JPWO2020031928A1 - Resin composition for dicing film base material, dicing film base material and dicing film - Google Patents

Abstract

Provided is a resin composition for a dicing film base material for producing a dicing film having both high strength and high heat shrinkage. Ionomer (A) of 30 parts by mass or more and 90 parts by mass or less of ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer, and ethylene-based copolymer (B) of 10 parts by mass or more and 70 parts by mass or less (however, components) A resin composition for a dicing film substrate, which contains (the total of (A) and component (B) is 100 parts by mass) and has a bicut softening point of less than 50 ° C. as defined by JIS K7206-1999. And a base material for a dicing film and a dicing film using the resin composition.

Description

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

In the manufacturing process of semiconductor devices such as ICs, it is common to thin a semiconductor wafer on which a circuit pattern is formed and then perform a dicing step for dividing the semiconductor wafer into chip units. In the dicing step, a stretchable wafer processing film (called a dicing film or a dicing tape) is attached to the back surface of the semiconductor wafer, and then the semiconductor wafer is divided into chip units by a dicing blade, laser light, or the like. Then, in the next expansion step (also referred to as an expanding step), the chip is made into small pieces by expanding the dicing tape corresponding to the cut wafer.

In the expanding step, for example, the dicing film is expanded (expanded) by pushing up the expansion table provided under the dicing film. At this time, in order to divide the chip, it is important that the dicing film spreads uniformly over the entire surface of the expansion table. Further, since the stress applied to the dicing film at the peripheral portion of the expansion table is larger than that at the central portion of the expansion table, the dicing film after the expansion step has slack in the portion corresponding to the peripheral portion of the expansion table. Such slack can make the intervals between the divided chips uneven, and can cause product defects in a later process.

As a means for eliminating the slack of the dicing film, a heat shrink process is known in which the slack portion is contracted by blowing warm air at an actual temperature of about 80 to 100 ° C. to heat the film and restore it to its original state. (See, for example, Patent Document 1). In order to carry out this step, the dicing film needs to have high heat shrinkage at a temperature of about 80 ° C.

In addition, the stealth dicing (registered trademark) method is a dicing method that has been attracting attention in recent years. In this method, cracks are formed not on the surface of the wafer but on the inside by laser light, and in the next expansion step carried out at a low temperature (about -15 ° C to 0 ° C), the stress of the dicing film is used to form the wafer. Divide. By doing so, it is possible to suppress the loss of the semiconductor product in the dicing process and increase the yield. The dicing film used here is required to have both strength that can withstand the stress required for dividing the wafer and heat shrinkage for eliminating the slack that may occur when the wafer is divided by the heat shrink process. There is.

As a base material for a dicing film used for a dicing film, a dicing film base material having an ionomer obtained by cross-linking a compound having a carboxyl group with a cation and an octene-containing copolymer (Patent Document 2), Bicut specified by JIS K7206. A dicing film base material having a bottom layer made of a thermoplastic resin having a softening point of 80 ° C. or higher and another layer made of a thermoplastic resin having a bicut softening point of 50 ° C. or higher and lower than 80 ° C. defined by JIS K7206 (patented). Document 3) and a dicing film base material (Patent Document 4) made of a thermoplastic resin having a Vicat softening point of 50 ° C. or higher and lower than 90 ° C. defined by JIS K7206 are known.

Further, in Patent Document 5, as a dicing film having excellent expandability suitable for stealth dicing (registered trademark), the initial elastic modulus at −10 ° C. is 200 MPa or more and 380 MPa or less, and Tanδ (loss elastic modulus / storage). A dicing film having an elastic modulus of 0.080 or more and 0.3 or less is disclosed.

JP-A-9-007976 Japanese Unexamined Patent Publication No. 2000-345129 JP-A-2009-231700 Japanese Unexamined Patent Publication No. 2011-216508 Japanese Unexamined Patent Publication No. 2015-185591

Patent Document 1 describes, as dicing films capable of removing slack by a heat shrink step, for example, an ionomer having a melting point of 71 ° C. (an ionomer of a ternary polymer obtained by polymerizing an acrylic acid ester, a methacrylic acid ester, or the like). A dicing film or the like having a layer made of a blend with an ethylene-vinyl acetate copolymer is described. However, there is no description about the basic performance required for the dicing film, such as the expandability and strength of the dicing film.

Patent Document 2 describes, as a specific example of the base material for a dying film, a base material for a dying film having an ionomer such as a ternary copolymer of ethylene / methacrylic acid / acrylic acid ester and an octene-containing copolymer. Has been done. However, there is no description about the heat shrinkage of the dicing film.

The dicing film base material of Patent Document 3 having a layer made of a thermoplastic resin having a Vicat softening point of 80 ° C. or higher, and the dicing film base material of Patent Document 4 made of a thermoplastic resin having a Vicat softening point of 50 ° C. or higher and lower than 90 ° C. According to the research by the present inventors, it is considered that the heat shrinkage at 80 ° C. is low, and it is difficult to restore the slack to the original state by the heat shrink process.

Further, Patent Document 5 describes a dicing film having a base material containing an ethylene / α-olefin copolymer and an ionomer of an ethylene / α-olefin copolymer. However, dicing containing an ionomer of a multi-element copolymer of three or more elements such as ethylene, an unsaturated carboxylic acid, and an unsaturated carboxylic acid ester, and a resin composition containing a multi-element copolymer of three or more elements and an ethylene-based copolymer. There is no description about the substrate for film.

The present invention has been made in view of the problems of the prior art, and the subject thereof is a dicing film base material for producing a dicing film having both high strength and high heat shrinkage. The purpose is to provide a resin composition for use. Further, an object of the present invention is to provide a dicing film base material and a dicing film using the resin composition for a dicing film base material of the present invention.

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

[1] 30 parts by mass or more and 90 parts by mass or less of the ionomer (A) of the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer, and 10 parts by mass or more and 70 parts by mass or less of the ethylene-based copolymer (B) ( However, the total of the component (A) and the component (B) is 100 parts by mass), and the bicut softening point defined by JIS K7206-1999 is less than 50 ° C. Composition.
[2] The vicut softening point of the ionomer (A) of the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer defined by JIS K7206-1999 is 25 ° C. or higher and 60 ° C. or lower. [1] ]. The resin composition for a dicing film base material.
[3] The ethylene-based copolymer (B) is a resin having a Vicat softening point of 50 ° C. or lower as defined by JIS K7206-1999, or a resin having no Vicat softening point, [1] or [2]. ]. The resin composition for a dicing film base material.
[4] The ethylene-based copolymer (B) is at least one selected from the group consisting of ethylene / α-olefin copolymers and ethylene / unsaturated carboxylic acid ester copolymers, [1] to [3]. ] The resin composition for a dicing film base material according to any one of.
[5] The melt flow rate (MFR) of the ethylene-based copolymer (B) measured at 190 ° C. and a load of 2160 g by a method according to JIS K7210-1999 is 0.2 g / 10 min to 30. The resin composition for a dicing film substrate according to any one of [1] to [4], which is 0 g / 10 minutes.
[6] The melt flow rate (MFR) of the resin composition for a dicing film base material measured at 190 ° C. and a load of 2160 g by a method according to JIS K7210-1999 is 0.1 g / 10 minutes to 50 g /. The resin composition for a dicing film base material according to any one of [1] to [5], which takes 10 minutes.
[7] A dicing film base material containing at least one layer containing the resin composition for the dicing film base material according to any one of [1] to [6].
[8] A first resin layer containing the resin composition for a dicing film base material according to any one of [1] to [6] and a resin (C) laminated on the first resin layer are included. The dicing film base material according to [7], which comprises a second resin layer.
[9] The resin (C) is at least one selected from the group consisting of an ethylene / unsaturated carboxylic acid-based copolymer and an ionomer of the ethylene / unsaturated carboxylic acid-based copolymer, according to [8]. The dicing film substrate according to the description.
[10] A dicing film comprising the dicing film base material according to the item 1 of [7] to [9] and an adhesive layer laminated on at least one surface of the dicing film base material. ..

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

It is sectional drawing which shows one Embodiment of the dicing film base material of this invention. It is sectional drawing which shows one Embodiment of the dicing film base material of this invention. It is sectional drawing which shows one Embodiment of the dicing film of this invention. It is sectional drawing which shows one Embodiment of the dicing film of this invention.

Hereinafter, the resin composition for a 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.
In the present specification, the notation of "~" indicating the numerical range includes the lower limit value and the upper limit value of the numerical range.
Further, "(meth) acrylic acid" is a notation used to include both "acrylic acid" and "methacrylic acid", and "(meth) acrylate" refers to both "acrylate" and "methacrylate". It is a notation used by including it.

In the manufacturing process of a semiconductor wafer, the dicing film is high at a temperature of around 80 ° C. in order to remove (restore to the original state) the slack of the dicing film after the expanding process by utilizing the heat shrinkage of the film. Must be heat shrinkable. In the present invention, 30 parts by mass or more and 90 parts by mass or less of the ionomer (A) of the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer and 10 parts by mass or more and 70 parts by mass of the ethylene-based copolymer (B). By producing a dicing film base material using a resin composition containing the following (however, the total of the component (A) and the component (B) is 100 parts by mass), high strength and high heat shrinkage can be obtained. We were able to produce a compatible dicing film. The mechanism is not clear, but it is thought to be as follows.

It is known that an ethylene-based copolymer enhances its heat shrinkage by blending it with a polyolefin-based resin. However, when a film is produced from a resin composition containing a polyolefin-based resin and an ethylene-based copolymer, the strength and expandability of the film are insufficient for a dicing film. On the other hand, in the present invention, a resin composition having a Vicat softening point of less than 50 ° C. is produced by using an ionomer of an ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer and an ethylene-based copolymer. By doing so, it was possible to obtain a dicing film having improved heat shrinkage without significantly reducing the film strength and expandability (divisionability) derived from the ionomer's ion-crosslinked structure.

The dicing film of the present invention can be suitably used in a method for manufacturing a semiconductor device that carries out a heat shrink step in addition to a dicing step and an expansion step for dividing a semiconductor wafer into chip units. In particular, since the dicing film of the present invention has both high strength and high heat shrinkage, stealth dicing in which a larger stress is applied to the dicing film than in the conventional method (blade dicing method, laser ablation method, etc.) in the expansion process. It can be suitably used for a manufacturing method that employs the (registered trademark) method. By using the dicing film of the present invention, it is possible to make the chip spacing after division uniform, reduce product defects in the subsequent steps, and manufacture a semiconductor device with a high 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. 1. Resin composition for dicing film base material The first aspect of the present invention is a resin composition for a dicing film base material. The resin composition for the base material of the dicing film contains 30 parts by mass or more and 90 parts by mass or less of the ionomer (A) of the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer and 10 parts by mass of the ethylene-based copolymer (B). It contains 70 parts by mass or more (however, the total of the component (A) and the component (B) is 100 parts by mass).

1-1. Resin (A)
The ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer ionomer used as the resin (A) (hereinafter, also simply referred to as “ionomer (A)”) is an ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid. A part or all of the carboxyl groups of the ester copolymer are neutralized with a metal (ion). In the present invention, at least a part of the acid group of the copolymer is neutralized with a metal (ion) as an "ionomer", and the acid group of the copolymer is not neutralized with a metal (ion). Is referred to as a "copolymer".

The ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer constituting the ionomer (A) has at least a ternary copolymerization of ethylene, an unsaturated carboxylic acid, and an unsaturated carboxylic acid ester. It may be a multi-element copolymer of four or more elements, which is a coalescence and further copolymerized with a fourth copolymerization component. The ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer may be used alone, or two or more kinds of ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer may be used in combination. May be good.

Examples of the unsaturated carboxylic acid constituting the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer include acrylic acid, methacrylic acid, etaclilic acid, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, and malein. Examples thereof include unsaturated carboxylic acids having 4 to 8 carbon atoms such as acids and maleic anhydride. In particular, acrylic acid or methacrylic acid is preferable.

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

When the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer is a quaternary or more multidimensional copolymer, it may contain a monomer (fourth copolymerization component) that forms the multidimensional copolymer. The fourth copolymerization component includes unsaturated hydrocarbons (eg, propylene, butene, 1,3-butadiene, penten, 1,3-pentadiene, 1-hexene, etc.), vinyl esters (eg, vinyl acetate, propionic acid, etc.). (Vinyl, etc.), oxides such as vinyl sulfuric acid and vinyl nitrate, halogen compounds (for example, vinyl chloride, vinyl fluoride, etc.), vinyl group-containing primary and secondary amine compounds, carbon monoxide, sulfur dioxide, and the like can be mentioned.

The form of the copolymer may be any of a block copolymer, a random copolymer, and a graft copolymer, and may be any of a ternary copolymer and a quaternary or more multidimensional copolymer. Among them, a ternary random copolymer or a graft copolymer of a ternary random copolymer is preferable, and a ternary random copolymer is more preferable, because it is industrially available.

Specific examples of the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer include ternary copolymers such as ethylene / methacrylic acid / acrylic acid butyl ester copolymer.

Unsaturated carboxylic acid when the total amount of the constituent units constituting the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer in the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer is 100% by mass. The content ratio of the constituent unit derived from the acid 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. Unsaturated when the total amount of the constituent units constituting the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer in the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer is 100% by mass. The content ratio of the structural unit derived from the carboxylic acid ester is preferably 1% by mass or more and 20% by mass or less, more preferably 5% by mass or more and 18% by mass or less, and particularly preferably 5% by mass or more and 17% by mass or less. The content ratio of the constituent unit derived from the unsaturated carboxylic acid ester is preferably 1% by mass or more, preferably 5% by mass or more, from the viewpoint of film expandability. The content ratio of the constituent unit derived from the unsaturated carboxylic acid ester is preferably 20% by mass or less, more preferably 18% by mass or less, and 17% by mass from the viewpoint of preventing blocking and fusion. The following is particularly preferable.

In the ionomer (A) used as the resin (A) in the present invention, the carboxyl group contained in the above ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer is crosslinked (neutralized) by metal ions at an arbitrary ratio. Is preferable. Examples of the metal ion used for neutralizing the acid group include metal ions such as lithium ion, sodium ion, potassium ion, rubidium ion, cesium ion, zinc ion, magnesium ion and manganese ion. Among these metal ions, magnesium ion, sodium ion and zinc ion are preferable, sodium ion and zinc ion are more preferable, and zinc ion is particularly preferable, from the viewpoint of availability of industrialized products.
One type of metal ion may be used alone, or two or more types may be used in combination.

The degree of neutralization of the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer in the ionomer (A) (hereinafter, also referred to as “the degree of neutralization of the ionomer (A)”) is not particularly limited, but is 10% or more. 100% is preferable, and 30% to 100% is more preferable. When the degree of neutralization is within the above range, the film strength and breakability are improved, which is preferable.
The degree of neutralization of the ionomer (A) is the degree of neutralization of the carboxyl groups neutralized by metal ions with respect to the number of moles of all the carboxyl groups contained in the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer. Percentage (mol%).

As the ionomer (A) of the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer, a commercially available product on the market may be used. Examples of commercially available products include the Hymilan (registered trademark) series manufactured by Mitsui-DuPont Polychemical Co., Ltd.

The melt flow rate (MFR) of the ionomer (A) of ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester is preferably in the range of 0.2 g / 10 minutes to 20.0 g / 10 minutes, and 0.5 g / 10 minutes. It is more preferably ~ 20.0 g / 10 minutes, and even more preferably 0.5 g / 10 minutes to 18.0 g / 10 minutes. When the melt flow rate is within the above range, it is advantageous when molding the film.
The MFR is a value measured at 190 ° C. and a load of 2160 g by a method based on JIS K7210-1999.

Further, the vicat softening point of the ionomer (A) of ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester is preferably 25 ° C. or higher and 60 ° C. or lower, and more preferably 35 ° C. or higher and 60 ° C. or lower. When the Vicat softening point of the ionomer (A) is within the above range, it is easy to adjust the Vicat softening point of the resin composition to less than 50 ° C.
The Vicat softening point is a value measured according to the A50 method defined in JIS K7206-1999.

The content of the resin (A) in the resin composition for a dicing film base material of the present invention is 30 parts by mass or more and 90 parts by mass or less with respect to a total of 100 parts by mass of the resin (A) and the resin (B) described later. It is preferably 40 parts by mass or more and 90 parts by mass or less, and more preferably 50 parts by mass or more and 70 parts by mass or less. When the content of the resin (A) is 30 parts by mass or more, sufficient strength as a dicing film can be obtained, and when it is 90 parts by mass or less, the heat 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 another monomer, and the type thereof. Is not particularly limited. However, when a resin composition is prepared together with the above-mentioned ionomer (A), it is important to combine the ionomer (A) and the copolymer (B) so that the bicut softening point of the composition is less than 50 ° C. Is. From this point of view, the copolymer (B) is preferably a resin having a Vicat softening point of 50 ° C. or lower, or a resin having no Vicat softening point. When the copolymer (B) has a Vicat softening point, the Vicat softening point is preferably 25 ° C. or higher from the viewpoint of processability.
The Vicat softening point is a value measured according to the A50 method defined in JIS K7206-1999.

Examples of the ethylene-based copolymer (B) used in the present invention include an ethylene / α-olefin copolymer, an ethylene / unsaturated carboxylic acid ester copolymer, and an ethylene / vinyl ester copolymer. Ethylene / α-olefin copolymers and ethylene / unsaturated carboxylic acid ester copolymers are preferable.

The ethylene / α-olefin copolymer is a copolymer of ethylene and an α-olefin. The copolymer may contain only one type of α-olefin, or may contain two or more types of α-olefin. 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 and the like are included. Of these, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene are preferable because of their availability. The ethylene / α-olefin copolymer may be a random copolymer or a block copolymer, and a random copolymer is preferable.

The content ratio of the ethylene-derived structural unit contained in the ethylene / α-olefin copolymer is not particularly limited, but is preferably more than 50 mol% and 95 mol% or less, and 70 mol% or more and 94 mol% or less. Is more preferable. The proportion of the constituent unit derived from the α-olefin (hereinafter, also referred to as “α-olefin unit”) contained in the ethylene / α-olefin copolymer is preferably 5 mol% or more and less than 50 mol%, preferably 6 mol% or more. It is more preferably 30 mol% or less. Such an ethylene / α-olefin copolymer is advantageous in ensuring shrinkage.

The ethylene / α-olefin copolymer having a density of 895 kg / m ³ or less, particularly 860 to 890 kg / m ³ , is preferable.

The ethylene / unsaturated carboxylic acid ester copolymer is a copolymer of ethylene and an unsaturated carboxylic acid ester. The copolymer may contain only one unsaturated carboxylic acid ester constituent unit, or may contain two or more unsaturated carboxylic acid ester constituent units. Examples of the unsaturated carboxylic acid constituting the unsaturated carboxylic acid ester constituent unit include carbons such as acrylic acid, methacrylic acid, etaclilic acid, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, maleic acid, and maleic anhydride. Examples thereof include unsaturated carboxylic acids of numbers 4 to 8. In particular, acrylic acid or methacrylic acid is preferable.

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

When the total amount of the constituent units constituting the ethylene / unsaturated carboxylic acid ester copolymer in the ethylene / unsaturated carboxylic acid ester copolymer is 100% by mass, the content ratio of the constituent units derived from the unsaturated carboxylic acid ester is It is preferably 5% by mass or more and 40% by mass or less, more preferably 7% by mass or more and 40% by mass or less, and particularly preferably 8% by mass or more and 40% by mass or less. It is preferable that the content ratio of the constituent unit derived from the unsaturated carboxylic acid ester is not more than the above upper limit value from the viewpoint of film processability. Further, when the content ratio of the constituent unit derived from the unsaturated carboxylic acid ester is at least the above lower limit value, it is preferable from the viewpoint of shrinkage.

The melt flow rate (MFR) of the ethylene-based copolymer (B) is preferably in the range of 0.2 g / 10 minutes to 30.0 g / 10 minutes, more preferably 0.5 g / 10 minutes to 25.0 g / 10 minutes. preferable. When the melt flow rate is within the above range, it is advantageous when molding the resin composition.
The MFR is a value measured at 190 ° C. and a load of 2160 g by a method based on JIS K7210-1999.

Further, the melting point of the ethylene-based copolymer (B) is preferably 30 ° C. or higher and 100 ° C. or lower, and more preferably 30 ° C. or higher and 80 ° C. or lower.
The melting point is the melting temperature measured by a differential scanning calorimeter (DSC) in accordance with JIS-K7121 (1987).

The content of the resin (B) in the resin composition for a dicing film base material is 10 parts by mass or more and less than 70 parts by mass with respect to a total of 100 parts by mass of the resin (A) and the resin (B), and is 10 parts by mass. It is preferably 60 parts by mass or more, and 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 improving the heat shrinkage rate by the resin (B) is exhibited, and if it is less than 70 parts by mass, the strength of the dicing film base material may be insufficient. Is low.

1-3. Other Polymers and Additives Other polymers and various additives may be added to the resin composition for a dicing film base material, if necessary, as long as the effects of the present invention are not impaired. Examples of other polymers include polyamides, polyurethanes, and binary copolymer ionomers. Such other polymers can be blended in a proportion of, for example, 20 parts by mass or less with respect to a total of 100 parts by mass of the resin (A) and the resin (B). Examples of additives include antistatic agents, antioxidants, heat stabilizers, light stabilizers, UV absorbers, pigments, dyes, lubricants, blocking inhibitors, antistatic agents, fungicides, antibacterial agents, flame retardants, Examples thereof include flame retardant aids, cross-linking agents, cross-linking aids, foaming agents, foaming aids, inorganic fillers, fiber reinforcing materials and the like.

1-4. Physical Properties of Resin Composition The resin composition of the present invention has a Vicat softening point of less than 50 ° C., preferably 25 ° C. or higher and lower than 50 ° C., as defined by JIS K7206-1999. When the Vicat softening point of the resin composition is less than 50 ° C., the heat shrinkage rate is improved, and when it is 25 ° C. or higher, the resin composition can be processed into a film.

In the resin composition of the present invention, the melt flow rate (MFR) measured at 190 ° C. and a load of 2160 g is preferably 0.1 g / 10 minutes to 50 g / 10 minutes, preferably 0.5 g / 10 minutes to. More preferably, it is 20 g / 10 minutes.
The MFR is a value measured at 190 ° C. and a load of 2160 g by a method based on JIS K7210-1999.

The degree of neutralization of the resin composition is not particularly limited, but is preferably 10% to 85%, more preferably 15% to 82%. When the degree of neutralization of the resin composition is 10% or more, the chip breakability can be further improved, and when it is 85% or less, the formability of the film is excellent. The degree of neutralization of the resin composition basically depends on the degree of neutralization of the ionomer (A) and its content, and can be calculated by the following formula. (Neutralization degree of resin composition) = (Neutralization degree of ionomer (A)) × (Ratio of ionomer (A) in resin composition)
Therefore, when the degree of neutralization of ionomer (A) is low, the content thereof is increased, and when the degree of neutralization of ionomer (A) is high, the content thereof is decreased. The degree of neutralization of the composition can be adjusted.

Further, in the resin composition of the present invention, the heat shrinkage rate of the film processed to a thickness of 100 μm at 80 ° C. is preferably 6% or more, more preferably 7% or more. When the heat shrinkage rate at 80 ° C. is 6% or more, it can be suitably used for producing a dicing film capable of eliminating slack by the heat shrink step. The upper limit of the heat shrinkage rate is not particularly limited, but is preferably 20% or less from the viewpoint of reducing the defect rate in the post-process (pickup process) after heat shrink.

In the present application, the heat 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 direction of 25 mm and a length direction of 150 mm, and marking was performed at a distance of 100 mm between marked lines to prepare a test piece sample. Place it on a glass plate dusted with starch powder, heat it on a hot plate at 80 ° C. for 2 minutes, measure the distance between the marked lines of the film after heating, and calculate the shrinkage rate (%) from the following formula. ..
Shrinkage rate (%) = 100 mm-distance between marked lines after shrinkage (mm) / 100 mm x 100

1-5. Method for Producing Resin Composition The resin composition for a dicing film base material can be obtained by mixing the resin (A) and the resin (B), and if necessary, other polymers and additives. As described above, since the resin composition of the present invention has a Vicat softening point of less than 50 ° C. as defined by JIS K7206-1999, the resin is prepared so that the Vicat softening point of the resin composition is less than 50 ° C. The type and amount of (A), resin (B) and, if desired, an additive are selected.

The method for producing the resin composition is not particularly limited, and for example, it can be obtained by dry-blending all the components and then melt-kneading.

2. The second aspect of the present invention is a dicing film base material containing at least one layer containing the above-mentioned resin composition for a dicing film base material. 1A and 1B are cross-sectional views showing an embodiment of the dicing film base material 10 of the present invention. FIG. 1A is a single-layer dying film base material composed of only the first resin layer 1 containing the above-mentioned resin composition for a dying film base material, and FIG. 1B contains the above-mentioned resin composition for a dying film base material. It is a multilayer dicing film base material in which a first resin layer 1 and a second resin layer 2 containing another resin or resin composition are laminated.

The strength of the dicing film substrate of the present invention preferably has a 25% modulus in the range of 5 MPa or more and 15 MPa or less, and more preferably 6 MPa or more and 12 MPa or less. When the 25% modulus is 5 MPa or more, the chip breakability (strength) as a dicing film base material is excellent, and when it is 15 MPa or less, the expandability is excellent.

The modulus in the present invention conforms to JIS K 7127-1999, and has a test speed of 500 mm / min in the MD direction (machine direction) and the TD direction (transverse direction) of the dicing film base material. Specimen: A value measured as a film strength (25% modulus or 50% modulus) at an elongation distance of 25% or 50% under the conditions of width 10 mm × length 200 mm and chuck distance: 100 mm.

The heat shrinkage rate of the dicing film substrate 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. When the heat shrinkage rate at 80 ° C. is 6% or more, the heat shrink property (elimination of slack) as a dicing film base material is excellent, and when it is 20% or less, the defect rate in the post-process (pickup process) after heat shrink. Excellent in reduction.
In the present application, the heat shrinkage rate at 80 ° C. is a value measured by the following method.
The dicing film base material was cut into a thickness of 100 μm, a width direction of 25 mm and a length direction of 150 mm, and marking was performed at a distance of 100 mm between marked lines to prepare a test piece sample. Place it on a glass plate dusted with starch powder, heat it on a hot plate at 80 ° C. for 2 minutes, measure the distance between the marked lines of the film after heating, and calculate the shrinkage rate (%) from the following formula. ..
Shrinkage rate (%) = 100 mm-distance between marked lines after shrinkage (mm) / 100 mm x 100

2-1. First Resin Layer The first resin layer is the above-mentioned resin composition for a dicing film base material, that is, 30 parts by mass or more and 90 parts by mass of ionomer (A) of an ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer. Contains 10 parts by mass or more and 70 parts by mass or less of the ethylene-based copolymer (B) (however, the total of the component (A) and the component (B) is 100 parts by mass), and JIS K7206-1999. A layer containing a resin composition for a dicing film substrate, which has a bicut softening point of less than 50 ° C. as defined in Further, the first resin layer may be a layer made of the resin composition for the dicing film base material. Such a resin composition layer has an excellent balance between strength and heat shrinkage.

When the dicing film base material has a single-layer structure, the content of ionomer (A) as a raw material is 70 parts by mass or more and 90 parts by mass or less, and the content of ethylene-based copolymer (B) is 10 parts by mass. It is preferably 30 parts by mass or more, the content of ionomer (A) is 80 parts by mass or more and 90 parts by mass or less, and the content of ethylene copolymer (B) is 10 parts by mass or more and 20 parts by mass or less (however). , The total of the component (A) and the component (B) is 100 parts by mass). As described above, by using the resin composition having a high ratio of ionomer (A), the strength required as a dicing film base material is achieved even if it is a single layer.

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

2-2. Second Resin Layer The second resin layer is a layer containing the resin (C) or a layer made of the resin (C), and the resin (C) has high adhesiveness to the resin composition constituting the first resin layer. As long as it is a resin, there is no particular limitation. By laminating the second resin layer containing (or consisting of) the resin (C) with the first resin layer, the strength of the dicing film base material is increased and dicing is performed without causing the problem of delamination. It is possible to maintain the balance between chip fragmentability and expandability required for the film.

<Resin C>
The resin (C) in the present invention is an ethylene / unsaturated carboxylic acid-based copolymer (hereinafter, also simply referred to as “copolymer (C)”) and an ionomer of the ethylene / unsaturated carboxylic acid-based copolymer (hereinafter, hereinafter. , It is preferable that it is at least one selected from the group consisting of simply "ionomer (C)"). The ionomer of the ethylene / unsaturated carboxylic acid-based copolymer used as the resin (C) was neutralized with a metal (ion) in part or all of the carboxyl groups of the ethylene / unsaturated carboxylic acid-based copolymer. It is a thing.
As will be described in detail below, the resin (C) may be the same resin as the resin (A) or the resin (B) contained in the resin composition constituting the first resin layer.

The above-mentioned copolymer (C) or the ethylene / unsaturated carboxylic acid-based copolymer constituting the ionomer (C) is at least a binary copolymer obtained by copolymerizing ethylene and an unsaturated carboxylic acid. Further, it may be a multi-element copolymer having three or more elements copolymerized with the third copolymerization component. The ethylene / unsaturated carboxylic acid-based copolymer may be used alone or in combination of two or more types of ethylene / unsaturated carboxylic acid-based copolymer.

Examples of the unsaturated carboxylic acid constituting the ethylene / unsaturated carboxylic acid binary copolymer include acrylic acid, methacrylic acid, etaclilic acid, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, maleic acid, and maleic anhydride. Examples thereof include unsaturated carboxylic acids having 4 to 8 carbon atoms such as acids. In particular, acrylic acid or methacrylic acid is preferable.

When the ethylene / unsaturated carboxylic acid-based copolymer (C) is a ternary or more ternary copolymer, it may contain a monomer (third copolymerization component) that forms the ternary copolymer. As the third copolymerization component, an unsaturated carboxylic acid ester (for example, methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate) , (Meta) acrylic acid alkyl esters such as dimethyl maleate, diethyl maleate), unsaturated hydrocarbons (eg, propylene, butene, 1,3-butadiene, penten, 1,3-pentadiene, 1-hexene, etc.), Vinyl esters (eg, vinyl acetate, vinyl propionate, etc.), oxides such as vinyl sulfuric acid and vinyl nitrate, halogen compounds (eg, vinyl chloride, vinyl fluoride, etc.), vinyl group-containing primary and secondary amine compounds, monoxide Examples thereof include carbon and sulfur dioxide, and unsaturated carboxylic acid esters are preferable as these copolymerization components.

For example, when the ethylene / unsaturated carboxylic acid-based copolymer (C) is a ternary copolymer, ethylene, a ternary copolymer of an unsaturated carboxylic acid and an unsaturated carboxylic acid ester, and ethylene , A ternary copolymer of unsaturated carboxylic acid and unsaturated hydrocarbon is preferable.

As the unsaturated carboxylic acid ester, an unsaturated carboxylic acid alkyl ester is preferable, and the alkyl moiety of the alkyl ester preferably has 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 4 carbon atoms. Examples of the alkyl moiety include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, 2-ethylhexyl, isooctyl and the like.

Specific examples of the unsaturated carboxylic acid ester include unsaturated carboxylic acid alkyl esters having 1 to 12 carbon atoms at the alkyl moiety (for example, methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, acrylate). Examples thereof include an acrylic acid alkyl ester such as isooctyl, a methacrylate alkyl ester such as methyl methacrylate, ethyl methacrylate and isobutyl methacrylate, and a maleic acid alkyl ester such as dimethyl maleate and diethyl maleate).
Among unsaturated carboxylic acid alkyl esters, (meth) acrylic acid alkyl esters having 1 to 4 carbon atoms at the alkyl moiety are more preferable.

The form of the copolymer may be any of a block copolymer, a random copolymer, and a graft copolymer, and may be any of a binary copolymer and a ternary or more plural copolymer. Among them, a binary random copolymer, a ternary random copolymer, a graft copolymer of a binary random copolymer, or a graft copolymer of a ternary random copolymer is preferable because it is industrially available. , More preferably a binary random copolymer or a ternary random copolymer.

Specific examples of the ethylene / unsaturated carboxylic acid-based copolymer include a binary copolymer such as an ethylene / acrylic acid copolymer, an ethylene / methacrylic acid copolymer, and an isobutyl acrylate copolymer of ethylene / methacrylic acid. And ternary copolymers such as. Further, a commercially available product marketed as an ethylene / unsaturated carboxylic acid-based copolymer may be used, and for example, the Nuclel series (registered trademark) manufactured by Mitsui / DuPont Polychemical Co., Ltd. can be used.

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

The ionomer (C) used as the resin (C) in the present invention is preferably one in which the carboxyl group contained in the ethylene / unsaturated carboxylic acid-based copolymer is crosslinked (neutralized) by metal ions at an arbitrary ratio. Examples of the metal ion used for neutralizing the acid group include metal ions such as lithium ion, sodium ion, potassium ion, rubidium ion, cesium ion, zinc ion, magnesium ion and manganese ion. Among these metal ions, magnesium ion, sodium ion and zinc ion are preferable, sodium ion and zinc ion are more preferable, and zinc ion is particularly preferable, from the viewpoint of availability of industrialized products.
One type of metal ion may be used alone, or two or more types may be used in combination.

The degree of neutralization of the ethylene / unsaturated carboxylic acid-based copolymer in the ionomer (C) is preferably 10% to 85%, more preferably 15% to 82%. When the degree of neutralization is 10% or more, the chip breakability can be further improved, and when it is 85% or less, the processability and moldability of the film are excellent.
The degree of neutralization is the ratio (mol%) of the carboxyl groups neutralized by the metal ion to the number of moles of the total carboxyl groups contained in the ethylene / unsaturated carboxylic acid-based copolymer.

The melt flow rate (MFR) of the resin (C) is preferably in the range of 0.2 g / 10 minutes to 20.0 g / 10 minutes, more preferably 0.5 g / 10 minutes to 20.0 g / 10 minutes, and 0. More preferably, 5 g / 10 minutes to 18.0 g / 10 minutes. When the melt flow rate is within the above range, it is advantageous when forming a film.
The MFR is a value measured at 190 ° C. and a load of 2160 g by a method based on JIS K7210-1999.

The resin (C) preferably has a Vicat softening point of 50 ° C. or higher and 100 ° C. or lower. By laminating a resin having a high Vicat softening point as a second resin layer on a first resin layer made of a resin composition having a Vicat softening point of less than 50 ° C., the strength and heat resistance of the dicing film base material can be increased. ..
The Vicat softening point is a value measured according to the A50 method defined in JIS K7206-1999.

<Other polymers and additives>
Various additives and other resins may be added to the resin (C) constituting the second resin layer, if necessary, as long as the effects of the present invention are not impaired. Examples of the additives include antioxidants, heat stabilizers, light stabilizers, UV absorbers, pigments, dyes, lubricants, blocking inhibitors, antistatic agents, fungicides, antibacterial agents, flame retardants, and flame retardants. Examples thereof include agents, cross-linking agents, cross-linking aids, foaming agents, foaming aids, inorganic fillers, fiber reinforcing materials and the like. From the viewpoint of preventing heat fusion, a small amount of the additive may be added.

2-3. Layer structure The dicing film base material of the present invention has a single-layer structure consisting of 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. There is a thing (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, but from the viewpoint of preventing delamination, the first resin layer and the second resin layer may be directly laminated. desirable.

The dicing film base material having a multi-layer structure may have a multi-layer structure having three or more layers. For example, a second resin layer may be provided in a place where a plurality of sheets formed by using the resin composition constituting the first resin layer are laminated, or a second resin layer may be provided. A resin layer may be sandwiched between them. Further, in addition to the first resin layer and the second resin layer, another resin layer may be laminated.

Typical examples of the resin constituting another resin layer laminated on the dicing film substrate of the present invention include linear low density polyethylene (LLDPE), low density polyethylene (LDPE), ethylene / α-olefin copolymer, and the like. Examples thereof include a single material or a blend consisting of any plurality of materials selected from polypropylene and an ethylene / vinyl ester copolymer.

Further, the other resin layer to be laminated may be a functional layer (for example, an adhesive sheet or the like), or may be a base material such as a polyolefin film (or sheet) or a polyvinyl chloride film (or sheet). .. The base material may have either a single layer structure or a multi-layer structure. In the present invention, these base materials are collectively referred to as "dicing film base material".

In order to improve the adhesive strength of the surface of the dicing film base material, the surface of the dicing film base material may be subjected to a known surface treatment such as a corona discharge treatment.
Further, from the viewpoint of improving heat resistance, the first resin layer, the second resin layer, another resin layer, or the dicing film base material may be irradiated with electron beams, if necessary.

2-4. Method for Producing Dicing Film Base Material As a method for producing a single-layer dicing film base material, a method of processing a resin composition for a dicing film into a film by a known method can be mentioned. The method for processing the resin composition into a film is not particularly limited, and for example, various molding methods such as a conventionally known T die casting molding method, T die nip molding method, inflation molding method, extrusion laminating method, and calendar molding method can be used. , Films can be manufactured.

As a method for producing the multi-layer dicing film base material, a method of processing the resin composition constituting the first resin layer and the resin (C) constituting the second resin layer into a film by a known method and laminating them is used. Can be mentioned. The method for processing the resin composition or the resin into a film is not particularly limited, and for example, various molding methods such as a conventionally known T die cast molding method, T die nip molding method, inflation molding method, extrusion laminating method, and calendar molding method. The film can be produced by the method.

Further, the multi-layer dicing film base material can be produced by, for example, attaching the resin composition constituting the first resin layer and the resin (C) constituting the second resin layer to a coextrusion laminate. ..

For example, when the resin composition constituting the first resin layer is laminated on the surface of the resin (C) film to be the second resin layer by a T-die film molding machine, an extrusion coating molding machine, or the like, the second resin layer is used. In order to improve the adhesiveness with the adhesive resin layer, the film may be formed by a coextrusion coating molding machine. Typical examples of such an adhesive resin include the above-mentioned various ethylene copolymers, or a simple substance or a blend consisting of any plurality of these unsaturated carboxylic acid grafts.

Further, as a molding example of the dicing film base material of the present invention, a T die film molding machine or an extrusion coating molding machine is used to form a first resin layer on the surface of the resin (C) film to be the second resin layer. Examples thereof include a method of forming a multi-layered body by heat-adhering the resin composition to be formed.

The method of forming a layer made of the resin composition to be the first resin layer on the film of the resin (C) to be the second resin layer has been described. On the contrary, the resin to be the first resin layer has been described. The dicing film base of the present invention can also be obtained by forming a layer from the resin (C) to be the second resin layer on the film of the composition, or by providing the first resin or the second resin layer on the other resin layer. The material can be manufactured.

The thickness of the dicing film base material is not particularly limited, but considering that it is used as a constituent member of the dicing film, it is preferably 65 μm or more from the viewpoint of holding the frame during dicing and 200 μm or less from the viewpoint of expandability. The thickness of each resin layer constituting the multi-layer 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, but both the first resin layer and the second resin layer are 30 μm. It is preferably 100 μm or less, and the thickness ratio of the first resin layer to the second resin layer is preferably 30/70 to 70/30.

3. 3. Dicing film A third aspect of the present invention is a dicing film comprising the above-mentioned dicing film base material of the present invention and an adhesive layer laminated on at least one surface 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 composed of only the first resin layer 1 and an adhesive layer 11 provided on the surface thereof, and the dicing film 20 shown in FIG. 2B is the first resin. It has a dicing film base material 10 including a layer 1 and a second resin layer 2, and an adhesive layer 11 provided on the surface thereof.

The dicing film preferably has an adhesive layer formed on the outermost surface layer. The adhesive layer is arranged on the surface of the dicing film base material. A dicing film can be attached to the semiconductor wafer via the adhesive layer to perform dicing of the semiconductor wafer. In FIG. 2B, the adhesive layer 11 is arranged on the first resin layer 1 made of the resin composition for the dicing film base material of the present invention, but the present invention is limited to such a configuration. is not it. The adhesive layer 11 may be arranged on the second resin layer 2 (or another resin layer).

<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 a semiconductor wafer to be diced is attached to the adhesive layer. It is fixed. The thickness of the pressure-sensitive adhesive layer is preferably 3 to 100 μm, more preferably 3 to 50 μm, although it depends on the type of pressure-sensitive adhesive.

A conventionally known pressure-sensitive adhesive can be used as the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer. Examples of the pressure-sensitive adhesive include rubber-based, acrylic-based, silicone-based, and polyvinyl ether-based pressure-sensitive adhesives; radiation-curable pressure-sensitive adhesives; and heat-foamed pressure-sensitive adhesives. In particular, considering the peelability of the dicing film from the semiconductor wafer, the adhesive layer preferably contains an ultraviolet curable adhesive.

Examples of acrylic pressure-sensitive adhesives that can form a pressure-sensitive adhesive layer include homopolymers of (meth) acrylic acid esters and copolymers of (meth) acrylic acid esters and copolymerizable monomers. Specific examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, (meth). (Meta) acrylic acid alkyl esters such as isononyl acrylate, (meth) acrylic acid hydroxyethyl esters, (meth) acrylic acid hydroxybutyl, (meth) acrylic acid hydroxyhexyl and the like (meth) acrylic acid hydroxyalkyl esters, ( Meta) Acrylic acid glycidyl ester and the like are included.

Specific examples of the copolymerizable monomer with (meth) acrylic acid ester include (meth) acrylic acid, itaconic acid, maleic anhydride, (meth) acrylic acid amide, (meth) acrylic acid N-hydroxymethylamide, ( Meta) Acrylic acid alkylaminoalkyl esters (eg, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, etc.), vinyl acetate, styrene, acrylonitrile and the like are included.

The ultraviolet curable pressure-sensitive adhesive that can form the adhesive layer is not particularly limited, but the acrylic pressure-sensitive adhesive and the UV-curable component (a component that can add a carbon-carbon double bond to the polymer side chain of the acrylic pressure-sensitive adhesive). And a photopolymerization initiator. Further, additives such as a cross-linking agent, a tackifier, a filler, an anti-aging agent, and a colorant may be added to the ultraviolet curable adhesive, if necessary.

The ultraviolet curable component contained in the ultraviolet curable pressure-sensitive adhesive is, for example, a monomer, oligomer, or polymer having a carbon-carbon double bond in the molecule and curable by radical polymerization. Specific examples of the ultraviolet curable component include trimethylolpropantri (meth) acrylate, pentaerythritol tri (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol (meth) acrylate, and neopentyl glycol. Esters of (meth) acrylic acids such as di (meth) acrylates and dipentaerythritol hexa (meth) acrylates with polyhydric alcohols, and their oligomers; 2-propenyldi-3-butenylcyanurate, 2-hydroxyethylbis ( Includes isocyanurates such as 2-acryloxyethyl) isocyanurate, tris (2-mecryryloxyethyl) isocyanurate, and tris (2-methacryloxyethyl) isocyanurate.

Specific examples of the photopolymerization initiator contained in the ultraviolet curable pressure-sensitive adhesive include benzoin alkyl ethers such as benzoin methyl ether, benzoin isopropyl ether and benzoin isobutyl ether, aromatic ketones such as α-hydroxycyclohexylphenyl ketone, and benzyl. Aromatic ketals such as dimethyl ketal, polyvinylbenzophenone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, thioxanthone such as diethylthioxanthone and the like are included.

Examples of the cross-linking agent contained in the ultraviolet curable pressure-sensitive adhesive include polyisocyanate compounds, melamine resins, urea resins, polyamines, and carboxyl group-containing polymers.

It is preferable to attach a separator to the surface of the adhesive layer of the dicing film of the present invention. By attaching the separator, the surface of the adhesive layer can be kept smooth. In addition, the semiconductor manufacturing film can be easily handled and transported, and can be labeled on the separator.

The separator may be paper, or a synthetic resin film such as polyethylene, polypropylene, or polyethylene terephthalate. Further, the surface of the separator in contact with the adhesive layer may be subjected to a mold release treatment such as a silicone treatment or a fluorine treatment, if necessary, in order to enhance the peelability from the adhesive layer. The thickness of the separator is usually 10 to 200 μm, preferably about 25 to 100 μm.

<Manufacturing method of dicing film>
When producing the dicing film of the present invention, the adhesive is used in a known method, for example, a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, a spray coater, or the like. A method of applying directly to the base material, or a method of applying an adhesive on a release sheet by the above-mentioned known method to provide an adhesive layer, and then attaching the adhesive layer to the surface layer of the dicing film base material to transfer the adhesive layer. Can be used.

Further, by coextruding the resin composition of the present invention and the material constituting the adhesive layer (coextrusion molding method), a dicing film which is a laminate of the dicing film base material of the present invention and the adhesive layer is obtained. be able to. Further, by providing the 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 the first resin layer and the second resin layer can be produced. it can.

Further, the layer of the pressure-sensitive adhesive composition may be heat-crosslinked as needed to form a pressure-sensitive adhesive layer.
Further, a separator may be attached on the surface of the adhesive layer.

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

1. 1. Resin (A)
As the resin (A), a zinc (Zn) ion-neutralized ionomer of an ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer or an ethylene / unsaturated carboxylic acid-based copolymer shown in Table 1 below (hereinafter, "Ionomer") was prepared.

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

The Vicat softening temperatures in Tables 1 and 2 are values measured according to 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 2160 g in accordance with JIS K7210-1999.
The melting points in Table 2 are values measured by the DSC method.

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

(Example 1)
The ratio (mass%) of the resin (A) and the resin (B) shown in Table 3 were dry-blended. Next, the dry-blended mixture was charged into the resin inlet of the 40 mmφ single-screw extruder and melt-kneaded at a die temperature of 200 ° C. to obtain a resin composition for the first resin layer.

The obtained resin composition for the first resin layer and the resin (C) for the second resin layer are charged into each extruder using a two-kind two-layer 40 mmφT die film forming machine, and the processing temperature is increased. Molding was performed under the condition of 240 ° C. to prepare a two-kind two-layer T-die film having a thickness of 100 μm. The thickness ratio of the first layer to the second layer of the produced laminated film having a two-layer structure and a thickness of 100 μm was set to 60/40.

(Examples 2-8 and 12-14, Comparative Examples 1-3, 5 and 10)
A resin composition for the first resin layer was prepared in the same manner as in Example 1 except that the types and amounts of the resin (A) and the resin (B) were changed as shown in Table 3 or Table 4. Next, the laminated film containing the first resin layer and the second resin layer was prepared in the same manner as in Example 1 except that the thicknesses of the first resin layer and the second resin layer were changed as shown in Table 3 or Table 4. Made.

(Examples 9 to 11, Comparative Examples 4 and 6 to 9)
A resin composition for the first resin layer was prepared in the same manner as in Example 1 except that the types and amounts of the resin (A) and the resin (B) were changed as shown in Table 3 or Table 4. Next, using the prepared resin composition, a one-layer T-die film having a thickness of 100 μm was prepared in the same manner as in Example 1 without using the resin (C).

The resin compositions and films for the first resin layer obtained in the above Examples and Comparative Examples were evaluated by the following methods. The evaluation results are shown in Table 3 or Table 4.

(1) Degree of Neutralization of Resin Composition The degree of neutralization was calculated from the degree of neutralization of the resin (A) and its content.

(2) MFR of resin composition
MFR was measured at 190 ° C. and a load of 2160 g according to JIS K7210-1999.

(3) Vicat softening temperature of the resin composition The Vicat softening temperature was measured according to the A50 method specified in JIS K7206-1999.

(4) Shrinkage rate at 80 ° C. The resin composition was molded on a film having a thickness of 100 μm, cut in a width direction of 25 mm × a length direction of 150 mm, and marked at a distance of 100 mm between marked lines to prepare a test piece sample. Starch powder (manufactured by Nikkari Co., Ltd., Nikkari powder) to prevent film adhesion is dusted on a glass plate, a test piece sample is placed on it, and the temperature is 80 ° C. on a hot plate of a press molding machine. Heated for 2 minutes. The distance between the marked lines of the film after heating was measured, and the shrinkage rate (%) was calculated from the following formula.
Shrinkage rate (%) = 100 mm-distance between marked lines after shrinkage (mm) / 100 mm x 100

(5) Tensile test (modulus)
The dicing film base material was cut into strips having a width of 10 mm and used as measurement targets. According to JIS K7127, under the conditions of test piece: width 10 mm x length 200 mm, chuck distance: 100 mm, the film strength (25% modulus and 25% modulus) at extension distances of 25% and 50% in the MD and TD directions of the measurement target, respectively. 50% modulus) was measured respectively. The test speed was 500 mm / min.

30 parts by mass or more and 90 parts by mass or less of the resin (A) which is an ionomer of an ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer (ternary copolymer), and a resin which is an ethylene-based copolymer (a resin which is an ethylene-based copolymer). The dicing film substrate of the example prepared by using a resin composition containing 10 parts by mass or more and 70 parts by mass or less of B) and having a Vicat softening point of less than 50 ° C. has thermal (80 ° C.) shrinkage and strength. Both were excellent. On the other hand, the resin composition of Comparative Example 1 using the binary copolymer ionomer had a Vicat softening point of more than 50 ° C. The dicing film base material produced using such a resin composition had a low heat shrinkage rate. The dicing film base material prepared by using the resin compositions of Comparative Examples 2 and 3 containing the resin (A) and the resin (B) but having the Vicat softening point exceeding 50 ° C. was also the same as in Comparative Example 1. , The heat shrinkage rate was low.

Example using a resin composition containing a resin (A) of 70 parts by mass or more and 90 parts by mass or less and a resin (B) of 30 parts by mass or more and 10 parts by mass or less and having a Vicat softening point of less than 50 ° C. Although the dicing film substrates of 9 to 11 were single layers, they exhibited sufficient strength and heat shrinkage at the same time.

The resin compositions of Comparative Examples 4 and 5 containing the resin (A) in an amount of more than 90 parts by mass and the resin (B) of less than 10 parts by mass had a Vicat softening point of more than 50 ° C. The dicing film base material produced by using such a resin composition had high strength but low heat shrinkage. Similarly, the dicing film substrates of Comparative Examples 6 to 10 using an ionomer as the first resin layer also showed high strength, but had a low heat shrinkage rate. In particular, the ionomer 2 used in Comparative Example 7 had a Vicat softening point of less than 50 ° C., but had a low heat shrinkage rate.

From these results, in order to obtain a dicing film base material having both high strength and high heat shrinkage rate, an ionomer of an ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer of a resin composition as a raw material. The content of the resin (A) is 30 parts by mass or more and 90 parts by mass or less, the content of the resin (B) which is an ethylene copolymer is 10 parts by mass or more and 70 parts by mass or less, and Bicut softening. It turns out that it is important that the points are below 50 ° C.

This application claims priority under Japanese Patent Application No. 2018-149562 filed on August 8, 2018. All the contents described in the application specification are incorporated in the application specification.

The dicing film of the present invention can be suitably used in a method for manufacturing a semiconductor device that carries out a heat shrink step in addition to a dicing step and an expansion step for dividing a semiconductor wafer into chip units. In particular, since the dicing film of the present invention has both high strength and high heat shrinkage, stealth dicing in which a larger stress is applied to the dicing film than in the conventional method (blade dicing method, laser ablation method, etc.) in the expansion process. It can be suitably used for a manufacturing method that employs the (registered trademark) method. By using the dicing film of the present invention, it is possible to make the chip spacing after division uniform, reduce product defects in the subsequent steps, and manufacture a semiconductor device with a high yield.

1 1st resin layer 2 2nd resin layer 10 Dicing film base material 11 Adhesive layer 20 Dicing film

Claims (10)

Ionomer (A) of ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer 30 parts by mass or more and 90 parts by mass or less.
It contains 10 parts by mass or more and 70 parts by mass or less of the ethylene-based copolymer (B) (however, the total of the component (A) and the component (B) is 100 parts by mass).
A resin composition for a dicing film base material, which has a Vicat softening point of less than 50 ° C. as defined by JIS K7206-1999. The first aspect of claim 1, wherein the ionomer (A) of the ethylene / unsaturated carboxylic acid / unsaturated carboxylic acid ester copolymer has a Vicat softening point defined by JIS K7206-1999 of 25 ° C. or higher and 60 ° C. or lower. Resin composition for dicing film base material. The invention according to claim 1 or 2, wherein the ethylene-based copolymer (B) is a resin having a Vicat softening point of 50 ° C. or lower as defined by JIS K7206-1999, or a resin having no Vicat softening point. Resin composition for dicing film base material. Any one of claims 1 to 3, wherein the ethylene-based copolymer (B) is at least one selected from the group consisting of an ethylene / α-olefin copolymer and an ethylene / unsaturated carboxylic acid ester copolymer. The resin composition for a dicing film base material according to the above item. The melt flow rate (MFR) of the ethylene-based copolymer (B) measured at 190 ° C. and a load of 2160 g by a method based on JIS K7210-1999 is 0.2 g / 10 minutes to 30.0 g / 10. The resin composition for a dicing film base material according to any one of claims 1 to 4, which is a minute. The melt flow rate (MFR) of the resin composition for a dicing film base material measured at 190 ° C. and a load of 2160 g by a method according to JIS K7210-1999 is 0.1 g / 10 min to 50 g / 10 min. The resin composition for a dicing film base material according to any one of claims 1 to 5. A dicing film base material comprising at least one layer containing the resin composition for a dicing film base material according to any one of claims 1 to 6. A first resin layer containing the resin composition for a dicing film base material according to any one of claims 1 to 6.
The dicing film base material according to claim 7, which includes a second resin layer containing a resin (C) laminated on the first resin layer. The dicing according to claim 8, wherein the resin (C) is at least one selected from the group consisting of an ethylene / unsaturated carboxylic acid-based copolymer and an ionomer of the ethylene / unsaturated carboxylic acid-based copolymer. Film substrate. The dicing film base material according to any one of claims 7 to 9, and the dicing film base material.
A dicing film characterized by having an adhesive layer laminated on at least one surface of the dicing film base material.

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