Manufacturing method for electronic component and resin composition

Abstract

To provide a method for manufacturing an electronic component, which can obtain an electronic component having excellent long-term reliability even in a fine bump pattern, and a resin composition suitable for the method.SOLUTION: A method for manufacturing an electronic component includes: a bump pattern forming step of forming a bump pattern containing a conductive component and a reactive organic component; a blooming step of placing the bump pattern between an electrode of a circuit board and an electrode of an element and heating and / or pressurizing the bump pattern to cause at least a portion of the reactive organic component to seep onto the surface of the bump pattern; a protective film forming step of reacting the exuded reactive organic component to form a protective film on the surface of the bump pattern; and a connecting step of connecting the electrode of the circuit board and the electrode of the electronic component.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a method for producing an electronic component and a resin composition. [Background technology]

[0002] In recent years, the display industry has actively explored microLEDs, which are LED chips with sides measuring less than 100 μm. The flip-chip mounting method is a preferred method for mounting microLEDs. This method involves forming electrodes on the surface of the chip and directly connecting them to electrodes on a substrate, thereby minimizing the wiring area between the chip and the substrate. In flip-chip mounting, the bonding material used to electrically connect the electrodes on the chip surface to those on the substrate is called a bump. While bumps have traditionally been formed primarily with solder, they require heat to melt during formation and connection. Therefore, when the electrode pitch is less than 20 μm, there is a high risk of short circuits between adjacent bumps due to the molten solder connecting them. Therefore, alternative materials to solder are being explored for use in bumps with finer structures.

[0003] Examples of packaging technologies using new connecting materials that can replace solder include a conductive paste containing an organic component and conductive particles, wherein the storage modulus of a dried film of the conductive paste is 0.01 MPa or less at 100°C and the storage modulus of the dried film at 25°C after heating at 140°C for 30 minutes is 0.01 MPa or more; a method for producing a printed circuit board (see, for example, Patent Document 1) that includes the steps of forming a dried film of the conductive paste on a printed wiring board, exposing and developing the dried film to light, thereby forming conductive bumps on electrodes of the printed wiring board, and thermocompressing electronic components having electrodes on the conductive bumps; and a method for producing a printed circuit board (see, for example, Patent Document 2), which includes a step of bringing bumps on a circuit board with bumps obtained by a method for producing a circuit board with bumps, the method including a step of forming a dry film of the positive photosensitive conductive composition on a circuit board, and a step of exposing and developing the dry film to form a conductive pattern on electrodes of the circuit board, into contact with electrodes of an electronic component having electrodes, and thermocompression-bonding the circuit board with bumps and the electronic component having electrodes at a temperature below 120°C, and a step of heating to 120°C or higher to cure the bumps. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2022 / 030324 [Patent Document 2] Japanese Patent Publication No. 2022-55761 Summary of the Invention [Problem to be solved by the invention]

[0005] The techniques described in Patent Documents 1 and 2 make it possible to easily form fine bump patterns and improve conductivity and bonding strength. However, because the bonded portions between the bumps and electrodes are exposed to the atmosphere, corrosion of the bonded portions is likely to occur due to the application of voltage over a long period of time, resulting in a decrease in conductivity and bonding strength, and thus posing a problem in terms of long-term reliability.

[0006] Therefore, an object of the present invention is to provide a method for producing electronic components that can provide electronic components with excellent long-term reliability even when they have a fine bump pattern, and a resin composition suitable for this method. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention mainly has the following configuration. <1> a bump pattern forming step of forming a bump pattern containing a conductive component and a reactive organic component; a blooming step in which the bump pattern is placed between the electrode of the circuit board and the electrode of the element and heated and / or pressurized to cause at least a portion of the reactive organic component to bleed onto the surface of the bump pattern; a protective film forming step of forming a protective film on the bump pattern surface by reacting the exuded reactive organic component; A process for connecting electrodes on a circuit board with electrodes on electronic components A method for manufacturing an electronic component having the above structure. <2> A resin composition comprising a conductive nanofiller (A), a binder resin (B), and a siloxane compound (C) having two or more structures represented by the following general formula (1):

[0008] [ka]

[0009] In the above general formula (1), R 1 represents a monovalent organic group having an epoxy group and / or an oxetanyl group, R 2 represents an alkyl group, a hydroxy group, or an alkoxy group. <3> The weight average molecular weight of the siloxane compound (C) is 3,000 or less. <2> The resin composition described above. <4> The total of the epoxy equivalent and the oxetanyl equivalent of the siloxane compound (C) is 500 g / eq or less. <2> or <3> The resin composition described above. <5> Furthermore, the epoxy compound (D) has a softening point of 50°C or higher. <2> ~ <4> The resin composition according to any one of the preceding claims. <6> The binder resin (B) contains an alkali-soluble resin, and further contains a photosensitizer (E). <2> ~ <5> The resin composition according to any one of the preceding claims. <7> The photosensitizer (E) contains a photopolymerization initiator. <6> The resin composition described above. <8> The photosensitizer (E) contains a naphthoquinone diazide compound. <6> The resin composition described above. <9> <2> ~ <8> a bump pattern forming step of forming a bump pattern from the resin composition according to any one of the preceding claims; a blooming step in which a bump pattern is placed between an electrode of a circuit board and an electrode of an element, and heat and / or pressure is applied to cause at least a part of the siloxane compound (C) to ooze out onto the surface of the bump pattern; a protective film forming step of reacting the exuded siloxane compound (C) to form a protective film on the surface of the bump pattern; A process for connecting electrodes on a circuit board with electrodes on electronic components A method for manufacturing an electronic component having the above structure. <10> The bump pattern forming step includes: <6> ~ <8> and a developing step of selectively removing soluble portions with a developer. <9> A method for manufacturing the electronic component described above. [Effects of the Invention]

[0010] By using the method for producing an electronic component and the resin composition of the present invention, it is possible to obtain an electronic component having excellent long-term reliability even when it has a fine bump pattern. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic plan view illustrating a blooming evaluation substrate prepared in an example. [Figure 2] 1A is a schematic plan view and FIG. 1B is a schematic cross-sectional view of a mounting substrate for blooming evaluation produced in an example. [Figure 3] FIG. 1 is a schematic plan view illustrating a glass substrate with gold electrodes used in the examples. [Figure 4] FIG. 2 is a schematic plan view showing a glass substrate with gold electrodes used in the examples and the arrangement of the bump patterns formed thereon. [Figure 5] 1A is a schematic plan view and FIG. 1B is a schematic cross-sectional view of an electronic component fabricated in an example. [Figure 6] FIG. 2 is a plan view schematically illustrating a blooming evaluation method in an example. DETAILED DESCRIPTION OF THE INVENTION

[0012] A first aspect of the present invention is a method for manufacturing an electronic component, which comprises connecting electrodes of a circuit board having electrodes to electrodes of a device having electrodes, and mounting the device on the circuit board. a bump pattern forming step of forming a bump pattern containing a conductive component and a reactive organic component; a blooming step in which the bump pattern is placed between the electrode of the circuit board and the electrode of the element and heated and / or pressurized to cause at least a portion of the reactive organic component to bleed onto the surface of the bump pattern; a protective film forming step of forming a protective film on the bump pattern surface by reacting the exuded reactive organic component; The method includes a connecting step for connecting electrodes of a circuit board with electrodes of an electronic component. The blooming step, protective film forming step, and connecting step may be performed in any order after the bump pattern forming step, and multiple steps may be performed simultaneously. However, the protective film forming step may be performed simultaneously with or after the blooming step. For example, after the bump pattern forming step, the blooming step, protective film forming step, and connecting step may be performed simultaneously, or the blooming step and connecting step may be performed simultaneously, followed by the protective film forming step. Furthermore, one step may be performed multiple times. For example, after the bump pattern forming step, the blooming step and connecting step may be performed simultaneously, and then the protective film forming step and an additional connecting step may be performed simultaneously.

[0013] The present invention is characterized in that at least a portion of the reactive organic component is exuded onto the surface of the bump pattern in the blooming process, and a protective film is formed on the surface of the bump pattern in the protective film forming process. In the blooming process, the exudation of the reactive organic component reduces the organic component in the bump pattern, thereby reducing the volume of the bump pattern, thereby forming a conductive path by the conductive component and reducing the connection resistance of the bump pattern. Furthermore, by forming a protective film on the bump pattern in the protective film forming process, even in fine bump patterns, the joint portion is protected from oxygen and moisture in the atmosphere, suppressing corrosion and improving long-term reliability.

[0014] A second aspect of the present invention is a resin composition containing a conductive nanofiller (A), a binder resin (B), and a siloxane compound (C) having two or more structures represented by the general formula (1) described below, which can be suitably used in the bump pattern forming step of the first aspect. In particular, the siloxane compound (C) described below easily seeps onto the bump pattern surface in the blooming step, and can form a strong protective film in the protective film forming step.

[0015] First, a method for manufacturing an electronic component according to a first embodiment of the present invention will be described.

[0016] <Bump pattern formation process> In the bump pattern forming step, a bump pattern containing a conductive component and a reactive organic component is formed, and the bump pattern is preferably formed on an electrode of a circuit board or an element.

[0017] The bump pattern is a pattern of connecting material equivalent to the bumps that connect electrodes of a circuit board and electrodes of an electronic component during the connection process. It contains a conductive component and a reactive organic component. The conductive component is preferably a conductive filler, and the bump pattern more preferably contains a conductive nanofiller (A), a binder resin (B), and a reactive organic component. The conductive nanofiller (A) ensures stable electrical connection between electrodes during the connection process. Furthermore, the binder resin (B) promotes the exudation of the reactive organic component from the conductive paths formed by the nanofiller during the blooming process, thereby further enhancing the effects of the blooming process. The binder resin (B) acts as a matrix for the bump pattern, suppressing the aggregation of the conductive nanofiller (A) and the formation of conductive paths. Therefore, the bump pattern is not electrically conductive before connection and becomes electrically conductive in the compression direction only after the connection process. The reactive organic component exudes onto the bump pattern surface during the blooming process and reacts with the reactive organic component during the protective film formation process to form a protective film around the bump pattern.

[0018] Examples of the conductive nanofiller (A) and the binder resin (B) include those exemplified in the second embodiment described below.

[0019] Examples of reactive organic components include compounds having a (meth)acryloyl group, compounds having a vinyl group, compounds having an epoxy group, compounds having an oxetanyl group, compounds having a silanol group, and compounds having an alkoxysilyl group. Two or more of these may be contained. When the photolithography method described below is used in the bump pattern formation step, it is preferable that the reactive organic component does not contribute to the photoreaction of the photolithography method. For example, when the bump pattern is formed by photoradical polymerization, preferred reactive organic components are compounds having a vinyl group, compounds having an epoxy group, compounds having an oxetanyl group, compounds having a silanol group, and compounds having an alkoxysilyl group, and more preferred is a siloxane compound (C) having two or more structures represented by general formula (1) described below in the second embodiment.

[0020] The reactive organic component preferably has insulating properties after the reaction.

[0021] When the photolithography method described later is used in the bump pattern forming step, the bump pattern preferably further contains a photosensitizer (E) exemplified in the second embodiment described later.

[0022] Examples of methods for forming a bump pattern include printing methods such as gravure printing, flexographic printing, offset printing, screen printing, and inkjet printing, coating methods such as a dispenser method, and photolithography using a photosensitive resin composition. A bump pattern formed on a release substrate by these methods may be transferred to a predetermined substrate. Among these, photolithography is preferred from the viewpoint of easily forming a high-resolution bump pattern.

[0023] When forming a bump pattern by photolithography, it is preferable to have an exposure step in which a film made of a photosensitive resin composition that constitutes the bump pattern is irradiated with ultraviolet light in a manner corresponding to the bump pattern, and a development step in which soluble portions are selectively removed with a developer.

[0024] Examples of methods for forming a film made of a photosensitive resin composition include spray coating, roll coating, screen printing, and methods using a blade coater, die coater, calendar coater, meniscus coater, bar coater, roll coater, comma roll coater, gravure coater, screen coater, and slit die coater.

[0025] If necessary, the coating film may be dried. When the photosensitive resin composition contains a solvent, it is preferable to remove the solvent by drying. Drying methods include, for example, heat drying using an oven, a hot plate, infrared rays, etc., and vacuum drying. The drying temperature and drying time can be appropriately selected within a range that allows the solvent to be removed by evaporation, and are preferably selected so that the coating film remains in an uncured state. The drying temperature is preferably 50 to 150°C, and may be increased in stages. The drying time is preferably 10 seconds to 30 minutes.

[0026] The thickness of the film made of the photosensitive material can be appropriately selected according to the desired thickness of the bump pattern. When dried, the film thickness after drying is preferably 0.5 μm or more and 10 μm or less.

[0027] Examples of light sources used in the exposure step include j-line, i-line, h-line, and g-line from a mercury lamp. Methods of irradiating ultraviolet light in accordance with the bump pattern include a method of exposing through a mask having a desired pattern, and a method of directly exposing the pattern using a laser exposure device. The exposure dose is 30 to 800 mJ / cm. 2 is preferred.

[0028] The developer used in the development step is preferably an aqueous solution of an alkaline compound such as tetramethylammonium, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, methylamine, dimethylamine, dimethylaminoethyl acetate, dimethylaminoethanol, dimethylaminoethyl methacrylate, cyclohexylamine, ethylenediamine, hexamethylenediamine, etc. Furthermore, it may contain a surfactant.

[0029] After development, the resist may be rinsed with a rinse solution, preferably pure water.

[0030] <Blooming process> In the blooming process, the bump pattern is placed between the electrode of the circuit board and the electrode of the element, and heated and / or pressurized to cause at least a portion of the reactive organic component to seep onto the surface of the bump pattern. Heating and pressurization are preferred, as this can further promote the exudation of the reactive organic component. As mentioned above, the blooming process may also serve as the protective film forming process and / or the connecting process, and these processes can be combined by selecting the heating and / or pressurization conditions, for example. When the blooming process also serves as the connecting process, the bump pattern may be cured into a bump, and even in this case, the process is still a process of causing at least a portion of the reactive organic component to seep onto the surface of the bump pattern.

[0031] A circuit board refers to a substrate on which electrodes are arranged and / or within which electrodes are arranged.

[0032] Examples of the element include chip-type elements having at least one connection electrode, such as an LED chip, a mini LED chip, a micro LED chip, an IC chip, an LSI chip, a resistor chip, and a capacitor chip. Among these, a micro LED chip has a fine structure of 100 μm or less and needs to be mounted precisely, and therefore is preferably used in the method for manufacturing an electronic component of the present invention.

[0033] Methods for arranging a bump pattern between an electrode of a circuit board and an electrode of an element include, for example, a method in which the electrode of the element is arranged to face the bump pattern formed on the electrode of the circuit board, and a method in which the electrode of the circuit board is arranged to face the bump pattern formed on the electrode of the element.

[0034] The heating temperature in the blooming step is preferably selected within a range in which the component to be exuded is easily fluidized and does not exhibit reactivity. For example, when exuding a siloxane compound (C) described below, the heating temperature is preferably 60°C or higher from the viewpoint of efficient exudation. On the other hand, the heating temperature is preferably 200°C or lower, more preferably 160°C or lower, from the viewpoint of suppressing thermal expansion and thermal contraction of the circuit board and elements and improving positional accuracy.

[0035] The pressure in the blooming step is preferably selected appropriately within a range in which the component to be exuded is easily fluidized and does not exhibit reactivity. For example, when exuding the siloxane compound (C) described below, the pressure is preferably 0.1 MPa or more, more preferably 0.4 MPa or more, from the viewpoint of uniform pressure application. On the other hand, from the viewpoint of protecting the circuit board and elements, the pressure is preferably 20 MPa, more preferably 10 MPa or less.

[0036] The heating time and pressurizing time in the blooming step are preferably selected appropriately within a range in which the component to be exuded is easy to flow and does not exhibit reactivity. For example, when exuding a siloxane compound (C) described later, the heating time and pressurizing time are preferably 1 second or more from the viewpoint of promoting exudation. On the other hand, when a highly reactive organic component such as an epoxy compound (D) described later is contained, the heating time and pressurizing time are preferably 1 minute or less.

[0037] Examples of heating / pressurizing devices used in the blooming step include a heat and pressure bonding tool for a flip chip bonder and a vacuum diaphragm type laminator.

[0038] <Protective film formation process> In the protective film forming step, the exuded reactive organic component is reacted to form a protective film on the surface of the bump pattern. As described above, the protective film forming step may also serve as the blooming step and / or the connecting step, and can perform these steps by selecting, for example, the heating and / or pressure conditions. When the protective film forming step also serves as the connecting step, the bump pattern may be cured into a bump, and even in this case, it is still considered a step of forming a protective film on the surface of the bump pattern.

[0039] Examples of methods for reacting the reactive organic component include heating, microwave irradiation, and laser irradiation. Two or more of these methods may be combined. When the protective film forming step also serves as the connecting step, microwave irradiation and laser irradiation are preferred in that they allow the bump pattern to be sintered in a short time, thereby improving production efficiency.

[0040] When reacting a reactive organic component by heating in the protective film forming step, the heating temperature is preferably selected appropriately within a range that enhances the reactivity of the component to be reacted. For example, when reacting a siloxane compound (C) described below, the heating temperature is preferably 140°C or higher, more preferably 160°C or higher, from the viewpoint of further accelerating the reaction. On the other hand, from the viewpoint of suppressing thermal expansion and thermal contraction of the circuit board or element and improving positional accuracy, the heating temperature is preferably 300°C or lower, more preferably 230°C or lower. The heating time is preferably 10 minutes or longer, from the viewpoint of sufficiently curing the protective film. On the other hand, the heating time is preferably 60 minutes or shorter, from the viewpoint of improving productivity.

[0041] When a reactive organic component is reacted by microwave irradiation in the protective film forming process, microwave irradiation methods include, for example, a box oven method, a waveguide method, a microwave antenna method, and a resonator method. Among these, the waveguide method is preferred from the viewpoint of mass productivity. The irradiation intensity is 100 to 3,000 W / cm. 2 The irradiation time is preferably 10 seconds to 30 minutes.

[0042] When reacting reactive organic components by laser irradiation in the protective film formation process, examples of laser light sources include solid-state lasers (ruby, glass, YAG, etc.), semiconductor lasers (GaAs, InGaAsP, etc.), liquid lasers (dye, etc.), and gas lasers (He-Ne, Ar, CO2, excimer, etc.). The irradiation intensity is 100 to 1,000 W / cm. 2 The irradiation time is preferably 1 msec to 100 sec.

[0043] <Connection process> In the connecting step, the electrodes of the circuit board and the electrodes of the element are connected. The electrodes of the circuit board and the electrodes of the element are bonded via a bump pattern to form a conductive path between the electrodes. At this time, the bump pattern hardens to form a bump. In order to obtain a stable conductive path, it is preferable to connect the electrodes by applying heat and pressure. As described above, the connecting step may also serve as the blooming step and / or the protective film forming step. For example, by selecting the heating and / or pressure conditions, these steps can be combined. When the conditions for the blooming step are set within the preferred ranges described above, a conductive path can be formed in the blooming step, and the connecting step can be performed simultaneously. Furthermore, when the conditions for the protective film forming step are set within the preferred ranges described above, a conductive path can also be formed in the protective film forming step, and an additional connecting step can be performed simultaneously.

[0044] Examples of heating / pressurizing devices used in the connection step include a heat and pressure bonding tool for a flip chip bonder and a vacuum diaphragm type laminator.

[0045] Next, a resin composition according to a second embodiment of the present invention will be described. The resin composition of the present invention contains a conductive nanofiller (A), a binder resin (B), and a siloxane compound (C) having two or more structures represented by general formula (1) described below. The siloxane compound (C) easily seeps onto the bump pattern surface during the blooming step, and can form a strong protective film during the protective film formation step. Therefore, the resin composition of the present invention can be suitably used for the bump pattern according to the first embodiment.

[0046] The inclusion of the conductive nanofiller (A) can impart conductivity to the bump. When applied to the first embodiment, this reduces connection resistance during the connection process and ensures stable electrical connection between electrodes. Furthermore, this promotes the exudation of the siloxane compound (C) from between the conductive paths formed by the conductive nanofiller (A) during the blooming process, further enhancing the effects of the blooming process. The binder resin (B) acts as a matrix for the resin composition, suppressing the aggregation of the conductive nanofiller (A) and the formation of conductive paths. Therefore, when applied to the first embodiment, the bump pattern is not electrically conductive before connection and only becomes electrically conductive in the compression direction after the connection process. When applied to the first embodiment, the siloxane compound (C) exudes onto the surface of the bump pattern during the blooming process and reacts in the protective film formation process to form a protective film around the bump pattern. In the present invention, any compound having the structure of general formula (1), whether it is a resin or an epoxy compound, is classified as a siloxane compound (C).

[0047] <Conductive nanofiller (A)> In the present invention, the conductive nanofiller (A) refers to a filler (conductive filler) having a resistivity of 1 Ω·cm or less and a median diameter of 300 nm or less. Here, the median diameter refers to the median diameter of the entire conductive filler. When two or more types of conductive fillers are used, if the median diameter of the two or more conductive fillers as a whole is 300 nm or less, the entire conductive filler is referred to as the "conductive nanofiller (A)." The inclusion of a conductive filler can reduce the connection resistance between the electrodes of the circuit board and the electrodes of the element. Furthermore, using a nanofiller with a median diameter of 300 nm as the conductive filler allows the siloxane compound (C), described later, to be efficiently exuded during the blooming process.

[0048] Here, the resistivity of the conductive nanofiller (A) is the value listed in the "Physics Dictionary" (Baifukan). When two or more types of nanofiller are contained, all those with a resistivity of 1 Ω cm or less are considered to be conductive nanofiller (A).

[0049] The median diameter of the conductive nanofiller (A) can be determined by dynamic light scattering. Specifically, a dynamic light scattering measurement device, NANOTRAC WAVE II (Microtrac), is used to irradiate a dispersion of conductive nanofiller (A) at a concentration of 0.01 to 0.1% by volume with light of 780 nm wavelength from a semiconductor laser, measure the scattered light, and then perform frequency analysis using the FFT-heterodyne method to calculate the median diameter.

[0050] Examples of the conductive nanofiller (A) include particles containing metals such as silver, gold, copper, platinum, lead, tin, nickel, aluminum, tungsten, molybdenum, chromium, titanium, indium, and palladium, alloys thereof, metal oxides such as ITO, tin oxide, and antimony-doped tin oxide, and conductive carbon. The surfaces of these particles may have a coating layer of the aforementioned metal or carbon, or the surfaces of insulating particles such as resins and inorganic oxides may have a coating layer of the aforementioned metal or carbon. Two or more of these may be contained. Among these, gold, silver, and copper particles are preferred from the viewpoint of reducing resistivity. On the other hand, conductive carbon particles such as diamond, graphene, carbon nanotubes, carbon black, and fullerene are preferred from the viewpoint of further reducing the connection resistance between electrodes.

[0051] The median diameter of the conductive nanofiller (A) is preferably 8 nm or more, more preferably 18 nm or more, from the viewpoint of dispersibility in the resin composition. On the other hand, the median diameter of the conductive nanofiller (A) is preferably 140 nm or less, from the viewpoint of further promoting the exudation of the siloxane compound (C) described later in the blooming step and further improving the bonding strength between the bump and the electrode and the long-term reliability of the electronic component. From the viewpoint of forming a finer bump pattern and improving the conductivity, the median diameter is more preferably 70 nm or less.

[0052] The content of the conductive nanofiller (A) in the resin composition of the present invention is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on the solid content, from the viewpoint of further reducing the connection resistance between the electrodes of the circuit board and the electrodes of the element. On the other hand, the content of the conductive nanofiller (A) is preferably 50% by mass or less, more preferably 35% by mass or less, based on the solid content, from the viewpoint of improving the bonding strength between the bumps and the electrodes and further promoting the exudation of the siloxane compound (C) described later in the blooming step, thereby further improving the bonding strength between the bumps and the electrodes and the long-term reliability of the electronic component.

[0053] <Binder resin (B)> Examples of the binder resin (B) include epoxy resin, polysiloxane, polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, polyamideimide, cardo resin, (meth)acrylic resin, and novolac resin. Two or more of these may be used. Among these, novolac resin, cardo resin, and (meth)acrylic resin are preferred from the viewpoint of dispersibility of the conductive nanofiller (A). Here, the (meth)acrylic resin refers to a polymer or copolymer of an acrylic monomer and / or a methacrylic monomer, and may also be copolymerized with other monomers. Examples of the (meth)acrylic monomer include methyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, benzyl (meth)acrylate, dicyclopentanyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, glycidyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate. Here, (meth)acrylate is a general term for acrylate and methacrylate. Examples of other monomers include compounds having a carbon-carbon double bond, such as aromatic vinyl compounds such as styrene and α-methylstyrene, and amide-based unsaturated compounds such as (meth)acrylamide.

[0054] The weight-average molecular weight (Mw) of the binder resin (B) is preferably 1,000 to 50,000. By setting Mw to 1,000 or more, the coating properties of the resin composition can be improved. Mw is more preferably 3,000 or more. On the other hand, by setting Mw to 50,000 or less, the exudation of the siloxane compound (C) described below can be further promoted, and the bonding strength between the bump and the electrode and the long-term reliability of the electronic component can be further improved. Mw is more preferably 20,000 or less. Here, Mw of the binder resin (B) refers to the polystyrene equivalent value measured by gel permeation chromatography (GPC). Here, when two or more types of binder resins (B) are used, Mw refers to the Mw of the two or more binder resins (B) as a whole.

[0055] When the resin composition of the present invention is to be photosensitive, it is preferable that the binder resin (B) contains an alkali-soluble resin, and a bump pattern can be formed by photolithography. The alkali-soluble resin refers to a resin having an alkali-soluble group, and examples of the alkali-soluble group include a carboxy group, a hydroxy group, a sulfo group, a phosphate group, and an acid anhydride group. Two or more of these groups may be contained. Among these, from the viewpoints of reactivity and versatility, a carboxy group and a hydroxy group are more preferred.

[0056] Examples of alkali-soluble resins include carboxyl group-containing (meth)acrylic resins, carboxylic acid-modified epoxy resins, carboxylic acid-modified phenolic resins, polyamic acids, and carboxylic acid-modified polysiloxanes. Two or more of these may be contained. Among these, carboxyl group-containing (meth)acrylic resins and carboxylic acid-modified epoxy resins are preferred because of their high ultraviolet light transmittance, and carboxyl group-containing (meth)acrylic resins are more preferred.

[0057] When negative photosensitivity is imparted to the resin composition of the present invention, the alkali-soluble resin preferably has a double bond in the side chain, which can promote curing in the connection step and further improve long-term reliability.

[0058] The content of the binder resin (B) in the resin composition of the present invention is preferably 10% by mass or more, more preferably 25% by mass or more, of the solid content, from the viewpoints of maintaining appropriate viscosity characteristics, improving the processability of the resin composition, and forming a finer bump pattern. On the other hand, the content of the binder resin (B) is preferably 80% by mass or less, more preferably 43% by mass or less, of the solid content, from the viewpoints of further reducing the connection resistance between the electrodes of the circuit board and the electrodes of the element.

[0059] <Siloxane Compound (C)> The resin composition of the present invention is characterized by containing a siloxane compound (C) having two or more structures represented by the following general formula (1). As described above, the siloxane compound (C) easily exudes onto the surface of the bump pattern in the blooming step and is capable of forming a strong protective film in the protective film forming step, making the resin composition of the present invention suitable for use in the bump pattern of the first aspect. In the blooming step, the exudation of the siloxane compound (C) reduces the organic components in the bump pattern, thereby reducing the volume of the bump pattern and thereby reducing the connection resistance of the bump pattern. Furthermore, by forming a protective film on the bump pattern in the protective film forming step, the connection strength can be increased even for fine bump patterns, and the bonded portions can be protected from oxygen and moisture in the atmosphere, suppressing corrosion and improving long-term reliability.

[0060] [ka]

[0061] In the above general formula (1), R 1 represents a monovalent organic group having an epoxy group and / or an oxetanyl group. 1 The epoxy and oxetanyl groups contained in R react and harden, forming a protective film on the surface of the bump pattern. 1 Preferably, the organic group has an epoxy group, and more preferably an alicyclic epoxy group. The alicyclic epoxy group has high reactivity, which can increase the strength of the protective film, further increase the bonding strength between the bump and the electrode, and further improve long-term reliability. Here, the alicyclic epoxy group refers to an epoxy group that shares a portion of the carbon-carbon bond on the alicyclic skeleton of the alicyclic compound. Examples of organic groups having an alicyclic epoxy group include a 3,4-epoxycyclohexyl group and a 2,3-epoxycyclopentyl group.

[0062] R 2 represents an alkyl group, a hydroxy group, or an alkoxy group. 2By having these groups as the alkyl group, the reactivity of the siloxane compound (C) can be appropriately suppressed, and the reactivity and storage stability of the resin composition can be improved. Among these, an alkyl group is preferred from the viewpoint of promoting exudation in the blooming process. The number of carbon atoms in the alkyl group is preferably 1 to 4.

[0063] Having two or more structures represented by general formula (1) can improve long-term reliability. The number of structures represented by general formula (1) in one molecule is preferably 30 or less, which can further promote exudation during the blooming process. In addition, it is preferable that the structures represented by general formula (1) form a ring.

[0064] The weight-average molecular weight of the siloxane compound (C) is preferably 300 or more, more preferably 600 or more, from the viewpoint of suppressing stickiness (tackiness) of the film or bump pattern formed from the resin composition. On the other hand, the weight-average molecular weight of the siloxane compound (C) is preferably 3,000 or less, more preferably 1,000 or less, from the viewpoint of reducing the viscosity of the resin composition and further promoting exudation during the blooming process. Here, the Mw of the siloxane compound (C) refers to the polystyrene equivalent value measured by gel permeation chromatography (GPC). Furthermore, when two or more types of siloxane compounds (C) are contained, the Mw refers to the Mw of the two or more siloxane compounds (C) as a whole.

[0065] The total epoxy equivalent and oxetanyl equivalent of the siloxane compound (C) is preferably 50 g / eq or more, more preferably 100 g / eq or more, from the viewpoint of appropriately suppressing compatibility with other components in the resin composition and further promoting exudation during the blooming process. On the other hand, the total epoxy equivalent and oxetanyl equivalent of the siloxane compound (C) is preferably 500 g / eq or less, more preferably 300 g / eq or less, from the viewpoint of further improving reactivity in the protective film formation process and further improving the bonding strength and long-term reliability of the bump and electrode. Here, the total epoxy equivalent and oxetanyl equivalent of the siloxane compound (C) refers to the equivalent weight when the siloxane compound (C) has only one of the epoxy group and the oxetanyl group. The epoxy equivalent or oxetanyl equivalent is the value obtained by dividing the molecular weight of the compound by the number of functional groups of the epoxy group or the oxetanyl group. When the siloxane compound (C) has an epoxy group and an oxetanyl group, the total equivalent weight is the value obtained by dividing the molecular weight of the compound by the total number of functional groups of the epoxy group and the oxetanyl group.

[0066] In the structure represented by the general formula (1), R 1 Examples of siloxane compounds having an epoxy group include bifunctional epoxy siloxanes (trade names: X-40-2728, X-40-2678, both manufactured by Shin-Etsu Chemical Co., Ltd.), tetrafunctional alicyclic epoxy siloxane compounds (trade name: KR-470, manufactured by Shin-Etsu Chemical Co., Ltd.), polymeric multifunctional epoxy siloxanes (trade name: X-12-981S, X-12-984S, both manufactured by Shin-Etsu Chemical Co., Ltd.), and epoxy siloxane oligomers (trade name: "COATSIL (registered trademark)" MP 200, manufactured by Momentive Performance Materials Japan, LLC). 1 Examples of the compound having an alicyclic epoxy group include a difunctional epoxy siloxane (trade name: X-40-2678, manufactured by Shin-Etsu Chemical Co., Ltd.) and a tetrafunctional alicyclic epoxy siloxane compound (trade name: KR-470, manufactured by Shin-Etsu Chemical Co., Ltd., a compound represented by the following structural formula (2)).

[0067] [ka]

[0068] In the structure represented by the general formula (1), R 1 An example of a siloxane compound having an oxetanyl group is polyfunctional oxetanylsiloxane (trade name: OXT-191, manufactured by Toagosei Co., Ltd.).

[0069] The content of the siloxane compound (C) in the resin composition of the present invention is preferably 1% by mass or more, more preferably 5% by mass or more, of the solid content, from the viewpoint of promoting exudation in the blooming process and improving the effect of the protective film. On the other hand, the content of the siloxane compound (C) is preferably 50% by mass or less, more preferably 20% by mass or less, from the viewpoint of increasing the content of the conductive nanofiller (A) and further reducing the connection resistance.

[0070] <Epoxy compound (D)> The resin composition of the present invention preferably further contains an epoxy compound (D) having a softening point of 50°C or higher. The fluidity of such an epoxy compound (D) is improved by heating and / or pressurization in the connection step, thereby improving the adhesion between the bump pattern and the electrode. Furthermore, the bonding strength between the bump and the electrode can be further increased by curing the epoxy groups. The softening point of the epoxy compound (D) is more preferably 60°C or higher. On the other hand, the softening point of the epoxy compound (D) is preferably 120°C or lower, more preferably 100°C or lower, from the viewpoint of performing connection at a lower temperature in the connection step.

[0071] The epoxy compound (D) preferably has a cresol / novolac structure or a bisphenol structure.

[0072] Examples of the epoxy compound (D) having a cresol / novolac structure include novolac epoxy resins such as trade name: "EPICLON (registered trademark)" N-770 (epoxy equivalent: 188, softening point: 70°C, manufactured by DIC Corporation), trade name: "EPICLON" N-775 (epoxy equivalent: 189, softening point: 75°C, manufactured by DIC Corporation), and trade name: "EPICLON" N-865 (epoxy equivalent: 208, softening point: 68°C, manufactured by DIC Corporation).

[0073] Examples of the epoxy compound (D) having a bisphenol structure include trade name: "EPICLON" 1050 (epoxy equivalent: 475, softening point: 69°C, manufactured by DIC Corporation), trade name: "EPICLON" 2050 (epoxy equivalent: 635, softening point: 85°C, manufactured by DIC Corporation), trade name: "EPICLON" 3050 (epoxy equivalent: 780, softening point: 96°C, manufactured by DIC Corporation), and trade name: "EPICLON" 4050. (epoxy equivalent: 950, softening point: 100°C, manufactured by DIC Corporation), trade name: "EPICLON" 7050 (epoxy equivalent: 1,930, softening point: 127°C, manufactured by DIC Corporation), trade name: "EPICLON" HM-091 (epoxy equivalent: 2,600, softening point: 143°C, manufactured by DIC Corporation), trade name: "EPICLON" HM-101 (epoxy equivalent: 3,500, softening point: 158°C, manufactured by DIC Corporation).

[0074] The content of the epoxy compound (D) in the resin composition of the present invention is preferably 1% by mass or more, more preferably 3% by mass or more, of the solid content from the viewpoint of improving the fluidity of the bump pattern in the connection step, while the content of the epoxy compound (D) is preferably 30% by mass or less, more preferably 20% by mass or less, from the viewpoint of increasing the content of the conductive nanofiller (A) and further reducing the connection resistance.

[0075] <Photosensitizer (E)> When imparting photosensitivity to the resin composition of the present invention, it is preferable to contain a photosensitizer (E). Examples of the photosensitizer (E) include a photopolymerization initiator and a naphthoquinone diazide compound, which is a photoacid generator. When a photopolymerization initiator is contained as the photosensitizer, it is preferable to contain a component having a double bond, and a negative bump pattern can be formed in which the exposed areas are photopolymerized in the exposure step. On the other hand, when a naphthoquinone diazide compound is contained as the photosensitizer, a positive bump pattern can be formed in which the solubility of the exposed areas is increased in the exposure step.

[0076] Examples of the photopolymerization initiator include benzophenone derivatives, acetophenone derivatives, thioxanthone derivatives, benzyl derivatives, benzoin derivatives, oxime compounds, α-hydroxyketone compounds, α-aminoalkylphenone compounds, phosphine oxide compounds, anthrone compounds, anthraquinone compounds, etc. Two or more of these may be contained.

[0077] The content of the photopolymerization initiator in the resin composition of the present invention is preferably 0.5 to 5 mass % of the solid content.

[0078] Examples of components having a double bond include those of the binder resin (B) described above that have a double bond in a side chain, and monomers and oligomers that have two or more double bonds in the molecule. Two or more of these may be contained. Among these, monomers and oligomers that have two or more (meth)acryloyl groups in the molecule are preferred, such as ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, 1,4-butanediol diacrylate, glycerin diacrylate, tripropylene glycol diacrylate, ethoxylated (4) bisphenol A diacrylate, ethoxylated (10) bisphenol A diacrylate, and compounds having two acryloyl groups such as acrylic acid adducts of ethylene glycol diglycidyl ether; pentaacrylate; Examples of the compound include compounds having three acryloyl groups, such as erythritol triacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolpropane ethoxy triacrylate, and glycerin propoxy triacrylate; compounds having four acryloyl groups, such as dipentaerythritol hexaacrylate, pentaerythritol tetraacrylate, pentaerythritol ethoxy tetraacrylate, and ditrimethylolpropane tetraacrylate; and compounds in which the acrylic groups in these compounds are substituted with methacrylic groups.

[0079] The content of the monomer or oligomer having a double bond in the resin composition of the present invention is preferably 5 to 40 mass % of the solid content.

[0080] Examples of naphthoquinone diazide compounds include compounds having a 5-naphthoquinone diazide sulfonyl group and a 4-naphthoquinone diazide sulfonyl group. Two or more of these may be used.

[0081] The content of the naphthoquinone diazide compound in the resin composition of the present invention is preferably 1 to 20 mass % of the solid content.

[0082] <Solvent> The resin composition of the present invention may contain a solvent. Examples of solvents include N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, dimethylimidazolidinone, dimethyl sulfoxide, γ-butyrolactone, ethyl lactate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, ethylene glycol mono-n-propyl ether, diacetone alcohol, tetrahydrofurfuryl alcohol, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol, and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate. Two or more of these solvents may be contained.

[0083] The resin composition of the present invention may contain additives such as plasticizers, leveling agents, surfactants, silane coupling agents, antifoaming agents, pigments, etc., to the extent that the desired properties are not impaired.

[0084] <Method of manufacturing resin composition> The resin composition of the present invention can be produced by mixing the aforementioned components (A) to (C) and, if necessary, component (D), a solvent, other additives, etc. Examples of mixing devices include dispersers and kneaders such as a three-roller mill, a ball mill, and a planetary ball mill.

[0085] <Electronic component manufacturing method> The resin composition of the present invention can be suitably used for the bump pattern in the first embodiment. That is, the method for producing an electronic component using the resin composition of the present invention includes the steps of: a bump pattern forming step of forming a bump pattern from the resin composition of the present invention; a blooming step in which a bump pattern is placed between an electrode of a circuit board and an electrode of an element, and heat and / or pressure is applied to cause at least a part of the siloxane compound (C) to ooze out onto the surface of the bump pattern; a protective film forming step of reacting the exuded siloxane compound (C) to form a protective film on the surface of the bump pattern; A process for connecting electrodes on a circuit board with electrodes on electronic components Each step is as described in the first embodiment.

[0086] When photolithography is used in the bump pattern formation step, it is preferable to have an exposure step of irradiating a film made of the resin composition of the present invention with ultraviolet light in accordance with the bump pattern, and a development step of selectively removing the soluble portion with a developer, each step being as described in the first embodiment. [Example]

[0087] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0088] The evaluation methods in each example are as follows.

[0089] <resolution> To evaluate the resolution of the bump pattern, a glass substrate was used instead of the glass substrate with gold electrodes, and a bump pattern was formed in the same manner as in each Example and Comparative Example. That is, a 2 μm-thick resin composition film was formed on the glass substrate from the resin composition for forming a bump pattern obtained in each Example and Comparative Example in the same manner as in each Example and Comparative Example. The resulting resin composition film was exposed, developed, and rinsed in the same manner as in each Example and Comparative Example through a photomask with circular openings of φ4, 6, 8, 10, 12, 14, 16, and 20 μm to obtain a substrate for resolution evaluation.

[0090] The bump patterns on the resulting resolution evaluation substrate were magnified and observed using an optical microscope. Among the patterns in which no residue or peeling between patterns was observed, the bump diameter of the pattern with the smallest value was taken as the resolution.

[0091] <Blooming> To evaluate blooming, a glass substrate was used instead of the glass substrate with gold electrodes, and the blooming process was carried out in the same manner as in each of the Examples and Comparative Examples. Specifically, a φ20 μm bump pattern was formed on the glass substrate in the same manner as in the evaluation of resolution. Figure 1 shows a schematic plan view of the substrate used for blooming evaluation. A bump pattern 2 is formed on a glass substrate 1.

[0092] A 1 cm square silicon chip with a gold thin film was placed on the bump pattern of the obtained blooming evaluation substrate, and the substrate was heated and pressed using a bonder (FC-3000, manufactured by Toray Engineering Co., Ltd.) at a temperature of 150°C, a pressure of 5 MPa, and a pressing time of 10 seconds to allow reactive organic components to ooze out of the bump pattern. Figure 2 shows a schematic plan view (a) and a schematic cross-sectional view (b) of the mounting substrate for blooming evaluation prepared in this example. Bumps 4 and a silicon chip 3 are connected on a glass substrate 1.

[0093] The bump pattern was magnified and observed using an optical microscope from the glass substrate side of the resulting blooming evaluation mounting board. Figure 6 shows a schematic plan view of the blooming evaluation method. The diameter of the bump pattern 6 and the diameter of the area 7 where the organic component had seeped out were measured, and the difference was taken as the exuded width of the organic component. The larger the exuded width, the more likely blooming occurs.

[0094] <Conductivity> In the silicon chip mounting substrates with gold thin films obtained in each of the Examples and Comparative Examples, the gold electrodes were connected with a tester, and the resistance value was measured to evaluate the conductivity. The lower the resistance value, the better the conductivity.

[0095] <Joining strength> To evaluate the bonding strength between the electrodes and the bumps, silicon chip mounting substrates for evaluating bonding strength were prepared in the same manner as in each Example and Comparative Example, except that a glass substrate was used instead of the glass substrate with gold electrodes. That is, a resin composition film having a thickness of 2 μm was formed on a glass substrate from the resin composition for forming a bump pattern obtained in each Example and Comparative Example in the same manner as in each Example and Comparative Example, and the entire surface of the resin composition film was subjected to exposure, development, and rinsing treatment in the same manner as in each Example and Comparative Example.

[0096] A wafer chip, prepared by cutting a 0.7 mm thick silicon wafer into 2 mm squares, was placed on the film after the rinsing treatment, and the blooming process, protective film formation process, and connection process were carried out in the same manner as in each of the examples and comparative examples, to produce a silicon chip mounting substrate for evaluation of bonding strength.

[0097] The die shear strength of each of the five silicon chip mounting substrates obtained for bonding strength evaluation was measured using a die shear strength measuring device (Dage Series 4000; manufactured by Dage) at a temperature of 25°C and a shear rate of 200 μm / sec, and the average value was calculated.

[0098] <Long-term reliability> The silicon chip-mounted substrates with gold thin films obtained in each Example and Comparative Example, and the silicon chip-mounted substrates for bonding strength evaluation obtained in the above evaluation of <Bonding Strength>, were each subjected to a moist heat treatment by being left standing for 240 hours in a thermo-hygrostat SH-661 (manufactured by Espec Corp.) at a temperature of 85°C and a humidity of 85% RH, and then the resistance value and die shear strength were measured using the methods described above. The rate of change in conductivity and rate of change in bonding strength were calculated using the following formulas to evaluate long-term reliability. Conductivity change rate (%) = {(resistance value after moist heat treatment - resistance value before moist heat treatment) / resistance value before moist heat treatment} × 100 Bond strength change rate (%) = {(bond strength after moist heat treatment - bond strength before moist heat treatment) / bond strength before moist heat treatment} × 100 The smaller the rate of change, the better the long-term reliability.

[0099] The materials used in the examples and comparative examples are as follows. [Conductive nanofiller (A)] Carbon particles 1: Cabot carbon particles (median diameter 450 nm, specific gravity 1.9 g / cm 3 , specific resistance 1.7mΩ cm) Carbon particles 2: Cabot carbon particles (median diameter 110 nm, specific gravity 1.9 g / cm 3 , specific resistance 1.7mΩ cm) [Other conductive fillers] Ag particles: median diameter 0.7 μm, aspect ratio 1.1 Ni particles: Micropearl (registered trademark) manufactured by Sekisui Chemical Co., Ltd. (median diameter 4 μm).

[0100] [Binder resin (B)] (Synthesis Example 1: Binder Resin (B-1)) A 500 ml flask was charged with 2.0 g of azobisisobutyronitrile and 50 g of propylene glycol monomethyl ether acetate (PGMEA). Then, 38.7 g of methacrylic acid, 79.3 g of benzyl methacrylate, and 22.0 g of tricyclo[5.2.1.0(2,6)]decan-8-yl methacrylate were added and stirred at room temperature for a while. The atmosphere in the flask was thoroughly purged with nitrogen by bubbling, and then heated and stirred at 70 °C for 5 hours. Next, 21.3 g of glycidyl methacrylate, 1 g of dimethylbenzylamine, 0.2 g of p-methoxyphenol, and 100 g of PGMEA were added to the resulting solution, heated and stirred at 90 °C for 4 hours, and cooled to room temperature. PGMEA was added to the resulting acrylic resin solution to a solids concentration of 40% by mass, yielding a solution of binder resin (B-1). The weight average molecular weight Mw of the acrylic resin (B-1) measured by GPC in terms of polystyrene was 18,000. Binder resin (B-2): A copolymer of methacrylic acid, methyl methacrylate, and styrene in a 54 / 23 / 23 (mass ratio) ratio, to which 0.4 equivalents of glycidyl methacrylate is added in reaction with the carboxyl groups. Weight-average molecular weight: 33,000. Binder resin (B-3): Styrene / acrylic copolymer (BASF, "JONCRYL (registered trademark)" 67.

[0101] (Synthesis Example 2: Binder Resin (B-4)) A reaction vessel under a nitrogen atmosphere was charged with 150 g of 2-methoxy-1-methylethyl acetate (PMA) and heated to 80°C using an oil bath. A mixture consisting of 20 g of ethyl acrylate, 45 g of p-hydroxyphenyl acrylate, 30 g of n-butyl acrylate, 15 g of N-methylolacrylamide, 0.8 g of 2,2'-azobisisobutyronitrile, and 15 g of PMA was added dropwise over 1 hour. After the dropwise addition, the mixture was heated at 80°C for an additional 6 hours to carry out the polymerization reaction. Then, 1 g of hydroquinone monomethyl ether was added to terminate the polymerization reaction. The resulting reaction solution was purified with methanol to remove unreacted impurities and further dried in vacuo for 24 hours to obtain a phenolic hydroxyl group-containing acrylic copolymer (B-4).

[0102] [Siloxane compound (C)] KR-470: tetrafunctional alicyclic epoxysiloxane compound (manufactured by Shin-Etsu Chemical Co., Ltd., a compound represented by the formula (2) above, molecular weight 730, epoxy equivalent 200 g / eq) X-40-2728: Difunctional glycidyl epoxy siloxane (manufactured by Shin-Etsu Chemical Co., Ltd., a compound represented by the following formula (3), molecular weight 553, epoxy equivalent 290 g / eq)

[0103] [ka]

[0104] OXT-191: Polyfunctional oxetanylsiloxane (manufactured by Toagosei Co., Ltd., molecular weight 1,586, oxetane equivalent 320) [Other siloxane compounds] KR-401: Siloxane compound (manufactured by Shin-Etsu Chemical Co., Ltd., a compound that does not contain epoxy groups and / or oxetanyl groups) KBM-403: Epoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., molecular weight 236, epoxy equivalent 236 g / eq, compound containing only one structure of general formula (1)) [Epoxy compound (D)] N-770: Phenol novolac epoxy resin (DIC Corporation, softening point 70°C, epoxy equivalent 188g / eq) JER4007P: Bisphenol F epoxy compound (manufactured by Mitsubishi Chemical Corporation, softening point 108°C, epoxy equivalent 2,000g / eq) [Other epoxy compounds] "Celloxide (registered trademark)" 2021P: 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (manufactured by Daicel Corporation, softening point -37°C, epoxy equivalent weight 135g / eq) [Polymerization initiator] PBG-358: Oxime ester polymerization initiator (TRONLY Co., Ltd.) OXE-04: Oxime ester polymerization initiator (manufactured by BASF).

[0105] [Compounds with double bonds] TMP-A: Trimethylolpropane triacrylate (Kyoeisha Chemical Industry Co., Ltd.) · BP-4EAL: Bisphenol A diacrylate (manufactured by Kyoeisha Chemical Co., Ltd.).

[0106] [Naphthoquinone diazide compounds] TDF-517: Sulfonic acid ester of 4,4',4"-Ethylidyne-trisphenol and 1,2-naphthoquinone-2-diazide-5-sulfonic acid (manufactured by Toyo Synthetic Industries, Ltd.).

[0107] (Synthesis Example 3: Carbon Particle 1 Dispersion) 27.0 g of carbon particles 1, 3 g of dispersant "DISPERBYK (registered trademark)"-2200 (manufactured by BYK-Chemie), and 70 g of PGMEA were mixed and mixed using a homogenizer at 1,200 rpm for 30 minutes. The mixture was then further dispersed using a high-pressure wet media-less atomizer "Nanomizer (registered trademark)" (Nanomizer Co., Ltd.) to obtain a carbon particle 1 dispersion with a median diameter (secondary particle diameter) of 140 nm and a conductive nanofiller content of 27.0 wt%.

[0108] (Synthesis Example 4: Carbon Particle 2 Dispersion) A dispersion of carbon particles 2 having a median diameter (secondary particle diameter) of 2350 nm was obtained in the same manner as in Synthesis Example 3, except that carbon particles 2 were used instead of carbon particles 1.

[0109] Example 1 (Production of Resin Composition for Bump Pattern Formation) Into a 100 mL clean bottle were placed 18.0 g of the solution (solid content 40% by mass) of the binder resin (B-1) obtained in Synthesis Example 1, 1.8 g of TDF-517 as a naphthoquinone diazide compound, 1.8 g of KR-470 as a siloxane compound (C), 1.8 g of N-770 as an epoxy compound (D), and 58.6 g of PGMEA as a solvent, and these were mixed using a rotation-revolution vacuum mixer "Awatori Rentaro" (registered trademark) ARE-310 (manufactured by Thinky Corporation) to obtain 82.0 g of an organic component solution.

[0110] Subsequently, 18.0 g of the carbon particle 1 dispersion obtained in Synthesis Example 3 was added to the obtained organic component solution, and mixed using a rotation-revolution vacuum mixer to obtain 100 g of a resin composition for forming a bump pattern.

[0111] (Bump pattern formation process) FIG. 3 shows a schematic plan view of a glass substrate with gold electrodes. A gold electrode 5 is provided on a glass substrate 1. A resin composition for forming a bump pattern was applied to this glass substrate with gold electrodes so that the film thickness after drying would be 2 μm, and the coating was dried in a drying oven at a temperature of 100°C for 10 minutes to form a resin composition film with a film thickness of 2 μm. A photomask was placed on the resulting resin composition film so that a φ20 μm circular pattern was positioned on the electrode as shown in FIG. 4, and the resulting resin composition film was exposed to i-line (wavelength 365 nm) at an exposure dose of 500 mJ / cm using an exposure device (PEM-6M; manufactured by Union Optical Co., Ltd.) equipped with an ultra-high pressure mercury lamp. 2 After exposure, the substrate was developed using a 2.38 wt % TMAH aqueous solution and rinsed with ultrapure water to form a bump pattern, yielding a substrate with a bump pattern. Figure 4 shows a schematic plan view of the glass substrate with gold electrodes used in the examples and the arrangement of the bump pattern formed. A bump pattern 2 is formed on a gold electrode 5.

[0112] (Blooming process and connection process) For the resulting substrate with bump pattern, a silicon chip with a gold thin film was placed on the bump pattern, and using a bonder (FC-3000, manufactured by Toray Engineering Co., Ltd.), heating and pressurization were performed under conditions of a temperature of 150°C, a pressure of 5 MPa, and a pressure time of 10 seconds, and electrode connection and blooming were performed.

[0113] (Protective film formation process) The substrate was then heated in a hot air oven at 200°C for 30 minutes to harden the bloomed components and form a protective film, yielding an electronic component. Figure 5 shows a schematic plan view (a) and a schematic cross-sectional view (b) of the resulting electronic component. Gold electrodes 5 on the glass substrate 1 are connected to a silicon chip with a gold thin film by bumps 4.

[0114] (Examples 2 to 18, Comparative Examples 1 to 6) Resin compositions for forming bump patterns were obtained in the same manner as in Example 1, except that the formulations of the resin compositions were changed as shown in Tables 1 to 3, and electronic components were produced using the obtained resin compositions.

[0115] Tables 1 to 3 show the main compositions of the examples and comparative examples and the results of evaluation by the above-mentioned methods.

[0116] [Table 1]

[0117] [Table 2]

[0118] [Table 3] [Explanation of symbols]

[0119] 1. Glass substrate 2 Bump Pattern 3 Silicon chip with gold thin film 4. Bump 5. Gold electrode 6 Bump Pattern 7. Extent of organic components seeping out

Claims

1. a bump pattern forming step of forming a bump pattern containing a conductive component and a reactive organic component; a blooming step in which the bump pattern is placed between the electrode of the circuit board and the electrode of the element and heated and / or pressurized to cause at least a portion of the reactive organic component to bleed onto the surface of the bump pattern; a protective film forming step of forming a protective film on the bump pattern surface by reacting the exuded reactive organic component; A process for connecting electrodes on a circuit board with electrodes on electronic components A method for manufacturing an electronic component having the above structure.

2. A resin composition containing a conductive nanofiller (A), a binder resin (B), and a siloxane compound (C) having two or more structures represented by the following general formula (1): 【Chemistry 1】 (In the above general formula (1), R １ represents a monovalent organic group having an epoxy group and / or an oxetanyl group, R ２ represents an alkyl group, a hydroxy group, or an alkoxy group.

3. 3. The resin composition according to claim 2, wherein the weight average molecular weight of the siloxane compound (C) is 3,000 or less.

4. 4. The resin composition according to claim 2, wherein the total of the epoxy equivalent and the oxetanyl equivalent of the siloxane compound (C) is 500 g / eq or less.

5. 4. The resin composition according to claim 2, further comprising an epoxy compound (D) having a softening point of 50° C. or higher.

6. 4. The resin composition according to claim 2, wherein the binder resin (B) is an alkali-soluble resin, and further comprises a photosensitizer (E).

7. The resin composition according to claim 6, wherein the photosensitizer (E) comprises a photopolymerization initiator.

8. 7. The resin composition according to claim 6, wherein the photosensitizer (E) comprises a naphthoquinone diazide compound.

9. a bump pattern forming step of forming a bump pattern from the resin composition according to claim 2 or 3; a blooming step in which a bump pattern is placed between an electrode of a circuit board and an electrode of an element, and heat and / or pressure is applied to cause at least a part of the siloxane compound (C) to ooze out onto the surface of the bump pattern; a protective film forming step of reacting the exuded siloxane compound (C) to form a protective film on the surface of the bump pattern; A process for connecting electrodes on a circuit board with electrodes on electronic components A method for manufacturing an electronic component having the above structure.

10. 10. The method for producing an electronic component according to claim 9, wherein the bump pattern forming step comprises an exposure step of irradiating a film made of the resin composition according to claim 6 with ultraviolet light in accordance with the bump pattern, and a development step of selectively removing soluble portions with a developer.

Images