JP7259219B2 - Resin composition, cured product thereof, and method for manufacturing semiconductor device - Google Patents

Description

The present invention relates to a resin composition, a cured product thereof, and a method for manufacturing a semiconductor device.

2. Description of the Related Art Conventionally, a wire bonding connection method using thin metal wires such as gold wires has been widely applied to connect semiconductor chips and substrates. On the other hand, in order to meet the demands for higher functionality, higher integration, and higher speed for semiconductor devices, a flip chip is a semiconductor chip or substrate that is directly connected to a substrate by forming conductive projections called bumps on the semiconductor chip or substrate. A connection method (FC connection method) is spreading.

Known flip-chip connection methods include, for example, a method using solder bumps, a method using gold bumps and a conductive adhesive, a thermocompression bonding method, an ultrasonic method, and the like. These methods have the problem that thermal stress resulting from the difference in coefficient of thermal expansion between the chip and the substrate concentrates on the connecting portion, resulting in reduced connection reliability. In order to prevent such problems, an underfill that fills the gap between the chip and the substrate is generally formed with a resin composition. Since thermal stress is relieved by dispersing in the underfill, it is possible to improve connection reliability.

As a method of forming an underfill, a method of injecting a liquid resin into the gap between the chip and the substrate after connecting the chip and the substrate is generally known (see Patent Document 1). Also known is a method of forming an underfill using a film-like resin in the step of connecting a chip and a substrate (see Patent Document 2).

By the way, the main metals used for the connection portion (bump or wiring) include, for example, solder, tin, gold, silver, copper, nickel, etc., and conductive materials containing multiple types of these are also used. . The metal used for the connection part may have impurities on the connection surface of the connection part because the surface is oxidized to form an oxide film, or impurities such as oxides adhere to the surface. . If such impurities remain, the connectivity and insulation reliability between the semiconductor chip and the substrate or between the two semiconductor chips will deteriorate, and there is concern that the advantage of adopting the above-described connection method will be lost.

In order to suppress the generation of these impurities, for example, an OSP (Organic Solderability Preservatives) process is known, in which the connecting portion is coated with an antioxidant film. This anti-oxidation film may cause deterioration of solder wettability and connectivity during the connection process. Therefore, as a method of removing the anti-oxidation film and impurities, a method of incorporating a fluxing agent into the underfill material has been proposed (see, for example, Patent Documents 3 to 5).

Japanese Patent Application Laid-Open No. 2000-100862 JP-A-2003-142529 JP-A-2002-283098 JP-A-2005-272547 JP 2006-169407 A

Flip-chip packages using the flip-chip connection method are being studied for higher functionality, higher integration, three-dimensional design, and the like. From the viewpoint of reliability, the underfill material used in such a flip chip package is required to have excellent migration resistance, connectivity, and the like.

Therefore, the main object of the present invention is to provide a resin composition that can suppress migration and has excellent connectivity, and a cured product thereof.

As a result of intensive studies by the present inventors in order to achieve the above objects, in the extracted water obtained by boiling the cured product of the resin composition at a high temperature, the chloride ion (chloride ion) concentration and pH (hydrogen ion index) is within a specific range, the resin composition can suppress migration and has excellent connectivity, and has completed the present invention.

That is, the present invention provides a resin composition shown in [1] to [6], a cured product of the resin composition shown in [7], and a method for manufacturing a semiconductor device shown in [8] below.

[1] A resin composition containing an epoxy resin, a thermoplastic resin, a curing agent, a fluxing agent, and an inorganic filler and satisfying the following condition (A).
Condition (A): A resin film made of a resin composition and having a thickness of 20 μm was heated in an air atmosphere at 240° C. for 60 minutes to prepare a cured resin film, and 1 g of the cured resin film and 40 g of deionized water were added. A mixture of and is boiled in a closed container at 121 ° C. under 2 atmospheres for 96 hours, and the extracted water obtained by passing through a mesh with a pore size of 0.45 μm has a chloride ion concentration of 1 mass ppm or less, and a pH value is 3.5 to 7.0.
[2] The resin composition according to [1], wherein the epoxy resin satisfies the following condition (B).
Condition (B): Extracted water obtained by boiling an epoxy resin mixture of 1 g of epoxy resin and 40 g of ion-exchanged water in a closed vessel at 121° C. under 2 atmospheres for 96 hours and passing it through a mesh with a pore size of 0.45 μm. has a chloride ion concentration of 0.3 ppm by mass or less.
[3] The resin composition according to [1] or [2], wherein the thermoplastic resin satisfies the following condition (C).
Condition (C): A thermoplastic resin mixture of 1 g of thermoplastic resin and 40 g of ion-exchanged water is boiled in a closed vessel at 121° C. under 2 atmospheres for 96 hours, and passed through a mesh with a pore size of 0.45 μm. The chloride ion concentration of the extracted water is 0.3 ppm by mass or less.
[4] The resin composition according to any one of [1] to [3], wherein the content of the inorganic filler is 20 to 70% by mass based on the total amount of the resin composition.
[5] The resin composition according to any one of [1] to [4], wherein the fluxing agent is a dicarboxylic acid.
[6] The resin composition according to any one of [1] to [5], which is in the form of a film.
[7] A cured product of the resin composition according to any one of [1] to [6].
[8] A method for manufacturing a semiconductor device in which respective connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, or a semiconductor device in which respective connection portions of a plurality of semiconductor chips are electrically connected to each other A method for manufacturing a semiconductor device, comprising a step of sealing a connection portion using the resin composition according to any one of [1] to [6].

ADVANTAGE OF THE INVENTION According to this invention, the resin composition which can suppress a migration and is excellent in connectivity is provided. The resin composition according to some forms has a flux activity (sufficiently reduces and removes the oxide film on the metal surface to allow the metal to be easily melted, does not prevent the molten metal from spreading and wets, and is effective for metal bonding. It is also excellent in terms of performance that can achieve a state in which a part is formed. Moreover, according to the present invention, a method for manufacturing a semiconductor device using the resin composition is provided.

1 is a schematic cross-sectional view showing an embodiment of a semiconductor device; FIG. It is process sectional drawing which shows typically one Embodiment of the manufacturing method of a semiconductor device.

DETAILED DESCRIPTION OF THE INVENTION Embodiments for carrying out the present invention will be described in detail below. However, the present invention is not limited to the following embodiments.

[Resin composition]
A resin composition according to one embodiment contains an epoxy resin, a thermoplastic resin, a curing agent, a fluxing agent, and an inorganic filler.

(Epoxy resin)
The epoxy resin is not particularly limited as long as it has an epoxy group in its molecule, but an epoxy resin having two or more epoxy groups in its molecule can be preferably used. Examples of such epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, triphenolmethane-type epoxy resin, dicyclopentadiene-type epoxy resin; and polyfunctional epoxy resins thereof. You may use an epoxy resin individually by 1 type or in combination of 2 or more types. Among these, the epoxy resin preferably contains a bisphenol type epoxy resin or a triphenolmethane type epoxy resin.

The epoxy resin is preferably one that can suppress the generation of volatile components due to decomposition during connection at high temperature. Therefore, it is preferable to use an epoxy resin having a mass reduction rate of 5% by mass or less under heating conditions during connection. For example, when the heating temperature at the time of connection is 250°C, it is preferable to use an epoxy resin having a mass reduction rate of 5% by mass or less at 250°C. It is preferable to use the following epoxy resins.

The content of the epoxy resin is preferably 5 to 75% by mass, more preferably 10 to 55% by mass, still more preferably 20 to 50% by mass, based on the total amount of the resin composition. When the content of the epoxy resin is in such a range, there is a tendency for excellent curability and adhesiveness.

The epoxy resin preferably satisfies the following condition (B). When such condition (B) is satisfied, there is a tendency that migration can be further suppressed.
Condition (B): Extracted water obtained by boiling an epoxy resin mixture of 1 g of epoxy resin and 40 g of ion-exchanged water in a closed vessel at 121° C. under 2 atmospheres for 96 hours and passing it through a mesh with a pore size of 0.45 μm. has a chloride ion concentration of 0.3 ppm by mass or less. The chloride ion concentration of the extracted water is more preferably 0.2 ppm by mass or less.

(Thermoplastic resin)
The thermoplastic resin is not particularly limited, but from the viewpoint of obtaining excellent heat resistance, film formability and connection reliability, phenoxy resin, polyimide resin, polyamide resin, polycarbodiimide resin, cyanate ester resin, acrylic resin, polyester resin , polyethylene resin, polyethersulfone resin, polyetherimide resin, polyvinyl acetal resin, urethane resin and acrylic rubber. From the viewpoint of better heat resistance and film formability, the thermoplastic resin preferably contains at least one selected from the group consisting of phenoxy resins, polyimide resins, acrylic rubbers, acrylic resins, cyanate ester resins and polycarbodiimide resins. More preferably, it contains at least one selected from the group consisting of phenoxy resins, polyimide resins, acrylic rubbers and acrylic resins.

The weight average molecular weight of the thermoplastic resin is preferably 10,000 or more, more preferably 20,000 or more, and still more preferably 30,000 or more. When the weight average molecular weight of the thermoplastic resin is 10,000 or more, the heat resistance and film formability of the resin composition tend to be further improved. The weight average molecular weight of the thermoplastic resin is preferably 1,000,000 or less, more preferably 500,000 or less. When the weight average molecular weight of the thermoplastic resin is 1,000,000 or less, the effect of high heat resistance tends to be obtained.

The weight average molecular weight means a value measured using GPC (Gel Permeation Chromatography) and converted using a standard polystyrene calibration curve. An example of measurement conditions for the weight average molecular weight is shown below.

Apparatus name: HCL-8320GPC, UV-8320 (manufactured by Tosoh Corporation), or HPLC-8020 (manufactured by Tosoh Corporation)
Column: TSKgel superMultiporeHZ-M × 2, or 2 pieces of GMHXL + 1 piece of G-2000XL (both manufactured by Tosoh Corporation)
Detector: RI or UV detector Column temperature: 25-40°C
Eluent: A solvent in which the measurement target dissolves can be selected. Examples of solvents include THF (tetrahydrofuran), DMF (N,N-dimethylformamide), DMA (N,N-dimethylacetamide), NMP (N-methyl-2-pyrrolidone), toluene and the like. When selecting a polar solvent, the concentration of phosphoric acid is 0.05 to 0.1 mol/L (usually 0.06 mol/L), and the concentration of LiBr is 0.5 to 1.0 mol/L ( Normally, it may be adjusted to 0.63 mol/L).
Flow rate: 0.30-1.5 mL/min Standard material: polystyrene

The mass ratio of the epoxy resin content to the thermoplastic resin content (epoxy resin content/thermoplastic resin content) based on the total amount of the resin composition is preferably 0.01 to 20, More preferably 0.05 to 15, still more preferably 0.1 to 10.

The thermoplastic resin preferably satisfies the following condition (C). When such condition (C) is satisfied, there is a tendency that migration can be further suppressed.
Condition (C): A thermoplastic resin mixture of 1 g of thermoplastic resin and 40 g of ion-exchanged water is boiled in a closed vessel at 121° C. under 2 atmospheres for 96 hours, and passed through a mesh with a pore size of 0.45 μm. The chloride ion concentration of the extracted water is 0.3 ppm by mass or less. The chloride ion concentration of the extracted water is more preferably 0.2 ppm by mass or less.

(curing agent)
The curing agent is not particularly limited, and examples thereof include imidazole-based curing agents, phenolic resin-based curing agents, acid anhydride-based curing agents, amine-based curing agents, and phosphine-based curing agents. Among these, the curing agent preferably contains an imidazole-based curing agent from the viewpoint of exhibiting good flux performance and being more excellent in storage stability and heat resistance of the cured product of the resin composition.

Examples of imidazole curing agents include 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole. , 1-cyano-2-phenylimidazole, 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′-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-s-triazine Isocyanuric acid adducts, isocyanuric acid adducts of 2-phenylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, adducts of epoxy resins and imidazoles etc. You may use these individually by 1 type or in combination of 2 or more types.

Among these, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate are used from the viewpoint of better curability, storage stability and connection reliability. , 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-s-triazine, 2,4-diamino-6-[2′-methylimidazolyl-(1′)]-ethyl-s-triazine At least one selected from the group consisting of isocyanuric acid adducts, isocyanuric acid adducts of 2-phenylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole is preferred. Alternatively, these may be microencapsulated and used as a latent curing agent.

The content of the curing agent is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin. When the content of the curing agent is 0.1 parts by mass or more with respect to 100 parts by mass of the epoxy resin, the curability tends to be further improved. Since the resin composition does not harden before it is applied, connection failure tends to be less likely to occur.

(flux agent)
As the fluxing agent, any compound having a carboxyl group can be used without particular limitation, but a dicarboxylic acid (a compound having two carboxyl groups) is preferred. Compared to monocarboxylic acids (compounds having one carboxyl group), dicarboxylic acids are less likely to volatilize even at high temperatures during connection, and tend to be able to further suppress the formation of voids. Moreover, the use of a dicarboxylic acid can further suppress the increase in the viscosity of the resin composition during storage, connection work, etc., as compared with the case of using a compound having three or more carboxyl groups. connectivity can be further improved.

The fluxing agent can be, for example, a dicarboxylic acid with linear or branched alkylene groups. Examples of such dicarboxylic acids include succinic acid (melting point: 184° C.), glutaric acid (melting point: 95-98° C.), adipic acid (melting point: 152° C.), pimelic acid (melting point: 103-105° C.), suberic acid (melting point: 141-144°C), azelaic acid (melting point: 109°C), sebacic acid (melting point: 133-137°C), undecanedioic acid (melting point: 28-31°C), dodecanedioic acid (melting point: 127°C) ~ 129 ° C.) and other dicarboxylic acids having a linear alkylene group; branched dicarboxylic acids in which one or more hydrogen atoms at the 2- or 3-position of these dicarboxylic acids having a linear alkylene group are substituted with alkyl groups A dicarboxylic acid having an alkylene group and the like can be mentioned. Dicarboxylic acids having a branched alkylene group include, for example, 2-methylglutaric acid (melting point: 80 to 82°C). The fluxing agent preferably contains 2-methylglutaric acid or glutaric acid.

The melting point of the fluxing agent is preferably 150° C. or lower, more preferably 140° C. or lower, and even more preferably 130° C. or lower. Such a flux agent tends to exhibit sufficient flux performance before the curing reaction between the epoxy resin and the curing agent occurs. Therefore, by using a resin composition containing such a fluxing agent, a semiconductor device with even better connection reliability can be produced. Moreover, the fluxing agent is preferably solid at room temperature (25° C.), and the melting point of the fluxing agent is preferably 25° C. or higher, more preferably 50° C. or higher.

The content of the fluxing agent may be, for example, 0.5 to 10% by mass based on the total amount of the resin composition.

(Inorganic filler)
By containing an inorganic filler, the resin composition tends to further suppress the generation of voids at the time of connection and further reduce the hygroscopicity of the cured product of the resin composition.

The inorganic filler is preferably an insulating substance from the viewpoint of excellent insulation reliability (especially HAST resistance). Examples of such inorganic fillers include glass, silica, alumina, titanium oxide, carbon black, mica, and boron nitride. You may use these individually by 1 type or in combination of 2 or more types. Among these, the inorganic filler is preferably at least one selected from the group consisting of silica, alumina, titanium oxide, and boron nitride, more preferably at least one selected from the group consisting of silica, alumina, and boron nitride. be. Their shape and particle size are not particularly limited. Moreover, the inorganic filler may be surface-treated.

The content of the inorganic filler is preferably 20 to 70% by mass, more preferably 25 to 65% by mass, still more preferably 30 to 60% by mass, based on the total amount of the resin composition. When the content of the inorganic filler is within this range, the resin composition tends to have a smooth appearance when formed into a film, and the components tend to be easily dispersed.

(resin filler)
The resin composition may further contain a resin filler. Examples of resin fillers include fillers made of resins such as polyurethane and polyimide. The content of the resin filler is preferably 1 to 30% by mass, more preferably 2 to 30% by mass, still more preferably 3 to 15% by mass, based on the total amount of the resin composition.

(other ingredients)
The resin composition may further contain, as other components, a curing accelerator, a silane coupling agent, a titanium coupling agent, an antioxidant, a leveling agent, an ion trapping agent, and the like. The content of other components can be appropriately adjusted so that each component exhibits its effect, and may be, for example, 0.1 to 20% by mass based on the total amount of the resin composition.

The resin composition satisfies the following condition (A).
Condition (A): A resin film made of a resin composition and having a thickness of 20 μm was heated in an air atmosphere at 240° C. for 60 minutes to prepare a cured resin film, and 1 g of the cured resin film and 40 g of deionized water were added. A mixture of and is boiled in a closed container at 121 ° C. under 2 atmospheres for 96 hours, and the extracted water obtained by passing through a mesh with a pore size of 0.45 μm has a chloride ion concentration of 1 mass ppm or less, and a pH value is 3.5 to 7.0.

From the viewpoint of suppressing migration, the chlorine ion concentration of the extraction water is preferably 0.8 mass ppm or less, more preferably 0.7 mass ppm. Chlorine ions in the extracted water are mainly chlorine ions that can be contained in epoxy resins and thermoplastic resins. Therefore, the chloride ion concentration of the extracted water can be adjusted by varying the types and contents of these components. In addition, in this specification, the chloride ion concentration of extraction water means the concentration obtained by measuring extraction water by the ion chromatography method.

The pH value (hydrogen ion index) of the extraction water is preferably 3.5 to 6.0, more preferably 3.6 to 5.5, and still more preferably 3.8 to 5.0, from the viewpoint of suppressing migration. is. The pH value of the extracted water is mainly hydrogen ions that can be contained in the fluxing agent. Therefore, the pH value (hydrogen ion index) of the extracted water can be adjusted by varying the type and content of the fluxing agent. In this specification, the pH value (hydrogen ion index) of the extraction water means the pH value (hydrogen ion index) obtained by measuring the extraction water by the glass electrode method.

The resin composition may be film-like. In this specification, a film-like resin composition may be referred to as a "resin film".

The resin film is prepared, for example, by adding an organic solvent to the resin composition as necessary, stirring, mixing, kneading, etc., and applying a resin composition varnish on a base film that has been subjected to mold release treatment, using a knife coater, Apply using a roll coater, applicator, or the like. After that, by heating the applied resin composition varnish to remove the organic solvent, a resin film can be formed on the substrate film.

The organic solvent used in the preparation of the resin composition varnish is not particularly limited as long as it has the property of uniformly dissolving or dispersing each component. Examples include dimethylformamide, dimethylacetamide, and N-methyl-2-pyrrolidone. , dimethyl sulfoxide, diethylene glycol dimethyl ether, toluene, benzene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, dioxane, cyclohexanone, ethyl acetate and the like. These organic solvents can be used singly or in combination of two or more. Among these, the organic solvent preferably contains methyl ethyl ketone.

Stirring and mixing, kneading, and the like in the preparation of the resin composition varnish can be performed using, for example, a stirrer, a kneader, a three-roll mill, a ball mill, a bead mill, a homodisper, and the like.

The base film is not particularly limited as long as it has heat resistance that can withstand the heating conditions when drying the organic solvent. Examples of the base film include polyolefin films such as polypropylene films and polymethylpentene films, polyester films such as polyethylene terephthalate films and polyethylene naphthalate films, polyimide films, and polyetherimide films. The substrate film may be a monolayer film of one kind alone, or a multilayer film in which two or more kinds are combined.

The thickness of the resulting resin film can be adjusted, for example, based on the height of the bumps before connection. It is preferably 0.6 to 1.3 times, more preferably 0.7 to 1.2 times. When the thickness of the resin film is 0.5 times or more the height of the bump, the occurrence of voids due to the unfilled resin film can be sufficiently suppressed, and the connection reliability can be further improved. Further, when the thickness of the resin film is 1.5 times or less, the amount of the resin film extruded from the chip connection region during connection can be sufficiently suppressed, and the adhesion of the resin film to unnecessary portions can be sufficiently prevented. can be prevented. Therefore, it is not necessary to remove the resin film from the bumps, so that it is possible to prevent defective conduction and reduce damage caused by weakening of the bumps (reduction of the diameter of the bumps) due to narrowing of the pitch and increase in the number of pins. Since the height of bumps is generally 5 to 100 μm, the thickness of the resin film is preferably 2.5 to 150 μm, more preferably 3.5 to 120 μm.

The drying conditions for volatilizing the organic solvent from the resin composition varnish applied to the base film are not particularly limited as long as the organic solvent is sufficiently volatilized, but the drying conditions are 50 to 200° C. for 0.1 to 90 minutes. Heating is preferred. The organic solvent is preferably removed to 1.5% by mass or less with respect to the total amount of the resin film.

The resin film may be formed directly on the wafer. Specifically, for example, a resin film may be formed directly on the wafer by directly spin-coating the resin composition varnish onto the wafer and then removing the organic solvent.

<Semiconductor device>
The resin composition according to the present embodiment is suitably used for semiconductor devices (suitable as an adhesive for semiconductors), and semiconductor devices in which respective connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, Alternatively, it is particularly suitably used for sealing the connecting portions in a semiconductor device in which the connecting portions of a plurality of semiconductor chips are electrically connected to each other.

A semiconductor device using the resin composition according to this embodiment will be described. The connection part in the semiconductor device may be either metal bonding between the bump and the wiring or metal bonding between the bump and the bump. In a semiconductor device, for example, flip-chip bonding that obtains electrical connection via an adhesive may be used.

FIG. 1 is a schematic cross-sectional view showing one embodiment of a semiconductor device. As shown in FIG. 1, a semiconductor device 100 includes a semiconductor chip 10 and a substrate (circuit wiring substrate) 20 facing each other, wirings 15 arranged on surfaces of the semiconductor chip 10 and the substrate 20 facing each other, and a semiconductor chip. 10 and the wiring 15 of the substrate 20 to each other, and a resin film 40 filling the gap between the semiconductor chip 10 and the substrate 20 without gaps. The semiconductor chip 10 and substrate 20 are flip-chip connected by wiring 15 and connection bumps 30 . The wiring 15 and the connection bumps 30 are sealed with a resin film 40 and isolated from the external environment.

<Method for manufacturing a semiconductor device>
The method for manufacturing a semiconductor device according to one embodiment includes, for example, a semiconductor device in which connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, or a semiconductor device in which connection portions of a plurality of semiconductor chips are electrically connected to each other. A method for manufacturing a semiconductor device connected to a semiconductor device, comprising a step of sealing at least a portion of a connection portion using the resin composition. A method for manufacturing the semiconductor device of this embodiment will be described below with reference to FIG. FIG. 2 is a process cross-sectional view schematically showing an embodiment of a method for manufacturing a semiconductor device.

First, as shown in FIG. 2A, a solder resist 60 having openings at positions where connection bumps 30 are to be formed is formed on a substrate 20 having wiring (for example, gold bumps) 15 . This solder resist 60 does not necessarily have to be provided. However, by providing a solder resist on the substrate 20, it is possible to suppress the occurrence of bridges between the wirings 15 and improve connection reliability and insulation reliability. The solder resist 60 can be formed using, for example, a commercially available package solder resist ink. Specific examples of commercially available solder resist inks for packages include SR series (manufactured by Hitachi Chemical Co., Ltd., trade name), PSR4000-AUS series (manufactured by Taiyo Ink Mfg. Co., Ltd., trade name), and the like.

Next, as shown in FIG. 2A, connection bumps (for example, solder bumps) 30 are formed in the openings of the solder resist 60. Next, as shown in FIG. Then, as shown in FIG. 2B, the resin film 40 is attached onto the substrate 20 on which the connection bumps 30 and the solder resist 60 are formed. The adhesion of the resin film 40 can be performed by hot pressing, roll lamination, vacuum lamination, or the like. The supply area and thickness of the resin film 40 are appropriately set according to the sizes of the semiconductor chip 10 and the substrate 20, the height of the connection bumps 30, and the like.

After the resin film 40 is attached to the substrate 20 as described above, the wiring 15 of the semiconductor chip 10 and the connection bumps 30 are aligned using a connection device such as a flip chip bonder. Subsequently, the semiconductor chip 10 and the substrate 20 are pressure-bonded while being heated at a temperature equal to or higher than the melting point of the connection bumps 30 to connect the semiconductor chip 10 and the substrate 20 as shown in FIG. 40 seal-fills the gap between the semiconductor chip 10 and the substrate 20 . As described above, the semiconductor device 600 is obtained.

In the manufacturing method of the semiconductor device according to the present embodiment, the semiconductor chip 10 and the substrate 20 may be connected to each other by temporarily fixing them after alignment and heat-treating them in a reflow furnace to melt the connection bumps 30 . . At the stage of temporary fixation, it is not always necessary to form a metal joint. Therefore, compared to the above-mentioned method of crimping while heating, crimping with a lower load, a shorter time, and a lower temperature is sufficient, which improves productivity and connection. It is possible to suppress the deterioration of the part.

Further, after connecting the semiconductor chip 10 and the substrate 20, heat treatment may be performed in an oven or the like to further improve connection reliability and insulation reliability. The heating temperature is preferably a temperature at which curing of the resin film proceeds, more preferably a temperature at which the resin film is completely cured. The heating temperature and heating time are appropriately set.

In the method of manufacturing the semiconductor device according to this embodiment, the substrate 20 may be connected after the resin film 40 is attached to the semiconductor chip 10 . Alternatively, after the semiconductor chip 10 and the substrate 20 are connected by the wiring 15 and the connection bumps 30, the space between the semiconductor chip 10 and the substrate 20 may be filled with a paste-like semiconductor sealing adhesive.

The connection load is set in consideration of the variation in the number and height of the connection bumps 30, the deformation amount of the connection bumps 30 due to pressure, or the wiring receiving the bumps of the connection portion. As for the connection temperature, it is preferable that the temperature of the connection portion is equal to or higher than the melting point of the connection bump 30, but the temperature may be any temperature at which metal bonding of each connection portion (bump and wiring) is formed. If the connection bumps 30 are solder bumps, the temperature should be approximately 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 connection time, the better. When the connection bumps 30 are solder bumps, 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 metal connection such as copper-copper or copper-gold, the connection time is preferably 60 seconds or less.

EXAMPLES The present invention will be specifically described below based on examples, but the present invention is not limited to these.

<Examples 1 to 3 and Comparative Examples 1 to 5>
Epoxy resins, curing agents, fluxing agents, inorganic fillers, resin fillers, and coupling agents of the types and contents shown in Table 1 were added to a ball mill container, and methyl ethyl ketone was added so that the solid content was 50% by mass. Beads with a diameter of 0.8 mm and beads with a diameter of 2.0 mm were added to the ball mill container in the same mass as the solid content, and stirred for 30 minutes using a ball mill device (manufactured by RETSCH Co., Ltd., trade name "planetary ball mill PM400"). bottom. Thereafter, a thermoplastic resin having the type and content shown in Table 1 was added to the ball mill container, and stirred again for 30 minutes with the ball mill. A resin composition varnish was obtained by removing the beads used for stirring by filtration.

The resulting resin composition varnish is coated on a substrate film (manufactured by Teijin Film Solution Co., Ltd., trade name "Purex A70") with a small precision coating device (Radoi Seiki Co., Ltd.), and then in a clean oven. (manufactured by Espec Co., Ltd.) and dried (70° C./10 min) to obtain resin films (thickness: 20 μm) of Examples 1 to 3 and Comparative Examples 1 to 5.

Materials used in Examples and Comparative Examples are as follows.
(Epoxy resin)
EP1032: Triphenolmethane skeleton-containing polyfunctional solid epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "EP1032H60", chloride ion concentration (measured value): 0.17 mass ppm)
YL983U: Bisphenol F type liquid epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name “YL983U”, chloride ion concentration (measured value): 0.16 mass ppm)
YX-7110: long-chain bisphenol F type liquid epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name “YX-7110”, chloride ion concentration (measured value): 0.80 mass ppm)
(Thermoplastic resin)
FX-293: fluorene skeleton-containing phenoxy resin (manufactured by Shin Nikka Epoxy Manufacturing Co., Ltd., trade name “FX-293”, chloride ion concentration (measured value): 0.21 mass ppm)
LA2250: Triblock copolymer of polymethyl methacrylate and polybutyl acrylate (manufactured by Kuraray Co., Ltd., trade name “Clarity LA2250”, chloride ion concentration (measured value): 0.10 mass ppm)
ZX-1356-2: Bisphenol A/F copolymerized phenoxy resin (Shin Nikka Epoxy Mfg. Co., Ltd., trade name “ZX1356”, chloride ion concentration (measured value): 0.82 mass ppm)
(curing agent)
2P4MHZ: 2-phenyl-4-methyl-5-hydroxymethylimidazole (manufactured by Shikoku Kasei Co., Ltd., trade name “2P4MHZ-PW”)
(flux agent)
Glutaric acid (manufactured by Tokyo Chemical Industry Co., Ltd., melting point about 98°C)
(Inorganic filler)
SE2050: Silica filler (manufactured by Admatechs Co., Ltd., trade name “SE2050”, average particle size 0.5 μm)
(resin filler)
EXL-2655: Organic filler (core-shell type organic fine particles) (manufactured by Dow Chemical Japan Co., Ltd., trade name “EXL-2655”)
(coupling agent)
SH6040: Silane coupling agent (Dow Corning Toray Co., Ltd., trade name "SH6040")

The chlorine ion concentration (actual value) of the epoxy resin and the thermoplastic resin was obtained by boiling a mixture of 1 g of each resin and 40 g of ion-exchanged water in a closed container at 121 ° C. under 2 atmospheres for 96 hours. .45 μm mesh (manufactured by Advantec Toyo Co., Ltd., trade name: membrane filter), and the chlorine ion concentration of the extracted water obtained by passing it through is measured by ion chromatography.

<Measurement of chlorine ion concentration and pH value of extracted water of cured product of resin film (resin composition)>
The resin films (thickness: 20 μm) of Examples 1 to 3 and Comparative Examples 1 to 5 were each heated at 240° C. for 60 minutes in an air atmosphere to obtain cured resin films. The obtained cured resin film was appropriately cut into a sealed container to prepare a mixture of 1 g of the cured resin film and 40 g of deionized water. The prepared mixture was placed in a container, sealed, boiled in a closed container at 121° C. under 2 atmospheres for 96 hours, and passed through a mesh with a pore size of 0.45 μm (manufactured by Advantec Toyo Co., Ltd., trade name: membrane filter). . The chloride ion concentration of the extracted water thus obtained was measured by ion chromatography. Moreover, the pH value of the extracted water obtained was measured by the glass electrode method. Table 1 shows the results of chloride ion concentration and pH value.

<Migration resistance evaluation (insulation reliability test (HAST test)>
The resin films (thickness: 20 μm) of Examples 1 to 3 and Comparative Examples 1 to 5 were attached to a comb-shaped electrode evaluation TEG (manufactured by Hitachi Chemical Co., Ltd., wiring pitch: 40 μm), and a clean oven (manufactured by Espec Co., Ltd. ) at 175° C. for 2 hours. The resin film after curing is installed in a highly accelerated life test device (manufactured by Hirayama Seisakusho Co., Ltd., product name “PL-422R8”, and 5V is applied at 130 ° C. / 85% RH / 100 hours to measure the insulation resistance. When the insulation resistance after 100 hours was 1.0×10 ⁶ Ω or more, it was evaluated as “A”, and when it was less than 1.0×10 ⁶ Ω, it was evaluated as “B”. Table 1 shows the results.

<Connectivity>
The resin film of the example or comparative example that was "A" in the migration resistance evaluation was cut into a predetermined size (length 8 mm × width 8 mm × thickness 0.040 mm), and a glass epoxy substrate (glass epoxy substrate: 420 µm (thickness, copper wiring: 9 μm thick), a semiconductor chip with solder bumps (chip size: length 7.3 mm × width 7.3 mm × thickness 0.15 mm, bump height: total of copper pillars and solder) 40 μm in height, 328 bumps) was mounted by a flip mounting device (manufactured by Panasonic Corporation, product name “FCB3”) (mounting conditions: crimping head temperature of 350° C., crimping time of 5 seconds, crimping pressure of 0.5 MPa). Thus, a semiconductor device (see FIG. 1) in which the glass epoxy substrate and the semiconductor chip with solder bumps are daisy chain connected was produced.

The initial conduction after mounting was evaluated by measuring the connection resistance value of the fabricated semiconductor device using a multimeter (manufactured by ADC Corporation, trade name "R6871E"). If the connection resistance value is 10.0 Ω or more and 13.5 Ω or less, the connection is evaluated as "A", and if the connection resistance value is more than 13.5 Ω and 20 Ω or less, the connection resistance value is evaluated as "B". is greater than 20Ω, or the connection resistance value is less than 10Ω, or the case of Open due to poor connection (when the resistance value is not displayed) was evaluated as "C". Table 1 shows the results.

<Flux activity evaluation>
Regarding the examples in which the connectivity was good in the connectivity evaluation, the cross section of the connection portion was observed, and the case where the solder wettability on the upper surface of the Cu wiring was 90% or more was evaluated as good and "A" was evaluated, and the solder wettability was 90%. % was evaluated as "B". Table 1 shows the results.

The resin compositions of Examples 1 to 3 were able to suppress the occurrence of migration and were excellent in connectivity. Furthermore, the resin compositions of Examples 1 to 3 were also excellent in flux activity. The resin compositions of Comparative Examples 1 and 2 did not satisfy the condition (A) in chloride ion concentration, and had insufficient migration resistance. The resin composition of Comparative Example 3 does not contain an inorganic filler, has a relatively increased content of the epoxy resin and the thermoplastic resin, does not satisfy the condition (A) in the chloride ion concentration, and has poor migration resistance. it wasn't enough. Since the resin composition of Comparative Example 4 had a pH value of less than 3.5, it did not satisfy the condition (A) and had insufficient migration resistance. The resin composition of Comparative Example 5 did not contain a fluxing agent and had insufficient connectivity.

DESCRIPTION OF SYMBOLS 10... Semiconductor chip, 15... Wiring (connection part), 20... Substrate (circuit wiring board), 30... Connection bump, 40... Resin film, 60... Solder resist, 100, 600... Semiconductor device.

Claims (4)

Contains epoxy resin, thermoplastic resin, curing agent, fluxing agent, and inorganic filler,
A resin composition that satisfies the following condition (A),
The epoxy resin comprises a bisphenol type epoxy resin or a triphenolmethane type epoxy resin,
The epoxy resin satisfies the following condition (B),
The thermoplastic resin contains at least one selected from the group consisting of phenoxy resins, polyimide resins, acrylic rubbers, and acrylic resins,
The thermoplastic resin satisfies the following condition (C),
the fluxing agent is a dicarboxylic acid,
The content of the epoxy resin is 20 to 50% by mass based on the total amount of the resin composition,
The mass ratio of the content of the epoxy resin to the content of the thermoplastic resin based on the total amount of the resin composition is 0.1 to 10,
The content of the curing agent is 0.1 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin,
The content of the flux agent is 0.5 to 10% by mass based on the total amount of the resin composition,
A resin composition in which the content of the inorganic filler is 30 to 60% by mass based on the total amount of the resin composition.
Condition (A): A resin film made of a resin composition and having a thickness of 20 μm was heated in an air atmosphere at 240° C. for 60 minutes to prepare a cured resin film, and 1 g of the cured resin film and 40 g of deionized water were added. A mixture of and is boiled in a closed container at 121 ° C. under 2 atmospheres for 96 hours, and the extracted water obtained by passing through a mesh with a pore size of 0.45 μm has a chloride ion concentration of 1 mass ppm or less, and a pH value is 3.8 to 5.0.
Condition (B): Extracted water obtained by boiling an epoxy resin mixture of 1 g of epoxy resin and 40 g of ion-exchanged water in a closed vessel at 121° C. under 2 atmospheres for 96 hours and passing it through a mesh with a pore size of 0.45 μm. has a chloride ion concentration of 0.3 ppm by mass or less.
Condition (C): A thermoplastic resin mixture of 1 g of thermoplastic resin and 40 g of ion-exchanged water is boiled in a closed vessel at 121° C. under 2 atmospheres for 96 hours, and passed through a mesh with a pore size of 0.45 μm. The chlorine ion concentration of the extraction water is 0.3 ppm by mass or less. The resin composition according to claim 1 , which is in the form of a film. A cured product of the resin composition according to claim 1 . A method for manufacturing a semiconductor device in which connection portions of a semiconductor chip and a printed circuit board are electrically connected to each other or a semiconductor device in which connection portions of a plurality of semiconductor chips are electrically connected to each other,
A method of manufacturing a semiconductor device, comprising the step of sealing the connecting portion using the resin composition according to claim 1 .

Images