JP2018166148A - Substrate film for dicing sheet and dicing sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate film for a dicing sheet and a dicing sheet which do not rupture at the time of expanding even when dicing is performed at a relatively high dicing speed, and furthermore, in which slacking hardly occurs after the expanding.SOLUTION: In substrate films 1 and 1' for a dicing sheet, both Elmendorf values in an MD direction and a TD direction are 3.0 N or more and 15.0 N or less, and both tensile modulus in the MD direction and the TD direction in an environment of temperature 23°C and relative humidity 50% RH are 65 MPa or more and less than 400 MPa, and both the elongations at break in the MD direction and the TD direction when a tensile test is conducted under the environment of the temperature of 23°C and the relative humidity of 50% RH are both 280% or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a substrate film for dicing sheet and a dicing sheet, and more preferably to a substrate film for dicing sheet and a dicing sheet used for step-cut type dicing.

  Semiconductor wafers such as silicon and gallium arsenide, substrates such as glass substrates and alumina substrates, and various packages (in this specification, these are collectively referred to as “objects to be cut”) are manufactured in a large diameter state, These are cut and separated (diced) into element pieces (hereinafter referred to as “chips”).

  The object to be cut attached to this dicing process is opposite to the side where the cutting tool for cutting is close in order to ensure the handleability of the object to be cut and the chips in the dicing process and subsequent processes. Affixed in advance to the surface of the workpiece to be cut.

  In a general dicing process, the workpiece is cut by passing a rotating round blade (dicing blade) in contact with the workpiece. At this time, not only the object to be cut but also a part of the dicing sheet may be cut so that the object to be cut to which the dicing sheet is attached is surely cut.

  A dicing method using a dicing blade includes a method in which cutting of an object to be cut is completed by passing through the dicing blade once (referred to as “single cut method” in this specification), and a method in which the dicing blade passes through a plurality of times. There is a method (hereinafter referred to as “step cut method”) that finally cuts an object to be cut. In the latter method, for example, a dicing blade having a relatively large thickness is passed while being in contact with the object to be cut, and a cut is made partway along the thickness direction of the object to be cut, and then the thickness of the dicing blade is compared. The object to be cut is completely cut by exchanging it with a thin one and passing the cut again.

  Patent Document 1 discloses an example of a dicing sheet. In the dicing sheet disclosed in Patent Document 1, a polyolefin film irradiated with 1 to 80 Mrad of an electron beam or γ-ray is used as a base film (Claim 1 of Patent Document 1). In Patent Document 1, by using such a base film, generation of thread-like dicing waste during wafer dicing can be reduced, and mechanical properties such as elasticity and strength of the base film are impaired. However, it is disclosed that the expansion of the adhesive sheet can be performed without any trouble (paragraph 0014 of Patent Document 1).

  Patent Document 2 discloses another example of a dicing sheet. In the dicing sheet disclosed in Patent Document 2, a substrate film having a cutting piece suppression layer (A) and an expanded layer (B) each made of a predetermined material is used (claim of Patent Document 2). Item 1). Patent Document 2 discloses that such a base film is excellent in expandability and recoverability (paragraph 0017 of Patent Document 2).

Japanese Patent Laid-Open No. 5-21234 International Publication No. 2015/146596

  In recent years, miniaturization of semiconductor chips has progressed, and in the dicing process of a semiconductor wafer, it is necessary to cut the semiconductor wafer more finely than in the past. However, when a small semiconductor chip is manufactured by single-cut dicing, the semiconductor chip is easily damaged. In particular, when a semiconductor chip having an elongated shape is manufactured, a problem that the semiconductor chip is broken at an intermediate position is likely to occur.

  On the other hand, according to the step-cut type dicing, the dicing blade is brought into contact with the semiconductor wafer in a plurality of times, so that the impact of the dicing blade on the semiconductor wafer by a single contact is reduced. Thereby, damage to the semiconductor chip is suppressed, and a fine semiconductor chip can be manufactured satisfactorily.

  Here, in the step-cut type dicing, the number of times the dicing blade is brought into contact with the semiconductor wafer is increased as compared with the single-cut method, so that the time required for dicing one semiconductor wafer is increased. Therefore, from the viewpoint of improving manufacturing efficiency in recent years, in order to manufacture a small semiconductor chip by step-cut dicing, the speed of moving the dicing blade in contact with the semiconductor wafer (in this specification, “ It is necessary to increase the dicing speed.)

  However, when the conventional dicing sheet as in Patent Documents 1 and 2 is used and dicing is performed at a relatively high dicing speed, the dicing sheet is easily broken in the subsequent process of expanding the dicing sheet (expanding process). The problem arises. It is also possible to produce a dicing sheet by prioritizing the viewpoint that it is difficult to break in the expanding process, and a dicing sheet made of such a material is easy to stretch, but remains stretched. It tends to be difficult to restore. For this reason, slack is likely to occur after expansion, and a pick-up failure is likely to occur in the subsequent pick-up process of the semiconductor chip.

  The present invention has been made in view of such a situation. Even when dicing is performed at a relatively high dicing speed, the present invention does not break at the time of expansion, and further, it is difficult for slack to occur after expansion. It aims at providing the base film for dicing sheets, and a dicing sheet.

  In order to achieve the above object, first, the present invention has an Elmendorf value in the MD direction and TD direction of both 3.0 N and 15.0 N, a temperature of 23 ° C. and a relative humidity of 50% RH. The tensile modulus in the MD direction and the TD direction is 65 MPa or more and less than 400 MPa, and the tensile elongation at break in the MD direction and TD direction when a tensile test is performed in an environment of a temperature of 23 ° C. and a relative humidity of 50% RH. Provided is a base film for a dicing sheet characterized in that the degrees are both 280% or more (Invention 1).

  In the base film for a dicing sheet according to the invention (Invention 1), the Elmendorf value, the tensile elastic modulus in an environment of a temperature of 23 ° C. and a relative humidity of 50% RH, and the environment of a temperature of 23 ° C. and a relative humidity of 50% RH The elongation at break when performing a tensile test shows the above-mentioned ranges, respectively, and as a result of these physical properties acting in a composite manner, even when dicing at a relatively high dicing speed is performed, breakage occurs during expansion. It is difficult to occur, and it is difficult for slack to occur after expansion.

  In the said invention (invention 1), it is preferable to consist of a single layer (invention 2).

  In the said invention (invention 1), it is preferable to consist of multiple layers (invention 3).

  In the said invention (invention 3), it is preferable to provide the cutting piece suppression layer and the expanded layer laminated | stacked on the one surface side of the said cutting piece suppression layer (invention 4).

  In the said invention (invention 4), the said expanded layer is the 1st resin system unit layer located proximal to the said cutting piece suppression layer, and the 2nd resin system unit located distal to the said cutting piece suppression layer It is preferable to provide a layer (Invention 5).

  In the said invention (invention 1-5), it is preferable that the said dicing sheet is a thing for using for the dicing of a step cut system (invention 6).

  In the said invention (invention 1-6), it is preferable that the said dicing sheet is for dicing the to-be-cut material into the chip | tip whose short side is 0.5 mm or more and 4.0 mm or less (invention 7). .

  2ndly this invention is equipped with the base film for said dicing sheets (invention 1-7), and the semiconductor sticking layer laminated | stacked on the single side | surface side of the said base film for dicing sheets, The dicing sheet characterized by the above-mentioned. Provided (Invention 8)

  The substrate film for dicing sheet and the dicing sheet according to the present invention do not break at the time of expansion even when dicing is performed at a relatively high dicing speed, and further, it is difficult for slack to occur after expansion.

It is sectional drawing of the base film for dicing sheets which concerns on the 1st Embodiment of this invention. It is sectional drawing of the base film for dicing sheets which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the dicing sheet which concerns on one Embodiment of this invention. It is a cross section which shows an example of the usage method of the dicing sheet which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
[Base film for dicing sheet]
FIG. 1 shows a cross-sectional view of a base film 1 for dicing sheets according to the first embodiment (hereinafter may be abbreviated as “base film 1”). The base film 1 according to this embodiment is composed of a single layer.

  Further, FIG. 2 shows a cross-sectional view of a base film for dicing sheet 1 ′ (hereinafter sometimes abbreviated as “base film 1 ′”) according to the second embodiment. The base film 1 ′ according to the present embodiment is composed of a plurality of layers, and in particular, a cutting piece suppressing layer (A) and an expanded layer (B) laminated on one surface side of the cutting piece suppressing layer (A). The expanded layer (B) further includes a first resin-based unit layer (B1) and a second resin-based unit layer (B2).

  In the base film 1, 1 'according to the present embodiment, the Elmendorf values in the MD direction and the TD direction are both 3.0 N or more and 15.0 N or less. Moreover, the tensile elastic modulus of MD direction and TD direction in the environment of temperature 23 degreeC and relative humidity 50% RH is both 65 MPa or more and less than 400 MPa. Furthermore, when the tensile test is performed in an environment of a temperature of 23 ° C. and a relative humidity of 50% RH, the breaking elongations in the MD direction and the TD direction are both 280% or more. Here, the MD direction refers to the flow direction during the production of the base films 1 and 1 ′, and the TD direction refers to a direction perpendicular to the MD direction.

  Dicing was performed at a relatively fast dicing speed by using the dicing sheet provided with the base film 1, 1 ′ when the base film 1, 1 ′ according to the present embodiment satisfies the above-described physical properties. Even in such a case, it is difficult to cause breakage during expansion, and it is difficult to cause looseness after expansion. These effects are obtained by combining the above-described physical properties, and it is difficult to individually explain the causal relationship between the physical properties and these effects. However, the following can be considered as a part of the reason why the above-described effect can be obtained. First, since the Elmendorf value and the elongation at break are in the above-mentioned ranges, resistance against the impact load generated in the base film 1, 1 ′ is exhibited, and the impact load is instantaneously caused by dicing at a relatively fast dicing speed. Even when the height is increased, breakage of the base film 1, 1 ′ is prevented during expansion. In addition, since the tensile modulus is in the above-described range, the base film 1, 1 ′ exhibits good elasticity, and the base film 1, 1 ′ has an ability to restore moderately even after stretching. Demonstrates and the occurrence of slack is suppressed.

1. Physical properties of base film, etc. In the base film 1, 1 ′ according to this embodiment, the Elmendorf values in the MD direction and the TD direction are preferably 3.0 N or more. The Elmendorf value is 15.0 N or less, preferably 13.0 N or less, particularly preferably 12.0 N or less. When the Elmendorf value is less than 3.0N, the substrate film 1, 1 ′ cannot withstand the impact load that is instantaneously increased by dicing at a relatively fast dicing speed. 1 'breaks. On the other hand, if the Elmendorf value exceeds 15.0 N, the base film 1, 1 ′ exhibits excessively high toughness and loses flexibility and cannot be expanded well. The Elmendorf value in the MD direction and the Elmendorf value in the TD direction may be the same value, or may be different values within the above-described range. Moreover, the Elmendorf value mentioned above is measured according to JIS K7128-2: 1998, and the details of the measuring method are as shown in the test examples described later.

  In the base film 1, 1 ′ according to this embodiment, the tensile elastic modulus in the MD direction and the TD direction in an environment of a temperature of 23 ° C. and a relative humidity of 50% RH is 65 MPa or more, and preferably 68 MPa or more. In particular, the pressure is preferably 70 MPa or more. Further, the tensile elastic modulus is less than 400 MPa, preferably 350 MPa or less, and particularly preferably 300 MPa or less. When the tensile elastic modulus is less than 65 MPa, the base film 1, 1 ′ does not have sufficient elasticity, and the base film is stretched when the dicing sheet is attached to the ring frame, and is excellent in applicability. It will not be. Further, if the tensile elastic modulus is 400 MPa or more, the base film 1, 1 ′ has excessively high elasticity, and it becomes difficult to expand, and after the base film 1, 1 ′ is stretched sufficiently It cannot be restored and sag occurs. The tensile modulus in the MD direction and the tensile modulus in the TD direction may be the same value, or may be different values as long as they are within the above-described range. Further, the above-described tensile elastic modulus is measured according to JIS K7161-1: 2014 and JIS K7127: 1999, and details of the measuring method are as shown in the test examples described later.

  In the base film 1, 1 ′ according to the present embodiment, when the tensile test is performed in an environment of a temperature of 23 ° C. and a relative humidity of 50% RH, the elongation at break in the MD direction and the TD direction is 280% or more. Yes, it is preferably 290% or more, particularly preferably 300% or more. When the elongation at break is less than 280%, when the base film 1, 1 'is diced at a relatively high dicing speed, the base film 1, 1' is broken in the subsequent expansion. The upper limit of the elongation at break is not particularly limited, but is usually preferably 700% or less, particularly preferably 650% or less. Note that the breaking elongation in the MD direction and the breaking elongation in the TD direction may be the same value, or different values as long as they are within the above-described range. Moreover, the measuring method of the breaking elongation mentioned above is measured according to JISK6732: 2006, and the detail of a measuring method is as showing to the test example mentioned later.

  The thickness of the base film 1, 1 ′ according to this embodiment is preferably 40 μm or more, particularly preferably 60 μm or more, and further preferably 80 μm or more. The thickness is preferably 300 μm or less, particularly preferably 250 μm or less, and more preferably 200 μm or less. When the thickness of the base film 1, 1 ′ is within the above range, the Elmendorf value and the elongation at break can be easily set within the above-described ranges, and when the dicing is performed at a relatively high dicing speed, The occurrence of breakage and slackening after expansion can be effectively suppressed.

2. Configuration and Composition of Base Film The base film according to this embodiment may be composed of a single layer as shown in FIG. 1 or may be composed of a plurality of layers as shown in FIG.

(1) Base film composed of a single layer The material of the base film 1 shown in FIG. 1 is not particularly limited as long as the base film 1 can achieve the physical properties described above, and a known material can be used. . For example, the base film 1 may include a film (resin film) whose main material is a resin-based material. Preferably, the base film 1 consists only of a resin film. Specific examples of the resin film include ethylene-based copolymer films such as ethylene- (meth) acrylic acid copolymer film, ethylene-vinyl acetate copolymer film, ethylene- (meth) acrylic acid ester copolymer film; polyethylene Polyolefin films such as films, polypropylene films, polybutene films, polybutadiene films, polymethylpentene films, ethylene-norbornene copolymer films and norbornene resin films; polyvinyl chloride films such as polyvinyl chloride films and vinyl chloride copolymer films Film; Polyester film such as polyethylene terephthalate film and polybutylene terephthalate film; Polyurethane film; Polyimide film; Polystyrene film; Polycarbonate Irumu; and fluororesin films. Examples of the polyethylene film include a low density polyethylene (LDPE) film, a linear low density polyethylene (LLDPE) film, and a high density polyethylene (HDPE) film. In addition, modified films such as these crosslinked films and ionomer films are also used. Among these, it is preferable to use an ethylene- (meth) acrylic acid copolymer film or a vinyl chloride copolymer film from the viewpoint of easily achieving the physical properties described above. In addition, “(meth) acrylic acid” in the present specification means both acrylic acid and methacrylic acid. The same applies to other similar terms.

  The base film 1 according to this embodiment may contain various additives such as pigments, dyes, flame retardants, plasticizers, antistatic agents, lubricants, and fillers. Examples of the pigment include titanium dioxide and carbon black. Examples of the filler include organic materials such as melamine resin, inorganic materials such as fumed silica, and metal materials such as nickel particles. The content of these additives is not particularly limited, but it is preferable that the base film 1 exhibits a desired function and can exhibit the above-described physical properties.

  When a layer containing a material curable by active energy rays is used as a semiconductor sticking layer to be described later laminated on the base film 1, the base film 1 preferably has transparency to the active energy rays.

  The surface of the base film 1 on which the semiconductor adhesive layer is laminated is subjected to surface treatment such as primer treatment, corona treatment, plasma treatment, and roughening treatment (matte treatment) in order to improve adhesion to the semiconductor adhesive layer. May be. Examples of the roughening treatment include an embossing method and a sandblasting method.

(2) Base film consisting of multiple layers

  The number of layers of the base film composed of a plurality of layers is not limited. Although FIG. 2 shows a multi-layer base film having three layers, the number of layers may be two, or four or more. Moreover, when a base film consists of multiple layers, each layer may be a layer which consists of mutually different materials, or a layer which consists of the same kind of material may be sufficient as an at least 2 layer.

  In the base film composed of a plurality of layers, the material constituting each layer is not particularly limited as long as the base film 1 exhibits the physical properties described above, and a known material can be used. As an example of the said material, what was mentioned above as a material of the base film 1 which consists of a single layer can be used. Further, at least one layer in the base film composed of a plurality of layers may contain various additives such as pigments as in the case of the base film 1 composed of a single layer. Moreover, when using the layer containing the material hardened | cured with an active energy ray as a semiconductor sticking layer laminated | stacked on the base film which consists of two or more layers, similarly to the base film 1 which consists of a single layer, a base film Preferably has transparency to active energy rays. Further, among the layers constituting the base film composed of a plurality of layers, the surface of the layer on which the semiconductor adhesive layer is laminated may be subjected to surface treatment in the same manner as the base film 1 composed of a single layer.

  Below, the base film 1 'shown by FIG. 2 is demonstrated as a preferable example of the base film which consists of multiple layers. FIG. 2 shows a base film 1 ′ composed of three layers as an example of the base film composed of a plurality of layers. The base film 1 ′ includes a cutting piece suppression layer (A) and an expanded layer (B) laminated on one surface side of the cutting piece suppression layer (A). Further, the expanded layer (B) includes a first resin-based unit layer (B1) positioned proximal to the cutting piece suppression layer (A) and a second resin unit positioned distal to the cutting piece suppression layer (A). And a resin-based unit layer (B2).

(2-1) Cutting piece suppression layer (A)
The cut piece suppressing layer (A) is a layer that contacts the semiconductor adhesive layer when a semiconductor adhesive layer described later is laminated on the base film 1 ′. Generally, when dicing a to-be-cut object on a dicing sheet, not only the to-be-cut object but also a semiconductor sticking layer is cut, and also a part of a substrate film is cut. At this time, the cutting piece which consists of the material which comprises a semiconductor sticking layer and a base film may generate | occur | produce from a dicing sheet. The cutting piece suppression layer (A) is a layer provided for the purpose of reducing the occurrence of such cutting pieces.

  As a material constituting the cutting piece suppression layer (A), it is preferable to select a material that can suppress the generation of the cutting piece. For example, the material is a ring-containing resin (a1) that is a thermoplastic resin having at least one of an aromatic ring and an aliphatic ring, and an olefin-based thermoplastic resin other than the ring-containing resin (a1). It is preferable to contain acyclic olefin resin (a2).

  The ring-containing resin (a1) is preferably a thermoplastic resin having at least one of an aromatic ring and an aliphatic ring. The number of atoms constituting the skeleton of the aromatic ring according to this embodiment is not limited, and a functional group such as a methyl group or a hydroxyl group may be bonded to one or more atoms forming this skeleton. Further, the number of skeletal atoms constituting the aliphatic ring according to this embodiment is not limited, and for one or more of hydrogen bonded to atoms forming the cyclic skeleton of the aliphatic ring, a methyl group, a hydroxyl group, etc. The functional group may be substituted.

  The positions of the aromatic ring and the aliphatic ring in the thermoplastic resin (hereinafter sometimes referred to as polymer) constituting the ring-containing resin (a1) are arbitrary. A part of the main chain in the polymer constituting the ring-containing resin (a1) may be formed, or the main chain or side chain of this polymer as a functional group having a cyclic structure (for example, phenyl group, adamantyl group, etc.) May be bonded to. Examples of the polymer in which the aromatic ring forms a part of the main chain include polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyimide, polyamideimide, and polyaryl ketone. As a polymer in which an aliphatic ring is part of the main chain, cycloolefin polymer, cycloolefin copolymer, norbornene resin using norbornene as a monomer, copolymer containing norbornene and ethylene, tetracyclododecene and ethylene as monomers And copolymers containing dicyclopentadiene and ethylene as monomers. Examples of the functional group having a cyclic structure include groups consisting of a ring assembly such as a fluorene group and a biphenyl group in addition to the above phenyl group and adamantyl group.

  A preferred structure of the ring-containing resin (a1) is a structure in which an aliphatic ring including a ring of a bridged ring skeleton constitutes at least a part of the main chain of the polymer constituting the resin, and has such a structure. Examples of the resin include a ring-opening metathesis polymer hydrogenated polymer of a norbornene-based monomer (specifically, available as ZEONEX (registered trademark) series manufactured by ZEON Corporation), a copolymer of norbornene and ethylene (specifically, poly Available as Plastics TOPAS (registered trademark) series), copolymers based on ring-opening polymerization of dicyclopentadiene and tetracyclopentadene (specifically, ZEONOR (registered trademark) series manufactured by Nippon Zeon Co., Ltd.) And a copolymer of ethylene and tetracyclododecene (specifically, manufactured by Mitsui Chemicals, Inc.) Per (registered trademark) series), cyclic olefin resins containing polar groups starting from dicyclopentadiene and methacrylic acid esters (specifically, available as JSR's Arton (registered trademark) series) Are preferred).

  The ring-containing resin (a1) preferably has a structure in which the aromatic ring constitutes at least a part of the main chain of the polymer constituting the resin. As a resin having such a structure, a styrene-butadiene copolymer (specifically, Asaflex (registered trademark) series manufactured by Asahi Kasei Chemicals Corporation, Clearen (registered trademark) series manufactured by Denki Kagaku Kogyo Co., Ltd., K manufactured by Chevron Phillips Co., Ltd.) The resin series, the BASF Styrolux series, and the Atofina Finaclear series are available.

  The acyclic olefin-based resin (a2) is composed of an olefin-based thermoplastic resin other than the above-described ring-containing resin (a1), that is, having substantially no aromatic ring or aliphatic ring. . In the present embodiment, the olefinic thermoplastic resin is a homopolymer or copolymer having an olefin as a monomer, and a copolymer having an olefin and a molecule other than an olefin as a monomer, and the olefin unit in the resin after polymerization. The general term for the thermoplastic resin whose mass ratio of the part based on is 1.0 mass% or more is meant.

  Specific examples of the acyclic olefin resin (a2) include polyethylene (linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene), ethylene-olefin copolymer (ethylene and olefin other than ethylene, and Copolymer, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, etc., ethylene copolymers, polypropylene, polybutene And polymethylpentene.

  The polymer constituting the acyclic olefin-based resin (a2) may be one type or a blend of a plurality of types of polymers.

  As the acyclic olefin-based resin (a2), polyethylene (linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene), ethylene-olefin copolymer, ethylene-vinyl acetate copolymer, ethylene -It is preferably an ethylene copolymer such as (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, polyethylene (low density polyethylene, medium density polyethylene, high density polyethylene), ethylene -More preferred is an olefin copolymer.

  Examples of the olefin constituting the ethylene-olefin copolymer include propylene such as propylene, 1-butene, 1-hexene, 1-octene and 4-methyl-1-pentene, and α-olefin having 4 to 18 carbon atoms. And monomers.

  The cutting piece suppressing layer (A) may contain other components in addition to the ring-containing resin (a1) and the acyclic olefin-based resin (a2). Examples of such other components include thermoplastic elastomer resins such as isoprene rubber, nitrile rubber, acrylic rubber, urethane rubber, butadiene rubber, and copolymers thereof. The content of these other components in the cutting piece suppressing layer (A) is preferably set in a range in which the cutting piece suppressing effect of the cutting piece suppressing layer (A) can be obtained.

  The thickness of the cutting piece suppressing layer (A) is preferably 20 μm or more, and particularly preferably 30 μm or more. Further, the thickness is preferably 120 μm or less, and particularly preferably 100 μm or less. If the cutting piece suppressing layer (A) has the above thickness, the cutting piece suppressing effect can be obtained more stably.

(2-2) Expanded layer (B)
The expanded layer (B) includes at least one resin-based unit layer. That is, the expanded layer (B) may have a single layer structure or a laminated structure. The expanded layer (B) is a first resin-based unit layer (B1) as a unit layer disposed closest to the cutting piece suppressing layer (A) among at least one resin-based unit layer included in the layer. ). When the expanded layer (B) has a single layer structure, the expanded layer (B) is composed of the first resin-based unit layer (B1).

  It is preferable that the 1st resin system unit layer (B1) arrange | positioned most proximally to the cutting piece suppression layer (A) contains linear polyethylene, a polypropylene, and a thermoplastic elastomer.

  In the present specification, “linear polyethylene” means a copolymer of ethylene and an α-olefin (alkene having 4 or more carbon atoms having an ethylenically unsaturated bond at the α-position). The specific structure of the linear polyethylene is not particularly limited. Examples of the α-olefin serving as a monomer that gives linear polyethylene include 1-butene, 1-hexene, 1-octene, and the like. The linear polyethylene may be composed of one type of polymer or a mixture of a plurality of types of polymers.

  In the present specification, “polypropylene” means a general term for homopolymers and copolymers of monomers containing propylene. Polypropylene may be composed of one type of polymer or a mixture of multiple types of polymers.

  When polypropylene contains a copolymer, the kind of monomer other than propylene related to the copolymer is not limited. Examples of such monomers include α-olefins having 4 to 18 carbon atoms such as ethylene, 1-butene, 1-hexene and 1-octene.

  In the case where polypropylene contains a copolymer, the specific mode of the copolymer is not particularly limited, and may be any of a random copolymer, a block copolymer, and a graft copolymer. You may contain these 2 or more types of copolymers.

  In the present specification, the term “thermoplastic elastomer” is still thermoplastic even when repeatedly heated and cooled within the temperature range specific to the material during processing and use, and has rubber-like elasticity at room temperature. A high molecular weight substance. Here, rubber-like elasticity indicates the tendency of a substance that, after being deformed considerably by a weak stress and then removing the stress, rapidly returns to its original size and shape. This tendency is mainly due to a decrease in entropy due to deformation. Due to

  Examples of thermoplastic elastomers include olefin elastomers, styrene elastomers, urethane elastomers, and the like.

  As an olefin elastomer, a copolymer of propylene and an α olefin; an α olefin polymer (a polymer formed by polymerizing an α olefin, which may be either a homopolymer or a copolymer); Examples include ethylene-propylene rubbers such as ethylene-propylene rubber (EPM) and ethylene-propylene-diene rubber (EPDM); chlorosulfonated polyethylene (CSM) and the like. Among these, as an α-olefin polymer, industrially, TAFMER (registered trademark) series manufactured by Mitsui Chemicals, AFFINITY (registered trademark) series manufactured by Dow Chemical, ENGAGE (registered trademark) series, EXACT manufactured by ExxonMobil Corporation Product names such as (Registered Trademark) series and Exelen (Registered Trademark) FX series manufactured by Sumitomo Chemical Co., Ltd.

  The styrene elastomer is made of a copolymer containing a structural unit derived from styrene or a derivative thereof (styrene compound), and has rubber-like elasticity and thermoplasticity in a temperature range including normal temperature. Examples of styrene elastomers include styrene-conjugated diene copolymers and styrene-olefin copolymers. Specific examples of the styrene-conjugated diene copolymer include styrene-butadiene copolymer, styrene-butadiene-styrene copolymer (SBS), styrene-butadiene-butylene-styrene copolymer, styrene-isoprene copolymer, styrene. -Unhydrogenated styrene-conjugated diene copolymers such as isoprene-styrene copolymer (SIS) and styrene-ethylene-isoprene-styrene copolymer; styrene-ethylene / propylene-styrene copolymer (SEPS, styrene-isoprene) -Styrene copolymer water additives), hydrogenated styrene-conjugated diene copolymers such as styrene-ethylene-butylene-styrene copolymers (SEBS, hydrogenated styrene-butadiene copolymers), etc. Can do. Industrially, Asahi Kasei's Toughprene (registered trademark), Clayton Polymer Japan Clayton (registered trademark), Sumitomo Chemical Co., Ltd. Sumitomo TPE-SB, Daicel Chemical Industries, Ltd. Epofriend (registered trademark), Mitsubishi Chemical Examples include trade names such as Lavalon (registered trademark) manufactured by Kuraray Co., Ltd., Septon (registered trademark) manufactured by Kuraray Co., Ltd.

  The thermoplastic elastomer may be composed of one kind of polymer or a mixture of plural kinds of polymers.

  Among these thermoplastic elastomers, an olefin elastomer is preferable from the viewpoint of enhancing compatibility with other components contained in the first resin unit layer (B1), particularly linear polyethylene and polypropylene.

The first resin-based unit layer (B1) may contain a resin other than the above-described resin (this resin is also referred to as “sub resin” in this specification). As a by-resin, low density polyethylene (LDPE, density: 910 kg / ^{m 3} or more and less than 930 kg / ^{m 3),} very low density polyethylene (VLDPE, density: 880 kg / ^{m 3} or more and less than 910 kg / ^{m 3),} ethylene - propylene Copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl acetate-maleic anhydride copolymer, ethylene- (meth) acrylic acid copolymer, ethylene-butyl acrylate copolymer (EBA), etc. And ethylene- (meth) acrylic acid ester copolymer, ethylene- (meth) acrylic acid ester-maleic anhydride copolymer, and the like. When the first resin-based unit layer (B1) contains a secondary resin, the secondary resin may be composed of one type of resin or may be composed of a plurality of types of resins.

  The thickness of the first resin-based unit layer (B1) is not particularly limited. If the first resin-based unit layer (B1) is excessively thin, the significance of providing the first resin-based unit layer (B1) may be lost, and the first resin-based unit layer (B1) may be lost. If it is excessively thick, it may be set as appropriate considering that the significance of providing the second resin-based unit layer (B2) described later may be lost. The thickness of the first resin-based unit layer (B1) is usually preferably 15 μm or more, particularly preferably 25 μm or more, and more preferably 35 μm or more. The thickness is preferably 200 μm or less, particularly preferably 150 μm or less, and more preferably 100 μm or less.

  When the expanded layer (B) is composed of a plurality of unit layers, the expanded layer (B) includes a second resin-based unit layer (B2) containing an ethylene- (meth) acrylic acid copolymer. It is preferable. Concerning the arrangement of the second resin-based unit layer (B2) in the expanded layer (B), the second resin-based unit layer (B2) is more than the first resin-based unit layer (B1), the cutting piece suppressing layer (A). It is preferable to arrange | position distally with respect to a cutting piece suppression layer (A). In the present specification, the “ethylene- (meth) acrylic acid copolymer” is a copolymer of ethylene and one or more compounds selected from the group consisting of (meth) acrylic acid and (meth) acrylic acid ester. Means coalescence. Examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, and butyl (meth) acrylate.

  The second resin unit layer (B2) may contain an ethylene resin (b1) other than the ethylene- (meth) acrylic acid copolymer. In the present specification, the “ethylene-based resin (b1)” means a thermoplastic resin whose main component is a polymer containing a structural unit derived from ethylene.

Examples of the ethylene-based resin (b1) include low-density polyethylene (LDPE, density: 910 kg / m ³ or more and less than 930 kg / m ³ ), very low-density polyethylene (VLDPE, density: 880 kg / m ³ or more, 910 kg / m). ³ ), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl acetate-maleic anhydride copolymer, and the like. The ethylene resin (b1) may be composed of one type of resin or may be composed of a plurality of types of resins.

  The second resin-based unit layer (B2) may contain a resin other than the ethylene- (meth) acrylic acid copolymer and the ethylene-based resin (b1). Examples of such a resin include polypropylene and styrene elastomer.

  The thickness of the second resin-based unit layer (B2) is not particularly limited. When the second resin-based unit layer (B2) is excessively thin, the physical properties of the entire expanded layer (B) are governed by the first resin-based unit layer (B1), and the second resin-based unit layer (B2). ) May be lost, and when the second resin-based unit layer (B2) is excessively thick, the thickness of the first resin-based unit layer (B1) becomes relatively thin. In view of the possibility that the significance of providing the first resin-based unit layer (B1) may be lost, it may be set as appropriate. The thickness of the second resin-based unit layer (B2) is usually preferably 5 μm or more, particularly preferably 10 μm or more, and particularly preferably 15 μm or more. The thickness is usually preferably 150 μm or less, particularly preferably 100 μm or less, and further preferably 60 μm or less.

  The expanded layer (B) is a unit layer other than the first resin-based unit layer (B1) and the second resin-based unit layer (B2) described above as long as it can fulfill a predetermined function as the expanded layer (B). May be provided.

  The thickness of the expanded layer (B) is preferably 20 μm or more, and particularly preferably 40 μm or more. The thickness is preferably 280 μm or less, and particularly preferably 200 μm or less. When the thickness of the expanded layer (B) is in the above range, even when dicing is performed at a relatively high dicing speed, the occurrence of breakage during the expansion is effectively suppressed.

3. Manufacturing method of base film The manufacturing method of base film 1, 1 'in this embodiment is not specifically limited, For example, melt extrusion methods, such as T-die method and a round die method; Calendar method; Dry method, Wet method etc. And the solution method. Especially, it is preferable to employ | adopt a melt extrusion method or a calendering method from a viewpoint of manufacturing the base film 1,1 'efficiently. When manufacturing the base film 1 which consists of a single layer by a melt extrusion method, the component which comprises the base film 1 is knead | mixed, and after manufacturing a pellet directly or once from the obtained kneaded material, a well-known extruder is used. It may be used to form a film. In addition, when the base film 1 ′ composed of a plurality of layers is produced by the melt extrusion method, the components constituting each layer are kneaded, and the pellets are produced directly or once from the obtained kneaded product, and then a known extruder. A plurality of layers may be extruded simultaneously to form a film.

[Dicing sheet]
1. Configuration of Dicing Sheet FIG. 3 shows a cross-sectional view of a dicing sheet 10 according to an embodiment. The dicing sheet 10 according to the present embodiment can be used for dicing or dicing die bonding. When used for dicing, it may be used for single-cut dicing or step-cut dicing. In particular, the dicing sheet 10 according to the present embodiment is preferably used for step-cut type dicing.

  The material to be cut that can be diced using the dicing sheet 10 according to the present embodiment is not particularly limited, and examples thereof include semiconductor wafers such as silicon and gallium arsenide, substrates such as glass substrates and alumina substrates, and various types. It may be a package.

  As shown in FIG. 3, the dicing sheet 10 according to the present embodiment is laminated on the one side of the dicing sheet base film 1, 1 ′ and the dicing sheet base film 1, 1 ′. A semiconductor adhesive layer 2. Moreover, the dicing sheet 10 which concerns on this embodiment may be equipped with the peeling sheet for protecting the semiconductor sticking layer 2 as needed until it uses the dicing sheet 10. FIG.

  The dicing sheet 10 according to the present embodiment includes the base film for dicing sheet 1, 1 ′, so that even when dicing is performed at a relatively fast dicing speed, the dicing sheet 10 does not break at the time of expansion. Is less likely to sag after expansion.

(1) Semiconductor Affixing Layer The semiconductor affixing layer 2 refers to a layer to which an object to be cut is affixed or a layer to be affixed to an object to be cut when the dicing sheet 10 according to the present embodiment is used. As described above, the object to be cut is not limited to one made of a semiconductor material, but is referred to as a semiconductor adhesive layer 2 for convenience. The sticking at this time may be sticking temporarily performed when the dicing sheet 10 is used, or may be sticking continued even after the dicing sheet 10 is used. Preferable examples of the semiconductor adhesive layer 2 include a pressure-sensitive adhesive layer, an adhesive layer, a laminate composed of the pressure-sensitive adhesive layer and the adhesive layer, and a laminate composed of the pressure-sensitive adhesive layer and the protective film forming layer.

  When the semiconductor sticking layer 2 is an adhesive layer, the dicing sheet 10 according to the present embodiment can be used as a dicing sheet or a dicing die bonding sheet, for example. The pressure-sensitive adhesive layer may be composed of a non-energy ray curable pressure sensitive adhesive or an energy ray curable pressure sensitive adhesive. As the non-energy ray curable pressure-sensitive adhesive, those having desired adhesive strength and removability are preferable. For example, acrylic pressure-sensitive adhesive, rubber-based pressure-sensitive adhesive, silicone-based pressure-sensitive adhesive, urethane-based pressure-sensitive adhesive, and polyester-based pressure-sensitive adhesive Polyvinyl ether-based pressure-sensitive adhesives can be used. Among these, an acrylic pressure-sensitive adhesive that can effectively suppress dropping of a workpiece or a chip in a dicing process or the like is preferable.

  When the semiconductor sticking layer 2 is an adhesive layer, the dicing sheet 10 according to the present embodiment can be used as, for example, a die bonding sheet. The material constituting the adhesive layer is not particularly limited as long as it can fix the wafer during dicing and can form the adhesive layer on the singulated chips. it can. As a material constituting such an adhesive layer, a material composed of a thermoplastic resin and a low molecular weight thermosetting adhesive component, a material composed of a B-stage (semi-cured) thermosetting adhesive component, or the like is used. It is done. Among these, it is preferable that the material constituting the adhesive layer includes a thermoplastic resin and a thermosetting adhesive component. Thermoplastic resins include (meth) acrylic copolymers, polyester resins, urethane resins, phenoxy resins, polybutene, polybutadiene, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, and ethylene (meth) acrylic acid copolymers. Examples include polymers, ethylene (meth) acrylic acid ester copolymers, polystyrene, polycarbonate, polyimide, etc. Among them, (meth) acrylic copolymers from the viewpoint of adhesiveness and film-forming properties (sheet processability) Is preferred. Thermosetting adhesive components include epoxy resins, polyimide resins, phenolic resins, silicone resins, cyanate resins, bismaleimide triazine resins, allylated polyphenylene ether resins (thermosetting PPE), formaldehyde resins , Unsaturated polyesters or copolymers thereof, and among them, epoxy resins are preferable from the viewpoint of adhesiveness.

  When the semiconductor sticking layer 2 is a laminate composed of a pressure-sensitive adhesive layer and an adhesive layer, in the dicing sheet 10, the pressure-sensitive adhesive layer is located on the side proximal to the base film 1, and the adhesive layer is the base film. Located on the side distal to 1. Such a dicing sheet 10 according to the present embodiment can be used as a dicing die bonding sheet, for example. As an adhesive which comprises an adhesive layer, what was mentioned above can be used, for example. Moreover, as an adhesive agent which comprises an adhesive bond layer, what was mentioned above can be used, for example.

  When the semiconductor sticking layer 2 is a laminate composed of an adhesive layer and a protective film forming layer, in the dicing sheet 10, the adhesive layer is located on the side proximal to the base film 1, and the protective film forming layer is a base layer. Located on the distal side of the material film 1. Such a dicing sheet 10 according to the present embodiment can be used for dicing of an object to be cut, and further, after dicing, the protective film forming layer can be heated to form a protective film on the obtained chip. it can. The protective film forming layer is preferably made of an uncured curable adhesive. Moreover, it is preferable that a protective film formation layer has adhesiveness at normal temperature, or exhibits adhesiveness by heating. As a curable adhesive which comprises the protective film formation layer which has these characteristics, what contains a sclerosing | hardenable component and a binder polymer component is mentioned, for example.

  As the curable component, a thermosetting component, an energy ray curable component, or a mixture thereof can be used. Among them, a thermosetting component is used from the viewpoint of a curing method and heat resistance after curing. preferable. Examples of thermosetting components include epoxy resins, phenol resins (low molecular weight), melamine resins, urea resins, polyester resins, urethane resins, acrylic resins, polyimide resins, benzoxazines. Examples include resins and the like and mixtures thereof. Among these, an epoxy resin, a phenol resin, and a mixture thereof are preferably used. As the binder polymer, for example, a (meth) acrylic copolymer, a polyester resin, a phenoxy resin, a urethane resin, a silicone resin, a rubber copolymer, and the like are used, and in particular, a (meth) acrylic copolymer. Coalescence is preferably used.

  The thickness of the semiconductor adhesive layer 2 is preferably 3 μm or more, and particularly preferably 5 μm or more. The thickness is preferably 100 μm or less, and preferably 80 μm or less.

(2) Release sheet As the release sheet, for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, Polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene- (meth) acrylic acid copolymer film, ethylene- (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film A fluororesin film or the like can be used. Moreover, you may use these bridge | crosslinking films. Furthermore, a laminated film in which a plurality of these films are laminated may be used.

  It is preferable that the surface (referred to as “peeling surface” in this specification) that contacts the semiconductor adhesive layer of the release sheet is subjected to a peeling treatment. Examples of the release agent used for the release treatment include alkyd, silicone, fluorine, unsaturated polyester, polyolefin, and wax release agents.

  In addition, it does not specifically limit about the thickness of a peeling sheet, For example, it can be 20 micrometers or more and 150 micrometers or less.

2. Manufacturing method of dicing sheet The manufacturing method of the dicing sheet 10 according to the present embodiment is not particularly limited, and a general method can be used.

  When the semiconductor adhesive layer 2 is composed of an adhesive layer or an adhesive layer, for example, the semiconductor adhesive layer 2 is formed on the release surface of the release sheet, and the base film 1 is pressure-bonded onto the semiconductor adhesive layer 2. The dicing sheet 10 can be manufactured by laminating. In this case, formation of the semiconductor sticking layer 2 on the peeling surface of a peeling sheet can be performed by a general method. First, a coating liquid containing a composition containing the material of the pressure-sensitive adhesive layer or the adhesive layer, and optionally further containing a solvent or a dispersion medium is prepared. Subsequently, the coating solution is applied onto the release surface of the release sheet using a coater such as a roll coater, knife coater, roll knife coater, air knife coater, die coater, bar coater, gravure coater, curtain coater, etc. The semiconductor adhesive layer 2 can be formed by drying or the like.

  When the semiconductor adhesive layer 2 is a laminate composed of a pressure-sensitive adhesive layer and an adhesive layer, or a laminate composed of a pressure-sensitive adhesive layer and a protective film forming layer, By the method mentioned above, the 1st laminated body by which the peeling sheet, the adhesive layer, and the base film 1 were laminated | stacked in order is obtained. In parallel with this, the coating liquid containing the composition containing the material of the adhesive layer or the protective film forming layer and, if desired, further a solvent or a dispersion medium is peeled off using the above-described coating machine. It is applied onto the surface and dried to obtain a second laminate composed of the release sheet and the adhesive layer or the protective film forming layer. Next, the release sheet is peeled from the first laminate, and the exposed adhesive layer side surface is bonded to the adhesive layer or protective film forming layer side surface of the second laminate, thereby dicing. Sheet 10 is obtained.

3. Method for Using Dicing Sheet An example of dicing a semiconductor wafer as an object to be cut by the step cut method will be described below. First, as shown in FIG. 4, the semiconductor wafer 20 is stuck to the semiconductor sticking layer 2 side of the dicing sheet 10 according to the present embodiment. Next, the semiconductor wafer 20 is cut by bringing a relatively thick dicing blade into contact with the semiconductor wafer 20 and moving the dicing blade. Subsequently, the object to be cut is completely cut by replacing the dicing blade with a relatively thin one and passing the dicing blade again over the cut.

  The step-cut type dicing will be described in detail from the viewpoint of the thickness direction of the semiconductor wafer 20 based on FIG. 4. First, the dicing sheet 10 of the semiconductor wafer 20 is passed by passing the first dicing blade. A notch is made from the position of the opposite surface (the position indicated by a in FIG. 4) to the position b in the middle of the thickness direction of the semiconductor wafer 20. Subsequently, a second dicing blade is used to make a cut from the position b of the semiconductor wafer 20 to the position c in the middle of the dicing sheet 10 in the thickness direction. The semiconductor wafer 20 is completely cut by this second cut.

  When performing the step-cut type dicing, it is preferable to set a relatively high speed (dicing speed) for moving the dicing blade on the semiconductor wafer 20 from the viewpoint of improving manufacturing efficiency. In this case, the dicing speed is preferably 40 mm / second or more, particularly preferably 60 mm / second or more, and more preferably 80 mm / second or more. The dicing speed is preferably 200 mm / second or less, particularly preferably 170 mm / second or less, and more preferably 150 mm / second or less.

  Following the dicing described above, the expanding step and the picking-up step are performed in a state where the chip obtained on the dicing sheet 10 is stuck. In the expanding step, the dicing sheet 10 is stretched so that the chips can be separated from each other. By separating them in this way, individual chips can be picked up favorably in the pickup process.

  According to the dicing sheet 10 according to the present embodiment, even if the impact load is momentarily increased in the base film 1, 1 ′ by performing dicing at a relatively high dicing speed as described above, the impact It can withstand the load and is less likely to break in subsequent expansions. Furthermore, since it is difficult for slack to occur after expansion, the pickup process can be performed well.

  Although the size of the chip obtained by using the dicing sheet 10 according to the present embodiment for dicing is not limited, the dicing sheet 10 according to the present embodiment can obtain a minute chip. In particular, by using the dicing sheet 10 for the above-described step-cut type dicing, the object to be cut can be diced into minute chips. For example, when the chip is rectangular, the length of the short side can be 4.0 mm or less, particularly 2.0 mm or less, and further 1.0 mm or less. It becomes possible. On the other hand, although the lower limit of the length of the short side is not particularly limited, for example, the short side can be 0.5 mm or more, 0.6 mm or more, and particularly 0.7 mm or more. Furthermore, it can be 0.8 mm or more. According to the dicing sheet 10 according to the present embodiment, it is possible to efficiently manufacture such a minute chip without causing damage.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, another layer may be interposed between the base film 1 and the semiconductor adhesive layer 2 in the dicing sheet 10 according to the present embodiment.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Example 1]
(1) Production of base film 30 parts by mass of cycloolefin copolymer (manufactured by Polyplastics, product name “TOPAS8007”) as ring-containing resin (a1) and low density as acyclic olefin resin (a2) 70 parts by mass of polyethylene (manufactured by Sumitomo Chemical Co., Ltd., product name “Sumikasen L705”) is melt-kneaded at 210 ° C. with a twin-screw kneader (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name “Laboplast Mill”), and a cut piece A resin composition (α) for forming the suppression layer (A) was obtained.

60 parts by mass of linear polyethylene (manufactured by Prime Polymer Co., Ltd., product name “Evolue SP2540”, density: 924 kg / m ³ ) and polypropylene (manufactured by Prime Polymer Co., Ltd., product name “Prime Polypro F-744NP”, density: 900 kg / m ³ ) 10 parts by mass and 30 parts by mass of an olefin-based elastomer (product name “Tuffmer DF640”, density: 864 kg / m ³ ) as a thermoplastic elastomer, a twin-screw kneader (Toyo Seiki Seisakusho Co., Ltd.) Manufactured and product name “Laboplast Mill”) at 210 ° C. to obtain a resin composition (β1) for forming the first resin unit layer (B1).

  100 parts by mass of an ethylene-methacrylic acid copolymer (produced by Mitsui DuPont Polychemical Co., Ltd., product name “Nucrel N0903HC”), which is one of ethylene- (meth) acrylic acid copolymers, is mixed with a twin-screw kneader (Toyo Seiki). A resin composition (β2) for forming the second resin-based unit layer (B2) was obtained by melting and kneading at 210 ° C. using a product name “Laboplast Mill” manufactured by Seisakusho Co., Ltd.

  Using the obtained resin composition (α), resin composition (β1), and resin composition (β2), co-extrusion with a small T-die extruder (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name “Lab Plast Mill”) Molded. As a result, a 40 μm-thick first resin-based unit layer (B1), a 40 μm-thick cutting piece suppression layer (A) laminated on one surface of the first resin-based unit layer (B1), A base film having a three-layer structure having a thickness of 100 μm and a second resin-based unit layer (B2) having a thickness of 20 μm laminated so as to be in contact with the other surface of the first resin-based unit layer (B1). Obtained. In this base film, an expanded layer (B) having a thickness of 60 μm is constituted by the first resin-based unit layer (B1) having a thickness of 40 μm and the second resin-based unit layer (B2) having a thickness of 20 μm. The

(2) Preparation of pressure-sensitive adhesive composition 100 parts by mass of a copolymer (Mw: 500,000) obtained by copolymerizing 95 parts by mass of n-butyl acrylate and 5 parts by mass of acrylic acid, urethane acrylate oligomer (Mw: 8000) 120 parts by mass, 5 parts by mass of an isocyanate curing agent (Nippon Polyurethane, product name “Coronate L”), and 4 parts by mass of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals, product name “Irgacure 184”) An energy ray-curable pressure-sensitive adhesive composition was obtained.

(3) Production of dicing sheet The obtained energy ray-curable pressure-sensitive adhesive composition was applied onto a silicone-treated release film (product name “SP-PET3811 (S)”) manufactured by Lintec, and at 100 ° C. It dried for 1 minute and formed the laminated body which consists of a 10-micrometer-thick adhesive layer and a peeling film. Subsequently, this laminated body was bonded to the surface of the base film produced as described above on the side of the cut piece suppressing layer (A) to obtain a dicing sheet having a base film having a three-layer structure.

[Example 2]
100 parts by mass of an ethylene-methacrylic acid copolymer (manufactured by Mitsui DuPont Polychemical Co., Ltd., product name “Nucrel N0908HC”), which is one of ethylene- (meth) acrylic acid copolymers, is mixed with a twin-screw kneader (Toyo Seiki) A resin composition was obtained by melting and kneading at 210 ° C. using a product name “Laboratory Mill” manufactured by Seisakusho Co., Ltd. The obtained resin composition was extruded using a small T-die extruder (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name “Laboplast Mill”) to obtain a substrate film having a single-layer structure having a thickness of 100 μm. A dicing sheet provided with a single-layer base film was produced in the same manner as in Example 1 except that this base film was used.

Example 3
A single-layer structure was used in the same manner as in Example 2 except that a resin composition obtained by melt-kneading polyvinyl chloride (manufactured by Showa Kasei Kogyo Co., Ltd., product name “Kane Vinyl Compound KVC G379D”) at 180 ° C. was used. A dicing sheet provided with a base film was produced.

[Comparative Example 1]
Except for using a resin composition obtained by melt-kneading polypropylene (manufactured by Prime Polymer Co., Ltd., product name “Prime Polypro F-704NP”, density: 900 kg / m ³ ) at 210 ° C., in the same manner as in Example 2, A dicing sheet including a base film having a single layer structure was manufactured.

[Comparative Example 2]
Except for using a resin composition obtained by melt-kneading polypropylene (manufactured by Prime Polymer Co., Ltd., product name “Prime Polypro F-113A”, density: 910 kg / m ³ ) at 210 ° C., in the same manner as in Example 2, A dicing sheet including a base film having a single layer structure was manufactured.

[Comparative Example 3]
A base film having a single-layer structure is provided in the same manner as in Example 2 except that a resin composition obtained by melt-kneading a cycloolefin copolymer (manufactured by Mitsui Chemicals, product name “APL6011T”) at 210 ° C. is used. A dicing sheet was manufactured.

[Comparative Example 4]
A dicing sheet comprising a single-layer base film in the same manner as in Example 2 except that a polyethylene terephthalate film (product name “Lumirror T-60”, thickness: 100 μm) is used as the base film. Manufactured.

[Comparative Example 5]
An ethylene- (meth) acrylic acid copolymer, an ethylene-methacrylic acid copolymer crosslinked with metal ions (Mitsui DuPont Polychemical Co., Ltd., product name “Himiran 1706”, density: 960 kg / m ³ ) A dicing sheet provided with a base film having a single layer structure was produced in the same manner as in Example 2 except that a resin composition obtained by melt kneading at 210 ° C. was used.

[Comparative Example 6]
Except for using a resin composition obtained by melt kneading linear polyethylene (manufactured by Prime Polymer Co., Ltd., product name “Evolue SP4030”, density: 938 kg / m ³ ) at 210 ° C., in the same manner as in Example 2, A dicing sheet including a base film having a single layer structure was manufactured.

[Test Example 1] (Measurement of Elmendorf value)
The base film produced by the Example and the comparative example was cut | judged to the size of 63 mm x 75 mm, and the test piece was obtained. At this time, two types were obtained: a test piece for MD direction in which the short side (63 mm side) of the test piece was parallel to the MD direction of the base film, and a test piece for TD direction in which the short side was parallel to the TD direction.

  For the two types of test pieces obtained, the Elmendorf value (N ) Was measured. At this time, the MD direction Elmendorf value (N) was measured using the MD direction test piece, and the TD direction Elmendorf value (N) was measured using the TD direction test piece. The results are shown in Table 1.

[Test Example 2] (Measurement of tensile modulus)
The resin compositions prepared in Examples and Comparative Examples were extruded using a small T-die extruder (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name “Laboplast Mill”) to obtain a base film having a thickness of 100 μm. In Example 1, the thicknesses of the cut piece suppressing layer (A), the first resin-based unit layer (B1), and the second resin-based unit layer (B2) are 40 μm, 30 μm, and 30 μm, respectively. Thus, the total thickness was set to 100 μm by coextrusion molding.

  The obtained base film was cut into 15 mm × 140 mm to obtain test pieces. At this time, two types were obtained: a test piece for MD direction in which the long side (140 mm side) of the test piece was parallel to the MD direction of the base film, and a test piece for TD direction parallel to the TD direction.

  About two types of test pieces, based on JIS K7161: 1994 and JIS K7127: 1999, the tensile elasticity modulus in the environment of temperature 23 degreeC and relative humidity 50% RH was measured. Specifically, the test piece was set to a distance between chucks of 100 mm with a tensile tester (manufactured by Shimadzu Corporation, product name “Autograph AG-IS 500N”), and then subjected to a tensile test at a speed of 200 mm / min. The tensile modulus (MPa) was measured. At this time, the tensile modulus (MPa) in the MD direction was measured using the test piece for MD direction, and the tensile modulus (MPa) in the TD direction was measured using the test piece for TD direction. The results are shown in Table 1.

[Test Example 3] (Measurement of elongation at break)
The base film produced by the Example and the comparative example was cut | judged to the size of 15 mm x 140 mm, and the test piece was obtained. At this time, two types were obtained: a test piece for MD direction in which the long side (140 mm side) of the test piece was parallel to the MD direction of the base film, and a test piece for TD direction parallel to the TD direction.

  With respect to the two types of test pieces, the elongation at break at 23 ° C. was measured according to JIS K6732: 2006. Specifically, the test piece was set to a distance between chucks of 100 mm with a tensile tester (manufactured by Shimadzu Corporation, product name “Autograph AG-IS 500N”), and then subjected to a tensile test at a speed of 200 mm / min. The breaking elongation (%) when the test piece was cut was measured. At this time, the breaking elongation (%) in the MD direction was measured using the test piece for MD direction, and the breaking elongation (%) in the TD direction was measured using the test piece for TD direction. The results are shown in Table 1.

[Test Example 4] (Evaluation of breaking during expansion)
(1) Dicing process The mirror wafer was stuck to the center part of the surface at the side of the adhesive layer in the dicing sheet manufactured by the Example and the comparative example, and also the ring frame was fixed to the peripheral part of the said dicing sheet. Thereafter, the wafer was set in a dicing apparatus (manufactured by DISCO, product name “DFD-6361”) and diced under the following conditions.
・ Dicing method: Step cut method ・ Work size: Diameter 8 inches, thickness 100μm
・ Dicing blade:
Z1; manufactured by Disco Corporation, product name “NBC-ZH203O-SE27HDD”
Z2; manufactured by Disco Corporation, product name “NBC-ZH103O-SE27HBB”
・ Blade rotation speed: 30000rpm
・ Dicing speed: 100 mm / sec. ・ Depth of cut: Use dicing blade Z1 to cut from the surface opposite to the dicing sheet to a depth of 50 μm, and then use dicing blade Z2 to adhere. A cut was made from the interface between the agent layer and the base film to a depth of 20 μm to completely cut the workpiece.
・ Dicing size: 1mm x 25mm

(2) Expanding Step Following the above dicing step, the dicing sheet with the chips obtained by dicing attached thereto is expanded using an expanding jig (manufactured by NEC Machinery, product name “Die Bonder CSP-100VX”). And stretched. The stretching conditions at this time are as follows: Condition 1 in which the pulling speed and length of the ring frame fixed to the dicing sheet is 4 mm at a speed of 300 mm / min, and Condition 2 in which the speed is 300 mm / min and 10 mm. The two types were as follows. The dicing sheet was checked for breakage when stretched, and the breakage during expansion was evaluated based on the following criteria. The results are shown in Table 1.
A: Breakage was not confirmed in both conditions.
B: Breakage was not confirmed under one condition, and breakage was confirmed under the other condition.
C: Breakage was confirmed in both conditions.

[Test Example 5] (Evaluation of looseness after expansion)
With the chip attached to the dicing sheet after performing the expanding process under Condition 1 in Test Example 4, using a dryer, hot air of 50 ° C. to 70 ° C. was applied to the surface with the chip attached Was fed to the opposite side for 1 minute.

Then, the peripheral portion (the ring on the upper surface) on the bottom surface with the surface (hereinafter referred to as “bottom surface”) opposite to the surface (hereinafter referred to as “upper surface”) to which the chip is attached in the dicing sheet facing down. The distance (mm) in the vertical direction of the central portion of the bottom surface was measured based on the bottom surface region corresponding to the region where the frame was attached. Based on the measurement results, the slackness after expansion was evaluated according to the following criteria. The results are shown in Table 1. In addition, the following evaluation of A and B is determined to be favorable, and evaluation of B is determined to be poor.
A: The separation distance was 1.5 mm or less.
B: The separation distance exceeded 1.5 mm and was 3 mm or less.
C: The separation distance exceeded 3 mm.

  As shown in Table 1, in the dicing sheet according to the example, even when the step-cut type dicing is performed at a relatively fast dicing speed as described in Test Example 4, breakage occurs at the time of expansion. It was found that the occurrence of looseness was suppressed after expansion.

DESCRIPTION OF SYMBOLS 1,1 '... Base film for dicing sheets (A) ... Cutting piece suppression layer (B) ... Expand layer (B1) ... 1st resin system unit layer (B2) ... 2nd resin system unit layer 2 ... Semiconductor Adhering layer 10 ... Dicing sheet 20 ... Semiconductor wafer

Claims (8)

The Elmendorf values in the MD and TD directions are both 3.0N or more and 15.0N or less,
The tensile elastic modulus in the MD direction and the TD direction in an environment of a temperature of 23 ° C. and a relative humidity of 50% RH are both 65 MPa or more and less than 400 MPa,
A base film for a dicing sheet, wherein the tensile elongation at break in the MD direction and the TD direction is 280% or more when a tensile test is performed in an environment of a temperature of 23 ° C. and a relative humidity of 50% RH.   It consists of a single layer, The base film for dicing sheets of Claim 1 characterized by the above-mentioned.   It consists of multiple layers, The base film for dicing sheets of Claim 1 characterized by the above-mentioned.   The base film for a dicing sheet according to claim 3, comprising a cutting piece suppression layer and an expanded layer laminated on one surface side of the cutting piece suppression layer.   The expanded layer includes a first resin-based unit layer positioned proximal to the cutting piece suppression layer, and a second resin-based unit layer positioned distal to the cutting piece suppression layer. The base film for dicing sheets according to claim 4.   The base film for a dicing sheet according to any one of claims 1 to 5, wherein the dicing sheet is for use in a step-cut type dicing.   The said dicing sheet is for dicing the to-be-cut object into the chip | tip whose short side is 0.5 mm or more and 4.0 mm or less, The any one of Claims 1-6 characterized by the above-mentioned. Base film for dicing sheet.   A dicing sheet comprising the base film for a dicing sheet according to any one of claims 1 to 7 and a semiconductor adhesive layer laminated on one side of the base film for the dicing sheet.

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