adhesive composition placed in the center of the silicon substrate S, the silicon substrate S and the glass substrate G are bonded together and the adhesive composition is spread over the entire substrate to form an adhesive composition. The physical layer 2 may be used.

  In bonding, as shown in FIG. 1, the adhesive composition layer 2 may be disposed between the silicon substrate S and the glass substrate G and irradiated with light having a wavelength of 300 nm or more and 900 nm or less, for example.

  For example, when the silicon substrate S and the glass substrate G on which the adhesive composition layer 2 is disposed are bonded by irradiation with light having a wavelength of 300 nm or more and 900 nm or less, the glass substrate on the opposite side of the adhesive composition layer 2 Bonding is performed by irradiating light from the back side of G. As for the wavelength of light, it is preferable to select light including the absorption wavelength of the radical photopolymerization initiator contained in the adhesive composition layer 2 or the absorption wavelength of the sensitizer when a sensitizer is added. For example, when 2-hydroxy-2-methyl-1-phenyl-propan-1-one (trade name, Darocur 1173, manufactured by Ciba Specialty Chemicals Co., Ltd.) is used as a radical photopolymerization initiator, Is preferably light having a wavelength of 300 nm or more and 420 nm or less, and as a light source in these wavelength ranges, a high pressure mercury lamp, an ultra high pressure mercury lamp, a medium pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a xenon flash lamp or an ultraviolet light emitting diode (LED) is used. Can be mentioned. When using Darocur 1173, although it depends on the amount of use and the thickness of the adhesive composition layer, the time sufficient for bonding is usually 10 seconds or more. In the case of Darocur 1173, the absorption wavelength of light may overlap with the ultraviolet absorbing foaming agent in the adhesive composition of the present invention. In that case, if the irradiation time of light is unnecessarily increased, ultraviolet absorption will occur in the bonding process. There is a risk that the foaming agent will foam. Therefore, when such a photoradical initiator is used, the light irradiation time is preferably as short as possible, specifically, the irradiation time is 300 seconds or shorter, preferably 120 seconds or shorter, particularly preferably 20 It is preferable to set it to 2 seconds or less.

  In addition, when camphorquinone is used as the radical photopolymerization initiator, light containing 470 nm, which is the absorption wavelength of camphorquinone, is preferable, and examples of the light source in these wavelength ranges include blue LEDs and halogen lamps. . When camphorquinone is used, although it depends on the amount used and the thickness of the adhesive composition layer, the time sufficient for bonding is usually 10 seconds or longer. In particular, when using a light source with a narrow wavelength band, such as a blue LED, the ultraviolet light foaming agent and the wavelength band are different from each other, so that the risk of foaming the ultraviolet foaming agent in the bonding process is reduced. The radical photopolymerization initiator of the present invention is particularly preferable. However, it is not necessary to unnecessarily increase the irradiation time. Specifically, the irradiation time is not longer than 600 seconds, and is preferably 300 seconds or less.

  The adhesive composition layer 2 is caused by the photo-initiator contained in the adhesive composition layer 2 being chemically changed by the light irradiation described above, and the polymerization reaction is initiated and progressed, and the adhesive composition layer 2 is cured. The silicon substrate S and the glass substrate G are bonded. Thus, if the adhesion method by the adhesive composition of this invention is used, adhesion | attachment can be completed in one hour by light irradiation. For example, it becomes possible to quickly bond the silicon substrate S and the glass substrate G as a support substrate at the time of TSV production.

3. Peeling method The adhesive part of the adhesive composition of the present invention and the bonding site using the same are foamed by being irradiated with ultraviolet rays having a wavelength of 200 nm or more and 420 nm or less and can be peeled quickly. This peeling is due to the action of the ultraviolet absorbing foaming agent contained in the adhesive composition.

  In the peeling method of the present invention, after the silicon substrate S and the glass substrate G are bonded using the adhesive composition of the present invention, the adhesive composition layer 2 is irradiated with ultraviolet rays, so that the silicon substrate S and the glass substrate are irradiated. This is a peeling method for peeling G. The adhesive composition of the present invention contains an ultraviolet absorbing foaming agent, and the silicon substrate S and the glass substrate G are peeled off when the ultraviolet absorbing foaming agent in the adhesive composition layer 2 is foamed by irradiation with ultraviolet rays. The wavelength of the ultraviolet rays used is preferably 200 nm or more and 420 nm or less, and it is preferable to use light having the wavelength. Examples of light sources in these wavelength ranges include high pressure mercury lamps, ultra high pressure mercury lamps, medium pressure mercury lamps, low pressure mercury lamps, metal halide lamps, xenon flash lamps, and ultraviolet light emitting diodes (LEDs). Although sufficient irradiation time for peeling depends on the type of the ultraviolet absorbing foaming agent, it is usually 30 seconds or longer, particularly preferably 120 seconds or longer. The irradiation time is not unnecessarily longer than 600 seconds, and is preferably 300 seconds or less.

  Specifically, as shown in FIG. 1C, the ultraviolet absorbing foaming agent in the cured adhesive composition layer 2 is foamed by irradiating ultraviolet rays, so that the silicon substrate S and the adhesive composition are foamed. It peels between the physical layers 2, and the silicon substrate S and the glass substrate G spontaneously peel. At that time, no residue of the adhesive composition is visually confirmed on the silicon substrate S side. This is because the adhesive force between the glass substrate G and the coating layer 1 and the bonding between the coating layer 1 and the adhesive composition layer 2 are stronger than the adhesive force between the adhesive composition layer 2 and the silicon substrate S. Compared with the glass substrate G having a large number of silanol groups on the surface, the surface of the silicon substrate S has no or few silanol groups.

  Further, the two substrates bonded by the adhesive composition layer 2 can be irradiated with ultraviolet rays while being heated by a hot plate or the like. By heating, foaming is more likely to occur than the adhesive composition layer 2, and peeling becomes easy. The heating temperature is preferably 60 ° C. or higher and 200 ° C. or lower.

  In addition, the two substrates bonded by the adhesive composition layer 2 can be irradiated with ultraviolet rays while being immersed in a liquid. In this case, since the liquid permeates the peeling interface, peeling becomes easy. Examples of the liquid in which the substrate is immersed include water, alcohols such as isopropanol and butanol, PGMEA, PGME, and butyl acetate, but are not limited thereto. Furthermore, in order to promote peeling, the liquid may be heated, a surfactant may be added to the liquid, or ultrasonic waves may be used in combination.

  For the above reason, peeling occurs selectively between the adhesive composition layer 2 and the silicon substrate S, and the residue of the adhesive composition layer 2 is not visually confirmed on the silicon substrate S side. When the adhesive composition of the present invention is used for the production of TSV, the adhesive residue is not confirmed on the silicon substrate S side, so that it is necessary to remove the adhesive residue that was necessary when using a conventional adhesive. This cleaning step may be omitted or simplified.

In addition, the adhesive composition of the present invention has an adhesive strength and heat resistance that can withstand mechanical processing such as substrate polishing after bonding, and can be easily peeled after predetermined processing. Application of Adhesive Composition of the Present Invention to Multilayer Semiconductors The adhesive composition of the present invention is useful for three-dimensional mounting technology of semiconductor chips by TSV, and the three-dimensional mounting technology by TSV using the adhesive composition of the present invention is Applications to logic semiconductors such as next-generation microprocessors, volatile memories such as Dynamic Random Access Memory (DRAM), flash memories, or Micro Electro Mechanical Systems (MEMS) are possible.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples.

[Example]
In this example, adhesive compositions of Examples 1 to 5 having different compositions and within the scope of the present invention were prepared. The adhesive compositions of Examples 1 to 5 include a hydrolysis condensate of alkoxysilane having a photopolymerizable group, a photopolymerization initiator, and an ultraviolet absorbing foaming agent.

  After the preparation, as shown in FIG. 1, the adhesive compositions of Examples 1 to 5 are arranged between the silicon substrate S and the alkali-free glass substrate G to form an adhesive composition layer 2. The silicon substrate S and the alkali-free glass substrate G were adhered by polymerizing the hydrolysis condensate of alkoxysilane having a photopolymerizable group to cure the adhesive composition layer 2 as a polymer. Next, the ultraviolet absorbing foaming agent in the adhesive composition layer 2 was foamed by irradiation with ultraviolet rays, and the silicon substrate S and the alkali-free glass substrate G were peeled off. The situation after peeling was confirmed, and the adhesive composition was evaluated.

1. Adhesive Composition The adhesive compositions of Examples 1 to 5 used in the present invention are shown in Table 1.

  In each of the adhesive compositions of Examples 1 to 5, an alkoxysilane hydrolysis condensate having a methacryloyl group was used as a hydrolysis condensate of an alkoxysilane having a photopolymerizable group.

  As the photopolymerization initiator, in the adhesive compositions of Examples 1, 2, and 5, photoradical polymerization that reacts to the irradiation of Blu-ray having a wavelength of 470 nm from a blue laser diode (hereinafter sometimes referred to as LED). In the adhesive compositions of Examples 3 and 4 using camphorquinone as an initiator, 2-hydroxy-2-methyl-1-phenyl-propane-1-responsive to ultraviolet light with a wavelength of 365 nm from a high-pressure mercury lamp ON (Ciba Specialty Chemicals, trade name, Darocur 1173) was used.

  In Examples 1 to 4, pentaerythritol triacrylate (trade name Viscoat # 300, manufactured by Osaka Organic Chemical Industry Co., Ltd.) was used to increase the adhesive strength between the silicon substrate S and the non-alkali glass substrate G as a curing aid. added. In Examples 1 and 2, 2- (dimethylamino) ethyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added as a polymerization accelerator for camphorquinone.

  As the ultraviolet absorbing foaming agent, anthracene diketone was used in Examples 1, 3, and 5, and 4-diazodiphenylamine sulfate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used in Examples 2 and 4.

2. 2. Bonding of silicon substrate S and non-alkali glass substrate G 2.1. Formation of Coating Layer As shown in FIG. 1, when the silicon substrate S and the non-alkali glass substrate G are bonded, before the adhesive composition layer 2 is provided using the adhesive compositions of Examples 1 to 5, A coating layer 1 made of a hydrolysis condensate of alkoxysilane was provided on an alkali glass substrate G. By providing the coating layer 1, the adhesive strength between the alkali-free glass substrate G and the adhesive composition layer 2 is increased.

2.1.1. Synthesis of hydrolysis-condensation product of alkoxysilane having photopolymerizable group Hydrolysis-condensation product of alkoxysilane having methacryloyl group as a photopolymerization group was synthesized. Subsequently, after dissolving it in propylene glycol methyl ether acetate (PGMEA) to prepare a cast solution, the surface of the glass substrate G was coated with non-alkali glass to obtain a coating layer 1.

  Specifically, in a 2 L flask equipped with a Dimroth and a stirring blade, 140.40 g of phenyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KBM-103), dimethyldiethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), After collecting product name KBE-22) 131.14 g, 3- (trimethoxysilyl) propyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) 48.56 g, isopropyl alcohol 213.32 g, water 160.96 g, and acetic acid 0.10 g, In the state heated up to 90 degreeC with the oil bath, it stirred for 6 hours and was made to react with the stirring speed of 200 rpm. After allowing to stand and bringing to room temperature (20 ° C.), 400 ml of isopropyl ether and 400 ml of water were added, and the organic layer was separated with a separatory funnel. After dehydration using magnesium sulfate, the organic solvent was distilled off with an evaporator to obtain 170.68 g of a colorless transparent solid. In this way, a hydrolytic condensate of alkoxysilane having a methacryloyl group was obtained. Next, the condensate was dissolved in PGMEA to obtain a cast solution having a condensate concentration of 33% by mass.

2.1.2. Application to an alkali-free glass substrate The surface of an alkali-free glass substrate G having a diameter of 100 mm and a thickness of 1.1 mm (manufactured by Corning Corp., product number 7059) was polished with fine particles of cerium oxide (manufactured by Aldrich Corp.). Subsequently, the cast solution was spin-coated on the surface of the alkali-free glass substrate G at 1000 rpm for 10 seconds using a spin coater. Next, the coating layer 1 shown in FIG. 1 was formed on the surface of the alkali-free glass substrate G by heating and drying on a hot plate at 200 ° C. for about 20 minutes. It was 0.7 micrometer when the thickness of the coating layer 1 was measured using the stylus type surface shape measuring device (the US Veeco make, type Dektak8).

2.2. Formation of Adhesive Composition Layer As the hydrolysis condensate of alkoxysilane having a photopolymerizable group, the above-mentioned hydrolysis condensate of alkoxysilane having a methacryloyl group was used. Subsequently, the hydrolysis condensate of the alkoxysilane which has a methacryloyl group, the predetermined photoinitiator, and the ultraviolet absorption foaming agent were added, and the adhesive composition of Examples 1-5 was prepared. Details are shown below.

2.2.1. Preparation of Adhesive Composition Using the aforementioned hydrolyzed condensate of alkoxysilane having a methacryloyl group, the predetermined photopolymerization initiator, ultraviolet absorbing foaming agent, curing agent and polymerization accelerator are adjusted to the mass ratio shown in Table 1. In addition, the adhesive compositions of Examples 1 to 5 were prepared.

<Formation of adhesive composition layer>
As shown in FIG. 1A, 0.6 g of the adhesive composition was applied on a silicon substrate S having a diameter of 100 mm with a spin coater to form an adhesive composition layer 2. Next, as shown in FIG. 1B, the silicon substrate S was overlapped with the alkali-free glass substrate G so that the coating layer 1 and the adhesive composition layer 2 were in contact with each other.

2.3. Adhesion The adhesive composition layer 2 was irradiated with light from the alkali-free glass substrate G side to cure the adhesive composition layer 2, and the silicon substrate S and the alkali-free glass substrate G were adhered.

  In Examples 1, 2, and 5, when the adhesive composition layer 2 was formed using an adhesive composition using camphorquinone as a radical photopolymerization initiator, a blue light irradiator (manufactured by Optcord Corporation, product) Name, 470 nm wavelength of Blu-ray oscillated from LED470) is irradiated to the adhesive composition layer 2 through an alkali-free glass substrate G for 1 minute to polymerize and cure the hydrolysis-condensation product of alkoxysilane having a methacryloyl group. The substrate S and the alkali-free glass substrate G were bonded. In Examples 3 and 4, an adhesive composition using 2-hydroxy-2-methyl-1-phenyl-propan-1-one (manufactured by Ciba Specialty Chemicals Co., Ltd., trade name, Darocur 1173) was used for adhesion. When the composition layer 2 is formed, the adhesive composition layer 2 is irradiated for 20 seconds through an alkali-free glass substrate G with ultraviolet light having a wavelength of 365 nm by an ultraviolet irradiator (trade name, UV LIGHT SOURCE EX250, manufactured by HOYA-SCHOTT). Then, the hydrolysis condensate of alkoxysilane having a methacryloyl group was polymerized and cured, and the silicon substrate S and the alkali-free glass substrate G were bonded.

3. 3. Separation of silicon substrate S and alkali-free glass substrate G and state after peeling 3.1. Peeling of the silicon substrate S and the alkali-free glass substrate G In order to peel the bonded silicon substrate S and the alkali-free glass substrate G by curing the adhesive composition layer 2 of the adhesive compositions of Examples 1 to 5, ultraviolet rays are used. Using an irradiation machine (trade name, UV LIGHT SOURCE EX250, manufactured by HOYA-SCHOTT), the adhesive composition layer 2 was irradiated with ultraviolet rays for 5 minutes from the alkali-free glass substrate G side. When the adhesive composition is used, the anthracene diketone which is an ultraviolet absorbing foaming agent is decomposed. When the adhesive compositions of Examples 2 and 4 are used, 4-diazodiphenylamine sulfate (manufactured by Tokyo Chemical Industry Co., Ltd.). ) Foamed, and the silicon substrate S and the alkali-free glass substrate G were peeled off.

  In addition, when the adhesive composition layer 2 using the adhesive composition of Examples 3 and 4 is irradiated with ultraviolet rays having a wavelength of 365 nm from an ultraviolet irradiator (manufactured by HOYA-SCHOTT, trade name, UV LIGHT SOURCE EX250). In this case, the photopolymerization initiator 2-hydroxy-2-methyl-1-phenyl-propan-1-one (trade name, Darocur 1173, manufactured by Ciba Specialty Chemicals Co., Ltd.) is obtained by irradiation for 20 seconds during curing. Reaction, the hydrolysis condensate of alkoxysilane having a methacryloyl group is polymerized, the adhesive composition layer 2 is cured, the silicon substrate S and the alkali-free glass substrate G are bonded, and irradiation for 5 minutes at the time of peeling after bonding Anthracene diketone or 4-diazodiphenylamine sulfate contained in the adhesive composition layer 2 (Tokyo Chemical Industry Co., Ltd.) Industry Co., Ltd.) is foamed, the silicon substrate S and non-alkali glass substrate G was peeled.

3.2. State after peeling In both Examples 1 to 5, the silicon substrate S and the alkali-free glass substrate G were peeled off spontaneously. Peeling occurs between the silicon substrate S and the adhesive composition layer 2, and the residue of the adhesive composition layer 2 is attached only to the glass substrate G. When visually confirmed, the residual adhesion to the silicon substrate S is I was not able to admit. This is because peeling occurred selectively between the adhesive composition layer 2 and the silicon substrate S.

  Thus, the silicon substrate S and the alkali-free glass substrate bonded by light irradiation or heating using the adhesive composition of the present invention are brought into a preferable state without leaving an adhesive residue on the silicon substrate S by irradiation with ultraviolet rays. It confirmed that it peeled.

[Comparative example]
In the same procedure as in Examples 1 to 5, an adhesive composition having the composition shown in Comparative Example 1 in Table 2 was prepared. Unlike Examples 1-5, the adhesive composition of Comparative Example 1 does not use an ultraviolet absorbing foaming agent.

Comparative Example 1: No ultraviolet absorbing foaming agent was used.

  As in Examples 1 to 5, as shown in FIG. 1A, 0.6 g of the adhesive composition of Comparative Example 1 was applied onto a silicon substrate S having a diameter of 100 mm using a spin coater. Layer 2 was formed. Next, as shown in FIG. 1B, the silicon substrate S was superposed on the alkali-free glass substrate G to form an adhesive composition layer 2.

  The adhesiveness of Comparative Example 1 in Table 2 using camphorquinone as the photoradical polymerization initiator after providing coating layer 1 made of a hydrolytic condensate of an alkoxysilane having a photopolymerizable group as in Example 1 When the adhesive composition layer 2 is formed using the composition, the adhesive composition passes through a non-alkali glass substrate G through a non-alkali glass substrate G using a Blu-ray having a wavelength of 470 nm oscillated from a blue light irradiator (trade name, LED470 manufactured by Optcord Corporation) The layer 2 was irradiated for 1 minute to polymerize and cure the hydrolysis condensate of alkoxysilane having a methacryloyl group, and the silicon substrate S and the alkali-free glass substrate G were bonded.

  The silicon substrate S and the alkali-free glass substrate G are firmly bonded, and it is difficult to peel the silicon substrate S and the alkali-free glass substrate G by irradiation with ultraviolet rays. It was found that when no ultraviolet absorbing foaming agent was added to the adhesive composition, foaming could not be used for the driving force for peeling.

[Reference example]
In Reference Example 1, as shown in Table 3, after preparing an adhesive composition having the same composition as Example 3, when bonding the silicon substrate S and the non-alkali glass substrate G as in Example, Unlike Example 3 (irradiation time of 20 seconds), ultraviolet light irradiation during bonding was performed for 400 seconds.

  Specifically, 2-hydroxy-2-methyl-1-phenyl-propan-1-one (manufactured by Ciba Specialty Chemicals, trade name, Darocur 1173) as a photo radical polymerization initiator, and anthracene as an ultraviolet absorbing foaming agent An adhesive composition layer 2 using the same adhesive composition as in Example 3 containing diquinone was formed, and an ultraviolet ray having a wavelength of 365 nm was obtained using an ultraviolet irradiator (trade name, UV LIGHT SOURCE EX250, manufactured by HOYA-SCHOTT). Was irradiated to the adhesive composition layer 2 through an alkali-free glass substrate G for 400 seconds to polymerize the hydrolysis condensate of alkoxysilane having a methacryloyl group.

  Moreover, in Reference Example 2, as shown in Table 3, the same adhesive composition as that used in Example 1 was used, except that the coating layer 1 was not provided on the alkali-free glass substrate G. Similarly to 1, the silicon substrate S and the alkali-free glass substrate G were bonded.

  In Reference Example 3, the silicon substrate S and the alkali-free glass substrate G were bonded in the same manner as in Example 1 except that the alkali-free glass substrate G was not polished. As shown in Table 3, Reference Example 2 used the same adhesive composition as used in Example 1.

  In Reference Examples 2 to 3, specifically, the silicon substrate S and the alkali-free glass substrate G were bonded and peeled by the following procedure.

<Adhesion>
By using camphorquinone, which is a radical photopolymerization initiator, Blu-ray having a wavelength of 470 nm oscillated from a blue light irradiator (trade name, LED 470, manufactured by Optcord Co., Ltd.) is applied to the adhesive composition layer 2 through an alkali-free glass substrate G. Irradiation was performed for 1 minute to polymerize and cure the hydrolysis condensate of alkoxysilane having a methacryloyl group, and the silicon substrate S and the alkali-free glass substrate G were bonded.

<Peeling>
In order to peel the bonded silicon substrate S and non-alkali glass substrate G from the opposite side of the adhesive composition layer 2 when viewed from the non-alkali glass substrate G, ultraviolet light having a wavelength of 365 nm is applied to an ultraviolet irradiator (HOYA-SCHOTT). (Product name, UV LIGHT SOURCE EX250), and irradiation was performed for 5 minutes. Anthracene diketone, which is an ultraviolet absorbing foaming agent, foamed in the adhesive composition layer 2, and the silicon substrate S and the alkali-free glass substrate G were peeled off.

Table 3 shows the compositions of the adhesive compositions used in Reference Examples 1 to 3.

  Reference example 1: The light irradiation time at the time of adhesion is 400 seconds.

 Reference Example 2: The coating layer 1 is not provided on the alkali-free glass substrate G.

 Reference Example 3: The alkali-free glass substrate G is not polished.

<Evaluation>
In Reference Example 1, anthracene diketone, which is an ultraviolet absorbing foaming agent, foamed in the adhesive composition layer 2 during curing. In Example 3, irradiation of ultraviolet rays having a wavelength of 365 nm to the adhesive composition layer 2 during curing was for 20 seconds. This is because, in Reference Example 1, ultraviolet rays were irradiated for 400 seconds at the time of curing and excessive irradiation was performed.

  In Reference Example 2, the silicon substrate S and the alkali-free glass substrate G were spontaneously separated. However, when visually confirmed, adhesion residues were slightly adhered to both the silicon substrate S and the non-alkali glass substrate G. When the coating layer 1 is formed on the alkali-free glass substrate G and the adhesive composition is coated and peeled off, the adhesive residue after peeling cannot be visually confirmed, and the coating layer 1 is formed in the present invention. Is preferred.

  In Reference Example 3, the silicon substrate S and the non-alkali glass substrate G were spontaneously separated. However, when visually confirmed, adhesion residues were slightly adhered to both the silicon substrate S and the non-alkali glass substrate G. When the alkali-free glass substrate G is ceria-polished and the adhesive composition is applied and bonded and peeled off, the adhesive residue after peeling cannot be visually confirmed. In the present invention, the alkali-free glass substrate G is ceria-polished in advance. Preferably it is done.

G glass substrate S silicon substrate 1 coating layer 2 adhesive composition layer (adhesive composition)

Claims (8)

An adhesive composition comprising a hydrolysis-condensation product of an alkoxysilane having a photopolymerizable group, a photopolymerization initiator, and an ultraviolet absorbing foaming agent. The adhesive composition according to claim 1, wherein the photopolymerizable group is a photopolymerizable group containing at least one group selected from the group consisting of an acryloyl group, a methacryloyl group, and a vinyl group. The adhesive composition according to claim 1 or 2, wherein the ultraviolet absorbing foaming agent is a diketone compound or a diazonium salt. The adhesive composition according to any one of claims 1 to 3, wherein the adhesive composition is sandwiched between substrates, and the adhesive composition is irradiated with light to cure the adhesive composition and bond the substrates together. Method. The bonding method according to claim 4, wherein bonding the substrates is bonding a silicon substrate and a glass substrate. The bonding method according to claim 4 or 5, wherein the adhesive composition is cured by irradiating light having a wavelength of 300 nm or more and 900 nm or less for a sufficient time to bond the substrates to bond the substrates together. The adhesion method according to any one of claims 4 to 6, comprising a step of applying a hydrolysis-condensation product of alkoxysilane having a photopolymerizable group to an adhesion surface of a glass substrate. A silicon substrate and a glass substrate bonded using the adhesive composition according to any one of claims 1 to 4 are irradiated with ultraviolet rays having a wavelength of 200 nm or more and 420 nm or less to fire an ultraviolet absorbing foaming agent. A method for peeling a silicon substrate and a glass substrate.

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