WO2013042632A1

WO2013042632A1 - Circuit connection material, connection method using same, and connection structure

Info

Publication number: WO2013042632A1
Application number: PCT/JP2012/073695
Authority: WO
Inventors: 慎一林
Original assignee: デクセリアルズ株式会社
Priority date: 2011-09-21
Filing date: 2012-09-14
Publication date: 2013-03-28
Also published as: TW201326333A; KR101944125B1; CN103370388A; JP5844588B2; JP2012041540A; TWI542652B; CN103370388B; KR20140065373A

Abstract

Provided is a circuit connection material that, while suppressing fluctuations in the resistance value between circuit electrodes when subjected to high-temperature, high-humidity processing, is able to evince superior connection reliability by increasing the adhesion with the interface to a silicon nitride film. By being interposed between a pair of circuit members disposed in a manner so that the circuit electrodes face each other, the circuit connection material electrically and mechanically connects the opposing circuit members. The circuit connection material contains: (1) a polyfunctional (meth)acrylate monomer; (2) a curing agent that generates free radicals by means of heat or light; and (3) a reactive acrylic polymer that has an ethylenic unsaturated group in a side chain and has 1000-12000 double bond equivalents.

Description

Circuit connection material, connection method using the same, and connection structure

The present invention relates to a circuit connection material, a connection method for connecting a pair of circuit members using the circuit connection material, and a connection structure obtained by the connection method.
This application claims priority on the basis of Japanese Patent Application No. 2011-206378 filed on Sep. 21, 2011 in Japan. This application is incorporated herein by reference. Incorporated.

Conventionally, when a pair of circuit members are electrically connected, a circuit connecting member in which conductive particles are dispersed has been used. Examples of the circuit connection member include an anisotropic conductive film (ACF), a connection surface on which a wiring electrode of a substrate is formed via an anisotropic conductive film, and a terminal electrode (bump of an electronic component). There is a method of connecting the connecting surface formed with a). In the connection method using the anisotropic conductive film, the anisotropic conductive film is temporarily attached on the connection surface of the substrate, and the anisotropic conductive film and the connection surface of the electronic component are opposed to each other on the anisotropic conductive film. An electronic component is placed on and heat-pressed. Thereby, the electroconductive particle in an anisotropic conductive film is inserted | pinched between the terminal electrode of an electronic component, and the wiring electrode of a board | substrate, and is crushed. As a result, the terminal electrode of the electronic component and the wiring electrode of the substrate are electrically connected via the conductive particles.

The conductive particles that are not between the terminal electrode and the wiring electrode are present in the insulating adhesive composition of the anisotropic conductive film and maintain an electrically insulated state. That is, electrical continuity is achieved only between the terminal electrode and the wiring electrode.

As an adhesive composition constituting such a circuit connecting member, there is a conventional one containing an epoxy resin or the like. This adhesive composition generally contains an epoxy resin, a curing agent such as a phenol resin that reacts with the epoxy resin, a latent curing agent that accelerates the reaction between the epoxy resin and the curing agent, and the like.

For example, Patent Document 1 describes a circuit connection member that can relieve stress at a connection interface with a connection object by dispersing acrylic rubber in an epoxy resin, thereby improving connection reliability. ing.

On the other hand, in recent years, an anisotropic conductive film is required to have an adhesive composition that cures at a low temperature in a short time in order to shorten the production time. In order to meet this demand, a radical curable adhesive composition containing a radical polymerization initiator such as a (meth) acrylate derivative and a peroxide has attracted attention. The radical curing type circuit connecting material is advantageous in shortening the production time because the curing reaction proceeds in a short time due to radicals rich in reactivity (see Patent Documents 2 and 3).

JP 2009-299079 A JP 2008-291199 A JP 2011-37953 A

However, (meth) acrylate derivatives tend to have a large curing shrinkage during polymerization and a large internal stress after curing compared to epoxy resins and the like. For this reason, generally, when a circuit connection material containing a radical curable adhesive composition is used, bubbles may be generated at the interface between the adhesive layer and a substrate such as an LCD panel, which may reduce connection reliability. is there. In particular, at the interface with the silicon nitride (SiN) film used as the insulating film on the panel wiring in the TFT (Thin Film Transistor) LCD panel, this bubble generation becomes remarkable and the adhesion is poor, resulting in connection. Reliability may be greatly reduced.

By reducing the content of the (meth) acrylate derivative in the circuit connecting material, this bubble generation is suppressed to some extent, but due to a decrease in the cohesive strength of the binder, the repulsion of the conductive particles cannot be suppressed, and the high temperature In the connection reliability test under high humidity, the resistance value between the circuit electrodes may greatly fluctuate.

The present invention has been proposed in view of such a conventional situation, and suppresses fluctuations in the resistance value between circuit electrodes when subjected to a high-temperature and high-humidity treatment, while maintaining an interface with the silicon nitride film. Circuit connection material capable of improving adhesion and exhibiting excellent connection reliability, connection method for connecting a pair of circuit members using this circuit connection material, and connection structure obtained by the connection method The purpose is to provide.

In order to solve the above-described problems, the circuit connection material of the present invention includes (1) a radical polymerizable resin, (2) a radical polymerization initiator that generates free radicals by heat or light, and (3) a side chain. And a reactive acrylic polymer having an ethylenically unsaturated group and having a double bond equivalent of 1000 to 12,000.

Further, in order to solve the above-described problem, the connection structure of the present invention is a circuit in which a circuit connection material is interposed between a pair of circuit members arranged so that circuit electrodes face each other, and face each other. In the connection structure in which the members are electrically and mechanically connected, one of the circuit members has a surface covered with a silicon nitride film, and the circuit connection material includes (1) a radical polymerizable resin, (2) Contains a radical polymerization initiator that generates free radicals by heat or light, and (3) a reactive acrylic polymer having an ethylenically unsaturated group in the side chain and a double bond equivalent of 1000 to 12,000. It is characterized by doing.

Further, in order to solve the above-described problem, the connection method of the present invention includes a circuit connection material interposed between a pair of circuit members arranged so that circuit electrodes face each other, and is subjected to thermal pressurization. In the connection method of electrically and mechanically connecting the circuit members facing each other, one surface of the circuit member is covered with a silicon nitride film, and the circuit connection material includes (1) a radical polymerizable resin and (2) a radical polymerization initiator that generates free radicals by heat or light, and (3) a reactive acrylic polymer having an ethylenically unsaturated group in the side chain and having a double bond equivalent of 1000 to 12000. The circuit connection material contained is used.

According to the present invention, while suppressing fluctuations in the resistance value between circuit electrodes when subjected to a high-temperature and high-humidity treatment, the adhesion with the interface with the silicon nitride film is improved and excellent connection reliability is exhibited. It is possible to provide a circuit connection material that can be used, a connection method for connecting a pair of circuit members using the circuit connection material, and a connection structure obtained by the connection method.

Hereinafter, a specific embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail in the following order with reference to the drawings.
<1. Circuit connection material>
<2. Connection method>
<3. Example>

<1. Circuit connection material>
The circuit connecting material in the present embodiment is interposed between a pair of circuit members arranged so that circuit electrodes face each other, and electrically and mechanically connects the facing circuit members. The circuit connection material in the present embodiment is applied to an anisotropic conductive film formed into a film shape by dispersing a plurality of conductive particles in an insulating adhesive composition.

The insulating adhesive composition includes a (meth) acrylate compound that is a radical polymerizable resin, a radical polymerization initiator that generates free radicals by heat or light, and a reactive acrylic having an ethylenically unsaturated group in the side chain. Contains a polymer and a film-forming resin. Here, (meth) acrylate includes acrylate and methacrylate.

The (meth) acrylate compound forms a cross-linked structure in the insulating adhesive composition when the anisotropic conductive film is heated, thereby curing the adhesive composition.

Examples of the (meth) acrylate compound that is a radical polymerizable resin include polyfunctional (meth) acrylate compounds such as polyfunctional (meth) acrylate monomers, polyfunctional (meth) acrylate oligomers, and polyfunctional (meth) acrylate polymers. it can. As the radical polymerizable resin, this polyfunctional (meth) acrylate compound and a monofunctional (meth) acrylate compound such as a monofunctional (meth) acrylate monomer, a monofunctional (meth) acrylate oligomer, a monofunctional (meth) acrylate polymer, and the like May be used in combination.

Monofunctional (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) ) Acrylate, t-butyl (meth) acrylate, 2-methylbutyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, 2-methylhexyl (meth) Acrylate, 2-ethylhexyl (meth) acrylate, 2-butylhexyl (meth) acrylate, isooctyl (meth) acrylate, isopentyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, cyclohexyl ( Acrylate), benzyl (meth) acrylate, phenoxy (meth) acrylate, n-nonyl (meth) acrylate, n-decyl (meth) acrylate, lauryl (meth) acrylate, hexadecyl (meth) acrylate, stearyl (meth) acrylate, etc. Is mentioned.

Bifunctional (meth) acrylates include bisphenol F-EO-modified di (meth) acrylate, bisphenol A-EO-modified di (meth) acrylate, polypropylene glycol di (meth) acrylate, polyethylene glycol (meth) acrylate, and tricyclodecanedi. Examples include methylol di (meth) acrylate and dicyclopentadiene (meth) acrylate.

Examples of the trifunctional (meth) acrylate include trimethylolpropane tri (meth) acrylate, trimethylolpropane PO-modified (meth) acrylate, and isocyanuric acid EO-modified tri (meth) acrylate.

Examples of tetrafunctional or higher functional (meth) acrylates include dipentaerythritol penta (meth) acrylate, pentaerythritol hexa (meth) acrylate, pentaerythritol tetra (meth) acrylate, and ditrimethylolpropane tetraacrylate. In addition, polyfunctional urethane (meth) acrylates can also be used.

If the blending amount of the (meth) acrylate compound in the insulating adhesive composition is too small, the adhesive strength decreases, and if it is too large, the film strength decreases and it becomes difficult to maintain the film shape. It is 50% by mass, more preferably 3 to 30% by mass.

As the reactive acrylic polymer, one having an ethylenically unsaturated group (—CH═CH 2) in the side chain is used. Examples of such a reactive acrylic polymer include a reactive acrylic rubber having an ethylenically unsaturated group in the side chain. The amount of ethylenically unsaturated groups in the reactive acrylic polymer is indicated by the double bond equivalent. The double bond equivalent is defined by [molecular weight of repeating structural unit (monomer) of reactive acrylic polymer] / [number of double bonds in repeating structural unit (monomer) of reactive acrylic polymer]. This double bond equivalent is a measure of the amount of double bonds contained in the molecule. For the same molecular weight, the amount of double bonds introduced increases as the value of the double bond equivalent decreases.

The double bond equivalent of the reactive acrylic polymer is preferably 1000 to 12000 for the following reasons.

When the double bond equivalent is small, that is, when the number of double bonds in the reactive acrylic polymer is large, the shrinkage of the reactive acrylic polymer during curing increases, and the internal stress after curing also increases. For this reason, the adhesiveness (adhesiveness) with respect to the silicon nitride of the insulating adhesive composition is lowered.

On the other hand, when the double bond equivalent is large, that is, when the number of reactive acrylic polymer double bonds is small, the curing shrinkage of the reactive acrylic polymer during polymerization is small, and the internal stress after curing is also small. For this reason, the adhesiveness with respect to silicon nitride of an insulating adhesive composition improves. However, when the reactive acrylic polymer does not have a double bond, or when the number of double bonds in one molecule of the reactive acrylic polymer is too small, the binding property between the reactive acrylic polymer and the radical polymerizable resin decreases. The insulating adhesive composition expands. For this reason, the adhesive composition cannot be completely removed between the opposing electrodes, and the conduction resistance value becomes high.

By connecting the circuit members using an anisotropic conductive film having a reactive acrylic polymer double bond equivalent of 1000 to 12000, the insulation resistance is maintained while maintaining a low conduction resistance value between the opposing electrodes. High adhesiveness can be obtained with respect to silicon nitride of the adhesive composition.

The glass transition temperature (Tg) of the reactive acrylic polymer is preferably −10 ° C. or lower. If Tg exceeds -10 ° C, the adhesion may be reduced.

The polymerization average molecular weight (Mw) of the reactive acrylic polymer is preferably 30,000 to 150,000. When Mw is less than 30000, it becomes impossible to ensure the adhesive strength by the polymer. When Mw exceeds 150,000, the rubber resistance increases and the heat resistance decreases, and the conduction resistance value increases.

The compounding amount of the reactive acrylic polymer in the insulating adhesive composition is preferably 10 to 30% by mass. Adhesiveness falls that it is less than 10 mass%. When it exceeds 30% by mass, the rubber property is increased, so that the cured product is inferior in heat resistance, and the conduction resistance value is increased.

Reactive acrylic rubber which is a kind of reactive acrylic polymer can be produced by, for example, synthesis by the following method. In a reaction vessel, a (meth) acrylic acid ester monomer having a predetermined mass ratio, glycidyl methacrylate, and water are added and mixed. The mixture is agitated to fully replace the nitrogen. Next, peroxide is added as an initiator to the mixture to initiate the polymerization reaction. Next, (meth) acrylic acid is reacted with the polymer having a glycidyl group in the side chain to produce a reactive acrylic rubber having a double bond.

In this production method, the double bond equivalent of the reactive acrylic rubber, which is a reactive acrylic polymer, can be controlled by the blending amount of glycidyl methacrylate and, as described above, [reactive structural unit (monomer) of the reactive acrylic polymer] Molecular weight] / [number of double bonds in the repeating structural unit (monomer) of the reactive acrylic polymer].

Thus, by containing a reactive acrylic polymer having an ethylenically unsaturated group in the side chain and a double bond equivalent of 1000 to 12000, resistance between circuit electrodes when subjected to high temperature and high humidity treatment While suppressing the fluctuation of the value, it is possible to improve the adhesion with the interface with the silicon nitride film and exhibit excellent connection reliability.

The radical polymerization initiator is a curing agent that decomposes by heat or light to generate free radicals, and a known radical polymerization initiator can be selected. For example, peroxide polymerization initiators such as diacyl peroxide, peroxydicarbonate, peroxyester, peroxyketal, dialkyl peroxide, hydroperoxide, azo polymerization initiator such as azobisbutyronitrile, redox System polymerization initiators and the like.

If the blending amount of the radical polymerization initiator in the insulating adhesive composition is too small, the curing becomes insufficient, and if it is too large, the cohesive force of the anisotropic conductive film decreases, and therefore the (meth) acrylate compound 100 mass. The amount is preferably 1 to 10 parts by mass, more preferably 3 to 7 parts by mass with respect to parts.

As the film forming resin, for example, a thermoplastic elastomer such as epoxy resin, polyester resin, polyurethane resin, phenoxy resin, polyamide, EVA, or the like can be used. Among them, for heat resistance and adhesiveness, polyester resins, polyurethane resins, phenoxy resins, particularly phenoxy resins such as bis A type epoxy resins and phenoxy resins having a fluorene skeleton can be mentioned.

If the amount of the film-forming resin is too small, a film is not formed. If the amount is too large, the resin exclusion property for obtaining electrical connection tends to be low, so the resin solid content (consisting of a polymerizable acrylic compound and a film-forming resin). Adhesive composition) It is 80 to 30 parts by mass, more preferably 70 to 40 parts by mass with respect to 100 parts by mass.

As the conductive particles, the conductive particles used in conventional anisotropic conductive films can be used. For example, metal particles such as gold particles, silver particles, and nickel particles, benzoguanamine resins, styrene resins, etc. Examples thereof include metal-coated resin particles whose surfaces are coated with a metal such as gold, nickel, and zinc. The average particle diameter of the conductive particles is preferably 1 to 20 μm, more preferably 2 to 10 μm, from the viewpoint of connection reliability.

The average particle density of the conductive particles in the insulating adhesive composition is preferably 500 to 50000 / mm ² , more preferably 1000 to 30000 / mm ² from the viewpoint of connection reliability and insulation reliability. .

Insulating adhesive composition can contain phosphate acrylate in order to improve adhesion to metal.

In addition, the insulating adhesive composition includes other additive compositions such as dilution monomers such as various acrylic monomers, fillers, softeners, colorants, flame retardants, thixotropic agents, silane coupling agents. Further, silica fine particles and the like can be contained.

By including a silane coupling agent, adhesion at the interface between the organic material and the inorganic material is improved. By including silica fine particles, the storage elastic modulus, the linear expansion coefficient, etc. can be adjusted to improve the connection reliability.

The anisotropic conductive film of the present embodiment includes a (meth) acrylate compound that is a radical polymerizable resin, a radical polymerization initiator, a reactive acrylic polymer having an ethylenically unsaturated group in the side chain, and a film-forming resin. The conductive particles are uniformly dispersed and mixed by a known dispersion method into the insulating adhesive composition containing the above, and the resulting mixture is applied to a release film such as a silicone release-treated polyester film using a known coating method such as a bar coater. Thus, it can be manufactured by applying to a dry thickness of 10 to 50 μm and putting it in a thermostat at 50 to 90 ° C. and drying. When an insulating adhesive film is laminated on this anisotropic conductive film, it can be obtained by applying an insulating adhesive composition on the anisotropic conductive film and drying it.

As the release film, for example, PET (PolyPoEthylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methlpentene-1), PTFE (Polytetrafluoroethylene), etc. are coated with a release agent such as silicone. While preventing the conductive conductive film from drying, the shape of the anisotropic conductive film is maintained.

According to the anisotropic conductive film of the present embodiment, high-temperature and high-humidity treatment is achieved by containing a reactive acrylic polymer having an ethylenically unsaturated group in the side chain and a double bond equivalent of 1000 to 12000. It is possible to improve the adhesion with the interface with the silicon nitride film and to exhibit excellent connection reliability while suppressing fluctuations in the resistance value between the circuit electrodes when receiving.
<2. Connection method>

Provided is a connection method in which a glass substrate constituting an LCD (Liquid Crystal Display) panel and a COF (Chip On Film) as a wiring material are crimped and connected via the anisotropic conductive film of the present embodiment. Wiring electrodes are formed on the glass substrate at a fine pitch. Further, terminal electrodes are formed on the COF according to the wiring pattern of the wiring electrodes. And by this connection method, the connection structure is obtained by anisotropically connecting the wiring electrode of the glass substrate and the terminal electrode of the COF.

Hereinafter, a connection method in which the glass substrate and the COF are crimped and connected via an anisotropic conductive film will be specifically described. First, a surface on which a wiring electrode on a glass substrate is formed and an anisotropic conductive film are temporarily attached to the glass substrate (temporary attaching step). In this temporary bonding, the pressure surface of the head part heated to a low temperature of the pressure bonder is lightly pressed against the upper surface of the conductive particle-containing layer and pressed at a low pressure. The heating temperature is a low temperature (for example, a predetermined value of 60 to 80 ° C.) such that the insulating adhesive composition flows but does not cure. Further, the pressure applied in the temporary sticking step is a predetermined value of 0.5 MPa to 2 MPa, for example. In addition, the heat pressurizing time in the temporary sticking step is, for example, a predetermined time of 1 to 3 seconds (sec).

After temporarily sticking the anisotropic conductive film in the temporary sticking step, check the alignment state of the anisotropic conductive film, and if there is a problem such as misalignment, after this temporary sticking step, anisotropic The repair process which peels a conductive conductive film and temporarily sticks an anisotropic conductive film in a correct position again is performed (repair process).

Next, the COF is placed on the anisotropic conductive film so that the bump and the wiring electrode are opposed to each other (placement step).

Then, the pressure surface (not shown) of the heated head part of the pressure bonder is pressed against the upper surface of the COF, and the glass substrate and the COF are connected by pressure bonding (connection process).

The pressurizing pressure in the connecting step is a predetermined value of 1 MPa to 5 MPa, for example. The heating temperature in the connecting step is a temperature (for example, a predetermined value of 160 to 210 ° C.) at which the insulating particles are melted and the insulating adhesive composition is cured. Further, the heat pressurizing time in the connecting step is a predetermined time of 3 to 10 seconds, for example.

In this way, the conductive particles are sandwiched between the wiring electrodes and the bumps, and the adhesive composition is cured. Thereby, a glass substrate and COF are electrically and mechanically connected. Then, a connection structure in which the glass substrate and the COF are anisotropically conductively connected is obtained. As described above, the obtained connection structure can exhibit excellent connection reliability and conduction reliability while maintaining good insulation reliability.

As mentioned above, although this Embodiment was demonstrated, it cannot be overemphasized that this invention is not what is limited to the above-mentioned embodiment, A various change is possible in the range which does not deviate from the summary of this invention.

In the above embodiment, an anisotropic conductive film is used as the anisotropic conductive adhesive member. However, the structure of the anisotropic conductive adhesive member is not limited to this, and may be, for example, a two-layer anisotropic conductive film in which an insulating adhesive layer is further laminated. In addition, for example, a conductive adhesive paste in which conductive particles are contained in an insulating adhesive composition, and an insulating adhesive paste made of an insulating adhesive composition, these are applied in layers. By doing so, it is good also as two adhesive layers.

In the above-described embodiment, the case where a glass substrate constituting an LCD (Liquid Crystal Display) panel is used as the glass substrate has been described. However, the glass substrate is not limited to this, for example, a PDP substrate (PDP panel) ), A glass substrate constituting an organic EL substrate (organic EL panel) or the like.

In the above-described embodiment, the case where a glass substrate is used as the substrate has been described. However, other substrates such as a rigid substrate and a flexible substrate may be used. In the above-described embodiment, the case where COF is used as an electronic component has been described. However, other electronic components such as an IC chip and TAB may be used.

Further, in the above-described embodiment, the case where the present invention is applied to FOG (Film On Glass) has been described. However, the present invention is applied to other mounting methods such as COG (Chip On Glass) and FOB (Film On Board) It can also be applied to.

Hereinafter, specific examples of the present invention will be described based on experimental results.

<Example 1>
As a film-forming resin, a polyester urethane resin (trade name: UR8200, manufactured by Toyobo Co., Ltd., dissolved in 20% by mass in a mixed solvent of methyl ethyl ketone / toluene = 50: 50) is 40 parts by mass in terms of solid content, side As a reactive acrylic polymer having an ethylenically unsaturated group in the chain, a reactive property having an ethylenically unsaturated group in the side chain having a double bond equivalent of 12000, Tg of −40 ° C., and a polymerization average molecular weight (Mw) of 100,000. 20 parts by mass of acrylic rubber, 34 parts by mass of radical polymerizable resin (trade name: EB-600, manufactured by Daicel Cytec Co., Ltd.), silane coupling agent (trade name: KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) 1 1 part by mass of a phosphoric acid acrylate (trade name: P-1M, manufactured by Kyoei Chemical Co., Ltd.), a radical polymerization initiator (trade name: Parge) Sa C, manufactured by NOF CORPORATION) in the adhesive composition of the insulating containing 4 parts by weight, the conductive particles (trade name: AUL704, manufactured by Sekisui Chemical Co., Ltd.) and the particle density 10000 / mm ² Then, the conductive particle-containing composition was applied onto a release film with a bar coater and dried to prepare a circuit connection material having a thickness of 15 μm.

Here, the reactive acrylic polymer was synthesized and produced by the following synthesis method. A total of 50 parts by mass of glycidyl methacrylate and (meth) acrylic acid ester monomer and 600 parts by mass of water were added and mixed in the reaction vessel. The mixture was agitated to fully replace the nitrogen. Next, 0.5 parts by mass of peroxide as an initiator was added to this mixture to initiate the polymerization reaction. Next, a reactive acrylic polymer (reactive acrylic rubber) having a double bond was produced by reacting a polymer having a glycidyl group in the side chain with (meth) acrylic acid.

Here, a reactive acrylic polymer having a double bond equivalent of 12000 was produced by controlling the blending amount of glycidyl methacrylate.

Next, a process of connecting the glass substrate and COF (50 μm P, Cu 8 μmt-Sn plating, 38 μmt-S′perflex base material) through the produced anisotropic conductive film was performed. Here, as a glass substrate, an IZO coated glass substrate (all surface IZO coating, glass thickness 0.7 mm) is used for subsequent conduction resistance measurement, and an SiN coated glass substrate (all surface SiN coating) is used for connection strength measurement. It was. First, an anisotropic conductive film was slit to a width of 1.5 mm on the surface of the glass substrate on which the wiring electrodes were formed, and temporarily pasted on the glass substrate (temporary pasting step). In this temporary attachment, the pressure surface of the head part heated to a low temperature of the pressure bonder was lightly pressed against the upper surface of the conductive particle-containing layer and pressed at a low pressure. The heating temperature was set to 70 ° C., which is a low temperature such that the insulating particles do not dissolve and the insulating adhesive composition flows but does not cure. Moreover, the pressurization pressure in the temporary sticking process was 1 MPa. Moreover, the heat-pressing time in the temporary sticking process was 2 seconds.

Next, the COF was disposed on the anisotropic conductive film so that the terminal electrode of the COF and the wiring electrode of the glass substrate were opposed to each other (arrangement step).

Then, the pressure surface (1.5 mm width) of the heated head part of the pressure bonder was pressed against the upper surface of the COF through a buffer material (100 μmt Teflon (registered trademark)) to press-connect the glass substrate and the COF. (Connection process).

The pressurizing pressure in the connection process was 4 MPa. The heating temperature in the connection process was 190 ° C. Further, the heat pressurizing time in the connecting step was 5 seconds.

Thus, conductive particles were sandwiched between the wiring electrodes and the bumps, the adhesive composition was cured, and the glass substrate and the COF were electrically and mechanically connected to obtain a connection structure.

<Example 2>
A circuit connection material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was 10,000, and a connection structure was obtained by the same treatment as in Example 1.

<Example 3>
A circuit connection material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was set to 5000, and a connection structure was obtained by the same treatment as in Example 1.

<Example 4>
A circuit connection material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was 1000, and a connection structure was obtained by the same treatment as in Example 1.

<Example 5>
A circuit connection material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was 5000 and Tg was −30 ° C., and the connection structure was obtained by the same treatment as in Example 1. Got the body.

<Example 6>
A circuit connecting material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was 5000 and Tg was −20 ° C., and the connection structure was obtained by the same treatment as in Example 1. Got the body.

<Example 7>
A circuit connection material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was 5000 and Tg was −10 ° C., and the connection structure was obtained by the same treatment as in Example 1. Got the body.

<Example 8>
A circuit connection material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was 5000 and Tg was 0 ° C., and the connection structure was obtained by the same treatment as in Example 1. Got.

<Example 9>
A circuit connection material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was 5000 and Mw was 10,000, and the connection structure was obtained by the same treatment as in Example 1. Got.

<Example 10>
A circuit connection material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was 5000 and Mw was 30,000, and the connection structure was obtained by the same treatment as in Example 1. Got.

<Example 11>
A circuit connection material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was 5000 and Mw was 50,000, and the connection structure was obtained by the same treatment as in Example 1. Got.

<Example 12>
A circuit connection material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was 5000 and Mw was 150,000, and the connection structure was obtained by the same treatment as in Example 1. Got.

<Example 13>
A circuit connection material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was 5000 and Mw was 200,000. Got.

<Example 14>
The double bond equivalent of the reactive acrylic rubber is 5000, the amount of the reactive acrylic rubber is 5 parts by mass (5% by mass), and the amount of the radical polymerizable resin is 49 parts by mass (49% by mass). Except for the above, a circuit connection material was produced under the same conditions as in Example 1, and a connection structure was obtained by the same treatment as in Example 1.

<Example 15>
The double bond equivalent of the reactive acrylic polymer is 5000, the amount of the reactive acrylic rubber is 10 parts by mass (10% by mass), and the amount of the radical polymerizable resin is 44 parts by mass (44% by mass). Except for the above, a circuit connection material was produced under the same conditions as in Example 1, and a connection structure was obtained by the same treatment as in Example 1.

<Example 16>
The double bond equivalent of the reactive acrylic polymer is 5000, the amount of the reactive acrylic rubber is 30 parts by mass (30% by mass), and the amount of the radical polymerizable resin is 24 parts by mass (24% by mass). Except for the above, a circuit connection material was produced under the same conditions as in Example 1, and a connection structure was obtained by the same treatment as in Example 1.

<Example 17>
The double bond equivalent of the reactive acrylic polymer is 5000, the amount of the reactive acrylic rubber is 35 parts by mass (35% by mass), and the amount of the radical polymerizable resin is 19 parts by mass (19% by mass). Except for the above, a circuit connection material was produced under the same conditions as in Example 1, and a connection structure was obtained by the same treatment as in Example 1.

<Comparative Example 1>
As a film-forming resin, a polyester urethane resin (trade name: UR8200, manufactured by Toyobo Co., Ltd., dissolved in 20% by mass in a mixed solvent of methyl ethyl ketone / toluene = 50: 50), 60 parts by mass in terms of solid content, radical 34 parts by mass of a polymerizable resin (trade name: KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.), 1 part by mass of a silane coupling agent (trade name: KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.), phosphoric acid acrylate (trade name: Conductive particles (trade name: P-1M, manufactured by Kyoei Chemical Co., Ltd.) in an adhesive composed of 1 part by weight and 4 parts by weight of a radical polymerization initiator (trade name: Perhexa C, manufactured by NOF Corporation). AUL704, to prepare a circuit-connecting material of a thickness 15μm dispersed so that the Sekisui Chemical Co., Ltd.) in particle density 10000 / mm ^2, example 1 By the same treatment to obtain a connection structure. Thus, in Comparative Example 1, no reactive acrylic polymer was contained.

<Comparative example 2>
The reactive acrylic polymer was the same as in Example 1 except that 20 parts by mass of a reactive acrylic rubber having no double bond, Tg of −40 ° C., and a polymerization average molecular weight (Mw) of 100,000 was contained. A circuit connection material was produced according to the conditions, and a connection structure was obtained by the same processing as in Example 1.

<Comparative Example 3>
A circuit connection material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was 15000, and a connection structure was obtained by the same treatment as in Example 1.

<Comparative Example 4>
A circuit connection material was produced under the same conditions as in Example 1 except that the double bond equivalent of the reactive acrylic polymer was 500, and a connection structure was obtained by the same treatment as in Example 1.

[Measurement of conduction resistance]
For the connection structures manufactured in Examples 1 to 17 and Comparative Examples 1 to 4, the initial conduction resistance and the conduction after a TH test (Thermal Humidity Test) at a temperature of 85 ° C. and a humidity of 85% RH for 500 hours. Resistance was measured. The measurement was performed using a digital multimeter (digital multimeter 7555, manufactured by Yokogawa Electric Corporation) to measure the connection resistance when a current of 1 mA was passed by the four-terminal method.

[Measurement of connection strength]
For the initial connection structures of Examples 1 to 17 and Comparative Examples 1 to 4, using a tensile tester (Tensilon, manufactured by Orientec Co., Ltd.) at 90 ° (Y-axis direction) at a peeling speed of 50 mm / min. The adhesive strength (N / cm) was measured. Further, the adhesive strength was measured in the same manner for the connection structures after the TH test (Thermal Humidity Test) in Examples 1 to 17 and Comparative Examples 1 to 4 at a temperature of 85 ° C., a humidity of 85% RH, and 500 hours.

[Table 1] summarizes the measurement results of the conditions, conduction resistance values, and connection strengths of Examples 1 to 17 and Comparative Examples 1 to 4.

In Examples 1 to 17, because the reactive acrylic rubber having an ethylenically unsaturated group in the side chain has a double bond equivalent of 1000 to 12000, the shrinkage at the time of polymerization of the reactive acrylic rubber and after curing It is considered that the internal stress is improved and the adhesiveness of the anisotropic conductive film to the silicon nitride film is increased. At the same time, the bonding resistance by the double bond between the reactive acrylic rubber and the radical polymerizable resin is also good, so that the insulating adhesive composition of the anisotropic conductive film does not expand, and the conduction resistance value is good. It is thought that it becomes.

On the other hand, in Comparative Example 1, since the reactive acrylic polymer having an ethylenically unsaturated group in the side chain is not contained, it is considered that the adhesion of the anisotropic conductive film to the silicon nitride film is lowered.

Moreover, in Comparative Example 2, since the reactive acrylic polymer having no double bond was contained, the binding property between the reactive acrylic rubber and the radical polymerizable resin was poor, and the insulating adhesion of the anisotropic conductive film was poor. It is considered that the agent composition expands, and as a result, the conduction resistance value increases.

In Comparative Example 3, since the double bond equivalent of the reactive acrylic rubber having an ethylenically unsaturated group in the side chain is 15000, the bondability between the reactive acrylic polymer and the radical polymerizable resin is reduced. It is considered that the insulating adhesive composition expands, and therefore the adhesive composition cannot be completely excluded between the opposing electrodes, and as a result, the conduction resistance value is increased.

In Comparative Example 4, since the double bond equivalent of the reactive acrylic rubber having an ethylenically unsaturated group in the side chain is 500, the curing shrinkage of the reactive acrylic polymer during polymerization is large, and the internal content after curing is large. Since the stress also increases, it is considered that the adhesion of the anisotropic conductive film to the silicon nitride film decreases.

Claims

(1) a radical polymerizable resin;
(2) a radical polymerization initiator that generates free radicals by heat or light;
(3) A circuit connecting material comprising: a reactive acrylic polymer having an ethylenically unsaturated group in a side chain and having a double bond equivalent of 1000 to 12000.
The circuit connecting material according to claim 1, wherein the reactive acrylic polymer has a glass transition temperature (Tg) of -10 ° C or lower.
3. The circuit connecting material according to claim 1, wherein the reactive acrylic polymer has a weight average molecular weight (Mw) of 30,000 to 150,000.
The circuit connection material according to any one of claims 1 to 3, wherein a compounding amount of the reactive acrylic polymer in the adhesive composition contained in the circuit connection material is 10 to 30% by mass.
In a connection structure in which a circuit connecting material is interposed between a pair of circuit members arranged so that circuit electrodes face each other, and the facing circuit members are electrically and mechanically connected.
One of the circuit members has a surface covered with a silicon nitride film,
The circuit connecting material is
(1) a radical polymerizable resin;
(2) a radical polymerization initiator that generates free radicals by heat or light;
(3) A connection structure comprising a reactive acrylic polymer having an ethylenically unsaturated group in a side chain and a double bond equivalent of 1000 to 12000.
In a connection method in which a circuit connection material is interposed between a pair of circuit members arranged so that circuit electrodes face each other, and the circuit members facing each other are electrically and mechanically connected by heat and pressure,
One of the circuit members has a surface covered with a silicon nitride film,
As the circuit connection material,
(1) a radical polymerizable resin;
(2) a radical polymerization initiator that generates free radicals by heat or light;
(3) A connection method using a circuit connection material containing a reactive acrylic polymer having an ethylenically unsaturated group in a side chain and a double bond equivalent of 1000 to 12000.