JP2022135663A - Conductive adhesive composition, organic electronics device, and method for manufacturing organic electronics device - Google Patents

Abstract

To mount an electronic component on a circuit board of an organic electronics device with high reliability while suppressing warpage.SOLUTION: A conductive adhesive composition contains (A) conductive particles, (B) a thermosetting resin, and (C) a flux activator and is used for electrically connecting a circuit board of an organic electronics device and an electronic component. The conductive particles include a metal part having a melting point of 136°C or lower. An average particle diameter of the conductive particles is 1.0-30 μm. The flux activator contains a compound having a hydroxyl group and a carboxyl group.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to conductive adhesive compositions, organic electronic devices, and methods of making organic electronic devices.

An organic electronic device is generally a device having an organic element such as an organic EL element formed on a circuit board. In addition to organic elements, other electronic components such as driver ICs are often mounted on circuit boards of organic electronic devices. Conventionally, an anisotropic conductive adhesive (ACF) is used to mount electronic components on a circuit board of an organic electronic device while ensuring electrical connection (for example, Patent Document 1). The anisotropic conductive adhesive contains conductive particles, and the circuit board and the electronic component are electrically connected via conductive paths due to contact between the conductive particles.

JP 2019-140344 A

An organic electronic device may warp due to heating for mounting electronic components on a circuit board. Lower heating temperatures tend to reduce warpage, but conventional anisotropic conductive adhesives may have difficulty in ensuring sufficiently reliable electrical connections.

TECHNICAL FIELD The present disclosure relates to a conductive adhesive composition capable of mounting an electronic component on a circuit board of an organic electronic device with high reliability while suppressing warpage.

One aspect of the present disclosure contains a binder resin containing a thermosetting resin and a flux activator, and conductive particles dispersed in the binder resin, a circuit board of an organic electronic device and a circuit board mounted on the circuit board The present invention relates to a conductive adhesive composition used for electrically connecting electronic parts. The conductive particles are metal particles containing a metal portion having a melting point of 136° C. or less. The average particle size of the conductive particles is 1.0 to 30 μm. The flux activator contains a compound having a hydroxyl group and a carboxyl group.

Another aspect of the present disclosure is a circuit board having a base and two or more connection terminals provided on the main surface of the base, an organic element provided on the main surface of the base, and An organic device comprising: an electronic component having two or more connection terminals facing the two or more connection terminals of a circuit board; and a connection portion disposed between and joining the circuit board and the electronic component. It relates to electronic devices. The connection portion is a layer formed from the conductive adhesive composition. The connection portion is a conductive portion interposed between the connection terminal of the circuit board and the connection terminal of the electronic component and electrically connecting them, and a resin portion formed around the conductive portion. including. The conductive portion is a metal layer formed by melting the conductive particles. The resin portion is a cured product formed from the binder resin.

According to one aspect of the present disclosure, an electronic component can be mounted on a circuit board of an organic electronic device with high reliability while suppressing warpage. Moreover, since electronic components can be mounted by a low-temperature process, thermal damage to organic elements can be suppressed.

1 is a perspective view showing an example of an organic electronic device; FIG. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1; 1 is a cross-sectional view showing an example of a method of manufacturing an organic electronic device; FIG. 1 is a cross-sectional view showing an example of a method of manufacturing an organic electronic device; FIG.

Several embodiments of the invention are described in detail below. However, the present invention is not limited to the following embodiments.

FIG. 1 is a perspective view showing an example of an organic electronic device. FIG. 2 is a cross-sectional view taken along line II-II of FIG. The organic electronic device 100 shown in FIGS. 1 and 2 includes a circuit board 1, an organic EL element 2 (organic element) formed on the circuit board 1, and a driver IC 3 (electronic component) mounted on the circuit board 1. and an organic EL panel.

The organic EL element 2 is composed of a cathode layer 21, an organic layer 25 and an anode layer 22, and the cathode layer 21, the organic layer 25 and the anode layer 22 are laminated in this order from the circuit board 1 side.

The cathode layer 21 can be a transparent conductive layer made of a transparent conductive material such as ITO (Indium Tin Oxide), AZO (Aluminum Zinc Oxide), or IZO (Indium Zinc Oxide). The organic layer 25 may be, for example, a laminate composed of a hole-injection layer, a hole-transport layer, an organic light-emitting layer, and an electron-transport layer. The anode layer 22 can be, for example, a metal layer formed of a metal material including a single metal selected from Au, Ni, Al, Ag, Cu, Mg, Co, Li and Zn or an alloy containing these.

The organic electronic device 100 further includes a sealing substrate 6 covering the organic EL element 2 and a sealing material 7 provided between the peripheral portion of the sealing substrate 6 and the circuit board 1 . An airtight space is formed on the circuit board 1 by the sealing substrate 6 and the sealing material 7, and the organic EL element 2 is arranged in the airtight space.

The circuit board 1 has a substrate 10 and wiring portions 4 formed on the main surface of the substrate 10 . The wiring portion 4 includes a cathode wiring portion 4a connecting the driver IC 3 and the cathode layer 21 of the organic EL element 2, an anode wiring portion 4b connecting the driver IC 3 and the anode layer 22 of the organic EL element 2, and It also includes a connection wiring portion 4c for inputting a power supply and various control signals. A flexible wiring board or the like is connected to the connection wiring portion 4c. The wiring portion 4 forms a connection terminal in a portion where the driver IC 3 is mounted.

The substrate 10 can be a transparent plate material, such as a glass plate. The base material 10 may be a flexible base material (for example, a transparent resin film).

The driver IC 3 has an IC main body 30 having a rectangular main surface and two or more bumps 31 as connection terminals provided on the main surface of the IC main body 30 . The bumps 31 of the driver IC 3 are electrically connected to the wiring portions 4 as connection terminals via the connection portions 5 formed from a conductive adhesive composition. Details of the conductive adhesive composition will be described later. Portions of the wiring portion 4 that function as connection terminals connected to the driver IC 3 are provided in the same number and at the same pitch as the bumps 31 . The connection terminals (wiring portion 4) of the circuit board and the connection terminals (bumps 31) of the driver IC 3 are aligned so as to face each other.

In order to reduce the size and height of electronic components, narrower bump widths and narrower intervals between bumps are required. For example, the wiring portions 4 as the connection terminals of the circuit board 1 may be arranged on the main surface of the base material 10 at intervals of 200 μm or less, or 100 μm or less. The interval between the wiring portions 4 as connection terminals may be 10 μm or more.

3 and 4 are cross-sectional views showing an example of a method of manufacturing an organic electronic device, including a step of mounting a driver IC 3 (electronic component) on a circuit board 1. FIG. In the method shown in FIGS. 3 and 4, the circuit board 1 and the driver IC 3 (electronic component) are arranged so that the wiring portions 4 (connection terminals) and the bumps 31 (connection terminals) face each other. A conductive adhesive composition 5A is placed between 1 and a driver IC 3, and a laminate composed of the circuit board 1, the conductive adhesive composition 5A and the driver IC 3 is heated by a thermocompression bonding head 80. pressing, thereby forming a connection 5 from the conductive adhesive composition 5A.

A pasty or liquid conductive adhesive composition 5A may be applied onto the circuit board 1 . After that, the circuit board 1 may be placed on the stage of the connecting device, and the circuit board 1, the conductive adhesive composition 5A and the driver IC 3 may be heated and pressed by the thermocompression bonding head 80 on the stage.

The conductive adhesive composition 5A includes a thermosetting binder resin 50A and a plurality of conductive particles 51A dispersed in the binder resin 50A. The thermocompression bonding head 80 is heated to a predetermined connection temperature at which the conductive particles 51A are melted. The connection temperature may be 130° C. or lower. The binder resin 50A flows and flows out from between the bumps 31 of the driver IC 3 and the wiring portions 4 of the circuit board 1 while being heated to a predetermined connection temperature and pressed by the thermocompression bonding head 80 . At the same time, the melted conductive particles 51A fuse with each other to form conductive portions 51 that are metal-bonded to the bumps 31 of the driver IC 3 and the wiring portions 4 of the circuit board 1 . As a result, the bump 31 and the wiring portion 4 are electrically connected via the conductive portion 51 interposed therebetween. The binder resin 50A is cured to form the cured resin portion 50 around the conductive portion 51 . In other words, the conductive adhesive composition 5A is melt-polarized into the conductive portion 51 and the resin portion 50 .

The conductive particles 51A in the conductive adhesive composition 5A can be particles containing a metal part having a melting point of 136° C. or less. The conductive particle 51A may be a metal particle composed only of a particulate metal portion, or may have a core particle composed of a solid material other than metal and a layered metal portion covering the surface of the core particle. It may be a composite particle or a combination thereof. The solid material that constitutes the core particles may be, for example, ceramics, silica, resin material, or a combination thereof.

A metal portion having a melting point of 136° C. or lower melts at a low temperature that can suppress warping, and can form the conductive portion 51 that enables electrical connection with good reliability. From the same point of view, the melting point of the metal portion may be 120° C. or less. Although the lower limit of the melting point of the metal portion is not particularly limited, it is, for example, about 60°C. If the metal part is an alloy containing two or more metals, the melting point of the alloy should be 136° C. or less.

The metal part usually contains one or more metals having a melting point of 136° C. or lower. A metal having a melting point of 136° C. or less may be, for example, indium (In). The indium content in the conductive particles 51A may be 10 to 70% by mass based on the mass of the conductive particles 51A. The metal part may further contain a high-melting-point metal within a range where the melting point of the metal part as a whole is 136° C. or less, in order to obtain better connection reliability. Examples of refractory metals are tin (Sn), zinc (Zn), platinum (Pt), gold (Au), silver (Ag), copper (Cu), nickel (Ni), palladium (Pd), and aluminum. (Al) is included.

The metal part of the conductive particles 51A may be an alloy containing indium and one or more high melting point metals selected from bismuth, tin and zinc. For example, the conductive particles 51A are Sn50-In50 solder (melting point 120° C.), Sn48-In52 solder (melting point 117° C.), Bi67-In33 solder (melting point 109° C.), Bi57-Sn17-In26 (melting point 79° C.), Bi55 - Sn25-In20 (melting point 79°C), Bi33.7-In66.3 (melting point 72°C), Bi32.5-Sn16.5-In51 (melting point 61°C), or a metal part consisting of a combination thereof good too. These alloys show a distinct solidification behavior after melting. Solidification behavior refers to the cooling and solidification of a metal after it has been melted. The conductive particles 51A may be metal particles comprising a metal portion containing Sn50-In50 solder. Sn50-In50 means an alloy containing Sn and In at a mass ratio of Sn:In=50:50. This also applies to other alloys.

The average particle size of the conductive particles 51A may be 1.0-30 μm. When the average particle size of the conductive particles 51A is less than 1.0 μm, the conductive adhesive composition tends to have a high viscosity, resulting in a decrease in workability, and the conductive particles are difficult to melt, resulting in a favorable It tends to be difficult to form a metallic bond. If the average particle size of the conductive particles exceeds 30 μm, there is a possibility that a short circuit may easily occur between the connection terminals arranged at narrow intervals. From a similar point of view, the average particle size of the conductive particles may be 2 to 25 μm. From the viewpoint of further improving the storage stability and connection reliability of the conductive adhesive composition, the average particle size of the conductive particles may be 5 to 20 μm. Here, the average particle size of the conductive particles is a value determined by a laser diffraction/scattering method.

The specific surface area of the conductive particles 51A may be 0.001-3.0 m ² /g. When the specific surface area of the conductive particles 51A is within this range, the effect of improving the meltability of the solder particles during heat connection and improving the insulation between adjacent electrodes can be obtained.

The content of the conductive particles 51A may be 5 to 95% by mass with respect to the mass of the conductive adhesive composition 5A. If the content of the conductive particles 51A is less than 5% by mass, the conductivity of the connecting portion 5 formed from the conductive adhesive composition 5A tends to decrease. When the content of the conductive particles 51A exceeds 95% by mass, the viscosity of the conductive adhesive composition tends to increase, resulting in a decrease in workability, and a tendency in which the effect of improving connection reliability tends to relatively decrease. There is From the same point of view, the content of the conductive particles 51A is 10% by mass or more, 15% by mass or more, 50% by mass or more, or 60% by mass or more with respect to the mass of the conductive adhesive composition 5A. It may be 90% by mass or less, or 85% by mass or less.

The conductive adhesive composition 5A further contains conductive particles 51A containing a metal part having a melting point of 136° C. or lower, and high-melting-point conductive particles containing a metal part having a melting point higher than 136° C. good too. The metal having a melting point higher than 136° C. is, for example, a single metal selected from Sn, Bi, Pt, Au, Ag, Cu, Ni, Pd, and Al, or an alloy composed of two or more metal species. . Specific examples of the high melting point conductive particles include Au powder, Ag powder, Cu powder, and Ag-plated Cu powder. "MA05K" (manufactured by Hitachi Chemical Co., Ltd., trade name), which is a silver-plated copper powder, is available as a commercially available high-melting-point conductive particle. Based on the total amount of conductive particles containing a metal part having a melting point of 136 ° C. or less and conductive particles with a high melting point, the proportion of the conductive particles with a high melting point is 1 to 50% by mass, or 1 to 40% by mass. may be

The binder resin 50A contains a thermosetting resin and a flux activator.

Thermosetting resins are organic compounds having reactive functional groups for curing, examples of which include epoxy resins, compounds having polymerizable carbon-carbon double bonds (e.g. (meth)acrylic resins, maleimide resins). and cyanate resins, and their precursors. (Meth)acrylic resin means methacrylic resin and acrylic resin. Thermosetting resins may include compounds with polymerizable carbon-carbon double bonds, epoxy resins, or combinations thereof. These thermosetting resins are excellent in heat resistance and adhesiveness, and can be handled in a liquid state by dissolving or dispersing them in an organic solvent as necessary. From the standpoint of availability and reliability, the thermosetting resin may contain an epoxy resin.

Epoxy resins are compounds having two or more epoxy groups, examples of which include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD type epoxy resins, phenol novolac type epoxy resins, cresol novolak type epoxy resins, Examples include epoxy resins having a naphthalene skeleton, aliphatic epoxy resins, glycidylamine type epoxy resins, and resorcinol type epoxy resins.

Specific examples of commercially available epoxy resins include AER-X8501 (manufactured by Asahi Chemical Industry Co., Ltd., trade name), R-301 (manufactured by Mitsubishi Chemical Corporation, trade name), and YL-980 (manufactured by Mitsubishi Chemical Corporation), which are bisphenol A type epoxy resins. Mitsubishi Chemical Co., Ltd., trade name), YDF-170 (manufactured by Tohto Kasei Co., Ltd., trade name), which is a bisphenol F type epoxy resin, YL-983U (Mitsubishi Chemical Co., Ltd., trade name), bisphenol AD type epoxy resin R-1710 (manufactured by Mitsui Petrochemical Industries Co., Ltd., trade name), N-730S (manufactured by Dainippon Ink and Chemicals, Inc., trade name) which is a phenol novolac epoxy resin, Quatrex-2010 (Dow Chemical Co., Ltd. Company, trade name), YDCN-702S (manufactured by Tohto Kasei Co., Ltd., trade name), which is a cresol novolak type epoxy resin, EOCN-100 (manufactured by Nippon Kayaku Co., Ltd., trade name), EPPN, which is a polyfunctional epoxy resin -501 (manufactured by Nippon Kayaku Co., Ltd., trade name), TACTIX-742 (manufactured by Dow Chemical Co., Ltd., trade name), VG-3010 (manufactured by Mitsui Petrochemical Industries, trade name), 1032S (Mitsubishi Chemical Corporation manufactured by Daicel Chemical Industries, Ltd., trade name), HP-4032 (manufactured by Dainippon Ink and Chemicals, Inc., trade name), which is an epoxy resin having a naphthalene skeleton, EHPE-3150, CEL-3000, which are alicyclic epoxy resins (both Daicel Chemical Industries, Ltd. company, trade name), DME-100 (manufactured by Shin Nippon Rika Co., Ltd., trade name), EX-216L (manufactured by Nagase Chemical Industry Co., Ltd., trade name), W-100 (Shin Nippon Rika Co., Ltd., trade name), an aliphatic epoxy resin Co., Ltd., trade name), ELM-100 (manufactured by Sumitomo Chemical Co., Ltd., trade name), which is an amine-type epoxy resin, YH-434L (manufactured by Tohto Kasei Co., Ltd., trade name), TETRAD-X, TETRAD-C (both manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name), 630, 630LSD (both manufactured by Mitsubishi Chemical Co., Ltd., trade name), Denacol EX-201 (manufactured by Nagase Chemicals Co., Ltd., trade name), which is a resorcinol-type epoxy resin, Denacol EX-211 (manufactured by Nagase Chemical Industry Co., Ltd., trade name), which is a neopentyl glycol type epoxy resin, and Denacol EX-212 (manufactured by Nagase Chemical Industry Co., Ltd., trade name) which is 1,6-hexanediol diglycidyl ether. , Denacol EX series (EX-810, 811, 850, 851, 821, 830, 832 , 841, 861 (both manufactured by Nagase Chemical Industries, Ltd., trade names)), epoxy resins E-XL-24 and E-XL-3L represented by the following general formula (I) (both manufactured by Mitsui Chemicals, Inc., product name).

式（Ｉ）中、ｋは１～５の整数を示す。

In formula (I), k represents an integer of 1-5.

The epoxy resins exemplified above may be used singly or in combination of two or more.

When the thermosetting resin contains an epoxy resin, the conductive adhesive composition 5A (or the binder resin 50A) may further contain a monofunctional epoxy compound having one epoxy group as a reactive diluent. good. Specific examples of commercially available monofunctional epoxy compounds include PGE (manufactured by Nippon Kayaku Co., Ltd., trade name), PP-101 (manufactured by Tohto Kasei Co., Ltd., trade name), ED-502, ED-509, and ED. -509S (manufactured by Asahi Denka Kogyo Co., Ltd., trade name), YED-122 (manufactured by Yuka Shell Epoxy Co., Ltd., trade name), KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), TSL-8350, TSL -8355 and TSL-9905 (manufactured by Toshiba Silicone Co., Ltd., trade name). These are used individually by 1 type or in combination of 2 or more types.

The content of the reactive diluent in the conductive adhesive composition 5A may be, for example, 0.1-30% by mass with respect to the mass of the epoxy resin.

When the thermosetting resin contains an epoxy resin, the conductive adhesive composition 5A (or the binder resin 50A) may further contain a curing catalyst that accelerates the curing reaction of the epoxy resin. The curing catalyst may be a compound having an imidazole group from the viewpoint of curability at a desired curing temperature, length of pot life, heat resistance of the cured product, and the like. Commercial products of compounds having an imidazole group that can be used as curing catalysts include 2P4MHZ-PW (2-phenyl-4-methyl-5-hydroxymethylimidazole), 2PHZ-PW (2-phenyl-4,5-dihydroxymethyl imidazole), C11Z-CN (1-cyanoethyl-2-undecylimidazole), 2E4MZ-CN (1-cyanoethyl-2-ethyl-4-methylimidazole), 2PZ-CN (1-cyanoethyl-2-phenylimidazole), 2MZ-A (2,4-diamino-6-[2'methylimidazolyl-(1')]-ethyl-s-triazine), 2E4MZ-A (2,4-diamino-6-[2'-ethyl-4 'methylimidazolyl-(1')]-ethyl-s-triazine), 2MAOK-PW (2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanurate product) (both manufactured by Shikoku Kasei Kogyo Co., Ltd., trade names). These curing catalysts are used singly or in combination of two or more.

The content of the curing catalyst may be 0.01 to 90 parts by weight, or 0.1 to 50 parts by weight with respect to 100 parts by weight of the epoxy resin. If the content of the curing catalyst is less than 0.01 parts by mass, the curability tends to decrease. When the content of the curing catalyst exceeds 90 parts by mass. The handleability of the conductive adhesive composition 5A tends to deteriorate.

When the thermosetting resin contains an epoxy resin, the conductive adhesive composition 5A (or the binder resin 50A) may further contain a curing agent for adjusting the curing speed of the epoxy resin.

Commercially available curing agents include, for example, phenol novolac resin H-1 (manufactured by Meiwa Kasei Co., Ltd., trade name), VR-9300 (manufactured by Mitsui Toatsu Chemicals Co., Ltd., trade name), and phenol aralkyl resin. XL-225 (manufactured by Mitsui Toatsu Chemicals Co., Ltd., trade name), p-cresol novolac resin MTPC (manufactured by Honshu Chemical Industry Co., Ltd., trade name), AL-VR-9300 (Mitsui Toatsu Chemical Co., Ltd., trade name), and PP-700-300 (manufactured by Nippon Petrochemical Co., Ltd., trade name), which is a special phenol resin.

(Meth)acrylic resins are compounds having a reactive functional group selected from acryloyl groups and methacryloyl groups, examples of which include monoacrylate compounds, monomethacrylate compounds, diacrylate compounds, and dimethacrylate compounds.

Examples of monoacrylate compounds include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 2- ethylhexyl acrylate, nonyl acrylate, decyl acrylate, isodecyl acrylate, lauryl acrylate, tridecyl acrylate, hexadecyl acrylate, stearyl acrylate, isostearyl acrylate, cyclohexyl acrylate, isobornyl acrylate, diethylene glycol acrylate, polyethylene glycol acrylate, polypropylene glycol acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, methoxydiethylene glycol acrylate, methoxypolyethylene glycol acrylate, dicyclopentenyloxyethyl acrylate, 2-phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxypolyethylene glycol acrylate, 2 -benzoyloxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, benzyl acrylate, 2-cyanoethyl acrylate, γ-acryloxyethyltrimethoxysilane, glycidyl acrylate, tetrahydrofurfuryl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, Acryloxyethyl phosphate and acryloxyethyl phenyl acid phosphate.

Examples of monomethacrylate compounds include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2- ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, isodecyl methacrylate, lauryl methacrylate, tridecyl methacrylate, hexadecyl methacrylate, stearyl methacrylate, isostearyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, diethylene glycol methacrylate, polyethylene glycol methacrylate, polypropylene glycol methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-butoxyethyl methacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, dicyclopentenyloxyethyl methacrylate, 2-phenoxyethyl methacrylate, phenoxydiethylene glycol methacrylate, phenoxypolyethylene glycol methacrylate, 2 -benzoyloxyethyl methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, benzyl methacrylate, 2-cyanoethyl methacrylate, γ-methacryloxyethyltrimethoxysilane, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, Methacryloxyethyl phosphate and methacryloxyethyl phenyl acid phosphate are included.

Examples of diacrylate compounds include ethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,3-butanediol diacrylate, neo 1 mol of pentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, bisphenol A, bisphenol F or bisphenol AD and 2 glycidyl acrylates moles of reactants, diacrylate of polyethylene oxide adduct of bisphenol A, bisphenol F or bisphenol AD, diacrylate of polypropylene oxide adduct of bisphenol A, bisphenol F or bisphenol AD, bis(acryloxypropyl)polydimethylsiloxane and bis (Acryloxypropyl)methylsiloxane-dimethylsiloxane copolymers.

Examples of dimethacrylate compounds include ethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,3-butanediol dimethacrylate, neo Pentyl glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tripropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, bisphenol A, bisphenol F or bisphenol AD 1 mol and glycidyl methacrylate 2 moles of reactants, dimethacrylate of polyethylene oxide adduct of bisphenol A, bisphenol F or bisphenol AD, polypropylene oxide adduct of bisphenol F or bisphenol AD, bis(methacryloxypropyl)polydimethylsiloxane and bis(methacryloxypropyl)methyl A siloxane-dimethylsiloxane copolymer may be mentioned.

The compounds exemplified above may be used singly or in combination of two or more.

Specific examples of commercially available (meth)acrylic resins include FINEDIC A-261 (manufactured by Dainippon Ink and Chemicals, Inc., trade name) and FINEDIC A-229-30 (manufactured by Dainippon Ink and Chemicals, Inc., product first name).

When the thermosetting resin contains a (meth)acrylic resin, the conductive adhesive composition 5A (or the binder resin 50A) may contain a radical polymerization initiator. The radical polymerization initiator may be an organic peroxide or an azo compound, or may be an organic peroxide from the viewpoint of void suppression. From the viewpoint of improving the curability and viscosity stability of the binder resin 50A, the decomposition temperature of the organic peroxide may be 130°C to 200°C.

Examples of organic peroxides include benzoyl peroxide and t-butyl peroxy-2-ethylhexanoate. Examples of azo compounds include azobisisobutyronitrile and azobisdimethylvaleronitrile.

The content of the radical polymerization initiator may be 0.01 to 20% by mass, 0.1 to 10% by mass, or 0.5 to 5% by mass with respect to the mass of the conductive adhesive composition 5A. .

The content of the thermosetting resin may be 1 to 60% by mass, 5 to 40% by mass, or 10 to 30% by mass with respect to the mass of the conductive adhesive composition 5A.

A flux activator is a component that exhibits the function of removing the oxide film formed on the surface of the conductive particles. When the oxide film is removed by the flux activator, the conductive particles 51A are melted and the conductive portions 51 are easily formed. A flux activator according to one embodiment includes a compound containing a hydroxyl group and a carboxyl group. The compound having a hydroxyl group and a carboxyl group may be an aliphatic dihydroxycarboxylic acid from the viewpoint of efficient oxide film removal. The aliphatic dihydroxycarboxylic acid may be a compound represented by general formula (V) below, tartaric acid, or a combination thereof.

In formula (V), R5 represents an alkyl group having 1 to 5 carbon atoms and may be a methyl group, an ethyl group or a propyl group. n and m each independently represent an integer of 0 to 5; n may be 0 and m may be 1, or both n and m may be 1.

Examples of compounds represented by the general formula (V) include 2,2-bis(hydroxymethyl)propionic acid, 2,2-bis(hydroxymethyl)butanoic acid, and 2,2-bis(hydroxymethyl) pentanoic acid and the like. The flux activator may contain at least one compound selected from these.

The content of the flux activator is 0.5 to 50% by mass, 0.5 to 40% by mass, 1.0 to 35% by mass, or 4.0 to 8.5% by mass with respect to the mass of the conductive particles. may be If the content of the flux activator is less than 0.5% by mass, the effect of improving connection reliability tends to be relatively small. When the content of the flux activator exceeds 50% by mass, the storage stability and printability of the conductive adhesive composition 5A tend to deteriorate.

The conductive adhesive composition 5A may further contain additives in addition to the components described above. The additive may be one or more selected from the group consisting of a flexibilizer for stress relaxation, a diluent for improving workability, an adhesive force improver, a wettability improver and an antifoaming agent.

Examples of flexibilizers include liquid polybutadiene (manufactured by Ube Industries, trade names "CTBN-1300x31" and "CTBN-1300x9"; manufactured by Nippon Soda Co., Ltd., trade name "NISSO-PB-C- 2000”). The content of the flexible agent may be 0.1 to 500 parts by mass with respect to 100 parts by mass of the thermosetting resin.

The conductive adhesive composition 5A may contain a coupling agent such as a silane coupling agent or a titanium coupling agent for the purpose of improving adhesive strength. Examples of commercially available silane coupling agents include Shin-Etsu Chemical Co., Ltd., trade name “KBM-573”. For the purpose of improving wettability, the conductive adhesive composition may contain a surfactant such as an anionic surfactant and a fluorosurfactant. The conductive adhesive composition may contain silicone oil or the like as an antifoaming agent. The content of the coupling agent, surfactant, and antifoaming agent may be 0.1 to 10% by mass with respect to the mass of the conductive adhesive composition 5A.

The conductive adhesive composition 5A may contain a diluent as necessary from the viewpoint of coating workability. The diluent is, for example, an organic solvent selected from butyl carbitol, butyl carbitol acetate, butyl cellosolve, carbitol, butyl cellosolve acetate, carbitol acetate, dipropylene glycol monomethyl ether, ethylene glycol diethyl ether, and α-terpineol. good too. The content of the diluent may be 0.1 to 30 mass % with respect to the mass of the conductive adhesive composition 5A.

The conductive adhesive composition 5A may contain a non-conductive filler. Examples of non-conductive fillers include polymeric particles such as acrylic rubber and polystyrene, and inorganic particles such as diamond, boron nitride, aluminum nitride, alumina, and silica. These fillers may be used singly or in combination of two or more.

The conductive adhesive composition 5A may be pasty at 25°C. The viscosity of the conductive adhesive composition 5A may be 5 to 400 Pa·s at 25°C.

The conductive adhesive composition 5A is obtained by mixing, dissolving, pulverizing and kneading or dispersing each component at once or in multiple batches, heating as necessary.

By applying the conductive adhesive composition according to the present disclosure, the driver IC 3 (electronic component) can be mounted on the circuit board 1 by heating and pressing (thermocompression bonding) at a low temperature. Thermal damage to the organic layer 25, which has particularly low heat resistance, is reduced compared to the case of using an anisotropic conductive agent (ACF), which is generally used and requires thermocompression bonding at a higher temperature. A low heating temperature for mounting electronic components also contributes to a reduction in warpage. The temperature of thermocompression bonding (connection temperature) for mounting an electronic component with the formation of a connection portion from the conductive adhesive composition may be 130° C. or lower or 100° C. or higher. The pressure of thermocompression bonding may be 0.5 to 20 MPa. The thermocompression bonding time may be 5.0 to 120 seconds.

The conductive adhesive composition according to the present disclosure is also advantageous in terms of connection reliability when the width of the connection terminals is narrow and the connection terminals are arranged at narrow intervals. In the case of an anisotropic conductive agent, if the width of the connection terminal is narrow, the number of conductive particles that contact the connection terminal tends to be insufficient, resulting in an increase in conduction resistance. As a result, for example, when a large current flows through the organic element, the wiring portion may locally generate heat and disconnect. In the case of the conductive adhesive composition according to the present disclosure, the conductive part is formed by integrating the conductive particles, and the conductive path is formed by metal bonding of the conductive part. Therefore, even if the width of the connection terminal is narrow, A sufficiently low conduction resistance is likely to be maintained.

Connection by the conductive adhesive composition according to the present disclosure does not require temporary pressure bonding before thermocompression bonding, so it is advantageous for ACF, which often requires temporary pressure bonding, in terms of process simplification. be.

Although the embodiments of the present disclosure have been described in detail above, they can be modified as necessary. For example, the organic element is not limited to an organic EL element, and may be an element including an organic layer having various functions. Examples of other organic elements include organic thin film solar cells and organic image sensor elements. The electronic component mounted on the circuit board is not limited to the driver IC, and may be, for example, a sensor element, a module component having a sensor element, a Schottky barrier diode, or a thermoelectric conversion element.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

1. Material (A) Conductive particles/Sn50-In50 solder particles (18 μm): manufactured by 5NPLUS, melting point: 120° C., average particle size: 18 μm
・Sn50-In50 solder particles (5 μm): manufactured by 5NPLUS, melting point 120° C., average particle size 5 μm
・ Bi67-In33 solder particles (12 μm): manufactured by 5NPLUS, melting point 109° C., average particle size 12 μm
・Bi57-Sn17-In26 solder particles (13 μm): manufactured by 5NPLUS, melting point 79° C., average particle diameter 13 μm
・Bi33.7-In66.3 solder particles (13 μm): manufactured by 5NPLUS, melting point 72° C., average particle diameter 13 μm
・Bi32.5-Sn16.5-In51 solder particles (14 μm): manufactured by 5NPLUS, melting point 61° C., average particle diameter 14 μm
・ Sn42-Bi58 solder particles (10 to 25 μm): manufactured by 5NPLUS, melting point 138° C., average particle size 10 to 25 μm
(B) Thermosetting resin YL980: manufactured by Mitsubishi Chemical Corporation, bisphenol F type epoxy resin (C) Flux activator BHPA: 2,2-bis (hydroxymethyl) propionic acid BHBA: 2,2-bis ( Hydroxymethyl)butanoic acid, glutaric acid, adipic acid (D) curing catalyst, 2P4MHZ-PW: manufactured by Shikoku Kasei Co., Ltd., imidazole compound

2. Conductive Adhesive Composition Example 1
22.5 parts by mass of YL980, 1.1 parts by mass of 2P4MHZ-PW, and 6.4 parts by mass of BHPA were mixed, and the mixture was passed through three rolls three times to prepare a binder resin component. 70 parts by mass of Sn50-In50 solder particles (average particle size: 18 μm) were added to 30 parts by mass of the binder resin component, and the resulting mixture was stirred using a planetary mixer. The stirred mixture was defoamed at 500 Pa or less over 10 minutes to obtain a pasty conductive adhesive composition.

Examples 2-9, Comparative Examples 1-3
A conductive adhesive composition was obtained in the same manner as in Example 1, except that the types and compounding ratios of the materials were changed as shown in Table 1 or Table 2.

Comparative Examples 4-7
The following commercially available conductive adhesive compositions were prepared.
・Sn42-Bi58 cream solder: Eco Solder (trade name) manufactured by Senju Metal Industry Co., Ltd.
・Sn96.5-Ag3-Cu0.5 cream solder: Eco Solder (trade name) manufactured by Senju Metal Industry Co., Ltd.
・ Anisotropic conductive film (ACF for COG): ANISOLM (trade name) manufactured by Showa Denko Materials

3. Production Example 1 of Connection Body
An IC for evaluation was prepared having an outer shape of 1.5 mm×15 mm, a thickness of 0.45 mm, a bump (Au-plated) area of 40 μ×125 μm, and a space between bumps of 15.0 μm. A circuit board for evaluation was prepared, which had a glass substrate with an outer size of 25 mm×040 mm and a thickness of 0.25 mm, and a wiring pattern formed on the glass substrate. The wiring pattern was formed from an ITO film plated with Ni—Au, and had a comb-like pattern having the same size and pitch as the bumps of the IC for evaluation.

The conductive adhesive composition of Example 1 was applied to a circuit board for evaluation. The evaluation IC was placed on the evaluation circuit board so that the applied conductive adhesive composition was sandwiched therebetween. At that time, the bumps of the IC for evaluation and the electrode patterns of the circuit board for evaluation were aligned. Next, the laminate composed of the evaluation circuit board, the conductive backing agent composition, and the IC for evaluation was heated and pressed under the conditions of 125° C., 10 MPa, and 30 seconds with a thermocompression head, thereby forming a connector for evaluation. Obtained.

Examples 2-9, Comparative Examples 1-8
A connection body for evaluation was prepared in the same manner as in Example 1, except that the conductive adhesive composition and, in some cases, the connection temperature (thermocompression head temperature) were changed as shown in Tables 1 and 2. made. However, in the case of Comparative Example 6, the thermocompression bonding conditions were changed to 180° C., 80 MPa, and 5 seconds. 160° C. adopted in Comparative Example 4 is a standard connection temperature for SnBi solder paste. 260° C. adopted in Comparative Example 5 is a standard connection temperature for SnAgCu solder paste.

4. Evaluation The connected body of each example and comparative example was evaluated on the following items. Evaluation results are shown in Tables 1 and 2.

(1) Continuity Resistance Value The connection body was subjected to a reliability test in which temperature cycles between -40° C. and 85° C. were repeated for 10,000 hours. A simple tester was used to measure the initial (before the reliability test) and the conduction resistance value of each connector after the reliability test. "OR" in the table means that the conduction resistance value was too high to exceed the measurable range due to extremely low conductivity.

(2) Warp The height (displacement) from the reference position on the side opposite to the electrode pattern of the evaluation wiring board before the evaluation IC is mounted is measured by a warp measurement device (manufactured by AKROMETRIX, product name: THERMOIRE). PS200) was used. The difference between the maximum and minimum displacement was recorded as the initial shape value. The height (displacement) from the reference position on the surface of the manufactured connection body opposite to the evaluation IC was measured. The difference between the maximum and minimum displacements was recorded as the post-mounting shape value. The value obtained by subtracting the initial shape value from the shape value after mounting was taken as the amount of warpage.

All of Examples 1 to 9 exhibited good conductivity, and almost no decrease in conductivity was observed after the reliability test. A sufficiently low amount of warpage of 2 μm or less was shown.

In the case of Comparative Example 1 in which conductive particles having a melting point of 138° C. were used, initial conductivity could not be ensured, and the conduction resistance value became over range (OR). This is probably because the Sn42-Bi58 solder particles did not melt at the connection temperature of 125°C.

The initial conduction resistance values of Comparative Examples 2 and 3, in which a flux activator having no hydroxyl group was used, were lower than the initial conduction resistance values of Examples 1-9. The conduction resistance value further increased after the reliability test.

The conduction resistance values of Comparative Examples 4 and 5 were initially good values, but increased to 10 times or more of the initial value after the reliability test. The amount of warpage in Comparative Examples 4 and 5 was about twice as large as the amount of warpage in Examples 1-9. It was suggested that the difference in connection temperature caused an increase in the amount of warpage.

The conduction resistance value of Comparative Example 6, in which the COG ACF was used, was a good value at the beginning, but increased to 15 times the initial value after the reliability test. The amount of warpage in Comparative Example 6 was about four times the amount of warpage in Examples 1-9. It was confirmed that the amount of warpage increases due to the high connection temperature.

In Comparative Example 7, in which the COG ACF was used and the connection was made under the same connection conditions as those of Examples 1 to 9, the initial conduction resistance value increased, and the conduction resistance was even higher after the reliability test. value was shown. In the case of ACF, it was confirmed that if the connection temperature is low, although the amount of warpage decreases, sufficient conductivity cannot be ensured.

DESCRIPTION OF SYMBOLS 1... Circuit board, 2... Organic EL element (organic element), 3... Driver IC (electronic component), 4... Wiring part (connection terminal), 4a... Cathode wiring part, 4b... Anode wiring part, 4c... Connection wiring part , 5... Connecting portion 5A... Conductive adhesive composition 6... Sealing substrate 7... Sealing material 10... Base material 21... Cathode layer 22... Anode layer 25... Organic layer 30... IC main body Part 31... Bump (connection terminal) 50... Resin part 50A... Conductive adhesive composition 51... Conductive part 51A... Conductive particles.

Claims (14)

a binder resin comprising a thermosetting resin and a flux activator;
conductive particles dispersed in the binder resin;
including
The conductive particles contain a metal portion having a melting point of 136° C. or less,
The conductive particles have an average particle size of 1.0 to 30 μm,
the flux activator contains a compound having a hydroxyl group and a carboxyl group,
A conductive adhesive composition used for electrically connecting a circuit board of an organic electronic device and electronic components mounted on the circuit board. 2. The conductive adhesive composition according to claim 1, wherein the content of said flux activator is 4.0 to 8.5% by mass with respect to the mass of said conductive particles. 3. The conductive adhesive composition according to claim 1 or 2, wherein said metal part contains indium. 4. The conductive adhesive composition according to claim 3, wherein the content of indium in the metal part is 10 to 70% by mass based on the mass of the metal part. The conductive adhesive composition according to any one of claims 1 to 4, wherein the conductive particles have a specific surface area of 0.001 to 3.0 m ² /g. The conductive adhesive composition according to any one of claims 1-5, wherein the thermosetting resin comprises an epoxy resin. 7. The conductive adhesive composition according to claim 6, further comprising (D) a curing catalyst that accelerates the curing reaction of the epoxy resin. The conductive adhesive composition according to any one of claims 1 to 7, wherein the conductive adhesive composition is pasty at 25°C. The circuit board has a substrate and two or more connection terminals provided on the main surface of the substrate,
The electronic component has two or more connection terminals,
The circuit board and the electronic component are electrically connected by forming a conductive portion interposed between the connection terminal of the circuit board and the connection terminal of the electronic component by melting the conductive particles. The conductive adhesive composition according to any one of claims 1 to 8, which is used for 10. The conductive adhesive composition according to claim 9, wherein the two or more connection terminals of the circuit board are arranged on the main surface of the base material with an interval of 200 [mu]m or less from each other. a circuit board having a substrate and two or more connection terminals provided on the main surface of the substrate;
an organic element provided on the main surface of the substrate;
an electronic component having two or more connection terminals facing the two or more connection terminals of the circuit board;
a connecting portion disposed between the circuit board and the electronic component to join them;
with
The connection portion is a layer formed from the conductive adhesive composition according to any one of claims 1 to 8,
a conductive portion in which the connection portion is interposed between the connection terminal of the circuit board and the connection terminal of the electronic component to electrically connect them; and a resin formed around the conductive portion. wherein the conductive portion is a metal layer formed by melting the conductive particles, and the resin portion is a cured product formed from the binder resin;
organic electronic devices. 12. The organic electronic device according to claim 11, wherein said electronic component is at least one selected from the group consisting of a driver IC, a sensor element, a module component having a sensor element, a Schottky barrier diode, and a thermoelectric conversion element. 13. The organic electronic device according to claim 11 or 12, wherein said substrate is a flexible substrate. A circuit board having a base material and two or more connection terminals provided on the main surface of the base material and an electronic component having connection terminals are arranged such that the connection terminals of the circuit board face the connection terminals of the electronic component. Placing the conductive adhesive composition according to any one of claims 1 to 8 between the circuit board and the electronic component while arranging as follows;
A connecting part that heats and presses a laminate composed of the circuit board, the conductive adhesive composition and the electronic component, thereby being disposed between and joining the circuit board and the electronic component. from the conductive adhesive composition;
in that order,
a conductive portion in which the connection portion is interposed between the connection terminal of the circuit board and the connection terminal of the electronic component to electrically connect them; and a resin formed around the conductive portion. wherein the conductive portion is a metal layer formed by melting the conductive particles, and the resin portion is a cured product formed from the binder resin;
A method of manufacturing an organic electronic device.

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