TW201910463A - Adhesive film for semiconductor and semiconductor back sheet - Google Patents

Abstract

The present application provides an adhesive film for a semiconductor which includes a heat-curable adhesive agent and 25 to 80 mass % of a barium titanate filer.

Description

Adhesive film for semiconductor and adhesive sheet for semiconductor

The present invention relates to an adhesive film for semiconductors and an adhesive sheet for semiconductors.

This application claims the priority of Japanese Patent Application No. 2017-144519 filed in Japan on July 26, 2017, and the contents of the application are incorporated herein.

Examples of the adhesive film for semiconductors include a film that bonds a sealing resin that seals a sensor for fingerprint authentication and a cover. In recent years, the structure of the sensor used for fingerprint authentication is to read the unevenness of the fingerprint in the form of an electrostatic capacitance type sensor by charge, and therefore requires a high relative dielectric constant.

Patent Literature 1 discloses an electrostatic capacitance type fingerprint sensor. The electrostatic capacitance type fingerprint sensor is provided with an epoxy resin and an inorganic filler in an insulator that seals a detection electrode provided on a substrate.

[Prior Technical Literature]

[Patent Literature]

Patent Literature 1: International Publication No. 2015/146816.

However, in Patent Document 1, there is no disclosure on the sealing resin that seals the capacitance-type fingerprint sensor and the cover that protects the capacitance-type fingerprint sensor, etc. to produce a subsequent adhesive film.

Therefore, an object of the present invention is to provide an adhesive film for semiconductors that allows a sealing resin that seals a semiconductor such as a fingerprint authentication sensor to adhere to a member such as a cover that protects the semiconductor, and has a high relative dielectric constant after thermal curing. Excellent electrical characteristics.

The inventors have found that by adding a barium titanate filler of 25% by mass or more and 80% by mass or less to a thermosetting resin, an adhesive film for semiconductor having a high relative dielectric constant and excellent dielectric characteristics after thermosetting can be obtained To complete the present invention.

That is, the present invention provides an adhesive film for semiconductors and an adhesive sheet for semiconductors having the following characteristics.

[1] An adhesive film for semiconductors containing a thermosetting adhesive and a barium titanate filler of 25% by mass or more and 80% by mass or less.

[2] The adhesive film for semiconductor according to [1], wherein the average particle diameter of the barium titanate filler is 10 nm or more and 500 nm or less.

[3] The adhesive film for a semiconductor described in [1] or [2], wherein the adhesive film for a semiconductor has a light transmittance of 10% or less at a wavelength of 380 nm to 780 nm when the thickness is 20 μm.

[4] The adhesive film for semiconductor according to any one of [1] to [3], wherein the relative dielectric constant at 1 MHz after thermal curing of the adhesive film for semiconductor is 5.0 or more.

[5] The adhesive film for a semiconductor as described in any one of [1] to [4], wherein the adhesive film for a semiconductor is an adhesive film for an electrostatic capacitance type fingerprint sensor.

[6] An adhesive sheet for semiconductor provided with the adhesive film for semiconductor as described in any one of [1] to [5] on a release sheet.

According to the present invention, there is provided an adhesive film for a semiconductor having a high relative dielectric constant and excellent dielectric characteristics at 1 MHz after thermal curing.

1‧‧‧ Adhesive film for semiconductor

2‧‧‧adhesive film for semiconductor

3‧‧‧Electrostatic fingerprint sensor

21‧‧‧ peeling

31‧‧‧Protection cover

32‧‧‧Sealing resin

33‧‧‧ Fingerprint sensor

34‧‧‧Interlayer membrane

35‧‧‧ substrate

FIG. 1 is a cross-sectional view of a semiconductor bonding sheet according to an embodiment of the present invention.

2 is a cross-sectional view schematically showing an embodiment of an electrostatic capacitance type fingerprint sensor using the adhesive film for semiconductor of the present invention.

The adhesive film for a semiconductor of the present invention contains a thermosetting adhesive and a barium titanate filler of 25% by mass or more and 80% by mass or less.

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

Examples of thermosetting components include epoxy resins, phenol resins, melamine resins, urea resins, polyimide resins, benzoxazine resins, and mixtures thereof. Among these, epoxy resin, phenol resin and mixtures of these can be preferably used.

Epoxy resin has the property of forming a three-dimensional network when heated and forming a strong coating. As such an epoxy resin, various conventionally known epoxy resins can be used, and those having a molecular weight of approximately 200 to 2000 are generally preferred, and those having a molecular weight of 300 to 500 are particularly preferred. Furthermore, it is preferably used in a form of blending an epoxy resin having a molecular weight of 310 to 400 which is liquid under normal conditions and an epoxy resin having a molecular weight of 400 to 2500, particularly 500 to 2000 which is solid at normal temperature. In addition, the epoxy equivalent of the epoxy resin is preferably 50 g/eq to 5000 g/eq.

In this specification, the "epoxy equivalent" refers to the number of grams (g/eq) of an epoxy compound containing 1 gram equivalent of epoxy groups, which can be based on JIS (Japanese Industrial Standards) K 7236:2001 Method.

Specific examples of such epoxy resins include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolak, and cresol novolak; butanediol, polyethylene glycol, Glycidyl ethers of alcohols such as polypropylene glycol; glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; bonded to nitrogen atoms such as aniline isocyanurate Epoxy resins of glycidyl type or alkyl glycidyl type with active hydrogen substituted by glycidyl or alkyl glycidyl group; such as diepoxy vinylcyclohexane, 3,4-epoxycyclohexyl Methyl-3,4-dicyclohexane carboxylate, 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane, etc. For example, a so-called alicyclic epoxide formed by introducing an epoxy group by oxidizing a carbon-carbon double bond in a molecule. In addition, an epoxy resin having a biphenyl skeleton, a dicyclopentadiene skeleton, a dicyclohexadiene skeleton, a naphthalene skeleton, etc. can also be used.

Among these, bisphenol glycidyl epoxy resin, o-cresol novolac epoxy resin, phenol novolac epoxy resin and epoxy resin having a dicyclopentadiene skeleton can be preferably used .

These epoxy resins can be used alone or in combination of two or more.

When using an epoxy resin, it is preferable to use a thermoactive latent epoxy resin hardener as an auxiliary agent in combination with a thermosetting adhesive. The so-called heat-active latent epoxy resin hardener is a type of hardener that does not react with the epoxy resin at room temperature, but is activated by heating above a certain temperature to react with the epoxy resin. The activation method of the heat-active latent epoxy resin hardener includes the following methods: a method of generating active species (anions, cations) by a chemical reaction caused by heating; stably dispersed in the epoxy resin near room temperature ，Compatible with high temperature epoxy resin, dissolve, start hardening reaction method; Use molecular sieve seal type hardener dissolve at high temperature and start hardening reaction method; Use microcapsule method, etc.

Specific examples of the heat-active latent epoxy resin hardener include various onium salts, diacid dihydrazide compounds, dicyandiamide, amine adduct hardeners, and imidazole compounds. Compounds etc. These thermally active latent epoxy resin hardeners can be used alone or in combination of two or more. The heat-active latent epoxy resin hardener described above is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, and more preferably 100 parts by mass of the epoxy resin. Used in a ratio of 0.3 parts by mass to 5 parts by mass.

As the phenol resin, condensates of phenols and aldehydes such as alkylphenol, polyhydric phenol, and naphthol can be used without particular limitation. Specifically, phenol novolak resin, o-cresol novolak resin, p-cresol novolak resin, third butylphenol novolak resin, dicyclopentadiene cresol resin, polyp-vinyl phenol resin, Bisphenol A novolak resin, or their modified products, etc.

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

The adhesive polymer component can impart moderate viscosity to the adhesive film for semiconductors, and improve the operability of the adhesive sheet 2 for semiconductors. The mass average molecular weight of the binder polymer is usually in the range of 20,000 to 2 million, preferably 50,000 to 1.5 million, and particularly preferably 100,000 to 1 million. If the molecular weight is too low, the film formation of the adhesive film for semiconductor becomes insufficient, and if it is too high, the compatibility with other components becomes poor, and as a result, a uniform film formation is hindered. If the mass average molecular weight is in the range of 20,000 to 2 million, preferably 50,000 to 1.5 million, and particularly preferably 100,000 to 1 million, the film for the semiconductor adhesive film is sufficiently formed, and it is compatible with other components The properties are also good and a uniform film is formed. As such a binder polymer, for example, acrylic polymers, polyester resins, phenoxy resins, urethane resins, silicone resins, rubber-based polymers, etc. can be used, and acrylic polymer is particularly preferably used Thing.

In addition, in this specification, the "mass average molecular weight" is the polystyrene conversion value measured by the gel permeation chromatography (GPC; Gel Permeation Chromatography) method unless otherwise specified.

Examples of the acrylic polymer include (meth)acrylate copolymers composed of structural units derived from alkyl (meth)acrylate monomers and other (meth)acrylic acid derivatives. . Here, as the alkyl (meth)acrylate monomer, it is preferable to use an alkyl (meth)acrylate having 1 to 18 carbon atoms in the alkyl group, for example, methyl (meth)acrylate, (meth) Ethyl acrylate, propyl (meth) acrylate, butyl (meth) acrylate, etc. In addition, examples of (meth)acrylic acid derivatives include (meth)acrylic acid, glycidyl (meth)acrylate, and hydroxyethyl (meth)acrylate.

In the above, if the glycidyl group is introduced into the acrylic polymer, the compatibility with the epoxy resin as the thermosetting component is improved, and the glass transition temperature (Tg) of the adhesive film for semiconductor after curing becomes high, Heat resistance is improved. In addition, if hydroxyethyl acrylate or the like is used as a structural unit and the hydroxyl group is introduced into the acrylic polymer, the adhesion to the semiconductor or the physical properties of the adhesive can be controlled.

When an acrylic polymer is used as the binder polymer, the mass average molecular weight of the polymer is preferably 100,000 or more, and particularly preferably 150,000 to 1 million. The glass transition temperature (Tg) of the acrylic polymer is usually 40°C or lower, preferably about -70 to 20°C.

In this specification, the so-called "glass transition temperature (Tg)" refers to the DSC (Differential Scanning Calorimetry) curve of a sample measured using a differential scanning calorimeter, expressed as the temperature of the inversion point of the resulting DSC curve .

The blending ratio of the thermosetting component and the binder polymer component is preferably 100 parts by mass relative to the binder polymer component, and the blending is preferably 50 parts by mass to 1500 parts by mass, and particularly preferably 70 parts by mass to 1200 parts by mass. Parts, more preferably 80 parts by mass to 1000 parts by mass of thermosetting components. If the thermosetting component and the adhesive polymer component are blended in such a ratio, the moderate viscosity will be displayed before curing, and the sticking operation can be stably performed. In addition, a film with excellent coating strength can be obtained after curing.

The content of the thermosetting adhesive in the adhesive film for semiconductor of the present invention is preferably 20% by mass to 75% by mass, and more preferably 20% by mass to 50% by mass relative to the total mass of the adhesive film for semiconductor. It is particularly preferably 20% by mass to 40% by mass.

The content of the thermosetting component relative to the total content of the thermosetting adhesive is preferably 30% by mass to 95% by mass, more preferably 40% by mass to 95% by mass, and particularly preferably 40% by mass to 92% by mass. In addition, with respect to the total content of the thermosetting adhesive, the content of the binder polymer component is preferably 5% by mass to 70% by mass, more preferably 5% by mass to 60% by mass, and particularly preferably 8% by mass to 60% by mass quality%. Among them, the sum 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 this invention may contain a coupling agent. By using a functional group having a functional group that reacts with an inorganic compound and a functional group that reacts with an organic functional group as a coupling agent, the adhesion and adhesion of the adhesive film for a semiconductor to an adherend can be improved. In addition, by using a coupling agent, the cured product obtained by curing the adhesive film for semiconductor can improve the water resistance without impairing the heat resistance of the cured product.

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 more preferably a silane coupling agent.

Examples of the preferred silane coupling agent include γ-glycidoxypropyltrimethoxysilane (also called 3-glycidoxypropyltrimethoxysilane) and γ-glycidoxypropyltrimethoxysilane. Ethoxysilane, γ-glycidoxypropylmethyl diethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-(methacryloxypropyl) Group) trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-6-(aminoethyl) -γ-aminopropylmethyl diethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane Silane, γ-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyl Silane compounds such as trimethoxysilane, vinyltriethoxysilane, imidazole silane, or hydrolyzed condensates of such silane compounds.

The coupling agent may be used alone or in combination of two or more.

In the case of using a coupling agent, the content of the coupling agent of the adhesive film for semiconductor is preferably 0.03 to 20 parts by mass, more preferably 0.05 with respect to 100 parts by mass of the total content of the thermosetting component and the binder polymer. The part by mass to 10 parts by mass, particularly preferably 0.1 part by mass to 5 parts by mass. If the content of the coupling agent is too small, the above-mentioned effects obtained by using the coupling agent may not be obtained. If the content of the coupling agent is too large, outgassing may occur. By setting the content of the coupling agent to the above range, the adhesion and adhesion of the adhesive film for semiconductor to the adherend can be improved without generating outgassing. In addition, for the cured product obtained by hardening the adhesive film for semiconductor, The water resistance can be improved without compromising the heat resistance of the cured product.

(Barium titanate filler)

The adhesive film for semiconductor of the present invention contains barium titanate filler in an amount of 25% by mass or more and 80% by mass or less relative to the total mass of the adhesive film for semiconductor, preferably 50% by mass or more and 80% by mass or less, more preferably 60% by mass % Above 80% by mass. By setting the content of the barium titanate filler to the above lower limit or more, the dielectric properties of the adhesive film for semiconductor can be further improved, and the sensitivity of the semiconductor sensor can be further improved.

The average particle size of the barium titanate filler is preferably 10 nm or more and 500 nm or less, more preferably 30 nm or more and 300 nm or less, and particularly preferably 50 nm or more and 200 nm or less. If the average particle size of the barium titanate filler is set to the upper limit or more, the densest packing of the particles cannot be achieved, and the dielectric channels are difficult to connect. By setting the average particle size of the barium titanate filler to the above range, the densest packing of the particles can be achieved, and the dielectric channels can be easily connected.

In this specification, the average particle size can be determined by measuring the particle size observed by a scanning electron microscope.

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 additives may be publicly known, and may be arbitrarily selected according to the purpose, and are not particularly limited. Preferred examples include fillers other than barium titanate fillers, plasticizers, antioxidants, colorants (dye, pigment), Aerosol etc.

The adhesive film for semiconductor of the present invention preferably has a light transmittance of 10% or less of visible light with a wavelength of 380 nm to 780 nm at a thickness of 20 μm. It has been confirmed that the light transmittance of visible light with a wavelength of 380 nm to 780 nm at a thickness of 20 μm becomes 10% or less, and the densest packing of particles can be achieved. That is, it has been confirmed that the dielectric channel obtained by the barium titanate filler is connected by setting the light transmittance of visible light with a wavelength of 380 nm to 780 nm at a thickness of 20 μm to 10% or less. If the light transmittance of visible light with a wavelength of 380 nm to 780 nm at a thickness of 20 μm exceeds 10%, the semiconductor adhesive film cannot achieve the densest packing of the barium titanate filler, and the dielectric channels obtained from the barium titanate filler are difficult to connect. Furthermore, the light transmittance of visible light with a wavelength of 380 nm to 780 nm at a thickness of 20 μm may be 0% or more, 1% or more, 0% or more and 10% or less, and 1% or more and 10% or less.

In this specification, the light transmittance can be calculated by irradiating light of a predetermined wavelength, measuring the transmitted light amount of the transmitted sample with a spectrophotometer, and obtaining the ratio (%) of the transmitted light amount to the irradiated light amount.

The relative dielectric constant (ε _r ) at 1 MHz after thermal curing of the adhesive film for semiconductor is preferably 5 or more, and more preferably 7 or more. By making the relative dielectric constant (ε _r ) equal to or higher than the above lower limit, the dielectric properties of the semiconductor adhesive film can be further improved, and the sensitivity of the semiconductor sensor can be further improved.

In addition, the relative dielectric constant (ε _r ) is preferably 100 or less, and more preferably 50 or less.

The adhesive film for semiconductors may be composed of one layer (single layer) or multiple layers of two or more layers. In the case where the adhesive film for semiconductor is composed of multiple layers, these multiple layers may be the same as or different from each other, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.

The thickness of the aforementioned adhesive film for semiconductor is not particularly limited, but is preferably 5 μm to 50 μm, more preferably 10 μm to 30 μm, and particularly preferably 15 μm to 20 μm. By making the thickness of the adhesive film for semiconductors equal to or greater than the above lower limit value, a higher adhesive force to the adherend such as a semiconductor sensor can be obtained. In addition, by making the thickness of the adhesive film for the semiconductor below the upper limit, the dielectric channels of the semiconductor sensor can be easily connected.

In addition, the "thickness of the adhesive film for semiconductor" refers to the thickness of the entire adhesive film for semiconductor. For example, the thickness of the adhesive film for semiconductor composed of multiple layers refers to the total thickness of all layers constituting the adhesive film for semiconductor.

In this specification, "thickness" can be measured as a value measured at any 5 locations and expressed as an average, according to JIS K 6783: 1994 using a constant pressure thickness measuring device to measure the element diameter 5mm and the pressure load 1.22N .

The adhesive film for semiconductor of the present invention can be manufactured by mixing a thermosetting adhesive, a barium titanate filler, and other additives, and diluting with an organic solvent such as ethyl acetate as necessary to prepare an adhesive film for semiconductor Using the coating agent, the coating agent for an adhesive film for semiconductor is applied to an adherend such as a release sheet, and then dried.

The adhesive film for semiconductor of the present invention can be used as an adhesive film for an electrostatic capacitance type fingerprint sensor, and is used for the sealing resin and the protective cover of the electrostatic capacitance type fingerprint sensor to produce an adhesion. The adhesive film for semiconductor of the present invention has a high relative dielectric constant after thermal curing, so that it can read the unevenness of the fingerprint with good sensitivity in the electrostatic capacitance type fingerprint sensor.

[Adhesive film for semiconductor]

The present invention provides a semiconductor adhesive sheet provided with the semiconductor adhesive film of the present invention on a release sheet. FIG. 1 is a cross-sectional view of a bonding sheet for semiconductor according to an embodiment of the present invention. As shown in FIG. 1, the adhesive sheet 2 for semiconductors of this embodiment has a configuration including an adhesive film 1 for semiconductors and a release sheet 21. Among them, the peeling sheet 21 is peeled when the adhesive film 1 for semiconductor is used.

The release sheet 21 protects the semiconductor adhesive film during the period before the semiconductor adhesive film 1 is used, and does not necessarily need to be present. The configuration of the peeling sheet 21 is arbitrary, and examples include a plastic film whose film itself has peelability to the adhesive film 1 for semiconductors, and a peeling treatment of the plastic film by a peeling agent or the like. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene or polyethylene. As the release agent, silicone-based, fluorine-based, long-chain alkane-based, etc. can be used, and among them, silicone-based ones that are inexpensive and can obtain stable performance are preferred. The thickness of the release sheet 21 is not particularly limited, but is generally about 20 μm to 250 μm.

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

When manufacturing the adhesive sheet 2 for semiconductors of this embodiment, the adhesive film 1 for semiconductors is formed on the peeling surface of the peeling sheet 21 (surface having peelability; usually the surface subjected to peeling treatment, but not limited thereto). Specifically, the coating agent for the adhesive film for semiconductor which comprises the adhesive film 1 for semiconductors is prepared by a roll coater, a blade coater, a roll knife coater, an air knife coater, a die coater, a bar A coater such as a coater, a gravure coater, and a curtain coater is applied to the peeling surface of the release sheet 21 and dried to form the adhesive film 1 for semiconductor.

The drying conditions of the coating agent for a semiconductor adhesive film are not particularly limited. When the coating agent for a semiconductor adhesive film contains an organic solvent such as ethyl acetate, it is preferably dried by heating. In this case, for example, Preferably, the drying is performed under the conditions of 70°C to 130°C and 10 seconds to 5 minutes.

(How to use the bonding sheet for semiconductor)

Hereinafter, as an example of how to use the adhesive sheet 2 for semiconductors of this embodiment, a method for an electrostatic capacitance type fingerprint sensor will be described.

The adhesive sheet 2 for semiconductor is attached to the cover 31 for protection of an electrostatic capacitance type fingerprint sensor such as ceramics. Then, after peeling off the peeling sheet 21 from the adhesive sheet 2 for semiconductor, it is attached to an electrostatic capacitance type fingerprint sensor in which the interlayer film 34 and the fingerprint sensor 33 formed on the substrate 35 are sealed by epoxy resin or the like The surface of the sealing resin 32 hardens the semiconductor adhesive film 1 (see FIG. 2 ).

[Example]

Hereinafter, the present invention will be described in more detail with specific examples. However, the present invention is not limited to the embodiments shown below.

[Example 1, Comparative Example 1]

The following components were mixed at the formulation ratio (solid content conversion) shown in Table 1, and diluted with methyl ethyl ketone so that the solid content concentration became 60% by mass to prepare a coating agent for an adhesive film for semiconductors.

(a): Acrylic copolymer ("Teisanresin SG-P3" manufactured by Nagase Chemtex).

(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 novolak resin ("Phenolite KA-1160" manufactured by DIC Corporation).

(d): Imidazole-based heat-active latent epoxy resin hardener ("Curezol 2PHZ-PW" manufactured by Shikoku Chemical Industry Co., Ltd.).

(e): Silane coupling agent ("X-41-1056" manufactured by Shin-Etsu Chemical Co., Ltd.).

(f)-1: Barium titanate filler ("High Purity Perovskite BT-01" manufactured by Sakai Chemical Industry Co., Ltd.; average particle size 100 nm).

The above-mentioned coating agent for a semiconductor adhesive film was applied to a peeling sheet as a polyethylene terephthalate-based film subjected to peeling treatment on one side by hand coating (SP-PET381031, Lintec) After production), it was dried in an oven at 100° C. for 1 minute to obtain a semiconductor adhesive sheet provided with a semiconductor adhesive film having a thickness of 20 μm on the release sheet.

[Example 2]

An adhesive sheet for semiconductors was produced in the same manner as in Example 1, except that the formulation amount of each component constituting the adhesive film for semiconductors was changed as shown in Table 1.

[Example 3]

In addition to using barium titanate filler (f)-2 ["High Purity Perovskite BT-02" manufactured by Sakai Chemical Industry Co., Ltd.; average particle diameter 200 nm] instead of barium titanate filler (f)-1, use and examples 1 The same method is used to manufacture a bonding sheet for semiconductors.

[Example 4]

In addition to using barium titanate filler (f)-3 ["High Purity Perovskite BT-05" manufactured by Sakai Chemical Industry Co., Ltd.; average particle size 500 nm] instead of barium titanate filler (f)-1, use and examples 1 The same method is used to manufacture a bonding sheet for semiconductors.

[Comparative Example 1, Comparative Example 2]

An adhesive sheet for semiconductors was produced in the same manner as in Example 1, except that the types and formulation amounts of the components constituting the adhesive film for semiconductors were changed as shown in Table 1.

[Comparative Example 3 to Comparative Example 5]

An adhesive sheet for semiconductors was produced in the same manner as in Example 1 except that titanium oxide filler (g) ["A-120" manufactured by Sakai Chemical Industry Co., Ltd.; average particle size 150 nm] was used instead of the barium titanate filler.

[Test Example 1] <Evaluation of Relative Dielectric Constant>

After peeling off the release sheet and stacking the adhesion film for semiconductor from each of the adhesive sheets for semiconductors obtained in Examples 1 to 4 and Comparative Examples 1 to 5, the laminate was pressed to obtain a sample sheet having a diameter of 10 mm and a thickness of 1 mm. The sample piece was heat-cured in a 160°C oven for 1 hour. Using 4194A manufactured by Hewlett Packard Company, the electrostatic capacitance of 1 MHz was measured according to JIS C 2138, and the relative dielectric constant was calculated based on the electrostatic capacitance value. The results are shown in Table 1 and Table 2.

[Test Example 2] <Evaluation of Light Transmittance>

Using a spectrophotometer (manufactured by SHIMADZU, UV-VIS-NIR SPECTROPHOTOMETER UV-3600), using a direct light-receiving unit, and without using an integrating sphere, an example was obtained when a peeling film (SP-PET381031, manufactured by Lintec) was used as a control. 1 to Example 4 and Comparative Example 1 to Comparative Example 5 The light transmittance of a semiconductor bonding sheet with a wavelength of 380 nm to 780 nm, and the light transmittance of 380 nm to 780 nm in the region of 10% or less is evaluated as ○, which exceeds 10 % Are rated as ×. The results are shown in Table 1 and Table 2.

[Table 1]

As shown in Table 1, the adhesive film for semiconductors with a content of barium titanate filler less than 25% by mass has a relative dielectric constant of less than 5.0 and poor dielectric properties. In contrast, the content of barium titanate filler is more than 25% by mass The adhesive film system for semiconductors has a relative dielectric constant of 5.0 or more and is excellent in dielectric characteristics. In addition, the adhesive sheet for semiconductors having a light transmittance of 10% or less at a wavelength of 380 nm to 780 nm at 20 μm has a relative dielectric constant of 5.0 or more and is excellent in dielectric characteristics.

In addition, as clearly shown in Table 2, even if the content of the titanium oxide filler is 60% or more in the semiconductor adhesive film using the titanium oxide filler instead of the barium titanate filler, the dielectric constant is less than 5.0, and the dielectric characteristics are poor.

(Industry availability)

The adhesive film for semiconductor of the present invention has a high relative dielectric constant at 1 MHz and excellent dielectric characteristics, which can improve the sensitivity of a semiconductor sensor such as an electrostatic capacitance type fingerprint sensor.

Claims (6)

An adhesive film for semiconductors containing a thermosetting adhesive and a barium titanate filler of 25% by mass or more and 80% by mass or less. The adhesive film for a semiconductor as recited in claim 1, wherein the average particle diameter of the barium titanate filler is 10 nm or more and 500 nm or less. The adhesive film for a semiconductor as described in claim 1 or 2, wherein the light transmittance of the aforementioned adhesive film for a semiconductor is 20% in thickness and has a wavelength of 380 nm to 780 nm of 10% or less. The adhesive film for a semiconductor according to any one of claims 1 to 3, wherein the relative dielectric constant at 1 MHz after thermal curing of the adhesive film for a semiconductor is 5.0 or more. The adhesive film for a semiconductor as described in any one of claims 1 to 4, wherein the adhesive film for a semiconductor is an adhesive film for an electrostatic capacitance type fingerprint sensor. An adhesive sheet for a semiconductor is provided with the adhesive film for a semiconductor as described in any one of claims 1 to 5 on a release sheet.