WO2012144033A1 - 光反射性導電粒子、異方性導電接着剤及び発光装置 - Google Patents

光反射性導電粒子、異方性導電接着剤及び発光装置 Download PDF

Info

Publication number
WO2012144033A1
WO2012144033A1 PCT/JP2011/059724 JP2011059724W WO2012144033A1 WO 2012144033 A1 WO2012144033 A1 WO 2012144033A1 JP 2011059724 W JP2011059724 W JP 2011059724W WO 2012144033 A1 WO2012144033 A1 WO 2012144033A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
particles
anisotropic conductive
particle
reflective
Prior art date
Application number
PCT/JP2011/059724
Other languages
English (en)
French (fr)
Inventor
秀次 波木
士行 蟹澤
英明 馬越
Original Assignee
ソニーケミカル＆インフォメーションデバイス株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ソニーケミカル＆インフォメーションデバイス株式会社 filed Critical ソニーケミカル＆インフォメーションデバイス株式会社
Priority to US13/575,786 priority Critical patent/US20130105841A1/en
Priority to JP2012534453A priority patent/JPWO2012144033A1/ja
Priority to PCT/JP2011/059724 priority patent/WO2012144033A1/ja
Priority to TW100128832A priority patent/TWI517456B/zh
Publication of WO2012144033A1 publication Critical patent/WO2012144033A1/ja
Priority to US14/222,249 priority patent/US8975654B2/en

Links

Images

Classifications

    • 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
    • H01B1/02—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of metals or alloys
    • 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
    • C08G59/42—Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof
    • 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
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/04—Non-macromolecular additives inorganic
    • 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
    • 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
    • C09J9/00—Adhesives characterised by their physical nature or the effects produced, e.g. glue sticks
    • C09J9/02—Electrically-conducting adhesives
    • 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
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L24/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L24/28—Structure, shape, material or disposition of the layer connectors prior to the connecting process
    • H01L24/29—Structure, shape, material or disposition of the layer connectors prior to the connecting process of an individual layer connector
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/58—Optical field-shaping elements
    • H01L33/60—Reflective elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/62—Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
    • 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
    • C08K9/00—Use of pretreated ingredients
    • C08K9/02—Ingredients treated with inorganic substances
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/02—Bonding areas; Manufacturing methods related thereto
    • H01L2224/04—Structure, shape, material or disposition of the bonding areas prior to the connecting process
    • H01L2224/05—Structure, shape, material or disposition of the bonding areas prior to the connecting process of an individual bonding area
    • H01L2224/0554—External layer
    • H01L2224/0556—Disposition
    • H01L2224/05568—Disposition the whole external layer protruding from the surface
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/02—Bonding areas; Manufacturing methods related thereto
    • H01L2224/04—Structure, shape, material or disposition of the bonding areas prior to the connecting process
    • H01L2224/05—Structure, shape, material or disposition of the bonding areas prior to the connecting process of an individual bonding area
    • H01L2224/0554—External layer
    • H01L2224/05573—Single external layer
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/10—Bump connectors; Manufacturing methods related thereto
    • H01L2224/15—Structure, shape, material or disposition of the bump connectors after the connecting process
    • H01L2224/16—Structure, shape, material or disposition of the bump connectors after the connecting process of an individual bump connector
    • H01L2224/161—Disposition
    • H01L2224/16151—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/16221—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/16225—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/10—Bump connectors; Manufacturing methods related thereto
    • H01L2224/15—Structure, shape, material or disposition of the bump connectors after the connecting process
    • H01L2224/16—Structure, shape, material or disposition of the bump connectors after the connecting process of an individual bump connector
    • H01L2224/161—Disposition
    • H01L2224/16151—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/16221—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/16225—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H01L2224/16227—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation the bump connector connecting to a bond pad of the item
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/28—Structure, shape, material or disposition of the layer connectors prior to the connecting process
    • H01L2224/29—Structure, shape, material or disposition of the layer connectors prior to the connecting process of an individual layer connector
    • H01L2224/29001—Core members of the layer connector
    • H01L2224/29099—Material
    • H01L2224/29198—Material with a principal constituent of the material being a combination of two or more materials in the form of a matrix with a filler, i.e. being a hybrid material, e.g. segmented structures, foams
    • H01L2224/29199—Material of the matrix
    • H01L2224/2929—Material of the matrix with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/28—Structure, shape, material or disposition of the layer connectors prior to the connecting process
    • H01L2224/29—Structure, shape, material or disposition of the layer connectors prior to the connecting process of an individual layer connector
    • H01L2224/29001—Core members of the layer connector
    • H01L2224/29099—Material
    • H01L2224/29198—Material with a principal constituent of the material being a combination of two or more materials in the form of a matrix with a filler, i.e. being a hybrid material, e.g. segmented structures, foams
    • H01L2224/29298—Fillers
    • H01L2224/29299—Base material
    • H01L2224/2939—Base material with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/28—Structure, shape, material or disposition of the layer connectors prior to the connecting process
    • H01L2224/29—Structure, shape, material or disposition of the layer connectors prior to the connecting process of an individual layer connector
    • H01L2224/29001—Core members of the layer connector
    • H01L2224/29099—Material
    • H01L2224/29198—Material with a principal constituent of the material being a combination of two or more materials in the form of a matrix with a filler, i.e. being a hybrid material, e.g. segmented structures, foams
    • H01L2224/29298—Fillers
    • H01L2224/29299—Base material
    • H01L2224/29393—Base material with a principal constituent of the material being a solid not provided for in groups H01L2224/293 - H01L2224/29391, e.g. allotropes of carbon, fullerene, graphite, carbon-nanotubes, diamond
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/28—Structure, shape, material or disposition of the layer connectors prior to the connecting process
    • H01L2224/29—Structure, shape, material or disposition of the layer connectors prior to the connecting process of an individual layer connector
    • H01L2224/29001—Core members of the layer connector
    • H01L2224/29099—Material
    • H01L2224/29198—Material with a principal constituent of the material being a combination of two or more materials in the form of a matrix with a filler, i.e. being a hybrid material, e.g. segmented structures, foams
    • H01L2224/29298—Fillers
    • H01L2224/29399—Coating material
    • H01L2224/294—Coating material with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
    • H01L2224/29438—Coating material with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
    • H01L2224/29444—Gold [Au] as principal constituent
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/28—Structure, shape, material or disposition of the layer connectors prior to the connecting process
    • H01L2224/29—Structure, shape, material or disposition of the layer connectors prior to the connecting process of an individual layer connector
    • H01L2224/29001—Core members of the layer connector
    • H01L2224/29099—Material
    • H01L2224/29198—Material with a principal constituent of the material being a combination of two or more materials in the form of a matrix with a filler, i.e. being a hybrid material, e.g. segmented structures, foams
    • H01L2224/29298—Fillers
    • H01L2224/29399—Coating material
    • H01L2224/294—Coating material with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
    • H01L2224/29438—Coating material with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
    • H01L2224/29447—Copper [Cu] as principal constituent
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/28—Structure, shape, material or disposition of the layer connectors prior to the connecting process
    • H01L2224/29—Structure, shape, material or disposition of the layer connectors prior to the connecting process of an individual layer connector
    • H01L2224/29001—Core members of the layer connector
    • H01L2224/29099—Material
    • H01L2224/29198—Material with a principal constituent of the material being a combination of two or more materials in the form of a matrix with a filler, i.e. being a hybrid material, e.g. segmented structures, foams
    • H01L2224/29298—Fillers
    • H01L2224/29399—Coating material
    • H01L2224/294—Coating material with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
    • H01L2224/29438—Coating material with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
    • H01L2224/29455—Nickel [Ni] as principal constituent
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/31—Structure, shape, material or disposition of the layer connectors after the connecting process
    • H01L2224/32—Structure, shape, material or disposition of the layer connectors after the connecting process of an individual layer connector
    • H01L2224/321—Disposition
    • H01L2224/32151—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/32221—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/32225—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/44—Structure, shape, material or disposition of the wire connectors prior to the connecting process
    • H01L2224/45—Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
    • H01L2224/45001—Core members of the connector
    • H01L2224/45099—Material
    • H01L2224/451—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
    • H01L2224/45138—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
    • H01L2224/45144—Gold (Au) as principal constituent
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/4805—Shape
    • H01L2224/4809—Loop shape
    • H01L2224/48091—Arched
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/481—Disposition
    • H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/48225—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H01L2224/48227—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation connecting the wire to a bond pad of the item
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/73—Means for bonding being of different types provided for in two or more of groups H01L2224/10, H01L2224/18, H01L2224/26, H01L2224/34, H01L2224/42, H01L2224/50, H01L2224/63, H01L2224/71
    • H01L2224/732—Location after the connecting process
    • H01L2224/73201—Location after the connecting process on the same surface
    • H01L2224/73203—Bump and layer connectors
    • H01L2224/73204—Bump and layer connectors the bump connector being embedded into the layer connector
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/73—Means for bonding being of different types provided for in two or more of groups H01L2224/10, H01L2224/18, H01L2224/26, H01L2224/34, H01L2224/42, H01L2224/50, H01L2224/63, H01L2224/71
    • H01L2224/732—Location after the connecting process
    • H01L2224/73251—Location after the connecting process on different surfaces
    • H01L2224/73265—Layer and wire connectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/80—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
    • H01L2224/81—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a bump connector
    • H01L2224/819—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a bump connector with the bump connector not providing any mechanical bonding
    • H01L2224/81901—Pressing the bump connector against the bonding areas by means of another connector
    • H01L2224/81903—Pressing the bump connector against the bonding areas by means of another connector by means of a layer connector
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/80—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
    • H01L2224/83—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a layer connector
    • H01L2224/838—Bonding techniques
    • H01L2224/8385—Bonding techniques using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
    • H01L2224/83851—Bonding techniques using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester being an anisotropic conductive adhesive
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/91—Methods for connecting semiconductor or solid state bodies including different methods provided for in two or more of groups H01L2224/80 - H01L2224/90
    • H01L2224/92—Specific sequence of method steps
    • H01L2224/921—Connecting a surface with connectors of different types
    • H01L2224/9211—Parallel connecting processes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L24/10—Bump connectors ; Manufacturing methods related thereto
    • H01L24/15—Structure, shape, material or disposition of the bump connectors after the connecting process
    • H01L24/16—Structure, shape, material or disposition of the bump connectors after the connecting process of an individual bump connector
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L24/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L24/31—Structure, shape, material or disposition of the layer connectors after the connecting process
    • H01L24/32—Structure, shape, material or disposition of the layer connectors after the connecting process of an individual layer connector
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/73—Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/80—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
    • H01L24/83—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a layer connector
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/0001—Technical content checked by a classifier
    • H01L2924/00014—Technical content checked by a classifier the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/06—Polymers
    • H01L2924/078—Adhesive characteristics other than chemical
    • H01L2924/0781—Adhesive characteristics other than chemical being an ohmic electrical conductor
    • H01L2924/07811—Extrinsic, i.e. with electrical conductive fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/10—Details of semiconductor or other solid state devices to be connected
    • H01L2924/11—Device type
    • H01L2924/12—Passive devices, e.g. 2 terminal devices
    • H01L2924/1204—Optical Diode
    • H01L2924/12041—LED
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
    • H01L2924/181—Encapsulation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/44—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the coatings, e.g. passivation layer or anti-reflective coating
    • H01L33/46—Reflective coating, e.g. dielectric Bragg reflector
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
    • Y10T428/2991—Coated
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
    • Y10T428/2991—Coated
    • Y10T428/2993—Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
    • Y10T428/2991—Coated
    • Y10T428/2998—Coated including synthetic resin or polymer

Definitions

  • the present invention uses a light-reflective conductive particle for an anisotropic conductive adhesive used for anisotropically conductive connection of a light emitting element to a wiring board, an anisotropic conductive adhesive containing the same, and the adhesive
  • the present invention relates to a light emitting device in which a light emitting element is mounted on a wiring board.
  • a light-emitting device using a light-emitting diode (LED) element is widely used, and the structure of an old-type light-emitting device is such that an LED element 33 is bonded onto a substrate 31 with a die bond adhesive 32 as shown in FIG.
  • the p electrode 34 and the n electrode 35 on the upper surface are wire-bonded to the connection terminal 36 of the substrate 31 with a gold wire 37, and the entire LED element 33 is sealed with a transparent mold resin 38.
  • the gold wire absorbs light having a wavelength of 400 to 500 nm emitted from the LED element 33 to the upper surface side, and a part of the light emitted to the lower surface side is emitted.
  • the luminous efficiency of the LED element 33 is reduced by being absorbed by the die bond adhesive 32.
  • the light reflecting layer 40 must be provided on the LED element 33 by a metal vapor deposition method or the like so that the p-electrode 34 and the n-electrode 35 are insulated from each other. There was a problem that it was not possible.
  • the surface of the conductive particles covered with gold, nickel or copper in the cured anisotropic conductive paste or anisotropic conductive film is brown to dark brown, and
  • the epoxy resin binder itself in which the conductive particles are dispersed is also brown due to the imidazole-based latent curing agent commonly used for curing, and the light emission efficiency of the light emitted from the light emitting element (light extraction efficiency) ) Is difficult to improve, and the color of light (light emission color) cannot be reflected as it is.
  • An object of the present invention is to solve the above-described problems of the prior art, and light-emitting elements such as light-emitting diodes (LEDs) are flip-chip mounted on a wiring board using an anisotropic conductive adhesive to emit light.
  • LEDs light-emitting diodes
  • the LED element does not have a light reflection layer that increases the manufacturing cost, and the light emission efficiency is not lowered.
  • an anisotropic conductive adhesive containing the same and a light-emitting device in which a light-emitting element is flip-chip mounted on a wiring board using the adhesive.
  • the present inventor can avoid reducing the luminous efficiency, on the surface of the conductive particles to be blended in the anisotropic conductive adhesive, By providing a white to gray light reflecting layer made of specific inorganic particles so as not to fall below a specific coverage, the light emission efficiency of the light emitting element and the reflected light color of the conductive particles are reduced.
  • the present inventors have found that a hue difference can be prevented during this period, and have completed the present invention.
  • the present invention is a light-reflective conductive particle for an anisotropic conductive adhesive used for anisotropic conductive connection of a light emitting element to a wiring board, the core particle coated with a metal material,
  • a light-reflective conductive particle comprising a light-reflective layer formed of light-reflective inorganic particles having a refractive index of 1.52 or more on a surface thereof, and a covering ratio of the light-reflective layer on the surface of the core particle being 70% or more.
  • the present invention also provides an anisotropic conductive adhesive for use in anisotropic conductive connection of a light emitting element to a wiring board, wherein the light reflective conductive particles described above are applied to visible light having a wavelength of 380 to 780 nm.
  • An anisotropic conductive adhesive is provided which is dispersed in a thermosetting resin composition that gives a cured product having an optical path length of 1 cm and a light transmittance (JIS K7105) of 80% or more.
  • the present invention provides a light emitting device in which a light emitting element is mounted on a wiring board by a flip chip method through the above-mentioned anisotropic conductive adhesive.
  • the light-reflective conductive particles of the present invention for anisotropic conductive adhesive used for anisotropic conductive connection of a light-emitting element to a wiring board are composed of core particles coated with a metal material and a refractive index on the surface thereof. Is composed of a white to gray light reflecting layer formed of light reflecting inorganic particles having a particle size of 1.52 or more, and the coverage of the surface of the core particles by the light reflecting layer is 70% or more. It is.
  • the anisotropic conductive adhesive of the present invention is a cured product in which the light-reflective conductive particles have a light transmittance (JIS K7105) of 80% or more with an optical path length of 1 cm with respect to visible light having a wavelength of 380 to 780 nm. It is made to disperse
  • JIS K7105 light transmittance
  • the light emitting device obtained by flip-chip mounting the light emitting element on the wiring board using the anisotropic conductive adhesive layer of the present invention does not cause coloring even when the anisotropic conductive adhesive is cured, and contains Since the light-reflecting conductive particles that are used have a small wavelength dependency of the reflection property with respect to visible light, the light emission efficiency is improved and the light emission color of the light-emitting element can be reflected as it is.
  • FIG. 1A and 1B are cross-sectional views of the light-reflective conductive particles 10 and 20 of the present invention for an anisotropic conductive adhesive. First, the light reflective conductive particles in FIG. 1A will be described.
  • the light-reflective conductive particle 10 includes a core particle 1 coated with a metal material and a light-reflecting layer 3 formed on the surface of the light-reflective inorganic particle 2 having a refractive index of 1.52 or more. .
  • the light-reflective inorganic particles 2 having a refractive index of 1.52 or more are inorganic particles that exhibit white under sunlight. Accordingly, the light reflecting layer 3 formed from them exhibits white to gray.
  • the expression of white to gray means that the wavelength dependency of the reflection characteristic for visible light is small and the visible light is easily reflected.
  • Preferred examples of the light reflecting inorganic particles 2 include at least one selected from titanium oxide (TiO 2 ) particles, zinc oxide (ZnO) particles, and aluminum oxide (Al 2 O 3 ) particles.
  • titanium oxide particles titanium oxide particles, zinc oxide particles, or aluminum oxide particles, if there is a concern about photodegradation of a cured product of a cured thermosetting resin of an anisotropic conductive adhesive, it is catalytic to photodegradation.
  • Zinc oxide having a high refractive index can be preferably used.
  • the core particle 1 Since the core particle 1 is subjected to anisotropic conductive connection, its surface is made of a metal material.
  • the surface is coated with a metal material, an aspect in which the core particle 1 itself is a metal material, or an aspect in which the surface of the resin particle is coated with a metal material can be given.
  • a metal material used in conventional conductive particles for anisotropic conductive connection can be used.
  • examples thereof include gold, nickel, copper, silver, solder, palladium, aluminum, alloys thereof, multilayered products thereof (for example, nickel plating / gold flash plating products), and the like. Above all, gold, nickel, and copper turn the conductive particles brown, so that the effects of the present invention can be enjoyed over other metal materials.
  • the resin particle portion of the metal-coated resin particle conventionally used as the conductive particle for anisotropic conductive connection is used as the resin particle.
  • resin particles include styrene resin particles, benzoguanamine resin particles, and nylon resin particles.
  • a method of coating the resin particles with a metal material a conventionally known method can be employed, and an electroless plating method, an electrolytic plating method, or the like can be used.
  • the layer thickness of the metal material to be coated is sufficient to ensure good connection reliability, and is usually 0.1 to 3 ⁇ m, preferably depending on the particle size of the resin particles and the type of metal. 0.1 to 1 ⁇ m.
  • the particle size of the core particle 1 having a metal material surface is too small, conduction will be poor, and if it is too large, a short circuit between patterns tends to occur. Therefore, it is preferably 1 to 20 ⁇ m, more preferably 3 to 5 ⁇ m, particularly preferably. 3 to 5 ⁇ m.
  • the shape of the core particle 1 is preferably a spherical shape, but may be a flake shape or a rugby ball shape.
  • the layer thickness of the light reflecting layer 3 formed from the light reflecting inorganic particles 2 is too small with respect to the particle size of the core particle 1 from the viewpoint of the relative size with respect to the particle size of the core particle 1, it is reflected.
  • the rate decreases, and if it is too large, there is a tendency for poor conduction, so the content is preferably 0.5 to 50%, more preferably 1 to 25%.
  • the light-reflecting inorganic particles 2 constituting the light-reflecting layer 3 have a particle size that is too small to cause the light-reflecting phenomenon, and if it is too large, it is difficult to form the light-reflecting layer. Therefore, it is preferably 0.02 to 4 ⁇ m, more preferably 0.1 to 1 ⁇ m, and particularly preferably 0.2 to 0.5 ⁇ m.
  • the particle size of the light-reflecting inorganic particles 2 is such that the light to be reflected (that is, the light emitted from the light emitting element) is not transmitted. It is preferable that it is 50% or more of the wavelength.
  • examples of the shape of the light-reflective inorganic particles 2 include an amorphous shape, a spherical shape, a scale shape, and a needle shape. Among them, a spherical shape from the viewpoint of the light diffusion effect, and a scale shape from the point of the total reflection effect. Shape is preferred.
  • the light-reflective conductive particles 10 in FIG. 1A are formed by a known film forming technique (so-called mechano-fusion method) in which a film composed of small-sized particles is formed on the surface of large-sized particles by physically colliding large and small powders. ).
  • the light-reflective inorganic particles 2 are fixed so as to bite into the metal material on the surface of the core particle 1.
  • the inorganic particles are hardly fused and fixed, the monolayer of the inorganic particles forms the light-reflective layer 3.
  • the layer thickness of the light reflecting layer 3 is considered to be equivalent to or slightly thinner than the particle size of the light reflecting inorganic particles 2.
  • the light reflective conductive particles 20 in FIG. 1B will be described.
  • the light-reflective layer 3 contains a thermoplastic resin 4 that functions as an adhesive, and the light-reflective inorganic particles 2 are fixed to each other by the thermoplastic resin 4. 2 differs from the light-reflective conductive particle 10 in FIG. 1A in that it is multilayered (for example, multilayered into two or three layers). By including such a thermoplastic resin 4, the mechanical strength of the light reflecting layer 3 is improved, and the inorganic particles are less likely to be peeled off.
  • the light reflective conductive particle 20 of FIG. 1B can be manufactured by a mechano-fusion method.
  • a particulate thermoplastic resin 4 may be used in combination.
  • the light reflective conductive particle 20 of FIG. 1B is also manufactured simultaneously.
  • thermoplastic resin 4 a halogen-free thermoplastic resin can be preferably used for the purpose of reducing the environmental load, and for example, polyolefins such as polyethylene and polypropylene, polystyrene, acrylic resins, and the like can be preferably used. .
  • Such light-reflective conductive particles 20 can also be manufactured by a mechanofusion method. If the particle size of the thermoplastic resin 4 applied to the mechano-fusion method is too small, the effect as an adhesive is small, and if it is too large, it is difficult to adhere to the core particle 1, so that it is preferably 0.02 to 4 ⁇ m, more preferably 0.1 to 1 ⁇ m. Further, if the blending amount of the thermoplastic resin 4 is too small, the effect as an adhesive is small, and if it is too large, an unintended particle aggregate is generated. Therefore, with respect to 100 parts by mass of the core particle 1, The amount is preferably 0.2 to 500 parts by mass, more preferably 4 to 25 parts by mass.
  • the coverage is 70% or more, preferably 80% or more.
  • the covering ratio is measured by arranging the light-reflective conductive particles on the pressure-sensitive adhesive tape so as to form a single-layer particle layer, and capturing a 100-fold enlarged planar image obtained by a CCD camera into a personal computer.
  • the image processing software can perform the calculation by calculating an average coverage based on a predetermined binarization process (a process for converting a grayscale image into a binary image) (coverage measurement method A).
  • 30 conductive particles arbitrarily selected with a scanning electron microscope are enlarged (for example, 8000 times), and for each conductive particle, a covering state with attached insulating particles is sketched in a plane, It can also be performed by calculating an average coverage of 30 pieces (coverage measurement method B). Or it can also carry out by empirically judging that it has coat
  • the core particle having a surface made of gold, nickel or copper has a brown surface color, whereas such a core particle can be observed in gray.
  • a criterion is that the coverage is 70% or more.
  • titanium oxide powder having an average particle size of 0.5 ⁇ m is added to the thermosetting epoxy binder composition used in the thermosetting epoxy binder composition used in Example 1 of the present specification. Dry the paint uniformly mixed in such an amount that the ratio of the titanium oxide powder to the total of the titanium oxide powder is 0%, 40%, 50%, 60%, 70%, 80%, 90%, 100%.
  • a black plate was coated to a thickness of 100 ⁇ m, heated at 200 ° C. for 1 minute to cure, and the resulting cured product was used with a spectrophotometer (U3300, Hitachi, Ltd.), wavelength 450 nm.
  • the reflectance (JIS K7105) with respect to light is measured, the reflectance curve of FIG. 1C is obtained. From FIG. 1C, it is observed that the ratio of the titanium oxide powder to the total of the thermosetting epoxy binder composition and the titanium oxide powder increases sharply at 70%.
  • This anisotropic conductive adhesive is obtained by dispersing the light-reflective conductive particles of the present invention in a thermosetting resin composition, and can take a form such as a paste or a film.
  • thermosetting resin composition used for the anisotropic conductive adhesive of the present invention it is preferable to use a transparent and colorless one as much as possible. This is because the light reflecting efficiency of the light-reflective conductive particles in the anisotropic conductive adhesive is reflected without decreasing, and the light color of incident light is not changed.
  • colorless and transparent means that the cured product of the anisotropic conductive adhesive has a light transmittance (JIS K7105) of 80% or more, preferably 90% or more with respect to visible light having a wavelength of 380 to 780 nm.
  • the amount of the light-reflective conductive particles with respect to 100 parts by mass of the thermosetting resin composition is preferably 1 to 100 parts by mass, more preferably 10 to 50 parts by mass.
  • the reflective property of the anisotropic conductive adhesive of the present invention is that the reflectance (JIS K7105) of light having a wavelength of 450 nm of a 100 ⁇ m-thick cured product of the anisotropic conductive adhesive is improved in order to improve the light emission efficiency of the light emitting element. , Preferably at least 15%.
  • the reflection characteristics and blending amount of the light-reflective conductive particles to be used, the blending composition of the thermosetting resin composition, and the like may be appropriately adjusted. Usually, if the amount of the light-reflective conductive particles having good reflection characteristics is increased, the reflectance tends to increase.
  • the reflective property of the anisotropic conductive adhesive can be evaluated from the viewpoint of refractive index (JIS K7142). That is, if the refractive index difference between the thermosetting resin composition of the anisotropic conductive adhesive and the light-reflective conductive particles is too large, the light-reflective conductive particles and the thermosetting resin composition surrounding the light-reflective conductive particles This is because the amount of light reflection at the interface with the cured product increases. Specifically, it is desired that the difference in refractive index between the thermosetting resin composition and the light-reflecting inorganic particles is 0.02 or more, preferably 0.3 or more. In general, the refractive index of a thermosetting resin composition mainly composed of an epoxy resin is about 1.5.
  • thermosetting resin composition constituting the anisotropic conductive adhesive of the present invention
  • those used in conventional anisotropic conductive adhesives and anisotropic conductive films can be used.
  • a thermosetting resin composition is obtained by blending a curing agent with an insulating binder resin.
  • the insulating binder resin is preferably an epoxy resin mainly composed of an alicyclic epoxy resin, a heterocyclic epoxy compound, a hydrogenated epoxy resin, or the like.
  • Preferred examples of the alicyclic epoxy compound include those having two or more epoxy groups in the molecule. These may be liquid or solid. Specific examples include glycidyl hexahydrobisphenol A, 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexene carboxylate, and the like. Among these, glycidyl hexahydrobisphenol A, 3,4-epoxycyclohexenylmethyl-3 ′, 4 is preferable because it can ensure light transmission suitable for mounting LED elements on the cured product and is excellent in rapid curing. '-Epoxycyclohexenecarboxylate can be preferably used.
  • heterocyclic epoxy compound examples include an epoxy compound having a triazine ring, and 1,3,5-tris (2,3-epoxypropyl) -1,3,5-triazine-2,4 is particularly preferable. , 6- (1H, 3H, 5H) -trione.
  • hydrogenated epoxy compound hydrogenated products of the above-described alicyclic epoxy compounds and heterocyclic epoxy compounds, and other known hydrogenated epoxy resins can be used.
  • the alicyclic epoxy compound, the heterocyclic epoxy compound and the hydrogenated epoxy compound may be used singly or in combination of two or more.
  • other epoxy compounds may be used in combination as long as the effects of the present invention are not impaired.
  • an acid anhydride As the curing agent, an acid anhydride, an imidazole compound, dicyan, or the like can be used.
  • acid anhydrides that are difficult to discolor the cured product particularly alicyclic acid anhydride-based curing agents, can be preferably used.
  • methylhexahydrophthalic anhydride (MeHHPA) or the like can be preferably used.
  • thermosetting resin composition of the anisotropic conductive adhesive of the present invention when an alicyclic epoxy compound and an alicyclic acid anhydride-based curing agent are used, the respective amounts used are alicyclic acid anhydrides. If the amount of the physical curing agent is too small, the amount of uncured epoxy compound increases, resulting in poor curing. If the amount is too large, the corrosion of the adherend material tends to be accelerated by the influence of the excess curing agent.
  • the alicyclic acid anhydride curing agent is preferably used in an amount of 80 to 120 parts by weight, more preferably 95 to 105 parts by weight, based on 100 parts by weight of the compound.
  • the anisotropic conductive adhesive of the present invention can be produced by uniformly mixing light-reflective conductive particles and a thermosetting resin composition. Also, when using anisotropic conductive adhesives as anisotropic conductive films, they are dispersed and mixed together with a solvent such as toluene, and applied to the peeled PET film so as to have the desired thickness. What is necessary is just to dry at the temperature of about 80 degreeC.
  • the light-emitting device 200 includes the connection terminal 22 on the substrate 21 and the connection bumps 26 formed on the n-electrode 24 and the p-electrode 25 of the LED element 23 as light-emitting elements.
  • an anisotropic conductive adhesive is applied and the substrate 21 and the LED element 23 are flip-chip mounted.
  • the cured product 100 of the anisotropic conductive adhesive is obtained by dispersing the light-reflective conductive particles 10 in the cured product 11 of the thermosetting resin composition.
  • light emitted from the LED element 23 toward the substrate 21 is light-reflective conductive in the cured product 100 of the anisotropic conductive adhesive. Reflected by the particles 10 and emitted from the upper surface of the LED element 23. Accordingly, it is possible to prevent a decrease in luminous efficiency.
  • Example 1 (Creation of light-reflective conductive particles) 4 parts by mass of titanium oxide powder (KR-380, Titanium Industry Co., Ltd.) having an average particle size of 0.5 ⁇ m and Au coated resin conductive particles having an average particle size of 5 ⁇ m with a brown appearance color (spherical shape having an average particle size of 4.6 ⁇ m) Particles obtained by electroless gold plating of 0.2 ⁇ m thickness on acrylic resin particles: 20 parts by weight of Bright 20GNB4.6EH, Nippon Chemical Industry Co., Ltd. are put into a mechanofusion apparatus (AMS-GMP, Hosokawa Micron Corporation).
  • AMS-GMP Hosokawa Micron Corporation
  • the light-reflective conductive particles of Example 1 were formed by forming a light-reflective layer made of titanium oxide particles with a thickness of about 0.3 ⁇ m on the surface of the conductive particles under the conditions of a rotation speed of 1000 rpm and a rotation time of 20 minutes. Obtained. The appearance color of the light reflective conductive particles was gray.
  • the obtained anisotropic conductive adhesive was applied to a white plate made of ceramic so as to have a dry thickness of 100 ⁇ m, and heated at 200 ° C. for 1 minute to be cured. About this hardened
  • a glass epoxy substrate having a wiring obtained by plating Ni / Au (5.0 ⁇ m thickness / 0.3 ⁇ m thickness) on a 50 ⁇ m pitch copper wiring using the anisotropic conductive adhesive prepared in the light reflectance evaluation test. , 15 [mu] m height of the test IC chips 6mm square with gold bumps (conductive connection area / conductor - space 1600 ⁇ m 2 / 50 ⁇ mP) to 200 ° C., and flip chip mounted in 60 seconds, provided that 1Kg / chip, test IC Got a module.
  • TCT temperature cycle test
  • Example 2 Light whose appearance color is gray as in Example 1, except that the rotation speed of the mechanofusion device (AMS-GMP, Hosokawa Micron Co., Ltd.) is changed from 1000 rpm to 700 rpm and the rotation time is changed from 20 minutes to 10 minutes. Reflective conductive particles were obtained, and an anisotropic conductive adhesive was obtained. Further, in the same manner as in Example 1, the coverage ratio and the reflectance were measured, and further an electrical property (conduction reliability, insulation reliability) evaluation test was performed. The obtained results are shown in Table 1.
  • AMS-GMP mechanofusion device
  • Example 3 The appearance color was the same as in Example 1 except that Ni coated resin conductive particles (52NR-4.6EH, Nippon Chemical Industry Co., Ltd.) having an average particle size of 5.0 ⁇ m were used instead of Au coated resin conductive particles. Obtained gray light-reflective conductive particles, and an anisotropic conductive adhesive was obtained. Further, in the same manner as in Example 1, the coverage ratio and the reflectance were measured, and further an electrical property (conduction reliability, insulation reliability) evaluation test was performed. The obtained results are shown in Table 1.
  • Ni coated resin conductive particles 52NR-4.6EH, Nippon Chemical Industry Co., Ltd.
  • Example 4 4 parts by mass of titanium oxide powder (KR-380, Titanium Industry Co., Ltd.) having an average particle size of 0.5 ⁇ m and polystyrene (PS) particles (Grossdale 204S, Mitsui Chemicals, Inc.) having an average particle size of 0.2 ⁇ m as adhesive particles Co., Ltd.) 3 parts by mass and conductive particles having an average particle size of 5 ⁇ m (particles obtained by subjecting spherical acrylic resin particles having an average particle size of 4.6 ⁇ m to electroless gold plating of 0.2 ⁇ m thickness: Bright 20GNB4.6EH, Nippon Chemical Industry ( 20 parts by mass into a mechanofusion apparatus (AMS-GMP, Hosokawa Micron Corporation), and on the surface of the conductive particles under the conditions of a rotation speed of 1000 rpm and a rotation time of 20 minutes, styrene and titanium oxide particles By forming a light reflection layer having a thickness of about 1 ⁇ m, light reflective conductive particles having a gray
  • Example 5 External color as in Example 3 except that Ni coated resin conductive particles (52NR-4.6EH, Nippon Chemical Industry Co., Ltd.) having an average particle size of 5.0 ⁇ m were used instead of Au coated resin conductive particles. Obtained gray light-reflective conductive particles, and an anisotropic conductive adhesive was obtained. Further, similarly to Example 1, the coverage and reflectance were measured, and further an electrical property (conduction reliability, insulation reliability) evaluation test was performed. The obtained results are shown in Table 1.
  • Example 6 Use polyethylene (PE) particles (Amipearl WF300, Mitsui Chemicals) with an average particle size of 0.2 ⁇ m instead of polystyrene particles (Grossdale 204S, Mitsui Chemicals, Inc.) with an average particle size of 0.2 ⁇ m.
  • PE polyethylene
  • Example 3 Light-reflective conductive particles having a gray appearance color were obtained, and an anisotropic conductive adhesive was further obtained. Further, in the same manner as in Example 1, the coverage ratio and the reflectance were measured, and further an electrical property (conduction reliability, insulation reliability) evaluation test was performed. The obtained results are shown in Table 1.
  • Example 7 The appearance color was the same as in Example 3 except that instead of the titanium oxide powder having an average particle diameter of 0.5 ⁇ m, zinc oxide powder having an average particle diameter of 0.5 ⁇ m (one type of zinc oxide, Hakusuitec Co., Ltd.) was used. Obtained gray light-reflective conductive particles, and an anisotropic conductive adhesive was obtained. Further, in the same manner as in Example 1, the coverage ratio and the reflectance were measured, and further an electrical property (conduction reliability, insulation reliability) evaluation test was performed. The obtained results are shown in Table 1.
  • Example 8 The appearance color was the same as in Example 3 except that aluminum oxide powder (AE-2500SI, Admatechs Co., Ltd.) having an average particle diameter of 0.5 ⁇ m was used instead of titanium oxide powder having an average particle diameter of 0.5 ⁇ m. Obtained gray light-reflective conductive particles, and an anisotropic conductive adhesive was obtained. Further, in the same manner as in Example 1, the coverage ratio and the reflectance were measured, and further an electrical property (conduction reliability, insulation reliability) evaluation test was performed. The obtained results are shown in Table 1.
  • aluminum oxide powder AE-2500SI, Admatechs Co., Ltd.
  • Example 9 Instead of titanium oxide powder having an average particle diameter of 0.5 ⁇ m, light-reflective conductive particles having a gray appearance color were obtained in the same manner as in Example 3 except that magnesium carbonate having an average particle diameter of 0.5 ⁇ m was used. An anisotropic conductive adhesive was obtained. Further, in the same manner as in Example 1, the coverage ratio and the reflectance were measured, and further an electrical property (conduction reliability, insulation reliability) evaluation test was performed. The obtained results are shown in Table 1.
  • Example 10 The appearance color is gray in the same manner as in Example 3 except that titanium oxide powder having an average particle diameter of 0.2 ⁇ m (JR405, Teika) is used instead of titanium oxide powder having an average particle diameter of 0.5 ⁇ m. Light-reflective conductive particles were obtained, and further an anisotropic conductive adhesive was obtained. Further, in the same manner as in Example 1, the coverage ratio and the reflectance were measured, and further an electrical property (conduction reliability, insulation reliability) evaluation test was performed. The obtained results are shown in Table 1.
  • Comparative Example 1 Using Au coated resin conductive particles having a brown appearance color (particles obtained by electroless gold plating of 0.2 ⁇ m thickness on spherical acrylic resin particles having an average particle diameter of 4.6 ⁇ m: Bright 20GNB4.6EH, Nippon Chemical Industry Co., Ltd.) An anisotropic conductive adhesive was obtained in the same manner as in Example 1. Further, in the same manner as in Example 1, the reflectance was measured, and further an electrical property (conduction reliability, insulation reliability) evaluation test was performed. The obtained results are shown in Table 1.
  • Comparative Example 2 Comparative Example 1 except that instead of the Au-coated resin conductive particles, Ni-coated resin conductive particles (52NR-4.6EH, Nippon Chemical Industry Co., Ltd.) having a brown appearance color and an average particle diameter of 5.0 ⁇ m are used. Similarly, an anisotropic conductive adhesive was obtained. Further, in the same manner as in Example 1, the reflectance was measured, and further an electrical property (conduction reliability, insulation reliability) evaluation test was performed. The obtained results are shown in Table 1.
  • Comparative Example 3 3 parts by mass of polystyrene-based particles (Grossdale 204S, Mitsui Chemicals, Inc.) with an average particle size of 0.2 ⁇ m and conductive particles with an average particle size of 5 ⁇ m (spherical acrylic resin particles with an average particle size of 4.6 ⁇ m are 0.2 ⁇ m thick) Electroless gold-plated particles: Bright 20GNB4.6EH, Nippon Kagaku Kogyo Co., Ltd.
  • Comparative Example 4 Instead of titanium oxide powder with an average particle size of 0.5 ⁇ m, use silicon oxide (silica) powder (Seahoster KEP-30, Nippon Shokubai Co., Ltd.) with a refractive index of 1.45 and an average particle size of 0.5 ⁇ m. Otherwise, conductive particles having a brown appearance color were obtained in the same manner as in Example 3, and further an anisotropic conductive adhesive was obtained. Further, in the same manner as in Example 1, the coverage ratio and the reflectance were measured, and further an electrical property (conduction reliability, insulation reliability) evaluation test was performed. The obtained results are shown in Table 1.
  • the anisotropic conductive adhesives using the light-reflective conductive particles of Examples 1 to 10 have a coverage by the light-reflective layer of 70% or more, and the light reflectivities are all 15% or more. Yes, the blue color of 450 nm light was reflected as it was. In addition, the conduction reliability and the insulation reliability were also good results.
  • the light-reflective conductive particle of the present invention increases the manufacturing cost when a light-emitting device is manufactured by flip-chip mounting a light-emitting element such as a light-emitting diode (LED) element on a wiring board using an anisotropic conductive adhesive.
  • a light-emitting element such as a light-emitting diode (LED) element
  • the anisotropic conductive adhesive of the present invention is useful when the LED element is flip-chip mounted.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Organic Chemistry (AREA)
  • Computer Hardware Design (AREA)
  • Power Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Dispersion Chemistry (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Led Device Packages (AREA)
  • Conductive Materials (AREA)
  • Powder Metallurgy (AREA)
  • Non-Insulated Conductors (AREA)

Abstract

　発光素子を配線板に異方性導電接続するために使用する異方性導電接着剤用の光反射性導電粒子は、金属材料で被覆されているコア粒子と、その表面に屈折率が１．５２以上の光反射性無機粒子から形成された光反射層とから構成される。屈折率が１．５２以上の光反射性無機粒子としては、酸化チタン粒子、酸化亜鉛粒子又は酸化アルミニウム粒子が挙げられる。コア粒子表面の光反射層による被覆率は７０％以上である。

Description

光反射性導電粒子、異方性導電接着剤及び発光装置
　本発明は、発光素子を配線板に異方性導電接続するために使用する異方性導電接着剤用の光反射性導電粒子、それを含有する異方性導電接着剤、その接着剤を用いて発光素子を配線板に実装してなる発光装置に関する。
　発光ダイオード（ＬＥＤ）素子を使用した発光装置が広く使用されており、旧タイプの発光装置の構造は、図４に示すように、基板３１上にダイボンド接着剤３２でＬＥＤ素子３３を接合し、その上面のｐ電極３４とｎ電極３５とを、基板３１の接続端子３６に金ワイヤ３７でワイヤボンディングし、ＬＥＤ素子３３全体を透明モールド樹脂３８で封止したものとなっている。ところが、図４の発光装置の場合、ＬＥＤ素子３３が発する光のうち、上面側に出射する４００～５００ｎｍの波長の光を金ワイヤが吸収し、また、下面側に出射した光の一部がダイボンド接着剤３２により吸収されてしまい、ＬＥＤ素子３３の発光効率が低下するという問題がある。
　このため、図５に示すように、ＬＥＤ素子３３をフリップチップ実装することが提案されている（特許文献１）。このフリップチップ実装技術においては、ｐ電極３４とｎ電極３５とにバンプ３９がそれぞれ形成されており、更に、ＬＥＤ素子３３のバンプ形成面には、ｐ電極３４とｎ電極３５とが絶縁されるように光反射層４０が設けられている。そして、ＬＥＤ素子３３と基板３１とは、異方性導電ペースト４１や異方性導電フィルム（図示せず）を用い、それらを硬化させて接続固定される。このため、図５の発光装置においては、ＬＥＤ素子３３の上方へ出射した光は金ワイヤで吸収されず、下方へ出射した光の殆どは光反射層４０で反射して上方に出射するので、発光効率（光取り出し効率）が低下しない。
特開平１１－１６８２３５号公報
　しかしながら、特許文献１の技術ではＬＥＤ素子３３に光反射層４０を、ｐ電極３４とｎ電極３５とが絶縁されるように金属蒸着法などにより設けなければならず、製造上、コストアップが避けられないという問題があった。
　他方、光反射層４０を設けない場合には、硬化した異方性導電ペーストや異方性導電フィルム中の金、ニッケルあるいは銅で被覆された導電粒子の表面は茶色乃至暗茶色を呈し、また、導電粒子を分散させているエポキシ樹脂バインダー自体も、その硬化のために常用されるイミダゾール系潜在性硬化剤のために茶色を呈しており、発光素子が発した光の発光効率（光取り出し効率）を向上させることが困難であり、しかも光の色（発光色）を、そのままの色で反射させることができないという問題もあった。
　本発明の目的は、以上の従来の技術の問題点を解決することであり、発光ダイオード（ＬＥＤ）素子等の発光素子を配線板に異方性導電接着剤を用いてフリップチップ実装して発光装置を製造する際に、製造コストの増大を招くような光反射層をＬＥＤ素子に設けなくても、発光効率を低下させずに、しかも発光素子の発光色と反射光色との間に色相差を生じさせない光反射性導電粒子、それを含有した異方性導電接着剤、その接着剤を使用して発光素子を配線板にフリップチップ実装してなる発光装置を提供することである。
　本発明者は、異方性導電接着剤そのものに光反射機能を持たせれば、発光効率を低下させないようにできるとの仮定の下、異方性導電接着剤に配合する導電粒子の表面に、特定の無機粒子からなる白色～灰色の光反射層を特定の被覆率を下回らないように設けることにより、発光素子の発光効率を低下させず且つ発光素子の発光色と導電粒子の反射光色との間に色相差を生じさないようにできることを見出し、本発明を完成させるに至った。
　即ち、本発明は、発光素子を配線板に異方性導電接続するために使用する異方性導電接着剤用の光反射性導電粒子であって、金属材料で被覆されているコア粒子と、その表面に屈折率が１．５２以上の光反射性無機粒子から形成された光反射層とからなり、該コア粒子表面の光反射層による被覆率が７０％以上である光反射性導電粒子を提供する。
　また、本発明は、発光素子を配線板に異方性導電接続するために使用する異方性導電接着剤であって、上述の光反射性導電粒子を、波長３８０～７８０ｎｍの可視光に対して光路長１ｃｍの光透過率（ＪＩＳ　Ｋ７１０５）が８０％以上である硬化物を与える熱硬化性樹脂組成物に分散させてなる異方性導電接着剤を提供する。
　また、本発明は、上述の異方性導電接着剤を介して、発光素子をフリップチップ方式で配線板に実装されてなる発光装置を提供する。
　発光素子を配線板に異方性導電接続するために使用する異方性導電接着剤用の本発明の光反射性導電粒子は、金属材料で被覆されているコア粒子と、その表面に屈折率が１．５２以上の光反射性無機粒子から形成された白色～灰色の光反射層とから構成されており、しかもコア粒子の表面の光反射層による被覆率が７０％以上となっているものである。また、本発明の異方性導電接着剤は、この光反射性導電粒子を、波長３８０～７８０ｎｍの可視光に対して光路長１ｃｍの光透過率（ＪＩＳ　Ｋ７１０５）が８０％以上である硬化物を与える熱硬化性樹脂組成物に分散させてなるものである。従って、本発明の異方性導電接着層を用いて、発光素子を配線板にフリップチップ実装して得た発光装置は、異方性導電接着剤を硬化させても着色が生じず、しかも含有されている光反射性導電粒子は、可視光に対する反射特性の波長依存性が小さいため、発光効率が向上し、しかも発光素子の発光色をそのままの色で反射させることができる。
異方性導電接着剤用の本発明の光反射性導電粒子の断面図である。 異方性導電接着剤用の本発明の光反射性導電粒子の断面図である。 光反射率と酸化チタンの配合量との関係図である。 本発明の発光装置の断面図である。 実施例１と比較例１の異方性導電接着剤の硬化物の波長に対する光反射率を示す図である。 従来の発光装置の断面図である。 従来の発光装置の断面図である。
　本発明を図面を参照しつつ詳細に説明する。
　図１Ａ、図１Ｂは、異方性導電接着剤用の本発明の光反射性導電粒子１０、２０の断面図である。まず、図１Ａの光反射性導電粒子から説明する。
　光反射性導電粒子１０は、金属材料で被覆されているコア粒子１と、その表面に屈折率が１．５２以上の光反射性無機粒子２から形成された光反射層３とから構成される。
　屈折率が１．５２以上の光反射性無機粒子２は、太陽光の下では白色を呈する無機粒子である。従って、それらから形成された光反射層３は白色～灰色を呈する。白色～灰色を呈しているということは、可視光に対する反射特性の波長依存性が小さく、且つ可視光を反射しやすいことを意味する。
　好ましい光反射性無機粒子２としては、酸化チタン（ＴｉＯ２）粒子、酸化亜鉛（ＺｎＯ）粒子又は酸化アルミニウム（Ａｌ２Ｏ３）粒子から選択された少なくとも一種を挙げることができる。なお、酸化チタン粒子、酸化亜鉛粒子又は酸化アルミニウム粒子のうち、硬化した異方性導電接着剤の熱硬化性樹脂の硬化物の光劣化が懸念される場合には、光劣化に対して触媒性がなく、屈折率も高い酸化亜鉛を好ましく使用することができる。
　コア粒子１は、異方性導電接続に供されるものであるので、その表面が金属材料で構成されている。ここで、表面が金属材料で被覆されている態様としては、コア粒子１そのものが金属材料である態様、もしくは樹脂粒子の表面が金属材料で被覆された態様が挙げられる。
　金属材料としては、異方性導電接続用の従来の導電粒子において用いられている金属材料を利用することができる。例えば、金、ニッケル、銅、銀、半田、パラジウム、アルミニウム、それらの合金、それらの多層化物（例えば、ニッケルメッキ／金フラッシュメッキ物）等を挙げることができる。中でも、金、ニッケル、銅は、導電粒子を茶色としてしまうことから、本発明の効果を他の金属材料よりも享受することができる。
　なお、コア粒子１が樹脂粒子を金属材料で被覆したものである場合、樹脂粒子としても、異方性導電接続用の導電粒子として従来より用いられている金属被覆樹脂粒子の樹脂粒子部分を利用することができる。このような樹脂粒子としては、スチレン系樹脂粒子、ベンゾグアナミン樹脂粒子、ナイロン樹脂粒子などが挙げられる。樹脂粒子を金属材料で被覆する方法としても従来公知の方法を採用することができ、無電解メッキ法、電解メッキ法等を利用することができる。また、被覆する金属材料の層厚は、良好な接続信頼性を確保するに足る厚さであり、樹脂粒子の粒径や金属の種類にもよるが、通常、０．１～３μｍ、好ましくは０．１～１μｍである。
　金属材料表面を有するコア粒子１の粒径は、小さすぎると導通不良となり、大きすぎるとパターン間ショートが発生する傾向があるので、好ましくは１～２０μｍ、より好ましくは３～５μｍ、特に好ましくは３～５μｍである。この場合、コア粒子１の形状としては球形が好ましいが、フレーク状、ラグビーボール状であってもよい。
　光反射性無機粒子２から形成された光反射層３の層厚は、コア粒子１の粒径との相対的大きさの観点からみると、コア粒子１の粒径に対し、小さすぎると反射率が低下し、大きすぎると導通不良となる傾向があるので、好ましくは０．５～５０％、より好ましくは１～２５％である。
　また、光反射性導電粒子１０において、光反射層３を構成する光反射性無機粒子２の粒径は、小さすぎると光反射現象が生じ難くなり、大きすぎると光反射層の形成が困難となる傾向があるので、好ましくは０．０２～４μｍ、より好ましくは０．１～１μｍ、特に好ましくは、０．２～０．５μｍである。この場合、光反射させる光の波長の観点からみると、光反射性無機粒子２の粒径は、反射させるべき光（即ち、発光素子が発する光）が透過してしまわないように、その光の波長の５０％以上であることが好ましい。この場合、光反射性無機粒子２の形状としては無定型、球状、鱗片状、針状等を挙げることができるが、中でも、光拡散効果の点から球状、全反射効果の点から鱗片状の形状が好ましい。
　図１Ａの光反射性導電粒子１０は、大小の粉末同士を物理的に衝突させることにより大粒径粒子の表面に小粒径粒子からなる膜を形成させる公知の成膜技術（いわゆるメカノフュージョン法）により製造することができる。この場合、光反射性無機粒子２は、コア粒子１の表面の金属材料に食い込むように固定され、他方、無機粒子同士が融着固定されにくいから、無機粒子のモノレイヤーが光反射層３を構成する。従って、図１Ａの場合、光反射層３の層厚は、光反射性無機粒子２の粒径と同等乃至わずかに薄くなると考えられる。
　次に、図１Ｂの光反射性導電粒子２０について説明する。この光反射性導電粒子２０においては、光反射層３が接着剤として機能する熱可塑性樹脂４を含有し、この熱可塑性樹脂４により光反射性無機粒子２同士も固定され、光反射性無機粒子２が多層化（例えば２層あるいは３層に多層化）している点で、図１Ａの光反射性導電粒子１０と相違する。このような熱可塑性樹脂４を含有することにより、光反射層３の機械的強度が向上し、無機粒子の剥落などが生じにくくなる。
　図１Ｂの光反射性導電粒子２０は、メカノフュージョン法により製造することができる。この場合、光反射性無機粒子２とコア粒子１に加えて、微粒子状の熱可塑性樹脂４を併用すればよい。なお、メカノフュージョン法により図１Ｂの光反射性導電粒子２０を製造する場合、図１Ａの光反射性導電粒子１０も同時に製造される。
　熱可塑性樹脂４としては、環境負荷の軽減を意図してハロゲンフリーの熱可塑性樹脂を好ましく使用することができ、例えば、ポリエチレン、ポリプロピレン等のポリオレフィンやポリスチレン、アクリル樹脂等を好ましく使用することができる。
　このような光反射性導電粒子２０も、メカノフュージョン法により製造することができる。メカノフュージョン法に適用する熱可塑性樹脂４の粒子径は、小さすぎると接着剤としての効果が小さく、大きすぎるとコア粒子１に付着し難くなるので、好ましくは０．０２～４μｍ、より好ましくは０．１～１μｍである。また、このような熱可塑性樹脂４の配合量は、少なすぎると接着剤としての効果が小さく、多すぎると意図しない粒子凝集体が生成してしまうので、コア粒子１の１００質量部に対し、好ましくは０．２～５００質量部、より好ましくは４～２５質量部である。
　また、光反射性導電粒子１０、２０において、光反射性無機微粒子２を構成要素とする光反射層３によるコア粒子１の表面の被覆率が低すぎると所望の光反射性を得ることができないことが懸念されるため、被覆率は７０％以上、好ましくは８０％以上である。
　このような被覆率の測定は、例えば、光反射性導電粒子を粘着テープ上に単層粒子層となるように配置させ、その１００倍拡大平面画像をＣＣＤカメラで取得した画像をパソコンに取り込み、画像処理ソフトにより、所定の２値化処理（濃淡画像を２値画像に変換する処理のこと）に基づいて平均被覆率を算出することにより行うことができる（被覆率測定Ａ法）。また、走査型電子顕微鏡で任意に選択した３０個の導電性粒子を拡大（例えば８０００倍）し、それぞれの導電性粒子について、付着している絶縁性粒子による被覆状態を平面的にスケッチし、３０個の平均被覆率を算出することにより行うこともできる（被覆率測定Ｂ法）。あるいは、もっとも低い被覆率から、それ以上に被覆されていると経験的に判断することで行うこともできる（被覆率測定Ｃ法）。
　また、被覆率の定性的で簡易な経験的判断基準としては、金、ニッケルまたは銅からなる表面を有するコア粒子の表面色が茶色であるのに対し、そのようなコア粒子が灰色に観察できる場合には、被覆率が７０％以上であるという基準が挙げられる。この基準は、樹脂材料と光反射性無機粒子とを配合した塗料の塗布膜の反射率がそのような被覆率と非常に高い相関関係があるという一般的な知見から支持されている。
　例えば、図１Ｃに示すように、本明細書の実施例１で使用した熱硬化型エポキシ系バインダー組成物に、平均粒径０．５μｍの酸化チタン粉末を、熱硬化型エポキシ系バインダー組成物と酸化チタン粉末との合計に対する酸化チタン粉末の割合が０％、４０％、５０％、６０％、７０％、８０％、９０％、１００％となるような量で均一に混合した塗料を、乾燥厚で１００μｍとなるように黒色板に塗工し、２００℃で１分間加熱し、硬化させ、得られた硬化物について、分光光度計（Ｕ３３００、（株）日立製作所）を用いて、波長４５０ｎｍの光に対する反射率（ＪＩＳ　Ｋ７１０５）を測定すると、図１Ｃの反射率曲線が得られる。図１Ｃから、熱硬化型エポキシ系バインダー組成物と酸化チタン粉末との合計に対する酸化チタン粉末の割合が７０％を境にして急激に増加することが観察される。
　次に、本発明の異方性導電接着剤について説明する。この異方性導電接着剤は、本発明の光反射性導電粒子を熱硬化性樹脂組成物に分散させたものであり、ペースト、フィルム状等の形態を取ることができる。
　本発明の異方性導電接着剤に使用する熱硬化性樹脂組成物としては、なるべく無色透明なものを使用することが好ましい。異方性導電接着剤中の光反射性導電粒子の光反射効率を低下させず、しかも入射光の光色を変えずに反射させるためである。ここで、無色透明とは、異方性導電接着剤の硬化物が、波長３８０～７８０ｎｍの可視光に対して光路長１ｃｍの光透過率（ＪＩＳ　Ｋ７１０５）が８０％以上、好ましくは９０％以上となることを意味する。
　本発明の異方性導電接着剤において、熱硬化性樹脂組成物１００質量部に対する光反射性導電粒子の配合量は、少なすぎると導通不良となり、多すぎるとパターン間ショートが発生する傾向があるので、好ましくは１～１００質量部、より好ましくは１０～５０質量部である。
　本発明の異方性導電接着剤の反射特性は、発光素子の発光効率を向上させるために、異方性導電接着剤の１００μｍ厚の硬化物の波長４５０ｎｍの光に対する反射率（ＪＩＳ　Ｋ７１０５）が、少なくとも１５％であることが望ましい。このような反射率とするためには、使用する光反射性導電粒子の反射特性や配合量、熱硬化性樹脂組成物の配合組成などを適宜調整すればよい。通常、反射特性の良好な光反射性導電粒子の配合量を増量すれば、反射率も増大する傾向がある。
　また、異方性導電接着剤の反射特性は屈折率（ＪＩＳ　Ｋ７１４２）という観点から評価することもできる。即ち、異方性導電接着剤の熱硬化性樹脂組成物と光反射性導電粒子との間の屈折率の差が大きすぎると、光反射性導電粒子とそれを取り巻く熱硬化性樹脂組成物の硬化物との界面での光反射量が増大するからである。具体的には、熱硬化性樹脂組成物と光反射性無機粒子との間の屈折率の差が０．０２以上、好ましくは０．３以上であることが望まれる。なお、通常、エポキシ樹脂を主体とする熱硬化性樹脂組成物の屈折率は約１．５である。
　本発明の異方性導電接着剤を構成する熱硬化性樹脂組成物としては、従来の異方性導電接着剤や異方性導電フィルムにおいて使用されているものを利用することができる。一般に、このような熱硬化性樹脂組成物は、絶縁性バインダー樹脂に硬化剤を配合したものである。絶縁性バインダー樹脂としては、脂環式エポキシ樹脂や複素環系エポキシ化合物や水素添加エポキシ樹脂などを主成分としたエポキシ系樹脂が好ましく挙げられる。
　脂環式エポキシ化合物としては、分子内に２つ以上のエポキシ基を有するものが好ましく挙げられる。これらは液状であっても、固体状であってもよい。具体的には、グリシジルヘキサヒドロビスフェノールＡ、３，４－エポキシシクロヘキセニルメチル－３′，４′－エポキシシクロヘキセンカルボキシレート等を挙げることができる。中でも、硬化物にＬＥＤ素子の実装等に適した光透過性を確保でき、速硬化性にも優れている点から、グリシジルヘキサヒドロビスフェノールＡ、３，４－エポキシシクロヘキセニルメチル－３′，４′－エポキシシクロヘキセンカルボキシレートを好ましく使用することができる。
　複素環系エポキシ化合物としては、トリアジン環を有するエポキシ化合物を挙げることができ、特に好ましくは１，３，５－トリス（２，３－エポキシプロピル）－１，３，５－トリアジン－２，４，６－（１Ｈ，３Ｈ，５Ｈ）－トリオンを挙げることができる。
　水素添加エポキシ化合物としては、前述の脂環式エポキシ化合物や複素環系エポキシ化合物の水素添加物や、その他公知の水素添加エポキシ樹脂を使用することができる。
　本発明において、脂環式エポキシ化合物や複素環系エポキシ化合物や水素添加エポキシ化合物は、単独で使用してもよいが、２種以上を併用することができる。また、これらのエポキシ化合物に加えて、本発明の効果を損なわない限り、他のエポキシ化合物を併用してもよい。例えば、ビスフェノールＡ、ビスフェノールＦ、ビスフェノールＳ、テトラメチルビスフェノールＡ、ジアリールビスフェノールＡ、ハイドロキノン、カテコール、レゾルシン、クレゾール、テトラブロモビスフェノールＡ、トリヒドロキシビフェニル、ベンゾフェノン、ビスレゾルシノール、ビスフェノールヘキサフルオロアセトン、テトラメチルビスフェノールＡ、テトラメチルビスフェノールＦ、トリス（ヒドロキシフェニル）メタン、ビキシレノール、フェノールノボラック、クレゾールノボラックなどの多価フェノールとエピクロルヒドリンとを反応させて得られるグリシジルエーテル；　グリセリン、ネオペンチルグリコール、エチレングリコール、プロピレングリコール、チレングリコール、ヘキシレングリコール、ポリエチレングリコール、ポリプロピレングリコールなどの脂肪族多価アルコールとエピクロルヒドリンとを反応させて得られるポリグリシジルエーテル；　ｐ－オキシ安息香酸、β－オキシナフトエ酸のようなヒドロキシカルボン酸とエピクロルヒドリンとを反応させて得られるグリシジルエーテルエステル；　フタル酸、メチルフタル酸、イソフタル酸、テレフタル酸、テトラハイドロフタル酸、エンドメチレンテトラハイドロフタル酸、エンドメチレンヘキサハイドロフタル酸、トリメリット酸、重合脂肪酸のようなポリカルボン酸から得られるポリグリシジルエステル；　アミノフェノール、アミノアルキルフェノールから得られるグリシジルアミノグリシジルエーテル；　アミノ安息香酸から得られるグリシジルアミノグリシジルエステル；　アニリン、トルイジン、トリブロムアニリン、キシリレンジアミン、ジアミノシクロヘキサン、ビスアミノメチルシクロヘキサン、４，４′－ジアミノジフェニルメタン、４，４′－ジアミノジフェニルスルホンなどから得られるグリシジルアミン；　エポキシ化ポリオレフィン等の公知のエポキシ樹脂類が挙げられる。
　硬化剤としては、酸無水物、イミダゾール化合物、ジシアンなどを使用することができる。中でも、硬化物を変色させ難い酸無水物、特に脂環式酸無水物系硬化剤を好ましく使用できる。具体的には、メチルヘキサヒドロフタル酸無水物（ＭｅＨＨＰＡ）等を好ましく使用することができる。
　本発明の異方性導電接着剤の熱硬化性樹脂組成物において、脂環式エポキシ化合物と脂環式酸無水物系硬化剤とを使用する場合、それぞれの使用量は、脂環式酸無水物系硬化剤が少なすぎると未硬化エポキシ化合物が多くなって硬化不良を生じ、多すぎると余剰の硬化剤の影響で被着体材料の腐食が促進される傾向があるので、脂環式エポキシ化合物１００質量部に対し脂環式酸無水物系硬化剤を好ましくは８０～１２０質量部、より好ましくは９５～１０５質量部の割合で使用する。
　本発明の異方性導電接着剤は、光反射性導電粒子と熱硬化性樹脂組成物とを均一に混合することにより製造することができる。また、異方性導電接着剤を異方性導電フィルムとして使用する場合には、それらをトルエン等の溶媒とともに分散混合し、剥離処理したＰＥＴフィルムに所期の厚さとなるように塗布し、約８０℃程度の温度で乾燥すればよい。
　次に、本発明の発光装置について図２を参照しながら説明する。発光装置２００は、基板２１上の接続端子２２と、発光素子としてＬＥＤ素子２３のｎ電極２４とｐ電極２５とのそれぞれに形成された接続用のバンプ２６との間に、前述の本発明の異方性導電接着剤を塗布し、基板２１とＬＥＤ素子２３とがフリップチップ実装されている発光装置である。ここで、異方性導電接着剤の硬化物１００は、光反射性導電粒子１０が熱硬化性樹脂組成物の硬化物１１中に分散してなるものである。なお、必要に応じて、ＬＥＤ素子２３の全体を覆うように透明モールド樹脂で封止してもよい。
　このように構成されている発光装置２００においては、ＬＥＤ素子２３が発した光のうち、基板２１側に向かって発した光は、異方性導電接着剤の硬化物１００中の光反射性導電粒子１０で反射し、ＬＥＤ素子２３の上面から出射する。従って、発光効率の低下を防止することができる。
　　実施例１
（光反射性導電粒子の作成）
　平均粒子径０．５μｍの酸化チタン粉末（ＫＲ－３８０、チタン工業（株））４質量部と、外観色が茶色の平均粒径５μｍのＡｕ被覆樹脂導電粒子（平均粒径４．６μｍの球状アクリル樹脂粒子に０．２μｍ厚の無電解金メッキを施した粒子：ブライト２０ＧＮＢ４．６ＥＨ、日本化学工業（株））２０質量部とを、メカノフュージョン装置（ＡＭＳ－ＧＭＰ、ホソカワミクロン（株））に投入し、回転速度１０００ｒｐｍ、回転時間２０分という条件で導電粒子の表面に、酸化チタン粒子からなる約０．３μｍ厚の光反射層を成膜することにより、実施例１の光反射性導電粒子を得た。この光反射性導電粒子の外観色は灰色であった。
（被覆率測定）
　得られた光反射性粒子の光反射層による被覆率を、前述した被覆率測定Ｂ法に従って測定した。得られた結果を表１に示す。
（光反射率測定）
　得られた光反射性導電粒子１５質量部と、屈折率が約１．５の無色透明な熱硬化型エポキシ系バインダー組成物（ＹＸ－８０００、ＪＥＲ（株））１００質量部とを真空脱泡撹拌装置を用いて均一に混合することにより、実施例１の異方性導電接着剤を得た。
　得られた異方性導電接着剤を、セラミック製の白色板に乾燥厚で１００μｍとなるように塗布し、２００℃で１分間加熱し、硬化させた。この硬化物について、分光光度計（Ｕ３３００、（株）日立製作所）を用いて、波長４５０ｎｍの光に対する反射率（ＪＩＳ　Ｋ７１０５）を測定した。得られた結果を表１及び図３に示す。
（電気特性（導通信頼性、絶縁信頼性）評価試験）
　光反射率評価試験の際に調製した異方性導電接着剤を用いて、５０μｍピッチの銅配線にＮｉ／Ａｕ（５．０μｍ厚／０．３μｍ厚）メッキ処理した配線を有するガラスエポキシ基板に、１５μｍ高の金バンプを有する６ｍｍ角の試験用ＩＣチップ（導体接続面積／導体－スペース＝１６００μｍ２／５０μｍＰ）を２００℃、６０秒、１Ｋｇ／チップという条件でフィリップチップ実装し、テスト用ＩＣモジュールを得た。
１．導通信頼性
　得られたテスト用ＩＣモジュールに対し、低温（－４０℃）と高温（１００℃）の温度に交互に加熱・冷却する温度サイクル試験（ＴＣＴ）（ＪＩＳ　Ｃ５０３０）を行い、初期と５００サイクル後の４端子法による抵抗値を測定した。抵抗値が１Ω未満の場合を良好「○」と評価し、１Ω以上となった場合を不良「×」と評価した。得られた結果を表１に示す。
２．絶縁信頼性　
　別途作成したテスト用ＩＣモジュールに対し、８５℃、８５％ＲＨの環境下に１０００時間放置というエージング試験を行い、初期と１０００時間後の抵抗値を測定した。抵抗値が１０６Ω以上の場合を良好「○」と評価し、１０６Ω未満となった場合を不良「×」と評価した。得られた結果を表１に示す。
　　実施例２
　メカノフュージョン装置（ＡＭＳ－ＧＭＰ、ホソカワミクロン（株））の回転速度を１０００ｒｐｍから７００ｒｐｍに変更し且つ回転時間を２０分から１０分に変更すること以外、実施例１と同様にして外観色が灰色の光反射性導電粒子を得、更に異方性導電接着剤を得た。また、実施例１と同様に、被覆率及び反射率を測定し、更に電気特性（導通信頼性、絶縁信頼性）評価試験を行った。得られた結果を表１に示す。
　　実施例３
　Ａｕ被覆樹脂導電粒子に代えて、平均粒子径５．０μｍのＮｉ被覆樹脂導電粒子（５２ＮＲ－４．６ＥＨ、日本化学工業（株））を使用すること以外、実施例１と同様にして外観色が灰色の光反射性導電粒子を得、更に異方性導電接着剤を得た。また、実施例１と同様に、被覆率及び反射率を測定し、更に電気特性（導通信頼性、絶縁信頼性）評価試験を行った。得られた結果を表１に示す。
　　実施例４
　平均粒子径０．５μｍの酸化チタン粉末（ＫＲ－３８０、チタン工業（株））４質量部と、接着剤粒子として平均粒子径０．２μｍのポリスチレン（ＰＳ）粒子（グロスデール２０４Ｓ、三井化学（株））３質量部と、平均粒径５μｍの導電粒子（平均粒径４．６μｍの球状アクリル樹脂粒子に０．２μｍ厚の無電解金メッキを施した粒子：ブライト２０ＧＮＢ４．６ＥＨ、日本化学工業（株））２０質量部とを、メカノフュージョン装置（ＡＭＳ－ＧＭＰ、ホソカワミクロン（株））に投入し、回転速度１０００ｒｐｍ、回転時間２０分という条件で導電粒子の表面に、スチレンと酸化チタン粒子とからなる約１μｍ厚の光反射層を成膜することにより、外観色が灰色の光反射性導電粒子を得、更に異方性導電接着剤を得た。また、実施例１と同様に、被覆率及び反射率を測定し、更に電気特性（導通信頼性、絶縁信頼性）評価試験を行った。得られた結果を表１に示す。
　　実施例５
　Ａｕ被覆樹脂導電粒子に代えて、平均粒子径５．０μｍのＮｉ被覆樹脂導電粒子（５２ＮＲ－４．６ＥＨ、日本化学工業（株））を使用すること以外、実施例３と同様にして外観色が灰色の光反射性導電粒子を得、更に異方性導電接着剤を得た。また、更に、実施例１と同様に、被覆率及び反射率を測定し、更に電気特性（導通信頼性、絶縁信頼性）評価試験を行った。得られた結果を表１に示す。
　　実施例６
　平均粒子径０．２μｍのポリスチレン粒子（グロスデール２０４Ｓ、三井化学（株））に代えて、平均粒子径０．２μｍのポリエチレン（ＰＥ）粒子（アミパールＷＦ３００、三井化学（株））を使用すること以外、実施例３と同様にして外観色が灰色の光反射性導電粒子を得、更に異方性導電接着剤を得た。また、実施例１と同様に、被覆率及び反射率を測定し、更に電気特性（導通信頼性、絶縁信頼性）評価試験を行った。得られた結果を表１に示す。
　　実施例７
　平均粒子径０．５μｍの酸化チタン粉末に代えて、平均粒子径０．５μｍの酸化亜鉛粉末（酸化亜鉛１種、ハクスイテック（株））を使用すること以外、実施例３と同様にして外観色が灰色の光反射性導電粒子を得、更に異方性導電接着剤を得た。また、実施例１と同様に、被覆率及び反射率を測定し、更に電気特性（導通信頼性、絶縁信頼性）評価試験を行った。得られた結果を表１に示す。
　　実施例８
　平均粒子径０．５μｍの酸化チタン粉末に代えて、平均粒子径０．５μｍの酸化アルミニウム粉末（ＡＥ－２５００ＳＩ、（株）アドマテックス）を使用すること以外、実施例３と同様にして外観色が灰色の光反射性導電粒子を得、更に異方性導電接着剤を得た。また、実施例１と同様に、被覆率及び反射率を測定し、更に電気特性（導通信頼性、絶縁信頼性）評価試験を行った。得られた結果を表１に示す。
　　実施例９
　平均粒子径０．５μｍの酸化チタン粉末に代えて、平均粒子径０．５μｍの炭酸マグネシウムを使用すること以外、実施例３と同様にして外観色が灰色の光反射性導電粒子を得、更に異方性導電接着剤を得た。また、実施例１と同様に、被覆率及び反射率を測定し、更に電気特性（導通信頼性、絶縁信頼性）評価試験を行った。得られた結果を表１に示す。
　　実施例１０
　平均粒子径０．５μｍの酸化チタン粉末に代えて、平均粒子径０．２μｍの酸化チタン粉末（ＪＲ４０５、テイカ（株））を使用すること以外、実施例３と同様にして外観色が灰色の光反射性導電粒子を得、更に異方性導電接着剤を得た。また、実施例１と同様に、被覆率及び反射率を測定し、更に電気特性（導通信頼性、絶縁信頼性）評価試験を行った。得られた結果を表１に示す。
　　比較例１
　外観色が茶色のＡｕ被覆樹脂導電粒子（平均粒径４．６μｍの球状アクリル樹脂粒子に０．２μｍ厚の無電解金メッキを施した粒子：ブライト２０ＧＮＢ４．６ＥＨ、日本化学工業（株））を用い、実施例１と同様に異方性導電接着剤を得た。また、実施例１と同様に、反射率を測定し、更に電気特性（導通信頼性、絶縁信頼性）評価試験を行った。得られた結果を表１に示す。
　　比較例２
　Ａｕ被覆樹脂導電粒子に代えて、外観色が茶色の平均粒子径５．０μｍのＮｉ被覆樹脂導電粒子（５２ＮＲ－４．６ＥＨ、日本化学工業（株））を使用すること以外、比較例１と同様に異方性導電接着剤を得た。また、実施例１と同様に、反射率を測定し、更に電気特性（導通信頼性、絶縁信頼性）評価試験を行った。得られた結果を表１に示す。
　　比較例３
　平均粒子径０．２μｍのポリスチレン系粒子（グロスデール２０４Ｓ、三井化学（株））３質量部と、平均粒径５μｍの導電粒子（平均粒径４．６μｍの球状アクリル樹脂粒子に０．２μｍ厚の無電解金メッキを施した粒子：ブライト２０ＧＮＢ４．６ＥＨ、日本化学工業（株））２０質量部とを、メカノフュージョン装置（ＡＭＳ－ＧＭＰ、ホソカワミクロン（株））に投入し、回転速度１０００ｒｐｍ、回転時間２０分という条件で導電粒子の表面に、０．２μｍ厚のスチレン層を成膜することにより、外観色が茶色の樹脂被覆導電粒子を得、更に異方性導電接着剤を得た。また、実施例１と同様に、反射率を測定し、更に電気特性（導通信頼性、絶縁信頼性）評価試験を行った。得られた結果を表１に示す。
　比較例４
　平均粒子径０．５μｍの酸化チタン粉末に代えて、屈折率が１．４５で平均粒子径０．５μｍの酸化ケイ素（シリカ）粉末（シーホスターＫＥＰ－３０、（株）日本触媒）を使用すること以外、実施例３と同様にして外観色が茶色の導電粒子を得、更に異方性導電接着剤を得た。また、実施例１と同様に、被覆率及び反射率を測定し、更に電気特性（導通信頼性、絶縁信頼性）評価試験を行った。得られた結果を表１に示す。
Figure JPOXMLDOC01-appb-T000001
　表１から解るように、実施例１～１０の光反射性導電粒子を使用した異方性導電接着剤は、光反射層による被覆率が７０％以上あり、光反射率がいずれも１５％以上あり、４５０ｎｍの光の青色がそのままの色で反射していた。しかも導通信頼性及び絶縁信頼性も良好な結果であった。
　それに対し、比較例１～３の場合、導電粒子の表面に光反射層を設けていないため、光反射率は１０％にも届かず、比較例１、２についてはショートが初期から発生し、比較例３の場合には、エージング後にショートが発生し、絶縁信頼性に問題があった。また、比較例４の場合、光反射層による被覆率が７０％以上であるものの、無機粒子として屈折率が１．５２未満の酸化ケイ素を使用したので、無機粒子層を形成した後も導電粒子の色が茶色となっており、光反射率が１０％程度であった。これは、酸化ケイ素と異方性導電接着剤のバインダー組成物との間の屈折率差が０．０２未満であったためと考えられる。
　本発明の光反射性導電粒子は、発光ダイオード（ＬＥＤ）素子等の発光素子を配線板に異方性導電接着剤を用いてフリップチップ実装して発光装置を製造する際に、製造コストの増大を招くような光反射層を発光素子に設けることなく、発光効率を低下させずに、しかも発光素子の発光色と反射光色との間に色相差を生じさせないようにできる。よって、本発明の異方性導電接着剤は、ＬＥＤ素子をフリップチップ実装する際に有用である。
１　コア粒子
２　光反射性無機粒子
３　光反射層
４　熱可塑性樹脂
１０、２０　光反射性導電粒子
１１　熱硬化性樹脂組成物の硬化物
２１　基板
２２　接続端子
２３　ＬＥＤ素子
２４　ｎ電極
２５　ｐ電極
２６　バンプ
１００　異方性導電接着剤の硬化物
２００　発光装置
 

Claims (15)

  1. 　発光素子を配線板に異方性導電接続するために使用する異方性導電接着剤用の光反射性導電粒子であって、金属材料で被覆されているコア粒子と、その表面に屈折率が１．５２以上の光反射性無機粒子から形成された光反射層とからなり、該コア粒子表面の光反射層による被覆率が７０％以上である光反射性導電粒子。
  2. 　コア粒子を被覆する金属材料が、金、ニッケル又は銅である請求項１記載の光反射性導電粒子。
  3. 　コア粒子そのものが、金、ニッケル又は銅の粒子である請求項１記載の光反射性導電粒子。
  4. 　コア粒子が、樹脂粒子を金、ニッケル又は銅で被覆したものである請求項１又は２記載の光反射性導電粒子。
  5. 　コア粒子の粒子径が１～２０μｍであり、光反射層の層厚がコア粒子径の０．５～５０％である請求項１～４のいずれかに記載の光反射性導電粒子。
  6. 　光反射性無機粒子が、酸化チタン粒子、酸化亜鉛粒子又は酸化アルミニウム粒子から選択された少なくとも一種の無機粒子である請求項１～５のいずれかに記載の光反射性導電粒子。
  7. 　光反射層が、熱可塑性樹脂を含有する請求項１～６のいずれかに記載の光反射性導電粒子。
  8. 　熱可塑性樹脂が、ポリオレフィンである請求項７記載の光反射性導電粒子。
  9. 　発光素子を配線板に異方性導電接続するために使用する異方性導電接着剤であって、請求項１～８のいずれかに記載の光反射性導電粒子を、波長３８０～７５０ｎｍの可視光に対して光路長１ｃｍの光透過率（ＪＩＳ　Ｋ７１０５）が８０％以上である硬化物を与える熱硬化性樹脂組成物に分散させてなる異方性導電接着剤。
  10. 　熱硬化性樹脂組成物１００質量部に対する光反射性導電粒子の配合量が、１～１００質量部である請求項９記載の異方性導電接着剤。
  11. 　異方性導電接着剤の１００μｍ厚の硬化物の波長４５０ｎｍの光に対する反射率（ＪＩＳ　Ｋ７１０５）が、少なくとも１５％である請求項９又は１０記載の異方性導電接着剤。
  12. 　熱硬化性樹脂組成物と光反射性無機粒子との間の屈折率の差が０．０２以上である請求項９～１１のいずれかに記載の異方性導電接着剤。
  13. 　熱硬化性樹脂組成物が、エポキシ樹脂と酸無水物系硬化剤とを含有する請求項９～１２のいずれかに記載の異方性導電接着剤。
  14. 　請求項９～１３のいずれかに記載の異方性導電接着剤を介して、発光素子をフリップチップ方式で配線板に実装されている発光装置。
  15. 　発光素子が、発光ダイオードである請求項１４記載の発光装置。
     
PCT/JP2011/059724 2011-04-20 2011-04-20 光反射性導電粒子、異方性導電接着剤及び発光装置 WO2012144033A1 (ja)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US13/575,786 US20130105841A1 (en) 2011-04-20 2011-04-20 Light-reflective conductive particle, anisotropic conductive adhesive, and light-emitting device
JP2012534453A JPWO2012144033A1 (ja) 2011-04-20 2011-04-20 光反射性導電粒子、異方性導電接着剤及び発光装置
PCT/JP2011/059724 WO2012144033A1 (ja) 2011-04-20 2011-04-20 光反射性導電粒子、異方性導電接着剤及び発光装置
TW100128832A TWI517456B (zh) 2011-04-20 2011-08-12 Light reflective conductive particles, anisotropic conductive adhesives and light-emitting devices
US14/222,249 US8975654B2 (en) 2011-04-20 2014-03-21 Light-reflective conductive particle, anisotropic conductive adhesive, and light-emitting device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2011/059724 WO2012144033A1 (ja) 2011-04-20 2011-04-20 光反射性導電粒子、異方性導電接着剤及び発光装置

Related Child Applications (2)

Application Number Title Priority Date Filing Date
US13/575,786 A-371-Of-International US20130105841A1 (en) 2011-04-20 2011-04-20 Light-reflective conductive particle, anisotropic conductive adhesive, and light-emitting device
US14/222,249 Continuation US8975654B2 (en) 2011-04-20 2014-03-21 Light-reflective conductive particle, anisotropic conductive adhesive, and light-emitting device

Publications (1)

Publication Number Publication Date
WO2012144033A1 true WO2012144033A1 (ja) 2012-10-26

Family

ID=47041183

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2011/059724 WO2012144033A1 (ja) 2011-04-20 2011-04-20 光反射性導電粒子、異方性導電接着剤及び発光装置

Country Status (4)

Country Link
US (2) US20130105841A1 (ja)
JP (1) JPWO2012144033A1 (ja)
TW (1) TWI517456B (ja)
WO (1) WO2012144033A1 (ja)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017228533A (ja) * 2017-07-20 2017-12-28 日本化学工業株式会社 被覆導電性粉体、被覆導電性粉体の製造方法、被覆導電性粉体を含む導電性接着剤及び接着構造体

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9053405B1 (en) * 2013-08-27 2015-06-09 Flextronics Ap, Llc Printed RFID circuit
KR20160061339A (ko) * 2013-09-26 2016-05-31 데쿠세리아루즈 가부시키가이샤 발광 장치, 이방성 도전 접착제, 발광 장치 제조 방법
US9812625B2 (en) * 2014-02-18 2017-11-07 Nichia Corporation Light-emitting device having resin member with conductive particles
JP2015153981A (ja) * 2014-02-18 2015-08-24 日亜化学工業株式会社 発光装置
JP6432416B2 (ja) * 2014-04-14 2018-12-05 日亜化学工業株式会社 半導体装置
KR20180016499A (ko) * 2015-06-11 2018-02-14 이 잉크 캘리포니아 엘엘씨 복합 컬러 입자들

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007123613A (ja) * 2005-10-28 2007-05-17 Nichia Chem Ind Ltd 発光装置
JP2007157940A (ja) * 2005-12-02 2007-06-21 Nichia Chem Ind Ltd 発光装置および発光装置の製造方法
JP2007258324A (ja) * 2006-03-22 2007-10-04 Matsushita Electric Ind Co Ltd 発光装置の製造方法および発光装置
JP2011057917A (ja) * 2009-09-14 2011-03-24 Sony Chemical & Information Device Corp 光反射性異方性導電接着剤及び発光装置

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11168235A (ja) 1997-12-05 1999-06-22 Toyoda Gosei Co Ltd 発光ダイオード

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007123613A (ja) * 2005-10-28 2007-05-17 Nichia Chem Ind Ltd 発光装置
JP2007157940A (ja) * 2005-12-02 2007-06-21 Nichia Chem Ind Ltd 発光装置および発光装置の製造方法
JP2007258324A (ja) * 2006-03-22 2007-10-04 Matsushita Electric Ind Co Ltd 発光装置の製造方法および発光装置
JP2011057917A (ja) * 2009-09-14 2011-03-24 Sony Chemical & Information Device Corp 光反射性異方性導電接着剤及び発光装置

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017228533A (ja) * 2017-07-20 2017-12-28 日本化学工業株式会社 被覆導電性粉体、被覆導電性粉体の製造方法、被覆導電性粉体を含む導電性接着剤及び接着構造体

Also Published As

Publication number Publication date
US20130105841A1 (en) 2013-05-02
TW201246634A (en) 2012-11-16
US20140225144A1 (en) 2014-08-14
JPWO2012144033A1 (ja) 2014-07-28
US8975654B2 (en) 2015-03-10
TWI517456B (zh) 2016-01-11

Similar Documents

Publication Publication Date Title
JP5526698B2 (ja) 光反射性導電粒子、異方性導電接着剤及び発光装置
JP5617210B2 (ja) 光反射性異方性導電接着剤及び発光装置
JP5609716B2 (ja) 光反射性異方性導電接着剤及び発光装置
JP5402804B2 (ja) 発光装置の製造方法
JP5888023B2 (ja) 光反射性異方性導電接着剤及び発光装置
JP5958107B2 (ja) 光反射性異方性導電接着剤及び発光装置
JP6347635B2 (ja) 異方性導電接着剤
WO2012144033A1 (ja) 光反射性導電粒子、異方性導電接着剤及び発光装置
WO2014046089A1 (ja) 接続構造体の製造方法及び異方性導電接着剤
JP5555038B2 (ja) 光反射性異方性導電接着剤及び発光装置
WO2012127978A1 (ja) 光反射性異方性導電接着剤及び発光装置
JP2014030026A (ja) 異方性導電接着剤及び発光装置
JP5785306B2 (ja) 光反射性異方性導電接着剤及び発光装置

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2012534453

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 13575786

Country of ref document: US

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11864019

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11864019

Country of ref document: EP

Kind code of ref document: A1