WO2017150018A1 - Semiconductor processing sheet - Google Patents

Abstract

Provided is a semiconductor processing sheet provided with a base film and a pressure-sensitive adhesive layer laminated on at least one side of the base film, the semiconductor processing sheet being characterized in that the base film contains a vinyl chloride-based resin and an adipate ester-based plasticizer and a terephthalate ester-based plasticizer as plasticizers and the mass ratio of the content of the adipate ester-based plasticizer with reference to the total content of the adipate ester-based plasticizer and the terephthalate ester-based plasticizer in the base film is 50-80 mass%. Even while using a replacement for alkyl phthalate esters as plasticizer, this semiconductor processing sheet exhibits a satisfactory flexibility and can suppress the occurrence of residues when peeled from an adherend.

Description

Semiconductor processing sheet

The present invention relates to a semiconductor processing sheet to which a workpiece is attached when the workpiece such as a semiconductor wafer is processed.

For example, semiconductor wafers such as silicon and gallium arsenide and various packages (hereinafter, these may be collectively referred to as “workpieces”) are manufactured in a large diameter state, It is cut and separated (diced) into “chips” and individually separated (picked up), and transferred to the mounting process, which is the next process. At this time, a workpiece such as a semiconductor wafer is attached to a semiconductor processing sheet having a base film and an adhesive layer, and is subjected to dicing, cleaning, drying, expanding, pick-up, and mounting processes. The

In the above-mentioned expanding, in order to facilitate chip pickup, the semiconductor processed sheet is expanded to separate the chip interval, and after the pickup, the semiconductor processed sheet is returned to the original state. Accordingly, the semiconductor processed sheet, particularly the base film of the semiconductor processed sheet, is required to have stretchability (expandability) that can be expanded and restored. Therefore, a polyvinyl chloride film containing a plasticizer is often used as the base film (Patent Documents 1 and 2).

As a plasticizer blended with polyvinyl chloride, alkyl esters of phthalic acid, typically dioctyl phthalate (DOP) and dibutyl phthalate (DBP) are used. Soft polyvinyl chloride (PVC) films containing plasticizers such as DOP and DBP have both the rigidity of their excellent mechanical properties (PVC) and the flexibility of plasticizers, so they are widely used as substrates for semiconductor processed sheets. in use.

However, phthalic acid alkyl esters, such as DOP and DBP, are candidates for regulation under the RoHS (Restriction on Hazardous Substances) Directive in Europe, and REACH (European Parliament for the protection of human health and the environment in the European Union and Europe) In the Board Regulations), it is listed as an approved substance for SVHC (substances of very high concern). For this reason, there is a very high possibility that the use of alkyl phthalates will be restricted in the future, and search for alternative substances is being conducted.

As an alternative to alkyl phthalate, an adhesive sheet using di (2-ethylhexyl) terephthalate or adipic acid polyester as a plasticizer for a vinyl chloride base material has been proposed (Patent Documents 3 and 4).

JP 2001-207140 A JP 2010-260893 A JP 2012-184369 A Japanese Patent Laying-Open No. 2015-187245

By the way, in the semiconductor processed sheet in which the adhesive layer is provided on one side of the vinyl chloride base material, the plasticizer inside the base material moves to the inside of the adhesive layer until it is used after the sheet is manufactured. It may be taken into the agent layer. In such a case, depending on the choice of the plasticizer, when the semiconductor processed sheet is peeled from the semiconductor, the plasticizer itself remains as a residue in the semiconductor, or remains in the semiconductor as a mixture with the adhesive component (hereinafter referred to as the adhesive). These may be collectively referred to simply as “residues”).

The present invention has been made in view of the actual situation as described above, and exhibits sufficient flexibility while using a substitute material for an alkyl phthalate as a plasticizer, and a residue when peeled from an adherend. It aims at providing the semiconductor processing sheet which can suppress generation | occurrence | production of a thing.

When the terephthalic acid ester plasticizer is used as the plasticizer of the vinyl chloride base material or when the adipic acid ester plasticizer is used, the present inventors generate a residue. It has been found that when an ester plasticizer and an adipic acid ester plasticizer are used in combination at a predetermined ratio, generation of a residue is suppressed, and the present invention has been completed.

That is, first, the present invention is a semiconductor processed sheet comprising a base film and an adhesive layer laminated on at least one surface side of the base film, wherein the base film is made of vinyl chloride. Content of the adipate ester plasticizer and terephthalate ester plasticizer as the plasticizer, and in the base film, the total content of the adipate ester plasticizer and the terephthalate ester plasticizer The semiconductor processed sheet is characterized in that the mass ratio of the content of the adipic acid ester plasticizer with respect to is 50 to 80% by mass (Invention 1).

The base film of the semiconductor processed sheet according to the above invention (Invention 1) exhibits sufficient flexibility while using an alternative material of alkyl phthalate as a plasticizer. Moreover, since the base film of the semiconductor processed sheet according to the invention (Invention 1) contains an adipate ester plasticizer and a terephthalate ester plasticizer in a predetermined ratio, a semiconductor including the base film When the processed sheet is peeled from the adherend, generation of a residue is suppressed.

In the above invention (Invention 1), the 25% stress in the MD direction in the tensile test according to JIS K7161-1: 2014 of the base film is preferably 5 to 16 MPa (Invention 2).

In the above inventions (Inventions 1 and 2), the total content of the plasticizer in the base film is preferably 18 to 65 parts by mass with respect to 100 parts by mass of the vinyl chloride resin (Invention 3).

In the above inventions (Inventions 1 to 3), the adipic acid ester plasticizer preferably contains adipic acid polyester (Invention 4), and the number average molecular weight of the adipic acid polyester is preferably 400 to 1500 (Invention). 5).

In the above inventions (Inventions 1 to 5), the adipic acid ester plasticizer preferably contains an adipic acid ester monomer (Invention 6).

In the above invention (Invention 6), the adipate ester monomer is selected from the group consisting of di (2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate and di (2-butoxyethyl) adipate, or Two or more types are preferred (Invention 7).

In the above inventions (Inventions 1 to 7), the terephthalate ester plasticizer is preferably di (2-ethylhexyl) terephthalate (Invention 8).

In the processed semiconductor sheet according to the above invention (Inventions 1 to 8), the content of di (2-ethylhexyl) phthalate, dibutyl phthalate, benzylbutyl phthalate and diisobutyl phthalate in the base film is all 0. The content is preferably 001% by mass or less (Invention 9).

In the above inventions (Inventions 1 to 9), the pressure-sensitive adhesive layer is preferably formed from an energy ray-curable pressure-sensitive adhesive composition (Invention 10).

ADVANTAGE OF THE INVENTION According to this invention, the semiconductor processed sheet which shows sufficient softness | flexibility, and can suppress generation | occurrence | production of a residue when peeling from a to-be-adhered body, using the substitute material of a phthalic acid alkylester as a plasticizer. Is provided.

Hereinafter, a semiconductor processed sheet according to an embodiment of the present invention will be described.

[Base film]
The base film included in the semiconductor processed sheet according to the present embodiment includes a vinyl chloride resin, and further contains adipic acid ester plasticizer and terephthalic acid ester plasticizer as a plasticizer in a predetermined ratio. .

1. Vinyl chloride-based resin The base film used in the present embodiment includes a vinyl chloride-based resin. The vinyl chloride resin means all polymers having a repeating unit represented by —CH ₂ —CHCl—, and vinyl chloride and a polymerizable monomer such as vinyl chloride homopolymer, ethylene-vinyl chloride copolymer, etc. Copolymers, modified polymers of homopolymers such as chlorinated vinyl chloride copolymers, and chlorinated polyolefins similar in structure to vinyl chloride resins such as chlorinated polyethylene. These vinyl chloride resins may be used alone or in combination of two or more.

The lower limit of the average degree of polymerization of the vinyl chloride resin is preferably 300 or more, and more preferably 800 or more. The vinyl chloride resin preferably has an upper limit of the average degree of polymerization of 2500 or less, more preferably 2000 or less. When the average degree of polymerization is in the above range, it is excellent in moldability and processability and can be processed into a uniform thin layer film. Here, the average degree of polymerization of the vinyl chloride resin is a value measured according to JIS K6720-2: 1999.

2. Plasticizer The base film used in the present embodiment contains an adipic acid ester plasticizer and a terephthalic acid ester plasticizer, and adipic acid relative to the total content of the adipic acid ester plasticizer and the terephthalic acid ester plasticizer. The mass proportion of the ester plasticizer content is 50 to 80 mass%.

By using an adipic acid ester plasticizer and a terephthalic acid ester plasticizer as a plasticizer, it is possible to plasticize a base material mainly composed of vinyl chloride resin, and a semiconductor processed sheet using such a base film Shows good expandability. Moreover, in this embodiment, it is not necessary to use alkyl phthalate, the possibility of containing phthalic acid as an impurity is drastically reduced, and there is no concern about environmental burden and toxicity. Furthermore, as shown in the examples described later, when terephthalic acid di (2-ethylhexyl) or adipic acid polyester is used alone as a plasticizer for a vinyl chloride base material, the semiconductor processed sheet is coated on a semiconductor wafer or the like. Residues are generated when peeling from the workpiece, but by containing the adipic acid ester plasticizer and terephthalic acid ester plasticizer in the above mass ratio, the generation of such residue is suppressed. can do.

The adipic acid ester plasticizer is composed of an ester of adipic acid and alcohol. In this embodiment, an adipic acid polyester may be used as an adipic acid ester plasticizer, an adipic acid ester monomer may be used, or both may be used in combination.

In this specification, “adipic acid polyester” refers to an ester of adipic acid and a polyol. The polyol constituting the adipic acid and the polyester is preferably a dihydric alcohol. Examples of the dihydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methyl-1, 5-pentadiol, neopentyl glycol, 1,4-dihydroxymethylcyclohexane and the like. These polyols may be used individually by 1 type, or may use 2 or more types together.

As the above polyol, the lower limit of the number of carbon atoms is preferably 2 or more, and more preferably 3 or more. The upper limit is preferably 10 or less, and more preferably 8 or less.

The above-mentioned adipic acid polyester preferably has a number average molecular weight lower limit of 400 or more, more preferably 600 or more. The upper limit of the number average molecular weight of the adipic acid polyester is preferably 1500 or less, and more preferably 1200 or less. When the number average molecular weight of the adipic acid polyester is in the above range, when the energy ray-curable adhesive described later is used as the adhesive constituting the adhesive layer, the control of the adhesive force due to the irradiation of energy rays is inhibited. Therefore, the adhesive force can be sufficiently reduced, and the adherend can be more easily peeled off.

In this specification, “adipic acid ester monomer” refers to an ester of adipic acid and monoalcohol. The adipic acid ester monomer includes a monoester composed of one molecule of adipic acid and one molecule of monoalcohol, and a diester composed of one molecule of adipic acid and two molecules of monoalcohol, and a diester is preferred.

Here, the transition from the base material of the plasticizer to the adhesive layer requires a long period of time (in some cases half a month) after the production of the semiconductor processed sheet, and the adhesive force changes during this period (in this specification, this This phenomenon is called “Change in adhesive strength over time”). However, when an adipic acid ester monomer is used as a plasticizer, it is possible to suppress a decrease in adhesive strength due to a change with time. The reason for this is considered to be that the adhesive force of the pressure-sensitive adhesive layer is stabilized early because the transfer rate of the adipic acid ester monomer from the base material to the pressure-sensitive adhesive layer is fast. Moreover, the storage period until it is used after preparation of a semiconductor process sheet | seat can be shortened by the fall of the adhesive force by a time-dependent change being suppressed.

Monoalcohols constituting the adipic acid ester monomer include methanol, ethanol, propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, 2-ethylhexanol, n-nonanol, isononanol, Examples include n-decanol, isodecanol, n-dodecanol, and n-tetradecanol. The monoalcohol may be one having an ether bond in the molecule, such as 1-butoxyethanol, 2-butoxyethanol, and the like. These monoalcohols may be used alone or in combination of two or more.

As the monoalcohol, the lower limit of the carbon number is preferably 4 or more, more preferably 6 or more. The upper limit is preferably 16 or less, and more preferably 12 or less. The carbon number of the monoalcohol constituting the adipic acid ester monomer is in the above range, so that the base material is excellent in moldability and processability, and the transition speed of the adipic acid ester monomer from the base material to the adhesive layer is increased. can do.

From the above, the monoalcohol constituting the adipic acid ester monomer is preferably 2-ethylhexanol, isononanol, isodecanol and 2-butoxyethanol, and particularly preferably 2-ethylhexanol and isononanol. The adipate monomer is preferably di (2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate and di (2-butoxyethyl) adipate, and di (2-ethylhexyl) adipate and diisononyl adipate. Is particularly preferred.

When an adipic acid polyester and an adipic acid ester monomer are used in combination as an adipic acid ester plasticizer, the mass ratio of the two may be that the adipic acid ester monomer is 1 part by mass or more with respect to 20 parts by mass of the adipic acid polyester. It is preferably 2 parts by mass or more, more preferably 3 parts by mass or more. The mass ratio of the adipic acid polyester and the adipic acid ester monomer is preferably 12 parts by mass or less, more preferably 10 parts by mass or less, and more preferably 8 parts by mass or less with respect to 20 parts by mass of the adipic acid polyester. It is particularly preferred. When the mass ratio of the adipic acid polyester and the adipic acid ester monomer is within the above range, a decrease in adhesive force due to a change with time is more effectively suppressed.

The terephthalic acid ester plasticizer is composed of an ester of terephthalic acid and alcohol, preferably a diester of terephthalic acid and alcohol. Examples of alcohols constituting terephthalic acid and esters include methanol, ethanol, propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, 2-ethylhexanol, n-nonanol, isononanol, n -Decanol, n-dodecanol, n-tetradecanol and the like. These alcohols may be used individually by 1 type, or may use 2 or more types together.

The alcohol is preferably an alcohol having 6 to 12 carbon atoms, more preferably an alcohol having 8 to 10 carbon atoms, and particularly preferably 2-ethylhexanol. That is, the terephthalic acid ester plasticizer particularly preferably used in the present embodiment is di (2-ethylhexyl) terephthalate.

In the base film of the present embodiment, the lower limit of the mass ratio of the content of the adipic acid ester plasticizer to the total content of the adipic acid ester plasticizer and the terephthalic acid ester plasticizer is 50% by mass or more. Yes, it is preferably 60% by mass or more, and more preferably 70% by mass or more. Moreover, the base film of this embodiment WHEREIN: As for the mass ratio of content of the adipic acid ester plasticizer with respect to the said total content, an upper limit is 80 mass% or less, and it is preferable that it is 75 mass% or less.

When the mass ratio is smaller than 50 mass% (the content ratio of the adipic ester plasticizer is small), the plasticizer moves to the pressure-sensitive adhesive layer, so that the cohesive force of the pressure-sensitive adhesive is insufficient and the plasticizer By shifting to the adherend itself, a residue is generated on the adherend. On the other hand, when the mass ratio exceeds 80 mass% (the content ratio of the adipic acid ester plasticizer is large), the adhesive force of the adhesive layer is excessively increased when the plasticizer moves to the adhesive layer. Further, a residue is generated on the adherend, and it is difficult to peel off the adherend, which tends to cause a pickup failure.

The base film of the present embodiment is a plasticizer other than the adipic acid ester plasticizer and the terephthalic acid ester plasticizer, as long as the effects of the present embodiment are not impaired, and is not a candidate for restriction under the RoHS directive, In addition, a plasticizer that is not an approved substance of SVHC (substance of high concern) of REACH regulations may be used in combination. Examples of such plasticizers include trimellitic acid ester plasticizers such as trimellitic acid-tri-2-ethylhexyl, alicyclic ester plasticizers such as diisononylcyclohexane dicarbonate, and sebacic acid esters such as dioctyl sebacate. And plasticizers, phosphate ester plasticizers such as tricresyl phosphate; and epoxy plasticizers such as epoxidized soybean oil. When the plasticizer other than the adipic acid ester plasticizer and the terephthalic acid ester plasticizer is contained, the content is not particularly limited, for example, preferably 25% by mass or less based on the total amount of the plasticizer, More preferably, it is 15 mass% or less.

In addition, the base film of this embodiment does not exclude what contains a phthalic acid alkylester plasticizer. For example, there is a possibility that contamination of the phthalic acid alkyl ester plasticizer may occur in the manufacturing process of the base film. However, since the alkyl ester phthalate plasticizer is a candidate substance subject to the regulation of the above-mentioned RoHS directive and is an approved substance of SVHC (substance of high concern) of the REACH regulation, the base film of this embodiment is The content of alkyl ester phthalate plasticizer, particularly di (2-ethylhexyl) phthalate, dibutyl phthalate, benzylbutyl phthalate and diisobutyl phthalate, is preferably 0.001% by mass or less. It is particularly preferable that the compound is not included.

The lower limit of the total content of the plasticizer in the base film is preferably 18 parts by weight or more and 22 parts by weight or more with respect to 100 parts by weight of the vinyl chloride resin constituting the base. More preferably, it is particularly preferably 25 parts by mass or more. Further, the upper limit of the total content of the plasticizer is preferably 65 parts by mass or less, more preferably 60 parts by mass or less, and 55 parts by mass or less with respect to 100 parts by mass of the vinyl chloride resin. It is particularly preferred.

Also, the content of the plasticizer in the base film can be specified by a plasticization efficiency conversion value obtained by multiplying the specific plasticization efficiency value of each plasticizer by the respective content. Here, the plasticization efficiency value is obtained by blending 50 parts by mass of di (n-octyl) phthalate (n-DOP) as a plasticizer with respect to 100 parts by mass of a vinyl chloride homopolymer having a degree of polymerization of 1450. The composition melt-kneaded in 1 is compression molded to a thickness of 1 mm, a test piece of No. 2 dumbbell is punched from the sheet, the test piece is stretched at 20 ° C. at a speed of 200 mm / min, and the elongation becomes 100%. Is defined as a value obtained by dividing the amount of plasticizer necessary to achieve this stress by 50 parts by mass, which is the amount of n-DOP. Become. A plasticizer having a small plasticization efficiency value achieves the same stress as when 50 parts by weight of n-DOP is blended with a small blending amount, and therefore can be said to have a good plasticization efficiency.

The plasticization efficiency conversion value is defined as a value obtained by multiplying the plasticization efficiency value of each plasticizer by the content of each plasticizer, and means a value obtained by converting the content of each plasticizer into n-DOP. In the present embodiment, the total plasticization efficiency conversion value of the plasticizer is preferably 25 parts by mass or lower with respect to 100 parts by mass of the vinyl chloride resin constituting the substrate, and 28 parts by mass. More preferably, it is more preferably 30 parts by mass or more. The upper limit of the plasticizer content is preferably 50 parts by mass or less, more preferably 48 parts by mass or less, and 45 parts by mass or less with respect to 100 parts by mass of the vinyl chloride resin. It is particularly preferred.

When the total content of the plasticizer in the base film or the sum of the plasticization efficiency conversion values is in the above range, the base film is given appropriate flexibility, for example, the expandability of the semiconductor processed sheet is sufficient. On the other hand, the base material is not excessively soft, and the handleability is excellent. Moreover, when content of the plasticizer in a base material exists in the said range, the performance of the adhesive layer by a plasticizer transfering from a base material to an adhesive layer can suppress a time-dependent change.

3. Other Components in Base Film The base film used in the present embodiment may contain a resin other than the vinyl chloride resin as long as the effects of the present embodiment are not impaired. Examples of the resin other than the vinyl chloride resin include an ethylene-vinyl acetate copolymer and an ethylene-acrylic acid ester copolymer. One kind may be used alone, or two kinds may be used. You may use the above together. When the resin other than the vinyl chloride resin is contained, the content thereof is not particularly limited. For example, the content is preferably 0 to 20% by mass, more preferably 0 to 10% by mass with respect to the base film. preferable.

The base film used in the present embodiment may contain various additives such as a heat stabilizer, a stabilizing aid, a lubricant, an ultraviolet absorber, a flame retardant, an antistatic agent, and a colorant. . The content of these various additives is not particularly limited as long as it does not impair the effects of the present embodiment (particularly, suppression of generation of residue) (small amount). For example, the content is 100 parts by weight of vinyl chloride resin. On the other hand, the upper limit value can be 10 parts by mass or less, 1 part by mass or less, 0.1 part by mass or less, and further 0.05 part by mass or less. Moreover, the lower limit of content of various additives can be 0.01 mass part or more, for example.

As heat stabilizers, metal soaps such as calcium stearate, barium stearate, magnesium stearate, dibasic lead stearate; lead stabilizers such as basic lead sulfite and dibasic lead phosphite; dibutyltin dilaurate Tin stabilizers such as dibutyltin malate and dibutyltin mercaptides; calcium stabilizers; zinc stabilizers; magnesium stabilizers; barium stabilizers, and the like. Or you may use 2 or more types together.

Examples of the lubricant include fatty acid-based lubricants, fatty acid amide-based lubricants, ester-based lubricants, polyethylene wax, liquid paraffin, and the like. One kind may be used alone, or two or more kinds may be used in combination.

Examples of the ultraviolet absorber include benzophenone-based, benzotriazole-based, cyanoacrylate-based, salicylic acid ester-based, and the like. One type may be used alone, or two or more types may be used in combination.

Examples of the antistatic agent include polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene alkyl ether, glycerin fatty acid ester, sorbitan fatty acid ester and the like, one kind may be used alone, or two kinds You may use the above together.

Examples of the colorant include phthalocyanine colorants, quinacridone colorants, Hansa yellow, alizarin lake, titanium oxide, zinc white, permanent red, carbon black, etc., or one kind may be used alone, or Two or more kinds may be used in combination.

4). Physical Properties of Base Film The thickness of the base film is not particularly limited as long as a desired work can be performed on a workpiece (semiconductor wafer or the like) to which a semiconductor processed sheet is attached. Specifically, the thickness of the substrate is preferably 25 μm or more, and particularly preferably 50 μm or more. The thickness is preferably 200 μm or less, and particularly preferably 150 μm or less.

In the base film of the present embodiment, the lower limit value of 25% stress in the MD direction in the tensile test is preferably 5 MPa or more, more preferably 7 MPa or more, and particularly preferably 9 MPa or more. The upper limit of 25% stress in the MD direction is preferably 16 MPa or less, more preferably 15 MPa or less, and particularly preferably 14 MPa or less. Here, the 25% stress in the MD direction in the tensile test is a value measured in accordance with JIS K7161-1: 2014, and a specific measuring method will be shown in an example described later.

In addition, the base film of the present embodiment preferably has a lower limit of the breaking stress in a tensile test of 14 MPa or more, more preferably 18 MPa or more, and particularly preferably 22 MPa or more. The upper limit of the stress at break is preferably 48 MPa or less, more preferably 44 MPa or less, and particularly preferably 38 MPa or less. Here, the stress at break in the tensile test is a value measured according to JIS K7161-1: 2014.

In the base film of this embodiment, the 25% stress in the MD direction and the stress at break in the tensile test are in the above ranges, so that the rigidity of the base film becomes appropriate. For example, the expandability of the semiconductor processed sheet is sufficient. On the other hand, the handleability is excellent and the adherend supportability during transportation is excellent.

5. Manufacturing method of base film The base film of the present embodiment includes a vinyl chloride resin, and if it contains adipic acid ester plasticizer and terephthalic acid ester plasticizer in a predetermined mass ratio, its manufacturing The method is not particularly limited. For example, it can be obtained by mixing a vinyl chloride resin, an adipate ester plasticizer and a terephthalate ester plasticizer, preferably a stabilizer, other additives, etc., and forming the resulting mixture into a film.

The mixing of each component is generally performed by a mechanical melt kneading method using a single screw extruder, a twin screw extruder, a Henschel mixer, a Banbury mixer, various kneaders, a brabender, a calender roll, or the like. At this time, the order of adding each component is not particularly limited. The temperature for melt kneading can be suitably selected from 140 ° C. to 220 ° C. The obtained mixture is processed into a film to obtain the substrate film. The film processing may be performed by general molding processing methods such as extrusion molding, calendar molding, and inflation molding.

Further, the film forming method may be a method in which the mixture exemplified above is made into a solution or a molten state, and coating is performed by a coating means such as a calender roll.

For the purpose of improving the adhesiveness with the pressure-sensitive adhesive layer laminated on one side of the base film, the base film is optionally subjected to a surface treatment by an oxidation method, an unevenness method, or a primer treatment on one side or both sides. be able to. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, ultraviolet irradiation treatment, and the like. Examples include a thermal spraying method.

Further, the surface of the base film on which the pressure-sensitive adhesive layer is not laminated may be subjected to a peeling treatment with a release agent. Thereby, even when a semiconductor processed sheet is used as a wound body without using a release film, the feeding can be satisfactorily performed.

[Semiconductor processing sheet]
The semiconductor processed sheet which concerns on this embodiment is comprised including the said base film and the adhesive layer laminated | stacked on the at least single side | surface of the said base film. A release film may be laminated on the surface of the pressure-sensitive adhesive layer opposite to the base film. This release film is peeled off when the semiconductor processed sheet is used, and protects the adhesive layer until then.

1. Pressure-sensitive adhesive layer The semiconductor processed sheet according to the present embodiment can use the pressure-sensitive adhesive conventionally used in a semiconductor processed sheet as the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer. Especially when adding additives such as tackifiers, pick-up property improving aids, antistatic agents, etc., the balance of compatibility inside the adhesive layer is lost due to the migration of the plasticizer, resulting in changes in adhesive strength and residues. However, according to this embodiment, since the base film containing the plasticizer is used, there is no need to review the pressure-sensitive adhesive composition, and dioctyl phthalate (DOP) is contained. It is possible to replace a conventional vinyl chloride base material.

Specifically, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer may be a non-curable pressure-sensitive adhesive or a curable pressure-sensitive adhesive. Moreover, the state before hardening may be sufficient as a curable adhesive, and the state after hardening may be sufficient as it. When the pressure-sensitive adhesive layer is composed of multiple layers, a combination of a non-curable pressure-sensitive adhesive and a curable pressure-sensitive adhesive may be used. Examples of non-curable adhesives include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, polyvinyl ether adhesives, phenoxy adhesives, and acrylic urethane adhesives. An adhesive etc. are mentioned. Examples of the curable pressure-sensitive adhesive include an energy beam curable pressure-sensitive adhesive and a thermosetting pressure-sensitive adhesive. Hereinafter, the energy ray curable adhesive will be described in some detail.

(1) Energy ray-curable pressure-sensitive adhesive main agent When the pressure-sensitive adhesive layer of the present embodiment is formed of an energy ray-curable pressure-sensitive adhesive, the energy ray-curable pressure-sensitive adhesive includes an energy ray-curable monomer and / or oligomer. It may be contained, or may contain a non-energy ray curable polymer and an energy ray curable monomer and / or oligomer, or contain an energy ray curable polymer. It may be a thing containing an energy ray curable polymer and an energy ray curable monomer and / or oligomer, or an energy ray curable polymer and an energy ray non-curing agent. May contain a functional polymer and an energy ray-curable monomer and / or oligomer. Yes. Among them, it is easy to increase the adhesive strength before energy beam curing, and can increase the difference from the adhesive strength after energy beam curing, energy beam non-curable polymer, energy beam curable monomer and An energy ray-curable pressure-sensitive adhesive containing / or an oligomer is preferred. The energy ray-curable pressure-sensitive adhesive may further contain a crosslinking agent. Among the above components, the energy ray curable monomer and / or oligomer and the energy ray curable polymer correspond to the energy ray curable component.

(1-1) Non-energy ray curable polymer When the energy ray curable adhesive contains a non-energy ray curable polymer, the energy ray non-curable polymer is contained as it is in the pressure-sensitive adhesive layer. In addition, at least a part thereof may have a crosslinked structure by performing a crosslinking reaction with the crosslinking agent. Examples of the energy ray non-curable polymer include acrylic polymers, phenoxy resins, urethane resins, polyester resins, rubber resins, acrylic urethane resins, silicone resins, and the like. A polymer is preferred. Hereinafter, the case where an acrylic polymer is used will be described in detail.

A conventionally known acrylic polymer can be used as the acrylic polymer. The acrylic polymer may be a homopolymer formed from one type of acrylic monomer, may be a copolymer formed from a plurality of types of acrylic monomers, or may be one type or a plurality of types. It may be a copolymer formed from various types of acrylic monomers and monomers other than acrylic monomers. Specific types of the compound that becomes the acrylic monomer are not particularly limited, and specific examples include (meth) acrylic acid, (meth) acrylic acid ester, and derivatives thereof (acrylonitrile, itaconic acid, and the like). In the present specification, (meth) acrylic acid means both acrylic acid and methacrylic acid. The same applies to other similar terms. In addition, the concept of “copolymer” may be included in the “polymer” in this specification.

Specific examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, n-butyl (meth) acrylate, n-pentyl ( (Meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-decyl (meth) acrylate, lauryl (meth) acrylate, myristyl (meth) acrylate, palmityl (meth) (Meth) acrylates having a chain skeleton such as acrylate and stearyl (meth) acrylate; cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (me ) (Meth) acrylates having a cyclic skeleton such as acrylate, tetrahydrofurfuryl (meth) acrylate, imide acrylate; hydroxy such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl acrylate (Meth) acrylate having a group; (meth) acrylate having a reactive functional group other than a hydroxy group such as glycidyl (meth) acrylate and N-methylaminoethyl (meth) acrylate. Examples of monomers other than acrylic monomers include olefins such as ethylene and norbornene, vinyl acetate, and styrene. When the acrylic monomer is an alkyl (meth) acrylate, the alkyl group preferably has 1 to 18 carbon atoms.

When the energy ray-curable pressure-sensitive adhesive in the present embodiment contains a crosslinking agent, the acrylic polymer preferably has a reactive functional group that reacts with the crosslinking agent. The type of the reactive functional group is not particularly limited, and may be appropriately determined based on the type of the crosslinking agent.

For example, when the crosslinking agent is a polyisocyanate compound, examples of the reactive functional group that the acrylic polymer has include a hydroxy group, a carboxy group, and an amino group. Further, when the crosslinking agent is an epoxy compound, examples of the reactive functional group that the acrylic polymer has include a carboxy group, an amino group, an amide group, and the like, and when the crosslinking agent is a chelate compound, Examples of the reactive functional group possessed by the acrylic polymer include a hydroxy group, a carboxy group, and an epoxy group.

The method for introducing the reactive functional group into the acrylic polymer is not particularly limited. For example, the acrylic polymer is formed using the monomer having the reactive functional group, and the structure is based on the monomer having the reactive functional group. Examples thereof include a method in which a unit is contained in a polymer skeleton. For example, when a hydroxy group is introduced into an acrylic polymer, the acrylic polymer may be formed using a monomer having a hydroxy group such as 2-hydroxyethyl acrylate. Moreover, what is necessary is just to form an acrylic polymer using the monomer which has carboxy groups, such as acrylic acid, when introducing a carboxy group into an acrylic polymer.

When the acrylic polymer has a reactive functional group, the proportion of the mass of the structural portion derived from the monomer having a reactive functional group in the total mass of the acrylic polymer is preferably 1% by mass or more. In particular, it is preferably 2% by mass or more. In addition, the ratio is preferably 30% by mass or less, and particularly preferably 20% by mass or less. When the ratio is in the above range, the degree of crosslinking can be improved.

The acrylic polymer can be obtained by copolymerizing the above monomers by a conventional method. A random copolymer may be sufficient as the superposition | polymerization aspect of an acryl-type polymer, and a block copolymer may be sufficient as it.

The weight average molecular weight (Mw) of the acrylic polymer is preferably 10,000 or more, particularly preferably 100,000 or more. The weight average molecular weight of the acrylic polymer is preferably 2 million or less, and particularly preferably 1.5 million or less. When the weight average molecular weight is in the above range, good adhesiveness can be exhibited, and the film forming property at the time of coating can be ensured satisfactorily. The weight average molecular weight in the present specification is a standard polystyrene equivalent value measured (GPC measurement) under the following conditions using a gel permeation chromatograph (manufactured by Tosoh Corporation, product name “HLC-8020”).

<GPC measurement conditions>
Column: “TSK guard column HXL-L”, “TSK gel G2500HXL”, “TSK gel G2000HXL”, “TSK gel G1000HXL” (all manufactured by Tosoh Corporation) • Column temperature: 40 ° C.
・ Developing solvent: Tetrahydrofuran ・ Flow rate: 1.0 mL / min
・ Detector: Differential refractometer ・ Standard sample: Polystyrene

(1-2) Energy ray curable monomer and / or oligomer The energy ray curable monomer and / or oligomer (hereinafter referred to as “energy ray curable compound”) has an energy ray curable group, and is an energy ray. Is a compound that polymerizes when irradiated with the above, and has a lower molecular weight than the energy ray-curable polymer described later.

The energy ray curable group possessed by the energy ray curable compound is, for example, a group containing an energy ray curable carbon-carbon double bond, and specific examples thereof include a (meth) acryloyl group and a vinyl group. Can do.

The energy ray curable compound may be monofunctional or polyfunctional, but is preferably polyfunctional. In that case, the energy ray curable compound is preferably bifunctional or more, particularly preferably trifunctional or more, and more preferably tetrafunctional or more. Moreover, it is preferable that the said energy-beam curable compound is 15 functional or less, It is especially preferable that it is 12 functional or less, Furthermore, it is preferable that it is 10 functional or less. When the energy ray curable compound is polyfunctional as described above, it is easy to control the adhesive force due to ultraviolet curing, and poor adhesion to the substrate due to increased volume shrinkage due to curing is less likely to occur.

Specific examples of energy ray curable compounds include trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol monohydroxy. Penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol poly (meth) acrylate, or 1,4-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, di Cyclopentadiene dimethoxydi (meth) acrylate, cycloborn skeleton-containing acrylates such as isobornyl (meth) acrylate, polyethylene glycol di (meth) acrylate Over DOO, oligoester (meth) acrylate, urethane (meth) acrylate oligomer, epoxy-modified (meth) acrylate, polyether (meth) acrylate, and acrylate compounds such as itaconic acid oligomer. These can also be used individually by 1 type and can also be used in combination of 2 or more type.

The molecular weight of the energy ray curable compound is preferably 100 or more, and particularly preferably 300 or more. Moreover, it is preferable that the molecular weight of an energy-beam curable compound is 30000 or less, and it is especially preferable that it is 10,000 or less. When the molecular weight of the energy ray-curable compound is in the above range, the effect of material volatilization during coating drying can be suppressed while ensuring film forming properties.

The ratio of the energy ray curable compound to the total of 100 parts by mass of the energy ray non-curable polymer and the curable polymer is preferably 30 parts by mass or more, particularly preferably 40 parts by mass or more, It is preferably 50 parts by mass or more. The proportion is preferably 200 parts by mass or less, particularly preferably 170 parts by mass or less, and more preferably 150 parts by mass or less. When the ratio is in the above range, good adhesive strength can be exhibited before curing, and the adhesive strength can be sufficiently reduced after curing.

(1-3) Energy ray curable polymer The energy ray curable polymer is preferably a polymer having an energy ray curable group introduced therein. The polymer into which the energy ray curable group is introduced may be contained as it is in the pressure-sensitive adhesive layer, or at least a part thereof may have a crosslinked structure by performing a crosslinking reaction with a crosslinking agent.

Examples of the polymer into which the energy ray curable group has been introduced include a functional group-containing acrylic polymer having a functional group-containing monomer containing a functional group as a constituent, a substituent that reacts with the functional group, and energy rays. Examples thereof include acrylic polymers obtained by reacting a curable group-containing compound having a curable carbon-carbon double bond.

The functional group-containing acrylic polymer is preferably a copolymer of an acrylic monomer containing a functional group, an acrylic monomer not containing a functional group, and a monomer other than the acrylic monomer if desired. That is, the functional group-containing monomer is preferably an acrylic monomer containing a functional group.

As the functional group of the acrylic monomer containing a functional group (functional group of the functional group-containing monomer), one capable of reacting with a substituent of the curable group-containing compound is selected. Examples of such functional groups include a hydroxy group, a carboxy group, an amino group, a substituted amino group, and an epoxy group. In addition, when the energy ray-curable adhesive in the present embodiment contains a crosslinking agent, the functional group-containing acrylic polymer contains a functional group-containing monomer having a functional group that reacts with the crosslinking agent as a constituent component. It is preferable that the functional group-containing monomer may also serve as a functional group-containing monomer having a functional group capable of reacting with a substituent of the curable group-containing compound.

The acrylic monomer that does not contain a functional group preferably contains a (meth) acrylic acid alkyl ester monomer. Examples of (meth) acrylic acid alkyl ester monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, and (meth) acrylic acid n- Pentyl, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-decyl (meth) acrylate, lauryl (meth) acrylate, myristyl (meth) acrylate, Examples include palmityl (meth) acrylate and stearyl (meth) acrylate. Among the (meth) acrylic acid alkyl ester monomers, those having an alkyl group having 1 to 18 carbon atoms are preferred, and those having 1 to 8 carbon atoms are particularly preferred. These may be used alone or in combination of two or more.

In addition to the above (meth) acrylic acid alkyl ester monomer, acrylic monomers not containing functional groups include, for example, methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, ( Non-crosslinkable acrylamides such as (meth) acrylic acid esters containing alkenyl groups such as ethoxyethyl (meth) acrylate and aromatic rings such as phenyl (meth) acrylate, acrylamide and methacrylamide (Meth) acrylic acid ester having a non-crosslinking tertiary amino group such as N, N-dimethylaminoethyl (meth) acrylate and N, N-dimethylaminopropyl (meth) acrylate may also be included.

Examples of monomers other than acrylic monomers include olefins such as ethylene and norbornene, vinyl acetate, and styrene.

In the functional group-containing acrylic polymer, the proportion of the mass of the structural portion derived from the functional group-containing monomer in the total mass of the functional group-containing acrylic polymer is preferably 0.1% by mass or more, particularly 1 mass. % Or more, and more preferably 3% by mass or more. In addition, the proportion is preferably 50% by mass or less, particularly preferably 40% by mass or less, and further preferably 30% by mass or less. Thereby, the amount of the curable group introduced by the curable group-containing compound (and the amount of reaction with the crosslinking agent) is adjusted to a desired amount, and the degree of crosslinking of the resulting pressure-sensitive adhesive layer can be controlled within a preferable range. it can.

The functional group-containing acrylic polymer can be obtained by copolymerizing the above monomers by a conventional method. The polymerization mode of the functional group-containing acrylic polymer may be a random copolymer or a block copolymer.

The curable group-containing compound has a substituent that reacts with the functional group of the functional group-containing acrylic polymer and an energy ray-curable carbon-carbon double bond. Examples of the substituent that reacts with the functional group of the functional group-containing acrylic polymer include an isocyanate group, an epoxy group, and a carboxy group, and among them, an isocyanate group that is highly reactive with a hydroxy group is preferable.

The curable group-containing compound preferably contains 1 to 5 energy beam-curable carbon-carbon double bonds per molecule of the curable group-containing compound, and particularly preferably contains 1 to 3.

Examples of such curable group-containing compounds include 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α, α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, and 1,1- (bisacryloyloxymethyl) ethyl. Isocyanate; acryloyl monoisocyanate compound obtained by reaction of diisocyanate compound or polyisocyanate compound and hydroxyethyl (meth) acrylate; obtained by reaction of diisocyanate compound or polyisocyanate compound, polyol compound and hydroxyethyl (meth) acrylate And acryloyl monoisocyanate compounds. A sclerosing | hardenable group containing compound can also be used individually by 1 type, and can also be used in combination of 2 or more type.

The polymer into which the energy ray curable group is introduced has a curable group derived from the curable group-containing compound with respect to a functional group (functional group that reacts with a substituent of the curable group-containing compound) of the polymer. The content is preferably 20 mol% or more, particularly preferably 35 mol% or more, and more preferably 50 mol% or more. Moreover, it is preferable to contain 120 mol% or less, and it is preferable to contain especially 100 mol% or less. In addition, when a curable group containing compound is monofunctional, an upper limit will be 100 mol%, but when a curable group containing compound is polyfunctional, it may exceed 100 mol%. When the ratio of the curable group to the functional group is within the above range, the adhesiveness lowering property due to the energy ray irradiation becomes better.

The weight average molecular weight (Mw) of the polymer into which the energy beam curable group is introduced is preferably 100,000 or more, and more preferably 300,000 or more. The weight average molecular weight is preferably 2 million or less, and more preferably 1.5 million or less. When the weight average molecular weight is in the above range, good adhesiveness can be exhibited, and the film forming property at the time of coating can be ensured satisfactorily.

(1-4) Cross-linking agent As the cross-linking agent, it is possible to use a polyfunctional compound having reactivity with the above-mentioned acrylic polymer or a functional group possessed by a polymer having an energy ray curable group introduced. . Examples of such polyfunctional compounds include polyisocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts. And reactive phenol resins. These crosslinking agents may be used individually by 1 type, or may use 2 or more types together.

Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate, and the like. , And their biuret bodies, isocyanurate bodies, and adduct bodies that are a reaction product with low molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Among these, from the viewpoint of reactivity with a functional group, trimethylolpropane-modified aromatic polyisocyanate, particularly trimethylolpropane-modified tolylene diisocyanate is preferable.

The content of the crosslinking agent is preferably 0.01 equivalents or more as a lower limit with respect to the functional group in the acrylic polymer or the polymer into which the energy ray curable group is introduced, and particularly 0.02 equivalents or more. It is preferable that Moreover, it is preferable that it is 1 equivalent or less as an upper limit, and it is especially preferable that it is 0.8 equivalent or less. When the content of the crosslinking agent is within the above range, the degree of crosslinking of the obtained pressure-sensitive adhesive layer can be controlled within a preferable range.

(1-5) Other components The pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer in the present embodiment includes, in addition to the above components, a photopolymerization initiator, a coloring material such as a dye or a pigment, an antistatic agent, and tackifying. You may contain various additives, such as an agent, a flame retardant, and a filler.

Examples of photopolymerization initiators include photoinitiators such as benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, thioxanthone compounds, and peroxide compounds, and photosensitizers such as amines and quinones. 1-hydroxycyclohexyl phenyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, β-chloranthraquinone 2,4,6-trimethylbenzoyldiphenylphosphine oxide and the like. These photoinitiators may be used individually by 1 type, or may use 2 or more types together. When ultraviolet rays are used as energy rays, the irradiation time and irradiation amount can be reduced by blending a photopolymerization initiator.

(1-6) Irradiation of energy rays Examples of the energy rays for curing the energy ray-curable pressure-sensitive adhesive described above include ionizing radiation, that is, X-rays, ultraviolet rays, and electron beams. Among these, ultraviolet rays that are relatively easy to introduce irradiation equipment are preferable.

When ultraviolet rays are used as the ionizing radiation, near ultraviolet rays including ultraviolet rays having a wavelength of about 200 to 380 nm may be used for ease of handling. The amount of light may be appropriately selected according to the type of energy beam curable group and the thickness of the pressure-sensitive adhesive layer possessed by the energy beam curable compound and the energy beam curable polymer, and is usually 50 to 500 mJ / cm ^2. 100 to 450 mJ / cm ² is preferable, and 200 to 400 mJ / cm ² is more preferable. The ultraviolet illumination is usually 50 ~ 500mW / cm ² or so, preferably 100 ~ 450mW / cm ^2, more preferably 200 ~ 400mW / cm ^2. The ultraviolet light source is not particularly limited, and for example, a high pressure mercury lamp, a metal halide lamp, a UV-LED, or the like is used.

When an electron beam is used as ionizing radiation, the acceleration voltage depends on the type of energy beam curable group and the thickness of the pressure-sensitive adhesive layer possessed by the energy beam curable compound and the energy beam curable polymer described above. It may be selected appropriately, and it is usually preferable that the acceleration voltage is about 10 to 1000 kV. The irradiation dose may be set in a range where the above-mentioned energy beam curable compound and energy beam curable polymer are appropriately cured, and is usually selected in a range of 10 to 1000 rad. The electron beam source is not particularly limited. For example, various electron beam accelerators such as a cockcroft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type should be used. Can do.

(2) Thickness of the pressure-sensitive adhesive layer The lower limit value of the thickness of the pressure-sensitive adhesive layer in the present embodiment is preferably 1 μm or more, particularly preferably 2 μm or more, and more preferably 3 μm or more. . Further, the thickness of the pressure-sensitive adhesive layer in this embodiment is preferably 50 μm or less, particularly preferably 40 μm or less, and further preferably 30 μm or less. Since the thickness of the pressure-sensitive adhesive layer is in the above range, a desired adhesive force can be effectively obtained. Moreover, when the pressure-sensitive adhesive layer is formed from an energy ray-curable pressure-sensitive adhesive, the energy ray-curable pressure-sensitive adhesive is easily cured when the upper limit value of the thickness of the pressure-sensitive adhesive layer is not more than the above.

2. Peeling film A peeling film protects an adhesive layer until a semiconductor processed sheet is used, and does not necessarily need to be. The configuration of the release film is arbitrary, and examples thereof include a plastic film having peelability with respect to the pressure-sensitive adhesive layer, and a film obtained by peeling the plastic film with a release agent or the like. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, silicone-based, fluorine-based, rubber-based, long-chain alkyl-based, and the like can be used, and among these, a silicone-based material that is inexpensive and provides stable performance is preferable. The thickness of the release film is not particularly limited, but is usually about 20 to 250 μm.

3. Other Examples of Semiconductor Processing Sheet Although the semiconductor processing sheet including the base film and the pressure-sensitive adhesive layer has been described above, the present invention is not limited to these.

For example, as another embodiment, the semiconductor processed sheet is provided with a primer layer for improving the adhesion between the base film and the pressure-sensitive adhesive layer between the base film and the pressure-sensitive adhesive layer. It may be. Moreover, the semiconductor processed sheet may be provided with an intermediate layer between the base film and the pressure-sensitive adhesive layer. As an intermediate | middle layer, what has the function to provide desired elasticity and the followable | trackability with respect to the processus | protrusion of a semiconductor chip with respect to a semiconductor processing sheet is mentioned, for example. Such an intermediate layer is made of, for example, a material containing urethane acrylate or the like.

As another embodiment, the semiconductor processed sheet may be provided with an adhesive layer located in the outermost layer. The adhesive layer preferably exhibits tackiness by a trigger such as heating. Such an adhesive layer can be used, for example, as an adhesive in die bonding.

As another embodiment, the semiconductor processed sheet may be provided with a protective film forming film located in the outermost layer. The protective film-forming film can be used as a protective film for protecting the back surface of the semiconductor chip, particularly when a semiconductor device is manufactured by a mounting method called a face-down method.

4). Manufacturing method of semiconductor processing sheet The semiconductor processing sheet which concerns on this embodiment can be manufactured similarly to the conventional semiconductor processing sheet. In particular, as a method for producing a semiconductor processed sheet comprising a substrate and an adhesive layer, the detailed method is particularly limited as long as the adhesive layer formed from the above-mentioned adhesive composition can be laminated on one surface of the substrate. Not. For example, a pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer and, if desired, a coating liquid further containing a solvent or a dispersion medium are prepared, and a die coater, a curtain coater, and a spray are formed on one surface of the substrate. The pressure-sensitive adhesive layer can be formed by applying the coating solution with a coater, slit coater, knife coater or the like to form a coating film and drying the coating film. The properties of the coating liquid are not particularly limited as long as it can be applied, and may contain a component for forming the pressure-sensitive adhesive layer as a solute or a dispersoid.

Moreover, as another example of the manufacturing method of a semiconductor processed sheet, a coating liquid is formed on the release surface of the release sheet to form a coating film, which is dried to form a pressure-sensitive adhesive layer and the release sheet. The laminated body which consists of a semiconductor process sheet | seat and a peeling sheet may be formed by sticking the surface on the opposite side to the surface at the side of the peeling sheet in the adhesive layer of this laminated body. The release sheet in this laminate may be peeled off as a process material, or the adhesive layer may be protected until being attached to an adherend such as a semiconductor chip or a semiconductor wafer.

When the coating solution contains a crosslinking agent, the energy ray non-curable polymer in the coating film can be changed by changing the drying conditions (temperature, time, etc.) or by separately providing a heat treatment. What is necessary is just to advance the crosslinking reaction of an energy-beam curable polymer and a crosslinking agent, and to form a crosslinked structure with a desired density in an adhesive layer.

5. Physical Properties of Semiconductor Processed Sheet The thickness of the semiconductor processed sheet according to the present embodiment is not particularly limited, but is preferably 50 μm or more, and particularly preferably 80 μm or more. Further, the thickness is preferably 200 μm or less, and particularly preferably 160 μm or less.

When the pressure-sensitive adhesive layer is formed of an energy ray-curable pressure-sensitive adhesive, the pressure-sensitive adhesive force of the semiconductor processed sheet according to the present embodiment on the silicon mirror wafer is referred to as the pressure-sensitive adhesive force before irradiation with energy rays (hereinafter referred to as “pressure before irradiation”) Is preferably 100 mN / 25 mm or more, particularly preferably 150 mN / 25 mm or more, and more preferably 200 mN / 25 mm or more. Thereby, it is possible to suppress unintended peeling during work on the adherend to which the semiconductor processed sheet is stuck. In addition, it can exhibit good adhesion to various materials and can be applied to a wide range of adherends. On the other hand, the adhesive strength before irradiation is preferably 20000 mN / 25 mm or less as an upper limit, particularly preferably 18000 mN / 25 mm or less, and more preferably 16000 mN / 25 mm or less. Thereby, it becomes easy to reduce the adhesive force after irradiation of energy rays to a preferable range. The adhesive strength before irradiation in this specification is measured by a 180 ° peeling test in accordance with JIS Z0237: 2000 using a silicon mirror wafer as an adherend.

When the pressure-sensitive adhesive layer is formed of an energy ray-curable pressure-sensitive adhesive, the adhesive strength after energy beam irradiation (hereinafter sometimes referred to as “post-irradiation adhesive strength”) is 800 mN / 25 mm or less as an upper limit. In particular, it is preferably 600 mN / 25 mm or less, and more preferably 500 mN / 25 mm or less. Thereby, a semiconductor processing sheet can be easily peeled from an adherend. On the other hand, the lower limit value of the post-irradiation adhesive strength is not particularly limited, but is usually preferably 5 mN / 25 mm or more, particularly preferably 10 mN / 25 mm or more, and more preferably 20 mN / 25 mm or more. preferable. The post-irradiation adhesive strength in this specification is measured by a 180 ° peeling test in accordance with JIS Z0237: 2000 using a silicon mirror wafer as an adherend, and a specific measurement method is a test example described later. As shown in

The ratio (A) / (B) of the adhesive strength (A) measured after storage at 40 ° C. for 7 days and the adhesive strength (B) measured after storage at 40 ° C. for 14 days is as follows. 1.0 or more is preferable. Moreover, it is preferable that the said adhesive force ratio (A) / (B) is 1.5 or less, and it is especially preferable that it is 1.2 or less. It can be said that the semiconductor processing sheet in which the adhesive force ratio (A) / (B) is in the above range is suppressed from changing with time. In the present embodiment, by using the plasticizer, in particular, by using an adipic acid ester monomer as an adipic acid ester plasticizer, the adhesive force ratio (A) / (B) can be easily within the above range. Become. Here, the adhesive strength measured after storage at 40 ° C. for 7 days and 14 days is the adhesive strength before irradiation when the pressure-sensitive adhesive layer is formed from an energy ray-curable pressure-sensitive adhesive. The method is as shown in the test examples described later.

In the semiconductor processed sheet according to the present embodiment, the values of 25% stress in the MD direction and stress at break in the tensile test are substantially the same as those of the base film described above. The reason is that the rigidity of a layer (such as an adhesive layer) other than the base film in the semiconductor processed sheet is sufficiently small and negligible compared to the rigidity of the base film. Here, the 25% stress in the MD direction and the stress at break in the tensile test of the semiconductor processed sheet were measured by measuring the force when the semiconductor processed sheet was stretched 25% in the MD direction and at break in accordance with JIS K7161-1: 2014. And the value divided by the cross-sectional area of the base film. In the case where the pressure-sensitive adhesive layer is formed of an energy ray-curable pressure-sensitive adhesive, the value is measured before irradiation with energy rays.

Specifically, in the semiconductor processed sheet according to the present embodiment, the lower limit value of 25% stress in the MD direction in the tensile test is preferably 5 MPa or more, more preferably 7 MPa or more, and 9 MPa or more. Particularly preferred. The upper limit value of 25% stress in the MD direction is preferably 24 MPa or less, more preferably 20 MPa or less, and particularly preferably 16 MPa or less.

Further, in the semiconductor processed sheet of the present embodiment, the lower limit of the breaking stress in the tensile test is preferably 14 MPa or more, more preferably 18 MPa or more, and particularly preferably 22 MPa or more. The upper limit of the stress at break is preferably 48 MPa or less, more preferably 44 MPa or less, and particularly preferably 38 MPa or less.

The semiconductor processed sheet of the present embodiment has sufficient expandability while having 25% stress in the MD direction and stress at break in the tensile test in the above range, while having excellent handling properties and adhesion during transportation. Excellent body support.

6). Use of Semiconductor Processing Sheet The semiconductor processing sheet according to the present embodiment can be used when supporting and dicing a semiconductor wafer, and further when picking up individual semiconductor chips.

For example, the semiconductor processed sheet according to the present embodiment can be used as a dicing sheet. In this case, the semiconductor wafer can be separated into semiconductor chips by affixing the semiconductor wafer after back grinding to the semiconductor processing sheet and dicing on the semiconductor processing sheet. Thereafter, a plurality of semiconductor chips can be individually picked up from the semiconductor processing sheet.

The semiconductor processed sheet according to the present embodiment can also be used in a tip dicing method in which a dicing process is performed before grinding the back surface of a semiconductor wafer, or a stealth dicing method in which a crushed layer is provided by a laser. Here, in the case of the tip dicing method, for example, after the dicing, an adhesive sheet for back surface grinding may be attached to the wafer surface, and the semiconductor wafer processing sheet according to the present embodiment may be peeled off. On the other hand, in the case of the stealth dicing method, for example, after attaching an adhesive sheet for back surface grinding to the front surface of the semiconductor wafer, the semiconductor wafer processing sheet according to this embodiment is attached to the back surface of the semiconductor wafer, and the semiconductor wafer processing sheet After performing stealth dicing over the semiconductor wafer processing sheet, the semiconductor wafer processing sheet may be peeled off.

The semiconductor processed sheet according to the present embodiment is not used for dicing but can be used only for picking up a semiconductor chip after dicing. In this case, after moving a plurality of semiconductor chips from the dicing sheet to the semiconductor processing sheet, the semiconductor chips can be picked up from the semiconductor processing sheet. Note that the movement from the dicing sheet to the semiconductor processed sheet may be performed by transfer or may be performed by pickup.

The semiconductor processed sheet according to the present embodiment can also be used as a dicing / die bonding sheet. In this case, the semiconductor processed sheet preferably includes the adhesive layer described above, and further suppresses the transfer of the additive to the adhesive layer between the adhesive layer and the adhesive layer described above. It is preferable to provide a barrier layer for the purpose. According to the semiconductor processed sheet, at the time of dicing, the adhesive layer is simultaneously cut along with the semiconductor wafer, and the semiconductor chip to which the adhesive is attached can be obtained by picking up the separated semiconductor chip. The pressure-sensitive adhesive layer in the dicing die-bonding sheet is a pressure-sensitive adhesive that combines a pressure-sensitive adhesive for fixing an adherend such as a semiconductor wafer and a die-bonding adhesive that adheres to a semiconductor chip and has a die-bonding function. Although there exists what functions as an adhesive layer, the said adhesive layer in this embodiment does not have a function as such an adhesive layer.

The semiconductor processed sheet according to the present embodiment can also be used as a protective film forming sheet for forming a protective film on a semiconductor wafer. In this case, the semiconductor processed sheet further includes a protective film forming film on the outermost layer. According to the semiconductor processed sheet (protective film forming sheet), the protective film forming film is cut simultaneously with the semiconductor wafer during dicing. Then, by picking up the separated semiconductor chip, a semiconductor chip having a protective film on the back surface can be obtained.

7). Method for Using Semiconductor Processed Sheet As an example of a method for using the semiconductor processed sheet according to the present embodiment, a method for using the semiconductor processed sheet as a dicing sheet will be described below.

In use, the semiconductor processed sheet according to the present embodiment attaches the surface on the pressure-sensitive adhesive layer side (that is, the surface opposite to the base film of the pressure-sensitive adhesive layer) to the semiconductor wafer. When a release film is laminated on the surface of the semiconductor processing sheet on the pressure-sensitive adhesive layer side, the release film is peeled off to expose the surface on the pressure-sensitive adhesive layer side, and the surface is attached to the bonding surface of the semiconductor wafer. Can be attached. The peripheral edge of the semiconductor processed sheet is usually attached to an annular jig called a ring frame for conveyance and fixation to an apparatus by an adhesive layer provided at that portion.

Next, a dicing process is performed to obtain a plurality of chips from the semiconductor wafer. Furthermore, when the pressure-sensitive adhesive layer is formed of an energy ray-curable pressure-sensitive adhesive, energy beam irradiation is performed from the base film side of the semiconductor processed sheet after the dicing step, thereby reducing the pressure-sensitive adhesive layer.

Subsequently, in order to make it easier to pick up a plurality of chips arranged close to each other on the semiconductor processed sheet, an expanding process for extending the semiconductor processed sheet in the plane direction is performed. The degree of extension may be set as appropriate in consideration of the distance that the chips arranged in close proximity should have, the tensile strength of the base film, and the like. In addition, you may perform an expanding process before energy beam irradiation.

After the expanding process, the chip on the adhesive layer is picked up. The pickup is performed by general means such as a suction collet. At this time, in order to facilitate the pickup, it is preferable to push up the target chip from the base film side of the semiconductor processed sheet with a pin or a needle.

Since the semiconductor processed sheet according to the present embodiment exhibits sufficient flexibility while using a substitute for alkyl phthalate as a plasticizer contained in the base film, it has excellent expandability, and the chips are spaced apart in the expanding process. The chip can be easily collected. Moreover, since the base film contains the adipic acid ester plasticizer and the terephthalic acid ester plasticizer in a predetermined ratio, generation of a residue on the chip is suppressed when the chip is peeled off. The picked-up chip is used for the next process such as a transport process.

The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

Hereinafter, the present invention will be described more specifically with reference to examples and the like, but the scope of the present invention is not limited to these examples and the like.

[Example 1]
(1) Preparation of vinyl chloride resin base material 100 parts by mass of polyvinyl chloride resin (manufactured by Taiyo PVC Co., TH-1000, average degree of polymerization: 1000) (solid content conversion value; the same shall apply hereinafter) 10 parts by weight of agent A (di (2-ethylhexyl) terephthalate, manufactured by ADEKA, Adekasizer D-810, molecular weight: 391) and adipic acid polyester B1 (manufactured by ADEKA, Adekasizer PN) -7160, average molecular weight: 800, plasticization efficiency value: 1.00) 20 parts by mass and adipic acid ester monomer C (manufactured by Shin Nippon Rika Co., Ltd., Sanso Sizer DINA, molecular weight 398) and phthalocyanine blue as a colorant -Based colorant (Dainipei Seika Kogyo Co., Ltd., DA EP4610 Blue) 0.13 parts by mass and quinaclide Red colorants and (Dainichiseika Color & Chemicals Mfg. Co., Ltd., DA P4121 Red) 0.03 parts by mass, a mixture of a minor amount of magnesium-containing stabilizer as a stabilizer were kneaded in a Banbury mixer at 180 ° C.. The obtained kneaded material was rolled with a calender roll to obtain a vinyl chloride resin base material having a thickness of 80 μm.

(2) Preparation of pressure-sensitive adhesive 20 parts by mass of 2-ethylhexyl acrylate, 78 parts by mass of vinyl acetate, 1 part by mass of acrylic acid, and 1 part by mass of 2-hydroxyethyl methacrylate were copolymerized to be non-curing energy beam. As a polymer, an acrylic polymer (weight average molecular weight: 170,000, glass transition temperature Tg: 5 ° C.) was obtained.

Here, the glass transition temperature Tg of the acrylic polymer is a theoretical value calculated by the FOX equation using the Tg of the homopolymer of each constituent monomer and the mass ratio of each constituent monomer. The glass transition temperature of the coalesced is as follows.
2-ethylhexyl acrylate homopolymer: -70 ° C (203K)
Vinyl acetate homopolymer: 32 ° C (305K)
Acrylic acid homopolymer: 103 ° C. (376 K)
Hydroxyethyl methacrylate homopolymer: 55 ° C (328K)

100 parts by mass of the above acrylic polymer, 3.2 parts by mass of a composition containing trimethylolpropane-modified tolylene diisocyanate (TDI-TMP) as a crosslinking agent (manufactured by Tosoh Corporation, Coronate L), an aliphatic aromatic copolymer Polymerized petroleum resin (softening point: 86 ° C.) 7.1 parts by mass, rosin polyol (molecular weight: 2700 (liquid)) 7.1 parts by mass, 2,2-dimethoxy-1, 5.1 parts by mass of 2-diphenylethane-1-one (trade name: Irgacure 651, manufactured by BASF), bifunctional urethane acrylate (weight average molecular weight 11000) and hexafunctional urethane acrylate (weight) 63.4 parts by mass of a mixture having an average molecular weight of 1500) (mixing mass ratio of 1: 1) and solid content concentration of 37 masses with toluene Diluted to, which was used as a coating solution of the adhesive composition.

(3) Production of semiconductor processed sheet On the release-treated surface of a release film (SP-PET 381031 manufactured by Lintec Corporation), one main surface of a polyethylene terephthalate film having a thickness of 38 μm is released by a silicone-based release agent. The pressure-sensitive adhesive composition coating solution obtained in (2) is applied with a die coater and dried to form a pressure-sensitive adhesive layer having a thickness of 10 μm, thereby obtaining a laminate composed of a release film and a pressure-sensitive adhesive layer. It was. Next, one surface of the vinyl chloride resin substrate (thickness: 80 μm) obtained in (1) above is corona-treated, and the surface of the laminate on the pressure-sensitive adhesive layer side is attached to the corona-treated surface. Then, a semiconductor processed sheet comprising a vinyl chloride resin base material and an adhesive layer was obtained in a state where a release film was laminated on the surface of the adhesive layer opposite to the base material.

[Examples 2 to 4, Comparative Examples 1 to 4, Reference Example 1]
A semiconductor processed sheet was obtained in the same manner as in Example 1 except that the type and blending amount of the plasticizer were changed as shown in Table 1.

Details of the abbreviations and the like described in Table 1 are as follows.
Plasticizer A: di (2-ethylhexyl) terephthalate, manufactured by ADEKA, Adeka Sizer D-810, molecular weight: 391
Plasticizer B1: Adipic acid polyester, manufactured by ADEKA, Adekasizer PN-7160, average molecular weight: 800, plasticization efficiency value: 1.00
Plasticizer B2: Adipic acid polyester, manufactured by J. Plus, D-643, average molecular weight: 1800, plasticization efficiency value: 1.16
Plasticizer C: isononyl adipate, manufactured by Shin Nippon Rika Co., Ltd., Sansosizer DINA, molecular weight: 398

[Test Example 1] <Measurement of 25% stress of substrate>
The semiconductor processed sheets produced in the examples and comparative examples were cut into a 15 mm × 150 mm rectangle so that the MD direction was the long side direction to obtain a measurement sample. The obtained measurement sample was set in a universal tensile tester (Orientec Co., Ltd., Tensilon RTA-T-2M) so that the gap between grips was 100 mm, and in accordance with JIS K7161-1: 2014, 23 A tensile test was performed at a tensile speed of 200 mm / min in an environment with a relative humidity of 50%. The force measured at the time of 25 mm elongation was divided by the cross-sectional area of the base material of the measurement sample to calculate the 25% stress of the base material. The results are shown in Table 1.

[Test Example 2] <Measurement of adhesive strength after UV irradiation>
The semiconductor processed sheets prepared in Examples and Comparative Examples were put under accelerated conditions (40 ° C. for 14 days). Thereafter, the sheet was stored for 24 hours in an environment of 23 ° C. and 50% relative humidity, and then cut to obtain an adhesive force measurement sheet having a length of 250 mm and a width of 25 mm. The pressure-sensitive adhesive layer side of the obtained pressure-sensitive adhesive measurement sheet is attached to a mirror-finished silicon mirror wafer (diameter 6 inches, thickness 650 μm) using a 2 kg roller, and the pressure-sensitive adhesive measurement sheet and the silicon wafer A laminate comprising: The obtained laminate was stored for 20 minutes in an environment of 23 ° C. and 50% relative humidity, and then irradiated with ultraviolet rays (ultraviolet irradiation device: Adwill (registered trademark) RAD-2000 m / 12 (manufactured by Lintec), 230 mW / cm ^2. , 190 mJ / cm ² ) to cure the pressure-sensitive adhesive layer, and stored for 10 minutes in an environment of 23 ° C. and 50% relative humidity to obtain an evaluation sample.

The evaluation sample was 180 ° at a peeling speed of 300 mm / min and a peeling angle of 180 ° in accordance with JIS Z0237: 2000 using a universal tensile tester (Orientec, TENSILON / UTM-4-100). A peeling test (adhesive strength measurement sheet was used as a member to be peeled off) was performed, and the post-irradiation adhesive strength was measured (unit: mN / 25 mm). Table 1 shows the measurement results of the adhesive strength after irradiation.

[Test Example 3] <Evaluation of residue>
In the measurement of adhesive strength after irradiation carried out in Test Example 2 (acceleration condition: 40 ° C. for 14 days), the presence or absence of residue on the silicon wafer surface at the part where the adhesive strength measurement sheet was peeled was confirmed. “◯” indicates that no residue was confirmed, “Δ” indicates that the residue was slightly confirmed within a practically acceptable range, and “x” indicates that the residue was confirmed.

[Test Example 4] <Measurement of adhesive strength ratio>
About the semiconductor processed sheet produced by the Example and the comparative example, except not having performed ultraviolet irradiation, it carried out similarly to Test Example 2, and measured the adhesive force (A) before ultraviolet irradiation after 40 degreeC 14 day promotion conditions. Further, the pressure-sensitive adhesive force (B) before ultraviolet irradiation after 40 ° C. for 7 days was measured in the same manner as in Test Example 2 except that the acceleration conditions were 40 ° C. for 7 days and no ultraviolet irradiation was performed. From the obtained result, the adhesive strength ratio (A) / (B) was calculated. The results are shown in Table 1.

As can be seen from Table 1, in the semiconductor processed sheet produced in the example, the generation of residue was suppressed.

The semiconductor processed sheet according to the present invention is suitably used, for example, in a semiconductor wafer processing step, particularly in a processing step having an expanding step.

Claims (10)

1. A semiconductor processed sheet comprising a base film and an adhesive layer laminated on at least one surface side of the base film,
   The base film contains a vinyl chloride resin and an adipate ester plasticizer and a terephthalate ester plasticizer as plasticizers,
   In the base film, the mass ratio of the content of the adipic acid ester plasticizer to the total content of the adipic acid ester plasticizer and the terephthalic acid ester plasticizer is 50 to 80% by mass. Characteristic semiconductor processing sheet.
2. 2. The semiconductor processed sheet according to claim 1, wherein the 25% stress in the MD direction in the tensile test based on JIS K7161-1: 2014 of the base film is 5 to 16 MPa.
3. 3. The processed semiconductor sheet according to claim 1, wherein a total content of the plasticizer in the base film is 18 to 65 parts by mass with respect to 100 parts by mass of the vinyl chloride resin.
4. The semiconductor processed sheet according to any one of claims 1 to 3, wherein the adipic acid ester plasticizer includes adipic acid polyester.
5. The semiconductor processed sheet according to claim 4, wherein the number average molecular weight of the adipic acid polyester is 400 to 1500.
6. 6. The semiconductor processed sheet according to claim 1, wherein the adipate ester plasticizer contains an adipate ester monomer.
7. The adipate monomer may be one or more selected from the group consisting of di (2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate and di (2-butoxyethyl) adipate The semiconductor processed sheet according to claim 6.
8. The semiconductor processed sheet according to any one of claims 1 to 7, wherein the terephthalic acid ester plasticizer is di (2-ethylhexyl) terephthalate.
9. The content of di (2-ethylhexyl) phthalate, dibutyl phthalate, benzyl butyl phthalate and diisobutyl phthalate in the base film is 0.001% by mass or less. The semiconductor processed sheet according to any one of 8.
10. 10. The processed semiconductor sheet according to claim 1, wherein the pressure-sensitive adhesive layer is formed from an energy ray-curable pressure-sensitive adhesive composition.