JP2008252098A - Method of manufacturing circuit board apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a circuit board apparatus capable of being connected at a low temperature, reducing a thermal influence to a circuit member, and having an excellent reliability of connection part after connection, and which is obtained by using a film-shaped circuit connection material without an influence to existing quality of ease of handling, and electrically connecting electrodes facing each other. <P>SOLUTION: A first circuit member having a first connection terminal and a second circuit member having a second connection terminal, which are two circuit members at least one of which has a light transparency, are arranged so that the first and second connection terminals face each other. A circuit connection material is essential to have (1) a radical polymerization material, (2) a compound generating activated radical by light irradiation, and (3) conductive particles, and has a heat generation peak temperature of 110 to 150°C in differential scanning calorimetry (DSC). By intervening the circuit connection material between the first and second connection terminals arranged so as to face each other and using both heating and pressurizing for a certain period of time and light irradiation for a certain period of time in combination, the first and second connection terminals arranged so as to face each other are electrically connected. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a circuit board device in which electrodes facing each other are electrically connected using a circuit connecting material containing a photocuring component and conductive particles.

  The film-like circuit connection material is made of an adhesive containing a predetermined amount of conductive particles such as metal particles. This film-like circuit connection material is provided between an electronic component and an electrode or circuit, and is pressurized or heated and pressurized. By performing the above, both electrodes are electrically connected to each other, and insulation between adjacent electrodes is imparted, so that the electronic component and the circuit are bonded and fixed. As adhesives used for the film-like circuit connecting material, thermoplastic materials such as styrene and polyester, and thermosetting materials such as epoxy and silicone are known. In order to cure the adhesive containing these substances, a curing agent is required. Further, the curing agent is inactive at room temperature and is higher than the activation temperature in order to enhance the storage stability of the film-like circuit connecting material. It must be accompanied by the potential to react only with. For this reason, in order to cure the adhesive, it is necessary to apply heat and pressure to improve the fluidity of the resin component and accelerate the curing reaction. That is, the temperature and pressure are required to melt and flow the adhesive, deform the conductive particles to increase the contact area with the circuit, and improve the adhesion to the circuit member. Depending on the curing component. In addition, paste materials using photo-curing resins are known as circuit connection materials having forms other than film-like, but these circuit connection materials connect circuit members by pressurization or heating and pressurization. The adhesive is then cured by light irradiation.

  However, the effects of heat and pressure on the circuit members due to heating and pressurization during resin curing exist regardless of their size. Especially regarding the thermal effects, not only the effects on the circuit members themselves, but also the connection of the circuit members. The influence of time is also great. That is, in the former case, for example, when connecting circuit members such as a liquid crystal panel, there is a concern about the influence on the liquid crystal panel itself such as a polarizing plate, thereby requiring a connection at a lower temperature than in the past or a connection in a shorter time than in the past. Yes. In the latter case, if the connection is performed under a condition where the temperature at the time of heating and pressurization is high, the two circuit members facing each other are different, and if the difference between the respective thermal expansion coefficients (α) is large, the circuit position shifts. Is likely to occur. This is more likely to occur as the pitch between adjacent circuits becomes narrower. The present invention enables connection at a lower temperature than in the past by using light irradiation in combination, reduces the thermal influence on the circuit member, is excellent in reliability of the connection part after connection, and has a simpler than in the past. The present invention provides a circuit board device obtained by electrically connecting electrodes facing each other using a film-like circuit connecting material that does not affect the quality of handleability.

According to the present invention, at least one of two circuit members having light transparency, that is, a first circuit member having a first connection terminal, and a second circuit member having a second connection terminal, A connection terminal and a second connection terminal are arranged to face each other, and (1) a radical polymerizable substance and (2) an active radical by light irradiation between the first connection terminal and the second connection terminal arranged to face each other. (3) a circuit connecting material that requires conductive particles, and a circuit connecting material having an exothermic peak temperature of 110 to 150 ° C. in differential scanning calorimetry (DSC) is interposed for a certain period of time. By using heating and pressurization and light irradiation for a predetermined time in combination, the first connection terminal and the second connection terminal arranged to face each other are electrically connected. In addition, after the start of heating and pressurization for a fixed time, light irradiation for a fixed time is started after a predetermined interval has elapsed, and the heat and pressure state is maintained while the light irradiation is performed. is there.

  In the present invention, as circuit members, chip parts such as semiconductor chips, resistor chips, capacitor chips, substrates such as printed boards, flexible wiring boards based on polyimide and polyester, indium oxide (ITO) on glass such as liquid crystal panels ) Or a transparent electrode wired with chromium or the like. On the electrode pad of the semiconductor chip or substrate, the bump formed by plating or the tip of the gold wire is melted with a torch or the like to form a gold ball, and after the ball is pressed onto the electrode pad, the wire is cut. Special electrodes such as wire bumps obtained in this way can be provided and used as connection terminals.

  These circuit members are usually provided with a large number of connection terminals (or a single connection terminal in some cases), and at least one of the circuit members having light transparency is provided on those circuit members. At least one part of the connection terminals is arranged oppositely, an adhesive is interposed between the oppositely arranged connection terminals, and the connection terminals arranged opposite to each other by heating and pressurizing and irradiating light are electrically connected to form a connection body. At this time, the thickness of the light transmissive circuit member is preferably 1.2 mm or less in terms of light transmissive property. In addition, by making the circuit connection material containing the radical polymerizable substance into a film form, it is easier to handle than the conventional paste-like circuit connection material, and the connection thickness can be made uniform. It is advantageous. Furthermore, in order to improve the adhesiveness with the circuit member, when heating is performed to such an extent that the curing reaction hardly proceeds and the resin flows, conduction between the connection terminal-conductive particle-connection terminal is performed by heating the connection material. It is possible to re-increase the melt viscosity of the connection material by introducing a cooling step after securing the above, whereby the pressure contact state of the conductive particles only by heating and cooling can be maintained and the resin can be fixed.

  In the present invention, the first connection terminal and the second connection terminal are arranged to face each other, and (1) a radical polymerizable substance, (2) a compound that generates an active radical by light irradiation, and (3) conductive particles. A circuit connection material having each of the above components as an essential component is interposed, and the first connection terminal and the second connection terminal that are arranged to face each other are electrically connected by heating and pressurization and light irradiation. Since the curing of the film-like circuit connection material is mainly carried out by photocuring, the role of the heating and pressurizing step is to melt and flow the adhesive so that the resin component around the part where the connection terminals and the conductive particles are in contact is sufficient. It can be considered that the conductive particles are sufficiently pressed between the connection terminals. For this reason, it may be heated to Tg of the adhesive or a temperature at which the flow of the adhesive necessary for sufficient deformation of the conductive particles can be obtained, and the temperature depends on the type of polymer resin that is a film forming material. The temperature is generally within the range of 80 to 140 ° C. This is lower than 150 to 190 ° C., which is a heating temperature necessary for connection of a film-like circuit connecting material using a conventional thermosetting resin as a curing component. Therefore, the connection temperature of the circuit member can be lowered by the above method. Further, by setting the exothermic peak temperature of the adhesive component in differential scanning calorimetry (DSC) to 110 to 150 ° C., the temperature given when the adhesive melts and flows is activated by the adhesive component, particularly by light irradiation. It can be used at a temperature at which the radical generator is thermally activated. Therefore, compared to the case of photocuring alone, the entire reaction system becomes more active due to the thermal effect, and it is expected that the curing properties of the adhesive are further improved. However, when the DSC exothermic peak temperature is lower than 110 ° C., the pot life (potential time) depending on the temperature is shortened. These differential scanning calorimetry can be measured, for example, under the conditions of a sample weight of 1 to 10 mg, a heating rate of 10 ° C./min, and a temperature range of 25 to 300 ° C. using a TA Instruments 910 DSC. It is.

  In addition, (1) a radical polymerizable substance, (2) a compound that generates active radicals upon irradiation with light, and (3) a conductive resin is an essential component, and a polymer resin having film-forming ability is further blended and dispersed to produce light. It is possible to provide a film-like circuit connecting material that can be cured. This is because the polymer resin used has a molecular weight of 10,000 or more, is solid at room temperature, and has a high film forming ability. By mixing this polymer resin and radically polymerizable substance, it is possible to improve the handleability and make the connection thickness uniform, which is a disadvantage of conventional circuit connection materials using photo-curing resin. It is.

  Furthermore, when performing heating and pressurization and light irradiation at the same time, it is necessary to adjust the melt fluidity and the light irradiation ability in order to sufficiently contact the conductive particles by the flow of the adhesive. The light irradiation capability here depends on the light source of the light irradiation device to be used, and in the case of a light irradiation device using a light source with a small amount of light, the curing rate of the adhesive is slowed, Therefore, heating and pressurization and light irradiation can be performed at the same time. In the case of a light irradiation device using a light source with a large amount of light, an interval of 1 to several seconds is provided between the heating and pressurizing step and the light irradiation step in order to prioritize resin flow, and light is emitted after the start of heating and pressing. Irradiation can also be performed. In this case, since the light irradiation is delayed, after the resin flows and the conduction of the connection terminal by the conductive particles is ensured, the amount of light may be increased to rapidly cure in a short time.

  Regarding the order of heating and pressing for a certain period of time and light irradiation for a certain period of time, as described above, the melt fluidity and the light irradiation ability are adjusted, and the heating and pressurization and the light irradiation are started and ended simultaneously. However, in view of the time required, it is most ideal, but in order to ensure better connection reliability, an appropriate interval is provided between the heating and pressurizing process and the light irradiation process. The method of ensuring the time for sufficient flow is optimal. It is ideal to set the interval between heating and pressurization and the time until the flow of the adhesive resin is almost completely completed. In this case, it is preferably 0.5 to 10 seconds. The pressure time and the melt viscosity of the adhesive resin are more preferably 2 to 5 seconds.

  According to the present invention, a film-like circuit connecting material containing a radically polymerizable substance and conductive particles as essential components is interposed in an adhesive, and circuit members are connected by light irradiation simultaneously with heating or pressing. Therefore, it is possible to lower the temperature required for connection than before, and by obtaining a thermally active photoinitiator, it is possible to obtain better adhesive strength and good electrical continuity more efficiently. Thus, a circuit board device having excellent reliability can be obtained.

The circuit connection material used in the present invention includes (1) a radically polymerizable substance and (2) an adhesive component essentially comprising a photocuring component comprising a compound that generates active radicals upon irradiation with light, and (3) from conductive particles. Furthermore, the polymer resin which has film-forming ability is further contained, and the connection material can be made into a film shape to improve the handleability when connecting circuit members.

  Examples of the radical polymerizable substance used in the present invention include photopolymerizable oligomers such as epoxy acrylate oligomers, urethane acrylate oligomers, polyether acrylate oligomers, and polyester acrylate oligomers, trimethylolpropane triacrylate, polyethylene glycol diacrylate, and polyalkylene glycol diacrylate. , Pentaerythritol acrylate 2-cyanoethyl acrylate, cyclohexyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, 2 (2-ethoxyethoxy) ethyl acrylate, 2-ethoxyethyl acrylate, 2-ethylhexyl acrylate, n-hexyl acrylate 2-hydroxyethyl acrylate, hydroxypro Acrylate, isobornyl acrylate, isodecyl acrylate, isooctyl acrylate, n-lauryl acrylate, 2-methoxyethyl acrylate, 2-phenoxyethyl acrylate, tetrahydrofurfryl acrylate, neopentyl glycol diacrylate, dipentaerythritol hexaacrylate Acrylic esters such as photopolymerizable monofunctional and polyfunctional acrylate monomers, etc., and similar tert-butylaminoethyl methacrylate, cyclohexyl methacrylate, dicyclopentenyloxyethyl methacrylate, 2-hydroxyethyl methacrylate, isobol Nyl methacrylate, isodecyl methacrylate, n-lauryl acrylate, stearyl methacrylate, tridecyl There are photopolymerization resins typified by methacrylic acid esters such as photopolymerizable monofunctional and polyfunctional methacrylate monomers such as methacrylate and glycidyl methacrylate, and these resins may be used alone or in combination as required. However, in order to suppress the curing shrinkage of the cured adhesive and give flexibility, it is preferable to add a urethane acrylate oligomer. In addition, since the above-mentioned photopolymerizable oligomer has a high viscosity, it is preferable to blend a monomer such as a low-viscosity polyfunctional acrylate monomer for adjusting the viscosity. In order to obtain 1 type, you may use 1 type or in mixture of 2 or more types.

  These radically polymerizable substances are polymerized and cured using a compound that generates active radicals upon irradiation with light. Photoinitiators used in the present invention include benzoin ethers such as benzoin ethyl ether and isopropyl benzoin ether, benzyl ketals such as benzyl and hydroxycyclohexyl phenyl ketone, ketones such as benzophenone and acetophenone and derivatives thereof, thioxanthones, and bisimidazoles Sensitizers such as amines, sulfur compounds and phosphorus compounds may be added to these photoinitiators in any ratio as necessary. At this time, it is necessary to select an optimal photoinitiator according to the wavelength of the light source to be used, desired curing characteristics, and the like. The polymer resin having film-forming ability used in the present invention preferably has good handleability when contained and is excellent in stress relaxation during curing, and adheres to an adherend when it has a functional group such as a hydroxyl group. It is more preferable because of improved properties. What modified each polymer with the radically polymerizable functional group is more preferable. The molecular weight of these polymers is preferably 10,000 or more, but if they are 1,000,000 or more, the mixing property is deteriorated. In addition, these radical polymerizable substances and polystyrene, polyethylene, polyvinyl butyral, polyvinyl formal, polyimide, polyamide, polyester, polyvinyl chloride, polyphenylene oxide, urea resin, melamine resin, phenol resin, xylene resin, epoxy resin, polyisocyanate resin There are phenoxy resins and the like, and these can be used alone or in combination of two or more. Further, when the adherend is an inorganic substance, it is possible to increase the adhesive strength with the adherend by mixing a silane coupling agent with the adhesive resin. Examples of silane coupling agents include vinyltrichlorosilane, vinyltriethoxysilane, vinyl-tris- (βmethoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-aminopropyltri There are ethoxysilane, β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, propyltriethoxysilane isocyanate, etc., but γ-methacryloxypropyltrimethoxysilane is used to increase the reactivity with the radical polymerizable substance. Is more preferable.

  The light used for curing can be ultraviolet light that is widely used in general, and can be generated by a mercury lamp, a metal halide lamp, an electrodeless lamp, or the like. In addition, when a radical reaction is used as the curing reaction, oxygen acts as a reaction inhibitor, so the amount of oxygen in the light irradiation atmosphere affects the curing of the radical polymerizable substance. This greatly depends on the types and concentrations of radical polymerizable substances, photoinitiators, sensitizers, and the like, and therefore needs to be examined in detail for each compounding system. As the conductive particles used in the present invention, there are metal particles such as Au, Ag, Ni, Cu, solder, carbon, etc., and these and non-conductive glass, ceramic, plastic, etc. are coated with the conductive layer described above. It may be formed. In the case of using plastic as a core or hot-melt metal particles, it is preferable because it has deformability by heating and pressurization, so that the contact area with the electrode is increased at the time of connection and reliability is improved. The conductive particles are selectively used in a wide range of 0.1 to 30 parts by volume with respect to 100 parts by volume of the adhesive component. In order to prevent an adjacent circuit from being short-circuited by excessive conductive particles, the amount is more preferably 0.2 to 15 parts by volume. The average particle size of the conductive particles at this time is more preferably 1 to 15 μm, although it depends on the amount of addition. Further, the compression elastic modulus of the conductive particles is preferably in the range of 1000 to 10,000 MPa in order to suppress the restoration of particles due to the elasticity of the adhesive when heating and pressurization and light irradiation are interrupted.

  The present invention may contain an additive selected from an inorganic filler, an organic filler, a white pigment, a polymerization inhibitor, a sensitizer, and combinations thereof depending on the application. The addition amount is preferably 1 to 100 parts by weight with respect to 100 parts by weight of the adhesive resin component, but there is no possibility of adversely affecting the reliability of the circuit board from which the kind and properties of the additive are obtained, or extremely low. It is necessary to use within such a range.

Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited thereto.
Example 1
40 g of phenoxy resin (trade name PKHC, manufactured by Union Carbide Co., Ltd., average molecular weight 45,000) in weight ratio with toluene (boiling point 110.6 ° C., SP value 8.90) / ethyl acetate (boiling point 77.1 ° C., SP Value 9.10) = dissolved in 60 g of 50/50 mixed solvent to obtain a solution having a solid content of 40%. The radical polymerizable substance includes an epoxy acrylate oligomer (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name NK Oligo EA-1020) and an acrylate monomer (manufactured by Shin Nakamura Chemical Co., Ltd., trade name NK Ester A-TMM-3L). It was used at a weight ratio of 3/1. As the photoinitiator, a bisimidazole type photoinitiator (manufactured by Kurogane Kasei Co., Ltd., 2,2′-bis (o-chlorophenyl) 4,4 ′, 5,5′-tetraphenyl1,2-biimidazole) is used. In addition, 4,4′-bisdiethylaminobenzophenone (manufactured by Hodogaya Chemical Co., Ltd., trade name EAB) was used as a sensitizer in a mixture so that the photoinitiator / sensitizer = 5/1. Further, a nickel layer having a thickness of 0.2 μm is provided on the surface of particles having polystyrene as a core, and a gold layer having a thickness of 0.02 μm is provided on the outside of the nickel layer. The conductivity is an average particle diameter of 5 μm and a specific gravity of 2.5. Particles were made. The phenoxy resin 50, the radical polymerization product 50, the photoinitiator 5 and the sensitizer 1 are blended in a solid weight ratio, and 3% by volume of conductive particles are further dispersed and coated on a fluororesin film having a thickness of 80 μm. The film-like circuit connecting material having an adhesive layer thickness of 20 μm was obtained by hot air drying at 70 ° C. for 10 minutes. The exothermic peak temperature in DSC of the obtained adhesive component was about 130 ° C. A flexible circuit board (FPC) having 500 copper circuits having a line width of 50 μm, a pitch of 100 μm, and a thickness of 18 μm, and a thin layer of 0.2 μm of indium oxide (ITO) using the film-like circuit connecting material obtained by the above manufacturing method Glass (thickness 1.1 mm, surface resistance 20 Ω / □) is used at 130 ° C. and 2 MPa for 20 seconds using an ultraviolet irradiation combined thermocompression bonding apparatus (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.). The heating and pressurization and the ultraviolet irradiation from the ITO glass side were simultaneously performed to connect over a width of 2 mm, and the pressure was released after the lapse of time to prepare a connection body. The ultraviolet irradiation amount irradiated to the adhesive was 2.0 J / cm ² . At this time, after adhering the adhesive surface of the film-like circuit connecting material on the ITO glass in advance, the film is temporarily connected by heating and pressing at 70 ° C. and 0.5 MPa for 5 seconds, and then the fluororesin film is peeled off. It connected with FPC which is one to-be-adhered body.

Example 2
A flexible circuit board (FPC) having 500 copper circuits having a line width of 50 μm, a pitch of 100 μm, and a thickness of 18 μm and a thin film of 0.2 μm of indium oxide (ITO) using the film-like circuit connecting material used in Example 1. The layer-formed glass (thickness 1.1 mm, surface resistance 20Ω / □) is 20 at 130 ° C. and 2 MPa using an ultraviolet irradiation combined thermocompression bonding apparatus (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.). Second heating and pressurization and UV irradiation from the ITO glass side were performed simultaneously to connect over a width of 2 mm, and after a lapse of time, the pressure was released to prepare a connection body. The ultraviolet irradiation amount irradiated to the adhesive was 2.0 J / cm ² . At this time, after adhering the adhesive surface of the film-like circuit connecting material on the ITO glass in advance, the film is temporarily connected by heating and pressing at 70 ° C. and 0.5 MPa for 5 seconds, and then the fluororesin film is peeled off. It connected with FPC which is one to-be-adhered body. When connecting for 20 seconds, only heating and pressurization was started, and after 3 seconds had elapsed, ultraviolet irradiation was started for 17 seconds, and after 20 seconds of heating and pressurization, the two steps were completed simultaneously.

Example 3
The radically polymerizable substance of the film-like circuit connecting material used in Example 1 was replaced with a urethane acrylate oligomer (made by Shin-Nakamura Chemical Co., Ltd., trade name NK Oligo UA-512) and an acrylate monomer (A-TMM-3L). Otherwise, a connection body was fabricated in the same manner as in Example 2.

Example 4
Example 2 except that the conductive particles of the film-like circuit connecting material used in Example 1 were replaced with nickel particles having an average particle diameter of 5 μm (trade name DSP3101, specific gravity 8.5, manufactured by Daido Special Tuna Co., Ltd.). A connected body was produced in the same manner as described above.

Example 5
A connector was prepared in the same manner as in Example 2 except that the photoinitiator of the film-like circuit connecting material used in Example 1 was replaced with a benzophenone derivative (trade name BTTB manufactured by NOF Corporation). The exothermic peak temperature in DSC of the obtained adhesive component was about 120 ° C.

Example 6
40 g of phenoxy resin (trade name PKHC, manufactured by Union Carbide Co., Ltd., average molecular weight 45,000) in weight ratio with toluene (boiling point 110.6 ° C., SP value 8.90) / ethyl acetate (boiling point 77.1 ° C., SP Value 9.10) = dissolved in 60 g of 50/50 mixed solvent to obtain a solution having a solid content of 40%. The radical polymerizable substance includes an epoxy acrylate oligomer (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name NK Oligo EA-1020) and an acrylate monomer (manufactured by Shin Nakamura Chemical Co., Ltd., trade name NK Ester A-TMM-3L). It was used at a weight ratio of 3/1. As the photoinitiator, a bisimidazole type photoinitiator (manufactured by Kurogane Kasei Co., Ltd., 2,2′-bis (o-chlorophenyl) 4,4 ′, 5,5′-tetraphenyl1,2-biimidazole) is used. In addition, 4,4′-bisdiethylaminobenzophenone (manufactured by Hodogaya Chemical Co., Ltd., trade name EAB) was used as a sensitizer in a mixture so that the photoinitiator / sensitizer = 5/1. Further, a nickel layer having a thickness of 0.2 μm is provided on the surface of particles having polystyrene as a core, and a gold layer having a thickness of 0.02 μm is provided on the outside of the nickel layer. The conductivity is an average particle diameter of 5 μm and a specific gravity of 2.5. Particles were made. It is blended so that it becomes phenoxy resin 50, radical polymerization product 50, photoinitiator 5, and sensitizer 1 in a solid weight ratio, and further 3% by volume of conductive particles, and inorganic filler (anhydrous silica fine particles, primary particles). 5% by weight (average particle diameter of about 12 nm) is dispersed and applied to a fluororesin film having a thickness of 80 μm using a coating apparatus, followed by drying with hot air at 70 ° C. for 10 minutes to form a film with a thickness of 20 μm. A circuit connection material was obtained. A flexible circuit board (FPC) having 500 copper circuits having a line width of 50 μm, a pitch of 100 μm, and a thickness of 18 μm, and a thin layer of 0.2 μm of indium oxide (ITO) using the film-like circuit connecting material obtained by the above manufacturing method Glass (thickness 1.1 mm, surface resistance 20 Ω / □) is used at 130 ° C. and 2 MPa for 20 seconds using an ultraviolet irradiation combined thermocompression bonding apparatus (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.). The heating and pressurization and the ultraviolet irradiation from the ITO glass side were simultaneously performed to connect over a width of 2 mm, and the pressure was released after the lapse of time to prepare a connection body. The ultraviolet irradiation amount irradiated to the adhesive was 2.0 J / cm ² . At this time, after adhering the adhesive surface of the film-like circuit connecting material on the ITO glass in advance, the film is temporarily connected by heating and pressing at 70 ° C. and 0.5 MPa for 5 seconds, and then the fluororesin film is peeled off. It connected with FPC which is one to-be-adhered body. In addition, at the time of connection for 10 seconds, only heating and pressurization was started, and after 2 seconds had elapsed, ultraviolet irradiation was started for 8 seconds, and two steps were completed simultaneously after 10 seconds of heating and pressurization.

Comparative Example 1
A connector was prepared in the same manner as in Example 2 except that the photoinitiator of the film-like circuit connecting material used in Example 1 was replaced with benzoin ethyl ether. The exothermic peak temperature in DSC of the obtained adhesive component was about 190 ° C.

Comparative Example 2
A flexible circuit board (FPC) having 500 copper circuits having a line width of 50 μm, a pitch of 100 μm, and a thickness of 18 μm and a thin film of 0.2 μm of indium oxide (ITO) using the film-like circuit connecting material used in Example 1. The layer-formed glass (thickness 1.1 mm, surface resistance 20Ω / □) is 10 at 130 ° C. and 2 MPa using an ultraviolet irradiation combined thermocompression bonding apparatus (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.). Second heating and pressurization and ultraviolet irradiation from the ITO glass side were simultaneously performed to connect over a width of 2 mm, and after a lapse of time, the pressure was released to prepare a connection body. The ultraviolet irradiation amount was 5.0 J / cm ² . At this time, after adhering the adhesive surface of the film-like circuit connecting material on the ITO glass in advance, the film is temporarily connected by heating and pressing at 70 ° C. and 0.5 MPa for 5 seconds, and then the fluororesin film is peeled off. It connected with FPC which is one to-be-adhered body.

Comparative Example 3
The phenoxy resin, which is a compounded resin of the film-like circuit connecting material used in Example 1, and the liquid epoxy resin containing the microcapsule-type latent curing agent are converted into the phenoxy resin 50 and the liquid epoxy resin 50 in a solid weight ratio. In addition, 3% by volume of the conductive particles used in Example 1 were mixed and dispersed, applied to a fluororesin film having a thickness of 80 μm using a coating apparatus, and dried by hot air at 70 ° C. for 10 minutes. A film-like circuit connecting material having a thickness of 20 μm was obtained. A flexible circuit board (FPC) having 500 copper circuits having a line width of 50 μm, a pitch of 100 μm, and a thickness of 18 μm, and a thin layer of 0.2 μm of indium oxide (ITO) using the film-like circuit connecting material obtained by the above manufacturing method The glass (thickness 1.1 mm, surface resistance 20 Ω / □) formed was connected to a 2 mm width by heating and pressing at 130 ° C. and 2 MPa for 20 seconds using a constant heat type thermocompression bonding apparatus (manufactured by our company). After the elapse of time, the pressure was released, and this was terminated. At this time, after adhering the adhesive surface of the film-like circuit connecting material on the ITO glass in advance, the film is temporarily connected by heating and pressing at 70 ° C. and 0.5 MPa for 5 seconds, and then the fluororesin film is peeled off. It connected with FPC which is one to-be-adhered body.

Comparative Example 4
The radical polymerizable substance includes an epoxy acrylate oligomer (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name NK Oligo EA-1020) and an acrylate monomer (manufactured by Shin Nakamura Chemical Co., Ltd., trade name NK Ester A-TMM-3L). The photoinitiator is a bisimidazole type photoinitiator (manufactured by Kurokin Kasei, 2,2′-bis (o-chlorophenyl) 4,4 ′, 5,5′-tetraphenyl 1). , 2-biimidazole), and 4,4′-bisdiethylaminobenzophenone (made by Hodogaya Chemical Co., Ltd., trade name EAB) as a sensitizer, photoinitiator / sensitizer = 5/1. Were used as mixed. In addition, a nickel layer having a thickness of 0.2 μm is provided on the surface of particles having polystyrene as a nucleus, and a gold layer having a thickness of 0.02 μm is provided outside the nickel layer, and a conductive material having an average particle diameter of 5 μm and a specific gravity of 2.5. Particles were prepared. Using these, they were blended so as to be a radically polymerizable substance 100, a photoinitiator 5, and a sensitizer 1 in a solid weight ratio, and further 3% by volume of conductive particles were mixed and dispersed to obtain a paste-like circuit connection material. . A flexible circuit board (FPC) having 500 copper circuits with an in width of 50 μm, a pitch of 100 μm, and a thickness of 18 μm, and a thin layer of 0.2 μm indium oxide (ITO) using the paste-like circuit connecting material obtained by the above-mentioned manufacturing method Glass (thickness 1.1 mm, surface resistance 20 Ω / □) is used at 130 ° C. and 2 MPa for 20 seconds using an ultraviolet irradiation combined thermocompression bonding apparatus (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.). The heating and pressurization and the ultraviolet irradiation from the ITO glass side were simultaneously performed to connect over a width of 2 mm, and the pressure was released after the lapse of time to prepare a connection body. The ultraviolet irradiation amount irradiated to the adhesive was 2.0 J / cm ² . At this time, after adhering the adhesive surface of the film-like circuit connecting material on the ITO glass in advance, the film is temporarily connected by heating and pressing at 70 ° C. and 0.5 MPa for 5 seconds, and then the fluororesin film is peeled off. It connected with FPC which is one to-be-adhered body. In addition, at the time of connection for 10 seconds, only heating and pressurization was started, and after 2 seconds had elapsed, ultraviolet irradiation was started for 8 seconds, and two steps were completed simultaneously after 10 seconds of heating and pressurization.

  The initial resistance and adhesiveness of the connectors obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were evaluated. Regarding the initial resistance, after connecting the circuit members, the resistance value between adjacent circuits of the FPC including the connection portion was measured with a multimeter. The measurement current was 1 mA, and the resistance value was shown as an average (x + 3σ) of 150 resistances between adjacent circuits. About the adhesiveness with respect to FPC and ITO glass, adhesive strength was measured and evaluated by the 90 degree | times peeling method according to JIS-Z0237. As a measuring device, Tensilon UTM-4 (peeling speed 50 mm / min, 25 ° C.) manufactured by Toyo Baldwin Co., Ltd. was used.

  In Example 1 in which heating and pressurization and ultraviolet irradiation were started and ended at the same time, both initial resistance and adhesive strength showed good values. In the case of Example 2, since heating and pressurization for 20 seconds and ultraviolet irradiation for 17 seconds are performed at intervals of 3 seconds, the adhesive resin flows sufficiently by heating, and the connection terminals, conductive particles, Thus, a circuit board having better connection characteristics than that of Example 1 was obtained particularly with respect to the initial resistance. Furthermore, in Examples 3 to 5 in which the conductive particles, the radical polymerizable substance, and the photoinitiator were replaced, it was possible to ensure a good connection state. Further, in the case of Example 6 in which an inorganic filler was added, good initial adhesive strength almost equal to that in the case of no addition was obtained, so that the photocuring reaction was hardly inhibited by the filler, and the moisture resistance reliability The adhesive strength after the test treatment is improved as compared with the case of no addition due to the stress relaxation action of the inorganic filler.

On the other hand, in the case of Comparative Example 1 using benzoin ethyl ether as a photoinitiator, since the exothermic peak temperature in DSC is higher than those in Examples 1 to 6, there is almost no thermal effect on the curing reaction. Compared with 6, the adhesive strength was low. In Comparative Example 2 in which heating and pressurization and ultraviolet irradiation were simultaneously performed under a light irradiation amount of 5.0 J / cm ² , since the curing reaction of the adhesive proceeds faster than the flow of the resin, the conductive particles are in a circuit. Insufficient contact with the member resulted in poor conduction. In Comparative Example 3 using an adhesive mainly composed of a thermosetting resin, the reaction rate of the adhesive is low under the connection conditions of 130 ° C., 2 MPa, and 20 seconds, so that sufficient curing cannot be obtained. The strength decreased considerably and the initial resistance increased. In the case of Comparative Example 4, since the polymer resin imparting film-forming property was not contained, the curing shrinkage was increased, and the adhesive strength, particularly the adhesive strength after the moisture resistance reliability test treatment was lowered.

Claims (4)

  A first circuit member having a first connection terminal and a second circuit member having a second connection terminal, wherein the first connection terminal and the second connection member are at least one of two circuit members having light transparency. Two connecting terminals are arranged opposite to each other, and (1) a radical polymerizable substance and (2) an active radical generated by light irradiation between the opposed first and second connecting terminals. (3) A circuit connecting material that essentially requires conductive particles, wherein a circuit connecting material having an exothermic peak temperature of 110 to 150 ° C. in differential scanning calorimetry (DSC) is interposed, A method of manufacturing a circuit board device, wherein the first connection terminal and the second connection terminal arranged to face each other are electrically connected by using light irradiation for a certain time.   2. The circuit board device according to claim 1, wherein after the start of heating and pressurizing for a certain time, light irradiation for a certain time is started after a predetermined interval has elapsed, and the heating and pressurizing state is maintained while the light irradiation is performed. Manufacturing method.   3. The method for manufacturing a circuit board device according to claim 1, wherein the circuit connecting material further contains a polymer resin having a film forming ability.   The circuit board device according to any one of claims 1 to 3, further comprising an additive selected from an inorganic filler, an organic filler, a white pigment, a polymerization inhibitor, a sensitizer, and a combination thereof in the circuit connecting material. Manufacturing method.