JP6474620B2 - Anisotropic conductive film and connection method - Google Patents

Description

  The present invention relates to an anisotropic conductive film and a connection method.

  Conventionally, as a means for connecting an electronic component to a substrate, a tape-like connection material in which a thermosetting resin in which conductive particles are dispersed is applied to a release film (for example, anisotropic conductive film (ACF)) ) Is used.

  This anisotropic conductive film is used, for example, for connection (FOB: Flex on Board) between a COF (Chip on Film) and a rigid substrate (for example, PWB (Printed Wiring Board)).

In order to improve the solderability of components such as an IC chip and a capacitor to be mounted on the rigid substrate, a rust prevention treatment using a rust preventive agent called a preflux (OSP: Organic Solderability Preservative) may be performed. is there. As the preflux, for example, imidazole preflux is known.
However, the substrate subjected to the rust prevention treatment has a problem that the adhesiveness of the anisotropic conductive film is lowered.

Therefore, in order to give stable connection reliability to the connection of the substrate subjected to the rust prevention treatment, it contains a curing agent that generates free radicals, a radical polymerizable substance, a phosphate ester, and conductive particles. When the entire circuit connecting material excluding particles is 100 parts by weight, a circuit connecting material is proposed in which the proportion of the phosphate ester is 0.5 to 2.5 parts by weight (for example, , See Patent Document 1).
However, although the proposed technique has excellent insulation between adjacent terminals, it cannot be said that long-term conductivity between connection terminals is sufficient.

JP 2009-277769 A

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention provides an anisotropic conductive film excellent in insulation between adjacent terminals and long-term conductivity between connection terminals even when connecting rust-proof substrates, and bonding using the same. The purpose is to provide a body.

Means for solving the problems are as follows. That is,
<1> a conductive particle-containing layer containing conductive particles, a thermosetting resin, and a curing agent;
A thermoplastic layer containing an acid component;
It is an anisotropic conductive film characterized by having.
<2> The anisotropic conductive film according to <1>, wherein the acid component is a phosphate ester compound.
<3> The anisotropic conductive film according to any one of <1> to <2>, wherein a melt viscosity of the conductive particle-containing layer is larger than a melt viscosity of the thermoplastic layer.
<4> A connection method for connecting the terminal of the first circuit member and the terminal of the second circuit member,
The anisotropic conductive film according to any one of <1> to <3> is disposed on the terminal of the first circuit member so that the thermoplastic layer is in contact with the terminal of the first circuit member. A first placement step to
A second arrangement step of arranging the second circuit member on the anisotropic conductive film;
Heating and pressing the second circuit member with a heating pressing member,
In the connection method, the terminal of the first circuit member is subjected to a rust prevention treatment with a rust inhibitor.

  According to the present invention, the conventional problems can be solved, the object can be achieved, and even when connecting a rust-proof substrate, insulation between adjacent terminals, and between connection terminals An anisotropic conductive film excellent in long-term conductivity and a joined body using the same can be provided.

FIG. 1A is a schematic cross-sectional view for explaining an example of a connection method of the present invention (part 1). FIG. 1B is a schematic cross-sectional view for explaining an example of the connection method of the present invention (part 2). FIG. 1C is a schematic cross-sectional view for explaining an example of the connection method of the present invention (part 3). FIG. 1D is a schematic cross-sectional view for explaining an example of the connection method of the present invention (part 4). FIG. 1E is a schematic cross-sectional view for explaining an example of the connection method of the present invention (No. 5).

(Anisotropic conductive film)
The anisotropic conductive film of the present invention contains at least a conductive particle-containing layer and a thermoplastic layer, and further contains other components as necessary.

<Conductive particle-containing layer>
The conductive particle-containing layer contains at least conductive particles, a thermosetting resin, and a curing agent, and further contains other components as necessary.

<< Conductive particles >>
There is no restriction | limiting in particular as said electroconductive particle, According to the objective, it can select suitably, For example, a metal particle, a metal covering resin particle, etc. are mentioned.

There is no restriction | limiting in particular as said metal particle, According to the objective, it can select suitably, For example, nickel, cobalt, silver, copper, gold | metal | money, palladium, solder etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
Among these, nickel, silver, and copper are preferable. These metal particles may be provided with gold or palladium on the surface for the purpose of preventing surface oxidation. Furthermore, you may use what gave the insulating film with the metal protrusion and organic substance on the surface.

The metal-coated resin particles are not particularly limited as long as the surfaces of the resin particles are coated with metal, and can be appropriately selected according to the purpose. For example, the surface of the resin particles is nickel, silver, solder , Particles coated with at least one of copper, gold, and palladium. Furthermore, you may use what gave the insulating film with the metal protrusion and organic substance on the surface. In the case of connection considering low resistance, particles in which the surface of resin particles is coated with silver are preferable.
There is no restriction | limiting in particular as the coating method of the metal to the said resin particle, According to the objective, it can select suitably, For example, an electroless-plating method, sputtering method, etc. are mentioned.
There is no restriction | limiting in particular as a material of the said resin particle, According to the objective, it can select suitably, For example, a styrene- divinylbenzene copolymer, a benzoguanamine resin, a crosslinked polystyrene resin, an acrylic resin, a styrene-silica composite resin etc. Is mentioned.

  The conductive particles only need to have conductivity in anisotropic conductive connection. For example, even if the surface of the metal particle is an insulating film, the conductive particle may be used as long as the particle is deformed during the anisotropic conductive connection and the metal particle is exposed.

There is no restriction | limiting in particular as an average particle diameter of the said electroconductive particle, Although it can select suitably according to the objective, 1 micrometer-50 micrometers are preferable, 2 micrometers-25 micrometers are more preferable, and 2 micrometers-10 micrometers are especially preferable.
The average particle diameter is an average value of particle diameters measured for 10 conductive particles arbitrarily.
The particle diameter can be measured, for example, by observation with a scanning electron microscope.

  There is no restriction | limiting in particular as content of the said electroconductive particle in the said electroconductive particle content layer, Although it can select suitably according to the objective, 0.5 mass%-10 mass% are preferable, and 1 mass%- 5 mass% is more preferable.

<< Thermosetting resin >>
There is no restriction | limiting in particular as said thermosetting resin, According to the objective, it can select suitably, For example, an epoxy resin, a polymeric acrylic compound, etc. are mentioned.

-Epoxy resin-
There is no restriction | limiting in particular as said epoxy resin, According to the objective, it can select suitably, For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin, those modified epoxy resins, alicyclic type An epoxy resin etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.

-Polymerizable acrylic compound-
There is no restriction | limiting in particular as said polymeric acrylic compound, According to the objective, it can select suitably, For example, polyethyleneglycol diacrylate, phosphate ester type acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4 -Hydroxybutyl acrylate, isobutyl acrylate, t-butyl acrylate, isooctyl acrylate, bisphenoxyethanol full orange acrylate, 2-acryloyloxyethyl succinic acid, lauryl acrylate, stearyl acrylate, isobornyl acrylate, tricyclodecane dimethanol dimethacrylate , Cyclohexyl acrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, tetrahydrofurfuryl acrylate DOO, o- phthalic acid diglycidyl ether acrylate, ethoxylated bisphenol A dimethacrylate, bisphenol A type epoxy acrylate, urethane acrylate, epoxy acrylate, and can be exemplified methacrylate corresponding thereto. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular as content of the said thermosetting resin in the said electroconductive particle content layer, Although it can select suitably according to the objective, 20 mass%-60 mass% are preferable, and 30 mass%-50 mass. The mass% is more preferable.

<< Curing agent >>
There is no restriction | limiting in particular as said hardening | curing agent, According to the objective, it can select suitably, For example, imidazoles, an organic peroxide, an anionic hardening | curing agent, a cationic hardening | curing agent etc. are mentioned.

Examples of the imidazoles include 2-ethyl 4-methylimidazole.
Examples of the organic peroxide include lauroyl peroxide, butyl peroxide, benzyl peroxide, dilauroyl peroxide, dibutyl peroxide, peroxydicarbonate, and benzoyl peroxide.
Examples of the anionic curing agent include organic amines.
Examples of the cationic curing agent include a sulfonium salt, an onium salt, and an aluminum chelating agent.
Among these, an organic peroxide is preferable and dilauroyl peroxide is more preferable in terms of excellent storage stability.

  The combination of the thermosetting resin and the curing agent is not particularly limited and may be appropriately selected according to the purpose. The combination of the epoxy resin and the cationic curing agent, the polymerizable acrylic compound And a combination of said organic peroxides.

  There is no restriction | limiting in particular as content of the said hardening | curing agent in the said electroconductive particle content layer, Although it can select suitably according to the objective, 1 mass%-15 mass% are preferable, and 2 mass%-10 mass% are preferable. Is more preferable.

<< Other ingredients >>
As said other component which the said electroconductive particle content layer contains, film forming resin, a filler, etc. are mentioned, for example.

-Film forming resin-
There is no restriction | limiting in particular as said film formation resin, According to the objective, it can select suitably, For example, phenoxy resin, unsaturated polyester resin, saturated polyester resin, urethane resin, butadiene resin, polyimide resin, polyamide resin, polyolefin Resin etc. are mentioned. The film forming resin may be used alone or in combination of two or more. Among these, phenoxy resin is preferable from the viewpoint of film forming property, processability, and connection reliability.
Examples of the phenoxy resin include a resin synthesized from bisphenol A and epichlorohydrin.
As the phenoxy resin, an appropriately synthesized product or a commercially available product may be used.

  There is no restriction | limiting in particular as content of the said film formation resin in the said electroconductive particle content layer, Although it can select suitably according to the objective, 20 mass%-60 mass% are preferable, 30 mass%-50 mass% % Is more preferable.

-Filler-
The filler is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include alumina, silica, talc, mica, kaolin, zeolite, barium sulfate, and calcium carbonate.

  There is no restriction | limiting in particular as content of the said filler in the said electroconductive particle content layer, Although it can select suitably according to the objective, 0.5 mass%-15 mass% are preferable, and 1 mass%-10 mass. % Is more preferable.

  The conductive particle-containing layer preferably does not contain an acid component. Examples of the acid component include the acid components described below.

There is no restriction | limiting in particular as average thickness of the said electroconductive particle content layer, Although it can select suitably, 10 micrometers-50 micrometers are preferable, and 20 micrometers-40 micrometers are more preferable.
Here, the said average thickness is an average value at the time of measuring the thickness of five places of the said electroconductive particle content layer arbitrarily.

<Thermoplastic layer>
The thermoplastic layer contains at least an acid component, and further contains other components as necessary.
The thermoplastic layer is a layer that exhibits plasticity by heat.
The thermoplastic layer may contain a compound having a reactive functional group such as an epoxy resin or a polymerizable acrylic compound, but in that case, it does not contain a curing agent for curing them.

<< acid component >>
The acid component is not particularly limited as long as it is an acidic component, and can be appropriately selected according to the purpose. Examples of the acidic group in the acid component include a phosphate group, a carboxyl group, and a sulfone group. Examples of the compound having an acidic group include (meth) acrylate having an acidic group.
The acid component may be rosin (abietic acid). The rosin generates an acid by melting.
Among these, a phosphoric acid ester compound is preferable in terms of strong acidity and easy removal of the rust inhibitor. Examples of the phosphate ester compound include phosphate ester acrylates.

  There is no restriction | limiting in particular as content of the said acid component in the said thermoplastic layer, Although it can select suitably according to the objective, 1 mass%-10 mass% are preferable, and 2 mass%-6 mass% are more. preferable. When the content is less than 1% by mass, the removal of the rust inhibitor may be insufficient. When the content exceeds 10% by mass, it is difficult to balance the blending with the other components of the thermoplastic layer. May be.

<< Other ingredients >>
Examples of the other components in the thermoplastic layer include a film-forming resin and other resins.

-Film forming resin-
There is no restriction | limiting in particular as said film formation resin, According to the objective, it can select suitably, For example, the said film formation resin etc. which were illustrated in description of the said electroconductive particle content layer are mentioned. The preferred embodiment is also the same.

  There is no restriction | limiting in particular as content of the said film formation resin in the said thermoplastic layer, Although it can select suitably according to the objective, 0 mass%-20 mass% are preferable, 0 mass%-10 mass% are More preferred.

-Other resins-
The other resin is not particularly limited as long as it is a resin other than the film-forming resin, and can be appropriately selected according to the purpose. Examples thereof include an epoxy resin and a polymerizable acrylic compound. Since these are components generally used in anisotropic conductive films, they can also be used as the material for the thermoplastic layer in the anisotropic conductive film of the present invention. However, when the thermoplastic layer contains a compound having these reactive functional groups, the thermoplastic layer usually does not contain a curing agent for curing them.

  There is no restriction | limiting in particular as content of the said other resin in the said thermoplastic layer, Although it can select suitably according to the objective, 60 mass%-99 mass are preferable, and 80 mass%-97 mass% are more. preferable.

There is no restriction | limiting in particular as average thickness of the said thermoplastic layer, Although it can select suitably, 1 micrometer-10 micrometers are preferable, and 2 micrometers-7 micrometers are more preferable. When the average thickness is within the more preferable range, it is advantageous in that the fluidity can be easily controlled and it is difficult to remain in the connection portion after the pressure bonding.
Here, the said average thickness is an average value at the time of measuring the thickness of five places of the said thermoplastic layer arbitrarily.

The melt viscosity of the conductive particle-containing layer is preferably larger than the melt viscosity of the thermoplastic layer in that the thermoplastic layer is easily excluded from between connection terminals. As the ratio of the melt viscosity, the melt viscosity of the conductive particle-containing layer is preferably at least 10 times the melt viscosity of the thermoplastic layer, in that the thermoplastic layer is more easily excluded from between connection terminals. It is more preferably 15 times to 70 times, and particularly preferably 20 times to 70 times.
Here, the melt viscosity is measured using, for example, a rheometer (manufactured by HAAKE). The measurement is performed using each layer, for example. Measurement is performed at the temperature in the flow region, and the result when the set temperature at the time of viscosity measurement is 85 ° C. is defined as melt viscosity.

(Connection method)
The connection method according to the present invention includes at least a first arrangement step, a second arrangement step, and a heating and pressing step, and further includes other steps as necessary.
The connection method is a method of connecting the terminal of the first circuit member and the terminal of the second circuit member.

<First circuit member and second circuit member>
The first circuit member and the second circuit member are not particularly limited as long as they are terminals that have terminals and are subjected to anisotropic conductive connection using the anisotropic conductive film. Depending on the purpose, it can be selected as appropriate. Examples thereof include a plastic substrate having terminals, Flex-on-Board (Flex-on-Board, FOB), Flex-on-Flex (Flex-On-Flex, FOF) and the like.

  The material of the terminal is not particularly limited and can be appropriately selected depending on the purpose. For example, Cu, Ni plated with Cu, Au, and Cu, Sn plated with Au are used. Examples thereof include plated Cu.

  There is no restriction | limiting in particular as a material and structure of the plastic substrate which has the said terminal, According to the objective, it can select suitably, For example, the rigid board | substrate which has a terminal, the flexible substrate which has a terminal, etc. are mentioned. As a rigid board | substrate which has the said terminal, the glass epoxy board | substrate etc. which have a copper wiring are mentioned, for example. Examples of the flexible substrate having the terminal include a polyimide substrate having a copper wiring.

There is no restriction | limiting in particular as a shape and a magnitude | size of a said 1st circuit member and a said 2nd circuit member, According to the objective, it can select suitably.
The first circuit member and the second circuit member may be the same circuit member or different circuit members.

The terminals of the first circuit member are subjected to rust prevention treatment with a rust inhibitor.
It is preferable that the terminal of the second circuit member is not subjected to rust prevention treatment with a rust inhibitor.

There is no restriction | limiting in particular as said rust preventive agent, According to the objective, it can select suitably. The rust preventive is generally referred to as preflux or OSP (Organic Solderability Preservative).
The said rust preventive agent contains an imidazole compound, a copper ion, and an organic acid at least, for example. Examples of the imidazole compound include benzimidazole. The benzimidazole may have a substituent.
The rust inhibitor is preferably water-soluble.

There is no restriction | limiting in particular as the method of the said rust prevention process, According to the objective, it can select suitably, For example, the circuit member processed is obtained by diluting the said rust inhibitor or the said rust inhibitor. Examples include a method of immersing in an aqueous solution.
By performing the antirust treatment, the terminals on the circuit member and the circuit portion are protected.

<First arrangement step>
As said 1st arrangement | positioning process, the anisotropic conductive film of this invention is arrange | positioned so that the said thermoplastic layer may contact the terminal of said 1st circuit member on the terminal of said 1st circuit member. If it is a process, there will be no restriction | limiting in particular, According to the objective, it can select suitably.

<Second arrangement step>
The second disposing step is not particularly limited as long as it is a step of disposing the second circuit member on the anisotropic conductive film, and can be appropriately selected according to the purpose.

<Heat pressing process>
The heating and pressing step is not particularly limited as long as it is a step of heating and pressing the second circuit member with a heating and pressing member, and can be appropriately selected according to the purpose. And can be pressed.
Examples of the heating and pressing member include a pressing member having a heating mechanism. Examples of the pressing member having the heating mechanism include a heat tool.
There is no restriction | limiting in particular as temperature of the said heating, Although it can select suitably according to the objective, 140 to 200 degreeC is preferable.
There is no restriction | limiting in particular as the pressure of the said press, Although it can select suitably according to the objective, 0.1 MPa-80 MPa are preferable.
There is no restriction | limiting in particular as the time of the said heating and press, According to the objective, it can select suitably, For example, 0.5 second-120 second etc. are mentioned.

Here, an example of the connection method of the present invention will be described with reference to the drawings.
1A to 1E are schematic cross-sectional views for explaining an example of the connection method of the present invention.
First, as shown in FIG. 1A, a first circuit member 1 is prepared. The first circuit member 1 has a base material 1A and a terminal 1B on the base material 1A. Further, the terminal 1B is subjected to a rust prevention treatment with a rust inhibitor 1C.
Subsequently, as shown in FIG. 1B, the anisotropic conductive film 2 is disposed on the first circuit member 1. The anisotropic conductive film 2 is formed by laminating a thermoplastic layer 2A and a conductive particle-containing layer 2B. The anisotropic conductive film 2 is disposed on the first circuit member 1 so that the thermoplastic layer 2 </ b> A is in contact with the terminal 1 </ b> B of the first circuit member 1. The conductive particle-containing layer 2B contains conductive particles 2C. At that time, as shown in FIG. 1C, the acid component in the thermoplastic layer 2A removes the rust inhibitor 1C from the terminal 1B.
Subsequently, as illustrated in FIG. 1D, the second circuit member 3 is disposed on the conductive particle-containing layer 2 </ b> B of the anisotropic conductive film 2. The second circuit member 3 includes a base material 3A and a terminal 3B on the base material 3A. The second circuit member 3 is disposed on the conductive particle-containing layer 2B of the anisotropic conductive film 2 so that the terminals 3B are in contact with the conductive particle-containing layer 2B.
Subsequently, as shown in FIG. 1E, the first circuit member 1 and the second circuit member 3 are connected by heating and pressing the second circuit member 3. In that case, since the rust preventive agent 1C does not exist on the terminal 1B, good connectivity is obtained. Further, since the thermoplastic layer 2A is extruded from at least between the terminal 1B and the terminal 3B during heating and pressing, the acid component in the thermoplastic layer 2A deteriorates the terminal 1B and the terminal 3B (for example, corrosion and dissolution). , Migration etc.).
Therefore, the connection method of the present invention makes it possible to make a connection with excellent insulation between adjacent terminals and long-term conductivity between connection terminals even when connecting a rust-proof substrate.

  In addition, in the said description by FIG. 1A-FIG. 1E, although the aspect from which the rust preventive agent 1C was removed was shown in FIG. 1C, the connection method of this invention is not limited to this aspect. For example, even if the rust preventive agent is not removed from the terminal during the first arrangement step, the rust preventive agent only needs to be removed from the terminal in the heating and pressing step. Such an aspect is also included in the connection method of the present invention.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
<Preparation of anisotropic conductive film>
<< Preparation of the first layer >>
55 parts by mass of bisphenol F-type epoxy resin (Mitsubishi Chemical Corporation, trade name: jER-4004P), 25 parts by weight of bifunctional acrylic monomer (Shin Nakamura Chemical Co., trade name: A-200), urethane acrylate (new 20 parts by mass of Nakamura Chemical Co., Ltd., trade name: U-2PPA) and 4 parts by mass of phosphate ester acrylate (trade name: PM-2, manufactured by Nippon Kayaku Co., Ltd.) are uniformly mixed by a conventional method. Thus, a composition for the first layer was prepared. The obtained composition was applied to a release polyester film and dried by blowing hot air at 70 ° C. for 3 minutes to produce a first layer having an average thickness of 5 μm.

<< Production of Second Layer >>
45 parts by mass of phenoxy resin (manufactured by Nippon Steel Chemical Co., Ltd., trade name: YP-50), 20 parts by mass of bifunctional acrylic monomer (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: A-200), urethane acrylate (Shin Nakamura) 20 parts by mass of chemical product, product name: U-2PPA, 5 parts by mass of silica filler (average particle size 5 μm, manufactured by Nippon Aerosil Co., Ltd., product name: Aerosil RY200), dilauroyl peroxide (manufactured by NOF Corporation) The composition for the second layer was prepared by uniformly mixing 5 parts by mass of manufactured product name: Parroyl L) and 3 parts by mass of nickel-plated resin particles having an average particle diameter of 10 μm by a conventional method. The obtained composition was applied to a release polyester film and dried by blowing hot air at 70 ° C. for 5 minutes to produce a second layer having an average thickness of 30 μm.

  The first layer and the second layer were bonded using a laminator to obtain an anisotropic conductive film having a two-layer structure.

(Example 2)
In Example 1, an anisotropic conductive film was produced in the same manner as in Example 1 except that the average thickness of the first layer was 3 μm and the average thickness of the second layer was 32 μm.

(Example 3)
An anisotropic conductive film was produced in the same manner as in Example 1 except that the composition of the first layer was changed to the composition shown in Table 1 in Example 1.

Example 4
In Example 1, the composition of the first layer, the average thickness of the first layer, and the average thickness of the second layer were changed in the same manner as in Example 1 except that the average thickness was changed as shown in Table 1. A conductive film was produced.

(Example 5)
An anisotropic conductive film was produced in the same manner as in Example 1 except that the composition of the first layer was changed as shown in Table 1 in Example 1.

(Example 6)
An anisotropic conductive film was produced in the same manner as in Example 1 except that the composition of the first layer was changed as shown in Table 1 in Example 1.

(Comparative Example 1)
An anisotropic conductive film was produced in the same manner as in Example 1 except that the composition of the first layer was changed as shown in Table 1 in Example 1.

(Comparative Example 2)
In Example 1, the composition of the first layer, the average thickness of the first layer, and the average thickness of the second layer were changed in the same manner as in Example 1 except that the average thickness was changed as shown in Table 1. A conductive film was produced.

(Comparative Example 3)
45 parts by mass of phenoxy resin (manufactured by Nippon Steel Chemical Co., Ltd., trade name: YP-50), 20 parts by mass of bifunctional acrylic monomer (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: A-200), urethane acrylate (Shin Nakamura) 20 parts by mass made by Kagaku Co., Ltd., trade name: U-2PPA), 4 parts by mass of phosphate ester acrylate (made by Nippon Kayaku Co., Ltd., trade name: PM-2), silica filler (average particle size 5 μm, Nippon Aerosil) 5 parts by mass, trade name: Aerosil RY200), 5 parts by mass of dilauroyl peroxide (manufactured by NOF Corporation, trade name: Parroyl L), and 3 parts by mass of nickel-plated resin particles having an average particle diameter of 10 μm, The composition for 2nd layers was prepared by mixing uniformly by a conventional method. The obtained composition was applied to a release polyester film and dried by blowing hot air at 70 ° C. for 5 minutes to produce an anisotropic conductive film having an average thickness of 35 μm.

<Preparation of joined body>
As the first circuit member, PWB (Dexerials evaluation base material, 200 μm P, Cu 35 μmt—with antirust treatment, FR-4 base material)
As the second circuit member, COF (base material for evaluation manufactured by Dexerials, 200 μmP, Cu 8 μmt-Sn plating, 38 μmt-S′perflex base material) was used.
Using the produced anisotropic conductive film, the first circuit member and the second circuit member were connected.
In addition, the 1st circuit member used what passed the reflow furnace of Top temperature 250 degreeC 3 times.
First, the anisotropic conductive film slit to a width of 2.0 mm is attached to the first circuit member so that the first layer is in contact with the terminal of the first circuit member, and the second circuit member is formed thereon. After the alignment, using a heating and pressing tool (buffer material 250 μmt silicon rubber, 2.0 mm width), pressure bonding was performed under pressure bonding conditions of 170 ° C.-3 MPa-5 sec to complete a joined body.

<Measurement of melt viscosity>
The melt viscosity of the 1st layer and the 2nd layer in an Example and a comparative example was measured using the rheometer (made by HAAKE). The measurement was performed using each layer before bonding the first layer and the second layer using a laminator. The measurement was performed at the temperature in the flow region, and the results are shown in Table 1 as the results when the set temperature at the time of viscosity measurement was 85 ° C.

<THB evaluation>
THB evaluation was performed using the produced joined body. The joined body was exposed in an environment of 60 ° C.-95% RH, and a DC voltage of 50 V was applied for 250 hours. After completion of the test, it was confirmed whether or not there was a decrease in insulation due to corrosion, migration, etc., and evaluated according to the following evaluation criteria. The results are shown in Table 1.
〔Evaluation criteria〕
○: Insulation resistance value is 1.0 × 10 ⁹ Ω or more △: Insulation resistance value is 1.0 × 10 ⁸ Ω or more and less than 1.0 × 10 ⁹ Ω ×: Insulation resistance value is less than 1.0 × 10 ⁸ Ω

<Measurement of conduction resistance>
About the created joined body, the connection resistance when a current of 1 mA was passed using the four-terminal method was measured both at the initial stage and after 85 ° C., 85% RH and 500 hours, and evaluated according to the following evaluation criteria. The results are shown in Table 1.
〔Evaluation criteria〕
○: Less than 0.3Ω △: 0.3Ω or more and less than 0.6Ω ×: 0.6Ω or more

The unit of the compounding amount shown in Table 1 is part by mass.
jER-4004P: bisphenol F type epoxy resin, manufactured by Mitsubishi Chemical Corporation YP-70: bisphenol A / F type epoxy type phenoxy resin, manufactured by Nippon Steel Chemical Co., Ltd. YP-50: bisphenol A type epoxy type phenoxy resin, Nippon Steel Chemical Co., Ltd. A-200: Bifunctional acrylic monomer, Shin-Nakamura Chemical Co., Ltd. U-2PPA: Urethane acrylate, Shin-Nakamura Chemical Co., Ltd. PM-2: Phosphate ester acrylate, Nippon Kayaku Co., Ltd. KE-604: Rosin, Arakawa Parroyl L: Dilauroyl peroxide, manufactured by NOF Corporation Aerosil RY200: Silica filler, manufactured by Nippon Aerosil Co., Ltd.

In Examples 1-6, it was excellent in the insulation between adjacent terminals, and the long-term electroconductivity between connection terminals.
In Comparative Example 1, the first layer contained an acid component, but since it contained a curing component and a curing agent, it was not a thermoplastic layer, so that the insulation resistance was insufficient. This is presumably because the first layer was not extruded from above the terminal after fabrication of the joined body, so that the acid component in the first layer damaged the terminal and caused migration at the terminal.
In Comparative Example 2, the conduction resistance was insufficient. This is probably because the first layer is a thermoplastic layer but does not contain an acid component, so the rust preventive agent on the terminals could not be removed, and as a result, the rust preventive agent reduced the connectivity between the terminals. .
In Comparative Example 3, the insulation resistance was insufficient. This is considered to be because the acid component damaged the terminal after the bonded body was produced, and the terminal was migrated.

  The anisotropic conductive film of the present invention is excellent in insulation between adjacent terminals and long-term conductivity between connection terminals even when connecting a substrate that has been subjected to rust prevention treatment, and thus has been subjected to rust prevention treatment. It can be suitably used for connection between a substrate and another substrate.

DESCRIPTION OF SYMBOLS 1 1st circuit member 1A base material 1B terminal 1C Rust preventive agent 2 Anisotropic conductive film 2A Thermoplastic layer 2B Conductive particle content layer 2C Conductive particle 3 2nd circuit member 3A Base material 3B terminal

Claims (4)

A conductive particle-containing layer containing conductive particles, a thermosetting resin, and a curing agent;
A thermoplastic layer containing an acid component;
I have a,
An anisotropic conductive film , wherein the melt viscosity of the conductive particle-containing layer is larger than the melt viscosity of the thermoplastic layer .   The anisotropic conductive film according to claim 1, wherein the acid component is a phosphate ester compound. A connection method for connecting a terminal of a first circuit member and a terminal of a second circuit member,
The 1st arrangement | positioning process which arrange | positions the anisotropic conductive film of Claim 1 or 2 on the terminal of a said 1st circuit member so that a thermoplastic layer may contact the terminal of a said 1st circuit member. When,
A second arrangement step of arranging the second circuit member on the anisotropic conductive film;
Heating and pressing the second circuit member with a heating pressing member,
A connection method, wherein the terminal of the first circuit member is subjected to a rust prevention treatment with a rust inhibitor. The joined body which made the 1st circuit member and the 2nd circuit member make anisotropic conductive connection through the hardened | cured material of the anisotropic conductive film of Claim 1 or 2.