TWI778939B - Adhesive tape for workpiece processing - Google Patents

Abstract

The adhesive tape for workpiece processing of the present invention comprises a substrate, and an adhesive layer provided on one side of the substrate, the adhesive layer comprising urethane resin (A) and energy A ray-curable compound (B) that is non-reactive to the aforementioned urethane-based resin (A), has a photopolymerizable unsaturated bond, and has a molecular weight of 35,000 or less.

Description

Adhesive tape for workpiece processing

The present invention relates to an adhesive tape for workpiece processing, in particular to an adhesive tape for protecting the surface of a semiconductor wafer used for protecting the surface of a semiconductor wafer with bumps.

Thinning, miniaturization, and multi-functionalization of information terminal devices are rapidly progressing, and the semiconductor devices mounted on these devices are also seeking thinning, high density, and thinning of semiconductor wafers. Conventionally, in order to meet this demand, the back surface of the semiconductor wafer has been polished to make it thinner. Also, in recent years, semiconductor wafers may have bumps made of solder or the like with a height of about 30 to 100 μm formed on the surface of the wafer. When such a semiconductor wafer with bumps has a ground backside, in order to protect the bump portion, a surface protection sheet may be attached to the surface of the wafer on which the bumps are formed.

Conventionally, as a surface protection sheet, a resin layer including a resin layer adjusted so that the storage elastic moduli at 25° C. and 60° C. are in a specific range is known (for example, refer to Patent Document 1). This surface protection sheet is provided with a resin layer with a difference between the storage elastic modulus at room temperature (25°C) and the storage elastic modulus at high temperature (60°C), and the surface of the wafer with concave-convex parts. Attaching at high temperature softens the resin layer and absorbs the unevenness of the wafer surface, making efforts to reduce the level difference of the wafer surface.

In addition, as a surface protection sheet, it is known that two resin layers having a predetermined tensile modulus are provided on a base material in order to improve adhesion and peelability, and that, among the two resin layers, sticking The resin layer on the surface side is formed of thermoplastic elastomers such as polystyrene elastomers, polyolefin elastomers, polyurethane elastomers, and polyester elastomers (see Patent Document 2).

Furthermore, an adhesive tape in which an intermediate layer and an adhesive layer are provided on the base material side surface is also known as a surface protection sheet. In this adhesive tape, it is known that in order to improve the absorption of unevenness, the storage elastic modulus of the intermediate layer at 25°C is set at about 30~1000kPa, and the adhesive layer is formed with an energy ray-curable adhesive (for example, refer to patent documents 3). As in Patent Document 3, when an energy ray-curable adhesive is used for the surface protection sheet, the adhesion and peelability to the semiconductor wafer tend to be better. In the past, the energy ray-curable adhesives used for surface protection sheets are mainly acrylic adhesives because they are easy to adjust the adhesion and ensure the embedding of the bumps.

[Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent No. 4603578

[Patent Document 2] Japanese Patent No. 4918181

[Patent Document 3] Japanese Patent No. 4367769

Therefore, in recent years, along with further densification and miniaturization of semiconductor devices, there is a tendency to increase the height of bumps, and those having a height of 200 μm or more have also been studied. However, increasing the bump height and using the acrylic surface protection sheet described in Patent Document 3 for a semiconductor wafer with a large height difference may cause a large amount of adhesive residue (paste residue) to be generated on the bump when the sheet is peeled off. Condition. Acrylic energy ray curing adhesives are relatively low in cohesion and mechanical strength.

On the other hand, for example, in Patent Documents 1 and 2, studies are underway to use materials other than acrylic adhesives such as polyurethane-based elastomers on the attachment surface of the surface protection sheet. However, in Patent Documents 1 and 2, it is not to study the application of these materials to energy ray-curable adhesives, but to ensure further improvement in adhesiveness, peelability, and embedding of bumps.

The present invention was accomplished in view of the above facts. The object of the present invention is to provide an adhesive tape for workpiece processing, which is representative of the adhesiveness, peelability, and embedding of bumps to workpieces such as semiconductor wafers. The tracking of the adhesive layer on the surface shape is good, and even if the surface shape of the attached workpiece is not flat, there is little paste residue on the surface of the workpiece.

As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by using a urethane-based adhesive as an adhesive and specifying its composition, and the following invention has been accomplished. The present invention provides Adhesive tapes for workpiece processing in (1)~(16) below.

(1) An adhesive tape for workpiece processing comprising a base material and an adhesive layer provided on one side of the base material, the adhesive layer comprising a urethane-based resin (A) and An energy ray-curable compound (B) which is non-reactive to the aforementioned urethane-based resin (A), has a photopolymerizable unsaturated bond, and has a molecular weight of 35,000 or less.

(2) The adhesive tape for workpiece processing according to the above (1), wherein the aforementioned energy ray-curable compound (B) is selected from (meth)acrylate monomer (B1), and urethane (methyl) ) at least one of acrylates (B2).

(3) The adhesive tape for workpiece processing according to (2) above, wherein the energy ray-curable compound (B) contains at least a (meth)acrylate monomer (B1), and the (meth)acrylate monomer Body (B1) is a complete ester of polyhydric alcohol and (meth)acrylic acid, that is, polyfunctional (meth)acrylate.

(4) The adhesive tape for workpiece processing according to any one of (1) to (3) above, wherein the energy ray-curable compound (B) is a (meth)acrylic acid having two or more functions in one molecule base.

(5) The adhesive tape for workpiece processing according to any one of (1) to (4) above, wherein the urethane-based resin (A) has a photopolymerizable unsaturated bond.

(6) The adhesive tape for workpiece processing according to any one of the above (1) to (5), wherein the aforementioned adhesive layer is made of at least a urethane polymer (A'), and the aforementioned energy ray hardening tape. The compound (B) and the adhesive composition of the cross-linking agent (C) are formed, and the above-mentioned urethane resin (A) is an amine The ethyl formate polymer (A') is cross-linked by the aforementioned cross-linking agent (C).

(7) The adhesive tape for workpiece processing according to (6) above, wherein the crosslinking agent (C) contains a photopolymerizable unsaturated bond-containing crosslinking agent (C1).

(8) The adhesive tape for workpiece processing according to the above (6) or (7), which is obtained by combining the aforementioned urethane polymer (A') and the aforementioned crosslinking agent (C) via a urethane bond. Make a bond.

(9) The adhesive tape for workpiece processing according to any one of the above (6) to (8), wherein the aforementioned adhesive composition further contains a compound (D), and the compound (D) has a photopolymerizable unsaturated A bond and a reactive functional group that can react with the aforementioned crosslinking agent (C).

(10) The adhesive tape for workpiece processing according to (9) above, wherein the compound (D) is a polyfunctional (meth)acrylate that is a partial ester of a polyhydric alcohol and (meth)acrylic acid.

(11) The adhesive tape for workpiece processing according to any one of (1) to (10) above, wherein the breaking stress of the adhesive layer after energy ray irradiation is 2.5 MPa or more.

(12) The adhesive tape for workpiece processing according to any one of (1) to (11) above, which has an intermediate layer between the base material and the adhesive layer.

(13) The adhesive tape for workpiece processing according to (12) above, wherein the thickness of the intermediate layer is 10 to 600 μm.

(14) The adhesive tape for workpiece processing according to the above (12) or (13), wherein the loss tangent of the intermediate layer at 50° C. measured at a frequency of 1 Hz is 1.0 or more.

(15) The adhesive tape for workpiece processing according to any one of the above (1)~(14), Among them, the adhesive force after energy ray irradiation is 2000mN/25mm or less.

(16) The adhesive tape for workpiece processing according to any one of (1) to (15) above, which is an adhesive tape for protecting the surface of a semiconductor wafer.

In the present invention, an adhesive tape for workpiece processing can be provided, which has good adhesiveness, peelability, and tracking of the adhesive layer on the surface shape of the workpiece, and has little paste residue on the surface of the workpiece.

In the description below, "weight average molecular weight (Mw)" is a polystyrene-equivalent value measured by gel permeation chromatography (GPC), and specifically, it is a value measured by the method described in Examples.

In addition, in the description in this specification, for example, "(meth)acrylate" is used as a term indicating both "acrylate" and "methacrylate", and the same applies to other similar terms.

Hereinafter, the present invention will be described using embodiments.

The adhesive tape for workpiece processing (hereinafter also simply referred to as "adhesive tape") of the present invention includes a base material and an adhesive layer provided on one side of the base material. In addition, the adhesive tape may have an intermediate layer between the adhesive layer and the base material. The adhesive tape may be composed of 2 or 3 layers as above, and further layers may be provided. For example, a release material is further provided on the adhesive layer.

Hereinafter, each member which comprises an adhesive tape is demonstrated in detail.

<Substrate>

The base material used for the adhesive tape is not particularly limited, but is preferably a resin film. Compared with paper or non-woven fabric, resin film is suitable for processing components of electronic parts because it generates less dust and mustard, and it is better because it is easy to obtain. The substrate may be a single-layer film composed of one resin film, or a multi-layer film in which multiple resin films are laminated.

Resin films used as substrates include, for example, polyolefin-based films, vinyl halide polymer-based films, acrylic resin-based films, rubber-based films, cellulose-based films, polyester-based films, polycarbonate-based films, polystyrene Vinyl films, polyphenylene sulfide films, cycloolefin polymer films, etc.

Among these, polyester films are preferred from the viewpoint of holding the wafer stably when the wafer is polished to an extremely thin thickness, and from the viewpoint of a film with high thickness accuracy. Among polyester films, polyester films are obtained from From the viewpoint of ease and high thickness accuracy, a polyethylene terephthalate film is preferable.

Moreover, although the thickness of a base material is not specifically limited, Preferably it is 10-200 micrometers, More preferably, it is 25-150 micrometers.

Also, from the viewpoint of improving the adhesiveness of the adhesive layer or the intermediate layer to the base material, a base material in which an easily bonding layer or an adhesive layer is further laminated on the surface of the resin film can be used. Furthermore, the substrate used in the present invention may contain fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, etc. within the range that does not impair the effects of the present invention. Also, the base material may be transparent, and may be colored as desired, but it is preferable to transmit energy rays to a sufficient degree in order to harden the adhesive layer.

<middle layer>

In the adhesive tape of the present invention, an intermediate layer may be provided on one side of the substrate. The adhesive tape of the present invention has an intermediate layer, and when the workpiece is provided with bumps, etc., even if the unevenness of the surface of the workpiece is large, the protrusions are embedded in the adhesive layer and the intermediate layer, and thereby it can be attached to the adhesive tape. It becomes easier to keep the surface on the opposite side of the workpiece to which the tape is attached flat. The intermediate layer used in the present invention preferably has a loss tangent (tan δ) at 50°C measured at a frequency of 1 Hz (hereinafter also simply referred to as "loss tangent") of 1.0 or more.

When the loss tangent of the intermediate layer is such a value, when the adhesive tape for workpiece processing is attached to a workpiece with bumps such as a wafer with bumps, the intermediate layer is sufficiently deformed and the unevenness can be easily tracked. The intermediate layer sufficiently absorbs the unevenness of bumps and the like. For example, from the viewpoint of obtaining a good adhesion state to the surface of the wafer with bumps, the loss tangent of the intermediate layer is more preferably 1.5 or more, and more preferably 1.65 or more. Still more preferably, it is 1.8 or more.

Also, from the viewpoint of adjusting the fluidity of the intermediate layer during heating to an appropriate range, the loss tangent of the intermediate layer is preferably 5.0 or less, more preferably 4.0 or less.

In addition, the loss tangent of the above-mentioned intermediate layer is a value measured more specifically by the method described in the Example mentioned later.

Also, although the thickness of the middle layer can be appropriately adjusted according to the state of the surface to which the adhesive tape is attached, it is preferably 10-600 μm, more preferably 25-600 μm, from the viewpoint of absorbing bumps with relatively high height 550 μm, more preferably 35~500 μm.

The intermediate layer is formed of a resin composition for an intermediate layer. Moreover, it is preferable that the resin composition for intermediate layers contains urethane (meth)acrylate.

(Urethane (meth)acrylate (X))

The urethane (meth)acrylate (X) is a compound having at least a (meth)acryl group and a urethane bond, and has a property of being polymerized by energy ray irradiation. Also, the so-called energy rays refer to those with energy quantum in electromagnetic waves or charged particle beams, that is, active light such as ultraviolet rays or electron beams.

The number of (meth)acryl groups in urethane (meth)acrylate (X) may be monofunctional, difunctional, or trifunctional or more, but since the loss tangent is likely to be 1.0 or more, the intermediate The layer resin composition preferably contains monofunctional urethane (meth)acrylate. Since the monofunctional urethane (meth)acrylate has nothing to do with the formation of a three-dimensional network structure in the polymerization structure, it is difficult to form a three-dimensional network structure in the intermediate layer, thereby increasing the loss tangent.

The urethane (meth)acrylate (X) used as the resin composition for the intermediate layer can be, for example, an isocyanate-terminated urethane prepolymer obtained by reacting a polyol compound and a polyisocyanate compound , It is obtained by reacting a compound having a (meth)acryloyl group. Urethane (meth)acrylate (X) can be used 1 type or in combination of 2 or more types.

[Polyol compound]

The polyol compound is not particularly limited as long as it is a compound having two or more hydroxyl groups.

As a specific polyol compound, an alkylene glycol, a polyether polyol, a polyester polyol, a polycarbonate polyol, etc. are mentioned, for example.

Among these, polyether polyols are preferable.

Furthermore, any of bifunctional diols, trifunctional triols, and tetrafunctional or higher polyols may be used as the polyol compound, but from the viewpoints of ease of acquisition, versatility, reactivity, etc. , preferably a difunctional diol, more preferably a polyether diol.

The polyether diol is preferably a compound represented by the following formula (1).

In the above formula (1), although R is a divalent hydrocarbon group, it is preferably an alkylene group, more preferably an alkylene group having 1 to 6 carbon atoms. Among alkylene groups having 1 to 6 carbon atoms, ethylidene, propylidene, and tetramethylene are preferred, and propylidene and tetramethylene are more preferred.

Also, n is the number of repeating units of the alkylene oxide, preferably 10-250, more preferably 25-205, still more preferably 40-185. When n is within the above range, it becomes easy to prepare the intermediate layer so that the urethane bond concentration of the obtained urethane (meth)acrylate is moderate and the loss tangent satisfies the above requirements.

Among the compounds represented by the above formula (1), polyethylene glycol, polypropylene glycol, and polytetramethylene glycol are preferred, and polypropylene glycol, polytetramethylene glycol, and polytetramethylene glycol are more preferred. diol.

Through the reaction of polyether diol and polyisocyanate compound, a terminal isocyanate urethane prepolymer with ether bond [-(-R-O-)n-] introduced is formed. By using such a polyether diol, the urethane (meth)acrylate contains a constituent unit derived from the polyether diol.

A polyester polyol is obtained by polycondensing a polyhydric alcohol component and a polybasic acid component. Examples of the polyol component include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4- Butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, hexane Diol, octanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 1,4-cyclohexanediol Various well-known diols such as methanol, ethylene glycol or propylene glycol adducts of bisphenol A, and the like.

As a polybasic acid component used for manufacture of a polyester polyol, the compound known as a polybasic acid component of polyester can be used generally.

Specific polybasic acid components include, for example, adipic acid, maleic acid, succinic acid, oxalic acid, fumaric acid, malonic acid, glutaric acid, pimelic acid, azelaic acid, sebacic acid, and suberic acid. Dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, etc., or polyacids such as trimellitic acid, pyromellitic acid, etc. Aromatic polyacids, corresponding anhydrides or their derivatives, dimer acids, hydrogenated dimer acids, etc. Among these, aromatic polybasic acids are preferred from the viewpoint of forming a coating film having moderate hardness. For the esterification reaction for producing polyester polyol, various well-known catalysts can be used if necessary.

It does not specifically limit as a polycarbonate polyol, For example, the reaction material of the said diol and an alkylene carbonate, etc. are mentioned.

The number average molecular weight calculated from the hydroxyl value of the polyol compound is preferably from 1,000 to 10,000, more preferably from 2,000 to 9,000, and still more preferably from 3,000 to 7,000. If the number average molecular weight is 1,000 or more, it is preferable to avoid the situation that the control of the viscoelastic properties of the intermediate layer becomes difficult due to the formation of excess urethane bonds. On the other hand, when the number average molecular weight is 10,000 or less, it is preferable because excessive softening of the obtained intermediate layer can be prevented.

Furthermore, the number average molecular weight calculated from the hydroxyl value of the polyol compound is a value calculated from [number of polyol functional groups]×56.11×1000/[hydroxyl value (unit: mgKOH/g)].

[Polyisocyanate compound]

Examples of polyisocyanate compounds include aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate; isophorone diisocyanate, norcamphene diisocyanate; , dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, ω,ω'-diisocyanate dimethylcyclohexane and other alicyclic diisocyanates; 4 ,4'-Diphenylmethane diisocyanate, Tolylene diisocyanate, Xylylene diisocyanate, Tolidine diisocyanate, Tetramethylene stubble diisocyanate, Naphthalene -Aromatic diisocyanates such as 1,5-diisocyanate, etc.

Among them, isophorone diisocyanate, hexamethylene diisocyanate, and stubble diisocyanate are preferable from the viewpoint of handleability.

{Compounds having a (meth)acryl group}

As a compound which has a (meth)acryloyl group, the (meth)acrylate which has a hydroxyl group is mentioned. The (meth)acrylate having a hydroxyl group is not particularly limited as long as it is a compound having a hydroxyl group and a (meth)acryl group in at least one molecule.

Examples of (meth)acrylates having specific hydroxyl groups include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate ester, 4-hydroxycyclohexyl (meth)acrylate, 5-hydroxycyclooctyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, pentaerythritol tri(methyl)acrylate ) acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate and other hydroxyalkyl(meth)acrylates; N-methylol(meth)acrylamide, etc. Hydroxyl-containing (meth)acrylamide; vinyl alcohol, vinylphenol, and bisphenol-A diglycidyl ester reacting (meth)acrylic acid, etc.

Among these, hydroxyalkyl (meth)acrylate is preferable, and 2-hydroxyethyl (meth)acrylate is more preferable.

The weight-average molecular weight of the urethane (meth)acrylate (X) for the resin composition for the intermediate layer obtained in this way is preferably 1,000 to 100,000, more preferably 3,000 to 80,000, and even more preferably 5,000 to 80,000. 65,000. If the weight average molecular weight is 1,000 or more, due to the polymerization of urethane (meth)acrylate and the polymerizable monomer described later, It is preferable to impart appropriate hardness to the intermediate layer due to the intermolecular force between structures derived from urethane (meth)acrylate.

The blending amount of urethane (meth)acrylate (X) in the resin composition for the intermediate layer is based on the total amount of the composition, preferably 20-70% by mass, more preferably 25-60% by mass, Still more preferably, it is 30 to 50 mass %, and still more preferably, it is 33 to 47 mass %. When the blending amount of the urethane (meth)acrylate is in such a range, it is easy to form an intermediate layer with a high loss tangent.

The resin composition for an intermediate layer may further contain, for example, a thiol group-containing compound (Y) or a polymerizable monomer (Z) in addition to the above-mentioned urethane (meth)acrylate (X). It is better to include both of these.

(compound (Y) containing thiol group)

The thiol group-containing compound (Y) is not particularly limited as long as it has at least one thiol group in the molecule, but it is preferably a polyfunctional compound (Y) from the viewpoint of easily increasing the loss tangent. The thiol compound is more preferably a quadrifunctional compound containing a thiol group.

Specific examples of the compound (Y) containing a thiol group include nonylmercaptan, 1-dodecylmercaptan, 1,2-ethanedithiol, 1,3-propanedithiol, Oxazine thiol, triazine dithiol, triazine trithiol, 1,2,3-propane trithiol, tetraethylene glycol-bis(3-mercaptopropionate), trimethylolpropane ginseng (3 -mercaptopropionate), pentaerythritol fourteenth (3-mercaptopropionate), pentaerythritol fourteenth thioglycolate, dipentaerythritol four (3-mercaptopropionate), ginseng [(3-mercaptopropionyloxy)-ethyl base]-isocyanurate, 1,4-bis(3-mercaptobutyryloxy (Butyryloxy)) butane, pentaerythritol tetrakis(3-mercaptobutyrate), 1,3,5-ginseng(3-mercaptobutoxyethyl)-1,3,5-triazine-2,4,6 -(1H,3H,5H)-trione, etc.

Furthermore, these thiol group-containing compounds (Y) can be used alone or in combination of two or more.

The molecular weight of the compound (Y) containing a thiol group is preferably from 200 to 3,000, more preferably from 300 to 2,000. When this molecular weight is the said range, compatibility with a urethane (meth)acrylate (X) becomes favorable, and film-forming property can be made favorable.

The blending amount of the compound (Y) containing a thiol group is preferably 1.0~ 4.9 parts by mass, more preferably 1.5 to 4.8 parts by mass.

When the blending amount is 1.0 parts by mass or more, an intermediate layer with a high loss tangent is likely to be formed, and pump absorbability can be improved. On the other hand, if the blending amount is 4.9 parts by mass or less, bleeding of the intermediate layer when wound into a roll, etc., can be suppressed.

(polymerizable monomer (Z))

In the resin composition for an intermediate layer used in the present invention, it is further preferable to include a polymerizable monomer (Z) from the viewpoint of improving film-forming properties. The polymerizable monomer (Z) is a polymerizable compound other than the above-mentioned urethane (meth)acrylate (X), and is a compound that can be polymerized with other components by irradiation of energy rays. However, the so-called polymerizable monomer (Z) refers to the removal of the resin component By. The polymerizable monomer (Z) is preferably a compound having at least one (meth)acryl group.

Furthermore, in this specification, the term "resin component" means an oligomer or a high molecular weight body having a repeating structure in the structure, and means a compound having a weight average molecular weight of 1,000 or more.

Examples of the polymerizable monomer (Z) include alkyl (meth)acrylates having an alkyl group having 1 to 30 carbon atoms, and (meth)acrylates having functional groups such as hydroxyl groups, amido groups, amino groups, and epoxy groups. base) acrylate, (meth)acrylate with alicyclic structure, (meth)acrylate with aromatic structure, (meth)acrylate with heterocyclic structure, styrene, hydroxyethyl vinyl Vinyl compounds such as ether, hydroxybutyl vinyl ether, N-vinyl formamide, N-vinyl pyrrolidone, N-vinyl caprolactam, allyl glycidyl ether, etc.

Examples of alkyl (meth)acrylates having an alkyl group having 1 to 30 carbon atoms include meth (meth)acrylate, ethyl (meth)acrylate, and n-propyl (meth)acrylate. ester, isopropyl(meth)acrylate, n-butyl(meth)acrylate, isobutyl(meth)acrylate, t-butyl(meth)acrylate, n-pentyl(meth)acrylate Base) acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, nonyl (meth)acrylate, decyl ( Meth)acrylate, Undecyl(meth)acrylate, Dodecyl(meth)acrylate, Tridecyl(meth)acrylate, Tetradecyl(meth)acrylate, Cetyl (meth)acrylate, octadecyl (meth)acrylate, eicosyl (meth)acrylate, etc.

Examples of (meth)acrylates having functional groups include those containing hydroxyl groups such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate. Meth)acrylate; (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(methyl)acrylamide Containing acrylamide, N-methylolpropane(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, etc. Compounds with amide groups; (meth)acrylates containing 1st grade amine groups, (meth)acrylates containing 2nd grade amine groups, (meth)acrylates containing 3rd grade amine groups, etc. Amino-based (meth)acrylates; epoxypropyl (meth)acrylates, methylglycidyl (meth)acrylates, etc., epoxy-containing (meth)acrylates, etc.

Examples of (meth)acrylates having an alicyclic structure include isocamphoryl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentyl (meth)acrylate, Dicyclopentenyloxy (meth)acrylate, cyclohexyl (meth)acrylate, adamantane (meth)acrylate, and the like.

Examples of (meth)acrylates having an aromatic structure include phenylhydroxypropyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (methyl) base) acrylate, etc.

As (meth)acrylate which has a heterocyclic structure, tetrahydrofurfuryl (meth)acrylate, morpholine (meth)acrylate, etc. are mentioned, for example.

Among these, from the viewpoint of compatibility with the above-mentioned urethane (meth)acrylate (X), it is preferable to have a relatively high volume More specifically, (meth)acrylates having an alicyclic structure, (meth)acrylates having an aromatic structure, and (meth)acrylates having a heterocyclic structure are preferable, and Preferred are (meth)acrylates having an alicyclic structure. Also, from the viewpoint that the loss tangent is likely to be 1.0 or more, as the polymerizable monomer, it is preferable to include (meth)acrylate having a functional group and a (meth)acrylate having an alicyclic structure, more preferably It includes hydroxyl-containing (meth)acrylate and isocamyl (meth)acrylate.

The blending amount of (meth)acrylate having an alicyclic structure in the resin composition for an intermediate layer is preferably 32 to 53% by mass, more preferably 35 to 53% by mass based on the total amount of the composition, from the above viewpoint. 51% by mass, more preferably 37-48% by mass, and still more preferably 40-47% by mass.

Also, from the above viewpoint, the amount of the (meth)acrylate having an alicyclic structure relative to the total amount of the polymerizable monomer (Z) contained in the resin composition for an intermediate layer is preferably 52 to 87% by mass, more preferably 55 to 85% by mass, still more preferably 60 to 80% by mass, and still more preferably 65 to 77% by mass. When the compounding quantity of the (meth)acrylate which has an alicyclic structure exists in such a range, a loss tangent becomes 1.0 or more easily.

In addition, the blending amount of the polymerizable monomer (Z) in the resin composition for the intermediate layer is preferably 30 to 80% by mass, more preferably 40 to 75% by mass, and still more preferably 50 to 70% by mass. Still more preferably, it is 53 to 67% by mass. If the blending amount of the polymerizable monomer (Z) is within such a range, the mobility of the portion formed by the polymerizable monomer (Z) polymerized in the intermediate layer tends to be high, and the intermediate layer tends to become soft, resulting in loss of Tangent is easier to form an intermediate layer that satisfies the above requirements.

Also, from the same viewpoint, the mass ratio of urethane (meth)acrylate (X) to polymerizable monomer (Z) in the resin composition for an intermediate layer [urethane (meth)acrylate Base) acrylate/polymerizable monomer] is preferably 20/80~60/40, more preferably 30/70~50/50, and even more preferably 35/65~45/55.

(Energy Ray Polymerization Initiator (R))

The resin composition for an intermediate layer more preferably contains an energy ray polymerization initiator (R). By containing the energy ray polymerization initiator (R), the resin composition for the intermediate layer can be easily cured by energy rays such as ultraviolet rays. Since the energy ray polymerization initiator (R) is generally also referred to as a "photopolymerization initiator", in this specification, hereinafter, it is also simply referred to as a "photopolymerization initiator".

Examples of photopolymerization initiators include photopolymerization initiators such as benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, thioxanthone compounds, and peroxide compounds, amines, and quinones. photosensitizers, etc., more specifically, for example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, benzoin, benzoin methyl ether, benzoin Ethyl ether, benzoin isopropyl ether, 2,2-dimethoxy-1,2-diphenylethan-1-one, etc.

These photopolymerization initiators can be used 1 type or in combination of 2 or more types.

The blending amount of the photopolymerization initiator is preferably 0.05 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the total of the urethane (meth)acrylate and the polymerizable monomer. , and more preferably 0.3 to 5 parts by mass.

(other additives)

The resin composition for an intermediate layer may contain other additives within the range that does not impair the effect of the present invention. Examples of other additives include crosslinking agents, antioxidants, softeners (plasticizers), fillers, antirust agents, pigments, and dyes. When these additives are blended, the blending amount of other additives is preferably 0.01 to 6 parts by mass, more preferably 0.1~3 parts by mass.

Furthermore, the resin composition for the intermediate layer may contain other than urethane (meth)acrylate in the range that does not impair the effect of the present invention. As a resin component, it is preferable to contain only urethane (meth)acrylate as a resin component.

The content of resin components other than urethane (meth)acrylate contained in the resin composition for an intermediate layer is preferably at most 5% by mass, more preferably at most 1% by mass, still more preferably at most 0.1% by mass Below, still more preferably, it is 0 mass %.

In addition, the intermediate layer may be formed by a resin composition for an intermediate layer containing other resin components in place of the urethane (meth)acrylate (X). For example, the intermediate layer can be formed using a curable composition comprising a non-reactive urethane polymer or oligomer, and a polymerizable monomer, or a composition comprising an ethylene-α-olefin copolymer. As the non-reactive urethane polymer or oligomer, known ones can be used, and as the polymerizable monomer, the same ones as above can be used. Such a curable composition may contain the aforementioned energy ray polymerization initiator.

Ethylene-α-olefin copolymer is obtained by polymerizing ethylene and α-olefin monomers. Examples of α-olefin monomers include propylene, 1-butene, 2-methyl-1-butene, 2-methyl-1-pentene, 1-hexene, 2,2-dimethyl-1 -butene, 2-methyl-1-hexene, 4-methyl-1-pentene, 1-heptene, 3-methyl-1-hexene, 2,2-dimethyl-1-pentene ene, 3,3-dimethyl-1-pentene, 2,3-dimethyl-1-pentene, 3-ethyl-1-pentene, 2,2,3-trimethyl-1- Butene, 1-octene, 2,2,4-trimethyl-1-octene, etc. These α-olefin monomers can be used alone or in combination of two or more.

Also, the ethylene-α-olefin copolymer may be one that polymerizes ethylene and α-olefin monomers and other monomers. Examples of other monomer components include vinyl compounds such as vinyl acetate, styrene, acrylonitrile, methacrylonitrile, and ketene; unsaturated carboxylic acids such as acrylic acid and methacrylic acid; methyl acrylate, ethyl acrylate , unsaturated carboxylic acid esters such as n-propyl acrylate, methyl methacrylate, ethyl methacrylate, and n-propyl methacrylate; unsaturated carboxylic acid esters such as acrylamide and methacrylamide Acid amides, etc. These monomers can be used individually or in combination of 2 or more types.

<Adhesive layer>

The adhesive layer is provided on the base material, and when an intermediate layer is provided, it is provided on the intermediate layer. The adhesive layer of the present invention contains at least urethane-based resin (A) and energy ray-curable compound (B), and the energy ray-curable compound (B) is urethane-based resin (A) It is non-reactive and has a molecular weight of 35,000 or less.

In the present invention, since the adhesive layer contains urethane-based resin Grease (A) improves the cohesion and mechanical strength of the adhesive layer, and when the adhesive tape is peeled off from the workpiece after hardening by energy rays, it is difficult to produce paste residue on the surface of the workpiece such as bumps. Moreover, by containing at least an energy ray curable compound (B), the adhesive layer becomes energy ray curable. Therefore, the peeling performance when peeling an adhesive tape from a workpiece becomes favorable. Furthermore, since the energy ray-curable compound (B) is non-reactive, as will be described later, the storage modulus of the adhesive layer is lowered, and it is easy to ensure traceability to unevenness on the workpiece surface.

The adhesive layer preferably has a breaking stress after energy ray irradiation of 2.5 MPa or more. When the fracture stress is 2.5 MPa or more, the mechanical strength becomes a sufficient value, and the above-mentioned paste residue is easily reduced. In addition, from the viewpoint of suppressing paste residue and improving the embedability of protrusions, the adhesiveness and peelability of the adhesive layer, the breaking stress is preferably 2.8 to 30 MPa, more preferably 3.0 to 25 MPa. In addition, the fracture stress is measured by the method described in the examples described later.

Furthermore, the fracture stress can be adjusted by changing the type of urethane-based resin (A). In addition, it can also be adjusted by the amount of photopolymerizable unsaturated bonds described later. When the amount of photopolymerizable unsaturated bonds contained in the adhesive layer increases, the fracture stress tends to increase, and when it decreases, the fracture stress tends to decrease. Similarly, it can also be adjusted by the amount of the cross-linking agent component described later. When the amount of the cross-linking agent component is increased, the fracture stress tends to increase, and when the amount of the cross-linker component is decreased, the fracture stress tends to decrease.

Since the adhesive layer is energy ray curable, it can become relatively soft before energy ray irradiation, and it is easy to trace the unevenness formed by the adhesive layer on the surface of the workpiece. In addition, the adhesive tape hardens by irradiating energy rays, reduces the adhesive force, and is easy to peel off from the workpiece.

From the viewpoint of suppressing paste residue when the adhesive tape is peeled off, the adhesive force of the adhesive tape after energy ray irradiation is preferably 2000 mN/25 mm or less. In particular, when the adhesive tape of the present invention having an intermediate layer is attached to a workpiece having large protrusions (for example, a height of 200 μm or more) such as bumps on the surface, it is usually an adhesive tape that is attached to the surface of the workpiece through the protrusions. The middle layer comes in the state of absorption. Therefore, although it is easy to generate paste residue when peeling off the adhesive tape from this intermediate|middle layer, it becomes easy to prevent the generation|occurrence|production of such paste residue by making adhesive force into 2000mN/25mm or less. The adhesive force of the adhesive tape after energy ray irradiation is preferably 50~1750mN/25mm, more preferably 100~1500nN/25mm.

In addition, although the adhesive force of the adhesive tape before energy ray irradiation is larger than 2000mN/25mm, for example, it is preferably 3000~30000mN/25mm, more preferably 3500~9000mN/m. When the adhesive force before energy ray irradiation is within such a range, the adhesion to the surface of the workpiece becomes good, and the protection performance of the workpiece becomes good.

Furthermore, the adhesive force of the adhesive tape is measured by attaching the adhesive layer of the adhesive tape to the silicon mirror wafer and peeling it off at a peeling angle of 180° and a peeling speed of 300mm/min in an environment of 23°C. Specifically, , is determined by the method described in the examples described later.

Adhesive force can be adjusted by changing the kind of urethane resin (A) or energy ray curable compound (B), etc. In addition, the adhesive force after energy ray irradiation can also be adjusted by the amount of photopolymerizable unsaturated bonds described later, and tends to decrease when the amount of photopolymerizable unsaturated bonds contained in the adhesive layer increases, and increase when it decreases. . Furthermore, the adhesive force after energy ray irradiation is as described later Even by blending a photopolymerizable unsaturated bond-containing crosslinking agent (C1) or compound (D), it is easy to decrease.

(Urethane resin (A))

The urethane-based resin (A) is a polymer containing at least one of a urethane bond and a urea bond. In addition, the adhesive layer of the present invention is composed of a urethane-based adhesive composition (hereinafter, also referred to simply as In the case of "adhesive composition"), the urethane-based resin (A) is composed of at least the urethane polymer (A') as the main ingredient. In addition, the urethane-based adhesive composition may further contain a crosslinking agent (C), a compound (D), and the like, if necessary.

The urethane-based resin (A) may be crosslinked by a crosslinking agent (C). Also, as described above, the urethane-based adhesive composition is directly or indirectly bonded to the urethane polymer (A') in addition to the crosslinking agent (C), such as the compound (D), The adhesive layer may contain a compound constituting the urethane-based resin (A) as a whole.

Still, such as crosslinking agent (C) and compound (D), collectively referred to as directly or indirectly bonded to the urethane polymer (A'), together with the urethane polymer (A') in the adhesive The compound constituting the urethane-based resin (A) as a whole is referred to as a "main agent-reactive compound".

In the present invention, the blending amount of the urethane polymer (A') is relative to the composition of the adhesive because the adhesiveness of the adhesive layer is ensured and the following components (B) to (E) are blended in an appropriate amount. The total amount of the substance is preferably 30-85% by mass, More preferably, it is 35-80 mass %, More preferably, it is 37-77 mass %. In addition, the total blending amount of the main ingredient reactive compound and the urethane polymer (A') is preferably 40 to 95% by mass, more preferably 45 to 94% by mass, based on the total amount of the adhesive composition. More preferably, it is 50 to 93% by mass.

The urethane-based resin (A) preferably has a photopolymerizable unsaturated bond. When the urethane-based resin (A) has a photopolymerizable unsaturated bond, the adhesive layer of the adhesive tape for workpiece processing becomes the urethane-based resin (A) and the energy ray-curable compound (B). ) all have photopolymerizable unsaturated bonds. Therefore, by irradiating energy rays to the adhesive layer, a bond is formed between the urethane resin (A) and the energy ray-curable compound (B) through a polymerization reaction, and it is easier to reduce the damage after energy ray irradiation. The adhesive force of the adhesive tape improves the peelability when the adhesive tape is peeled off from the workpiece. Furthermore, it becomes possible to further reduce the paste residue generated when the adhesive tape is peeled off from the workpiece. In addition, when the hardening of the adhesive layer by energy ray irradiation is compared with the case of only the energy ray curable compound (B), there is a tendency to increase the strength of the adhesive layer after energy ray irradiation, and it is easier to suppress paste residue. produce.

The method for introducing a photopolymerizable unsaturated bond into the urethane-based resin (A) is not particularly limited. For example, when the urethane polymer (A') before the introduction of photopolymerizable unsaturated bonds has a hydroxyl group, it can be combined with a photopolymer containing a (meth)acryl group or the like that has a functional group that can react with the hydroxyl group. The compound of the functional group of a polymerizable unsaturated bond reacts with the said hydroxyl group, and introduces a photopolymerizable unsaturated bond. As a compound having a functional group reactive with the aforementioned hydroxyl group and a functional group containing a photopolymerizable unsaturated bond, for example Examples thereof include methacryloxyethyl isocyanate and the like. Such a compound may be reacted with the urethane polymer (A') in advance, or the adhesive layer may contain the compound, and the urethane polymer (A') may be reacted when the adhesive layer is formed. react.

Also, as described later as the crosslinking agent (C), it is possible to introduce photopolymerizable unsaturated bonds by crosslinking the urethane polymer (A') using a crosslinking agent (C1) having a photopolymerizable unsaturated bond. Bonded to the urethane resin (A). Furthermore, a photopolymerizable unsaturated bond can be introduced into the urethane resin (A) by the compound (D) mentioned later.

<Urethane polymer (A')>

The urethane polymer (A') includes at least one of a urethane bond and a urea bond, specifically, one having a hydroxyl group at the terminal obtained by reacting a polyol and a polyisocyanate compound. Polyurethane polyol. Also, as the urethane polymer (A'), an isocyanate-terminated urethane polymer obtained by reacting a polyol and a polyisocyanate compound can be used.

Examples of the polyol used for the urethane polymer (A') include polyester polyol and polyether polyol.

A well-known polyester polyol is used as a polyester polyol. Polyester polyol-based acid components, esters with at least one of diol components and polyol components. Examples of acid components include terephthalic acid, adipic acid, azelaic acid, sebacic acid, and anhydrous phthalic acid. Formic acid, isophthalic acid, trimellitic acid, etc. Moreover, as a glycol component, ethylene glycol, propylene glycol, diethylene glycol, butanediol, alcohol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3'-dimethylolheptane, polyoxyethylene glycol, polyoxypropylene glycol, 1,4 -Butanediol, neopentyl glycol, butylethylpentanediol, glycerol, trimethylolpropane, pentaerythritol, etc. are mentioned as a polyhydric alcohol component.

Others may be polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, poly(β-methyl-γ-valerolactone), and polyvalerolactone.

Moreover, a well-known polyether polyol is used as a polyether polyol. For example, ethylene oxide (ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, etc.) As the polyether polyol obtained by polymerizing an Oxirane) compound, specifically, polypropylene glycol, polyethylene glycol, polytetramethylene glycol, etc. having two or more functional groups are used.

As the polyisocyanate compound, well-known aromatic polyisocyanate, aliphatic polyisocyanate, araliphatic polyisocyanate, alicyclic polyisocyanate, etc. are mentioned. Examples of aromatic polyisocyanate include 1,3-phenylene diisocyanate, 4,4'-diphenylene diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate , 2,4-methylene phenylene diisocyanate, 2,6-methylene phenylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-tri Benzene isocyanate, dianisidine diisocyanate, 4,4'-diphenylether diisocyanate, 4,4',4"-triphenylmethane triisocyanate, etc.

Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, Pentamethylene diisocyanate, 1,2-propene diisocyanate, 2,3-butene diisocyanate, 1,3-butene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethyl Hexamethylene diisocyanate, etc.

Examples of araliphatic polyisocyanates include ω,ω'-diisocyanate-1,3-dimethylbenzene, ω,ω'-diisocyanate-1,4-dimethylbenzene, ω,ω'-diisocyanate - 1,4-diethylbenzene, 1,4-tetramethyl-diisocyanate, 1,3-tetramethyl-diisocyanate, etc.

Examples of alicyclic polyisocyanate include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1, 4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylene bis(cyclohexyl isocyanate), 1 ,4-bis(isocyanate methyl)cyclohexane, 1,4-bis(isocyanate methyl)cyclohexane, etc.

Furthermore, the above-mentioned polyisocyanate compound may be used in combination with a trimethylolpropane adduct of the above-mentioned polyisocyanate compound, a biuret product reacted with water, a trimer having an isocyanurate ring, or the like.

As the polyisocyanate compound, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate), etc.

In addition, polyurethane polyol can be further made of ethylenediamine, N-aminoethylethanolamine, isophoronediamine, stubble diamine, etc. in addition to polyol and polyfunctional isocyanate. Diamine reactants. Furthermore, as the polyol, in addition to the above-mentioned polyester polyol and polyether polyol, ethylene glycol, 1,4-butanediol, neopentyl glycol, butyl Ethylpentanediol, glycerin, trimethylolpropane, pentaerythritol, etc.

Furthermore, the reaction with a polyol and a polyisocyanate compound is usually carried out in the presence of a catalyst such as a tertiary amine compound, an organometallic compound, or the like.

The urethane polymer (A') is not limited to those described above, and may be, for example, a Myco-addition type urethane polymer.

As a mycoaddition type urethane polymer, the following (1) or (2) is mentioned, for example.

(1) Made by reacting an amino compound with a urethane prepolymer obtained by reacting the above-mentioned polyol with a polyisocyanate compound and having an isocyanate group (- NCO), the amine-based compound is formed by the addition reaction of polyamine and unsaturated compound. (2) In addition to the above-mentioned polyols and polyisocyanate compounds, polyamines with primary or secondary amine groups Ethyl formate urea is produced by the Michael addition reaction of unsaturated compounds. The polyurethane urea is obtained by reacting polyamine and has primary or secondary amine groups at the end.

Known ones can be used as the polyamine used in the Myco-addition type urethane polymer, specifically, ethylenediamine, propylenediamine, trimethylenediamine, tetramethylenediamine, etc. , pentamethylenediamine, hexamethylenediamine, triethylenetetramine, diethylenetriamine, triaminopropane, 2,2,4-trimethylhexamethylenediamine, methylenediamine Aliphatic polyamines such as diamine, hydrazine, piperazine, etc., aliphatic polyamines such as isophorone diamine, dicyclohexylmethane-4,4'-diamine, etc., and phenylenediamine, stubble Aromatic polyamines such as diamines. Furthermore, 2-hydroxyethylethylenediamine, N-(2-hydroxyethyl)propylenediamine, (2-hydroxyethylpropylene)diamine, (di-2-hydroxyethyl ethylene) diamine, (di-2-hydroxyethylpropylene) diamine, (2-hydroxypropyl ethylene) diamine, (di-2-hydroxypropyl ethylene) diamine, etc. have hydroxyl groups in the molecule Diamines, dimer diamines obtained by converting carboxyl groups of dimer acids into amine groups, polyoxyalkylene glycol diamines having propoxylamine at both ends and represented by the following general formula (2), and the like.

H ₂ -NCH ₂ -CH ₂ -CH ₂ -O(C _n H _2n -O) _m -CH ₂ -CH ₂ -CH ₂ -NH ₂ (2) (Shang, in formula (2), n represents 2~ Any integer of 4, m represents any integer of 2~50).

Furthermore, as polyamine, it can also be used for the dendrimer (Dendrimer) which has a primary or secondary amine group at the terminal.

Among the above-mentioned polyamines, isophoronediamine, 2,2,4-trimethylhexamethylenediamine, and hexamethylenediamine are preferable from the viewpoint of ease of control of the reaction of hexamethylenediamine.

In addition, the unsaturated compound used in the Michael addition-type urethane polymer is used for the purpose of modifying the urethane polymer. Accordingly, the type of unsaturated compound used can be selected arbitrarily according to the purpose of modification. Examples of unsaturated compounds include (meth)acrylic unsaturated compounds, amide unsaturated compounds, fatty acid vinyl ester unsaturated compounds, vinyl ether unsaturated compounds, α-olefin unsaturated compounds, allyl Base-based unsaturated compounds, allyl acetate-based unsaturated compounds, vinyl cyanide-based unsaturated compounds, styrene or vinylbenzene-based unsaturated compounds, etc.

Although the type of unsaturated compound used can be selected arbitrarily according to the purpose of modification, it is better to pay attention to the functional group of the unsaturated compound to make a selection. Examples of functional groups possessed by such unsaturated compounds include alkyl groups, polyalkylene glycol groups, alkoxy groups, phenoxy groups, hydroxyl groups, carboxyl groups, perfluoroalkyl groups, alkoxysilyl groups, cyclic Oxygen group, further, amide group, dialkylamine group, nitrogen-containing group such as quaternary ammonium base, etc. can be exemplified, but as mentioned above, since the urethane polymer (A') contains a hydroxyl group, it is represented by It preferably has a hydroxyl group.

Furthermore, as specific examples of these unsaturated compounds, for example, those described in JP 2002-121256 A (European Publication EP1146061 A1) are used.

The urethane polymer (A') used in the present invention preferably has a weight average molecular weight of 10,000-300,000, more preferably 30,000-150,000. By being 10,000 or more, the cohesive force of the adhesive layer is enhanced and the effect of suppressing higher paste residues is obtained. In addition, when it is 300,000 or less, when an adhesive layer is formed from an adhesive composition, there is an advantage that even if it is diluted with a solvent or heated and melted, it is difficult to cause an increase in viscosity that affects process suitability.

(Energy Beam Curing Compound (B))

The energy ray-curable compound (B) used in the present invention is non-reactive to the urethane-based resin (A), and has a photopolymerizable unsaturated bond.

Here, the so-called non-reactive means that in addition to the "photopolymerizable unsaturated bond", not only the urethane polymer (A') does not contain a functional group that reacts with the reactive compound of the main agent, the compound (B) is a compound that does not react with the urethane-based resin (A) in the adhesive layer.

That is, the energy ray-curable compound (B) is composed of a urethane polymer (A'), a crosslinking agent (C), and other components (such as (D) component) if necessary. A compound that does not react with these (A'), (C), and (D) components when reacting to form an adhesive layer.

Thus, the energy ray-curable compound (B) exists as a component which does not comprise a urethane-type resin (A) in an adhesive layer. Since urethane polymers generally have high cohesive force and high storage elastic modulus, although it is difficult to embed protrusions such as bumps on the surface of the workpiece alone, in the present invention, no urethane polymerization is formed by blending. The energy ray hardening compound (B) of the material chain reduces the storage elastic modulus of the adhesive layer and easily ensures the embedding property of the bump.

Still, in the present invention, the photopolymerizable unsaturated bond refers to an unsaturated bond that reacts by energy ray irradiation, usually an ethylenic double bond, preferably a carbon-carbon contained in a (meth)acryl group double bond.

The molecular weight of the energy ray-curable compound (B) is 35,000 or less. When the molecular weight is larger than 35,000, it becomes difficult to lower the storage elastic modulus of the adhesive layer, and it becomes difficult to ensure embedding property to bumps. Moreover, there exists a possibility that the compatibility with a urethane resin (A) may deteriorate. The molecular weight of the energy ray-curable compound (B) is preferably from 150 to 35,000, more preferably from 200 to 34,000. Also, the molecular weight means a formula weight when the formula weight can be specified, and a weight average molecular weight when the formula weight cannot be specified.

The blending amount of the energy ray-curing compound (B) varies depending on the compound used, but it is based on 100 parts by mass of the urethane-based resin (A) (that is, urethane Reactivity of ester polymer (A') and main ingredient 100 parts by mass in total of the compound, the same below), usually 1 to 120 parts by mass, preferably 2 to 100 parts by mass, more preferably 4 to 90 parts by mass. By setting the blending amount of the energy ray-curable compound (B) within such a range, it is easy to obtain an adhesive layer that has both traceability to the workpiece surface and suppression of paste residue.

Specific examples of the energy ray-curable compound (B) include compounds having a (meth)acryloyl group. The (meth)acryl group (photopolymerizable unsaturated bond) in one molecule of the energy ray-curable compound (B) may be monofunctional or higher, but preferably bifunctional or higher, more preferably 2 to 12 functional.

In addition, specific examples of the energy ray-curable compound (B) used in the present invention include (meth)acrylate monomers (B1) and urethane (meth)acrylates (B2). ) at least 1 species.

The (meth)acrylate monomer (B1) is a compound having a (meth)acryl group in the molecule, and the number of (meth)acryl groups is preferably more than 2, more preferably 3-6. In particular, when the urethane-based resin (A) does not have a photopolymerizable unsaturated bond, it is preferable to easily reduce the adhesive force of the adhesive tape after irradiation of the adhesive layer with energy rays. The adhesive layer contains the (meth)acrylate monomer (B1) whose number of (meth)acryl groups is 4 or more functional.

As the (meth)acrylate monomer (B1), for example, all the hydroxyl groups of the polyhydric alcohol are polyfunctional (meth)acrylates that form complete esters of (meth)acrylic acid and esters. Here, the carbon number of the polyol is preferably 4-10. Also, (meth)acrylate monomer (B1) is preferably 150~1000 with molecular weight, more The best is 200~800.

As specific compounds of polyfunctional (meth)acrylates, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1, 4-Butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, etc., Among these, pentaerythritol tetra(meth)acrylate is preferable.

Furthermore, the (meth)acrylate monomer (B1) means that the structure can be specified, and the molecular weight is a formula weight.

(Meth)acrylate monomer (B1) is preferable since it can prevent paste residue even with a small compounding quantity, and can moderately reduce adhesive force by energy ray hardening.

In addition, the blending amount of the (meth)acrylate monomer (B1) is specifically, preferably 1 to 20 parts by mass, more preferably 2 parts by mass, based on 100 parts by mass of the urethane resin (A). ~15 parts by mass, more preferably 3~10 parts by mass. The energy ray-curable compound (B) can suitably prevent the paste residue of an adhesive layer by using such a compounding quantity, and can suitably reduce the adhesive force of an adhesive layer by irradiation of an energy ray.

Urethane (meth)acrylate (B2) is a polymer having a urethane bond and a (meth)acryl group at the end. Urethane (meth)acrylate (B2) includes terminal isocyanate urethane polymer formed by the reaction of polyol compound and polyisocyanate compound, and the functional group at its terminal has (form A compound obtained by reacting an acryl group compound, etc. Such urethane (meth)acrylate (B2) has energy due to the action of (meth)acryl group line hardening.

Furthermore, the polyol compound, the polyisocyanate compound, and the compound having a (meth)acryl group used to obtain the urethane (meth)acrylate (B2) are obtained from the amines of the above-mentioned intermediate layer, respectively. The polyol compound, polyisocyanate compound, and compound having a (meth)acryl group used in the ethyl methacrylate (X) are appropriately selected and used, and specific description thereof will be omitted.

Urethane (meth)acrylate (B2) has (meth)acryl groups, and the (meth)acryl groups in one molecule are preferably 2 or more functional, more preferably 2 to 12 functional , and more preferably 2 to 10 functions. In this way, by being multifunctional, it is easy to lower the adhesive force by energy ray hardening.

Moreover, although the molecular weight of urethane (meth)acrylate (B2) will be 35000 or less, Preferably it is 2000-35000, More preferably, it is 5000-34000. Also, the molecular weight of the urethane (meth)acrylate (B2) means a weight average molecular weight. By setting the molecular weight of the urethane (meth)acrylate in such a range, the storage elastic modulus of the adhesive layer is lowered, and it is easy to ensure traceability to the unevenness of the workpiece surface. Also, the movement of the urethane (meth)acrylate (B2) in the adhesive layer is suppressed, and the stability of the adhesive tape over time is improved.

When the energy ray-curing compound (B) is urethane (meth)acrylate (B2), the blending amount of urethane (meth)acrylate (B2) relative to the urethane 100 parts by mass of the resin (A), preferably 30-120 parts by mass, more preferably 40-100 parts by mass, and more preferably 50-90 parts by mass. Urethane (meth)acrylate (B2) becomes Such a blending amount can maintain the adhesive performance of the adhesive layer well and ensure the embedding property easily. In addition, the adhesive force is sufficiently reduced by energy ray hardening, and it is also easy to reduce paste residue.

(Crosslinking agent (C))

The adhesive composition of the present invention preferably further contains a crosslinking agent (C). The crosslinking agent (C) reacts with the urethane polymer (A') to crosslink the urethane polymer (A'). By containing the crosslinking agent (C), the adhesive composition increases the crosslinking density and easily forms an adhesive layer with high mechanical strength. In addition, it is also easy to prevent paste residue when the adhesive tape is peeled off.

As the crosslinking agent (C), when the urethane polymer (A') has a hydroxyl group, it is preferably a crosslinking agent having two or more isocyanate groups that can react with the hydroxyl group. Also, when the adhesive composition contains a crosslinking agent, it is usually crosslinked by heating after coating.

Also, on the contrary, the urethane polymer (A') already has isocyanate groups, and the crosslinking agent (C) may have hydroxyl groups. Since the urethane polymer (A') generally has a hydroxyl group or an isocyanate group in the production method, the urethane polymer (A') and the crosslinking agent (C) are preferably formed by Bonded by urethane linkages.

As a crosslinking agent (C) which can be used in this invention, it is preferable to use the crosslinking agent (C1) containing a photopolymerizable unsaturated bond.

Also, as the crosslinking agent (C1) containing a photopolymerizable unsaturated bond, it is preferable to use a compound having two or more isocyanate groups and (meth)acryl groups, more preferably to use an amine group having at least two isocyanate groups Ethyl formate (methyl) Acrylate.

The urethane (meth)acrylate preferably has a weight average molecular weight of 500-2000, more preferably 700-1000. Moreover, when one molecule of a crosslinking agent (C1) has 2 or more photopolymerizable unsaturated bonds, the photopolymerizable unsaturated bonds in the same molecule of a crosslinking agent (C1) tend to superpose|polymerize easily. Therefore, it is difficult to cause a reaction between the photopolymerizable unsaturated bond of the crosslinking agent (C1) and the photopolymerizable unsaturated bond of other molecules, and the adhesion of the adhesive tape is reduced due to the energy ray irradiation to the adhesive layer. The case where the force effect is low. Accordingly, it is preferable that the crosslinking agent (C1) has one photopolymerizable unsaturated bond in one molecule. Moreover, the urethane (meth)acrylate used as a crosslinking agent (C1) is mentioned, for example, "EBECRYL 4150" by DAICEL-ALLNEX company.

In this embodiment, by using the crosslinking agent (C1) which has a photopolymerizable unsaturated bond, the urethane-type resin (A) will have a photopolymerizable unsaturated bond in an adhesive agent layer.

As a crosslinking agent containing a hydroxyl group and a photopolymerizable unsaturated bond, an acrylic polymer which has a hydroxyl group and a (meth)acryl group in a side chain is mentioned, for example. In this case, although the urethane resin (A) crosslinked by the crosslinking agent (C1) is an acrylic urethane resin, it is used in the urethane resin (A) of the present invention. A) also includes such urethane acrylate resins.

The blending amount of the crosslinking agent (C1) containing a photopolymerizable unsaturated bond is preferably 5 to 60 parts by mass, more preferably 10 to 50 parts by mass, based on 100 parts by mass of the urethane resin (A). parts by mass, more preferably 15~45 parts by mass. By setting such a blending amount of the crosslinking agent (C1), the crosslink density of the adhesive layer becomes favorable, and at the same time, an appropriate amount of photopolymerizable unsaturated bonds can be introduced into the urethane resin (A).

In addition, the adhesive composition may contain a crosslinking agent (C2) not containing a photopolymerizable unsaturated bond as the crosslinking agent (C). As the crosslinking agent (C2), when the urethane polymer (A') has a hydroxyl group, it can be appropriately selected from those used for the synthesis of the urethane polymer (A') listed above. Polyisocyanate compounds are used. Moreover, when the polymer (A') before crosslinking has an isocyanate group, a well-known polyhydric alcohol can be used as a crosslinking agent (C2). The adhesive composition can sufficiently increase the crosslink density of the adhesive layer by containing the crosslinking agent (C2).

The crosslinking agent (C) may be all crosslinking agents (C1) having photopolymerizable unsaturated bonds, although it may be all crosslinking agents (C2) not having photopolymerizable unsaturated bonds, but preferably It contains the crosslinking agent (C1) which has a photopolymerizable unsaturated bond, More preferably, it contains both a crosslinking agent (C1) and a crosslinking agent (C2).

The amount of the crosslinking agent (C2) that does not contain a photopolymerizable unsaturated bond is preferably 0.2 to 15 parts by mass, more preferably 0.5 to 100 parts by mass of the urethane resin (A). 10 parts by mass. Also, as mentioned above, when the crosslinking agent (C1) is used in combination, the blending amount of the crosslinking agent (C2) that does not contain a photopolymerizable unsaturated bond can be relatively small. (A) 100 parts by mass, preferably 0.2 to 5 parts by mass, more preferably 0.5 to 2 parts by mass.

(Compound (D))

When the adhesive composition contains a crosslinking agent (C), it is preferable to further contain a compound (D) having a photopolymerizable unsaturated bond and a reactive functional group capable of reacting with the crosslinking agent (C). The compound (D) having a reactive functional group is bound to the crosslinking agent (C) when the urethane polymer (A') reacts with the crosslinking agent (C) to form a urethane polymer chain. react.

When the adhesive composition contains the compound (D), photopolymerizable unsaturated bonds can be introduced into the urethane-based resin (A) due to the compound (D). Therefore, when the adhesive layer is cured by energy rays, the adhesive force of the adhesive layer can be easily reduced, and it is also easy to prevent paste residue and the like. In addition, it also has the effect of stabilizing the performance of the adhesive tape over time.

An isocyanate group or a hydroxyl group is mentioned as a reactive functional group contained in a compound (D). Moreover, as a compound (D), the (meth)acrylate monomer which has a hydroxyl group and a (meth)acryl group is mentioned. The number of (meth)acryl groups (that is, photopolymerizable unsaturated bonds) in one molecule of compound (D) is preferably 2 or more functions in 1 molecule, more preferably 2 to 5 functions.

The (meth)acrylate monomer used as component (D) preferably has a molecular weight of 150-3,000, more preferably 200-2,000.

As a (meth)acrylate monomer used as a component (D), the polyfunctional (meth)acrylate of the partial ester of a polyhydric alcohol and (meth)acrylic acid is mentioned. Here, the carbon number of the polyol is preferably 4-10. As specific compounds, pentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, etc. are exemplified, but among these, pentaerythritol tri(meth)acrylate is preferred. base) acrylate.

The blending amount of the compound (D) is preferably 1 to 30 parts by mass, more preferably 2 to 20 parts by mass, and still more preferably 3 to 15 parts by mass, based on 100 parts by mass of the urethane resin (A). share. By blending the compound (D) in such a range, it is easy to reduce the adhesive force due to hardening of the energy ray without adversely affecting the adhesive performance of the adhesive layer, and it is also easy to prevent paste residue. In addition, when the compound (D) is an energy ray-curable compound (B) containing a (meth)acrylate monomer (B1), it is usually used preferably. Thus, when compound (D) and (meth)acrylate monomer (B1) are used together, the effect of this invention is exhibited more easily.

(Energy ray polymerization initiator (E))

It is preferable that the adhesive composition further contains an energy ray polymerization initiator (E). The adhesive layer can be cured easily by irradiation of energy rays by containing the energy ray polymerization initiator (E). As the energy ray polymerization initiator (E), it can be appropriately selected from the photopolymerization initiators listed above that can be used in the resin composition for an intermediate layer.

The blending amount of the energy ray polymerization initiator (E) relative to the urethane polymer (A') having a photopolymerizable unsaturated bond, the crosslinking agent (C1), and the energy ray-curable compound (B ), compound (D) and the like with a total of 100 parts by mass of compounds having photopolymerizable unsaturated bonds, preferably 0.05 to 25 parts by mass, more preferably 0.1 to 20 parts by mass, and more preferably 0.3 to 15 parts by mass .

In addition, the adhesive composition may contain other additives used in the past in urethane adhesives, such as fillers such as calcium carbonate and titanium oxide, colorants, antioxidants, defoamers, light stabilizers, etc. .

Although the thickness of the adhesive layer can be appropriately adjusted according to the height of the bump on the wafer surface, etc., and the surface state of the surface to which the adhesive tape is attached, it is preferably 2~150 μm, more preferably 5~100 μm, and even better 8~50μm.

<Peeling material>

The release material provided on the adhesive layer, or the release material used in the steps of the manufacturing method described later, use a release sheet that has undergone a single-side release treatment, or a release sheet that has undergone a double-side release treatment, and can be listed in the release material Used for coating release agent on the base material, etc.

Examples of the base material for the release material include polyester resin films such as polyethylene terephthalate resin, polybutylene terephthalate resin, and ethylene naphthalate resin, polypropylene resin, polyethylene resin, etc. Plastic films such as polyolefin resin films such as resins, etc.

Examples of release agents include rubber-based elastomers such as silicone-based resins, olefin-based resins, isoprene-based resins, and butadiene-based resins, long-chain alkyl-based resins, alkyd-based resins, and fluorine-based resins. Wait.

Moreover, although the thickness of a peeling material is not specifically limited, Preferably it is 5-200 micrometers, More preferably, it is 10-120 micrometers.

[Manufacturing method of adhesive tape]

The manufacturing method of the adhesive tape of this invention is not specifically limited, It can manufacture by a well-known method.

The intermediate layer is, for example, directly coated with a solution of a resin composition for an intermediate layer on one side of the substrate to form a coating film, and then dried if necessary, and It can be formed by hardening treatment. In addition, the intermediate layer is coated with a solution of the resin composition for the intermediate layer on the peeling surface of the release material to form a coating film, and then dried if necessary, and a semi-hardened layer is formed on the release material by performing a semi-hardening treatment. This semi-hardened layer is bonded to the substrate, and the semi-hardened layer is completely hardened. In this case, the peeling material may be appropriately removed before or after the semi-cured layer is completely cured. Furthermore, it is preferable to harden the intermediate layer by irradiating the coating film with energy rays to polymerize and harden it. The energy rays are preferably ultraviolet rays. Also, when the intermediate layer is formed using an olefin-based material, the intermediate layer can be formed by extrusion molding or the like.

In addition, the adhesive layer is preferably formed by applying the adhesive composition, heating the adhesive composition to perform crosslinking, and drying if necessary. At this time, the adhesive composition can be directly coated on the intermediate layer or the substrate, and coated on the peeled surface of the release material to form an adhesive layer, and then the adhesive layer can be pasted on the intermediate layer or the substrate. form. The release material placed on the adhesive layer can be peeled off as needed.

When forming an intermediate layer or an adhesive layer, an organic solvent can be further mixed with the resin composition for an intermediate layer or an adhesive composition, and can be used as a diluent of the resin composition or an adhesive composition for an intermediate layer. Examples of organic solvents used include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, isopropanol Wait.

In addition, as these organic solvents, the organic solvents used in the synthesis of the components contained in the resin composition for the intermediate layer or the adhesive composition may be used as they are, or one or more other organic solvents may be added. .

The resin composition or adhesive composition for the intermediate layer can be coated by a known coating method. Examples of coating methods include spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating.

[How to use adhesive tape]

The adhesive tape of the present invention is attached to various workpieces, and is used when processing workpieces. It is better to be attached to the surface of workpieces with concavo-convex or protrusions.

Moreover, it is more preferable to stick on the surface of a semiconductor wafer, especially the surface of a wafer on which bumps are formed, and use it as an adhesive tape for protecting the surface of a semiconductor wafer. Furthermore, it is more preferable that the adhesive tape is attached to the surface of the semiconductor wafer, and used as a back grinding tape for protecting the circuit formed on the surface of the wafer when the wafer is subsequently ground. When the adhesive tape of the present invention has an intermediate layer, since the embedding property is good even if there is a level difference on the wafer surface due to bumps or the like, the protection performance of the wafer surface is improved. In this case, the temperature of the adhesive tape when attaching the adhesive tape to the surface of the semiconductor wafer is, for example, about 40-80°C, preferably 50-70°C.

In the present invention, the adhesive layer is an energy ray curing type, and the adhesive tape affixed to the surface of a workpiece such as a semiconductor wafer is irradiated with energy rays to cure the energy ray, and then peeled off from the surface of the workpiece. Accordingly, since the adhesive tape is peeled off after the adhesive force is lowered, the peelability is improved. Also, as described above, when the hardened adhesive tape is peeled off, it is difficult to generate paste residue.

Furthermore, when the adhesive tape is used for a semiconductor wafer, it is not limited to a back grinding sheet, and may be used for other purposes. e.g. adhesive tape Attached to the back of the wafer, it can also be used as a dicing sheet to hold the wafer when dicing the wafer. In this case, the wafer may be formed with through-hole electrodes, etc., or may have protrusions or irregularities such as bumps formed on the back surface of the wafer.

[Example]

Hereinafter, although the present invention will be further described in detail based on examples, the present invention is not limited to these examples.

The measurement method and evaluation method in the present invention are as follows.

[Weight average molecular weight (Mw), number average molecular weight (Mn)]

Using a gel permeation chromatography device (product name "HLC-8220", manufactured by Tosoh Co., Ltd.), it was measured under the following conditions, and the value measured in terms of standard polystyrene was used.

(measurement conditions)

Column: "TSK guard column HXL-H", "TSK gel GMHXL(×2)" and "TSK gel G2000HXL" (all manufactured by Tosoh Co., Ltd.)

Column temperature: 40°C Developing solvent: tetrahydrofuran Flow rate: 1.0mL/min

[loss tangent (tanδ)]

The resin composition for the intermediate layer used in each example and comparative example was placed on a polyethylene terephthalate film-based release film (manufactured by Lintec Co., Ltd., product name "SP-PET381031", thickness 38 μm) Coating was performed by a fountain die method to form a coating film. And from the coating side UV rays are irradiated to form a semi-hardened layer.

As for the ultraviolet irradiation system, a belt conveyor type ultraviolet irradiation device (manufactured by iGrafx Corporation, product name "ECS-4011GX") was used as the ultraviolet irradiation device, and a high-pressure mercury lamp (manufactured by iGrafx Corporation, product name "H04-L41") was used as the ultraviolet source. Irradiation conditions were carried out under the conditions of illuminance of 112 mW/cm ² and light intensity of 177 mJ/cm ² (measured with an ultraviolet light meter "UVPF-A1" manufactured by iGrafx Corporation) with a light wavelength of 365 nm.

A polyethylene terephthalate film-based release film (manufactured by Lintec Co., Ltd., product name "SP-PET381031", thickness 38 μm) was laminated on the formed semi-hardened layer, and then irradiated with ultraviolet rays (using the above-mentioned Ultraviolet irradiation device, ultraviolet light source, illuminance 271mW/cm ² , light intensity 1,200mJ/cm ² as irradiation conditions), make it completely hardened, and form a 200μm-thick middle layer with a peeling film on both sides.

Five interlayers formed in this way were prepared, and the PET-based release film was peeled off, and the peeled surfaces were sequentially laminated to prepare an interlayer laminate (thickness: 1,000 μm).

Next, the obtained intermediate layer laminate was punched into a circle with a diameter of 10 mm to obtain a sample for measuring viscoelasticity. Using a viscoelasticity measurement device (manufactured by TA Instruments, product name "ARES"), the above-mentioned sample was given a twist at a frequency of 1 Hz, and the storage elastic modulus (G' ) to obtain the loss tangent (tanδ) at 50°C.

[fracture stress]

Prepare and attach polyethylene terephthalate peel-off film (Lin Adhesive layer (thickness: 200 μm) manufactured by TEC Co., Ltd., product name “SP-PET381031”). Here, in the same manner as in Examples and Comparative Examples, the thickness was changed to 40 μm on one side of the release film to form an adhesive layer, and then the other side of the release film was attached to the adhesive layer. Five adhesive layers sandwiching such a release film were prepared, and the release film on one side was peeled off so that the exposed surfaces of the adhesive layers faced each other and were laminated. By repeating this procedure, an adhesive layer with a thickness of 200 μm in which five adhesive layers were laminated was obtained. After irradiating the laminated body of the adhesive layer sandwiched between two peeling films with UV irradiation device "RAD-2000m/12" manufactured by Lintec Co., Ltd. with an illuminance of 220mW/cm and an irradiation speed of 15mm/second, the The cured product of the adhesive layer is cut out to a size of 15mm×150mm. Next, a label for stretching the film was attached to the 25 mm portion at both ends, and a strip-shaped sample with a measurement target portion of 15 mm×100 mm was produced. The fracture stress when measured at a tensile speed of 200 mm/min was measured with "Autograph AG-IS 500N" manufactured by Shimadzu Corporation.

[Adhesion before energy ray irradiation]

Cut the adhesive tapes of Examples and Comparative Examples equally into 25 mm wide, temporarily place the adhesive tape on the silicon mirror wafer to be attached, and make a roller weighing 1 kg reciprocate once on it, by applying the weight due to its own weight The resulting load is attached. After attaching, store at 23°C and a relative humidity of 50% for 1 hour, and measure the peel adhesion at a peel angle of 180° and a peel speed of 300mm/min using a tensile tester (manufactured by Orientec Corporation, product name "TENSILON") Adhesive force of adhesive tape.

[Adhesion after energy ray irradiation]

Cut the adhesive tapes of Examples and Comparative Examples equally into 25 mm wide, temporarily place the adhesive tape on the silicon mirror wafer to be attached, and make a roller weighing 1 kg reciprocate once on it, by applying the weight due to its own weight The resulting load is attached. After sticking, store it at 23°C and relative humidity of 50% for 1 hour, and then use the UV irradiation device "RAD-2000 m/12" manufactured by Lintec Co., Ltd. After irradiating the side of the adhesive tape with ultraviolet rays, leave it for 5 minutes at 23°C and a relative humidity of 50%, and then test it at a peeling angle of 180° and a peeling speed of 300mm/min using a tensile tester (manufactured by Orientec, product name "TENSILON") Measure the adhesive force when the adhesive tape is peeled off.

[Embedded Evaluation]

Spherical bumped wafer with a bump height of 250 μm, a pitch of 500 μm, and a diameter of 300 μm in plan view (manufactured by Waltz, 8-inch wafer, bump specification Sn/Ag/Cu=96.5/3/0.5% by mass , Wafer surface material SiO ₂ ) Adhesive tapes produced in Examples and Comparative Examples were attached using a laminator "RAD-3510F/12" manufactured by Lintec Co., Ltd. Also, when attaching, set the lamination table and lamination rollers of the device at 60°C. After lamination, UV irradiation device "RAD-2000 m/12" manufactured by Lintec Co., Ltd. was irradiated with ultraviolet rays from the side of the adhesive tape at an illumination intensity of 220mW/cm and an irradiation speed of 15mm/sec. Using a digital microscope (manufactured by Keyence Co., Ltd., product name "VHX-1000"), the evaluation wafer to which the thus-obtained adhesive tape was attached was measured for the diameter of the circular void formed from the base material side to the periphery of the bump, as follows: The formula calculates the embeddedness.

Embedding = diameter of void/diameter of bump × 100[%]

The calculated embeddability with a moderate gap of 110% or more but less than 130% is evaluated as the best, and is evaluated according to the following evaluation criteria.

A: Embedding = more than 110% but less than 130%

B: Embedding = more than 130% but less than 140%

C: Embedding = less than 110%, or more than 140%

[Evaluation of Paste Residue on Bumps]

From the evaluation wafer prepared in the same way as the above-mentioned embedding evaluation test and attached with an adhesive tape, it was stretched in a tensile tester (manufactured by Orientec Corporation, product name "TENSILON") in an environment of 23°C and a relative humidity of 50%. Peel off the adhesive tape at a speed of 120mm/min. After peeling off, put the wafer on an electron microscope "VE-9800" from Keyence Co., Ltd., and observe the bump portion of the wafer to confirm whether there is any paste residue.

[Manufacturing of the base material for the middle layer]

Blending 40 parts by mass of monofunctional urethane acrylate, 45 parts by mass of isocamphoryl acrylate (IBXA), 15 parts by mass of hydroxypropyl acrylate (HPA), pentaerythritol four (3-mercaptobutyrate) ( Showa Denko Co., Ltd., product name "KarenzMT PE1", a compound containing a second-stage tetrafunctional thiol, a solid content concentration of 100 parts by mass %) 3.5 parts by mass, a crosslinking agent 1.8 parts by mass, and as a photopolymerization initiator 2-Hydroxy-2-methyl-1-phenyl - 1.0 parts by mass of propan-1-one (manufactured by BASF Corporation, product name "Darocure 1173", solid content concentration: 100 parts by mass %) to adjust the resin composition for the intermediate layer. The resin composition for the intermediate layer was coated on a polyethylene terephthalate film-based release film (manufactured by Lintec Co., Ltd., product name "SP-PET381031", thickness 38 μm) with a pool doctor blade method to form a coating film.

Further, ultraviolet rays are irradiated from the coating film side to form a semi-cured layer. As for the ultraviolet irradiation system, a belt conveyor type ultraviolet irradiation device (manufactured by iGrafx Corporation, product name "ECS-401GGX") was used as the ultraviolet irradiation device, and a high-pressure mercury lamp (manufactured by iGrafx Corporation, product name "H04-L41") was used as the ultraviolet source. Irradiation conditions were carried out under conditions of illuminance of 112 mW/cm ² and light intensity of 177 mJ/cm ² (manufactured by iGrafx Corporation, measured under the product name "UVPF-A1") at a wavelength of 365 nm.

A substrate made of polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd., product name "Cosmo Shine A4100", thickness 50 μm) is laminated on the formed semi-hardened layer. From the PET film The side is further irradiated with ultraviolet rays (using the above-mentioned ultraviolet irradiation device, ultraviolet light source, illuminance 271mW/cm ² , light intensity 1200mJ/cm ² as irradiation conditions) to completely harden it, and form an intermediate layer with a thickness of 300μm on the PET film of the substrate , to obtain the sub-substrate of the intermediate layer.

Furthermore, the loss tangent (tan δ) of the intermediate layer measured at a frequency of 1 Hz at 50° C. was 1.92.

Furthermore, in the following examples and comparative examples, each part by mass is expressed in terms of solid content with respect to those diluted with a diluent.

[Example 1]

A polyurethane polyol (manufactured by Toyochem Co., Ltd., product name "SH-101", weight-average molecular weight: 100,000) having a urethane skeleton and multiple hydroxyl groups was prepared. 100 parts by mass of ester polymer (A') As urethane polymer (A'), urethane acrylate having multiple isocyanate groups (manufactured by DAICEL-ALLNEX, product name "EBECRYL 4150", weight Average molecular weight: 1,040) 32 parts by mass as the crosslinking agent (C1), pentaerythritol tetraacrylate (formula: 352) as the energy ray-curable compound (B), and pentaerythritol triacrylate (formula) as the compound (D) :298) mixture (mass ratio (C:D)=40:60) (manufactured by Shin-Nakamura Chemical Co., Ltd., product name "A-TMM-3LM-N") added 17 parts by mass, added 2,2-di Methoxy-1,2-diphenylethan-1-one (manufactured by BASF, product name "Irgacure 651") was used as an energy ray polymerization initiator (E) in 5 parts by mass, and a polyisocyanate compound (Toyochem Co., Ltd. "T-501B" manufactured by the company) 1 part by mass as a crosslinking agent (C2), stirred for 10 minutes, and diluted with toluene to adjust the adhesive composition with a solid content concentration of 40% by mass.

Next, apply the adjusted adhesive composition on a polyethylene terephthalate-based release film (manufactured by Lintec Co., Ltd., product name "SP-PET381031", thickness 38 μm), and heat at 100°C for 2 minutes , and dried to form an adhesive layer with a thickness of 10 μm on the release film.

Then, remove the peeling film on the base material with the intermediate layer prepared earlier, stick the adhesive layer on the peeling film to the exposed intermediate layer, and then cut An adhesive tape in which a base material, an intermediate layer, an adhesive layer, and a release film were provided in this order was obtained by removing unnecessary portions at the ends in the width direction. Table 1 shows the evaluation results of this adhesive tape.

[Example 2]

Except that the urethane polymer (A') was changed to Toyochem Co., Ltd., product name "SP-205", weight average molecular weight: 98,000) to adjust the adhesive composition, the others were the same as in Example 1. Make the adhesive tape in the same order.

[Example 3]

Except changing 17 parts by mass of "A-TMM-3LM-N" to urethane acrylate (manufactured by Negami Industry Co., Ltd., product name "UN-6200", 2 Functional, weight average molecular weight 6,270) 100 parts by mass to adjust the adhesive composition, other than Example 1 in the same procedure to produce an adhesive tape.

[Example 4]

An adhesive tape was produced in the same procedure as in Example 3, except that the urethane polymer (A') was changed to Toyochem Co., Ltd. product name "SP-205" to adjust the adhesive composition.

[Example 5]

In addition to changing 17 parts by mass of "A-TMM-3LM-N" as energy An adhesive tape was produced in the same procedure as in Example 1 except for 100 parts by mass of urethane acrylate (6-functional, weight average molecular weight: 33,000) of the line-curing compound (B).

[Comparative example 1]

In the acrylic copolymer obtained by polymerizing 94 parts by mass of 2-ethylhexyl acrylate and 6 parts by mass of 2-hydroxyethyl acrylate, 2-isocyanate ethyl methacrylate (made by Showa Denko Co., Ltd., product name "KarenzMOI") to the methacryl-added acrylic copolymer (weight average molecular weight: 900,000, solid content: 35% by mass). To 100 parts by mass of this copolymer, 3 parts by mass of 1-hydroxycyclohexyl phenyl ketone (manufactured by BASF Corporation, product name "Irgacure 184") was added as a photopolymerization initiator, and a polyisocyanate compound (manufactured by Toyochem Co., Ltd., product Name "BHS-8515") 0.8 parts by mass as a crosslinking agent, stirring for 30 minutes to adjust the acrylic adhesive composition. The obtained acrylic adhesive composition was coated on a polyethylene terephthalate release film (manufactured by Lintec Co., Ltd., product name "SP-PET381031", thickness 38 μm), and dried to a thickness of 10 μm. the adhesive layer.

Remove the peeling film on the substrate with the intermediate layer prepared previously, and after bonding the exposed intermediate layer and the adhesive layer on the peeling film, cut and remove the unnecessary part at the end in the width direction to obtain the substrate, intermediate layer, adhesive layer, and release film in this order of the adhesive tape. sticky tape The evaluation results are shown in Table 1.

[Comparative example 2]

In the acrylic copolymer obtained by polymerizing 90 parts by mass of 2-ethylhexyl acrylate and 10 parts by mass of 4-hydroxybutyl acrylate, 2-isocyanate ethyl methacrylate (made by Showa Denko Co., Ltd. KarenzMOI") to the hydroxyl group in the acrylic copolymer was added so that the molar basis became 65% to obtain a methacryl group-added acrylic copolymer (weight average molecular weight: 1,000,000, solid content: 25 mass %). To 100 parts by mass of this copolymer, 3 parts by mass of 1-hydroxycyclohexyl phenyl ketone (manufactured by BASF Corporation, product name "Irgacure 184") was added as a photopolymerization initiator, and a polyisocyanate compound (manufactured by Toyochem Co., Ltd., product name "BHS-8515") 1.1 parts by mass as a crosslinking agent, and stirred for 30 minutes to adjust the acrylic adhesive composition. Other than that, the adhesive tape was produced in the same procedure as in Comparative Example 1.

[Comparative example 3]

In the acrylic copolymer obtained by polymerizing 90 parts by mass of 2-ethylhexyl acrylate and 10 parts by mass of 4-hydroxybutyl acrylate, 2-isocyanate ethyl methacrylate (made by Showa Denko Co., Ltd. KarenzMOI") to the hydroxyl group in the acrylic copolymer was added so that the molar basis became 75% to obtain a methacryl group-added acrylic copolymer (weight average molecular weight: 1,000,000, solid content: 25 mass %).

To 100 parts by mass of this copolymer, 5 parts by mass of 1-hydroxycyclohexyl phenyl ketone (manufactured by BASF Corporation, product name "Irgacure 184") was added as a photopolymerization initiator, and a polyisocyanate compound (manufactured by Toyochem Co., Ltd., product Name "BHS-8515") 1.2 parts by mass as a crosslinking agent, stirring for 30 minutes to adjust the acrylic adhesive composition. Other than that, the adhesive tape was produced in the same procedure as in Comparative Example 1.

[Comparative example 4]

An adhesive tape was produced in the same procedure as in Example 1 except that "A-TMM-3LM-N" was not added.

In Examples 1 to 5 above, the adhesive composition is urethane-based, and at the same time, the urethane-based resin (A) contains a non-reactive energy ray-curing compound (B) to make the bumps The embedding property (tracking of the adhesive layer on the surface shape of the workpiece) becomes better, and the fracture stress is increased to prevent paste residue during peeling. Furthermore, since the adhesive force before energy ray curing can be increased and the adhesive force after curing can be sufficiently reduced, peelability and adhesiveness are excellent.

On the other hand, in Comparative Examples 1-3, since the adhesive composition is acrylic, reducing the fracture stress cannot prevent paste residue. In addition, in Comparative Example 4, although it is a urethane system, since the energy ray-curable compound (B) is not contained, the flexibility of the adhesive layer is poor, and the embedding property is not sufficient.

Claims (15)

An adhesive tape for workpiece processing, comprising a substrate, and an adhesive layer provided on one side of the substrate, the adhesive layer comprising urethane-based resin (A) and energy ray curing The energy ray-curable compound (B) is non-reactive to the aforementioned urethane-based resin (A), has a photopolymerizable unsaturated bond, has a molecular weight of 35,000 or less, and the aforementioned urethane The ethyl ester resin (A) has a photopolymerizable unsaturated bond, and the aforementioned adhesive layer is composed of at least the urethane polymer (A'), and the urethane polymer (A') directly or indirectly. ') bonded to become the adhesive composition of the main ingredient reactive compound of the urethane resin (A), the aforementioned main ingredient reactive compound is the crosslinking agent (C) and the compound (D), and the aforementioned The compound (D) is a compound having a photopolymerizable unsaturated bond and a reactive functional group that can react with the crosslinking agent (C), and the weight average molecular weight of the aforementioned urethane polymer (A') is 10,000 to 300,000 , the total blending amount of the above-mentioned main ingredient reactive compound and the above-mentioned urethane polymer (A') is 40 to 95% by mass relative to the total amount of the above-mentioned adhesive composition, and the above-mentioned adhesive layer is an energy ray hardening type , The adhesive tape for workpiece processing attached to the surface of the workpiece is irradiated with energy rays and hardened by the energy rays, and then peeled off from the surface of the workpiece. The adhesive tape for workpiece processing according to claim 1, wherein the energy ray-curable compound (B) is selected from (meth)acrylate monomer (B1) and urethane (meth)acrylate ( At least one of B2). The adhesive tape for workpiece processing according to claim 2, wherein the energy ray-curable compound (B) contains at least a (meth)acrylate monomer (B1) At the same time, the aforementioned (meth)acrylate monomer (B1) is a complete ester of polyhydric alcohol and (meth)acrylic acid, that is, a multifunctional (meth)acrylate. An adhesive tape for workpiece processing, comprising a substrate, and an adhesive layer provided on one side of the substrate, the adhesive layer comprising urethane-based resin (A) and energy ray curing The energy ray-curable compound (B) is non-reactive to the aforementioned urethane-based resin (A), has a photopolymerizable unsaturated bond, and has a molecular weight of 35,000 or less, and the aforementioned adhesive layer It is composed of at least urethane polymer (A'), and the aforementioned energy ray-curable compound (B), and a crosslinking agent (C), and has a photopolymerizable unsaturated bond and can be combined with the aforementioned crosslinking agent (C) The adhesive composition formed by the compound (D) of the reactive functional group of the reaction, the aforementioned urethane resin (A) is the urethane polymer (A') through the aforementioned exchange When the linking agent (C) is used for cross-linking, the weight average molecular weight of the above-mentioned urethane polymer (A') is 10,000~300,000, and the above-mentioned reactive compound of the main agent and the above-mentioned urethane polymer (A') The total blending amount of the above-mentioned adhesive composition is 40~95% by mass relative to the total amount of the above-mentioned adhesive composition. The above-mentioned adhesive layer is an energy ray hardening type. After that, it is peeled off from the workpiece surface. The adhesive tape for workpiece processing according to claim 4, wherein the crosslinking agent (C) contains a crosslinking agent (C1) containing a photopolymerizable unsaturated bond. The adhesive tape for workpiece processing according to claim 4, wherein the aforementioned urethane polymer (A') and the aforementioned crosslinking agent (C) are bonded via urethane bonds. The adhesive tape for workpiece processing according to claim 6, wherein the blending amount of the compound (D) is 1 to 30 parts by mass relative to 100 parts by mass of the urethane-based resin (A). The adhesive tape for workpiece processing according to claim 6, wherein the compound (D) is a partial ester of polyhydric alcohol and (meth)acrylic acid, that is, a polyfunctional (meth)acrylate. An adhesive tape for workpiece processing, comprising a substrate, and an adhesive layer provided on one side of the substrate, the adhesive layer comprising urethane-based resin (A) and energy ray curing The energy ray-curable compound (B) is non-reactive to the aforementioned urethane-based resin (A), has a photopolymerizable unsaturated bond, and has a molecular weight of 35,000 or less, and the aforementioned adhesive layer The breaking stress after the irradiation of energy rays is above 2.5MPa. The aforementioned adhesive layer is composed of at least urethane polymer (A'), and directly or indirectly bonded to urethane polymer (A'). The knot is formed by an adhesive composition that becomes the main ingredient reactive compound of the urethane resin (A), the aforementioned main ingredient reactive compound is a crosslinking agent (C) and a compound (D), and the aforementioned compound (D ) is a compound having a photopolymerizable unsaturated bond and a reactive functional group that can react with the crosslinking agent (C), the weight average molecular weight of the aforementioned urethane polymer (A') is 10,000 to 300,000, and the aforementioned main The total blending amount of the agent-reactive compound and the aforementioned urethane polymer (A') is 40 to 95% by mass relative to the total amount of the aforementioned adhesive composition. After the adhesive tape for workpiece processing on the surface of the workpiece is irradiated with energy rays and hardened by the energy rays, it is peeled off from the surface of the workpiece. An adhesive tape for workpiece processing, comprising a substrate, and an adhesive layer provided on one side of the substrate, the adhesive layer comprising urethane-based resin (A) and energy ray curing The energy ray-curable compound (B) is non-reactive to the aforementioned urethane-based resin (A), has a photopolymerizable unsaturated bond, and has a molecular weight of 35,000 or less. There is an intermediate layer between the aforementioned adhesive layer, the loss tangent of the aforementioned intermediate layer at 50°C measured at a frequency of 1 Hz is 1.0 or more, and the aforementioned adhesive layer is composed of at least urethane polymer (A'), and Directly or indirectly bonded to the urethane polymer (A') to form an adhesive composition that becomes the main agent reactive compound of the urethane resin (A), the aforementioned main agent reactive compound is Crosslinking agent (C) and compound (D), the aforementioned compound (D) is a compound having a photopolymerizable unsaturated bond and a reactive functional group that can react with the crosslinking agent (C), and the aforementioned urethane polymer The weight-average molecular weight of the substance (A') is 10,000 to 300,000, and the total blending amount of the aforementioned main ingredient reactive compound and the aforementioned urethane polymer (A') is 40 to 300,000 relative to the total amount of the aforementioned adhesive composition. 95% by mass, the aforementioned adhesive layer is an energy ray hardening type, and the adhesive tape for workpiece processing attached to the surface of the workpiece is irradiated with energy ray and hardened by the energy ray, and then peeled off from the surface of the workpiece. The adhesive tape for workpiece processing according to claim 10, wherein the thickness of the aforementioned intermediate layer is 10-600 μm. An adhesive tape for workpiece processing, comprising a substrate, and an adhesive layer provided on one side of the substrate, the adhesive layer comprising urethane-based resin (A) and energy ray curing sexual compound (B) The energy ray curable compound (B) is non-reactive to the aforementioned urethane resin (A), has a photopolymerizable unsaturated bond, has a molecular weight of 35,000 or less, and adheres after energy ray irradiation The force is less than 2000mN/25mm, the aforementioned adhesive layer is composed of at least urethane polymer (A'), and is directly or indirectly bonded to urethane polymer (A') to form urethane Formed from the adhesive composition of the main agent reactive compound of ethyl ester resin (A), the aforementioned main agent reactive compound is a crosslinking agent (C) and compound (D), and the aforementioned compound (D) is photopolymerizable A compound having an unsaturated bond and a reactive functional group that can react with the cross-linking agent (C), the weight average molecular weight of the aforementioned urethane polymer (A') is 10,000 to 300,000, the aforementioned main ingredient reactive compound and the aforementioned The total blending amount of the urethane polymer (A') is 40 to 95% by mass relative to the total amount of the aforementioned adhesive composition. After the energy rays are irradiated with the adhesive tape system and the energy rays harden, it is peeled off from the surface of the workpiece. The adhesive tape for workpiece processing according to any one of claims 1 to 12 is an adhesive tape for protecting the surface of a semiconductor wafer. The adhesive tape for workpiece processing according to any one of claims 1 to 12, wherein the energy ray-curable compound (B) has a (meth)acryl group having two or more functions in one molecule. The adhesive tape for workpiece processing according to any one of claims 1 to 12, wherein the blending amount of the aforementioned energy ray-curable compound (B) relative to 100 parts by mass of the aforementioned urethane-based resin (A) is: 1 to 120 parts by mass.