JP2011089009A - Radiation-curable adhesive composition, adhesive film for dicing using the same and method for producing cut piece - Google Patents

Abstract

In a dicing process, it has a high adhesive force and suppresses detachment and scattering of a cut piece of a semiconductor element or the like, and in a pick-up process, it has excellent light peelability even for a workpiece having an active surface. An adhesive film for dicing provided with an adhesive layer is provided.
A base polymer having a solubility parameter of 9.6 (cal / cm ³ ) ^1/2 or more and 10.0 (cal / cm ³ ) ^1/2 or less in an adhesive layer of an adhesive film for dicing, A radiation-curable pressure-sensitive adhesive composition containing a (meth) acrylic polymer obtained by reacting with a radiation-reactive compound having a radiation-reactive carbon-carbon double bond is used.
[Selection] Figure 1

Description

  The present invention relates to a radiation-curable pressure-sensitive adhesive composition, a dicing pressure-sensitive adhesive film using the same, and a method for producing a cut piece. More specifically, the present invention relates to a dicing pressure-sensitive adhesive film suitably used for cutting a workpiece such as a semiconductor wafer or a semiconductor package having an active surface.

  Conventionally, a semiconductor-related material of the semiconductor wafer and a semiconductor package is cut using a rotary blade, it is separated into small pieces semiconductor elements and IC components. For example, a semiconductor wafer made of silicon, germanium, gallium-arsenide, or the like is manufactured in a large diameter state and then back-grinded (back grind) until a predetermined thickness is obtained. Back surface processing (etching processing, polishing processing, etc.) is performed. Next, the semiconductor wafer is cut and separated (diced) into element pieces, and then transferred to the subsequent process. In this manufacturing process, a mounting process in which an adhesive film for dicing is previously attached to a semiconductor wafer, a dicing process in which the semiconductor wafer is diced into element pieces with the adhesive film being attached to the semiconductor wafer, a cleaning process, an expanding process, and a pickup Various processes such as processes are performed. In the pick-up step, the dicing adhesive film is stretched to some extent, the dicing adhesive film below the semiconductor element to be picked up is lifted in a dotted or linear shape, and the semiconductor element and the dicing adhesive film are peeled off. A system in which a semiconductor element is obtained by picking up from the upper part by vacuum suction or the like while being promoted is employed.

  The dicing pressure-sensitive adhesive film generally has a configuration in which a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive composition is formed on a substrate such as a plastic film. When manufacturing a semiconductor element, the dicing adhesive film does not peel from the adhesive film even if water pressure of washing water is applied during dicing in order to suppress the detachment and scattering of the semiconductor element from the adhesive film in the dicing process. While a high degree of adhesive strength is required, it is required that the adhesive layer has a light release property that provides a low adhesive strength that does not damage the semiconductor wafer during peeling in the pickup process.

  As a pressure-sensitive adhesive composition satisfying the above characteristics, for example, a base polymer made of a (meth) acrylic copolymer is reacted with a radiation-reactive compound having a radiation-reactive carbon-carbon double bond, and the side A radiation-curable pressure-sensitive adhesive composition mainly composed of a (meth) acrylic polymer having a radiation-reactive carbon-carbon double bond introduced at the chain and / or terminal has been proposed (Patent Document 1). According to this radiation-curable pressure-sensitive adhesive composition, since the (meth) acrylic polymer has a high adhesive force before being cured with radiation, it is possible to suppress detachment scattering of the semiconductor element in the dicing process. Also, when the pressure-sensitive adhesive layer is irradiated with radiation, the (meth) acrylic polymer is cured by the radiation reactive carbon-carbon double bond introduced at the side chain and / or the terminal and the adhesive strength is significantly reduced. In, the semiconductor element can be easily peeled off from the dicing adhesive film.

JP 2008-60434 A

  By the way, in recent years, in the semiconductor manufacturing process, within a short time after the back surface grinding process or after the back surface grinding process and the back surface process are completed, for the purpose of preventing damage due to the thinning of the semiconductor wafer (for example, 100 μm or less). In addition, an adhesive film for dicing is often attached to a semiconductor wafer. After such back grinding, or after back grinding and back treatment, if the adhesive film for dicing is attached to a thin semiconductor wafer within a short time, the adhesive strength between the semiconductor wafer and the adhesive layer is increased, There is a problem that peeling after curing by radiation is difficult and pick-up property is lowered. In particular, in a semiconductor element manufacturing process, when the dicing process and the pick-up process are performed at different locations, the semiconductor wafer may be left with the dicing adhesive film attached. In such a case, the problem that the adhesive force is further increased and the pickup property is further lowered has been clarified.

  The present invention solves the above-mentioned problems, and an object of the present invention is to provide a radiation-curable pressure-sensitive adhesive composition having excellent adhesive strength before curing with radiation and lightly peelable after curing with radiation. By using the radiation curable pressure-sensitive adhesive composition, the dicing process has a high adhesive force, and it is possible to suppress detachment and scattering of a cut piece such as a semiconductor element, and excellent light peeling in the pickup process. It is providing the adhesive film for dicing provided with the adhesive layer which has property.

The present invention is a radiation-curable pressure-sensitive adhesive composition containing a (meth) acrylic polymer having a radiation-reactive carbon-carbon double bond at a side chain and / or terminal,
Radiation curable adhesive in which the base polymer constituting the (meth) acrylic polymer has a solubility parameter of 9.6 (cal / cm ³ ) ^1/2 or more and 10.0 (cal / cm ³ ) ^1/2 or less Agent composition.

  The base polymer preferably has a glass transition temperature of 225K or more and less than 228K. In particular, the base polymer preferably contains at least a linear or branched alkyl group-containing (meth) acrylic monomer having 8 or more carbon atoms and a hydroxyl group-containing (meth) acrylic monomer as copolymerization monomer components.

The present invention is a pressure-sensitive adhesive film for dicing having a base material and an adhesive layer on at least one surface of the base material,
The pressure-sensitive adhesive layer is a pressure-sensitive adhesive film for dicing containing a radiation curable pressure-sensitive adhesive composition containing a crosslinking agent, a photopolymerization initiator, and the (meth) acrylic polymer.

And this invention sticks the said adhesive film for dicing on the one surface of a workpiece,
The workpiece to which the adhesive film for dicing is attached is cut and separated into cut pieces,
Radiation is applied to the adhesive layer attached to the cut piece to reduce the adhesive strength of the adhesive layer,
It is the manufacturing method of the cut piece which picks up the said cut piece from the adhesive film for dicing which reduced the said adhesive force. In particular, when the workpiece is a semiconductor wafer having an active surface, the method for manufacturing the cut piece is effective.

  According to the present invention, since the pressure-sensitive adhesive layer contains the radiation-curable pressure-sensitive adhesive composition, a high adhesive force can be obtained in the dicing process, and a semiconductor wafer having an active surface in the pickup process can be obtained. A pressure-sensitive adhesive film for dicing having excellent light releasability on a workpiece can be provided. As a result, the separation and scattering of the cut pieces in the dicing step can be reduced, and the cut pieces can be easily peeled off from the dicing adhesive film in the pick-up step.

FIG. 1 is a schematic cross-sectional view showing an example of a dicing adhesive film according to an embodiment of the present invention.

  As described above, when a radiation curable pressure-sensitive adhesive composition containing a (meth) acrylic polymer having a radiation-reactive carbon-carbon double bond is used for the pressure-sensitive adhesive layer of the dicing pressure-sensitive adhesive film, after the back surface grinding treatment Or, if the adhesive film for dicing is attached to a thin semiconductor wafer within a short time after the backside grinding and backside treatment, the adhesive strength between the semiconductor wafer and the adhesive layer increases, and it is difficult to peel off after curing by radiation. Therefore, the pick-up property tends to be lowered. This is because the natural oxide film is not sufficiently formed on the entire surface of the semiconductor wafer on the processed surface where the backside grinding process or the backside processing of the semiconductor wafer is performed, and the surface of the semiconductor wafer is not oxidized in the active atoms (for example, Therefore, when a dicing adhesive film is attached to the active surface, it is contained in the unoxidized active atom and the radiation-curable adhesive composition (meta). A polar group such as a hydroxyl group or a carboxyl group introduced into the molecule of an acrylic polymer or a polar site such as an ester group comes into contact, and a chemical bond is formed between the active atom in an unoxidized state and the adhesive layer. It is presumed that it will occur. That is, when synthesizing a (meth) acrylic polymer having a radiation-reactive carbon-carbon double bond in the molecule, a polar group such as a hydroxyl group or a carboxyl group is introduced into the base polymer made of a (meth) acrylic copolymer. In addition, it is necessary to react the radiation-reactive compound having a functional group capable of bonding with these polar groups with the base polymer. Therefore, the functional group of the radiation reactive compound and the unreacted hydroxyl group may remain in the (meth) acrylic polymer, and this polar group is considered to form a chemical bond with the active atom. In particular, when a crosslinking agent is used to crosslink the (meth) acrylic polymer, a large number of polar groups are added to the (meth) acrylic polymer in consideration of the number of polar groups such as hydroxyl groups for reacting with the crosslinking agent. It is necessary to introduce it, and therefore, an unreacted polar group may remain in the (meth) acrylic polymer. As a result, even if a curing treatment with radiation is performed, it is considered that the adhesive strength is not sufficiently lowered due to the bond between the polar group remaining in the (meth) acrylic polymer and the active atom.

In order to reduce the adhesive strength of a dicing adhesive film affixed to a semiconductor wafer having an active surface by irradiation with radiation, the present inventors have the polar groups and polarities of the (meth) acrylic polymer as described above. From the viewpoint that it is effective to reduce the number of parts as much as possible, as a result of examining a radiation curable pressure-sensitive adhesive composition that can ensure light release in the pick-up process, the solubility parameter of the base polymer constituting the (meth) acrylic polymer Is 9.6 (cal / cm ³ ) ^1/2 or more and 10.0 (cal / cm ³ ) ^1/2 or less, it shows high adhesive strength before radiation curing, and light peelability after radiation curing. It has been found that a radiation-curable pressure-sensitive adhesive composition having the following can be obtained. The reason for this is not necessarily clear, but if the adhesive force between the semiconductor wafer having the active surface and the adhesive layer is due to the bond between the active atom and the polar group or polar part of the (meth) acrylic polymer, Since a decrease in solubility parameter means a decrease in polarity, the use of a base polymer having a low solubility parameter can reduce the number of polar groups and polar sites in the resulting (meth) acrylic polymer, thereby It is expected that the bond between the active atom and the polar group is reduced, and the adhesive strength after radiation curing can be sufficiently reduced. On the other hand, if the solubility parameter is too low, polar groups such as hydroxyl groups in the base polymer for introducing a radiation-reactive carbon-carbon double bond also decrease. Therefore, the amount of radiation-reactive carbon-carbon double bonds introduced into the (meth) acrylic polymer is reduced, and the curability when irradiated with radiation is reduced. In addition, when a crosslinking agent is used to crosslink the (meth) acrylic polymer, polar groups such as hydroxyl groups that react with the crosslinking agent are reduced, and unreacted components remain in the adhesive layer. Contamination of the adherend is likely to occur. Thus, in the radiation-curable pressure-sensitive adhesive composition using the (meth) acrylic polymer having a radiation-reactive carbon-carbon double bond, the polar group of the base polymer constituting the (meth) acrylic polymer, etc. From the viewpoint that the reduction is effective in suppressing the bond between the active atom and the (meth) acrylic polymer, an example of examining the light release property of the adhesive film for dicing after radiation curing, focusing on the solubility parameter of the base polymer Is not found.

In this Embodiment, the solubility parameter of a base polymer can be calculated | required from the product of the solubility parameter and molar ratio of each (meth) acrylic-type monomer which comprises the base polymer which is a copolymer. For example, when the base polymer is composed of two types of (meth) acrylic monomers X and Y, the content of each (meth) acrylic monomer used to synthesize the base polymer with respect to the total amount of copolymerization monomer components Is x mass%, y mass%, and the molecular weight is Mx and My, the molar ratio Cx and Cy of each (meth) acrylic monomer is represented by x / Mx and y / My, and the molar ratio C of the base polymer is , X / Mx + y / My. Therefore, when the solubility parameter of each (meth) acrylic monomer is SPx (cal / cm ³ ) ^1/2 and SPy (cal / cm ³ ) ^1/2 , the solubility parameter SP (cal / cm ³ ) ^{1 of the} base polymer. ^{/ 2} can be obtained by the following equation (1).
SP = [(x × SPx / Mx) + (y × SPy / My)] × (1 / C) (1)
In addition, it is known that the solubility parameter of each (meth) acrylic monomer is calculated from the molecular structure, and the solubility parameter of each (meth) acrylic monomer in this specification is a method by Fedors (written by Yuji Harasaki, It means the value at 25 ° C. obtained by “Basic Science of Coating”, Chapter 3, page 35, 1977, published by Tsubaki Shoten.

  Further, in this embodiment, the base polymer having the above solubility parameter, or 225K, and more preferably has a glass transition temperature of less than 228K. The glass transition temperature affects the adhesive strength of the adhesive are known, as the glass transition temperature is lower adhesive strength becomes high. Therefore, for the purpose of easy releasability, as the base polymer constituting the (meth) acrylic polymer, having a high glass transition temperature may be preferred. However, according to the study by the present inventors, when a base polymer having the above solubility parameter is used, a base polymer having a glass transition temperature lower than the conventional one can obtain a dicing pressure-sensitive adhesive film with better light peelability. I also found out.

In this Embodiment, the glass transition temperature of a base polymer can be calculated | required from the glass transition temperature and weight fraction of the homopolymer of each (meth) acrylic-type monomer which comprises a copolymer. For example, similarly to the calculation of the solubility parameter, when the base polymer is composed of two types of (meth) acrylic monomers X and Y, the weight fraction (mass% / 100 of each (meth) acrylic monomer. ) Is Wx, Wy, and the glass transition temperature of the homopolymer of each (meth) acrylic monomer is Tgx (K), Tgy (K), the glass transition temperature Tg (K) of the base polymer is represented by the following formula (2): Can be obtained from
1 / Tg = Wx / Tgx + Wy / Tgy (2)

  Next, a configuration of the radiation-curable pressure-sensitive adhesive composition of the present embodiment and a manufacturing method thereof, and a configuration of a pressure-sensitive adhesive film for dicing having a pressure-sensitive adhesive layer using the radiation-curable pressure-sensitive adhesive composition and a manufacturing method thereof. explain.

  The (meth) acrylic polymer having a radiation-reactive carbon-carbon double bond at the side chain and / or the terminal of the present embodiment is composed of a base polymer obtained by copolymerizing a (meth) acrylic monomer, and a radiation reaction. It can be synthesized by reacting with a radiation reactive compound having a radiation reactive carbon-carbon double bond as a reactive component. In the present specification, (meth) acryl means acryl or methacryl.

  The base polymer is a linear or branched alkyl group-containing (meth) acrylic monomer having 8 or more carbon atoms that does not have a polar group such as a hydroxyl group as a main component of the copolymerization monomer component, and a hydroxyl group-containing (meth) acrylic monomer. Is preferable, and it is more preferable to contain only a linear or branched alkyl group-containing (meth) acrylic monomer having 8 or more carbon atoms and a hydroxyl group-containing (meth) acrylic monomer. Hydroxyl group for introducing a radiation-reactive carbon-carbon double bond into a (meth) acrylic polymer by using a hydroxyl group-containing (meth) acrylic monomer or for crosslinking a (meth) acrylic polymer with a crosslinking agent Can be imparted to the base polymer. In particular, if the base polymer contains only a linear or branched alkyl group-containing (meth) acrylic monomer having 8 or more carbon atoms and a hydroxyl group-containing (meth) acrylic monomer, the polarity of the base polymer is determined by the long-chain alkyl group. , And the amount of polar groups introduced is reduced, so that a base polymer having a low solubility parameter can be synthesized.

  Specific examples of the linear or branched alkyl group-containing (meth) acrylic monomer having 8 or more carbon atoms include, for example, octyl (meth) acrylate, isooctyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. , Nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, Examples include (meth) acrylic acid esters such as tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, and octadecyl (meth) acrylate. These may be used alone or in combination of two or more. In addition, the number of alkyl groups of a linear or branched alkyl group-containing (meth) acrylic monomer having 8 or more carbon atoms is preferably as long as possible, but considering the availability in the market, the number of alkyl groups is 18 or less. Preferably, 12 or less is more preferable. Among these, one kind selected from the group consisting of octyl (meth) acrylate, isooctyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate containing a linear or branched alkyl group having 8 carbon atoms is preferable. More preferred is 2-ethylhexyl (meth) acrylate.

  Specific examples of the hydroxyl group-containing (meth) acrylic monomer include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (meth ) 6-hydroxyhexyl acrylate and the like. These may be used alone or in combination of two or more.

  The content of the linear or branched alkyl group-containing (meth) acrylic monomer having 8 or more carbon atoms is preferably 87.0 to 93.5% by mass, based on the total amount of copolymerization monomer components constituting the base polymer. Preferably, it is 90.0-93.5% by mass, and the content of the hydroxyl group-containing (meth) acrylic monomer is preferably 5.0-13.0% by mass, more preferably 5.0-10.0% by mass. %. If the content of the linear or branched alkyl group-containing (meth) acrylic monomer having 8 or more carbon atoms is too low and the content of the hydroxyl group-containing (meth) acrylic monomer is too high, the solubility parameter of the base polymer is high. As a result, the active atoms and the polar groups on the active surface of the semiconductor wafer or the like are bonded to each other, and the adhesive force cannot be sufficiently reduced even by curing with radiation, and as a result, the light peelability is lowered. On the other hand, if the content of the linear or branched alkyl group-containing (meth) acrylic monomer having 8 or more carbon atoms is excessively increased and the content of the hydroxyl group-containing (meth) acrylic monomer is excessively decreased, the hydroxyl group in the base polymer The number of hydroxyl groups required to react with the radiation-reactive compound and introduce a radiation-reactive carbon-carbon double bond into the (meth) acrylic polymer due to the reduced number of solubility parameters. Decreases and curability decreases. In addition, if the amount of radiation-reactive carbon-carbon double bonds introduced is increased in order to improve curability, when a crosslinking agent is used for increasing the molecular weight, the number of hydroxyl groups that react with the crosslinking agent decreases. Reactive components remain, and glue stains are likely to occur.

  In this embodiment, the base polymer, cohesion, and for the purpose of heat resistance, may contain other copolymerizable monomer component as required. Specific examples of such other copolymerization monomer components include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, (meth) Butyl acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, etc. (Meth) acrylic acid ester having a short chain alkyl group; epoxy group-containing monomer such as glycidyl (meth) acrylate; (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, etc. Carboxyl group-containing monomer; acid anhydride group-containing monomer such as maleic anhydride and itaconic anhydride; ) Acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxy Amide monomers such as methyl (meth) acrylamide; amino group-containing monomers such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, and t-butylaminoethyl (meth) acrylate; Cyano group-containing monomers such as (meth) acrylonitrile; Olefin-based monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene; Styrene monomers such as styrene, α-methylstyrene, and vinyltoluene; Vinyl acetate and vinyl propionate Vinyl ester monomers such as methyl; vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether; halogen atom-containing monomers such as vinyl chloride and vinylidene chloride; alkoxy groups such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate Containing monomer: N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole , N- vinyl oxazole, N- vinyl morpholine, N- vinyl caprolactam, and monomers having a nitrogen atom-containing ring such as N- (meth) acryloyl morpholine. Moreover, you may use a polyfunctional monomer for a copolymerization monomer component as needed for the purpose of bridge | crosslinking etc. Furthermore, as a copolymerization monomer component, an ethylene-vinyl acetate copolymer, a vinyl acetate polymer, or the like may be used as necessary. These other copolymerization monomer components may be used alone or in combination of two or more. However, in order to obtain a base polymer having the above solubility parameter, other copolymer monomer components having a polar group other than a (meth) acrylic acid ester having a short-chain alkyl group or a hydroxyl group-containing (meth) acrylic monomer may be used. The content is preferably as low as possible. Therefore, these other copolymerizable monomer component, relative to copolymerized total amount of monomer components, in a total amount, preferably not more than 2.0 wt%, more preferably not more than 1.0 mass%.

  Examples of the polymerization method for synthesizing the base polymer include conventionally known solution polymerization methods, emulsion polymerization methods, bulk polymerization methods, and suspension polymerization methods. Among these, the solution polymerization method in which the polymerization of the copolymerization monomer component of the present embodiment proceeds uniformly is preferable. Specific examples of the organic solvent for solution polymerization include ketone-based, ester-based, alcohol-based, and aromatic-based organic solvents. These organic solvents may be used alone or in combination of two or more. Among these, organic solvents having a boiling point of 60 to 120 ° C. are generally good solvents for the base polymer, such as toluene, ethyl acetate, isopropyl alcohol, benzene methyl cellosolve, ethyl cellosolve, acetone, and methyl ethyl ketone. Examples of the polymerization initiator include radical generators such as azobis type such as α, α′-azobisisobutylnitrile; organic peroxide type such as benzoperoxide. In the polymerization, a catalyst, a polymerization inhibitor or the like may be used as necessary.

  The (meth) acrylic polymer of the present embodiment is reacted with a radiation reactive compound containing a radiation reactive carbon-carbon double bond with the base polymer obtained as described above, and the (meth) acrylic polymer side. It can be synthesized by introducing a radiation-reactive carbon-carbon double bond at the chain and / or the terminal.

  As the radiation-reactive compound, a compound having a radiation-reactive carbon-carbon double bond and a functional group that reacts with the polar group of the base polymer can be used. Specific examples include carboxyl group-containing monomers such as (meth) acrylic acid, cinnamic acid, itaconic acid, fumaric acid, and phthalic acid; and isocyanate group-containing monomers such as isocyanate ethyl (meth) acrylate. These radiation reactive compounds may be used alone or in combination of two or more. Among these, an isocyanate group-containing monomer that is excellent in reactivity with a hydroxyl group is preferable. In addition, when the base polymer contains an epoxy group-containing monomer, a carboxyl group-containing monomer, an acid anhydride group-containing monomer, or the like as a copolymerization monomer component, an epoxy group or a carboxylic acid introduced into the molecule by these copolymerization monomer components A hydroxyl group-containing monomer such as 2-hydroxyethyl (meth) acrylate and hydroxyethyl (meth) acrylate having a functional group that reacts with a functional group such as a group or an acid anhydride group; glycidyl (meth) acrylate, (meta ) Epoxy group-containing monomers such as glycidyl acrylate; amino group-containing monomers such as aminoethyl (meth) acrylate may be used.

  The content of the radiation-reactive compound is preferably 5 to 25 parts by mass and more preferably 6 to 9 parts by mass with respect to 100 parts by mass of the base polymer. If content of a radiation reactive compound is less than 5 mass parts, the introduction amount of a radiation reactive carbon-carbon double bond will decrease, and sclerosis | hardenability will fall. When the content of the radiation-reactive compound is more than 25 parts by mass, the curability is saturated, but the fluidity of the pressure-sensitive adhesive after curing by radiation is lowered, and the gap between the cut pieces after stretching becomes insufficient. . For this reason, it may be difficult to recognize the image of each cut piece during pickup. In addition, the stability of the (meth) acrylic polymer may be reduced, making it difficult to manufacture.

  As a reaction between the base polymer for synthesizing the (meth) acrylic polymer and the radiation-reactive compound, there is a method in which these are subjected to a condensation reaction or an addition reaction while maintaining the radiation reactivity of the carbon-carbon double bond. Can be mentioned. In these reactions, it is preferable to use a polymerization inhibitor so that the radiation reactivity of the carbon-carbon double bond is maintained. As such a polymerization inhibitor, a quinone polymerization inhibitor such as hydroquinone monomethyl ether is preferable. The amount of the polymerization inhibitor is not particularly limited, but is usually 0.01 to 0.1 parts by mass with respect to the total amount of the base polymer and the radiation reactive compound.

  The weight average molecular weight of the (meth) acrylic polymer obtained as described above is preferably 300,000 to 2,000,000, more preferably 400,000 to 1,500,000. When the weight average molecular weight is less than 300,000, paste stains are likely to occur on the cut piece. In addition, the cohesive force of the (meth) acrylic polymer is reduced, and the position of the workpiece is likely to shift during dicing. On the other hand, when the weight average molecular weight is larger than 2 million, the pressure-sensitive adhesive composition may be gelated at the time of synthesis and when the pressure-sensitive adhesive composition is applied onto the substrate. In addition, the said weight average molecular weight is a polystyrene conversion weight average molecular weight by GPC (gel permeation chromatography) (solvent: tetrahydrofuran).

  It is preferable that the radiation-curable pressure-sensitive adhesive composition of the present embodiment further contains a crosslinking agent for increasing the molecular weight of the (meth) acrylic polymer. Such a crosslinking agent is not particularly limited, and a known crosslinking agent can be used. Specifically, for example, polyisocyanate crosslinking agent, epoxy crosslinking agent, aziridine crosslinking agent, melamine resin crosslinking agent, urea resin crosslinking agent, acid anhydride compound crosslinking agent, polyamine crosslinking agent, carboxyl group-containing Examples thereof include a polymer-based crosslinking agent. These crosslinking agents may be used alone or in combination of two or more. The amount of the crosslinking agent is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer. If the amount of the crosslinking agent is too large, depending on the type of (meth) acrylic polymer, the adhesive strength when applying the dicing adhesive film to the workpiece may be reduced, or uncrosslinked components may adhere to the cut pieces. , Glue stains may occur.

  The radiation-curable pressure-sensitive adhesive composition of the present embodiment preferably further contains a photopolymerization initiator when ultraviolet rays are used as radiation. Specific examples of such photopolymerization initiators include benzoin alkyl ether initiators such as benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; benzophenone and benzoylbenzoic acid. Benzophenone initiators such as 3,3′-dimethyl-4-methoxybenzophenone and polyvinylbenzophenone; α-hydroxycyclohexyl phenyl ketone, 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, α -Hydroxy-α, α'-dimethylacetophenone, methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1- [ Aromatic ketone initiators such as-(methylthio) -phenyl] -2-morpholinopropane-1; aromatic ketal initiators such as benzyldimethyl ketal; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2-ethyl Thioxanthone initiators such as thioxanthone, 2-isopropylthioxanthone, 2-dodecylthioxanthone, 2,4-dichlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone; benzyl such as benzyl Benzoin initiators such as benzoin; α-ketol compounds such as 2-methyl-2-hydroxypropiophenone; aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride; 1 Photoactive oxime compounds such as phenone-1,1-propanedione-2- (o-ethoxycarbonyl) oxime; camphorquinone compounds; halogenated ketone compounds: acyl phosphinoxide compounds; acyl phosphonate compounds Etc. These may be used alone or in combination of two or more. The blending amount of the photopolymerization initiator is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer.

  If the radiation-curable pressure-sensitive adhesive composition of the present embodiment contains the above (meth) acrylic polymer, a tackifier, an anti-aging agent may be used as necessary for the purpose of improving other properties. Further, known additives such as fillers, colorants, flame retardants, antistatic agents, softeners, ultraviolet absorbers, antioxidants, plasticizers and surfactants may be further contained. However, it is preferable that the number of radiation-reactive compounds having radiation-reactive carbon-carbon double bonds and low-molecular compounds such as polyethylene glycol (for example, the number average molecular weight is 3,000 or less) is as small as possible, and less than 2% by mass. More preferably, it is most preferable not to contain substantially. When the radiation curable pressure-sensitive adhesive composition of the present embodiment contains such a low molecular weight compound, it not only causes contamination of the workpiece, but also tends to reduce the adhesive force in the dicing process, and in the pickup process. Curability tends to decrease.

  The dicing pressure-sensitive adhesive film of the present embodiment can be produced by coating the radiation curable pressure-sensitive adhesive composition on at least one surface of a substrate by a known method. Moreover, when using the separator mentioned later, after coating a radiation-curable adhesive composition on one surface of a separator, you may adhere a base material to an adhesive layer. In addition, when using a crosslinking agent, you may further heat, after forming the adhesive layer containing a radiation-curable adhesive composition. As the substrate, any substrate can be used without particular limitation as long as it has a property of transmitting radiation (X-rays, ultraviolet rays, electron beams, etc.) at least partially. Examples of such a base material include base materials such as plastic, metal, and paper, and among these, a plastic base material is preferable. Specific examples of such plastic substrates include polyolefin resins (low density polyethylene, linear polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, random copolymer polypropylene, block copolymer). Polymerized polypropylene, homopolypropylene, polybutene, polymethylpentene, etc.), ethylene-vinyl acetate copolymer, ionomer resin, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer (random) Copolymer, alternating copolymer, etc.), ethylene-butene copolymer, ethylene-hexene copolymer, polyurethane resin, polyester resin (polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphtha) Polyimide resin, polyamide resin, polyether ketone resin, polyether resin, polyether sulfone resin, polystyrene resin (polystyrene, etc.), polyvinyl chloride resin, polyvinylidene chloride resin, Groups consisting of constituent materials such as polyvinyl alcohol resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate copolymers, polycarbonate resins, fluorine resins, silicone resins, cellulose resins, and cross-linked products of these resins Materials. These constituent materials may be used alone or in combination of two or more. The above-mentioned constituent materials may have a functional group as necessary. Further, a functional monomer or a modifying monomer may be grafted to the constituent material. Furthermore, the surface of the plastic substrate may be subjected to a known surface treatment method in order to improve the adhesion with an adjacent layer. Specific examples of such surface treatment include corona discharge treatment, ozone exposure treatment, high piezoelectric impact exposure treatment, and ionizing radiation treatment. In addition, the base material may be subjected to coating treatment with a primer, primer treatment, mat treatment, crosslinking treatment, and the like.

  The substrate may have a single layer form or may have a laminated form. Further, in the base material, as necessary, for example, known fillers, flame retardants, anti-aging agents, antistatic agents, softeners, ultraviolet absorbers, antioxidants, plasticizers, surfactants, etc. Additives may be included. Although the thickness of a base material is not specifically limited, Preferably it is 10-300 micrometers, More preferably, it is 30-200 micrometers.

  The thickness of the adhesive layer is not particularly limited, preferably 3 to 50 [mu] m, more preferably 5 to 20 [mu] m. When the thickness of the adhesive layer is 3μm or more, it is possible to reliably hold the semiconductor wafer during dicing the dicing adhesive film. In the dicing process, a workpiece such as a semiconductor wafer may vibrate. Therefore, when the vibration width is large, chipping (chipping) is likely to occur in a cut piece such as a semiconductor element. However, if the thickness of the pressure-sensitive adhesive layer is 50 μm or less, it is possible to prevent the vibration width of vibrations generated during dicing from becoming too large, thereby reducing the above-described chipping.

  When a semiconductor wafer having an active surface (silicon mirror wafer) is used as a workpiece, the adhesive force of the adhesive layer on the semiconductor wafer before curing by radiation (peeling angle: 180 °, tensile speed: 300 mm / min, temperature) : 23 ± 3 ° C.) is preferably 0.5 (N / 10 mm width) or more, and more preferably 1.0 (N / 10 mm width) or more. If the adhesive force before curing by radiation is 0.5 (N / 10 mm width) or more, the detachment scattering of the semiconductor element in the dicing process can be sufficiently suppressed or prevented. In addition, the adhesive force (peeling angle: 180 °, tensile speed: 300 mm / min, temperature: 23 ± 3 ° C.) after curing of the adhesive layer to the semiconductor wafer having an active surface by radiation is left for a long time. After (for example, after standing at room temperature for 5 days), it is preferably 0.4 (N / 10 mm width) or less, more preferably 0.2 (N / 10 mm width) or less. If the pressure-sensitive adhesive layer has such a low adhesive strength after being cured by radiation, the pick-up property is good, and the adhesive residue (residual of the pressure-sensitive adhesive component) can also be reduced.

  FIG. 1 is a schematic cross-sectional view showing an example of the configuration of the dicing adhesive film of the present embodiment. As shown in FIG. 1, dicing adhesive film 1 of the present embodiment has a configuration in which the pressure-sensitive adhesive layer 3 formed on one surface of the base material 2. Moreover, as shown in FIG. 1, the separator 4 may be provided on the adhesive layer 3 as needed. The separator 4 is not particularly limited, and a known separator can be used. Examples of the material for such a separator 4, specifically, for example, paper, polyethylene, polypropylene, synthetic resins such as polyethylene terephthalate. Moreover, in order to improve the peelability of the adhesive layer 3, the surface of the separator 4 may be subjected to treatments such as silicone treatment, long-chain alkyl treatment, and fluorine treatment as necessary. The thickness of the separator 4 is not particularly limited, but is usually 10 to 200 μm. The pressure-sensitive adhesive layer 3 may be a single layer or two or more layers. In FIG. 1, the pressure-sensitive adhesive layer 3 is provided only on one side of the base material 2, but the pressure-sensitive adhesive layer 3 may be provided on both sides of the base material 2. Moreover, although not shown in figure, according to the usage form, another adhesive layer, a mold release process layer, etc. may be formed on the other surface of the base material 2 instead of the separator 4. Specific examples of the pressure-sensitive adhesive composition for forming other pressure-sensitive adhesive layers include acrylic pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, polyester-based pressure-sensitive adhesives, and polyamides. system adhesives, epoxy pressure-sensitive adhesives, vinyl alkyl ether pressure-sensitive adhesives, can be used a pressure-sensitive adhesive composition containing a known adhesive such as a fluorine-based adhesive. The pressure-sensitive adhesive composition formed on the other surface of the substrate may contain various additives, a radiation curable component and a blowing agent as necessary. Specific examples of the release treatment agent (release agent) for forming the release treatment layer include, for example, a silicone release treatment agent, a long-chain alkyl release treatment agent, and a fluorine release treatment. A known release treatment agent such as an agent can be used. The dicing adhesive film may have a form wound in a roll shape or a form in which wide sheets are laminated. Moreover, you may have the form of the sheet shape or tape shape which cut and processed these to predetermined size.

  The dicing adhesive film of this embodiment can be used when a workpiece is diced to produce a cut piece. In particular, the above dicing pressure-sensitive adhesive film can be suitably used when a cut piece is produced by dicing a workpiece having an active surface. Specific examples of such a workpiece include a semiconductor wafer, a semiconductor package, glass, and ceramics. These workpieces are composed of compounds such as silicon compounds, germanium compounds, and gallium-arsenic compounds, and active silicon atoms (Si) in an unoxidized state are exposed on the exposed surfaces by back grinding or the like. ), There are many unoxidized active atoms such as unoxidized active germanium atoms (Ge) and unoxidized active gallium atoms (Ga). Therefore, when a pressure-sensitive adhesive film for dicing is applied to a workpiece in order to dice the workpiece having such active atoms, it is introduced into the (meth) acrylic polymer contained as a main component in the pressure-sensitive adhesive layer. A polar group or the like and an active atom are bonded to each other to exhibit high adhesive force even after curing by radiation, and it becomes difficult to separate the cut piece from the dicing adhesive film. However, according to the dicing pressure-sensitive adhesive film of the present embodiment, even if the dicing pressure-sensitive adhesive film is pasted on the workpiece having the active surface, when the cut piece is peeled off from the dicing pressure-sensitive adhesive film, the pasting time is reduced. Regardless, the adhesive force to the active surface can be sufficiently reduced by irradiation with radiation, and the cut piece can be easily peeled off. Therefore, according to the adhesive film for dicing of the present embodiment, for example, after the backside grinding process of the semiconductor wafer, or after the backside grinding process and the backside process of the semiconductor wafer, the adhesive film for dicing on the active surface exposed within a short time Even if affixed, it can be used effectively for a dicing process, a pick-up process, and the like to be performed thereafter.

  In the present embodiment, as a method of manufacturing a cut piece by dicing a workpiece, a mounting step of sticking a dicing adhesive film on one surface of the workpiece and a workpiece on which a dicing adhesive film is stuck From the dicing adhesive film for dicing, in which the adhesive force of the adhesive layer is reduced by irradiating the adhesive layer applied to the cut piece with radiation, and the dicing step of cutting the adhesive piece into pieces. A production method having at least a pick-up step for picking up the cut piece can be suitably used.

  In the mounting process in which a dicing adhesive film is attached to one surface of a workpiece, the workpiece such as a semiconductor wafer and the dicing adhesive film are usually stacked in a form in which the one surface of the workpiece and the adhesive layer are in contact with each other. combined, by pressing by a known pressing means such as pushing means using a press roll it, for dicing adhesive film is attached to the workpiece. Further, in a pressurizable container (for example, an autoclave), the work piece and the dicing adhesive film are overlapped in the same manner as described above, and the inside of the container is pressurized to dicing the work piece. An adhesive film may be attached. Further, a dicing adhesive film may be attached to the workpiece in a reduced pressure chamber (vacuum chamber) in the same manner as in the case of attaching by pressurization.

  Next, in the dicing process, a workpiece such as a semiconductor wafer to which a dicing adhesive film is attached is diced by a dicing means such as a blade to produce a cut piece of the workpiece. In such a dicing process, a blade that rotates at high speed while supplying cleaning water to a workpiece such as a semiconductor wafer to which a pressure-sensitive adhesive film for dicing is usually attached in order to prevent the removal of frictional heat and adhesion of cutting waste. The workpiece is cut into a predetermined size. For this reason, although the adhesive strength of the adhesive layer is likely to decrease, the adhesive film for dicing of the present embodiment can maintain excellent adhesive strength even when the adhesive layer and the washing water come into contact with each other. It is possible to reduce the detachment scattering of the cut pieces from the film. The dicing apparatus is not particularly limited, and a conventionally known apparatus can be used. In addition, a washing | cleaning process, an expanding process, etc. may be performed after a dicing process as needed.

  In the pickup step, the adhesive layer of the dicing adhesive film is irradiated with radiation to reduce the adhesive strength of the adhesive layer, and then the cut piece is picked up from the dicing adhesive film. Examples of radiation include X-rays, electron beams, and ultraviolet rays. Among these, ultraviolet rays are preferable. Various conditions such as irradiation intensity and irradiation time when irradiating with radiation are not particularly limited, and can be set as appropriate. The pickup method is not particularly limited, and various conventionally known pickup methods can be employed. For example, there is a method in which individual cut pieces are pushed up by a needle from the dicing adhesive film side, and the pushed up cut pieces are picked up by a pickup device. Since the adhesive film for dicing according to the present embodiment can sufficiently reduce the adhesive force by radiation curing, even in the case where a workpiece having an active surface is used, it is easy to perform the above pick-up process. The cut piece can be peeled from the dicing adhesive film, and adhesion of the adhesive component to the cut piece after peeling can be reduced.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples. In the following description, “part” means “part by mass”.

<Synthesis of (meth) acrylic polymer>
As a copolymerization monomer component, ethyl acrylate containing a linear alkyl group having 2 carbon atoms [solubility parameter (SP value, the same applies hereinafter): 10.2 (cal / cm ³ ) ^1/2 , homopolymer Tg: 249 K ], Butyl acrylate containing a linear alkyl group having 4 carbon atoms [SP value: 9.8 (cal / cm ³ ) ^1/2 , homopolymer Tg: 219 K], containing a branched alkyl group having 8 carbon atoms 2-ethylhexyl acrylate [SP value: 9.2 (cal / cm ³ ) ^1/2 , homopolymer Tg: 223 K], dodecyl acrylate containing a linear alkyl group having 12 carbon atoms [SP value: 9 .2 (cal / cm ³ ) ^1/2 , homopolymer Tg: 270 K], 2-hydroxyethyl acrylate containing a hydroxyl group [SP value: 13.3 (cal / cm ³ ) ^{1 / 2} , homopolymer Tg: 258 K], and acrylic acid containing a carboxyl group [SP value: 14.0 (cal / cm ³ ) ^1/2 , homopolymer Tg: 379 K]. The glass transition temperature of 2-hydroxyethyl acrylate homopolymer is based on the catalog of Kyoeisha Chemical Co., Ltd. The glass transition temperature of other homopolymers of (meth) acrylic monomers is POLYMER HANDBOOK (No. 3). Edition, 1989, published by JOHN WILEY & SONS). These copolymerizable monomer components were mixed at a blending ratio shown in Table 1, and solution radical polymerization was performed to synthesize each base polymer. In the polymerization, the reaction of the copolymerization monomer component was traced by GPC, and the polymerization was terminated when the copolymerization monomer component disappeared.

  Next, 100 parts of each base polymer is reacted with 2-isocyanate ethyl methacrylate containing a radiation-reactive carbon-carbon double bond at each compounding ratio shown in Table 1 to obtain each (meth) acrylic polymer. Was synthesized. In the above reaction, 0.05 part of hydroquinone monomethyl ether was used as a polymerization inhibitor. Synthesized the (meth) GPC weight average molecular weight of the acrylic polymer (solvent: tetrahydrofuran) was measured by, it was 500,000 to 800,000.

<Preparation of adhesive film for dicing>
100 parts of each (meth) acrylic polymer obtained as described above, 0.1 part of a polyisocyanate compound (trade name: Coronate L, manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, and 1- Each radiation-curable pressure-sensitive adhesive composition was prepared by mixing 0.5 part of hydroxycyclohexyl phenyl ketone (manufactured by Ciba Specialty Chemicals, trade name: Irgacure-184).

  Next, after each radiation-curable pressure-sensitive adhesive composition obtained as described above was applied on a polyethylene terephthalate separator (thickness: 38 μm) to a thickness of 10 μm to form a pressure-sensitive adhesive layer And heated at 100 ° C. for 3 minutes. Thereafter, a polyolefin film (thickness: 100 μm) having a corona discharge treatment on one side was bonded to the pressure-sensitive adhesive layer. The bonded samples were stored in a constant temperature bath at 40 ° C. for 72 hours to produce each dicing adhesive film.

  The following evaluation was performed using each dicing adhesive film produced as described above. Table 1 shows the composition of each (meth) acrylic polymer, the solubility parameter and glass transition temperature of the base polymer, and the evaluation results.

[Evaluation]
(Adhesive strength before curing by radiation)
A dicing adhesive film cut into a 25 mm width strip was attached to a 5-inch silicon mirror wafer immediately after mirror polishing in an atmosphere of 23 ° C., and a measurement sample was left standing at room temperature for 30 minutes. Produced. The adhesive strength of this measurement sample was measured, and the adhesive strength before curing was evaluated according to the following criteria. The adhesive strength was measured at a peeling angle of 180 °, a peeling speed of 300 mm / min, and a temperature of 23 ± 3 ° C.
○: The measured value of adhesive strength is 0.5 N / 10 mm or more. X: The measured value of adhesive strength is less than 0.5 N / 10 mm.

(Adhesive strength after curing by radiation)
A measurement sample was obtained by sticking a dicing adhesive film cut into a 25 mm width strip to a 5-inch silicon mirror wafer immediately after mirror polishing in an atmosphere of 23 ° C. and allowing it to stand at room temperature for 5 days. Produced. The measurement sample was irradiated with ultraviolet rays (irradiation intensity: 300 mJ / cm ² ) from the substrate side of the dicing adhesive film, and the adhesive strength after irradiation was measured in the same manner as the adhesive strength before curing with the above-mentioned radiation. The adhesive strength after curing was evaluated on the basis of
○: The measured value of adhesive force is less than 0.2 N / 10 mm. Δ: The measured value of adhesive force is 0.2 N / 10 mm or more and 0.4 N / 10 mm or less. X: The measured value of adhesive force is 0.4 N / Over 10mm

(Pickup property)
A 5-inch silicon mirror wafer having a thickness of 100 μm was mirror-polished, and then a dicing adhesive film was immediately attached to the polished surface in an atmosphere at 23 ° C. Next, the wafer was fully cut into a size of 3 mm × 3 mm while supplying cleaning water to the wafer with the adhesive film attached thereto.
Next, ultraviolet rays (irradiation intensity: 300 mJ / cm ² ) were irradiated from the substrate side of the adhesive film for dicing and expanded, and then the semiconductor element was peeled off from the adhesive film and picked up. When picking up 50 arbitrary semiconductor elements, if all semiconductor elements have been successfully picked up, ○, if 1 to 5 semiconductor elements cannot be picked up normally, Δ, 6 or more semiconductors When the element could not be picked up normally, the picking property was evaluated as x.

As is apparent from Table 1, it was synthesized using a base polymer having a solubility parameter of 9.6 (cal / cm ³ ) ^1/2 or more and 10.0 (cal / cm ³ ) ^1/2 or less (meta It can be seen that the dicing pressure-sensitive adhesive film of the example provided with a pressure-sensitive adhesive layer containing an acrylic polymer has a high pressure-sensitive adhesive force before being cured by radiation, and the pressure-sensitive adhesive force is significantly reduced after being cured by radiation. Moreover, when the adhesive film for dicing of an Example is used, it turns out that it has the outstanding light peelability in a pick-up process. Furthermore, when the glass transition temperature of the base polymer is in the range of 225 or more and less than 228K, it can be seen that a dicing pressure-sensitive adhesive film with better light peelability can be obtained. The pressure-sensitive adhesive layer contains a (meth) acrylic polymer synthesized from a base polymer containing only a (meth) acrylic monomer having 8 carbon atoms and a hydroxyl group-containing (meth) acrylic monomer as a copolymerization monomer component. Compared to the adhesive film for dicing with a pressure-sensitive adhesive layer containing a (meth) acrylic polymer synthesized from a base polymer containing other copolymerizable monomer components, the adhesive film for dicing with It turns out that it is excellent.

  On the other hand, it can be seen that the dicing pressure-sensitive adhesive film including a pressure-sensitive adhesive layer containing a (meth) acrylic polymer synthesized using a base polymer having a too high solubility parameter is inferior in pick-up property. This is because the number of hydroxyl groups in the base polymer is too large, so that the radiation-reactive compound or crosslinking agent and unreacted hydroxyl groups remain in the (meth) acrylic polymer, and this results in dicing semiconductor wafers having active surfaces. when using the dicing adhesive film, presumably because the adhesive strength is not sufficiently reduced by the binding of a hydroxyl group and the active atoms. On the other hand, it can be seen that the adhesive film for dicing provided with an adhesive layer containing a (meth) acrylic polymer synthesized using a base polymer having a solubility parameter that is too low is also poor in pick-up property. This is probably because the number of hydroxyl groups in the base polymer is small, so that the radiation-reactive carbon-carbon double bonds introduced into the (meth) acrylic polymer are reduced and the curability is lowered. In addition, even if the glass transition temperature is in the range of 225 or more and less than 228K, it can be seen that if the solubility parameter is out of the range, the pickup property is similarly inferior.

DESCRIPTION OF SYMBOLS 1 Adhesive film for dicing 2 Base material 3 Adhesive layer 4 Separator

Claims (6)

A radiation-curable pressure-sensitive adhesive composition containing a (meth) acrylic polymer having a radiation-reactive carbon-carbon double bond at a side chain and / or a terminal,
The base polymer constituting the (meth) acrylic polymer is a radiation curable adhesive having a solubility parameter of 9.6 (cal / cm ³ ) ^1/2 or more and 10.0 (cal / cm ³ ) ^1/2 or less. Agent composition.   The radiation curable pressure-sensitive adhesive composition according to claim 1, wherein the base polymer has a glass transition temperature of 225K or more and less than 228K.   The base polymer contains at least a linear or branched alkyl group-containing (meth) acrylic monomer having 8 or more carbon atoms and a hydroxyl group-containing (meth) acrylic monomer as copolymerization monomer components. Radiation curable pressure-sensitive adhesive composition. A dicing adhesive film having a base material and an adhesive layer on at least one surface of the base material,
The said adhesive layer is for dicing containing the radiation-curable adhesive composition containing a crosslinking agent, a photoinitiator, and the (meth) acrylic-type polymer of any one of Claims 1-3. Adhesive film. Affixing the adhesive film for dicing according to claim 4 on one surface of the workpiece,
The workpiece to which the adhesive film for dicing is attached is cut and separated into cut pieces,
Radiation is applied to the adhesive layer attached to the cut piece to reduce the adhesive strength of the adhesive layer,
The manufacturing method of the cut piece which picks up the said cut piece from the adhesive film for dicing which reduced the said adhesive force.   The method for manufacturing a cut piece according to claim 5, wherein the workpiece is a semiconductor wafer having an active surface.

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