Dicing die bonding tape

Abstract

Provided is a dicing die bonding tape comprising a base material film, a pressure-sensitive adhesive layer, and an adhesive layer in contact with the pressure-sensitive adhesive layer laminated in this order. The dicing die bonding tape is characterized in that: the pressure-sensitive adhesive layer has a structure in which a base polymer is crosslinked by a curing agent containing a 1,2-polybutadiene skeleton and is of an ultraviolet-curable type; the curing agent component is contained in an amount of 3 to 25 parts by mass with respect to 100 parts by mass of the base polymer; and the adhesive layer has a surface free energy of 40 to 70 mN / m.

Description

Dicing and die bonding tape

[0001] The present invention relates to a dicing die bonding tape.

[0002] In the manufacturing process of semiconductor devices such as ICs (integrated circuits), adhesive and stretchable semiconductor processing tape is applied to the backside of a semiconductor wafer on which a circuit pattern is formed, followed by a process of cutting (dicing) the semiconductor wafer into chip units, a process of picking up the cut chips, and a process of bonding the picked-up chips to a lead frame, package substrate, etc., or, in the case of stacked packages, a die bonding (mounting) process of stacking and bonding semiconductor chips together is carried out.

[0003] Known dicing die bonding tapes used in the manufacturing process of semiconductor devices include adhesive tapes having an adhesive layer on a substrate film and an adhesive layer further provided on the adhesive layer of the adhesive tape. The adhesive tape is required to secure the wafer with sufficient adhesive strength to prevent the diced chips from scattering during the semiconductor wafer dicing process, while also requiring low adhesive strength to allow easy peeling and chip pick-up between the adhesive layer and the adhesive layer during the chip pick-up process. For example, Patent Document 1 describes a semiconductor wafer dicing and die-bonding sheet comprising a substrate film, an adhesive layer, and an adhesive layer containing at least an epoxy resin and an epoxy resin curing catalyst laminated in this order, wherein the adhesive layer contains a hydrogenated 1,2-polybutadiene resin and / or a hydrogenated 1,2-polybutadiene derivative resin. Patent Document 1 also describes that the sheet described in Patent Document 1 enables highly reliable wafer dicing and pick-up.

[0004] Japanese Patent Application Laid-Open No. 2006-165045

[0005] In dicing die bonding tapes, from the viewpoint of improving adhesive function, such as improving adhesion to semiconductor wafers, the adhesive layer must have a high surface free energy (approximately 40 mN / m or more). After extensive research, the inventors discovered that by adjusting the chemical structure of the base polymer of a UV-curable adhesive layer, such as that described in Patent Document 1, the surface free energy of the adhesive layer after UV irradiation can be lowered, thereby reducing adhesion to adhesive layers with a surface free energy of 40 mN / m or more. However, adjusting the surface free energy of the adhesive layer to a low level results in cloudiness due to low compatibility of the adhesive layer. Since cloudiness of the adhesive layer can reduce chip pickup stability, the adhesive layer must also have excellent compatibility. The present invention aims to provide a dicing die bonding tape having an adhesive layer with a surface free energy within a specific high range, which has sufficient adhesion to prevent peeling of the semiconductor wafer during dicing, allows easy peeling between the adhesive layer and the adhesive layer during pickup, and further, the adhesive layer exhibits excellent compatibility.

[0006] The above-mentioned problems of the present invention have been solved by the following means. [1] A dicing die bonding tape comprising a substrate film, a pressure-sensitive adhesive layer, and an adhesive layer in contact with the pressure-sensitive adhesive layer, laminated in this order, wherein the pressure-sensitive adhesive layer has a structure in which a base polymer is crosslinked with a curing agent containing a 1,2-polybutadiene skeleton and is ultraviolet-curable, the content of the curing agent component per 100 parts by mass of the base polymer is 3 to 25 parts by mass, and the surface free energy of the adhesive layer is 40 to 70 mN / m. [2] The dicing die bonding tape according to [1], wherein the adhesive layer has a melt viscosity of 10,000 to 60,000 Pa·s at 70°C. [3] The dicing die bonding tape according to [1] or [2], wherein the adhesive layer contains a phenoxy resin. [4] The dicing die bonding tape according to any one of [1] to [3], characterized in that the surface free energy of the pressure-sensitive adhesive layer after ultraviolet irradiation is 30 to 39 mN / m.

[0007] In the present invention, a numerical range expressed using "to" means a range including the numerical values ​​before and after "to" as the lower and upper limits. In the present invention, "(meth)acrylic" is used to mean either or both of "acrylic" and "methacrylic".

[0008] The dicing die bonding tape of the present invention is a dicing die bonding tape having an adhesive layer with high surface free energy, and has sufficient adhesiveness so that the semiconductor wafer does not peel off during dicing, and can be easily picked up by peeling between the adhesive layer and the pressure-sensitive adhesive layer during pick-up, and further, the pressure-sensitive adhesive layer can exhibit excellent compatibility.

[0009] Fig. 1 is a cross-sectional view schematically showing the structure of a dicing die bonding tape according to an embodiment of the present invention, and Fig. 2 is an end view illustrating a state in which a semiconductor wafer is bonded to a ring frame by the dicing die bonding tape according to an embodiment of the present invention.

[0010] [Dicing Die Bonding Tape] The dicing die bonding tape of the present invention comprises a substrate film, a pressure-sensitive adhesive layer, and an adhesive layer in contact with the pressure-sensitive adhesive layer, laminated in this order. The pressure-sensitive adhesive layer has a structure in which a base polymer is crosslinked with a curing agent containing a 1,2-polybutadiene skeleton, and the pressure-sensitive adhesive layer is UV-curable. The content of the curing agent component per 100 parts by mass of the base polymer is 3 to 25 parts by mass, and the surface free energy of the adhesive layer is 40 to 70 mN / m. The dicing die bonding tape of the present invention combines an adhesive layer with a high surface free energy (specifically, an adhesive layer with a surface free energy of 40 to 70 mN / m) with the above-mentioned specific pressure-sensitive adhesive layer, thereby providing sufficient adhesion to prevent peeling of the semiconductor wafer during dicing, and allowing for easy peeling between the adhesive layer and the pressure-sensitive adhesive layer during pickup. Furthermore, the pressure-sensitive adhesive layer itself maintains excellent compatibility.

[0011] FIG. 1 is a cross-sectional view schematically illustrating a dicing die bonding tape (10) according to one embodiment of the present invention. The dicing die bonding tape (10) shown in FIG. 1 has a configuration in which a base film (11), a pressure-sensitive adhesive layer (12), and an adhesive layer (13) are laminated in this order. The laminate of the base film (11) and the pressure-sensitive adhesive layer (12) functions as an adhesive tape (15). The dicing die bonding tape (10) is used in the dicing and die bonding process by adhering the adhesive layer (13) side to the back surface of a semiconductor wafer (the surface on which no circuits are formed). The dicing die bonding tape (10) may be pre-cut into a predetermined shape in accordance with the process and equipment used, or may be cut into individual semiconductor wafer pieces. The dicing die bonding tape (10) may also be in the form of a long sheet wound into a roll, or a long sheet formed by cutting multiple pieces, each of which corresponds to a single semiconductor wafer, and wound into a roll. In the pressure-sensitive adhesive tape (15) composed of a laminate of a base film (11) and a pressure-sensitive adhesive layer (12), it is preferable that the pressure-sensitive adhesive layer (12) is formed directly on the base film (11). Also, the adhesive layer (13) is provided directly on the pressure-sensitive adhesive layer (12) so as to be in contact with it. The adhesive layer (13) may have a release liner (release film, not shown in FIG. 1) laminated on the surface of the adhesive layer (13) opposite to the surface that contacts the pressure-sensitive adhesive layer (12). The release liner covers the pressure-sensitive adhesive tape (15) and protects the pressure-sensitive adhesive layer (12) and the adhesive layer (13).

[0012] In the present invention, the adhesive layer (12) is in a state in which the base polymer contained in the adhesive is crosslinked by a curing agent containing a 1,2-polybutadiene skeleton, thereby exerting adhesive strength and cohesive strength. Furthermore, since the adhesive layer (12) is ultraviolet-curable, the adhesive layer (12) is in a state before being cured by ultraviolet irradiation, which will be described later. In the pickup process using the dicing die bonding tape of the present invention, the adhesive layer is cured by ultraviolet irradiation, resulting in a state in which the adhesion between the adhesive layer (13) and the adhesive layer is reduced. In the present invention, the adhesive layer (13) is in a state in which the resin contained in the adhesive exerts adhesive strength or cohesive strength. When the adhesive contains a thermally polymerizable component, which will be described later, the adhesive layer (13) is in a state before being semi-cured by heating during die bonding, which will be described later.

[0013] Each layer of the dicing die bonding tape of the present invention will now be described.

[0014] <Substrate Film (11)> The substrate film (11) is preferably easily stretched (preferably easily stretched uniformly and isotropically) and does not break during the expanding process of the dicing die bonding tape. The material of the substrate film (11) is not particularly limited as long as it has these properties. Generally, crosslinked resins have a greater restoring force against tension than non-crosslinked resins, and experience a greater shrinkage stress when heat is applied to the stretched state after the expanding process. Therefore, crosslinked resins are advantageous in that they can remove slack in the tape after the expanding process by thermal shrinkage, tensioning the tape and stably maintaining the spacing between individual chips (kerf width). Among crosslinked resins, thermoplastic crosslinked resins are more preferably used. On the other hand, non-crosslinked resins have a lower restoring force against tension than crosslinked resins. Therefore, after the expanding process at a low temperature range, such as −15°C to 0°C, the tape is relaxed and then returned to room temperature, and is less likely to shrink when proceeding to the pick-up and mounting processes. This is advantageous in that it can prevent the adhesive layers (13) attached to the chips from coming into contact with each other. Among the non-crosslinked resins, olefin-based non-crosslinked resins are more preferably used.

[0015] Preferred examples of such thermoplastic crosslinked resins include ionomer resins, which are synthetic resins that utilize the cohesive force of metal ions to form polymer aggregates. Examples include ionomer resins obtained by crosslinking ethylene-(meth)acrylic acid binary copolymers or terpolymers whose main polymer components are ethylene-(meth)acrylic acid-(meth)acrylic acid alkyl esters with metal ions. These resins are particularly suitable for the expanding process in terms of uniform expandability and exhibit strong restoring forces upon heating due to crosslinking. The metal ions contained in the ionomer resins are not particularly limited, but examples include zinc ions and sodium ions. Zinc ions are preferred due to their low elution and low contamination. Regarding the alkyl (meth)acrylate esters constituting the terpolymers, alkyl (meth)acrylate esters with alkyl groups having 1 to 4 carbon atoms are preferred because they increase the elastic modulus of the substrate film (11) and allow for the transmission of strong forces to the wafer. Examples of such alkyl (meth)acrylates include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate.

[0016] In addition to the ionomer resins, suitable examples of the thermoplastic crosslinked resin include those obtained by crosslinking a thermoplastic resin selected from low-density polyethylene with a specific gravity of 0.910 or more but less than 0.930, ultra-low-density polyethylene with a specific gravity of less than 0.910, and ethylene-vinyl acetate copolymers by irradiating them with energy rays such as electron beams. Such thermoplastic crosslinked resins have a certain degree of uniform expandability due to the coexistence of crosslinked and non-crosslinked regions within the resin. Furthermore, because they exhibit a strong restoring force upon heating, they are also suitable for removing slack in the tape generated during the expanding process. Furthermore, because they contain almost no chlorine atoms in their molecular chain structure, incineration of unused tape after use does not generate chlorinated aromatic hydrocarbons such as dioxins and their analogs, thereby reducing the environmental impact. By appropriately adjusting the amount of energy rays irradiated onto the thermoplastic resins such as polyethylene and ethylene-vinyl acetate copolymers, resins with sufficient uniform expandability can be obtained.

[0017] An example of the non-crosslinked resin is a mixed resin composition of polypropylene and a styrene-butadiene copolymer.

[0018] As the polypropylene, for example, a propylene homopolymer or a propylene copolymer such as a block or random propylene-ethylene copolymer can be used. Random propylene-ethylene copolymers are preferred because of their low rigidity. A content of ethylene structural units in the propylene-ethylene copolymer of 0.1% by mass or more is preferred in terms of the rigidity of the base film (11) and the high compatibility between the resins in the mixed resin. Appropriate rigidity of the base film (11) improves the cuttability of the wafer, and high compatibility between the resins tends to stabilize the extrusion discharge rate. A content of 1% by mass or more is more preferred. Furthermore, a content of ethylene structural units in the propylene-ethylene copolymer of 7% by mass or less is preferred in terms of the stable polymerization reaction to obtain the propylene-ethylene copolymer. A content of 5% by mass or less is more preferred.

[0019] A hydrogenated styrene-butadiene copolymer may be used. When the styrene-butadiene copolymer is hydrogenated, it has good compatibility with propylene and can prevent embrittlement and discoloration due to oxidative degradation caused by the double bonds in butadiene. Furthermore, a content of styrene structural units in the styrene-butadiene copolymer of 5% by mass or more is preferred because the styrene-butadiene copolymer is easily polymerized stably. Furthermore, a content of 40% by mass or less is excellent in terms of flexibility and extensibility. A content of 25% by mass or less is more preferred, and a content of 15% by mass or less is even more preferred. Either a block copolymer or a random copolymer can be used as the styrene-butadiene copolymer. A random copolymer is preferred because the styrene phase is uniformly dispersed, excessive rigidity can be prevented, and the extensibility of the base film (11) is improved.

[0020] A polypropylene content of 30% by mass or more in the mixed resin of polypropylene and a styrene copolymer is advantageous in that it can suppress thickness unevenness of the base film (11). A uniform thickness facilitates isotropic expansion and also facilitates preventing excessive stress relaxation of the base film (11), which reduces the inter-chip distance over time and causes the adhesive layers (13) to come into contact with each other and re-fuse. A polypropylene content of 50% by mass or more is more preferable. Furthermore, a polypropylene content of 90% by mass or less facilitates appropriate adjustment of the rigidity of the base film (11). If the rigidity of the base film (11) becomes too high, the force required to expand the base film (11) increases, which increases the load on the device and may prevent the film from being sufficiently expanded to separate the wafer or adhesive layer (13). Therefore, it is important to adjust the rigidity appropriately. The lower limit of the styrene-butadiene copolymer content in the composite resin composition is preferably 10% by mass or more, which facilitates adjustment of the rigidity of the base film (11) to a level suitable for the device. An upper limit of 70% by mass or less is excellent in terms of suppressing thickness unevenness, and 50% by mass or less is more preferable.

[0021] In the example shown in FIG. 1 , the substrate film (11) is a single layer, but is not limited thereto. It may have a multi-layer structure in which two or more resins are laminated, or a structure in which one type of resin is laminated in two or more layers. Two or more resins, whether crosslinked or non-crosslinked, are preferred in terms of enhancing the respective properties, while a combination of crosslinked and non-crosslinked resins is preferred in terms of compensating for their respective drawbacks. The thickness of the substrate film (11) is not particularly limited, as long as it is easily stretchable during the expanding process of the dicing die bonding tape 10 and has sufficient strength to prevent breakage. For example, a thickness of approximately 50 to 300 μm is sufficient, with a thickness of 70 to 200 μm being preferred.

[0022] There is no particular limitation on the method for producing the single-layer substrate film (11), and a conventional method such as extrusion can be used. A conventional method such as extrusion or lamination can be used to produce the multi-layer substrate film (11). When lamination is used, an adhesive may be interposed between the layers. A conventional adhesive can be used as the adhesive.

[0023] <Adhesive Layer (12)> The adhesive layer (12) may be any adhesive layer as long as it has sufficient retention to prevent peeling from the adhesive layer (13) during the semiconductor wafer dicing process, prevent defects such as semiconductor chip breakage, transmit stress due to expansion to the adhesive layer (13), and allow easy peeling from the adhesive layer (13) during pickup. In the dicing die bonding tape of the present invention, the adhesive layer (12) has a structure in which a base polymer is crosslinked with a curing agent containing a 1,2-polybutadiene skeleton. The adhesive layer (12) is UV-curable, and the content of the curing agent component per 100 parts by mass of the base polymer is 3 to 25 parts by mass. By configuring the pressure-sensitive adhesive layer (12) in this manner, in the dicing die bonding tape of the present invention having an adhesive layer (13) with a surface free energy of 40 to 70 mN / m, peeling between the pressure-sensitive adhesive layer (12) and the adhesive layer (13) is unlikely to occur during the dicing process, and the pressure-sensitive adhesive layer is cured at the time of pickup, and its surface free energy is considerably smaller than that of the adhesive layer (13). As a result, peeling between the pressure-sensitive adhesive layer and the adhesive layer (13) is facilitated, and the transparency of the pressure-sensitive adhesive layer (12) itself (compatibility of the components of the pressure-sensitive adhesive layer (12)) can also be ensured.

[0024] The structure in which a base polymer is crosslinked with a curing agent containing a 1,2-polybutadiene skeleton (hereinafter also simply referred to as "curing agent") may be a structure formed as a result of a chemical reaction in which the curing agent containing a 1,2-polybutadiene skeleton acts as a crosslinking agent on the base polymer. In other words, the base polymer has functional groups for forming a crosslinked structure with the curing agent containing a 1,2-polybutadiene skeleton.

[0025] The pressure-sensitive adhesive layer (12) is an ultraviolet-curable pressure-sensitive adhesive layer that cures upon irradiation with ultraviolet light. Therefore, an ultraviolet-curable carbon-carbon double bond that participates in the curing reaction upon irradiation with ultraviolet light is introduced into the base polymer. The pressure-sensitive adhesive layer (12) preferably contains a photopolymerization initiator. The ultraviolet-curable carbon-carbon double bond is preferably an ethylenically unsaturated group, i.e., a group having a carbon-carbon double bond, and examples thereof include a vinyl group, an allyl group, a styryl group, a (meth)acryloyloxy group, and a (meth)acryloylamino group.

[0026] (Base Polymer) The base polymer is a polymer that serves as the base of the adhesive that constitutes the adhesive layer (12). This base polymer may be any polymer that can be crosslinked by a curing agent containing a 1,2-polybutadiene skeleton. For example, it is preferable that the base polymer has a functional group for forming a crosslinked structure with a curing agent containing a 1,2-polybutadiene skeleton and a UV-curable carbon-carbon double bond. Typically, the base polymer does not have a functional group for reacting with other base polymers and is crosslinked by a crosslinking agent. The amount of UV-curable carbon-carbon double bonds in the base polymer is preferably 0.5 to 50, more preferably 0.5 to 45, and even more preferably 0.5 to 40, in terms of iodine value. When the amount of UV-curable carbon-carbon double bonds is within the above range, the adhesive strength can be reduced after UV irradiation, while sufficient fluidity of the adhesive can ensure sufficient gaps between elements after stretching. Furthermore, the base polymer itself is stable, which is preferable from the standpoint of ease of production. The amount of ultraviolet-curable carbon-carbon double bonds in the base polymer is a value measured and calculated according to JIS (Japanese Industrial Standards) K 0070 (1992).

[0027] The base polymer preferably has a glass transition temperature of −70° C. to 0° C., more preferably −66° C. to −28° C. If the glass transition temperature (hereinafter also referred to as “Tg”) is within the above range, sufficient heat resistance to heat associated with ultraviolet irradiation and sufficient effect of preventing elements from scattering after dicing of a wafer with a rough surface can be obtained.

[0028] The base polymer may be produced by any method, but for example, a polymer obtained by reacting a (meth)acrylic copolymer (A1) having a functional group with a compound (A2) having a functional group reactive with the functional group and having an ultraviolet-curable carbon-carbon double bond is used.

[0029] Among these, the (meth)acrylic copolymer (A1) having the functional group may be, for example, one obtained by copolymerizing a monomer (A1-1) having a carbon-carbon double bond, such as an alkyl acrylate or an alkyl methacrylate, with a monomer (A1-2) having a carbon-carbon double bond and a functional group. Examples of the monomer (A1-1) include (meth)acrylic acid alkyl esters having an alkyl group with 6 to 12 carbon atoms, such as hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, and decyl (meth)acrylate, as well as (meth)acrylic acid alkyl esters having an alkyl group with 5 or less carbon atoms, such as pentyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, ethyl (meth)acrylate, and methyl (meth)acrylate.

[0030] In addition, components of the monomer (A1-1) having an alkyl chain containing 6 to 12 carbon atoms have a low elastic modulus at room temperature, which provides excellent adhesive strength at the interface between the pressure-sensitive adhesive layer (12) and the adhesive layer (13). Furthermore, the peel strength between the pressure-sensitive adhesive layer (12) and the adhesive layer (13) can be reduced, resulting in excellent pickup properties. The glass transition temperature decreases as the number of carbon atoms in the alkyl group increases, making it possible to produce a composition with a desired glass transition temperature. Furthermore, for the purpose of improving the glass transition temperature and compatibility and various performance characteristics, it is also possible to blend low-molecular-weight compounds having a carbon-carbon double bond, such as vinyl acetate, styrene, and acrylonitrile, in an amount of up to 5% by mass of the total mass of the monomer (A1-1).

[0031] Examples of functional groups possessed by the monomer (A1-2) include a carboxyl group, a hydroxyl group, an amino group, a cyclic acid anhydride group, a glycidyl group, an isocyanate group, etc. Specific examples of the monomer (A1-2) include (meth)acrylic acid, cinnamic acid, itaconic acid, fumaric acid, phthalic acid, 2-hydroxyalkyl (meth)acrylates, 2-isocyanatoalkyl (meth)acrylates, glycol mono(meth)acrylates, N-methylol (meth)acrylamide, allyl alcohol, N-alkylaminoethyl (meth)acrylates, (meth)acrylamides, maleic anhydride, itaconic anhydride, fumaric anhydride, phthalic anhydride, glycidyl (meth)acrylate, and allyl glycidyl ether.

[0032] Examples of the functional group used in compound (A2) include a hydroxyl group, a glycidyl group, an isocyanato group, etc. when the functional group possessed by compound (A1), i.e., monomer (A1-2), is a carboxyl group or a cyclic acid anhydride group; when the functional group is a hydroxyl group, examples include a cyclic acid anhydride group, an isocyanato group, etc.; when the functional group is an amino group, examples include a glycidyl group, an isocyanato group, etc.; when the functional group is a glycidyl group, examples include a carboxyl group, a cyclic acid anhydride group, an amino group, etc. Specific examples of compound (A2) include the same groups as those enumerated as specific examples of monomer (A1-2).

[0033] By leaving unreacted functional groups in the reaction between a (meth)acrylic copolymer (A1) having a functional group and a compound (A2) having a functional group reactive with the functional group and an ultraviolet-curable carbon-carbon double bond, it is possible to produce a copolymer with desired properties, such as acid value or hydroxyl value. In the present invention, it is also preferable to use the unreacted functional groups remaining in the reaction between the copolymer (A1) and the compound (A2) as functional groups for forming a crosslinked structure with a curing agent containing a 1,2-polybutadiene skeleton, which is contained in the base polymer.

[0034] In the synthesis of the base polymer described above, when the reaction is carried out by solution polymerization, ketones, esters, alcohols, and aromatic solvents can be used as organic solvents. Among these, solvents that are generally good solvents for acrylic polymers and have a boiling point of 60 to 120°C, such as toluene, ethyl acetate, isopropyl alcohol, benzene, methyl cellosolve, ethyl cellosolve, acetone, and methyl ethyl ketone, are preferred. Radical generators, such as azobis-based solvents such as α,α'-azobisisobutylnitrile and organic peroxide-based solvents such as benzoyl peroxide, are typically used as polymerization initiators. In this case, catalysts and polymerization inhibitors can be used in combination as needed, and base polymers with the desired molecular weight can be obtained by adjusting the polymerization temperature and polymerization time. Furthermore, for molecular weight control, mercaptans and carbon tetrachloride-based solvents are preferred. This reaction is not limited to solution polymerization; other methods, such as bulk polymerization and suspension polymerization, can also be used.

[0035] The base polymer can be obtained as described above, and in the present invention, the molecular weight of the base polymer is preferably about 300,000 to 1,500,000. If the molecular weight is within this range, the cohesive force due to ultraviolet irradiation is large, and gelation during synthesis and coating can be suppressed. Note that the molecular weight in the present invention is the weight average molecular weight (Mw) in terms of polystyrene.

[0036] It is preferable that the base polymer has OH groups with a hydroxyl value of 5 to 100 mgKOH / g, since this reduces the adhesive strength after irradiation, thereby further reducing the risk of pick-up errors.

[0037] If the hydroxyl value of the base polymer is too low, the effect of reducing adhesive strength after irradiation is insufficient, whereas if it is too high, the fluidity of the adhesive after irradiation tends to be impaired.

[0038] (Curing Agent) The curing agent is a curing agent containing a 1,2-polybutadiene skeleton, and may be a compound containing a 1,2-polybutadiene skeleton capable of crosslinking the base polymer. The 1,2-polybutadiene skeleton refers to a skeleton having a 1,2-polybutadiene structure. In order to form a crosslinked structure with the base polymer, the curing agent typically has three or more functional groups that react with the base polymer. Examples of such curing agents include at least one compound selected from polyisocyanate compounds, melamine-formaldehyde resins, and epoxy resins, and any compound containing a 1,2-polybutadiene skeleton can be used without particular limitation. The curing agents may be used alone or in combination of two or more. This curing agent acts as a crosslinking agent for the base polymer, and upon reaction with the base polymer, the pressure-sensitive adhesive layer (12) has a crosslinked structure (three-dimensional network structure). In particular, the curing agent constituting the pressure-sensitive adhesive layer (12) of the present invention has a 1,2-polybutadiene skeleton, which functions to reduce the surface free energy of the pressure-sensitive adhesive layer (12). This 1,2-polybutadiene skeleton can suppress bleed-out of compounds having a 1,2-polybutadiene skeleton from the pressure-sensitive adhesive layer (12), and is believed to function satisfactorily in the dicing die bonding tape of the present invention. Furthermore, by incorporating a 1,2-polybutadiene skeleton into the curing agent rather than the base polymer, the surface free energy of the pressure-sensitive adhesive layer (12) can be adjusted to reduce while maintaining sufficient compatibility between the components constituting the pressure-sensitive adhesive layer (12) (base polymer, curing agent, etc.). Furthermore, as described above, the curing agent acts as a crosslinking agent, and the crosslinked structure formed as a result of the reaction with the base polymer can improve the cohesive strength of the pressure-sensitive adhesive, primarily composed of the base polymer and curing agent, after application.

[0039] The polyisocyanate compound having a 1,2-polybutadiene skeleton is not particularly limited, and preferably has an isocyanato group at the end of a polymer chain having a 1,2-polybutadiene skeleton, more preferably has an isocyanato group at the end of a linear polymer chain having a 1,2-polybutadiene skeleton, and even more preferably has an isocyanato group at both ends of a linear polymer chain having a 1,2-polybutadiene skeleton. For example, a commercially available product such as NISSO-PB TP-1001 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene with terminal isocyanate groups introduced) can be mentioned. Furthermore, examples of epoxy resins having a 1,2-polybutadiene skeleton include JP-100 and JP-200 (both trade names, manufactured by Nippon Soda Co., Ltd., epoxidized 1,2-polybutadiene). It is preferable to use a polyisocyanate compound having a 1,2-polybutadiene skeleton as the curing agent.

[0040] The content of the curing agent component per 100 parts by mass of the base polymer is 3 to 25 parts by mass, preferably 5 to 20 parts by mass, more preferably 7 to 20 parts by mass, and even more preferably 10 to 20 parts by mass from the viewpoint of further improving pick-up properties. The curing agent component refers to a component derived from a curing agent containing a 1,2-polybutadiene skeleton. For example, when a base polymer having a 1,2-polybutadiene skeleton is contained in addition to a curing agent having a 1,2-polybutadiene skeleton, the 1,2-polybutadiene skeleton derived from the base polymer is not counted as part of the "curing agent component" described above. Furthermore, although hydrogenated polymers having a 1,2-polybutadiene skeleton typically contain less than 10% residual carbon-carbon double bonds, these are not included as a skeletal structure similar to the 1,2-polybutadiene skeleton in polymers having a 1,2-polybutadiene skeleton. Therefore, hydrogenated polymers having a 1,2-polybutadiene skeleton do not in the first place fall under the category of polymers having a "1,2-polybutadiene skeleton" as defined in the present invention, and are not counted as the above-mentioned "curing agent component." When a pressure-sensitive adhesive layer is constructed using a base polymer having a 1,2-polybutadiene skeleton instead of a curing agent having a 1,2-polybutadiene skeleton so as to satisfy the above-mentioned content of the curing agent component, molding of the pressure-sensitive adhesive layer itself is difficult, compatibility is poor, and pick-up properties are poor (see Comparative Examples 3 and 6 described below).

[0041] (Photopolymerization initiator) The pressure-sensitive adhesive layer 12 preferably contains a photopolymerization initiator. There are no particular limitations on the photopolymerization initiator, and any conventionally known photopolymerization initiator can be used. For example, benzophenone, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, benzophenones such as 4,4'-dichlorobenzophenone, acetophenone, acetophenones such as diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropanone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-methylpropanone, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one and other α-hydroxyalkylphenones, 2-ethylanthraquinone, anthraquinones such as t-butylanthraquinone, 2-chlorothioxanthone, benzoin ethyl ether, benzoin isopropyl ether, benzyl, 2,4-triaryl-imidazole dimer (lophine dimer), acridine compounds, and the like can be mentioned, which can be used alone or in combination of two or more.

[0042] The amount of the photopolymerization initiator added is preferably 0.1 to 10 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 3 to 8 parts by mass, per 100 parts by mass of the base polymer.

[0043] Furthermore, the ultraviolet-curable adhesive used to form the ultraviolet-curable adhesive layer may contain, as required, a tackifier, an adhesive adjuster, a surfactant, or other modifiers and conventional components.

[0044] The surface free energy of the pressure-sensitive adhesive layer (12) after UV irradiation is, for example, preferably 25 to 40 mN / m, more preferably 25 to 39 mN / m, even more preferably 30 to 39 mN / m, and particularly preferably 30 to 37 mN / m. As described above, the surface free energy of the pressure-sensitive adhesive layer (12) after UV irradiation can be adjusted to a smaller value by incorporating a 1,2-polybutadiene skeleton into the pressure-sensitive adhesive layer (12). From the viewpoint of achieving excellent pickup properties, the difference obtained by subtracting the surface free energy of the pressure-sensitive adhesive layer (12) after UV irradiation from the surface free energy of the adhesive layer (13) is preferably 10 mN / m or more, more preferably 10 to 40 mN / m, even more preferably 10 to 35 mN / m, and particularly preferably 12 to 30 N / m. In the present invention, the "surface free energy" is a value measured and calculated as follows. First, diiodomethane, ethylene glycol, and pure water are dropped at five different locations on the pressure-sensitive adhesive layer (12) or adhesive layer (13) after UV irradiation in the contact angle measurement sample, and the contact angles θ at each location are measured using an automatic contact angle meter (for example, an automatic contact angle meter DMo-601 (trade name) manufactured by Kyowa Interface Science Co., Ltd.), and the contact angle θ is calculated from the average value of the five locations. The measurements are performed at room temperature (23°C), and the contact angle of the pressure-sensitive adhesive layer (12) after UV irradiation is measured after leaving the pressure-sensitive adhesive layer to stand for 1 hour at room temperature (23°C) after UV irradiation to stabilize the temperature. The contact angle θ values ​​(average values ​​of five locations) of diiodomethane, ethylene glycol, and pure water obtained as described above were substituted into the "Hata and Kitazaki's Extended Hawkes' Equation (Reference: Kitazaki Yasuaki, Hata Toshio: Japan Adhesion Association Paper, 8, (3) 131 (1972))" shown in the examples below, and the surface free energy (γ in the Hata and Kitazaki's Extended Hawkes' Equation shown below) was calculated. Ｓ : surface free energy of the solid) is calculated.

[0045] The thickness of the adhesive layer (12) is not particularly limited, but is usually 2 to 50 μm.

[0046] <Adhesive Layer (13)> The adhesive layer (13) is attached to a semiconductor wafer, diced, and then divided along the semiconductor chip by the expanding process of dicing die bonding. When the chip is picked up, the adhesive layer (13) is peeled off from the pressure-sensitive adhesive layer (12) after UV irradiation and adheres to the semiconductor chip (remains on the semiconductor chip). It is then used as an adhesive when fixing the semiconductor chip to a substrate or lead frame. In the dicing die bonding tape of the present invention, the surface free energy of the adhesive layer (13) is 40 to 70 mN / m, preferably 45 to 70 mN / m, more preferably 45 to 65 mN / m, and even more preferably 47 to 65 mN / m. Thus, due to its high surface free energy, the adhesive layer (13) in the dicing die bonding tape of the present invention exhibits excellent adhesion to the semiconductor wafer.

[0047] The adhesive layer (13) is preferably a film-like adhesive obtained by previously forming an adhesive into a film. The material of the adhesive layer (13) is not particularly limited as long as it satisfies the above-mentioned specific surface free energy. For example, it is preferable for the adhesive layer (13) to contain at least one of phenoxy resin, polycarbonate resin, thermoplastic polyimide resin, polyamide resin such as 6-nylon and 6,6-nylon, and polyurethane resin, and phenoxy resin is more preferable. The content of phenoxy resin, polycarbonate resin, thermoplastic polyimide resin, polyamide resin such as 6-nylon and 6,6-nylon, and polyurethane resin (preferably phenoxy resin) in the resin constituting the adhesive layer (13) is not limited as long as it satisfies the above-mentioned specific surface free energy. For example, it can be 70% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more. All of the resins constituting the adhesive layer (13) may be phenoxy resin, polycarbonate resin, thermoplastic polyimide resin, polyamide resin such as 6-nylon and 6,6-nylon, and polyurethane resin (preferably phenoxy resin).

[0048] The adhesive layer (13) is formed by containing at least a thermosetting resin, and is preferably formed by at least a thermosetting resin and a thermoplastic resin. When the adhesive layer (13) contains a thermosetting resin, it is preferable to cure the thermosetting resin by heating in the die bonding process to exhibit adhesive strength. Hereinafter, resins will be described, including the above-mentioned resins exhibiting high surface free energy, as well as thermosetting resins and / or thermoplastic resins that may be used in combination.

[0049] Examples of thermoplastic resins include natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, polybutadiene resin, polycarbonate resin, thermoplastic polyimide resin, polyamide resins such as nylon 6 and nylon 6,6, phenoxy resin, acrylic resin, saturated polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polyamide-imide resin, and fluororesin. Thermoplastic resins may be used alone or in combination of two or more. Among these thermoplastic resins, acrylic resins are particularly preferred because they contain fewer ionic impurities and have excellent stress relaxation properties, while phenoxy resins are particularly preferred because they combine flexibility and strength with high toughness, making it easier to ensure the reliability of semiconductor elements from each of these perspectives. Examples of acrylic resins that can be used include those described in paragraphs

[0078] to

[0079] of Japanese Patent No. 6,429,824.

[0050] The phenoxy resin is preferably a resin obtained by a method of reacting various bisphenols with epichlorohydrin or a method of reacting a liquid epoxy resin with bisphenols, and examples of bisphenols include bisphenol A, bisphenol AF, bisphenol AD, bisphenol F, and bisphenol S. Phenoxy resins have a similar structure to epoxy resins and are therefore well compatible with epoxy resins, making them suitable for imparting good adhesive properties to adhesives.

[0051] The phenoxy resin may be, for example, a resin having a repeating unit represented by the following general formula (2).

[0052]

[0053] In the above general formula (2), X represents a single bond or a divalent linking group. The divalent linking group may be an alkylene group, a phenylene group, —O—, —S—, —SO—, or —SO ２ Here, the alkylene group is preferably an alkylene group having 1 to 10 carbon atoms, and -C(R ５ ) (R ６ )- is more preferred. ５ , R ６ represents a hydrogen atom or an alkyl group, and the alkyl group is preferably a linear or branched alkyl group having 1 to 8 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, isooctyl, 2-ethylhexyl, and 1,3,3-trimethylbutyl. The alkyl group may be substituted with a halogen atom, such as a trifluoromethyl group. X represents an alkylene group, -O-, -S-, a fluorene group, or -SO ２ - is preferred, and an alkylene group or -SO ２ Among them, —C(CH ３ ) ２ -, -CH(CH ３ ) -, -CH ２ -or-SO ２ - is preferred, and -C(CH ３ ) ２ -, -CH(CH ３ )- or -CH ２ - is more preferred, and -C(CH ３ ) ２ - is more preferred.

[0054] The phenoxy resin having a repeating unit represented by the general formula (2) may be a resin having a plurality of repeating units of the general formula (2) where X is different, or may be a resin constituted only of repeating units where X is the same. In the present invention, a resin constituted only of repeating units where X is the same is preferred.

[0055] Furthermore, when the phenoxy resin represented by the general formula (2) contains a polar substituent such as a hydroxyl group or a carboxyl group, the compatibility with the thermosetting resin is improved, and uniform appearance and properties can be imparted.

[0056] A mass average molecular weight of the phenoxy resin of 5,000 or more is preferred in terms of film formability. It is more preferably 10,000 or more, and even more preferably 30,000 or more. A mass average molecular weight of 150,000 or less is preferred in terms of fluidity during thermocompression bonding to a wafer and compatibility with other resins. It is more preferably 100,000 or less. A glass transition temperature of -50°C or more is preferred in terms of film formability, more preferably 0°C or more, and even more preferably 50°C or more. A glass transition temperature of 150°C or less is preferred because the adhesive strength of the adhesive layer (13) during die bonding is high, and is more preferably 120°C or less, and even more preferably 110°C or less.

[0057] Examples of thermosetting resins include epoxy resins, phenolic resins, amino resins, unsaturated polyester resins, polyurethane resins, silicone resins, and thermosetting polyimide resins. The thermosetting resins may be used alone or in combination of two or more. Epoxy resins, which contain little ionic impurities that corrode semiconductor elements, are particularly suitable as thermosetting resins.

[0058] The epoxy resin is not particularly limited as long as it has adhesive properties when cured. For example, bifunctional, trifunctional or higher functional epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, brominated bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol AF type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, triphenylmethane type epoxy resin, trishydroxyphenylmethane type epoxy resin, tetraphenylolethane type epoxy resin, or epoxy resins such as hydantoin type epoxy resin, trisglycidyl isocyanurate type epoxy resin, or glycidylamine type epoxy resin can be used.

[0059] Of the examples of epoxy resins, particularly preferred are novolac type epoxy resins, bisphenol A type epoxy resins, biphenyl type epoxy resins, triphenylmethane type epoxy resins, trishydroxyphenylmethane type epoxy resins, and tetraphenylolethane type epoxy resins.

[0060] Examples of the curing agent for the epoxy resin include known curing agents such as phenolic resin, imidazoles, amines, and acid anhydrides, with imidazoles being preferred. Examples of the imidazoles include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-ethylimidazole, 1-benzyl-2-ethyl-5-methylimidazole, 2-phenyl-4-methyl-5-hydroxydimethylimidazole, and 2-phenyl-4,5-dihydroxymethylimidazole.

[0061] It is important that the adhesive layer (13) has adhesiveness (adhesion) to an adherend such as an electronic device. Therefore, in order to crosslink the adhesive layer (13) to some extent in advance, a multifunctional compound that reacts with functional groups at the molecular chain terminals of the polymer may be added as a crosslinking agent. This improves the adhesive properties at high temperatures and improves heat resistance.

[0062] The crosslinking agent is not particularly limited, and known crosslinking agents can be used. Specific examples include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, peroxide-based crosslinking agents, urea-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, carbodiimide-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, and amine-based crosslinking agents. Suitable crosslinking agents include isocyanate-based crosslinking agents and epoxy-based crosslinking agents. The crosslinking agents can be used alone or in combination of two or more.

[0063] In the present invention, instead of using a crosslinking agent, or in addition to using a crosslinking agent, it is also possible to carry out a crosslinking treatment by irradiation with electron beams, ultraviolet rays, or the like.

[0064] Other additives may be appropriately blended into the adhesive layer (13) as needed, such as fillers, flame retardants, silane coupling agents, ion trapping agents, extenders, antioxidants, antioxidants, surfactants, etc.

[0065] The filler may be either an inorganic or organic filler, with inorganic fillers being preferred. The incorporation of fillers such as inorganic fillers can improve the thermal conductivity and adjust the modulus of elasticity of the adhesive layer (13). Examples of inorganic fillers include ceramics such as silica, clay, gypsum, calcium carbonate, barium sulfate, alumina, beryllium oxide, silicon carbide, aluminum nitride, and silicon nitride; metals or alloys such as aluminum, copper, silver, gold, nickel, chromium, lead, tin, zinc, palladium, and solder; and various inorganic powders made of carbon. Fillers may be used alone or in combination of two or more. Among fillers, silica or alumina is particularly preferred, with fused silica being particularly preferred for silica. The average particle size of the inorganic filler is preferably within the range of 0.001 μm to 80 μm. The average particle size of the inorganic filler is the average particle size (d50) measured by the method described below for polyhedral alumina fillers.

[0066] The blending amount of the filler (particularly inorganic filler) is preferably 98% by mass or less (0 to 98% by mass) relative to the organic resin component (total of resin and curing agent), and in particular, in the case of silica, it is preferably 0 to 70% by mass, and in the case of functional inorganic fillers such as thermally conductive and electrically conductive fillers, it is preferably 10 to 98% by mass.

[0067] Examples of flame retardants include antimony trioxide, antimony pentoxide, and brominated epoxy resins. Flame retardants may be used alone, or two or more may be used in combination. Examples of silane coupling agents include β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane. Silane coupling agents may be used alone or in combination. Examples of ion trapping agents include hydrotalcites and bismuth hydroxide. Ion trapping agents may be used alone or in combination.

[0068] From the viewpoint of adhesiveness and reliability, the adhesive layer (13) preferably contains, in particular, (A) an epoxy resin, (B) a curing agent, (C) a phenoxy resin, and (D) a surface-treated inorganic filler and / or a polyhedral alumina filler.

[0069] By using the (A) epoxy resin, high adhesiveness, water resistance, and heat resistance can be obtained. As the epoxy resin, the above-mentioned known epoxy resins can be used. As the (B) curing agent, the above-mentioned known curing agents can be used.

[0070] (C) Phenoxy resin has a long molecular chain and a structure similar to that of epoxy resin, and acts as a flexible material in a composition with a high crosslink density, imparting high toughness, thereby obtaining a composition that is strong yet tough. Preferred phenoxy resins are those whose main skeleton is bisphenol A, but other commercially available phenoxy resins such as bisphenol F phenoxy resin, bisphenol A / F mixed phenoxy resin, and brominated phenoxy resin are also preferred.

[0071] (D) Examples of surface-treated inorganic fillers include inorganic fillers surface-treated with a coupling agent. The above-mentioned known inorganic fillers can be used as the inorganic filler, but silica and alumina are preferred. Surface treatment with a coupling agent improves the dispersibility of the inorganic filler. This results in excellent fluidity, which can improve the adhesive strength with the metal layer 3. Furthermore, since the inorganic filler can be highly loaded, the water absorption rate can be reduced, improving moisture resistance.

[0072] For example, the surface treatment of an inorganic filler with a silane coupling agent is carried out by a known method in which the inorganic filler is dispersed in a silane coupling agent solution, and hydroxyl groups present on the surface of the inorganic filler react with silanol groups formed by hydrolysis of hydrolyzable groups such as alkoxy groups of the silane coupling agent, thereby generating Si—O—Si bonds on the surface of the inorganic filler.

[0073] (D) Polyhedral alumina filler refers to an inorganic powder of alumina (aluminum oxide) that has a polyhedral shape. In the present invention, "polyhedron" refers to a solid having multiple planes. The polyhedron needs to have at least two planes, preferably four or more planes, and more preferably eight or more planes. The upper limit of the number of planes constituting the polyhedron is not particularly limited, but for example, about 20 is practical. The shape of the plane is not particularly limited, and examples thereof include polygons (triangles, quadrangles, pentagons, hexagons, etc.). The polyhedron may have curved surfaces in addition to flat surfaces. Examples of polyhedrons include plate-shaped, columnar, prism-shaped, cylindrical, and regular polyhedrons. The polyhedral alumina filler may contain spherical alumina filler, and the proportion of the polyhedral alumina filler in the total of the polyhedral alumina filler and the spherical alumina filler may be 40% by volume or less, 30% by volume or less, 10% by volume or less, or even 5% by volume or less. The amount of spherical alumina filler contained in the polyhedral alumina filler may be 80% by mass or less, 50% by mass or less, 30% by mass or less, 20% by mass or less, or 10% by mass or less of the total amount of polyhedral alumina filler. Furthermore, all of the alumina filler contained in the polyhedral alumina filler may be polyhedral alumina filler. The preferred range of the average particle size of the polyhedral alumina filler described below also applies to the average particle size of the spherical alumina filler. The shape of the polyhedral alumina filler can be confirmed by observation using a scanning electron microscope (SEM), and it can be determined to be "polyhedral" when two or more flat surfaces can be confirmed. By using polyhedral alumina filler, it is possible to improve thermal conductivity compared to when spherical alumina filler is used, even with the same filling amount, due to the increased contact area between fillers.

[0074] The average particle size (d50) of the polyhedral alumina filler is not particularly limited, but from the viewpoint of thinning the film-like adhesive, it is preferably 0.01 to 6.0 μm, more preferably 0.01 to 5.0 μm, more preferably 0.1 to 4.0 μm, and even more preferably 0.3 to 3.5 μm. The average particle size (d50) is the so-called median diameter, and refers to the particle size at 50% cumulative when the total volume of particles in the cumulative distribution is 100% as measured by a laser diffraction / scattering method. It is preferable to use a combination of multiple types of polyhedral alumina filler (D) with different average particle sizes (d50), and more preferably to use a combination of two types with different average particle sizes (d50). This can increase the content of polyhedral alumina filler (D) in the adhesive layer (13) and improve thermal conductivity. When two types of polyhedral alumina filler (D) having different average particle diameters (d50) are used in combination, for example, the average particle diameter (d50) of the polyhedral alumina filler (D1) having a relatively large average particle diameter (d50) is preferably 1.0 to 8.0 μm, more preferably 2.0 to 6.0 μm, even more preferably 2.5 to 5.0 μm, and even more preferably 2.5 to 4.0 μm. The average particle diameter (d50) of the polyhedral alumina filler (D2) having a relatively small average particle diameter (d50) is preferably 0.10 to 0.80 μm, more preferably 0.20 to 0.70 μm, even more preferably 0.30 to 0.70 μm, and even more preferably 0.35 to 0.65 μm. Furthermore, the ratio (D1 / D2) (mass ratio) of the content of the polyhedral alumina filler (D1) having a relatively large average particle size (d50) to the content of the polyhedral alumina filler (D2) having a relatively small average particle size (d50) is preferably 2 to 8, more preferably 3 to 7. When a combination of alumina fillers having different average particle sizes (d50) is used as the polyhedral alumina filler (D), at least one of the alumina fillers can be a spherical alumina filler.For example, a polyhedral alumina filler having a relatively large average particle size (d50) can be replaced with a spherical alumina filler having a relatively large average particle size (d50), and a polyhedral alumina filler having a relatively small average particle size (d50) can be replaced with a spherical alumina filler having a relatively small average particle size (d50). In the present invention, "spherical" does not correspond to the above-mentioned "polyhedron" and refers to a sphericity of 0.5 to 1.0 (preferably 0.6 to 1.0, more preferably 0.7 to 1.0, and even more preferably 0.8 to 1.0). The sphericity can be determined by observing the alumina filler using a scanning electron microscope and based on its area and perimeter. The specific method is as follows. (Sphericity of Alumina Filler) A small amount of alumina filler is placed on a glass plate and observed at a magnification of 10,000 times using a scanning electron microscope (model number: FlexSEM 1000II, manufactured by Hitachi High-Technologies Corporation). Based on the observed image, the area and perimeter of each alumina filler are measured using particle analysis software, and the irregularity of each inorganic filler is calculated using the following formulas (1) and (2). Irregularity of alumina filler = (perimeter 2 × area) × 1 / 4π (1) Sphericity of alumina filler = 1 / Irregularity of alumina filler (2) Ten alumina fillers are randomly observed in the observed image, and the arithmetic mean value of the sphericities of the 10 alumina fillers is taken as the sphericity of the alumina filler.

[0075] The polyhedral alumina filler (D) may be surface-treated or surface-modified. Examples of surface treatment agents used for such surface treatment or surface modification include silane coupling agents, phosphoric acid or phosphoric acid compounds, and surfactants. In addition to the matters described in this specification, for example, the descriptions of silane coupling agents, phosphoric acid or phosphoric acid compounds, and surfactants in the section on thermally conductive fillers in WO 2018 / 203527 or the section on aluminum nitride fillers in WO 2017 / 158994 can be applied.

[0076] From the viewpoint of ensuring sufficient adhesion of the adhesive layer (13) to the semiconductor wafer, the melt viscosity of the adhesive layer (13) at 70°C is preferably 10,000 to 60,000 Pa·s, more preferably 10,000 to 55,000 Pa·s, and even more preferably 10,000 to 50,000 Pa·s. The melt viscosity is a value measured by the following method. The adhesive layer (13) of the dicing die bonding tape of the present invention, or the adhesive film used in producing the dicing die bonding tape of the present invention, is cut into a square measuring 5.0 cm long x 5.0 cm wide, and the adhesive layers (13) are laminated together and bonded together with a hand roller on a stage at 70°C to obtain a test piece with a thickness of approximately 1.0 mm. The test piece thus obtained is subjected to measurement of the change in viscous resistance at a temperature range of 20 to 250°C at a heating rate of 5°C / min using a rheometer (for example, HAAKE MARS 40 (trade name), manufactured by Thermo Fisher Scientific), and the melt viscosity (Pa s) at 70°C is calculated from the obtained temperature-viscous resistance curve.

[0077] The thickness of the adhesive layer (13) is not particularly limited, but is preferably 3 to 100 μm, more preferably 5 to 150 μm, from the viewpoint of ease of handling and thinning of the semiconductor package. The adhesive layer (13) may be composed of a single layer or multiple layers.

[0078] [Method for manufacturing dicing / die bonding tape] The pressure-sensitive adhesive layer (12) can be formed using a conventional pressure-sensitive adhesive layer forming method. For example, the pressure-sensitive adhesive layer (12) can be formed on the substrate film (11) by preparing a pressure-sensitive adhesive composition containing the above-mentioned pressure-sensitive adhesive and applying the pressure-sensitive adhesive composition to a predetermined surface of the substrate film (11), or by applying the pressure-sensitive adhesive composition to a separator (e.g., a plastic film or sheet coated with a release agent) to form the pressure-sensitive adhesive layer (12), and then transferring the pressure-sensitive adhesive layer (12) to a predetermined surface of the substrate film (11). The pressure-sensitive adhesive layer (12) may have a single-layer form or a laminate form.

[0079] The adhesive layer (13) may be formed by directly or indirectly laminating a pre-formed film (hereinafter referred to as adhesive film) onto the pressure-sensitive adhesive layer (12). The temperature during lamination is preferably in the range of 10 to 100°C, and a linear pressure of 0.01 to 10 N / m is applied. The adhesive film may be one in which the adhesive layer (13) is formed on a release film. In this case, the release film may be peeled off after laminating the adhesive film onto the pressure-sensitive adhesive layer (12). Alternatively, the release film may be used as a cover film for the dicing die bonding tape 10, and the release film may be peeled off when laminating the wafer.

[0080] The adhesive film may be laminated over the entire surface of the pressure-sensitive adhesive layer (12), or a pre-cut adhesive film cut to a shape corresponding to the wafer to be bonded may be laminated onto the pressure-sensitive adhesive layer (12). When an adhesive film corresponding to the wafer shape is laminated in this manner, as shown in FIG. 2, an adhesive layer (13) is present in the area where the wafer W is bonded, while the adhesive layer (13) is absent in the area where the ring frame (20) is bonded, and only the adhesive layer (12) is present. Generally, the adhesive layer (13) is difficult to peel from the adherend, so using a pre-cut adhesive film allows the ring frame (20) to be bonded to the adhesive layer (12), resulting in less adhesive residue on the ring frame (20) when the tape is peeled off after use. The ring frame (20) is an example of a dicing frame. As a preliminary step to the dicing process of the wafer W, a surface protection tape (14) for protecting the circuit pattern, which contains an ultraviolet-curable component in its adhesive, is usually applied to the surface of the wafer W on which a circuit pattern has been formed, and a back-grinding process is then carried out to grind the back surface of the wafer W. After the back-grinding process is completed, the wafer W is placed with its front surface side facing down on a heater table (25) of a wafer mounter, as shown in FIG. 2, and a dicing die bonding tape (10) is then applied to the back surface of the semiconductor wafer W.

[0081] [Uses and Methods of Use of Dicing and Die Bonding Tape] The dicing and die bonding tape (10) of the present invention can be used in the manufacture of semiconductor devices. Specifically, in the dicing process in which a semiconductor wafer is cut into chips, it is used to fix the semiconductor wafer to a dicing frame. Furthermore, in the die bonding process, it is used to bond the chips cut by the dicing and picked up, each with the adhesive layer (13), to a lead frame or package substrate via the adhesive layer (13), and / or to stack and bond the chips together. When fixing a semiconductor wafer to the dicing frame, the adhesive layer (13) is present in the portion that will be bonded to the semiconductor wafer, while the adhesive layer (13) is absent in the portion that will be bonded to the dicing frame, and the pressure-sensitive adhesive layer (12) is present instead. This is described in detail below.

[0082] (Fixing a semiconductor wafer to a dicing frame in a dicing process) If the dicing die bonding tape 10 has a release liner, the release liner is removed to expose the adhesive layer (13). Next, as shown in FIG. 2, the adhesive layer (13) is attached to the wafer W, and the side of the adhesive tape (15) is fixed with a ring frame (20). The ring frame (20) is an example of a dicing frame. The adhesive layer (13) is laminated at least on the portion of the adhesive tape (15) that will be bonded to the wafer W. On the other hand, the adhesive film 13 is not present on the portion of the adhesive tape (15) that contacts the ring frame (20), and the adhesive tape (15) is bonded to the ring frame (20).

[0083] (Dicing Process to Semiconductor Chip Pickup Process) The dicing process to the semiconductor chip pick-up process are not particularly limited and can be performed by conventional methods. For example, while the underside of the adhesive tape (15) is suction-fixed to a suction table, the semiconductor wafer is diced to a predetermined size using a thin grindstone or the like to produce multiple semiconductor chips. Then, with the adhesive tape (15) fixed by a ring frame, a push-up member is raised to deflect the center of the adhesive tape (15) upward, and radiation such as ultraviolet light is irradiated onto the adhesive tape (15) (adhesive layer (12)) to weaken the adhesive strength of the adhesive layer (12). Then, a push-up pin is raised at a position corresponding to each semiconductor chip, and the semiconductor chip with the adhesive layer (13) attached is picked up by a suction collet. For an explanation of the above process, see paragraph

[0084] and Figures 3 to 5 of Japanese Patent No. 5,503,342, and these descriptions can be directly applied to the present invention.

[0084] The semiconductor chip with the adhesive layer (13) attached thereto is then adhered to a support member such as a lead frame or a package substrate, or the semiconductor chips are stacked and adhered (die bonded) to each other, and then subjected to processes such as the attachment of gold wires and heat curing, thereby obtaining a semiconductor device.

[0085] By using the dicing die bonding tape (10) of the present invention, the adhesive layer (13) has a high surface free energy, and therefore when the semiconductor wafer is cut into small element pieces (during dicing processing), the adhesive layer (13) has sufficient element-fixing adhesive strength to fix the cut elements (semiconductor chips) sufficiently to prevent chip flying, and after ultraviolet irradiation, the difference in surface free energy between the adhesive layer (12) and the adhesive layer (13) is adjusted, allowing the adhesive layer (12) and the adhesive layer (13) to be easily peeled apart, and the cut elements (semiconductor chips with the adhesive layer (13)) can always be easily picked up from the adhesive tape (15).

[0086] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0087] [Preparation of Dicing Die Bonding Tape] (Example 1) <1> Preparation of Pressure-Sensitive Adhesive Tape (1) Preparation of Substrate Film An ionomer resin composition in which ethylene-methacrylic acid copolymer molecules were crosslinked with metal ions (sodium ions and zinc ions) was melt-kneaded and molded to obtain a substrate film with a thickness of 90 μm. (2) Preparation of Pressure-Sensitive Adhesive Layer A copolymer consisting of 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, and methyl methacrylate was prepared, and 2-isocyanatoethyl methacrylate was added and reacted to produce a (meth)acrylic copolymer P1 having a Mw of 800,000, a glass transition temperature of −64° C., an ultraviolet-curable carbon-carbon double bond content of 23 (iodine value), and a hydroxyl value of 33.7 mg KOH / g. Thereafter, 30 parts by mass (15 parts by mass of resin blending amount) of NISSO-PB TP-1001 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene with terminal isocyanate groups, solvent-diluted, resin content 50% by mass) as a curing agent per 100 parts by mass of this (meth)acrylic copolymer P1, and 5 parts by mass of Irgacure 184 (manufactured by Nippon Ciba-Geigy Co., Ltd., trade name, 1-hydroxycyclohexyl phenyl ketone) as a photopolymerization initiator were added to obtain an ultraviolet-curable pressure-sensitive adhesive A. Thereafter, the pressure-sensitive adhesive A was coated onto the substrate film so that the thickness after drying was 10 μm, and a pressure-sensitive adhesive tape A was obtained, which is a laminate of a 10 μm-thick pressure-sensitive adhesive layer and a substrate film.

[0088] <2> Preparation of adhesive film (1) Preparation of adhesive composition An adhesive composition G1 was prepared by dissolving 28 parts by mass of bisphenol A phenoxy resin (manufactured by Nippon Steel Epoxy Corporation, trade name "YP-50S", Mw 60,000, Tg 84°C), 55 parts by mass of solid bisphenol A epoxy resin (manufactured by Nippon Steel Epoxy Corporation, trade name "YD-011", Mw 1,000, epoxy equivalent 450 g / eq), 49 parts by mass of liquid bisphenol A epoxy resin (manufactured by Nippon Steel Epoxy Corporation, trade name "YD-128", Mw 400, epoxy equivalent 190 g / eq), 9 parts by mass of an imidazole epoxy resin curing agent (manufactured by Shikoku Chemicals Corporation, trade name "Curesol 2PHZ-PW"), and 74 parts by mass of silica filler (manufactured by Admatechs Corporation, trade name "SO-C2", average particle size (d50) 0.5 μm) in methyl ethyl ketone (MEK). (2) Preparation of adhesive film This adhesive composition G1 was applied to a 50 μm thick polyethylene terephthalate film (release liner) that had been subjected to a silicone release treatment, and then dried at 130° C. for 5 minutes to prepare an adhesive film G1, which was a laminate of a 20 μm thick adhesive layer and a release liner.

[0089] <3> Preparation of Dicing Die Bonding Tape The adhesive layer of the adhesive film G1 prepared above was bonded to the adhesive layer side of the adhesive tape A prepared above to prepare the dicing die bonding tape of Example 1. The bonding was performed by pressing with a hand roller at a pressure of approximately 0.3 MPa on a hot plate with a stage temperature of 70°C. The dicing die bonding tape (10) of Example 1 obtained in this manner has a structure in which, as shown in FIG. 1 , a base film (11), an adhesive layer (12), and an adhesive layer (13) are laminated in this order, with a release liner (not shown in FIG. 1 ) further laminated on the adhesive layer (13). The dicing die bonding tapes of Examples 2 to 7 and Comparative Examples 1 to 9 prepared below also have the same laminate structure as the dicing die bonding tape of Example 1.

[0090] Example 2 A dicing die bonding tape of Example 2 was produced in the same manner as in Example 1, except that in the production of the dicing die bonding tape of Example 1, the blending amount of NISSO-PB TP-1001 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene having an isocyanate group introduced at the end, solvent diluted type, resin content 50% by mass) was changed to 40 parts by mass (20 parts by mass as the resin blending amount).

[0091] Example 3 A dicing die bonding tape of Example 3 was produced in the same manner as in Example 1, except that in the production of the dicing die bonding tape of Example 1 above, the blending amount of NISSO-PB TP-1001 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene having an isocyanate group introduced at the end, solvent diluted type, resin content 50% by mass) was changed to 10 parts by mass (5 parts by mass as the resin blending amount).

[0092] Example 4 A dicing die bonding tape of Example 4 was produced in the same manner as in Example 1, except that adhesive composition G2 prepared as follows was used instead of adhesive composition G1 in the production of the dicing die bonding tape of Example 1. 56 parts by mass of triphenylmethane type epoxy resin (trade name "EPPN-501H", Mw 1000, softening point 55°C, solid, epoxy equivalent 167 g / eq, manufactured by Nippon Kayaku Co., Ltd.), 49 parts by mass of liquid bisphenol A type epoxy resin (trade name "YD-128", Mw 400, epoxy equivalent 190 g / eq, manufactured by Nippon Steel Epoxy Co., Ltd.), and bisphenol A type phenoxy resin (trade name "YP-50", Mw 7 In a 1000 ml separable flask, 30 parts by mass of ethylenediaminetetraacetic acid (TEA, Tg: 84°C, manufactured by Nippon Steel Epoxy Co., Ltd.) and 67 parts by mass of MEK were heated and stirred at a temperature of 110°C for 2 hours. Then, the entire amount of this resin varnish (202 parts by mass) was transferred to an 800 ml planetary mixer, and a polyhedral alumina filler (trade name "Advanced Alumina AA-05", average particle size (d50) of 0.58 μm, BET specific surface area of ​​3.2 m) was added. ２ / g, manufactured by Sumitomo Chemical Co., Ltd.) 479 parts by mass, imidazole-based epoxy resin curing agent (trade name "Curezol 2PHZ-PW", manufactured by Shikoku Chemical Industry Co., Ltd.) 8.5 parts by mass, silane coupling agent (3-glycidyloxypropyltrimethoxysilane, trade name "KBM-403", minimum coverage area of ​​silane coupling agent 330 m ２ 3.0 parts by mass of PEG-100 / g (manufactured by Shin-Etsu Silicones Co., Ltd.) was added to prepare adhesive composition G2.

[0093] Example 5 A dicing die bonding tape of Example 5 was produced in the same manner as in Example 1, except that adhesive composition G3 prepared as described below was used in place of adhesive composition G1 in the production of the dicing die bonding tape of Example 1. In adhesive composition G2 of Example 4, a polyhedral alumina filler (trade name "Advanced Alumina AA-05", average particle size (d50) 0.58 μm, BET specific surface area 3.2 m) was used. ２ / g, manufactured by Sumitomo Chemical Co., Ltd.) was changed from 479 parts by mass to 96 parts by mass, and further a polyhedral alumina filler (trade name "Advanced Alumina AA-3", average particle size (d50) 3.5 μm, BET specific surface area 0.6 m ２ An adhesive composition G3 was prepared in the same manner as in Example 4, except that 383 parts by mass of PEG-10 ...

[0094] Example 6 The dicing die bonding tape of Example 6 was produced in the same manner as in Example 1, except that the (meth)acrylic copolymer P2 below was used instead of the (meth)acrylic copolymer P1 in the production of the dicing die bonding tape of Example 1, and the blending amount of NISSO-PB TP-1001 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene with terminal isocyanate groups, solvent-diluted type, resin content 50% by mass) was changed to 24 parts by mass (12 parts by mass as resin blending amount). A copolymer consisting of 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, and methyl methacrylate was prepared, and 2-isocyanatoethyl methacrylate was further added and reacted to produce (meth)acrylic copolymer P2 having a Mw of 970,000, a glass transition temperature of -59°C, an ultraviolet-curable carbon-carbon double bond content of 38 (iodine value), and a hydroxyl value of 27.2 mgKOH / g.

[0095] Example 7 The dicing die bonding tape of Example 7 was produced in the same manner as in Example 1, except that in the production of the dicing die bonding tape of Example 1 above, the (meth)acrylic copolymer P1 was replaced with the (meth)acrylic copolymer P3 below, and the amount of NISSO-PB TP-1001 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene with terminal isocyanate groups, solvent-diluted type, resin content 50% by mass) blended was changed to 18 parts by mass (9 parts by mass as resin blending amount). A copolymer consisting of butyl acrylate, 2-hydroxyethyl acrylate, and methyl methacrylate was prepared, and 2-isocyanatoethyl methacrylate was further added and reacted to produce (meth)acrylic copolymer P3 having a Mw of 330,000, a glass transition temperature of -45°C, an ultraviolet-curable carbon-carbon double bond content of 38 (iodine value), and a hydroxyl value of 19.8 mgKOH / g.

[0096] Comparative Example 1 A dicing die bonding tape of Comparative Example 1 was produced in the same manner as in Example 1, except that in the production of the dicing die bonding tape of Example 1 above, the blending amount of NISSO-PB TP-1001 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene having an isocyanate group introduced at the end, solvent diluted type, resin content 50% by mass) was changed to 76 parts by mass (resin blending amount 38 parts by mass).

[0097] Comparative Example 2 A dicing die bonding tape of Comparative Example 2 was produced in the same manner as in Example 1, except that adhesive composition G4 prepared as follows was used instead of adhesive composition G1 in the production of the dicing die bonding tape of Example 1 above. Adhesive composition G4 was prepared in the same manner as in Example 1, except that 30 parts by mass of NISSO-PB JP-100 (trade name, manufactured by Nippon Soda Co., Ltd., epoxidized 1,2-polybutadiene) was used instead of 49 parts by mass of liquid bisphenol A-type epoxy resin (manufactured by Nippon Steel Epoxy Co., Ltd., trade name "YD-128", Mw 400, epoxy equivalent 190 g / eq) in adhesive composition G1 of Example 1 above.

[0098] Comparative Example 3 In the preparation of the dicing die bonding tape of Example 1 above, the amount of (meth)acrylic copolymer P1 was changed from 100 parts by mass to 70 parts by mass, and 30 parts by mass of NISSO-PB G-3000 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene having hydroxyl groups at both ends) was further used, and 6 parts by mass of Coronate L (trade name, manufactured by Tosoh Corporation, polyisocyanate compound) was used instead of 30 parts by mass of NISSO-PB TP-1001 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene having isocyanate groups introduced at the ends, solvent-diluted type, resin content 50% by mass) as the curing agent. The dicing die bonding tape of Comparative Example 3 was prepared in the same manner as in Example 1, except that

[0099] Comparative Example 4 A dicing die bonding tape of Comparative Example 4 was produced in the same manner as in Comparative Example 3, except that in the production of the dicing die bonding tape of Comparative Example 3, 30 parts by mass of NISSO-PB GI-3000 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene with hydrogenated hydroxyl groups at both ends) was used instead of 30 parts by mass of NISSO-PB G-3000 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene with hydroxyl groups at both ends).

[0100] Comparative Example 5 An attempt was made to produce a dicing die bonding tape of Comparative Example 5 in the same manner as in Example 1, except that in the production of the dicing die bonding tape of Example 1 described above, 100 parts by mass of NISSO-PB GI-3000 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene with hydrogenated hydroxyl groups at both ends) was used instead of 100 parts by mass of the (meth)acrylic copolymer P1, and no curing agent was used, but a pressure-sensitive adhesive layer could not be formed.

[0101] Comparative Example 6 An attempt was made to produce a dicing die bonding tape of Comparative Example 6 in the same manner as in Example 1, except that in the production of the dicing die bonding tape of Example 1, 100 parts by mass of NISSO-PB G-3000 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene having hydroxyl groups at both ends) was used instead of 100 parts by mass of the (meth)acrylic copolymer P1, and no curing agent was used; however, it was not possible to form a pressure-sensitive adhesive layer.

[0102] Comparative Example 7 A dicing die bonding tape of Comparative Example 7 was produced in the same manner as in Example 1, except that in the production of the dicing die bonding tape of Example 1, 6 parts by mass of Coronate L (trade name, manufactured by Tosoh Corporation, polyisocyanate compound) was used instead of 30 parts by mass of NISSO-PB TP-1001 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene with terminal isocyanate groups, solvent-diluted type, resin content 50% by mass).

[0103] Comparative Example 8 A dicing die bonding tape of Comparative Example 8 was produced in the same manner as in Example 6, except that in the production of the dicing die bonding tape of Example 6, 6 parts by mass of Coronate L (trade name, manufactured by Tosoh Corporation, polyisocyanate compound) was used instead of 30 parts by mass of NISSO-PB TP-1001 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene with terminal isocyanate groups, solvent-diluted type, resin content 50% by mass).

[0104] Comparative Example 9 A dicing die bonding tape of Comparative Example 9 was produced in the same manner as in Example 7, except that in the production of the dicing die bonding tape of Example 7, 6 parts by mass of Coronate L (trade name, manufactured by Tosoh Corporation, polyisocyanate compound) was used instead of 30 parts by mass of NISSO-PB TP-1001 (trade name, manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene with terminal isocyanate groups, solvent-diluted type, resin content 50% by mass).

[0105] The obtained pressure-sensitive adhesive tapes, adhesive films, and dicing die bonding tapes were evaluated as follows, and the results are shown in Tables 1-1 and 1-2 (collectively referred to as "Table 1").

[0106] [1. Compatibility] The adhesive layer (12) of the adhesive tape (15) was visually observed, and transparency was evaluated as "◯", and opaqueness was evaluated as "×".

[0107] [2. Surface Free Energy] (1) Preparation of a sample for contact angle measurement The substrate film (11) side of the adhesive tape (15) was fixed to a wafer with a flat surface using double-sided tape, and then the adhesive layer (12) was exposed to a high-pressure mercury lamp with an integrated irradiation dose of 200 mJ / cm. ２The adhesive layer (12) was irradiated with ultraviolet light so that the contact angle was measured. A sample for measuring the contact angle of the adhesive layer (12) after ultraviolet light irradiation was prepared. The release liner side of the adhesive film was fixed to a wafer with a flat surface using double-sided tape, and a sample for measuring the contact angle of the adhesive layer (13) was prepared. (2) Measurement of Contact Angle Diiodomethane, ethylene glycol, and pure water were dropped at five different locations on the adhesive layer (12) or adhesive layer (13) after ultraviolet light irradiation in each contact angle measurement sample. The contact angle θ of each sample was measured using an automatic contact angle meter DMo-601 (trade name) manufactured by Kyowa Interface Science Co., Ltd., and the average value of the five locations was taken as the contact angle θ. The measurement was performed at room temperature (23°C). The contact angle of the adhesive layer (12) after ultraviolet light irradiation was measured after allowing it to stand at room temperature (23°C) for 1 hour to stabilize the temperature of the adhesive layer. (3) Calculation of Surface Free Energy The values ​​of the contact angle θ (average of five points) of diiodomethane, ethylene glycol, and pure water obtained above were substituted into the "Extended Hawks' Equation of Hata and Kitazaki (Reference: Yasuaki Kitazaki, Toshio Hata: Japan Adhesion Association Journal, 8, (3) 131 (1972))" shown below, and the surface free energy (γ in the following equation) of the pressure-sensitive adhesive layer (12) surface and the adhesive layer (13) surface before and after ultraviolet irradiation was calculated. Ｓ : surface free energy of the solid) was calculated.

[0108]

[0109] [3. Peeling Force] A test piece measuring 25 mm in width and 100 mm in length was taken from the dicing die bonding tape obtained above, and a test piece for measuring the peeling force between the adhesive layer (13) and the pressure-sensitive adhesive layer (12) of the pressure-sensitive adhesive tape (15) before ultraviolet irradiation was prepared. The obtained test piece was irradiated with a high-pressure mercury lamp from the adhesive layer (13) side with an integrated irradiation dose of 200 mJ / cm. ２By irradiating ultraviolet light so that the peel strength between the adhesive layer (13) and the pressure-sensitive adhesive layer (12) of the pressure-sensitive adhesive tape (15) after ultraviolet irradiation was measured, a test piece for measuring the peel strength between the adhesive layer (13) and the pressure-sensitive adhesive layer (12) of the pressure-sensitive adhesive tape (15) after ultraviolet irradiation was prepared. Using each test piece prepared as described above before and after ultraviolet irradiation, the peel strength between the adhesive layer (13) and the pressure-sensitive adhesive layer (12) of the pressure-sensitive adhesive tape (15) was measured by a 180° peel test in accordance with JIS (Japanese Industrial Standards) Z 0237 (2022). The test was carried out at a measurement temperature of 23°C and a peel speed of 300 mm / min.

[0110] [4. Pick-up property] The release liner of each dicing die bonding tape was peeled off, and the adhesive layer (13) side was heat-attached to a silicon wafer having a thickness of 50 μm at 70° C. for 10 seconds, and then the tape was diced into a 10 mm × 10 mm square. Thereafter, a high-pressure mercury lamp was used to irradiate the pressure-sensitive adhesive layer (12) with an integrated dose of 200 mJ / cm. ２ After irradiating with ultraviolet light so that the chips were uniform, a pick-up test was performed on 30 chips in the center of the silicon wafer using a die bonder (trade name "DB-800", manufactured by Hitachi High-Technologies Corporation) with a push-up pin at a height of 0.2 mm. Of the picked-up chips, those in which only the adhesive layer (13) peeled from the pressure-sensitive adhesive layer (12) was retained on the chip were considered to have been successfully picked up, and the pick-up success rate ({number of chips successfully picked up / 30 chips} x 100%) was calculated. The pick-up success rate was evaluated according to the following criteria. - Evaluation criteria - ◎: The pick-up success rate was 100%. ○: The pick-up success rate was 80% or more but less than 100%. ×: The pick-up success rate was less than 80%.

[0111] [5. Melt Viscosity] Each adhesive film (thickness 20 μm) was cut into a square measuring 5.0 cm length × 5.0 cm width, the release liner was peeled off, and the adhesive layers (13) were laminated together and bonded with a hand roller on a stage at 70 ° C. to obtain a test piece with a thickness of approximately 1.0 mm. For this test piece, the change in viscous resistance was measured using a rheometer (HAAKE MARS 40 (trade name), manufactured by Thermo Fisher Scientific) in the temperature range of 20 to 250 ° C. at a heating rate of 5 ° C. / min, and the melt viscosity (Pa s) at 70 ° C. was calculated from the obtained temperature-viscous resistance curve.

[0112]

[0113]

[0114] (Table Notes) (Adhesive layer (12)) P1 to P3: respectively represent the (meth)acrylic copolymers P1 to P3 prepared above. G-3000: NISSO-PB G-3000 (trade name), manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene having hydroxyl groups at both ends. GI-3000: NISSO-PB GI-3000 (trade name), manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene with hydrogenated hydroxyl groups at both ends. TP-1001: NISSO-PB TP-1001 (trade name), manufactured by Nippon Soda Co., Ltd., 1,2-polybutadiene having isocyanate groups introduced at the ends, solvent-diluted, resin content 50% by mass. Coronate L: trade name, manufactured by Tosoh Corporation, polyisocyanate compound. (Adhesive layer (13)) G1 to G4: respectively represent the adhesive compositions G1 to G4 prepared above. (Others) "-" indicates that the component is not contained. For base polymers 1 and 2, the type is shown in the upper row and the amount added is shown in the lower row. The content of the curing agent component means the content of the component derived from the curing agent containing a 1,2-polybutadiene skeleton per 100 parts by mass of the base polymer in the pressure-sensitive adhesive layer. ＊: In Comparative Examples 5 and 6, the pressure-sensitive adhesive layer could not be molded, so no measurement or evaluation was performed. Surface free energy (post-UV) means the surface free energy after ultraviolet irradiation. Peel strength (pre-UV) means the peel strength between the adhesive layer (13) and the pressure-sensitive adhesive layer (12) in the pressure-sensitive adhesive tape (15) before ultraviolet irradiation, and peel strength (post-UV) means the peel strength between the adhesive layer (13) and the pressure-sensitive adhesive layer (12) in the pressure-sensitive adhesive tape (15) after ultraviolet irradiation. The words in brackets [ ] indicate units.

[0115] The results in Table 1 reveal the following. The dicing die bonding tape of Comparative Example 1 is not a dicing die bonding tape of the present invention in that the content of the component (curing agent component) derived from the curing agent containing a 1,2-polybutadiene skeleton in the pressure-sensitive adhesive layer (12) is 30 parts by mass per 100 parts by mass of the base polymer. The dicing die bonding tape of Comparative Example 1 was inferior in that the pressure-sensitive adhesive layer (12) was cloudy and did not exhibit the compatibility required from the perspective of dicing die bonding tape manufacturing efficiency. As shown in Comparative Example 2, the surface free energy of the adhesive layer (13) was 39.7 mN / m, which is smaller than the surface free energy range of 40 to 70 mN / m specified in the present invention, and the chip pickup ability was inferior. Furthermore, the dicing die bonding tape of Comparative Example 3 is not a dicing die bonding tape of the present invention in that a base polymer having a 1,2-polybutadiene skeleton is used as the base polymer rather than the curing agent. The dicing die bonding tape of Comparative Example 3 had a cloudy adhesive layer (12) and also had poor chip pickup properties. The dicing die bonding tape of Comparative Example 4 was not a dicing die bonding tape of the present invention in that the curing agent constituting the adhesive layer (12) did not contain a 1,2-polybutadiene skeleton. The dicing die bonding tape of Comparative Example 4 was not a dicing die bonding tape of the present invention in that the curing agent constituting the adhesive layer (12) did not contain a 1,2-polybutadiene skeleton. The dicing die bonding tape of Comparative Example 4 was not a dicing die bonding tape of the present invention in that the curing agent constituting the adhesive layer (12) did not contain a 1,2-polybutadiene skeleton. Furthermore, as shown in Comparative Examples 5 and 6, when an attempt was made to form the adhesive layer (12) using a base polymer having a 1,2-polybutadiene skeleton or a hydrogenated 1,2-polybutadiene skeleton without using a curing agent, the adhesive layer (12) could not be molded, and a dicing die bonding tape could not be obtained. The dicing die bonding tapes of Comparative Examples 7 to 9 were not dicing die bonding tapes of the present invention in that the curing agent constituting the adhesive layer (12) did not contain a 1,2-polybutadiene skeleton. The dicing die bonding tapes of Comparative Examples 7 to 9 all exhibited poor chip pick-up properties.In contrast, the dicing die bonding tapes of Examples 1 to 7, which are dicing die bonding tapes defined in the present invention, have a surface free energy of the adhesive layer (13) in the range of 40 to 70 mN / m. Despite having a high surface free energy, the adhesive layer (12) does not become cloudy and has excellent compatibility because it has the specific pressure-sensitive adhesive layer (12) defined in the present invention. The peel force between the adhesive layer (13) and the pressure-sensitive adhesive layer (12) in the pressure-sensitive adhesive tape (15) before ultraviolet irradiation was 0.61 to 1.53 N / 25 mm, which means that the tape has sufficient adhesive strength required for dicing semiconductor wafers and also exhibits excellent pick-up properties.

[0116] While the present invention has been described in connection with embodiments thereof, we do not intend to limit our invention to any of the details of the description unless otherwise specified, and believe that the claims should be construed broadly without departing from the spirit and scope of the invention as set forth in the appended claims.

[0117] This application claims priority based on Japanese Patent Application No. 2024-052875, filed on March 28, 2024, the contents of which are incorporated herein by reference as part of the present specification.

[0118] REFERENCE SIGNS LIST 10 Dicing die bonding tape 11 Base film 12 Pressure sensitive adhesive layer 13 Adhesive layer 14 Surface protection tape 15 Pressure sensitive adhesive tape 20 Ring frame 25 Heater table W Wafer

Claims

1. A dicing die bonding tape comprising a substrate film, a pressure-sensitive adhesive layer, and an adhesive layer in contact with the pressure-sensitive adhesive layer, laminated in this order, wherein the pressure-sensitive adhesive layer has a structure in which a base polymer is crosslinked with a curing agent containing a 1,2-polybutadiene skeleton and is UV-curable, the content of the curing agent component per 100 parts by mass of the base polymer is 3 to 25 parts by mass, and the surface free energy of the adhesive layer is 40 to 70 mN / m.

2. The dicing die bonding tape according to claim 1, wherein the adhesive layer has a melt viscosity of 10,000 to 60,000 Pa·s at 70°C.

3. The dicing die bonding tape according to claim 1 or 2, wherein the adhesive layer contains a phenoxy resin.

4. The dicing die bonding tape according to any one of claims 1 to 3, wherein the surface free energy of the adhesive layer after ultraviolet irradiation is 30 to 39 mN / m.

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