Dicing substrate film

Abstract

To provide a base film for dicing that exhibits good expandability.SOLUTION: A base film for dicing is provided that includes a three-layer structure laminated in the order of at least A layer / B layer / C layer. The A layer is made of a resin composition containing an ionomer resin. The B layer is made of a resin composition containing an ionomer resin and a polyolefin resin, and the resin composition contains 90% to 30% by weight of an ionomer resin and 10% to 70% by weight of a polyolefin resin. The C layer is made of a resin composition containing a polyolefin resin. The same polyolefin resin as the B layer is used for the C layer, and the polyolefin resins used for the layer B and the layer C have the same melt flow rate.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a dicing substrate film that is adhered to and fixed on a semiconductor wafer when dicing the semiconductor wafer into chips. [Background technology]

[0002] One method for manufacturing semiconductor chips is to first manufacture a large-area semiconductor wafer, then dice (cut and separate) the semiconductor wafer into chips, and finally pick up the diced chips. In recent years, stealth dicing has become known as a method for cutting semiconductor wafers, in which a laser processing device is used to cut (divide) the semiconductor wafer without touching it.

[0003] Patent Document 1 describes a substrate film for a dicing film that includes a substrate layer and a surface layer, the substrate layer containing low-density polyethylene, and the surface layer containing an ionomer resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. WO2016 / 080324 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a dicing substrate film that exhibits good expandability. [Means for solving the problem]

[0006] The present inventors have conducted extensive research to solve the above problems and have found that a dicing base film having a three-layer structure in which at least Layer A, Layer B, and Layer C are laminated in this order can provide a dicing base film with good expandability.

[0007] Section 1. A dicing substrate film including a three-layer structure in which at least an A layer, a B layer, and a C layer are laminated in this order, Layer A is made of a resin composition containing an ionomer resin, Layer B is made of a resin composition containing an ionomer resin and a polyolefin-based resin, The resin composition contains 90% by weight to 30% by weight of an ionomer resin and 10% by weight to 70% by weight of a polyolefin resin, The C layer is made of a resin composition containing an ionomer resin or a polyolefin resin. Dicing substrate film.

[0008] Section 2. Item 2. The dicing substrate film according to item 1, wherein the polyolefin resin is at least one selected from the group consisting of branched low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, and a propylene-α-olefin copolymer.

[0009] Section 3. 3. A dicing film having a pressure-sensitive adhesive layer on one side of the dicing base film according to item 1 or 2.

[0010] Section 4. A dicing substrate film including a three-layer structure in which at least an A layer, a B layer, and a C layer are laminated in this order, Layer A is made of a resin composition containing an ionomer resin, Layer B is made of a resin composition containing an ionomer resin and a polyolefin-based resin, The resin composition contains 90% by weight to 30% by weight of an ionomer resin and 10% by weight to 70% by weight of a polyolefin resin, The C layer is made of a resin composition containing a polyolefin resin, The same polyolefin resin as that used in the B layer is used in the C layer, and the polyolefin resins used in the B layer and the C layer have the same melt flow rate. Dicing substrate film. [Effects of the Invention]

[0011] The dicing substrate film of the present invention exhibits good expandability. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention relates to a substrate film for dicing.

[0013] The present invention further relates to a dicing film comprising a dicing base film and a pressure-sensitive adhesive layer and a die-bonding layer provided in this order on the dicing base film.

[0014] (1) Dicing substrate film The dicing substrate film of the present invention includes at least a three-layer structure in which Layer A / Layer B / Layer C are laminated in this order.

[0015] In the dicing substrate film of the present invention, Layer A is made of a resin composition containing an ionomer resin.

[0016] In the dicing substrate film of the present invention, Layer B is made of a resin composition containing an ionomer resin and a polyolefin-based resin, and the resin composition contains 90% by weight to 30% by weight of the ionomer resin and 10% by weight to 70% by weight of the polyolefin-based resin.

[0017] In the dicing substrate film of the present invention, the layer C is made of a resin composition containing an ionomer resin or a polyolefin resin.

[0018] Each layer constituting the dicing substrate film of the present invention will be described in detail below.

[0019] (1-1) A layer In the dicing substrate film of the present invention, Layer A is a layer located on the outer surface, is made of a resin composition containing an ionomer resin, and is the layer in contact with the pressure-sensitive adhesive layer when made into a dicing film.

[0020] In the dicing substrate film of the present invention, Layer A is made of a resin composition containing an ionomer resin, which allows the entire film to stretch uniformly and provides good expandability.The dicing substrate film of the present invention also provides the effect of reducing cutting waste during dicing.

[0021] Layer A may contain a polyethylene resin in addition to the ionomer resin. The PE resin may be at least one component selected from the group consisting of branched low-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-methyl methacrylate copolymer, and ethylene-methacrylic acid copolymer.

[0022] Ionomer Resin Ionomer resin is a resin in which a binary copolymer whose polymer components are ethylene and (meth)acrylic acid, or a ternary copolymer whose polymer components are ethylene, (meth)acrylic acid, and a (meth)acrylic acid ester, is crosslinked with metal ions.

[0023] The metal ion is preferably a potassium ion (K + ), sodium ions (Na + ), lithium ion (Li + ), magnesium ions (Mg 2+ ), zinc ions (Zn 2+ ) etc.

[0024] The degree of neutralization by cations of the carboxyl groups of the binary copolymer containing ethylene and (meth)acrylic acid as polymer components, or the ternary copolymer containing ethylene, (meth)acrylic acid, and a (meth)acrylic acid ester as polymer components, is preferably 40 mol% to 75 mol%.

[0025] The melting point of the ionomer resin is preferably 80°C or higher, which is preferable because it improves the heat resistance of the surface layer. The upper limit of the melting point of the ionomer resin is not particularly limited, but is substantially about 100°C.

[0026] The ionomer resin preferably has a melt flow rate (MFR) of 3 g / 10 min or less at a test temperature of 190°C and a test load of 21.18 N according to the test method specified in ISO 1133:2011. This can suppress the generation of cutting waste from the dicing film. The lower limit of the MFR of the ionomer resin is not particularly limited, but is substantially 0.8 g / 10 min.

[0027] The density of ionomer resin is 930 kg / m 3 ~960Kg / m 3 The density is a value determined in accordance with ISO1183:2004.

[0028] As the (meth)acrylic acid alkyl ester constituting the ionomer resin, an alkyl ester having 3 to 8 carbon atoms is preferably used. Specific preferred examples of the (meth)acrylic acid alkyl ester include propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-methylpropyl (meth)acrylate, 2-ethylpropyl (meth)acrylate, 2-methylbutyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, 2-methylhexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and 1,2-dimethylbutyl (meth)acrylate.

[0029] antistatic agent In the dicing substrate film of the present invention, at least one of the A layer and the C layer (the resin composition constituting the layer) may contain an antistatic agent.

[0030] In the dicing substrate film of the present invention, at least one of the layers A and C contains an antistatic agent, which has the effect of preventing peeling static electricity from occurring when peeling off the semiconductor chip, and thus preventing damage to the chip circuitry.

[0031] In the dicing substrate film of the present invention, it is preferable to use, as the antistatic agent, at least one component selected from the group consisting of polyether ester amide resins (PEEA resins) and hydrophilic polyolefin resins (hydrophilic PO resins).

[0032] The content of the antistatic agent in the layer (in the resin composition constituting the layer) is preferably about 10 to 30% by weight, more preferably about 15 to 25% by weight. By blending the antistatic agent in the above range, generated static electricity can be effectively and quickly removed without impairing the properties of the film of the present invention.

[0033] Polyester ether amide resin (PEEA resin) The polyetheresteramide resin is a polymer composed of a polyetherester, which is a main unit component imparting hydrophilicity, and a polyamide unit. Commercially available polyetheresteramide resins can be used, or they can be easily produced by known methods.

[0034] An example of a polyether ester amide resin is Pelestat NC6321 manufactured by Sanyo Chemical Industries, Ltd. Furthermore, Japanese Patent Application Laid-Open Nos. 64-45429 and 6-287547 describe methods for producing polyether ester amide resins.

[0035] The polyetheresteramide resin can be produced, for example, by reacting a polydiol component having an ether group in the main chain with a dicarboxylic acid component to convert it into a terminal ester, and then reacting this with an aminocarboxylic acid or a lactam. In the dicing substrate film of the present invention, the polyetheresteramide resin is preferably used because it has good compatibility with acrylic resins and does not bleed out at all.

[0036] Hydrophilic polyolefin resin (polyether / polyolefin block copolymer) In the dicing substrate film of the present invention, at least one component of the hydrophilic PO resin (polyether / polyolefin block copolymer), for example, hydrophilic polyethylene (hydrophilic PE), hydrophilic polypropylene (hydrophilic PP), etc. can be preferably used.

[0037] Hydrophilic PE and hydrophilic PP resins are basically formed by block bonding between polyethylene chains or polypropylene chains and polyoxyalkylene chains. Hydrophilic PE and hydrophilic PP exhibit high antistatic properties, eliminating static buildup. The block bonds are formed by ester groups, amide groups, ether groups, urethane groups, etc. In the dicing substrate film of the present invention, the block bonds are preferably ester groups or ether groups in terms of compatibility with the film resin.

[0038] Examples of polyether / polyolefin block copolymers include Pelestat and Pelektron manufactured by Sanyo Chemical Industries, Ltd.

[0039] (1-2)B layer In the dicing substrate film of the present invention, Layer B is a so-called central layer, and is made of a resin composition containing an ionomer resin and a polyolefin resin.

[0040] In the dicing substrate film of the present invention, Layer B is made of a resin composition containing an ionomer resin and a polyolefin resin (PO resin), which allows the entire film to stretch uniformly and provides good expandability.The dicing substrate film of the present invention also provides good heat shrinkability.

[0041] As the ionomer resin, the ionomer resin used in the layer A can be used.

[0042] Polyolefin resin Preferred examples of polyolefin resins include branched low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, and propylene-α-olefin copolymers, and one type may be used or two or more types may be used in appropriate combination.

[0043] The α-olefin preferably includes an α-olefin having two or more carbon atoms (excluding those having three carbon atoms), and more preferably includes, for example, ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, etc. These α-olefins may be used alone or in appropriate combination of two or more from the above components.

[0044] As the polyolefin resin, it is preferable to use branched low-density polyethylene and / or linear low-density polyethylene.

[0045] Branched-chain low-density polyethylene is a thermoplastic resin obtained by polymerizing ethylene. The number-average molecular weight of the branched-chain low-density polyethylene is preferably about 10,000 to 1,000,000, and more preferably about 50,000 to 500,000. By setting the number-average molecular weight of the branched-chain low-density polyethylene to about 10,000 or more, molding into a film is improved. On the other hand, by setting the number-average molecular weight of the branched-chain low-density polyethylene to about 1,000,000 or less, extrusion molding of the resin is improved.

[0046] The density of branched low density polyethylene is 915 kg / m 3 ~935Kg / m 3 The preferred level is 917 kg / m 3 ~935Kg / m 3 Density is determined in accordance with ISO 1183-1:2004.

[0047] The melting point of the branched low-density polyethylene is preferably about 100°C to 130°C.

[0048] The MFR (melt flow rate) of the branched low-density polyethylene, measured in accordance with ISO 1133:2011 at a temperature of 190°C and a load of 21.18 N, is preferably about 0.3 g / 10 min to 20 g / 10 min, and more preferably about 0.5 g / 10 min to 10 g / 10 min. By setting the MFR of the branched low-density polyethylene within the above range, stable film formation becomes possible.

[0049] Linear low-density polyethylene is a copolymer of ethylene and an α-olefin, and examples of the α-olefin include 1-butene, 1-hexene, and 1-octene.

[0050] The number-average molecular weight of the linear low-density polyethylene is preferably about 10,000 to 1,000,000, and more preferably about 50,000 to 500,000. By setting the number-average molecular weight of the linear low-density polyethylene to about 10,000 or more, molding into a film is more favorable. On the other hand, by setting the number-average molecular weight of the low-density polyethylene to about 1,000,000 or less, resin extrusion molding is more favorable.

[0051] The density of linear low density polyethylene is 880 kg / m 3 ~940Kg / m 3 About 900 kg / m 3 ~935Kg / m 3 Density is determined in accordance with ISO 1183-1:2004.

[0052] The melting point of the linear low-density polyethylene is preferably about 100°C to 130°C.

[0053] The MFR (melt flow rate) of the linear low-density polyethylene, measured in accordance with ISO 1133:2011 at a temperature of 190°C and a load of 21.18 N, is preferably about 0.3 g / 10 min to 20 g / 10 min, and more preferably about 0.5 g / 10 min to 10 g / 10 min. By setting the MFR of the linear low-density polyethylene within the above range, stable film formation becomes possible.

[0054] Resin composition of layer B In the dicing substrate film of the present invention, Layer B comprises an ionomer resin and a polyolefin resin, and is made of a resin composition containing 90 to 30% by weight of an ionomer resin and 10 to 70% by weight of a polyolefin resin. Layer B preferably comprises a resin composition containing 75 to 35% by weight of an ionomer resin and 25 to 65% by weight of a polyolefin resin.

[0055] In the dicing substrate film of the present invention, by adjusting the blending composition of the ionomer resin and polyolefin resin contained in Layer B to fall within the above-mentioned ranges, effects such as better extrusion molding of the resin, better molding into a film, and stable film formation are achieved.

[0056] (1-3)C layer In the dicing substrate film of the present invention, Layer C is located on the opposite side of Layer A across Layer B. Layer C is made of a resin composition containing an ionomer resin or a polyolefin-based resin.

[0057] As the ionomer resin and polyolefin-based resin, the ionomer resin and polyolefin-based resin used in the A layer and B layer can be used.

[0058] In the dicing substrate film of the present invention, Layer C is the surface that comes into contact with the expanding ring, and it is preferable that the resin composition constituting Layer C contains an ionomer resin or a polyolefin resin, which can provide good sliding properties with the expanding ring.

[0059] (1-4) Layer structure of dicing substrate film The dicing substrate film of the present invention includes at least a three-layer structure in which Layer A / Layer B / Layer C are laminated in this order.

[0060] In the dicing substrate film of the present invention, Layer A is a layer located on the surface (surface layer) and is made of a resin composition containing an ionomer resin. At least one of Layer A and Layer C (the resin composition constituting the layer) may contain an antistatic agent.

[0061] The total thickness of the dicing substrate film of the present invention is preferably about 20 μm to 300 μm, more preferably about 30 μm to 250 μm, and even more preferably about 40 μm to 220 μm. By setting the total thickness of the dicing substrate film to 20 μm or more, it becomes possible to protect the semiconductor wafer from impact when dicing the semiconductor wafer.

[0062] As a specific example of a dicing base film, a case where the total thickness is about 20 μm to 150 μm will be described.

[0063] The thickness of Layer A is preferably about 2 μm to 100 μm, more preferably about 5 μm to 75 μm, and even more preferably about 8 μm to 50 μm.

[0064] The thickness of layer B is preferably about 7 μm to 100 μm, more preferably about 10 μm to 75 μm, and even more preferably about 13 μm to 50 μm.

[0065] The thickness of the C layer is preferably about 2 μm to 100 μm, more preferably about 5 μm to 75 μm, and even more preferably about 8 μm to 50 μm.

[0066] (2) Manufacturing method of dicing substrate film In the present invention, a dicing substrate film having a three-layer structure in which at least Layer A / Layer B / Layer C are laminated in this order can be produced by multilayer coextrusion molding of the resin compositions used for each of Layer A, Layer B, and Layer C. Specifically, it can be produced by coextrusion molding the resin compositions for forming each layer so that they are laminated in the order of Layer A / Layer B / Layer C.

[0067] In the present invention, the layer A of the dicing substrate film is a layer located on the surface.

[0068] The resins for each layer are fed to a screw extruder in the stated order, extruded through a multilayer T-die at 180 to 240°C into a film, and cooled by passing through cooling rolls at 30 to 70°C, and taken up without being stretched substantially. Alternatively, the resins for each layer may be obtained as pellets and then extruded as described above.

[0069] The reason for not stretching the film substantially during take-up is that it is advantageous to effectively expand the film after dicing. This "substantially not stretching" includes no stretching or slight stretching that does not adversely affect the expansion of the dicing film. Usually, the film should be pulled to a degree that does not cause sagging during take-up.

[0070] (3) Dicing film manufacturing The dicing film of the present invention can be produced according to well-known techniques. For example, the adhesive constituting the adhesive layer is dissolved in a solvent such as an organic solvent, and the solution is applied to a dicing base film, followed by removing the solvent to obtain a film having a base film / adhesive layer configuration. [Example]

[0071] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.

[0072] (1) Raw material for dicing substrate film Table 1 shows the raw materials for the dicing substrate film.

[0073] [Table 1]

[0074] [Explanation of abbreviations] IO: Ionomer resin PO: Polyolefin resin (branched low-density polyethylene)

[0075] (2) Manufacturing of A-layer / B-layer / C-layer dicing base film Resin compositions were blended with the components and compositions shown in Table 2 to form Layer A / Layer B / Layer C (3 layers), to prepare a substrate film for dicing.

[0076] The resin compositions constituting each layer were fed into respective extruders adjusted to 220°C, extruded through a T-die at 220°C in the order of Layer A / Layer B / Layer C, laminated, and co-extruded onto a chill roll through which cooling water at 30°C was circulated to obtain a flat three-layer film.

[0077] [Table 2]

[0078] (3) Evaluation of dicing substrate film (3-1) Interlaminar peel strength <Evaluation method> The films obtained in the examples and comparative examples were cut into strips 150 mm long x 10 mm wide (the length direction was the MD direction) to prepare test samples. The obtained test samples were subjected to measurement of the interlayer peel strength between layer A and layer B of the film using a peel strength tester (HEIDON TYPE 17 manufactured by Shinto Scientific Co., Ltd.) at a tensile speed of 200 mm / min. The interlayer peel strength was measured four times, and the average value was calculated and evaluated according to the following criteria.

[0079] <Evaluation criteria> ○: 0.4N / 10mm or more.

[0080] ×: Less than 0.4N / 10mm.

[0081] (3-2) Uniform expansion <Evaluation method> The films obtained in the examples and comparative examples were cut into strips measuring 120 mm in length and 10 mm in width to prepare measurement samples. The measurement samples were set in a Strograph VE1D (manufactured by Toyo Seiki Seisakusho) with a gauge distance of 40 mm, and a tensile test was performed at a tensile reading of 200 mm / min to obtain a stress-strain curve. The stress value at an elongation rate of 30% was read from the obtained stress-strain curve. Measurements were performed five times in each of the MD and TD directions, and the average value was taken as the stress value at 30% elongation to calculate the stress ratio (MD / TD).

[0082] <Evaluation criteria> ◯: The stress ratio (MD / TD) is less than 1.5.

[0083] ×: The stress ratio (MD / TD) is 1.5 or more.

[0084] [Table 3]

[0085] In the dicing substrate film of the present invention, Layer B is the central layer and is made of a resin composition containing an ionomer resin and a polyolefin resin, which allows the entire film to stretch uniformly, providing good expandability and exhibiting good interlayer peel strength between Layer A and Layer B of the film.

[0086] The dicing substrate film of the present invention can be evaluated as exhibiting good expandability and good interlayer peel strength of the film.

Claims

1. A dicing substrate film including a three-layer structure in which at least an A layer, a B layer, and a C layer are laminated in this order, Layer A is made of a resin composition containing an ionomer resin, Layer B is made of a resin composition containing an ionomer resin and a polyolefin-based resin, The resin composition contains 90% by weight to 30% by weight of an ionomer resin and 10% by weight to 70% by weight of a polyolefin resin, The C layer is made of a resin composition containing a polyolefin resin, The same polyolefin resin as that used in the B layer is used in the C layer, and the polyolefin resins used in the B layer and the C layer have the same melt flow rate. The total thickness of the dicing base film is 20 μm to 300 μm. Dicing substrate film.

2. 2. The dicing substrate film according to claim 1, wherein the polyolefin resins used in the layers B and C have the same density.

3. 3. The dicing substrate film according to claim 1, wherein the polyolefin resins used in the layers B and C have the same melting point.

4. 4. The dicing substrate film according to claim 1, wherein the polyolefin resin used in the layers B and C is at least one selected from the group consisting of branched low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, and a propylene-α-olefin copolymer.

5. 4. The dicing substrate film according to claim 1, wherein the polyolefin resin used in the layers B and C is a branched low-density polyethylene and / or a linear low-density polyethylene.

6. 6. A dicing film comprising the dicing base film according to claim 1, and a pressure-sensitive adhesive layer on one side of the dicing base film.

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