JP2010260897A - Adhesive film and tape for processing wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive film which prevents an adhesive layer to be wound from rupturing during a step of winding the adhesive layer in the preparation of a tape for processing a wafer precut-processed into a shape corresponding to that of a semiconductor wafer, and improves productivity of the precut tape for processing a wafer; and to provide a tape for processing a wafer prepared by using the same. <P>SOLUTION: Rupture strength per unit of the adhesive layer 12 is ≥87.5 times, preferably ≥100 times greater than the peel force per unit of the adhesive layer 12 from the mold release film 11. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an adhesive film and a wafer processing tape. In particular, the present invention relates to an adhesive film and a wafer processing tape having a laminated dicing die bonding film having two functions of a dicing tape and a die bonding film.

  Recently, a dicing tape for fixing a semiconductor wafer when the semiconductor wafer is cut and separated into individual chips (dicing) and a semiconductor chip that has been cut are bonded to a lead frame, a package substrate, or the like, or stacked. As a package, a dicing die bonding film (DDF) has been developed which has two functions of an adhesive film (also referred to as a die bonding film or die attach film) for laminating and bonding semiconductor chips.

  As such a dicing die bonding film, there is a film that has been precut in consideration of workability such as attachment to a semiconductor wafer or attachment to a ring frame during dicing.

  In order to produce a wafer processing tape having a dicing die bonding film that has been subjected to pre-cut processing, for example, as described in Patent Document 1, an adhesive layer is laminated on the entire surface of a long release film. The adhesive layer of the adhesive film is cut with a circular blade corresponding to the semiconductor wafer, and the outside of the circular portion is peeled off from the release film (hereinafter referred to as the adhesive layer winding process), The adhesive layer of the circular adhesive film hollowed out by the winding process of the adhesive layer and the adhesive layer of the dicing tape in which the adhesive layer is laminated on the base film are bonded together by heating and pressing, and the dicing tape A circular blade corresponding to the ring frame is cut into a ring frame, and a portion corresponding to the ring frame is peeled off and wound up.

JP 2007-2173 A

  In the above-described winding process of the adhesive layer, the adhesive layer on the outer side of the circular portion is peeled off from the release film while being wound on the adhesive layer on the outer side of the circular portion. Therefore, the phenomenon that the adhesive layer outside the circular portion is cut off during the operation of winding up the adhesive layer has occurred. In order to wind up the adhesive layer, there is an initial operation such as setting the end of the adhesive layer on a roll for winding in advance, and when the adhesive layer is cut, the winding operation of the adhesive layer is performed. There is a problem that the productivity of the wafer processing tape having the dicing die bonding film subjected to the pre-cut processing is lowered because it must be temporarily stopped and restarted after the initial work.

  In addition, if the width of the wafer processing tape is widened in order to solve the above problem, the phenomenon that the adhesive layer outside the circular portion is cut in the winding process of the adhesive layer is eliminated, but unnecessary. As a result, the amount of the adhesive layer on the outer side of the circular portion, the amount of unnecessary wafer processing tape in semiconductor wafer dicing, semiconductor die bonding chips, and the like increases.

  Therefore, the present invention has been made to solve the above-described problems, and an unnecessary adhesive layer when producing a wafer processing tape precut into a shape corresponding to the shape of a semiconductor wafer. Adhesive film capable of preventing breakage of the wound adhesive layer and improving the productivity of precut processed wafer processing tape in the process of peeling off the film from the release film and winding the film An object is to provide a wafer processing tape manufactured using a film.

  As a result of intensive studies on the above problems, the present inventors have found that the breaking strength per unit of the adhesive layer is 87.5 times the peeling force per unit from the release film of the adhesive layer. As described above, in the step of winding the adhesive layer when producing a pre-cut wafer processing tape by using an adhesive film that is preferably 100 times or more, the outer adhesive layer having a predetermined shape is broken. We have found that it can be prevented, and also found that the adhesive layer of this adhesive film and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film are bonded together to improve the productivity of precut processed wafer processing tape, and the present invention is completed. did.

  That is, the adhesive film according to the first aspect of the present invention is an adhesive film in which an adhesive layer is laminated on a long release film, and the adhesive layer is peeled per unit from the release film. The breaking strength per unit of the adhesive layer is 87.5 times or more with respect to force.

  Here, the peeling force varies depending on the magnitude in the direction perpendicular to the peeling direction, and the breaking strength varies depending on the magnitude in the tensile direction. Therefore, “per unit” means that the size in the direction perpendicular to the peeling direction and the size in the pulling direction are the same (for example, the size in the direction perpendicular to the peeling direction is 10 mm, and the peeling force is When measured, the breaking strength is measured assuming that the size in the tensile direction is 10 mm), and the breaking strength with respect to the peeling force at this time is 87.5 times or more.

  Note that the adhesive film is an adhesive film in which the cut corresponding to the semiconductor wafer as described above is in the adhesive layer in advance, but the cut is not in the adhesive layer. Also good.

  The adhesive film according to the second aspect of the present invention is the adhesive film according to the first aspect of the present invention described above, wherein the adhesive layer is bonded to the peeling force per unit of the adhesive layer from the release film. The breaking strength per unit of the agent layer is 100 times or more.

  The tape for wafer processing which concerns on the 1st aspect of this invention is the said adhesive layer of the adhesive film by which the adhesive layer was laminated | stacked on the base film, and said 1st or 2nd aspect of this invention. The adhesive layer of the said adhesive film is bonded together, It is characterized by the above-mentioned.

  By using the adhesive film of the present invention, an outer adhesive layer having a predetermined shape that is not necessary when producing a wafer processing tape precut into a predetermined shape corresponding to the shape of the semiconductor wafer is removed from the release film. In the winding process of the adhesive layer that is peeled off and wound, the outer adhesive layer having a predetermined shape can be prevented from being broken. In addition, the productivity of a pre-cut wafer processing tape in which the adhesive layer of the adhesive layer film and the adhesive layer of the adhesive film are bonded together can be improved. Also, it is possible to produce a wafer processing tape with a high production efficiency with a small amount of an adhesive layer on the outer side of a predetermined shape, a semiconductor wafer dicing, an unnecessary amount of a wafer processing tape in a semiconductor die bonding chip, etc. it can.

(A) is a general-view figure of the adhesive film which concerns on one Embodiment of this invention, (b) is the same sectional drawing. (A) is a top view of the adhesive film for demonstrating the formation process of a notch | incision, (b) is the same sectional drawing. It is a schematic diagram for demonstrating the winding-up process of an adhesive bond layer. (A) is a general-view figure of the wafer processing tape which concerns on one Embodiment of this invention, (b) is the same top view, (c) is the same sectional drawing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Fig.1 (a) is a general-view figure of the adhesive film which concerns on one Embodiment of this invention, FIG.1 (b) is the same sectional drawing. As shown in FIGS. 1A and 1B, the adhesive film 20 </ b> B has a configuration in which an adhesive layer 12 is laminated on a long release film 11. Further, in the present embodiment, the release film 11A is further laminated on the adhesive layer 12, and the adhesive film is capable of producing a rolled product. The release film described in the claims corresponds to the release film 11.

  In the manufacturing process of the semiconductor device, an adhesive film 20 (for example, see FIG. 4C) in which the adhesive layer 12 is precut into a circular label shape corresponding to the shape of the semiconductor wafer is used. Then, next, the method to produce the adhesive film 20 by which the precut process was carried out is demonstrated with reference to FIG.2 and FIG.3.

  Fig.2 (a) is a top view of the adhesive film 20A for demonstrating the formation process of the cut | notch which cuts into the adhesive bond layer 12 in a circular label shape, (b) is the same sectional drawing. FIG. 3 is a schematic diagram for explaining a winding process of the adhesive layer that peels and winds the adhesive layer 12 outside the unnecessary circular label shape from the release film 11.

  In order to produce the adhesive film 20 that has been pre-cut, first, the adhesive film 20A (see FIG. 1B) is formed by peeling the release film 11A from the adhesive film 20B.

  Next, as shown in FIGS. 2A and 2B, in the adhesive film 20A, a circular label-shaped cut 22 corresponding to the shape of the semiconductor wafer is formed in the adhesive layer 12 (forming process of the cut 22). . By the notch 22, the adhesive layer 12 is formed into an adhesive layer (hereinafter referred to as a circular adhesive layer portion) 12a having a circular label shape inside the notch 22, and an adhesive layer outside the notch 22 (hereinafter referred to as peripheral adhesive). 12b). Here, the notch 22 is formed so as to reach from the front surface 23 a of the adhesive layer 12 to the back surface 23 b of the adhesive layer 12 in contact with the release film 11.

  Finally, as shown in FIG. 3, in the adhesive film 20A, the peripheral adhesive layer portion 12b was peeled off from the release film 11 and wound up while applying a certain force to the peripheral adhesive layer portion 12b. Only the circular adhesive layer portion 12a is left on the release film 11 (adhesive layer winding step). Thereby, the adhesive film 20 in which the adhesive layer 12 is precut into a circular label shape corresponding to the shape of the semiconductor wafer is produced.

The adhesive film 20B according to this embodiment is characterized in that it has the following configuration.
When the adhesive layer 12 is peeled from the release film 11, the breaking strength per unit of the adhesive layer 12 is 87.5 times or more, preferably 100 times or more with respect to the peeling force per unit. . Here, the peeling force varies depending on the magnitude in the direction perpendicular to the peeling direction, and the breaking strength varies depending on the magnitude in the tensile direction. Therefore, “per unit” means that the size in the direction perpendicular to the peeling direction is the same as the size in the pulling direction. For example, the size in the direction perpendicular to the peeling direction is 10 mm, and the peeling force is measured. In this case, the breaking strength is measured by setting the size in the tensile direction to 10 mm.

Next, a wafer processing tape (dicing die bonding film) in which an adhesive layer of an adhesive film and an adhesive layer of an adhesive film in which an adhesive layer is laminated on a base film are bonded together will be described.
FIG. 4A is a schematic view of a wafer processing tape (dicing die bonding film) according to an embodiment of the present invention, FIG. 4B is a plan view thereof, and FIG. FIG.

  As shown in FIGS. 4A, 4B, and 4C, the wafer processing tape 10 has a pressure-sensitive adhesive on the circular adhesive layer portion 12a of the pre-cut adhesive film 20 and the base film 14. It has the structure by which the adhesive layer 15 of the adhesive film 13 with which the layer 15 was laminated | stacked was bonded together.

  The pressure-sensitive adhesive film 13 covers the circular adhesive layer portion 12a and has a circular label portion 13a provided so as to be in contact with the release film 11 around the circular adhesive layer portion 12a, and an outer side of the circular label portion 13a. And a peripheral portion 13b that surrounds. The peripheral portion 13b includes a form that completely surrounds the outer side of the circular label portion 13a and a form that is not completely surrounded as illustrated. The circular label portion 13a has a shape corresponding to a ring frame for dicing.

  First, the pre-cut wafer processing tape 10 is manufactured as shown in FIGS. 2 and 3 in which the adhesive film 20 in a state where the circular adhesive layer portion 12 a is laminated on the release film 11. Thereafter, the pressure-sensitive adhesive film 13 and the adhesive film 20 are bonded together by heating so that the pressure-sensitive adhesive layer 15 and the circular adhesive layer portion 12a overlap each other. By peeling and forming the circular label portion 13a and the peripheral portion 13b, the pre-cut wafer processing tape 10 is produced.

  After the adhesive film 13 is cut into the shape of the circular label portion 13a and the peripheral portion 13b, the adhesive film 20 that has been precut and the circular label portion 13a and the peripheral portion 13b are heated and bonded together to be precut. Alternatively, the wafer processing tape 10 may be manufactured.

  The wafer processing tape 10 according to the present embodiment is produced using the adhesive film 20B according to the above-described embodiment, and thus has the same characteristics as the adhesive film 20B according to the above-described embodiment. That is, the breaking strength per unit of the adhesive layer 12 is 87.5 times or more, preferably 100 times or more with respect to the peeling force per unit from the release film 11 of the adhesive layer 12.

  Hereinafter, each component of the adhesive film 20B according to the present embodiment and the wafer processing tape 10 according to the present embodiment will be described in detail.

(Release film)
The release film 11 is used for the purpose of improving the handleability of the adhesive layer 12.

  As the release film 11, for example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polychloride chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, a polyethylene naphthalate film, a polybutylene terephthalate film. , Polyurethane film, ethylene / vinyl acetate copolymer film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film A fluororesin film or the like is used. These crosslinked films are also used. Furthermore, these laminated films may be sufficient.

The surface tension of the release film 11 is preferably 40 mN / m or less, and more preferably 35 mN / m or less. Such a release film 11 having a low surface tension can be obtained by appropriately selecting the material, and can also be obtained by applying a release treatment by applying a silicone resin or the like to the surface of the film. .
The film thickness of the release film 11 is usually 5 to 300 μm, preferably 10 to 200 μm, and particularly preferably about 20 to 150 μm.
The release film 11A is not limited as long as it can be peeled off from the adhesive layer 12, but a polyethylene terephthalate film, a polypropylene film, and a polyethylene film are preferable. The release film 11A is preferably coated or baked with silicon. The thickness of the release film 11A is not particularly limited, but is preferably 15 to 125 μm.

(Adhesive layer)
The adhesive layer 12 is attached to the back surface of the semiconductor chip when the semiconductor chip is picked up after the semiconductor wafer is bonded and diced, and is used as an adhesive for fixing the chip to the substrate or the lead frame. It is what is done.

  As the adhesive layer 12, polyimide resin, polyamide resin, polyetherimide resin, polyamideimide resin, polyester resin, polyester resin, polyesterimide resin, phenoxy resin, polysulfone resin, polyethersulfone resin, polyphenylene sulfide resin, polyetherketone Resins, chlorinated polypropylene resins, acrylic resins, polyurethane resins, epoxy resins, polyacrylamide resins, melamine resins, and the like, and mixtures thereof can be used.

  It is preferable to use an epoxy group-containing acrylic copolymer as the polymer. This epoxy group-containing acrylic copolymer contains 0.5 to 6% by mass of glycidyl acrylate or glycidyl methacrylate having an epoxy group. In order to obtain a high adhesive force with a semiconductor wafer, the content is preferably 0.5% by mass or more, and gelation can be suppressed if it is 6% by mass or less. The glass transition temperature (Tg) of the epoxy group-containing acrylic copolymer is preferably −10 ° C. or higher and 30 ° C. or lower.

  The amount of glycidyl acrylate or glycidyl methacrylate used as the functional group monomer is a copolymer ratio of 0.5 to 6% by mass, but the remainder is an alkyl having 1 to 8 carbon atoms such as methyl acrylate and methyl methacrylate. Mixtures of acrylates, alkyl methacrylates, and styrene and acrylonitrile can be used. Among these, ethyl (meth) acrylate and / or butyl (meth) acrylate are particularly preferable. The mixing ratio is preferably adjusted in consideration of the glass transition temperature (Tg) of the copolymer. There is no restriction | limiting in particular in a polymerization method, For example, pearl polymerization, solution polymerization, etc. are mentioned, A copolymer is obtained by these methods. Examples of such an epoxy group-containing acrylic copolymer include HTR-860P-3 (trade name, manufactured by Nagase ChemteX Corporation).

  The weight average molecular weight of the acrylic copolymer is preferably 50,000 or more, particularly preferably in the range of 200,000 to 1,000,000. If the molecular weight is too low, film formation will be insufficient, and if it is too high, compatibility with other components will deteriorate, resulting in hindering film formation.

  When an epoxy resin is used as the thermosetting component, for example, a phenolic resin can be used as the curing agent. As the phenolic resin, a condensate of phenols such as alkylphenol, polyhydric phenol, naphthol and aldehydes is used without particular limitation. The phenolic hydroxyl group contained in these phenolic resins can easily undergo an addition reaction with the epoxy group of the epoxy resin by heating to form a cured product having high impact resistance.

  The phenolic resin includes phenol novolak resin, o-cresol novolak resin, p-cresol novolak resin, t-butylphenol novolak resin, dicyclopentadiene cresol resin, polyparavinylphenol resin, bisphenol A type novolak resin, or a modification thereof. A thing etc. are used preferably.

  In addition, a thermally activated latent epoxy resin curing agent can also be used as the curing agent. This curing agent is a type of curing agent that does not react with the epoxy resin at room temperature but is activated by heating above a certain temperature and reacts with the epoxy resin.

  As an activation method, a method of generating active species (anions and cations) by a chemical reaction by heating, a dispersion that is stably dispersed in the epoxy resin near room temperature, is compatible with and dissolved in the epoxy resin at a high temperature, and a curing reaction is performed. There are a method for starting, a method for starting a curing reaction by elution at a high temperature with a molecular sieve encapsulated type curing agent, a method using a microcapsule, and the like.

  Examples of the thermally active latent epoxy resin curing agent include various onium salts, high melting point active hydrogen compounds such as dibasic acid dihydrazide compounds, dicyandiamide, amine adduct curing agents, and imidazole compounds.

  When an epoxy resin is used as the thermosetting component, a curing accelerator or the like can be used as an auxiliary agent. There is no restriction | limiting in particular as a hardening accelerator which can be used for this invention, For example, a tertiary amine, imidazoles, a quaternary ammonium salt etc. can be used. Examples of imidazoles preferably used in the present invention include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, and the like. These may be used alone or in combination of two or more. Imidazoles are commercially available from Shikoku Kasei Kogyo Co., Ltd. under the trade names 2E4MZ, 2PZ-CN, 2PZ-CNS, for example.

  Moreover, you may mix | blend a filler. Examples of the filler include silica such as crystalline silica and synthetic silica, and inorganic filler such as alumina and glass balloon. By adding an inorganic filler to the curable protective film forming layer 2, the hardness of the protective film after curing can be improved. Moreover, the thermal expansion coefficient of the protective film after curing can be brought close to the thermal expansion coefficient of the wafer, thereby reducing the warpage of the semiconductor wafer during processing. Synthetic silica is preferable as the filler, and in particular, synthetic silica of the type from which the α-ray source that causes malfunction of the semiconductor device is removed as much as possible is optimal. As the shape of the filler, any of a spherical shape, a needle shape, and an amorphous type can be used, but a spherical filler capable of closest packing is particularly preferable.

  Furthermore, in order to improve the interfacial bonding between different materials, a coupling agent can be blended. A silane coupling agent is preferable as the coupling agent. As silane coupling agents, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, N-β-aminoethyl-γ- Examples include aminopropyltrimethoxysilane. The blending amount of the coupling agent is preferably 0.1 to 10 parts by weight with respect to a total of 100 parts by weight of the composition forming each of the dispersed phase and the continuous phase, from the effects of addition, heat resistance and cost. .

As the varnishing solvent, it is preferable to use methyl ethyl ketone, acetone, methyl isobutyl ketone, 2-ethoxyethanol, toluene, butyl cellosolve, methanol, ethanol, 2-methoxyethanol or the like having a relatively low boiling point. Moreover, you may add a high boiling point solvent for the purpose of improving coating-film property. Examples of the high boiling point solvent include dimethylacetamide, dimethylformamide, methylpyrrolidone, cyclohexanone and the like.
The thickness of the adhesive layer 12 may be set as appropriate, but is preferably about 5 to 100 μm.

  In order to increase the breaking strength of the adhesive layer 12, it is effective to increase the polymer, decrease the filler, and decrease the epoxy resin (solid). Further, in order to reduce the peeling force of the adhesive layer 12 from the release film 11, it is effective to reduce the polymer and the epoxy resin (liquid).

(Adhesive film)
The adhesive film 13 is not particularly limited, and has a sufficient adhesive force so that the semiconductor wafer does not peel when dicing the semiconductor wafer. When the chip is picked up after dicing, it can be easily removed from the adhesive layer 12. Any material may be used as long as it exhibits low adhesive strength so that it can be peeled off. For example, what provided the adhesive layer 15 in the base film 14 can be used conveniently.

The base film 14 of the adhesive film 13 can be used without particular limitation as long as it is a conventionally known film. However, when a radiation curable material is used as the adhesive layer 15 described later, It is preferable to use a material having permeability.
For example, as the material, polyethylene, polypropylene, ethylene-propylene copolymer, polybutene-1, poly-4-methylpentene-1, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic Α-olefin homopolymer or copolymer such as acid methyl copolymer, ethylene-acrylic acid copolymer, ionomer or a mixture thereof, polyurethane, styrene-ethylene-butene or pentene copolymer, polyamide-polyol Listed are thermoplastic elastomers such as copolymers, and mixtures thereof. Moreover, the base film 14 may be a mixture of two or more materials selected from these groups, or may be a single layer or a multilayer.
The thickness of the base film 14 is not particularly limited and may be appropriately set, but is preferably 50 to 200 μm.

The resin used for the pressure-sensitive adhesive layer 15 of the pressure-sensitive adhesive film 13 is not particularly limited, and known chlorinated polypropylene resins, acrylic resins, polyester resins, polyurethane resins, epoxy resins and the like used for pressure-sensitive adhesives are used. Can be used.
It is preferable to prepare a pressure-sensitive adhesive by appropriately mixing an acrylic pressure-sensitive adhesive, a radiation polymerizable compound, a photopolymerization initiator, a curing agent and the like with the resin of the pressure-sensitive adhesive layer 15. The thickness of the pressure-sensitive adhesive layer 15 is not particularly limited and may be appropriately set, but is preferably 5 to 30 μm.

A radiation-polymerizable compound can be blended in the pressure-sensitive adhesive layer 15 to facilitate peeling from the adhesive layer 12 by radiation curing. As the radiation polymerizable compound, for example, a low molecular weight compound having at least two photopolymerizable carbon-carbon double bonds in a molecule that can be three-dimensionally reticulated by light irradiation is used.
Specifically, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butylene glycol diacrylate, 1,6 hexanediol diacrylate Acrylate, polyethylene glycol diacrylate, oligoester acrylate, and the like are applicable.

In addition to the above acrylate compounds, urethane acrylate oligomers can also be used. The urethane acrylate oligomer includes a polyol compound such as a polyester type or a polyether type, and a polyvalent isocyanate compound (for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diene). A terminal isocyanate urethane prepolymer obtained by reacting isocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc.) with an acrylate or methacrylate having a hydroxyl group (for example, 2-hydroxyethyl) Acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, polyethylene glycol acrylate, polyethylene glycol methacrylate, etc.) Obtained by the reaction.
The pressure-sensitive adhesive layer 15 may be a mixture of two or more selected from the above resins.

  When using a photopolymerization initiator, for example, isopropyl benzoin ether, isobutyl benzoin ether, benzophenone, Michler's ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, benzyldimethyl ketal, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethylphenyl Propane or the like can be used. The blending amount of these photopolymerization initiators is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the acrylic copolymer.

(Example)
Next, examples of the present invention will be described, but the present invention is not limited to these examples.

(Preparation of adhesive film)
Methyl ethyl ketone was added to the adhesive layer compositions 1A to 1D having the composition shown in Table 1 below, followed by stirring and mixing to prepare an adhesive varnish. The adhesive varnishes of the prepared adhesive layer compositions 1A to 1D were applied on the release film 11 in combinations shown in Tables 2 and 3 so that the thickness after drying was 20 μm, and 110 ° C. Then, an adhesive layer 12 was produced on the release film 11 respectively. Then, another release film 11A similar to the above is bonded onto each adhesive layer 12, and in Examples 1 to 4 shown in Table 2 below and Comparative Examples 1 to 4 shown in Table 3 below. An adhesive film 20B having a three-layer structure in which the release film 11, the adhesive layer 12, and the release film 11A were laminated in this order was produced.

  The unit of the mixing ratio of each component in Table 1 is part by mass. A1 (acrylic polymer) in Table 1 is an acrylic copolymer having a weight average molecular weight of 850,000 and a glass transition temperature (Tg) of 15 ° C. B1 (epoxy resin (solid)) is a phenol biphenylene type epoxy resin having an epoxy equivalent of 265 to 285. B2 (epoxy resin (liquid)) is a liquid bisphenol A type epoxy resin having an epoxy equivalent of 162 to 172. C1 (curing agent (1)) is dicyandiamide, and C2 (curing agent (2)) is an aralkylphenol resin. D1 (curing accelerator) is an imidazole compound (2-phenyl 4,5-dihydroxymethylimidazole). E1 (silica filler) is spherical synthetic silica having an average particle diameter of 2 μm.

  In Tables 2 and 3, S314 is a polyethylene terephthalate (PET) film (trade name) manufactured by Teijin DuPont Film, and K-1504 is a PET film (Toyobo Co., Ltd.) that has been subjected to the mold release process. Product name).

About Examples 1-4 and Comparative Examples 1-4, while breaking strength and peeling force were measured, respectively, precut property was evaluated. Tables 2 and 3 show the measurement results of breaking strength, peeling force, ratio of breaking strength to peeling force (breaking strength / peeling force), and evaluation of precut property.
<Measurement of breaking strength>
The adhesive film 20B according to Examples 1 to 4 and the adhesive films according to Comparative Examples 1 to 4 in a state in which the adhesive layer 12 is sandwiched between the release film 11 and the release film 11A are punched into a No. 1 dumbbell shape, The release film 11 and the release film 11A were peeled off to prepare a test piece having only the adhesive layer 12. The maximum load until the specimen is pulled and broken at a linear speed of 300 mm / min using a strograph (VE10) manufactured by Toyo Seiki Seisakusho in accordance with JIS B 7721 and JIS K 6301. Was measured. The unit of breaking strength is [N / 10 mm].

<Measurement of peel force>
The adhesive film 20B according to Examples 1 to 4 and the release film 11A on one side of the adhesive films according to Comparative Examples 1 to 4 were peeled off, and the shape-retaining tape (Sekisui Chemical Co., Ltd.) was applied to the surface of the adhesive layer 12 from which the release film 11A was peeled off. A three-layer structure in which a product made by Kogyo Co., Ltd., trade name: Forte) is pasted together by a 2 kg roller, cut into a 25 mm width strip, and a release film 11, an adhesive layer 12, and a shape-retaining tape are laminated in this order. A test piece was prepared. The produced test piece was divided into a release film 11, an adhesive layer 12, and a laminate of a shape-retaining tape by a strograph (VE10) manufactured by Toyo Seiki Seisakusho Co., Ltd., and a linear velocity of 300 mm / min. The peeling force between the release film 11 and the adhesive layer 12 was measured. The unit of peeling force is [N / 10 mm]. Also, the adhesive layer 12 is separated from the release film 11 and the laminate of the shape-retaining tape, and the adhesive layer 12 and the shape-retained tape laminate are separated from the release film 11. This is because the adhesive layer 12 is stretched when only it is grasped and peeled off.

<Evaluation of precut property>
Evaluation of precut property consists of the release film 11 and the adhesive layer 12 from which the release film 11A on one side is peeled off for the adhesive films 20B according to Examples 1 to 4 and the adhesive films according to Comparative Examples 1 to 4. Into the adhesive layer film 20A having a layer structure, circular notches with a diameter of 320 mm for 12-inch wafers are put at 58.5 mm intervals, the processing speed is 10 m / min, 100 m, and the peripheral adhesive layer portion 12 b is separated from the release film 11. The case where it peeled and wound and a fracture did not occur was evaluated as “◯”, and the case where a fracture occurred was evaluated as “x”. Moreover, the width | variety of the original fabric of an adhesive film is 390 mm and 450 mm.

  As shown in Table 2, in the adhesive film 20B of Example 1, the ratio between the breaking strength and the peeling force (breaking strength / peeling force) is in the range of 87.5 or more that defines the ratio between the breaking strength and the peeling force. Since it was 150, the pre-cut property resulted in no breaks in both cases where the width of the original fabric was 390 mm and 450 mm.

  The adhesive film 20B of Example 2 is pre-cut because the ratio between the breaking strength and the peeling force (breaking strength / peeling force) is 100 in the above range of 87.5 or more that defines the ratio between the breaking strength and the peeling force. As for the property, both the case where the width of the original fabric was 390 mm and the case where it was 450 mm resulted in no breakage.

  The adhesive film 20B of Example 3 is pre-cut because the ratio between the breaking strength and the peeling force (breaking strength / peeling force) is 225 in the range of 87.5 or more that defines the ratio between the breaking strength and the peeling force. As for the property, both the case where the width of the original fabric was 390 mm and the case where it was 450 mm resulted in no breakage.

  In the adhesive film 20B of Example 4, the ratio between the breaking strength and the peeling force (breaking strength / peeling force) is 150 in the above range of 87.5 or more which defines the ratio between the breaking strength and the peeling force. As for the property, both the case where the width of the original fabric was 390 mm and the case where it was 450 mm resulted in no breakage.

  As shown in Table 3, in the adhesive film of Comparative Example 1, the ratio between the breaking strength and the peeling force (breaking strength / peeling force) was outside the above 87.5 range that defines the ratio between the breaking strength and the peeling force. Since it was 83.3, the pre-cut property was the result that the fracture did not occur when the width of the original fabric was 450 mm, but the fracture occurred when it was 390 mm.

  The adhesive film of Comparative Example 2 has a pre-cut because the ratio between the breaking strength and the peeling force (breaking strength / peeling force) is 50 outside the above 87.5 range that defines the ratio between the breaking strength and the peeling force. The property was the result of the occurrence of breakage in both cases where the width of the original fabric was 390 mm and 450 mm.

  In the adhesive film of Comparative Example 3, the ratio between the breaking strength and the peeling force (breaking strength / peeling force) is 58.3 outside the above range of 87.5 or more which defines the ratio between the breaking strength and the peeling force. As for the precut property, when the width of the original fabric was 450 mm, the fracture never occurred, but when it was 390 mm, the fracture occurred.

  In the adhesive film of Comparative Example 4, the ratio between the breaking strength and the peeling force (breaking strength / peeling force) is 38.9 outside the above range of 87.5 or more that defines the ratio between the breaking strength and the peeling force. The precut property was the result of occurrence of breakage in both cases where the width of the original fabric was 390 mm and 450 mm.

  From the results shown in Table 2 and Table 3, the breaking strength per unit of the adhesive layer 12 is 87.5 times or more with respect to the peeling force per unit from the release film 11 of the adhesive layer 12, preferably Is a winding process of the adhesive layer when producing the wafer processing tape 10 precut into a shape corresponding to the shape of the semiconductor wafer by using the adhesive film 20 according to this embodiment which is 100 times or more. It is possible to prevent the peripheral adhesive layer portion 12b from being broken. Moreover, the productivity of the pre-cut wafer processing tape 10 produced using the adhesive film 20 according to the present embodiment can be improved. Further, the production of the wafer processing tape 10 with high production efficiency with a small amount of the peripheral adhesive layer portion 12b which becomes unnecessary and a small amount of the wafer processing tape 10 which becomes unnecessary in the dicing of the semiconductor wafer, the semiconductor die bonding chip, etc. can do.

10: Wafer processing tape 11: Release film 12: Adhesive layer 12a: Circular adhesive layer part 12b: Peripheral adhesive layer part 13: Adhesive film 13a: Circular label part 13b: Peripheral part 14: Base film 15: Adhesive layers 20, 20A, 20B: adhesive film 21: dicing die bonding film 22: notch

Claims (3)

An adhesive film in which an adhesive layer is laminated on a long release film,
An adhesive film, wherein the breaking strength per unit of the adhesive layer is 87.5 times or more with respect to the peeling force per unit of the adhesive layer from the release film.   2. The adhesive film according to claim 1, wherein the breaking strength per unit of the adhesive layer is 100 times or more with respect to the peeling force per unit of the adhesive layer from the release film. . 3. For wafer processing, wherein the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film in which a pressure-sensitive adhesive layer is laminated on a base film and the adhesive layer of the adhesive film according to claim 1 or 2 are bonded together tape.

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