KR20050039656A - An adhesive sheet for dicing, a dicing method, and a method for manufacturing a semiconductor - Google Patents

Abstract

Provided is a pressure-sensitive adhesive sheet for dicing, in which there is no deterioration of product quality and no disadvantage in cost, less generation of thread-like waste during dicing, and no film tearing even in the expanding process, and chipping is suppressed low.

In the dicing adhesive sheet 1 in which the adhesive layer 12 is provided on one or more surfaces of the base film 11, the base film 11 is a multilayer film of two or more layers, and two or more layers of the multilayer film. An olefinic thermoplastic elastomer containing this propylene as a polymerization component, an olefinic thermoplastic elastomer having a melting point peak temperature of 120 to 170 ° C, and an olefinic thermoplastic elastomer contained in the two or more layers are different in their propylene contents. .

Description

Adhesive sheet for dicing, dicing method and manufacturing method of a semiconductor element {AN ADHESIVE SHEET FOR DICING, A DICING METHOD, AND A METHOD FOR MANUFACTURING A SEMICONDUCTOR}

The present invention relates to an adhesive sheet for dicing. Moreover, it is related with the method of dicing using the said adhesive sheet for dicing. Moreover, it is related with the manufacturing method of the semiconductor element using the said adhesive sheet for dicing. The adhesive sheet for dicing of this invention is especially useful as an adhesive sheet for semiconductor wear dicing used in order to fix to-be-cut objects, such as the said semiconductor wear, when cut | disconnecting (dicing) element fragments, such as a semiconductor wear. For example, the adhesive sheet for dicing of this invention can be used as an adhesive sheet for silicon semiconductor dicing, an adhesive sheet for compound semiconductor wear dicing, an adhesive sheet for semiconductor package dicing, an adhesive sheet for glass dicing, etc.

BACKGROUND ART Conventionally, semiconductor wear made of silicon, gallium, arsenic, or the like is manufactured in a state of large diameter, and then cut and diced (dicing) into element pieces, and transferred to a mounting process. At this time, each process of a dicing process, a washing | cleaning process, an expanding process, a pick-up process, and a mounting process is performed in the state in which the semiconductor wear was attached to the adhesive sheet and hold | maintained. As the pressure-sensitive adhesive sheet, one having an acrylic pressure-sensitive adhesive applied on the substrate made of a plastic film about 1 to 200 μm is generally used.

In the dicing step, the wafer is cut by a circular knife moving while rotating, but at this time, a cutting method called full cut, which cuts to the inside of the base material of the adhesive sheet for dicing holding the semiconductor wear, is mainstream. have. And as a cutting method by a full cut, as cutting | disconnection is performed to the inside of an adhesive sheet, the cutting waste in which the plastic film itself which is a base material becomes a thread shape arises. When the yarn-like garbage adheres to the side of the chip (the cut body) or the like, the bonded yarn-like garbage is mounted as it is in the later step and sealed, which causes a problem of significantly lowering the reliability of the semiconductor element. Further, in the pick-up step, pick-up is performed after the individual chips are recognized by the CCD camera and aligned, but there is also a defect that causes a recognition error that there is real garbage.

As a means for solving such a problem, the adhesive sheet which used the ethylene-methacrylate copolymer as a base material, for example is proposed (refer Japanese Unexamined-Japanese-Patent No. 1993-156214). However, in this adhesive sheet, although the generation | occurrence | production of thread-shaped waste reduces to some extent, after that, it did not satisfy | fill the level with which it can endure the dicing process of high reliability semiconductor manufacture. In addition, at the time of the expansion step in the expanding step, the sheet base material is more likely to be torn than the cut portion in the dicing, and it is difficult to use stably in a step requiring a large amount of expansion.

Moreover, the adhesive sheet using the film which irradiated the base film with radiation, such as 1-80MRad electron beam or (gamma) ray, is proposed (refer Japanese Unexamined-Japanese-Patent No. 1993-211234). However, in this adhesive sheet, the film damage by radiation irradiation is large and it is difficult to obtain a favorable film externally, and enormous cost in film manufacture is unfavorable in terms of quality and price. Moreover, according to this method, since the film promotes the property which tears well, it is not especially preferable about the adhesive sheet for dicing which needs expansion.

Moreover, as a base film, the adhesive sheet which uses olefinic thermoplastic elastomer which contains propylene and ethylene and / or (alpha) -olefin of C4-C8 as a polymerization component, and whose melting point peak temperature is 120 degreeC or more is proposed (Japanese patent) See Published Publication No. 2003-7654). This adhesive sheet can suppress generation | occurrence | production of thread-shaped garbage.

On the other hand, in the dicing process using an adhesive sheet, there exists a problem that the crack (crack) called chipping generate | occur | produces on the back surface of the cut | disconnected semiconductor element (wafer). In recent years, with the widespread use of IC cards and the like, thinning of semiconductor devices is progressing, so that chipping of semiconductor devices causes a significant decrease in strength of the semiconductor devices, which significantly lowers the reliability thereof, and also lowers the yield. However, the pressure-sensitive adhesive sheet of Japanese Patent Laid-Open No. 2003-7654 was not able to sufficiently satisfy both the tearing of the film and the chipping in the expansion step.

The present invention is to solve the problems according to the prior art as described above, there is no deterioration of product quality or costly disadvantages, less generation of yarn-like waste during dicing, and the film does not tear even in the expansion process Moreover, it aims at providing the adhesive sheet for dicing which suppresses generation | occurrence | production of chipping low.

Moreover, an object of this invention is to provide the dicing method using the said adhesive sheet for dicing. Moreover, it aims at providing the manufacturing method of the semiconductor element using the said adhesive sheet for dicing, and providing the semiconductor element obtained by the said manufacturing method.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining about the base film which comprises the adhesive sheet for dicing in order to solve the said subject, it discovered that the said objective can be achieved by obtaining the multilayer film which used the specific olefinic thermoplastic elastomer as a base film. The present invention has been accomplished.

That is, this invention is an adhesive sheet for dicing in which an adhesive layer is provided in one or more surfaces on a base film,

The base film is a multilayer film of two or more layers,

Two or more layers of the said multilayer film are olefinic thermoplastic elastomers which contain propylene as a polymerization component, contain a olefinic thermoplastic elastomer whose melting point peak temperature is 120-170 degreeC,

Moreover, the olefinic thermoplastic elastomer contained in the said 2 or more layer relates to the adhesive sheet for dicing characterized by each propylene content being different.

The base film of the adhesive sheet for dicing of this invention is comprised by the multilayer film, and two or more layers of a multilayer film are olefinic thermoplastic elastomers which contain propylene as a polymerization component, and are olefins whose melting point peak temperature is 120-170 degreeC. It contains a thermoplastic elastomer. In such an olefinic thermoplastic elastomer, elongation of the base film at the time of dicing decreases, and generation | occurrence | production of the yarn-like waste at the time of dicing is suppressed. The melting point peak temperature of the olefinic thermoplastic elastomer is preferably 140 ° C or higher, more preferably 160 ° C or higher. Melting point peak temperature is generally measured with a differential scanning calorimeter (DSC) in accordance with JIS K7121.

Moreover, in the said multilayer film, what differs in each propylene content is used for the olefinic thermoplastic elastomer contained in two or more layers. By changing the propylene content, different properties can be given to each layer.

In the adhesive sheet for dicing, in the multilayer film containing two or more olefinic thermoplastic elastomers, it is preferable that the layer containing the olefinic thermoplastic elastomer having less propylene content becomes the pressure sensitive adhesive layer side.

By using a layer having a relatively low propylene content as a layer in which dicing is cut, chipping can be suppressed. Moreover, the pick-up property after dicing can be made favorable. On the other hand, by using a layer having a relatively high propylene content as a layer which is not subjected to dicing, it is possible to give the film strength against tearing even in an expand process.

In the pressure-sensitive adhesive sheet for dicing, the propylene content of the olefinic thermoplastic elastomer contained in at least one layer of the multilayer film of the two or more layers is 45 to 90 mol%, and the olefinic thermoplastic elastomer contained in the other one or more layers. It is preferable that propylene content is 65-98 mol%.

It is preferable to use the layer containing the olefin thermoplastic elastomer whose propylene content is 45-90 mol% as one of the layers to which dicing is cut. 50-85 mol% is preferable and, as for the propylene content of the olefin thermoplastic elastomer used for the said layer, it is preferable that it is 55-78 mol%.

It is preferable to use the layer containing the olefin thermoplastic elastomer whose propylene content is 65-98 mol% as one of the layers which are not cut of dicing. 70-96 mol% is preferable and, as for the propylene content of the olefin thermoplastic elastomer used in the said layer, it is more preferable that it is 78-96 mol%.

In the pressure-sensitive adhesive sheet for dicing, the elution fraction at 0 ° C. in the temperature rise dissolution fractionation between the temperatures of 0 to 140 ° C. using o-dichlorobenzene as the solvent of the olefinic thermoplastic elastomer is 10 to the total amount of elution. It is preferable that it is to 60 weight%.

The ratio of the olefin thermoplastic elastomer to the total elution amount of the eluent at 0 ° C suppresses the generation of the yarn-like waste during dicing and can satisfy the adhesiveness of the expandable or adhesive layer of the base film. It is a preferable range. When the proportion of the eluate at 0 ° C. decreases, the base film obtained by molding the olefinic thermoplastic elastomer is hard, and since the extensibility at the time of expansion is poor, there is a tendency that pick-up also becomes difficult to perform. It is preferable that the ratio of the eluent at 0 degreeC is 20 weight% or more. Moreover, when the ratio of the eluent at 0 degreeC becomes large, since it exists in the tendency for adhesiveness with the adhesive layer of the base film obtained by shape | molding an olefinic thermoplastic elastomer to be inferior, the ratio of the elution content at said 0 degreeC. It is preferable that silver is 50 weight% or less.

In addition, the said temperature rising elution fractionation (TREF) is a well-known analysis method. In principle, the polymer is completely dissolved in a solvent at a high temperature and then cooled to form a thin polymer layer on the surface of the inert carrier present in solution. At this time, the polymer layer is formed from the high crystalline component which is easy to crystallize in the order of the low crystalline or amorphous component which is difficult to crystallize. Subsequently, if it heats up continuously or stepwise, in contrast to the above, it elutes from a low crystalline or amorphous component, and a high crystalline component elutes at last. The composition distribution of the polymer is analyzed from the dissolution curve drawn by the dissolution amount and the dissolution temperature at each temperature.

As a measuring apparatus, Coros fractionation apparatus (made by Mitsubishi Chemical Corporation, CFC, T150A) was used. The sample to be measured (olefinic thermoplastic elastomer) was dissolved at 140 ° C. to a concentration of 30 mg / ml using a solvent (o-dichlorobenzene), and this was injected into the sample loop in the measuring device. The following measurements were performed automatically in accordance with the set conditions. 0.4 ml of the sample solution held in the sample loop was injected into a TREF column (a stainless column with an inner diameter of 4 mm and a 150 mm long device filled with inert glass beads) fractionated using a dissolution temperature difference. The sample was cooled from 140 ° C. to 0 ° C. at a rate of 1 ° C./min and coated with the inert carrier. At this time, a polymer layer is formed on the surface of the inert carrier in order from the high crystalline component (which is easy to crystallize) to the low crystalline component (which is difficult to crystallize). The TREF column was held for an additional 30 minutes at 0 ° C., and then stepped up as follows, and held for 30 minutes at each temperature, and the elution at that temperature was measured. Elution temperature (° C): 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 49, 52, 55, 58, 61, 64, 67, 70, 73, 76, 79, 82, 85, 88, 91, 94, 97, 100, 102, 120, 140.

In the adhesive sheet for dicing, it is preferable that two or more layers containing the olefinic thermoplastic elastomer contain 50% by weight or more of the olefinic thermoplastic elastomer.

As for content of the said olefinic thermoplastic elastomer in a base film, 1 or more layers of a single | mono layer film or a multilayer film are 50 weight% or more normally, Preferably it is 80 weight% or more from a yarn waste prevention effect. When the base film is a multilayer, for example, when dicing by providing a low-extension layer containing the olefinic thermoplastic elastomer in at least one layer (more) to a depth at which a round knife is cut during full cut. The generation of the yarn-like garbage can be prevented, and by providing a layer having excellent extensibility at the time of expansion in another layer, the low extensibility of the layer contained in the olefinic thermoplastic elastomer can be supplemented. In addition, a functional layer such as a layer having excellent antistatic property may be provided and multilayered to add additional functions such as antistatic performance.

In the pressure-sensitive adhesive sheet for dicing, the thickness of the pressure-sensitive adhesive layer is effective when it is 1 to 200μm.

The thickening of the pressure-sensitive adhesive layer significantly lowers the quality of the dicing due to vibration of the semiconductor wear during dicing and the like, which is also disadvantageous in terms of cost, so that the thickness of the pressure-sensitive adhesive layer is 1 to 200 µm, particularly preferably 3 to 50 µm. do. Usually, as a dicing process, since a round knife cuts and cut | disconnects about 5-230 micrometers with respect to the adhesive sheet for dicing, an adhesive layer is thinner than the cutting depth, and it cuts to a base film, and the seal | sticker with a base film When shape garbage becomes a problem, the adhesive sheet for dicing of this invention functions effectively.

In the pressure sensitive adhesive sheet for dicing, the pressure sensitive adhesive layer is preferably formed of a radiation curable pressure sensitive adhesive.

When the radiation-curable pressure-sensitive adhesive layer is used, the adhesive force can be lowered by irradiating radiation, so that the adhesive sheet can be easily removed from the wafer or the like after cutting and separating the wafer or the like.

Moreover, this invention relates to the dicing method characterized by dicing the to-be-cut object by sticking the said dicing adhesive sheet to a to-be-cut object, and then cutting to the base film of the said adhesive sheet.

Furthermore, this invention is equipped with the process of dicing by cutting to the base film of the said adhesive sheet after attaching the said adhesive sheet for dicing to a semiconductor component, and the process of expanding the said adhesive sheet, It is characterized by the above-mentioned. A method for manufacturing a semiconductor device.

Hereinafter, the adhesive sheet for dicing of this invention is demonstrated concretely, referring FIG. As shown in FIG. 1, the adhesive sheet 1 for dicing of this invention is a base film 11, the adhesive layer 12 provided in at least one surface of the said base film 11, and the adhesive layer (if needed) It consists of the separator 13 which contact | connected 12) and stuck on the surface opposite to the base film 11. In FIG. 1, although the adhesive layer 12 is provided in one side of the base film 11, the adhesive layer 12 can also be formed in both surfaces of a base film. The base film is a multilayer film of two or more layers. As FIG. 1, the case where the base film 11 is two layers is illustrated. The dicing-side base material layer 11b may be a layer which is cut at the time of dicing on the side of the adhesive layer 12. On the other hand, the sheet back side base material layer 11a is on the opposite side to the adhesive layer 12, and it can be set as the layer which is not cut at the time of dicing. The dicing adhesive sheet 1 can also be wound in a tape shape.

Two or more layers of the base film 11 are olefinic thermoplastic elastomers containing propylene as a polymerization component. The olefinic thermoplastic elastomer usually contains, in addition to propylene, ethylene and / or α-olefin having 4 to 8 carbon atoms as the polymerization component. Examples of the α-olefin having 4 to 8 carbon atoms include butene-1, 3-methylpentene-1, 4-methylpentene-1, hexene-1, octene-1 and the like. As an olefinic thermoplastic elastomer, the copolymer of propylene and ethylene is preferable.

The ratio of each of the polymerization components constituting the olefinic thermoplastic elastomer is not particularly limited as long as the olefinic thermoplastic elastomer satisfies the requirements related to the melting point peak temperature and the temperature eluting fractionation. The proportion of propylene is usually adjusted in the range of 45 to 98% by weight, and it is preferable to use two or more kinds of olefinic thermoplastic elastomers having different propylene content in this range. Ethylene and / or α-olefin having 4 to 8 carbon atoms is the residual amount minus the proportion of propylene.

As described above, at least one layer is a layer containing an olefinic thermoplastic elastomer having a propylene content of 45 to 90 mol%, and the layer is preferably a layer on the side to be cut. On the other hand, at least one other layer is a layer containing an olefinic thermoplastic elastomer having a propylene content of 65 to 98 mol%, and the layer is preferably a layer on the side where no cutting is performed.

The olefinic thermoplastic elastomer of the present invention contains the polymerization component, and the production method is not limited as long as it satisfies the conditions related to the melting point peak temperature and the temperature eluting fractionation. For example, in one step, a propylene homopolymer or a random copolymer of propylene and ethylene and / or an α-olefin having 4 to 8 carbon atoms is produced, followed by propylene and ethylene and / or other α having 4 to 8 carbon atoms after the second step. A two or more sequential polymerization process for preparing a random copolymer of olefins; A propylene homopolymer or a random copolymer of propylene with ethylene and / or an α-olefin having 4 to 8 carbon atoms, a random copolymer of ethylene with an α-olefin having 4 to 8 carbon atoms, or with ethylene and / or 4 to 8 carbon atoms The manufacturing method which blends what superposed | polymerized the random copolymer with propylene each separately is mentioned. As these methods, two or more sequential polymerization methods are preferable.

Hereinafter, this sequential polymerization method is explained in full detail. Although the catalyst used for sequential superposition | polymerization is not specifically limited, It is preferable to consist of an organoaluminum compound, the solid component which consists essentially of a titanium atom, a magnesium atom, a halogen atom, and an electron donating compound.

Here, as the organoaluminum compound, the polymerization of this species is known in general formula (R ^l ) _m AlX _(3-m) (wherein R ¹ is a hydrocarbon moiety having 1 to 12 carbon atoms, X represents a halogen atom, and m is A dialkyl aluminum halide such as trialkylaluminum such as trimethylaluminum or triethylaluminum, dimethylaluminum chloride, diethylaluminum chloride, methylaluminum sesquichloride, Alkyl aluminum hydrides such as alkyl aluminum sesquihalides such as ethyl aluminum sesquichloride, methyl aluminum dichloride and ethyl aluminum dichloride, and alkyl aluminum hydrides such as diethyl aluminum hydride.

Moreover, as a solid component which makes a titanium atom, a magnesium atom, a halogen atom, and an electron donating compound essential, a well-known thing can be used for this kind of superposition | polymerization. As a titanium compound which is a source of a titanium atom, the chemical formula is: Ti (OR ² ) _(4-n) X _n (wherein R ² is a hydrocarbon moiety having 1 to 10 carbon atoms, X represents a halogen atom, and n represents 0 to 0). And an integer of 4). Especially, titanium tetrachloride, tetraethoxy titanium, tetrabutoxy titanium, etc. are preferable. Examples of the magnesium compound serving as the source of the magnesium atom include dialkyl magnesium, magnesium dihalide, dialkoxy magnesium, alkoxy magnesium halide and the like, and magnesium dihalide is particularly preferable. Examples of the halogen atom include fluorine, chlorine, bromine and iodine. Of these halogen atoms, chlorine is preferred. In addition, these halogen atoms are usually supplied from the titanium compound, but may also be supplied from other halogen sources such as halogen compounds of aluminum, halogen compounds of silicon, halogen compounds of tungsten and the like.

Examples of the electron donating compound include oxygen-containing compounds such as alcohols, phenols, ketones, aldehydes, carboxylic acids, organic acids or inorganic acids and derivatives thereof, and nitrogen-containing compounds such as ammonia, amines, nitriles and isocyanates. Can be. In particular, inorganic acid esters, organic acid esters, organic acid halides, and the like are preferable, and silicon esters, cellosolve esters, phthalate halides, and the like are more preferable, and a chemical formula: R ³ R ⁴ _(3-p) Si (OR ⁵ ) _p (above) Wherein R ³ represents a branched aliphatic hydrocarbon residue having 3 to 20 carbon atoms, preferably 4 to 10 carbon atoms or a cyclic aliphatic hydrocarbon residue having 5 to 20 carbon atoms, preferably 6 to 10 carbon atoms, and R ⁴ represents 1 to 20 carbon atoms. Preferably a branched or straight chain aliphatic hydrocarbon residue of 1 to 10, p being an integer of 1 to 3), such as t-butyl-methyl-diethoxysilane, cyclo Hexyl-methyl-dimethoxysilane, cyclohexyl-methyl-diethoxysilane, etc. are particularly preferable.

In the sequential polymerization method, in the first step, propylene or additionally ethylene and / or α-olefin having 4 to 8 carbon atoms is supplied, and in the presence of the catalyst, a temperature of 50 to 150 ° C, preferably 50 to 100 ° C, propylene Propylene homopolymer or the like at a partial pressure of 0.5 to 4.5 MPa, preferably 1 to 3.5 MPa, followed by propylene and ethylene and / or? -Olefins having 4 to 8 carbon atoms in the second step, In the presence of a catalyst at a temperature of 50 to 150 ° C., preferably 50 to 100 ° C., and a partial pressure of propylene and ethylene and / or an alpha olefin having 4 to 8 carbon atoms, respectively, of 0.3 to 4.5 MPa, preferably 0.5 to 3.5 MPa. And polymerization of propylene and ethylene and / or an α-olefin copolymer having 4 to 8 carbon atoms.

In addition, the superposition | polymerization at this time can be based on either batch type, continuous type, or semi-batch type. In addition, the polymerization of the first stage is carried out in a gaseous phase or a liquid phase, and the polymerization of the second stage is also carried out in a gaseous phase or a liquid phase. However, each step is particularly preferably carried out in the gas phase. In addition, the residence time of each step is 0.5 to 10 hours, preferably 1 to 5 hours, respectively.

In addition, when a problem such as stickiness occurs in the powder particles of the olefin-based thermoplastic elastomer produced by the above method, for the purpose of imparting fluidity of the powder particles, after the polymerization in the first step, before the polymerization starts in the second step or the polymerization On the way, it is preferable to add an active hydrogen containing compound. As an addition amount of an active hydrogen containing compound, the range of 100-1000 times mole with respect to the titanium atom in the solid component of a catalyst, and the range of 2-5 times mole with respect to the organoaluminum compound of a catalyst are preferable. Examples of the active hydrogen-containing compound include water, alcohols, phenols, aldehydes, carboxylic acids, acid amides ammonia and amines.

In addition, the melt fluorate (MFR) measured by the temperature of 230 degreeC and the load of 21.18N based on JISK7210 of the olefinic thermoplastic elastomer manufactured by the said method is 0.1-50 g / 10min, and it is underwater in accordance with JIS K7112. The density measured by the substitution method is about 0.87 to 0.89 g / cm ³ , and the flexural modulus measured at a temperature of 23 ° C. in accordance with JIS K7203 is 600 MPa or less.

The olefinic thermoplastic elastomer may also be subjected to dynamic heat treatment in the presence of a known organic peroxide or additionally a crosslinking agent having at least one, preferably at least two, double bonds in the molecule to adjust the MFR.

The base film 11 of this invention has two or more layers containing the said olefinic thermoplastic elastomer. As the olefinic thermoplastic elastomer contained in the two or more layers, those having different propylene contents are used. Each layer may be formed of only a layer containing an olefinic thermoplastic elastomer. In addition, each layer can also be implemented with the layer which consists of a mixture with another plastic resin or an elastomer as needed. Such plastic resins or elastomers include known polyolefins such as polypropylene, polyethylene, polybutene, polyethylene terephthalate, polyvinyl chloride, polyurethane, polystyrene, styrene-based elastomers, ethylene, propylene and / or α- having 4 to 8 carbon atoms. Resin for ordinary plastics or elastomer sheets, such as an ethylene-prene- alpha olefin copolymer (rubber) which consists of olefins, can be used preferably. As described above, the content of the olefin-based thermoplastic elastomer in the base film is usually 50% by weight or more, preferably 80% by weight or more, from the effect of preventing the occurrence of trash wastes. Moreover, if the base film of this invention contains two or more layers containing the said olefinic thermoplastic elastomer, you may further provide the layer formed by another plastic resin or an elastomer.

In addition, in the base film 11, softeners such as mineral oil, fillers such as calcium carbonate, silica, talc, cloudiness, clay, antioxidants, light stabilizers, antistatic agents, lubricants, dispersants, neutralizing agents, α-nucleated agents, β-nucleated Various additives, such as an agent, may be mix | blended as needed.

The base film 11 of this invention is a 2-layer film or a multilayer film of three or more layers, and can be manufactured in accordance with conventional methods, such as a multilayer coextrusion method. Moreover, it can manufacture by usual film lamination methods, such as a dry lamination method.

The thickness of the base film 11 is 10-300 micrometers normally, Preferably it is about 30-200 micrometers. In the base film (multilayer film) 11, the thickness of each layer is suitably determined in consideration of the range assumed to reach the round knife at the time of dicing. Usually, it is assumed that a round knife reaches to about 150 micrometers at the time of dicing on the surface which the adhesive layer 12 contact | connects. Therefore, usually, the thickness of the layer (layer 11b in FIG. 1) that is assumed to reach a round knife at the time of dicing, that is, the thickness of the layer containing the olefin-based thermoplastic elastomer, preferably of which the propylene content is smaller is 10 to About 150 micrometers, Preferably it is adjusted to the range of 20-120 micrometers. On the other hand, if the round knife does not reach that deep during dicing, the thickness of the layer (layer 11a in FIG. 1) assumed, that is, the thickness of the layer containing the olefin-based thermoplastic elastomer having the higher propylene content is 20 to 20. About 150 micrometers, Preferably it adjusts to the range of 30-100 micrometers.

In addition, the obtained base film 11 can also be uniaxially or biaxially stretched as needed. When performing an extending | stretching process, it is preferable to carry out about 60-100 degreeC. The base film thus formed can be subjected to conventional physical or chemical treatments such as matt treatment, corona discharge treatment, primer treatment and the like as necessary.

The adhesive layer 12 can use a well-known or usual adhesive. Although such an adhesive is not restrict | limited at all, Various adhesives, such as rubber type, an acryl type, silicone type, polyvinyl ether type, are used, for example.

As said adhesive, an acrylic adhesive is preferable. The acrylic polymer, which is an acrylic pressure-sensitive adhesive base polymer, is usually a copolymer of an alkyl (meth) acrylate or copolymerizable monomer. As a main monomer of an acryl-type polymer, the alkyl (meth) acrylate whose glass transition temperature of the homopolymer is 20 degrees C or less is preferable.

As an alkyl group of (meth) acrylate, a methyl group, an ethyl group, a butyl group, 2-ethylhexyl group, an octyl group, an isononyl group, etc. are mentioned, for example. Moreover, as said copolymerizable monomer, hydroxyalkyl ester of (meth) acrylic acid (for example, hydroxyethyl ester, hydroxybutyl ester, hydroxyhexyl ester, etc.), (meth) acrylic-acid glycidyl ester, (meth) acrylic acid, Itaconic acid, maleic anhydride, (meth) acrylic acid amide, (meth) acrylic acid N-hydroxymethylamide, (meth) acrylate alkylaminoalkyl, (e.g., dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate) Vinyl acetate, styrene, acrylonitrile, etc. are mentioned.

As the pressure-sensitive adhesive, a radiation-curable pressure-sensitive adhesive or a heat-expandable pressure-sensitive adhesive that is cured by ultraviolet rays, electron beams, or the like can also be used. Moreover, the adhesive which can be used for a dicing die bond may be sufficient. In the present invention, it is preferable to use a radiation curable pressure sensitive adhesive, particularly an ultraviolet curable pressure sensitive adhesive. Moreover, when using a radiation curable adhesive as an adhesive, since the radiation is irradiated to an adhesive before or after a dicing process, it is preferable that the said base film has sufficient radiation transmittance.

The radiation curable pressure sensitive adhesive contains, for example, the base polymer (acrylic polymer) and a radiation curable component. The radiation curable component has a carbon-carbon double bond in the molecule, and any monomer, oligomer or polymer that can be cured by radical polymerization can be used without particular limitation. Examples of the radiation curable component include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tetraethylene glycol di (meth) acrylate, and 1,6-hexanediol di (meth) acryl. Esters of (meth) acrylic acid and polyhydric alcohols such as late, neopentyl glycol di (meth) acrylate and dipentaerythritol hexa (meth) acrylate; Esteracrylate oligomers; Isocyanu, such as 2-propenyl-di-3-butenylcyanurate, 2-hydroxyethylbis (2-acryloxyethyl) isocyanurate, and tris (2-methacryloxyethyl) isocyanurate Elate or isocyanurate compound, etc. are mentioned.

As the base polymer (acrylic polymer) of the radiation curable pressure sensitive adhesive, a radiation curable polymer having a carbon-carbon double bond in the polymer side chain can also be used. In this case, it is not necessary to add the said radiation hardening component in particular.

When hardening a radiation curable adhesive with an ultraviolet-ray, a photoinitiator is needed. As a polymerization initiator, For example, benzoin alkyl ether, such as benzoyl methyl ether, benzoin propyl ether, benzoin isobutyl ether; Aromatic ketones such as benzyl, benzoin, benzophenone and α-hydroxycyclohexylphenyl ketone; Aromatic ketals such as benzyl dimethyl ketal; Polyvinylbenzophenone; Thioxanthones, such as a chloro thioxanthone, a dodecyl thioxanthone, a dimethyl thioxanthone, and a diethyl thioxanthone, etc. are mentioned.

The said adhesive can also be made to contain common additives, such as a crosslinking agent, a tackifier, a filler, anti-aging agent, a coloring agent, as needed. Examples of the crosslinking agent include polyisocyanate compounds, melamine resins, urea resins, aziridine compounds, epoxy resins, anhydrides, polyamines, and carboxyl group-containing polymers.

In the adhesive sheet 1 for dicing of this invention, an adhesive is apply | coated to the surface of the base film 11, for example, it heat-crosslinks as needed, the adhesive layer 12 is formed, and this adhesive is needed. It can manufacture by adhering the separator 13 to the surface of the layer 12. In addition, after forming the adhesive layer 12 in the separator 13, the method etc. which adhere these to the base film 11 can be employ | adopted.

The thickness of the adhesive layer 12 can be more suitably determined by the kind of adhesive or the dicing cut depth. The thickness of the pressure-sensitive adhesive layer 12 is usually 1 to 200 μm, preferably about 3 to 50 μm.

The separator 13 is provided as needed for label processing or for the purpose of smoothing the adhesive layer 12. As a constituent material of the separator 13, synthetic resin films, such as paper, polyethylene, a polypropylene, and a polyethylene terephthalate, etc. are mentioned. In order to improve the peelability from the adhesive layer 12, the surface of the separator 13 may be subjected to a peeling treatment such as silicon treatment, long chain alkyl treatment, fluorine treatment or the like as necessary. Moreover, lamination | stacking may be performed by uniaxial or biaxial stretching process, another plastic film, etc. according to the purpose of raising rigidity, etc. The thickness of the separator is usually 10 to 200 m, preferably about 25 to 100 m.

Example

Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited by these Examples.

Example 1

(Production of base film)

Mitsubishi Chemical Co., Ltd. product name "Jeras 5053" and Mitsubishi Chemical Co., Ltd. product "Product Name: Geras 7053" were supplied to Purako Co., Ltd., 2 type 2-layer T-die molding machine (setting temperature 230 degreeC), Unveiled. This produced the 2-layer base film of thickness 100micrometer (layer ratio = 50: 50), and width 29cm.

Mitsubishi Chemical Co., Ltd. product name "Geras 5053" is an olefinic thermoplastic elastomer of 72.5 mol% of a propylene component and 17.5 mol% of an ethylene component, and the temperature between 0-140 degreeC which used o-dichlorobenzene as a solvent. The elution fraction at 0 ° C in the eluting fractionation was 41.7% by weight, the melting point peak temperature was 164 ° C, the density was 0.88 g / cm ³ , and the MFR (230 ° C, 21.18N) was 6.8 g / 10 minutes.

On the other hand, Mitsubishi Chemical Co., Ltd. product name "Geras 7053" is an olefinic thermoplastic elastomer of 86.0 mol% of a propylene component and 14.0 mol% of an ethylene component, and is between 0-140 degreeC using o-dichlorobenzene as a solvent. The eluted fraction at 0 ° C. in the temperature rising elution fraction was 21.5% by weight based on the total amount of elution, the melting point peak temperature was 164 ° C., the density was 0.89 g / cm ³ , and the MFR (230 ° C., 21.18N) was 7.0 g / 10 minutes.

(Preparation of Adhesive)

Dipentaerythritol hexaacrylate (trade name "Kayalad DPHA) in a solution containing a weight average molecular weight of 500,000 acrylic copolymer obtained by copolymerizing 95 parts by weight of butyl acrylate and 5 parts by weight of acrylic acid in toluene by a conventional method. , Nippon Kayaku Co., Ltd.) 60 parts by weight, photopolymerization initiator (trade name "Ilgacua 184", Chiba Specialty Chemical Co., Ltd.) 3 parts by weight, polyisocyanate compound (brand name "Colonate L", Japan 5 parts by weight of Polyurethane Co., Ltd.) was added to prepare an acrylic ultraviolet curable pressure-sensitive adhesive solution.

(Production of the adhesive sheet for dicing)

The adhesive solution prepared above was apply | coated on the corona treatment surface of the base film obtained above, and it heat-crosslinked at 80 degreeC for 10 minutes, and formed the ultraviolet curable adhesive layer of thickness 20micrometer. In addition, formation of an adhesive layer was performed to the layer side formed by "brand name: Geras 5053" which is a Mitsubishi Chemical Corporation product. Subsequently, the separator was stuck to the said adhesive layer surface, and the adhesive sheet for ultraviolet curable dicing was produced.

Comparative Example 1

In the preparation of the pressure-sensitive adhesive sheet for dicing of Example 1, an ethylene-methyl methacrylate copolymer (Sumitomo Chemical Co., Ltd. product, trade name Arclift WD201) was formed into a film with a T die molding machine so as to have a thickness of 100 μm. Except for using a film, it carried out similarly to Example 1, and produced the dicing adhesive sheet. Moreover, melting | fusing point peak temperature of an ethylene-methacrylic acid copolymer is 100 degreeC, and a density is 0.93g / cm <^3> , MFR (190 degreeC, 21.18N) 2.0g / 10min.

Comparative Example 2

In the preparation of the pressure-sensitive adhesive sheet for dicing of Example 1, the present invention was carried out as a base film except that a film formed by Mitsubishi Chemical Co., Ltd. product "Jeras 5053" was formed into a single layer by a T-die molding machine so as to have a thickness of 100 μm. In the same manner as in Example 1, an adhesive sheet for dicing was produced.

Comparative Example 3

In the production of the pressure-sensitive adhesive sheet for dicing of Example 1, except that a film formed by Mitsubishi Chemical Co., Ltd. product name "Jeras 7053" was formed into a single layer by a T-die molding machine so as to have a thickness of 100 μm. In the same manner as in Example 1, an adhesive sheet for dicing was produced.

Comparative Example 4

In preparation of the adhesive sheet for dicing of Example 1, as a base film, Mitsubishi Chemical Co., Ltd. product brand name: "Jeras 5053" and Sumitomo Chemical Co., Ltd. product "Arclift WM 305) are two types of two-layer T A pressure-sensitive adhesive sheet for dicing was produced in the same manner as in Example 1 except that the two-layer base film was supplied to a die molding machine (set temperature 230 ° C.) and formed into a film having a thickness of 100 μm (layer ratio = 50: 50). In addition, formation of the adhesive layer was performed on the layer side formed by JERAS 5053.

(Evaluation test)

The adhesive sheet for dicing obtained by the Example and each comparative example was evaluated by the following method. The results are shown in Table 1.

(Fish eye)

In the Example and each comparative example, 30 m of adhesive sheets for dicing were produced, and the number of fish eyes of 1 mm or more in diameter was visually measured. Table 1 shows the number per 1 m ² .

(Chipping evaluation)

On the adhesive sheet for dicing obtained by the Example and each comparative example, the 6-inch wafer of 150 micrometers in thickness which was back grind | polished (# 2000 finish) was mounted. Then, the wafer with an adhesive sheet for dicing was diced at 23 degreeC (room temperature) on condition of the following. After dicing, the ultraviolet-ray was irradiated (500mJ / cm <^2> ) from the back surface of the sheet | seat, and 50 arbitrary semiconductor chips were then picked up (peeled off). Subsequently, the depth of the chip thickness direction of chipping on the semiconductor chip side was observed with an optical microscope (200 times), and the number of chippings (number) was counted for each size.

(yield)

About 50 arbitrary semiconductor chips which performed the chipping evaluation, the ratio of the chipping size not being 50 micrometers or more was made into the yield (%).

<Dicing Condition>

Dicing Device: Manufactured by DISCO, DFD-651

Blade: DISCO, 27HECC

Blade Speed: 40000rpm

Dicing Speed: 120mm / sec

Dicing Depth: 25μm

Cut Mode: Down Cut

Dicing size: 2.5 × 2.5mm

(Expand evaluation)

On the adhesive sheet for dicing obtained by the Example and each comparative example, the 6-inch wafer of 150 micrometers in thickness which was back grind | polished (# 2000 finish) was mounted. Thereafter, using a CPS-100 manufactured by NEC Machinery Co., Ltd., an expansion amount of 15 mm was expanded and the presence or absence of tearing of the film was visually observed in the state (expand).

(Room shape garbage)

The wafer surface cut | disconnected by the said dicing conditions was observed with the optical microscope. The dicing line of the wafer center part was observed about each of length and width, and the confirmed real garbage was counted.

As can be seen from Table 1, the fish eye (the generation of thread-like garbage) is not observed as the adhesive sheet for dicing of the Example. In addition, it is observed that the occurrence of chipping size of 50 µm or more is very small and the yield is good, and that the film does not tear even in the expanding process. On the other hand, in the comparative examples 1, 3, and 4, the generation | occurrence | production of chipping size 50 micrometers or more is large and a yield is not favorable. In Comparative Example 2, the film was torn when expanded, and thus could not be used in a process requiring expansion.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows an example of the adhesive sheet for dicing of this invention.

Explanation of the sign

Adhesive sheet for 1 dicing

11 base film

11a dicing-side base layer

11b sheet back side base material layer

12 adhesive layer

13 separator

Claims (9)

In the adhesive sheet for dicing which an adhesive layer is provided in one or more surfaces on a base film, The base film is a multilayer film of two or more layers, Two or more layers of the multilayer film are olefinic thermoplastic elastomers containing propylene as a polymerization component, and contain a olefinic thermoplastic elastomer having a melting point peak temperature of 120 to 170 ° C, Moreover, the olefinic thermoplastic elastomer contained in the said 2 or more layer differs in each propylene content, The adhesive sheet for dicing characterized by the above-mentioned. The method of claim 1, The adhesive sheet for dicing characterized in that the layer containing the olefinic thermoplastic elastomer with the less propylene content consists of an adhesive layer side in the multilayer film containing the said 2 or more olefinic thermoplastic elastomer. The method of claim 1, The propylene content of the olefinic thermoplastic elastomer contained in at least one layer of the two or more multilayer films is 45 to 90 mol%, Moreover, the olefinic thermoplastic elastomer contained in another 1 or more layer is propylene content 65-98 mol%, The adhesive sheet for dicing characterized by the above-mentioned. The method of claim 1, The elution at 0 ° C in the temperature rise dissolution fractionation between 0 to 140 ° C using the o-dichlorobenzene of the olefinic thermoplastic elastomer as a solvent is 10 to 60% by weight based on the total amount of elution. A pressure-sensitive adhesive sheet. The method of claim 1, Two or more layers containing the said olefinic thermoplastic elastomer contain 50 weight% or more of an olefinic thermoplastic elastomer, The adhesive sheet for dicing. The method of claim 1, The thickness of an adhesive layer is 1-200 micrometers, The adhesive sheet for dicing characterized by the above-mentioned. The method of claim 1, The pressure-sensitive adhesive layer is formed of a radiation curable pressure-sensitive adhesive, characterized in that the adhesive sheet for dicing. The dicing method of Claim 1 which dicing a to-be-cut object by sticking the adhesive sheet for dicing to a to-be-cut object, and then cutting to the base film of the said adhesive sheet. After attaching the adhesive sheet for dicing according to Claim 1 to a semiconductor component, it has a process of dicing by cutting to the base film of the said adhesive sheet, and the semiconductor process characterized by the expansion process of the said adhesive sheet. Method of manufacturing the device.