US20090032293A1 - Electroconductive Bonding Material and Electric/Electronic Device Using the Same - Google Patents

Electroconductive Bonding Material and Electric/Electronic Device Using the Same Download PDF

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Publication number
US20090032293A1
US20090032293A1 US11/886,722 US88672206A US2009032293A1 US 20090032293 A1 US20090032293 A1 US 20090032293A1 US 88672206 A US88672206 A US 88672206A US 2009032293 A1 US2009032293 A1 US 2009032293A1
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United States
Prior art keywords
conductive paste
conductive
hardening
metallic particles
sulfur
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Abandoned
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US11/886,722
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English (en)
Inventor
Hidenori Miyakawa
Shigeaki Sakatani
Kumiko Sugiyama
Takayuki Higuchi
Atsushi Yamaguchi
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Panasonic Corp
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Individual
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Assigned to MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. reassignment MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: YAMAGUCHI, ATSUSHI, SUGIYAMA, KUMIKO, HIGUCHI, TAKAYUKI, MIYAKAWA, HIDENORI, SAKATANI, SHIGEAKI
Assigned to PANASONIC CORPORATION reassignment PANASONIC CORPORATION CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Publication of US20090032293A1 publication Critical patent/US20090032293A1/en
Abandoned legal-status Critical Current

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/09—Use of materials for the conductive, e.g. metallic pattern
    • H05K1/092—Dispersed materials, e.g. conductive pastes or inks
    • H05K1/095—Dispersed materials, e.g. conductive pastes or inks for polymer thick films, i.e. having a permanent organic polymeric binder
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
    • C08G59/66—Mercaptans
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C08G59/68—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the catalysts used
    • C08G59/687—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the catalysts used containing sulfur
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J163/00—Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
    • H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
    • H05K3/321—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by conductive adhesives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/36—Sulfur-, selenium-, or tellurium-containing compounds
    • C08K5/37—Thiols
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/02—Fillers; Particles; Fibers; Reinforcement materials
    • H05K2201/0203—Fillers and particles
    • H05K2201/0206—Materials
    • H05K2201/0224—Conductive particles having an insulating coating
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
    • H05K2203/12—Using specific substances
    • H05K2203/122—Organic non-polymeric compounds, e.g. oil, wax or thiol
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
    • H05K3/4038—Through-connections; Vertical interconnect access [VIA] connections
    • H05K3/4053—Through-connections; Vertical interconnect access [VIA] connections by thick-film techniques
    • H05K3/4069—Through-connections; Vertical interconnect access [VIA] connections by thick-film techniques for via connections in organic insulating substrates

Definitions

  • the present invention relates to an electroconductive (hereinafter, also referred to as “conductive”) bonding material comprising an electroconductive particles ingredient, an epoxy resin ingredient and an epoxy resin-hardening ingredient, a method for producing an electric/electronic circuit, as well as an electric/electronic device having such an electric/electronic circuit.
  • conductive electroconductive
  • an electroconductive bonding material i.e. an electroconductive adhesive is widely used for the purposes of mounting electric/electronic components (hereinafter, also collectively referred to as “electric components”) onto a circuit board and the purposes of forming conductor pattern on a circuit board.
  • the electroconductive adhesives which are used in the field of mounting the electric components, basically having a composition comprising a resin composition as a binder and conductive particles of such as metallic particles which are dispersed in the resin composition.
  • the conductive adhesives, wherein the resin composition has a paste-like form are referred to as the conductive paste.
  • Such resin composition contains a resin-hardening ingredient, which makes the resin composition harden by being subjected to a condition, e.g. by being subjected to a predetermined temperature condition.
  • a conductive adhesive is subjected to a predetermined temperature condition, the resin composition therein volumetrically shrinks while hardening, so that the volume of the resin composition as a whole decreases.
  • the conductive particles which were dispersed in the resin composition come to contact one another and form a continuous conductive path through the hardened conductive adhesive.
  • an epoxy-based conductive adhesive composition which contains an epoxy resin as the resin composition, a hardening agent for hardening the epoxy resin, and metallic particles such as silver or nickel as the conductive ingredient.
  • the conductive adhesive compositions of such type hardens generally by being heated to a temperature of 120 degree centigrade or more.
  • a conductive adhesive i.e. a bonding material for mounting
  • preservation stability for a period from several days to several weeks in the adhesive component state is also required for a one-component adhesive composition as mentioned in the above.
  • a resin composition containing an epoxy resin, a thiol compound as the hardening agent and a latent hardening promotor of solid dispersed type is known as an adhesive (Patent Document 1).
  • Patent Document 1 a resin composition containing an epoxy resin, a thiol compound as the hardening agent and a latent hardening promotor of solid dispersed type is known as an adhesive (Patent Document 1).
  • Patent Document 2 a conductive paste containing a borate ester compound in addition to the above composition is proposed (Patent Document 2).
  • Patent Document 1 Japanese Patent Kokai Publication No. 211969/1994
  • Patent Document 2 Japanese Patent Kokai Publication No. 2000-230112
  • Another object of the present invention of the present application is to provide a conductive paste which can be hardened at a desired condition, preferably can be quickly hardened at a relatively low temperature and has an improved preservation stability without an additional component such as borate ester compound.
  • Another object of the present invention is to provide a method of producing circuit boards and electric components mounted products (or body) using such a conductive paste.
  • Another object of the present invention is to provide a conductive paste, which can prevent or reduce emanating unpleasant stench and allow the operator to identify the end of the hardening reaction more easily relating to an epoxy-based conductive adhesive.
  • a further object of the present invention is to provide a method of producing circuit boards and electric components mounted products using such a conductive paste.
  • the present application provides an invention of a conductive bonding material comprising a conductive particle ingredient, an epoxy resin ingredient, and an epoxy resin-hardening agent, wherein the epoxy resin-hardening agent further contains linear or cyclic sulfur-containing compound. It is preferable that such sulfur-containing compound is a compound that has a thiol group (—SH).
  • the first invention in the present application provides a bonding material for mounting (or a conductive adhesive) comprising an epoxy resin, a latent hardening promotor for hardening the epoxy resin and conductive particles, wherein the bonding material further contains sulfur-containing compounds at a ratio of about 1 to 100 parts by weight on the basis of 100 parts by weight of the epoxy resin.
  • the sulfur-containing compound has a SH-group therein, the “—S—” moiety in the compound inherent in the SH-group attacks the C+ (carbocation) in the epoxy group through a nucleophilic substitution reaction to open the epoxy ring, thereby the hardening reaction starts, according to the bonding material for mounting of the first invention.
  • the other reforming agent for example the reforming agent of a silane-based, a titanate-based and an aluminate-based coupling agent (or surface treatment agent) can not start the hardening reaction.
  • the coupling agent is added to the conductive adhesive containing an epoxy resin and a latent hardening promotor and having a standard hardening condition of about 10 minutes at a temperature of 120 degree centigrade, on the one hand, adhesion strength could be somewhat improved, and on the other hand, hardening property would be rarely influenced, or rather higher hardening temperature would be required, for example a hardening condition of heating at a temperature of 130 degree centigrade for about 10 minutes would be required.
  • the epoxy resin-hardening ingredient is activated and the epoxy resin ingredient can be hardened by being heated at a relatively low temperature, for example at a temperature from about 70 degree centigrade to 110 degree centigrade for about 10 minutes since the bonding material contains a sulfur-containing compound at an adequate amount. Therefore, when the bonding material for mounting of the present invention would be used, electric components can be mounted on a circuit board with avoiding thermal damage and without the necessity of particular treatment and/or apparatus, even when the electric components had an allowable temperature limit of 120 degree centigrade or lower. Further, the bonding material for mounting of the present invention has an advantage that it has an improved preservation stability and it is suitable for producing circuit boards successively (or at the same conditions).
  • the amount of the sulfur-containing compound is about 1 to 100 parts by weight based on 100 parts by weight of the epoxy resin. On the one hand, sufficient decreasement of the hardening temperature is not attained when the amount of the reforming agent is less than about 1 part by weight, and on the other hand, sufficient preservation stability is not attained when the amount of the reforming agent is more than about 100 parts by weight.
  • the bonding material for mounting of the first invention further contains a thickening agent. It becomes to be possible to suitably supply the present bonding material for mounting to desired regions on the circuit board depending on the methods such as transfer printing, screen printing, dispensing by adjusting the viscosity of the present bonding material for mounting by adding a thickening agent.
  • Another aspect of the present first invention also provides an electric/electronic device containing one or more circuit boards, which boards one or more electric components were mounted on using the present bonding material of the first invention.
  • Those circuit boards can be prepared by a method comprising the steps:
  • the present application provides, as a second invention, a conductive bonding material as recited in claim 1 characterized in that the conductive particles ingredient are metallic particles and the sulfur-containing compounds are co-ordinated with the surface of the metallic particles, and that the sulfur-containing compounds (thiol-compounds) remove (or dissociate) from the metallic particles to change to the epoxy resin-hardening agent by being subjected to a predetermined condition.
  • the present second invention in one embodiment, is characterized in that the conductive particles comprise metallic particles selected from the group consisting of gold, silver and copper.
  • the present second invention in another embodiment, is characterized in that subjecting to a predetermined condition is to subject to any of ultraviolet ray irradiation, electron ray irradiation and heating operation. According to any of these operation, the epoxy resin-hardening ingredient can be activated.
  • the present second invention in another embodiment, is characterized in that the metallic particles have a mean particle diameter ranging from 1 nm to 100 micrometer.
  • the present second invention in another embodiment, is characterized in that the metallic particles have a mean particle diameter ranging from 1 nm to 100 nm.
  • metallic particles in nano-size i.e. the dimension in the order of nanometer (nm)
  • metallic nano-particles are dispersed in a liquid medium. Since the metallic nano-particles have higher activity rather than metallic particles having larger diameter or dimension and easily agglomerate together at normal temperature, they have a problem relating to the preservation stability.
  • a method comprising adding dispersing agent to the metallic nano-particles, which dispersing agent can form coordinate bond with the metallic nano-particles, thereby the metallic nano-particles being protected and stabilized, and then eliminating the dispersing agent from the metallic nano-particles by heating and trapping them by acid-anhydrides (for example, see the Japanese Patent Kokai Publication 2002-299833).
  • the inventors have completed the present invention as a result of extensive and intensive efforts, while paying attention to the matter that the coordinating state of the sulfur-containing compounds to the metallic particles can be controlled by use of the sulfur-containing compounds.
  • a conductive paste comprising metallic particles, a sulfur-containing compound and a resin characterized in that the sulfur-containing compound coordinates at the end group thereof with the surface of the metallic particles, and then the end group performs as the hardening agent for the resin component after being dissociated from the surface of the metallic particles.
  • the sulfur-containing compound can coordinate at the end group thereof with the surface of the metallic particles (hereinafter, those sulfur-containing compound are also referred to as “coordinatable sulfur-containing compound” in the present specification), do not perform as the hardening agent for the resin component in the coordinating state and performs as the hardening agent for the resin component in the state that it dissociated from the surface of the metallic particles.
  • the coordinated sulfur-containing compound is one kind of latent hardening agent.
  • the hardening reaction of the latent hardening agent can be inhibited by capping the end group thereof through the coordinated bond, which group can cause hardening reaction. When the end group is freed by breaking the bond, the agent can cause the hardening reaction.
  • These conductive paste can show high preservation stability while the sulfur-containing compound keeps coordinating state, and start hardening reaction by dissociating the coordinated bond when desired.
  • the paste can show an improved preservation stability and can immediately harden at a low temperature when desired.
  • the recitation “performs as the hardening agent” means that it causes hardening reaction of the resin components, for example, by facilitating the bonding reaction among the resin components or by forming cross-link among the resin components through bonding with the resin components.
  • the end group of the coordinatable sulfur-containing compound it is necessary for the end group of the coordinatable sulfur-containing compound that it can form a coordinated state with the metallic particles in a normal state and break the coordinated state when desired.
  • Such end group may be those containing one or more of coordinated atoms having lone-pair electrons.
  • the coordinated bond among the metallic particles and the coordinated atoms can be broken by external influences, such as irradiation of ultraviolet ray or electron ray or by being heated.
  • the exposure dose of ultraviolet ray or electron ray and the temperature and period of heating may be optionally selected.
  • the end group of the coordinatable sulfur-containing compound contributes to the hardening reaction of the resin and performs as a hardening agent, while the degree of such properties may vary depending on the combination of the resin to be used and hardening method.
  • the coordinatable sulfur-containing compound may immediately perform as a hardening agent in its dissociated state, or alternatively, may perform as a hardening agent by being subjected to any external influences, such as by being heated.
  • the end group of the coordinatable sulfur-containing compound may be, for example a thiol group.
  • the thiol group can coordinate with a metal due to having a sulfur atom having lone-pair electrons and contributes to the hardening of resins, in particular the fast hardening of epoxy resins at a low temperature.
  • coordinatable sulfur-containing compounds are, for example, alkane thiol compounds, in particular monothiol compounds such as 1-decanetihol and 1-hexanethiol, polythiol compounds such as 1,10-decanedithiol, 1,8-octadithiol and 1,6-hexanedithiol and the other mono- or poly-thiol compounds which have one or more thiol end group.
  • the hardening period of polythiol compounds is rather shorter than that of monothiol compounds.
  • un-hardened epoxy resin that is, a resinous material having two or more epoxy groups in one molecule
  • epoxy resins which are known in the prior art, such as glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins and cyclic aliphatic type epoxy resins may be used.
  • precursors of such compounds may also be used.
  • the present second invention is not limited to the above matters and can use optionally suitable materials as the coordinatable sulfur-containing compound and resins without departing from the concept of the invention.
  • the end group of the coordinatable sulfur-containing compound may be an amino group.
  • the metallic particles may be those comprising metallic materials selected from the group of gold, silver and copper.
  • the sulfur atom in the thiol group as mentioned in the above can suitably coordinate with the surface of the metallic particles comprising such metallic materials, on the other hand, it substantially not coordinate with the surface of the metallic particles comprising for example nickel particles.
  • the metallic particles have a mean diameter for example between about 1 nm and 100 micrometer, preferably between about 1 nm and 100 nm.
  • a conductive paste using metallic particles having a mean diameter between about 1 nm and 100 micrometer exhibits favorable printing property when applied to printing methods and attains sufficiently low resistivity as a conductive material after the resin hardened.
  • a conductive paste using nano-sized metallic particles having a mean diameter between about 1 nm and 100 nm may cause metallic particles to sinter at a relatively low temperature, so that particularly lower resistivity can be stably achieved relative to the volumetric change of the hardening resin due to temperature variation.
  • the conductive paste can contain two or more kinds of metallic particles and the coordinatable sulfur-containing compound can coordinate at the end group thereof with the surface of at least one kind of metallic particles.
  • These metallic particles may have different mean diameters.
  • it is preferable that the conductive paste contains the nano-sized metallic particles and the other metallic particles having larger diameters.
  • the combination of the metallic particles having different mean diameters is used, the filling density of the metallic particles is improved, while the printing property is also improved rather than using merely nano-sized metallic particles. Further, use of such combination of the metallic particles can decrease the material cost by decreasing the relative amount of the expensive nano-sized metallic particles in the metallic particle ingredient.
  • the ratio of the metallic particles, the coordinatable sulfur-containing compound and the resin can be selected, so that the coordinatable sulfur-containing compound performs as the hardening agent for the resin and the metallic particles can contact with each other or get closer to each other to exhibit sufficient conductivity after the resin volumetrically shrinked and hardened.
  • the conductive paste of the present second invention may contain the other optional ingredient in addition to the metallic particles, the coordinatable sulfur-containing compound and the resin, which other optional ingredient may be suitably selected depending on the applications of the conductive paste.
  • the conductive paste of the present second invention can be prepared through any available and suitable methods.
  • the constituent ingredients such as the metallic particles and the coordinatable sulfur-containing compound (without at least the resin) are firstly prepared, and thereafter the remainder ingredients containing the resin are combined with the above prepared constituents to obtain the conductive paste so as to prevent the coordinatable sulfur-containing compound from performing as the hardening agent for the resin (i.e. so as to prevent causing hardening of the resin) before the coordinatable sulfur-containing compound make coordinate bonds with the surfaces of the metallic particles.
  • the metallic particles being used for preparation of the conductive paste that they have sufficient chemical activity so that the coordinatable sulfur-containing compound can make coordinate bonds with the surfaces of the metallic particles, i.e. the surface of the metallic particles are exposed without being coated with for example with oxidized film-layer.
  • the present conductive paste may be used for various applications.
  • the present conductive paste may be used as the material for forming a circuit wiring pattern on a circuit board; for forming conductive connections among a plurality of circuit wiring patterns on a plurality of circuit boards (including double sided circuit boards); and for bonding materials for forming mounted electric components.
  • a method of preparing a circuit board having a circuit-wiring pattern on the surface of said board comprising:
  • Such a method has an advantage that management and the handling of the conductive paste during production are easy, so that the method can be performed at a relatively low temperature compared with the method using conventional conductive pastes.
  • the conductive paste containing the nano-sized metallic particles is used in the above method, a circuit board having low and stable wiring resistivity can be provided.
  • a method of preparing a circuit board having a circuit-wiring pattern on the surface of said board comprising:
  • a conductive paste of the present second invention subjecting a conductive paste of the present second invention to any of ultraviolet ray irradiation, electron ray irradiation and heating operation, thereby dissociating the sulfur-containing compound from the surface of the metallic particles;
  • Such a method has an advantage that management and the handling of the conductive paste during production are easy, so that the method can be performed at a relatively low temperature, preferably with least heating of the circuit board and the other parts optionally arranged on the board, compared with the method using conventional conductive pastes.
  • the conductive paste containing the nano-sized metallic particles is used in the above method, a circuit board having low and stable wiring resistivity can be provided.
  • a method of preparing a multilayered circuit board wherein a plurality of wiring layers are superposed on each other and at least two wiring layers are electrically connected to each other through one or more holes penetrating the circuit board, comprising:
  • a conductive paste of the present second invention subjecting a conductive paste of the present second invention to any of ultraviolet ray irradiation, electron ray irradiation and heating operation, thereby dissociating the sulfur-containing compound from the surface of the metallic particles;
  • Such a method has an advantage which is similar to the method of the third aspect of the present invention.
  • a multilayered circuit board having at least one electric connections among superposed wiring layers having low and stable connection resistivity can be provided.
  • the multilayered circuit board can be prepared by a method comprising:
  • an “electric-component mounted body” having one or more circuit boards to which one or more electric components are mounted comprising:
  • Such a method has an advantage which is similar to the method of the second aspect of the present invention.
  • an electric-component mounted body having bonding portions having low and stable wiring resistivity can be provided.
  • the conductive paste of the present second invention subjecting the conductive paste of the present second invention to any of ultraviolet ray irradiation, electron ray irradiation and heating operation, thereby dissociating the sulfur-containing compound from the surface of the metallic particles;
  • Such a method has an advantage which is similar to the method of the third aspect of the present invention.
  • an electric-component mounted body having connecting portions having low and stable wiring resistivity can be provided.
  • each of the bonding material of the first invention and the conductive paste of the second invention further contains a fragrance material.
  • the conductive bonding material of the third invention is characterized in that it has a conductive particle ingredient as the metallic particles and the fragrance material has a reducing ability.
  • the problems relating to bad stench from the compounds having a thiol group are discussed.
  • a method of masking the bad stench from the thiol group by adding vanillin, lemon oil and/or ester-based solvents for example, see Japanese Patent Kokai Publication No. 04/23882
  • a method of absorbing low molecular weight mercaptans being the bad stench ingredients by Sepiolite which is hydrated magnesium silicate mineral for example, see Japanese Patent Kokai Publication No. 10/60097
  • the inventors have completed the present invention as a result of extensive and intensive efforts, while paying attention to the masking of the bad stench.
  • a conductive paste comprising metallic fillers, resin and a hardening agent for hardening the resin, and a fragrance material.
  • bad stench can be masked by the perfume from the fragrance material although the resin and/or hardening agent emanates bad stench since the fragrance material is added to the conductive paste.
  • uncomfortable sense that the operator feel are decreased, rather preferably, the operator can feel comfortable sense by using the conductive paste.
  • the perfume is emanated from the fragrance material before the hardening reaction is completed, however no or little perfume is emanated from the resin after the hardening reaction is completed.
  • the operator can confirm completion of the hardening reaction based on the absence of the perfume (or the extent of the strength of the perfume) from the paste by his olfactory perception or any detecting machine, even if the conductive fillers are not transparent.
  • fragrance material means the materials which emanate good perfume (or diffuse an aroma) and give pleasant feeling to a human by stimulating his olfactory perception as generally acknowledged.
  • the fragrance material may contain, in addition to the ingredient emanating fragrant or aroma, i.e. fragrant ingredient, the other ingredient.
  • the fragrance material may be natural fragrance material or synthetic fragrance material, or blended fragrance material which is made by combining two or more fragrance materials of the group consisting of natural fragrance materials and synthetic fragrance materials.
  • the natural fragrance materials comprise a fragrant oil (essential oil) which is extracted from bodies of animals and/or botanicals.
  • animal natural fragrance materials are musk, civet, castoreum and ambergris, wherein each fragrant ingredient thereof is muscone, civetone, castoreum and ambrein.
  • the botanical natural fragrance material mainly consists of fragrant oils obtained from flowers, fruits, tree bark or leaves of plants.
  • each fragrant ingredient thereof is, for example, anethole, eugenol, cadinene, carvone, coumalin, geraniol, acetate esters (for example, cinnamyl acetate, linalol acetate, menthyl acetate), safrole, methyl salicylate, santalol, citral, citronellal, cineole, camphor, cinnamic aldehyde, terpineol, decyl aldehyde, vanillin, alpha-pinene, beta-
  • examples of the synthetic fragrance materials contain ionone, hydroxycitronellal, heliotropine, beta-naphthol methyl ether, gamma-undecalactone, gamma-nonalactone, methylphenylglycide acid ethyl, maltol, cyclotene, ethylmaltol, vanillin and ethylvanillin (or bourbonal), each of which may be used solely or as a mixture of two or more.
  • the resin is an epoxy resin and the hardener agent is a compound which has a thiol group.
  • the hardener agent is a compound which has a thiol group.
  • Those conductive paste has an advantage that it hardens quickly at a relatively low temperature and that the bad stench particularly emanated from the compound having a thiol group can be masked by the fragrance materials. Therefore, the present conductive paste can be used in the appliances that are used in human's living environment such as electric/electronic components wherein bad stench is an unfavorable problem, for example, portable devices, devices used for processing or preservation of foods and devices used for health and beauty.
  • the conductive filler is metallic particles
  • the fragrance material contains an ingredient which has a reducing ability (hereinafter, merely also referred to as “reducible ingredient”).
  • the metallic particles can be oxidized by air and so on and can be sulfurated by the compound having a thiol group.
  • the material produced through the hardening of the conductive paste shows higher volumetric resistivity compared with the material in which the surface of the metallic particles is not coated with oxides and/or sulfide.
  • oxidation and/or sulfurization of the surface of the metallic particles can be prevented by adding reducible ingredients containing the fragrance material to the conductive paste, so that increasing the volumetric resistivity of the hardened product due to the oxidation and/or sulfurization can be avoided.
  • the “metallic particles” used in the present third invention may be particles consisting of a single kind of metal or alloys of such as soldering materials, preferably the lead-free soldering materials.
  • the present third invention is not limited to the above matters.
  • the conductive fillers may be not only metallic particles, but also particles of powders made of carbon and also the other conductive polymer.
  • the resin not only epoxy resin but also phenol resin may be used.
  • the hardening agent may be selected from for example amine-based compounds or phenol-based compounds other than thiol-based compounds depending on the resin to be used.
  • the conductive paste of the present third invention can comprise, in addition to the conductive fillers, the resin, the hardening agent and the fragrance material, any other optional ingredient.
  • the ratio of the conductive fillers, the resin, the hardening agent, the fragrance material and the optionally added ingredient are selected so that the conductive fillers come to contact with each other or get closer to each other to exhibit sufficient conductivity after the resin volumetrically shrinked and hardened.
  • the ratio of the fragrance material may be selected depending on the kind and the level (or strength) of the stench from the ingredient emanating bad stench to be masked, as well as the kind and the level of the perfume of the fragrance material.
  • the present conductive paste can be prepared by any suitable methods, for example, by merely mixing or kneading the constituent materials.
  • the conductive paste of the present third invention as explained in the above can be used for various applications, for example, as the material for bonding materials for forming mounted electric components; for forming a circuit-wiring pattern on a circuit board; and for forming conductive connections among a plurality of circuit wiring patterns on a plurality of circuit boards.
  • a method of preparing an electrical/electronic device having circuit boards, which boards are equipped with conductive hardened products formed from a conductive paste through hardening of the resin ingredient contained in the conductive paste comprising:
  • the hardening reaction of the conductive paste is not completed while the perfume of the fragrance material is present.
  • the operator can determine that the hardening reaction of the conductive paste is completed. Accordingly, the operator can easily determine completion of the hardening reaction rather than the case where completion of the hardening reaction is determined by the change of the color tone. Therefore, it is possible to establish a method of preparing an electrical/electronic device having improved quality reliability.
  • an electrical/electronic device equipped with conductive hardened products formed from a conductive paste of the present third invention through hardening of the resin ingredient contained in the conductive paste.
  • Those devices have an advantage of improved quality reliability.
  • the electrical/electronic device of the present third invention comprises for example an electric-component mounted body wherein one or more electric components are mounted on a circuit board by the conductive hardened products.
  • the electrical/electronic device of the present third invention comprises a circuit board on which conductive hardened products functions as the circuit wiring pattern, as well as a multilayered circuit board, wherein a plurality of wiring layers are superposed on each other and at least two wiring layers are electrically connected to each other with the conductive hardened products filling one or more holes penetrating the circuit board.
  • a bonding material for preparing a mounted body which can harden at a relatively low temperature and has a improved preservation stability since the bonding material contains a sulfur-containing compound, in particular a reforming agent containing a —SH group which causes the epoxy resin to start hardening reaction in a suitable amount. Further, a method of preparing circuit boards using the bonding material for preparing a mounted body and an electrical/electronic device having such circuit boards are also provided.
  • a conductive paste containing a coordinatable sulfur-containing compound which makes coordinate bond at the end group thereof with the surface of the metallic particles and which functions as hardening agent for the resin when the end group dissociates from the surface of the metallic particles.
  • the state of the coordinated bond of the sulfur-containing compound can be controlled so as to show an improved preservation stability when it is preserved and to cause hardening reaction only when it is desired.
  • a coordinatable sulfur-containing compound which functions as a quick and low temperature-hardening agent at the dissociated state is used, a conductive paste which hardens quickly at a low temperature and shows a high preservation stability is realized.
  • a method of preparing a circuit board, a multilayered circuit board and an electric-component mounted body using the conductive paste as mentioned in the above have an advantage that the handling of the conductive paste is easy.
  • each of the circuit board, the multilayered circuit board and the electric-component mounted body that were prepared using the above methods has an advantage that the connection resistivity of each connection of the circuit board, the multilayered circuit board and the electric-component mounted body is low.
  • a conductive paste containing a fragrance material thereby it is possible to reduce or kill bad stench and it is easily determined to confirm completion of the hardening reaction.
  • epoxy resin and a compound having a thiol group as the hardening agent are used in one-component conductive paste which can harden at a relatively low temperature, the bad stench emanated from the compound having a thiol group can be masked by the perfume from the fragrance material.
  • the conductive paste may be used for broad applications, for example, the portable devices, the devices used for processing or preservation of foods and the devices used for health and beauty.
  • FIG. 1 is a schematic view of the conductive paste in the third embodiment of the second invention.
  • FIG. 2 is a schematic flow sheet of cross sectional view of preparing a circuit board in the forth embodiment of the second invention.
  • FIG. 3 is a schematic flow sheet of cross sectional view of preparing a circuit board in the fifth embodiment of the second invention.
  • FIG. 4 is a schematic flow sheet of cross sectional view of preparing a multilayered circuit board in the sixth embodiment of the second invention.
  • FIG. 5 is a schematic flow sheet of cross sectional view of preparing an electric-component mounted body in the seventh embodiment of the second invention.
  • FIG. 6 is a schematic flow sheet of cross sectional view of preparing an electric-component mounted body in the eighth embodiment of the second invention.
  • the present embodiment relates to a bonding material for preparing a mounted body (or conductive adhesive).
  • the bonding material in the present embodiment is one-component composition comprising an epoxy resin ingredient, a latent hardening agent for hardening the epoxy resin, a conductive particle ingredient and a sulfur-containing compound.
  • the present bonding material preferably contains the other ingredient such as thickening agent.
  • the bonding material contains the sulfur-containing ingredient about 1-100 parts by weight, preferably about 2-80 parts by weight based on 100 parts by weight of the epoxy resin.
  • the bonding material may contain about 0.1-30 parts by weight of the latent hardening agent, about 100-1000 parts by weight of the conductive particles, and optionally about 0.5-25 parts by weight of the thickening agent (each based on 100 parts by weight of the epoxy resin).
  • un-hardened epoxy resin i.e. a resinous material having two or more epoxy groups in one molecule
  • epoxy resins which are known in the prior art, such as glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins and cyclic aliphatic type epoxy resins may be used.
  • the precursors of such compounds may be also used.
  • the latent hardening agent for hardening the epoxy resin is a hardening agent having functions that, when contained in one-component epoxy resin material (also containing epoxy resin and its hardening agent), the epoxy resin material can be preserved at room temperature (e.g. about 15-30 degree centigrade) for a long time period without changing the property and when heated to a predetermined temperature, it quickly causes the epoxy resin to harden.
  • latent hardening agent examples include dicyandiamide, organic acid dihydrazide, amineimide, tertiary amine salt, imidazole salt, salts of Lewis acid and Bronsted acid, preferably latent hardening agent having an amine structure in the molecule thereof (for example, see “epoxy resin handbook”, edited by Niiho Masaki, Nikkan Kogyo Shinbun-sya, pp. 225-230).
  • any materials having electroconductivity by itself may be used.
  • particles made of metals such as gold, silver, copper, nickel, silver-palladium alloy and solder alloy, or particles made of the other conductive materials such as carbon can be used.
  • the shape and the size of the conductive particles are not particularly limited, the particles may have a number average particle size in a range for example from 0.1 to 50 micrometer.
  • the term “reforming agent” means one or more compounds that affects at least one of the epoxy resin and the conductive particles to reform the property thereof, for example, to improve the adhesion strength thereof.
  • the reforming agent which is applicable to the first invention has such functions and further has one or more of —SH groups in the molecule.
  • the sulfur-containing compound also being such a reforming agent having one or more of —SH groups in the molecule can lower the hardening temperature thereof due to the presence of the latent hardening agent.
  • sulfur-containing compounds contain mercapto-propionic acid derivatives (for example, 3-mercapto-propionic acid, methoxybuthyl mercaptopropinate, octyl mercaptopropinate, tridecyl mercaptopropinate, trimethylolpropane tris(mercaptopropionate) and pentaerythritol tetrakis-thiopropionate); thioglycol acid derivatives (for example, thioglycol acid, ammonium thioglycolate, monoethanolamine thioglycolate, methyl thioglycolate, octyl thioglycolate, methoxybuthyl thioglycolate, ethyleneglycol bisthioglycolate, butanediol bisthioglycolate, trimethylolpropane tris(thioglycolate), pentaerythritol tetrakis(thio
  • a sulfur-containing compound which does not have a —SH group, but can produce a —S— group may be used as the sulfur-containing compound.
  • thiirane and cyclic or linear thiirane derivatives for example, salts and complexes of thiirane
  • thickening agent typical inorganic thickening materials (or thixotropic agent) can be used.
  • other optional additives e.g. hardening promoting agents, fillers, pigments, dyes, flexibility adding agent and dispersants can be optionally added.
  • the bonding material for preparing a mounted body of the present embodiment can be prepared by appropriately mixing or kneading the constituent materials.
  • the bonding material of the present embodiment is grasped as a conductive adhesive and is understood that it do not show any electroconductivity before it hardens. However, when the bonding material is heated, the epoxy resin volumetrically shrinks and hardens, so that the conductive particles therein come to contact one another or get closer to each other, thereby shows electroconductivity. Since the bonding material of the present embodiment contains a sulfur-containing compound, which causes hardening of the epoxy resin at a proper amount, the present bonding material can be stably preserved for relatively long time, at least over seven days. In addition, the present bonding material can harden at a relatively low temperature, particularly at a temperature in a range from 70 to 110 degree centigrade.
  • the present embodiment relates to the method of preparing circuit boards and electric/electronic devices containing such circuit boards.
  • a bonding material of the first invention as mentioned in the above first embodiment is applied to the electrode (or land) of a board.
  • the bonding material can be applied by any of various methods, for example, transfer printing, screen printing or dispensing.
  • a board which is generally known in the technical field, comprises an insulating board (substrate) and a circuit-wiring pattern, wherein the circuit-wiring pattern is integrally formed on the board can be used.
  • an electric component is arranged onto the circuit board so that the electrodes of the electric component are suitably aligned with and contacted with the bonding material on the board.
  • the obtained board is subjected to heating, for example by passing through a reflow oven, thereby the bonding material is maintained at a temperature condition in a range between 70 to 110 degree centigrade for suitable period of time, for example from 0.5 to 10 minutes.
  • the epoxy resin sufficiently hardens to bond the electrode of the board with the electrode of the electric component, and thereby the conductive particles therein come to contact one another or get closer to each other to show electroconductivity.
  • the electric component can be mechanically and electrically bonded with the electrode of the board by the hardened adhesive.
  • the electric component used in the present embodiment is sufficient to have an allowable temperature limit which is higher than the heating temperature.
  • an electric component having an allowable temperature limit lower than 120 degree centigrade may be used in the present embodiment as far as its allowable temperature limit is higher than the heating temperature.
  • the heating temperature may be appropriately set in a temperature range from 70 to 110 degree centigrade considering the allowable temperature limit of the electric component so as to obtain sufficient hardening.
  • a circuit board to which electric components are mounted is prepared according to the above method.
  • Such circuit board can be used by being built-in various electrical/electronic devices. Examples of such electrical/electronic devices are as follows:
  • Portable electronic devices such as video-camera, portable CD, portable MD, portable DVD, mobile phone and laptop computer;
  • stationary settled electronic devices such as stereo set, desk-top type computer, video telephone, DVD player, CD player, DVD recorder, CD recorder and television set;
  • Home appliance electronic devices such as rice cooking device, microwave oven, refrigerator, cleaner, washing machine, air conditioner, lighting apparatus, intercom, security camera, monitoring camera, gas leakage detector and the toilet seat with the washing functions;
  • Electronic devices for vehicles for example for automobile and two-wheeled motor vehicle, such as car stereo, car navigation system, car air-conditioner, car sensor, engine controller, loading camera, automatic brake safe control system (ABS) and headlight.
  • car stereo car navigation system
  • car air-conditioner car sensor
  • engine controller loading camera
  • ABS automatic brake safe control system
  • headlight headlight
  • FIGS. 1-6 various embodiments of the second invention are illustrated in detail with reference to FIGS. 1-6 .
  • similar members are denoted with the same reference numerals.
  • an explanation of one member in one embodiment is also applicable to the other member in the other embodiment.
  • the present embodiment relates to a conductive paste, a method of preparing the conductive paste and a method of using the same in one preferred embodiment of the second invention.
  • the conductive paste 7 of the present embodiment comprises a first metallic particles 1 , a coordinatable sulfur-containing compound 2 and an insulating resin 4 .
  • the coordinatable sulfur-containing compound 2 coordinates at the end group thereof with the surface of the first metallic particles 1 to form metal coordination compounds 3 .
  • the end group of the coordinatable sulfur-containing compound 2 coordinating with the first metallic particles 1 may be for example a thiol group and the sulfur atom therein performs as a coordinating atom.
  • the resin 4 may be for example an epoxy resin. Since the thiol group relates to hardening of the epoxy resin, the coordinatable sulfur-containing compound 2 functions as the hardening agent for the resin 4 when the end group of the coordinatable sulfur-containing compound 2 dissociates from the surface of the metallic particles 1 .
  • the first metallic particles 1 may consist of any of gold, silver or copper.
  • the thiol group (particularly, sulfur atom) of the coordinatable sulfur-containing compound 2 can suitably coordinate with such metallic particles.
  • the mean particle diameter of the first metallic particles 1 may be, for example, in a range from about 1 nm to 100 ⁇ m and preferably in a range from about 1 to 100 nm.
  • the first metallic particles 1 were nano-size particles, they can be dispersed in the resin 4 due to the coordination of the coordinatable sulfur-containing compound 2 thereto.
  • FIG. 1 Although merely several particles of resin 4 are imaginarily shown in FIG. 1 , there are a lot of particles or constituent elements of resin 4 in the practical reacting system of the conductive paste. Thus, the imaginarily shown particles or constituent elements of resin 4 play a role as dispersion medium.
  • the conductive paste 7 of the present embodiment may further contain second metallic particles 5 as shown in FIG. 1( a ).
  • the second metallic particles 5 may consist of for example gold, silver, copper, platinum, palladium, rhodium, osmium, ruthenium, iridium, iron, zinc, cobalt, nickel, chromium, titanium, tantalum, indium and silicon.
  • the coordinatable sulfur-containing compound 2 may coordinate with the second metallic particles 5 or not.
  • the mean particle diameter of the second metallic particles 5 may be, for example, in a range from about 0.1 to 100 ⁇ m, and in particular in a range from 0.1 to 20 ⁇ m.
  • the conductive paste of the second invention may not contain the second metallic particles 5 , without being limited to the above explanation.
  • mean particle diameter means a number average particle diameter of the aggregation of the particles. It can be measured by a laser diffraction (light scattering) method, for example using Microtrac particle size analyzers 9320 HRA (available form NIKKISO CO., LTD., Tokyo, Japan).
  • the conductive paste 7 contains the first metallic particles 1 , the coordinatable sulfur-containing compound 2 , the resin 4 and the second metallic particles 5 if present, in a ratio for example of about 100 parts by weight of the first metallic particles 1 , about 60-95 parts by weight of the coordinatable sulfur-containing compound 2 , about 30-2 parts by weight of the resin 4 and about 30-2 parts by weight of the second metallic particles 5 if present.
  • the ratio of each ingredient of the present second invention may be selected optionally.
  • the present conductive paste may further contain the other ingredients as needed, for example hardening promotor, filler, extender, solvent, pigment, plasticity additive and dispersant at an adequate amount.
  • the conductive paste 7 in the present embodiment can be prepared by mixing the first metallic particles 1 having an exposed surface with the coordinatable sulfur-containing compound 2 to form the metal coordination compounds 3 , and then insulating resin 4 is added and mixed with the metal coordination compounds 3 .
  • the second metallic particles 5 (as well as the other optional ingredients) may be mixed simultaneously with the first metallic particles 1 and the coordinatable sulfur-containing compound 2 or may be added to the mixture together with the resin 4 .
  • the coordinate bond between the first metallic particles 1 and the end groups of the sulfur-containing compound 2 is broken.
  • the metal coordination compound 3 is dissolved and the sulfur-containing compound 2 dissociates from the surface of the metallic particles 1 as shown in FIG. 1( b ).
  • the irradiation dose may be optionally adjusted, and the temperature of the conductive paste 7 and the board 6 may increase slightly.
  • heating is applied, the conductive paste 7 and the board 6 may be heated at a temperature from 60 to 120 degree centigrade for about 5 to 60 minutes, but it is not limited thereto.
  • the dissociated sulfur-containing compound 2 can operate as the hardening agent for the resin. For example, when heating is applied, it causes the resin 4 to harden as shown in FIG. 1( c ) without additional operation.
  • the resin 4 is epoxy resin and the end group of the sulfur-containing compound 2 is a thiol group, for example, the resin hardens by maintaining the temperature from about 80 to 120 degree centigrade for about 5 to 60 minutes.
  • the resin hardens by irradiation of ultraviolet ray or electron ray.
  • this operation can be performed at a condition different from the operation to dissociate the sulfur-containing compound 2 .
  • both operations can be combined with together or performed in sequence.
  • the epoxy resin 4 volumetrically shrinks and hardens, so that the metallic particles 1 therein come to contact one another or get closer to each other, thereby a hardened product 7 ′ which shows electroconductivity as a whole is formed.
  • the mean diameter of the metallic particles 1 is in a range from about 1 to 100 nm
  • the metallic particles 1 sinter one another upon dissociating the sulfur-containing compound 2 and/or hardening of the resin 4 by being heated at a temperature from about 25 to 110 degree centigrade for about 2 to 30 minutes.
  • the obtained conductive hardened product 7 ′ shows very low resistivity.
  • the resistivity of the conductive hardened product 7 ′ is substantially not influenced by the volume change of the hardened resin 4 due to a temperature change.
  • the conductive paste of the present embodiment may form a conductive hardened product by using at a relatively low temperature. Further, the resistivity of the obtainable hardened product may be further lowered and stabilized by using nano-size metallic particles as the conductive paste and sintering them.
  • the present embodiment relates to a method of preparing a circuit board in one embodiment of the second invention.
  • an insulated board (or substrate) 6 is provided, as shown in FIG. 2( a ). Any material selected from polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, thermoplastic resin, aramide nonwoven and glass nonwoven may be used as the board 6 , but it is not limited thereto.
  • FIG. 2( b ) schematically shows a screen printing method, wherein squeegee 9 is pressingly moved over a mask 8 , so that the conductive paste 7 is printed on the board 6 through openings of desired pattern in the mask 8 . After printed, the mask 8 is removed from the board 6 .
  • the conductive paste 7 on the board 6 is irradiated with ultraviolet ray or electron ray 10 or the conductive paste 7 is heated together with the board 6 .
  • the sulfur-containing compound coordinated with the surface of the metallic particles in the conductive paste 7 dissociates from the surface of the metallic particles.
  • the resin is hardened by causing the dissociated sulfur-containing compound to operate the hardening agent, thereby a hardened product 7 ′ is obtained as shown in FIG. 2( d ). It is preferable that the resin hardens quickly at a relative low temperature. For example, in the case where heating operation is required, the hardening preferably starts after the dissociation without any additional operation.
  • a circuit board having a circuit wiring pattern made of the conductive hardened product 7 ′ on the surface of said board 6 is prepared.
  • the conductive paste of the second invention is used as the material for preparing the circuit wiring pattern, a good preservation stability is attained and easier handling during preparation is also attained.
  • the sulfur-containing compound dissociates from the surface of the metallic particles.
  • the resin starts to harden before or during application of the conductive paste to the board, so that it is not necessary to pay particular attention to handling.
  • the conductive paste containing the nano-sized metallic particles is used in the above method, a circuit board having low and stable wiring resistivity can be provided.
  • the present embodiment relates to a method of preparing a circuit board in another embodiment in the present second invention.
  • the present embodiment is a modified version of the forth embodiment, so that the difference from the forth embodiment is mainly explained hereinafter.
  • an insulated board (or substrate) 6 is provided, as shown in FIG. 3( a ).
  • a conductive paste 7 as explained in the first embodiment is irradiated with ultraviolet ray or electron ray 10 or the conductive paste 7 is heated as shown in FIG. 3( b ), so that the sulfur-containing compound coordinated with the surface of the metallic particles is dissociated from the surface of the metallic particles.
  • the above conductive paste 7 is applied to the board 6 in a pattern corresponding to the desired circuit wiring pattern as shown in FIG. 3( c ).
  • the conductive paste 7 does not substantially start hardening reaction after the sulfur-containing compound was dissociated from the surface of the metallic particles and before the application completes.
  • the dissociated sulfur-containing compound causes hardening reaction of the epoxy resin to obtain a conductive hardened product 7 ′ as shown in FIG. 3( d ). It is preferable that the resin hardens quickly and at a relatively low temperature. Such a hardening reaction can be caused by heating the conductive paste 7 ′ together with the board 6 .
  • the conductive paste of the second invention is used as the material for preparing the circuit wiring pattern, a good preservation stability is attained and easier handling during the preparation is also attained.
  • the sulfur-containing compound has been dissociated from the surface of the metallic particles before the conductive paste is applied to the board, it is not necessary to expose the board to ultraviolet ray or electron ray or to heat the board.
  • the conductive paste containing the nano-sized metallic particles is used in the above method, a circuit board having low and stable wiring resistivity can be provided.
  • the present embodiment relates to a method of preparing a multilayered circuit board, in particular a double sided circuit board in one embodiment of the second invention.
  • a substrate 6 ′ having a penetrating hole 11 at an adequate position is provided, as shown in FIG. 4( b ).
  • This substrate 6 ′ is the same as that of the above forth embodiment and to which substrate a hole 11 is formed through machining processing such as drilling or punching or thermal processing such as laser irradiation.
  • a conductive paste 7 as explained in the first embodiment is irradiated with ultraviolet ray or electron ray 10 or the conductive paste 7 is heated as shown in FIG. 4( b ), so that the sulfur-containing compound coordinated with the surface of the metallic particles is dissociated from the surface of the metallic particles.
  • FIG. 4( c ) schematically shows a screen printing method.
  • the conductive paste 7 does not substantially start hardening reaction after the sulfur-containing compound was dissociated from the surface of the metallic particles and before the application completes
  • the dissociated sulfur-containing compound causes hardening reaction of the epoxy resin to obtain a conductive hardened product 7 ′. It is preferable that the resin hardens quickly and at a relatively low temperature. Such a hardening reaction can be caused by heating the conductive paste 7 ′ together with the board 6 .
  • a wiring layer 12 a is formed on the top side of the substrate 6 ′ and another wiring layer 12 b is formed on the bottom side of the substrate 6 ′.
  • the wiring layer 12 a is electrically connected with the wiring layer 12 b via the conductive hardened product 7 ′ which fills the through hole 11 .
  • Each wiring layer can be formed according to the methods explained in the above second or third embodiment. Alternatively, a method to form a wiring layer which is known in the prior art can be also applicable.
  • the conductive paste of the second invention is used as the material for preparing the circuit wiring pattern, a good preservation stability is attained and easier handling during the preparation is also attained.
  • the sulfur-containing compound is dissociated from the surface of the metallic particles before the conductive paste fills the hole of the board, it is not necessary to expose the board to ultraviolet ray or electron ray or to heat the board.
  • the conductive paste containing the nano-sized metallic particles is used in the above method, a multilayered circuit board having an electric connections having low and stable wiring resistivity can be provided.
  • a multilayered circuit board in particular a double sided circuit board wherein two wiring layers are arranged on both sides of the board is explained.
  • a multilayered circuit board having more layers, wherein each layer has two wiring layers on both sides can be obtained by a method which is similar to the method explained in the present embodiment.
  • the wiring layers 12 a and 12 b were formed on the board 6 ′ after the hole 11 was filled with the conductive paste 7
  • filling the conductive paste 7 can be performed after forming both wiring layers 12 a and 12 b on the board 6 ′.
  • the conductive paste is irradiated with ultraviolet ray or electron ray or the conductive paste is heated together with the board, and then such a conductive paste is filled in the hole which was formed on the board.
  • the dissociation is caused by heating, untreated conductive paste is filled in the hole of the board, and then the conductive paste can be heated together with the board, thereby the sulfur-containing compound coordinated with the surface of the metallic particles in the conductive paste can be dissociated from the surface of the metallic particles.
  • the dissociated sulfur-containing compound may perform as hardening agent to obtain a hardened resin.
  • the present embodiment relates to a method of preparing an electric-component mounted body in one embodiment of the second invention.
  • a circuit board 13 is provided as shown in FIG. 5( a ) (wherein any wiring layer is not shown).
  • the circuit board 13 can be formed according to the methods explained in the above second or third embodiment or can be formed by a method which is known in the prior art or can be commercially available one.
  • FIG. 5( b ) schematically shows a screen printing method.
  • the conductive paste 7 on the board 13 is irradiated with ultraviolet ray or electron ray 10 or the conductive paste 7 is heated together with the board 13 .
  • the sulfur-containing compound coordinated with the surface of the metallic particles in the conductive paste 7 dissociates from the surface of the metallic particles.
  • an electric component 14 is arranged onto the circuit board 13 so that the electric component is suitably aligned with and contacted with the conductive paste 7 on the board 13 .
  • the resin is hardened by causing the dissociated sulfur-containing compound to operate the hardening agent, thereby a conductive hardened product 7 ′ is obtained as shown in FIG. 5( d ). It is preferable that the resin hardens quickly at a relative low temperature. For example, in the case where heating operation is required, the hardening preferably starts after the dissociation without any additional operation.
  • the electric component 14 is mechanically and electronically bonded to the wiring circuit board 13 by means of the conductive hardened products 7 ′ which is arranged between the wiring circuit board 13 and the electric component 14 , so that the electric component 14 is mounted on the circuit board 13 .
  • an electric-component mounted body having bonding portions (or connecting regions) wherein the conductive hardened product 7 ′ forms the connecting regions mounting the electric component 14 on the circuit board 13 can be prepared.
  • the conductive paste of the second invention is used as the material for bonding material for mounting, good preservation stability is attained and easier handling during the preparation is also attained.
  • the sulfur-containing compound dissociates from the surface of the metallic particles.
  • the resin starts to harden before or during application of the conductive paste to the board, so that it is not necessary to pay particular attention to handling.
  • the conductive paste containing the nano-sized metallic particles is used and sintered in the above method, an electric-component mounted body having conductive connections having low and stable bonding resistivity can be provided.
  • the present embodiment relates to a method of preparing an electric-component mounted body in another embodiment of the second invention.
  • This embodiment is a modified version of the seventh embodiment, so that the difference from the seventh embodiment is mainly explained hereinafter.
  • a circuit board 13 is provided, as shown in FIG. 6( a ).
  • a conductive paste 7 as explained in the first embodiment is irradiated with ultraviolet ray or electron ray 10 or the conductive paste 7 is heated as shown in FIG. 6( b ), so that the sulfur-containing compound coordinated with the surface of the metallic particles is dissociated from the surface of the metallic particles.
  • the above conductive paste 7 is applied to the board 13 at desired regions, for example to the lands (not shown) which is electrically connected with the wiring layer as shown in FIGS. 6( c ) and ( d ).
  • the conductive paste 7 does not substantially start hardening reaction after the sulfur-containing compound was dissociated from the surface of the metallic particles and before the application completes
  • an electric component 14 is arranged onto the circuit board 13 so that the electric component 14 is suitably aligned with and contacted with the conductive paste 7 on the board 13 .
  • the resin is hardened by causing the dissociated sulfur-containing compound to operate the hardening agent, thereby a conductive hardened product 7 ′ is obtained as shown in FIG. 6( e ). It is preferable that the resin hardens quickly at a relative low temperature. For example, hardening of the resin can be caused by heating the conductive paste 7 together with the circuit board 13 and the electric component 14 .
  • the electric component 14 is mechanically and electronically bonded to the wiring circuit board 13 by means of the conductive hardened products 7 ′ which is arranged between the wiring circuit board 13 and the electric component 14 , so that the electric component 14 is mounted on the circuit board 13 .
  • an electric-component mounted body having bonding portions wherein the conductive hardened product 7 ′ forms the bonding portions mounting the electric component 14 on the circuit board 13 can be prepared.
  • the conductive paste of the second invention is used as the material for bonding material for mounting, good preservation stability is attained and easier handling during the preparation is also attained.
  • the sulfur-containing compound is dissociated before the conductive paste is applied to the board, there is no danger that the board is exposed to ultraviolet ray or electron ray or heated for dissociation.
  • the conductive paste containing the nano-sized metallic particles is used and sintered in the above method, an electric-component mounted body having conductive connections having low and stable bonding resistivity can be provided.
  • the present embodiment relates to a conductive paste in one embodiment of the present third invention.
  • the conductive paste of the present embodiment comprises metallic particles which is conductive fillers, an epoxy resin, a hardening agent consisting of a compound having a thiol group and a fragrance material.
  • the metallic particles may be the particles of a single kind of metal selected from the group of gold, silver, copper and nickel, or of an alloy or a mixture comprising two or more kinds of the metals as mentioned in the above, or the particles of the soldering materials of, for example an Sn—Bi based alloy and Sn—Bi—In based alloy, an Sn—Ag based alloy, an Sn—Cu based alloy, an Sn—Ag—Cu based alloy, and one or more of those alloys to which Bi and/or In is further added.
  • the number average particle size of the metallic particles is for example, from about 1 to 50 micrometer, preferably from about 2 to 20 micrometer.
  • epoxy resin for example bisphenol A type epoxy resin, bisphenol F type epoxy resin and modified epoxy resins thereof may be used.
  • the compound having a thiol group is desirable in this invention since it performs as the hardening agent for the epoxy resin, in particular makes it possible to harden quickly at a lower temperature.
  • the examples of such compound are for example, thioglycol acid and the derivatives thereof, mercaptopropionic acid and the derivatives thereof, thiomalic acid, mercaptopyrizine, stearyl mercaptan and mercapto-ethyloctanoate ester.
  • fragrance material for example, plant-derived natural fragrance materials having terpene series compounds and the derivatives thereof (in particular, limonen, linalool and citral etc) as the perfume component thereof, such as ionone, hydroxycitronellal, maltol, vanillin and ethylvanillin (or bourbonal) or synthetic fragrance materials may be used.
  • a fragrance material having so strong perfume that the bad stench emanated from the compound could be masked it is preferable to use a fragrance material having so strong perfume that the bad stench emanated from the compound could be masked.
  • a fragrance material synthetic fragrance material or prepared fragrance material is suitable rather than plant-derived natural fragrance materials.
  • the metallic particles are made of a metal which is susceptible to being sulfurized, or made of a metal which is susceptible to being oxidized
  • fragrance materials which have a reducing ability to reduce or preferably prevent the sulfurization or oxidization of the surface of the metallic particles, thus to reduce or preferably prevent the volume resistivity of the conductive hardened product from being increased, (or, which have more susceptible ability to being sulfurized or being oxidized rather than the metal consisting of the metallic particles).
  • Such fragrance materials are for example a kind of fragrance having a carboxyl group in the molecule, such as cinnamic acid, and a kind of fragrance having an aldehyde group in the molecule, such as vanillin, ethylvanillin, heliotropine, anisaldehyde, amyl cinnamic aldehyde, cinnamic aldehyde, citral, citronellal, decyl aldehyde, hydroxycitronellal.
  • a kind of fragrance having a carboxyl group in the molecule such as cinnamic acid
  • a kind of fragrance having an aldehyde group in the molecule such as vanillin, ethylvanillin, heliotropine, anisaldehyde, amyl cinnamic aldehyde, cinnamic aldehyde, citral, citronellal, decyl aldehy
  • the fragrance material may have an optional form, for example, generally a powder form in the case of vanillin, ethylvanillin and heliotropine, and generally a liquid form in the case of anisaldehyde, amylcinnamic aldehyde, cinnamic aldehyde, citral, citronellal, decyl aldehyde, and hydroxycitronellal.
  • an optional form for example, generally a powder form in the case of vanillin, ethylvanillin and heliotropine, and generally a liquid form in the case of anisaldehyde, amylcinnamic aldehyde, cinnamic aldehyde, citral, citronellal, decyl aldehyde, and hydroxycitronellal.
  • the conductive paste of the present embodiment may contain the ingredients thereof in a ratio of, for example, about 100 parts by weight of epoxy resin, about 25-600 parts by weight of the metallic particles, about 1-100 parts by weight of the hardening agent and about 1-100 parts by weight of the fragrance materials. However, the ratio thereof may be optionally selected without being limited thereto.
  • the conductive paste of the present embodiment may contain the other ingredients, for example hardening promotors, fillers, extenders, solvents, pigments, plasticity additives and dispersants at an adequate amount.
  • the conductive paste of the present embodiment can be prepared through any optional methods, for example by merely mixing or kneading the ingredients, i.e. commercially available metallic particles, epoxy resin, hardening agent, fragrance and optional additional ingredient.
  • the compound having thiol group When the conductive paste of the present embodiment is heated, the compound having thiol group performs as a hardening agent for the epoxy resin, thereby the epoxy resin volumetrically shrinks and hardens, so that the metallic particles therein come to contact one another or get closer to each other. After sufficiently hardened, the hardened product shows an improved electroconductivity and emanates substantially no perfume.
  • the conductive paste of the present embodiment since the particularly bad stench emanated from the compound having a thiol group is masked by the perfume of the fragrance material, on the one hand, the bad and unpleasant stench can be efficiently reduced, and on the other hand, the paste can emanate pleasant perfume.
  • the conductive paste of the present embodiment comes not to emanate perfume when the hardening completes, an operator in charge of the mounting performance can easily confirm that the hardening operation has completed.
  • the conductive paste of the present embodiment can be used for the portable devices, the devices used for processing or preservation of foods and the devices used for health and beauty due to the bad stench emanated from the conventional conductive paste.
  • the present embodiment relates to a method of preparing the electric-component mounted body in one embodiment of the present third invention.
  • a circuit board made of an insulating material for example, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, epoxy resin, aramide nonwoven, glass woven, glass nonwoven, on at least one side of which board a circuit wiring pattern is formed with a conductive material, for example, copper, gold, a hardened product of a conductive paste is provided.
  • a circuit board which is one of commercially available boards or prepared through the preparing methods known in the prior art can be used as the circuit board.
  • the conductive paste explained in the above ninth embodiment is applied to desired regions of the circuit board, particularly to the electrodes (for example lands) by a screen printing method.
  • a mask having one or more openings having a predetermined pattern is arranged on the circuit board, a squeegee is pressingly moved over the mask, so that the conductive paste is printed on the board through the opening in the mask.
  • the mask is a metal mask (or made of a metal) and the squeegee is made of a fluorine contained resin.
  • the mask is removed from the circuit board.
  • the other method for example ink-jet printing, dispensing by dispenser, impregnation, spin-coating can be applicable to apply the conductive paste on the board at a desired region.
  • an electric component is arranged onto the circuit board so that the electrodes (for example leads) of the electric component are suitably aligned with and contacted with the bonding material on the board.
  • the way how to arrange may vary depending on the kinds of the electric component. However, it may also be sufficient to merely put the electric component on the conductive paste since the viscosity of the conductive paste decreases and the paste covers the conductive connections in the following heating step. It will be appreciated that another arrangement wherein the electric component is relatively forced on the conductive paste, thereby causing intimate attachment therebetween may be adopted.
  • Heating may be performed for example at a temperature of from about 70 to 200 degree centigrade, preferably from about 70 to 120 degree centigrade for about 1.5 to 15 minutes.
  • the presence or absence of the perfume of the fragrance material in the conductive paste is determined by an inspection. Such inspection may be performed by an operator who have a normal olfactory perception or using inspection machine. When the perfume of the conductive paste is substantially absent, the fragrance ingredient is sealed within the hardened product due to hardening of the conductive paste, so that completion of the hardening operation may be confirmed.
  • the fragrance ingredient is not sufficiently sealed within the hardened product.
  • the hardening operation is not sufficient, so that completion of the hardening can not be confirmed. Accordingly, in this case, hardening operation and the following inspection should be repeated until the hardening can be confirmed by confirming the absence of the perfume.
  • the conductive paste becomes to be a conductive hardened product.
  • the electric components are mechanically and electronically bonded to the wiring circuit board, thereby mounted.
  • the electric-component mounted body obtained as mentioned above may be installed in a various electric/electronic components.
  • the electric/electronic components produced by the present embodiment are, for example portable electronic devices such as mobile phone and headphone stereos, the devices used for processing or preservation of foods, for example, rice cooking device, microwave oven, refrigerator, and the devices used for health and beauty, for example, body fat scale, skin moisture measuring system, electric toothbrush and electric shaver.
  • the method of preparing electric/electronic components in the present embodiment completion of the hardening of the resin in the conductive paste can be confirmed based on the perfume of the conductive paste, so that an inspection at a low cost with a high degree of accuracy can be performed.
  • the electric-component mounted body obtained by the preparing method in the present embodiment therefore the obtained electric/electronic components attains a high reliability of quality.
  • an epoxy resin ingredient, a latent hardening agent ingredient, an inorganic thickening materials, conductive particles and reforming agent A as shown below are blended and kneaded in a roll mixer and defoamed by subjecting the blend to a depressurization operation (lower than or equal to 10 mmHg) to obtain a bonding material for mounting electric devices as an inventive example of the first invention (Examples 1-3).
  • the blend ratio of each ingredient is shown in Table 1.
  • Epoxy resin 1,6-hexanedioldiglycidyl ether type epoxy resin (available from Asahi Denka Kogyo Co. Ltd, Trade name: ACR epoxy);
  • Latent hardening agent 2-methylimidazoleazine (Japan Epoxy Resin Co. Ltd., trade name: epicure M12AZ);
  • Inorganic thickening material AEROSIL (Registered Trademark) #200 (manufactured by Nippon Aerosil Co., Ltd.)
  • Conductive particles Silver powder having a mean diameter of about 6 micrometer (manufactured by Mitsui Mining & Smelting Co., Ltd.)
  • Reforming agent A trimethylolpropane tristhiopropionate (liquid) which is a sulfur-containing compound.
  • Reforming agent B silane coupling agent; vinyltrimethoxysilane (manufactured by Dow Corning Toray Co., Ltd.)
  • Reforming agent C Titanate-type coupling agent
  • Plainact KR TTS manufactured by Ajinomoto Fine-Techno. Co., Ltd.
  • Each bonding material was directly printed on a surface of each glass-epoxy board, respectively, which surface was already coated with a copper plating.
  • Each of the printed bonding material had a rectangular parallelepiped form having 1 mm length, 1 mm width and 0.1 mm height.
  • Each of samples was heated for 10 minutes at 60 degree centigrade, 70 degree centigrade, 80 degree centigrade, 90 degree centigrade, 100 degree centigrade, 110 degree centigrade, 120 degree centigrade and 130 degree centigrade, respectively, followed by being naturally-cooled to a room temperature (about 25 degree centigrade).
  • a transfer printing technique which provides the accuracy comparable with the above printing could be adopted instead of the printing method.
  • Each of the obtained samples was settled in a Differential Thermal Analyzer (DTA) and heated at a uniform rate of heating (10 degree centigrade per minutes), thereby heat quantity Q 1 which was used during the period from just after starting of heating at the predetermined temperature until the completely hardened state was measured, respectively.
  • DTA Differential Thermal Analyzer
  • the viscosity ⁇ 0 thereof was measured. Thereafter, the viscosity ⁇ 1 of the same sample was repeatedly measured while keeping the temperature of the sample at about 25 degree centigrade. An E type Viscometer was used to measure the viscosity. The period of days that the measured viscosity took to reach a condition showing ⁇ 1 ⁇ 2 ⁇ 0 was assigned as the “Period of stable preservation.” According to the inventor's extensive experience, it is known that a bonding material which shows 7 days or more of Period of stable preservation involves no practical problem.
  • each bonding material in Examples 1-3 shows too low hardening temperature, and also practically suitable Period of stable preservation.
  • each bonding material in Comparative Examples 1-4 shows higher hardening temperature rather than that of the bonding materials of Examples 1-3 and the bonding material in Comparative Example 5 did not show sufficient preservation stability.
  • the bonding material was applied to the surface of the electrode on a board by printing or transfer printing and then an electric component was arranged onto the circuit board so that the electrodes of the electric component were suitably aligned with and contacted with the bonding material on the board.
  • each board was passed through a reflow oven which is set at each conditions corresponding to each of the hardening temperatures of the bonding materials of Examples 1-3 and Comparative Examples 1-3 for 10 minutes of heating period, thereby each of the electric components were mounted on the board to obtain a mounted circuit board, respectively.
  • a connector a molded component made of polyethylene having an allowable temperature of 90 degree centigrade was used.
  • each electric device equipped with a circuit board prepared using the bonding material in Examples 1-3 showed a reflow peak temperature lower than the allowable temperature of the electric device and could normally operate without causing thermal damage of the electric device.
  • each electric device equipped with a circuit board prepared using the bonding material in Comparative Examples 1-3 showed a reflow peak temperature higher than the allowable temperature of the electric device and could not operate properly, which seemed to be due to causing thermal damage of the electric device.
  • a dispersion of the silver particles (also referred to as “silver nano-particles” in this example) was prepared.
  • 100 parts by weight of another silver particles (having a mean diameter of about 5 ⁇ m) and 20 parts by weight of bisphenol F type epoxy resin (trade name “Epikote 871”, manufactured by Japan Epoxy Resin Co. Ltd.) based on 100 parts by weight of the silver particles in the dispersion were mixed and the mixture was kneaded by a three-roll mixer to obtain a conductive paste.
  • Example 4 The procedure of Example 4 was repeated to obtain a conductive material except that 1,10-decanedithiol as the sulfur-containing compound having an end group of thiol group was replaced with 1,10-diaminodecane as the sulfur-containing compound having an end group of amino group.
  • a conductive paste is preserved in a constant-temperature bath under an air atmosphere which is set to keep 25 degree centigrade and the period of time until the conductive paste looses flowability, in particular until the viscosity of the conductive paste exceeds about 50 Pa-s was measured for a month.
  • a conductive paste was coated on the surface of a PET (polyethylene terephthalate) film at a region of 3 mm width and 150 mm length with 50 ⁇ m thickness, which film was irradiated with a ultraviolet ray at an accumulated amount of light of 5000 mJ, followed by being heated at a predetermined temperature for 30 hours to obtain a hardened product.
  • the volume resistivity of thus obtained hardened product was measured according to JIS (Japanese Institute Standard) K6911, and from the result the specific resistance was calculated. The results are shown in table 4.
  • Example 6 Preservation over over over 2 hours Stability 1 month 1 month 1 month Specific 1 ⁇ 10 ⁇ 5 2 ⁇ 10 ⁇ 4 1 ⁇ 10 ⁇ 5 5 ⁇ 10 ⁇ 3 Resistance ( ⁇ ) (120° C.) (120° C.) (200° C.) (120° C.) (heating temperature)
  • the conductive paste of Examples 4-6 did not lose flowability within the period of the of the preservation reliability test (one month) and maintained a high level preservation reliability (Table 4). The reason seems to be that the sulfur-containing compound coordinates at the thiol end group or the amino end group thereof with the surface of the silver particles to form a metal coordination compound, thereby the thiol group or the amino group being capped, so that they did not react with the epoxy resin to cause the hardening reaction.
  • the conductive paste of Examples 4-6 after the preservation test finished, it was visually confirmed that the silver particles were stably dispersed and the agglomeration of the silver particles was not observed.
  • the conductive paste of Example 4 contained nano-sized particles which tend to easily agglomerate, it seems that such particles could stably exist in the resin by forming a metal coordination compound.
  • the conductive paste of Examples 4-6 showed sufficiently satisfactory low resistance as the conductive material in the specific resistance test (Table 4). The reason seems to be that the sulfur-containing compounds having the thiol group or the amino group dissociated from the silver particles by irradiation of ultraviolet ray and the following heating, the dissociated sulfur-containing compound performed as the hardening agent to harden the resin, so that silver particles came to contact one another or got closer to each other after the resin volumetrically shrinked and hardened.
  • the conductive paste of Example 4 showed a much lower resistance rather than the conductive paste of Example 5. The reason seems to be that the silver nano-particles sintered at a low temperature by the heating in the specific resistance test.
  • the specific resistance of the conductive paste of Example 6 could not be measured at the heating temperature of 120 degree centigrade and showed no conductivity. The reason seems to be that the sulfur-containing compound having the amino end group did not dissociate from the silver particle and could not perform as the hardening group for the epoxy resin.
  • the heating temperature was increased to 200 degree centigrade as shown in Table 4, it was confirmed that the conductive paste showed a sufficiently low resistance.
  • the specific resistance thereof could be measured at the heating temperature of about 120 degree centigrade. Such resistance value was allowable level for the conductive material.
  • the sulfur-containing compounds could perform as the hardening agent for the epoxy resin by the irradiation of ultraviolet ray and the heating to harden the resin, so that nickel particles came to contact one another or got closer to each other after the resin volumetrically shrinked and hardened.
  • conductive paste of the present third invention various kinds of conductive paste were prepared by mixing the constituents shown in Table 5 with the ratio shown in Table 6.
  • common materials are used as the resin and the conductive fillers.
  • Bisphenol A type epoxy resin was used as the resin, and silver particles having a mean diameter from 2-15 ⁇ m (Trade Name “silcoat”, manufactured by Fukuda Metal Foil & Powder Co., Ltd) was used as the conductive particles.
  • an imidazole type hardener (Trade Name “Curezole (registered trademark)”, Shikoku Chemicals, Co.
  • Example 9 Volume resistivity of the hardened product obtained from each of Example 9 and Comparative Example 8 was measured.
  • the conductive paste of each Example was hardened by heating at a temperature of 100 degree centigrade for 10 minutes and then the Volume resistivity of each sample was measured according to Japanese Industrial Standard (JIS) K 6911 .
  • JIS Japanese Industrial Standard
  • Comparative Example 7 was measured. The results are shown in Table 8.
  • Example 8 In Comparative Example 8, the same procedure was repeated as the inventive Example 9 except that the fragrance was not added. With reference to Table 8, the volume resistivity of inventive Example 9 was compared with that of Comparative Example 8. The volume resistivity of inventive Example 9 was lower than that of Comparative Example 8, so that it was confirmed that inventive Example 9 showed suitable conductivity.
  • cinnamic acid was used as the fragrance, which has a reducing ability.
  • sulfurization of the silver particles, which were used as the conductive filler was efficiently prevented by cinnamic acid although a compound having thiol group (—SH) was used as the hardening agent in Example 9.
  • Comparative Example 8 which uses a compound having a thiol group as a hardening agent showed higher volume resistivity rather than Comparative Example 7 which uses a compound without a thiol group as a hardening agent. It was conceived that a thiol group sulfurized the metal in the conductive filler to form a sulfide when the conductive paste did not contain a compound having a reducing ability.
  • Example 8 An easiness of inspecting completion of the hardening in the method of producing electric components mounted products by mounting electric components on circuit boards with the hardened product obtained from the conductive pastes was measured in Example 8 and Comparative Example 8.
  • Example 8 the hardening of the conductive paste did not completed while the perfume of the conductive paste is present.
  • an operator can determine that the hardening of the conductive paste was completed when the perfume of the conductive paste comes to absent, so that evaluated with an open circle ( ⁇ ).
  • the method to determine completion of the hardening is limited in the Comparative Example 8. Such method is either to inspect visually the change of the color tone of the resin, or to measure the connection strength or connection resistance.
  • Comparative Example 8 was difficult as to inspecting completion of the hardening rather than Example 8, so that evaluated with a triangle ( ⁇ ).
  • the applicability ratio of the conductive paste among electric devices is defined by the formula (3):
  • Example 8 As shown in Table 9, inspection was easier in Example 8 rather than in Comparative Example 8 and the applicability ratio of the conductive paste among electric devices in Example 8 was significantly improved rather than in Comparative Example 8.
  • circuit boards prepared using any conductive paste of first to third invention of the present application can be used for any of arbitrary electric/electronic devices.
  • the examples of such electric/electronic devices are as shown below:
  • Portable electronic devices such as video-camera, portable CD, portable MD, portable DVD, mobile phone and laptop computer;
  • stationary settled electronic devices such as stereo set, desk-top type computer, video telephone, DVD player, CD player, DVD recorder, CD recorder and television set;
  • Home appliance electronic devices such as rice cooking device, microwave oven, refrigerator, cleaner, washing machine, air conditioner, lighting apparatus, intercom, security camera, monitoring camera, gas leakage detector and the toilet seat with the washing functions;
  • Electronic devices for vehicles for example for automobile and two-wheeled motor vehicle, such as car stereo, car navigation system, car air-conditioner, car sensor, engine controller, loading camera, automatic brake safe control system (ABS) and headlight.
  • car stereo car navigation system
  • car air-conditioner car sensor
  • engine controller loading camera
  • ABS automatic brake safe control system
  • headlight headlight
  • the conductive bonding materials in the first and second inventions are applicable to various fields such as for forming a circuit wiring pattern on a circuit board; the materials for forming electric connections among multilayer circuit boards; and the bonding materials for bonding materials for forming mounted electric components in the technical field of forming electric/electronic circuit
  • the conductive bonding materials in the third invention is applicable to various fields such as portable electronic devices, devices for processing or preservation of foods, and home appliance electronic devices as the electric-component mounted bodies.

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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070023313A1 (en) * 2005-08-01 2007-02-01 Stora Enso Ab Method of holding together packages and components thereto
US20100018768A1 (en) * 2008-07-22 2010-01-28 Hitachi Cable, Ltd. Cable with crimping terminal and method of making the same
US20100307805A1 (en) * 2007-10-29 2010-12-09 Hitachi Chemical Company, Ltd. Circuit connecting material, connection structure and method for producing the same
US20120140375A1 (en) * 2010-12-06 2012-06-07 Samsung Electro-Mechanics Co., Ltd. Conductive paste for inner electrode and multilayer ceramic electronic component having the same
CN105144856A (zh) * 2013-04-26 2015-12-09 株式会社村田制作所 多层布线基板及其制造方法、以及探针卡用基板
US20150359106A1 (en) * 2012-12-31 2015-12-10 Amogreentech Flexible printed circuit board and method for manufacturing same
US20170271295A1 (en) * 2014-10-21 2017-09-21 Osram Opto Semiconductors Gmbh Electronic Device and Method for Producing an Electronic Device
DE102013020248B4 (de) 2012-11-30 2019-10-02 Lg Display Co., Ltd. Adhäsives Material für elektrische Verbindung, Verwendung des adhäsiven Materials
CN110461949A (zh) * 2017-04-07 2019-11-15 哈利玛化成株式会社 无机颗粒分散体
EP3706438A4 (en) * 2017-11-01 2021-01-06 FUJIFILM Corporation COMPOSITION OF RESIN FOR ACOUSTIC ADAPTATION LAYER, CURED PRODUCT, ACOUSTIC ADAPTATION SHEET, ACOUSTIC WAVES PROBE, ACOUSTIC WAVE MEASURING DEVICE, PRODUCTION PROCESS FOR ACOUSTICAL WAVES PROBE AND ACOUSTIC ADAPTATION LAYER MATERIALS
DE102016225246B4 (de) 2016-12-16 2023-04-13 Vitesco Technologies Germany Gmbh Verfahren zur Herstellung einer elektronischen Komponente und elektronische Komponente

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5602743B2 (ja) * 2009-08-26 2014-10-08 積水化学工業株式会社 異方性導電材料、接続構造体及び接続構造体の製造方法
KR101819785B1 (ko) * 2011-01-05 2018-01-17 나믹스 가부시끼가이샤 수지 조성물
KR20120108500A (ko) * 2011-03-24 2012-10-05 한국전자통신연구원 서브마이크로미터 또는 수마이크로미터 직경의 솔더 입자 제조방법
JP5954066B2 (ja) * 2012-09-11 2016-07-20 セイコーエプソン株式会社 検出装置及び検出方法
JP2016011406A (ja) * 2014-06-03 2016-01-21 太陽インキ製造株式会社 導電性接着剤およびそれを用いた電子部品
WO2016104275A1 (ja) * 2014-12-26 2016-06-30 積水化学工業株式会社 導電ペースト、接続構造体及び接続構造体の製造方法
JP7220974B2 (ja) * 2016-09-06 2023-02-13 株式会社スリーボンド エポキシ樹脂組成物
US11053348B2 (en) * 2017-02-15 2021-07-06 3M Innovative Properties Company Epoxy stabilization using metal nanoparticles and nitrogen-containing catalysts, and methods
EP3682986A4 (en) 2017-09-15 2020-07-22 Asahi Kasei Kabushiki Kaisha ANNULAR STRUCTURE OF METAL PARTICLES, ANNULAR STRUCTURE OF METALLIC PARTICLES COATED WITH INSULATION AND COMPOSITION
CN113088215A (zh) * 2021-04-16 2021-07-09 厦门韦尔通科技有限公司 一种用于手机摄像头模组封装的导电胶及其使用方法

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040004209A1 (en) * 2000-10-25 2004-01-08 Yorishige Matsuba Electroconductive metal paste and method for production thereof

Family Cites Families (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0198674A (ja) * 1987-10-09 1989-04-17 Daido Steel Co Ltd 導電性組成物
JP2505909B2 (ja) 1990-05-17 1996-06-12 積水化学工業株式会社 メルカプタン臭をマスキングしたシ―リング材または接着剤
JPH05274911A (ja) 1992-03-25 1993-10-22 Furukawa Electric Co Ltd:The 導電性レジンペースト
CN1069508A (zh) * 1992-09-03 1993-03-03 孙明 美能达万能胶及其配制方法
EP0594133B1 (en) 1992-10-22 1998-05-06 Ajinomoto Co., Inc. Polythiol epoxy resin composition with extended working life
JP3367531B2 (ja) 1992-10-22 2003-01-14 味の素株式会社 エポキシ樹脂組成物
JP3114529B2 (ja) * 1994-10-06 2000-12-04 住友金属鉱山株式会社 積層セラミックコンデンサー内部電極用ペースト
JP3323072B2 (ja) 1996-08-22 2002-09-09 アイシン化工株式会社 エポキシ樹脂組成物
JPH10298526A (ja) 1997-04-24 1998-11-10 Hitachi Chem Co Ltd 回路接続用組成物及びこれを用いたフィルム
JPH1112346A (ja) 1997-06-26 1999-01-19 Hitachi Chem Co Ltd 組成物及びこれを用いたフィルム
EP1005509B1 (en) 1997-08-19 2002-01-16 Minnesota Mining And Manufacturing Company Conductive epoxy resin compositions, anisotropically conductive adhesive films and electrical connecting methods
JPH11106731A (ja) 1997-09-30 1999-04-20 Hitachi Chem Co Ltd 回路接続用組成物及びこれを用いたフィルム
JPH11130841A (ja) 1997-10-29 1999-05-18 Hitachi Chem Co Ltd エポキシ樹脂組成物、接着剤、回路接続用組成物及びこれを用いたフィルム
JPH11199842A (ja) 1998-01-08 1999-07-27 Matsushita Electric Ind Co Ltd 電子部品実装用接着剤および電子部品の実装方法
JP3882374B2 (ja) 1999-02-12 2007-02-14 味の素株式会社 導電性樹脂組成物
JP2001049219A (ja) 1999-08-16 2001-02-20 Tomoegawa Paper Co Ltd 接着剤組成物
CN1454238A (zh) 2000-05-29 2003-11-05 味之素株式会社 导电性树脂组合物
JP2001354942A (ja) 2000-06-15 2001-12-25 Matsushita Electric Ind Co Ltd 導電性接着剤ならびに実装構造体およびその製造方法
JP4715010B2 (ja) * 2001-03-27 2011-07-06 味の素株式会社 硬化性エポキシ樹脂組成物、接着剤、及びシール剤
JP3900248B2 (ja) 2001-03-30 2007-04-04 ハリマ化成株式会社 多層配線板およびその形成方法
JP3802367B2 (ja) * 2001-04-27 2006-07-26 ハリマ化成株式会社 異方性導電材料を利用する基板間導通の形成方法
JP4178774B2 (ja) * 2001-08-28 2008-11-12 ソニーケミカル＆インフォメーションデバイス株式会社 異方性導電接着剤
JP2003183609A (ja) 2001-12-17 2003-07-03 Sumitomo Bakelite Co Ltd 異方導電性接着剤
JP4192554B2 (ja) * 2002-10-25 2008-12-10 株式会社デンソー 多層回路基板の製造方法
JP2004189954A (ja) * 2002-12-13 2004-07-08 Ricoh Co Ltd 熱硬化型導電性接着剤
JP2004277444A (ja) * 2003-03-12 2004-10-07 Ricoh Co Ltd 導電性接着剤
JP3858902B2 (ja) * 2004-03-03 2006-12-20 住友電気工業株式会社 導電性銀ペーストおよびその製造方法
CN1737072B (zh) * 2004-08-18 2011-06-08 播磨化成株式会社 导电粘合剂及使用该导电粘合剂制造物件的方法

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040004209A1 (en) * 2000-10-25 2004-01-08 Yorishige Matsuba Electroconductive metal paste and method for production thereof

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7963395B2 (en) * 2005-08-01 2011-06-21 Stora Enso Ab Method of holding together packages and components thereto
US20070023313A1 (en) * 2005-08-01 2007-02-01 Stora Enso Ab Method of holding together packages and components thereto
US20100307805A1 (en) * 2007-10-29 2010-12-09 Hitachi Chemical Company, Ltd. Circuit connecting material, connection structure and method for producing the same
US20100018768A1 (en) * 2008-07-22 2010-01-28 Hitachi Cable, Ltd. Cable with crimping terminal and method of making the same
US9230737B2 (en) 2010-12-06 2016-01-05 Samsung Electro-Mechanics Co., Ltd. Multilayer ceramic electronic component having a conductive paste
US20120140375A1 (en) * 2010-12-06 2012-06-07 Samsung Electro-Mechanics Co., Ltd. Conductive paste for inner electrode and multilayer ceramic electronic component having the same
US9053856B2 (en) * 2010-12-06 2015-06-09 Samsung Electro-Mechanics Co., Ltd. Conductive paste for inner electrode and multilayer ceramic electronic component having the same
DE102013020248B4 (de) 2012-11-30 2019-10-02 Lg Display Co., Ltd. Adhäsives Material für elektrische Verbindung, Verwendung des adhäsiven Materials
US9648753B2 (en) * 2012-12-31 2017-05-09 Amogreentech Co., Ltd. Flexible printed circuit board and method for manufacturing same
US20150359106A1 (en) * 2012-12-31 2015-12-10 Amogreentech Flexible printed circuit board and method for manufacturing same
US20160044782A1 (en) * 2013-04-26 2016-02-11 Murata Manufacturing Co., Ltd. Multilayer wiring substrate, manufacturing method therefor, and substrate for probe card
US9961768B2 (en) * 2013-04-26 2018-05-01 Murata Manufacturing Co., Ltd. Multilayer wiring substrate, manufacturing method therefor, and substrate for probe card
CN105144856A (zh) * 2013-04-26 2015-12-09 株式会社村田制作所 多层布线基板及其制造方法、以及探针卡用基板
US20170271295A1 (en) * 2014-10-21 2017-09-21 Osram Opto Semiconductors Gmbh Electronic Device and Method for Producing an Electronic Device
US10147696B2 (en) * 2014-10-21 2018-12-04 Osram Opto Semiconductors Gmbh Electronic device and method for producing an electronic device
DE102016225246B4 (de) 2016-12-16 2023-04-13 Vitesco Technologies Germany Gmbh Verfahren zur Herstellung einer elektronischen Komponente und elektronische Komponente
CN110461949A (zh) * 2017-04-07 2019-11-15 哈利玛化成株式会社 无机颗粒分散体
US11186740B2 (en) 2017-04-07 2021-11-30 Harima Chemicals, Inc. Inorganic particle dispersion
EP3706438A4 (en) * 2017-11-01 2021-01-06 FUJIFILM Corporation COMPOSITION OF RESIN FOR ACOUSTIC ADAPTATION LAYER, CURED PRODUCT, ACOUSTIC ADAPTATION SHEET, ACOUSTIC WAVES PROBE, ACOUSTIC WAVE MEASURING DEVICE, PRODUCTION PROCESS FOR ACOUSTICAL WAVES PROBE AND ACOUSTIC ADAPTATION LAYER MATERIALS
US11572467B2 (en) 2017-11-01 2023-02-07 Fujifilm Corporation Resin composition for acoustic matching layer, cured product, acoustic matching sheet, acoustic probe, acoustic measuring apparatus, method for producing acoustic probe, and acoustic matching layer material set

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US8012379B2 (en) 2011-09-06
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