JP2004228539A - Manufacturing method of ic chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of IC chips which enables each wafer to completely peel off by itself in a process of peeling each wafer off a double-sided adhesive tape. <P>SOLUTION: This manufacturing method of IC chips includes a process 1 of using a double-sided adhesive tape containing a gas generating agent, which generates gas when exposed to light, in the adhesive layer on at least one of its sides to attach a wafer on the side containing the gas generating agent for securing the wafer to a support plate, a process 2 of polishing the wafer secured to the support plate with the double-sided adhesive tape, a process 3 of exposing the double-sided adhesive tape to light, and a process 4 of peeling the double-sided adhesive tape off the wafer. The gas generating rate in the process 3 is at least 10μL/cm<SP>2</SP>×min. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of manufacturing an IC chip capable of completely self-peeling a wafer in a step of separating a double-sided adhesive tape and a wafer.
[0002]
[Prior art]
2. Description of the Related Art A semiconductor integrated circuit (IC chip) is usually formed by slicing a high-purity rod-shaped semiconductor single crystal or the like into a wafer, forming a predetermined circuit pattern on the wafer surface using a photoresist, and then forming a wafer back surface. It is manufactured by polishing with a polishing machine to reduce the thickness of the wafer to about 100 to 600 μm, and finally dicing to make chips.
[0003]
Here, at the time of the polishing, an adhesive sheet (polishing tape) is attached to the wafer surface to prevent breakage of the wafer and facilitate the polishing process. At the time of the dicing, the adhesive sheet is attached to the back surface of the wafer. (Dicing tape) is attached, and the wafer is diced in a state where the wafer is bonded and fixed. The formed chip is picked up by a needle from the film substrate side of the dicing tape with a needle, and is fixed on the die pad.
[0004]
In recent years, as the use of IC chips has expanded, an extremely thin semiconductor wafer having a thickness of about 50 μm that can be used for IC cards or stacked and used has been required. However, a semiconductor wafer having a thickness of about 50 μm has a larger warp than a conventional semiconductor wafer having a thickness of about 100 to 600 μm and is more likely to be broken by an impact. Then, it may be damaged.
[0005]
A semiconductor wafer having a thickness of about 50 μm has a high risk of being damaged in a polishing process or a dicing process, which is easily affected by an impact, and is also easily damaged when a bump is formed on an electrode of an IC chip. For this reason, it has been an important issue to improve the handleability of a wafer in the process of manufacturing IC chips from a thin semiconductor wafer having a thickness of about 50 μm.
[0006]
Patent Literature 1 discloses a method in which a foaming agent is contained in an adhesive layer of a double-sided pressure-sensitive adhesive tape for fixing a wafer to a support, and the foaming agent is foamed to reduce the adhesive force and to self-peel the wafer from the double-sided pressure-sensitive adhesive tape. Proposed. However, the method described in Patent Document 1 cannot form complete self-peeling because foaming of the heat-expandable microcapsules causes irregularities to be formed on the surface of the pressure-sensitive adhesive tape to reduce the bonding area and reduce the bonding strength. Was. Further, since the hydrocarbon gas existing in the core escapes after the microcapsules expand, the gas is not spouted vigorously.
[0007]
If the amount of generated gas is not sufficient as described above, a gas escape path is formed at the bonding interface due to the generated gas, and once the gas escape path is generated, the generated gas cannot push up the bonding interface and the bonding interface is partially formed. In some cases, incomplete peeling may occur in which the adhesive portion is left in an island shape.
[0008]
[Patent Document 1]
JP-A-63-30581
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing an IC chip in which a wafer can be completely peeled off in a step of peeling a double-sided pressure-sensitive adhesive tape from a wafer.
[0010]
[Means for Solving the Problems]
The present invention provides, at least, a double-sided pressure-sensitive adhesive tape containing a gas generating agent that generates a gas by light irradiation in at least one surface of an adhesive layer, and bonding the surface containing the gas generating agent to a wafer, Fixing the wafer to the support plate, polishing the wafer while fixing the wafer to the support plate via the double-sided adhesive tape, irradiating light to the double-sided adhesive tape, and removing the wafer from the wafer. A method for manufacturing an IC chip having a step 4 of peeling the double-sided pressure-sensitive adhesive tape, wherein the gas release rate in the step 3 is 5 μL / cm ² · min or more.
Hereinafter, the present invention will be described in detail.
[0011]
The method for manufacturing an IC chip of the present invention includes a step of fixing a wafer to a support plate via a double-sided adhesive tape.
By fixing the wafer to the support plate, the handleability of the wafer is improved, the breakage of the wafer can be prevented even for an extremely thin wafer having a thickness of about 50 μm, and the IC chip can be favorably processed.
The wafer at this time is a semiconductor wafer obtained by slicing a silicon single crystal or gallium arsenide single crystal or the like, and has a predetermined circuit pattern formed on the wafer surface, and has a thickness of about 500 μm to 1 mm. When fixing the wafer to the support plate, the surface of the wafer on which the circuits are formed and the double-sided adhesive tape are bonded together.
[0012]
The support plate is not particularly limited, but is preferably a transparent plate for transmitting or transmitting light. Examples of such a support plate include a plate-like body made of a resin such as acryl, olefin, polycarbonate, vinyl chloride, ABS, PET, nylon, urethane, and polyimide.
[0013]
A preferred lower limit of the thickness of the support plate is 500 μm, a preferred upper limit is 3 mm, a more preferred lower limit is 1 mm, and a more preferred upper limit is 2 mm. It is preferable that the variation in the thickness of the support plate is 1% or less.
[0014]
The double-sided pressure-sensitive adhesive tape contains a gas generating agent that generates a gas by light irradiation in at least one surface of the pressure-sensitive adhesive layer.
The pressure-sensitive adhesive tape may be a support tape in which a pressure-sensitive adhesive layer is formed on both surfaces of a substrate, or a non-support tape having no substrate.
The substrate is not particularly limited, but preferably transmits or transmits light. For example, a transparent material such as acryl, olefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), nylon, urethane, and polyimide is used. Examples of the sheet include a sheet made of various resins, a sheet having a mesh structure, and a sheet having holes.
[0015]
Examples of light for generating a gas from the gas generating agent include ultraviolet light and visible light. The pressure-sensitive adhesive layer containing the gas generating agent is preferably capable of transmitting or transmitting light.
The gas generating agent that generates a gas upon irradiation with light is not particularly limited. For example, an azo compound or an azide compound is preferably used.
[0016]
Examples of the azo compound include 2,2′-azobis- (N-butyl-2-methylpropionamide) and 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-Hydroxyethyl] propionamide {, 2,2'-azobis {2-methyl-N- [2- (1-hydroxybutyl)] propionamide}, 2,2'-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2′-azobis [N- (2-propenyl) -2-methylpropionamide], 2,2′-azobis (N-butyl-2-methylpropionamide), 2,2′-azobis (N-cyclohexyl-2-methylpropionamide), 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochlora , 2,2'-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] disulfatedi Hydrorate, 2,2′-azobis [2- (3,4,5,6-tetrahydropyrimidin-2-yl) propane] dihydrochloride, 2,2′-azobis {2- [1- (2- (Hydroxyethyl) -2-imidazolin-2-yl] propane dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane], 2,2′-azobis (2-methylpropion) Amidine) dihandrochloride, 2,2′-azobis (2-aminopropane) dihydrochloride, 2,2′-azobis [N- (2-carboxyacyl) -2-methyl-propyl Pionamidyne], 2,2′-azobis {2- [N- (2-carboxyethyl) amidine] propane}, 2,2′-azobis (2-methylpropionamidooxime), dimethyl 2,2′-azobis (2-methylpropionate), dimethyl 2,2'-azobisisobutyrate, 4,4'-azobis (4-cyancarbonic acid), 4,4'-azobis (4-cyanopentanoic acid) , 2,2'-azobis (2,4,4-trimethylpentane) and the like.
In the production of IC chips, a step of performing high-temperature treatment is included if necessary, and among these, 2,2′-azobis- (N-butyl-2-methylpropionamide), which has a high thermal decomposition temperature, 2,2′-azobis (N-butyl-2-methylpropionamide) and 2,2′-azobis (N-cyclohexyl-2-methylpropionamide) are preferred.
These azo compounds generate nitrogen gas when irradiated with light.
[0017]
Examples of the azide compound include 3-azidomethyl-3-methyloxetane, terephthalazide, p-tert-butylbenzazide; and glycidyl azide polymer obtained by ring-opening polymerization of 3-azidomethyl-3-methyloxetane. Polymers having an azide group are exemplified.
These azide compounds generate nitrogen gas when irradiated with light.
[0018]
Among these gas generating agents, the azide compound described above has a problem that it is difficult to handle because it easily decomposes and gives off nitrogen gas even when subjected to impact. Furthermore, once the decomposition starts, the azide compound causes a chain reaction, explosively releases nitrogen gas, and the control cannot be performed. Therefore, there is a problem that the explosively generated nitrogen gas may damage the wafer. is there. Due to such a problem, the amount of the azide compound used is limited, but the limited amount may not provide a sufficient effect.
[0019]
On the other hand, the azo compound, unlike the azide compound, does not generate gas by impact, and is therefore extremely easy to handle. In addition, since there is no explosive gas generated due to a chain reaction, the wafer is not damaged, and gas generation can be interrupted by interrupting light irradiation. There is also the advantage that it is possible. Therefore, it is more preferable to use an azo compound as the gas generating agent.
[0020]
By containing the gas generating agent, a gas is generated from the gas generating agent when irradiating the double-sided pressure-sensitive adhesive tape with light, and by peeling off at least a part of the adhesive surface, the adhesive force is reduced and the adherend is reduced. It can be easily peeled off.
It is desirable that the gas generating agent be contained in a ratio of 5 parts by weight to 50 parts by weight per 100 parts by weight of the adhesive. If the amount is less than 5 parts by weight, the amount of generated gas is insufficient, and the desired releasability may not be obtained.
On the other hand, when the amount exceeds 50 parts by weight, the solubility is deteriorated, and problems such as bleeding may occur.
[0021]
The pressure-sensitive adhesive constituting the surface containing the gas generating agent is preferably a stimulus-curable pressure-sensitive adhesive whose adhesive force is reduced by stimulation. The stimulus for reducing the adhesive strength of the stimulus-curable pressure-sensitive adhesive may be light irradiation, or other stimuli such as heat or ultrasonic waves. Examples of such a stimulus-curable pressure-sensitive adhesive include a polymerizable polymer of an alkyl acrylate type and / or an alkyl methacrylate type having a radical polymerizable unsaturated bond in a molecule, and a radical polymerizable polymer. A photocurable pressure-sensitive adhesive comprising a polyfunctional oligomer or monomer as a main component and optionally containing a photopolymerization initiator, or an alkyl acrylate having a radical polymerizable unsaturated bond in the molecule And / or a methacrylic acid alkyl ester-based polymerizable polymer and a radical-polymerizable polyfunctional oligomer or monomer as main components, and a thermosetting pressure-sensitive adhesive containing a thermal polymerization initiator. .
The number of functional groups per molecule of the polyfunctional oligomer or monomer is preferably 5 or more. If it is less than 5, curing (crosslinking) of the pressure-sensitive adhesive is insufficient, and the decrease in adhesive strength may not be sufficient.
The stimulus-curable pressure-sensitive adhesive is also one of the present invention.
[0022]
Post-curing pressure-sensitive adhesives such as light-curing pressure-sensitive adhesives or heat-curing pressure-sensitive adhesives are uniformly and quickly polymerized and cross-linked by light irradiation or heating, so that they are integrated. The increase in the elastic modulus due to curing becomes remarkable, and the adhesive strength is greatly reduced. Also, when gas is generated from the gas generating agent in a hard cured product, most of the generated gas is released to the outside, and the released gas peels off at least a part of the adhesive surface of the adhesive from the adherend and adheres Decrease power.
[0023]
As the polymerizable polymer, for example, a (meth) acrylic polymer having a functional group in a molecule (hereinafter referred to as a (meth) acrylic polymer containing a functional group) is synthesized in advance and reacted with the functional group in the molecule. (Hereinafter, referred to as a functional group-containing unsaturated compound) having a functional group and a radical polymerizable unsaturated bond.
[0024]
The functional group-containing (meth) acrylic polymer is a polymer having tackiness at room temperature, and is an acryl polymer having an alkyl group having a carbon number of usually 2 to 18 as in a general (meth) acrylic polymer. An acid alkyl ester and / or a methacrylic acid alkyl ester as a main monomer, and a functional group-containing monomer and, if necessary, another copolymerizable monomer copolymerizable therewith by a conventional method. It is obtained. The weight average molecular weight of the functional group-containing (meth) acrylic polymer is usually about 200,000 to 2,000,000.
[0025]
Examples of the functional group-containing monomer include a carboxyl group-containing monomer such as acrylic acid and methacrylic acid; a hydroxyl group-containing monomer such as hydroxyethyl acrylate and hydroxyethyl methacrylate; and an epoxy group-containing monomer such as glycidyl acrylate and glycidyl methacrylate. Monomers; isocyanate group-containing monomers such as isocyanate ethyl acrylate and isocyanate ethyl methacrylate; and amino group-containing monomers such as aminoethyl acrylate and aminoethyl methacrylate.
[0026]
Examples of other copolymerizable modifying monomers include various monomers used in general (meth) acrylic polymers such as vinyl acetate, acrylonitrile, and styrene.
[0027]
As the functional group-containing unsaturated compound to be reacted with the functional group-containing (meth) acrylic polymer, the same compound as the functional group-containing monomer described above according to the functional group of the functional group-containing (meth) acrylic polymer is used. it can. For example, when the functional group of the functional group-containing (meth) acrylic polymer is a carboxyl group, an epoxy group-containing monomer or an isocyanate group-containing monomer is used, and when the functional group is a hydroxyl group, an isocyanate group-containing monomer is used. When the functional group is an epoxy group, a carboxyl group-containing monomer or an amide group-containing monomer such as acrylamide is used. When the functional group is an amino group, an epoxy group-containing monomer is used.
[0028]
The polyfunctional oligomer or monomer preferably has a molecular weight of 10,000 or less, and more preferably has a molecular weight of 5,000 or less so that the three-dimensional network of the pressure-sensitive adhesive layer can be efficiently formed by heating or irradiation with light. And the number of radically polymerizable unsaturated bonds in the molecule is from 2 to 20. Such more preferred polyfunctional oligomers or monomers include, for example, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate Alternatively, methacrylates similar to the above may be used. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligomeric ester acrylates, epoxy acrylates, urethane acrylates, and methacrylates similar to those described above. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.
[0029]
Preferably, the polyfunctional oligomer or monomer is blended in a ratio of 10 to 100 parts by weight with respect to 100 parts by weight of the (meth) acrylic acid alkyl ester-based polymerizable polymer. In some cases, the desired resilience cannot be obtained due to insufficient elasticity and a desired elastic modulus.
[0030]
On the other hand, if it exceeds 100 parts by weight, the solubility deteriorates, and problems such as bleeding occur. Further, before the application of the stimulus (light), the compound is blended as an uncrosslinked component, so that an initial cohesive strength may not be obtained.
[0031]
Examples of the photopolymerization initiator include those activated by irradiation with light having a wavelength of 250 to 800 nm. Examples of such photopolymerization initiators include acetophenone derivative compounds such as methoxyacetophenone. Benzoin ether compounds such as benzoin propyl ether and benzoin isobutyl ether; ketal derivative compounds such as benzyl dimethyl ketal and acetophenone diethyl ketal; phosphine oxide derivative compounds; bis (η5-cyclopentadienyl) titanocene derivative compound, benzophenone and Michler's ketone , Chlorothioxanthone, todecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexylphenylketone, 2-hydroxymethylphenylpro Examples include a photo-radical polymerization initiator such as bread. These photopolymerization initiators may be used alone or in combination of two or more.
[0032]
Examples of the thermal polymerization initiator include those which generate an active radical which is decomposed by heat to initiate polymerization curing. Specific examples thereof include dicumyl peroxide, di-t-butyl peroxide, and t-butyl. Examples include peroxybenzoate, t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, di-t-butyl peroxide and the like. Among them, cumene hydroperoxide, paramenthane hydroperoxide, di-t-butyl peroxide, and the like are preferable because of high thermal decomposition temperature. Among these thermal polymerization initiators, commercially available ones are not particularly limited, but, for example, perbutyl D, perbutyl H, perbutyl P, permentor H (all of these are manufactured by NOF Corporation) and the like are preferable. These thermal polymerization initiators may be used alone or in combination of two or more.
[0033]
In the post-curing pressure-sensitive adhesive, in addition to the above components, for the purpose of adjusting the cohesive force as a pressure-sensitive adhesive, isocyanate compounds, melamine compounds, various kinds of compounds that are blended into a general pressure-sensitive adhesive such as an epoxy compound, if desired. A polyfunctional compound may be appropriately blended. Known additives such as a plasticizer, a resin, a surfactant, a wax, and a fine particle filler can also be added.
[0034]
In the method of manufacturing an IC chip according to the present invention, the wafer is fixed to the support plate via the double-sided adhesive tape by bonding the surface of the double-sided adhesive tape containing the gas generating agent to the wafer. It is preferable to perform bonding in a vacuum state using a vacuum laminator or the like in order to bond with better flatness.
By fixing the wafer to the support plate, a very thin wafer of about 50 μm is reinforced, so that it does not chip or break when the wafer is transported or processed. When the step is completed, it can be easily separated from the IC chip by irradiating light.
[0035]
Next, in the method for manufacturing an IC chip according to the present invention, the wafer is polished while being fixed to the support plate. By fixing to the support plate, breakage of the wafer in the polishing step can be prevented, and the wafer can be polished smoothly.
[0036]
Next, in the method for manufacturing an IC chip of the present invention, light is applied to the double-sided adhesive tape. As a result, gas is generated from the gas generating agent in the adhesive layer on the surface of the double-sided adhesive tape that contacts the wafer, and the adhesive strength between the double-sided adhesive tape and the wafer can be reduced.
[0037]
In the method of manufacturing an IC chip of the present invention, the gas release rate when light is irradiated from the transparent support plate side of the double-sided adhesive tape bonded to the transparent support plate and the wafer is 5 μL / cm ² · min or more. If it is less than 5 μL / cm ² · minute, the adhesive layer of the adhesive tape may not completely peel off from the wafer, and the adhesive portion may remain in an island shape. As described above, this gas release rate can be achieved by mixing 5 to 50 parts by weight of the gas generating agent with respect to 100 parts by weight of the adhesive on at least the surface portion of the adhesive. In this specification, as shown in FIG. 1, the gas release rate is measured by preparing a sealed chamber whose irradiation surface is sealed with glass, connecting the outlet of the chamber to a female pipette with a rubber tube, and further connecting the other end of the female pipette. Connect the two outlets to the funnel with a rubber tube, pour an appropriate amount of water, stand the pipette vertically, open the three-way valve, adjust the position of the funnel, adjust the water surface position to zero, and open the three-way valve. It is calculated by closing it, irradiating it with light under normal pressure, collecting generated gas, calculating the integrated generation amount of gas every 10 seconds, and dividing by the surface area of the irradiated sheet.
[0038]
In the method of manufacturing an IC chip according to the present invention, it is preferable that the gel fraction of the adhesive layer on the surface in contact with the wafer at the time of irradiating one-third of the total irradiation amount is 90% or more. In order to make the gel fraction 90% or more, the photoreactive polyfunctional oligomer may be blended in an amount of 10 to 100 parts by weight based on 100 parts by weight of the polymerizable polymer. If it is less than 90%, the pressure-sensitive adhesive layer at the start of gas generation is not sufficiently hard, and the generated gas is absorbed by the soft pressure-sensitive adhesive layer, or the pressure-sensitive adhesive layer foams and self-peeling occurs. It may be difficult to happen. Note that, in the present specification, the total irradiation amount means an integrated light amount irradiated until the wafer is lifted up by self-peeling.
[0039]
In the method for manufacturing an IC chip of the present invention, it is preferable that the elastic modulus of the adhesive layer on the surface in contact with the wafer at the time of irradiating 1/3 of the total irradiation amount is 5 × 10 ⁴ Pa or more. In order to make the elastic modulus 5 × 10 ⁴ Pa or more, the photoreactive polyfunctional oligomer may be blended in the range of 10 to 100 parts by weight based on 100 parts by weight of the polymerizable polymer. If the pressure is less than 5 × 10 ⁴ Pa, the hardness of the pressure-sensitive adhesive layer at the start of gas generation is not sufficient, and the generated gas is absorbed by the soft pressure-sensitive adhesive layer and self-peeling may not easily occur.
[0040]
In the present invention, the total irradiation amount of light irradiating the double-sided pressure-sensitive adhesive tape is not particularly limited, it can be appropriately determined by the thickness of the support, the content of the gas generating agent in the pressure-sensitive adhesive layer, and the like, irradiating light of normal 20~60mW / cm ² intensity of about irradiates light integrated to the energy of 2000~6000mJ / cm ^2. Therefore, the third light total dose, for example, if the cumulative amount of light is 2000 mJ / cm ² refers to the dose of about 700 mJ / cm ^2.
As for the irradiation device, a scanning irradiation device is difficult to irradiate uniformly, so that it may be partially peeled off and the wafer may be broken, so that it is possible to irradiate the irradiation surface with light evenly if possible. Irradiation with an irradiation device is preferred.
[0041]
Next, in the method for manufacturing an IC chip of the present invention, the double-sided adhesive tape is peeled from the wafer. Since the adhesive force between the double-sided pressure-sensitive adhesive tape and the wafer is reduced, the double-sided pressure-sensitive adhesive tape can be easily separated from the wafer.
[0042]
In a normal process, after the polishing process is completed, a dicing tape is attached to the polished wafer before the wafer is peeled by irradiating light to generate gas and then the wafer is peeled and then dicing is performed. However, these steps may be appropriately omitted or the order may be changed as necessary.
[0043]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.
[0044]
(Example 1)
<Preparation of adhesive>
The following compounds were dissolved in ethyl acetate, and the mixture was polymerized by irradiation with ultraviolet rays to obtain an acrylic copolymer having a weight average molecular weight of 700,000.
3.5 parts by weight of 2-isocyanatoethyl methacrylate was added to 100 parts by weight of the resin solid content of the ethyl acetate solution containing the obtained acrylic copolymer to cause a reaction, and further, the resin of the ethyl acetate solution after the reaction was added. Adhesive (1) was obtained by mixing 40 parts by weight of pentaerythritol triacrylate (trifunctional), 0.5 part by weight of polyisocyanate, and 0.1 part by weight of a photopolymerization initiator (Irgacure 651) with respect to 100 parts by weight of the solid content. Was prepared in ethyl acetate.
79 parts by weight of butyl acrylate 15 parts by weight of ethyl acrylate 1 part by weight of acrylic acid 5 parts by weight of 2-hydroxyethyl acrylate 0.2 parts by weight of photopolymerization initiator (Irgacure 651, 50% ethyl acetate solution)
Lauryl mercaptan 0.01 parts by weight [0045]
30 parts by weight of 2,2'-azobis (N-butyl-2-methylpropionamide) and 3.6 parts of 2,4-diethylthioxanthone are based on 100 parts by weight of the resin solid content of the ethyl acetate solution of the pressure-sensitive adhesive (1). By weight, 4 parts by weight of Irgacure and 0.5 part by weight of polyisocyanate were mixed to prepare a pressure-sensitive adhesive (2) containing a gas generating agent.
[0046]
<Preparation of double-sided adhesive tape>
An ethyl acetate solution of the pressure-sensitive adhesive (1) is coated with a doctor knife on one side of a transparent polyethylene terephthalate (PET) film having a thickness of 100 μm and corona-treated on both sides so that the thickness of the dried film is about 30 μm. Then, the coating solution was dried by heating at 110 ° C. for 5 minutes. Next, a PET film subjected to a release treatment was attached to the surface of the pressure-sensitive adhesive (1) layer. Then, it left still at 40 degreeC for 3 days.
[0047]
An ethyl acetate solution of the pressure-sensitive adhesive (2) is applied on a PET film having a surface subjected to a release treatment by a doctor knife so that the thickness of a dried film becomes about 50 μm, and heated at 110 ° C. for 5 minutes. The solvent was volatilized to dry the coating solution. The dried pressure-sensitive adhesive layer showed tackiness in a dry state. Next, a PET film subjected to a release treatment was attached to the surface of the pressure-sensitive adhesive (2) layer. Then, it was left at 40 ° C. for 3 days for curing.
[0048]
Next, a corona-treated PET film provided with an adhesive (1) layer and a corona-treated surface without the adhesive (1) layer and a release treatment provided with an adhesive (2) layer are applied. The surface of the pressure-sensitive adhesive (2) layer of the PET film was bonded. Thus, a double-sided pressure-sensitive adhesive tape was obtained in which pressure-sensitive adhesive layers were provided on both sides and the surface of which was protected by a PET film subjected to a release treatment. The pressure-sensitive adhesive layers of the double-sided pressure-sensitive adhesive tape were all transparent.
[0049]
<Manufacture of IC chips>
(Lamination of silicon wafer and glass plate)
Peel off the PET film that protects the adhesive (2) layer of the double-sided adhesive tape and attach it to a silicon wafer having a diameter of 20 cm and a thickness of about 700 μm using a laminator. Cut. Next, the PET film protecting the pressure-sensitive adhesive (1) layer was peeled off, and a glass plate having a diameter of 20.4 cm was attached to the pressure-sensitive adhesive (1) layer in a vacuum state. The bonded surface was strongly bonded immediately after bonding.
[0050]
(Polishing process)
A silicon wafer reinforced with a glass plate was attached to a polishing apparatus and polished until the thickness of the silicon wafer became about 50 μm. At this time, the operation was performed while spraying water on the silicon wafer so that the temperature of the silicon wafer did not increase due to frictional heat of polishing. The silicon wafer was removed from the polishing device, and a dicing tape was stuck on the silicon wafer.
[0051]
(UV irradiation step)
Ultraviolet light of 365 nm was irradiated from the glass plate side for 125 seconds by adjusting the illuminance so that the illuminance on the surface of the glass plate was 24 mW / cm ² (integrated light amount: 3000 mJ / cm ² ).
[0052]
(Wafer peeling process)
The silicon wafer was fixed, and the glass plate was pulled right above and peeled off from the silicon wafer together with the double-sided adhesive tape. The double-sided pressure-sensitive adhesive tape was lifted up by the generated gas and lifted up, and peeled off by itself. No adhesive residue was observed on the silicon wafer.
When one series of steps was performed three times, the silicon wafer could be easily peeled off from the glass plate on which the double-sided adhesive tape was adhered in all three times.
[0053]
(Example 2)
In the UV irradiation step, the same as in Example 1 except that the ultraviolet light of 365 nm was irradiated for 50 seconds while adjusting the illuminance so that the illuminance on the glass plate surface became 60 mW / cm ² (integrated light amount 3000 mJ / cm ² ). did.
When one series of steps was performed three times, the silicon wafer could be easily peeled off from the glass plate on which the double-sided adhesive tape was adhered in all three times.
[0054]
(Example 3)
When preparing the pressure-sensitive adhesive (2), the amount of 2,2′-azobis (N-butyl-2-methylpropionamide) used was 50 parts by weight, and the amount of 2,4-diethylthioxanthone was 6 parts by weight. The procedure was the same as in Example 1 except that the parts were used.
When one series of steps was performed three times, the silicon wafer could be easily peeled off from the glass plate on which the double-sided adhesive tape was adhered in all three times.
[0055]
(Example 4)
The procedure of Example 1 was repeated except that the amount of 2,4-diethylthioxanthone used was 7.2 parts by weight when preparing the pressure-sensitive adhesive (2).
When one series of steps was performed three times, the silicon wafer could be easily peeled off from the glass plate on which the double-sided adhesive tape was adhered in all three times.
[0056]
(Example 5)
In the UV irradiation step, the procedure was the same as that in Example 1 except that the surface of the glass plate was irradiated with ultraviolet rays in an atmosphere at 100 ° C.
When one series of steps was performed three times, the silicon wafer could be easily peeled off from the glass plate on which the double-sided adhesive tape was adhered in all three times.
[0057]
(Example 6)
When preparing the pressure-sensitive adhesive (1), 30 parts by weight of NK Oligo U324A (manufactured by Shin-Nakamura Chemical Co., Ltd., urethane acrylate (10-functional)) was used instead of 40 parts by weight of pentaerythritol triacrylate, and the UV irradiation step was performed. The procedure was the same as that of Example 1, except that the ultraviolet light of 365 nm was adjusted for illuminance on the surface of the glass plate to be 7 mW / cm ² and irradiated for 125 seconds (integrated light amount: 880 mJ / cm ² ).
When one series of steps was performed three times, the silicon wafer could be easily peeled off from the glass plate on which the double-sided adhesive tape was adhered in all three times.
[0058]
In Examples 1 to 6, the gas release rates were all 10 μL / cm ² · min or more, and the gel fraction at the time of 全 irradiation of all irradiation amounts was 95% or more.
[0059]
(Comparative Example 1)
In the UV irradiation step, the procedure was the same as that in Example 1 except that the UV light of 365 nm was irradiated for 125 seconds while adjusting the illuminance so that the illuminance on the glass plate surface became 7 mW / cm ² (integrated light amount: 880 mJ / cm ² ). .
When one series of steps was performed three times, the silicon wafer could be easily peeled from the glass plate with the double-sided adhesive tape adhered twice, but once the glass wafer could not be peeled and the glass plate was broken. Was.
[0060]
(Comparative Example 2)
In the UV irradiation step, the process was performed in the same manner as in Example 1 except that the UV light of 365 nm was irradiated for 42 seconds while adjusting the illuminance so that the illuminance on the glass plate surface became 7 mW / cm ² (integrated light amount: 300 mJ / cm ² ). .
When a series of steps was performed three times, the silicon wafer could not be peeled off from the glass plate on which the double-sided adhesive tape was adhered, and the glass plate was broken.
[0061]
【The invention's effect】
Since the present invention has the above-described configuration, it is possible to provide a method of manufacturing an IC chip in which the wafer can be completely self-peeled in the step of separating the double-sided pressure-sensitive adhesive tape and the wafer.
[Brief description of the drawings]
FIG. 1 is a diagram showing an apparatus for measuring a gas release rate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Double-sided adhesive tape 2 Female pipette 3 Three-way valve 4 Opening / closing cock

Claims (4)

at least,
A surface of the double-sided adhesive tape containing a gas generating agent that generates a gas by light irradiation in at least one surface of the adhesive layer, the surface containing the gas generating agent and a wafer are attached to each other, and the wafer is fixed to a support plate. Step 1,
Polishing the wafer in a state where the wafer is fixed to the support plate via the double-sided adhesive tape;
Step 3 of irradiating the double-sided adhesive tape with light, and
A method for manufacturing an IC chip, comprising a step 4 of peeling the double-sided adhesive tape from the wafer,
A method for producing an IC chip, wherein the gas release rate in step 3 is 5 μL / cm ² · min or more. 2. The method for manufacturing an IC chip according to claim 1, wherein the gel fraction of the adhesive layer on the surface in contact with the wafer at the time when one third of the total irradiation amount is irradiated in the step 3 is 90% or more. . 3. The IC according to claim 1, wherein an elastic modulus of the pressure-sensitive adhesive layer on a surface in contact with the wafer at the time of irradiating light of の of a total irradiation amount in step 3 is 5 × 10 ⁴ Pa or more. Chip manufacturing method. A stimulation-curable pressure-sensitive adhesive containing a polyfunctional monomer or a polyfunctional oligomer,
A stimulus-curable pressure-sensitive adhesive, wherein the number of functional groups per molecule of the polyfunctional monomer or polyfunctional oligomer is 5 or more.

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