JP7277380B2 - Adhesive films for semiconductors and adhesive sheets for semiconductors - Google Patents

Description

TECHNICAL FIELD The present invention relates to an adhesive film for semiconductors and an adhesive sheet for semiconductors.
This application claims priority based on Japanese Patent Application No. 2017-229522 filed in Japan on November 29, 2017, the content of which is incorporated herein.

A semiconductor adhesive film is used for fixing a semiconductor chip to a substrate or an electrode member. The lower the dielectric loss tangent of this adhesive film for semiconductors, the more the interference with other chips and devices is suppressed, the noise can be reduced, and the film can be used as a shield against electromagnetic waves.

Patent Document 1 discloses an adhesive film for embedding a first semiconductor element fixed on an adherend and fixing a second semiconductor element different from the first semiconductor element to the adherend, , discloses that an adhesive film having a dielectric constant of 4.00 or less at 1 MHz after heat curing suppresses corrosion of connection structures and conduction between wirings, and can manufacture highly reliable semiconductor devices.

JP 2015-122433 A

However, Patent Literature 1 does not disclose any adhesive film for semiconductors in which the dielectric loss tangent is lowered and the electromagnetic wave shielding property is improved by adding an inorganic filler.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an adhesive film for a semiconductor which has a low dielectric loss tangent and excellent electromagnetic wave shielding properties.

The inventors have found that by adding 15% by mass or more and 70% by mass or less of titanium oxide to a thermosetting resin, it is possible to obtain an adhesive film for semiconductors having a low dielectric loss tangent after thermosetting and excellent electromagnetic wave shielding properties. and completed the present invention.
That is, the present invention provides an adhesive film for semiconductors and an adhesive sheet for semiconductors having the following features.
[1] An adhesive film for a semiconductor, containing a thermosetting adhesive and 15% by mass or more and 70% by mass or less of a titanium oxide filler.
[2] The adhesive film for semiconductors according to [1], which has a dielectric loss tangent at 1 MHz after heat curing of 0.01 or less.
[3] An adhesive sheet for a semiconductor, comprising a release sheet and the adhesive film for a semiconductor according to [1] or [2] provided thereon.

ADVANTAGE OF THE INVENTION According to this invention, the dielectric loss tangent after thermosetting is low, and the adhesive film for semiconductors excellent in electromagnetic wave shielding property is provided.

1 is a cross-sectional view of an adhesive sheet for a semiconductor according to one embodiment of the present invention; FIG. 1 is a cross-sectional view of a semiconductor device using an adhesive film for a semiconductor according to one embodiment of the present invention; FIG.

The adhesive film for semiconductors of the present invention contains a thermosetting adhesive and 15% by mass or more and 70% by mass or less of titanium oxide filler. In addition, unless otherwise specified, in this specification, % by mass means the ratio of each component when the adhesive film for semiconductor is taken as 100% by mass.

The adhesive film for a semiconductor of the present invention can reduce the dielectric loss tangent and is excellent in electromagnetic wave shielding properties by containing 15% by mass or more and 70% by mass or less of the titanium oxide filler.

The thermosetting adhesive constituting the adhesive film for semiconductor of the present invention preferably contains a thermosetting component and a binder polymer component.

Thermosetting components include, for example, epoxy resins, phenolic resins, melamine resins, urea resins, polyimide resins, benzoxazine resins, and mixtures thereof. Among these, epoxy resins, phenolic resins and mixtures thereof are preferably used.

Epoxy resin has the property of forming a three-dimensional network and forming a strong coating when heated. As such an epoxy resin, various known epoxy resins are conventionally used, but those having a molecular weight of about 200 to 2,000 are generally preferable, and those having a molecular weight of 300 to 500 are particularly preferable. Further, it is preferable to use a blend of an epoxy resin having a molecular weight of 310 to 400 which is normally liquid and an epoxy resin having a molecular weight of 400 to 2500, especially 500 to 2000 which is solid at room temperature. Also, the epoxy equivalent of the epoxy resin is preferably 50 to 5000 g/eq.
As used herein, "epoxy equivalent" means the number of grams (g/eq) of an epoxy compound containing 1 gram equivalent of an epoxy group, and can be measured according to the method of JIS K 7236:2001.

Specific examples of such epoxy resins include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolak, and cresol novolak; glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid and tetrahydrophthalic acid; glycidyl-type or alkylglycidyl-type epoxy resins in which active hydrogens bonded to nitrogen atoms such as aniline isocyanurate are substituted with glycidyl groups or alkylglycidyl groups; Cyclohexanediepoxide, 3,4-epoxycyclohexylmethyl-3,4-dicyclohexanecarboxylate, 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane, etc. and so-called alicyclic epoxides in which epoxy is introduced by, for example, oxidation of carbon-carbon double bonds in the molecule. In addition, an epoxy resin having a biphenyl skeleton, a dicyclopentadiene skeleton, a dicyclohexadiene skeleton, a naphthalene skeleton, or the like can also be used.

Among these, bisphenol-based glycidyl type epoxy resins, o-cresol novolak type epoxy resins, phenol novolak type epoxy resins and epoxy resins having a dicyclopentadiene skeleton are preferably used. These epoxy resins can be used singly or in combination of two or more.

When an epoxy resin is used, it is preferable to use a thermosetting latent epoxy resin curing agent as an auxiliary agent in combination with the thermosetting adhesive. A heat-activated latent epoxy resin curing agent is a type of curing agent that does not react with epoxy resin at room temperature, but is activated by heating at a certain temperature or higher and reacts with epoxy resin. Heat-activated latent epoxy resin curing agents are activated by a method of generating active species (anions, cations) through a chemical reaction by heating; a method in which a curing reaction is initiated by dissolving and compatibilizing with a molecular sieve;

Specific examples of heat-activated latent epoxy resin curing agents include various onium salts, dibasic acid dihydrazide compounds, dicyandiamide, amine adduct curing agents, and high melting point active hydrogen compounds such as imidazole compounds. These heat-activated latent epoxy resin curing agents can be used singly or in combination of two or more. The amount of the heat-activatable latent epoxy resin curing agent as described above is preferably 0.1 to 20 parts by mass, particularly preferably 0.2 to 10 parts by mass, and more preferably 0.1 to 20 parts by mass, with respect to 100 parts by mass of the epoxy resin. It is used in a proportion of 3 to 5 parts by mass.

As the phenolic resin, alkylphenols, polyhydric phenols, condensates of phenols such as naphthol and aldehydes are used without particular limitation. Specifically, phenol novolak resin, o-cresol novolak resin, p-cresol novolak resin, t-butylphenol novolak resin, dicyclopentadiene cresol resin, polyparavinylphenol resin, bisphenol A type novolak resin, or modified products thereof etc. are used.

The phenolic hydroxyl groups contained in these phenolic resins can easily undergo an addition reaction with the epoxy groups of the epoxy resins by heating to form cured products with high impact resistance. Therefore, an epoxy resin and a phenol resin may be used together.

The binder polymer component can impart appropriate tackiness to the adhesive film for semiconductor and improve the operability of the adhesive sheet for semiconductor. The weight average molecular weight of the binder polymer is usually in the range of 20,000 to 2,000,000, preferably 50,000 to 1,500,000, and particularly preferably 100,000 to 1,000,000. If the molecular weight is too low, film formation of the adhesive film for semiconductors will be insufficient, and if it is too high, the compatibility with other components will be poor, resulting in an impediment to uniform film formation. When the mass average molecular weight is in the range of 20,000 to 2,000,000, preferably 50,000 to 1,500,000, and particularly preferably 100,000 to 1,000,000, the film of the adhesive film for semiconductor is sufficiently formed, and other components It has good compatibility with and forms a uniform film. Examples of such binder polymers include acrylic polymers, polyester resins, phenoxy resins, urethane resins, silicone resins, rubber polymers, etc. Acrylic polymers are particularly preferred.
In this specification, unless otherwise specified, the term "mass average molecular weight" is a polystyrene-equivalent value measured by a gel permeation chromatography (GPC) method.

Examples of acrylic polymers include (meth)acrylic acid ester copolymers composed of (meth)acrylic acid alkyl ester monomers and structural units derived from other (meth)acrylic acid derivatives. Here, the (meth)acrylic acid alkyl ester monomer is preferably a (meth)acrylic acid alkyl ester having an alkyl group having 1 to 18 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, ( Propyl meth)acrylate, butyl (meth)acrylate, and the like are used. Examples of (meth)acrylic acid derivatives include (meth)acrylic acid, glycidyl (meth)acrylate, and hydroxyethyl (meth)acrylate.

Among the above, when a glycidyl group is introduced into the acrylic polymer, compatibility with the epoxy resin as the thermosetting component described above is improved, the glass transition temperature (Tg) of the adhesive film for semiconductors after curing is increased, and heat resistance is improved. improve sexuality. In addition, among the above, if a hydroxyl group is introduced into the acrylic polymer using hydroxyethyl acrylate or the like as a structural unit, it is possible to control the adhesiveness to the semiconductor and adhesive physical properties.

When an acrylic polymer is used as the binder polymer, the weight average molecular weight of the polymer is preferably 100,000 or more, particularly preferably 150,000 to 1,000,000. The glass transition temperature (Tg) of the acrylic polymer is usually 40°C or less, preferably about -70 to 20°C.
As used herein, "glass transition temperature (Tg)" is expressed as the temperature at the inflection point of the DSC curve obtained by measuring the DSC curve of a sample using a differential scanning calorimeter.

The blending ratio of the thermosetting component and the binder polymer component is preferably 50 to 1500 parts by mass, particularly preferably 70 to 1200 parts by mass, more preferably 70 to 1200 parts by mass of the thermosetting component per 100 parts by mass of the binder polymer component. It is preferable to blend 80 to 1000 parts by mass. When the thermosetting component and the binder polymer component are blended in such a ratio, the film exhibits appropriate tackiness before curing, can be stably applied, and exhibits excellent film strength after curing. is obtained.

The content of the thermosetting adhesive in the adhesive film for semiconductors of the present invention is preferably 20 to 75% by mass, more preferably 20 to 50% by mass, based on the total mass of the adhesive film for semiconductors. More preferably, 20 to 40% by mass is particularly preferable.
The content of the thermosetting component with respect to the total content of the thermosetting adhesive is preferably 30 to 95% by mass, more preferably 40 to 95% by mass, and 40 to 92% by mass. is particularly preferred. Further, the content of the binder polymer component with respect to the total content of the thermosetting adhesive is preferably 5 to 70% by mass, more preferably 5 to 60% by mass, and 8 to 60% by mass. It is particularly preferred to have However, the sum total of the content of the thermosetting component and the content of the binder polymer component does not exceed 100% by mass.

The adhesive film for semiconductors of the present invention may contain a coupling agent. By using a coupling agent having a functional group that reacts with an inorganic compound and a functional group that reacts with an organic functional group, the adhesion and adhesion of the adhesive film for a semiconductor to an adherend can be improved. Moreover, by using the coupling agent, the water resistance of the cured product obtained by curing the adhesive film for semiconductor can be improved without impairing the heat resistance thereof.

The coupling agent is preferably a compound having a functional group that reacts with a functional group possessed by an acrylic polymer, epoxy resin, phenol resin, or the like, and is preferably a silane coupling agent.
Preferred silane coupling agents include γ-glycidoxypropyltrimethoxysilane (also referred to as 3-glycidoxypropyltrimethoxysilane), γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldisilane. Ethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-(methacryloxypropyl)trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropyl trimethoxysilane, N-6-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, Silane compounds such as γ-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazolesilane, and these A hydrolytic condensate of a silane compound can be exemplified.
A coupling agent may be used individually by 1 type, and may use 2 or more types together.

When a coupling agent is used, the content of the coupling agent in the adhesive film for semiconductor is preferably 0.03 to 20 parts by mass with respect to 100 parts by mass of the total content of the thermosetting component and the binder polymer. , more preferably 0.05 to 10 parts by mass, particularly preferably 0.1 to 5 parts by mass. If the content of the coupling agent is too small, the above-mentioned effects of using the coupling agent may not be obtained, and if the content of the coupling agent is too large, outgassing may occur. By setting the content of the coupling agent within the above range, the adhesiveness and adhesion of the adhesive film for semiconductors to the adherend can be improved without outgassing, and the adhesive film for semiconductors can be cured. The water resistance of the resulting cured product can be improved without impairing its heat resistance.

(Titanium oxide filler)
The adhesive film for semiconductors of the present invention contains 15% by mass or more and 70% by mass or less of titanium oxide filler relative to the total mass of the adhesive film for semiconductors, preferably 20% by mass or more and 70% by mass or less. , more preferably 20% by mass or more and 60% by mass or less, and particularly preferably 30% by mass or more and 60% by mass. By setting the content of the titanium oxide filler to the above lower limit or more, the dielectric loss tangent of the adhesive film for semiconductor can be further reduced, and the electromagnetic wave shielding property can be further improved.

The titanium oxide filler used in the adhesive film for a semiconductor of the present invention may be of the anatase type, the rutile type, or a mixture of the anatase type and the rutile type. In addition, in order to impart hydrophilicity or water repellency to the titanium oxide particles, a titanium oxide filler that has undergone surface modification can also be used. The surface treatment may be an inorganic surface treatment or an organic surface treatment.

The titanium oxide filler preferably has a granular shape. The average particle size of the titanium oxide filler is preferably 10 nm or more and 500 nm or less, more preferably 30 nm or more and 400 nm or less. By setting the average particle size of the titanium oxide filler within the above range, it becomes easier to adjust the dielectric loss tangent of the adhesive film for semiconductors.

The adhesive film for semiconductors of the present invention may contain general-purpose additives within a range that does not impair the effects of the present invention.
The general-purpose additive may be a known one, can be arbitrarily selected according to the purpose, and is not particularly limited, but preferable examples include fillers other than titanium oxide, plasticizers, antioxidants, colorants (dyes, pigments), gettering agents, and the like.

The filler other than titanium oxide may be either an organic filler or an inorganic filler (excluding titanium oxide), but an inorganic filler (excluding titanium oxide) is preferred.
Preferable inorganic fillers include, for example, powders of silica, alumina, talc, calcium carbonate, red iron oxide, silicon carbide, and boron nitride; beads obtained by spheroidizing these inorganic fillers; surface-modified products of these inorganic fillers; single crystal fiber; glass fiber and the like.
Among these, the inorganic filler is preferably silica or alumina.
The silica powder (silica filler) may have a surface modifying group such as an organic group on its surface.

The filler other than titanium oxide preferably has a granular shape. The average particle size of the filler other than titanium oxide may be 1 nm to 25 μm, 20 nm to 1000 nm, or 30 nm to 200 nm.
The average particle diameter is the volume average diameter measured by the dynamic light scattering method using a particle size distribution analyzer.

The fillers other than titanium oxide that the adhesive film for semiconductor may contain may be of one type or two or more types.

The dielectric loss tangent at 1 MHz after thermosetting of the adhesive film for semiconductor of the present invention is preferably 0.01 or less. When the dielectric loss tangent at 1 MHz after thermosetting of the adhesive film for semiconductor is equal to or less than the upper limit, the electromagnetic wave shielding property can be further improved.
Moreover, the dielectric loss tangent is preferably 0.0001 or more.
The dielectric loss tangent at 1 MHz after thermosetting of the adhesive film for semiconductor of the present invention can be measured by the method described later.

The adhesive film for semiconductors may consist of one layer (single layer) or may consist of two or more layers. When the adhesive film for a semiconductor consists of multiple layers, these multiple layers may be the same or different, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.

Although the thickness of the adhesive film for semiconductors is not particularly limited, it is preferably 1 to 100 μm, more preferably 3 to 40 μm. When the thickness of the adhesive film for semiconductors is at least the above lower limit, a higher adhesive strength to adherends such as semiconductor chips can be obtained. Moreover, since the thickness of the adhesive film for a semiconductor is equal to or less than the upper limit, it is possible to manufacture the film with a stable thickness.
Here, the "thickness of the adhesive film for semiconductors" means the thickness of the entire adhesive film for semiconductors. means the total thickness of the layers of

As used herein, the term “thickness” refers to a value represented by the average value of thickness measured at any five points, using a constant pressure thickness measuring instrument in accordance with JIS K 6783: 1994, measuring a probe diameter of 5 mm, applying pressure. It can be measured with a pressure load of 1.22N.

The adhesive strength (N/25 mm) of the semiconductor adhesive film to the semiconductor wafer before curing can be measured by the following method.
That is, a laminated sheet of an adhesive film for a semiconductor and an adhesive tape having a width of 25 mm and an arbitrary length is produced. This laminated sheet is obtained by laminating an adhesive film for a semiconductor on the adhesive surface of an adhesive tape. Next, this laminate sheet is attached to a semiconductor wafer with an adhesive film for semiconductors heated to 40 to 70° C. to produce a laminate in which the adhesive tape, the adhesive film for semiconductors and the semiconductor wafer are laminated in this order. Immediately after the production, this laminate was left to stand in an environment of 23° C. for 30 minutes, and then the laminated sheet of the adhesive film for semiconductor and the adhesive tape was removed from the semiconductor wafer, and the surfaces of the adhesive film for semiconductor and the semiconductor wafer that were in contact with each other were removed. So-called 180° peeling is performed so that the two films form an angle of 180° with each other at a peeling speed of 300 mm/min. The peel force at this time is measured, and the measured value is defined as the adhesive force (N/25 mm) of the semiconductor adhesive film to the semiconductor wafer before curing. The length of the laminated sheet to be measured is not particularly limited as long as the peel force can be stably measured, but it is preferably 100 to 300 mm.

The adhesive strength of the semiconductor adhesive film to a semiconductor wafer before curing is preferably 100 mN/25 mm or more, and can be, for example, 200 mN/25 mm or more, 300 mN/25 mm or more, but is not limited thereto. .
Also, the upper limit of the adhesive strength is not particularly limited, and can be selected from, for example, 10 N/25 mm, 800 mN/25 mm, 600 mN/25 mm, etc., but these are just examples.
For example, the adhesive strength can be 100 mN/25 mm or more and 10 N/25 mm or less, 200 mN/25 mm or more and 800 mN/25 mm or less, or 300 mN/25 mm or more and 600 mN/25 mm or less.

The adhesive force of the adhesive film for semiconductors before curing to a semiconductor wafer can be adjusted as appropriate by adjusting the types and amounts of components contained in the adhesive film for semiconductors, for example.
For example, by adjusting the molecular weight of the binder polymer, the ratio of each monomer component constituting the binder polymer, the softening point of the thermosetting component, and the content of each component of the adhesive film for semiconductors, the adhesive film for semiconductors can be produced. The adhesive force can be easily adjusted.
However, these adjustment methods are only examples.

The shear strength of the adhesive film for semiconductors can be measured by the following method.
A silicon wafer with a thickness of 350 μm and polished #2000 was attached with an adhesive film for semiconductors on the back surface, diced into 2 mm×2 mm pieces, and picked up together with the adhesive film for semiconductors. It is attached to a copper plate having a thickness of 30 mm and a thickness of 300 μm, and cured at 160° C. for 60 minutes to obtain a sample. Using a bond tester (series 4000, manufactured by Daisy), the shear bond strength (N/2 mm×2 mm) of the sample is measured. At the time of measurement, the sample is held on a hot plate at 250° C. for 30 seconds, and the load speed is measured at 0.2 mm/sec.

The shear strength of the adhesive film for semiconductors is preferably 2 N/(2 mm×2 mm) or more. When the adhesive film for semiconductors has a shear strength of 2 N/(2 mm×2 mm) or more, the adhesiveness as an adhesive film for semiconductors is excellent.

The adhesive film for semiconductors of the present invention is prepared by mixing a thermosetting adhesive, a titanium oxide filler, and other additives, and diluting with an organic solvent such as ethyl acetate if necessary. It can be produced by preparing an adhesive film coating agent, applying it to an adherend such as a release sheet, and then drying it.

The adhesive film for semiconductor of the present invention can be used as an adhesive film between a substrate and a semiconductor. Since the adhesive film for semiconductors of the present invention has a low dielectric loss tangent, interference with other semiconductor chips and devices is suppressed, noise can be reduced, and it can be used as a shield against electromagnetic waves.

The adhesive film for semiconductors of the present embodiment is an adhesive film for semiconductors containing a thermosetting adhesive and a titanium oxide filler of 15% by mass or more and 70% by mass or less. It preferably contains a thermosetting component and a binder polymer component. As the thermosetting component, epoxy resins, phenolic resins, and mixtures thereof are preferable, and bisphenol-based glycidyl-type epoxy resins, o-cresol novolac-type epoxy resins, phenol novolak-type epoxy resins, and epoxy resins having a dicyclopentadiene skeleton are more preferable. preferable. As the binder polymer component, an acrylic polymer is preferred.
Further, in the adhesive film for semiconductor of the present embodiment, the content of the thermosetting adhesive is 20% by mass or more and 75% by mass or less, and the content of the titanium oxide filler is 20% by mass or more and 70% by mass or less. More preferably, the content of the thermosetting adhesive is 20% by mass or more and 75% by mass or less, and the content of the titanium oxide filler is 20% by mass or more and 60% by mass. The average particle size of the titanium oxide filler is preferably 10 nm or more and 500 nm or less.

[Adhesive sheets for semiconductors]
The present invention provides a semiconductor adhesive sheet comprising a release sheet and the semiconductor adhesive film of the present invention provided thereon. FIG. 1 is a cross-sectional view of an adhesive sheet for semiconductors according to an embodiment of the present invention. As shown in FIG. 1 , the semiconductor adhesive sheet 2 according to this embodiment comprises an adhesive film 1 for semiconductors and a release sheet 21 . However, the release sheet 21 is to be released when the adhesive film 1 for semiconductors is used.

The release sheet 21 protects the adhesive film for semiconductors until the adhesive film for semiconductors 1 is used, and is not necessarily required. The configuration of the release sheet 21 is arbitrary, and exemplified are a plastic film whose film itself is releasable from the semiconductor adhesive film 1, and a plastic film subjected to release treatment with a release agent or the like. Specific examples of plastic films include polyester films such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, a silicone-based, fluorine-based, long-chain alkyl-based, or the like can be used. Although the thickness of the release sheet 21 is not particularly limited, it is usually about 20 to 250 μm.

The release sheet 21 as described above may also be laminated on the surface of the adhesive film for semiconductor 1 opposite to the release sheet 21 (upper surface in FIG. 1). In this case, it is preferable to increase the release force of one release sheet 21 to make it a heavy release type release sheet, and to decrease the release force of the other release sheet 21 to make it a light release type release sheet.

In order to manufacture the semiconductor adhesive sheet 2 according to the present embodiment, the release surface of the release sheet 21 (a surface having releasability; usually a surface subjected to a release treatment, but not limited to this) is coated with a semiconductor. to form an adhesive film 1 for Specifically, a semiconductor adhesive film coating agent containing a thermosetting adhesive constituting the semiconductor adhesive film 1 is prepared, and coated with a roll coater, a knife coater, a roll knife coater, an air knife coater, a die coater, and a bar coater. , a gravure coater, a curtain coater, or the like on the release surface of the release sheet 21 and dried to form the adhesive film 1 for a semiconductor.

The drying conditions for the adhesive film coating agent for semiconductors are not particularly limited. , 70 to 130° C. for 10 seconds to 5 minutes.

(How to use the adhesive sheet for semiconductors)
A method of using the adhesive sheet 2 for a semiconductor according to this embodiment will be described below with reference to FIG.
The semiconductor adhesive sheet 2 is attached onto the substrate 32 with the surface of the semiconductor adhesive film 1 (the surface opposite to the release sheet 21) as the adhesive surface. Next, after peeling off the release sheet 21 from the semiconductor adhesive sheet 2, the semiconductor chip 31 is attached to the surface of the semiconductor adhesive film 1, and the semiconductor adhesive film 1 is cured.

The present invention will be described in more detail below with reference to specific examples. However, the present invention is by no means limited to the examples shown below.

[Example 1]
The following components were mixed at the compounding ratio (in terms of solids) shown in Table 1 and diluted with methyl ethyl ketone so that the solids concentration was 60% by mass to prepare a coating agent for adhesive films for semiconductors.
(a): Acrylic copolymer (manufactured by Nagase ChemteX "Teisan Resin SG-P3"
(b)-1: Bisphenol F type epoxy resin (“jER YL983U” manufactured by Mitsubishi Chemical Corporation)
(b)-2: Dicyclopentadiene skeleton epoxy resin (“XD-1000” manufactured by Nippon Kayaku Co., Ltd.)
(c): o-cresol type novolac resin (“Phenolite KA-1160” manufactured by DIC)
(d): Imidazole-based heat-activated latent epoxy resin curing agent (“Curesol 2PHZ-PW” manufactured by Shikoku Kasei Kogyo Co., Ltd.)
(e): Silane coupling agent ("X-41-1056" manufactured by Shin-Etsu Chemical Co., Ltd.)
(f): Titanium oxide-containing filler (“DIMIC SZ 7030 White” manufactured by Dainichiseika Kogyo Co., Ltd., average particle size 300 nm) (about 60% by mass of the total amount of titanium oxide-containing filler is titanium oxide)
(g): Silica filler (“SC2050MA” manufactured by Admatechs, average particle size 0.5 μm)

After coating the adhesive film coating agent for semiconductors on a release sheet (SP-PET381031, manufactured by Lintec), which is a polyethylene terephthalate film that has been subjected to release treatment on one side, it is dried in an oven at 100 ° C. for 1 minute. An adhesive sheet for a semiconductor was obtained in which an adhesive film for a semiconductor having a thickness of 30 μm was provided on a release sheet.

[Example 2]
An adhesive sheet for semiconductor was produced in the same manner as in Example 1, except that the blending amounts of the components constituting the adhesive film for semiconductor were changed as shown in Table 1.

[Comparative Examples 1 and 2]
An adhesive sheet for semiconductor was produced in the same manner as in Example 1, except that the types and blending amounts of the components constituting the adhesive film for semiconductor were changed as shown in Table 1.

[Comparative Examples 3 and 4]
Silica filler (g) [“SC2050MA” manufactured by Admatechs; average particle size 0.5 μm] was used instead of titanium oxide filler, and the compounding amounts of each component constituting the adhesive film for semiconductor were as shown in Table 1. An adhesive sheet for a semiconductor was manufactured in the same manner as in Example 1, except that the method was changed.

[Test Example 1] <Dielectric loss tangent evaluation>
After peeling off the release sheet from each adhesive sheet for semiconductors obtained in Examples 1 and 2 and Comparative Examples 1 to 4 and laminating a plurality of adhesive films for semiconductors, the laminate was punched out to obtain a laminate having a diameter of 10 mm and a thickness of 1 mm. A sample piece was obtained. The sample piece was heat cured in a 160° C. oven for 1 hour. Using 4194A manufactured by Hewlett-Packard, the dielectric loss tangent at 1 MHz was calculated according to JIS C 2138. Table 1 shows the results.

[Test Example 2] <Evaluation of shear strength>
A silicon wafer with a thickness of 350 μm and polished #2000 was attached with an adhesive film for semiconductors on the back surface, diced into 2 mm×2 mm pieces, and picked up together with the adhesive film for semiconductors. It is attached to a copper plate having a thickness of 30 mm and a thickness of 300 μm, and cured at 160° C. for 60 minutes to obtain a sample. Using a bond tester (series 4000, manufactured by Daisy), the shear bond strength (N/(2 mm×2 mm)) of the sample is measured. At the time of measurement, the sample was held on a hot plate at 250° C. for 30 seconds, and the load speed was measured at 0.2 mm/sec. A sample with a shear strength of 2 N/(2 mm×2 mm) or more was evaluated as ◯, and a sample with a shear strength of less than 2 N/(2 mm×2 mm) was evaluated as ×. Table 1 shows the results.

As is clear from Table 1, the adhesive films for semiconductors of Comparative Examples 1 and 2, in which the content of the titanium oxide filler is less than 15% by mass, had a dielectric loss tangent exceeding 0.01. The dielectric loss tangent of the adhesive films for semiconductors of Examples 1 and 2, which had a filler content of 15% by mass or more, was 0.01 or less. Moreover, the adhesive films for semiconductors of Examples 1 and 2 both had good shear strength.
Moreover, the dielectric loss tangent of the semiconductor adhesive films of Comparative Examples 3 and 4, which used silica filler instead of titanium oxide filler, exceeded 0.01.

The adhesive film for semiconductors of the present invention has a low dielectric loss tangent at 1 MHz and is excellent in shielding properties against electromagnetic waves.

DESCRIPTION OF SYMBOLS 1... Adhesive film for semiconductors 2... Adhesive sheet for semiconductors 21... Release sheet 3... Semiconductor device 31... Semiconductor chip 32... Substrate

Claims (3)

containing a thermosetting adhesive and 15% by mass or more and 70% by mass or less of titanium oxide filler,
An adhesive film for a semiconductor , having a dielectric loss tangent at 1 MHz after heat curing of 0.01 or less . 2. The adhesive film for a semiconductor according to claim 1 , wherein said titanium oxide filler has an average particle size of 10 nm or more and 500 nm or less . An adhesive sheet for a semiconductor, comprising a release sheet and the adhesive film for a semiconductor according to claim 1 or 2 provided on the release sheet.

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