TW201906956A - Adhesive for semiconductors, method for producing semiconductor device, and semiconductor device - Google Patents

Abstract

An adhesive for semiconductors containing a thermoplastic resin having a glass transition temperature of 35 ° C or lower.

Description

Adhesive for semiconductor, method for manufacturing semiconductor device, and semiconductor device

The present disclosure relates to a semiconductor adhesive, a method for manufacturing a semiconductor device, and a semiconductor device.

Conventionally, when connecting a semiconductor chip to a substrate, a wire bonding method using thin metal wires such as gold wires has been widely used. On the other hand, in order to meet the requirements for higher functionality, higher integration, and higher speed of semiconductor devices, conductive bumps called bumps are formed on semiconductor wafers or substrates to directly connect semiconductor wafers to substrates. The flip-chip connection method (FC (flip chip) connection method) is being promoted.

For example, regarding the connection between semiconductor wafers and substrates, Chip On Board (COB) type connections commonly used in Ball Grid Array (BGA), Chip Size Package (CSP), etc. The method is also equivalent to the FC connection method. In addition, the FC connection method is also widely used in chip on chip (COC) types in which connection portions (bumps or wirings) are formed on semiconductor wafers and semiconductor wafers are connected, and connection portions are formed on semiconductor wafers ( Bump or wiring) and a chip-on-wafer (COW) type connection method that connects a semiconductor wafer and a semiconductor wafer (for example, refer to Patent Document 1).

In addition, in a package where there is a strong demand for further miniaturization, thinning, and high functionality, the above-mentioned connection method is laminated, and a multi-stage chip stack type package, package on package (POP) is used. , Through-Silicon Via (TSV), etc. have also begun to be widely popularized. Such a multi-layer / multi-segmentation technique arranges semiconductor wafers and the like in a three-dimensional manner, and thus can reduce the size of the package compared to a method of arranging two-dimensionally. In addition, it is also effective in improving semiconductor performance, reducing noise, reducing packaging area, and saving power. Therefore, it has attracted attention as a next-generation semiconductor wiring technology.

In addition, in the connection of the connection parts, metal bonding is always used from the viewpoint of sufficiently ensuring connection reliability (for example, insulation reliability). As a main metal used in the connection portion (for example, a bump and a wiring), there are solder, tin, gold, silver, copper, nickel, and the like, and a conductive material including a plurality of these materials is also used. The metal used in the connection portion generates an oxide film due to surface oxidation, and impurities such as oxides are adhered to the surface. Therefore, impurities may be generated on the connection surface of the connection portion. If such impurities remain, the connection reliability (for example, insulation reliability) between the semiconductor wafer and the substrate or between the two semiconductor wafers may be reduced, and the advantages of using the connection method may be impaired.

In addition, as a method for suppressing the generation of these impurities, there are known methods such as an organic solderable protective layer (Organic Solderability Preservatives (OSP) treatment), which coat the connection portion with an anti-oxidation film, but the anti-oxidation The film may cause a decrease in solder wettability and a decrease in connectivity during the connection process.

Therefore, as a method of removing the oxide film and impurities, a method of including a flux in a semiconductor material has been proposed (for example, refer to Patent Document 2). [Prior Art Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2008-294382 Patent Document 2: International Publication No. 2013/125086

[Problems to be Solved by the Invention] As described above, in the connection of the connection portions, metal bonding is always used from the viewpoint of sufficiently securing connection reliability (for example, insulation reliability). When the semiconductor material does not have sufficient flux activity (removal effect of oxide film and impurities on the metal surface), sometimes the oxide film and impurities on the metal surface cannot be removed, so that a good metal-metal bond is not formed. There is no guarantee of continuity.

In addition, a semiconductor device manufactured using a semiconductor material is required to have excellent heat resistance and moisture resistance, and to have sufficient reflow resistance such as peeling of the semiconductor material and poor connection at the connection portion at a reflow temperature of about 250 ° C.

In addition, in recent years, from the viewpoint of improving productivity, it is required to reduce the assembly time of a flip-chip package, and a wafer-level packaging process has been proposed.

In a wafer-level package, after a plurality of wafers are packaged on a wafer, a plurality of packages can be efficiently manufactured through wafer-level batch sealing and singulation of a cut wafer.

However, the larger the number of chip packages, the more stress will be applied to each package due to the effect of the curing shrinkage of the adhesive and the thermal history during the reflow step, and the larger the warpage in the wafer, the more it will cause During the sealing step, the wafer cannot be fixed on the vacuum chuck table, and the wafer may be broken during this process.

An object of the present disclosure is to provide a semiconductor adhesive, which can be manufactured in a semiconductor device with reduced wafer warpage during a wafer-level packaging process. Another object of the present disclosure is to provide a method for manufacturing a semiconductor device and a semiconductor device using the semiconductor adhesive. [Means for solving problems]

One aspect of the present disclosure provides an adhesive for semiconductors, which contains a thermoplastic resin having a glass transition temperature of 35 ° C. or lower. According to the adhesive for semiconductors, it is possible to manufacture a semiconductor device having a reduced wafer warpage amount during a wafer-level packaging process. The reason is speculated that the adhesive contains the thermoplastic resin having a soft property at 35 ° C. near the room temperature, and the thermoplastic resin can be used to cause the adhesive to undergo shrinkage or temperature change after curing (in Stress dispersion due to expansion and contraction, such as temperature change when cooled to room temperature after high-temperature compression bonding, reduces the amount of wafer warpage as a result. In addition, in the adhesive, the thermosetting component and the thermoplastic component usually undergo phase separation to form a sea-island structure. However, in this state, it is considered that the thermoplastic resin exists in a state where the thermosetting component is interposed, so that The thermoplastic resin can be used to effectively reduce strain caused by curing shrinkage generated in the cured adhesive.

The pre-applied method can improve the workability in the case where the gap between the semiconductor wafer and the wiring substrate or the gap between the plurality of semiconductor wafers is sealed. Therefore, the adhesive for semiconductors in this aspect is less The shape is preferably a film at 35 ° C.

The adhesive for semiconductors of the present disclosure preferably contains a thermosetting resin. In this case, since the amount of shrinkage is further reduced in the temperature cycle test, it is easy to obtain further excellent connection reliability. In addition, the hardened adhesive exhibits high heat resistance and adhesion to the wafer, and it is easy to obtain further excellent reflow resistance.

The thermosetting resin preferably contains an epoxy resin. In this case, it is easy to obtain further excellent reflow resistance and storage stability.

The adhesive for semiconductors of the present disclosure preferably does not substantially contain an epoxy resin that is liquid at 35 ° C. In this case, the liquid epoxy resin can be packaged without being decomposed or volatilized during thermocompression bonding, and outgas contamination at the periphery of the chip is suppressed, so that further excellent package yield is easily obtained. .

The adhesive for semiconductors of the present disclosure preferably has an elastic modulus at 35 ° C. of the cured adhesive of 2.0 GPa to 4.0 GPa. Thereby, the stress applied to each package can be dispersed, and warpage of the entire wafer can be suppressed.

The adhesive for semiconductors of the present disclosure preferably contains a latent hardener as a hardener. In this case, it is easy to obtain further excellent storage stability.

The latent sclerosing agent is preferably an imidazole compound. In this case, it is easy to obtain further excellent storage stability.

The adhesive for semiconductors of the present disclosure preferably contains a flux compound. In this case, since the metal oxide film and the OSP process of the connection portion can be removed, it is easy to obtain further excellent connection reliability.

The flux compound is preferably a carboxylic acid derivative. In this case, it is easy to obtain further excellent connection reliability.

The flux compound is preferably a compound having a carboxyl group. In this case, it is easy to obtain further excellent connection reliability.

The flux compound is preferably a compound having two or more carboxyl groups. In this case, it is easy to obtain further excellent connection reliability. In addition, a compound having two or more carboxyl groups is not easily volatile even at a high temperature at the time of linking, and can further suppress generation of voids.

The flux compound is preferably a compound represented by the following formula (2). In this case, it is easy to obtain further excellent connection reliability. [Chemical 1] [In formula (2), R ¹ and R ² each independently represent a hydrogen atom or an electron-donating group, n represents an integer of 0 to 15, and a plurality of R ² may be the same or different from each other]

The melting point of the flux compound is preferably 150 ° C or lower. In this case, when the thermocompression bonding is performed, the flux compound is melted before the adhesive is hardened to remove the oxide film on the surface of the solder, so that further excellent connection reliability is easily obtained.

The semiconductor adhesive of this aspect can be suitably used for a semiconductor device which electrically connects the connection portions of the semiconductor wafer and the printed circuit board to each other, or a semiconductor device where the connection portions of the plurality of semiconductor wafers are electrically connected to each other. At least a part of the connecting portion is sealed.

According to this aspect of the flux compound, by combining with a thermoplastic resin, a thermosetting resin, and a hardener having a glass transition temperature of 35 ° C or lower, a semiconductor adhesive can be realized, and the semiconductor adhesive can be produced on a wafer. Semiconductor devices that reduce the amount of wafer warpage during the packaging process.

Another aspect of the present disclosure provides a method for manufacturing a semiconductor device, which is a method of manufacturing a semiconductor device in which respective connection portions of a semiconductor wafer and a printed circuit board are electrically connected to each other, or each of connection portions of a plurality of semiconductor wafers is electrically connected to each other. A method of a semiconductor device including the step of sealing at least a part of the connection portion using the semiconductor adhesive.

According to the manufacturing method of this aspect, by using the semiconductor adhesive, a semiconductor device having a reduced amount of wafer warpage can be obtained.

According to another aspect of the present disclosure, there is provided a semiconductor device including a connection structure in which connection portions of a semiconductor wafer and a printed circuit board are electrically connected to each other, or a connection structure in which connection portions of a plurality of semiconductor wafers are electrically connected to each other; And a bonding material that seals at least a part of the connection portion, the bonding material including a cured product of the semiconductor adhesive. The semiconductor device of this aspect is a semiconductor device in which the amount of warpage of the wafer is reduced. [Effect of the invention]

According to the present disclosure, there is provided an adhesive for semiconductors capable of manufacturing a semiconductor device having a small amount of wafer warpage during packaging. In addition, according to the present disclosure, there are provided a method for manufacturing a semiconductor device using the adhesive for semiconductors, and a semiconductor device.

Hereinafter, suitable embodiments of the present disclosure will be described in detail with reference to the drawings as appropriate. In the drawings, the same or corresponding parts are denoted by the same symbols, and repeated explanations are omitted. In addition, a positional relationship such as up, down, left, right, etc. is considered to be based on the positional relationship shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios of the drawings are not limited to the ratios shown in the drawings.

<Adhesive for Semiconductors> The adhesive for semiconductors of this embodiment contains a thermoplastic resin (hereinafter referred to as "(a) component" as appropriate). The adhesive for semiconductors of this embodiment contains a thermoplastic resin having a glass transition temperature of 35 ° C. or lower as a thermoplastic resin. The adhesive for semiconductors of this embodiment contains a thermosetting resin (hereinafter referred to as "(b) component" as appropriate), a hardener (hereinafter referred to as "(c) component" as appropriate), a flux compound ( Hereinafter referred to as "(d) component").

According to the adhesive for semiconductors of this embodiment, by using a combination of a thermoplastic resin, a thermosetting resin, a hardening agent, and a flux compound having a glass transition temperature of 35 ° C or lower, crystals can be reduced during a wafer-level packaging process. It is possible to manufacture a semiconductor device having a circular warpage amount.

The adhesive for semiconductors of this embodiment may contain a filler as needed (henceforth "the (e) component").

Hereinafter, each component which comprises the adhesive agent for semiconductors which concerns on this embodiment is demonstrated.

(A) Thermoplastic resin (a) The components are not limited, and examples thereof include phenoxy resin, polyimide resin, polyimide resin, polycarbodiimide resin, cyanate resin, acrylic resin, and polymer. Ester resin, polyethylene resin, polyether 聚 resin, polyether 醯 imine resin, polyethylene acetal resin, urethane resin, and acrylic elastomer (acrylic rubber, etc.). Among these, a phenoxy resin, a polyimide resin, an acrylic elastomer, a cyanate resin, and a polycarbodiimide resin are more preferable from the viewpoint of excellent heat resistance and film formation. It is a phenoxy resin, a polyimide resin, and an acrylic elastomer. These (a) components may be used alone or as a mixture or copolymer of two or more.

The weight-average molecular weight of the component (a) is preferably 10,000 or more, more preferably 60,000 or more, and even more preferably 100,000 or more. According to such a component (a), the film-forming property and the heat resistance of an adhesive agent can be improved more.

The weight average molecular weight of the component (a) is preferably 1,000,000 or less, and more preferably 500,000 or less. According to such a component (a), the film processability can be further improved.

In addition, in this specification, the said weight average molecular weight means the polystyrene equivalent weight average molecular weight measured using the gel permeation chromatography (GPC). An example of the measurement conditions of the GPC method is shown below. Device: HCL-8320GPC, UV-8320 (product name, manufactured by Tosoh Co., Ltd.), or HPLC-8020 (product name, manufactured by Tosoh Co., Ltd.). Column: TSKgel superMultiporeHZ-M × 2, or two pieces of GMHXL + one piece of G-2000XL (2pieces of GMHXL + 1piece of G-2000XL) Detector: refractive index (RI) detector or Ultra Violet (UV) detector. Column temperature: 25 ℃ ～ 40 ℃ Eluent: Select the solvent that dissolves the polymer components. For example, TetrahydroFuran (THF), N, N-Dimethyl Formamide (DMF), N, N-Dimethyl Acetamide (DMA), N-methylpyrrolidone (N-Methyl Pyrrolidone, NMP), toluene. In addition, when a polar solvent is selected, the concentration of phosphoric acid can be adjusted to 0.05 mol / L to 0.1 mol / L (usually 0.06 mol / L), and the concentration of LiBr can be adjusted to 0.5 mol / L to 1.0 mol. / L (typically 0.63 mol / L). Flow rate: 0.3 mL / min ～ 1.5 mL / min Standard material: polystyrene

When the semiconductor comprising component (a) with the adhesive, the content of C (b) content of component C _{a b-phase} (a), the component ratio of C _b / C _a (mass ratio) is preferably 0.01 to 5, more preferably It is 0.05 to 3, and more preferably 0.1 to 2. By setting the ratio C _b / C _a to 0.01 or more, better hardenability and adhesion can be obtained, and by setting the ratio C _b / C _a to 5 or less, more favorable film formability can be obtained.

The component (a) includes at least a thermoplastic resin having a glass transition temperature of 35 ° C or lower, but may further include a thermoplastic resin having a glass transition temperature of higher than 35 ° C. (A) The glass transition temperature of the component is preferably -50 ° C to 50 ° C, more preferably -30 ° C to 45 ° C, even more preferably -25 ° C to 35 ° C, even more preferably -25 ° C to 25 ° C. Preferably it is -25 ° C to 20 ° C. According to the semiconductor adhesive containing such a component (a), the amount of warpage of the wafer can be further reduced during the wafer-level packaging process, and the heat resistance and film formation properties of the semiconductor adhesive can be further improved. The glass transition temperature of the component (a) can be measured by a differential scanning calorimeter (DSC).

Based on the total solid content of the semiconductor adhesive, the content of the component (a) is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less. If the content of the component (a) is 20% by mass or less, the semiconductor adhesive can obtain good reflow resistance, and even after moisture absorption, a good adhesion can be obtained at a reflow temperature around 250 ° C. In addition, based on the total solid content of the semiconductor adhesive, the content of the component (a) is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more. When the content of the component (a) is 1% by mass or more, the semiconductor adhesive can further reduce the amount of wafer warpage during the wafer-level packaging process, and can further improve the heat resistance and film formation of the semiconductor adhesive. .

(B) Thermosetting resin As the component (b), if it has two or more reactive groups in the molecule, it can be used without particular limitation. Examples of the component (b) include epoxy resins, phenol resins, fluorene imine resins, urea resins, melamine resins, silicone resins, (meth) acrylic compounds, and vinyl compounds. Among these, from the viewpoint of excellent heat resistance and storage stability, epoxy resins, phenol resins, and fluorene imine resins are preferable, and epoxy resins and fluorene imine resins are more preferable. These (b) components may be used alone or as a mixture or copolymer of two or more kinds.

As the epoxy resin and fluorene imine resin, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, and cresol novolac type ring can be used. Oxygen resin, phenol aralkyl epoxy resin, biphenyl epoxy resin, triphenylmethane epoxy resin, dicyclopentadiene epoxy resin and various multifunctional epoxy resins; Resins, allyl antidiamidine resins, maleimide diimide resins, amidine diimide resins, diammonium acrylate resins, various polyfunctional imine resins and various polyimide resins. These may be used alone or as a mixture of two or more.

From the viewpoint of suppressing the generation of volatile components due to decomposition at the time of connection at a high temperature, when the temperature at the connection is 250 ° C, the component (b) is preferably used at a temperature of 250 ° C. In the following case, when the temperature at the time of connection is 300 ° C, the component (b) is preferably one having a thermal weight loss rate of 300 ° C or less.

Based on the total solid content of the semiconductor adhesive, the content of the component (b) is, for example, 5% to 75% by mass, preferably 15% to 60% by mass, and more preferably 30% to 50% by mass. .

(C) Hardener Examples of the component (c) include phenol resin-based hardeners, acid anhydride-based hardeners, amine-based hardeners, imidazole-based hardeners, and phosphine-based hardeners. When the component (c) contains a phenolic hydroxyl group, an acid anhydride, an amine, or an imidazole, it exhibits a flux activity that suppresses the generation of an oxide film in the connection portion, thereby improving connection reliability and insulation reliability. Each of the hardeners will be described below.

(I) Phenolic resin-based hardener is not particularly limited as long as it has two or more phenolic hydroxyl groups in the molecule. For example, phenol novolac resin, cresol novolac resin, Phenol aralkyl resin, cresol naphthol formaldehyde polycondensate, triphenylmethane type polyfunctional phenol resin and various polyfunctional phenol resins. These may be used alone or as a mixture of two or more.

From the viewpoints of good hardenability, adhesion, and storage stability, the equivalent ratio of the phenol resin-based hardener to the component (b) (phenolic hydroxyl group / (b) component reactive group, mole ratio) It is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and even more preferably 0.5 to 1.0. If the equivalence ratio is 0.3 or more, the hardenability will be improved, and the adhesion force will tend to increase. If it is 1.5 or less, the unreacted phenolic hydroxyl group will not remain excessively, the water absorption rate is suppressed to a low value, and the insulation reliability is improved Propensity.

(Ii) Acid anhydride-based hardener As the acid anhydride-based hardener, for example, methylcyclohexanetetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, and ethyl Diol trimellitic anhydride. These may be used alone or as a mixture of two or more.

From the viewpoints of good hardenability, adhesion, and storage stability, the equivalent ratio of the acid anhydride-based hardener to the component (b) (acid anhydride group / (b) component reactive group, molar ratio) is preferred. It is 0.3 to 1.5, more preferably 0.4 to 1.0, and even more preferably 0.5 to 1.0. If the equivalence ratio is 0.3 or more, the hardenability is improved and the adhesion force is increased. If it is 1.5 or less, the unreacted acid anhydride does not remain excessively, the water absorption is suppressed to a low value, and the insulation reliability tends to be improved. .

(Iii) Amine-based hardener As the amine-based hardener, for example, dicyandiamine can be used.

From the viewpoints of good hardenability, adhesion, and storage stability, the equivalent ratio of the amine hardener to the component (b) (reactive group of amine / (b) component, mole ratio) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and even more preferably 0.5 to 1.0. If the equivalence ratio is 0.3 or more, the hardenability will be improved and the adhesion force will tend to increase. If it is 1.5 or less, unreacted amine will not remain excessively, and the insulation reliability tends to be improved.

(Iv) Imidazole-based hardeners Examples of the imidazole-based hardener include 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl- 2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitic acid Ester, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-homo Triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2' -Ethyl-4'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1')]- Ethyl-mesytriazine isotricyanic acid adduct, 2-phenylimidazole isotricyanic acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4 -Methyl-5-hydroxymethylimidazole, and an adduct of epoxy resin and imidazoles. Among these, 1-cyanoethyl-2-undecylimidazole and 1-cyano-2-phenylimidazole are preferable from a viewpoint of excellent hardenability, storage stability, and connection reliability. , 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6- [2'-Methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl-4'-methylimidazolyl- (1' )]-Ethyl-tris-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine isotricyanic acid adduct, 2-phenylimidazole isotricyanic acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole. These can be used alone or in combination of two or more. In addition, a latent curing agent obtained by microencapsulating these may be formed.

The content of the imidazole-based hardener is preferably 0.1 to 20 parts by mass, and more preferably 0.1 to 10 parts by mass based on 100 parts by mass of the component (b). If the content of the imidazole-based hardener is 0.1 parts by mass or more, the hardenability tends to be improved, and if it is 20 parts by mass or less, the adhesive for semiconductors will not be hardened before the formation of metal bonding, and there will be a tendency that connection failure will not easily occur.

(V) Phosphine-based hardener Examples of the phosphine-based hardener include triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra (4-methylphenyl) borate, and tetrabenzene Hydrazone (4-fluorophenyl) borate.

The content of the phosphine-based hardener is preferably 0.1 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the component (b). When the content of the phosphine-based hardener is 0.1 parts by mass or more, the hardenability tends to be improved, and when it is 10 parts by mass or less, the semiconductor adhesive does not harden before the formation of metal bonding, and there is a tendency that connection failure is unlikely to occur.

Each of the phenol resin-based hardener, the acid anhydride-based hardener, and the amine-based hardener may be used alone or as a mixture of two or more. The imidazole-based hardener and the phosphine-based hardener may be used alone or in combination with a phenol resin-based hardener, an acid anhydride-based hardener, or an amine-based hardener.

From the viewpoint of further improving storage stability and preventing decomposition or deterioration due to moisture absorption, the component (c) is preferably selected from the group consisting of a phenol resin-based hardener, an amine-based hardener, an imidazole-based hardener, and a phosphine-based hardener. Hardener in the group of agents. Moreover, from a viewpoint of the ease of adjustment of a hardening speed, and a viewpoint of realizing a short-term connection which aims at improving productivity by using quick hardening, (c) component is more preferably selected from a phenol resin hardener, an amine A hardener in the group consisting of a system-based hardener and an imidazole-based hardener.

The component (c) is not particularly limited as long as it functions as a curing agent of the component (b), and a curing agent other than the above may be used. The hardening system is preferably a radical polymerization. The component (c) is preferably a radical generator. Examples of the radical generator include a thermal radical generator (a radical generator using heat), a photo radical generator (a radical generator using light), and the like. The component (c) is preferably a thermal radical generator from the viewpoint of excellent workability. (C) A component can be used individually by 1 type or in combination of 2 or more types.

Examples of the thermal radical generator include an azo compound and a peroxide (such as an organic peroxide). As the thermal radical generator, from the viewpoint of excellent handling and storage stability, a peroxide is preferred, and an organic peroxide is more preferred. Examples of the organic peroxide include ketone peroxide, ketal peroxide, hydroperoxide, dialkyl peroxide, difluorenyl peroxide, peroxydicarbonate, and peroxyester. From the viewpoint of storage stability, the organic peroxide is preferably a hydroperoxide, a dialkyl peroxide, or a peroxide ester. Furthermore, as an organic peroxide, a hydroperoxide and a dialkyl peroxide are preferable from a heat resistant viewpoint.

The content of the component (c) is preferably 0.5 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1 to 5 parts by mass with respect to 100 parts by mass of the component (b). When the content is 0.5 parts by mass or more, hardening tends to proceed sufficiently, and when the content is 20 parts by mass or less, there is a tendency that hardening can be prevented from progressing rapidly and the number of reaction points can be increased, so that it can be prevented. When the molecular chain becomes shorter, or unreacted groups remain, reliability may be reduced.

When the semiconductor adhesive contains a phenol resin-based hardener, an acid anhydride-based hardener, or an amine-based hardener as the component (c), it exhibits the activity of a flux for removing an oxide film, which can further improve connection reliability.

(D) Flux Compound (d) The component is a compound having a flux activity, and functions as a flux in the semiconductor adhesive of the present embodiment. The component (d) preferably contains a carboxylic acid derivative. Examples of the component (d) include compounds having a group represented by the following formula (1). As component (d), one type of flux compound may be used alone, or two or more types of flux compounds may be used in combination.

[Chemical 2]

In formula (1), R ¹ represents a hydrogen atom or an electron-donating group.

Examples of the electron-donating group include an alkyl group, a hydroxyl group, an amino group, an alkoxy group, and an alkylamino group. The electron-donating group is preferably a group that does not easily react with other components (for example, the epoxy resin of component (b)). Specifically, it is preferably an alkyl group, a hydroxyl group, or an alkoxy group, and more preferably an alkyl group. .

When the electron-donating property of the electron-donating group becomes strong, the effect of suppressing the decomposition of the ester bond tends to be easily obtained. In addition, if the steric hindrance of the electron-donating group is large, the effect of suppressing the reaction between the carboxyl group and the epoxy resin is easily obtained. The electron-donating group preferably has electron-donating properties and steric hindrance with good balance.

The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 1 to 5 carbon atoms. As the number of carbon atoms having an alkyl group increases, the electron donating property and the steric hindrance tend to increase. The alkyl group having a carbon number within the above-mentioned range is excellent in the electron-donating property and the balance of steric hindrance. Therefore, according to the alkyl group, the effects of the present disclosure can be exhibited more significantly.

The alkyl group may be linear or branched, and among them, linear is preferred. When the alkyl group is linear, the carbon number of the alkyl group is preferably equal to or less than the carbon number of the main chain of the flux compound from the viewpoint of the balance between the electron donating property and the steric hindrance. For example, when the flux compound is a compound represented by the following formula (2) and the electron-donating group is a linear alkyl group, the carbon number of the alkyl group is preferably the carbon number of the main chain of the flux compound. (N + 1) or less.

The alkoxy group is preferably an alkoxy group having 1 to 10 carbon atoms, and more preferably an alkoxy group having 1 to 5 carbon atoms. As the number of carbon atoms having an alkoxy group increases, the electron donor property and the steric hindrance tend to increase. The alkoxy group having a carbon number within the above-mentioned range is excellent in electron-donating properties and steric hindrance, and therefore, the effect of the present disclosure can be more significantly exhibited by the alkoxy group.

The alkyl portion of the alkoxy group may be linear or branched, and among them, linear is preferred. When the alkoxy group is linear, the number of carbon atoms in the alkoxy group is preferably equal to or less than the number of carbon atoms in the main chain of the flux compound from the viewpoint of the balance between the electron donor property and the steric hindrance. For example, when the flux compound is a compound represented by the following formula (2) and the electron-donating group is a linear alkoxy group, the carbon number of the alkoxy group is preferably the same as that of the main chain of the flux compound. Carbon number (n + 1) or less.

Examples of the alkylamino group include a monoalkylamino group and a dialkylamino group. The monoalkylamino group is preferably a monoalkylalkyl group having 1 to 10 carbon atoms, and more preferably a monoalkylamino group having 1 to 5 carbon atoms. The alkyl portion of the monoalkylamino group may be linear or branched, and is preferably linear.

The dialkylamino group is preferably a dialkylalkyl group having 2 to 20 carbon atoms, and more preferably a dialkylamino group having 2 to 10 carbon atoms. The alkyl portion of the dialkylamino group may be linear or branched, and is preferably linear.

The flux compound is preferably a compound (dicarboxylic acid) having two carboxyl groups. Compared with a compound having one carboxyl group (monocarboxylic acid), a compound having two carboxyl groups is less volatile even at a high temperature at the time of connection, which can further suppress the generation of pores. In addition, when a compound having two carboxyl groups is used, it is possible to further suppress the increase in viscosity of the semiconductor adhesive during storage, connection operation, etc., as compared with the case of using a compound having three or more carboxyl groups, and further improve semiconductors. Device connection reliability.

As the flux compound, a compound represented by the following formula (2) can be suitably used. According to the compound represented by the following formula (2), reflow resistance and connection reliability of a semiconductor device can be further improved.

[Chemical 3]

In formula (2), R ¹ and R ² each independently represent a hydrogen atom or an electron-donating group, n represents an integer of 0 or 1 or more, and a plurality of R ² may be the same as or different from each other.

N in the formula (2) is preferably 1 or more. When n is 1 or more, compared with the case where n is 0, the flux compound is less volatile even due to the high temperature at the time of connection, and the generation of voids can be further suppressed. In addition, n in the formula (2) is preferably 15 or less, more preferably 11 or less, even more preferably 4 or less, and may be 2 or less. When n is 15 or less, further excellent connection reliability can be obtained.

The flux compound is more preferably a compound represented by the following formula (3). According to the compound represented by the following formula (3), reflow resistance and connection reliability of a semiconductor device can be further improved.

[Chemical 4]

In formula (3), R ¹ and R ² each independently represent a hydrogen atom or an electron donating group, and m represents an integer of 0 or 1 or more.

M in the formula (3) is preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. When m is 10 or less, further excellent connection reliability can be obtained.

In formula (3), R ¹ and R ² may be a hydrogen atom or an electron-donating group. When R ¹ and R ² are hydrogen atoms, the melting point tends to be low, and the connection reliability of the semiconductor device may be further improved in some cases. In addition, if R ¹ and R ² are different electron donor groups, the melting point tends to be lower than when R ¹ and R ² are the same electron donor group, and the semiconductor device may be further improved in some cases. Connection reliability.

Among the compounds represented by formula (3), as the compound in which R ¹ is an electron-donating group and R ² is a hydrogen atom, methyl succinic acid, 2-methylglutaric acid, and 2-methyl adipic acid are listed. , 2-methyl pimelic acid, 2-methyl suberic acid, and the like. These compounds can further improve the connection reliability of the semiconductor device. Among these compounds, methyl succinic acid and 2-methylglutaric acid are particularly preferred.

In addition, in formula (3), if R ¹ and R ^{2 have} the same electron-donating group, there is a tendency that the melting point becomes a symmetric structure, but in this case, the effects of the present disclosure can be sufficiently obtained. In particular, when the melting point is sufficiently lower than 150 ° C., even if R ¹ and R ² are the same group, the same degree of connection reliability can be obtained as when R ¹ and R ² are different groups.

As the flux compound, for example, a compound selected from the group consisting of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid can be used. Dicarboxylic acids and compounds in which an electron-donating group is substituted at the 2-position of these compounds. Among these, succinic acid and glutaric acid, and compounds in which an electron-donating group is substituted at the 2-position of these compounds are particularly preferable because they can further improve the connection reliability of a semiconductor device.

The melting point of the flux compound is preferably 150 ° C or lower, more preferably 140 ° C or lower, and even more preferably 130 ° C or lower. Such a flux compound easily develops a flux activity sufficiently before a reaction reaction between a reaction component such as an epoxy resin, a fluorene imine resin, and the hardener occurs. Therefore, the semiconductor adhesive containing such a flux compound can realize a semiconductor device having further excellent connection reliability. The melting point of the flux compound is preferably 25 ° C or higher, and more preferably 50 ° C or higher. The flux compound is preferably solid at room temperature (25 ° C).

The melting point of a flux compound can be measured using a general melting point measuring device. Regarding a sample for measuring the melting point, it is required to reduce the temperature variation in the sample by pulverizing into a fine powder and using a small amount. As a container for a sample, a capillary tube having one of its ends closed is used in many cases, but depending on the measurement device, it may be sandwiched between two cover glasses for microscopes as a container. In addition, if the temperature is increased sharply, a temperature gradient will occur between the sample and the thermometer, which will cause measurement errors. Therefore, the temperature at the time of measuring the melting point is preferably measured at a rise rate of 1 ° C per minute or less. .

Since the fine powder is adjusted as described above, the sample before melting is opaque due to diffuse reflection on the surface. Generally, the temperature at which the appearance of the sample starts to become transparent is the lower limit point of the melting point, and the temperature at which it completely melts is the upper limit point. There are various types of measuring devices. The most classic device is a device in which a capillary tube filled with a sample is mounted on a dual-tube thermometer, and the heating is performed using a warm bath. In order to attach a capillary tube to a dual-tube thermometer, a highly viscous liquid is used as a warming liquid. In most cases, concentrated sulfuric acid or silicone oil is used, and the sample is moved to the vicinity of the accumulation part at the top of the thermometer. . In addition, the melting point measuring device may be a device that performs heating using a metal heat block, adjusts the heating while measuring the transmittance of light, and automatically determines the melting point.

In this specification, the melting point of 150 ° C or lower means that the upper limit of the melting point is 150 ° C or lower, and the melting point of 25 ° C or higher means that the lower limit of the melting point is 25 ° C or higher.

From the viewpoint of further reducing the amount of warpage of the wafer when manufacturing a semiconductor device, the content of the component (d) is preferably 0.5% to 10% by mass based on the total solid content of the semiconductor adhesive. It is 0.5 to 5 mass%.

(E) Filler The semiconductor adhesive according to this embodiment contains a filler ((e) component) as necessary. The component (e) can control the viscosity of the semiconductor adhesive, the physical properties of the cured product of the semiconductor adhesive, and the like. Specifically, according to the component (e), for example, it is possible to suppress generation of voids during connection, reduce the moisture absorption rate of a cured product of a semiconductor adhesive, and the like.

As (e) component, an insulating inorganic filler, a whisker, a resin filler, etc. can be used. In addition, as component (e), one type may be used alone, or two or more types may be used in combination.

Examples of the insulating inorganic filler include glass, silicon dioxide, aluminum oxide, titanium oxide, carbon black, mica, and boron nitride. Among these, silicon dioxide, aluminum oxide, titanium oxide, and boron nitride are preferable, and silicon dioxide, aluminum oxide, and boron nitride are more preferable.

Examples of the whiskers include aluminum borate, aluminum titanate, zinc oxide, calcium silicate, magnesium sulfate, and boron nitride.

Examples of the resin filler include fillers containing resins such as polyurethane and polyimide.

The resin filler has a smaller thermal expansion rate than the organic components (epoxy resin, hardener, etc.), so it has an excellent effect of improving connection reliability. In addition, the viscosity of the adhesive for semiconductors can be easily adjusted by the resin filler. Moreover, compared with an inorganic filler, a resin filler is excellent in the function which relieves a stress.

The inorganic filler has a smaller thermal expansion coefficient than the resin filler. Therefore, the inorganic filler can reduce the thermal expansion coefficient of the adhesive composition. In addition, most of the inorganic fillers are general purpose and have particle size control, so it is also preferable for viscosity adjustment.

Each of the resin filler and the inorganic filler has advantageous effects. Therefore, either of them can be used depending on the application, or both of them can be used in order to show the functions of both.

(E) The shape, particle size, and content of the component are not particularly limited. The (e) component may be one whose physical properties have been appropriately adjusted by surface treatment.

The content of the component (e) is preferably 10% by mass to 80% by mass, and more preferably 15% by mass to 60% by mass based on the total solid content of the semiconductor adhesive.

The (e) component is preferably composed of an insulator. If the component (e) is made of a conductive substance (for example, solder, gold, silver, copper, etc.), there is a concern that the insulation reliability (especially, the resistance of the Highly Accelerated Storage Test (HAST)) may decrease.

(Other components) Additives, such as an antioxidant, a silane coupling agent, a titanium coupling agent, a leveling agent, and an ion trapping agent, can also be mix | blended with the adhesive for semiconductors of this embodiment. These can be used individually by 1 type or in combination of 2 or more types. These blending amounts may be appropriately adjusted so that the effect of each additive is exhibited.

The elastic modulus at 35 ° C after curing of the semiconductor adhesive of this embodiment is not particularly limited, but may be 1.0 GPa to 5.0 GPa, preferably 2.0 GPa to 4.0 GPa, and more preferably 2.5 GPa to 4.0 GPa. If the elastic modulus is 4.0 GPa or less, the stress applied to each package can be dispersed, and the warpage of the entire wafer can be further suppressed. On the other hand, if the elastic modulus is 2.0 GPa or more, even after moisture absorption, a further good adhesive force can be obtained at a reflow temperature around 250 ° C. Here, the said elastic modulus is a storage elastic modulus measured by the method as described in an Example.

The adhesive for semiconductors of this embodiment can be formed into a film. An example of a method for producing a film-shaped adhesive using the adhesive for semiconductors of this embodiment is shown below.

First, (a) component, and (b) component, (c) component, (d) component, (e) component etc. which are added as needed are added to an organic solvent, and it dissolves by stirring, mixing, kneading, etc. Disperse to prepare a resin varnish. Then, a resin varnish is applied to the substrate film subjected to the mold release treatment using a doctor blade coater, a roll coater, an applicator, etc., and then the organic solvent is removed by heating to thereby apply the resin varnish to the substrate. A film-like adhesive is formed on the film.

The thickness of the film-shaped adhesive is not particularly limited. For example, it is preferably 0.5 to 1.5 times the height of the bump before connection, more preferably 0.6 to 1.3 times, and still more preferably 0.7 to 1.2 times.

When the thickness of the film-shaped adhesive is 0.5 times or more the height of the bump, the generation of voids due to the unfilled adhesive can be sufficiently suppressed, and the connection reliability can be further improved. In addition, if the thickness is 1.5 times or less, the amount of the adhesive that is extruded from the wafer connection region at the time of connection can be sufficiently suppressed, and thus the adhesion of the adhesive to unnecessary portions can be sufficiently prevented. If the thickness of the film-shaped adhesive is more than 1.5 times, a large amount of the adhesive must be excluded from the bump, which is likely to cause conduction failure. In addition, for the weakening of the bumps (minimization of the bump diameter) caused by narrowing the pitch and increasing the number of pins, excluding a large amount of resin increases the damage to the bumps, which is not preferable.

Usually, the height of the bump is 5 μm to 100 μm, and accordingly, the thickness of the film-shaped adhesive is preferably 2.5 μm to 150 μm, and more preferably 3.5 μm to 120 μm.

The organic solvent used in the preparation of the resin varnish is preferably one having properties capable of uniformly dissolving or dispersing each component, and examples thereof include dimethylformamide, dimethylacetamide, and N-methyl -2-Pyrrolidone, dimethyl sulfene, diethylene glycol dimethyl ether, toluene, benzene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl cellosolve, ethyl cellosolve acetate , Butyl cellosolve, dioxane, cyclohexanone, and ethyl acetate. These organic solvents can be used alone or in combination of two or more. Stirring, mixing, and kneading in the preparation of the resin varnish can be performed using, for example, a mixer, a mill, a three-roller, a ball mill, a bead mill, or a homogenizer.

The substrate film is not particularly limited as long as it has heat resistance that can withstand heating conditions when the organic solvent is volatilized, and examples thereof include polyolefin films such as polypropylene films and polymethylpentene films; polyparaphenylene Polyester films such as ethylene dicarboxylate film and polyethylene naphthalate film; polyimide film and polyetherimide film. The base film is not limited to a single layer including these films, and may be a multilayer film including two or more materials.

The drying conditions when the organic solvent is volatilized from the resin varnish applied to the substrate film are preferably conditions under which the organic solvent is sufficiently volatilized, and specifically, heating at 50 ° C to 200 ° C for 0.1 minute to 90 minutes is preferred. . The organic solvent is preferably removed to be 1.5% by mass or less with respect to the total amount of the film-shaped adhesive.

In addition, the adhesive for semiconductors of this embodiment can be directly formed on a wafer. Specifically, for example, the resin varnish can be spin-coated directly on a wafer to form a film, and then the organic solvent can be removed, and an adhesive for semiconductors can be directly formed on the wafer.

<Semiconductor Device> The semiconductor device of this embodiment will be described below using FIGS. 1 and 2 (a) and 2 (b). FIG. 1 is a schematic cross-sectional view showing an embodiment of a semiconductor device of the present disclosure. As shown in (a) of FIG. 1, the semiconductor device 100 includes a semiconductor wafer 10 and a substrate (circuit wiring substrate) 20 facing each other, wirings 15 disposed on mutually facing surfaces of the semiconductor wafer 10 and the substrate 20, and The connection bumps 30 that connect the semiconductor wafer 10 and the wiring 15 of the substrate 20 to each other, and the bonding material 40 that fills the gap between the semiconductor wafer 10 and the substrate 20 without a gap. The semiconductor wafer 10 and the substrate 20 are connected via flip-chip bonding via the wiring 15 and the connection bump 30. The wiring 15 and the connection bumps 30 are sealed by the bonding material 40 and blocked from the external environment.

As shown in FIG. 1 (b), the semiconductor device 200 includes a semiconductor wafer 10 and a substrate 20 facing each other, bumps 32 arranged on the mutually facing surfaces of the semiconductor wafer 10 and the substrate 20, and filling without gaps. A bonding material 40 is placed in a gap between the semiconductor wafer 10 and the substrate 20. The semiconductor wafer 10 and the substrate 20 are connected to each other by the bumps 32 facing each other, and are connected via flip-chip bonding. The bumps 32 are sealed from the external environment by a bonding material 40. The adhesive material 40 is a cured product of the semiconductor adhesive of this embodiment.

2 (a) and 2 (b) are schematic cross-sectional views illustrating another embodiment of a semiconductor device according to the present disclosure. As shown in FIG. 2 (a), the semiconductor device 300 is the same as the semiconductor device 100 except that the two semiconductor wafers 10 are flip-chip connected via the wiring 15 and the connection bump 30. As shown in FIG. 2 (b), the semiconductor device 400 is the same as the semiconductor device 200 except that the two semiconductor wafers 10 are flip-chip connected by the bumps 32.

The semiconductor wafer 10 is not particularly limited, and an element semiconductor composed of the same type of elements such as silicon and germanium; a compound semiconductor such as gallium arsenide and indium phosphide can be used.

The substrate 20 is not particularly limited as long as it is a circuit substrate, and can be used as a main component including glass epoxy, polyimide, polyester, ceramic, epoxy, bis-cis- butadiene-imine triazine, and the like. A circuit board having wiring (wiring pattern) 15 formed by etching and removing an unnecessary portion of a metal film on the surface of an insulating substrate; and a circuit board having wiring 15 formed on the surface of the insulating substrate by metal plating or the like Circuit board; a circuit board on which wiring 15 is formed by printing a conductive substance on the surface of the insulating substrate.

Connections such as the wiring 15 and the bump 32 include gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper), nickel, tin, and lead As a main component, various metals may be contained.

Among these metals, gold, silver, and copper are preferred, and silver and copper are more preferred from the viewpoint of forming a package having excellent electrical and thermal conductivity of the connection portion. From the viewpoint of forming a package with reduced cost, silver, copper, and solder are preferred, copper and solder are more preferred, and solder is more preferred because of its low cost. If an oxide film is formed on the surface of a metal at room temperature, productivity may decrease and cost may increase. Therefore, from the viewpoint of suppressing the formation of the oxide film, gold, silver, copper, and solder are preferred. More preferred is gold, silver, and solder, and further preferred is gold and silver.

On the surfaces of the wiring 15 and the bumps 32, gold, silver, copper, and solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, and tin- Copper), tin, nickel and other metal layers as main components. The metal layer may include only a single component or a plurality of components. In addition, the metal layer may have a structure in which a single layer or a plurality of metal layers are laminated.

In addition, in the semiconductor device of this embodiment, a plurality of structures (packages) shown in the semiconductor device 100 to the semiconductor device 400 may be stacked. In this case, the semiconductor device 100 to the semiconductor device 400 may include gold, silver, copper, and solder (the main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, and tin-silver-copper). , Tin, nickel, and other bumps or wiring are electrically connected to each other.

As a method of stacking a plurality of semiconductor devices, as shown in FIG. 3, for example, a Through-Silicon Via (TSV) technology can be cited. FIG. 3 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present disclosure, and is a semiconductor device using TSV technology. In the semiconductor device 500 shown in FIG. 3, the wiring 15 formed on the interposer 50 is connected to the wiring 15 of the semiconductor wafer 10 via the connection bump 30, thereby flip-chipping the semiconductor wafer 10 and the interposer 50. connection. The gap between the semiconductor wafer 10 and the interposer 50 is filled with a bonding material 40 without a gap. A semiconductor wafer 10 is laminated on the surface of the semiconductor wafer 10 opposite to the interposer 50 through the wiring 15, the connection bump 30, and the bonding material 40. The wirings 15 on the pattern surface of the front and back of the semiconductor wafer 10 are connected to each other by a through electrode 34 filled in a hole penetrating inside the semiconductor wafer 10. In addition, as a material of the through electrode 34, copper, aluminum, or the like can be used.

With this TSV technology, signals can also be obtained from the back of a semiconductor wafer that is not normally used. Furthermore, since the penetrating electrode 34 is vertically inserted in the semiconductor wafer 10, the distance between the opposing semiconductor wafers 10 or between the semiconductor wafer 10 and the interposer 50 can be shortened and a flexible connection can be made. In such a TSV technology, the semiconductor adhesive of the present embodiment can be suitably used as a semiconductor adhesive between opposing semiconductor wafers 10 or between the semiconductor wafers 10 and the interposer 50.

In addition, in a bump forming method having a high degree of freedom such as an area bump wafer technology, a semiconductor wafer can be directly packaged on a mother board without an interposer. The adhesive for semiconductors of this embodiment is also applicable to the case where a semiconductor wafer is directly packaged on a mother board. In addition, when two printed circuit boards are laminated, the adhesive for semiconductors of this embodiment can also be applied when sealing the space between the substrates.

<Method for Manufacturing Semiconductor Device> A method for manufacturing a semiconductor device according to this embodiment will be described below using FIGS. 4 (a) to 4 (c). 4 (a) to 4 (c) are cross-sectional views schematically showing steps in an embodiment of a method for manufacturing a semiconductor device according to the present disclosure.

First, as shown in FIG. 4 (a), a solder resist 60 having an opening at a position for forming the connection bump 30 is formed on the substrate 20 having the wiring 15. This solder resist 60 is not necessarily provided. However, since the solder resist is provided on the substrate 20, the occurrence of bridging between the wirings 15 can be suppressed, thereby improving connection reliability and insulation reliability. The solder resist 60 can be formed using, for example, a commercially available ink for a solder resist for packaging. Specific examples of commercially available inks for packaging solder resists include SR series (manufactured by Hitachi Chemical Co., Ltd., trade name) and PSR4000-AUS series (manufactured by Sun Ink Manufacturing Co., Ltd., trade name).

Next, as shown in FIG. 4 (a), a connection bump 30 is formed at the opening of the solder resist 60. Then, as shown in FIG. 4 (b), a film-shaped semiconductor adhesive (hereinafter, referred to as a “film-shaped adhesive”) is attached to the substrate 20 on which the connection bumps 30 and the solder resist 60 are formed. 41. The film-like adhesive 41 can be attached by heat pressing, roll lamination, vacuum lamination, or the like. The supply area and thickness of the film-like adhesive 41 are appropriately set in accordance with the sizes of the semiconductor wafer 10 and the substrate 20 and the height of the connection bumps 30.

After the film-like adhesive 41 is attached to the substrate 20 as described above, the wiring 15 of the semiconductor wafer 10 and the connection bump 30 are aligned using a connection device such as a flip-chip bonding machine. Next, the semiconductor wafer 10 and the substrate 20 are pressure-bonded while being heated at a temperature higher than the melting point of the connection bump 30, so that the semiconductor wafer 10 and the substrate 20 are connected as shown in FIG. 4 (c). The adhesive material 40 of the cured product of the film-shaped adhesive 41 seals and fills the space between the semiconductor wafer 10 and the substrate 20. The semiconductor device 600 is obtained as described above.

In the method for manufacturing a semiconductor device according to this embodiment, it is also possible to temporarily fix (position in which the semiconductor adhesive is interposed) after the alignment, and perform heat treatment in a reflow furnace to melt the connection bumps 30. The semiconductor wafer 10 is connected to the substrate 20. Since it is not necessary to form a metal joint in the temporary fixing stage, compared with the method of performing crimping while heating, the crimping can be performed at a lower load, in a shorter time, and at a lower temperature, and productivity can be improved. Suppression of deterioration of the connection portion.

In addition, after the semiconductor wafer 10 and the substrate 20 are connected, heat treatment may be performed using an oven or the like, thereby further improving connection reliability and insulation reliability. The heating temperature is preferably a temperature at which the film-like adhesive is cured, and more preferably a temperature at which the film-shaped adhesive is completely cured. The heating temperature and heating time can be set appropriately.

In the method of manufacturing a semiconductor device according to this embodiment, the substrate 20 may be connected after the film-shaped adhesive 41 is attached to the semiconductor wafer 10. In addition, after the semiconductor wafer 10 and the substrate 20 are connected by the wiring 15 and the connection bumps 30, a paste-like semiconductor adhesive may be filled in the space between the semiconductor wafer 10 and the substrate 20 and hardened.

From the viewpoint of improving productivity, a semiconductor adhesive may be supplied to a semiconductor wafer to which a plurality of semiconductor wafers 10 are connected, and then cut and singulated to obtain a semiconductor wafer 10. Structure of semiconductor adhesive. In addition, when the adhesive for semiconductors is in a paste state, there is no particular limitation, as long as the wiring or bumps on the semiconductor wafer 10 are buried by a coating method such as spin coating to make the thickness uniform. In this case, since the supply amount of the resin is fixed, productivity is improved, and generation of voids and reduction in crystallinity due to insufficient landfilling can be suppressed. On the other hand, when the adhesive for semiconductors is film-shaped, there is no particular limitation, as long as the wiring or bumps on the semiconductor wafer 10 are buried by means of attachment methods such as heat pressing, roll lamination, and vacuum lamination. It is sufficient to supply a film-like semiconductor adhesive in a preferred manner. In this case, since the supply amount of the resin is fixed, productivity is improved, and generation of voids and reduction in crystallinity due to insufficient landfilling can be suppressed.

Compared with the method of spin-coating a paste-like semiconductor adhesive, the method of laminating a film-like semiconductor adhesive tends to have a good flatness after being supplied. Therefore, the form of the adhesive for semiconductors is preferably a film. In addition, the film-shaped adhesive is also excellent in applicability and operability in various processes.

In addition, in a method of supplying a semiconductor adhesive by laminating a film-shaped adhesive, there is a tendency that it is easier to ensure the connectivity of a semiconductor device.

The connection load can be set in consideration of variations in the number and height of the connection bumps 30, and the amount of deformation of the wiring of the connection bumps 30 or the bumps receiving the connection portions due to pressure. Regarding the connection temperature, the temperature of the connection portion is preferably equal to or higher than the melting point of the connection bump 30, but may be a temperature that can form a metal bond of each connection portion (bump or wiring). When the connection bump 30 is a solder bump, the connection temperature is preferably about 240 ° C or higher.

The connection time at the time of connection varies depending on the constituent metal of the connection portion, but from the viewpoint of improving productivity, the shorter the time, the better. When the connection bump 30 is a solder bump, the connection time is preferably 20 seconds or less, more preferably 10 seconds or less, and even more preferably 5 seconds or less. In the case of copper-copper or copper-gold metal connection, the connection time is preferably 60 seconds or less.

As mentioned above, although suitable embodiment of this indication was described, this indication is not limited to the said embodiment.

In addition, the other aspect of the present disclosure may be a use of a composition containing a thermoplastic resin having a glass transition temperature of 35 ° C. or lower, which is used as an adhesive for semiconductors. In addition, the other aspect of the present disclosure may also be a use of a composition containing a thermoplastic resin having a glass transition temperature of 35 ° C. or lower, which is used for manufacturing an adhesive for semiconductors. [Example]

Hereinafter, the present disclosure will be described more specifically by way of examples, but the present disclosure is not limited to the examples.

The compounds used in the examples and comparative examples are as follows. (A) Ingredients: Thermoplastic resin and phenoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., trade name "ZX1356-2", Tg: about 71 ° C, Mw: about 63000) Manufactured by Tetsujukin Chemical Co., Ltd., trade name "FX293", Tg: about 160 ° C, Mw: about 40,000) ・ Polyurethane (manufactured by DIC Covestro Polymer Co., Ltd., Trade name "T-8175N", Tg: -23 ° C, Mw: 120,000) ・ Acrylic elastomer (manufactured by Nagase ChemteX Co., Ltd., trade name "HTR-860 No.25", Tg: about 58 ℃, Mw: about 600,000) ・ Acrylic elastomer (manufactured by Hitachi Chemical Co., Ltd., trade name "CT-D12", Tg: about 13 ° C, Mw: about 530,000) ・ acrylic elastomer (manufactured by Hitachi Chemical Co., Ltd., Trade name "CT-D21", Tg: about -11 ° C, Mw: about 550,000) ・ Acrylic elastomer (manufactured by Kuraray Co., Ltd., trade name "LA4285", Tg: about -27 ° C, Mw: Approx. 60000) ・ Acrylic elastomer (Kuraray Kuraray Co., Ltd., trade name "LA2140", Tg: about -24 ° C, Mw: about 60,000) ・ Acrylic elastomer (manufactured by Kuraray Co., Ltd., trade name "LA2250", Tg: about- 23 ° C, Mw: about 160,000)

(B) Ingredients: Thermosetting resin (b-1) Epoxy resin • Multifunctional solid epoxy resin containing triphenol methane skeleton (manufactured by Mitsubishi Chemical Corporation, trade name “EP1032H60”) • Bisphenol F-type liquid Epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "YL983U") ・ Flexible epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "YX7110B80") (b-2) 醯 imine resin, 4, 7-methanol-1H-isoindole-1,3 (2H) -dione (manufactured by Maruzen Petrochemical Co., Ltd., trade name "BANI-M") ・ bis- (3-ethyl-5-methyl- 4-cis-butenediamidophenyl) methane (manufactured by KI Kasei Co., Ltd., trade name "BMI-70")

(C) Ingredient: hardener, 2,4-diamino-6- [2'-methylimidazole- (1 ')]-ethyl-triazine isocyanuric acid adduct (Shikoku Chemical Co., Ltd. Co., Ltd., trade name "2MAOK-PW") ・ 1,4-bis-((third butyl peroxy) diisopropyl) benzene (manufactured by Nippon Oil Co., Ltd., trade name "Perbutyl ) P ")

(D) Ingredients: Flux • Glutaric acid (manufactured by Wako Pure Chemical Industries, Ltd., melting point of about 98 ° C) • 2-methylglutaric acid (manufactured by Wako Pure Chemical Industries, Ltd., melting point of about 78 ° C)

(E) Ingredients: Filler (e-1) Inorganic filler • Silicon dioxide filler (manufactured by Admatechs Co., Ltd., trade name “SE2030”, average particle size 0.5 μm) • Epoxysilane surface treatment dioxide Silicon filler (manufactured by Admatechs Co., Ltd., trade name "SE2030-SEJ", average particle size 0.5 μm) ・ methacrylic surface-treated silicon dioxide filler (manufactured by Admatechs Co., Ltd., Trade name "YA050C-SM1", average particle size is about 0.05 μm) (e-2) Organic filler, butadiene / styrene copolymer (manufactured by Rohm and Haas Japan Co., Ltd., trade name "EXL-2655", average particle size is about 0.1 μm)

(A) The weight average molecular weight (Mw) of a component is calculated | required by GPC method. The details of the GPC method are as follows. Device name: HPLC-8020 (product name, manufactured by Tosoh Co., Ltd.) Columns: two GMHXL + one G-2000XL detector: RI detector column temperature: 35 ° C flow rate: 1 mL / min standard Substance: Polystyrene

(Examples 1 to 18 and Comparative Examples 1 to 7) <Production of Adhesives for Film Semiconductors> (a) Thermoplastic resins were prepared in the amounts (units: mass parts) shown in Tables 1 and 2 (B) Thermosetting resin, (c) Hardener, (d) Flux, and (e) Filler with NV value ([Quality of coating ingredients after drying] / [Quality of coating ingredients before drying] × 100) It added to the organic solvent (cyclohexanone) so that it might become 50 mass%. Thereafter, ϕ1.0 mm zirconia beads of the same mass as the total amount of the components (thermoplastic resin, thermosetting resin, hardener, flux, filler, cyclohexanone) were added to the same container. The mixture was stirred for 30 minutes using a ball mill (manufactured by Fritsch Japan Co., Ltd., planetary micro-pulverizer P-7). After stirring, the zirconia beads were removed by filtration to prepare a coated varnish.

The obtained coating varnish was applied to a base film using a small precision coating device (manufactured by Lianjing Seiki Co., Ltd. (manufactured by Teijin DuPont Film Co., Ltd., trade name "Purex A55") In the above, a clean oven (manufactured by ESPEC) was used for drying (100 ° C / 10 min) to obtain a film-like adhesive having a film thickness of 20 μm.

The evaluation methods of the film-like adhesive obtained by the Example and the comparative example are shown below. The evaluation results are shown in Tables 1 and 2.

<Measurement of the elastic modulus of the cured product at 35 ° C> A film-shaped adhesive having a total thickness of 60 μm produced by laminating the film-shaped adhesive obtained in Examples or Comparative Examples at 50 ° C was cut It was formed into a predetermined size (40 mm in length × 4.0 mm in width × 0.06 mm in thickness), and was cured (240 ° C, 1 h) in a clean oven (manufactured by ESPEC) to obtain a test sample.

About the said test sample, the elasticity modulus (storage elasticity modulus) at 35 degreeC was measured using the dynamic viscoelasticity measuring device. The details of the method for measuring the elastic modulus are as follows. Device name: Dynamic viscoelasticity measuring device (manufactured by UBM Co., Ltd., Rheogel-E4000) Measurement temperature range: 30 ° C to 270 ° C Heating rate: 5 ° C / min Frequency: 10 Hz Strain: 0.05% Measurement mode: Tensile mode

<Evaluation of Wafer Warpage> Using a vacuum laminator (LMPC, LM-50X50-S), the film-like adhesives obtained in the examples or comparative examples were laminated on a silicon wafer (10 mm in height × horizontal) 10 mm × thickness 0.05 mm, oxide film coating). Next, in a clean oven (manufactured by ESPEC), a sample obtained by laminating a film-shaped adhesive was cured (240 ° C, 1 h) to prepare a test sample.

Using a surface shape measuring device (manufactured by Akrometrix), the wafer warpage amount of the test sample was measured. Specifically, in a state where the test sample is placed with the silicon wafer as the lower side, the maximum value of the height difference of the surface on the side of the film-shaped adhesive is measured using a surface shape measuring device, and the warpage is set the amount.

<Measurement of Adhesive Force at 250 ° C after Moisture Absorption> The film-shaped adhesives produced in the examples or comparative examples were cut to a predetermined size (3.2 mm in height × 3.2 mm in width × 0.02 mm in thickness) at 70 Attached to a silicon wafer (5 mm in height × 5 mm in width × 0.725 mm in thickness, oxide film coating) at ℃, and attached to the silicon wafer using a thermocompression tester (manufactured by Hitachi Chemical Co., Ltd.) Crimping on a film-shaped adhesive (crimping conditions: crimping temperature: 190 ° C, crimping time: 5 seconds, crimping load: 1.3 kgf (12.7 N)), another silicon wafer (3 mm × 3 mm × 0.775 in thickness) mm, oxide film coating). Next, the obtained sample was crimped again using a thermal crimping tester (crimping conditions: crimping temperature 240 ° C, crimping time 5 seconds, and crimping load 1.3 kgf). In a clean oven (manufactured by ESPEC), the pressure-bonded sample was post-cured (175 ° C, 2 h) to produce a semiconductor device as a test sample.

The test sample was placed in a constant temperature and humidity device (manufactured by ESPEC, PR-2KP) at 85 ° C and 85% relative humidity for 24 hours, and after being taken out, it was placed on a heating plate at 250 ° C Using a bonding force measuring device (bond tester DAGE4000 made by DAGE Corporation), the tool height from the top surface of the silicon wafer (5 mm in height × 5 mm in width × 0.725 mm in thickness) was 0.05 The adhesion force was measured under the conditions of mm and tool speed of 0.05 mm / s.

<Easy gas evaluation> Using a vacuum laminator (manufactured by NPC Co., Ltd., LM-50X50-S), the conditions obtained in the examples or comparative examples were measured at a plateau temperature of 70 ° C, a time of 60 sec, and a pressure of 0.5 MPa. The film-like adhesive was laminated on a silicon wafer (5 mm in length × 5 mm in width × 0.765 mm in thickness and an oxide film coating). Next, a chip-on-chip packaging device "FCB3" (manufactured by Panasonic Co., Ltd., trade name) was used to package a wafer laminated with a film-shaped adhesive on a glass plate. The package conditions were a contact temperature of 100 ° C, a crimping temperature of 250 ° C, a crimping time of 3 seconds, and a crimping pressure of 0.5 MPa. Thereby, a test sample was prepared.

Using a metal microscope (manufactured by Keyence Co., Ltd.), from the upper surface of the test sample prepared as described above, the contaminated portion of the peripheral portion (four sides) of the semiconductor wafer from the wafer end (the glass plate is crimped by pressure When the outgas is polluted and the white turbidity is generated, the average value of the polluted area is calculated as the amount of outgas.

[Table 1]

[Table 2]

In the semiconductor device manufactured using the semiconductor adhesive of Examples 1-18, it was confirmed that the amount of wafer warpage was reduced. Furthermore, in the semiconductor adhesives of Examples 14 to 18, it was confirmed that outgassing was unlikely to occur and the evaluation results were good. In addition, it was confirmed that the semiconductor adhesives of Examples 1, 2, 10, 15 and 16 had high adhesive strength at 250 ° C after moisture absorption.

10‧‧‧Semiconductor wafer

15‧‧‧Wiring (connection section)

20‧‧‧ substrate (wiring circuit substrate)

30‧‧‧ connecting bump

32‧‧‧ bump (connection part)

34‧‧‧through electrode

40‧‧‧ Adhesive Materials

41‧‧‧Adhesives for semiconductors (film adhesives)

50‧‧‧ intermediary

60‧‧‧solder resist

100, 200, 300, 400, 500, 600‧‧‧ semiconductor devices

FIG. 1 is a schematic cross-sectional view showing an embodiment of a semiconductor device of the present disclosure. 2 (a) and 2 (b) are schematic cross-sectional views illustrating another embodiment of a semiconductor device according to the present disclosure. FIG. 3 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present disclosure. 4 (a) to 4 (c) are cross-sectional views schematically showing steps in an embodiment of a method for manufacturing a semiconductor device according to the present disclosure.

Claims (13)

An adhesive for semiconductors containing a thermoplastic resin having a glass transition temperature of 35 ° C or lower. The adhesive for semiconductors according to item 1 of the scope of patent application, which is film-like at 35 ° C. The adhesive for semiconductors according to the first or second scope of the patent application, further comprising a thermosetting resin. The adhesive for semiconductors according to claim 3, wherein the thermosetting resin contains an epoxy resin. The adhesive for semiconductors according to any one of claims 1 to 4, in which the elastic modulus at 35 ° C. of the cured adhesive is 2.0 GPa to 4.0 GPa. The adhesive for semiconductors according to any one of claims 1 to 5, further comprising a carboxylic acid derivative. The adhesive for semiconductors according to item 6 of the application, wherein the carboxylic acid derivative is a compound having a carboxyl group. The adhesive for semiconductors according to claim 6 or claim 7, wherein the carboxylic acid derivative is a compound having two or more carboxyl groups. The adhesive for semiconductors according to any one of claims 6 to 8 in the scope of patent application, wherein the carboxylic acid derivative is a compound represented by the following formula (2); In formula (2), R ¹ and R ² each independently represent a hydrogen atom or an electron-donating group, n represents an integer of 0 to 15, and a plurality of R ² may be the same or different from each other. The adhesive for semiconductors according to any one of claims 6 to 9, in which the melting point of the carboxylic acid derivative is 150 ° C or lower. The adhesive for semiconductors according to any one of claims 1 to 10 in the scope of patent application, which does not substantially contain an epoxy resin that is liquid at 35 ° C. A method for manufacturing a semiconductor device is a method for manufacturing a semiconductor device in which connection portions of a semiconductor wafer and a printed circuit board are electrically connected to each other, or a semiconductor device in which connection portions of a plurality of semiconductor wafers are electrically connected to each other, The manufacturing method of the device includes a step of sealing at least a part of the connection portion using the semiconductor adhesive according to any one of claims 1 to 11 of the scope of patent application. A semiconductor device includes a connection structure in which connection portions of a semiconductor wafer and a printed circuit board are electrically connected to each other, or a connection structure in which connection portions of a plurality of semiconductor wafers are electrically connected to each other; and at least the connection portion A part of the hermetically sealed adhesive material includes a cured product of a semiconductor adhesive as described in any one of claims 1 to 11 of the scope of patent application.