Classifications

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  • 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
• • 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
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  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J5/00—Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers
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  • C09J9/00—Adhesives characterised by their physical nature or the effects produced, e.g. glue sticks
  • C09J9/02—Electrically-conducting adhesives
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  • 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
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  • 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
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  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
  • H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
  • H05K3/321—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by conductive adhesives
  • H05K3/323—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by conductive adhesives by applying an anisotropic conductive adhesive layer over an array of pads
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
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  • 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
  • C09J2463/00—Presence of epoxy resin
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  • 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
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  • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
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  • H01L2224/29199—Material of the matrix
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  • 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
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  • 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
  • H01L2224/293—Base 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
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  • 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
  • H01L2224/8319—Arrangement of the layer connectors prior to mounting
  • H01L2224/83192—Arrangement of the layer connectors prior to mounting wherein the layer connectors are disposed only on another item or body to be connected to the semiconductor or solid-state body
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  • 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
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  • 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
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  • H01L2924/14—Integrated circuits
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  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
  • H05K2201/02—Fillers; Particles; Fibers; Reinforcement materials
  • H05K2201/0203—Fillers and particles
  • H05K2201/0206—Materials
  • H05K2201/0209—Inorganic, non-metallic particles
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  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/36—Assembling printed circuits with other printed circuits
  • H05K3/361—Assembling flexible printed circuits with other printed circuits

Definitions

• the present invention relates to an anisotropic conductive adhesive, a bonding method using the adhesive, and an integrated circuit package using the adhesive, and more particularly, to an anisotropic conductive adhesive available in the manufacture of a module for a flat panel display, such as a liquid crystal display panel (LCD), plasma display panel (PDP), electroluminescent display (ELD), etc., and available in bonding micro circuits to package a semiconductor, a bonding method using the anisotropic conductive adhesive, and an integrated circuit package obtained using the bonding method. More particularly, the present invention directs to methods of flip-chip bonding and chip-scale packaging of a semiconductor.
• LCD liquid crystal display panel
• PDP plasma display panel
• ELD electroluminescent display
• Japanese Patent Laid-open No. 8-20629 discloses an epoxy resin composition prepared by mixing a resin mixture, which includes an epoxy resin containing a non-cross-linked, thermoplastic elastomer component, an epoxy resin containing a cross-linked rubber component, and a solid epoxy resin having a softening point of 50°C or greater, with a urea-based hardener for expoxy resin and a latent catalyst which is stable at 40°C and is activated at 80°C or less.
• U.S. Patent No. 6,020,059 discloses an anisotropic conductive adhesive containing a film-forming resin and conductive particles and having a melting viscosity greater than 100 poises at 150°C.
• U.S. Patent No. 5,543,486 discloses an epoxy resin composition containing an epoxy resin having more than two epoxy groups in one molecule, a solid-dispersing, amine adduct-type latent hardener, and a metal alkoxide as the essential components.
• Most conventional anisotropic conductive adhesives suggested so far use a thermocurable epoxy resin or a modified epoxy resin alone or a mixture of a variety of types of thermoplastic resins as a polymeric resin.
• conductive particles for the conventional anisotropic conductive adhesives nickel or a gold and nickel-coated composite has been mostly used.
• additives including a hardener for the thermocurable resin, an adhesion imparting agent, an anti-oxidant, a coupling agent, etc. has been used.
• FIGS. 1A and 1 B are sectional views illustrating a process of bonding circuits using an anisotropic conductive adhesive in the manufacture of a module for a general flat panel display or in the packaging of a semiconductor.
• FIG. 1A is a cross-sectional view after the anisotropic conductive additive is applied to a substrate 60 with a lower circuit 50 on its top surface and before an IC circuit 10 is bound to the substrate 60.
• FIG. 1 B is a cross-sectional view after an upper circuit 20 on the IC chip 10 is connected to the lower circuit 50 on the substrate 60 by heating and pressing.
• Conductive particles 30 contained in the anisotropic conductive adhesive are immobilized between the upper circuit 20 and the lower circuit 50 by heating and pressing, as shown in FIG. 1 B.
• the upper circuit 20 and the lower circuit 50 are electrically connected by the conductive particles 30 and are insulated from and bound to each other by an adhesive resin 40 constituting the anisotropic conductive adhesive.
• the bonding of the upper circuit 20 and the lower circuit 50 using the anisotropic conducrive adhesive is a high-temperature process performed at 150-250°C. Therefore, a change in the fluidity of the adhesive resin 40 from a time point of heating the adhesive resin 40 to a time point at which the adhesive resin 40 is completely cured considerably affects the connection reliability of the upper circuit 20 and the lower circuit 50.
• FIG. 2 is a graph of a viscosity variation pattern of the adhesive resin over heating time when bonding circuits at a high temperature using a conventional anisotropic conductive adhesive.
• FIG. 2 in the interval of state A appearing immediately after heating, viscosity increases.
• the temperature of the adhesive resin contained in the anisotropic conductive adhesive rises in the initial stage of bonding, a curing reaction is initiated, and viscosity gradually increases with increasing heating time.
• the curing reaction of the adhesive resin constituting the anisotropic conductive adhesive become active, and viscosity increases with respect to heating time at a faster rate than in the interval of state A.
• the interval of state C the curing reaction of the adhesive resin constituting the anisotropic conductive adhesive is accelerated, and viscosity tends to suddenly increase with respect to heating time.
• FIG. 3 is an optical microscopic photograph showing a state of circuits 80 bound together using a conventional anisotropic conductive adhesive 70.
• state A as shown in FIG. 2, which corresponds to the initial stage of bonding where the adhesive resin contained in the anisotropic conductive adhesive has a great fluidity, is sustained for a long time, so that the adhesive resin of the anisotropic conductive adhesive 70 is not retained between the circuits 80 to be connected and flows down to form voids 90 resulting from bubbles present in a region between the circuits 80 unfilled with the adhesive resin. Due to the presence of the voids 90 between the connected circuits 80, insulating resistance, connection resistance, and adhesive force between the circuits 80 are lowered, thereby degrading reliability of the device.
• an anisotropic conductive adhesive comprising: an adhesive composition including an epoxy-based base resin, a hardener, and conductive particles; and a viscosity enhancer of 5-95% by weight based on the total amount of the anisotropic conductive adhesive for adjusting the fluidity of the adhesive composition.
• the anisotropic conductive adhesive comprises an inorganic material.
• the inorganic material may be selected from the group consisting of alumina, silicon carbide, silica, copper oxide, titanium dioxide, and a mixture of at least two of these materials.
• the inorganic material is in a granular form having an average particle size of 0.1-5 microns and is contained in an amount of 5-60% by weight based on the total amount of the anisotropic conductive adhesive.
• the viscosity enhancer comprises a radical curable resin and a radical initiator.
• the radical curable resin may comprise an acrylic monomer or methacrylic monomer having a C ⁇ -C 20 main chain, an acrylic oligomer or methacrylic oligomer having a C 2 ⁇ -C ⁇ oo main chain, a thermocurable resin including a reactive acrylic or methacrylic unit, a thermoplastic resin including a reactive acrylic or methacrylic unit, or a mixture of these materials
• the radical initiator comprises a peroxide initiator, an azo initiator, or a mixture of these materials.
• the radical initiator comprises cumil peroxyoctoate, acetyl peroxide, t-butyl peroxybenzoate, dicumil peroxide, azobisisobutyronitril, or a mixture of these materials.
• the UV initiator is formed of a material responsive to light of a UV wavelength of 200-400 nm.
• the UV initiator may comprise 2,2-dimethoxy-2-phenylacetophenone, 1 -hydroxy- cyclohexyl-penylketone, para-phenylbenzophenone, benzyldimethylketal, or a mixture of these materials.
• the anisotropic conductive adhesive according to the present invention may further comprise a conductive impurity ion of 1-100 ppm.
• the conductive impurity ion may be selected from the group consisting of Na + , K ⁇ and cr.
• the base resin may be selected from the group consisting of bisphenol-A type epoxy resin, bisphenol-F type epoxy resin, phenol nobolak type epoxy resin, cresol nobolak type epoxy resin, dimeric modified epoxy resin, rubber modified epoxy resin, urethane modified epoxy resin, bromated epoxy resin, melamine resin, urethane resin, polyimide resin, polyamide resin, polyethylene resin, polypropylene resin, styrene resin, styrene-butadiene resin, phenol resin, formaldehyde resin, silicon resin, acrylate resin, or a mixture of these resins.
• the hardener is selected from the group consisting of imidazole derivatives, amine derivatives, amide derivatives, acidic anhydrides, phenol derivatives, and a mixture of at least two of these materials.
• the conductive particles comprises pure nickel particles or composite particles obtained by sequentially coating the surface of polymeric beads with nickel and gold.
• the adhesive composition further comprises an adhesion imparting agent selected from the group consisting of rosin resin, terpene resin, and cumarone-indene resin.
• the adhesive composition further comprises a coupling agent for dispersing and stabilizing the conductive particles.
• the coupling agent may comprise a silane derivative.
• an integrated circuit package comprising: a first substrate on which a first circuit including a first electrode is implemented; a second substrate on which a second circuit including a second electrode disposed to face the first substrate is implemented; and an anisotropic conductive adhesive applied between the first and second substrates to bond the same together while the first and second electrodes are in contact to be electrically connected, wherein the anisotropic conductive adhesive comprises a resin, a hardener, conductive particles dispersed in the resin, and a viscosity enhancer for increasing the viscosity of the resin.
• the viscosity enhancer comprises an inorganic material selected from the group consisting of silica, silicon carbide, alumina, and a mixture of at least two of the materials and is contained in an amount of 5-60% by weight based on the total amount of the anisotropic conductive adhesive.
• the first substrate is a component of a liquid crystal display (LCD), for example, a glass substrate or a flexible printed circuit board (FPC).
• LCD liquid crystal display
• FPC flexible printed circuit board
• a method for bonding a first substrate with a first circuit having a first electrode, and a second substrate with a second circuit having a second electrode comprising applying an anisotropic conductive adhesive to the first substrate.
• the applied anisotropic conductive adhesive is pre-pressed against the first substrate at a temperature of 60-100°C.
• the first and second substrates are aligned such that the first and second circuits face each other.
• the first and second substrates are bound together by pressing the first and second substrates against each other such that the first and second electrodes are electrically connected.
• the bonding method according to the present invention further comprises: aligning a third substrate on the first substrate against which the anisotropic conductive adhesive has been pre-pressed; and pre-pressing the third substrate against the first substrate by applying a pressure of 0.1-1 MP at a temperature 60-100°C.
• FIG. 1A is a cross-sectional view after an anisotropic conductive additive is applied to a substrate before an IC circuit is bound to the substrate in the manufacture of a module of a conventional flat panel display or in the packaging of a semiconductor;
• FIG. 1 B is a cross-sectional view after an upper circuit on the IC chip is connected to a lower circuit on the substrate by heating and pressing;
• FIG. 2 is a graph of a viscosity variation pattern of an adhesive resin over heating time when bonding circuits at a high temperature using a conventional anisotropic conductive adhesive;
• FIG. 3 is an optical microscopic photograph showing a state of the circuits bound together using a conventional anisotropic conductive adhesive
• FIG. 4 is a flowchart illustrating a first embodiment of a method for preparing an anisotropic conductive adhesive according to the present invention
• FIG. 5 is a flowchart illustrating a second embodiment of the method for preparing the anisotropic conductive adhesive according to the present invention
• FIG. 6 is a flowchart illustrating a third embodiment of the method for preparing the anisotropic conductive adhesive according to the present invention
• FIG. 7 is a graph showing a viscosity variation pattern of an adhesive resin with respect to heating time when micro circuits are bound at a high temperature using an anisotropic conductive adhesive according to the present invention
• FIG. 8 is an optical microscopic photograph showing the state of the connection of circuits when an example of the anisotropic conductive adhesive according to the present invention is applied;
• FIG. 1 1 is a graph comparatively showing the change in connection resistance over time when a conventional anisotropic conductive adhesive and a variety of anisotropic conductive adhesives prepared according to the present invention with different compositions by different methods are applied to bond circuits;
• FIG. 12 is a flowchart illustrating a preferred embodiment of a bonding method using an anisotropic conductive adhesive according to the present invention.
• an inorganic viscosity enhancer is incorporated as a component of an anisotropic conductive adhesive to adjust the fluidity of an adhesive resin.
• a viscosity enhancer composed of a radical curable resin and radical initiator is incorporated as a component of the anisotropic conductive adhesive to the fluidity of an adhesive resin.
• a radical initiator which is highly reactive at a comparatively low temperature of about 100-150°C is used to increase the rate of curing reaction.
• a viscosity enhancer composed of a UV-curable resin and UV initiator is incorporated as a component of the anisotropic conductive adhesive to the fluidity of an adhesive resin. In this case, UV of an appropriate wavelength for curing is radiated in the preparation of the anisotropic conductive adhesive to partially or entirely cure the UV curable resin. Alternatively, heating may be performed while the UV radiation to induce the curing reaction.
• the fluidity of the adhesive composition can be reduced in an initial attachment process, which is performed at a comparatively high temperature, thereby preventing formation of voids between connected circuits in a resultant final circuit construct to ensure the reliability of the connected circuits.
• an anisotropic conductive adhesive includes the following basic components: (a) an adhesive composition comprising an epoxy-based base resin, a hardener, and conductive particles, and (b) a viscosity enhancer for adjusting the fluidity of the adhesive composition.
• Suitable base resins for the anisotropic conductive adhesive according to the present invention include, for example, bisphenol-A type epoxy resin, bisphenol-F type epoxy resin, phenol nobolak type epoxy resin, cresol nobolak type epoxy resin, dimeric modified epoxy resin, rubber modified epoxy resin, urethane modified epoxy resin, bromated epoxy resin, melamine resin, urethane resin, polyimide resin, polyamide resin, polyethylene resin, polypropylene resins, styrene resin, styrene-butadiene resin, phenol resin, formaldehyde resin, silicon resin, acrylate resin, or a mixture of these resins.
• Suitable hardeners for the anisotropic conductive adhesive according to the present invention include, for example, imidazole derivatives, such as 2-methyl imidazole, 2-ethyl imidazole, and 1 -cyanoethyl-2-methyl imidazole, amide derivatives, such as dicyandiamide, amine derivatives, acidic anhydrides, or phenol derivatives.
• imidazole derivatives such as 2-methyl imidazole, 2-ethyl imidazole, and 1 -cyanoethyl-2-methyl imidazole
• amide derivatives such as dicyandiamide
• amine derivatives such as dicyandiamide
• acidic anhydrides or phenol derivatives.
• phenol derivatives phenol derivatives.
• one compound selected from the above-listed hardeners may be used alone, or at least two compounds among the hardeners may be used in a mixed form.
• the hardener may be encapsulated into a microcapsule with a thermo
• Suitable conductive particles for the anisotropic conductive adhesive according to the present invention include pure nickel particles or composite particles obtained by sequentially coating the surface of polymeric beads with nickel and gold to a thickness of about 500A each.
• the composite particles have a gravity of 1-3. This level of gravity is similar to that of the adhesive composition of the anisotropic conductive adhesive according to the present invention, and thus dispersion stability is better than using pure nickel particles. In addition, due to their particle sizes that are almost uniform, advantageously, there is no deviation in electrical conductivity between individual circuits connected with each other.
• the viscosity enhancer for the anisotropic conductive adhesive which is used to adjust the fluidity of the adhesive composition
• an inorganic material, a radical curable resin and radical initiator, or a UV-curable resin and UV initiator can be used.
• the viscosity enhancer is contained in an amount of 5-95% by weight based on the total amount of the anisotrotropic conductive adhesive.
• An inorganic material having thixotropic behavior may be used as the viscosity enhancer.
• Suitable inorganic materials for the anisotropic conductive adhesive according to the present invention include, for example, aluminum oxide (AI 2 O 3 ), silicon carbide (SiC), silica (SiO 2 ), copper oxide (CuO), or titanium dioxide (TiO 2 ).
• One material selected from the listed materials may be used alone. Alternatively, at least two of the materials may be used in a mixed form.
• the inorganic materials are in a granular form of an average particle size of 0.1-5 microns.
• silica is used in an amount of 5-60% by weight based on the total amount of the anisotropic conductive adhesive.
• an increase in the viscosity of the anisotropic conductive adhesive and characteristics improvements in terms of thermal expansion coefficient and glass transition temperature are expected.
• Suitable radical initiators include a peroxide initiator, an azo initiator, or a mixture of these materials, and more particularly, cumil peroxyoctoate, acetyl peroxide, t-butyl peroxybenzoate, dicumil peroxide, azobisisobutyronitril, or a mixture of these materials.
• suitable UV curable resins include a multi-functional monomer selected from the group consisting of dipentaerythritol hexaacrylate, methyleneglycol bisacrylate, trimethylolpropane triacrylate, ethyleneglycol diacrylate, and pentaerythritol triacrylate, a multi-functional oligomer selected from the group consisting of epoxy acrylate, urethane acrylate, and polyester acrylate, a reactive acrylate polymer, or a mixture of these materials.
• Any UV initiator capable of inducing a photoreaction with a UV wavelength preferably a UV wavelength of 200-400nm, may be used.
• Suitable UV initiators include, for example, 2,2-dimethoxy-2-phenylacetophenone, 1 -hydroxy-cyclohexyl-penylketone, para-phenylbenzophenone, benzyldimethylketal, or a mixture of these materials.
• a mixture of at least two photoinitiators having a reactivity with respect to different wavelengths is used, deviations in characteristics of the anisotropic conductive adhesive depending on different preparation conditions can be reduced.
• a benzophenone photosensitizer, or an anti-polymerization agent such as hydroquinone monoethylether may be additionally used.
• the anisotropic conductive adhesive according to the present invention may further include conductive impurity ions if necessary.
• the addition of the conductive impurity ions can prevent the connected circuits from corrosion.
• conductive impurity ions cations or anions, for example, Na + , K*, and Cl " , may be used.
• the conductive impurity ions are contained in an amount of, preferably 1-100 ppm, and more preferably less than 10 ppm. The components and composition of the anisotropic conductive adhesive are adjusted in consideration of the amount of the conductive impurity ions.
• FIG. 4 is a flowchart illustrating a first embodiment of a method for preparing the anisotropic conductive adhesive according to the present invention.
• FIG. 5 is a flowchart illustrating a second embodiment of the method for preparing the anisotropic conductive adhesive according to the present invention.
• anisotripic conductive adhesives according to the present invention and a variety of characteristics measured for the resulting anisotripic conductive adhesives will be described in greater detail with reference to the following examples.
• An anisotropic conductive adhesive with the composition of Table 1 was prepared in a film form, and the characteristics of the anisotropic conductive adhesive were measured.
• the anisotropic conductive adhesive with the above composition was processed into a film without additional thermal treatment and applied for circuit connections, and the characteristics of the anisotropic conductive adhesive were determined.
• FIG. 9 is an optical microscopic photograph showing a state of the connection of circuits 280 when the anisotropic conductive adhesive 270 according to the present invention with the composition of Table 2 is applied.
• the anisotropic conductive adhesive 270 prepared in this example to contain the radical curable resin and the radical initiator as a viscosity enhancer according to the present invention, voids are almost not generated.
• adhesive force and connection resistance were measured in the same manner as used in Example 1. As a result, the adhesive force between the circuits was 910 g/cm, and the connection resistance was 0.7 ⁇ .
• UV light of an appropriate wavelength in the range of 200-400 nm was radiated and then the anisotrpic conductive adhesive was processed into a film.
• the appropriate wavelength of UV for curing was determined in consideration of the absorptive wavelength range of the UV initiator.
• FIG. 12 is a flowchart illustrating a preferred embodiment of a bonding method using an anisotropic conductive adhesive according to the present invention.
• a substrate with a first circuit having a first electrode, a chip having a second circuit having a second electrode, which are to be bound together, and the anisotropic conductive adhesive are prepared.
• the anisotropic conductive adhesive any anisotropic conductive adhesive having a different composition described above according to the present invention is prepared (Step 510).
• the anisotropic conductive adhesive is applied to the prepared substrate
• a plurality of FPCs are bound on one glass substrate.
• a step of aligning a new FPC on the pre-pressed substrate and pre-pressing the new FPC may be further included. The same conditions as in
• Step 530 of FIG. 12 can be applied. However, the pre-pressing duration can be reduced if necessary.

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• 2002
  • 2002-06-24 WO PCT/KR2002/001198 patent/WO2003000816A1/en not_active Application Discontinuation
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