TWI608073B - Heat strip type adhesive tape and cutting method for 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 and a method of cutting an electronic component using the same.

In recent years, miniaturization or precision of parts required for electronic parts has been made. The same is true for module parts or sensors mounted on computers or mobile phones, including ceramic capacitors. Moreover, the uneven shape, depth, material, and the like of the electrode portion of the electronic component are various.

In the step of dicing these electronic parts, a method of using a heat-peelable adhesive tape is widely used. By using the heat-peelable adhesive tape, the electronic component can be firmly fixed during the cutting step, and the adhesive force is lowered by heating after the cutting step, so that the cut electronic component can be easily self-heated and peeled off. The tape is peeled off (for example, refer to Patent Document 1 to Patent Document 6).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2002-146299

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2008-297412

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2010-214947

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2010-229399

[Patent Document 5] International Publication No. 2005/087887

[Patent Document 6] International Publication No. 2005/087888

As described above, it has been known that a heat-peelable adhesive tape is used for cutting an electronic component, and it is usually practically used. However, in recent years, especially in the cutting process of electronic parts having metal electrodes formed by plating, vapor deposition, sputtering, etc., such as module parts or sensors, in particular, cutting and cutting processes have been used. In the case of the heat-peelable adhesive tape, the electrode surface which is heated and peeled off by the heat-peelable adhesive tape is contaminated by the adhesive component in the portion where the electrode surface is in contact with the adhesive surface, causing so-called "electrode contamination", thereby causing The reduction in yield is a problem. However, the approach to this topic has not yet been clarified.

The industry believes that "electrode contamination" is caused by an adhesion-imparting resin added to control the adhesion of the heat-peelable adhesive tape. However, if the amount of addition of the adhesion-imparting resin is reduced in order to prevent electrode contamination, the adhesion is inevitably lowered, so that the retention of the electronic component is extremely lowered, and the yield reduction due to the "wafer scattering" becomes a problem. Therefore, it is a problem to simultaneously suppress the scattering of the wafer during the cutting process and the low contamination of the electrode after the processing.

Regarding the above-mentioned "electrode contamination", it is considered that the presence of the adhesion-imparting resin has a large influence as described above. Further, since the adhesion-providing resin directly contacts the electrode surface, printing contamination occurs, and as a result, contamination of the electrode surface is progressed, and the mounting abnormality in the subsequent step is caused, resulting in a decrease in yield.

The adhesive imparting resin is usually used to control the adhesion of the adhesive by being added to the adhesive. In order to prevent "electrode contamination", it is considered that the adhesion-free resin is not added, and the adhesion is significantly reduced in the compounding system in which the adhesion-imparting resin is not added, and the electronic component is insufficiently retained in the electronic component cutting process (for example, the cutting step). Therefore, it is impossible to maintain electronic parts, and wafer scattering occurs, which not only causes a decrease in yield, but also causes a possibility of stopping or breaking the device.

In addition, it is also considered to reduce the amount of adhesion imparted to the resin, but only a small amount of Adding can increase the adhesion of the adhesion, the type of resin is limited, the upper limit of the amount of addition is limited, and it is difficult to control the adhesion, etc., so the degree of freedom in the design of the adhesive is deprived, and as a result, the thermal peeling type adhesive matching the process cannot be provided. Belt, so it is hard to say that it is better. Further, in the method of reducing the adhesion-imparting resin, in order to improve the adhesion by other methods, for example, a method of reducing the amount of the crosslinking agent and thickening the thickness of the adhesive can be considered.

However, when the amount of the crosslinking agent is reduced, the gel fraction of the adhesive is lowered, and when it is heated and peeled off, there is a case where the adhering body remains on the heat-peelable pressure-sensitive adhesive tape or the paste remains. The possibility. Also, the thick adhesive layer is also limited in equipment, and it is not preferable in consideration of productivity. That is, it is difficult to simultaneously achieve the problems of "electrode contamination" and "wafer scattering" by the above method.

The present invention has been made in view of the above problems, and an object of the invention is to provide a heat-peelable adhesive tape for cutting an electronic component and a method for cutting an electronic component using the heat-peelable adhesive tape, the heat-peelable adhesive tape It is characterized in that it has sufficient retention during the cutting process of the electronic component, and does not cause electrode contamination of the electronic component after the heat stripping step.

That is, the present invention provides the following 1 to 15.

A heat-peelable adhesive tape comprising a heat-expandable adhesive layer, and a probe viscosity value of the heat-expandable adhesive layer (immersion speed: 30 mm/min, test speed: 30 mm/min, preload: 100gf, pressurization time: 1.0sec.) is 60N/5mm the above.

2. The heat-peelable pressure-sensitive adhesive tape according to the above 1, wherein the heat-expandable pressure-sensitive adhesive layer has a gel fraction of 50% or more.

3. The heat-peelable adhesive tape according to the above 1 or 2, wherein the heat-expandable pressure-sensitive adhesive layer contains an adhesion-imparting resin.

4. The heat-peelable adhesive tape according to the above 3, wherein the hydroxyl value of the adhesion-imparting resin is 40 KOHmg/g or more.

5. The heat-peelable pressure-sensitive adhesive tape according to any one of the above 1 to 4, wherein, after being attached to a polyethylene terephthalate film (thickness: 25 μm) at 23 ° C, it is placed in an environment of 23 ° C. At this time, the adhesion of the above-mentioned heat-expandable pressure-sensitive adhesive layer at 23 ° C (peeling angle: 180°, tensile speed: 300 mm/min) was 0.2 N/20 mm width to 20 N/20 mm width.

6. The heat-peelable adhesive tape according to any one of the above 1 to 5, wherein the heat-expandable pressure-sensitive adhesive layer contains heat-expandable microspheres.

7. The heat-peelable pressure-sensitive adhesive tape according to any one of the above 1 to 6, wherein the adhesive constituting the heat-expandable pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive.

8. The heat-peelable adhesive tape according to any one of the above 1 to 7, wherein the heat-expandable pressure-sensitive adhesive layer contains a crosslinking agent.

The heat-peelable adhesive tape according to any one of the above 1 to 8, wherein the heat-expandable pressure-sensitive adhesive layer has a thickness of 5 to 300 μm.

10. The heat-peelable pressure-sensitive adhesive tape according to any one of the above 1 to 9, wherein the heat-peelable pressure-sensitive adhesive layer is formed directly on at least one side of the substrate.

The heat-peelable pressure-sensitive adhesive tape according to any one of the above 1 to 9, wherein the heat-peelable adhesive layer is formed by forming at least one of the rubber-like organic elastic layers on the substrate.

12. The heat-peelable adhesive tape according to the above 11, wherein the rubber-like organic elastic layer has a thickness of from 3 to 200 μm.

13. The heat-peelable adhesive tape according to any one of the above 1 to 12, which is used when the electronic component is cut.

14. The thermal peeling type adhesive tape according to the above 12, which is for cutting a member for a ceramic capacitor.

A method of cutting an electronic component, comprising: a step of attaching an electronic component to the heat-peelable adhesive tape according to any one of 1 to 13, and a step of performing a cutting process on the electronic component.

When the electronic component or the like is subjected to the cutting and cutting process, the wafer is not scattered and the electrode contamination is not caused by the heating, and the wafer subjected to the cutting process is easily peeled off by heating.

1‧‧‧Support substrate

2‧‧‧Rubber-like organic elastic layer

3‧‧‧ Thermally expansive adhesive layer

4‧‧‧Smooth peelable film

Fig. 1 is a schematic view showing a heat-peelable adhesive tape of the present invention.

In the present invention, it is important to simultaneously achieve two problems of "electrode contamination" and "wafer scattering". Further, the "heat peeling property" which is a necessary function of the heat-peelable pressure-sensitive adhesive tape should not be impaired.

As a result of intensive research on these two problems, the present inventors have found that by setting the viscosity of the probe of the heat-peelable adhesive tape to a specific value, the electronic component can be cut without causing "wafer scattering". The present invention has been completed by recovering the chipped electronic parts without "electrode contamination" after the heat stripping step.

Furthermore, the present invention is characterized in that the gel fraction of the heat-expandable pressure-sensitive adhesive layer is set to a specific range, the heat-expandable pressure-sensitive adhesive layer contains the adhesion-imparting resin, or the hydroxyl value of the adhesion-imparting resin is made specific. In the range, the adhesive force of the heat-peelable pressure-sensitive adhesive tape can be set to a specific value, and the heat-expandable pressure-sensitive adhesive layer can be contained in the heat-expandable pressure-sensitive adhesive layer by using an acrylic pressure-sensitive adhesive as an adhesive constituting the heat-expandable pressure-sensitive adhesive layer or The cross-linking agent or the thickness of the heat-expandable pressure-sensitive adhesive layer is set to a specific range, and the electronic component can be cut more reliably.

The term "electrode" as used herein refers to Au, Ag, and Cu formed by various processes represented by vapor deposition, printing, plating, and sputtering on a printed circuit board such as a glass epoxy substrate or a phenol resin substrate. Metals such as Al, Ni, Pt, Pb, Pd, Cu, and Fe are not limited to simple substances and alloys. Further, for example, a wafer of a semiconductor wafer such as a germanium wafer or a sapphire wafer, or a wafer after the circuit is printed, and a PKG after sealing are also in accordance with this. However, the above is merely an example and is not limited thereto.

Regarding the viscosity value of the probe, when the adhesive imparts uneven distribution on the surface of the adhesive, the viscosity of the probe is lowered. This is because the glass transition temperature (Tg) of the adhesive-imparting resin is usually 25° C. or more. Therefore, the adhesion-imparting resin is unevenly distributed on the surface of the adhesive to increase the apparent elastic modulus of the surface of the adhesive. That is, by measuring the viscosity value of the probe of the adhesive, the uneven distribution of the adhesion-imparting resin can be confirmed.

When the cross section of the tape in the case of "electrode contamination" was observed, it was confirmed that the adhesion-imparting resin component was unevenly distributed on the surface layer of the tape. The uneven distribution of the adhesive-imparting resin component on the surface layer depends on the adhesion of the adhesive-imparting resin to the surface of the adhesive.

Therefore, in the present invention, by further suppressing the bleeding of the adhesion-imparting resin, uneven distribution of the adhesion-imparting resin on the surface of the adhesive can be prevented, and the contact ratio with the electrode surface can be reduced, whereby "electrode contamination" can be reduced.

In order to prevent the adhesion of the resin to the surface of the adhesive, that is, the phase separation from the adhesive, it is considered to use an adhesion-imparting resin which is preferably compatible with the adhesive. It is considered that the uneven distribution of the adhesion of the resin to the surface of the adhesive can be prevented, and the contact of the resin with the electrode can be suppressed by the adhesion, thereby preventing "electrode contamination".

Therefore, the heat-peelable adhesive tape of the present invention is characterized by the viscosity of the probe of the heat-expandable adhesive layer (immersion speed: 30 mm/min, test speed: 30 mm/min, preload: 100 gf, pressurization time: 1.0) Sec.) is 60N/5mm the above.

Fig. 1 shows an example of a heat-peelable adhesive tape used in the present invention.

In this example, 1 is a support substrate, 2 is a rubbery organic elastic layer, 3 is a heat-expandable adhesive layer, and 4 is a smooth peelable film (separator). Here, in the present invention, 3 is necessary, and 1, 2, and 4 are provided for arbitrary selection, and thus may or may not be present. Furthermore, in the case of setting 1, 2, and 4, as long as at least one side of 3 is provided as a junction surface, it can be set in any order. Hereinafter, the heat-peelable adhesive tape of the present invention will be described.

(substrate)

The substrate is used as a support body for a heat-peelable double-sided adhesive tape or sheet. As 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)).

(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); Alkenes, such as ethylene (PE), polypropylene (PP), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), olefin resin, polyamide (nylon), and wholly aromatic A guanamine resin such as polyamine (aromatic polyamide), a polyimine (PI) film, a polyvinyl chloride (PVC) film, a polyphenylene sulfide (PPS) film, a fluorine film, or a polyether ether ketone ( PEEK) film and the like. These materials may be used singly or in combination of two or more.

Specifically, examples of the polyethylene terephthalate (PET) film include "Lumirror" of Toray Co., Ltd., "Teijin Tetoron Film" of "Teijin Dupont Films Co., Ltd.", "Melinex", and shares of Mitsubishi Plastics. "Diafoil" of the company, etc.; as a polyethylene naphthalate (PEN) film, "Teonex" of Teijin Dupont Films Co., Ltd., etc.; as a polyimide film (PI) film, the east is mentioned. "Kapton" of Li Dubang Co., Ltd., "Apical" of Kaneka Co., Ltd., "Upilex" of Ube Industries Co., Ltd., etc.; as a polypropylene (PP) film, "Torayfan of Toray Co., Ltd." "Suntox" of Sun-tox Co., Ltd., "Pylen Film" of Toyobo Co., Ltd., etc.; as a polyvinyl chloride (PVC) film, "ARUTORON" of Mitsubishi Plastics Co., Ltd., Achilles Co., Ltd. "Achilles Type C+" and the like; as the polyethylene (PE) film, "NSO" of Ogura Industrial Co., Ltd., etc.; and polyphenylene sulfide (PPS) film, Toray Co., Ltd. of "TORELINA" and the like; as the fluorine film, "Toyoflon" of Toray Co., Ltd. and "Tedlar Film" of Dupont Co., Ltd., etc. are mentioned. 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 a natural fiber 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 the above 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 be composed of a single layer or may also include a laminate.

In order to improve the adhesion to the heat-expandable adhesive layer 3 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, and the like. The coating treatment by a primer or the like may be carried out by an oxidation treatment by a chemical or physical method or the like.

(heat-expandable adhesive layer)

The heat-expandable adhesive layer 3 contains an adhesive for imparting adhesion, and may further contain There is a heat-expandable microsphere for imparting thermal expansion. When the heat-expandable pressure-sensitive adhesive layer 3 contains the heat-expandable microspheres, the adhesive tape is bonded to the adherend, and the heat-expandable pressure-sensitive adhesive layer 3 is heated at any time to foam the heat-expandable microspheres. Alternatively, the expansion treatment can reduce the adhesion area of the heat-expandable pressure-sensitive adhesive layer 3 and the adherend, and the adhesive tape can be easily peeled off.

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

Further, from the viewpoint of the balance between the appropriate adhesion force before the heat treatment and the decrease in the adhesion force after the heat treatment, it is more preferable that the adhesive has a dynamic elastic modulus at 25 to 150 ° C at 5 kPa to 1 MPa. The range of polymers is the basis for pressure sensitive adhesives.

Further, in the present invention, it is important that the heat-expandable pressure-sensitive adhesive layer has the following constitution or characteristics. Further, by adjusting the gel fraction of the heat-expandable pressure-sensitive adhesive layer, the adhesion of the heat-expandable pressure-sensitive adhesive layer and the heat peeling property can be controlled.

The gel fraction of the heat-expandable pressure-sensitive adhesive layer is 50% by weight or more, preferably 60% by weight or more (more preferably 65% by weight or more). When the gel fraction of the heat-expandable pressure-sensitive adhesive layer is 50% by weight or more, the adherend does not remain on the heat-peelable pressure-sensitive adhesive tape when peeled off from the adherend, and peeling by heating alone can be efficiently performed ( Naturally stripped).

Specifically, when the gel fraction of the heat-expandable pressure-sensitive adhesive layer is 50% by weight or more, the heat-expandable pressure-sensitive adhesive layer is subjected to heat treatment, and only the heat-peelable pressure-sensitive adhesive tape is placed in the air in the opposite direction. The wafer that has been cut can be peeled off by inverting (by cutting the wafer on the heat-expandable adhesive layer downward). Further, it is also possible to suppress or prevent the residual of the paste on the surface of the adherend (or the wafer to be cut).

As the adhesive constituting the heat-expandable pressure-sensitive adhesive layer 3, it is preferred that the foaming and/or expansion of the heat-expandable microspheres are not restrained as much as possible during heating. Examples of such an adhesive include an acrylic adhesive, a rubber adhesive, a vinyl alkyl ether adhesive, a polyoxygen adhesive, a polyester adhesive, a polyamide adhesive, and an amine base. Formate adhesion Agent, styrene-diene block copolymer-based adhesive, and a heat-melting resin having a melting point of about 200 ° C or less, which is a viscosity-improving adhesive, a radiation-curable adhesive, etc. In the case of the known adhesives, one type may be used, or two or more types may be used in combination (for example, refer to JP-A-56-61468, JP-A-63-17981, and the like).

Further, as the adhesive, an acrylic adhesive or a rubber-based adhesive can be preferably used, and an acrylic adhesive is particularly preferable. The acryl-based adhesive is an acrylic resin based on an acrylic polymer (homopolymer or copolymer) having one or two or more kinds of alkyl (meth) acrylate as a monomer component. Adhesive.

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 An alkyl group such as a heptaalkyl ester, an octadecyl (meth)acrylate, a nonadecyl (meth)acrylate or an amyl (meth)acrylate has a carbon number of 1 to 20 and has a straight 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, for the purpose of improving the cohesive force, heat resistance, crosslinkability, etc., the acrylic polymer may optionally contain a unit corresponding to other monomer components copolymerizable with the above (meth)acrylic acid alkyl ester. .

Examples of such a monomer component include a carboxyl group such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxy amyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Anhydride monomer such as maleic anhydride or itaconic anhydride; hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyl group (meth)acrylate a hydroxyl group-containing monomer such as ester, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl methacrylate; benzene Ethylene sulfonic acid, allyl sulfonic acid, 2-(methyl) propylene decylamine-2-methylpropane sulfonic acid, (meth) acrylamide propyl sulfonic acid, sulfopropyl (meth) acrylate, (A) a sulfonic acid group-containing monomer such as acryloxynaphthalenesulfonic acid; (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylonitrile (N-substituted) guanamine monomer such as amine, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, etc.; aminoethyl (meth) acrylate, N,N-dimethylamino group (meth)acrylic acid Ethyl aminoalkyl (meth)acrylate such as ester, tert-butylaminoethyl (meth)acrylate; methoxyethyl (meth)acrylate, ethoxylate (meth)acrylate Alkoxyalkyl (meth) acrylate monomer such as ester; N-cyclohexyl maleimide, N-isopropyl maleimide, N-lauryl butene a maleimide monomer such as quinone imine or N-phenyl maleimide; N-methyl Ikonide, N-ethyl Ikonide, N-butyl伊ikonimide, N-octyl Icinoimine, N-2-ethylhexylkamponium imine, N-cyclohexylkkonium imine, N-lauryl Ikonide, etc. Ikonium imine monomer; N-(methyl) propylene oxymethylene succinimide, N-(methyl) propylene fluorenyl-6-oxyhexamethylene succinimide, Amber quinone imine monomer such as N-(methyl)propenyl-8-oxy octamethylene succinimide; vinyl acetate, vinyl propionate, N-vinyl pyrrolidone, 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-based monomer such as glycidyl (meth)acrylate; polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, methoxyethylene glycol (meth) acrylate a diol-based acrylate monomer such as an ester or a methoxypolypropylene glycol (meth) acrylate; a tetrahydrofurfuryl (meth) acrylate, a fluorine (meth) acrylate, or a poly methoxy (meth) acrylate; An acrylate monomer having a hetero ring, a halogen atom, a ruthenium atom or the like; hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(methyl) Acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol Polyfunctional monomers such as (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate; isoprene, An olefin monomer such as butadiene or isobutylene; a vinyl ether monomer such as vinyl ether; These monomer components can 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 parts 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, 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, polyiso Butene or such modified body, etc.) is a rubber-based adhesive as a base polymer.

Further, the above-mentioned adhesive constituting the heat-expandable pressure-sensitive adhesive layer 3 may contain a crosslinking agent, an adhesion-imparting resin, a pigment, a dye, a filler, and the like in addition to a polymer component such as an adhesive component (base polymer). Suitable additives such as anti-aging agents, conductive materials, antistatic agents, ultraviolet absorbers, light stabilizers, peel adjusters, softeners, surfactants, flame retardants, antioxidants, and the like.

(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 can be appropriately determined depending on the case where the adhesion is controlled. In general, it is equivalent to 0.1 to 20 weights per 100 parts by weight of the base polymer. Preferably, it is formulated in an amount of 0.5 to 10 parts by weight.

(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 Co., Ltd. Manufactured), propylene glycol diglycidyl ether (product name "Epolight 70P" manufactured by Kyoeisha Chemical Co., Ltd.), polyethylene glycol diglycidyl ether (product name "EPIOL E-400" manufactured by Nippon Oil Co., Ltd.), Polypropylene glycol diglycidyl ether (product name "EPIOL P-200" manufactured by Nippon Oil & Fat Co., Ltd.), sorbitol polyglycidyl ether (product name "DENACOL EX-611" manufactured by Nagase ChemteX Co., Ltd.), glycerin polycondensate Glycerol ether (product name "DENACOL EX-314" N Agarase ChemteX Co., Ltd.), pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether (product name "DENACOL EX-512" manufactured by Nagase ChemteX Co., Ltd.), sorbitan polyglycidyl ether, trimethylol Propane polyglycidyl ether, diglycidyl adipate, diglycidyl phthalate, triglycidyl-tris(2-hydroxyethyl) isocyanurate, resorcinol diglycidyl ether, The bisphenol S-diglycidyl ether may, for example, be an epoxy resin having two or more epoxy groups in the molecule. 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 case where the adhesion is controlled. In general, it is equivalent to 0.01 to 10 parts by weight, preferably 0.03 to 5 parts by weight, per 100 parts by weight of the base polymer.

(adhesive to resin)

As a standard for the adhesion-imparting resin which is preferably compatible with the adhesive, attention is paid to the hydroxyl value of the adhesive to the resin. Specifically, it is preferably 40 KOHmg/g or more, preferably 50 to 500 KOHmg/g or more, and further The adhesive is preferably a resin of 70 to 400 KOHmg/g or more. Further, the above numerical value of the hydroxyl value is a value measured by an acetylation method based on JIS K 0070-1992.

By setting the value of the hydroxyl value to 40 KOHmg/g or more, the affinity with the ester group contained in the acrylic polymer can be ensured, and the state of being dispersed in the adhesive can be maintained, and as a result, phase separation is preferable. On the other hand, when the hydroxyl value is a small value, the affinity for the polymer is lowered, and the adhesion-providing resin forms a region in which the resin forms a stable state, and the region is generally formed on the surface of the adhesive, so that the adhesion imparts a resin bias. It exists on the surface of the adhesive and therefore becomes an important factor causing "electrode contamination".

In the present invention, the adhesive-imparting resin which can be used to satisfy the above conditions is not particularly limited, and is preferably an adhesive-imparting resin obtained by copolymerizing a phenol group such as indophenol, an alkylphenol or rosin. The reason for this is that the molecular structure of indophenol or alkylphenol and rosin is not spatially squeezed together, so that the hydroxyl group of the phenol group and the ester group in the acrylic adhesive are easily interacted, so that the compatibility is improved.

Specifically, as the phenolic resin, YS Polyster S145 manufactured by Yasuhara Chemical Co., Ltd. or TAMANOL 901 manufactured by Arakawa Chemical Co., Ltd., and alkylphenol resin can be used as the alkylphenol-based resin. TAMANOL 1010R", "TAMANOL 200N", etc.

The amount of the tackifying resin to be added is generally 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.

(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. One type of the plasticizer may be used, or two or more types may be used in combination.

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 30 parts by weight, preferably 1 to 20 parts by weight, per 100 parts by weight of the base polymer.

(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, for example, propane, propylene, butene, n-butane, isobutane, isopentane, neopentane, n-pentane, n-hexane, isohexane, heptane, octane, A substance such as petroleum ether, methane halide, tetraalkyl decane-like low-boiling liquid, azo dimethyl hydrazine which is thermally decomposed by heating to be gaseous, and which is easily gasified 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. As examples of the monomer, there may be exemplified a nitrile monomer such as acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethoxy acrylonitrile or fumaronitrile; for example, acrylic acid, methacrylic acid, Ikonic acid, maleic acid, fumaric acid, methyl maleic acid-like carboxylic acid monomer; such as vinylidene chloride; vinyl acetate; methyl (meth) acrylate, (a Ethyl acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, (meth) acrylate Ester, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, β-carboxyethyl acrylate (meth) acrylate; such as styrene, α-methyl styrene, chlorostyrene a styrene monomer; such as acrylamide, substituted acrylamide, methacrylamide, methacrylamide, or any mixture thereof, etc., as long as it contains a hot meltable substance in the present invention. Or a substance that is destroyed by thermal expansion or the like.

Further, many of the shell-forming substances are produced by copolymerization of one or more kinds of materials, and examples thereof include a vinylidene chloride-methyl methacrylate-acrylonitrile copolymer and a methyl methacrylate-acrylonitrile- A methacrylonitrile copolymer, a methyl methacrylate-acrylonitrile copolymer, an acrylonitrile-methacrylonitrile-iconic acid copolymer, or 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, "Matsumoto Microsphere" manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd. (product names F-30, F-36LV, F-50, F-65, FN-100SS, FN-) can also be used. 180SS, F-190D, F-260D, F-2800D), "Expancel" manufactured by Japan Fillite Co., Ltd. (product names 053-40, 031-40, 920-40, 909-80, 930-120), Wu "Daifoam" (product name H750, H850, H1100, S2320D, S2640D, M330, M430, M520) manufactured by Yuki Chemical Industry Co., Ltd., "Advancell" manufactured by Sekisui Chemical Industry Co., Ltd. (product names EML101, EMH204, EHM301) Commercial products such as EHM302, EHM303, EM304, EHM401, EM403, and EM501).

Further, in the present invention, the above other may be used as the heat-expandable microspheres. 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. Further, examples of the organic foaming agent include water; chlorofluoroalkane compounds such as trichloromonofluoromethane and dichloromonofluoromethane; azobisisobutyronitrile and azoquinone; An azo compound such as an amine or bismuth azodicarboxylate; p-toluenesulfonate, diphenylphosphonium-3,3'-disulfonium, 4,4'-oxybis(phenylsulfonate), An oxime compound such as allyl bis(sulfonate); an aminourea compound such as p-tolylsulfonyl urea or 4,4'-oxybis(phenylsulfonylaminourea); 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.

As the heat-expandable microspheres, in order to efficiently reduce the adhesion force of the adhesive layer by heat treatment, it is preferable that the volume expansion ratio is 5 times or more, 7 times or more, particularly 10 times or more, without breaking. A heat-expandable microsphere having moderate strength.

The blending amount of the heat-expandable microspheres can be appropriately set according to the expansion ratio of the adhesive layer or the decrease in adhesion force, and the like, and is generally, 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.

(Rubber-like organic elastic layer)

In order to impart deformability to the heat-peelable pressure-sensitive adhesive tape or to improve peelability after heating, a rubber-like organic elastic layer 2 is provided between the base material and the heat-expandable pressure-sensitive adhesive layer 3, but the rubber-like organic elastic layer 2 is optionally required. Set the layer, you don't have to set it. By providing the rubber-like organic elastic layer 2, the thermal exfoliation type adhesive tape 3 can be attached to the adherend (processed product or the like) by the heat-expandable adhesive layer 3, and the thermal exfoliation type adhesive tape can be thermally expanded. The surface of the adhesive layer 3 satisfactorily follows the surface shape of the adherend and increases the adhesion area.

Moreover, when the heat-peelable pressure-sensitive adhesive tape is peeled off from the adherend, the thermal expansion of the heat-expandable pressure-sensitive adhesive layer 3 can be controlled with high precision (preferred), and the heat-expandable pressure-sensitive adhesive layer 3 can be preferentially oriented in the thickness direction. Spread evenly.

That is, the rubber-like organic elastic layer 2 has a function of providing a large contact area when the heat-peelable pressure-sensitive adhesive tape is attached to the adherend, and the surface thereof follows the surface shape of the adherend. Further, it also has the effect of helping to reduce the heat-peeling type adhesion when the heat-expandable pressure-sensitive adhesive layer 3 is heated to be foamed and/or expanded in order to peel off the adhesive body from the heat-peelable pressure-sensitive adhesive tape. The heat-expandable pressure-sensitive adhesive layer 3 undergoes a three-dimensional structural change in the direction of foaming and/or expansion in the direction of the belt to form an undulating structure.

The rubber-like organic elastic layer 2 is preferably provided on the side of the base material side of the heat-expandable pressure-sensitive adhesive layer 3 so as to overlap the heat-expandable pressure-sensitive adhesive layer 3. Further, the rubber-like organic elastic layer 2 may be provided in a portion other than the substrate and the heat-expandable pressure-sensitive adhesive layer 3. The rubbery organic elastic layer 2 can be placed on one or both sides of the substrate.

An adhesive layer may be used for the rubber-like organic elastic layer 2, and the material thereof is not particularly limited, and an adhesive agent or the like exemplified in the heat-expandable pressure-sensitive adhesive layer 3 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 creep property-improving adhesive, and the radiation-curable adhesive are appropriately selected.

More specifically, for example, a rubber-based adhesive using a natural rubber or a synthetic rubber as a base polymer; an acrylic-based adhesive having an acrylic polymer as a base polymer; and the acrylic polymer-based Base, ethyl, propyl, butyl, 2-ethylhexyl, isooctyl, isodecyl, isodecyl, dodecyl, lauryl, tridecyl, pentadecyl, hexadecane Acrylic alkyl esters such as acrylic acid or methacrylic acid having an alkyl group having a carbon number of 20 or less, such as a heptadecyl group, an octadecyl group, a hexadecyl group or an eicosyl group; acrylic acid, methacrylic acid, and y Hydronic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, N-methylol acrylamide, acrylonitrile, methacrylonitrile, glycidyl acrylate, A Glycidyl acrylate, vinyl acetate, styrene, isoprene, butadiene, isobutylene, vinyl ether and the like are the main components.

The rubber-like organic elastic layer 2 may be formed of natural rubber, synthetic rubber or a synthetic resin having rubber elasticity, in addition to the above-mentioned adhesive. Examples of the synthetic resin include synthetic rubbers such as nitrile-based, diene-based, and acrylic-based resins; thermoplastic elastomers such as polyolefins and polyesters; and ethylene-vinyl acetate copolymers and polyamines. A rubber-elastic synthetic resin such as an acid ester, a polybutadiene or a 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 expressing rubber elasticity by a combination with a compounding agent such as a plasticizer or a softener.

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

The formation of the rubber-like organic elastic layer 2 can be carried out, for example, by applying a coating liquid containing a constituent material of the rubber-like organic elastic layer onto the substrate 1 (coating method); A film of a rubber-like organic elastic layer forming material or a laminated film in which a layer containing the rubber-like organic elastic layer forming material is formed in advance on one or more layers of the heat-expandable adhesive layer 3, and a substrate 1 (dry type) A method of co-extruding 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 2 may be formed of a foamed film or the like mainly composed of the component. The foaming can be carried out by a conventional method, for example, by mechanical stirring, a method of generating a gas by a reaction, a method of using a foaming agent, a method of removing a soluble substance, a method of forming a coagulation bubble by a sprayer, The sintering method or the like is performed. The rubber-like organic elastic layer 2 may be one layer or may be composed of a laminated structure including two or more layers.

The rubber-like organic elastic layer 2 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 tape can be provided to follow the surface shape of the adherend to provide a large contact area, and contribute to the heat-expandable adhesive layer 3 . A three-dimensional structural change occurs to form an undulating structure. Further, since the thickness is not too thick, aggregation failure occurs in the rubber-like organic elastic layer 2 after foaming.

(bead)

As a protective material for the surface (adhesive surface) of the heat-expandable adhesive layer 3 or the like, it can be used. Spacers, spacers can be used as needed or not. As the separator, the both surfaces may be the release surface, or the one surface (one surface) may be the release surface. Further, the separator is peeled off when the adhesive layer protected by the separator is utilized.

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 adhesion of fluorine-based polymers such as polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, and chlorofluoroethylene-vinylidene fluoride copolymer A base material; a low-adhesive base material 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.

The heat-expandable pressure-sensitive adhesive layer 3 of the heat-peelable pressure-sensitive adhesive tape can be formed, for example, by a method of preparing a coating liquid containing an adhesive or heat-expandable microspheres by using a solvent as needed, and coating the coating liquid. a method of supporting the substrate 1 or the rubber-like organic elastic layer 2 formed on the support substrate 1 as follows; applying the above coating liquid to a suitable separator (release paper or the like) to form thermal expansion The adhesive layer, a method of transferring (transferring) the heat-expandable pressure-sensitive adhesive layer to the support substrate 1 or the rubber-like organic elastic layer 2, and the like. At this time, the heat-expandable adhesive layer 3 may be either a single layer or a composite layer.

The heat-peelable adhesive tape is characterized in that the viscosity of the probe of the heat-expandable adhesive layer (immersion speed: 30 mm/min, test speed: 30 mm/min, preload: 100 gf, pressurization time: 1.0 sec.) is 60 N /5mm the above.

The probe viscosity value is used as a method for confirming the uneven distribution of the adhesion-imparting resin on the surface of the adhesive. The adhesion measurement is not only represented by the interfacial properties but also by the combination of the rigidity of the substrate. On the other hand, the probe viscosity measurement can ignore the rigidity of the substrate. The effect is more sensitive to the physical properties of the surface of the adhesive.

When the adhesion imparts uneven distribution of the resin on the surface of the adhesive, the viscosity of the probe is lowered. This is because the glass transition temperature (Tg) of the adhesive-imparting resin is usually 25° C. or more. Therefore, the adhesion-imparting resin is unevenly distributed on the surface of the adhesive to increase the apparent elastic modulus of the surface of the adhesive. That is, by measuring the viscosity value of the probe of the adhesive, the uneven distribution of the adhesion-imparting resin can be confirmed.

Specifically, it is preferred that the probe viscosity value is 60N/5 mm. Above, preferably 80~700N/5mm Above, further preferably 100N~500N/5mm the above. By setting the probe viscosity value within the above range, uneven distribution of the resin to the adhesion can be prevented, and as a result, "electrode contamination" can be prevented.

Further, the heat-peelable pressure-sensitive adhesive tape of the present invention preferably has the following characteristics: the surface of the heat-expandable pressure-sensitive adhesive layer is attached to the surface of the silicon wafer, and the surface of the silicon wafer after the peeling is heated (the heat-expandable pressure-sensitive adhesive layer The carbon element ratio R _C1 (%) measured by XPS on the surface of the wafer contacted by the surface satisfies the following relation (1).

R _C1 ≦60+R _C2 relation (1)

[In relation (1), R _C2 represents the carbon element ratio (%) of the wafer surface measured by XPS before attachment]

That is, the heat-peelable adhesive tape of the present invention preferably has a property of attaching the surface of the heat-expandable adhesive layer to the surface of the silicon wafer so as to heat the peeled silicon wafer. Carbon ratio R _C1 (%) measured by XPS on the surface (the peeling surface of the heat-peelable adhesive tape), and carbon measured by XPS on the surface of the wafer before the thermal peeling adhesive tape is attached The difference [R _{C1 -} R _C2 ] of the element ratio R _C2 (%) (in the case of " _{ΔR C1-2} ") is 50 or less.

_{ΔR C1-2 is} preferably 50 or less, and may be, for example, 0 to 50 (preferably 30 or less (for example, 0.1 to 30), further preferably 20 or less (for example, 0.5 to 20), and particularly preferably 5 or less (for example, The range of 1~5)] is selected. Further, _{ΔR C1-2} may also be a negative number. When _{ΔR C1-2} exceeds 50, the degree of contamination of the electrode surface of the electronic component in contact with the surface of the heat-expandable pressure-sensitive adhesive layer becomes high, that is, electrode contamination occurs, and the processed electronic component becomes a defective product.

Such an element ratio [carbon element ratio R _C1 (%), carbon element ratio R _C2 (%), etc.] is measured by XPS (X-ray Photoelectron Spectroscopy).

Specifically, regarding the carbon element ratio R _C1 (%) measured by XPS, for example, the heat-peelable adhesive tape may be attached to the tantalum wafer in such a manner that the surface of the heat-expandable adhesive layer contacts the surface of the wafer. After the surface, heat treatment was performed for 3 minutes in a hot air dryer at a specific temperature (any temperature at which the heat-peelable adhesive tape was naturally peeled off), and the wafer was peeled off from the tantalum wafer, and thereafter an X-ray photoelectron spectroscopic analyzer was used ( Model name "5400" manufactured by ULVAC-PHI Co., Ltd., with X-ray source: MgKα15 KV (300W), sweeping angle: 45°, measuring area: 1×3.5 mm, peeling off the adhesive tape of the wafer The surface was subjected to X-ray photoelectron spectroscopy to thereby determine the carbon element ratio R _C1 (%).

On the other hand, regarding the carbon element ratio R _C2 (%) measured by XPS, for example, an X-ray photoelectron spectroscopy apparatus (model name "5400" manufactured by ULVAC-PHI Corporation) can be used, and an X-ray source: MgKα15 KV can be used. (300W), sweep angle: 45°, measurement area: 1×3.5 mm [in the same device and the same condition as the ratio of carbon element R _C1 (%)], before attaching the heat-peelable adhesive tape Then, the surface of the wafer was subjected to X-ray photoelectron spectroscopy to determine the carbon element ratio R _C2 (%).

The heat treatment conditions for allowing the adhesive tape to be more easily peeled off from the adherend are based on the reduction in the adhesion area based on the surface state of the adherend or the type of the heat-expandable microsphere, and the heat resistance of the substrate or the adherend. It is determined by conditions such as heating method, and the general conditions are 100 to 250 ° C, 1 to 90 seconds (heating plate, etc.) or 5 to 15 minutes (hot air dryer, etc.).

The heat-peelable adhesive tape is preferably laminated on a polyethylene terephthalate film (thickness: 25 μm) at 23 ° C, and then left at 23 ° C for 30 minutes, at which time thermal expansion at 23 ° C Adhesion of the adhesive layer (peeling angle: 180°, stretching speed: 300 The mm/min) is 0.2 to 20 N/20 mm wide, preferably 1.0 to 20 N/20 mm wide. When the adhesive force in the environment of 23 ° C is 0.2 to 20 N / 20 mm, the adherend can be sufficiently held, and no wafer peeling is performed during the cutting process. When the width is less than 0.2 N/20 mm, it is difficult to sufficiently hold the adherend, and wafer peeling occurs during the cutting process. Further, in the case of 20 N/20 mm or more, even if the heat-expandable microspheres are foamed by heat treatment, there is a case where the adherend cannot be peeled off.

(adhesive layer)

In the case of the heat-peelable pressure-sensitive adhesive tape of the present invention, when a heat-dissipating adhesive layer containing heat-expandable microspheres is provided on one surface of the substrate, for example, it should be fixed at least in the cutting step of the object to be cut. 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 separately prepared base may be provided on the other surface of the substrate.

Regarding the adhesive layer at this time, it is also necessary to stabilize the stimulus such as heat or vibration generated during processing such as cutting. As the adhesive layer, for example, a resin used as the above-mentioned adhesive can be used as a substrate.

(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 tape 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 any method. It is particularly preferable to use a member for cutting a ceramic capacitor.

Such an electronic component is fixed to the substrate by an adhesive force via the heat-peelable adhesive tape of the present invention. Thereafter, the electronic component is cut by any method such as a boring method or a cutting method using a rotary blade, and then the heat-peelable adhesive tape of the present invention is heated to foam the thermally expandable adhesive layer. , thereby reducing the heat of the cut electronic parts The adhesive force of the intumescent adhesive layer picks up the cut electronic parts.

Various measurement methods and criteria for determination of the present invention are shown in the following examples.

[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 (trade name "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 thickness of 100 μm so that the thickness after drying became 10 μm. On the PET substrate (coating a rubbery organic elastic layer).

Furthermore, 30 parts by weight of an indophenol-based adhesion resin (trade name "YS Polyster S145" manufactured by Yasuhara Chemical Co., Ltd.) having a hydroxyl value of 100 KOHmg/g and an acid value of 2 mgKOH/g, and an isocyanate-based crosslinking agent (trade name "Coronate" L"Nippon Polyurethane Industry Co., Ltd.) 1.7 parts, a foaming agent (thermal expansion microspheres; trade name "Matsumoto Microsphere F-50" Matsumoto Oil & Fat Pharmaceutical Co., Ltd.; 120 ° C foam expansion type) 30 parts, and Toluene was uniformly mixed, and the solution was dissolved in 100 parts by weight of the copolymer to obtain a coating liquid, and the obtained coating liquid was applied to a PET substrate separator (38 μm) so as to have a thickness of 35 μm after drying. After drying, the film was bonded to the rubber-like organic elastic layer side of the polyester film coated with the rubber-like organic elastic layer to obtain a heat-peelable pressure-sensitive adhesive tape (heat-peelable pressure-sensitive adhesive tape 1).

(Example 2)

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 (trade name "Coronate L" Nippon Polyurethane Industry Co., Ltd.) was added, and toluene was added thereto, and the solution was uniformly mixed, and the thickness was 10 μm after drying. It was spread on a PET substrate having a thickness of 100 μm (coating a rubber-like organic elastic layer).

Furthermore, 50 parts by weight of an indophenol-based adhesive resin (trade name "TAMANOL 901", manufactured by Arakawa Chemical Industries Co., Ltd.) having a hydroxyl value of 45 KOHmg/g, and an isocyanate-based crosslinking agent (trade name "Coronate L" Nippon Polyurethane Industry Ltd.) 1.7 parts, a foaming agent (thermal expansion microspheres; trade name "Matsumoto Microsphere F-50" Matsumoto Oil & Fat Pharmaceutical Co., Ltd.; 120 ° C foam expansion type) 30 parts, and toluene are uniformly mixed These were dissolved in 100 parts by weight of the above copolymer to obtain a coating liquid, and the obtained coating liquid was applied onto a PET substrate separator (38 μm) so as to have a thickness of 35 μm after drying, and dried, and then applied. The heat-peelable adhesive tape (heat-peelable adhesive tape 2) was obtained by the rubber-like organic elastic layer side of the polyester film coated with the above-mentioned rubber-like organic elastic layer.

(Example 3)

Manufactured on acrylic copolymer (ethyl acrylate: butyl acrylate: hydroxyethyl acrylate: acrylic acid: trimethylolpropane triacrylate = 50 parts by weight: 50 parts by weight: 0.1 parts by weight: 5 parts by weight: 0.3 parts by weight 1 part by weight of an epoxy-based crosslinking agent (Tetrad C manufactured by Mitsubishi Gas Chemical Co., Ltd.), a hydroxyl value of 100 mgKOH/g, and an acid value of 2 mgKOH/g of a nonylphenol-based adhesion-imparting resin (product) 20 parts by weight of a heat-expandable microsphere (Matsumoto Microsphere F50 manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd.), 30 parts by weight and a mixture of toluene, which are manufactured by YS Polyster S145, manufactured by Yasuhara Chemical Co., Ltd., and dried. The film was applied to a PET substrate having a thickness of 100 μm so as to have a thickness of 38 μm to obtain a heat-peelable pressure-sensitive adhesive tape (heat-peelable pressure-sensitive adhesive tape 3).

(Comparative 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 Formulated with isocyanate crosslinker (trade name "Coronate L" 2 parts by weight of a solution prepared by mixing Nippon Polyurethane Industry Co., Ltd., and uniformly mixed, and applied to a PET substrate having a thickness of 100 μm by drying to a thickness of 10 μm (coating a rubber-like organic elastic layer) ).

Furthermore, 20 parts by weight of a phenolic-based adhesion resin (trade name "YS Polyster U115" manufactured by Yasuhara Chemical Co., Ltd.) having a hydroxyl value of 30 KOHmg/g, and an isocyanate-based crosslinking agent (trade name "Coronate L" manufactured by Nippon Polyurethane Co., Ltd. 1.7 parts, a foaming agent (thermal expansion microspheres; trade name "Matsumoto Microsphere F-50" manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd.; 120 ° C foam expansion type), 30 parts, and toluene are uniformly mixed to dissolve the same A coating liquid was obtained in 100 parts by weight of the copolymer, and the obtained coating liquid was applied onto a PET substrate separator (38 μm) so as to have a thickness of 35 μm after drying. After drying, the coating liquid was applied to the coating. The rubber-like organic elastic layer side of the polyester film having the rubber-like organic elastic layer was obtained, and a heat-peelable pressure-sensitive adhesive tape (heat-peelable pressure-sensitive adhesive tape 4) was obtained.

(cutting workability)

On the heat-expandable adhesive layer of each of the heat-peelable adhesive tapes, an electronic component substrate having a metal-plated electrode surface is attached (temporarily fixed) (size: 100 mm × 100 mm × thickness 1 mm; electrode surface is formed with a bump of 10 μm) The wafer was mounted and fixed to a dicing ring, and was cut into a wafer having a size of 1 mm × 1 mm by a dicer (a cutting process by dicing was performed), and the number of wafer scattering at the time of dicing was calculated. At this time, the cutting blade was ZH05-SD2000-N1-110-DD manufactured by DISCO Corporation. 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.

The ratio (wafer scattering ratio) (%) of the number of wafer self-heating release type adhesive tape peeling (wafer scattering) in the cutting process was determined, and the cutting workability was evaluated. Further, when all the wafers were bonded to the heat-peelable pressure-sensitive adhesive tape without being peeled off, the wafer scattering rate was 0% (that is, the wafer scattering rate was 0%). The number of wafers to be diced is A ₀ , the number of wafer scattering is set to A, and the wafer scattering rate X is obtained from the equation (1).

Therefore, the smaller the ratio of wafer peeling (wafer flying rate), the better the anti-wafer scattering property. The evaluation results of the wafer cutting workability are shown in the "cutting workability (%)" column of Table 1.

(heat stripping)

After the above-mentioned cutting, a thermostat (hot air dryer) ("SPH-201" manufactured by ESPEC Co., Ltd.) was used, and heat treatment was performed at 130 ° C for 10 minutes. After the heat treatment, the heat-peelable adhesive tape is turned over in the air in the opposite manner (the wafer is made downward), and the wafer is peeled off by the self-heating peeling adhesive tape by natural dropping, and the ratio of the wafer peeling is determined (heating peeling) Rate) (%) as heat peelability. In addition, when all the wafers were peeled off and did not remain in the heat-peelable pressure-sensitive adhesive tape, the heat peeling rate was 100%. Therefore, the larger the ratio (heating peeling rate) at which the wafer is not left by peeling, the better the heat peeling property. The evaluation results of the heat peelability are shown in the column "heat peelability (%)" in Table 1. The number of wafers before peeling was set to B ₀ , the number of wafers that were naturally dropped was B, and the heat peelability X was obtained from the equation (2).

(electrode contamination)

With respect to the above-mentioned wafer which was peeled off by the natural peeling of the heat-peelable adhesive tape, the degree of contamination of the surface (the surface to which the heat-peelable adhesive tape was bonded) was visually observed, and the ratio of the electrode contamination (contamination rate) was determined (%). ). Furthermore, when all the electrode faces were not contaminated, the contamination rate became 0%. Therefore, the smaller the ratio of the electrode contamination (contamination rate), the better the electrode contamination. The evaluation results of the contamination rate are shown in the "electrode contamination" column of Table 1. The number of wafers that were naturally peeled off was C ₀ , the number of wafers on which the electrodes were contaminated was C, and the electrode contamination X was determined according to the formula (3).

(Probe viscosity measurement method)

Each of the heat-peelable adhesive tapes was cut into a width of 20 mm and a length of 50 mm. The slides (76 mm × 26 mm) manufactured by Songlang Glass Industry Co., Ltd. were attached to both sides of Nitto Denko Co., Ltd. No. 531, the cut sample was bonded from above using a hand roller. In the state where the heat-expandable pressure-sensitive adhesive layer was placed on the probe, the probe was measured by a probe (trade name "TACKINESS TESTER Model TAC-II" manufactured by RHESCA) at an immersion speed of 30 mm/min and a test speed of 30 mm/ Min, preload: 100gf, pressurization time: 1.0sec., detection range: 5mm The measurement was performed under the condition of circle (SUS), and the measured value was set as the probe viscosity value (N/5 mm). ). Furthermore, the measurement result of the adhesive force is shown in Table 1 "Probe Viscosity (N/5 mm) )"column.

(Adhesive force measurement method)

Each of the heat-peelable adhesive tapes was cut into a size of 20 mm in width and 140 mm in length, and a polyethylene terephthalate film (trade name "Lumirror S-" as a member to be bonded according to JIS Z 0237 (2000). 10" manufactured by Toray Industries Co., Ltd.; thickness: 25 μm, width: 20 mm) adhered to the heat-expandable adhesive layer (specifically, in an environment of temperature: 23 ± 2 ° C and humidity: 65 ± 5% RH, The 2 kg roller was reciprocated once and pressed, and bonded, and then placed in a tensile tester equipped with a thermostat set at 23 ° C (trade name "Shimadzu Autograph AG-120kN" manufactured by Shimadzu Corporation) , put it for 30 minutes. After standing, at a temperature of 23 ° C, the peeling angle: 180 °, peeling speed (stretching speed): The condition of 300 mm/min was peeled off by the adhesive body from the heat-peelable adhesive tape, and the load at this time was measured, and 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. This maximum load was set as the adhesion (N/20 mm width) of the heat-expandable pressure-sensitive adhesive layer. In addition, the measurement result of this adhesive force is shown in the "adhesion (N/20mm)" column of Table 1.

(Method for measuring gel fraction)

Approximately 0.1 g of the self-expanding adhesive layer (not subjected to heat treatment for thermal expansion) is accurately weighed (weight of the sample), and is made of a mesh sheet (trade name "NTF-1122" manufactured by Nitto Denko Corporation). After the sample was wrapped, it was immersed in about 50 ml of toluene at room temperature for 1 week. Thereafter, the solvent-insoluble component (the content of the mesh sheet) was extracted from toluene, and dried at 70 ° C for about 2 hours, and the solvent-insoluble component (the weight after immersion and drying) after drying was weighed, according to the following. The gel fraction (% by weight) was calculated in the formula (a).

Gel fraction (% by weight) = [(weight after dipping, drying) / (weight of sample)] × 100 (a)

Further, the gel fraction of the heat-expandable adhesive layer can be adjusted by adjusting the composition of the base polymer of the adhesive for forming the heat-expandable adhesive layer, the kind or content of the crosslinking agent added to the adhesive, and adhesion. It is controlled by the kind or content of the resin.

(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 an acetamidine reagent. Approximately 2 g of the sample was accurately weighed and placed in a flat-bottomed flask, and 5 mL of an acetamidine reagent and 10 mL of pyridine were added to install an air cooling tube. After heating at 100 ° C for 70 minutes, it was left to cool, and 35 mL of toluene was added as a solvent 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 was added as a solvent, followed by stirring. Add 0.5 mol/L potassium hydroxide B to the solution using a full pipette 25 mL of an alcohol solution was subjected to potentiometric titration using a 0.5 mol/L potassium hydroxide ethanol solution, and a hydroxyl value was calculated according to the following formula.

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: the amount of sample taken (g)

D: acid value

(Method for measuring acid value)

The acid value of the sample was evaluated in accordance with JIS K 0070-1992 (potential difference titration method). To the solvent obtained by mixing diethyl ether and ethanol in 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 is determined by the following formula.

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: the amount of sample taken (g)

According to Table 1, it was confirmed that the heat-peelable pressure-sensitive adhesive tapes 1 to 3 of Examples 1 to 3 can effectively perform the cutting and cutting process without causing the wafer to scatter, and the electrode can be adhered without causing electrode contamination by heating. The cut wafer is easily peeled off.

On the other hand, it is considered that the thermal release type adhesive tape 4 of Comparative Example 1 has a small hydroxyl value due to the adhesion-imparting resin to be added, and thus causes phase separation from the acrylic polymer which is a main component of the adhesive, and adhesion is imparted to the resin. The ingredients become prone to uneven distribution on the surface of the adhesive. In other words, it is presumed that the glass transition temperature (Tg) of the resin to be adhered to the resin is usually 25° C. or more, and the resin component is unevenly distributed on the surface of the adhesive, so that the apparent elastic modulus of the surface of the adhesive increases. The viscosity value is reduced. Further, since the adhesion imparting unevenness of the resin to the surface of the adhesive is in close contact with the electrode, the electrode is contaminated.

The present invention has been described in detail with reference to the specific embodiments thereof. It is understood 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. 2013-151140, filed on Jan.

1‧‧‧Support substrate

2‧‧‧Rubber-like organic elastic layer

3‧‧‧ Thermally expansive adhesive layer

4‧‧‧Smooth peelable film

Claims (14)

A heat-peelable adhesive tape comprising a heat-expandable adhesive layer, a probe viscosity value of the above-mentioned heat-expandable adhesive layer (immersion speed: 30 mm/min, test speed: 30 mm/min, preload: 100 gf, plus Pressing time: 1.0 sec.) is 60N/5mm The above; and the gel fraction of the heat-expandable pressure-sensitive adhesive layer is 50% or more. The heat-peelable pressure-sensitive adhesive tape according to claim 1, wherein the heat-expandable pressure-sensitive adhesive layer contains an adhesion-imparting resin. The heat-peelable adhesive tape of claim 2, wherein the adhesion-imparting resin has a hydroxyl value of 40 KOHmg/g or more. The heat-peelable adhesive tape of claim 1, wherein the film is adhered to a polyethylene terephthalate film (thickness: 25 μm) at 23 ° C, and then left at 23 ° C for 30 minutes, at 23 ° C. The adhesion of the above-mentioned heat-expandable pressure-sensitive adhesive layer (peeling angle: 180°, tensile speed: 300 mm/min) was 0.2 N/20 mm wide to 20 N/20 mm wide. The heat-peelable pressure-sensitive adhesive tape according to claim 1, wherein the heat-expandable pressure-sensitive adhesive layer contains heat-expandable microspheres. The heat-peelable pressure-sensitive adhesive tape according to claim 1, wherein the adhesive constituting the heat-expandable pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive. The heat-peelable adhesive tape of claim 1, wherein the heat-expandable adhesive layer contains a crosslinking agent. The heat-peelable adhesive tape of claim 1, wherein the heat-expandable adhesive layer has a thickness of 5 to 300 μm. The heat-peelable adhesive tape of claim 1, which is formed by directly forming the heat-peelable adhesive layer on at least one side of the substrate. The heat-peelable adhesive tape of claim 1 which is attached to at least one side of the substrate The organic elastic layer is formed by forming the above-mentioned heat-peelable adhesive layer. The heat-peelable adhesive tape of claim 10, wherein the rubber-like organic elastic layer has a thickness of 3 to 200 μm. The heat-peelable adhesive tape of claim 1, which is used when the electronic component is cut. A heat-peelable adhesive tape according to claim 11, which is used for cutting a member for a ceramic capacitor. A method of cutting an electronic component, comprising: a step of attaching an electronic component to a heat-peelable adhesive tape according to any one of claims 1 to 12, and a step of performing a cutting process on the electronic component.