TWI823981B - Resin composition for dicing film base material, dicing film base material and dicing film - Google Patents

Abstract

The present invention provides a resin composition for a dicing film base material used for manufacturing a dicing film having both higher strength and higher thermal shrinkage. The present invention provides a resin composition for a dicing film base material, a dicing film base material and a dicing film using the resin composition. The resin composition for a dicing film base material contains: ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid. The ionic polymer (A) of the acid ester copolymer is not less than 30 parts by mass and not more than 90 parts by mass, and the vinyl copolymer (B) is not less than 10 parts by mass and not more than 70 parts by mass (wherein, component (A) and component (B) are ) is 100 parts by mass), and the Fica softening point specified in JIS K7206-1999 is less than 50°C.

Description

Resin composition for dicing film base material, dicing film base material and dicing film

The present invention relates to a resin composition for a dicing film base material, a dicing film base material and a dicing film using the same.

In the manufacturing process of semiconductor devices such as integrated circuits (ICs), generally, after thinning a semiconductor wafer on which a circuit pattern is formed, a dicing step is performed to divide the semiconductor wafer into chip units. In the dicing step, a stretchable wafer processing film (called a dicing film or dicing tape) is attached to the back of the semiconductor wafer, and then the semiconductor wafer is divided into chip units using a dicing knife or laser light. . Then, in the next expansion step (also called an extension step), the dicing tape corresponding to the cut wafer is expanded, and the pieces are reduced into wafers.

In the extending step, the dicing film is expanded (stretched), for example, by lifting an expansion table disposed under the dicing film. At this time, in order to divide the wafer, it is important that the dicing film expands uniformly over the entire surface of the expansion table. In addition, since the stress exerted on the cutting film at the peripheral portion of the expansion table is greater than that at the center portion of the expansion table, the portion of the cutting film corresponding to the peripheral portion of the expansion table relaxes after the expansion step. Such relaxation may cause uneven spacing between divided wafers, which may cause product defects in subsequent steps.

As a means to eliminate the slack of the cut film, a heat shrinkage step is known, that is, by blowing hot air with an actual temperature of about 80 to 100° C. to the slack part of the film. It shrinks due to heat and returns to its original state (see, for example, Patent Document 1). In order to implement this step, the cutting film needs to have high heat shrinkability at a temperature of about 80°C.

In addition, the invisible cutting (registered trademark) method is a cutting method that has attracted much attention in recent years. In this method, laser light is used to form cracks inside the wafer instead of on the surface. In the next expansion step performed at low temperature (about -15°C~0°C), the stress of the dicing film is used to divide the wafer. . Thereby, the loss of the semiconductor product during the cutting step can be suppressed, thereby improving the yield. The dicing film used here is required to have both strength to withstand the stress required for dividing the wafer, and heat shrinkability to eliminate slack that may occur when the wafer is divided in the heat shrink step.

As a dicing film base material used for a dicing film, a dicing film base material containing an ionomer obtained by cationically cross-linking a compound having a carboxyl group and an octene-containing copolymer is known (Patent Document 2) ; Having a bottom layer containing a thermoplastic resin having a FICA softening point of 80°C or higher as specified in JIS K7206, and other layers containing a thermoplastic resin having a FICA softening point of 50°C or higher and less than 80°C as specified in JIS K7206 A dicing film base material (Patent Document 3); and a dicing film base material containing a thermoplastic resin having a FICA softening point specified in JIS K7206 of 50°C or more and less than 90°C (Patent Document 4).

Furthermore, Patent Document 5 discloses a dicing film that is suitable for invisible cutting (registered trademark) and has excellent expandability. The initial elastic modulus at -10°C is 200 MPa or more and 380 MPa or less. Tan δ (loss elastic modulus/storage elastic modulus) is 0.080 or more and 0.3 or less.

[Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 9-007976

[Patent Document 2] Japanese Patent Application Laid-Open No. 2000-345129

[Patent Document 3] Japanese Patent Application Laid-Open No. 2009-231700

[Patent Document 4] Japanese Patent Application Laid-Open No. 2011-216508

[Patent Document 5] Japanese Patent Application Laid-Open No. 2015-185591

Patent Document 1 describes, for example, a dicing film that can remove slack by a heat shrinkage step, including a terpolymer containing an ionic polymer with a melting point of 71° C. (acrylates, methacrylates, etc. are polymerized) Cutting films formed from a blend of ionic polymers) and ethylene-vinyl acetate copolymers. However, there is no description of the basic properties required for dicing films, such as the expandability and strength of the dicing film.

Patent Document 2 describes a dicing film base material containing a ternary copolymer plasma polymer of ethylene/methacrylic acid/acrylate and an octene-containing copolymer as specific examples of a dicing film base material. However, there is no record on the heat shrinkability of the dicing film.

According to the research of the present inventors, it is considered that the dicing film base material of Patent Document 3 has a layer containing a thermoplastic resin with a Fica softening point of 80°C or higher, or a layer containing a Fica softening point of 50°C or more and less than 90°C. The dicing film base material of Patent Document 4 of thermoplastic resin has low heat shrinkability at 80°C, and it is difficult to restore the relaxation to the original state through the heat shrinkage step.

Furthermore, Patent Document 5 describes a dicing film having a base material including an ethylene-α-olefin copolymer or an ionomer containing an ethylene-α-olefin copolymer. However, there is no description of a base material for a dicing film that contains an ionic polymer or a trivalent or higher copolymer including ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester or the like. Resin composition of multi-component copolymer and ethylene copolymer.

The present invention was completed in view of the problems existing in the above-mentioned conventional technologies, and its object is to provide a resin composition for a dicing film base material for producing a dicing film having both high strength and high heat shrinkability. Furthermore, an object of the present invention is to provide a dicing film base material and a dicing film using the resin composition for dicing film base materials of the present invention.

That is, according to the present invention, there are provided a resin composition for a dicing film base material, a dicing film base material, and a dicing film shown below.

[1] A resin composition for a dicing film base material, containing: 30 parts by mass or more and 90 parts by mass or less of an ionic polymer (A) of an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, and an ethylene-based Copolymer (B) 10 parts by mass or more and 70 parts by mass or less (where the total of component (A) and component (B) is 100 parts by mass), and the Fica softening point specified in JIS K7206-1999 is less than 50℃.

[2] The resin composition for a dicing film base material according to [1], wherein the ionic polymer (A) of the above-mentioned ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer is phenanthrene specified in JIS K7206-1999 The card softening point is 25°C or more and 60°C or less.

[3] The resin composition for a dicing film base material according to [1] or [2], wherein the ethylene-based copolymer (B) is a resin having a Fica softening point of 50°C or less as specified in JIS K7206-1999, Or resins that do not have the above-mentioned Fika softening point.

[4] The resin composition for a dicing film base material according to any one of [1] to [3], wherein The above-mentioned ethylene copolymer (B) is at least one selected from the group consisting of ethylene-α-olefin copolymer and ethylene-unsaturated carboxylic acid ester copolymer.

[5] The resin composition for dicing film substrates according to any one of [1] to [4], wherein the above-mentioned ethylene copolymer is measured by the method according to JIS K7210-1999 at 190° C. and a load of 2160 g. The melt flow rate (MFR) of the composite (B) is 0.2g/10 minutes to 30.0g/10 minutes.

[6] The resin composition for a dicing film base material according to any one of [1] to [5], wherein the dicing film base material is measured by a method according to JIS K7210-1999 at 190° C. and a load of 2160 g. The melt flow rate (MFR) of the resin composition for materials is 0.1g/10 minutes to 50g/10 minutes.

[7] A dicing film base material containing at least one layer containing the resin composition for a dicing film base material according to any one of [1] to [6].

[8] The dicing film base material according to [7], which contains: a first resin layer containing the resin composition for a dicing film base material according to any one of [1] to [6], and a layer laminated on the above The first resin layer includes a second resin layer containing resin (C).

[9] The dicing film base material according to [8], wherein the resin (C) is a group consisting of an ethylene-unsaturated carboxylic acid copolymer and an ionic polymer of the ethylene-unsaturated carboxylic acid copolymer. At least 1 of the group’s choices.

[10] A dicing film characterized by having: the dicing film base material according to any one of [7] to [9]; and an adhesive layer laminated on at least one side of the dicing film base material.

The present invention provides a resin composition for a dicing film base material used to produce a dicing film having both high strength and high heat shrinkage, and a dicing film base material and dicing film using the resin composition.

1‧‧‧The 1st resin layer

2‧‧‧The second resin layer

10‧‧‧Cutting film substrate

11‧‧‧Adhesive layer

20‧‧‧Cutting film

FIG. 1A is a cross-sectional view showing one embodiment of the dicing film base material of the present invention.

FIG. 1B is a cross-sectional view showing one embodiment of the dicing film base material of the present invention.

FIG. 2A is a cross-sectional view showing one embodiment of the dicing film of the present invention.

FIG. 2B is a cross-sectional view showing one embodiment of the dicing film of the present invention.

Hereinafter, the resin composition for the dicing film base material of the present invention will be described in detail, and the dicing film base material and the dicing film will also be described in detail.

Furthermore, in this specification, the notation "~" indicating a numerical range includes the meaning of the lower limit and upper limit of the numerical range.

In addition, "(meth)acrylic acid" includes both "acrylic acid" and "methacrylic acid", and "(meth)acrylate" includes both "acrylate" and "methacrylate". notation.

In the manufacturing process of semiconductor wafers, the dicing film needs to have high thermal shrinkage at temperatures around 80°C, so that the thermal shrinkage of the film can be used to eliminate the relaxation of the dicing film after the expansion (extension) step (restore to the original state). status). In the present invention, by using the following resin composition to produce a dicing film base material, a dicing film with both higher strength and higher heat shrinkability can be produced. The resin composition includes ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid. The ionomer (A) of the ester copolymer is not less than 30 parts by mass and not more than 90 parts by mass, and the ethylene-based copolymer (B) is not less than 10 parts by mass and not more than 70 parts by mass (wherein, component (A) and component (B) The total is set to 100 parts by mass). Although its mechanism is not clear, it can be considered as follows.

It is known that polyolefin-based resins are prepared by blending ethylene-based copolymers. High thermal shrinkage. However, if a film is produced using a resin composition containing a polyolefin resin and an ethylene copolymer, the strength and expandability of the film are not sufficient as a cutting film. On the other hand, in the present invention, by using an ionic polymer of an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer and an ethylene-based copolymer, a resin composition having a Fica softening point of less than 50° C. can be produced. A cutting film whose heat shrinkability is improved without significantly reducing the film strength or expandability (dividability) derived from the ionically cross-linked structure of the ionic polymer is obtained.

The dicing film of the present invention can be preferably used in a manufacturing method of a semiconductor element that performs not only the dicing step and the expanding step of dividing the semiconductor wafer into wafer units, but also the heat shrinking step. In particular, since the dicing film of the present invention has both high strength and high thermal shrinkage, it can be preferably used to apply a method to the dicing film in the expansion step than conventional methods (blade cutting method or laser ablation method, etc.) A manufacturing method using invisible cutting (registered trademark) method for high stress. By using the dicing film of the present invention, the distance between divided wafers can be made uniform, product defects in subsequent steps can be reduced, and semiconductor devices can be manufactured at a higher yield.

Hereinafter, the present invention will be described with reference to exemplary embodiments, but the present invention is not limited to the following embodiments.

1. Resin composition for cutting film base material

A first aspect of the present invention is a resin composition for a dicing film base material. The resin composition for a dicing film base material contains: 30 parts by mass or more and 90 parts by mass or less of an ionic polymer (A) of an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, and 10 parts by mass of an ethylene-based copolymer (B) More than 70 parts by mass and less than 70 parts by mass (where the total of component (A) and component (B) is 100 parts by mass).

1-1. Resin (A)

The ionic polymer of ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer (hereinafter, also referred to as "ionic polymer (A)") used as the resin (A) is an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer. It is obtained by neutralizing part or all of the carboxyl groups of saturated carboxylate copolymers with metals (ions). In the present invention, those in which at least part of the acidic groups of the copolymer are neutralized with metal (ions) are called "ionic polymers", and those in which the acidic groups of the copolymer are not neutralized with metals (ions) are called "copolymers" ”.

The ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer system constituting the above-mentioned ionic polymer (A) may also be an at least ternary copolymer formed by copolymerizing ethylene, unsaturated carboxylic acid and unsaturated carboxylic acid ester. It is a multi-component copolymer of four or more elements that is further copolymerized with the fourth copolymer component. Furthermore, one type of ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer may be used alone, or two or more types of ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer may be used in combination.

Examples of the unsaturated carboxylic acid constituting the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer include acrylic acid, methacrylic acid, ethylacrylic acid, itaconic acid, itaconic anhydride, fumaric acid, Unsaturated carboxylic acids with 4 to 8 carbon atoms such as crotonic acid, maleic acid, maleic anhydride, etc. Particularly preferred are acrylic or methacrylic.

As the unsaturated carboxylic acid ester constituting the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, an unsaturated carboxylic acid alkyl ester is preferred. The number of carbon atoms in the alkyl moiety of the alkyl ester is preferably 1 to 12, more preferably 1 to 8, and still more preferably 1 to 4. Examples of the alkyl moiety include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, 2-butyl, 2-ethylhexyl, isooctyl, and the like. Specific examples of unsaturated carboxylic acid alkyl esters include: methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, Alkyl (meth)acrylates such as isooctyl acrylate, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, dimethyl maleate, diethyl maleate, etc. .

When the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer is a multi-component copolymer of four or more members, it may also contain a monomer (the fourth copolymer component) forming the multi-component copolymer. Examples of the fourth copolymerized component include unsaturated hydrocarbons (for example, propylene, butene, 1,3-butadiene, pentene, 1,3-pentadiene, 1-hexene, etc.), vinyl esters ( For example, vinyl acetate, vinyl propionate, etc.), oxides of vinyl sulfuric acid or vinyl nitric acid, halogen compounds (for example, vinyl chloride, vinyl fluoride, etc.), vinyl-containing primary/secondary amine compounds, carbon monoxide , sulfur dioxide, etc.

The form of the copolymer may be any of block copolymers, random copolymers, and graft copolymers, or may be any of ternary copolymers and multi-component copolymers of four or more members. Among them, in terms of industrial availability, a ternary random copolymer or a graft copolymer of a ternary random copolymer is preferred, and a ternary random copolymer is more preferred.

Specific examples of the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer include terpolymers such as ethylene-methacrylic acid-butyl acrylate copolymer.

When the total amount of the structural units constituting the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer is 100% by mass, the amount of the unsaturated carboxylic acid-derived ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer in the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer The content ratio of the constituent units is preferably 4% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less. When the total amount of the structural units constituting the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer is 100% by mass, the The content ratio of the constituent units of the unsaturated carboxylic acid ester is preferably 1 mass% or more and 20 mass% or less, more preferably 5 mass% or more and 18 mass% or less, particularly preferably 5 mass% or more and 17 mass% or less. . From the viewpoint of the expandability of the film, the content ratio of the structural unit derived from the unsaturated carboxylic acid ester is preferably 1 mass % or more, and more preferably 5 mass % or more. Moreover, from the viewpoint of preventing adhesion and fusion, the content ratio of the structural unit derived from the unsaturated carboxylic acid ester is preferably 20 mass% or less, more preferably 18 mass% or less, and particularly preferably 17 mass% or less.

In the present invention, the ionic polymer (A) used as the resin (A) is preferably one in which the carboxyl groups contained in the above-mentioned ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer are cross-linked by metal ions in any proportion. (Neutralization) Gainer. Examples of metal ions used for neutralization of acid groups include metal ions such as lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, zinc ions, magnesium ions, and manganese ions. Among these metal ions, in terms of easy availability of industrialized products, magnesium ions, sodium ions and zinc ions are preferred, sodium ions and zinc ions are more preferred, and zinc ions are particularly preferred.

One type of metal ions may be used alone, or two or more types of metal ions may be used in combination.

The degree of neutralization of the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer in the ionic polymer (A) (hereinafter also referred to as the "neutralization degree of the ionic polymer (A)") is not particularly limited. The best range is 10%~100%, and the more preferred range is 30%~100%. When the degree of neutralization is within the above range, it is preferable because the film strength and separability are improved.

Furthermore, the degree of neutralization of the ionic polymer (A) is the ratio of the molar number of carboxyl groups neutralized by metal ions to the total carboxyl groups contained in the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer ( mol%).

As the ionic polymer (A) of the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, commercially available products can be used. Examples of commercially available products include: Himilan (registered trademark) series manufactured by Dow-Mitsui Polychemicals Co., Ltd., etc.

The melt flow rate (MFR) of the ionic polymer (A) of ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester is preferably in the range of 0.2g/10 minutes to 20.0g/10 minutes, more preferably 0.5g/10 minutes to 20.0g/10 minutes, and more preferably 0.5g/10 minutes to 18.0g/10 minutes. If the melt flow rate is within the above range, it is advantageous when forming a film.

In addition, MFR is a value measured at 190°C and a load of 2160g according to the method of JIS K7210-1999.

Furthermore, the Fica softening point of the ionic polymer (A) of ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester is preferably 25°C or more and 60°C or less, more preferably 35°C or more and 60°C or less. If the Fica softening point of the ionomer (A) is within the above range, it is easy to adjust the Fica softening point of the resin composition to less than 50°C.

In addition, the Fica softening point is a value measured based on the A50 method specified in JIS K7206-1999.

The content of resin (A) in the resin composition for dicing film base materials of the present invention is 30 parts by mass or more and 90 parts by mass or less based on 100 parts by mass of the total of resin (A) and the following resin (B). Preferably, it is 40 parts by mass or more and 90 parts by mass or less, and more preferably, it is 50 parts by mass or more and 70 parts by mass or less. If the content of the resin (A) is 30 parts by mass or more, sufficient strength as a dicing film can be obtained, and if it is 90 parts by mass or less, the thermal shrinkage rate can be increased.

1-2. Resin (B)

The ethylene-based copolymer (B) used as the resin (B) (hereinafter also simply referred to as "copolymer (B)") is a copolymer of ethylene and other monomers, and its type is not particularly limited. However, it is important that when preparing a resin composition together with the above-mentioned ionic polymer (A), the ionic polymer (A) and the copolymer (B) such that the Fika softening point of the composition is less than 50°C are added. combination. From this point of view, the copolymer (B) is preferably a resin having a Fica softening point of 50° C. or lower, or a resin having no Fica softening point. Moreover, when the copolymer (B) has a Ficca softening point, from the viewpoint of processability, it is preferable that the Ficca softening point is 25° C. or higher.

In addition, the Fica softening point is a value measured based on the A50 method specified in JIS K7206-1999.

Examples of the ethylene-based copolymer (B) used in the present invention include ethylene-α-olefin copolymer, ethylene-unsaturated carboxylic acid ester copolymer, ethylene-vinyl ester copolymer, etc., and ethylene is preferred. -a olefin copolymer, and ethylene-unsaturated carboxylic acid ester copolymer.

Ethylene-α-olefin copolymer system is a copolymer of ethylene and α-olefin. The copolymer may contain only one type of α-olefin, or may contain two or more types. Specific examples of α-olefins include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 3- Methyl-1-pentene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, etc. Among them, in terms of easy availability, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene are preferred. Furthermore, the ethylene-α-olefin copolymer may be a random copolymer or a block copolymer, and is preferably a random copolymer.

The content ratio of the structural units derived from ethylene contained in the ethylene-α-olefin copolymer is not particularly limited, but is preferably more than 50 mol% and not more than 95 mol%, more preferably not less than 70 mol% and not more than 94 mol%. The proportion of structural units derived from α-olefins (hereinafter also referred to as "α-olefin units") contained in the ethylene-α-olefin copolymer is preferably 5 mol% or more and less than 50 mol%, more preferably 6 mol% More than 30mol% Down. Such an ethylene-α-olefin copolymer is advantageous for ensuring shrinkage properties.

As the ethylene-α-olefin copolymer, one with a density of 895 kg/m ³ or less, particularly 860 to 890 kg/m ³ is preferred.

Ethylene-unsaturated carboxylic acid ester copolymer system is a copolymer of ethylene and unsaturated carboxylic acid ester. The copolymer may contain only one type of unsaturated carboxylic acid ester structural unit, or may contain two or more types. Examples of the unsaturated carboxylic acid constituting the unit of the unsaturated carboxylic acid ester include acrylic acid, methacrylic acid, ethacrylic acid, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, and maleic acid. Diacids, maleic anhydride and other unsaturated carboxylic acids with 4 to 8 carbon atoms, etc. Particularly preferred are acrylic or methacrylic.

Furthermore, as the unsaturated carboxylic acid ester constituent unit contained in the ethylene-unsaturated carboxylic acid ester copolymer, an unsaturated carboxylic acid alkyl ester is preferred. The number of carbon atoms in the alkyl moiety of the alkyl ester is preferably 1 to 12, more preferably 1 to 8, and still more preferably 1 to 4. Examples of the alkyl moiety include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, 2-butyl, 2-ethylhexyl, isooctyl, and the like. Specific examples of unsaturated carboxylic acid alkyl esters include: methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, methyl methacrylate, and ethyl methacrylate. Alkyl (meth)acrylates such as isobutyl methacrylate, dimethyl maleate, and diethyl maleate.

When the total amount of the structural units constituting the ethylene-unsaturated carboxylic acid ester copolymer is 100% by mass, the content ratio of the structural units derived from the unsaturated carboxylic acid ester in the ethylene-unsaturated carboxylic acid ester copolymer is preferably: 5 mass % or more and 40 mass % or less, more preferably 7 mass % or more and 40 mass % or less, particularly preferably 8 mass % or more and 40 mass % or less. It is preferable from the viewpoint of film processability when the content ratio of the structural unit derived from the unsaturated carboxylic acid ester is equal to or less than the above-mentioned upper limit. Also, if it comes from unsaturated carboxylic acid It is preferable from the viewpoint of shrinkage that the content ratio of the constituent units of the acid ester is equal to or higher than the above-mentioned lower limit.

The melt flow rate (MFR) of the ethylene-based copolymer (B) is preferably in the range of 0.2g/10 minutes to 30.0g/10 minutes, more preferably 0.5g/10 minutes to 25.0g/10 minutes. If the melt flow rate is within the above range, it is advantageous when molding the resin composition.

In addition, MFR is a value measured at 190°C and a load of 2160g according to the method of JIS K7210-1999.

Furthermore, the melting point of the ethylene-based copolymer (B) is preferably from 30°C to 100°C, more preferably from 30°C to 80°C.

In addition, the melting point is the melting temperature measured with a differential scanning calorimeter (DSC) in accordance with JIS-K7121 (1987).

The content of resin (B) in the resin composition for dicing film base materials is 10 parts by mass or more and less than 70 parts by mass, preferably 10 parts by mass, based on 100 parts by mass of the total of resin (A) and resin (B). Parts by mass or more and 60 parts by mass or less, more preferably 20 parts by mass or more and 50 parts by mass or less. If the content of the resin (B) is 10 parts by mass or more, the effect of increasing the thermal shrinkage rate of the resin (B) is exerted. If it is less than 70 parts by mass, there is less concern that the strength of the dicing film base material will become insufficient. .

1-3. Other polymers and additives

Other polymers or various additives may also be added to the resin composition for dicing film base materials as necessary within the range that does not impair the effects of the present invention. Examples of other polymers include polyamide, polyurethane, binary copolymer and ionic polymer. Such other polymers can be prepared in a proportion of 20 parts by mass or less based on 100 parts by mass of the resin (A) and the resin (B) in total. Examples of additives include: Antistatic agents, antioxidants, heat stabilizers, light stabilizers, UV absorbers, pigments, dyes, slip agents, anti-adhesive agents, antistatic agents, antifungal agents, antibacterial agents, flame retardants, flame retardant auxiliaries , cross-linking agents, cross-linking aids, foaming agents, foaming aids, inorganic fillers, fiber reinforced materials, etc.

1-4. Physical properties of resin composition

The Fika softening point specified in JIS K7206-1999 of the resin composition of the present invention is less than 50°C, and preferably is 25°C or more and less than 50°C. If the Ficcar softening point of the resin composition is less than 50°C, the thermal shrinkage rate increases. If it is 25°C or more, the resin composition can be processed into a film shape.

The melt flow rate (MFR) of the resin composition of the present invention measured at 190°C and a load of 2160g is preferably 0.1g/10min~50g/10min, more preferably 0.5g/10min~20g/10min.

In addition, MFR is a value measured at 190°C and a load of 2160g according to the method of JIS K7210-1999.

The degree of neutralization of the resin composition is not particularly limited, but is preferably 10% to 85%, and more preferably 15% to 82%. If the neutralization degree of the resin composition is 10% or more, the wafer separation property can be further improved, and if it is 85% or less, the film formability will be excellent. The degree of neutralization of the resin composition basically depends on the degree of neutralization of the ionic polymer (A) and its content, and can be calculated by the following formula.

(Degree of neutralization of the resin composition) = (Degree of neutralization of the ionic polymer (A)) × (Proportion of the ionic polymer (A) in the resin composition)

Therefore, when the degree of neutralization of the ionic polymer (A) is low, the content is slightly larger, or when the degree of neutralization of the ionic polymer (A) is high, the content is slightly smaller. This can adjust the degree of neutralization of the resin composition.

Furthermore, when the resin composition of the present invention is processed into a film with a thickness of 100 μm, the thermal shrinkage rate at 80°C is preferably 6% or more, more preferably 7% or more. If the heat shrinkage rate at 80°C is 6% or more, it can be preferably used to produce a cutting film that can eliminate slack through a heat shrinkage step. The upper limit of the heat shrinkage rate is not particularly limited, but from the viewpoint of reducing the defective rate in the subsequent step (pickup step) after heat shrinkage, it is preferably 20% or less.

In addition, in this case, the thermal shrinkage rate at 80°C is a value measured by the following method.

The resin composition film was cut into a thickness of 100 μm, a width of 25 mm and a length of 150 mm, and marking lines were marked at intervals of 100 mm to prepare a test piece sample. Place it on a glass plate sprinkled with starch, heat it on a hot plate at 80°C for 2 minutes, measure the distance between the marking lines on the film after heating, and calculate the shrinkage rate (%) according to the following formula.

Shrinkage rate (%)=100mm-distance between marking lines after shrinkage (mm)/100mm×100

1-5. Manufacturing method of resin composition

The resin composition for a dicing film base material can be obtained by mixing resin (A) and resin (B), and optionally other polymers or additives. As described above, since the Fica softening point of the resin composition of the present invention specified in JIS K7206-1999 is less than 50°C, the resin (A) is selected so that the Fica softening point of the resin composition is less than 50°C. , resin (B) and the type or amount of additives required.

The manufacturing method of the resin composition is not particularly limited. For example, it can be obtained by dry blending all the components and then melting and kneading them.

2. Cutting film substrate

A second aspect of the present invention is a dicing film base material including at least one layer including the resin composition for dicing film base materials. 1A and 1B are cross-sectional views showing one embodiment of the dicing film base material 10 of the present invention. Figure 1A shows a single-layer dicing film base material including only the first resin layer 1 including the above-mentioned resin composition for dicing film base materials. Figure 1B shows a single-layer dicing film base material including the first resin layer 1 including the above-mentioned resin composition for dicing film base materials. A multilayer dicing film base material obtained by laminating the second resin layer 2 containing other resins or resin compositions.

The strength of the cutting film base material of the present invention is preferably in the range of 25% modulus from 5 MPa to 15 MPa, more preferably from 6 MPa to 12 MPa. If the 25% modulus is 5 MPa or more, the dicing film base material will have excellent wafer splitting properties (strength), and if it is 15 MPa or less, the dicing film base material will have excellent expandability.

The modulus in the present invention is based on JIS K 7127-1999. For the machine direction (MD direction, Machine Direction) and orthogonal direction (TD direction, Transverse Direction) of the cutting film substrate, the test speed is: 500mm/min, Test piece: width 10mm x length 200mm, clamp spacing: 100mm, measured as the film strength (25% modulus or 50% modulus) when the elongation distance is 25% or 50%.

The thermal shrinkage rate of the cutting film base material of the present invention at 80°C is preferably in the range of 6% or more and 20% or less, and more preferably 7% or more. If the heat shrinkage rate at 80°C is 6% or more, the heat shrinkage characteristics (removal of slack) of the dicing film base material will be excellent. If it is 20% or less, the subsequent steps (picking up steps) after heat shrinkage will be Excellent reduction in defective rate.

In addition, in this case, the thermal shrinkage rate at 80°C is a value measured by the following method.

Cut the dicing film base material into a thickness of 100 μm and a thickness of 25 mm in the width direction × length direction. 150mm, mark the marking lines at intervals of 100mm, and use them as test specimens. Place it on a glass plate sprinkled with starch, heat it on a hot plate at 80°C for 2 minutes, measure the distance between the marking lines on the film after heating, and calculate the shrinkage rate (%) according to the following formula.

Shrinkage rate (%)=100mm-distance between marking lines after shrinkage (mm)/100mm×100

2-1. 1st resin layer

The first resin layer contains the above-mentioned resin composition for dicing film base materials, that is, 30 parts by mass or more and 90 parts by mass or less of the ionic polymer (A) containing an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, and Ethylene-based copolymer (B) 10 parts by mass or more and 70 parts by mass or less (where the total of component (A) and component (B) is 100 parts by mass), and the FICA softening point specified in JIS K7206-1999 The layer of the resin composition used as the base material of the cutting film below 50°C. Furthermore, the first resin layer may be a layer composed of the above-mentioned resin composition for dicing film base materials. This resin composition layer has an excellent balance between strength and thermal shrinkage.

When the dicing film base material has a single-layer structure, it is preferable that the content of the ionomer (A) in the resin composition used as the raw material is 70 parts by mass or more and 90 parts by mass or less, and the ethylene-based copolymer (B) The content of the ionomer (A) is 10 parts by mass or more and 30 parts by mass or less. More preferably, the content of the ionomer (A) is 80 parts by mass or more and 90 parts by mass or less, and the content of the ethylene-based copolymer (B) is 10 parts by mass or more and 20 parts by mass or less (where the total of component (A) and component (B) is 100 parts by mass). In this way, by using a resin composition with a high ratio of ionomer (A), it is possible to achieve the required strength as a dicing film base material even in a single layer.

On the other hand, when the dicing film base material has a multi-layer structure, the resin composition used as the raw material of the first resin layer only needs to be the above-mentioned resin composition of the present invention. The ratio of the ionic polymer (A) and the copolymer (B) is not particularly limited, as long as the content of the ionic polymer (A) is 30 parts by mass or more and 90 parts by mass or less, and the content of the ethylene-based copolymer (B) is 10 parts by mass. It may be more than 70 parts by mass and less than 70 parts by mass.

2-2. Second resin layer

The second resin layer is a layer including resin (C) or a layer composed of resin (C). The resin (C) is not particularly limited as long as it has high adhesion to the resin composition constituting the first resin layer. . By laminating the second resin layer containing resin (C) (or consisting of resin (C)) and the first resin layer, the strength of the dicing film base material can be improved without causing the problem of interlayer delamination, and Maintain the balance between wafer segmentability and expandability required for cutting films.

<Resin C>

The resin (C) in the present invention is preferably an ionic polymer formed from an ethylene-unsaturated carboxylic acid copolymer (hereinafter, also referred to as "copolymer (C)") and the above-mentioned ethylene-unsaturated carboxylic acid copolymer. (Hereinafter, also referred to as "ionic polymer (C)"), at least one selected from the group consisting of. The ionic polymer of the ethylene-unsaturated carboxylic acid copolymer used as the resin (C) is obtained by neutralizing part or all of the carboxyl groups of the ethylene-unsaturated carboxylic acid copolymer with a metal (ion).

Furthermore, as described in detail below, the resin (C) may be the same resin as the resin (A) or resin (B) contained in the resin composition constituting the first resin layer.

The above-mentioned copolymer (C), or an at least binary copolymer obtained by copolymerizing ethylene and an unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid copolymer system constituting the ionic polymer (C) may also be further combined with More than three elements copolymerized by the third copolymer component of multiple copolymers. Furthermore, one type of ethylene-unsaturated carboxylic acid copolymer may be used alone, or two or more types of ethylene-unsaturated carboxylic acid copolymer may be used in combination.

Examples of the unsaturated carboxylic acid constituting the ethylene-unsaturated carboxylic acid binary copolymer include: acrylic acid, methacrylic acid, ethacrylic acid, itaconic acid, itaconic acid anhydride, fumaric acid, crotonic acid, Unsaturated carboxylic acids with 4 to 8 carbon atoms such as maleic acid and maleic anhydride. Particularly preferred are acrylic or methacrylic.

When the ethylene-unsaturated carboxylic acid copolymer (C) is a three- or higher-valent multi-valent copolymer, it may also contain a monomer (third copolymerization component) that forms the multi-valent copolymer. Examples of the third copolymerizable component include unsaturated carboxylic acid esters (for example, methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, methyl methacrylate, methacrylic acid Ethyl ester, isobutyl methacrylate, dimethyl maleate, diethyl maleate and other (meth)acrylic acid alkyl esters), unsaturated hydrocarbons (for example, propylene, butene, 1 , 3-butadiene, pentene, 1,3-pentadiene, 1-hexene, etc.), vinyl ester (for example, vinyl acetate, vinyl propionate, etc.), vinyl sulfuric acid or vinyl nitric acid, etc. Oxides, halogen compounds (for example, vinyl chloride, vinyl fluoride, etc.), vinyl-containing primary/secondary amine compounds, carbon monoxide, sulfur dioxide, etc. As these copolymerization components, unsaturated carboxylic acid esters are preferred.

For example, when the ethylene-unsaturated carboxylic acid copolymer (C) is a terpolymer, preferably: a terpolymer of ethylene, an unsaturated carboxylic acid, and an unsaturated carboxylic acid ester; Ternary copolymers of unsaturated carboxylic acids and unsaturated hydrocarbons, etc.

The unsaturated carboxylic acid ester is preferably an unsaturated carboxylic acid alkyl ester, and the number of carbon atoms in the alkyl moiety of the alkyl ester is preferably 1 to 12, more preferably 1 to 8, and still more preferably 1 to 4. Examples of alkyl moieties include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, 2-butyl, 2-ethylhexyl, isooctyl, etc.

Specific examples of unsaturated carboxylic acid esters include unsaturated carboxylic acid alkyl esters having 1 to 12 carbon atoms in the alkyl moiety (for example, methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate ester, isooctyl acrylate and other alkyl acrylates, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate and other alkyl methacrylates, dimethyl maleate, maleate Diethyl diacid and other maleic acid alkyl esters), etc.

Among the unsaturated carboxylic acid alkyl esters, a (meth)acrylic acid alkyl ester having a carbon number of 1 to 4 in the alkyl moiety is more preferred.

The form of the copolymer may be any of a block copolymer, a random copolymer, or a graft copolymer, or may be any of a binary copolymer, and a multi-component copolymer of three or more elements. Among them, in terms of industrial availability, preferred are binary random copolymers, ternary random copolymers, graft copolymers of binary random copolymers, or graft copolymers of ternary random copolymers. The combination is preferably a binary random copolymer or a ternary random copolymer.

Specific examples of ethylene-unsaturated carboxylic acid copolymers include binary copolymers such as ethylene-acrylic acid copolymers and ethylene-methacrylic acid copolymers, and tertiary copolymers such as ethylene-methacrylic acid-isobutyl acrylate copolymers. meta-copolymer. In addition, commercially available products marketed as ethylene-unsaturated carboxylic acid copolymers can also be used. For example, Nucrel Series (registered trademark) manufactured by Dow-Mitsui Polychemicals, etc. can be used.

The copolymerization ratio (mass ratio) of the unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid copolymer is preferably 4% to 20% by mass, more preferably 5% to 15% by mass. Copolymerization ratio of unsaturated carboxylic acid ester in ethylene-unsaturated carboxylic acid copolymer (Mass ratio) is preferably 1 mass% to 20 mass%, more preferably 5 mass% to 18 mass%. From the viewpoint of expandability, the content ratio of the structural unit derived from the unsaturated carboxylic acid ester is preferably 1 mass % or more, and more preferably 5 mass % or more. Moreover, from the viewpoint of preventing adhesion and fusion, the content ratio of the structural unit derived from the unsaturated carboxylic acid ester is preferably 20 mass% or less, more preferably 18 mass% or less.

In the present invention, the ionic polymer (C) used as the resin (C) is preferably obtained by cross-linking (neutralizing) the carboxyl groups contained in the above-mentioned ethylene-unsaturated carboxylic acid copolymer with metal ions in any proportion. By. Examples of metal ions used for neutralization of acid groups include metal ions such as lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, zinc ions, magnesium ions, and manganese ions. Among these metal ions, in terms of easy availability of industrialized products, magnesium ions, sodium ions and zinc ions are preferred, sodium ions and zinc ions are more preferred, and zinc ions are particularly preferred.

One type of metal ions may be used alone, or two or more types of metal ions may be used in combination.

The degree of neutralization of the ethylene-unsaturated carboxylic acid copolymer in the ionic polymer (C) is preferably 10% to 85%, and more preferably 15% to 82%. If the degree of neutralization is 10% or more, the wafer separability can be further improved, and if it is 85% or less, the processability or formability of the film will be excellent.

Furthermore, the degree of neutralization is the ratio (mol%) of the molar number of carboxyl groups neutralized by metal ions to the total carboxyl groups contained in the ethylene-unsaturated carboxylic acid copolymer.

The melt flow rate (MFR) of the resin (C) is preferably in the range of 0.2g/10 minutes to 20.0g/10 minutes, more preferably 0.5g/10 minutes to 20.0g/10 minutes, and further preferably 0.5g/ 10 minutes~18.0g/10 minutes. If the melt flow rate is within the above range, it is advantageous during film formation.

Furthermore, the MFR is measured at 190°C under load according to the method of JIS K7210-1999. Value measured at 2160g.

The resin (C) preferably has a Ficar softening point of 50°C or more and 100°C or less. By laminating a resin with a higher Fica softening point as a second resin layer on the first resin layer containing a resin composition having a Fica softening point of less than 50° C., the strength or heat resistance of the dicing film base material can be improved.

In addition, the Fica softening point is a value measured based on the A50 method specified in JIS K7206-1999.

<Other polymers and additives>

Various additives or other resins may be added as necessary to the resin (C) constituting the second resin layer within a range that does not impair the effects of the present invention. Examples of the above-mentioned additives include antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, pigments, dyes, lubricants, anti-adhesive agents, antistatic agents, antifungal agents, antibacterial agents, and flame retardants. , flame retardant additives, cross-linking agents, cross-linking additives, foaming agents, foaming aids, inorganic fillers, fiber reinforcements, etc. From the viewpoint of preventing thermal fusion, the above-mentioned additives may also be added in small amounts.

2-3. Layer composition

The dicing film base material of the present invention has a single-layer structure including only the first resin layer 1 (Fig. 1A), and a multi-layer structure including the first resin layer 1 and the second resin layer 2 (Fig. 1B). The layer structure of the multi-layered dicing film base material is not particularly limited as long as it includes the above two layers. From the viewpoint of preventing interlayer delamination, it is preferable that the first resin layer and the second resin layer are directly laminated.

The multi-layer dicing film base material may also have a multi-layer structure of three or more layers. For example, the resin composition constituting the first resin layer may be used in several laminated layers. The structure in which a second resin layer is provided after forming the sheet may also be a structure in which the second resin layer is sandwiched between two first resin layers. Moreover, it may be a structure which not only has a 1st resin layer and a 2nd resin layer, but also has other resin layers laminated|stacked.

Representative examples of the resin constituting the other resin layer laminated with the dicing film base material of the present invention include linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), and ethylene-α-olefin. Monomers or blends of any number of copolymers, polypropylene, and ethylene-vinyl ester copolymers.

In addition, the other laminated resin layer may be a functional layer (for example, an adhesive sheet, etc.), or may be a base material such as a polyolefin film (or sheet) or a polyvinyl chloride film (or sheet). The above-mentioned substrate can be any structure having a single layer or multiple layers. In the present invention, these substrates are referred to as "cutting film substrates".

The surface of the dicing film base material can also be subjected to known surface treatments such as corona discharge treatment to improve the adhesion of the surface of the dicing film base material.

Moreover, from the viewpoint of improving heat resistance, the first resin layer, the second resin layer, other resin layers, or the diced film base material may be irradiated with electron beams as necessary.

2-4. Manufacturing method of cutting film base material

An example of a method for manufacturing a single-layer dicing film base material is a method of processing a resin composition for a dicing film into a film shape by a known method. The method of processing the resin composition into a film is not particularly limited. For example, the conventionally known T-shaped die casting method, T-shaped roll forming method, inflation molding method, extrusion lamination method, calendar forming method, etc. Various forming methods are used to manufacture membranes.

As a method of manufacturing the multilayer dicing film base material, the resin composition constituting the first resin layer and the resin (C) constituting the second resin layer are each prepared by a well-known method. The method is to process it into a film shape and laminate it. The method of processing the resin composition or resin into a film is not particularly limited. For example, the conventionally known T-shaped die casting method, T-shaped roll forming method, inflation molding method, extrusion lamination method, and calendering method can be used. Films can be manufactured using various forming methods, including the

In addition, the multilayer dicing film base material can be produced by, for example, coextrusion and lamination of the resin composition constituting the first resin layer and the resin (C) constituting the second resin layer.

For example, when the resin composition constituting the first resin layer is laminated on the surface of the film of the resin (C) that becomes the second resin layer using a T-die film molding machine or an extrusion coating molding machine, in order to improve The adhesiveness with the second resin layer can be formed through the adhesive resin layer using a coextrusion coating molding machine. Typical examples of such adhesive resins include monomers selected from the above-mentioned various ethylene copolymers or unsaturated carboxylic acid grafts thereof, or blends containing any number thereof.

In addition, as an example of molding the dicing film base material of the present invention, there can be cited a method in which the resin composition constituting the first resin layer is thermally bonded using a T-die film molding machine or an extrusion coating molding machine. The surface of the resin (C) film serving as the second resin layer forms a multilayer body.

Furthermore, although the method described is a method of forming a layer including the resin composition that becomes the first resin layer on the film of the resin (C) that becomes the second resin layer, it may also be conversely possible by forming a layer of the resin composition that becomes the first resin layer. The cutting film base of the present invention is produced by forming a layer of resin (C) that becomes the second resin layer on the film of the resin composition of the first resin layer, or by providing the first resin or the second resin layer on other resin layers. material.

The thickness of the dicing film base material is not particularly limited, but if it is considered to be used as a component of the dicing film, from the viewpoint of maintaining the frame during cutting, it is preferably 65 μm or more. From the viewpoint of expandability, it is preferably 200 μm or less. In addition, the thickness of each resin layer constituting the multi-layered dicing film base material is not particularly limited as long as the total of them does not exceed the above-mentioned thickness of the dicing film base material. It is preferable that the first resin layer and the second resin layer are both 30 μm or more. And 100 μm or less, the ratio of the thickness of the first resin layer and the second resin layer is preferably 30/70~70/30.

3. Cutting film

A third aspect of the present invention is a dicing film provided with the above-mentioned dicing film base material of the present invention and an adhesive layer laminated on at least one side thereof. 2A and 2B are cross-sectional views showing an embodiment of the dicing film 20 of the present invention. The dicing film 20 shown in FIG. 2A has a dicing film base material 10 including only the first resin layer 1 and an adhesive layer 11 provided on its surface. The dicing film 20 shown in FIG. 2B has a dicing film base material 10 including the first resin layer 1 and the first resin layer 1. 2. The cutting film base material 10 of the resin layer 2 and the adhesive layer 11 provided on its surface.

The cutting film is preferably formed with an adhesive layer on the outermost surface layer. The adhesive layer is arranged on the surface of the cutting film base material. The cutting film can be attached to the semiconductor wafer through the adhesive layer to perform cutting of the semiconductor wafer. Furthermore, in FIG. 2B , the adhesive layer 11 is disposed on the first resin layer 1 including the resin composition for the dicing film base material of the present invention, but the present invention is not limited to this configuration. The adhesive layer 11 can also be disposed on the second resin layer 2 (or other resin layers).

<Adhesive layer>

The dicing film of the present invention includes the dicing film base material of the present invention and an adhesive layer provided on one side of the dicing film base material, and the semiconductor wafer to be diced is bonded and fixed to the adhesive layer. The thickness of the adhesive layer also depends on the type of adhesive, preferably 3 to 100 μm, and more preferably 3 to 50 μm.

As the adhesive constituting the adhesive layer, conventionally known adhesives can be used. Examples of adhesives include: rubber-based, acrylic-based, polysilicone-based, polyvinyl ether-based adhesives; radiation hardening adhesives; heating foaming adhesives, etc. Among them, considering the peelability of the dicing film from the semiconductor wafer, etc., the adhesive layer preferably contains an ultraviolet curable adhesive.

Examples of acrylic adhesives that can constitute the adhesive layer include homopolymers of (meth)acrylate and copolymers of (meth)acrylate and copolymerizable monomers. Specific examples of (meth)acrylate include: (methyl)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (meth)acrylate )Alkyl (meth)acrylates such as octyl acrylate, isononyl (meth)acrylate, etc., hydroxyethyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyhexyl (meth)acrylate, etc. Hydroxyalkyl (meth)acrylate, glycidyl (meth)acrylate, etc.

Specific examples of copolymerizable monomers with (meth)acrylate include: (meth)acrylic acid, itaconic acid, maleic anhydride, (meth)acrylamide, (meth)acrylic acid N-hydroxyl group Methylamide, alkylaminoalkyl (meth)acrylate (for example, dimethylaminoethyl methacrylate, tert-butylaminoethyl methacrylate, etc.), vinyl acetate, benzene Ethylene, acrylonitrile, etc.

The ultraviolet curable adhesive that can form the adhesive layer is not particularly limited and contains the above-mentioned acrylic adhesive, an ultraviolet curable component (a component that can add carbon-carbon double bonds to the polymer side chain of the acrylic adhesive), and photopolymerization starter. Furthermore, additives such as a cross-linking agent, an adhesion-imparting agent, a filler, an anti-aging agent, and a colorant may be added to the ultraviolet curing adhesive as necessary.

Examples of ultraviolet curing ingredients contained in ultraviolet curing adhesives Such as monomers, oligomers or polymers that have carbon-carbon double bonds in the molecule and can be hardened by free radical polymerization. Specific examples of ultraviolet curing components include: trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol ( Meth)acrylate, neopentyl glycol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate and other esters of (meth)acrylic acid and polyols or their oligomers; cyanuric acid 2-propenyl Di-3-butenyl ester, 2-hydroxyethyl bis(2-propenyloxyethyl) isocyanurate, tris(2-propenyloxyethyl)isocyanurate, triisocyanurate Isocyanurates such as (2-methacryloyloxyethyl) ester, etc.

、十二烷基9-氧硫

、二甲基9-氧硫

、二乙基9-氧硫

等9-氧硫

類等。 Specific examples of photopolymerization initiators contained in ultraviolet curing adhesives include: benzoin alkyl ethers such as benzoin methyl ether, benzoin isopropyl ether, and benzoin isobutyl ether, and aromatic compounds such as α-hydroxycyclohexyl phenyl ketone. Ketones, aromatic ketals such as benzyl dimethyl ketal, polyvinyl benzophenone, chlorine-9-oxosulfide

, dodecyl 9-oxosulfide

, dimethyl 9-oxosulfide

, diethyl 9-oxosulfide

Etc. 9-oxysulfur

Class etc.

Examples of cross-linking agents contained in UV-curable adhesives include polyisocyanate compounds, melamine resins, urea resins, polyamines, carboxyl-containing polymers, etc.

Preferably, a release film is attached to the surface of the adhesive layer of the cutting film of the present invention. By attaching a release film, the surface of the adhesive layer can be kept smooth. In addition, the film for semiconductor manufacturing can be easily handled and transported, and marking processing can also be performed on the isolation film.

The isolation film can be paper, or a synthetic resin film such as polyethylene, polypropylene, polyethylene terephthalate, etc. In addition, the surface of the isolation film that is in contact with the adhesive layer may be subjected to a release treatment such as silicone treatment or fluorine treatment if necessary to improve the peelability of the self-adhesive layer. The thickness of the isolation film is usually about 10 to 200 μm, preferably about 25 to 100 μm.

<Manufacturing method of cutting film>

When manufacturing the cutting film of the present invention, the following method can be used, that is, using a known method such as a gravure roll coater, a reverse roll coater, a contact roll coater, a dip roll coater, and a rod coater. , blade coater, spray coater, etc. to directly apply the adhesive to the cutting film base material, or apply the adhesive to the peeling sheet by the above-mentioned known method and then lay the adhesive layer on the peeling sheet. Methods of cutting the surface layer of the film substrate and transferring the adhesive layer, etc.

Furthermore, by co-extruding the resin composition of the present invention and the material constituting the adhesive layer (co-extrusion molding method), a dicing film as a laminate of the dicing film base material and the adhesive layer of the present invention can be obtained. Furthermore, by providing a second resin layer on the base material (first resin layer) side of the obtained laminate, a dicing film having a dicing film base material including a first resin layer and a second resin layer can also be produced.

Moreover, if necessary, the layer of the adhesive composition may be heated and cross-linked to form an adhesive layer.

Furthermore, a separation film may be attached to the surface of the adhesive layer.

[Example]

Next, the present invention will be described in detail based on examples, but the present invention is not limited to these examples.

1.Resin(A)

As the resin (A), an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer or an ethylene-unsaturated carboxylic acid copolymer zinc (Zn) ion-neutralized ion polymer ( Hereinafter, referred to as "ionic polymer").

[Table 1]

2.Resin(B)

As the resin (B), an ethylene-based copolymer shown in Table 2 below was prepared.

The Fica softening temperatures in Tables 1 and 2 are values measured based on the A50 method specified in JIS K7206-1999.

The MFR (melt flow rate) in Table 2 is a value measured at 190°C and a load of 2160g in accordance with JIS K7210-1999.

The melting points in Table 2 are values measured by the DSC method.

3.Resin(C)

As the resin (C), ionomer 1 (IO-1) (the same as used as the resin (A)) was prepared (see Table 1 above).

(Example 1)

Dry blend resin (A) and resin (B) in the ratio (mass %) shown in Table 3. Then, the dry-blended mixture was put into the resin input port of a 40mmΦ single-screw extruder, and melt-kneaded at a die nozzle temperature of 200°C to obtain a resin composition for the first resin layer.

Using two types of two-layer 40mmΦT-shaped mold film forming machines, the obtained resin composition for the first resin layer and the resin (C) for the second resin layer were put into their respective extruders, and the processing temperature was 240°C. Forming is carried out to produce two types of 2-layer T-shaped mold films with a thickness of 100 μm. The thickness ratio of the first layer and the second layer in the 100 μm-thick laminated film having a double-layer structure was set to 60/40.

(Examples 2 to 8 and 12 to 14, Comparative Examples 1 to 3, 5 and 10)

The resin composition for the first resin layer was produced in the same manner as in Example 1 except that the types and amounts of resin (A) and resin (B) were changed as shown in Table 3 or Table 4. Next, except that the thicknesses of the first resin layer and the second resin layer were changed as shown in Table 3 or Table 4, a laminate including the first resin layer and the second resin layer was produced in the same manner as in Example 1. membrane.

(Examples 9 to 11, Comparative Examples 4 and 6 to 9)

The resin composition for the first resin layer was produced in the same manner as in Example 1 except that the types and amounts of resin (A) and resin (B) were changed as shown in Table 3 or Table 4. Then, without using resin (C), the prepared resin composition is used, In the same manner as in Example 1, a layer of T-shaped mold film with a thickness of 100 μm was produced.

The resin composition and film for the first resin layer obtained in the above-mentioned Examples and Comparative Examples were evaluated by the following method. The evaluation results are shown in Table 3 or Table 4.

(1) Neutralization degree of resin composition

The degree of neutralization is calculated based on the degree of neutralization of resin (A) and its content.

(2) MFR of resin composition

MFR is measured in accordance with JIS K7210-1999 at 190°C and 2160g load.

(3) Fica softening temperature of resin composition

Fika softening temperature is measured according to the A50 method specified in JIS K7206-1999.

(4)Shrinkage rate at 80℃

The resin composition was formed on a film with a thickness of 100 μm, cut into a shape of 25 mm in the width direction × 150 mm in the length direction, and marked with marking lines at intervals of 100 mm to prepare a test piece sample. Starch to prevent film adhesion (Nikkari powder, manufactured by Nikka Co., Ltd.) was sprinkled on the glass plate, a test piece sample was placed on it, and it was heated at 80° C. for 2 minutes on the hot plate of the pressure molding machine. Measure the distance between the markings on the film after heating, and calculate the shrinkage (%) according to the following formula.

Shrinkage rate (%)=100mm-distance between marking lines after shrinkage (mm)/100 mm×100

(5) Tensile test (modulus)

The cutting film base material was cut into short strips with a width of 10 mm and used as measurement objects. According to JIS K7127, under the conditions of test piece: width 10mm × length 200mm, clamp spacing: 100mm, the film strength (25%) is measured when the elongation distance in the MD direction and TD direction of the object is 25% and 50% respectively. Modulus and 50% modulus) are measured. Furthermore, the test speed is set to 500mm/min.

[table 3]

[Table 4]

Regarding the use of 30 parts by mass or more and 90 parts by mass or less of the resin (A) as an ionic polymer containing an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer (terpolymer) and the resin (B) as an ethylene-based copolymer ) 10 parts by mass or more and 70 parts by mass or less, and the resin composition having a Fica softening point of less than 50°C, the slit film base material of the example is excellent in both thermal (80°C) shrinkage and strength. On the other hand, the resin composition of Comparative Example 1 obtained using an ionic polymer of a binary copolymer had a Fica softening point exceeding 50°C. The thermal shrinkage rate of the cutting film base material produced using this resin composition is low. The dicing film base materials produced using the resin compositions of Comparative Examples 2 and 3, which contain resin (A) and resin (B) but have a Ficar softening point exceeding 50°C, also have a lower thermal shrinkage rate as in Comparative Example 1. Low.

Example obtained using a resin composition containing 70 to 90 parts by mass of resin (A) and 30 to 10 parts by mass of resin (B), and having a Fica softening point of less than 50°C. Although the cutting film base material of 9~11 is a single layer, it exhibits sufficient strength and heat shrinkability at the same time.

The resin compositions of Comparative Examples 4 and 5 containing more than 90 parts by mass of the resin (A) and less than 10 parts by mass of the resin (B) have a Fica softening point exceeding 50°C. Although the cutting film base material produced using this resin composition has high strength, it has a low thermal shrinkage rate. Similarly, although the dicing film base materials of Comparative Examples 6 to 10 using ionomers as the first resin layer also showed higher strength, their thermal shrinkage rates were lower. In particular, the ionic polymer 2 used in Comparative Example 7 has a low thermal shrinkage rate even though the Fica softening point is less than 50°C.

From these results, it can be seen that in order to obtain a dicing film base material that has both high strength and high thermal shrinkage, it is important to use the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer in the resin composition as the raw material. Content of ionic polymer (resin (A)) It is 30 parts by mass or more and 90 parts by mass or less, the content of the resin (B) which is a vinyl copolymer is 10 parts by mass or more and 70 parts by mass or less, and the Fika softening point is less than 50°C.

This application claims priority based on Japanese Patent Application No. 2018-149562, which was filed on August 8, 2018. All contents recorded in the application specification are quoted in the specification of this case.

(industrial availability)

The dicing film of the present invention can be preferably used in a manufacturing method of a semiconductor element that performs not only the dicing step and the expanding step of dividing the semiconductor wafer into wafer units, but also the heat shrinking step. In particular, since the dicing film of the present invention has both high strength and high thermal shrinkage, it can be preferably used to apply a method to the dicing film in the expansion step than conventional methods (blade cutting method or laser ablation method, etc.) A manufacturing method using invisible cutting (registered trademark) method for high stress. By using the dicing film of the present invention, the distance between divided wafers can be made uniform, product defects in subsequent steps can be reduced, and semiconductor devices can be manufactured at a higher yield.

1‧‧‧The 1st resin layer

2‧‧‧The second resin layer

10‧‧‧Cutting film substrate

Claims (9)

A resin composition for cutting film base materials, which contains: 30 to 90 parts by mass of an ionic polymer (A) of an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, and an ethylene-based copolymer (A) B) 10 parts by mass or more and 70 parts by mass or less (where the total of component (A) and component (B) is 100 parts by mass), and the above-mentioned ethylene-based copolymer (B) is specified in JIS K7206-1999 The resin has a FICA softening point of 41°C or lower, or a resin that does not have the above FICA softening point; the FICA softening point specified in JIS K7206-1999 for the above-mentioned resin composition for cutting film substrates is less than 50°C. The resin composition for a dicing film base material according to claim 1, wherein the ionic polymer (A) of the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer has a FICA softening point specified in JIS K7206-1999 It is above 25℃ and below 60℃. The resin composition for dicing film substrates according to claim 1, wherein the ethylene copolymer (B) is selected from the group consisting of ethylene-α-olefin copolymer and ethylene-unsaturated carboxylate copolymer. At least one. The resin composition for a dicing film base material according to claim 1, wherein the melt flow rate (MFR) of the ethylene-based copolymer (B) is measured at 190° C. and a load of 2160 g according to the method of JIS K7210-1999. It is 0.2g/10 minutes~30.0g/10 minutes. The resin composition for dicing film base materials according to Claim 1, wherein the melt flow rate (MFR) of the resin composition for dicing film base materials is measured at 190°C and a load of 2160 g according to the method of JIS K7210-1999. ) is 0.1g/10 minutes ~ 50g/10 minutes. A dicing film base material containing at least one layer containing the resin composition for dicing film base materials of claim 1. The dicing film base material of Claim 6, which contains: a first resin layer containing the resin composition for the dicing film base material of Claim 1, and a second resin containing resin (C) laminated on the first resin layer. layer. The cutting film base material of claim 7, wherein the resin (C) is selected from the group consisting of an ethylene-unsaturated carboxylic acid copolymer and an ionic polymer of the ethylene-unsaturated carboxylic acid copolymer. At least 1 species. A dicing film characterized by having: the dicing film base material according to any one of claims 6 to 8; and an adhesive layer laminated on at least one side of the dicing film base material.

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