CN110719944A

CN110719944A - Adhesive composition, adhesive tape, and method for protecting semiconductor device

Info

Publication number: CN110719944A
Application number: CN201880037160.XA
Authority: CN
Inventors: 利根川亨
Original assignee: Sekisui Chemical Co Ltd
Current assignee: Sekisui Chemical Co Ltd
Priority date: 2017-08-29
Filing date: 2018-08-22
Publication date: 2020-01-21
Also published as: TWI797152B; KR20200044722A; TW201917189A; KR102576890B1; JPWO2019044623A1; WO2019044623A1; JP7181087B2

Abstract

The purpose of the present invention is to provide an adhesive composition that has high adhesive force and can be peeled off while suppressing adhesive residue, an adhesive tape having an adhesive layer containing the adhesive composition, and a method for protecting a semiconductor device using the adhesive composition or the adhesive tape. The present invention is an adhesive composition comprising a crosslinked adhesive polymer composed of an adhesive polymer and a crosslinking agent, wherein the adhesive composition has a gel swell ratio of 500% or more and a gel fraction of 87% or more.

Description

Adhesive composition, adhesive tape, and method for protecting semiconductor device

Technical Field

The invention relates to an adhesive composition, an adhesive tape and a method for protecting a semiconductor device.

Background

In the manufacturing process of semiconductor devices, in order to facilitate handling and prevent breakage during processing, an operation of attaching and protecting an adhesive tape having an adhesive layer containing an adhesive composition is performed (for example, patent document 1 and the like).

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 5-32946

Disclosure of Invention

Problems to be solved by the invention

In recent years, bump connection is used for improving the reliability of electrical connection, and semiconductor devices having a bump height of about 100 to 200 μm are also used. An adhesive composition for protecting a semiconductor device having a bump by adhering to a surface on which the bump is formed is required to have an adhesive force with which peeling does not occur during processing of the semiconductor device.

However, the adhesive composition having high adhesion has a problem that adhesive residue sometimes occurs on the surface of the semiconductor device when peeling. For example, in the case of a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive composition attached to both surfaces of a semiconductor device having bumps, if the pressure-sensitive adhesive attached to the surface opposite to the surface on which the bumps are formed is peeled, a large load is applied to the surface on which the bumps are formed, and therefore the pressure-sensitive adhesive tape attached to the bump side is also easily peeled. However, when a high-adhesion pressure-sensitive adhesive composition is used to prevent such unintended peeling, adhesive residue occurs on the surface of the semiconductor device during peeling. In particular, when a high-temperature process is performed on a semiconductor device, the adhesive composition is strongly adhered by heat, and therefore, adhesive residue is more likely to occur. Further, in the case of a semiconductor device having a high bump, an adhesive layer containing an adhesive composition is embedded in the bumpy shape of the bump, and therefore, the adhesive residue occurs more remarkably.

In view of the above-described situation, an object of the present invention is to provide an adhesive composition having high adhesive force and capable of being peeled off while suppressing adhesive residue, an adhesive tape having an adhesive layer containing the adhesive composition, and a method for protecting a semiconductor device using the adhesive composition or the adhesive tape.

Means for solving the problems

In one embodiment of the present invention, there is provided an adhesive composition comprising a crosslinked adhesive polymer composed of an adhesive polymer and a crosslinking agent, wherein the adhesive composition has a gel swell ratio of 500% or more and a gel fraction of 87% or more.

The present invention is described in detail below.

The present invention can achieve both high adhesion and excellent peelability with suppressed adhesive residue during peeling when the adhesive is attached to an adherend, particularly to a surface of a semiconductor device on which bumps are formed.

An adhesive composition as one embodiment of the present invention includes a crosslinked adhesive polymer composed of an adhesive polymer and a crosslinking agent.

The adhesive composition according to one embodiment of the present invention needs to satisfy the gel swell ratio and gel fraction described below.

The adhesive composition according to one embodiment of the present invention has a gel swell ratio of 500% or more.

When the gel swelling ratio of the pressure-sensitive adhesive composition is in the above range, the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition can exhibit high adhesive force and prevent adhesive residue. From the viewpoint of achieving both high adhesion and reduced residual gum, the gel swell ratio is preferably 550% at the lower limit, more preferably 580% at the lower limit, still more preferably 600% at the lower limit, particularly preferably 650% at the lower limit, and particularly preferably 700% at the lower limit. The upper limit of the gel swelling ratio is not particularly limited, but is preferably 2000% (e.g., about 2000%), and more preferably 1500% (e.g., about 1500%).

When the pressure-sensitive adhesive composition according to an embodiment of the present invention is used in the form of a pressure-sensitive adhesive tape, the gel swell ratio can be measured by the following method.

Only 0.1g of the adhesive composition was scraped off the adhesive tape, and the adhesive tape was immersed in 50ml of ethyl acetate and shaken by a shaker at a temperature of 23 ℃ and 200rpm for 24 hours. After shaking, the mixture was separated into ethyl acetate and an adhesive composition swollen by absorbing ethyl acetate using a metal mesh (mesh # 200). The weight of the adhesive composition swollen by absorbing ethyl acetate, including the metal mesh, was measured, and thereafter dried at 110 ℃ for 1 hour. The weight of the dried adhesive composition including the metal mesh was measured, and the gel swell ratio was calculated by using the following formula.

Gel swelling ratio (%) - (V)₁-V₂)/(V₃-V₂)×100

(V₁: weight of the swollen adhesive composition including the Metal Screen, V₂: initial weight of Metal Screen, V₃: weight of adhesive composition including metal mesh after drying)

The adhesive composition according to one embodiment of the present invention has a gel fraction of 87% or more.

By setting the gel fraction of the pressure-sensitive adhesive composition to 87% or more, the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition can exhibit high adhesive force and prevent adhesive residue. From the viewpoint of achieving both high adhesion and reduced residual gum, the lower limit of the gel fraction is preferably 88%, more preferably 88.5%, still more preferably 89%, and particularly preferably 90%. The upper limit of the gel fraction is not particularly limited, but is preferably 100%, and more preferably about 99%. When the pressure-sensitive adhesive composition according to one embodiment of the present invention is used in the form of a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition, the gel fraction can be measured by the following method.

Only 0.1g of the adhesive composition was scraped off the adhesive tape, and the adhesive tape was immersed in 50ml of ethyl acetate and shaken by a shaker at a temperature of 23 ℃ and 200rpm for 24 hours. After shaking, the mixture was separated into ethyl acetate and an adhesive composition swollen by absorbing ethyl acetate using a metal mesh (mesh # 200). The separated adhesive composition was dried at 110 ℃ for 1 hour. The weight of the dried adhesive composition including the metal mesh was measured, and the gel fraction was calculated by using the following formula.

Gel fractionThe ratio (wt%) was 100 × (W)₁-W₂)/W₀

(W₀: initial adhesive composition weight, W₁: weight of dried adhesive composition including Metal Screen, W₂: initial weight of Metal Screen mesh)

In the present invention, the gel swell ratio and the gel fraction are measured by the above-described methods even when an inorganic compound such as an inorganic filler is contained in the adhesive composition.

The gel swell ratio of the crosslinked adhesive polymer is preferably 500% or more.

When the gel swelling ratio of the crosslinked adhesive polymer is in the above range, the adhesive layer containing the adhesive composition can exhibit high adhesive force and prevent adhesive residue. From the viewpoint of achieving both high adhesion and reduced residual gum, the gel swell ratio is more preferably 550% at the lower limit, still more preferably 580% at the lower limit, particularly preferably 600% at the lower limit, particularly preferably 650% at the lower limit, and very preferably 700% at the lower limit. The upper limit of the gel swelling ratio is not particularly limited, but is preferably 2000% (e.g., about 2000%), and more preferably 1500% (e.g., about 1500%).

When the pressure-sensitive adhesive composition according to an embodiment of the present invention is used in the form of a pressure-sensitive adhesive tape, the gel swell ratio of the crosslinked pressure-sensitive adhesive polymer can be measured by the same method as the gel swell ratio of the pressure-sensitive adhesive composition.

The gel fraction of the crosslinked adhesive polymer is preferably 87% or more.

When the gel fraction of the crosslinked adhesive polymer is 87% or more, the adhesive layer containing the adhesive composition can exhibit high adhesive force and prevent adhesive residue. From the viewpoint of achieving both high adhesion and reduced residual gum, the lower limit of the gel fraction is preferably 88%, more preferably 88.5%, particularly preferably 89%, and particularly preferably 90%. The upper limit of the gel fraction is not particularly limited, but is preferably 100%, and more preferably about 99%. When the pressure-sensitive adhesive composition according to one embodiment of the present invention is used in the form of a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition, the gel fraction of the crosslinked pressure-sensitive adhesive polymer can be measured by the same method as the gel fraction of the pressure-sensitive adhesive composition.

The lower limit of the vertical peeling force of the pressure-sensitive adhesive composition according to one embodiment of the present invention measured by a tack tester is preferably 12N/cm²The upper limit is preferably 42N/cm²。

By adjusting the vertical peeling force to be within this range, when the pressure-sensitive adhesive composition is attached to a surface of a semiconductor device on which bumps are formed, excellent adhesive force of the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition, which can sufficiently protect the surface, and excellent peeling property, which can suppress adhesive residue during peeling, can be both satisfied. If the above-mentioned vertical peeling force is 12N/cm²As described above, the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition is more difficult to peel from the adherend, and the vertical peel force is 42N/cm²In the following, the pressure-sensitive adhesive tape including the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition is easily peeled off after no longer requiring the pressure-sensitive adhesive tape, and the adhesive residue is further suppressed. From the viewpoint of suppressing peeling from an adherend, a more preferable lower limit of the vertical peeling force is 13N/cm²More preferably, the lower limit is 14N/cm²Particularly preferred lower limit is 15N/cm². Further, from the viewpoint of easy peelability at the time of peeling from the semiconductor device and suppression of adhesive residue, the upper limit is more preferably 40N/cm²More preferably, the upper limit is 38N/cm²Particularly preferred upper limit is 35N/cm²。

In the present specification, the vertical peel force with respect to the adhesive composition means: a peel force when the SUS probe was pressed to the adhesive layer including the adhesive composition and peeled in a vertical direction using a tack tester. The method specifically comprises the following steps: an SUS probe having a probe diameter of 5.8mm and a tip R2.9 was processed at a height of 10000gf/cm from the vertical direction²After pressing an adhesive layer (thickness: 40 μm) containing the adhesive composition for 1 second, the load was 0.8 in the vertical directionPeeling force at speed of m/s. As the adhesion tester, for example, an adhesion tester TA-500 manufactured by UBM corporation can be used.

The lower limit of the elongation at break of the adhesive composition according to one embodiment of the present invention, which is measured using a sample having a thickness of 350 μm, a width of 5mm and a length of 50mm, is preferably 600% and the upper limit thereof is preferably 1400%. When the elongation at break is 600% or more, the pressure-sensitive adhesive composition is less likely to become brittle, and chipping of the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition during peeling is suppressed, and the adhesive residue is suppressed. When the elongation at break is 1400% or less, the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition that is excessively stretched at the time of peeling is inhibited from being chipped, and the adhesive residue can be inhibited. When the elongation at break is adjusted to be within the above range, excellent peelability can be exhibited in which the adhesive residue during peeling is suppressed when the adhesive is stuck to the surface of the semiconductor device on which the bumps are formed. From the viewpoint of further suppressing the residual gum, the lower limit of the elongation at break is more preferably 630%, the upper limit is more preferably 1300%, the lower limit is more preferably 650%, the upper limit is more preferably 1250%, the lower limit is particularly preferably 700%, and the upper limit is particularly preferably 1200%.

In the present specification, the elongation at break means: elongation at break was measured as the elongation at break at which the sample was broken by performing a tensile test at a speed of 300mm/min on a test piece having a thickness of 350 μm and a width of 5mm while setting the distance between chucks of the sample to 50mm using a tensile tester. For example, in the case of elongation at break of 500mm, when a sample of 50mm is elongated to 500mm, the elongation at break is 1000%.

The molecular weight distribution Mw/Mn of the binder polymer is preferably 4.1 or less.

By setting the molecular weight distribution of the adhesive polymer to 4.1 or less, the gel swell ratio and gel fraction of the adhesive composition and the crosslinked adhesive polymer can be easily adjusted to the above ranges. The upper limit of the molecular weight distribution is more preferably 3.5, still more preferably 3, and particularly preferably 2.5. The lower limit of the molecular weight distribution is not particularly limited, but is preferably 1.1, more preferably 1.2, and still more preferably about 1.3.

The molecular weight distribution (Mw/Mn) is the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn).

The weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured as molecular weights in terms of polystyrene by a Gel Permeation Chromatography (GPC) method. Specifically, the weight average molecular weight (Mw) and the number average molecular weight (Mn) were determined as follows: the adhesive polymer was diluted 50-fold with Tetrahydrofuran (THF), the thus-obtained diluted solution was filtered with a filter, and the obtained filtrate was used to measure the molecular weight as polystyrene by GPC. For example, 2690Separations Model (manufactured by Waters corporation) or the like can be used in the GPC method.

The weight average molecular weight of the binder polymer is preferably 30 ten thousand or more.

By making the weight average molecular weight of the binder polymer 30 ten thousand or more, an adhesive composition having more excellent adhesive force can be obtained. The lower limit of the weight average molecular weight is more preferably 35 ten thousand, still more preferably 40 ten thousand, and particularly preferably 45 ten thousand. The upper limit of the weight average molecular weight of the binder polymer is not particularly limited, and is, for example, 500 ten thousand or less, preferably 300 ten thousand or less, and more preferably 150 ten thousand or less.

The method for producing the adhesive polymer is not particularly limited, and can be obtained by various methods such as living radical polymerization, emulsion polymerization, suspension polymerization, coordination polymerization, and UV polymerization. In addition, in a preferred embodiment of the present invention, the adhesive polymer is produced by combining living radical polymerization and dropwise polymerization, and therefore, the uniformity of each monomer in the adhesive polymer chain can be improved, and therefore, the crosslinking uniformity of the crosslinked adhesive polymer can be improved, and the gel swelling ratio can be easily controlled to the above range. In one embodiment of the present invention, the binder polymer is preferably an acrylic polymer, and is preferably a binder polymer obtained by living radical polymerization or a combination of living radical polymerization and dropwise polymerization. The acrylic polymer is a polymer composed of a (meth) acrylic monomer. Further, the binder polymer preferably has a crosslinkable functional group, and more preferably contains an acrylic polymer having a crosslinkable functional group obtained by living radical polymerization (particularly, a combination of living radical polymerization and dropwise polymerization) (hereinafter, also simply referred to as "living radical polymerization acrylic polymer").

By using an adhesive polymer having a crosslinkable functional group (particularly, a living radical polymerization acrylic polymer) as the adhesive polymer, the gel swell ratio and gel fraction of the adhesive composition and the crosslinked adhesive polymer can be easily adjusted to the above ranges. The living radical polymerization acrylic polymer is obtained by living radical polymerization, preferably living radical polymerization using an organotellurium polymerization initiator, using an acrylic monomer such as (meth) acrylate or (meth) acrylic acid as a raw material. Living radical polymerization is polymerization in which a molecular chain gradually grows and a polymerization reaction is not hindered by side reactions such as a termination reaction and a chain transfer reaction. According to living radical polymerization, a polymer having a more uniform molecular weight and composition can be obtained as compared with, for example, free radical polymerization or the like, and generation of low molecular weight components or the like can be suppressed, and therefore, the pressure-sensitive adhesive layer including the pressure-sensitive adhesive composition becomes less likely to peel even at high temperatures.

In the living radical polymerization, various polymerization methods can be employed. For example, iron, ruthenium, copper catalysts, and halogen-based initiators (ATRP), TEMPO, and organic tellurium polymerization initiators may be used. Among them, organic tellurium polymerization initiators are preferably used. In contrast to other living radical polymerizations: living radical polymerization using an organotellurium polymerization initiator enables polymerization with the same initiator without protecting all radical polymerizable monomers having a polar functional group such as a hydroxyl group or a carboxyl group, and a polymer having a uniform molecular weight and composition to be obtained. Therefore, the radical polymerizable monomer having a polar functional group can be easily copolymerized.

The organic tellurium polymerization initiator is not particularly limited as long as it is a polymerization initiator generally used for living radical polymerization, and examples thereof include organic tellurium compounds, organic telluride compounds and the like.

Examples of the organic tellurium compound include (methylhydrotelluro-methyl) benzene, (1-methylhydrotelluro-ethyl) benzene, (2-methylhydrotelluro-propyl) benzene, 1-chloro-4- (methylhydrotelluro-methyl) benzene, 1-hydroxy-4- (methylhydrotelluro-methyl) benzene, 1-methoxy-4- (methylhydrotelluro-methyl) benzene, 1-amino-4- (methylhydrotelluro-methyl) benzene, 1-nitro-4- (methylhydrotelluro-methyl) benzene, 1-cyano-4- (methylhydrotelluro-methyl) benzene, 1-methylcarbonyl-4- (methylhydrotelluro-methyl) benzene, and, 1-phenylcarbonyl-4- (methylhydrotelluro-methyl) benzene, 1-methoxycarbonyl-4- (methylhydrotelluro-methyl) benzene, 1-phenoxycarbonyl-4- (methylhydrotelluro-methyl) benzene, 1-sulfonyl-4- (methylhydrotelluro-methyl) benzene, 1-trifluoromethyl-4- (methylhydrotelluro-methyl) benzene, 1-chloro-4- (1-methylhydrotelluro-ethyl) benzene, 1-hydroxy-4- (1-methylhydrotelluro-ethyl) benzene, 1-methoxy-4- (1-methylhydrotelluro-ethyl) benzene, 1-amino-4- (1-methylhydrotelluro-ethyl) benzene, methyl-4- (1-methylhydrogen telluro, 1-nitro-4- (1-methylhydrotelluro-ethyl) benzene, 1-cyano-4- (1-methylhydrotelluro-ethyl) benzene, 1-methylcarbonyl-4- (1-methylhydrotelluro-ethyl) benzene, 1-phenylcarbonyl-4- (1-methylhydrotelluro-ethyl) benzene, 1-methoxycarbonyl-4- (1-methylhydrotelluro-ethyl) benzene, 1-phenoxycarbonyl-4- (1-methylhydrotelluro-ethyl) benzene, 1-sulfonyl-4- (1-methylhydrotelluro-ethyl) benzene, 1-trifluoromethyl-4- (1-methylhydrotelluro-ethyl) benzene, 1-chloro-4- (2-methylhydrotelluro-propyl) benzene, 1-hydroxy-4- (2-methylhydrotelluro-propyl) benzene, 1-methoxy-4- (2-methylhydrotelluro-propyl) benzene, 1-amino-4- (2-methylhydrotelluro-propyl) benzene, 1-nitro-4- (2-methylhydrotelluro-propyl) benzene, 1-cyano-4- (2-methylhydrotelluro-propyl) benzene, 1-methylcarbonyl-4- (2-methylhydrotelluro-propyl) benzene, 1-phenylcarbonyl-4- (2-methylhydrotelluro-propyl) benzene, 1-methoxycarbonyl-4- (2-methylhydrotelluro-propyl) benzene, 1-methyloxycarbonyl-4- (2-methylhydrotelluro-propyl) benzene, 1-phenoxycarbonyl-4- (2-methylhydrotelluro-propyl) benzene, 1-sulfonyl-4- (2-methylhydrotelluro-propyl) benzene, 1-trifluoromethyl-4- (2-methylhydrotelluro-propyl) benzene, 2- (methylhydrotelluro-methyl) pyridine, 2- (1-methylhydrotelluro-ethyl) pyridine, 2- (2-methylhydrotelluro-propyl) pyridine, 2-methylhydrotelluro-methyl acetate, 2-methylhydrotelluro-methyl propionate, 2-methylhydrotelluro-methyl-2-methylpropionate, 2-methylhydrotelluro-ethyl acetate, 2-methylhydrotelluro-ethyl propionate, 2-methylhydrotelluro-ethyl 2-methylpropionate, ethyl 2-methylhydrotelluro-2-methylpropionate, 2-methylhydrotelluroacetonitrile, 2-methylhydrotelluropropionitrile, 2-methyl-2-methylhydrotelluropropionitrile, etc. The methyl hydrogen tellurium group in these organic tellurium compounds may be an ethyl hydrogen tellurium group, an n-propyl hydrogen tellurium group, an isopropyl hydrogen tellurium group, an n-butyl hydrogen tellurium group, an isobutyl hydrogen tellurium group, a tert-butyl hydrogen tellurium group, a phenyl hydrogen tellurium group or the like, and these organic tellurium compounds may be used alone or in combination of two or more.

Examples of the organic telluride compound include dimethyl ditelluride, diethyl ditelluride, di-n-propyl ditelluride, diisopropyl ditelluride, dicyclopropyl ditelluride, di-n-butyl ditelluride, di-sec-butyl ditelluride, di-tert-butyl ditelluride, dicyclobutyl ditelluride, diphenyl ditelluride, bis (p-methoxyphenyl) ditelluride, bis (p-aminophenyl) ditelluride, bis (p-nitrophenyl) ditelluride, bis (p-cyanophenyl) ditelluride, bis (p-sulfonylphenyl) ditelluride, dinaphthyl ditelluride, and bipyridyl ditelluride. These organic telluride compounds may be used alone, or two or more thereof may be used in combination. Among them, dimethyl ditelluride, diethyl ditelluride, di-n-propyl ditelluride, di-n-butyl ditelluride, and diphenyl ditelluride are preferable.

In addition to the above-mentioned organotellurium polymerization initiator, an azo compound as a polymerization initiator may be used for the purpose of accelerating the polymerization rate within the range not to impair the effects of the present invention.

The azo compound is not particularly limited as long as it is an azo compound generally used for radical polymerization, and examples thereof include 2, 2 ' -azobis (isobutyronitrile), 2 ' -azobis (2-methylbutyronitrile), 2 ' -azobis (2, 4-dimethylvaleronitrile), 2 ' -azobis (4-methoxy-2, 4-dimethylvaleronitrile), 1-azobis (cyclohexane-1-carbonitrile), 1- [ (1-cyano-1-methylethyl) azo ] formamide, 4 ' -azobis (4-cyanopentanoic acid), dimethyl-2, 2 ' -azobis (2-methylpropionate), dimethyl-1, 1 ' -azobis (1-cyclohexanecarboxylate), and the like, 2, 2 '-azobis { 2-methyl-N- [1, 1' -bis (hydroxymethyl) -2-hydroxyethyl ] propionamide }, 2 '-azobis [ 2-methyl-N- (2-hydroxyethyl) propionamide ], 2' -azobis [ N- (2-propenyl) -2-methylpropionamide ], 2 '-azobis (N-butyl-2-methylpropionamide), 2' -azobis (N-cyclohexyl-2-methylpropionamide), 2 '-azobis [2- (2-imidazolin-2-yl) propane ] dihydrochloride, 2' -azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl ] propane } di-hydrochloride Hydrochloride, 2 ' -azobis [2- (2-imidazolin-2-yl) propane ], 2 ' -azobis (2-amidinopropane) dihydrochloride, 2 ' -azobis [ N- (2-carboxyethyl) -2-methylpropionamidine ] tetrahydrate, 2 ' -azobis (1-imino-1-pyrrolidinyl-2-methylpropane) dihydrochloride, 2 ' -azobis (2, 4, 4-trimethylpentane), and the like. These azo compounds may be used alone, or two or more of them may be used in combination.

When the binder polymer contains a crosslinkable functional group, a monomer having a crosslinkable functional group is blended as a monomer to be polymerized.

Examples of the crosslinkable functional group include a hydroxyl group, a carboxyl group, a glycidyl group, an amino group, an amide group, and a nitrile group. Among these, from the viewpoint of easy adjustment of the gel fraction of the pressure-sensitive adhesive composition and the crosslinked pressure-sensitive adhesive polymer, a hydroxyl group or a carboxyl group is preferable, and a hydroxyl group is more preferable.

When the binder polymer is a living radical polymerization acrylic polymer, examples of the monomer having a hydroxyl group include (meth) acrylates having a hydroxyl group such as 4-hydroxybutyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate.

Examples of the monomer having a carboxyl group include (meth) acrylic acid.

Examples of the monomer having a glycidyl group include glycidyl (meth) acrylate.

Examples of the monomer having an amide group include hydroxyethyl acrylamide, isopropyl acrylamide, and dimethylaminopropyl acrylamide.

Examples of the monomer having a nitrile group include acrylonitrile.

When the (meth) acrylate having a hydroxyl group is used, the content thereof is not particularly limited, and the preferable upper limit of the content of the radically polymerizable monomer that is polymerized in the living radical polymerization is 30% by weight. If the content is 30% by weight or less, the gel fraction of the pressure-sensitive adhesive composition and the crosslinked pressure-sensitive adhesive polymer is not excessively high, and peeling of the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition is suppressed, whereby the heat-resistant adhesion can be improved.

When the acrylic monomer having a carboxyl group is used, the content thereof is not particularly limited, and the lower limit of the content of the radical polymerizable monomer to be polymerized in the living radical polymerization is preferably 0.1% by weight, and the upper limit thereof is preferably 10% by weight. When the content is 0.1% by weight or more, the crosslinked adhesive polymer does not become too soft, and a decrease in heat-resistant adhesion can be suppressed. When the content is 10% by weight or less, the crosslinked adhesive polymer does not become too hard, and peeling of the adhesive layer containing the adhesive composition can be suppressed.

As the acrylic monomer to be polymerized in the living radical polymerization, other radical polymerizable monomers than the acrylic monomer having a crosslinkable functional group can be used. Examples of the other radically polymerizable monomers include other (meth) acrylic acid esters. Further, acrylic monomers having other polar functional groups such as amino groups, amide groups, and nitrile groups may also be used. Further, a vinyl compound may be used as a monomer in addition to the above-mentioned acrylic monomer.

The other (meth) acrylic acid esters are not particularly limited, and examples thereof include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isomyristyl (meth) acrylate, and stearyl (meth) acrylate; cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, polypropylene glycol mono (meth) acrylate, and the like. These (meth) acrylates may be used alone or in combination of two or more.

The vinyl compound is not particularly limited, and examples thereof include (meth) acrylamide compounds such as N, N-dimethylacrylamide, N-diethylacrylamide, N-isopropylacrylamide, N-hydroxyethylacrylamide, and acrylamide; n-vinyl pyrrolidone, N-vinyl caprolactam, N-vinyl acetamide, N-acryloyl morpholine, acrylonitrile, styrene, vinyl acetate, and the like. These vinyl compounds may be used alone or in combination of two or more.

When the acrylic monomer to be polymerized in the living radical polymerization contains (meth) acrylic acid, the amount of (meth) acrylic acid in 100 parts by weight of all the monomers is preferably 0.1 part by weight or more, more preferably 0.5 part by weight or more, from the viewpoint of improving the adhesive force and uniformizing the crosslinking point of the crosslinked adhesive polymer. The amount of (meth) acrylic acid in 100 parts by weight of the total monomers is preferably 15 parts by weight or less, more preferably 10 parts by weight or less.

In the living radical polymerization, a dispersion stabilizer may be used. Examples of the dispersion stabilizer include polyvinylpyrrolidone, polyvinyl alcohol, methyl cellulose, ethyl cellulose, poly (meth) acrylic acid, poly (meth) acrylate, and polyethylene glycol.

As the living radical polymerization method, conventionally known methods can be used, and examples thereof include solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, and bulk polymerization.

When a polymerization solvent is used in the living radical polymerization, the polymerization solvent is not particularly limited. As the polymerization solvent, for example, a nonpolar solvent such as hexane, cyclohexane, octane, toluene, xylene, etc.; water, methanol, ethanol, propanol, butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dioxane, N-dimethylformamide and the like. These polymerization solvents may be used alone, or two or more of them may be used in combination.

In addition, from the viewpoint of polymerization rate, the polymerization temperature is preferably 0 to 110 ℃.

The crosslinking agent is not particularly limited, and a crosslinking agent capable of crosslinking the crosslinking agent is appropriately selected depending on the crosslinking group.

Examples of the crosslinking agent include isocyanate crosslinking agents, aziridine crosslinking agents, epoxy crosslinking agents, and metal chelate crosslinking agents. Among them, an isocyanate-based crosslinking agent and an epoxy-based crosslinking agent are preferable in order to have excellent adhesion stability to a base material. The crosslinking agents may be used alone or in combination of two or more. In a preferred embodiment of the present invention, when (meth) acrylic acid is used as a monomer constituting the adhesive polymer, an epoxy-based crosslinking agent is preferable from the viewpoint of easy formation of a uniform network of the crosslinked adhesive polymer and easy control of the gel swelling ratio.

Examples of the isocyanate crosslinking agent include COLONATE HX (manufactured by Nippon polyurethane industries Co., Ltd.), COLONATE L (manufactured by Nippon polyurethane industries Co., Ltd.), MYTEC NY260A (manufactured by Mitsubishi chemical Co., Ltd.). Examples of the epoxy crosslinking agent include E-5XM (manufactured by Soken chemical Co., Ltd.) and E-AX (manufactured by Soken chemical Co., Ltd.).

The amount of the crosslinking agent is preferably 0.01 part by weight in the lower limit and 5 parts by weight in the upper limit, based on 100 parts by weight of the binder polymer (for example, a living radical polymerization acrylic polymer).

The gel swell ratio and gel fraction of the pressure-sensitive adhesive composition and the crosslinked pressure-sensitive adhesive polymer can be adjusted by appropriately adjusting the kind or amount of the crosslinking agent.

The adhesive composition according to one embodiment of the present invention preferably contains an exudation agent.

By containing the bleeding agent, the bleeding agent bleeds out to the surface of the adhesive layer containing the adhesive composition, and peeling from the semiconductor device can be easily performed. The bleeding agent is not particularly limited, and a known bleeding agent used for a binder can be used. Among them, silicone-based bleeding agents are preferable from the viewpoint of high heat resistance. In particular, when the binder polymer is the living radical polymerization acrylic polymer, a bleeding agent having an acrylic site is preferably used from the viewpoint of high compatibility with the crosslinked binder polymer.

In the case where the pressure-sensitive adhesive composition according to one embodiment of the present invention contains a bleeding agent, the lower limit of the content of the bleeding agent is preferably 0 part by weight and the upper limit thereof is preferably 10 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive polymer (for example, a living radical polymerization acrylic polymer) from the viewpoint of controlling the adhesive strength. The content of the bleeding agent is more preferably 0.1 part by weight in the lower limit, more preferably 5 parts by weight in the upper limit, particularly preferably 0.3 part by weight in the lower limit, and particularly preferably 2 parts by weight in the upper limit.

The adhesive composition as one embodiment of the present invention may contain an inorganic filler.

Examples of the inorganic filler include hydroxides and oxides of metals such as aluminum hydroxide, magnesium hydroxide, calcium oxide, magnesium oxide, aluminum oxide, zinc oxide, titanium oxide, and antimony oxide; metal powders such as zinc; carbonates of metals such as calcium carbonate, magnesium carbonate, barium carbonate, and zinc carbonate; alkali metal bicarbonates such as sodium bicarbonate and potassium bicarbonate; alkaline earth metal hydrogen carbonates such as calcium hydrogen carbonate and magnesium hydrogen carbonate; calcium sulfate, barium sulfate, calcium silicate, mica, talc, bentonite, zeolite, silica gel, and the like. Among them, when a strong acid is used as the acid catalyst, it is necessary to add a metal powder or a carbonate within a range not affecting the adjustment of the effective period. These inorganic fillers may be used alone in 1 kind, or two or more kinds may be used in combination.

In the case where the adhesive composition according to one embodiment of the present invention contains an inorganic filler, the content of the inorganic filler is preferably 0 part by weight at the lower limit, more preferably 20 parts by weight at the upper limit, even more preferably 3 parts by weight at the lower limit, and even more preferably 15 parts by weight at the upper limit, based on 100 parts by weight of the adhesive polymer (for example, a living radical polymerization acrylic polymer), from the viewpoint of controlling the elastic modulus.

The adhesive composition according to one embodiment of the present invention is not particularly limited in its application, and is particularly suitable for use in applications where it is protected by being attached to a surface of a semiconductor device on which bumps are formed, from the viewpoint of excellent adhesive performance and adhesive residue suppression performance.

An adhesive tape can be manufactured using the adhesive composition as one embodiment of the present invention.

An adhesive tape having an adhesive layer containing such an adhesive composition as one embodiment of the present invention is also one of the present invention.

The pressure-sensitive adhesive tape may be a supporting tape having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition on one or both sides of a substrate, or may be an unsupported tape having no substrate.

When the pressure-sensitive adhesive tape is a support tape, examples of the substrate include a sheet, a sheet having a mesh structure, a sheet having openings, and the like, which are made of a transparent resin such as acrylic, olefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, urethane, polyimide, or the like.

The thickness of the substrate is not particularly limited, but preferably has a lower limit of 25 μm, more preferably a lower limit of 50 μm, and preferably an upper limit of 250 μm, more preferably an upper limit of 125 μm. By setting the base layer in this range, handling properties are excellent, and the pressure-sensitive adhesive tape can be easily processed into a roll.

The base material may contain additives such as antistatic agents, mold release agents, antioxidants, weather-resistant agents, crystal nucleating agents, and the like; and resin modifiers such as polyolefins, polyesters, polyamides, and elastomers.

The vertical peeling force of the adhesive tape measured by a viscosity measuring machine is preferably 12-42N/cm²。

When the vertical peeling force of the pressure-sensitive adhesive tape is in the above range, when the pressure-sensitive adhesive tape is attached to a surface of a semiconductor device on which bumps are formed, both excellent adhesive force of the pressure-sensitive adhesive layer that can sufficiently protect the surface and excellent peeling property that can suppress adhesive residue during peeling can be satisfied. In the present specification, the vertical peeling force of the adhesive tape means: using a tack tester, the peel force at which the SUS probe was pressed to the adhesive layer of the adhesive tape and peeled in the vertical direction. The method specifically comprises the following steps: an SUS probe having a probe diameter of 5.8mm and a tip R2.9 was processed at a height of 10000gf/cm from the vertical direction²The pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape was pressed for 1 second and then peeled off at a speed of 0.8m/s in the vertical direction. As the adhesion tester, for example, an adhesion tester TA-500 manufactured by UBM corporation can be used.

The vertical peeling force of the adhesive composition was measured by molding the adhesive composition into an adhesive layer having a thickness of 40 μm, but the vertical peeling force of the adhesive tape was measured directly regardless of the thickness of the adhesive layer of the adhesive tape.

The thickness of the pressure-sensitive adhesive layer is preferably 5 μm or more, more preferably 10 μm or more, further preferably 15 μm or more, and particularly preferably 20 μm or more, from the viewpoint of sufficiently protecting the bumps of the semiconductor device. From the viewpoint of suppressing blocking in the roll form of the pressure-sensitive adhesive tape, the thickness of the pressure-sensitive adhesive layer is preferably 500 μm or less, more preferably 300 μm or less, still more preferably 200 μm or less, particularly preferably 150 μm or less, particularly preferably 100 μm or less, and very preferably 75 μm or less.

The method for producing the pressure-sensitive adhesive tape is not particularly limited, and examples thereof include a method in which a pressure-sensitive adhesive solution containing a pressure-sensitive adhesive composition is applied to a PET film subjected to mold release treatment, and then dried to form a pressure-sensitive adhesive layer, and the obtained pressure-sensitive adhesive layer is transferred to one surface or both surfaces of a substrate. Further, a method of directly applying a binder solution to the substrate and then drying the substrate may be mentioned. The adhesive solution may be applied to a PET film subjected to mold release treatment, and then dried, and the adhesive layer formed thereby may be directly formed into a double-sided adhesive tape of the unsupported type without a substrate.

The adhesive tape may be subjected to UV treatment in advance.

The pre-UV treatment refers to: and (3) irradiating the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape with ultraviolet rays before or after the pressure-sensitive adhesive tape is attached to an adherend. By performing the UV treatment in advance, various physical properties of the pressure-sensitive adhesive tape can be adjusted, and for example, the elongation at break can be controlled.

The pre-UV treatment can be specifically performed by, for example, using a UV lamp at an illuminance of 10 to 100mW/cm²The cumulative dose of irradiation was 3000mJ/cm²Irradiating the adhesive layer of the adhesive tape with ultraviolet rays having a wavelength of 300 to 450 nm. As the UV lamp, for example, a high-pressure mercury lamp or the like can be used.

In one embodiment of the present invention, the adhesive composition and the adhesive tape can be used for protection by being attached to a surface of a semiconductor device on which a bump is formed.

A method for protecting a semiconductor device, which comprises a step of applying an adhesive composition to a surface of a semiconductor device on which bumps are formed or a step of attaching an adhesive tape to the surface of the semiconductor device on which bumps are formed, wherein the adhesive tape has an adhesive layer containing the adhesive composition, the adhesive composition contains a crosslinked adhesive polymer composed of an adhesive polymer and a crosslinking agent, the adhesive composition has a gel swell ratio of 500% or more and a gel fraction of 87% or more. According to this method of use, the adhesive tape has high adhesive force and can suppress adhesive residue during peeling.

The semiconductor device is not particularly limited as long as it has a bump. Among them, the pressure-sensitive adhesive composition and the pressure-sensitive adhesive tape of the present invention are excellent in adhesion and residual glue suppression, and therefore, exhibit a particularly high effect in protecting a semiconductor device having a high protrusion with a height of the protrusion of about 100 to 200 μm.

Examples of the adhesive tape include an adhesive tape in which a surface of a semiconductor device on which a bump is formed is directly coated with an adhesive composition according to an embodiment of the present invention to form an adhesive layer; unsupported adhesive tapes comprising an adhesive layer comprising the above adhesive composition; a support tape having an adhesive layer containing the adhesive composition on one surface of a substrate. The attaching may further include the act of directly applying the adhesive composition to form an adhesive layer.

In the case where the surface of the semiconductor device on which the bumps are formed is protected by the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition according to one embodiment of the present invention, the thickness of the pressure-sensitive adhesive layer is preferably 70% or less with respect to the height of the bumps of the semiconductor device, from the viewpoint of further suppressing adhesive residue. Note that the thickness of the adhesive layer is generally greater than 0% with respect to the bump height of the semiconductor device.

Fig. 1 is a cross-sectional view schematically showing a state in which a surface of a semiconductor device on which a bump is formed is protected by an adhesive tape having an adhesive layer containing an adhesive composition according to an embodiment of the present invention. The semiconductor device 1 has a bump 12 formed on one surface thereof, and is protected by attaching a support tape, which has an adhesive layer 2 containing the adhesive composition laminated on one surface of a substrate 3, to the surface on the side of the bump 12. The support plate 5 is attached to the surface of the semiconductor device 1 on which the bumps 12 are not formed via the layer 4 containing the adhesive composition for preliminary fixing, thereby protecting the surface side.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide an adhesive composition having high adhesive force and capable of being peeled while suppressing adhesive residue, an adhesive tape having an adhesive layer containing the adhesive composition, and a method for protecting a semiconductor device using the adhesive composition or the adhesive tape.

Drawings

Fig. 1 is a sectional view schematically showing a state in which a surface of a semiconductor device on which a bump is formed is protected by an adhesive tape having an adhesive layer containing an adhesive composition as one embodiment of the present invention.

FIG. 2 is an overall view and a sectional view of a SUS420 jig A used in the heat resistance evaluation of the example.

Detailed Description

The mode of the present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

(Synthesis of resin A)

6.38g (50mmol) of Tellurium (40mesh, metallic Tellurium, manufactured by ALDRICH Co., Ltd.) was suspended in 50mL of Tetrahydrofuran (THF), and 34.4mL (55mmol) of a 1.6mol/L n-butyllithium/hexane solution (manufactured by ALDRICH Co., Ltd.) was slowly added dropwise thereto at room temperature. The reaction solution was stirred until the metallic tellurium disappeared completely. To the reaction solution was added 10.7g (55mmol) of ethyl-2-bromoisobutyrate at room temperature, and the mixture was stirred for 2 hours. After the reaction was completed, the solvent was concentrated under reduced pressure, followed by distillation under reduced pressure to obtain 2-methyl-2-n-butylhydrotelluro-propionic acid ethyl ester as a yellow oil.

Into a glove box replaced with argon, 0.026mL of the obtained 2-methyl-2-n-butylhydrogentelluro-ethyl propionate, 0.007g of V-60(2, 2' -azobisisobutyronitrile, Wako pure chemical industries, Ltd.), and 1mL of ethyl acetate were charged, and then the reaction vessel was closed and taken out from the glove box. Then, 50g of ethyl acetate as a polymerization solvent was introduced into the reaction vessel while flowing argon gas into the reaction vessel, and the temperature was set at 60 ℃. Thereafter, a mixture of 100g of the mixed monomers shown in Table 1 in total and 50g of ethyl acetate as a polymerization solvent was added dropwise at a rate of 0.5 g/min, and polymerization was carried out at 60 ℃ for 20 hours to obtain a solution containing a living radical polymerized resin A (adhesive polymer).

Next, the resulting solution containing the binding polymer was diluted to 50 times with Tetrahydrofuran (THF). The obtained diluted solution was filtered with a filter, and the filtrate was subjected to gel permeation chromatography, GPC measurement was performed under conditions of a sample flow rate of 1 ml/min and a column temperature of 40 ℃, and the polystyrene-equivalent molecular weight of the polymer was measured to obtain a weight average molecular weight (Mw) and a molecular weight distribution (Mw/Mn). The gel permeation chromatography used a 2690 separationmodel manufactured by Waters. The filter used was a polytetrafluoroethylene filter having a pore size of 0.2. mu.m. GPC KF-806L (manufactured by SHOWA DENKO K.K.) was used as a column, and a differential refractometer was used as a detector.

(Synthesis of resins B to E)

The amounts of 2-methyl-2-n-butylhydrotelluro-propionic acid ethyl, V-60(2, 2' -azobisisobutyronitrile, Wako pure chemical industries, Ltd.) and the composition of the mixed monomers were changed as shown in Table 1. In the same manner as in the synthesis of the resin a, other points were obtained as solutions containing the resins B to E (binder polymer), and the weight average molecular weight (Mw) and the molecular weight distribution (Mw/Mn) were determined.

(Synthesis of resin F)

A reactor equipped with a thermometer, a stirrer, and a cooling tube was prepared, and 85 parts by weight of 2-ethylhexyl acrylate as an alkyl (meth) acrylate, 10 parts by weight of hydroxyethyl methacrylate as a functional group-containing monomer, 5 parts by weight of acrylic acid, 0.01 part by weight of lauryl mercaptan, and 80 parts by weight of ethyl acetate were added to the reactor. The reactor was heated to initiate reflux. Then, 0.01 part by weight of 1, 1-bis (t-hexylperoxy) -3, 3, 5-trimethylcyclohexane as a polymerization initiator was added to the reactor, and polymerization was started under reflux. Then, 1-bis (t-hexylperoxy) -3, 3, 5-trimethylcyclohexane was added in an amount of 0.01 part by weight each 1 hour and 2 hours after the start of the polymerization, and tert-hexyl peroxypivalate was added in an amount of 0.05 part by weight 4 hours after the start of the polymerization to continue the polymerization reaction. Then, an ethyl acetate solution of the adhesive polymer was obtained after 8 hours from the start of the polymerization. The weight average molecular weight (Mw) and the molecular weight distribution (Mw/Mn) were determined in the same manner as in the synthesis of resin A, and as a result, Mw was 59.3 ten thousand and Mw/Mn was 8.2.

(example 1)

(1) Adhesive composition and production of adhesive tape

To the obtained solution containing the resin a, ethyl acetate was added and stirred relative to 100 parts by weight of nonvolatile components thereof, and a bleeding agent and an epoxy-based crosslinking agent were added and stirred in the kinds and amounts shown in table 2, to obtain an ethyl acetate solution of an adhesive composition containing a crosslinked adhesive polymer (hereinafter, simply referred to as an adhesive composition) having 30% by weight of nonvolatile components.

The ethyl acetate solution of the obtained adhesive composition was applied with a doctor blade to a corona-treated surface of a transparent polyethylene naphthalate film having a thickness of 50 μm, one surface of which was subjected to corona treatment, so that the thickness of a dry film became 40 μm, and the applied solution was dried by heating at 110 ℃ for 5 minutes. Thereafter, the adhesive tape was left to stand and cured at 40 ℃ for 3 days.

As the epoxy crosslinking agent, E-5XM available from Soken chemical Co. EBECRYL350 manufactured by DAICEL ALLNEX was used as a bleeding agent. MT-10 manufactured by TOKUYAMA was used as the inorganic filler.

(2) Measurement of gel swelling ratio

From the obtained adhesive tape, only 0.1g of the adhesive composition was scraped off, and the adhesive composition was immersed in 50ml of ethyl acetate and shaken by a shaker at a temperature of 23 ℃ and 200rpm for 24 hours. After shaking, the mixture was separated into ethyl acetate and an adhesive composition swollen by absorbing ethyl acetate using a metal mesh (mesh # 200). The weight of the adhesive composition swollen by absorbing ethyl acetate, including the metal mesh, was measured, and it was dried at 110 ℃ for 1 hour. The weight of the dried adhesive composition including the metal mesh was measured, and the gel swell ratio was calculated by using the following formula. The results are shown in Table 2.

Gel swelling ratio (%) - (V)₁-V₂)/(V₃-V₂))×100

(3) Determination of gel fraction

From the obtained adhesive tape, only 0.1g of the adhesive composition was scraped off, and the adhesive composition was immersed in 50ml of ethyl acetate and shaken by a shaker at a temperature of 23 ℃ and 200rpm for 24 hours. After shaking, the mixture was separated into ethyl acetate and an adhesive composition which had absorbed and swelled ethyl acetate, using a metal mesh (mesh #200 mesh). The separated adhesive composition was dried at 110 ℃ for 1 hour. The weight of the dried adhesive composition including the metal mesh was measured, and the gel fraction was calculated by using the following formula. The results are shown in Table 2.

Gel fraction (wt%) < 100 × (W)₁-W₂)/W₀

(4) Measurement of vertical peeling force

With respect to the adhesive layer of the obtained adhesive tape, a SUS probe processed to have a probe diameter of 5.8mm and a tip R2.9 was measured at 10000gf/cm from the vertical direction using a tack tester²The pressure-sensitive adhesive composition was pressed for 1 second and then peeled at a speed of 0.8m/s in the vertical direction. The average of 5 median values among the 9 points measured was taken as the vertical peeling force. The results are shown in Table 2.

As the adhesion tester, an adhesion tester TA-500 manufactured by UBM was used.

(5) Determination of elongation at Break

The elongation at break was determined as follows: in a tensile testing machine, a test piece having a thickness of 350 μm and a width of 5mm was subjected to a tensile test at a speed of 300mm/min with the distance between chucks of the sample set to 50mm, and the elongation at break of the test piece at that time was measured. The results are shown in Table 2.

(examples 2 to 14, comparative examples 1 to 4)

An adhesive composition and an adhesive tape were obtained in the same manner as in example 1, except that the kind of the resin, the blending amount of the bleeding agent and the inorganic filler, and the kind and the blending amount of the crosslinking agent were changed as shown in tables 2 and 3. With respect to the obtained adhesive composition, the gel swell ratio, gel fraction, vertical peel force and elongation at break were measured by the same method as in example 1. The results are shown in tables 2 and 3. COLONATE L-45 manufactured by Nippon polyurethane industries, Inc. was used as the isocyanate crosslinking agent.

(evaluation)

The adhesive compositions obtained in examples and comparative examples were evaluated for heat resistance by the following method. The results are shown in tables 2 and 3.

For the heat resistance evaluation, a chip with a bump (WALTS-TEG FC150SCJY LF (PI) Type A, manufactured by WALTS corporation) was placed in the center of a SUS420 jig A shown in FIG. 2, and an adhesive tape cut to a size of 40mm in the vertical direction and 40mm in the horizontal direction was pasted at a speed of 10mm/sec using a 2kg roller, and cured at room temperature for 15 minutes.

Thereafter, the heat treatment step was performed at 180 ℃ for 6 hours in an oven, and at 250 ℃ for 10 minutes in a hot plate. The heat resistance was visually observed and evaluated according to the following criteria.

A: no peeling occurred in the process, and no adhesive residue was observed during peeling.

B: partial peeling (less than 10% by area) occurred during the process, and no residual glue was observed upon peeling.

C: no peeling occurred in the process, but residual gum was observed upon peeling. The residual glue cannot be removed even by washing.

[ Table 1]

[ Table 2]

[ Table 3]

Industrial applicability

According to the present invention, an adhesive composition having high adhesive force and capable of being peeled off while suppressing adhesive residue, an adhesive tape having an adhesive layer containing the adhesive composition, and a method for protecting a semiconductor device using the adhesive composition or the adhesive tape can be provided.

Description of the symbols

1 semiconductor device

12 convex

2 adhesive layer comprising an adhesive composition

3 base material

4 layer comprising an adhesive composition for pre-fixing

5 support plate

Claims

1. An adhesive composition comprising a crosslinked adhesive polymer composed of an adhesive polymer and a crosslinking agent,

the adhesive composition has a gel swell ratio of 500% or more and a gel fraction of 87% or more.

2. The adhesive composition according to claim 1, which has a vertical peel force of 12N/cm as measured by a tack tester²～42N/cm²And has an elongation at break of 600 to 1400% as measured using a sample having a thickness of 350 μm, a width of 5mm and a length of 50 mm.

3. The adhesive composition according to claim 1 or 2, wherein the adhesive polymer has a molecular weight distribution Mw/Mn of 4.1 or less.

4. The adhesive composition according to claim 1, 2 or 3, wherein the weight average molecular weight of the adhesive polymer is 30 ten thousand or more.

5. The adhesive composition of claim 1, 2, 3 or 4, wherein the adhesive composition further comprises a bleed agent.

6. The adhesive composition according to claim 1, 2, 3, 4 or 5, which is used for being attached to a surface of a semiconductor device on which projections are formed to protect the semiconductor device.

7. An adhesive tape having an adhesive layer comprising the adhesive composition of claim 1, 2, 3, 4, 5, or 6.

8. The adhesive tape according to claim 7, wherein the vertical peel force of the adhesive layer measured by a tack tester is 12N/cm²～42N/cm²。

9. A method of protecting a semiconductor device, having: a step of applying an adhesive composition to the surface of the semiconductor device on which the bumps are formed or a step of attaching an adhesive tape to the surface of the semiconductor device on which the bumps are formed,

the adhesive tape has an adhesive layer comprising the adhesive composition,

the adhesive composition comprises a crosslinked adhesive polymer composed of an adhesive polymer and a crosslinking agent,