JP6667671B2 - Dicing film substrate and dicing film - Google Patents

Description

  The present invention relates to a dicing film substrate and a dicing film.

  In the process of manufacturing a semiconductor device such as an IC, it is general to perform a dicing process for cutting a semiconductor wafer having a circuit pattern formed thereon into thin films and then dividing the semiconductor wafer into chips. In the dicing step, an elastic wafer processing film (referred to as dicing film or dicing tape) is attached to the back surface of the semiconductor wafer, and the semiconductor wafer is cut into chips by a dicing blade using cooling water and cleaning water. . Then, in the next expansion step, the dicing tape corresponding to the cut wafer is expanded to chip into chips. At this time, the semiconductor wafer is fixed with a dicing film to prevent chips from scattering.

  Since a dicing film may be attached to a semiconductor wafer under heating conditions, heat resistance is required. If the heat resistance of the dicing film is low, the film may be softened by heat or the like, making it difficult to peel off, or may be fixed on a work table (die). Furthermore, if the dicing film is deformed due to heat, such as distortion or warpage, the thinned semiconductor wafer may be deformed. For this reason, the dicing film is required to have heat resistance as well as expandability for fixing the semiconductor wafer as the dicing film.

  Further, in the stealth dicing process, in order to form a crack layer inside the semiconductor wafer by laser and to completely cut the semiconductor wafer, it is required to cut the semiconductor wafer by the stress of the dicing film holding the wafer. . Therefore, in the dicing film, it is important to balance the chip dividing property and the expandability.

  As a material for forming a dicing film, an ionomer obtained by crosslinking an ethylene / (meth) acrylic acid copolymer with metal ions is used. For example, a radiation-curable pressure-sensitive adhesive tape for processing a wafer (Patent Document 1) composed of a resin composition containing an ionomer and an antistatic resin containing a polyether component, and ethylene, (meth) acrylic acid, and (meth) ) A resin composition for a dicing film substrate containing a polymer containing an alkyl acrylate as a constituent component (Patent Document 2).

  Further, as the resin composition containing an ionomer as described above, an ionomer / polyamide blend containing a polyamide and a copolymer ionomer containing ethylene and an α, β-ethylenically unsaturated carboxylic acid (Patent Document 3) ) Is also known.

JP 2011-210887 A JP 2012-89732 A JP 2000-516984 A

  The pressure-sensitive adhesive tape for wafer processing described in Patent Literature 1 combining an ionomer and an antistatic resin has excellent antistatic properties, but does not describe heat resistance. In addition, the resin composition for a dicing film substrate of Patent Document 2 in which an ionomer is combined with a polymer having ethylene, (meth) acrylic acid, and an alkyl (meth) acrylate as constituent components has heat resistance. Although it was described as improved, the results of the heat resistance test in the examples show that all of the samples including the comparative example were ○ (not fully stretched), indicating a marked improvement in heat resistance over the prior art. I don't think it was done. Furthermore, the ionomer compound described in Patent Document 3 is for the production of molded parts and the like, and there is no description on applications related to semiconductors such as dicing films. Further, since this blend contains a large amount of polyamide as 40 to 60% by mass, it can be pelletized, but cannot be formed into a film.

  The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a dicing film base having excellent heat resistance and a good balance between chip breaking and expandability. Material and a dicing film.

  That is, according to the present invention, the following dicing film substrate and dicing film are provided.

[1] 30 mass parts or more and 95 mass parts or less of at least one resin (A) selected from the group consisting of an ethylene / unsaturated carboxylic acid copolymer and an ionomer of the ethylene / unsaturated carboxylic acid copolymer. ,
At least one resin (B) selected from the group consisting of polyamides and polyurethanes in an amount of 5 parts by mass or more and less than 40 parts by mass;
0 parts by mass or more and 30 parts by mass or less of the antistatic agent (C) other than the polyamide (but the total of the components (A), (B) and (C) is 100 parts by mass)
A first resin layer comprising a resin composition containing:
Dicing, comprising a second resin layer containing at least one resin (D) 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.
[2] The dicing film substrate according to [1], wherein the content of the antistatic agent (C) is 0 parts by mass.
[3] The dicing film substrate according to [1], wherein the content of the antistatic agent (C) is 5 parts by mass or more and 30 parts by mass or less.
[4] The dicing film substrate according to any one of [1] to [3], wherein the polyurethane is a thermoplastic polyurethane elastomer.
[5] The dicing film substrate according to any one of [1] to [4],
A dicing film having a pressure-sensitive adhesive layer laminated on at least one surface of the dicing film substrate.

  The present invention provides a dicing film substrate and a dicing film having excellent heat resistance and exhibiting well-balanced chip cutting properties and expandability suitable as a dicing film.

FIG. 1 is a cross-sectional view showing one embodiment of a dicing film substrate of the present invention. It is a sectional view showing one embodiment of a dicing film of the present invention.

Hereinafter, the dicing film substrate of the present invention will be described in detail, and the dicing film will also be described in detail.
In this specification, the notation “to” indicating a numerical range means that the lower limit and the upper limit of the numerical range are included.
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 inclusively.

1. Dicing film substrate A first aspect of the present invention is a dicing film substrate. FIG. 1 is a cross-sectional view showing one embodiment of the dicing film substrate of the present invention. As shown in FIG. 1, the dicing film substrate 10 of the present embodiment has a structure in which a first resin layer 1 and a second resin layer 2 are laminated. Next, each layer will be described.

1-1. First resin layer The first resin layer has a mass of at least one resin (A) selected from the group consisting of an ethylene / unsaturated carboxylic acid-based copolymer and an ionomer of the ethylene / unsaturated carboxylic acid-based copolymer. To 95 parts by mass, at least 5 parts by mass and less than 40 parts by mass of at least one resin (B) selected from the group consisting of polyamide and polyurethane, and 0 parts by mass of the antistatic agent (C) other than the polyamide. As described above, the layer is made of a resin composition containing 30 parts by mass or less (provided that the total of the components (A), (B) and (C) is 100 parts by mass). Such a resin composition layer is excellent in heat resistance, and is excellent in balance between chip breaking property and expandability.

<Resin (A)>
The resin (A) in the present invention includes an ethylene / unsaturated carboxylic acid-based copolymer (hereinafter, also simply referred to as “copolymer (A)”) and an ionomer of the ethylene / unsaturated carboxylic acid-based copolymer (hereinafter referred to as “ionomer”). , Simply referred to as “ionomer (A)”). In the present invention, the ionomer of the ethylene / unsaturated carboxylic acid copolymer used as the resin (A) is such that a part or all of the carboxyl groups of the ethylene / unsaturated carboxylic acid copolymer is a metal (ion). It has been neutralized. In the present invention, an ionomer in which at least a part of the acid groups of the ethylene / unsaturated carboxylic acid-based copolymer is neutralized with a metal (ion) is referred to as an “ionomer”. Those whose groups are not neutralized by a metal (ion) are referred to as “copolymers”.

  The ethylene / unsaturated carboxylic acid copolymer constituting the copolymer (A) or the ionomer (A) thereof is at least a binary copolymer obtained by copolymerizing ethylene and an unsaturated carboxylic acid, Further, the third copolymer component may be a terpolymer or higher copolymer obtained by copolymerization. The ethylene / unsaturated carboxylic acid copolymer may be used alone or in combination of two or more ethylene / unsaturated carboxylic acid copolymers.

  Examples of the unsaturated carboxylic acid constituting the ethylene / unsaturated carboxylic acid binary copolymer include acrylic acid, methacrylic acid, ethacrylic 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. Particularly, acrylic acid or methacrylic acid is preferred.

  When the ethylene / unsaturated carboxylic acid-based copolymer (A) is a tertiary or higher multi-component copolymer, it may contain a monomer (third copolymer component) forming the multi-component 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) Dimethyl maleate, alkyl (meth) acrylates such as diethyl maleate), unsaturated hydrocarbons (eg, propylene, butene, 1,3-butadiene, pentene, 1,3-pentadiene, 1-hexene, etc.), Vinyl esters (eg, vinyl acetate, vinyl propionate, etc.), oxides such as vinyl sulfuric acid and vinyl nitric acid, halogen compounds (eg, vinyl chloride, vinyl fluoride, etc.), vinyl group-containing primary and secondary amine compounds, monoxide Carbon, sulfur dioxide and the like, and as these copolymerization components, Saturated carboxylic acid esters are preferred.

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

  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, and still 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 ester include unsaturated carboxylic acid alkyl esters having 1 to 12 carbon atoms in the alkyl portion (for example, methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, acrylic acid Alkyl acrylates such as isooctyl; alkyl methacrylates such as methyl methacrylate, ethyl methacrylate and isobutyl methacrylate; and alkyl maleates such as dimethyl maleate and diethyl maleate).
Among the unsaturated carboxylic acid alkyl esters, alkyl (meth) acrylates having 1 to 4 carbon atoms in the alkyl moiety are more preferred.

  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 copolymer. Among them, in terms of industrial availability, 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. And more preferably a binary random copolymer or a ternary random copolymer.

  Specific examples of the ethylene / unsaturated carboxylic acid copolymer include binary copolymers such as ethylene / acrylic acid copolymer and ethylene / methacrylic acid copolymer, and ethylene / methacrylic acid / isobutyl acrylate copolymer And other terpolymers. Further, a commercially available product which is marketed as an ethylene / unsaturated carboxylic acid copolymer may be used. For example, Nucrel series (registered trademark) manufactured by DuPont-Mitsui Polychemicals and the like can be used.

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

  The ionomer (A) used as the resin (A) in the present invention is preferably one in which the carboxyl group contained in the above-mentioned ethylene / unsaturated carboxylic acid-based copolymer is crosslinked (neutralized) at an arbitrary ratio by a metal ion. 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 preferred from the viewpoint of easy availability of industrialized products, and sodium ion and zinc ion are more preferred.

The degree of neutralization of the ethylene / unsaturated carboxylic acid copolymer in the ionomer (A) is preferably from 10% to 85%, more preferably from 15% to 82%. When the degree of neutralization is 10% or more, the chip breaking property can be further improved, and when it is 85% or less, workability and moldability are excellent.
The degree of neutralization is a compounding ratio (mol%) of a metal ion with respect to the number of moles of an acid group, particularly a carboxyl group, of an ethylene / unsaturated carboxylic acid copolymer.

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

The content of the resin (A) in the resin composition constituting the first resin layer is 30 parts by mass based on the total amount of the resin (A), the resin (B) described later, and the antistatic agent (C) described later. It is at least 95 parts by mass, preferably at least 40 parts by mass and at most 90 parts by mass, more preferably at least 50 parts by mass and at most 90 parts by mass.
When the content of the resin (A) is within the above range, the film processability is excellent.

<Resin (B)>
The resin (B) in the present invention is at least one selected from the group consisting of polyamide and polyurethane. Generally, the melting point of the ethylene / unsaturated carboxylic acid copolymer or its ionomer used as the resin (A) is as low as 100 ° C. or less, and the heat resistance of the resin composition mixed with the resin having a higher melting point is somewhat higher. The rise is within the estimates. However, by combining a polyamide and / or polyurethane with an ethylene / unsaturated carboxylic acid-based copolymer or its ionomer (resin (A)) among resins having relatively high melting points, it is expected from the melting point of polyamide or polyurethane. Thus, a resin composition having higher heat resistance than that of the resin composition is obtained. Further, a film produced using such a resin composition has not only excellent heat resistance but also a well-balanced chip cutting property and expandability suitable as a dicing film.

  Examples of the polyamide include carboxylic acids such as oxalic acid, adipic acid, sebacic acid, dodecanoic acid, terephthalic acid, isophthalic acid, and 1,4-cyclohexanedicarboxylic acid, and ethylenediamine, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine. , Polycondensates with diamines such as decamethylenediamine, 1,4-cyclohexyldiamine and m-xylylenediamine; cyclic lactam ring-opening polymers such as ε-caprolactam and ω-laurolactam; 6-aminocaproic acid; Examples include polycondensates of aminocarboxylic acids such as aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid, and copolymerization of the above-mentioned cyclic lactam, dicarboxylic acid, and diamine.

The polyamide may be commercially available. Specifically, nylon 4, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 6T, nylon 11, nylon 12, copolymer nylon (for example, nylon 6/66, nylon 6/12, nylon 6/610, nylon 66/12, nylon 6/66/610), nylon MXD6, nylon 46 and the like.
Among these polyamides, nylon 6 and nylon 6/12 are preferred.

  As the polyurethane, a thermoplastic polyurethane elastomer is preferably used. Examples of the thermoplastic polyurethane elastomer include polyisocyanates (for example, aliphatic, alicyclic or aromatic diisocyanates), polymer polyols (for example, polyether polyols, polycarbonate polyols, acrylic polyols), and chain extenders (for example, ethylene glycol). Diols such as 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, bisphenol A and p-xylylene glycol. Examples include those obtained by polymerization.

  The content of the resin (B) in the resin composition constituting the first resin layer is 5 parts by mass or more and 40 parts by mass or more based on the total amount of the resin (A), the resin (B), and the antistatic agent (C) described later. It is less than 5 parts by mass, preferably from 5 parts by mass to 35 parts by mass, more preferably from 5 parts by mass to 30 parts by mass.

  When the content of the resin (B) is less than 5 parts by mass, the effect of improving the heat resistance by the resin (B) is not exhibited. When the content of the resin (B) is 40 parts by mass or more, it becomes difficult to manufacture a dicing film base material including the first resin layer and the second resin layer. Specifically, when the content of the resin (B) is 40 parts by mass or more and less than 60 parts by mass, although the film can be formed, the extrusion of the first layer becomes unstable, and the thickness of the film to be the first resin layer becomes thicker. Accuracy tends to be insufficient. Further, when the content of the resin (B) is 60 parts by mass or more, although the thickness accuracy of the film is sufficient, the interlayer adhesiveness with the second resin layer tends to decrease.

<Antistatic agent (C)>
The resin composition constituting the first resin layer preferably contains an antistatic agent (C) in addition to the resin (A) and the resin (B). The antistatic agent (C) not only imparts antistatic properties to the resin composition, but also further improves the heat resistance of the resin composition by interaction with the resin (A) and the resin (B).

  Examples of the antistatic agent (C) include a high molecular weight antistatic agent and a low molecular weight antistatic agent such as a surfactant. Among these antistatic agents, a polymer type antistatic agent is preferable because surface contamination due to bleed out is suppressed.

The polymer type antistatic agent includes a conductive portion (for example, a structural portion derived from polyether, a quaternary ammonium base portion, etc.) and a non-conductive portion (for example, a structural portion derived from polyamide, a structure derived from polyolefin such as polyethylene, etc.). And a acrylate-derived structural portion, a methacrylate-derived structural portion, a styrene-derived structural portion, etc.) and a molecular weight of 300 or more (preferably 1,000 to 10,000). The molecular weight is a weight average molecular weight in terms of polystyrene measured by GPC.
In addition, conductivity means that the surface resistivity measured based on ASTM D257 is 10 ¹⁰ Ω / □ or less.

  Examples of the polymer type antistatic agent include, for example, nonionic polymer type antistatic agents such as polyethylene oxide, polypropylene oxide, polyethylene glycol, polyetheresteramide, polyetherester, polyetherpolyolefin, and ethylene oxide / epichlorohydrin copolymer. Polymer, anionic polymer type antistatic agent such as polystyrene sulfonic acid, cationic polymer such as quaternary ammonium salt-containing acrylate polymer, quaternary ammonium salt-containing styrene polymer, quaternary ammonium salt-containing polyethylene glycol methacrylate polymer And the like.

  More specifically, for example, a polyetheresteramide described in JP-A-1-163234 and a polyolefin block described in JP-A-2001-278895 and a block of a hydrophilic polymer are used. A block copolymer having a structure in which an olefin monomer is polymerized and a hydrophilic block in which a hydrophilic monomer is polymerized; Coalescence.

  Among these antistatic agents, polyetheresteramide is preferable from the viewpoint of compatibility with the resin (A) and the resin (B), heat resistance and antistatic properties. The polyether ester amide refers to a copolymer having a structural part derived from polyamide and a structural part derived from polyether, and these structural parts are ester-bonded.

Examples of the polyamide that forms a structural site derived from the polyamide in the polyetheresteramide include dicarboxylic acids (eg, oxalic acid, succinic acid, adipic acid, sebacic acid, dodecandioic acid, terephthalic acid, isophthalic acid, 1,4-cyclohexane) Dicarboxylic acid) and a diamine (eg, ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, decamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, Polycondensation with 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, methylenebis (4-aminocyclohexane), m-xylylenediamine, p-xylylenediamine, etc., ε- Caprolactam ring-opening polymerization of lactams such as ω-dodecalactam, polycondensation of aminocarboxylic acids such as 6-aminocaproic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, or the lactam, dicarboxylic acid and diamine And the like. Such polyamide segments include nylon 4, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 6T, nylon 11, nylon 12, nylon 6/66, nylon 6/12, nylon 6/610, nylon 66/12 and nylon 6/66/610, and nylon 11 and nylon 12 are particularly preferred. The molecular weight of the polyamide block is, for example, about 400 to 5000.
When a polyamide is used as the resin (B), the antistatic agent (C) is a compound other than the polyamide used as the resin (B).

  Examples of the polyether block include polyoxyalkylene glycols such as polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, polyoxyethylene / polyoxypropylene glycol, and mixtures thereof. These molecular weights are, for example, preferably about 400 to 6000, and more preferably about 600 to 5000.

  As the polyetheresteramide, the structural portion derived from polyoxyalkylene glycol (preferably polyethylene glycol or polypropylene glycol) is 5% by mass to 80% by mass (more preferably 15% by mass) based on the total mass of the polyetheresteramide. To 70% by mass). Further, the polyetheresteramide having a melting point of less than 190 ° C. has a melt flow rate (MFR) measured at 190 ° C. under a load of 2160 g of 0.1 to 1000 g / 10 min (more preferably 1 to 100 g / 10 min). Preferably, the polyetheresteramide having a melting point of 190 ° C or higher has a melt flow rate measured at 230 ° C and a load of 2160 g of 0.1 to 1000 g / 10 min (more preferably 1 to 100 g / 10 min). ) Are preferred. In addition, the polyetheresteramide preferably has a melting point (a temperature indicating the maximum endothermic amount) of 130 ° C to 175 ° C measured by a differential scanning calorimeter (DSC). Such a polyetheresteramide can be obtained by reacting a polyamide having a molecular weight of 600 to 5,000 with a polyoxyalkylene glycol and, if necessary, a carboxylic acid.

  Examples of the low molecular weight antistatic agent include quaternary ammonium salts, pyridinium salts, cationic antistatic agents having a cationic group such as a primary to tertiary amino group, sulfonate groups, sulfate ester groups, and phosphorus compounds. Anionic antistatic agents having anionic groups such as acid ester bases, amino acid antistatic agents, amphoteric antistatic agents such as aminosulfuric acid ester antistatic agents, amino alcohol antistatic agents, glycerin antistatic agents, polyethylene glycol antistatic agents And nonionic antistatic agents.

  As the antistatic agent, a commercially available product may be used, and specific examples thereof include PELESTAT 230, PELESTAT HC250, PELESTAT 300, PELESTAT 2450, PELECTRON PVL, IRGASTAT P-16 manufactured by BASF Japan, manufactured by Sanyo Chemical Industries, Ltd. P-18FCA, P-20, P-22 and the like.

  Further, from the viewpoint of enhancing the effect of improving the heat resistance of the resin composition, the antistatic agent preferably has a melting point of 100 ° C or more and 200 ° C or less, and more preferably 120 ° C or more and 200 ° C or less. As the melting point, a melting temperature measured by a differential scanning calorimeter (DSC) according to JIS-K7121 (1987) can be used.

  The content of the antistatic agent (C) in the resin composition constituting the first resin layer is 0 parts by mass or more with respect to the total amount of the resin (A), the resin (B) and the antistatic agent (C). It is preferably at most 5 parts by mass and less than 30 parts by mass, more preferably at least 5 parts by mass and less than 25 parts by mass. When the content of the antistatic agent (C) is less than 5 parts by mass, the effect of improving the heat resistance by the antistatic agent is hardly exhibited, and when it exceeds 30 parts by mass, the expandability of the film may be deteriorated. The total content of the resin (A), the resin (B) and the antistatic agent (C) in the first resin layer is preferably from 80% by mass to 100% by mass, more preferably from 90% by mass to 100% by mass. .

<Other polymers and additives>
If necessary, other polymers and various additives may be added to the resin composition constituting the first resin layer as long as the effects of the present invention are not impaired. Examples of the other polymer include polyolefins such as polyethylene, polypropylene, and ethylene / α-olefin copolymer (α-olefin includes propylene, butylene, octene and the like). Such other polymer can be blended in a proportion of, for example, 20 parts by mass or less based on 100 parts by mass of the total of (A), (B) and (C). Examples of the additives include an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, a pigment, a dye, a lubricant, an antiblocking agent, an antistatic agent, a fungicide, an antibacterial agent, a flame retardant, and a fire retardant. Agents, crosslinking agents, crosslinking aids, foaming agents, foaming aids, inorganic fillers, fiber reinforcements, and the like. From the viewpoint of preventing thermal fusion, the additive may be added in a small amount. Specific examples of the ultraviolet absorber include benzophenone type, benzoate type, benzotriazole type, cyanoacrylate type, hindered amine type and the like; specific examples of the filler include silica, clay, calcium carbonate, barium sulfate, glass beads, talc and the like. Can be mentioned.

<Production method of resin composition>
The resin composition constituting the first resin layer is obtained by mixing the resin (A), the resin (B) and, if desired, the antistatic agent (C), and if necessary, other polymers and additives. Can be. The method for producing the resin composition is not particularly limited. For example, the resin composition can be obtained by dry-blending all components and then melt-kneading.

  The resin composition constituting the first resin layer preferably has a melt flow rate (MFR) measured at 230 ° C. and a load of 2160 g of 1 g / 10 min to 50 g / 10 min. In particular, when an ethylene / (meth) acrylic acid copolymer or an ionomer (A) is used as the resin (A), the MFR at 230 ° C. is preferably 20 g / 10 minutes or less. When the MFR at 230 ° C. is not more than 20 g / 10 minutes, a film having an excellent balance between heat resistance and expandability at 140 ° C. can be obtained.

1-2. Second resin layer The second resin layer is a layer containing the resin (D), and the resin (D) is an ionomer of the ethylene / unsaturated carboxylic acid copolymer and the ethylene / unsaturated carboxylic acid copolymer. At least one resin selected from the group consisting of The resin (D) is a material having high adhesiveness to the resin composition constituting the first resin layer. Therefore, by laminating with the first resin layer, it is possible to increase the strength of the dicing film substrate and maintain the balance between the chip dividing property and the expandability required for the dicing film without causing the problem of delamination. It becomes possible.

<Resin D>
The resin (D) in the present invention includes an ethylene / unsaturated carboxylic acid-based copolymer (hereinafter, also simply referred to as “copolymer (D)”) and an ionomer of the ethylene / unsaturated carboxylic acid-based copolymer (hereinafter referred to as “ionomer”). , Simply referred to as “ionomer (D)”). In the present invention, the ionomer of the ethylene / unsaturated carboxylic acid-based copolymer used as the resin (D) is such that a part or all of the carboxyl groups of the ethylene / unsaturated carboxylic acid-based copolymer is a metal (ion). It has been neutralized. In the present invention, an ethylene / unsaturated carboxylic acid-based copolymer in which at least a part of the acid groups is neutralized with a metal (ion) is referred to as an “ionomer”. Those whose groups are not neutralized by a metal (ion) are referred to as “copolymers”.
In addition, as described in detail below, the resin (D) is the same resin as the resin (A) included in the resin composition constituting the first resin layer.

  The ethylene / unsaturated carboxylic acid copolymer constituting the copolymer (D) or its ionomer (D) is at least a binary copolymer obtained by copolymerizing ethylene and an unsaturated carboxylic acid, Further, the third copolymer component may be a terpolymer or higher copolymer obtained by copolymerization. The ethylene / unsaturated carboxylic acid copolymer may be used alone or in combination of two or more ethylene / unsaturated carboxylic acid copolymers.

  Examples of the unsaturated carboxylic acid constituting the ethylene / unsaturated carboxylic acid binary copolymer include acrylic acid, methacrylic acid, ethacrylic 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. Particularly, acrylic acid or methacrylic acid is preferred.

  When the ethylene / unsaturated carboxylic acid-based copolymer (D) is a tertiary or higher terpolymer, it may contain a monomer (third copolymer component) that forms the terpolymer. 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) Dimethyl maleate, alkyl (meth) acrylates such as diethyl maleate), unsaturated hydrocarbons (eg, propylene, butene, 1,3-butadiene, pentene, 1,3-pentadiene, 1-hexene, etc.), Vinyl esters (eg, vinyl acetate, vinyl propionate, etc.), oxides such as vinyl sulfuric acid and vinyl nitric acid, halogen compounds (eg, vinyl chloride, vinyl fluoride, etc.), vinyl group-containing primary and secondary amine compounds, monoxide Carbon, sulfur dioxide and the like, and as these copolymerization components, Saturated carboxylic acid esters are preferred.

  For example, when the ethylene / unsaturated carboxylic acid copolymer (D) is a terpolymer, a terpolymer of ethylene, an unsaturated carboxylic acid, and an unsaturated carboxylic acid ester, and ethylene and And a ternary copolymer of an unsaturated carboxylic acid and an unsaturated hydrocarbon.

  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, and still 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 ester include unsaturated carboxylic acid alkyl esters having 1 to 12 carbon atoms in the alkyl portion (for example, methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, acrylic acid Alkyl acrylates such as isooctyl; alkyl methacrylates such as methyl methacrylate, ethyl methacrylate and isobutyl methacrylate; and alkyl maleates such as dimethyl maleate and diethyl maleate).
Among the unsaturated carboxylic acid alkyl esters, alkyl (meth) acrylates having 1 to 4 carbon atoms in the alkyl moiety are more preferred.

  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 copolymer. Among them, in terms of industrial availability, 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. And more preferably a binary random copolymer or a ternary random copolymer.

  Specific examples of the ethylene / unsaturated carboxylic acid copolymer include binary copolymers such as ethylene / acrylic acid copolymer and ethylene / methacrylic acid copolymer, and ethylene / methacrylic acid / isobutyl acrylate copolymer And other terpolymers. Further, a commercially available product which is marketed as an ethylene / unsaturated carboxylic acid copolymer may be used. For example, Nucrel series (registered trademark) manufactured by DuPont-Mitsui Polychemicals and the like can be used.

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

  The ionomer (D) used as the resin (D) in the present invention is preferably one in which a carboxyl group contained in the above-mentioned ethylene / unsaturated carboxylic acid copolymer is crosslinked (neutralized) at an arbitrary ratio by a metal ion. 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 preferred from the viewpoint of easy availability of industrialized products, and sodium ion and zinc ion are more preferred.

The degree of neutralization of the ethylene / unsaturated carboxylic acid copolymer in the ionomer (D) is preferably from 10% to 85%, more preferably from 15% to 82%. When the degree of neutralization is 10% or more, the chip breaking property can be further improved, and when it is 85% or less, workability and moldability are excellent.
The degree of neutralization is a compounding ratio (mol%) of a metal ion with respect to the number of moles of an acid group, particularly a carboxyl group, of an ethylene / unsaturated carboxylic acid copolymer.

The melt flow rate (MFR) of the ethylene / unsaturated carboxylic acid copolymer and its ionomer is preferably in the range of 0.2 g / 10 min to 20.0 g / 10 min, and more preferably in the range of 0.5 g / 10 min to 20.0 g. / 10 minutes is more preferable, and 0.5 g / 10 minutes to 18.0 g / 10 minutes is still more preferable. When the melt flow rate is within the above range, it is advantageous when molding.
The MFR is a value measured at 190 ° C. under a load of 2160 g by a method based on JIS K7210-1999.
The content of the resin (D) in the second resin layer is preferably from 80% by mass to 100% by mass, and more preferably from 90% by mass to 100% by mass.

<Additives>
Various additives and other resins may be added to the resin (D) constituting the second resin layer, if necessary, as long as the effects of the present invention are not impaired. Examples of the additives include an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, a pigment, a dye, a lubricant, an antiblocking agent, an antistatic agent, a fungicide, an antibacterial agent, a flame retardant, and a fire retardant. Agents, crosslinking agents, crosslinking aids, foaming agents, foaming aids, inorganic fillers, fiber reinforcements, and the like. From the viewpoint of preventing thermal fusion, the additive may be added in a small amount. Specific examples of the ultraviolet absorber include benzophenone type, benzoate type, benzotriazole type, cyanoacrylate type, hindered amine type and the like; specific examples of the filler include silica, clay, calcium carbonate, barium sulfate, glass beads, talc and the like. Can be mentioned. Other resins include polyethylene, polypropylene, ethylene / α-olefin copolymer and the like.

1-3. Layer Configuration The dicing film substrate of the present invention is a dicing film substrate including the first resin layer and the second resin layer (see FIG. 1). The layer configuration of the dicing film substrate is not particularly limited as long as it includes the above two layers, but it is preferable that the first resin layer and the second resin layer are directly laminated from the viewpoint of preventing delamination.

  The resin (A) contained in the resin composition constituting the first resin layer and the resin (D) constituting the second resin layer may be the same resin or different. As a preferable combination of the first resin layer and the second resin layer, a combination of an ionomer of an ethylene / unsaturated carboxylic acid copolymer and an ionomer of an ethylene / unsaturated carboxylic acid copolymer is preferable for chip breaking and expansion. It is desirable from the viewpoint of sex.

  The dicing film substrate may have a multilayer structure of three or more layers. For example, a configuration in which a second resin layer is provided on a plurality of sheets formed by using a resin composition constituting the first resin layer may be used, or the second resin layer may be formed by two first resin layers. A configuration in which a resin layer is interposed may be used. Further, a configuration in which another resin layer is laminated in addition to the first resin layer and the second resin layer may be employed.

  The resin constituting another resin layer to be laminated on the dicing film substrate of the present invention includes linear low density polyethylene (LLDPE), low density polyethylene (LDPE), ethylene-α-olefin copolymer, polypropylene, and ethylene. As a typical example, a blend composed of a single substance or an arbitrary plural substance selected from vinyl ester copolymers can be mentioned.

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 substrate may have a single-layer or multilayer structure. In the present invention, these substrates are referred to as “dicing film substrates”.
In order to improve the adhesive strength of the surface of the dicing film substrate, the surface of the dicing film substrate 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 substrate may be irradiated with an electron beam as needed.

1-4. Production Method As a method for producing the dicing film substrate of the present invention, a resin composition constituting the first resin layer and a resin (D) constituting the second resin layer are each processed into a film by a known method, and laminated. Method. The method of processing the resin composition or the resin into a film is not particularly limited, and examples thereof include various known molding methods such as a conventionally known T-die casting method, a T-die nip molding method, an inflation molding method, an extrusion laminating method, and a calendar molding method. In a manner, a film can be produced.

  Further, the dicing film substrate of the present invention can be produced by subjecting a resin composition constituting the first resin layer and a resin (D) constituting the second resin layer to, for example, co-extrusion lamination. it can.

  For example, when the resin composition constituting the first resin layer is laminated on the surface of the resin (D) film to be the second resin layer by a T-die film molding machine or an extrusion coating molding machine, the second resin layer In order to improve the adhesiveness with the resin, the resin may be formed via an adhesive resin layer by a co-extrusion coating molding machine. Representative examples of such an adhesive resin include the above-mentioned various ethylene copolymers and a single or arbitrary plural blends selected from the unsaturated carboxylic acid grafts thereof.

  Further, as a forming example of the dicing film substrate of the present invention, a first resin layer is formed on the surface of a resin (D) film to be a second resin layer using a T-die film forming machine or an extrusion coating forming machine. A method of forming a multilayer body by heat bonding the resin composition to be formed.

  In addition, although the method of forming the layer made of the resin composition to be the first resin layer on the film of the resin (D) to be the second resin layer has been described, the resin to be the first resin layer is conversely described. The dicing film base of the present invention can also be formed by forming a layer from the resin (D) serving as the second resin layer on the film of the composition, or providing the first resin or the second resin layer on another resin layer. Materials can be manufactured.

  Although the thickness of the dicing film substrate is not particularly limited, 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 in consideration of use as a constituent member of the dicing film. The thickness of each resin layer constituting the dicing film substrate is not particularly limited as long as the total does not exceed the above-mentioned thickness of the dicing film substrate, but both the first resin layer and the second resin layer have a thickness of 30 μm to 100 μm. It is preferable that the ratio be the following, and the ratio of the thickness of the first resin layer to the thickness of the second resin layer be 30/70 to 70/30.

2. Dicing Film A second aspect of the present invention is a dicing film including the above-described dicing film substrate of the present invention and an adhesive layer laminated on at least one surface thereof. FIG. 2 is a sectional view showing one embodiment of the dicing film 20 of the present invention. As shown in FIG. 2, a dicing film 20 of the present invention has a dicing film substrate 10 including a first resin layer 1 and a second resin layer 2, and an adhesive layer 11 provided on the surface thereof.

  From the viewpoint of heat resistance, the dicing film is preferably configured such that the first resin layer is the outermost layer, and is more preferably configured such that an adhesive layer is formed on the outermost layer. The adhesive layer is disposed on the surface of the dicing film substrate. The dicing of the semiconductor wafer can be performed by attaching a dicing film to the semiconductor wafer via the adhesive layer.

  As described above, since the dicing film substrate of the present invention has excellent heat resistance, the dicing film of the present invention also has excellent heat resistance, and has an excellent balance between chip splitting properties and expandability. Film. Therefore, the use of the dicing film of the present invention makes it possible to process a semiconductor wafer efficiently and with high precision.

<Adhesive layer>
The dicing film of the present invention includes the dicing film substrate of the present invention and an adhesive layer provided on one surface of the dicing film substrate, and a semiconductor wafer to be subjected to dicing is attached to the adhesive layer. Fixed. The thickness of the pressure-sensitive adhesive layer depends on the type of the pressure-sensitive adhesive, but is preferably 3 to 100 μm, and more preferably 3 to 50 μm.

  As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, a conventionally known pressure-sensitive adhesive can be used. Examples of the pressure-sensitive adhesive include a rubber-based, acrylic, silicone-based, and polyvinyl ether-based pressure-sensitive adhesive; a radiation-curable pressure-sensitive adhesive; a heat-foamable pressure-sensitive adhesive. Above all, it is preferable that the pressure-sensitive adhesive layer contains an ultraviolet-curable pressure-sensitive adhesive in consideration of the releasability of the dicing film from the semiconductor wafer.

  Examples of the acrylic pressure-sensitive adhesive that can form the pressure-sensitive adhesive layer include a homopolymer of a (meth) acrylate and a copolymer of a (meth) acrylate and a copolymerizable monomer. Specific examples of the (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, ( (Meth) alkyl acrylates such as isononyl methacrylate, hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyalkyl (meth) acrylates such as hydroxyhexyl (meth) acrylate, ( (Meth) glycidyl acrylate and the like.

  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, ( (Meth) acrylic acid alkylaminoalkyl esters (for example, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, etc.), vinyl acetate, styrene, acrylonitrile and the like.

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

  The UV-curable component contained in the UV-curable pressure-sensitive adhesive is, for example, a monomer, oligomer, or polymer having a carbon-carbon double bond in a molecule and curable by radical polymerization. Specific examples of the ultraviolet curing component include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol (meth) acrylate, neopentyl glycol Esters of (meth) acrylic acid and polyhydric alcohol such as di (meth) acrylate and dipentaerythritol hexa (meth) acrylate, and oligomers thereof; 2-propenyldi-3-butenyl cyanurate, 2-hydroxyethylbis ( Isocyanurates such as 2-acryloxyethyl) isocyanurate, tris (2-methacryloxyethyl) isocyanurate, and tris (2-methacryloxyethyl) isocyanurate are included.

  Specific examples of the photopolymerization initiator contained in the ultraviolet curable adhesive include benzoin methyl ethers, benzoin isopropyl ether, benzoin alkyl ethers such as benzoin isobutyl ether, aromatic ketones such as α-hydroxycyclohexyl phenyl ketone, benzyl Examples include aromatic ketals such as dimethyl ketal, and thioxanthones such as polyvinyl benzophenone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, and diethylthioxanthone.

  Examples of the crosslinking agent contained in the ultraviolet curable pressure-sensitive adhesive include a polyisocyanate compound, a melamine resin, a urea resin, a polyamine, a carboxyl group-containing polymer, and the like.

  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 handling and transportation of the film for semiconductor production becomes easy, and label processing can be performed on the separator.

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

<Dicing film manufacturing method>
When producing the dicing film of the present invention, a pressure-sensitive adhesive is prepared by a known method, for example, using 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, and the like. A method of directly applying to a substrate, or a method of applying an adhesive on a release sheet by the above-mentioned known method to form an adhesive layer, and then attaching the adhesive layer to a surface layer of a dicing film substrate and transferring the adhesive layer. Can be used.

Alternatively, a resin composition constituting the first resin layer and a material constituting the adhesive layer are co-extruded to obtain a laminated film (co-extrusion molding method), and the second resin layer is provided thereon. A dicing film can be manufactured.
Further, the pressure-sensitive adhesive composition layer may be subjected to heat crosslinking as necessary 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. Unless otherwise specified, “parts” are based on mass.

1. Resin (A)
As the resin (A), the following ionomer of an ethylene / unsaturated carboxylic acid-based copolymer (hereinafter, referred to as “ionomer”) and an ethylene / unsaturated carboxylic acid-based copolymer (hereinafter, abbreviated as “copolymer”) Was prepared. The melt flow rate (MFR) of the following resin is a value measured at 190 ° C. under a load of 2160 g in accordance with JIS K7210 (1999).
・ Ionomer 1 (IO1)
Ethylene content: 80% by mass, methacrylic acid content: 10% by mass, acrylate butyl ester content: 10% by mass, degree of neutralization: 70% neutralization with zinc, MFR: 1 g / 10 minutes Ionomer 2 (IO2)
Ethylene content: 85% by mass, methacrylic acid content: 15% by mass, degree of neutralization: 59% zinc neutralization, MFR: 1 g / 10 min.Ionomer 3 (IO3)
Ethylene content: 89% by mass, methacrylic acid content: 11% by mass, degree of neutralization: 65% zinc neutralization, MFR: 5 g / 10 minutes Ionomer 4 (IO4)
Ethylene content: 85% by mass, methacrylic acid content: 15% by mass, degree of neutralization: 23% zinc neutralization, MFR: 5 g / 10 minutes ・ Ionomer 5 (IO5)
Ethylene content: 90% by mass, methacrylic acid content: 10% by mass, degree of neutralization: 50% sodium neutralization, MFR: 1 g / 10 minutes Copolymer (EMAA1)
Ethylene content: 91% by mass, methacrylic acid content: 9% by mass, MFR 3 g / 10 minutes Copolymer (EMAA2)
Ethylene content: 79% by mass, methacrylic acid content: 11% by mass, butyl acrylate: 10% by mass, MFR 10 g / 10 min

2. Resin (B)
The following resin was prepared as resin (B).
-Polyamide 1 (PA1): Nylon 6 (Amilan CM1021XF manufactured by Toray Industries, Inc.)
-Polyamide 2 (PA2): Nylon 6-12 (UBE Nylon 7024B manufactured by Ube Industries, Ltd.)
-Polyurethane (TPU): thermoplastic polyurethane elastomer (Milactran P485RSUI manufactured by Tosoh Corporation)

3. Antistatic agent (C)
The following compounds were prepared as antistatic agents (C).
-Polyetheresteramide (PEEA): Perestat 230 manufactured by Sanyo Chemical Industries, Ltd.

4. Resin (D)
The following resin was prepared as resin (D).
・ Ionomer 1 (IO1) (same as that used as resin (A))
Ethylene content: 80% by mass, methacrylic acid content: 10% by mass, butyl acrylate content: 10% by mass, degree of neutralization: 70% zinc neutralization, MFR: 1 g / 10 min. Acid copolymer (EMAA1)
Ethylene content: 91% by mass, methacrylic acid content: 9% by mass, MFR: 3 g / 10 minutes Other resin (LDPE1)
Low density polyethylene, MFR: 1.6 g / 10 min, density: 921 kg / m ³

(Example 1)
The resin (A) and the resin (B) at the ratio (mass%) shown in Table 1 were dry-blended. Next, the mixture obtained by dry blending was introduced into the resin inlet of a 30 mmφ twin-screw extruder, and melt-kneaded at a die temperature of 230 ° C. to obtain a resin composition for the first resin layer.
The MFR of the obtained resin composition for the first resin layer was measured at 230 ° C. under a load of 2160 g according to JIS K7210 (1999), and the results are shown in Table 1.

  The obtained resin composition for the first resin layer and the resin (D) for the second resin layer were put into respective extruders using a two-layer, two-layer 40 mmφT die film forming machine, and the processing temperature was changed. Molding was performed under the condition of 240 ° C. to produce a two-layer, two-layer T-die film having a thickness of 100 μm.

  As described above, a 100 μm-thick laminated film having a two-layer structure (thickness ratio of the first layer to the second layer = 50/50) was obtained. The obtained laminated film was used as a dicing film substrate and evaluated by the following method. The evaluation results are shown in Table 1.

(1) Heat resistance at 160 ° C. Each dicing film substrate was cut in a machine direction (MD) 10 cm × TD direction (Transverse Direction) 3 cm to obtain a film for evaluation. At the center of the evaluation film in the MD direction, a mark line having a length of 60 mm was drawn in the MD direction.
After each evaluation film was left at 160 ° C. under a load of 5 g for 2 minutes, the length of the marked line was measured, and the length of the marked line after the heating test was calculated with respect to the length of the marked line before the heating test. did.
Length of marked line after heating test [%] = (length of marked line after heating test / 60 mm) × 100

When the reference line length is 100, it means that the film has not changed by heating. When the reference line length exceeds 100, it means that the film has been elongated by heating. If the length is less than 100, it means that the film has shrunk by heating.
The 160 ° C. heat resistance was evaluated according to the following criteria based on the length of the marked line after the heating test.
：: The length of the marked line after the heating test is 100.0.
：: The length of the marked line after the heating test is 100.1 to 110.0, or 90.0 to 99.9.
Δ: The length of the marked line after the heating test is 110.1 to 115.0, or 86.0 to 89.9.
×: The length of the marked line after the heating test is 115.1 or more, or 85.9 or less.

(2) Interlayer adhesiveness The adhesive strength between the first layer and the second layer of the dicing film substrate was determined when peeling was performed at a peeling angle of 90 ° (T-peel), a peeling speed of 300 mm / min, and a specimen width of 15 mm. It was shown by strength (N / 15 mm).
Further, based on the adhesive strength, the interlayer adhesion was evaluated according to the following criteria.
：: The interlayer adhesive strength between the first resin layer and the second resin layer is 5 N / 15 mm or more. ×: The interlayer adhesive strength between the first resin layer and the second resin layer is less than 5 N / 15 mm.

(3) Surface resistivity According to JIS K6911, the surface resistivity was measured using a Hiresta-UP manufactured by Mitsubishi Chemical Corporation under an atmosphere of 23 ° C. and 50% relative humidity with an applied voltage of 500 V and a measurement time of 30 seconds. It was measured.

(4) Expandability (expansion rate)
A square of 300 mm or more in the MD direction × 300 mm or more in the TD direction was cut out from the dicing film substrate, and a 141 mm square was drawn using a writing tool such as an oil pen (hereinafter, a measurement object). The measurement target was set on a wafer expansion device for an 8-inch wafer (wafer expansion device TEX-218G GR-8 manufactured by Technovision). At this time, the stage was set so that the center of the stage of the wafer expanding apparatus was aligned with the center of the square drawn on the object to be measured. Next, after raising the stage by 15 mm and expanding the dicing film substrate, the stage was allowed to stand for 60 seconds, and the length (side length) of each side of the square drawn on the measurement object was measured. The elongation rate (%) (= side length after expansion / side length before expansion × 100) was calculated for each of the obtained two MD-direction side lengths, and the average value was taken as the expansion rate [%]. The expansion ratio is preferably 103% or more.

(5) Tensile test (modulus)
The dicing film substrate was cut into strips having a width of 10 mm and used as measurement targets. According to JIS K7127, a 25% modulus was measured in each of the MD and TD directions of the measurement target. The test speed was 500 mm / min.
The 25% modulus is preferably 8 Mpa or more from the viewpoint of chip breaking.

(Examples 2 to 15, Comparative Examples 1 to 5)
The types and amounts of the resin (A), the resin (B), the antistatic agent (C) and the resin (D), and the thicknesses of the first resin layer and the second resin layer were changed as shown in Tables 1 and 2. A laminated film including a first resin layer and a second resin layer was prepared in the same manner as in Example 1 except for performing the above. The antistatic agent (C) was dry blended with the resin (A) and the resin (B) in the amounts shown in Table 1 and used.
The obtained laminated film was used as a dicing film substrate and evaluated by the above method. The evaluation results are shown in Tables 1 and 2.

  As is clear from the results shown in Tables 1 and 2, the dicing films of Examples 1 to 15 each having the first resin layer made of the resin composition containing the resin (A) and the resin (B) as essential components. The substrate showed less change in the film after the heat resistance test at 160 ° C. and showed more excellent heat resistance as compared with Comparative Example 1 having the first resin layer composed of the resin (A) alone.

  Examples in which the second resin layer contains at least one resin (D) selected from the group consisting of an ethylene / unsaturated carboxylic acid copolymer and an ionomer of the ethylene / unsaturated carboxylic acid copolymer. The dicing film substrates Nos. 1 to 15 have higher film interlayer adhesion and no delamination at all as compared with the dicing film substrate of Comparative Example 2 having the second resin layer made of another resin (low-density polyethylene). I couldn't. Such excellent interlayer adhesion can be obtained by using either the ethylene / unsaturated carboxylic acid copolymer (EMAA) or the ionomer of the ethylene / unsaturated carboxylic acid copolymer (IO) as the resin (D). Was also recognized.

  Further, in Comparative Example 4 containing an excessive amount of the antistatic agent (C) and Comparative Example 5 containing an excessive amount (but not less than 40 parts by mass and less than 60 parts by mass) of the resin (B), a resin composition was used. Although the film could be formed by extrusion, the extrusion of the first resin layer became unstable and the thickness accuracy of the film was insufficient, so that various physical properties could not be measured. However, in Comparative Example 3 further including an excessive amount (60 parts by mass or more) of the resin (B), although it was possible to mold a laminated film having the first resin layer and the second resin layer, The adhesive strength between them was low.

  This application claims the priority based on Japanese Patent Application No. 2006-253244 filed on December 27, 2016. The contents described in the specification of this application are all incorporated herein by reference.

  The dicing film substrate of the present invention has excellent heat resistance, and is excellent in the balance between chip breaking properties and expandability. Therefore, by using the dicing film base material and the dicing film of the present invention, the dicing step and the subsequent expanding step at the time of manufacturing the semiconductor can be smoothly performed, and the semiconductor without tape residue or deformation can be manufactured.

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

Claims (5)

30 mass parts or more and 95 mass parts or less of at least one resin (A) selected from the group consisting of an ethylene / unsaturated carboxylic acid-based copolymer and an ionomer of the ethylene / unsaturated carboxylic acid-based copolymer;
At least one resin (B) selected from the group consisting of polyamides and polyurethanes in an amount of 5 parts by mass or more and less than 40 parts by mass;
0 parts by mass or more and 30 parts by mass or less of the antistatic agent (C) other than the polyamide (but the total of the components (A), (B) and (C) is 100 parts by mass)
A first resin layer comprising a resin composition containing:
Dicing, comprising a second resin layer containing at least one resin (D) 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 substrate according to claim 1, wherein the content of the antistatic agent (C) is 0 parts by mass.   The dicing film substrate according to claim 1, wherein the content of the antistatic agent (C) is 5 parts by mass or more and 30 parts by mass or less.   The dicing film substrate according to any one of claims 1 to 3, wherein the polyurethane is a thermoplastic polyurethane elastomer. Dicing film substrate according to any one of claims 1 to 3,
A dicing film having an adhesive layer laminated on at least one surface of the dicing film substrate.

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