CN102408840A - Adhesive film, and connection structure and connecting method for circuit member - Google Patents

Abstract

The present invention provides an adhesive film, a connection structure and a connection method of circuit components, the adhesive film is laminated with a conductive adhesive layer containing conductive particles and an insulating adhesive layer, and the insulating adhesive layer contains double Phenol F type phenoxy resin.

Description

Adhesive film, and connection structure and connection method of circuit components

The present invention is an invention application with the application number 200780041598.7 (the international application number is PCT/JP2007/071800), the application date is November 9, 2007, and the invention title is "adhesive film, and connection structure and connection method of circuit components" divisional application.

technical field

The present invention relates to an adhesive film, and a connection structure and connection method of circuit components.

Background technique

Conventionally, LCD driver ICs have been mounted on glass panels for liquid crystal displays through COG (Chip-On-Glass: chip-on-glass) mounting and COF (Chip-On-Flex: chip-on-flexible substrate) mounting. COG mounting is to use an adhesive film containing conductive particles to directly bond the IC for liquid crystal driving to the glass panel. In COF mounting, ICs for driving liquid crystals are bonded to flexible tapes with metal wiring, and then bonded to glass panels using an adhesive film containing conductive particles.

On the other hand, with the high precision of liquid crystal displays in recent years, the pitch and area of gold bumps serving as electrodes of ICs for driving liquid crystals have been increasingly narrowed. Therefore, in the conventional adhesive film, the conductive particles in the circuit connection member flow out between adjacent electrodes (connection terminals) to cause a short circuit or the like. In addition, when the number of conductive particles in the adhesive tape is reduced to avoid short circuits, there is a problem that the number of conductive particles in the adhesive film caught between bumps and panels decreases, and as a result, the gap between circuits is reduced. The contact resistance increases, resulting in poor connection.

Therefore, as a method for solving these problems, a method of preventing deterioration of joint quality in COG mounting or COF mounting by forming an insulating adhesive layer on at least one side of an adhesive film has been developed (for example, see Patent Document 1), and by A method of controlling the fluidity of an adhesive film during heat and pressure to ensure the number of conductive particles captured between bumps and panels (for example, see Patent Document 2).

Patent Document 1: Japanese Patent Application Laid-Open No. 8-279371

Patent Document 2: Japanese Patent Laid-Open No. 2002-201450

Contents of the invention

The problem to be solved by the invention

However, in the method of forming an insulating adhesive layer on one side of the adhesive film, when the bump area is small, for example, less than 3000 μm ² , if the number of conductive particles is increased in order to obtain stable contact resistance, the adjacent circuit There is still room for improvement between the electrodes. In addition, in the method of controlling the fluidity of the adhesive film under heat and pressure, when an IC for driving a liquid crystal is mounted on a glass panel for liquid crystal display, the storage modulus of the cured product of the adhesive film after heat and pressure is prevented from increasing However, the resulting panel warpage still leaves room for improvement.

Therefore, the present invention was invented in view of the above-mentioned circumstances, and its object is to provide an electrical connection that can obtain low resistance for COG mounting and COF mounting, and can sufficiently prevent panel warpage after mounting an IC for liquid crystal driving on a glass panel for liquid crystal display. The adhesive film, and the connection method and connection structure of circuit components using the adhesive film.

means of solving problems

The present invention provides an adhesive film in which a conductive adhesive layer containing conductive particles and an insulating adhesive layer are laminated, and the cured insulating adhesive is heat-pressed under predetermined conditions in the lamination direction. C/D, which is a value obtained by dividing the area C of the main surface of the layer by the area D of the main surface of the cured conductive adhesive layer, is 1.2 to 3.0.

According to the adhesive film of the present invention, low-resistance electrical connection can be obtained for COG mounting and COF mounting, and it is possible to sufficiently prevent panel warpage and short-circuit between adjacent electrodes after mounting an IC for liquid crystal driving on a glass panel for liquid crystal display. occur.

According to the adhesive film of the present invention, the reason why the above-mentioned object can be achieved is not necessarily clear, but it is considered that the value of the above-mentioned C/D is at least the above-mentioned range. Also, the value of C/D is an index showing the difference between the fluidity of the insulating adhesive layer and the fluidity of the conductive adhesive layer.

When the value of C/D is within the above numerical range, the fluidity of the insulating adhesive layer with respect to the fluidity of the conductive adhesive layer becomes higher than when the value is less than 1.2.

In the adhesive film of the present invention, the insulating adhesive film flows preferentially over the conductive adhesive film when heated and pressed. Therefore, it is considered that when the circuit is connected, the insulating adhesive layer is easy to fill in the gap between the circuit electrodes on the circuit substrate, and it is easy to prevent the conductive particles in the conductive adhesive layer from flowing into the gap, and it is possible to fully prevent the gap between adjacent electrodes. occurrence of a short circuit.

Furthermore, it is considered that if the conductive particles in the conductive adhesive layer are prevented from flowing into the above-mentioned gaps, the number of conductive particles trapped between the electrodes of the circuit to be connected increases, and a low-resistance electrical connection can be easily obtained.

In addition, when the value of C/D is within the above numerical range, the fluidity of the insulating adhesive layer with respect to the fluidity of the conductive adhesive layer is not too high compared with the case where the value exceeds 3.0. From this, it is considered that the excellent conduction characteristics and adhesiveness of the circuit electrodes can be compatible, and the high reliability of the adhesive film can be maintained.

In addition, the above-mentioned predetermined conditions are heating and pressing at 160° C. and 2 MPa for 10 seconds in a state where the adhesive film of the present invention is sandwiched between two glass plates.

The insulating adhesive layer preferably contains bisphenol F type phenoxy resin, and the conductive adhesive layer preferably contains at least 1 selected from the group consisting of bisphenol A type phenoxy resin and bisphenol A·F copolymer type phenoxy resin. kind of resin. Thereby, the fluidity of the insulating adhesive layer and the fluidity of the conductive adhesive layer can be more highly controlled.

The adhesive film of the present invention is the above-mentioned adhesive film for electrically connecting opposing connection terminals, and the storage modulus E' of the cured product of the aforementioned adhesive film at 40° C. and a frequency of 10 Hz is preferably 0.5. ~2.5GPa.

Thereby, the cohesive strength of the components in the cured product of the adhesive film after connecting the connection terminals is improved, and internal stress is reduced. Therefore, there is an advantageous effect that the display quality, adhesive force, and conduction characteristics of the mounted product are improved. When the storage elastic modulus is less than 0.5 GPa, the cohesive force of the components of the cured product of the adhesive film tends to be lower than when it is in the above range, and the resistance of the connection portion when connecting circuit components tends to increase. In addition, when the storage elastic modulus exceeds 2.5 GPa, compared with the case where it is in the above range, the hardness of the cured product of the adhesive film tends to increase, and the effect of preventing panel warpage of the mounted product tends to decrease.

The insulating adhesive layer and/or the conductive adhesive layer preferably contain a film forming material, an epoxy resin, and a latent curing agent. Accordingly, the above-mentioned effects of the present invention can be achieved more reliably.

The present invention also provides an adhesive film in which a conductive adhesive layer containing conductive particles and an insulating adhesive layer are laminated, and the insulating adhesive layer contains a bisphenol F-type phenoxy resin. According to such an adhesive film, a low-resistance electrical connection can be obtained for COG mounting and COF mounting, and it is possible to sufficiently prevent panel warpage and short-circuit between adjacent electrodes after mounting a liquid crystal driving IC on a glass panel for liquid crystal display. .

In addition, the present invention provides a connection structure in which a first circuit component having a first connection terminal and a second circuit component having a second connection terminal are arranged such that the first connection terminal and the second connection terminal face each other, Interpose the adhesive film between the first connection terminal and the second connection terminal arranged oppositely, heat and press, and electrically connect the first connection terminal and the second connection terminal to form the connection structure of the circuit components, bonding The film has a conductive adhesive layer containing conductive particles and an insulating adhesive layer, and after heating and pressing, the area C of the main surface of the cured insulating adhesive layer is divided by the area C of the cured conductive adhesive layer The value of the area D of the main surface, that is, C/D is 1.2 to 3.0. According to such a connection structure of circuit components, connection reliability is sufficiently high by employing the adhesive film of the present invention.

In the above connection structure, at least one of the first and second circuit components may be an IC chip.

In the above connection structure, the surface of at least one of the first and second connection terminals may contain at least one selected from the group consisting of gold, silver, tin, platinum group metals, and indium-tin oxide (ITO). .

In the above connection structure, at least one of the surfaces of at least one of the first and second circuit components may be coated or attached with at least one selected from the group consisting of silicon nitride, organosilicon compounds, and polyimide resins. deal with.

In addition, the present invention provides a connection method in which a first circuit component having a first connection terminal and a second circuit component having a second connection terminal are arranged such that the first connection terminal and the second connection terminal face each other, The adhesive film is interposed between the first connection terminal and the second connection terminal arranged oppositely, and heat and pressure are performed to electrically connect the first connection terminal and the second connection terminal. The connection method of the circuit components, the adhesive film has The conductive adhesive layer and the insulating adhesive layer containing conductive particles, after heating and pressing, the area C of the main surface of the cured insulating adhesive layer, divided by the cured conductive adhesive layer The value C/D of the area D of the principal surface is 1.2 to 3.0. According to such a connection method, a highly reliable connection structure can be obtained by using the adhesive film of the present invention.

Invention effect

The present invention can provide a low-resistance electrical connection for COG mounting and COF mounting, and can sufficiently prevent panel warpage and short-circuit between adjacent electrodes after mounting a liquid crystal driving IC on a glass panel for liquid crystal display. Adhesive film, and connection method and connection structure of circuit components using the adhesive film.

Description of drawings

FIG. 1 is a schematic cross-sectional view showing an embodiment of a circuit component connection structure of the present invention.

FIG. 2 is a diagram showing an image captured by a scanner of a cured adhesive film after heating and pressing.

Symbol Description

10: 1st circuit part; 11: 1st circuit board; 12: 1st electrode; 20: 2nd circuit part; 21: 2nd circuit board; 22: 2nd electrode; 30: circuit connection part; 100: connection structure .

Detailed ways

Hereinafter, suitable examples of the present invention will be described, but the present invention is not limited to the following embodiments. In addition, in the drawings, the same elements are attached with the same symbols, and repeated explanations are omitted. In addition, the positional relationship such as up, down, left, and right is based on the positional relationship shown in the figure unless otherwise specified. Furthermore, the dimensional ratio of the drawing is not limited to the illustrated ratio.

(adhesive film)

The present invention provides an adhesive film in which a conductive adhesive layer containing conductive particles and an insulating adhesive layer are laminated, and the cured insulating adhesive is heat-pressed under predetermined conditions in the lamination direction. The value C/D obtained by dividing the area C of the main surface of the layer by the area D of the main surface of the cured conductive adhesive layer is 1.2 to 3.0.

According to the adhesive film of the present invention, low-resistance electrical connection can be obtained for COG mounting and COF mounting, and it is possible to sufficiently prevent panel warping after mounting a liquid crystal driving IC on a glass panel for liquid crystal display and short-circuiting between adjacent electrodes. happened. Further, the following disadvantages can be prevented: when the circuit is connected, the conductive adhesive layer does not flow, and the poor conduction caused by the resin remaining between the electrodes cannot be eliminated; or, due to the excessive flow of the insulating adhesive layer, the connected circuit The bonding strength is low due to insufficient resin filling between them. From the same viewpoint, the value of C/D is more preferably 1.5 to 2.5.

The areas of the main surfaces of the insulating adhesive layer and the conductive adhesive layer before heating and pressing under the above-mentioned predetermined conditions are substantially the same. Let the area of this main surface be A. In addition, the areas of the main surfaces of the insulating adhesive layer and the conductive adhesive layer after heating and pressing under the above-mentioned predetermined conditions are respectively C and D as described above. C/A and D/A are defined as indicators of the fluidity of the insulating adhesive layer and the conductive adhesive layer accompanying the above-mentioned heating and pressing. The higher the numerical value of these fluidity indexes, the easier it is to flow along with the above-mentioned heating and pressure. The value C/D in the present invention is the same as the value obtained by dividing the fluidity index C/A of the insulating adhesive layer by the fluidity index D/A of the insulating adhesive layer.

Examples of conductive particles include metal particles such as gold (Au), silver (Ag), nickel (Ni), copper (Cu), and solder; carbon particles; coatings on surfaces of non-conductive materials such as glass, ceramics, and plastics. Particles of a conductive material such as Au, Ag, or Cu; and particles of a noble metal such as Au coated on the surface of a transition metal such as Ni. From the viewpoint of obtaining a sufficient usable time, the surface layer of the conductive particles is preferably noble metals such as Au, Ag, and platinum, more preferably Au. In addition, as conductive particles, when using non-conductive material coated noble metal particles or hot-melt metal particles, they have deformability due to heat and pressure, increase the contact area with the electrode and improve reliability during connection, so preferred.

In order to obtain good resistance, the thickness of the coating layer that coats the surface of the non-conductive material with noble metal particles is preferably 100 angstroms or more. In addition, when the surface of a transition metal such as Ni is coated with particles of noble metals, oxidation-reduction reactions are generated due to lack of coating layers made of noble metals or lack of coating layers that occur when conductive particles are mixed and dispersed. Oxidation-reduction reactions may generate free radicals and cause reduced shelf life. Therefore, it is preferable that the thickness of the covering layer is 300 angstroms or more. When the thickness of the coating layer is 1 μm or more, the above-mentioned effect is saturated. Therefore, it is desirable that the thickness of the coating layer is less than 1 μm, but this does not limit the thickness of the coating layer. The said electroconductive particle can be used individually by 1 type or in combination of 2 or more types.

Such conductive particles are preferably contained in an amount of 0.1 to 30 parts by volume, more preferably 0.1 to 10 parts by volume, based on 100 parts by volume of the resin component in the adhesive film. Thereby, the short circuit of an adjacent circuit by an excess conductive particle can be prevented more highly. The above-mentioned "resin component" refers to components other than conductive particles in the adhesive film, and specifically refers to film forming materials, epoxy resins, latent curing agents, and the like which will be described later.

The insulating adhesive layer and the conductive adhesive layer preferably contain a film-forming material, an epoxy resin, and a latent curing agent. Thereby, the said effect of this invention can be exhibited more reliably.

The so-called film-forming material is a material that solidifies the liquid and forms the constituent composition into a film, the film is easy to handle, and provides mechanical properties that are not easily cracked, broken or sticky. A material that is handled as a film in a normal state. Specific examples thereof include phenoxy resins, polyvinyl formal resins, polystyrene resins, polyvinyl butyral resins, polyester resins, polyamide resins, xylene resins, and polyurethane resins. These can be used individually by 1 type or in combination of 2 or more types. Among them, phenoxy resins are particularly preferable because they are excellent in adhesiveness, compatibility, heat resistance, and mechanical strength.

The phenoxy resin can be obtained by, for example, reacting a difunctional phenol with epihalohydrin to a high molecular weight, or performing addition polymerization of a difunctional epoxy resin and a difunctional phenol. Specifically, the phenoxy resin can be obtained as follows: make 1 mole of difunctional phenols and 0.985-1.015 epihalohydrin, in the presence of alkali metal hydroxide, in a non-reactive solvent, at 40-120 ° C obtained by reacting at a temperature.

As such a phenoxy resin, from the standpoint of improving mechanical properties and thermal properties, it is particularly preferable to obtain a phenoxy resin in which the compounding equivalent ratio of the difunctional epoxy resin and the difunctional phenol is expressed as epoxy group/phenolic hydroxyl group Calculated at 1/0.9 to 1/1.1, in the presence of catalysts such as alkali metal compounds, organophosphorus compounds, and cyclic amine compounds, amides, ethers, ketones, and lactones with a boiling point of 120°C or higher Addition polymerization is carried out by heating at 50 to 200° C. in an organic solvent such as an alcohol-based or alcohol-based solvent with a reaction solid content of 50% by mass or less.

Examples of bifunctional epoxy resins include bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol AD epoxy resins, and bisphenol S epoxy resins. Bifunctional phenols have two phenolic hydroxyl groups, and bisphenols, such as bisphenol A, bisphenol F, bisphenol AD, and bisphenol S, are mentioned, for example. Phenoxy resins can be modified by radically polymerizable functional groups.

The above-mentioned phenoxy resins may be used alone or in combination of two or more. In addition, the insulating adhesive layer and the conductive adhesive layer may contain different types of phenoxy resins. For example, it is preferable to make the insulating adhesive layer contain bisphenol F type phenoxy resin, and to make the conductive adhesive layer contain bisphenol A type phenoxy resin and bisphenol A·F copolymerization type phenoxy resin. of at least 1 resin. Accordingly, the heat resistance and fluidity of the insulating adhesive layer are improved, and the modulus of elasticity and fluidity of the conductive adhesive layer are decreased. Therefore, the fluidity of the conductive adhesive layer with respect to the insulating adhesive layer can be suppressed.

As epoxy resins, for example bisphenol type epoxy resins derived from epichlorohydrin and bisphenol A, bisphenol F or bisphenol AD; epoxy novolacs derived from epichlorohydrin and phenol novolac or cresol novolac can be used Resins; naphthalene-based epoxy resins having a skeleton containing a naphthalene ring; various epoxy compounds having two or more glycidyl groups in one molecule, such as glycidylamine, glycidyl ether, biphenyl, and alicyclic. These epoxy resins can be used individually or in mixture of 2 or more types. In order to prevent electron migration, it is preferable to use high-purity products in which impurity ions (Na ⁺ , Cl- ^, etc.) and hydrolyzable chlorine are reduced to 300 ppm or less for these epoxy resins.

Examples of latent curing agents used in the present invention include imidazole-based curing agents, hydrazide-based curing agents, boron trifluoride-amine complexes, sulfonium salts, amine imides, polyamine salts, Dicyandiamide. These latent curing agents may be used alone or in combination of two or more, and may be used in admixture with decomposition accelerators, inhibitors, and the like. In addition, it is preferable to coat these curing agents with a polyester-based polymer substance or the like to form microcapsules because the time can be extended.

The adhesive film of the present invention may contain a polymer containing at least one of acrylic acid, acrylate, methacrylate, or acrylonitrile as a monomer component in the insulating adhesive layer and/or the conductive adhesive layer. or copolymers. When a glycidyl acrylate containing a glycidyl ether group or a copolymer system acrylic rubber containing a glycidyl methacrylate is used in combination, it is preferable because it is excellent in stress relaxation. The molecular weight of such acrylic rubber (polystyrene-equivalent weight average molecular weight obtained by size exclusion chromatography) is preferably 200,000 or more from the viewpoint of increasing the cohesive force of the adhesive film.

The adhesive film may further contain fillers, softeners, accelerators, anti-aging agents, flame retardants, pigments, thixotropic agents, coupling agents, and melamine resins in the insulating adhesive layer and/or the conductive adhesive layer. and isocyanates.

When a filler is contained, it is preferable because connection reliability and the like are improved. The filler can be used as long as its maximum diameter is smaller than the particle diameter of the conductive particles. The content ratio of the filler is preferably in the range of 5 to 60 parts by volume relative to 100 parts by volume of the resin component in the adhesive film. When the content ratio exceeds 60 parts by volume, the effect of improving reliability is likely to be saturated, and when it is less than 5 parts by volume, the effect of adding the filler is small.

The coupling agent is preferably one containing a ketimine group, a vinyl group, an acryl group, an amino group, an epoxy group, and an isocyanate group from the viewpoint of improving adhesiveness. Specific examples thereof include N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropylmethyl Dimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane. In addition, examples of the silane coupling agent having a ketimine include those obtained by reacting the above-mentioned silane coupling agent having an amino group with a ketone compound such as acetone, methyl ethyl ketone, or methyl isobutyl ketone. joint agent.

The storage modulus E' of the cured product of the above adhesive film at 40°C and a frequency of 10 Hz is preferably 0.5 to 2.5 GPa, more preferably 1.0 to 2.0 GPa.

According to this, compared with the case where the storage elastic modulus is out of the above-mentioned range, the cohesive force of the components in the cured product of the adhesive film after connecting the connecting terminals is improved, and the internal stress is reduced. Therefore, advantageous effects such as improvement in display quality, adhesive force, and conduction characteristics of mounted products using the adhesive film are obtained. When the storage elastic modulus is less than 0.5 GPa, the cohesive force of the components in the cured product of the adhesive film tends to be lower than when it is in the above range, and the resistance of the connection portion when connecting circuit components tends to increase. In addition, when the storage elastic modulus exceeds 2.5 GPa, compared with the case where it is in the above range, the hardness of the cured product of the adhesive film tends to increase, and the effect of preventing panel warpage of the mounted product tends to decrease.

The adhesive film of the present invention may be composed of two layers of an insulating adhesive layer and a conductive adhesive layer, or may be composed of three or more layers. When it consists of three or more layers, it is preferable to laminate|stack alternately the insulating adhesive layer and the electroconductive adhesive layer. For example, as an adhesive film composed of three layers, a film in which a conductive adhesive layer, an insulating adhesive layer, and a conductive adhesive layer are laminated in this order, or an insulating adhesive layer, a conductive adhesive layer, layer and the insulating adhesive layer are laminated in this order. In these cases, the conductive adhesive layers or the insulating adhesive layers may be different in material, configuration, and/or film thickness, or may be the same.

In an adhesive film consisting of three or more layers, after heating and pressing under specified conditions in the lamination direction, the C/D of at least one set of the contacting conductive adhesive layer and insulating adhesive layer The value is 1.2 to 3.0. Furthermore, in an adhesive film composed of three or more layers, after heating and pressing under predetermined conditions in the lamination direction, the C/D values of the contacting conductive adhesive layers and insulating adhesive layers Both are preferably 1.2 to 3.0.

The adhesive film of the present invention that satisfies the numerical range of the above C/D can be obtained by combining, for example, an insulating adhesive layer of any one of the following (1) and (2) and the following (3) to (5) Any one layer of the conductive adhesive layer can be obtained.

(1) An insulating adhesive layer containing a bisphenol F-type phenoxy resin.

(2) Contains bisphenol A type solid epoxy resin with a weight average molecular weight of 1000-10000, A·F type solid epoxy resin with a weight average molecular weight of 1000-10000 and F-type solid epoxy resin with a weight average molecular weight of 1000-10000 An insulating adhesive layer of at least one of epoxy resins.

(3) A conductive adhesive layer containing a bisphenol A phenoxy resin or a bisphenol A·F copolymer phenoxy resin.

(4) A conductive adhesive layer containing a phenoxy resin having a fluorene ring in its molecule.

(5) A conductive adhesive layer containing 5 to 30 parts by volume of non-conductive fine particles having a particle diameter of 0.1 to 1.0 μm with respect to 100 parts by volume of the resin component.

The above-mentioned adhesive film can be used, for example, to electrically connect an IC chip and a flexible tape or a glass substrate in COG mounting or COF mounting.

(Connection structure of circuit components)

The present invention provides a connection structure of circuit components, wherein a first circuit component having a first connection terminal and a second circuit component having a second connection terminal are arranged such that the first connection terminal and the second connection terminal face each other. A connection structure of circuit components formed by interposing the above-mentioned adhesive film between the first connection terminal and the second connection terminal arranged oppositely, heating and pressing, and electrically connecting the first connection terminal and the second connection terminal.

FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the circuit component connection structure of the present invention. The connection structure 100 shown in FIG. 1 is provided with a first circuit component 10 and a second circuit component 20 facing each other, and a circuit connection component for connecting it is provided between the first circuit component 10 and the second circuit component 20. 30.

Specific examples of the first and second circuit components 10 and 20 include chip components such as semiconductor chips, resistor chips, and capacitor chips, and substrates such as printed circuit boards. Connection methods of the connection structure 100 include connection of an IC chip to a chip-mounted substrate, connection of circuits, connection of an IC chip to a glass substrate or flexible tape in COG mounting or COF mounting, and the like.

Especially preferably, at least one of the circuit components 10 and 20 is an IC chip.

In addition, the surface of at least one of the circuit components 10, 20 is preferably coated or adhered with at least one selected from the group consisting of silicon oxide, organosilicon compound, and polyimide resin. According to the above-mentioned adhesive film, the adhesive strength with respect to such a circuit component is especially favorable.

The first circuit component 10 has a first circuit board 11 and first electrodes (connection terminals) 12 formed on the main surface 11 a of the first circuit board 11 . The second circuit component 20 has a second circuit board 21 and second electrodes (connection terminals) 22 formed on the main surface 21 a of the second circuit board 21 . In the connection structure 100, the first electrode 12 and the second electrode 22 are arranged to face each other and are electrically connected. In addition, an insulating layer (not shown) may be formed on the main surface 11a of the first circuit board 11 and on the main surface 21a of the second circuit board 21 in some cases.

The surface of at least one of the first and second electrodes 11 and 12 preferably contains at least one selected from the group consisting of gold, silver, tin, platinum group metals, and indium-tin oxide (ITO).

The circuit connection member 30 is a cured product of the above-mentioned adhesive film. The first electrode 12 and the second electrode 22 are electrically connected by conductive particles (not shown) in the cured product of the adhesive film.

The manufacturing method of the connection structure 100 of this embodiment, that is, the connection method of the circuit components 10 and 20 is as follows, for example. First, the above-mentioned adhesive film is interposed between the first and second circuit components 10 and 20 . At this time, the first and second circuit components 10 and 20 are arranged such that the first electrode 12 and the second electrode 22 face each other. In addition, the adhesive film may be interposed so that the insulating adhesive layer side thereof is in contact with the first electrode 12 , or may be interposed so as to be in contact with the second electrode 22 . Next, while heating the adhesive film through the first and second circuit components 10 and 20 , pressure is applied in the stacking direction to cure the adhesive film to form the connection structure 100 . The curing treatment can be performed by a general method, and the method is appropriately selected according to the adhesive film.

Preferred embodiments of the present invention have been described above, however, the present invention is not limited to the above-described embodiments. Various modifications can be made to the present invention without departing from the gist thereof.

Example

Hereinafter, the present invention will be described in detail through examples, however, the present invention is not limited thereto. In addition, in the following examples, the bisphenol F type phenoxy resin used the resin of the trade name "FX-316" manufactured by Tohto Chemical Co., Ltd., and the bisphenol A type phenoxy resin used the resin manufactured by Inchem Corp. The resin with the trade name "PKHC", the resin with the trade name "ZX-1356-2" manufactured by Tohto Kasei Co., Ltd. was used for the bisphenol A·F copolymer resin, and the resin with the trade name "ZX-1356-2" manufactured by Sanshin Chemical Industry Co., Ltd. was used for the aromatic sulfonium salt. The product name "San Ed SI-60" manufactured by the company. In addition, as the liquid epoxy resin, a liquid epoxy resin containing a microcapsule-type latent curing agent (trade name "Nobakyua HX-3941" manufactured by Asahi Kasei Chemical Co., Ltd., epoxy equivalent 185) was used.

(Example 1)

Dissolve 100 g of bisphenol F type phenoxy resin in a mixed solvent of toluene (boiling point 110.6° C., SP value 8.90) and ethyl acetate (boiling point 77.1° C., SP value 9.10) at a mass ratio of 50:50 to obtain a solid content of 60 mass %The solution. A liquid epoxy resin was blended in this solution, and 2.4 g of an aromatic sulfonium salt as a latent curing agent was further added to obtain a liquid mixture. The compounding quantity of the above-mentioned liquid epoxy resin is compounded so that the solid mass ratio of bisphenol F type phenoxy resin:liquid epoxy resin is 60:40. The obtained mixed solution was applied to a PET film surface-treated with silicone on one side with a thickness of 50 μm using a coating device, and then dried with hot air at 70° C. for 5 minutes to form an insulating adhesive layer with a thickness of 10 μm.

Separately, 50 g of bisphenol A phenoxy resin was dissolved in a mixed solvent of toluene and ethyl acetate at a mass ratio of 50:50 to obtain a first solution having a solid content of 40% by mass. On the other hand, 50 g of bisphenol A·F copolymerized phenoxy resin was dissolved in a mixed solvent of toluene and ethyl acetate at a mass ratio of 50:50 to obtain a second solution having a solid content of 45% by mass.

The above-mentioned first and second solutions are mixed, and a liquid epoxy resin is further blended into the mixed solution. The compounding quantity of these was calculated by solid mass ratio, bisphenol A type phenoxy resin: bisphenol A·F copolymerization type phenoxy resin: liquid epoxy resin was 30:30:40. The dispersion|distribution conductive particle was further mix|blended with the obtained compounded liquid so that it may be 10 volume% with respect to a resin component, and 2.4 g of aromatic sulfonium salts were further added as a latent hardening|curing agent, and the mixed liquid was obtained. The obtained mixed solution was applied to a PET film surface-treated with silicone on one side with a thickness of 50 μm using a coating device, and then dried with hot air at 70° C. for 5 minutes to form a conductive adhesive layer with a thickness of 10 μm. The formed insulating adhesive layer and conductive adhesive layer were bonded together using a laminator to obtain an adhesive film sandwiched between PET films.

(Example 2)

The formation of the insulating adhesive layer was replaced as follows, and it carried out similarly to Example 1, and obtained the adhesive film with a PET film. 100 g of bisphenol F-type phenoxy resin was dissolved in a mixed solvent of toluene and ethyl acetate at a mass ratio of 50:50 to obtain a first solution having a solid content of 60% by mass. On the other hand, 50 g of bisphenol A·F copolymerized phenoxy resin was dissolved in a mixed solvent of toluene and ethyl acetate at a mass ratio of 50:50 to obtain a second solution having a solid content of 45% by mass. The above-mentioned first and second solutions are mixed, and a liquid epoxy resin is further blended into the mixed solution. The compounding quantity of these was calculated by solid mass ratio, bisphenol F type phenoxy resin: bisphenol A·F copolymerization type phenoxy resin: liquid epoxy resin was 30:30:40. 2.4 g of aromatic sulfonium salts as a latent curing agent were further added to the obtained mixed liquid to obtain a mixed liquid. The obtained mixed solution was applied to a PET film surface-treated with silicone on one side with a thickness of 50 μm using a coating device, and then dried with hot air at 70° C. for 5 minutes to form an insulating adhesive layer with a thickness of 10 μm.

(comparative example 1)

50 g of bisphenol A phenoxy resin was dissolved in a mixed solvent of toluene and ethyl acetate at a mass ratio of 50:50 to obtain a first solution having a solid content of 40% by mass. On the other hand, 50 g of bisphenol A·F copolymerized phenoxy resin was dissolved in a mixed solvent of toluene and ethyl acetate at a mass ratio of 50:50 to obtain a second solution having a solid content of 45% by mass. The above-mentioned first and second solutions are mixed, and a liquid epoxy resin is further blended into the mixed solution. The compounding quantity of these was calculated by solid mass ratio, bisphenol A type phenoxy resin: bisphenol A·F copolymerization type phenoxy resin: liquid epoxy resin was 30:30:40. 2.4 g of aromatic sulfonium salts as a latent curing agent were further added to the obtained mixed liquid to obtain a mixed liquid. The obtained mixed solution was applied to a PET film surface-treated with silicone on one side with a thickness of 50 μm using a coating device, and then dried with hot air at 70° C. for 5 minutes to form an insulating adhesive layer with a thickness of 10 μm.

100 g of bisphenol F-type phenoxy resin was dissolved in a mixed solvent of toluene and ethyl acetate at a mass ratio of 50:50 to obtain a first solution having a solid content of 60% by mass. On the other hand, 50 g of bisphenol A·F copolymerized phenoxy resin was dissolved in a mixed solvent of toluene and ethyl acetate at a mass ratio of 50:50 to obtain a second solution having a solid content of 45% by mass. The above-mentioned first and second solutions are mixed, and a liquid epoxy resin is further blended into the mixed solution. The compounding quantity of these was calculated by solid mass ratio, bisphenol F type phenoxy resin:bisphenol A·F copolymerization type phenoxy resin:liquid epoxy resin was 30:30:40. To the obtained compounded liquid, dispersed conductive particles were further compounded so as to be 10% by volume with respect to the resin component, and 2.4 g of an aromatic sulfonium salt as a latent curing agent was further added to obtain a dispersion liquid. The obtained dispersion liquid was applied to a PET film surface-treated with silicone on one side with a thickness of 50 μm using a coating device, and then dried with hot air at 70° C. for 5 minutes to form a conductive adhesive layer with a thickness of 10 μm. The formed insulating adhesive layer and conductive adhesive layer were bonded together using a laminator to obtain an adhesive film sandwiched between PET films.

(comparative example 2)

The formation of the insulating adhesive layer was replaced as follows, and it carried out similarly to Example 1, and obtained the adhesive film with a PET film. 100 g of bisphenol F-type phenoxy resin was dissolved in a mixed solvent of toluene and ethyl acetate at a mass ratio of 50:50 to obtain a solution having a solid content of 60% by mass. A liquid epoxy resin is mixed with this solution to obtain a liquid mixture. The compounding quantity of the above-mentioned liquid epoxy resin is calculated by solid mass ratio, bisphenol F type phenoxy resin: liquid epoxy resin is 60:40. Without adding an aromatic sulfonium salt as a latent curing agent, the resulting mixture was coated on a PET film with a thickness of 50 μm on one surface treated with silicone on one side using a coating device, and then passed through a 70°C, 5-minute It dried with hot air to form an insulating adhesive layer with a thickness of 10 μm.

(Formation of connection structure of circuit components)

Using the adhesive films of Examples 1 and 2 and Comparative Examples 1 and 2, respectively, connection structures of circuit components were produced. Specifically, first, the PET film on the conductive adhesive layer side of the adhesive film was peeled off to expose the surface of the conductive adhesive layer. Next, an ITO film was formed by vapor deposition on glass with a thickness of 0.5 mm to obtain an ITO substrate (surface resistance<20Ω/□). Next, make the surface of the conductive adhesive layer of the above-mentioned adhesive film face the surface of the ITO film to contact the surface of the ITO film, and at the same time, heat and press in their lamination direction at 70 ° C, 0.5 MPa, and 3 seconds. Temporarily fix the adhesive film on the ITO substrate. Then, the PET film on the other side was peeled and removed from the adhesive film. Next, an IC chip provided with gold bumps in two rows (checkerboard arrangement) with a bump area of 30 μm×50 μm, a pitch of 40 μm, and a height of 15 μm was placed on the adhesive film. The adhesive film on which the IC chip is mounted is sandwiched between quartz glass and a pressure head, and the ITO substrate and the IC chip are connected by heating and pressing under the conditions of 160°C, 100MPa, and 10 seconds to produce a circuit part. connection structure.

(Measurement of the number of captured particles between bumps and glass substrate wiring)

For the above connection structure, 200 areas of 30 μm×50 μm were observed from the glass side of the ITO substrate with a metal microscope (magnification 500 times), and the number of conductive particles sandwiched between the ITO substrate and the gold bumps was counted. Then, the number of conductive particles per region was obtained by summing and averaging. The results are shown in Table 1.

(Measurement of connection resistance)

For the connection structure of circuit components obtained by using the adhesive films of Examples 1, 2 and Comparative Examples 1, 2, after the initial stage and after being kept in a high-temperature and high-humidity tank (85°C 85RH environment) for 500 hours, a 4-terminal Measuring method The resistance value of the connection part was measured with a multimeter. The results are shown in Table 1.

(Measurement of C/D value)

The adhesive films of Examples 1 and 2 and Comparative Examples 1 and 2 were cut into a disk shape of Φ5.5 mm. Next, the cut out adhesive film was sandwiched between two glass plates with a thickness of 0.7 mm and 15 mm×15 mm, and heated and pressed at 160° C. and 2 MPa for 10 seconds. The value of C/A was obtained from the area A of the main surface of the adhesive film before heating and pressing and the area C of the main surface of the cured insulating adhesive layer after heating and pressing. Further, the value of D/A is obtained from the area A of the main surface of the adhesive film before heating and pressing and the area D of the main surface of the cured conductive adhesive layer after heating and pressing, and by using C/ The value of A is divided by the value of D/A to calculate the value of C/D. The results are shown in Table 1.

The areas C and D of the above-mentioned main surfaces are obtained by imaging the width of the cured adhesive film after heating and pressing the glass plate using a scanner or the like and using an image processing device. The area C is the area of the part surrounded by the outermost periphery of the adhesive film, and the area D is the area of the part surrounded by the inner periphery of the outermost periphery. The part between the outermost circumference and the outermost inner circumference is white and transparent when viewed with the naked eye, and appears light blue when photographed by a scanner. In addition, the inner part of the outermost inner circumference tends to be black when viewed with the naked eye, They appear white when photographed with a scanner, so they can be distinguished. An image taken by a scanner of the cured adhesive film after heating and pressing is shown in FIG. 2 . The outermost diameter of the cured adhesive film shown in FIG. 2 was about 9 mm.

Table 1

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Table 1, continued from previous page

Claims (8)

1. An adhesive film, wherein a conductive adhesive layer containing conductive particles and an insulating adhesive layer are laminated, The insulating adhesive layer contains bisphenol F type phenoxy resin. 2. The adhesive film according to claim 1, wherein the conductive adhesive layer contains at least 1 selected from the group consisting of bisphenol A type phenoxy resin and bisphenol A·F copolymer type phenoxy resin. kind of resin. The adhesive film according to claim 1 or 2, wherein the storage modulus E' of the cured product of the adhesive film at 40°C and a frequency of 10 Hz is 0.5 to 2.5 GPa. 4. The adhesive film according to claim 1 or 2, wherein the insulating adhesive layer and/or the conductive adhesive layer contain a film forming material, an epoxy resin, and a latent curing agent. 5. The adhesive film according to claim 1 or 2, wherein the insulating adhesive layer and/or the conductive adhesive layer contain an epoxy resin and a latent curing agent. 6. A connection structure of circuit components, wherein a first circuit component having a first connection terminal and a second circuit component having a second connection terminal face each other through the first connection terminal and the second connection terminal arranged in a manner such that the adhesive film according to any one of claims 1 to 5 is interposed between the first connection terminal and the second connection terminal which are arranged facing each other, and heat and pressure are carried out so that the A connection structure of a circuit component in which the first connection terminal is electrically connected to the second connection terminal. 7. A method for connecting circuit components, wherein a first circuit component having a first connection terminal and a second circuit component having a second connection terminal face each other through the first connection terminal and the second connection terminal way to configure, The adhesive film according to any one of claims 1 to 5 is interposed between the first connection terminal and the second connection terminal which are arranged facing each other, followed by heating and pressing, so that the first connection terminal which is arranged opposite The first connection terminal is electrically connected to the second connection terminal. 8. Use of the adhesive film according to any one of claims 1 to 5 for electrically connecting opposing connection terminals.

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