TWI702644B - Semiconductor processing plate - Google Patents

Abstract

A semiconductor processing sheet is provided with a substrate film and an adhesive layer laminated on at least one side of the substrate film, characterized in that the substrate film contains a vinyl chloride resin as a plastic Adipate-based plasticizers and terephthalate-based plasticizers, the content of adipate-based plasticizers and terephthalate-based plasticizers in the substrate film The mass ratio of the total content of the plasticizer is 50 to 80% by mass. When such a semiconductor processing sheet is used, although a substitute for alkyl phthalate is used as a plasticizer, it can exhibit sufficient flexibility and can suppress the generation of residues when peeling from an adherend.

Description

Semiconductor processing plate

The present invention relates to a semiconductor processing sheet for attaching a processed object such as a semiconductor wafer when the processed object is processed.

For example, semiconductor wafers such as silicon and gallium arsenide and various components (hereinafter, these are collectively referred to as "processed objects") are manufactured in a large diameter state and then cut and separated ( Dicing) into small component pieces (hereinafter, referred to as "wafer"), and at the same time, peel off (pick up) each and move to the next step of assembly. At this time, the processed objects such as semiconductor wafers are subjected to the various steps of dicing, cleaning, drying, expansion, picking, and assembly in the state of being attached to the semiconductor processing sheet with the base film and the adhesive layer. .

In the above-mentioned expansion, in order to facilitate the pickup of wafers, the semiconductor processing plates are expanded to separate the wafers, and the semiconductor processing plates are restored to their original state after pickup. Therefore, the semiconductor processing sheet, especially the base film of the semiconductor processing sheet, is required to be expandable and recoverable (expandability). Therefore, as the base film, a polyvinyl chloride film containing a plasticizer is mostly used (Patent Documents 1 and 2).

As the plasticizer formulated in polyvinyl chloride, alkyl phthalate is used, typically dioctyl phthalate (DOP) and dibutyl phthalate (DBP) are used. Soft polyvinyl chloride containing plasticizers such as DOP and DBP Vinyl (PVC) films are widely used as substrates for semiconductor processing plates because they have both the rigidity of excellent mechanical properties (PVC) and the flexibility of plasticizers.

However, the alkyl phthalates of DOP and DBP are candidate substances under the control of the RoHS (Restriction on Hazardous Substances) Directive in Europe, and in REACH (European Parliament for the protection of human health and the environment in the EU). And the European Council Regulations), can be cited as SVHC (Substances of Very High Concern) approved substances. Therefore, the possibility that the use of alkyl phthalate will be restricted in the future is very high, and a search for substitute substances will be carried out.

As an alternative to alkyl phthalate, there is a proposal to disclose an adhesive sheet that uses bis(2-ethylhexyl) terephthalate and adipic acid polyester as a plasticizer for vinyl chloride-based substrates (patent Literature 3, 4).

Prior art literature Patent literature

[Patent Document 1] Japanese Patent Application Publication No. 2001-207140

[Patent Document 2] JP 2010-260893 A

[Patent Document 3] JP 2012-184369 A

[Patent Document 4] Japanese Patent Application Publication No. 2015-187245

However, for semiconductor processing plates with an adhesive layer provided on one side of a vinyl chloride-based substrate, the plasticizer inside the substrate migrates to the inside of the adhesive layer and is absorbed in the period after the plate is made to the time of use. Inside the adhesive layer situation. At this time, according to the choice of plasticizer, when the semiconductor processing sheet is peeled from the semiconductor, the plasticizer itself may remain in the semiconductor as a residue or a mixture with the adhesive component. There are cases where these are collectively referred to as "residues").

The present invention has been made in view of the above-mentioned actual situation, and its object is to provide a semiconductor processing sheet that uses alkyl phthalate substitutes as plasticizers, but can exhibit sufficient flexibility and can suppress Residues are generated when the adhesive is peeled off.

The inventors of the present invention have discovered that when terephthalate plasticizers and adipate plasticizers are used as plasticizers for vinyl chloride-based substrates, although residues are generated, the use of benzene When a diformate-based plasticizer and an adipate-based plasticizer are used in combination at a predetermined ratio, the generation of residues can be suppressed, and the present invention has been completed.

That is, the first aspect of the present invention provides a semiconductor processing sheet comprising a substrate film and an adhesive layer laminated on at least one side of the substrate film, characterized in that the substrate The film contains vinyl chloride resin, adipate plasticizer and terephthalate plasticizer as plasticizers. In the base film, the content of the adipate plasticizer is relative to the above The mass ratio of the total content of the diacid ester plasticizer and the aforementioned terephthalate plasticizer is 50 to 80% by mass (Invention 1).

The substrate film of the semiconductor processing sheet of the above-mentioned invention (Invention 1), although using an alkyl phthalate substitute as a plasticizer, exhibits sufficient flexibility. Also, because the semiconductor processing plate of the above invention (Invention 1) The material film contains adipate-based plasticizer and phthalate-based plasticizer in a predetermined ratio, so the semiconductor processing board provided with the substrate film is capable of suppressing the generation of residues when peeling from the adherend By.

In the above invention (Invention 1), the 25% stress in the MD direction of the tensile test in accordance with JIS K7161-1:2014 of the base film is preferably 5-16 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 relative 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 is preferably a polyester containing adipic acid (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 adipate plasticizer system preferably contains an adipate monomer (Invention 6).

In the above invention (Invention 6), the aforementioned adipate mono-system is selected from the group consisting of di(2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate, and adipate. One type or two or more types of bis(2-butoxyethyl) acid esters are preferred (Invention 7).

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

The above inventions (Inventions 1 to 8), in the aforementioned base film, bis(2-ethylhexyl) phthalate, dibutyl phthalate, benzylbutyl phthalate and phthalic acid The content of diisobutyl ester is preferably 0.001% by mass or less (Invention 9).

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

According to the present invention, it is possible to provide a semiconductor processing sheet that uses an alkyl phthalate substitute as a plasticizer, but exhibits sufficient flexibility and can suppress the generation of residues when peeling from an adherend.

The form used to implement the invention

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

[Base film]

The substrate film included in the semiconductor processing sheet of this embodiment contains vinyl chloride resin, and contains an adipate-based plasticizer and a terephthalate-based plasticizer as plasticizers at a predetermined ratio.

1. Vinyl chloride resin

The base film used in this embodiment contains vinyl chloride resin. The so-called vinyl chloride resin means all polymers having repeating units represented by -CH ₂ -CHCl-, including copolymers of vinyl chloride and polymerizable monomers such as homopolymers of vinyl chloride and ethylene-vinyl chloride copolymers. Chlorinated polyolefins, such as chlorinated vinyl chloride copolymers, modified homopolymers or copolymers, and chlorinated polyethylene, which is similar in structure to vinyl chloride resins. These vinyl chloride resins may be used individually by 1 type, and may use 2 or more types together.

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. In addition, the upper limit of the average degree of polymerization of the vinyl chloride resin is preferably 2500 or less, and more preferably 2000 or less. When the average degree of polymerization is in the above range, it has excellent moldability and processability and can be processed into a uniform thin film. Here, the average degree of polymerization of the vinyl chloride resin is a value measured in accordance with JIS K6720-2:1999.

2. Plasticizer

The base film used in this embodiment contains adipate plasticizers and terephthalate plasticizers, and the content of adipate plasticizers terephthalate plasticizers and terephthalate plasticizers The mass ratio of the total content of the formate-based plasticizer is 50 to 80% by mass.

By using adipate-based plasticizers and terephthalate-based plasticizers as plasticizers, substrates with vinyl chloride resins as main components can be plasticized. Semiconductor processing boards using such substrate films The film series shows good scalability. In addition, in this embodiment, since 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 impact and toxicity. Furthermore, as disclosed in the later-mentioned examples, when bis(2-ethylhexyl) terephthalate or adipic acid polyester are used alone as a plasticizer for vinyl chloride-based substrates, semiconductor processing Residues are generated when the sheet is peeled from the processed objects such as semiconductor wafers, but by containing the adipate-based plasticizer and the terephthalate-based plasticizer in the above-mentioned mass ratio, such residues can be suppressed The production.

Adipic acid ester is composed of adipic acid and alcohol ester. In this embodiment, as adipic acid ester plasticizer, adipic acid polyester can be used, and it can also be used The adipate monomer can also use the two together.

In this specification, "adipate polyester" refers to the ester of adipic acid and polyol. The polyols constituting adipic acid and polyester are preferably divalent alcohols. Examples of divalent alcohols include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 1,6- Hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,4-dimethylolcyclohexane, etc. These polyhydric alcohols can be used individually by 1 type or in combination of 2 or more types.

As the above-mentioned polyol, the lower limit of the carbon number 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 lower limit of the number average molecular weight of the adipic acid polyester is preferably 400 or more, more preferably 600 or more. In addition, 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 that constitutes the adhesive layer, it will not hinder the control of the adhesive force by irradiation of energy rays, and can make Adhesion is sufficiently reduced and the adherend can be peeled off more easily.

In this specification, "adipate monomer" refers to the ester of adipic acid and monoalcohol. In addition to the monoester composed of 1 molecule of adipic acid and 1 molecule of monoalcohol, the adipate mono-system also includes diesters composed of 1 molecule of adipic acid and 2 molecules of monoalcohol. Diesters are preferred.

Here, the plasticizer migrates from the base material to the adhesive layer. It takes a long period of time (half a month according to the situation) after the manufacture of the semiconductor processing plate, and the adhesive force changes during this period (in this specification, the system will This phenomenon is called "change in adhesion with time"). However, when an adipate monomer is used as a plasticizer, it is possible to suppress the decrease in adhesion due to changes over time. It is believed that the reason is due to The migration speed of the diacid ester monomer from the substrate to the adhesive layer is relatively fast, so that the adhesive force of the adhesive layer is stabilized early. In addition, it is possible to shorten the storage period from the manufacture of the semiconductor processing sheet to the use of the semiconductor processing sheet by suppressing the decrease in adhesive force caused by changes over time.

Examples of the monoalcohol constituting the adipate monomer include methanol, ethanol, propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, 2-ethylhexanol, n-nonane Alcohol, isononanol, n-decyl alcohol, isodecanol, n-dodecanol, n-tetradecanol, etc. In addition, as the above-mentioned monoalcohol, one having an ether bond in the molecule may be used, such as 1-butoxyethanol, 2-butoxyethanol, and the like. These monoalcohols may be used individually by 1 type, and may use 2 or more types together.

As the above-mentioned monool, the lower limit of the carbon number is preferably 4 or more, preferably 6 or more. The upper limit is preferably 16 or less, and more preferably 12 or less. When the carbon number of the monoalcohol constituting the adipate monomer is in the above range, the substrate has excellent formability and processability, and can increase the speed of the adipate monomer from the substrate to the adhesive layer. .

From the above, as the monoalcohol constituting the adipate monomer, 2-ethylhexanol, isononanol, isodecyl alcohol and 2-butoxyethanol are preferred, and 2-ethylhexanol and iso Nonanol is particularly good. In addition, as the adipate monomer, di(2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate and di(2-butoxy adipate) Ethyl ethyl) ester is preferred, and di(2-ethylhexyl) adipate and diisononyl adipate are particularly preferred.

As adipic acid ester plasticizer, when adipic acid polyester and adipic acid ester monomer are used together, the mass ratio of the two is relative to 20 parts by mass of adipic acid polyester, adipic acid ester single system 1 part by mass or more is preferable, 2 parts by mass or more Preferably, 3 parts by mass or more is particularly preferred. In addition, the mass ratio of the adipic acid polyester and the adipate monomer is relative to 20 parts by mass of the adipic acid polyester, preferably 12 parts by mass or less, preferably 10 parts by mass or less, and 8 parts by mass The following are particularly good. When the mass ratio of the adipic acid polyester and the adipic acid ester monomer is within the above-mentioned range, it is possible to more effectively suppress the decrease in adhesive force caused by changes over time.

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

As the above alcohol, an alcohol having 6 to 12 carbon atoms is preferred, an alcohol having 8 to 10 carbon atoms is more preferred, and 2-ethylhexanol is particularly preferred. That is, the terephthalate plasticizer particularly suitably used in this embodiment is bis(2-ethylhexyl) terephthalate.

In the base film of this embodiment, the lower limit of the mass ratio of the content of the adipate plasticizer relative to the total content of the adipate plasticizer and the terephthalate plasticizer is 50% by mass or more, preferably 60% by mass or more, and more preferably 70% by mass or more. In addition, in the base film of the present embodiment, the upper limit of the mass ratio of the adipate-based plasticizer content to the total content is 80% by mass or less, preferably 75% by mass or less.

When the above-mentioned mass ratio is less than 50% by mass (the content ratio of adipate-based plasticizer is small), the plasticizer migrates to the adhesive layer, the cohesive force of the adhesive is insufficient, and the plasticizer itself migrates to the adherend While being Adhesives produce residues. On the other hand, when the above-mentioned mass ratio is greater than 80% by mass (the content ratio of the adipate-based plasticizer is large), when the plasticizer migrates to the adhesive layer, the adhesive force of the adhesive layer is excessively increased and the adhesive is At the same time as residues are generated, it is not easy to peel off the adhered objects and easy to pick up defects.

The base film of this embodiment is in a range that does not impair the effect of this embodiment, and plasticizers other than adipate-based plasticizers and terephthalate-based plasticizers can also be used in combination, and are not RoHS-compliant. Candidates for control, and are not plasticizers for SVHC (Substances of Very High Concern) approved under REACH regulations. Examples of such plasticizers include trimellitic acid-based plasticizers such as trimellitic acid-tri-2-ethylhexyl, and alicyclic ester-based plasticizers such as diisononylcyclohexane dicarbonate. Sebacate plasticizers such as dioctyl sebacate; phosphate plasticizers such as tricresyl phosphate; epoxy plasticizers such as epoxidized soybean oil. When plasticizers other than adipate-based plasticizers and terephthalate-based plasticizers are contained, the content is not particularly limited. For example, relative to the total amount of plasticizer, it is preferably 25% by mass or less, and 15% by mass % Or less is better.

In addition, the base film of this embodiment does not exclude the thing containing alkyl phthalate type plasticizer. For example, it is considered that the alkyl phthalate plasticizer may cause contamination in the manufacturing step of the base film. However, because the alkyl phthalate plasticizer is a candidate substance under the control of the RoHS directive and is an approved substance of SVHC (Substances of Very High Concern) under the REACH Regulation, the base film of this embodiment is phthalate The content of alkyl formate plasticizers, especially bis(2-ethylhexyl) phthalate, dibutyl phthalate, benzylbutyl phthalate and diisobutyl phthalate Any one is preferably 0.001% by mass or less, and it is particularly preferable not to contain any compound.

With respect to 100 parts by mass of the vinyl chloride resin constituting the substrate, the lower limit of the total content of the above-mentioned plasticizer in the substrate film is preferably 18 parts by mass or more, preferably 22 parts by mass or more, and 25 Part by mass or more is particularly good. In addition, the upper limit of the total content of the plasticizer is preferably 65 parts by mass or less, preferably 60 parts by mass or less, and particularly preferably 55 parts by mass or less relative to 100 parts by mass of the vinyl chloride resin.

In addition, the content of the plasticizer in the base film can also be specified by the plasticization efficiency conversion value obtained by multiplying the inherent plasticization efficiency value of each plasticizer by the respective content. Here, the so-called plasticization efficiency value refers to the blending of 50 parts by mass of bis(n-octyl) phthalate (n-DOP) as a plasticizer based on 100 parts by mass of a vinyl chloride homopolymer with a degree of polymerization of 1450. The composition was melt-kneaded at 180°C and compression molded into a thickness of 1mm, and a No. 2 dumbbell-shaped test piece was punched from the plate, and the test piece was stretched at 20°C at a speed of 200mm/min. Elongation, and the stress at which the elongation becomes 100% is set as a reference value, and defined as the value obtained by dividing the amount of plasticizer necessary to achieve the stress by the blending amount of n-DOP, which is 50 parts by mass, and It becomes a value unique to each plasticizer. A plasticizer with a smaller plasticization efficiency value can achieve the same stress as when 50 parts by weight of n-DOP is blended with a smaller blending amount, so it can be said to be a better plasticization efficiency.

The plasticization efficiency conversion value can be 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 this embodiment, the total plasticization efficiency conversion value of the above-mentioned plasticizer is based on 100 parts by mass of the vinyl chloride resin constituting the base material, and the lower limit is preferably 25 parts by mass or more, and 28 parts by mass The amount is more than preferably, and more than 30 parts by mass is particularly preferred. In addition, the upper limit of the content of the plasticizer is preferably 50 parts by mass or less, preferably 48 parts by mass or less, and particularly preferably 45 parts by mass or less based on 100 parts by mass of the vinyl chloride resin.

When the total content of the plasticizer in the base film or the total of the above-mentioned plasticization efficiency conversion value is in the above range, the base film can be given appropriate flexibility, for example, the expandability of the semiconductor processing sheet can be made sufficient On the other hand, the substrate does not become excessively soft and has excellent operability. In addition, when the content of the plasticizer of the base material is in the above range, it is possible to suppress the change in the performance of the adhesive layer due to the migration of the plasticizer from the base material to the adhesive layer.

3. Other ingredients in the base film

The base film used in this embodiment may contain resins other than vinyl chloride resins in a range that does not impair the effects of this embodiment. As other resins other than the above-mentioned vinyl chloride resins, for example, ethylene-vinyl acetate copolymers, ethylene-acrylate copolymers, etc. may be mentioned, and one type may be used alone or two or more types may be used in combination. When a resin other than a vinyl chloride resin is contained, the content is not particularly limited. For example, relative to the base film, it is preferably 0-20% by mass, and more preferably 0-10% by mass.

In addition, the base film used in this embodiment may contain various additives such as heat stabilizers, stabilizers, lubricants, ultraviolet absorbers, flame retardants, antistatic agents, and colorants. The content of these various additives is not particularly limited as long as it does not impair the effects of this embodiment (especially the suppression of the generation of residues) (small amounts). For example, it can be higher than 100 parts by mass of the vinyl chloride resin. The limit is set to 10 parts by mass or less, 1 part by mass or less, 0.1 parts by mass Parts or less, and moreover 0.05 parts by mass or less. In addition, the lower limit of the content of various additives can be set to 0.01 parts by mass or more, for example.

Examples of heat stabilizers include metal soaps such as calcium stearate, barium stearate, magnesium stearate, and dibasic lead stearate; alkaline lead sulfite, dibasic lead phosphite, etc. Lead stabilizer; dibutyl tin dilaurate, dibutyl tin dimalate, dibutyl tin mercaptan and other tin stabilizers; calcium stabilizers; zinc stabilizers; magnesium stabilizers; barium stabilizers Agents, etc., can be used singly or in combination of two or more.

Examples of the slip agent include fatty acid-based slip agents, fatty acid amide-based slip agents, ester-based slip agents, polyethylene waxes, fluidized paraffins, etc., and may be used alone or in combination of two or more kinds.

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

Examples of antistatic agents include polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, polyoxyethylene alkyl ether, glycerin fatty acid ester, sorbitan fatty acid ester, etc. One type is used alone, or two or more types are used in combination.

Examples of colorants include phthalocyanine colorants, quinacridone colorants, Hansa Yellow, alizarin lake, titanium oxide, zinc bloom, and permanent red. (permanent red), carbon black, etc., can be used alone or in combination of two or more.

4. Physical properties of the base film, etc.

The thickness of the base film is not particularly limited as long as the workpiece (semiconductor wafer, etc.) to which the semiconductor processing board is attached can perform the required work. Specifically, the thickness of the substrate is preferably 25 μm or more, and particularly preferably 50 μm or more. In addition, the thickness is preferably 200 μm or less, and particularly preferably 150 μm or less.

In the base film of this embodiment, the lower limit of the 25% stress in the MD direction of the tensile test is preferably 5 MPa or more, preferably 7 MPa or more, and particularly preferably 9 MPa or more. In addition, the upper limit of the 25% stress in the MD direction is preferably 16 MPa or less, preferably 15 MPa or less, and particularly preferably 14 MPa or less. Here, the 25% stress in the MD direction of the tensile test is a value measured in accordance with JIS K7161-1:2014. The specific measurement method is disclosed in the following Examples.

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

In the base film of this embodiment, since the 25% stress and the breaking point stress in the MD direction of the tensile test are within the above-mentioned ranges, the rigidity of the base film becomes appropriate. For example, the expandability of the semiconductor processing sheet can be improved. The one that is sufficient, on the other hand, the one that has excellent operability and excellent support of the adherend during transportation.

5. Manufacturing method of base film

The base film of this embodiment contains vinyl chloride resin and contains adipate plasticizer and terephthalate plasticizer in a predetermined mass ratio. However, the manufacturing method is not particularly limited. For example, it can be obtained by mixing a vinyl chloride resin, an adipate-based plasticizer, and a terephthalate-based plasticizer, preferably a stabilizer, other additives, etc., and forming a film of the resulting mixture .

The mixing of the ingredients is usually done by mechanical melting and kneading, and can use single-shaft extruder, twin-shaft extruder, Henschel mixer, Banbury mixer, various kneaders, brabun Brabender mixer, calender roll, etc. At this time, the order of addition of each component is not particularly limited. In addition, the temperature of melt-kneading can be appropriately selected from 140°C to 220°C. The above-mentioned base film can be obtained by processing the obtained mixture into a film shape. The film processing can be performed by ordinary forming processing methods such as extrusion forming, roll forming, calender forming, and blow molding.

In addition, as a method of forming a film, the above-exemplified mixture may be brought into a solution or molten state, and applied by a coating means such as calender roll forming.

The above-mentioned base film is for the purpose of improving the adhesion with the adhesive layer laminated on one side. It can also be surface treated or bottomed on one or both sides by oxidation, embossing, etc., as required. Paint treatment. As the above-mentioned oxidation method, for example, corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, ultraviolet irradiation treatment, etc. can be mentioned, and as the unevenness method, for example, Sandblasting treatment method, spray treatment method, etc.

In addition, the surface of the base film on the side where the adhesive layer is not laminated may be peeled off using a release agent. Thereby, even when the semiconductor substrate sheet is made into a winding object without using a release film, it can be wound up well.

[Semiconductor processing plate]

The semiconductor processing sheet of this embodiment is constituted by the base film of the above-mentioned embodiment and an adhesive layer laminated on at least one surface of the base film. A release film may be laminated on the surface of the adhesive layer on the opposite side to the base film. The peeling film is peeled and removed when the semiconductor processing sheet is used, and protects the adhesive layer before that.

1. Adhesive layer

In the semiconductor processing sheet of this embodiment, as the adhesive constituting the adhesive layer, it is possible to use the adhesive conventionally used in the semiconductor processing sheet. In particular, when adding additives such as adhesion imparting agents, pick-up enhancement aids, antistatic agents, etc., due to the migration of the plasticizer, the balance of compatibility in the adhesive layer is collapsed, and adhesion changes and residues are likely to occur. According to this embodiment, since the base film containing the above-mentioned plasticizer is used, there is no need to reconsider the composition of the adhesive, and the previous vinyl chloride base containing dioctyl phthalate (DOP) can be replaced.

Specifically, the adhesive constituting the adhesive layer may be a non-curing adhesive or a curable adhesive. In addition, the curable adhesive may be in the state before or after curing. When the adhesive layer is composed of multiple layers, it may be a combination of a non-hardening adhesive and a hardening adhesive. Examples of non-curing adhesives include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, and polyvinyl ether adhesives. , Phenoxy-based adhesives, acrylic urethane-based adhesives, etc. Examples of curable adhesives include energy ray curable adhesives and thermosetting adhesives. Below, the energy line is explained in a little detail Hardening adhesive

(1) Energy ray hardening adhesive main agent

When the adhesive layer of this embodiment is formed of an energy-ray-curable adhesive, such an energy-ray-curable adhesive may contain energy-ray-curable monomers and/or oligomers, or may contain Energy-ray non-curable polymers, energy-ray-curable monomers and/or oligomers may contain energy-ray-curable polymers, energy-ray-curable polymers, energy-ray-curable monomers The substance and/or oligomer may contain an energy ray curable polymer, an energy ray non-curable polymer, an energy ray curable monomer and/or an oligomer. In particular, energy-ray curable adhesives containing energy-ray non-curable polymers, energy-ray-curable monomers and/or oligomers are preferred, which easily increase the adhesive force before energy-ray curing and can increase the Poor adhesion after hardening of the energy line. The energy ray curable adhesive may further contain a crosslinking agent. In addition, among the above-mentioned components, energy-ray-curable monomers and/or oligomers, and energy-beam-curable polymers correspond to energy-beam-curable components.

(1-1) Energy ray non-curable polymer

When the energy-ray curable adhesive contains an energy-ray non-curable polymer, the energy-ray non-curable polymer may be directly contained in the adhesive layer, and at least a part of it may undergo crosslinking reaction with the crosslinking agent to have crosslinking Joint structure. Examples of the energy-ray non-curable polymer include acrylic polymers, phenoxy resins, urethane resins, polyester resins, rubber resins, acrylic urethane resins, silicone resins, etc. Especially the acrylic polymer which is easy to control the adhesive force is preferred. Hereinafter, the case of using an acrylic polymer is explained in detail.

As acrylic polymer, previously known propylene can be used Acid-based polymer. The acrylic polymer may be a homopolymer formed from one type of acrylic monomer, or a copolymer formed from plural types of acrylic monomers, or may be composed of one type or plural types of acrylic monomers. A copolymer formed by monomers and monomers other than acrylic monomers. The specific type of the compound used as the acrylic monomer is not particularly limited, and specific examples include (meth)acrylic acid, (meth)acrylate, and derivatives thereof (acrylonitrile, itaconic acid, etc.). In addition, in this specification, the term “(meth)acrylic acid” means both acrylic acid and methacrylic acid. The same goes for other similar terms. In addition, the "polymer" in this specification may also include the concept of "copolymer".

When further revealing specific examples of (meth)acrylate, 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, (meth) N-decyl acrylate, lauryl (meth)acrylate, myristyl (meth)acrylate, palmetyl (meth)acrylate, stearate (meth)acrylate and other (meth)acrylic acids with a chain skeleton Esters; cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, acrylate (Meth) acrylates with cyclic skeletons such as imine esters; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl acrylate, etc. (Meth)acrylates; (meth)acrylates having reactive functional groups other than hydroxyl groups, such as glycidyl (meth)acrylate and N-methylaminoethyl (meth)acrylate. In addition, examples of monomers other than acrylic monomers include olefins such as ethylene and norbornene, vinyl acetate, and styrene. In addition, when the acrylic monomer is an alkyl (meth)acrylate, The carbon number of the alkyl group is preferably in the range of 1-18.

When the energy-ray curable adhesive system of this embodiment contains a crosslinking agent, the acrylic polymer system 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 crosslinking agent and the like.

For example, when the crosslinking agent is a polyisocyanate compound, examples of the reactive functional group possessed by the acrylic polymer include a hydroxyl group, a carboxyl group, and an amino group. In addition, when the crosslinking agent is an epoxy compound, examples of the reactive functional group possessed by the acrylic polymer include a carboxyl group, an amino group, and an amide group. When the crosslinking agent is a clamping compound, it is used as an acrylic polymer Examples of the reactive functional group possessed by the substance include a hydroxyl group, a carboxyl group, and an epoxy group.

The method of introducing the reactive functional group into the acrylic polymer is not particularly limited. As an example, a monomer having a reactive functional group is used to form an acrylic polymer, and the polymer backbone contains The method of the structural unit of the monomer of the functional group. For example, when introducing a hydroxyl group into an acrylic polymer, a monomer having a hydroxyl group such as 2-hydroxyethyl acrylate may be used to form an acrylic polymer. In addition, when introducing a carboxyl group into an acrylic polymer, a monomer having a carboxyl group such as acrylic acid may be used to form an acrylic polymer.

When the acrylic polymer has a reactive functional group, the mass ratio of the structural part derived from the monomer having the reactive functional group occupied by the total mass of the acrylic polymer is preferably 1% by mass or more. 2% by mass or more is particularly preferred. In addition, the ratio is preferably 30% by mass or less, and particularly preferably 20% by mass or less. With the above ratio in the above range, crosslinking can be achieved The degree becomes good.

The acrylic polymer can be obtained by copolymerizing each of the above-mentioned monomers using a common method. The polymerization state of the acrylic polymer may be a random copolymer or a block copolymer.

The weight average molecular weight (Mw) of the acrylic polymer is preferably 10,000 or more, and particularly preferably 100,000 or more. In addition, 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 above-mentioned weight average molecular weight is in the above-mentioned range, it is possible to ensure good film forming properties during coating while exhibiting good adhesiveness. In addition, the weight average molecular weight in this specification is based on a standard polystyrene conversion measured (GPC measurement) using a gel permeation chromatograph device (manufactured by TOSOH Co., Ltd., product name "HLC-8020") and measured under the following conditions (GPC measurement) value.

<GPC measurement conditions>

. Column: "TSK guard column HXL-L", "TSK gel G2500HXL", "TSK gel G2000HXL", "TSK gel G1000HXL" (any of them are manufactured by TOSOH Corporation) are connected in sequence

. Column temperature: 40℃

. Developing solvent: tetrahydrofuran

. Flow rate: 1.0mL/min

. Detector: differential refractometer

. Standard sample: polystyrene

(1-2) Energy ray hardenable monomer and/or oligomer

Energy-ray-curable monomers and/or oligomers (hereinafter referred to as "energy-ray-curable compounds") that have energy-ray-curable groups and are irradiated with energy rays A compound that is polymerized and has a molecular weight lower than that of the energy-ray curable polymer described later.

The energy-beam-curable group possessed by the energy-beam-curable compound is, for example, a group containing an energy-beam-curable carbon-carbon double bond. Specifically, (meth)acryloyl and vinyl groups can be exemplified.

The energy ray curable compound may be monofunctional or polyfunctional, preferably polyfunctional. In this case, the energy-beam curable compound is preferably bifunctional or higher, particularly preferably trifunctional or higher, and more preferably tetrafunctional or higher. In addition, the energy ray curable compound preferably has 15 functions or less, particularly preferably 12 functions or less, and particularly preferably 10 functions or less. When the energy ray curable compound is polyfunctional as described above, it is easy to control the adhesive force by ultraviolet curing, and it is not easy to cause poor adhesion to the substrate due to increased volume shrinkage.

Specific examples of the energy ray curable compound include trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, and neopentylerythritol tri(meth)acrylate , Neopentaerythritol tetra (meth) acrylate, Dineopentaerythritol monohydroxy penta (meth) acrylate, Dineopentaerythritol hexa (meth) acrylate, Dineopentaerythritol poly (meth) ) Acrylate, or 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, dicyclopentadiene dimethoxydi(meth)acrylic acid Cyclic aliphatic skeleton-containing acrylates such as esters, isobornyl (meth)acrylate, polyethylene glycol di(meth)acrylate, oligopolyester (meth)acrylate, urethane (meth) ) Acrylate compounds such as acrylate oligomers, epoxy-modified (meth)acrylates, polyether (meth)acrylates, and itaconic acid oligomers. These can be used individually by 1 type, and can also be used in combination of 2 or more types.

The molecular weight of the energy ray curable compound is preferably 100 or more, particularly preferably 300 or more. In addition, the molecular weight of the energy ray curable compound is preferably 30,000 or less, and particularly preferably 10,000 or less. When the molecular weight of the energy ray curable compound is in the above range, it is possible to suppress the influence of material volatilization during coating and drying while ensuring film forming properties.

The ratio of the energy ray curable compound relative 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, and 50 parts by mass The above is better. In addition, the ratio is preferably 200 parts by mass or less, particularly preferably 170 parts by mass or less, and particularly preferably 150 parts by mass or less. When the above ratio is in the above range, a good adhesive force can be exerted before curing, and after curing, the adhesive force can be sufficiently reduced.

(1-3) Energy ray curable polymer

The energy-ray curable polymer is preferably a polymer formed by introducing energy-ray curable groups. The polymer into which the energy ray curable group is introduced may be directly contained in the adhesive layer, and at least a part thereof may undergo a crosslinking reaction with a crosslinking agent to have a crosslinked structure.

Examples of polymers in which energy-ray curable groups are introduced include functional group-containing acrylic polymers that can be contained by using functional group-containing monomers as monomer units as monomer units, and those having and An acrylic polymer obtained by reacting the functional group-reacted substituent and the curable group-containing compound of the energy-beam curable carbon-carbon double bond.

The functional group-containing acrylic polymer is based on the functional group-containing acrylic monomer, and the functional group-free acrylic monomer, and as required It is preferable to copolymerize monomers other than acrylic monomers. That is, the above-mentioned functional group-containing single system is preferably a functional group-containing acrylic monomer.

As the functional group of the functional group-containing acrylic monomer (functional group of the functional group-containing monomer), one that can react with the substituent of the curable group-containing compound is selected. As such a functional group, a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, an epoxy group, etc. are mentioned, for example. In addition, when the energy-ray curable adhesive of this embodiment contains a crosslinking agent, the functional group-containing acrylic polymer is composed of a functional group-containing monomer having a functional group that reacts with the crosslinking agent It is preferable to contain it as a component, and the functional group-containing monomer may also serve as a functional group-containing monomer having a functional group capable of reacting with the substituent of the curable group-containing compound.

The acrylic monomer which does not contain a functional group is preferably an alkyl (meth)acrylate monomer. Examples of alkyl (meth)acrylate monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, Base) n-pentyl acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-decyl (meth)acrylate, (meth)acrylic acid Lauryl ester, myristyl (meth)acrylate, palmityl (meth)acrylate, stearate (meth)acrylate, etc. Among the alkyl (meth)acrylate monomers, the carbon number of the alkyl group is preferably 1 to 18, and the carbon number is particularly preferably 1 to 8. These may be used individually by 1 type, and may be used in combination of 2 or more types.

Acrylic monomers that do not contain functional groups, in addition to the above alkyl (meth)acrylate monomers, for example, methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, (Meth) ethoxy methyl acrylate, (meth) ethoxy ethyl acrylate and other (meth) acrylates containing alkoxy alkyl groups, (meth) (Meth)acrylates with aromatic rings such as phenyl acrylate, non-crosslinkable acrylamides such as acrylamide, methacrylamide, and (meth)acrylic acid N,N-dimethylaminoethyl (Meth)acrylates having non-crosslinkable tertiary amino groups such as N,N-dimethylaminopropyl (meth)acrylate and the like.

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 mass ratio of the structural part derived from the functional group-containing monomer to the total mass of the functional group-containing acrylic polymer is preferably 0.1% by mass or more. 1% by mass or more is particularly preferable, and 3% by mass or more is more preferable. In addition, the ratio is preferably 50% by mass or less, particularly preferably 40% by mass or less, and more preferably 30% by mass or less. Thereby, the introduction amount of the curable group of the curable group-containing compound (and the amount of reaction with the crosslinking agent) can be adjusted to the required amount, and the degree of crosslinking of the resulting adhesive layer can be controlled In the preferred range.

The functional group-containing acrylic polymer can be obtained by copolymerizing the above-mentioned monomers by a common method. The polymerization state 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 carboxyl group. In particular, an isocyanate group having relatively high reactivity with a hydroxyl group is preferable.

The compound containing a sclerosing group preferably contains 1 to 5 energy ray-curable carbon-carbon double bonds per molecule of the compound containing the sclerosing group. It is better to contain 1~3.

As such a curable group-containing compound, for example, 2-methacryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, alkene Propyl isocyanate, 1,1-(bisacryloxymethyl) ethyl isocyanate; acryl monoisocyanate obtained by reaction of diisocyanate compound or polyisocyanate compound with hydroxyethyl (meth)acrylate Compound; Acrylic monoisocyanate compound obtained by the reaction of diisocyanate compound or polyisocyanate compound and polyol compound with hydroxyethyl (meth)acrylate. The curable group-containing compound can be used individually by 1 type, and can also be used in combination of 2 or more types.

The energy-ray-curable group-introduced polymer is derived from the curable group of the curable group-containing compound relative to the functional group of the polymer (functional group that reacts with the substituent of the curable group-containing compound), It is preferably more than 20 mol%, particularly preferably more than 35 mol%, and more preferably more than 50 mol%. Moreover, it is preferable to contain 120 mol% or less, and it is especially preferable to contain 100 mol% or less. In addition, when the curable group-containing compound is monofunctional, the upper limit is 100 mol%, but when the curable group-containing compound is polyfunctional, it may be more than 100 mol%. When the ratio of the curable group to the above-mentioned functional group is within the above-mentioned range, the adhesive force reduction property obtained by the irradiation of energy rays becomes good.

The weight average molecular weight (Mw) of the polymer into which the energy-ray curable group is introduced is preferably 100,000 or more, and more preferably 300,000 or more. In addition, the weight average molecular weight is preferably 2 million or less, and particularly preferably 1.5 million or less. Since the above weight average molecular weight is in the above range, the At the same time, it is possible to ensure good film-forming properties during coating.

(1-4) Crosslinking agent

唑啉化合物、金屬烷氧化物化合物、金屬鉗合物化合物、金屬鹽、銨鹽、反應性酚樹脂等。該等交聯劑可單獨使用1種，亦可併用2種以上。 As the crosslinking agent, a polyfunctional compound having reactivity with the functional group of the aforementioned acrylic polymer and the polymer obtained by introducing the energy ray curable group can be used. Examples of such polyfunctional compounds include polyisocyanate compounds, epoxy compounds, amine compounds, melamine compounds, acrylcyclopropane compounds, hydrazine compounds, aldehyde compounds,

Oxazoline compounds, metal alkoxide compounds, metal clamp compounds, metal salts, ammonium salts, reactive phenol resins, etc. These crosslinking agents may be used individually by 1 type, and may use 2 or more types together.

Examples of the polyisocyanate compound include aromatic polyisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, and xylyl diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, and isophorone diisocyanate. Alicyclic polyisocyanates such as isocyanate, hydrogenated diphenylmethane diisocyanate, etc., and these biuret bodies, trimeric isocyanate bodies, and further with ethylene glycol, propylene glycol, neopentyl glycol, and trimethylolpropane , Castor oil and other low-molecular-weight active hydrogen-containing compounds, that is, adducts, etc. In particular, from the viewpoint of reactivity with functional groups, trimethylolpropane-modified aromatic polyisocyanate, particularly trimethylolpropane-modified toluene diisocyanate is preferred.

The lower limit of the content of the crosslinking agent is preferably 0.01 equivalent or more, and particularly preferably 0.02 equivalent or more with respect to the functional group of the acrylic polymer or the polymer into which the energy ray curable group is introduced. In addition, the upper limit is preferably 1 equivalent or less, and particularly preferably 0.8 equivalent or less. When the content of the crosslinking agent is in the above range, the degree of crosslinking of the resulting adhesive layer can be controlled in a preferable range.

(1-5) Other ingredients

In this embodiment, in addition to the above-mentioned components, the adhesive composition system forming the adhesive layer may also contain coloring materials such as photopolymerization initiators, dyes, and pigments, antistatic agents, adhesion imparting agents, flame retardants, and fillers. And other additives.

Examples of the photopolymerization initiator include photoinitiators such as benzoin compounds, acetophenone compounds, phosphine oxide compounds, titanocene compounds, thioxanthone compounds, and peroxide compounds. Photosensitizers such as amines, benzoquinones, etc., specifically, 1-hydroxycyclohexyl phenyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl Diphenyl sulfide, tetramethylthiuram monosulfide, azobisbutyronitrile, dibenzyl, diacetin, β-chloroanthraquinone, 2,4,6-trimethylbenzyl Diphenyl phosphine oxide, etc. These photopolymerization initiators may be used individually by 1 type, and may use 2 or more types together. When ultraviolet rays are used as energy rays, by preparing a photopolymerization initiator, the irradiation time and amount can be reduced.

(1-6) Irradiation of energy rays

Examples of the energy rays used to harden the aforementioned energy ray curable adhesive include ionizing radiation, that is, X-rays, ultraviolet rays, and electron rays. Among them, the ultraviolet rays that are easier to introduce into the irradiation equipment are better.

When using ultraviolet rays as ionizing radiation, in terms of ease of handling, it is sufficient to use near ultraviolet rays containing ultraviolet rays with a wavelength of about 200 to 380 nm. As far as the light quantity is concerned, it can be appropriately selected according to the type of energy ray curable group possessed by the aforementioned energy ray curable compound and energy ray curable polymer and the thickness of the adhesive layer, usually around 50~500mJ/cm ² , 100~450mJ/cm ^{2 is} better, 200~400mJ/cm ² is better. Further, the intensity of ultraviolet lines are usually 50 ~ 500mW / cm ² or so, to 100 ~ 450mW / cm ² preferably, to 200 ~ 400mW / cm ² is preferred. The ultraviolet source is not particularly limited, and for example, high-pressure mercury lamps, metal halide lamps, UV-LEDs, etc. can be used.

When electron beams are used as ionizing radiation, the accelerating voltage can be appropriately selected according to the type of energy-ray-curable group and the thickness of the adhesive layer of the aforementioned energy-ray-curable compound and energy-ray-curable polymer. , Usually the acceleration voltage is around 10~1000kV. In addition, the irradiation dose may be set in a range where the aforementioned energy ray curable compound and energy ray curable polymer are appropriately cured, and it is usually selected in the range of 10 to 1000 krad. The electron beam source is not particularly limited. For example, Cockroft-Walton type, Van de Graaff type, resonance transformer type, insulated core transformer type, or Various electron beam accelerators such as linear type, high-frequency high-voltage electron accelerator (dynamitron) type, and high-frequency type.

(2) The thickness of the adhesive layer

The lower limit of the thickness of the adhesive layer in this embodiment is preferably 1 μm or more, particularly preferably 2 μm or more, and more preferably 3 μm or more. In addition, the thickness of the adhesive layer in this embodiment is preferably 50 μm or less, particularly preferably 40 μm or less, and more preferably 30 μm or less. When the thickness of the adhesive layer is in the above range, the required adhesive force can be effectively obtained. In addition, when the adhesive layer is formed of an energy ray curable adhesive, when the upper limit of the thickness of the adhesive layer is equal to or less than the above, the energy ray curable adhesive is likely to be hardened.

2. Peel off the film

The release film is used to protect the adhesive layer and may not be necessary until the semiconductor processing sheet is used. The structure of the release film is arbitrary, and examples of the film itself are plastic films that have releasability from the adhesive layer, and plastic films that use a release agent, etc. It is made by peeling off the film. Specific examples of plastic films include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyamides such as polypropylene and polyethylene. Olefin film. As the release agent, silicone-based, fluorine-based, rubber-based, long-chain alkyl-based, etc. can be used. Among these, silicone-based products that are inexpensive and can obtain stable performance are preferred. The thickness of the release film is not particularly limited, but it is usually about 20 to 250 μm.

3. Other examples of semiconductor processing plates

Above, the semiconductor processing sheet provided with the base film and the adhesive layer has been described, but the present invention is not limited to these.

For example, as another embodiment, a semiconductor processing sheet may be provided with a primer layer or the like between the base film and the adhesive layer to improve the adhesion between the base film and the adhesive layer. In addition, the semiconductor processing sheet may have an intermediate layer between the base film and the adhesive layer. As the intermediate layer, for example, a function of imparting required elasticity to the semiconductor processing sheet and followability to the protrusion of the semiconductor wafer can be cited. Such an intermediate layer can be made of a material containing urethane acrylate or the like, for example.

In addition, as another embodiment, the semiconductor processing sheet may be provided with an adhesive layer located at the outermost layer. The adhesive layer preferably exhibits adhesion by triggering action such as heating. Such an adhesive layer can be used, for example, as an adhesive for die bonding.

In addition, as another embodiment, the semiconductor processing sheet may be provided with a protective film forming film located in the outermost layer. The protective film formation film can be used as a protective film for protecting the back surface of a semiconductor chip, especially when manufacturing a semiconductor device by a packaging method called a face-down method.

4. Manufacturing method of semiconductor processing plate

The semiconductor processing sheet of this embodiment can be manufactured in the same manner as the conventional semiconductor processing sheet. Especially as a method of manufacturing a semiconductor processing sheet composed of a substrate and an adhesive layer, as long as the adhesive layer formed of the aforementioned adhesive composition can be laminated on one side of the substrate, there is no detailed method. Specially limited. To give an example, a die coater, curtain coater, spray coating can be used by preparing a coating solution containing an adhesive composition that constitutes the adhesive layer, and if necessary, a solvent or dispersion medium. The coating liquid is applied to one surface of the substrate by a squeegee, a slit coater, a knife coater, etc., to form a coating film, and an adhesive layer is formed by drying the coating film. The properties of the coating liquid are not particularly limited as long as it can be applied. The components used to form the adhesive layer may be contained as a solute or as a disperse.

In addition, as another example of the method of manufacturing a semiconductor processing sheet, a coating liquid is applied to the peeling surface of the aforementioned release sheet to form a coating film, which is dried to form an adhesive layer and a release sheet. In the laminate, the surface of the adhesive layer of the laminate on the opposite side to the surface on the release sheet side is attached to the base material to obtain a laminate of the semiconductor processing sheet and the release sheet. The peeling sheet of the laminate can be set as a process material and peeled off, and it can also protect the adhesive layer until it is attached to an adherend such as a semiconductor wafer or a semiconductor wafer.

When the coating liquid contains a cross-linking agent, change the above-mentioned drying conditions (temperature, time, etc.), or heat treatment separately, to make the energy ray non-curable polymer or energy ray curable polymer in the coating film The material and the cross-linking agent undergo cross-linking reaction, and the cross-linked structure is formed in the adhesive layer with the required density. can.

5. Physical properties of semiconductor processing plates

The thickness of the semiconductor processing sheet of the present embodiment is not particularly limited, but is preferably 50 μm or more, and particularly preferably 80 μm or more. In addition, the thickness is preferably 200 μm or less, and particularly preferably 160 μm or less.

The adhesive force of the semiconductor processing plate to the mirror silicon wafer of this embodiment. When the adhesive layer is formed of an energy ray curable adhesive, the adhesive force before energy ray irradiation (hereinafter referred to as "adhesion before irradiation") The lower limit of the case) is preferably 100mN/25mm or more, particularly preferably 150mN/25mm or more, and more preferably 200mN/25mm or more. As a result, it is possible to prevent unplanned peeling during the operation of the adherend to which the semiconductor processing plate is attached. 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 upper limit of the adhesion force before irradiation is preferably 20,000 mN/25mm or less, preferably 18,000 mN/25mm or less, and more preferably 16,000 mN/25mm or less. Thereby, the adhesive force after the irradiation of the energy ray can be easily reduced to a preferable range. In addition, the adhesion force before irradiation in this specification is measured by setting the mirror-surface silicon wafer as the adherend and measuring it in accordance with the 180° peeling test of JIS Z0237:2000.

In addition, when the adhesive layer is formed of an energy ray curable adhesive, the adhesive force after energy ray irradiation (hereinafter referred to as "adhesive force after irradiation"), the upper limit is 800mN/25mm or less Best, 600mN/25mm or less is particularly preferred, and 500mN/25mm or less is more preferred. Thereby, the adherend can be easily peeled from the semiconductor processing sheet. On the other hand, the lower limit of the adhesive force after irradiation is not particularly limited, and it is usually 5mN/25mm or more. 10mN/25mm or more is particularly preferable, and 20mN/25mm or more is more preferable. In addition, the adhesion force after irradiation in this specification is the value measured in accordance with the 180° peel test of JIS Z0237:2000 with a mirror surface silicon wafer as the adherend. The specific measurement method is the test example described later Revealed.

The semiconductor processing plate of this embodiment is the ratio (A)/(B) of the adhesive force (A) measured after storage at 40°C for 7 days to the adhesive force (B) measured after storage at 40°C for 14 days , Is preferably 1.0 or more. In addition, the adhesive force ratio (A)/(B) is preferably 1.5 or less, and particularly preferably 1.2 or less. The above-mentioned adhesive force ratio (A)/(B) is a semiconductor processing sheet in the above-mentioned range, which can suppress changes over time. In the present embodiment, when the above-mentioned plasticizer is used, particularly by using an adipate monomer as the adipate-based plasticizer, the above-mentioned adhesive force ratio (A)/(B) can be easily brought into the above-mentioned range. Here, the so-called adhesive force measured after storage at 40°C for 7 days and 14 days is the adhesive force before irradiation when the adhesive layer is formed of an energy-ray curable adhesive. The specific measurement method is as described later The test example revealed.

In the semiconductor processing sheet of this embodiment, the values of the 25% stress and the stress at the breaking point in the MD direction of the tensile test are substantially the same as the values of the aforementioned base film. The reason is that the rigidity of the layers (adhesive layer, etc.) other than the base film of the semiconductor processing sheet is sufficiently small compared to the rigidity of the base film and can be ignored. Here, the 25% stress and the stress at the breaking point in the MD direction of the tensile test of the semiconductor processing sheet are measured according to JIS K7161-1:2014 when the semiconductor processing sheet is stretched and broken at 25% in the MD direction , And divided by the cross-sectional area of the base film. In addition, when the adhesive layer is formed of an energy ray curable adhesive, it is set to the value measured before the energy ray is irradiated.

Specifically, the semiconductor processing plate of this embodiment is The lower limit of the 25% stress in the MD direction of the tensile test is preferably 5 MPa or more, preferably 7 MPa or more, and particularly preferably 9 MPa or more. In addition, the upper limit of the 25% stress in the MD direction is preferably 24 MPa or less, preferably 20 MPa or less, and particularly preferably 16 MPa or less

In addition, in the semiconductor processing sheet of the present embodiment, the lower limit of the stress at the breaking point in the tensile test is preferably 14 MPa or more, more preferably 18 MPa or more, and particularly preferably 22 MPa or more. In addition, the upper limit of the stress at the breaking point is preferably 48 MPa or less, preferably 44 MPa or less, and particularly preferably 38 MPa or less.

The semiconductor processing sheet of the present embodiment has the 25% stress and the breaking point stress in the MD direction of the tensile test within the above-mentioned range, and has sufficient expandability. On the other hand, it has excellent operability and is transportable. Those with excellent support for adherends.

6. The use of semiconductor processing plates

The semiconductor processing sheet of this embodiment can be used for supporting semiconductor wafers, dicing, and picking up individualized semiconductor wafers.

For example, the semiconductor processing sheet of this embodiment can be used as a dicing sheet. At this time, by attaching the semiconductor wafer after the back surface grinding to the semiconductor processing plate, and dicing on the semiconductor processing plate, the semiconductor wafers can be divided into semiconductor wafers. Subsequently, a plurality of semiconductor wafers can be picked up individually from the semiconductor processing plate.

In addition, the semiconductor processing plate of the present embodiment can also be used in a dicing method in which a dicing step is performed before the back side grinding of a semiconductor wafer, and a stealth dicing method in which a crushing layer is provided by a laser. here, In the case of the first dicing method, for example, after dicing, an adhesive sheet for back grinding is attached to the surface of the wafer, and the semiconductor wafer processing sheet of this embodiment can be peeled off. On the other hand, in the case of the stealth dicing method, for example, after attaching an adhesive sheet for back grinding to the surface of a semiconductor wafer, the semiconductor wafer processing sheet of this embodiment is attached to the back surface of the semiconductor wafer, over the semiconductor wafer. After performing stealth dicing of the wafer processing sheet, the wafer processing sheet may be peeled off.

The semiconductor processing plate of this embodiment can also be used not for dicing, but only for picking up the diced semiconductor wafer. At this time, after moving a plurality of semiconductor wafers from the dicing sheet to the semiconductor processing sheet, the semiconductor wafers can be picked up from the semiconductor processing sheet. In addition, the movement from the dicing sheet to the semiconductor processing sheet can be carried out by transfer or by picking up.

The semiconductor processing plate of this embodiment can also be used for cutting. Die bonding plates. At this time, the semiconductor processing board is preferably equipped with the aforementioned adhesive layer, and between this adhesive layer and the aforementioned adhesive layer, etc., a barrier is provided to inhibit the migration of additives to the adhesive layer. Layers are better. When the semiconductor processing sheet is used, the semiconductor wafer and the adhesive layer are cut at the same time during dicing, and the individualized semiconductor wafers are picked up, so that the semiconductor wafer with the adhesive attached can be obtained. Also, as cutting. The adhesive layer of the die-bonding board is also used as an adhesive that also serves as an adhesive for fixing adherends such as semiconductor wafers, and an adhesive layer for chip bonding that is attached to the semiconductor wafer and has a chip bonding function However, the above-mentioned adhesive layer in this embodiment does not have the function as such an adhesive layer.

In addition, the semiconductor processing sheet of this embodiment can also be used as a sheet for forming a protective film for forming a protective film on a semiconductor wafer. this When the semiconductor processing sheet is further provided with a protective film forming film on the outermost layer, this semiconductor processing sheet (sheet for forming a protective film) is used to cut the semiconductor wafer and the protective film at the same time. And pick up the sliced semiconductor wafers to obtain a semiconductor wafer with a protective film on the back.

7. How to use semiconductor processing plates

As an example of the method of using the semiconductor processing sheet of this embodiment, a method of using the semiconductor processing sheet as a dicing sheet will be described below.

When using the semiconductor processing sheet of this embodiment, the surface on the side of the adhesive layer (that is, the surface opposite to the base film of the adhesive layer) is attached to the semiconductor wafer. When laminating the release film on the adhesive layer side surface of the semiconductor processing sheet, peel the release film to expose the adhesive layer side surface and attach the surface to the attaching surface of the semiconductor wafer . The peripheral part of the semiconductor processing plate is usually attached to a ring-shaped jig called a ring frame for conveying and fixing to a device by means of an adhesive layer provided on the part.

Next, by performing a dicing step, a plurality of wafers can be obtained from the semiconductor wafer. Furthermore, when the adhesive layer is formed of an energy-ray curable adhesive, after the cutting step is completed, energy ray irradiation is performed from the substrate film side of the semiconductor processing sheet to reduce the adhesiveness of the adhesive layer.

Next, in order to easily pick up a plurality of wafers arranged on the semiconductor processing plate in close proximity, an expansion step of extending the semiconductor processing plate in the plane direction is performed. The extent of this elongation may be appropriately set in consideration of the distance between the wafers to be arranged close to, the tensile strength of the base film, and the like. In addition, the expansion step may be performed before the energy ray irradiation.

After the expansion step, pick up the chip on the adhesive layer. Picking is carried out by general means such as suction collets. However, in order to facilitate picking, pins, needles, etc. are used to push the target wafer up from the substrate film side of the semiconductor processing sheet. It is better to proceed.

The semiconductor processing sheet of this embodiment exhibits sufficient flexibility even if a substitute for alkyl phthalate is used as the plasticizer contained in the base film, so it has excellent expandability and can be used in the expansion step. The wafers are easily separated, and the wafers can be easily recovered. In addition, since the base film system contains the adipate-based plasticizer and the terephthalate-based plasticizer at a predetermined ratio, it is possible to suppress the generation of residues on the wafer when the wafer is peeled off. In addition, the picked up wafers are supplied to the next step such as the transport step.

The embodiments described above are described in order to facilitate the understanding of the present invention, and are not described in order to limit the present invention. Therefore, the gist of each element disclosed in the above embodiment also includes all design changes and equivalents belonging to the technical scope of the present invention.

[Example]

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

[Example 1]

(1) Manufacturing of vinyl chloride resin base material

100 parts by mass of polyvinyl chloride resin (manufactured by Taiyo Vinyl, TH-1000, average degree of polymerization: 1000) (solid content conversion value; the same below), terephthalate plasticizer A (diterephthalate (2-ethylhexyl) ester, manufactured by ADEKA, ADK CIZER D-810, molecular weight: 391) 10 parts by mass, as hexamethylene Adipic acid polyester B1 (manufactured by ADEKA, ADK CIZER PN-7160, average molecular weight: 800, plasticization efficiency value: 1.00) 20 parts by mass of adipic acid ester plasticizer and adipate monomer C (New Japan Company made, SANSOCIZER DINA, molecular weight 398) 5 parts by mass, phthalocyanine blue coloring agent (DA EP4610 BLUE) as a coloring agent, 0.13 parts by mass, and quinacridone red coloring A mixture of 0.03 parts by mass of a magnesium-based stabilizer (manufactured by Dainichi Seiki Kogyo Co., Ltd., DA P4121 RED) and a small amount of magnesium stabilizer as a stabilizer was kneaded at 180°C using a Banbury mixer. The obtained mixture was rolled using a calender roll to obtain a vinyl chloride resin base material having a thickness of 80 μm.

(2) Preparation of 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 methyl methacrylate were copolymerized to obtain an energy-ray non-curable polymer The acrylic polymer (weight average molecular weight: 170,000, glass transition temperature Tg: 5°C).

Here, the glass transition temperature Tg of the above-mentioned acrylic polymer is a theoretical value calculated in accordance with the FOX formula using the Tg of the homopolymer of each constituent monomer and the mass ratio of each constituent monomer. The glass transition temperature of the homopolymer is as follows.

Homopolymer of 2-ethylhexyl acrylate: -70℃(203K)

Vinyl acetate homopolymer: 32°C (305K)

Acrylic acid homopolymer: 103℃(376K)

Homopolymer of hydroxyethyl methacrylate: 55°C (328K)

100 parts by mass of the above acrylic polymer as a crosslinking agent The composition containing trimethylolpropane-modified toluene diisocyanate (TDI-TMP) (manufactured by TOSOH, CORONATE L) 3.2 parts by mass, aliphatic aromatic copolymerization petroleum resin (softening point: 86°C) 7.1 mass Parts, rosin-based polyol (molecular weight: 2700 (liquid)) 7.1 parts by mass, 2,2-dimethoxy-1,2-diphenylethane-1-one (BASF) as a photopolymerization initiator Product made by the company, trade name: IRGACURE 651) 5.1 parts by mass, difunctional urethane acrylate (weight average molecular weight 11000) and 6-functional urethane acrylate (weight average molecular weight 1500) as energy ray curable compounds The mixture (mixing mass ratio 1:1) 63.4 parts by mass was mixed, diluted with toluene to a solid content concentration of 37% by mass, and this was used as a coating liquid for the adhesive composition.

(3) Manufacturing of semiconductor processing plates

By applying the coating solution of the adhesive composition obtained in (2) above, using a die coater, it was applied to one of the main surfaces of a polyethylene terephthalate film with a thickness of 38 μm and was peeled off by the silicone The peeling surface of the peeling film (manufactured by LINTEC, SP-PET381031) obtained by the agent peeling treatment was dried to form an adhesive layer with a thickness of 10 μm, and a laminate composed of the peeling film and the adhesive layer was obtained. Next, one side of the vinyl chloride resin substrate (thickness: 80 μm) obtained in the above (1) is corona treated, and the corona treated surface is attached to the surface of the laminate on the side of the adhesive layer. In the state where the release film is laminated on the surface of the adhesive layer opposite to the base material, a semiconductor processing sheet composed of a vinyl chloride resin base material and an adhesive layer is obtained.

[Examples 2 to 4, Comparative Examples 1 to 4, Reference Example 1]

Except having changed the kind and compounding amount of a plasticizer as shown in Table 1, it carried out similarly to Example 1, and obtained the semiconductor processing board.

In addition, the details of the abbreviations and the like described in Table 1 are as follows.

Plasticizer A: bis(2-ethylhexyl) terephthalate, manufactured by ADEKA, ADK CIZER D-810, molecular weight: 391

Plasticizer B1: Adipic acid polyester, manufactured by ADEKA, ADK CIZER 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 New Japan Rika Co., Ltd., SANSOCIZER DINA, molecular weight: 398

[Test Example 1] <Measurement of 25% stress of base material>

The semiconductor processing plates manufactured in the examples and comparative examples were cut into a rectangle of 15 mm×150 mm so that the MD direction became the longitudinal direction, and a measurement sample was obtained. The obtained measurement sample was mounted on a universal tensile tester (manufactured by ORIENTEC, TENSILON RTA-T-2M) so that the gap between the grippers became 100 mm, and the relative humidity was 23°C according to JIS K7161-1: 2014 Under a 50% environment, the tensile test was performed at a tensile speed of 200 mm/min. The force measured at the time of 25 mm extension is 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 Adhesion after UV Irradiation>

The semiconductor processing plates manufactured in the Examples and Comparative Examples were put under accelerated conditions (40°C for 14 days). Then, after storing the plate in an environment with a relative humidity of 50% at 23° C. for 24 hours, each was cut to obtain an adhesive force measuring plate having a length of 250 mm and a width of 25 mm. Using a 2kg roller, the adhesive layer side of the obtained adhesive force measurement plate was attached to a mirror-finished silicon wafer (diameter 6 inches, thickness 650μm) to obtain a plate for adhesive force measurement And a laminate composed of silicon wafers. The resulting laminate was stored for 20 minutes in an environment with a relative humidity of 50% at 23°C, and then irradiated with ultraviolet light (ultraviolet radiation device: Adwill (registered trademark) RAD-2000m/12 (manufactured by LINTEC), 230mW/cm ² , 190mJ /cm ² ) The adhesive layer was cured and stored in an environment with a relative humidity of 50% at 23° C. for 10 minutes, and used as an evaluation sample.

For the evaluation sample, a universal tensile testing machine (manufactured by ORIENTEC, TENSILON/UTM-4-100) was used to perform a 180° peeling test at a peeling speed of 300 mm/min and a peeling angle of 180° in accordance with JIS Z0237: 2000 ( The adhesive force measurement plate was set as the member on the side to be peeled off, and the adhesive force after irradiation (unit: mN/25mm) was measured. The results of the adhesion measurement after irradiation are shown in Table 1.

[Test Example 3] <Evaluation of Residues>

In the measurement of the adhesive force after the irradiation performed in Test Example 2 (accelerated condition: 40° C. for 14 days), it was confirmed whether there was any residue on the surface of the silicon wafer after the sheet for adhesive force measurement was peeled off. Those who could not confirm the residues were rated as "○", those who were able to confirm very slight residues within a practically no problem area were rated as "△", and those who were able to confirm the residues were rated as "×".

[Test Example 4] <Measurement of Adhesion Ratio>

For the semiconductor processing sheets manufactured in the Examples and Comparative Examples, the adhesion force (B) before ultraviolet irradiation after the accelerated conditions of 40° C. for 14 days was measured in the same manner as in Test Example 2 except that ultraviolet irradiation was not performed. In addition, except that the acceleration conditions were set to 40°C for 7 days and UV irradiation was not performed, the same procedure as in Test Example 2 was carried out to measure the adhesion force before UV irradiation after the acceleration conditions at 40°C for 7 days. (A), from the obtained results, calculate the adhesive force (A)/(B). The results are shown in Table 1.

It can be seen from Table 1 that the semiconductor processing sheet manufactured in the examples can suppress the generation of residues.

Industrial availability

The semiconductor processing sheet of the present invention can be suitably used, for example, in a processing step of a semiconductor wafer, particularly a processing step having an extended step.

Claims (10)

A semiconductor processing sheet comprising a substrate film and an adhesive layer laminated on at least one side of the substrate film, characterized in that the substrate film contains vinyl chloride resin, As plasticizers, adipate-based plasticizers and terephthalate-based plasticizers, the content of the aforementioned adipate-based plasticizer in the aforementioned substrate film is relative to the aforementioned adipate-based plasticizer and the aforementioned pair of plasticizers. The mass ratio of the total content of the phthalate plasticizer is 50 to 80% by mass. The semiconductor processing plate described in the first item of the scope of patent application, wherein the 25% stress in the MD direction of the aforementioned base film in the tensile test according to JIS K7161-1:2014 is 5-16 MPa. The semiconductor processing sheet according to the first item of the patent application, wherein the total content of the plasticizer in the base film is 18 to 65 parts by mass relative to 100 parts by mass of the vinyl chloride resin. The semiconductor processing board described in the first item of the patent application, wherein the adipic acid ester plasticizer contains adipic acid polyester. As described in item 4 of the scope of patent application, the number average molecular weight of the adipic acid polyester is 400-1500. The semiconductor processing board described in the first item of the patent application, wherein the adipic acid ester plasticizer contains an adipic acid ester monomer. The semiconductor processing plate described in item 6 of the scope of patent application, wherein the aforementioned adipate mono-system is selected from the group consisting of di(2-ethylhexyl) adipate, diisononyl adipate, and adipic acid Diisodecyl ester and bis(2-butoxyethyl) adipate group One or more types in groups. The semiconductor processing plate described in item 1 of the scope of patent application, wherein the aforementioned terephthalate-based plasticizer is bis(2-ethylhexyl) terephthalate. The semiconductor processing plate described in the first item of the scope of patent application, wherein in the aforementioned substrate film, bis(2-ethylhexyl) phthalate, dibutyl phthalate, and benzyl phthalate The content of butyl ester and diisobutyl phthalate is either 0.001% by mass or less. The semiconductor processing board described in the first item of the patent application, wherein the adhesive layer is formed of an energy-ray curable adhesive composition.