TWI521040B - Method of cutting off hot peeling adhesive tape and electronic parts - Google Patents

Description

Thermal peeling type adhesive tape and cutting method of electronic parts

The present invention relates to a heat-peelable adhesive tape for fixing the electronic component during processing of an electronic component or the like, and a method of cutting the electronic component using the same.

In the field of semiconductors, etc., the wafers have been expanded to a larger diameter (450 mm) and thinner (less than 100 μm), and LEDs (Light Emitting Diodes) have been required to increase the demand for compound semiconductors that require attention.

Moreover, in the processing of an electronic component, it is widely used for the heat-peelable adhesive sheet which can be reliably fixed at the time of processing, and the adhesive force is removed by heating after processing, and the heat-peelable adhesive sheet of the processed body can be easily peeled off.

In recent years, the miniaturization or precision of electronic components has continued to develop, and the industry has demanded unprecedented processing precision. For example, the ceramic capacitor is being miniaturized from a size of 1005 (1 mm × 0.5 mm) to a size of 0603 (0.6 mm × 0.3 mm) and a size of 0402 (0.4 mm × 0.2 mm).

With such miniaturization or precision, especially in the cutting step, a large amount of wafer scattering occurs, and the wafer is scattered to cause a decrease in yield. The reason why the wafer is scattered is vibration or the like at the time of cutting, and it is required to reliably hold the adhesive sheet of the wafer even in such an environment.

In addition, when a green sheet (pre-calcined sheet of ceramics such as a ceramic capacitor) is processed, an adhesive is added to the adhesive to increase the adhesive force, thereby improving the retention of the adhesive to be processed. Sex. Therefore, by this method, the adhesion of the resin is increased to increase the adhesion, thereby suppressing the scattering of the wafer. However, the frequency of wafer scattering Slightly reduced, but did not improve dramatically. When the adhesion-imparting resin is further added to increase the adhesive force, when the wafer is peeled off, the adhesion of the adhesive layer is sufficiently strong to cause peeling.

As described in Patent Document 1, a method of cutting a green sheet by using a non-thermally expandable releasable temporary fixing sheet in order to eliminate such a phenomenon is known, and as disclosed in Patent Document 2, it is known to contain A heat-peelable adhesive sheet made of a thermally expandable adhesive layer of a heat-expandable microsphere and a layered tantalate.

However, these known methods do not set the rate of change of the viscosity of the probe to a specific range, and the adhesive itself does not maintain the retention characteristics of the wafer during heating. Moreover, in the field of semiconductors, the demand for compound semiconductors such as LEDs has rapidly expanded. However, the compound semiconductor is liable to be broken by a slight impact, and it is necessary to pay close attention to processing such as back grinding or wafer cutting when the wafer is thinned.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2012-52038

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2008-266455

In the cutting step of the wafer, the wafer-like adhesive tape can be sufficiently fixed even after the cutting, and the problem to be solved is to prevent the wafer from scattering during the cutting, thereby improving the wafer cutting. rate.

In order to solve the above problems, the inventors of the present invention have found that it is extremely effective to add a small amount of adhesion-imparting resin to the heat-expandable pressure-sensitive adhesive layer to set a specific viscosity change rate of the probe. Suppresses wafer scattering. Further, it is also known that the wafer scattering varies greatly depending on the type of the adhesion-imparting resin.

It is generally believed that the reason for this phenomenon is that the adhesive and the adhesion impart compatibility with the resin.

That is, the present invention provides the following heat-peelable adhesive tape.

The heat-peelable adhesive tape of the present invention has a heat-expandable adhesive layer, and the probe viscosity value of the heat-expandable adhesive layer is set to B ₀ , and the heat-expandable adhesive layer is allowed to stand at 0 ° C for one week. The probe viscosity value after the setting is B, and the rate of change W of the probe viscosity value expressed by Formula 1 in this case is 19.0% or less.

W=|(B ₀ -B)/B ₀ ×100| (Formula 1)

It is preferred that the thermal exfoliation adhesive tape of the present invention is attached to a polyethylene terephthalate film (thickness: 25 μm) at 23 ° C and then thermally expanded at 23 ° C for 30 minutes in an environment of 23 ° C. The adhesive force of the adhesive layer (peeling angle: 180°, tensile speed: 300 mm/min) was 2.5 N/20 mm or more.

It is preferable that the adhesive constituting the heat-expandable pressure-sensitive adhesive layer contains an acrylic pressure-sensitive adhesive.

It is preferable that the heat-expandable pressure-sensitive adhesive layer contains an adhesive-imparting resin.

Preferably, the adhesion-imparting resin is a phenol-based resin and/or a rosin-based resin.

Preferably, the heat-peelable pressure-sensitive adhesive tape of the present invention has a reduction rate of total light transmittance of 2% or less before and after storage at 0 ° C for one week.

It is preferred that the heat-expandable pressure-sensitive adhesive layer contains a crosslinking agent.

Preferably, the heat-peelable adhesive tape of the present invention is formed by directly forming a heat-expandable adhesive layer on at least one side of the substrate.

Preferably, the heat-peelable adhesive tape of the present invention is formed by forming a heat-expandable adhesive layer with a rubber-like organic elastic layer formed on at least one side of the substrate.

It is preferable that the rubber-like organic elastic layer has a thickness of 3 to 200 μm.

Preferably, the heat-peelable adhesive tape of the present invention is used in the cutting of electronic parts.

Moreover, the present invention provides a cutting of an electronic component using the above-described heat-peelable adhesive tape Break method.

According to the present invention, by forming an adhesive tape having an adhesive layer containing an adhesive having a specific probe viscosity change rate, in the cutting step of the wafer, the cut wafer is not scattered. And the effect of being fixed to the surface of the adhesive layer of the adhesive tape.

1‧‧‧Support substrate

2‧‧‧ Thermally expansive adhesive layer

3‧‧‧ spacer

Fig. 1 is an example of a heat-peelable adhesive tape of the present invention.

An example of a heat-peelable adhesive tape used in the present invention is shown in Fig. 1 .

In this example, 1 is a support substrate (sometimes referred to simply as a substrate), 2 is a heat-expandable adhesive layer, and 3 is a smooth peelable film (separator). Here, in the present invention, it is necessary to have a heat-expandable pressure-sensitive adhesive layer of 2, and 1 and 3 are optional, and may or may not be provided. The heat-peelable adhesive tape of the present invention will be described below.

(substrate)

The substrate can be used as a support matrix for a heat-peelable adhesive tape in the present invention. As the substrate, for example, a plastic substrate such as a plastic film or a sheet, a rubber-based substrate such as a non-woven fabric, a metal foil, a paper, a cloth, or a rubber sheet, or a foam such as a foamed sheet or a laminate thereof may be used. A suitable sheet such as a laminate (especially a laminate of a plastic substrate and another substrate, or a laminate of plastic films (or sheets)).

Further, in the present invention, a substrate-free heat-peelable adhesive tape can be obtained.

(plastic base material)

As the substrate, a plastic substrate such as a plastic film or a sheet can be preferably used. It is not particularly limited, and examples thereof include polyester films such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); and polyethylene. (PE), polypropylene (PP), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), etc., olefin-based resin containing α-olefin as a monomer component; polyamine (nylon), wholly aromatic Polyamine Amine-based resin such as amine; polyimine (PI) film, polyvinyl chloride (PVC) film, polyphenylene sulfide (PPS) film, fluorine film, polyetheretherketone (PEEK) film, and the like. These materials may be used alone or in combination of two or more.

Specifically, examples of the polyethylene terephthalate (PET) film include "Lumirror" of Toray Co., "Teijin Tetoron Film" and "Melinex" of Teijin Dupont Films, and Mitsubishi Resin ( "Diafoil", etc., as the polyethylene naphthalate (PEN) film, "Teonex" of Teijin Dupont Films, etc., and as a polyimine (PI) film, Toray Dupont "Kapton" of "shares", "Apical" of Kaneka (shares), "Upilex" of Ube Industries (shares), etc., as polypropylene (PP) film, "Torayfan" of Toray (share), San . "San Tox" of Tox Co., Ltd., "Pylen Film" of Toyo Textile Co., Ltd., etc., as a polyvinyl chloride (PVC) film, "Artron" of Mitsubishi Resin Co., Ltd., and Achilles Co., Ltd. Achilles Type C+", etc., as the polyethylene (PE) film, "NSO" of the Okura Industry Co., Ltd., etc., and as a polyphenylene sulfide (PPS) film, "Torelina" of Toray (share), etc. Examples of the fluorine film include "Toyofron" from Toray Co., Ltd., and "Tedlar Film" from Dupont Co., Ltd., and the like. Further, when a plastic base material is used as the base material, deformation such as elongation can be controlled by stretching treatment or the like.

(not woven)

As the non-woven fabric, a non-woven fabric made of natural fibers having heat resistance can be preferably used, and among them, a non-woven fabric containing Manila hemp is preferred. In addition, examples of the synthetic resin nonwoven fabric include a polypropylene resin nonwoven fabric, a polyethylene resin nonwoven fabric, and an ester resin nonwoven fabric.

(metal foil)

The metal foil is not particularly limited, and a general metal foil such as a copper foil, a stainless steel foil, or an aluminum foil may be used, and various materials such as an alloy of silver, iron, nickel, and chromium having a thickness may be used.

(paper)

The paper is not particularly limited, and generally, paper, kraft paper, cellophane, dalin paper, synthetic paper, topcoat paper, or the like can be used.

The thickness of the substrate can be appropriately selected depending on the strength, flexibility, purpose of use, etc., and is, for example, generally 1000 μm or less (for example, 1 to 1000 μm), preferably 1 to 500 μm, more preferably 3 to 300 μm, and particularly preferably 5 to 5°. It is about 250 μm, but it is not limited to these. Further, the substrate may have a single layer form or a laminated form.

In order to improve the adhesion to the heat-expandable adhesive layer 2 and the like, the surface of the substrate can be subjected to conventional surface treatment such as corona treatment, chromic acid treatment, ozone exposure, flame exposure, high-voltage shock exposure, ionizing radiation treatment, etc. The oxidizing treatment by chemical or physical methods, or the like, may be carried out by a coating treatment using a primer.

(heat-expandable adhesive layer)

The heat-expandable pressure-sensitive adhesive layer 2 contains an adhesive which is adhesive, and may further contain heat-expandable microspheres for imparting thermal expansion. In the case of containing a thermally expandable microsphere, the adhesive sheet is adhered to the adherend, and the heat-expandable adhesive layer 2 is heated at any time to foam and/or expand the thermally expandable microsphere. Thereby, the adhesion area of the heat-expandable pressure-sensitive adhesive layer 2 and the adherend can be reduced, and the adhesive sheet can be easily peeled off.

The thickness of the heat-expandable pressure-sensitive adhesive layer 2 is 3 to 300 μm, preferably 5 to 150 μm, and more preferably about 10 to 100 μm.

Further, in terms of the balance between the moderate adhesion force before the heat treatment and the decrease in the adhesion force after the heat treatment, it is more preferable that the adhesive is at a dynamic elastic modulus at 25 ° C to 150 ° C at 5 kPa to A polymer in the range of 1 MPa is used as a base pressure sensitive adhesive.

As the adhesive constituting the heat-expandable pressure-sensitive adhesive layer 2, it is preferred that the foaming and/or expansion of the heat-expandable microspheres are not restrained as much as possible during heating. As such an adhesive, for example, an acrylic adhesive, a rubber adhesive, a vinyl alkyl ether adhesive, or a polyfluorene can be used. An oxygen-based adhesive, a polyester-based adhesive, a polyamide-based adhesive, a urethane-based adhesive, a styrene-diene block copolymer-based adhesive, and a melting point in the adhesives For example, a known adhesive such as a modified adhesive or a radiation-curable adhesive having a heat-fusible resin of 200 ° C or less is used, and one or a combination of two or more types is used as appropriate (for example, refer to Japanese Patent Laid-Open No. 56) -61468, Japanese Patent Laid-Open No. 63-17981, and the like.

Among them, as the adhesive, an acrylic adhesive or a rubber-based adhesive can be preferably used, and an acrylic adhesive is particularly preferable. Examples of the acrylic adhesive include an acrylic adhesive (a homopolymer or a copolymer) using one or two or more of (meth)acrylic acid alkyl esters as a monomer component, and an acrylic adhesive as a base polymer. Agent. Examples of the (meth)acrylic acid alkyl ester in the acrylic pressure-sensitive adhesive include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and (meth)acrylic acid. Isopropyl ester, butyl (meth)acrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, Methyl)hexyl acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, bismuth (meth)acrylate Esters, isodecyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, Tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, cetyl (meth)acrylate, (meth)acrylic acid Heptaalkyl ester, octadecyl (meth) acrylate, pentadecyl (meth) acrylate, eicosyl (meth) acrylate, etc., having an alkyl group having a carbon number of 1 to 20 Chain or branched alkyl Alkyl (meth)acrylate or the like. In the present specification, the term "(meth)acrylic acid" means "acrylic acid" and/or "methacrylic acid". Among the above, an alkyl (meth)acrylate having an alkyl group having 4 to 18 carbon atoms is more preferred. The content of the alkyl (meth)acrylate is preferably 50 to 100% by weight, and more preferably 70 to 100% by weight based on the total amount of the monomer component (100% by weight) constituting the acrylic pressure-sensitive adhesive.

Further, in order to improve the cohesive force, heat resistance, crosslinkability, and the like, the acrylic polymer may optionally contain a unit corresponding to another monomer component copolymerizable with the alkyl (meth)acrylate. Examples of such a monomer component include carboxyl groups such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxy amyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Monomer; anhydride monomer such as maleic anhydride or itaconic anhydride; hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyl group (meth)acrylate Hydroxyl-containing monomer such as hexyl ester, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl methacrylate ; styrene sulfonic acid, allyl sulfonic acid, 2-(methyl) propylene decylamine-2-methylpropane sulfonic acid, (meth) acrylamide propylene sulfonic acid, sulfopropyl (meth) acrylate, a sulfonic acid group-containing monomer such as (meth)acryloxynaphthalenesulfonic acid; (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl (methyl) a (N-substituted) guanamine monomer such as acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide or the like; Ethyl ester, N,N-di(meth)acrylate Aminoalkyl (meth) acrylate monomer such as arylaminoethyl ester or tert-butylaminoethyl (meth)acrylate; methoxyethyl (meth)acrylate, (meth)acrylic acid (A) alkoxyalkyl (meth) acrylate monomer such as ethoxyethyl ester; N-cyclohexyl maleimide, N-isopropyl maleimide, N-lauryl a maleimide-based monomer such as maleimide or N-phenyl maleimide; N-methyl Ikonide, N-ethyl Ikonide , N-butyl Ikonium imidate, N-octyl ikyl imine, N-2-ethylhexyl ketimine, N-cyclohexyl ketimine, N-Lauryl Ikon Ikonide imine monomer such as quinone imine; N-(methyl) propylene oxymethylene succinimide, N-(methyl) propylene fluorenyl-6-oxyhexamethylene amber An amber quinone imine monomer such as quinone imine or N-(methyl)propenyl-8-oxy octamethylene succinimide; vinyl acetate, vinyl propionate, N-vinyl pyrrolidine Ketone, methyl vinyl pyrrolidone, vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl pipe Vinylpyr , vinyl pyrrole, vinyl imidazole, vinyl Azole, vinyl a vinyl monomer such as a porphyrin, an N-vinyl carboxamide, a styrene, an α-methylstyrene or an N-vinyl caprolactam; a cyanoacrylate monomer such as acrylonitrile or methacrylonitrile; An epoxy group-containing acrylic resin monomer such as glycidyl (meth)acrylate; polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, methoxyethylene glycol (methyl) a diol-based acrylate monomer such as acrylate or methoxypolypropylene glycol (meth) acrylate; tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate, or polyoxymethylene (meth) acrylate An acrylate monomer having a hetero ring, a halogen atom or a ruthenium atom such as an ester; hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, or (poly)propylene glycol di( Methyl) acrylate, neopentyl glycol di(meth) acrylate, pentaerythritol di(meth) acrylate, trimethylolpropane tri(meth) acrylate, pentaerythritol tri(meth) acrylate, two Polyfunctional monomer such as pentaerythritol hexa(meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate; An olefin monomer such as an olefin, a butadiene or an isobutylene; a vinyl ether monomer such as a vinyl ether; These monomer components may be used alone or in combination of two or more. Among the above monomer components, from the viewpoint of improving cohesive force or crosslinkability, a hydroxyl group-containing monomer or a carboxyl group-containing monomer is preferred, and hydroxyethyl (meth)acrylate or acrylic acid is more preferred. The content of the hydroxyl group-containing monomer is preferably less than 10% by weight, more preferably 8% by weight or less, even more preferably 5% by weight or less based on the total amount of the monomer component (100% by weight) constituting the acrylic polymer. . The content of the carboxyl group-containing monomer is preferably less than 20% by weight, and more preferably 5% by weight or less based on the total amount of the monomer component (100% by weight) constituting the acrylic pressure-sensitive adhesive.

Further, examples of the rubber-based adhesive include natural rubber or various synthetic rubbers (for example, polyisoprene rubber, styrene-butadiene (SB) rubber, and styrene-isoprene (SI) rubber. Styrene-isoprene-styrene block copolymer (SIS) rubber, styrene-butadiene-styrene block copolymer (SBS) rubber, styrene-ethylene-butylene-styrene block copolymerization (SEBS) rubber, styrene-ethylene-propylene-styrene block copolymer (SEPS) rubber, styrene-ethylene-propylene block copolymer (SEP) rubber, recycled rubber, butyl rubber, polyisobutylene or A modified body or the like] is a rubber-based adhesive as a base polymer.

Further, the heat-expandable pressure-sensitive adhesive layer 2 may contain heat-expandable microspheres, a crosslinking agent, an adhesion-imparting resin, a pigment, a dye, a filler, an anti-aging agent, a conductive agent, an antistatic agent, and the like, in addition to the above-mentioned adhesive. Suitable additives such as ultraviolet absorbers, light stabilizers, peel adjusters, softeners, surfactants, flame retardants, antioxidants, and the like. It is especially preferred to provide a resin with a crosslinking agent and/or adhesion.

(crosslinking agent)

Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, a melamine crosslinking agent, and a peroxide crosslinking agent, and examples thereof include a urea crosslinking agent and a metal alkoxide. a crosslinking agent, a metal chelate crosslinking agent, a metal salt crosslinking agent, a carbodiimide crosslinking agent, As the oxazoline crosslinking agent, the aziridine crosslinking agent, the amine crosslinking agent, and the like, an isocyanate crosslinking agent or an epoxy crosslinking agent can be preferably used.

(isocyanate crosslinking agent)

Specific examples of the isocyanate-based crosslinking agent include lower aliphatic polyisocyanates such as butyl diisocyanate and hexamethylene diisocyanate, cyclopentane diisocyanate, cyclohexane diisocyanate, and isophor. An alicyclic isocyanate such as keto diisocyanate, an aromatic isocyanate such as 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate or benzodimethylisocyanate, or a trimethylolpropane/toluene Isocyanate trimer adduct (trade name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.), trimethylolpropane / hexamethylene diisocyanate trimer adduct (trade name Coronate HL, Nippon Polyurethane Industry An isocyanate adduct such as an isocyanurate body (trade name: Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.) of hexamethylene diisocyanate. These compounds may be used singly or in combination of two or more.

The amount of the isocyanate crosslinking agent to be formulated can be appropriately determined depending on the desired adhesive force. In general, it is preferably 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, per 100 parts by weight of the base polymer.

(epoxy crosslinker)

Examples of the epoxy-based crosslinking agent include N,N,N',N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, and 1,3-bis(N,N-shrinkage). Glycerylaminomethyl)cyclohexane (product name "Tetrad C", manufactured by Mitsubishi Gas Chemical Co., Ltd.), 1,6-hexanediol diglycidyl ether (product name "Epolight 1600", Kyoeisha Chemical Co., Ltd. (manufactured by the company), neopentyl glycol diglycidyl ether (product name "Epolight 1500NP", manufactured by Kyoeisha Chemical Co., Ltd.), ethylene glycol diglycidyl ether (product name "Epolight 40E", Kyoeisha Chemical (manufacturing), propylene glycol diglycidyl ether (product name "Epolight 70P", manufactured by Kyoeisha Chemical Co., Ltd.), polyethylene glycol diglycidyl ether (product name "Epiol E-400", Japanese fat (manufactured by the company), polypropylene glycol diglycidyl ether (product name "Epiol P-200", manufactured by Nippon Oil & Fats Co., Ltd.), sorbitol polyglycidyl ether (product name "Denacol EX-611", Nagase ChemteX ( Co., Ltd.), glycerol polyglycidyl ether (product name "Denacol EX-314", manufactured by Nagase ChemteX), pentaerythritol polyglycidyl ether, polyglycerol condensation Glycerol ether (product name "Denacol EX-512", manufactured by Nagase ChemteX), sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, diglycidyl adipate, phthalic acid Diglycidyl formate, triglycidyl-tris(2-hydroxyethyl) isocyanurate, resorcinol diglycidyl ether, bisphenol S-diglycidyl ether, and may also be exemplified in the molecule Two or more epoxy-based epoxy resins. These crosslinking agents may be used singly or in combination of two or more.

The amount of the epoxy-based crosslinking agent can be appropriately determined depending on the desired adhesive force. In general, it is preferably 0.01 to 10 parts by weight, preferably 0.03 to 5 parts by weight, per 100 parts by weight of the base polymer.

(Plasticizer)

The plasticizer used in the present invention is not particularly limited, and for example, a trimellitate plasticizer, a pyromellitic plasticizer, a polyester plasticizer, or adipic acid plasticization can be used. For the agent or the like, a trimellitate plasticizer or a pyromellitic acid plasticizer can be preferably used. Agent. The plasticizers may be used singly or in combination of two or more.

Specific examples of the trimellitate-based plasticizer include tris(n-octyl) trimellitate, tris(2-ethylhexyl) trimellitate, and trimellitic acid III. Trialkyl isophthalate such as isooctyl ester, triisodecyl trimellitate or triisodecyl trimellitate. Further, examples of the pyromellitic acid ester plasticizer include tetrakis(n-octyl) pyromellitate and tetrakis(tetraethylhexyl) tetracarboxylate. Base ester and the like. The blending amount of the plasticizer is appropriately determined depending on the purpose, and is 1 to 20 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of the base polymer.

(adhesive to resin)

When selecting an adhesive-imparting resin, it is necessary to select an excellent compatibility with an adhesive rather than a poor compatibility with an adhesive.

When the adhesion-imparting resin having poor compatibility with the adhesive is adjusted, not only the adhesive portion of the adhesive and the adhesive-imparting resin are formed in the adhesive, but also the adhesive and the adhesive-imparting resin are separated. Incompatible part. That is, a region where the adhesion-imparting resin having a high glass transition temperature (Tg) is locally generated on the surface of the adhesive, and a surface having a low adhesive force is partially generated.

Therefore, the surface of the region where the adhesion is imparted to the resin is exposed, and the minute member of the object to be processed is adhered to the surface of the adhesive layer by the weak adhesive force, so that it is easy to be processed during cutting or the like. Peeled by vibration. This tendency becomes remarkable as follows: in particular, the smaller the workpiece to be processed after cutting, the larger the area of the adhesive-imparting resin with respect to the size of the workpiece.

Therefore, regardless of the extent to which only the adhesion-imparting resin is added to improve the adhesion, as long as the compatibility of the adhesion-imparting resin with the adhesive is poor, the adhesion force may be referred to as the average value of the entire adhesive surface. Physical properties, so it is impossible to eliminate the scattering of the wafer due to the in-plane physical properties when the surface of the adhesive layer is observed under the microscopic state.

As the adhesion-imparting resin used in the present invention, a rosin tree derived from rosin can be used. A steroid group, a terpene resin derived from terpene such as decene, an aliphatic hydrocarbon resin derived from a petroleum fraction, an aromatic hydrocarbon resin, or the like, preferably a phenol group such as rosin or phenol. The adhesion of the phenolic resin or the rosin phenol resin to the resin. The molecular structure of rosin or especially indophenol is not spatially entangled, so that the hydroxyl group of the phenol group easily interacts with the ester group in the acrylic adhesive, thereby improving the compatibility.

Specifically, as the phenol-based resin, YS Polystar S145 manufactured by Yasuhara Chemical Co., Ltd. or Tamanol 901 manufactured by Arakawa Chemical Co., Ltd. may be mentioned as the rosin-based resin, and examples of the rosin-based resin may be mentioned. Sumilite Resin PR-12603 manufactured by Sumitomo Bakelite.

On the other hand, the rosin ester-based resin is expected to be compatible by the intermolecular interaction between the ester group contained in the structure and the ester group in the acrylic adhesive, but the composition of the rosin ester resin has an alicyclic ring. The structure is such that the rosin ester resin is spatially squeezed together compared to the indophenol resin or the like, so that the influence of the interaction of the functional groups is lowered.

Further, as an index of compatibility between the adhesive and the resin, a hydroxyl value or an acid value can be used. Regarding the resin having a high hydroxyl value, the interaction between the hydroxyl group and the ester group in the acrylic adhesive is expected, and in the case of the resin having a higher acid value, the ratio of the carboxyl group in the structure becomes higher, and the acrylic group can be used. The ester groups in the adhesive undergo intermolecular interactions, and as a result, the compatibility is improved. The rosin ester-based resin having a structure which is spatially packed together has an increased probability of intermolecular interaction with the ester group in the acrylic pressure-sensitive adhesive as long as the acid value or the hydroxyl value is high, so that the compatibility is improved. For example, Super Ester A115 manufactured by Arakawa Chemical Co., Ltd. of rosin ester resin can be used. The value of the hydroxyl value which is expected to improve the compatibility is preferably 30 or more, more preferably 45 or more, still more preferably 70 or more, or a value of the acid value of preferably 15 or more, and more preferably 40 or more.

Further, the amount of the tackifying resin to be added is usually 5 to 100 parts by weight, preferably 10 to 50 parts by weight, per 100 parts by weight of the base polymer forming the heat-expandable pressure-sensitive adhesive layer.

(heat-expandable microspheres)

The heat-expandable microspheres are not particularly limited, and may be appropriately selected from known heat-expandable microspheres, and may be used singly or in combination of two or more. Examples of the heat-expandable microspheres include propane, propylene, butene, n-butane, isobutane, isopentane, neopentane, n-pentane, n-hexane, isohexane, heptane, octane, and petroleum. a substance such as an ether, a methane halide, a tetraalkyl decane-like low-boiling liquid, a azo dimethyl hydrazine which is thermally decomposed by heating and which is gaseous, and which is easily expanded by heating by heating, is encapsulated in elasticity. A tiny ball made inside the shell can be used.

Further, the shell-forming substance forming the heat-expandable microspheres is composed of, for example, a polymer of a monomer capable of undergoing radical polymerization. Examples of the monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethoxy acrylonitrile, and fumaronitrile-like nitrile monomers; acrylic acid, methacrylic acid, and IKON. Acid, maleic acid, fumaric acid, methyl maleic acid-like carboxylic acid monomer; vinylidene chloride; vinyl acetate; methyl (meth)acrylate, (meth)acrylic acid Ethyl ester, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, (meth)acrylic acid Ester, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, β-carboxyethyl acrylate (meth) acrylate; styrene, α-methyl styrene, chlorostyrene-like benzene Ethylene monomer; acrylamide, substituted acrylamide, methacrylamide, substituted methacrylamide, guanamine monomer or any mixture thereof, etc., in the present invention, as long as it contains thermal meltability The substance or the substance destroyed by thermal expansion may be used.

Further, the shell-forming substance can also be produced by copolymerization using one or more substances, and examples thereof include a vinylidene chloride-methyl methacrylate-acrylonitrile copolymer and a methyl methacrylate-acrylonitrile-methyl group. Acrylonitrile copolymer, methyl methacrylate-acrylonitrile copolymer, acrylonitrile-methacrylonitrile-iconic acid copolymer, and the like.

The heat-expandable microspheres can be produced by a conventional method such as a coacervation method, an interfacial polymerization method, or the like.

As such a heat-expandable microsphere, for example, it is also manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd. "Matsumoto Microsphere" (product name F-30, F-36LV, F-50, F-65, FN-100SS, FN-180SS, F-190D, F-260D, F-2800D), manufactured by Japan Fillite Co., Ltd. "Expancel" (product name 053-40, 031-40, 920-40, 909-80, 930-120), "Daifoam" manufactured by Wu Yu Chemical Industry Co., Ltd. (product name H750, H850, H1100, S2320D) Commercial products such as "Advancell" (product names EML101, EMH204, EHM301, EHM302, EHM303, EM304, EHM401, EM403, EM501) manufactured by Sekisui Chemical Industry Co., Ltd., S2640D, M330, M430, M520).

Further, in the present invention, as the heat-expandable microspheres, those other than the above may be used. Examples of such heat-expandable microspheres include various inorganic foaming agents and organic foaming agents. Typical examples of the inorganic foaming agent include ammonium carbonate, ammonium hydrogencarbonate, sodium hydrogencarbonate, ammonium nitrite, sodium borohydride, and various kinds of azide. Moreover, as a typical example of the organic foaming agent, for example, water; a chlorofluoroalkane compound such as trichloromonofluoromethane or dichloromonofluoromethane; azobisisobutyronitrile; azodi An azo compound such as formamide or azodicarboxylate; p-toluenesulfonyl hydrazine, diphenyl hydrazine-3,3'-disulfonyl hydrazine, 4,4'-oxy bis ( Anthraquinone compounds such as phenylsulfonyl hydrazine, allyl bis(sulfonylhydrazine); p-tolylsulfonylaminourea, 4,4'-oxybis(phenylsulfonylaminourea) Iso-ureidourea compound; 5- Triazole compound such as phenyl-1,2,3,4-thiatriazole; N,N'-dinitrosopentamethylenetetramine, N,N'-dimethyl-N,N'- An N-nitroso compound such as dinitroso-p-xylyleneamine or the like.

In order to efficiently reduce the adhesion force of the adhesive layer by heat treatment, the heat-expandable microspheres preferably have a volume expansion ratio of 5 or more, 7 or more times thereof, and particularly 10 times or more. A moderately intensifying heat-expandable microsphere.

The amount of the heat-expandable microspheres can be appropriately set according to the expansion ratio of the adhesive layer or the decrease in the adhesion force, etc., but generally, it is, for example, 1 to 150 with respect to 100 parts by weight of the base polymer forming the heat-expandable pressure-sensitive adhesive layer 2. The parts by weight are preferably 10 to 130 parts by weight, more preferably 25 to 100 parts by weight.

The heat-expandable pressure-sensitive adhesive layer 2 can be formed, for example, by a method in which a coating liquid containing an adhesive or a heat-expandable microsphere is prepared by using a solvent, and the coating liquid is applied to the support substrate 1 or formed in advance. a method of supporting the rubber-like organic elastic layer shown below on the substrate 1; applying the coating liquid to a suitable separator (peeling paper or the like) to form a heat-expandable pressure-sensitive adhesive layer, and expanding the heat. The method of transferring (moving) the adhesive layer to the support substrate 1 or the rubber-like organic elastic layer. At this time, the heat-expandable pressure-sensitive adhesive layer 2 may be either a single layer or a composite layer.

The heat treatment condition in which the adhesive sheet can be easily peeled off from the adherend can be reduced depending on the surface state of the adherend, the contact area depending on the type of the heat-expandable microsphere, or the heat resistance of the adherend. It is determined by conditions such as heating method. The general conditions are 100 to 250 ° C, 1 to 90 seconds (heating plate, etc.) or 5 to 15 minutes (hot air dryer, etc.).

(Rubber-like organic elastic layer)

A rubber-like organic elastic layer may be provided between the substrate and the heat-expandable adhesive layer 2 in terms of imparting deformability to the heat-peelable adhesive sheet or improving peelability after heating, and the rubber-like organic elastic layer may be The layer set as needed does not necessarily need to be set. By providing the rubber-like organic elastic layer in such a manner, the heat-peelable adhesive sheet can be adhered to the adherend (processed product or the like) by the heat-expandable pressure-sensitive adhesive layer 2, and the heat-peelable adhesive sheet can be made. The surface of the heat-expandable pressure-sensitive adhesive layer 2 satisfactorily follows the surface shape of the adherend to increase the adhesion area, and can be highly heated when the heat-peelable adhesive sheet is peeled off from the adherend. The heat expansion of the heat-expandable pressure-sensitive adhesive layer 2 is controlled to cause the heat-expandable pressure-sensitive adhesive layer 2 to preferentially and uniformly expand in the thickness direction.

That is, the rubber-like organic elastic layer functions to provide a large contact area when the surface of the heat-peelable adhesive sheet follows the surface shape of the adherend when the heat-peelable adhesive sheet is attached to the adherend. And the heat-expandable adhesive layer 2 is heated to be foamed and/or expanded in order to peel off the adherend self-heating release adhesive sheet In this case, it is helpful to form a relief structure by causing a three-dimensional structural change of the heat-expandable pressure-sensitive adhesive layer 2 by reducing the foaming and/or expansion constraint in the direction of the surface of the heat-peelable pressure-sensitive adhesive sheet.

The rubber-like organic elastic layer is preferably provided on the surface of the heat-expandable pressure-sensitive adhesive layer 2 on the side of the substrate on the side of the heat-expandable pressure-sensitive adhesive layer 2 . Further, the rubber-like organic elastic layer may be provided at a portion other than between the substrate and the heat-expandable pressure-sensitive adhesive layer 2. The rubbery organic elastic layer can be placed on one or both sides of the substrate.

The rubber-like organic elastic layer may be an adhesive layer, and the material thereof is not particularly limited, and an adhesive or the like exemplified for the above-described heat-expandable pressure-sensitive adhesive layer 2 can be preferably used as a constituent material. The adhesive may be an acrylic adhesive, a rubber adhesive, a vinyl alkyl ether adhesive, a polyoxygen adhesive, a polyester adhesive, a polyamide adhesive, or a urethane. The ester-based adhesive, the styrene-diene block copolymer-based adhesive, the latent-change-modified adhesive, and the radiation-curable adhesive are appropriately selected.

More specifically, for example, a rubber-based adhesive using natural rubber or synthetic rubber as a base polymer, an acrylic-based adhesive using an acrylic polymer as a base polymer, and the like, and the acrylic polymer may have Methyl, ethyl, propyl, butyl, 2-ethylhexyl, isooctyl, isodecyl, isodecyl, dodecyl, lauryl, tridecyl, pentadecyl, hexa An alkyl group such as an alkyl group, a heptadecyl group, an octadecyl group, a hexadecyl group or an eicosyl group having an alkyl group having a carbon number of 20 or less and an acrylic acid group such as acrylic acid or methacrylic acid. Acrylic acid, itaconic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, N-methylol acrylamide, acrylonitrile, methacrylonitrile, acrylic acid shrinkage Glyceride, glycidyl methacrylate, vinyl acetate, styrene, isoprene, butadiene, isobutylene, vinyl ether or the like is a main component.

The rubber-like organic elastic layer may be formed of natural rubber, synthetic rubber or a synthetic resin having rubber elasticity in addition to the above-mentioned adhesive. As the above synthetic tree Examples of the fat include synthetic rubbers such as nitrile type, diene type, and acrylic resin type; thermoplastic elastomers such as polyolefin type and polyester type; ethylene-vinyl acetate copolymer and polyurethane, and A rubber-elastic synthetic resin such as polybutadiene or soft polyvinyl chloride. Further, even if it is a hard polymer as in the case of polyvinyl chloride or the like, it can be used by being combined with a compounding agent such as a plasticizer or a softener to exhibit rubber elasticity.

Further, in the rubber-like organic elastic layer containing the materials, a crosslinking agent, an adhesion-imparting resin, a plasticizer, a filler, and an anti-adhesion agent may be added to the above-mentioned adhesive or synthetic resin in the same manner as the above-described heat-expandable pressure-sensitive adhesive layer 2. A suitable additive such as an aging agent.

The formation of the rubber-like organic elastic layer can be carried out, for example, by applying a coating liquid containing a constituent material of the rubber-like organic elastic layer onto the support substrate 1 (coating method); A film of the rubber-like organic elastic layer forming material or a laminated film obtained by forming a layer including the rubber-like organic elastic layer forming material on the heat-expandable pressure-sensitive adhesive layer 2 including one or more layers, and the support substrate 1 (dry lamination method); a method of coextruding a resin composition containing a constituent material of the support substrate 1 and a resin composition containing the rubber-like organic elastic layer forming material (co-extrusion method).

Further, the rubber-like organic elastic layer may be formed of a foamed film or the like mainly composed of related components. The foaming can be carried out by a conventional method such as a method using mechanical stirring, a method of generating a gas by a reaction, a method using a foaming agent, a method of removing a soluble substance, a method using a spray, a method of forming a coagulated bubble, a sintering method, and the like. get on. The rubber-like organic elastic layer may be a single layer or may be composed of two or more layers.

The rubber-like organic elastic layer has a thickness of 3 to 200 μm, preferably 5 to 100 μm. When it is in the range of 3 to 200 μm, it is not too thin, and the heat-peelable adhesive sheet can be provided to follow the surface shape of the adherend to provide a large adhesion area, and contribute to the heat-expandable adhesive layer. 2 The three-dimensional structural change occurs to form an undulating structure. Further, since the thickness is not too thick, aggregation failure does not occur in the rubber-like organic elastic layer after foaming.

(adhesive layer)

In the case of providing a heat-peelable pressure-sensitive adhesive layer which may include heat-expandable microspheres on one surface of the substrate, for example, in order to cut at least the object to be cut, the heat-peelable pressure-sensitive adhesive tape should be fixed. The object to be cut is fixed while the object is fixed, and an adhesive layer for fixing the heat-peelable pressure-sensitive adhesive tape to the base to be separately prepared may be provided on the other surface of the substrate.

At this time, the adhesive layer must also be stable to stimuli such as heat or vibration generated during processing such as cutting.

As the above-mentioned adhesive layer, for example, a resin used as the above-mentioned adhesive can be used as a base.

(bead)

As the protective material for the surface (adhesive surface) of the heat-expandable pressure-sensitive adhesive layer 2 or the like, the separator 3 may be used, and the separator may be used as needed, and may not necessarily be used. As the separator, the both surfaces may be the release surface, or the one surface (one surface) may be the release surface. Further, when the adhesive layer protected by the separator is used, the separator is peeled off.

As such a separator, a known or conventional release paper or the like can be used. Specifically, as the separator, for example, a substrate having a release agent layer such as a plastic film or a paper surface-treated with a release agent such as a polyfluorene-based, a long-chain alkyl group, a fluorine-based or a molybdenum sulfide; Low-adhesive substrate of fluorine-based polymer such as polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chlorofluoroethylene-vinylidene fluoride copolymer A low-adhesive substrate containing a nonpolar polymer such as an olefin resin (for example, polyethylene or polypropylene). Of course, in the substrate having the release agent layer, the surface of the release agent layer is a release surface, and in the low adhesion substrate, the surface of the low adhesion substrate is a release surface.

Further, the separator can be formed by a known or customary method. Further, the thickness of the separator or the like is not particularly limited.

(change rate of probe viscosity value)

If only the composition of the adhesion-imparting resin is blended in the adhesive, the original compatibility can be judged to be good or bad by the optical properties of the adhesive, such as haze or light transmission intensity.

However, in the present invention, heat-expandable microspheres may be mixed in the adhesive layer, and in order to improve the convenience of the peelable adhesive tape, in particular, in order to improve visibility, a dye or the like may be added to the substrate or the adhesive layer. The above-mentioned changes in optical properties due to poor compatibility are masked by changes in optical properties caused by such operations, making identification extremely difficult.

Therefore, the inventors of the present invention have decided to study whether or not the compatibility is good by measuring the change in the adhesive property according to the probe viscosity method as a method of confirming the in-plane unevenness of the adhesive property. Further, in order to make the detection by the probe adhesion method reliable, the research was carried out using a sample placed at 0 ° C for one week.

Compatibility is not governed by thermodynamics and governed by velocity theory. In other words, the compatibility is good, and the compatibility is good after being left at 0 ° C for one week. However, in the case of poor compatibility, the phase separation is further progressed, and the compatibility is easily detected. Therefore, the above is 0. It was left to stand at °C for 1 week, and it became clear that the compatibility was good.

Therefore, the probe viscosity value (B ₀ ) of the heat-peelable adhesive tape immediately after manufacture and the probe viscosity value (B) after storage for 1 week at 0 ° C were measured, and the probes were adhered twice. The measured values of the properties are compared, and as a result, in the system in which the wafer is scattered frequently, the measured value of the probe viscosity value is significantly increased or decreased. That is, the rate of change in the viscosity of the probe obtained by the following formula (1) is large. On the other hand, when the rate of change in the viscosity of the probe is 19% or less, the effect of improving the scattering of the wafer is remarkable, and the rate of change of the viscosity of the probe is preferably 15% or less, more preferably 10% or less, particularly A heat-peelable adhesive tape of 5% or less has been capable of drastically suppressing wafer scattering. According to the above, the improvement in the adhesive property can be confirmed by the change rate of the probe viscosity value.

W=|(B ₀ -B)/B ₀ ×100| Equation (1)

In the same manner, in order to confirm the compatibility according to the light transmittance of the total light, the total light transmittance A ₀ of the heat-peelable adhesive tape immediately after manufacture and the total light transmittance A after storage for one week at 0 ° C The measurement was performed, and the measured values of the total light transmittance were compared, and as a result, the measured value was remarkably reduced in the system in which the wafer was scattered frequently. In other words, the decrease in the total light transmission intensity obtained by the following formula (2) is large. On the other hand, when the reduction range of the total light transmittance is 3.0% or less, the wafer scattering improvement effect is remarkable, and the reduction of the total light transmission intensity is preferably 2.0% or less, and further preferably 1.5% or less. The peel-off adhesive tape has achieved a dramatic suppression of wafer scattering.

The heat-expandable adhesive layer of the present invention is adhered to a polyethylene terephthalate film (thickness: 25 μm) at 23 ° C and then placed at 23 ° C for 30 minutes at 23 ° C of the heat-expandable adhesive layer. The adhesion (peeling angle: 180°, stretching speed: 300 mm/min) is preferably 2.5 N/20 mm or more. More preferably, it is 2.5N/20mm amplitude ~20N/20mm amplitude, and further preferably 4.5N/20mm amplitude ~20N/20mm amplitude. When the adhesive force in the environment of 23 ° C is 2.5 N/20 mm or more, the adherend can be sufficiently held, so that the wafer does not peel off during the cutting process.

(Method of using the heat-peelable adhesive tape of the present invention)

The heat-peelable adhesive tape of the present invention is used exclusively for an adhesive sheet for fixing the electronic component to a substrate when the electronic component is cut.

The electronic component to be cut is an electronic component such as a capacitor, an inductor, a coil, a resistor, a piezoelectric element, a converter, an LED, a semiconductor, or a display device, and is an electronic component that is cut by an arbitrary method.

Such an electronic component is fixed by adhesion by the heat-peelable adhesive tape of the present invention On the substrate. Thereafter, the electronic component is cut by any method such as a cutting method using a trowel or a cutting method by a rotary blade, and then the heat-peelable adhesive tape of the present invention is heated to cause a thermal expansion adhesive layer to be emitted. The foam is thereby used to reduce the adhesion of the cut electronic component to the thermally expandable adhesive layer and pick up the cut electronic component.

(Probe viscosity measurement method)

The heat-peelable adhesive sheet was cut into a width of 20 mm and a length of 50 mm, and the two sides of Nitto Denko Electric Co., Ltd. were attached with a glass slide manufactured by Songlang Glass Industry Co., Ltd. (76 mm). ×26 mm), the cut sample was bonded from above using a hand roller. In the state where the heat-expandable pressure-sensitive adhesive layer is placed on the probe adhesion measuring machine (trade name "TACKINESS TESTER Model TAC-II", manufactured by RHESCA), the Immersion speed is 30 mm/min. Test speed: 30mm/min, preload: 100gf, press time: 1.0sec., probe area: 5mm The value measured under the condition of a circle (SUS) is used as the probe viscosity value (N/5 mm ). The viscosity value of the probe immediately after the sample was prepared was B ₀ , and the viscosity of the probe after the sample was prepared and allowed to stand at 0 ° C for 1 week was set to B, and the accelerated test was calculated according to the formula (1). The increase or decrease rate of the probe viscosity value is W (%).

W=|(B ₀ -B)/B ₀ ×100| Equation (1)

W: increase or decrease rate of probe viscosity value (%)

B ₀ : probe viscosity value of the sample just after preparation (N/5mm )

B: Viscosity of the probe after the sample was prepared and allowed to stand at 0 ° C for 1 week (N/5 mm) )

(0°C preservation method)

After each heat-peelable adhesive sheet is sealed in a plastic bag with a chuck, it is kept at a temperature of 0±2° C. for 168±2 hours without condensation, and then at a temperature of 23±2. The measurement was carried out for 1 hour in an environment of ° C and humidity: 65 ± 5% RH.

(Adhesive force measurement method)

The heat-peelable adhesive sheet was cut into a width of 20 mm and a length of 140 mm, and it was used as an adhesive-attached polyethylene terephthalate film according to JIS Z 0237 (2009) (trade name "Lumirror S- 10", manufactured by Toray; thickness: 25μm, width: 20mm) adhered to the heat-expandable adhesive layer (specifically, in the environment of temperature: 23 ± 2 ° C and humidity: 65 ± 5% RH, make 2kg The roll was placed one by one and pressed and bonded, and then placed in a tensile tester (trade name "Shimadzu Autograph AG-120 kN", manufactured by Shimadzu Corporation) with a thermostat set at 23 ° C. 30 minutes. After standing, at a temperature of 23 ° C, the adhered self-heating release adhesive sheet was peeled off at a peeling angle of 180° and a peeling speed (tensile speed): 300 mm/min, and the load at this time was measured. The maximum load at this time (the maximum value of the load other than the peak value at the initial stage of measurement) was obtained, and the maximum load was defined as the adhesion force (N/20 mm width) of the heat-expandable pressure-sensitive adhesive layer.

(Method for measuring total light transmittance)

The heat-peelable adhesive sheet was cut into a size of 30 mm in width and 30 mm in length, and the total light transmittance (%) was measured based on JIS K 7361 using Haze Meter HM-150 manufactured by Murakami Color Research Institute. The value of the total light transmittance (%) immediately after the sample was prepared was A ₀ , and the total light transmittance (%) after the sample was prepared and allowed to stand at 0 ° C for one week was set to A, according to the formula ( 2) Calculate the total light transmittance reduction rate V (%) after the acceleration test.

V: total light transmittance increase and decrease rate (%)

A ₀ : total light transmittance (%) before acceleration of the sample immediately after manufacture

A: Total light transmittance value (%) after the sample was prepared and allowed to stand at 0 ° C for 1 week.

(Method for measuring hydroxyl value)

The hydroxyl value of the sample was evaluated in accordance with JIS K 0070-1992 (Ethylation Method). About 25 g of acetic anhydride was added, and pyridine was added to make a total amount of 100 mL, and the mixture was sufficiently stirred to prepare acetamidine. Reagents.

About 2 g of the sample was accurately weighed and placed in a flat-bottomed flask, and 5 mL of acetamidine reagent and 10 mL of pyridine were added, and an air cooling tube was installed. After heating at 100 ° C for 70 minutes, it was left to cool, and 35 mL of toluene as a solvent was added from the upper portion of the cooling tube and stirred, and then 1 mL of water was added thereto and stirred to decompose acetic anhydride. In order to completely decompose it, it was heated again for 10 minutes and left to cool.

The cooling tube was washed with 5 mL of ethanol and removed, and 50 mL of pyridine as a solvent was added and stirred. 25 mL of a 0.5 mol/L potassium hydroxide ethanol solution was added to the solution using a full pipette, and potentiometric titration was performed using a 0.5 mol/L potassium hydroxide ethanol solution, and the hydroxyl value was calculated according to the following formula (3).

B: The amount of 0.5 mol/L potassium hydroxide ethanol solution used in the blank test (mL)

C: The amount of 0.5 mol/L potassium hydroxide ethanol solution used in the sample (mL)

f: factor of 0.5 mol/L potassium hydroxide ethanol solution

S: sample collection amount (g)

D: acid value

The acid value of the sample was evaluated in accordance with the JIS K 0070-1992 potentiometric titration method. To the solvent in which diethyl ether and ethanol were mixed at a volume ratio of 4:1, a phenolphthalein solution was added as an indicator, and neutralization was carried out using a 0.1 mol/L potassium hydroxide ethanol solution. About 5 g of the sample was accurately weighed and placed in a beaker, 50 mL of a solvent was added, and the mixture was completely stirred and dissolved on a panel heater (80 ° C), and potentiometric titration was performed using a 0.1 mol/L potassium hydroxide ethanol solution. The acid value was determined according to the following formula (4).

B: The amount of 0.1 mol/L potassium hydroxide ethanol solution used in the sample (mL)

F: factor of 0.1 mol/L potassium hydroxide ethanol solution

S: sample collection amount (g)

[Examples]

(Example 1)

Manufactured in an acrylic copolymer (ethyl acrylate: 2-ethylhexyl acrylate: hydroxyethyl acrylate: methyl methacrylate = 70 parts by weight: 30 parts by weight: 5 parts by weight: 6 parts by weight) in 100 parts by weight 2 parts by weight of an isocyanate-based crosslinking agent (Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd.) was added, and toluene was added thereto, and a solution obtained by uniformly mixing was applied to a PET base having a thickness of 100 μm so as to have a thickness of 10 μm after drying. On the material (rubber-like organic elastic layer).

In addition, 2 parts by weight of an isocyanate-based crosslinking agent and an indophenol-based adhesion-imparting resin (YsPolystar S145 manufactured by Yasuhara Chemical Co., Ltd., a hydroxyl value of 100 mgKOH/g, an acid value of 2 mgKOH/) were prepared in an amount of 100 parts by weight of the acrylic copolymer. g) 30 parts by weight of a heat-expandable microsphere (Matsumoto Microsphere F-50 manufactured by Matsumoto Oil & Fats Co., Ltd.) in a toluene solution, which was applied to a PET substrate at a thickness of 35 μm after drying. On the sheet (38 μm) (heat-expandable adhesive layer 1).

After the heat-expandable pressure-sensitive adhesive layer 1 is dried, the rubber-like organic elastic layer side of the polyester film coated with the rubber-like organic elastic layer is bonded to the heat-expandable pressure-sensitive adhesive layer 1 to obtain the heat-peeling used in the present invention. Type of adhesive sheet 1.

(Example 2)

2 parts by weight of an isocyanate-based crosslinking agent (Coronate L manufactured by Nippon Polyurethane Industry) and a phenol-based adhesion-imparting resin (Tamanol 901 manufactured by Arakawa Chemical Co., Ltd.) were prepared in an amount of 100 parts by weight of the acrylic copolymer. a toluene solution of 35 parts by weight of a heat-expandable microsphere (Matsumoto Microsphere F-50 manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd.) having a hydroxyl value of 45 mgKOH/g, an acid value of 52 mgKOH/g, and 30 parts by weight. The thickness was 35 μm and applied to a PET substrate separator (38 μm) (the heat-expandable pressure-sensitive adhesive layer 2). The heat-peelable adhesive sheet 2 was obtained in the same manner as in Example 1 except that the heat-expandable pressure-sensitive adhesive layer 2 was used.

(Example 3)

2 parts by weight of an isocyanate-based crosslinking agent (Coronate L manufactured by Nippon Polyurethane Industry) and a rosin-based adhesive-imparting resin (Sumilite Resin PR-12603 manufactured by Sumitomo Bakelite) were prepared in an amount of 100 parts by weight of the acrylic copolymer. 30 parts by weight of a heat-expandable microsphere (Matsumoto Microsphere F-50, manufactured by Matsumoto Oil & Fats Co., Ltd.) in an amount of 35 parts by weight, and a toluene solution of 35 parts by weight. PET substrate separator (38 μm) (heat-expandable adhesive layer 3). The heat-peelable adhesive sheet 3 was obtained in the same manner as in Example 1 except that the heat-expandable pressure-sensitive adhesive layer 3 was used.

(Example 4)

2 parts by weight of an isocyanate-based crosslinking agent (Coronate L manufactured by Nippon Polyurethane Industry), and a rosin ester-based adhesion-imparting resin (Super Ester A115 manufactured by Arakawa Chemical Co., Ltd., hydroxy group) was prepared in an amount of 100 parts by weight of the copolymer. a toluene solution of 35 parts by weight of a heat-expandable microsphere (Matsumoto Microsphere F50, manufactured by Matsumoto Oil & Fats Co., Ltd.) having a value of 25 mg KOH/g, an acid value of 18 mg KOH/g, and a thickness of 35 μm after drying. It was coated on a PET substrate separator (38 μm) (heat-expandable adhesive layer 4). The heat-peelable adhesive sheet 4 was obtained in the same manner as in Example 1 except that the heat-expandable pressure-sensitive adhesive layer 4 was used.

(Example 5)

Prepared in 100 parts by weight of copolymer containing ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, acrylic acid, trimethylolpropane triacrylate (50 parts: 50 parts: 0.1 parts: 5 parts: 0.3 parts) 1 part by weight of an epoxy-based crosslinking agent (Tetrad C manufactured by Mitsubishi Gas Chemical Co., Ltd.), a phenol-based adhesion-imparting resin (manufactured by Yasuhara Chemical Co., Ltd.) YS Polystar S145, a hydroxyl value of 100 mgKOH/g, an acid value of 2 mgKOH/g), 20 parts by weight, and a heat-expandable microsphere (Matsumoto Microsphere F50, manufactured by Matsumoto Oil & Fats Co., Ltd.), 30 parts by weight of a toluene solution, dried The thickness was 35 μm (the adhesive layer was temporarily fixed) on a PET substrate having a thickness of 100 μm (the heat-expandable pressure-sensitive adhesive layer 5). The heat-peelable adhesive sheet 5 was obtained in the same manner as in Example 1 except that the heat-expandable pressure-sensitive adhesive layer 5 was used.

(Comparative Example 1)

2 parts by weight of an isocyanate-based crosslinking agent (Coronate L manufactured by Nippon Polyurethane Industry) and a rosin-based adhesion-providing resin (Pensel D125 manufactured by Arakawa Chemical Co., Ltd.) having a hydroxyl value of 40 mgKOH were prepared in an amount of 100 parts by weight of the copolymer. /g, acid value: 13 mg KOH / g) 30 parts by weight, heat-expandable microspheres (Matsumoto Microsphere F50, manufactured by Matsumoto Oil & Fats Co., Ltd.), 35 parts by weight of a toluene solution, which was applied so as to have a thickness of 35 μm after drying. On a PET substrate separator (38 μm) (heat-expandable adhesive layer 6). A heat-peelable adhesive sheet 6 was obtained in the same manner as in Example 1 except that the heat-expandable pressure-sensitive adhesive layer 6 was used.

With respect to the heat-peelable pressure-sensitive adhesive sheets 1 to 6 obtained in Examples 1 to 5 and Comparative Example 1, the probe viscosity increase and decrease rate, the adhesion force, and the total light transmittance were measured by the above methods. The measurement results are shown in Table 1.

(Validation results)

(Evaluation method for cutting workability)

The laminated ceramic sheet ((*1) 100 mm × 100 mm) obtained by the following method was bonded to the heat-expandable adhesive layer of each of the heat-peelable adhesive sheets 1 to 6, and each of the ceramic sheets was bonded thereto. The heat-peelable adhesive sheets 1 to 6 are attached and fixed to the cutting ring, and the wafer is completely cut into a size of 0402 (0.4 mm × 0.2 mm) by a microtome (the cutting process by cutting is performed), at the time of cutting Visually confirm the presence or absence of wafer peeling. At this time, the cutting blade used ZH05-SD2000-N1-110-DD manufactured by DISCO. The feed speed of the cutting blade was set to 70 mm/s, and the number of revolutions of the cutting blade was set to 50,000/s. When all of the wafers were attached to the heat-peelable adhesive sheet without being peeled off, the wafer scattering rate was 0%. Therefore, the smaller the wafer scattering rate, the better the wafer scattering prevention. The evaluation result of the wafer scattering prevention property is shown in the "wafer scattering rate (%)" column of Table 1. The number of wafers that have been cut is set to C ₀ , and the number of wafers scattered is set to C, and the wafer scattering rate X is obtained according to the equation (5).

<*1 method for making laminated ceramic sheets>

100 parts by weight of barium titanate (manufactured by Sigma Chemical Industry Co., Ltd.: trade name "BT-03/high-purity perovskite"), polyvinyl butyral (manufactured by Electrochemical Industry Co., Ltd.: trade name "PVB 』) 100 parts by weight (propylene glycol extended ether dissolved product, 10% substrate), bis(2-ethylhexyl) phthalate (manufactured by J-PLUS: "DOP"), 6 parts by weight, diglycerin 2 parts by weight of an ether oleate (manufactured by Riken Vitamin: "Rikemal 0-71-D (E)") and 80 parts by weight of toluene were stirred and mixed to prepare a coating liquid for producing a ceramic sheet. Then, the coating liquid was applied onto a separator having a polyxanylene mold release agent coated on one side so as to have a thickness of about 50 μm after drying, and dried at 80 ° C for 5 minutes, and then peeled off from the separator. Ceramic sheet. Ten sheets of the ceramic sheet were laminated and pressed at a pressure of 300 kg/cm ² to obtain a laminated ceramic sheet.

The adhesive sheet of the present invention (Examples 1 to 5) greatly suppresses wafer scattering during dicing, and in particular, the adhesive sheet (Examples 1 to 3, and 5) having better compatibility is not produced at all. Scattered.

In Comparative Example 1, it was confirmed that there were a plurality of wafer scattering numbers. As a factor of this, it is generally presumed that since the compatibility is poor, a region of the resin having a low adhesive force is locally generated, and the adhesion between the wafer and the adhesive sheet is largely lowered.

The present invention has been described in detail with reference to the specific embodiments thereof, and it is obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

The present application is based on Japanese Patent Application No. 2013-151139, filed on Jan.

1‧‧‧Support substrate

2‧‧‧ Thermally expansive adhesive layer

3‧‧‧ spacer

Claims (9)

A heat-peelable pressure-sensitive adhesive tape comprising a heat-expandable pressure-sensitive adhesive layer containing an acrylic pressure-sensitive adhesive, wherein the heat-expandable pressure-sensitive adhesive layer contains an adhesion-imparting resin, and the adhesion-imparting resin is a phenol-based resin and/or a rosin-based resin. And the hydroxyl value is 45 to 100 mgKOH/g, and the rate of change of the viscosity of the probe shown in Formula 1 of the heat-expandable pressure-sensitive adhesive layer is 19.0% or less, W=|(B ₀ -B)/B ₀ ×100| (Formula 1) (In Equation 1, W is the rate of change of the viscosity of the probe, B ₀ is the viscosity of the probe of the heat-peelable adhesive tape, and B is the viscosity of the probe after storage for 1 week at 0 ° C) Adhesion of the heat-expandable adhesive layer at 23 ° C when the above-mentioned heat-peelable adhesive tape is attached to a polyethylene terephthalate film (thickness: 25 μm) at 23 ° C for 30 minutes in an environment of 23 ° C for 30 minutes. (peeling angle: 180°, drawing speed: 300 mm/min) was 2.5 N/20 mm or more. The heat-peelable pressure-sensitive adhesive tape according to claim 1, wherein the amount of the adhesion-imparting resin is from 10 to 50 parts by weight based on 100 parts by weight of the base polymer forming the heat-expandable pressure-sensitive adhesive layer. The heat-peelable adhesive tape of claim 1, which has a total light transmittance reduction rate of 2% or less after storage at 0 ° C for one week. The heat-peelable adhesive tape of claim 1, wherein the heat-expandable adhesive layer contains a crosslinking agent. The heat-peelable pressure-sensitive adhesive tape according to claim 1, wherein the heat-expandable pressure-sensitive adhesive layer is formed on at least one side of the substrate. The heat-peelable pressure-sensitive adhesive tape according to claim 1, wherein the heat-expandable pressure-sensitive adhesive layer is formed on at least one side of the substrate by interposing a rubber-like organic elastic layer. The heat-peelable adhesive tape of claim 6, wherein the thickness of the rubber-like organic elastic layer is 3~200μm. The heat-peelable adhesive tape of claim 1 is used when the electronic component is cut. A method of cutting an electronic component using the heat-peelable adhesive tape according to any one of claims 1 to 8.